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Curtin University Australia | Date: 2015-02-24

The present disclosure provides a fastener that has a body that has an axis. The body comprises a head portion and at least one body portion projecting from the head portion. The at least one body portion has an actuating surface portion and is arranged such that at least a part of the at least one body portion is urged away from the axis when an actuating member is received along the axis and urges against the actuating surface portion. The at least one body portion has a substantially flat surface portion facing away from the axis.

The pressure-temperature (P-T) path for the Palaeoproterozoic Willyama Supergroup rocks in the Olary Domain, South Australia has been reconstructed through detailed petrographic observations, in conjunction with calculation of compositionally specific P-T pseudosections of metapelitic rock units and Sm-Nd garnet geochronology. The P-T path for the Willyama Complex has historically been interpreted to follow a single anticlockwise path, however the results of this study demonstrate that this path can be better described by two metamorphic events (M 1 and M 2) separated by 1100 Ma. The M 1 event occurred at c. 1600 Ma and was associated with high temperature-low pressure metamorphism. Sm-Nd garnet geochronology constrains the timing of garnet growth at c. 1585 Ma. The growth of large andalusite porphroblasts during M 1 exerted a first order control on the bulk composition during the subsequent M 2 event. Mineral chemistries coupled with quantitative phase diagrams constrain peak conditions to be in the order of c. 550°C and 5.5 kbar during M 2. The identification of two metamorphic events calls into question interpretations of metamorphic core complex formation and the single anticlockwise P-T paths being associated with the early stages of the tectonic evolution of the terrain. © 2009 Elsevier B.V. All rights reserved.

MacQuart J.-P.,Curtin University Australia
Astrophysical Journal | Year: 2011

We relate the underlying properties of a population of fast radio-emitting transient events to its expected detection rate in a survey of finite sensitivity. The distribution of the distances of the detected events is determined in terms of the population luminosity distribution and survey parameters, for both extragalactic and Galactic populations. The detection rate as a function of Galactic position is examined to identify regions that optimize survey efficiency in a survey whose field of view is limited. The impact of temporal smearing caused by scattering in the interstellar medium has a large and direction-dependent bearing on the detection of impulsive signals, and we present a model for the effects of scattering on the detection rate. We show that the detection rate scales as ΩS -3/2 + δ 0, where Ω is the field of view, S 0 is the minimum detectable flux density, and 0 < δ ≤ 3/2 for a survey of Galactic transients in which interstellar scattering or the finite volume of the Galaxy is important. We derive formal conditions on the optimal survey strategy to adopt under different circumstances for fast transient surveys on next generation large-element, wide-field arrays, such as ASKAP, LOFAR, the MWA, and the SKA, and show how interstellar scattering and the finite spatial extent of a Galactic population modify the choice of optimal strategy. © 2011. The American Astronomical Society. All rights reserved.

Suenaga H.,Curtin University Australia | Smith A.,University of California at Davis
Energy Journal | Year: 2011

We examine the volatility dynamics of three major petroleum commodities traded on the NYMEX: crude oil, unleaded gasoline, and heating oil. Using the partially overlapping time-series (POTS) framework of Smith (2005), we model jointly all futures contracts with delivery dates up to a year into the future and extract information from these prices about the persistence of market shocks. The model depicts highly nonlinear volatility dynamics that are consistent with the observed seasonality in demand and storage of the three commodities. Specifically, volatility of the three commodity prices exhibits time-to-delivery effects and substantial seasonality, yet their patterns vary systematically by contract delivery month. The conditional variance and correlation across the three commodities also vary over time. High price volatility of near-delivery contracts and their low correlation with concurrently traded distant contracts imply high shorthorizon price risk for an unhedged position in the calendar or crack spread. Price risk at the one-year horizon is much lower than short-horizon risk in all seasons and for all positions, but it is still substantial in magnitude for crack-spread positions. Crack-spread hedgers ignore nearby high-season price risk at their peril, but they would also be remiss to ignore the long horizon. Copyright © 2011 by the IAEE. All rights reserved.

Newsholme P.,Curtin University Australia | Krause M.,Biomedical Research Group
Clinical Biochemist Reviews | Year: 2012

Pancreatic β-cells are exquisitely organised to continually monitor and respond to dietary nutrients, under the modulation of additional neurohormonal signals, in order to secrete insulin to best meet the needs of the organism. β-cell nutrient sensing requires complex mechanisms of metabolic activation, resulting in production of stimulus-secretion coupling signals that promote insulin biosynthesis and release. The primary stimulus for insulin secretion is an elevation in blood glucose concentration and β-cells are particularly responsive to this important nutrient secretagogue via the tight regulation of glycolytic and mitochondrial pathways at steps such as glucokinase, pyruvate dehydrogenase, pyruvate carboxylase, glutamate dehydrogenase and mitochondrial redoxshuttles. With respect to development of type-2 diabetes (T2DM), it is important to consider individual effects of different classes of nutrient or other physiological or pharmacological agents on metabolism and insulin secretion and to also acknowledge and examine the interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids (such as arginine and glutamine) and fatty acids. It is the mixed nutrient sensing and outputs of glucose, amino and fatty acid metabolism that generate the metabolic coupling factors (MCFs) essential for signalling for insulin exocytosis. Primary MCFs in the β-cell include ATP, NADPH, glutamate, long chain acyl coenzyme A and diacylglycerol. It is the failure to generate MCFs in a coordinated manner and at sufficient levels that underlies the failure of β-cell secretion during the pathogenesis of T2DM.

Evans K.A.,Curtin University Australia
Geology | Year: 2013

Banded iron formations (BIF) are the protolith to most of the world's largest iron ore deposits. Previous hypogene genetic models for Paleoproterozoic "Lake Superior" BIF-hosted deposits invoke upwards, down-temperature flow of basinal brines via complex silica and carbonate precipitation/dissolution processes. Such models are challenged by the necessary SiO2 removal. Thermodynamic and mass balance constraints are used to refine conceptual models of the formation of BIF-hosted iron ore. These constraints, plus existing isotope and halogen ratio evidence, are consistent with removal of silica by down- or up-directed infiltration of high-pH hypersaline brines, with or without a contribution from basinal brines. The proposed link to surface environments suggest that Paleoproterozoic BIF-ore upgrade may provide a record of a critical time in the evolution of the Earth's biosphere and hydrosphere. © 2012 Geological Society of America.

Pearce A.F.,Curtin University Australia | Feng M.,CSIRO
Journal of Marine Systems | Year: 2013

Record high ocean temperatures were experienced along the Western Australian coast during the austral summer of 2010/2011. Satellite-derived sea surface temperature (SST) anomalies in February 2011 peaked at 3. °C above the long-term monthly means over a wide area from Ningaloo (22°S) to Cape Leeuwin (34°S) along the coast and out to >200km offshore. Hourly temperature measurements at a number of mooring sites along the coast revealed that the temperature anomalies were mostly trapped in the surface mixed layer, with peak nearshore temperatures rising to ~. 5. °C above average in the central west coastal region over a week encompassing the end of February and early March, resulting in some devastating fish kills as well as temporary southward range extensions of tropical fish species and megafauna such as whale sharks and manta rays. The elevated temperatures were a result of a combination of a record strength Leeuwin Current, a near-record La Niña event, and anomalously high air-sea heat flux into the ocean even though the SST was high. This heat wave was an unprecedented thermal event in Western Australian waters, superimposed on an underlying long-term temperature rise. © 2012 Elsevier B.V..

Shahin M.A.,Curtin University Australia
Journal of Constructional Steel Research | Year: 2014

In this study, the feasibility of using evolutionary computing for modelling ultimate pure bending of steel circular tubes was investigated. The behaviour of steel circular tubes under pure bending is complex and highly non-linear, and the literature has a number of solutions, most of which are difficult to use in routine design practice as they do not provide a closed-form solution. This work presents a new approach, based on evolutionary polynomial regression (EPR), for developing a simple and easy-to-use formula for prediction of ultimate pure bending of steel circular tubes. The EPR model was calibrated and verified using a large database that was obtained from the literature and comprises a series of 104 pure bending tests conducted on fabricated and cold-formed tubes. The predicted ultimate pure bending of steel circular tubes using this model can be obtained from a number of inputs including the tube thickness, tube diameter, steel yield strength and modulus of elasticity of steel. A sensitivity analysis was carried out on the developed EPR model to investigate the model generalisation ability (or robustness) and relative importance of model inputs to its output. Predictions from the EPR model were compared with those obtained from artificial neural network (ANN) models previously developed by the authors, as well as most available codes and standards. The results indicate that the EPR model is capable of predicting the ultimate pure bending of steel circular tubes with a high degree of accuracy and outperforms most available codes and standards. The results also indicate that the performance of the EPR model agrees well with that of the previously developed ANN models. It was also shown that the EPR model was able to learn the complex relationship between the ultimate pure bending and most influencing factors, and render this knowledge in the form of a simple and transparent function that can be readily used by practising engineers. The advantages of the proposed EPR technique over the ANN approach were also addressed. © 2013 Elsevier Ltd.

Kadyrov A.S.,Curtin University Australia | Rawlins C.M.,Curtin University Australia | Stelbovics A.T.,Curtin University Australia | Bray I.,Curtin University Australia | Charlton M.,University of Swansea
Physical Review Letters | Year: 2015

Utilizing the two-center convergent close-coupling method, we find a several order of magnitude enhancement in the formation of antihydrogen via antiproton scattering with positronium in an excited state over the ground state. The effect is greatest at the lowest energies considered, which encompass those achievable in experiment. This suggests a practical approach to creating neutral antimatter for testing its interaction with gravity and for spectroscopic measurements. © 2015 American Physical Society.

Goh Y.M.,Curtin University Australia | Chua D.K.H.,National University of Singapore
Journal of Construction Engineering and Management | Year: 2010

Risk assessment, consisting of hazard identification and risk analysis, is an important process that can prevent costly incidents. However, due to operational pressures and lack of construction experience, risk assessments are frequently poorly conducted. In order to improve the quality of risk assessments in the construction industry, it is important to explore the use of artificial intelligence methods to ensure that the process is efficient and at the same time thorough. This paper describes the adaptation process of a case-based reasoning (CBR) approach for construction safety hazard identification. The CBR approach aims to utilize past knowledge in the form of past hazard identification and incident cases to improve the efficiency and quality of new hazard identification. The overall approach and retrieval mechanism are described in earlier papers. This paper is focused on the adaptation process for hazard identification. Using the proposed CBR approach, for a new work scenario (the input case), a most relevant hazard identification tree and a set of incident cases will be retrieved to facilitate hazard identification. However, not all information contained in these cases are relevant. Thus, less relevant information has to be pruned off and all the retrieved information has to be integrated into a hazard identification tree. The proposed adaptation is conducted in three steps: (1) pruning of the retrieved hazard identification tree; (2) pruning of the incident cases; and (3) insertion of incident cases into the hazard identification tree. The adaptation process is based on the calculation of similarity scores of indexes. A case study based on actual hazard identifications and incident cases is used to validate the feasibility of the proposed adaptation techniques. © 2010 ASCE.

Derakhshandeh S.Y.,Isfahan University of Technology | Masoum A.S.,Transmission Maintenance Delivery | Deilami S.,Curtin University Australia | Masoum M.A.S.,Curtin University Australia | Hamedani Golshan M.E.,Isfahan University of Technology
IEEE Transactions on Power Systems | Year: 2013

Conventional industrial microgrids (IMGs) consist of factories with distributed energy resources (DERs) and electric loads that rely on combined heat and power (CHP) systems while the developing IMGs are expected to also include renewable DERs and plug-in electric vehicles (PEVs) with different vehicle ratings and charging characteristics. This paper presents an electricity and heat generation scheduling method coordinated with PEV charging in an IMG considering photovoltaic (PV) generation systems coupled with PV storages. The proposed method is based on dynamic optimal power flow (DOPF) over a 24-hour period and includes security-constrained optimal power flow (SCOPF), IMG's factories constraints, PV storage constraints and PEVs dynamic charging constraints. It will utilize the generators waste heat to fulfill thermal requirements while considering the status of renewable DERs to decrease the overall cost of IMGs. To demonstrate the effectiveness of the proposed method, detailed simulation results are presented and analyzed for an 18-bus IMG consisting of 12 factories and 6 types of PEVs without/with PV generation systems operating in grid-connected and stand-alone modes. The main contribution is including PEVs with dynamic constraints that have changed the nature of scheduling formulation from a simple hourly OPF to a dynamic OPF. © 1969-2012 IEEE.

Chong S.,Curtin University Australia | Sen T.K.,Curtin University Australia | Kayaalp A.,West Corporation | Ang H.M.,Curtin University Australia
Water Research | Year: 2012

Nowadays, carbon emission and therefore carbon footprint of water utilities is an important issue. In this respect, we should consider the opportunities to reduce carbon footprint for small and large wastewater treatment plants. The use of anaerobic rather than aerobic treatment processes would achieve this aim because no aeration is required and the generation of methane can be used within the plant. High-rate anaerobic digesters receive great interests due to their high loading capacity and low sludge production. Among them, the upflow anaerobic sludge blanket (UASB) reactors have been most widely used. However, there are still unresolved issues inhibiting the widespread of this technology in developing countries or countries with climate temperature fluctuations (such as subtropical regions). A large number of studies have been carried out in order to enhance the performance of UASB reactors but there is a lack of updated documentation. In face of the existing limitations and the increasing importance of this technology, the authors present an up-to-date review on the performance enhancements of UASB reactors over the last decade. The important aspects of this article are: (i) enhancing the start-up and granulation in UASB reactors, (ii) coupling with post-treatment unit to overcome the temperature constraint, and (iii) improving the removal efficiencies of the organic matter, nutrients and pathogens in the final effluent. Finally the authors have highlighted future research direction based on their critical analysis. © 2012 .

Macquart J.-P.,Curtin University Australia | Koay J.Y.,Curtin University Australia | Koay J.Y.,University Tunku Abdul Rahman
Astrophysical Journal | Year: 2013

The temporal smearing of impulsive radio events at cosmological redshifts probes the properties of the ionized intergalactic medium (IGM). We relate the degree of temporal smearing and the profile of a scattered source to the evolution of a turbulent structure in the IGM as a function of redshift. We estimate the degree of scattering expected by analyzing the contributions to the scattering measure of the various components of baryonic matter embedded in the IGM, including the diffuse IGM, intervening galaxies, and intracluster gas. These estimates predict that the amount of temporal smearing expected at 300 MHz is typically as low as ∼1 ms and suggests that these bursts may be detectable with low-frequency widefield arrays. A generalization of the dispersion-measure-scattering-measure relation observed for Galactic scattering to the densities and turbulent conditions relevant to the IGM suggests that scattering measures on the order of 10-6 kpc m-20/3 would be expected at z ∼ 1. This scattering is sufficiently low enough that its effects would not, for most lines of sight, be manifested in existing observations of the scatter broadening in images of extragalactic compact sources. The redshift dependence on the temporal smearing discriminates between scattering that occurs in the host galaxy of the burst and the IGM, with τhost (1 + z)-3 if the scattering probes length scales below the inner scale of the turbulence or τhost (1 + z) -17/5 if the turbulence follows a Kolmogorov spectrum. This differs strongly from the expected IGM scaling τIGM ∼ z 2 for z ≲ 1 and (1 + z)0.2-0.5 for z ≳ 1. © 2013. The American Astronomical Society. All rights reserved.

Raimondo T.,University of Adelaide | Clark C.,Curtin University Australia | Hand M.,University of Adelaide | Faure K.,Institute of Geological & Nuclear Sciences
Journal of Metamorphic Geology | Year: 2011

The Reynolds-Anmatjira Ranges, central Australia, form part of a high-grade basement terrane dissected by intensely metasomatized transpressional shear zones active during the Ordovician-Carboniferous Alice Springs Orogeny. Unlike typical retrograde structures associated with discrete fluid flow, the mid-crustal setting and intracontinental nature of these shear systems present significant problems for the source and ingress mechanism of the fluid involved in their rehydration. To address these issues, we describe two detailed traverses across deformed and metasomatized basement rocks in this region, and interrogate their record of fluid-rock interaction from various perspectives. Both traverses combine structural and petrological observations with Zr-in-rutile and Ti-in-quartz thermobarometry, oxygen and hydrogen stable isotope analysis, and major, trace and rare earth element mobility trends. Each technique is critically evaluated for its utility in this study and its more widespread applicability to alternative field areas, providing a strategic framework for the general investigation of fluid-affected shear zones. Ultimately, the integrated data sets specify pressure-temperature conditions of ~530°C and 4-5kbar, implying average apparent thermal gradients of 29-36°Ckm-1 and depths of 14-18km. Other characteristic features to emerge include strongly variable element mobilities and pronounced isotopic depletion fronts consistent with the alteration effects of an externally derived, non-equilibrium fluid. This is confirmed by calculated fluid compositions indicative of contributions from a fluid of meteoric origin, with estimated δ18O and δD values as low as 2.3‰ and -59.8‰, respectively. We propose that these surficial fluid signatures are imposed on the mid-crust by the prograde burial and dehydration of hydrothermally altered fault panels produced during pre-orogenic basin formation. Progressive fluid release with continued subsidence then leads to the accumulation of increasing fluid volumes in the vicinity of the brittle-ductile transition, promoting extensive hydration, metasomatism and reaction softening at the locus of stress transmission from plate-boundary sources. The sustained injection of externally derived fluids into refractory crustal material may thus stimulate a critical reduction in the long-term strength of the lithosphere, providing strong impetus for the initiation and advancement of intracontinental orogenesis. © 2011 Blackwell Publishing Ltd.

Liu J.,Curtin University Australia | Liu J.,University of Queensland | Yang T.,University of Queensland | Wang D.-W.,University of Queensland | And 4 more authors.
Nature Communications | Year: 2013

Owing to the weak self-assembly ability of precursor components and the serious crosslinking of neighbouring nanospheres during a hydrothermal process, the synthesis of monodisperse mesoporous polymer nanospheres with diameters below 500 nm remains a great challenge. Here we extend the synthesis method of mesoporous silica nanospheres to enable the preparation of ordered mesoporous resorcinol formaldehyde nanospheres with particle size from 80 to 400 nm and mesopores of ∼3.5 nm in diameter. By finely tuning the synthesis parameters, multi-layered mesoporous resorcinol formaldehyde hollow nanospheres can be successfully synthesized. Mesoporous carbon nanospheres and hollow nanospheres with high surface area are further obtained through carbonization of the polymer spheres. The resulting mesoporous carbon nanospheres are demonstrated as the host cathode material for lithium-sulphur batteries. The synthesis strategy provides a benchmark for fabricating well-defined porous carbonaceous nanospheres with potential for energy storage and conversion applications. © 2013 Macmillan Publishers Limited.

Cao X.G.,Guangdong University of Technology | Jiang S.P.,Curtin University Australia
Journal of Alloys and Compounds | Year: 2012

Apatite ceramics are interesting alternative solid oxide fuel cells (SOFCs) electrolytes because of their open structure for the transportation of oxide ions and their good chemical stability. This study reports the influence of barium doping on the microstructure, sinterability and oxide conductivity properties of the aluminium lanthanum oxyapatite La 9.5Ba 0.5Si 5.5Al 0.5O 26.5. SEM results show that lanthanum substitution with barium improves the sinterability of apatite ceramics. The barium doping also enhances the conductivity of the aluminium lanthanum silicates. The oxygen ion conductivity of La 9.5Ba 0.5Si 5.5Al 0.5O 26.5 sintered at 1600 °C is 2.21 × 10 -2 S cm -1 at 800 °C, higher than 9.81 × 10 -3 S cm -1 of La 10Si 5AlO 26.5 sample prepared under the same conditions. The results in the present study demonstrate that doping Ba on the La site for aluminium lanthanum oxyapatite reduces the sintering temperature and improves the ion conductivity. The enhancement of Ba dopant is mainly on the improvement of the densification and thus substantially reduced grain boundary resistance of aluminium lanthanum oxyapatite particularly at low temperatures © 2012 Elsevier B.V.

Karkee R.,BP Koirala Institute of Health science | Lee A.H.,Curtin University Australia
BMJ Open | Year: 2014

Objective: This study aims to assess the role of need factors with respect to the utilisation of institutional delivery services in Nepal. Design: An analytic study was conducted using a subset of 4079 ever married women from the 2011 Nepal Demographic and Health Survey, which utilised two-stage cluster sampling. Logistic regression with complex sample analysis was performed to evaluate the effects of antenatal care visits and birth preparedness activities on facility delivery. Outcome measures: Facility delivery. Results: Overall facility delivery rate was low at 36.9% (95% CI 33.5% to 40.2%, SE 1.69). Only half (50.1%) of the women made four or more antenatal care visits while 62.9% (95% CI 59.9% to 65.8%, SE 1.51) did not indicate any of the four birth preparation activities. After adjusting for external, predisposing and enabling factors, women who made more than four antenatal care visits were five times more likely to deliver at a health facility when compared to those who paid no visit (adjusted OR 4.94, 95% CI 3.14 to 7.76). Similarly, the likelihood for facility delivery increased by 3.4-fold among women who prepared for at least two of the four activities compared to their counterparts who made no preparation (adjusted OR 3.41, 95% CI 2.01 to 5.58). Conclusions: The perceived need, as expressed by the frequency of antenatal care visits and birth preparedness activities, plays an important role in institutional delivery service utilisation for Nepali women. These findings have implications for behavioural interventions to change their intention to deliver at a health facility.

Meredith R.W.,Montclair State University | Zhang G.,CAS Beijing Institute of Genomics | Zhang G.,Copenhagen University | Gilbert M.T.P.,Copenhagen University | And 3 more authors.
Science | Year: 2014

Edentulism, the absence of teeth, has evolved convergently among vertebrates, including birds, turtles, and several lineages of mammals. Instead of teeth, modern birds (Neornithes) use a horny beak (rhamphotheca) and a muscular gizzard to acquire and process food.We performed comparative genomic analyses representing lineages of nearly all extant bird orders and recovered shared, inactivating mutations within genes expressed in both the enamel and dentin of teeth of other vertebrate species, indicating that the common ancestor of modern birds lacked mineralized teeth.We estimate that tooth loss, or at least the loss of enamel caps that provide the outer layer of mineralized teeth, occurred about 116 million years ago.

Cirik A.C.,University of California at Riverside | Cirik A.C.,University of Oulu | Rong Y.,Curtin University Australia | Hua Y.,University of California at Riverside
IEEE Transactions on Signal Processing | Year: 2014

We study the theoretical performance of two full-duplex multiple-input multiple-output (MIMO) radio systems: a full-duplex bi-directional communication system and a full-duplex relay system. We focus on the effect of a (digitally manageable) residual self-interference due to imperfect channel estimation (with independent and identically distributed (i.i.d.) Gaussian channel estimation error) and transmitter noise. We assume that the instantaneous channel state information (CSI) is not available the transmitters. To maximize the system ergodic mutual information, which is a nonconvex function of power allocation vectors at the nodes, a gradient projection algorithm is developed to optimize the power allocation vectors. This algorithm exploits both spatial and temporal freedoms of the source covariance matrices of the MIMO links between transmitters and receivers to achieve higher sum ergodic mutual information. It is observed through simulations that the full-duplex mode is optimal when the nominal self-interference is low, and the half-duplex mode is optimal when the nominal self-interference is high. In addition to an exact closed-form ergodic mutual information expression, we introduce a much simpler asymptotic closed-form ergodic mutual information expression, which in turn simplifies the computation of the power allocation vectors. © 2014 IEEE.

Cao X.G.,Guangdong University of Technology | Jiang S.P.,Curtin University Australia
International Journal of Hydrogen Energy | Year: 2013

Oxygen reduction reaction of (La,Sr)MnO3 (LSM) cathode on La9.5Si6O26.25 apatite (LSO) electrolyte is studied over the temperature range 750-900 °C and the oxygen partial pressure range 0.01-1 atm by electrochemical impedance spectroscopy. The impedance responses show two separable arcs and are analyzed in terms of two different equivalent circuits with comparable information on the electrode processes at high and low frequencies. The electrode process associated with the high frequency arc (σ1) is basically independent of oxygen partial pressure. The activation energy of σ1 is 188 ± 15 kJ mol-1 for the O2 reduction reaction on the LSM electrode sintered at 1150 °C, and decreases to 120 kJ mol-1 for the O2 reduction reaction on the LSM electrode sintered at 850 °C, which is close to 80-110 kJ mol-1 observed for the same electrode process at LSM/YSZ interface. The reaction order with respect to PO2 and the activation energy of the electrode process associated with low frequency arc (σ2) are generally close to that of σ2 at the LSM/YSZ interface. The activation process of the cathodic polarization treatment is noticeably slower for the reaction at LSM/LSO interface as compared to that at LSM/YSZ interface. The impedance responses of O2 reduction reaction at the LSM/LSO interface are significantly higher than that at the LSM/YSZ interface due to the silicon spreading. The impedance responses decrease with the decrease of the sintering temperature of LSM electrode on LSO electrolyte. At the sintering temperature of 1000 °C, the impedance responses of O2 reduction reaction is 1.74 Ω cm2 at 900 °C, which is significantly smaller than that of LSM electrode sintered at 1150 °C. Copyright © 2012, Hydrogen Energy Publications, LLC.

Collins A.S.,University of Adelaide | Clark C.,Curtin University Australia | Plavsa D.,University of Adelaide
Gondwana Research | Year: 2014

Peninsular India forms a keystone in Gondwana, linking the East African and Malagasy orogens with Ediacaran-Cambrian orogenic belts in Sri Lanka and the Lützow Holm Bay region of Antarctica with similar aged belts in Mozambique, Malawi and Zambia. Ediacaran-Cambrian metamorphism and deformation in the Southern Granulite Terrane (SGT) reflect the past tectonic setting of this region as the leading vertex of Neoproterozoic India as it collided with Azania, the Congo-Tanzania-Bangweulu Block and Kalahari on one side and the Australia/Mawson continent on the other. The high-grade terranes of southern India are made up of four main tectonic units; from north to south these are a) the Salem Block, b) the Madurai Block, c) the Trivandrum Block, and d) the Nagercoil Block. The Salem Block is essentially the metamorphosed Dharwar craton and is bound to the south by the Palghat-Cauvery shear system - here interpreted as a terrane boundary and the Mozambique Ocean suture. The Madurai Block is interpreted as a continuation of the Antananarivo Block (and overlying Palaeoproterozoic sedimentary sequence - the Itremo Group) of Madagascar and a part of the Neoproterozoic microcontinent Azania. The boundary between this and the Trivandrum Block is the Achankovil Zone, that here is not interpreted as a terrane boundary, but may represent an Ediacaran rift zone reactivated in latest Ediacaran-Cambrian times. © 2013 International Association for Gondwana Research.

Macquart J.-P.,Curtin University Australia | Johnston S.,CSIRO
Monthly Notices of the Royal Astronomical Society | Year: 2015

We examine the effect of Galactic diffractive interstellar scintillation as a means of explaining the reported deficit of fast radio burst (FRB) detections at low Galactic latitude. We model the unknown underlying FRB flux density distribution as a power lawwith a rate scaling as S-v5/2+Δ and account for the fact that the FRBs are detected at unknown positions within the telescope beam. We find that the event rate of FRBs located off the Galactic plane may be enhanced by a factor of ~30-300 per cent relative to objects near the Galactic plane without necessarily affecting the slope of the distribution. For FRBs whose flux densities are subject to relatively weak diffractive scintillation, as is typical for events detected at high Galactic latitudes, we demonstrate that an effect associated with Eddington bias is responsible for the enhancement. The magnitude of the enhancement increases with the steepness of the underlying flux density distribution, so that existing limits on the disparity in event rates between high and lowGalactic latitudes suggest that the FRB population has a steep differential flux density distribution, scaling as S-v3.5 or steeper. Existing estimates of the event rate in the flux density range probed by the High Time Resolution Universe survey overestimate the true rate by a factor of ~3. © 2015 The Authors.

Li N.,Peking University | Chen Y.-J.,Peking University | Chen Y.-J.,CAS Guangzhou Institute of Geochemistry | Fletcher I.R.,Curtin University Australia | Zeng Q.-T.,University of Western Australia
Gondwana Research | Year: 2011

The Xiaoqinling terrane in central China is the second largest gold producing area in China. Previous application of age constraints has yielded ages for the gold mineralization ranging from Paleoproterozoic, through Triassic (Indosinian), to Jurassic and Cretaceous (Yanshanian). SHRIMP U-Th-Pb dating of hydrothermal monazite in a Mo-mineralized quartz vein from the Dahu Au-Mo deposit in the northern Xiaoqinling terrane identifies two mineralization episodes. Hydrothermal monazite intergrown with molybdenite yields an initial precipitation age of 216 ± 5. Ma, which is identical to, but more precise than, the molybdenite Re-Os isochron age of 218 ± 41. Ma. A younger generation of monazite is distinguished by data falling on a mixing array. It is inferred that the younger monazite was formed at the expense of the older ones during the Yanshanian, probably during a single event that occurred at ~. 125. Ma. Combining these results with available geochronological data and geological evidence, we conclude that molybdenum mineralization accompanied by monazite deposition took place in the Indosinian, followed by a Yanshanian tectono-hydrothermal event that resulted in large-scale gold mineralization in the Xiaoqinling terrane. Our observation demonstrates that monazite is sensitive to hydrothermal overprint, and thus is useful for dating fluid infiltration event. © 2011 International Association for Gondwana Research.

Collins A.S.,University of Adelaide | Collins A.S.,University of Sao Paulo | Kinny P.D.,Curtin University Australia | Razakamanana T.,University of Toliary
Gondwana Research | Year: 2012

Southern Madagascar is the core of a >1million km 2 Gondwanan metasedimentary belt that forms much of the southern East African Orogen of eastern Africa, Madagascar, southern India and Sri Lanka. Here the Vohibory Series yielded U-Pb isotopic data from detrital zircon cores that indicate that it was deposited in the latest Tonian to late Cryogenian (between ~900 and 640Ma). The deposition of the Graphite and Androyen Series protoliths is poorly constrained to between the late Palaeoproterozoic and the Cambrian (~1830-530Ma). The Vohibory Series protoliths were sourced from very restricted-aged sources with a maximum age range between 910 and 760Ma. The Androyen and Graphite Series protoliths were sourced from Palaeoproterozoic rocks ranging in age between 2300 and 1800Ma. The best evidence of the timing of metamorphism in the Vohibory Series is a weighted mean 206Pb/ 238U age of 642±8Ma from 3 analyses of zircon from sample M03-01. A considerably younger 206Pb/ 238U metamorphic age of 531±7Ma is produced from 10 analyses of zircon from sample M03-28 in the Androyen Series. This ~110Ma difference in age is correlated with the early East African Orogeny affecting the west of Madagascar along with its type area in East Africa, whereas the Cambrian Malagasy Orogeny affected the east of Madagascar and southern India during the final suturing of the Mozambique Ocean. © 2010 International Association for Gondwana Research.

Background: There has recently been a call for an analysis of the way in which professionals see their role and status in the context of palliative care and the interdisciplinary team. This is particularly salient in the provision of psychosocial care. Method: This study qualitatively explored team members' perceptions and experiences of team dynamics. An in-depth qualitative research design was adopted using semistructured interviews and was guided by a social constructivist framework. Seven palliative care team members were recruited from across three palliative care sites. Two palliative care nurses, a palliative care medical specialist, a consultant psychiatrist, a social worker, a counselor, and an occupational therapist comprised our prototypical interdisciplinary team. Analysis was conducted using a method of constant comparison. Results: Two major themes emerged from our research: "Lack of clear role boundaries" and "Strategies for maintenance of role boundaries," which included: "Claiming access to specialist expertise and knowledge" and "Minimizing the knowledge of other professions and professionals." It is argued that effective team functioning can be enhanced through the development of interdisciplinary team training programs and policies, resources and structures that provide support for the interdisciplinary team model. © Copyright 2011, Mary Ann Liebert, Inc.

Xu J.,Southern Cross University of Australia | Quaddus M.,Curtin University Australia
Knowledge-Based Systems | Year: 2012

This study investigates the factors influencing the adoption and diffusion of knowledge management systems in Western Australia. The study uses a mixed methodology approach. The research was carried out in three stages: field study, pilot survey, and state survey (top 300 companies). The data of the survey in Western Australia was analyzed through Partial Least Square approach. Results indicate that "individual factors", "external inspiring", "organizational factors" and "task complexity" are the significant factors which influence the "perceived usefulness" of knowledge management systems, which in turn significantly influences the "intention" to adopt knowledge management systems and the diffusion process. Some unexpected results are also revealed. The results provide practical suggestions to those companies who are embarking on the adoption and diffusion of knowledge management systems in Australia or elsewhere. © 2011 Elsevier B.V. All rights reserved.

Agency: GTR | Branch: STFC | Program: | Phase: Research Grant | Award Amount: 879.19K | Year: 2016

How from a cloud of dust and gas did we arrive at a planet capable of supporting life? This is one of the most fundamental of questions, and engages everyone from school children to scientists. We now know much of the answer: We know that stars, such as our Sun, form by the collapse of interstellar clouds of dust and gas. We know that planets, such as Earth, are constructed in a disk around their host star known as the planetary nebula, formed by the rotation of the collapsing cloud of dust and gas. We know that 4.5 billion years ago in the solar nebula, surrounding the young Sun, all the objects in our Solar System were created through a process called accretion. And among all those bodies the only habitable world yet discovered on which life evolved is Earth. There is, however, much that we still do not know about how our Solar System formed. Why, for example, are all the planets so different? Why is Venus an inferno with a thick carbon dioxide atmosphere, Mars a frozen rock with a thin atmosphere, and Earth a haven for life? The answer lies in events that predated the assembly of these planets; it lies in the early history of the nebula and the events that occurred as fine-dust stuck together to form larger objects known as planetesimals; and in how those planetesimals changed through collisions, heating and the effects of water to become the building blocks of planets. Our research will follow the evolution of planetary materials from the origins of the first dust grains in the protoplanetary disk, through the assembly of planetesimals within the solar nebula to the modification of these objects as and after they became planets. Evidence preserved in meteorites provides a record of our Solar Systems evolution. Meteorites, together with cosmic dust particles, retain the fine-dust particles from the solar nebula. These dust grains are smaller than a millionth of a metre but modern microanalysis can expose their minerals and compositions. We will study the fine-grained components of meteorites and cosmic dust to investigate how fine-dust began accumulating in the solar nebula; how heating by an early hot nebula and repeated short heating events from collisions affected aggregates of dust grains; and whether magnetic fields helped control the distribution of dust in the solar nebula. We will also use numerical models to simulate how the first, fluffy aggregates of dust were compacted to become rock. As well as the rocky and metallic materials that make up the planets, our research will examine the source of Earths water and the fate of organic materials that were crucial to the origins of life. By analysing the isotopes of the volatile elements Zn, Cd and Te in meteorites and samples of Earth, Moon and Mars we will establish the source and timing of water and other volatiles delivered to the planets in the inner Solar System. In addition, through newly developed methods we can trace the history of organic matter in meteorites from their formation in interstellar space, through the solar nebula and into planetesimals. Reading the highly sensitive record in organic matter will reveal how cosmic chemistry furnished the Solar System with the raw materials for life. Once the planets finally formed, their materials continued to change by surface processes such as impacts and the flow of water. Our research will examine how impacts of asteroids and comets shaped planetary crusts and whether this bombardment endangered or aided the emergence of life. We will also study the planet Mars, which provides a second example of a planetary body on which life could have appeared. Imagery of ancient lakes on Mars will reveal a crucial period in the planets history, when global climate change transformed the planet into an arid wasteland, to evaluate the opportunity for organisms to adapt and survive and identify targets for future rover and sample return missions.

Agency: Cordis | Branch: H2020 | Program: RIA | Phase: ICT-22-2016 | Award Amount: 2.87M | Year: 2017

The STORIES project aims to contribute to a dynamic future of childrens ebooks evolution by a) developing user-friendly interfaces for young students (10-12 years old) to create their own multi-path stories expressing their imagination and creativity and b) by integrating the latest AR, VR and 3D printing technologies to visualize their stories in numerous innovative ways. In the heart of this intervention lies the vision for integrated curricula and deeper learning outcomes. The project will offer these innovations through a single environment, the STORIES Storytelling Platform which will be the place for students artistic expression and scientific inquiry at the same time. The creations of the students (paintings, models, dioramas and constructions, 3D objects and landscapes, animations, science videos and science theatre plays) will be captured and integrated in the form of interactive ebooks. The STORIES technical team will design advanced interfaces in which students will be able to augment characters, buildings, greenhouses and different 3D geometrical structures on a tablet or their computer and inspect their work using a mobile device. The outcome of their work will be detected and tracked, and the video stream is augmented with an animated 3D version of the character or the artefact. The platform will be tested in real settings in Germany, Greece, Portugal, France, Finland and Japan, involving 60 teachers and 3000 students (5th and 6th grade). To achieve this, the proposed project is developing a novel cooperation between creative industries and electronic publishing, educational research institutions in the field of STEM, schools and informal learning centres. The consortium includes 15 partners from Europe, USA, Japan and Australia. But STORIES is going beyond that: The consortium will cooperate in the design of the platform and in the development of the storyline mechanism with Eugene (Eugenios) Trivizas, well known writer of childrens books.

Aoun S.M.,Curtin University Australia | Skett K.,Silver Chain Hospice Care
Health and Social Care in the Community | Year: 2013

As a home death seems to be the perceived ideal, terminally ill people who live alone are at a disadvantage in terms of their place of care and death and little is known about their end-of-life preferences. This study aimed at eliciting patient preferences for their place of care and death longitudinally at two points during their illness trajectory, and reporting on the extent they were able to achieve their place of choice or congruence between preferred and actual place of death. A questionnaire was administered by a researcher in the patients' homes during two visits, 6-12 weeks apart depending on patient prognosis. Forty-three patients of Silver Chain Hospice Care Service in Western Australia participated during 2009-2010. The results indicated that preferences were in favour of either a home or hospice death, with more preferring home as a place of death rather than a place of care. However, overall congruence between preferred and actual place of death was between 53% and 41% dependent on whether it was based on first or second visit preferences respectively. This is the first longitudinal study to elicit the end-of-life preferences of terminally ill people who live alone. As home may not be the preferred location for dying for many patients (nearly half of the patients in this study), ability to die in the place of choice needs to be looked at as a possible indicator of meeting patient needs or as a quality measure in end-of-life care. © 2013 Blackwell Publishing Ltd.

Hardcastle S.,University of Brighton | Blake N.,Hastings and Rother Primary Care Trust | Hagger M.S.,Curtin University Australia
Journal of Behavioral Medicine | Year: 2012

Little research exists on the impact of behavior change interventions in disadvantaged communities. We conducted a prospective study to explore the effectiveness of motivational interviewing on physical activity change within a deprived community and the social-psychological and motivational predictors of change in physical activity including stage of change, self-efficacy, social support, and variables from self-determination theory and the theory of planned behavior. Five motivational interviewing counsellors recruited 207 patients and offered motivational interviewing sessions to support physical activity behavior change. At 6-months there were significant improvements in physical activity, stage of change, and social support. A dose-response relationship was evident; those who attended 2 or more consultations increased their total physical activity, stage of change and family social support more than those who attended just one. Hierarchical regression analyses indicated that number of sessions and change in stage of change predicted 28.4 % of the variance in change in total physical activity and, with social support from friends, 21.0 % of the variance in change walking time. Change in perceived behavioral control and attitudes, friend social support, and number of sessions predicted 16.8 % of the variance in change in vigorous physical activity. Motivational interviewing is an effective approach for promoting physical activity amongst lower socio-economic status groups in the short term. The study demonstrates good translational efficacy, and contributes to a limited number of physical activity interventions targeting low income groups in the UK. © Springer Science+Business Media, LLC 2011.

Aldrich C.,Curtin University Australia | Aldrich C.,Stellenbosch University
Minerals Engineering | Year: 2013

In this study, the current understanding of the factors affecting the consumption of steel media in comminution systems in mineral processing are reviewed, together with models predicting wear losses in grinding media. Media wear arises as a consequence of complex interaction between a range of variables related to processing conditions, the characteristics of the media, as well as the ores or slurries, and is not well understood as yet, despite extensive study over the last 50 years and more. The three basic wear mechanisms, impact, abrasion and corrosion, can simultaneously influence mass loss in grinding media. Present studies are difficult to compare directly, owing to imprecise information with regard to the composition of the media or grinding conditions. As a result, most current models do not account for varying conditions inside the mill and their use is restricted to conditions similar to those associated with their calibration. This may not always be possible and alternative modelling methodologies are discussed and demonstrated by means of a case study on simulated data. © 2013 Elsevier Ltd. All rights reserved.

Glasser L.,Curtin University Australia | Jenkins H.D.B.,University of Warwick
Inorganic Chemistry | Year: 2011

Thermodynamic properties, such as standard entropy, among others, have been shown to correlate well with formula volume, V m, thus permitting prediction of these properties on the basis of chemical formula and density alone, with no structural detail required. We have termed these procedures "volume-based thermodynamics" (VBT). We here extend these studies to ambient isobaric heat capacities, C p,m, of a wide range of materials. We show that heat capacity is strongly linearly correlated with formula volume for large sets of minerals, for ionic solids in general, and for ionic liquids and that the results demonstrate that the Neumann-Kopp rule (additivity of heat capacity contributions per atom) is widely valid for ionic materials, but the smaller heat capacity contribution per unit volume for ionic liquids is noted and discussed. Using these correlations, it is possible to predict values of ambient (298 K) heat capacities quite simply. We also show that the heat capacity contribution of water molecules of crystallization is remarkably constant, at 41.3 ± 4.7 J K -1 (mol of water) -1, so that the heat capacities of various hydrates may be reliably estimated from the values of their chemical formula neighbors. This result complements similar observations that we have reported for other thermodynamic differences of hydrates. © 2011 American Chemical Society.

Middleton M.J.,Astronomical Institute Anton Pannekoek | Miller-Jones J.C.A.,Curtin University Australia | Fender R.P.,University of Southampton | Fender R.P.,University of Oxford
Monthly Notices of the Royal Astronomical Society | Year: 2014

Transitions to high mass accretion rates in black hole X-ray binaries are associated with the ejection of powerful, relativistically moving jets. The mechanism that powers such events is thought to be linked to tapping of the angular momentum (spin) of the black hole, the rate of accretion through the disc or some combination of the two. We can attempt to discriminate between these different possibilities by comparing proxies for jet power with spin estimates. Because of the small number of sources that reach Eddington mass accretion rates and have therefore been suggested to act as 'standard candles', there has been much recent debate as to whether a significant correlation exists between jet power and black hole spin. We perform continuum fitting to the high-quality, disc-dominated XMM-Newton spectra of the extragalactic microquasar discovered in M31. Assuming prograde spin,we find that for sensible constraints the spin is always very low (a* ≤ 0.15 at 3σ). When combined with a proxy for jet power derived from the maximum 5 GHz radio luminosity during a bright flaring event, we find that the source sits well above the previously reported, rising correlation that would indicate that spin tapping is the dominant mechanism for powering the jets, i.e. it is too 'radio loud' for such a low spin. The notable exceptions require the inclination to be improbably small or the jet to be very fast. We investigate whether this could be a byproduct of selecting prograde-only spin, finding that the data statistically favour a substantially retrograde spin for the same constraints (a* ≤ -0.17 at 3σ). Although theoretically improbable, this remarkable finding could be confirmation that retrograde spin can power such jets via spin-tapping, as has been suggested for certain radio quasars. In either case this work demonstrates the value of studying local extragalactic microquasars as a means to better understand the physics of jet launching. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

Winstock A.R.,King's College London | Barratt M.J.,Curtin University Australia
Drug and Alcohol Dependence | Year: 2013

Background: The last decade has seen the appearance of myriad novel psychoactive substances with diverse effect profiles. Synthetic cannabinoids are among the most recently identified but least researched of these substances. Methods: An anonymous online survey was conducted in 2011 using a quantitative structured research tool. Missing data (median 2%) were treated by available-case analysis. Results: Of 14,966 participants, 2513 (17%) reported use of synthetic cannabis. Of these, 980 (41% of 2417) reported its use in the last 12 months. Almost all recent synthetic cannabis users (99% of 975) reported ever use of natural cannabis. Synthetic cannabis reportedly had both a shorter duration of action (. z=. 17.82, p<. .001) and quicker time to peak onset of effect (. z=. -9.44, p<. .001) than natural cannabis. Natural cannabis was preferred to synthetic cannabis by 93% of users, with natural cannabis rated as having greater pleasurable effects when high (. t(930). =. -37.1, p<. .001, d=. -1.22) and being more able to function after use (. t(884). =. -13.3, p<. .001, d=. -0.45). Synthetic cannabis was associated with more negative effects (. t(859). =. 18.7, p<. .001, d=. 0.64), hangover effects (. t(854). =. 6.45, p<. .001, d=. 0.22) and greater paranoia (. t(889). =. 7.91, p<. .001, d=. 0.27). Conclusions: Users report a strong preference for natural over synthetic cannabis. The latter has a less desirable effect profile. Further research is required to determine longer term consequences of use and comparative dependence potential. © 2013 .

Odijk D.,Curtin University Australia | Teunissen P.J.G.,Curtin University Australia | Teunissen P.J.G.,Delft Institute for Earth Observation and Space Systems
GPS Solutions | Year: 2013

The Global Positioning System (GPS) and Galileo will transmit signals on similar frequencies, that is, the L1-E1 and L5-E5a frequencies. This will be beneficial for mixed GPS and Galileo applications in which the integer carrier phase ambiguities need to be resolved, in order to estimate the positioning unknowns with centimeter accuracy or better. In this contribution, we derive the mixed GPS + Galileo model that is based on "inter-system" double differencing, that is, differencing the Galileo phase and code observations relative to those corresponding to the reference or pivot satellite of GPS. As a consequence of this, additional between-receiver inter-system bias (ISB) parameters need to be solved as well for both phase and code data. We investigate the size and variability of these between-receiver ISBs, estimated from L1 and L5 observations of GPS, as well as E1 and E5a observations of the two experimental Galileo In-Orbit Validation Element (GIOVE) satellites. The data were collected using high-grade multi-GNSS receivers of different manufacturers for several zero- and short-baseline setups in Australia and the USA. From this analysis, it follows that differential ISBs are only significant for receivers of different types and manufacturers; for baselines formed by identical receiver types, no differential ISBs have shown up; thus, implying that the GPS and GIOVE data are then fully interoperable. Fortunately, in case of different receiver types, our analysis also indicates that the phase and code ISBs may be calibrated, since their estimates, based on several datasets separated in time, are shown to be very stable. When the single-frequency (E1) GIOVE phase and code data of different receiver types are a priori corrected for the differential ISBs, the short-baseline instantaneous ambiguity success rate increases significantly and becomes comparable to the success rate of mixed GPS + GIOVE ambiguity resolution based on identical receiver types. © 2012 Springer-Verlag Berlin Heidelberg.

Glasser L.,Curtin University Australia | Jenkins H.D.B.,University of Warwick
Journal of Chemical and Engineering Data | Year: 2011

Thermodynamics, as both thermochemistry and thermophysics, is fundamental and central to the science of matter and, in particular, of condensed materials. While extensive data resources for thermodynamic quantities do exist, none of the experimental, simulation, or theoretical studies can keep pace with the rate of synthesis of new materials or provide reliable data for hypothesized materials. Correlation methods can fill this gap. We describe a range of recently developed correlation methods that rely on volume to predict thermodynamic quantities. In parallel with these, thermodynamic difference rules, which describe how properties of materials (say, of a group of solvates) may be inferred from corresponding properties of materials that neighbor them in composition, have recently been reviewed. © 2010 American Chemical Society.

Lannes A.,University Paris - Sud | Teunissen P.J.G.,Technical University of Delft | Teunissen P.J.G.,Curtin University Australia
Journal of Geodesy | Year: 2011

The first objective of this paper is to show that some basic concepts used in global navigation satellite systems (GNSS) are similar to those introduced in Fourier synthesis for handling some phase calibration problems. In experimental astronomy, the latter are at the heart of what is called 'phase closure imaging.' In both cases, the analysis of the related structures appeals to the algebraic graph theory and the algebraic number theory. For example, the estimable functions of carrier-phase ambiguities, which were introduced in GNSS to correct some rank defects of the undifferenced equations, prove to be 'closure-phase ambiguities:' the so-called 'closure-delay' (CD) ambiguities. The notion of closure delay thus generalizes that of double difference (DD). The other estimable functional variables involved in the phase and code undifferenced equations are the receiver and satellite pseudo-clock biases. A related application, which corresponds to the second objective of this paper, concerns the definition of the clock information to be broadcasted to the network users for their precise point positioning (PPP). It is shown that this positioning can be achieved by simply having access to the satellite pseudo-clock biases. For simplicity, the study is restricted to relatively small networks. Concerning the phase for example, these biases then include five components: a frequency-dependent satellite-clock error, a tropospheric satellite delay, an ionospheric satellite delay, an initial satellite phase, and an integer satellite ambiguity. The form of the PPP equations to be solved by the network user is then similar to that of the traditional PPP equations. As soon as the CD ambiguities are fixed and validated, an operation which can be performed in real time via appropriate decorrelation techniques, estimates of these float biases can be immediately obtained. No other ambiguity is to be fixed. The satellite pseudo-clock biases can thus be obtained in real time. This is not the case for the satellite-clock biases. The third objective of this paper is to make the link between the CD approach and the GNSS methods based on the notion of double difference. In particular, it is shown that the information provided by a maximum set of independent DDs may not reach that of a complete set of CDs. The corresponding defect is analyzed. One of the main results of the corresponding analysis concerns the DD-CD relationship. In particular, it is shown that the DD ambiguities, once they have been fixed and validated, can be used as input data in the 'undifferenced CD equations.' The corresponding algebraic operations are described. The satellite pseudo-clock biases can therefore be also obtained via particular methods in which the notion of double differencing is involved. © 2011 The Author(s).

Jenkins H.D.B.,University of Warwick | Glasser L.,Curtin University Australia
Journal of Chemical and Engineering Data | Year: 2010

Thermodynamic data are required for an understanding of the behavior of materials but are often lacking (or even unreliable) for a variety of reasons such as synthetic problems, purity issues, failure to correctly identify hydrolysis products, instability of the material, etc. Thus, it is necessary to develop procedures for the estimation of that data. The Thermodynamic Difference Rules (TDR) are additive approximations by which the properties of materials are estimated by reference to those of related materials. These rules appear in the form of the reliable Hydrate Difference Rule (HDR), based on the well-established properties of the large number of known hydrates, and the somewhat less certain Solvate Difference Rule (SDR). These rules are briefly surveyed and their application carefully delineated by a scheme and demonstrated by a number of calculated examples. © 2010 American Chemical Society.

Williams C.J.,Curtin University Australia | Williams C.J.,Curtin Health Innovation Research Institute | McLeod S.,Charles Sturt University
International Journal of Speech-Language Pathology | Year: 2012

Within predominantly English-speaking countries such as the US, UK, Canada, New Zealand, and Australia, there are a significant number of people who speak languages other than English. This study aimed to examine Australian speech-language pathologists' (SLPs) perspectives and experiences of multilingualism, including their assessment and intervention practices, and service delivery methods when working with children who speak languages other than English. A questionnaire was completed by 128 SLPs who attended an SLP seminar about cultural and linguistic diversity. Approximately one half of the SLPs (48.4%) reported that they had at least minimal competence in a language(s) other than English; but only 12 (9.4%) reported that they were proficient in another language. The SLPs spoke a total of 28 languages other than English, the most common being French, Italian, German, Spanish, Mandarin, and Auslan (Australian sign language). Participants reported that they had, in the past 12 months, worked with a mean of 59.2 (range 1-100) children from multilingual backgrounds. These children were reported to speak between two and five languages each; the most common being: Vietnamese, Arabic, Cantonese, Mandarin, Australian Indigenous languages, Tagalog, Greek, and other Chinese languages. There was limited overlap between the languages spoken by the SLPs and the children on the SLPs' caseloads. Many of the SLPs assessed children's speech (50.5%) and/or language (34.2%) without assistance from others (including interpreters). English was the primary language used during assessments and intervention. The majority of SLPs always used informal speech (76.7%) and language (78.2%) assessments and, if standardized tests were used, typically they were in English. The SLPs sought additional information about the children's languages and cultural backgrounds, but indicated that they had limited resources to discriminate between speech and language difference vs disorder. © 2012 The Speech Pathology Association of Australia Limited.

O'Leary M.J.,Curtin University Australia | Hearty P.J.,University of North Carolina at Wilmington | Thompson W.G.,Woods Hole Oceanographic Institution | Raymo M.E.,Lamont Doherty Earth Observatory | And 2 more authors.
Nature Geoscience | Year: 2013

During the last interglacial period, 127-116 kyr ago, global mean sea level reached a peak of 5-9m above present-day sea level. However, the exact timing and magnitude of ice sheet collapse that contributed to the sea-level highstand is unclear. Here we explore this timing using stratigraphic and geomorphic mapping and uranium-series geochronology of fossil coral reefs and geophysical modelling of sea-level records from Western Australia. We show that between 127 and 119 kyr ago, eustatic sea level remained relatively stable at about 3-4 m above present sea level. However, stratigraphically younger fossil corals with U-series ages of 118.1±1.4 kyr are observed at elevations of up to 9.5 m above present mean sea level. Accounting for glacial isostatic adjustment and localized tectonics, we conclude that eustatic sea level rose to about 9 m above present at the end of the last interglacial. We suggest that in the last few thousand years of the interglacial, a critical ice sheet stability threshold was crossed, resulting in the catastrophic collapse of polar ice sheets and substantial sea-level rise. © 2013 Macmillan Publishers Limited. All rights reserved.

Coolen M.J.L.,Woods Hole Oceanographic Institution | Coolen M.J.L.,Curtin University Australia | Orsi W.D.,Woods Hole Oceanographic Institution
Frontiers in Microbiology | Year: 2015

Thawing of permafrost soils is expected to stimulate microbial decomposition and respiration of sequestered carbon. This could, in turn, increase atmospheric concentrations of greenhouse gasses, such as carbon dioxide and methane, and create a positive feedback to climate warming. Recent metagenomic studies suggest that permafrost has a large metabolic potential for carbon processing, including pathways for fermentation and methanogenesis. Here, we performed a pilot study using ultrahigh throughput Illumina HiSeq sequencing of reverse transcribed messenger RNA to obtain a detailed overview of active metabolic pathways and responsible organisms in up to 70 cm deep permafrost soils at a moist acidic tundra location in Arctic Alaska. The transcriptional response of the permafrost microbial community was compared before and after 11 days of thaw. In general, the transcriptional profile under frozen conditions suggests a dominance of stress responses, survival strategies, and maintenance processes, whereas upon thaw a rapid enzymatic response to decomposing soil organic matter (SOM) was observed. Bacteroidetes, Firmicutes, ascomycete fungi, and methanogens were responsible for largest transcriptional response upon thaw. Transcripts indicative of heterotrophic methanogenic pathways utilizing acetate, methanol, and methylamine were found predominantly in the permafrost table after thaw. Furthermore, transcripts involved in acetogenesis were expressed exclusively after thaw suggesting that acetogenic bacteria are a potential source of acetate for acetoclastic methanogenesis in freshly thawed permafrost. Metatranscriptomics is shown here to be a useful approach for inferring the activity of permafrost microbes that has potential to improve our understanding of permafrost SOM bioavailability and biogeochemical mechanisms contributing to greenhouse gas emissions as a result of permafrost thaw. © 2015 Coolen and Orsi.

Coombe D.R.,Curtin University Australia | Kett W.C.,Glycan Biosciences Inc.
Handbook of Experimental Pharmacology | Year: 2012

Explorations of the therapeutic potential of heparin mimetics, anionic compounds that are analogues of glycosaminoglycans (GAGs), have gone hand-in-hand with the emergence of understanding as to the role of GAGs in many essential biological processes. A myriad of structurally different heparin mimetics have been prepared and examined in many diverse applications. They range in complexity from heterogeneous polysaccharides that have been chemically sulphated to well-defined compounds, designed in part to mimic the natural ligand, but with binding specificity and potency increased by conjugation to non-carbohydrate pharmacophores. The maturity of the field is illustrated by the seven heparin mimetics that have achieved marketing approval and there are several more in late-stage clinical development. An overview of the structural determinants of heparin mimetics is presented together with an indication of their activities. The challenges in developing heparin mimetics as drugs, specificity and potential toxicity issues, are highlighted. Finally, the development path of three structurally very different mimetics, PI-88 ®, GMI-1070 and RGTAs, each of which is in clinical trials, is described. © 2012 Springer-Verlag Berlin Heidelberg.

Devanathan R.,Pacific Northwest National Laboratory | Weber W.J.,University of Tennessee at Knoxville | Weber W.J.,Oak Ridge National Laboratory | Gale J.D.,Curtin University Australia
Energy and Environmental Science | Year: 2010

We have used molecular dynamics simulations to investigate the effects of radiation damage accumulation in two pyrochlore-structured ceramics, namely Gd2Ti2O7 and Gd2Zr2O 7. It is well known from experiment that the titanate is susceptible to radiation-induced amorphization, while the zirconate does not go amorphous under prolonged irradiation. Our simulations show that cation Frenkel pair accumulation eventually leads to amorphization of Gd2Ti 2O7, and both anion disorder and cation disorder occur during damage accumulation. Amorphization in Gd2Ti2O 7 is accompanied by a density decrease of about 12.7% and a decrease of about 50% in the elastic modulus. In Gd2Zr2O 7, amorphization does not occur, because the residual damage introduced by radiation is not sufficiently energetic to destabilize the crystal structure and drive the material amorphous. Subtle differences in damage accumulation and annealing between the two pyrochlores lead to drastically different radiation response as the damage accumulates. © 2010 The Royal Society of Chemistry.

Winstock A.R.,King's College London | Barratt M.J.,Curtin University Australia
Human Psychopharmacology | Year: 2013

Objective: A wide range of synthetic cannabinoid products have recently become available through the Internet and shop fronts across the globe. Concerns about the consequences of their use have been prompted by increasing reports of emergency department presentations. Methods: An anonymous global online survey was conducted using a research tool based on previous work carried out by the group. Data collection took place during a 4-week period at the end of 2011. Results: Among 950 last-year users, 23 (2.4%) reported having sought emergency medical treatment following the use of a synthetic cannabinoid product. The most common presentations were panic and anxiety, followed by paranoia and breathing difficulties. Recent users who reported seeking emergency medical treatment were significantly younger (median age 20 years,interquartile range 18-22) than those who did not report seeking treatment (median age 23 years, interquartile range 19-28; Mann-Whitney test, z = 2.89, p = 0.004). Conclusions: Synthetic cannabinoid use appears to be associated with a high prevalence of adverseexperiences among users, especially younger users. Further research is required to determine whether particular compounds carry a higher risk of harm than others and to assess potential consequences of longer term use. © 2013 John Wiley & Sons, Ltd.

Nicholls R.J.,University of Southampton | Hanson S.E.,University of Southampton | Lowe J.A.,University of Reading | Warrick R.A.,Curtin University Australia | And 2 more authors.
Wiley Interdisciplinary Reviews: Climate Change | Year: 2014

Global-mean sea-level rise will drive impacts and adaptation needs around the world's coasts over the 21st century and beyond. A key element in assessing these issues is the development of scenarios (or plausible futures) of local relative sea-level rise to support impact assessment and adaptation planning. This requires combining a number of different but uncertain components of sea level which can be linked to climatic and non-climatic (i.e., uplift/subsidence of coastal land) factors. A major concern remains about the possibility of significant contributions from the major Greenland and Antarctic ice sheets and this must be factored into the assessments, despite the uncertainty. This paper reviews the different mechanisms which contribute to sea-level change and considers a methodology for combining the available data to create relative (or local) sea-level rise scenarios suitable for impact and adaptation assessments across a range of sophistication of analysis. The methods that are developed are pragmatic and consider the different needs of impact assessment, adaptation planning, and long-term decision making. This includes the requirements of strategic decision makers who rightly focus on low probability but high consequence changes and their consequences. Hence plausible high end sea-level rise scenarios beyond the conventional Intergovernmental Panel on Climate Change (IPCC) range and which take into account evidence beyond that from the current generation of climate models are developed and their application discussed. Continued review and development of sea-level scenarios is recommended, starting with assimilating the insights of the forthcoming IPCC AR5 assessment. © 2013 John Wiley & Sons, Ltd.

Demichelis R.,Curtin University Australia | Raiteri P.,Curtin University Australia | Gale J.D.,Curtin University Australia | Quigley D.,University of Warwick | Gebauer D.,University of Konstanz
Nature Communications | Year: 2011

Calcium carbonate is an abundant substance that can be created in several mineral forms by the reaction of dissolved carbon dioxide in water with calcium ions. Through biomineralization, organisms can harness and control this process to form various functional materials that can act as anything from shells through to lenses. The early stages of calcium carbonate formation have recently attracted attention as stable prenucleation clusters have been observed, contrary to classical models. Here we show, using computer simulations combined with the analysis of experimental data, that these mineral clusters are made of an ionic polymer, composed of alternating calcium and carbonate ions, with a dynamic topology consisting of chains, branches and rings. The existence of a disordered, flexible and strongly hydrated precursor provides a basis for explaining the formation of other liquid-like amorphous states of calcium carbonate, in addition to the non-classical behaviour during growth of amorphous calcium carbonate. © 2011 Macmillan Publishers Limited. All rights reserved.

Fachrunnisa O.,Curtin University Australia | Fachrunnisa O.,Islamic University of Sultan Agung | Hussain F.K.,Curtin University Australia
IEEE Transactions on Industrial Electronics | Year: 2013

Trust is widely considered to be essential for the smooth functioning of digital ecosystems. However, trust by its very nature, and due to the virtual connection between entities, is extremely fragile. Trust has a life cycle which is composed of building, maintaining, and declining. Given the fragility of trust in virtual environments, it is challenging to work out how to maintain the level of trust (specifically positive trust) between two interacting parties. Once positive trust has been established in the trust building phase, a methodological framework is needed to maintain the existing trust level, so that the relationship may be sustained in the future. In this paper, we present a methodology for maintaining trust in industrial digital ecosystems. The methodology proposes the use of a third party agent, an iterative negotiation process, proactive performance monitoring, and intelligence metrics recalibration of the trust level. In a trust-based relationship, trust can be regarded as having been maintained if the final trust is greater than or equal to initial trust. We demonstrate the validity of the methodology by engineering a prototype setup and running simulations under various operational conditions. © 2012 IEEE.

Barratt M.J.,Curtin University Australia | Ferris J.A.,University of Queensland | Winstock A.R.,King's College London
Addiction | Year: 2014

Aims: To investigate the prevalence of awareness of the online illicit drug marketplace Silk Road (SR), consumption of drugs purchased from SR and reasons for use and non-use of SR. Design and setting: Global Drug Survey: purposive sample collected in late 2012. Participants: The base sample (n=9470) reported recent drug purchase and resided in the United Kingdom (n=4315, median age 24, 76% male), Australia (n=2761, median age 32, 76% male) or the United States (n=2394, median age 21, 80% male). Measurements: Online questionnaire. Findings: A total of 65% of US, 53% of Australian and 40% of UK respondents had heard of SR; 18% of US, 10% of UK and 7% of Australian respondents had consumed drugs purchased through SR. Across the three countries, 3,4-methylenedioxy-N-methylamphetamine (MDMA) was the most commonly purchased drug (53-60%), followed by cannabis (34-51%), lysergic acid diethylamide (LSD) (29-45%) and the 2C family (16%-27%). The most common reasons for purchasing from SR were wider range (75-89%), better quality (72-77%), greater convenience (67-69%) and the use of vendor rating systems (60-65%). The most common reasons for avoiding SR purchase were adequate drug access (63-68%) and fear of being caught (41-53%). Logistic regressions found that, compared with people from the UK, Australians [odds ratio (OR)=3.37; 95% confidence interval (CI)=2.29, 4.97) and Americans (OR=1.46; 95% CI=1.10, 1.94) were more likely to use SR due to lower prices; and to avoid SR purchase due to fear of being caught (Australia: OR=1.65; 95% CI=1.39, 1.96; USA: OR=1.62; 95% CI=1.37, 1.92). Conclusions: While reasons for Silk Road use accord with broader online commerce trends (range, quality, convenience, ratings), its appeal to drug purchasers is moderated by country-specific deterrents and market characteristics. © 2013 Society for the Study of Addiction.

Raiteri P.,Curtin University Australia | Gale J.D.,Curtin University Australia | Quigley D.,University of Warwick | Rodger P.M.,University of Warwick
Journal of Physical Chemistry C | Year: 2010

The performance of existing force-field models for the calcium carbonate - water system has been critically assessed with particular reference to the thermodynamic consequences. It is demonstrated that all currently available parametrizations fail to describe the calcite-aragonite phase transition, and the free energies of solvation for the calcium cation are also considerably in error leading to a poor description of the dissolution enthalpy for calcite. A new force-field, based on rigid carbonate ions, has been developed that corrects these deficiencies and accurately describes the thermodynamics of the aqueous calcium carbonate system within molecular dynamics simulations. Not only does this new model lead to quantitative changes in the properties of the calcite (10̄14) surface in contact with water, but also significant qualitative differences. With this more accurate model it is found that calcium ions do not adsorb at the pristine basal plane of calcite, while carbonate ions only weakly bind. Carbonate diffusion across the surface is found to occur only when the anion is solvent separated from the underlying surface, with there being an equal tendency to readsorb or migrate into the bulk liquid. © 2010 American Chemical Society.

Fenter P.,Argonne National Laboratory | Kerisit S.,Pacific Northwest National Laboratory | Raiteri P.,Curtin University Australia | Gale J.D.,Curtin University Australia
Journal of Physical Chemistry C | Year: 2013

New insights into the understanding of calcite-water interface structure are obtained through direct comparisons of multiple classical molecular dynamics (MD) simulations with high-resolution specular X-ray reflectivity (XR) data. This set of comparisons, with four different state-of-the-art force fields (including two nonpolarizable, one polarizable, and one reactive force field), reveal new insights into the absolute accuracy of the simulated structures and the uniqueness of the XR-derived structural results. These four simulations, though qualitatively similar, have visibly distinct interfacial structures and are distinguished through a quantitative comparison of the XR signals calculated from these simulations with experimental XR data. The results demonstrate that the simulated calcite-water interface structures, taken as a whole, are not consistent with the XR data (i.e., within the precision and accuracy of the XR data). This disagreement is largely due to the simulated calcite interfacial structure. The simulated interfacial water profiles show a higher level of consistency with the XR data, but with substantially different levels of agreement, with the rigid-ion model (RIM) simulations showing semiquantitative agreement. Further comparisons of the structural parameters that describe the interfacial structure (derived from both the MD simulations and the XR data) provide further insight into the sources of differences between these two approaches. Using the new insights from the RIM simulations, new structures of the calcite-water interface consistent with both the experimental data and the simulation are identified and compared to recent results. © 2013 American Chemical Society.

Glasser L.,Curtin University Australia | Jenkins H.D.B.,University of Warwick
Inorganic Chemistry | Year: 2012

Single-ion heat capacities, C p(298) ion, are additive values for the estimation of room-temperature (298 K) heat capacities of ionic solids. They may be used for inferring the heat capacities of ionic solids for which values are unavailable and for checking reported values, thus complementing our independent method of estimation from formula unit volumes (termed volume-based thermodynamics, VBT). Analysis of the reported heat-capacity data presented here provides a new self-consistent set of heat capacities for both cations and anions that is compatible (and thus may be combined) with an extensive set developed by Spencer. The addition of a large range of silicate species permits the estimation of the heat capacities of many silicate minerals. The single-ion heat capacities of individual silicate anions are observed to be strictly proportional to the total number of atoms (Si plus O), n, contained within the silicate anion complex itself (e.g., for the anion Si 2O 7 2-, n = 9, for SiO 4 2-, n = 5), C p(silicate anion)/J K -1 mol -1 = 13.8n, in a new rule that is an extension of the Neumann-Kopp relationship. The same linear relationship applies to other homologous anion series (for example, oxygenated heavy-metal anion complexes such as niobates, bismuthates, and tantalates), although with a different proportionality constant. A similar proportionality, C p(complex anion)/J K -1 mol -1 ≈ 17.5n, which may be regarded as a convenient "rule of thumb", also applies, although less strictly, to complex anions in general. The proportionality constants reflect the rigidity of the complex anion, being always less than the Dulong-Petit value of 25 J K -1 mol -1. An emergent feature of our VBT and single-ion approaches to an estimation of the thermodynamic properties is the identification of anomalies in measured values, as is illustrated in this paper. © 2012 American Chemical Society.

Soares M.J.,Curtin University Australia | Murhadi L.L.,Curtin University Australia | Kurpad A.V.,St Johns National Academy of Health science | Chan She Ping-Delfos W.L.,Curtin University Australia | Piers L.S.,University of Melbourne
Obesity Reviews | Year: 2012

Low intakes of calcium and inadequate vitamin D status often cluster with higher prevalence rates of obesity. Consequently, there has been much interest in the mechanisms by which calcium and vitamin D could regulate body weight and adiposity. This review has focused on randomized controlled trials (RCTs) that have manipulated these nutrients and studied pathways of energy balance. Overall, there is consistent evidence that calcium and vitamin D increase whole body fat oxidation after single and multiple meals, and that calcium promotes a modest energy loss through increased faecal fat excretion. The evidence is equivocal for a greater diet-induced thermogenesis, increased lipolysis, suppression of key lipogenic enzymes, decreased hunger ratings or reduced energy/macronutrient intake. Emerging evidence suggests a potential improvement in insulin sensitivity following vitamin D that would impinge on food intake and substrate oxidation. However, the very few RCTs on supplemental vitamin D and energy balance have not explored postprandial avenues of the hormone's actions. Future efforts in this area need to define the threshold intake of these nutrients that would maximize metabolic and gastrointestinal outcomes. Such studies would provide a platform for endorsing the non-skeletal role of calcium and vitamin D in human pathophysiology. © 2012 The Authors. obesity reviews © 2012 International Association for the Study of Obesity.

Voon D.,Monash University | Hasking P.,Curtin University Australia | Hasking P.,Monash University | Martin G.,University of Queensland
Journal of Abnormal Psychology | Year: 2014

This longitudinal study examines the extent to which changes in the use of cognitive reappraisal, expressive suppression, and rumination impact on frequency, duration, and medical severity of nonsuicidal self-injury (NSSI) among adolescents. Data from 3,143 predominantly female high school students recruited from 40 Australian secondary schools were analyzed using latent growth curve modeling. Significant differences in the psychological factors between the 555 participants with a history of NSSI and non-self-injurers were reported at baseline. Self-injurers experienced significantly greater accumulation of life stressors over time compared with non-self-injurers. After controlling for adverse life events, psychological distress and other emotion regulation strategies, use of cognitive reappraisal at baseline was associated with less severe NSSI presentations, and slower growth in medical severity of NSSI over time. Findings indicate that while both cohorts have similar emotion regulation trajectories, adolescents who self-injure start off at a disadvantage and have a propensity to engage in less helpful processes that tend to heighten negative emotional states. Results recommend increasing focus on improving adolescents' frequency and skills in use of cognitive reappraisal in efforts to reduce NSSI among this population. © 2014 American Psychological Association.

Huang X.-L.,CAS Guangzhou Institute of Geochemistry | Wilde S.A.,Curtin University Australia | Zhong J.-W.,CAS Guangzhou Institute of Geochemistry | Zhong J.-W.,Kunming University of Science and Technology
Precambrian Research | Year: 2013

The Dengfeng and Taihua Complexes are well-exposed Neoarchean to Paleoproterozoic units in the southern segment of the Trans-North China Orogen (TNCO). Zircon U-Pb dating shows that the Dengfeng Complex records two episodes (2568±11Ma and 2306±6Ma) of tonalite-trondhjemite-granodiorite (TTG) magmatism. All of the TTG rocks are characterized by high SiO2 (66.7-75.4wt%), Na2O (3.20-5.06wt%) and relatively low MgO (0.40-1.78wt%). The Late Neoarchean TTG gneisses have very low contents of HREE (YbN=0.69-2.75) and Y (1.73-7.07ppm), with moderate [La/Yb]N (24.1-53.8) and high Sr/Y (65.1-291.3) ratios. The Early Paleoproterozoic TTG gneisses have low contents of HREE (YbN=2.93-6.37) and Y (6.7-11.0ppm), with moderate [La/Yb]N (10.1-27.0) and Sr/Y (10.6-52.1) ratios. Both suites show pronounced negative Nb-Ta, P and Ti anomalies but positive Sr and Pb anomalies. The Late Neoarchean TTG gneisses all have similar bulk-rock Nd and zircon Hf model ages with mainly positive eNd(t), and are interpreted as resulting from the melting of dominantly juvenile thickened lower crust with residual garnet and amphibole. The Early Paleoproterozoic TTG gneisses have extremely variable eNd(t) (-6.23 to +4.23) and heterogeneous zircon eHf(t) (-3.3 to +3.1), which are also best interpreted as resulting from the partial melting of thickened lower crust with residual amphibole and garnet. The Taihua Complex in the Xiaoqinling area records three episodes of Early Paleoproterozoic TTG magmatism (2.48Ga at Caotan, 2.31Ga at Houjiacun and 2.16Ga at Bayuan), younger than the Taihua Complex in the Lushan area (2.85-2.72Ga). All rocks have relatively low contents of HREE (YbN=1.03-8.32) and Y (2.84-24ppm), with moderate [La/Yb]N (8.7-88.4) and Sr/Y (19.8-125.8) ratios, and show negative Ta-Nb and Ti anomalies and positive Sr and Pb anomalies. The Caotan gneisses at 2.48Ga and the Houjiacun TTG gneisses at 2.31Ga have low Mg# (0.14-0.45), low Cr (<42ppm) and Ni contents (1-21ppm), with variable but overall positive eNd(t) and eHf(t) values, and were derived from the partial melting of thickened lower crust with residual garnet and amphibole. The younger Bayuan TTG gneisses at 2.16Ga have low SiO2 (57.11-64.89wt%), high MgO (2.64-4.62wt%), Cr (100-247ppm) and Ni (32-80ppm), with negative whole rock eNd(t) and zircon eHf(t) values, resulted from the partial melting of delaminated lower crust that interacted with peridotitic mantle.The geochronology of the Dengfeng Complex (in the Dengfeng area) and the Taihua Complex (in the Lushan, Xiong'er and Xiaoqinling areas) reveals at least four magmatic episodes in the southern segment of the TNCO from the Late Mesoarchean to Early Paleoproterozoic (2.85-2.72Ga, 2.57-2.48Ga, 2.34-2.30Ga and 2.20-2.07Ga). The rocks of the two early episodes are dominantly of juvenile compositions with mostly positive whole rock eNd(t) and zircon eHf(t) values, suggesting two episodes of crustal growth formed in a subduction tectonic setting. The magmatic rocks of the third episode consist of both the juvenile and pre-existing crustal materials with variable whole rock eNd(t) and zircon eHf(t) values, which were generated in a subduction zone during the initial assembly of the NCC within the Columbia supercontinent cycle. The final episode of magmatism lacks juvenile materials with whole rock eNd(t) and zircon eHf(t) values being consistently negative. These may have resulted from the orogenic collapse. The episodic continental growth recorded in the southern segment of the TNCO was caused by subduction and consequent orogeny, consistent with global supercontinent cycles within the Late Archean and Early Paleoproterozoic. © 2013 Elsevier B.V.

Xiang Y.,Beihang University | Lu S.,Beihang University | Jiang S.P.,Curtin University Australia
Chemical Society Reviews | Year: 2012

As one of the most effective synthesis tools, layer-by-layer (LbL) self-assembly technology can provide a strong non-covalent integration and accurate assembly between homo- or hetero-phase compounds or oppositely charged polyelectrolytes, resulting in highly-ordered nanoscale structures or patterns with excellent functionalities and activities. It has been widely used in the developments of novel materials and nanostructures or patterns from nanotechnologies to medical fields. However, the application of LbL self-assembly in the development of highly efficient electrocatalysts, specific functionalized membranes for proton exchange membrane fuel cells (PEMFCs) and electrode materials for supercapacitors is a relatively new phenomenon. In this review, the application of LbL self-assembly in the development and synthesis of key materials of PEMFCs including polyelectrolyte multilayered proton-exchange membranes, methanol-blocking Nafion membranes, highly uniform and efficient Pt-based electrocatalysts, self-assembled polyelectrolyte functionalized carbon nanotubes (CNTs) and graphenes will be reviewed. The application of LbL self-assembly for the development of multilayer nanostructured materials for use in electrochemical supercapacitors will also be reviewed and discussed (250 references). © 2012 The Royal Society of Chemistry.

Nemchin A.A.,Curtin University Australia | Horstwood M.S.A.,British Geological Survey | Whitehouse M.J.,Swedish Museum of Natural History
Elements | Year: 2013

High-spatial-resolution isotope analyses have revolutionised U-(Th-)Pb geochronology. These analyses can be done at scales of a few tens of microns or less using secondary ion mass spectrometry or laser ablation inductively coupled plasma mass spectrometry. They allow determination of the internal age variation of uranium- and thorium-bearing minerals and as a consequence much greater understanding of Earth system processes. The determination of variation on the micron scale necessitates the sampling of small volumes, which restricts the achievable precision but allows discrimination of discrete change, linkage to textural information, and determination of multiple isotopic and elemental data sets on effectively the same material. High-spatial-resolution analysis is being used in an increasing number of applications. Some of these applications have become fundamental to their scientific fields, while others have opened new opportunities for research.

Gao S.,Northwestern Polytechnical University | Zhong Y.,Curtin University Australia | Shirinzadeh B.,Monash University
Information Sciences | Year: 2010

This paper adopts the concept of random weighting estimation to multi-sensor data fusion. It presents a new random weighting estimation methodology for optimal fusion of multi-dimensional position data. A multi-sensor observation model is constructed for multi-dimensional position. Based on this observation model, a random weighting estimation algorithm is developed for estimation of position data from single sensors. Using the random weighting estimations from each single sensor, an optimization theory is established for optimal fusion of multi-sensor position data. Experimental results demonstrate that the proposed methodology can effectively fuse multi-sensor dimensional position data, and the fusion accuracy is much higher than that of the Kalman fusion method. © 2010 Elsevier Inc. All rights reserved.

Moore D.,Curtin University Australia | Fraser S.,Curtin University Australia | Fraser S.,Monash University
Qualitative Health Research | Year: 2013

In this article, we argue that the "problem" of addiction emerges as an effect of treatment policy and practice as well as a precursor to it. We draw on the work of Marrati to analyze interviews with policy makers and practitioners in Australia. The interviews suggest that the episode-of-care system governing service activity, outcomes, and funding relies on certain notions of addiction and treatment that compel service providers to designate service users as addicts to receive funding. This has a range of effects, not least that in acquiring the label of "addict," service users enter into bureaucratic and epidemiological systems aimed at quantifying addiction. Rather than treating pre-existing addicts, the system produces "addicts" as an effect of policy imperatives. Because addiction comes to be produced by the very system designed to treat it, the scale of the problem appears to be growing rather than shrinking. © The Author(s) 2013.

Venkatesh V.,University of Arkansas | Chan F.K.Y.,Curtin University Australia | Thong J.Y.L.,Hong Kong University of Science and Technology
Journal of Operations Management | Year: 2012

Advances in Internet technologies have led to the popularity of technology-based self-services, with the design of such services becoming increasingly important. Using technology-based services in the public sector as the setting, we identified the key service attributes driving adoption and use of transactional e-government services, and citizens' preference structures across these attributes. After identifying four key attributes, i.e., usability, computer resource requirement, technical support provision and security provision, we conducted a Web-based survey and a conjoint experiment among 2465 citizens. In a two-stage Web-based survey, citizens reported their perceptions about a smartcard technology for transactional e-government services before use, and their use and satisfaction 4 months later. Results showed that the key attributes (noted above) influenced citizens' intentions, subsequent use and satisfaction. In the conjoint experiment, citizens reported their preferences for key service attributes for two transactional e-government services. Further, a cluster analysis uncovered four distinct citizen segments, i.e., balanced, usability-focused, risk-conscious and resource-conservative, that can inform efforts in designing e-government services. A post hoc analysis confirmed the appropriateness of the market segmentation in understanding citizens' adoption and use of transactional e-government services. © 2011 Published by Elsevier B.V.

Pisarevsky S.A.,Curtin University Australia | Pisarevsky S.A.,University of Western Australia | Elming S.-A.,Lulea University of Technology | Pesonen L.J.,University of Helsinki | Li Z.-X.,Curtin University Australia
Precambrian Research | Year: 2014

A set of global paleogeographic reconstructions for the 1770-1270. Ma time interval is presented here through a compilation of reliable paleomagnetic data (at the 2009 Nordic Paleomagnetic Workshop in Luleå, Sweden) and geological constraints. Although currently available paleomagnetic results do not rule out the possibility of the formation of a supercontinent as early as ca. 1750. Ma, our synthesis suggests that the supercontinent Nuna/Columbia was assembled by at least ca. 1650-1580. Ma through joining at least two stable continental landmasses formed by ca. 1.7. Ga: West Nuna (Laurentia, Baltica and possibly India) and East Nuna (North, West and South Australia, Mawson craton of Antarctica and North China). It is possible, but not convincingly proven, that Siberia and Congo/São Francisco were combined as a third rigid continental entity and collided with Nuna at ca.1500. Ma. Nuna is suggested to have broken up at ca. 1450-1380. Ma. West Nuna, Siberia and possibly Congo/São Francisco were rigidly connected until after 1270. Ma. East Nuna was deformed during the breakup, and North China separated from it. There is currently no strong evidence indicating that Amazonia, West Africa and Kalahari were parts of Nuna. © 2013 Elsevier B.V.

Mansour H.E.,University of Tabuk | Dillon T.,Curtin University Australia
IEEE Transactions on Services Computing | Year: 2011

In this paper, we propose a service-oriented reliability model that dynamically calculates the reliability of composite web services with rollback recovery based on the real-time reliabilities of the atomic web services of the composition. Our model is a hybrid reliability model based on both path-based and state-based models. Many reliability models assume that failure or error arrival times are exponentially distributed. This is inappropriate for web services as error arrival times are dependent on the operating state including workload of servers where the web service resides. In this manuscript, we modify our previous model (for software based on the Doubly Stochastic Model and Renewal Processes) to evaluate the reliability of atomic web services. In order to fix our idea, we developed the case of one simple web service which contains two states, i.e., idle and active states. In real-world applications, where web services could contain quite a large number of atomic services, the calculus as well as the computing complexity increases greatly. To limit our computing efforts and calculus, we chose the bounded set techniques that we apply using the previously developed stochastic model. As a first type of system combination, we proposed to study a scheme based on combining web services into parallel and serial configurations with centralized coordination. In this case, the broker has an acceptance testing mechanism that examines the results returned from a particular web service. If it was acceptable, then the computation continues to the next web service. Otherwise, it involves rollback and invokes another web service already specified by a checkpoint algorithm. Finally, the acceptance test is conducted using the broker. The broker can be considered as a single point of failure. To increase the reliability of the broker introduced in our systems and mask out errors at the broker level, we suggest a modified general scheme based on Triple modular redundancy and N-version programming. To imitate a real scenario where errors could happen at any stage of our application and improve the quality of Service QoS of the proposed model, we introduce fault-tolerance techniques using an adaption of the recovery block technique. © 2011 IEEE.

Yuan W.,Curtin University Australia | Lu S.,Beihang University | Xiang Y.,Beihang University | Jiang S.P.,Curtin University Australia
RSC Advances | Year: 2014

Due to their unique electronic and mechanical properties, carbon nanotubes (CNTs) have been attracting much attention as favourite catalyst supports for energy conversion and storage applications. However, CNTs require molecular engineering such as solubilization and surface modification or functionalization to tailor their surface properties for the catalyst support applications. Among various functionalization methods, non-covalent functionalization is preferred, because it enables the attachment of molecules, solvents or polyelectrolytes through π-π, CH-π or hydrophobic interactions, forming effective active sites for the uniform assembly and dispersion of Pt-based precursor and/or nanoparticles (NPs) and at the same time preserving the intrinsic electronic and structural integrity of CNTs. Non-covalent functionalization is also effective to incorporate a multi-component electrocatalyst system with significantly enhanced synergistic effects. Here, the progress in the synthesis and development of highly dispersed Pt, and Pt-based NPs such as PtRu, PtSn and PtPd on non-covalent functionalized CNTs will be presented. The significant effect of interactions between CNTs, Pt-based NPs and functionalization agents on the electrocatalytic activity of Pt-based NPs on non-covalent functionalized CNTs is discussed. This journal is © the Partner Organisations 2014.

Arnott D.,Monash University | Pervan G.,Curtin University Australia
Journal of the Association of Information Systems | Year: 2012

Design science has been an important strategy in decision support systems (DSS) research since the field's inception in the early 1970s. Recent reviews of DSS research have indicated a need to improve its quality and relevance. DSS design-science research has an important role in this improvement because design-science research can engage industry and the profession in intellectually important projects. The Hevner, March, Park, and Ram's (HMPR) guidelines for the conduct and assessment of information systems design-science research, published in MIS Quarterly in 2004, provides a vehicle for assessing DSS design-science research. This paper presents research that used bibliometric content analysis to apply the HMPR guidelines to a representative sample of 362 DSS design-science research papers in 14 journals. The analysis highlights major issues in DSS research that need attention: research design, evaluation, relevance, strategic focus, and theorizing.

Soria R.,Curtin University Australia | Hau G.K.T.,European Southern Observatory | Pakull M.W.,University of Strasbourg
Astrophysical Journal Letters | Year: 2013

We studied the optical spectrum of HLX-1 during its latest outburst, using the FORS2 spectrograph on the Very Large Telescope. We detect an Hα emission line centered at λ = 6718.9 ± 0.9 Å and find that its projected radial velocity with respect to the nucleus of ESO 243-49 is 424 ± 27 km s-1, while the maximum rotational velocity of the stars in that galaxy is ≈209 km s-1. This suggests that HLX-1 and its surrounding stars were not formed in situ, but came either from a disrupted dwarf galaxy or from a nuclear recoil. We also find that the Hα emission line is resolved with FWHM ≈400 km s-1, suggesting a nebular rather than disk origin for the emission. Its luminosity (L Hα ≈ a few 1037 erg s-1, equivalent width ≈70 Å) is also consistent with emission from a nebula photoionized by HLX-1. © 2013. The American Astronomical Society. All rights reserved.

Lu J.,Curtin University Australia | Lu J.,Nanyang Technological University | Lu S.,Beihang University | Jiang S.P.,Curtin University Australia
Chemical Communications | Year: 2011

A highly ordered mesoporous Nafion membrane with a remarkable water retention ability was synthesized via a micelle templating method with self-assembled Pluronic F108 surfactants and its capability to operate under completely dry gas streams is demonstrated. © 2011 The Royal Society of Chemistry.

Zhang K.,Curtin University Australia | Shao Z.,Monash University | Li C.,Curtin University Australia | Liu S.,Curtin University Australia
Energy and Environmental Science | Year: 2012

Here we report a new concept for oxygen separation by the oxygen ion conducting ceramic membrane with an external short circuit. With the strong chemical stability against acidic gases like CO 2 and the higher oxygen fluxes at lower temperatures, this novel membrane concept could possibly result in a breakthrough for tonnage oxygen production to improve the viability of these clean energy technologies. © 2011 The Royal Society of Chemistry.

Andrews R.K.,Monash University | Berndt M.C.,Curtin University Australia
Seminars in Thrombosis and Hemostasis | Year: 2013

Bernard-Soulier syndrome (BSS) is a rare inherited platelet bleeding disorder characterized by low platelet count and abnormally large platelets (macrothrombocytopenia). Platelets from BSS patients are typically defective in surface expression of glycoprotein (GP)Ib-IX-V, a platelet-specific adhesion-signaling complex, composed of GPIbα disulfide linked to GPIbβ, and noncovalently associated with GPIX and GPV. The major ligand-binding subunit, GPIbα, binds the adhesive ligands von Willebrand factor (VWF) or thrombospondin, counterreceptors on activated endothelial cells (P-selectin) or activated leukocytes (integrin αMβ 2), and coagulation factors (thrombin, factors XI and XII, high-molecular-weight kininogen). The cytoplasmic domain of GPIb-IX-V interacts with the cytoskeletal protein, filamin-A via a binding site within the GPIbα cytoplasmic tail, and with structural-signaling proteins including calmodulin, 14-3-3ζ and the p85 subunit of phosphoinositide 3-kinase. GPIbα is physically/functionally co-associated on the platelet surface with the major platelet collagen receptor, GPVI. As such, it is easy to see how genetic defects impacting GPIb-IX-V expression or function can have significant consequences on normal platelet size, adhesion to VWF/collagen and/or stable thrombus formation, and why BSS is often associated with clinical bleeding. Furthermore, the rarity, multiple genetic causes, and variable clinical phenotype of BSS can complicate routine diagnosis. Here, we discuss how studies of BSS have contributed to platelet biology and recent studies to improve diagnosis and treatment. © 2013 by Thieme MedicalPublishers, Inc.

Selvey L.A.,Curtin University Australia | Antao C.,Curtin University Australia | Hall R.,Monash University
Emerging Infectious Diseases | Year: 2015

In response to the severe acute respiratory syndrome (SARS) pandemic of 2003 and the influenza pandemic of 2009, many countries instituted border measures as a means of stopping or slowing the spread of disease. The measures, usually consisting of a combination of border entry/exit screening, quarantine, isolation, and communications, were resource intensive, and modeling and observational studies indicate that border screening is not effective at detecting infectious persons. Moreover, border screening has high opportunity costs, financially and in terms of the use of scarce public health staff resources during a time of high need. We discuss the border-screening experiences with SARS and influenza and propose an approach to decision-making for future pandemics. We conclude that outbreak-associated communications for travelers at border entry points, together with effective communication with clinicians and more effective disease control measures in the community, may be a more effective approach to the international control of communicable diseases. © Centers for Disease Control and Prevention (CDC). All rights reserved.

Soares M.J.,Curtin University Australia | Chan She Ping-Delfos W.,West Health Institute | Ghanbari M.H.,Curtin University Australia
European Journal of Clinical Nutrition | Year: 2011

Obesity often coexists with low calcium intake and vitamin D insufficiency. There is emerging evidence of a role for these nutrients in the regulation of body weight. However, it is unclear whether increasing intakes of calcium and/or vitamin D during energy restriction, is a better strategy for weight and fat loss. We searched the literature from 2000 to date for randomized controlled trials (RCTs) on weight loss that had increased calcium or vitamin D per se, or in combination. Primary and secondary studies were included for this analysis. A total of 15 RCTs on calcium with or without vitamin D and seven on vitamin D alone met our criteria. Two studies reported that supplemental calcium significantly increased fat loss during caloric restriction by 1.8 and 2.2 kg, three found differences between 1 and 3.5 kg but were statistically nonsignificant, while nine trials were equivocal (±0.7 kg). The data on vitamin D supplementation during weight loss were too few to make firm conclusions. Current evidence from RCTs did not consistently support the contention that calcium and vitamin D accelerated weight or fat loss in obesity. There were studies that favoured the hypothesis but lacked the statistical power. There is a need for RCTs to examine the influence of vitamin D on body fat. © 2011 Macmillan Publishers Limited All rights reserved.

Tang T.,Beihang University | Wang Y.,Beihang University | Yang X.,Beijing Jiaotong University | Wu Y.,Curtin University Australia
Nonlinear Dynamics | Year: 2012

In this paper, we develop a new car-following model with consideration of varying road condition based on the empirical data. Firstly, we explore the effects of road condition on uniform flow from analytical and numerical perspectives. The results indicate that road condition has great influences on uniform flow, i.e., good road condition can enhance the velocity and flow and their increments will increase when road condition becomes better; bad road conditions will reduce the velocity and flow and their reductions will increase when road condition turns worse. Secondly, we study the effects of road conditions on the starting and braking processes. The numerical results show that good road condition will speed up the two processes and that bad road condition will slow down the two processes. Finally, we study the effects of road condition on small perturbation. The numerical results indicate that the stop-and-go phenomena resulted by small perturbation will become more serious when the road condition becomes better. © Springer Science+Business Media B.V. 2012.

Cartwright J.H.E.,University of Granada | Checa A.G.,University of Granada | Gale J.D.,Curtin University Australia | Gebauer D.,University of Konstanz | Sainz-Diaz C.I.,University of Granada
Angewandte Chemie - International Edition | Year: 2012

Although the polymorphism of calcium carbonate is well known, and its polymorphs-calcite, aragonite, and vaterite-have been highly studied in the context of biomineralization, polyamorphism is a much more recently discovered phenomenon, and the existence of more than one amorphous phase of calcium carbonate in biominerals has only very recently been understood. Here we summarize what is known about polyamorphism in calcium carbonate as well as what is understood about the role of amorphous calcium carbonate in biominerals. We show that consideration of the amorphous forms of calcium carbonate within the physical notion of polyamorphism leads to new insights when it comes to the mechanisms by which polymorphic structures can evolve in the first place. This not only has implications for our understanding of biomineralization, but also of the means by which crystallization may be controlled in medical, pharmaceutical, and industrial contexts. Coming in to form: A summary is given of what is known about polyamorphism in calcium carbonate as well as the role of amorphous calcium carbonate in biomineralization. The amorphous forms of calcium carbonate within the physical notion of polyamorphism lead to new insights when it comes to the mechanisms by which polymorphic structures can evolve. This also has implications beyond biomineralization. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metharom P.,Curtin University Australia | Berndt M.C.,Curtin University Australia | Baker R.I.,Murdoch University | Andrews R.K.,Monash University
Arteriosclerosis, Thrombosis, and Vascular Biology | Year: 2015

An unresolved problem with clinical use of antiplatelet therapy is that a significant number of individuals either still get thrombosis or run the risk of life-threatening bleeding. Antiplatelet drugs are widely used clinically, either chronically for people at risk of athero/thrombotic disease or to prevent thrombus formation during surgery. However, a subpopulation may be resistant to standard doses, while the platelet targets of these drugs are also critical for the normal hemostatic function of platelets. In this review, we will briefly examine current antiplatelet therapy and existing targets while focusing on new potential approaches for antiplatelet therapy and improved monitoring of effects on platelet reactivity in individuals, ultimately to improve antithrombosis with minimal bleeding. Primary platelet adhesion-signaling receptors, glycoprotein (GP)Ib-IX-V and GPVI, that bind von Willebrand factor/collagen and other prothrombotic factors are not targeted by drugs in clinical use, but they are of particular interest because of their key role in thrombus formation at pathological shear.

Carcione J.M.,National Institute of Oceanography and Applied Geophysics - OGS | Gurevich B.,Curtin University Australia
Geophysics | Year: 2011

The squirt-flow wave attenuation mechanism is implemented in Biot's theory of poroelasticity in the form of differential equations. All the stiffnesses involved in the stress-strain relation become complex and frequency dependent, which can exactly be expressed in terms of kernels based on the Zener mechanical model. In the time domain, this approach implies time convolutions, which are circumvented by introducing memory variables. The differential equations are consistent with Gassmann's and Mavko-Jizba equations at low and high frequencies, respectively. All the coefficients in the poro-viscoelastic differential equations have a clear physical meaning and can be obtained or estimated from independent measurements. The key additional parameters are the dry-rock bulk modulus at a confining pressure where all the compliant pores are closed, i.e., a hypothetical rock without the soft porosity, the grain-contact aspect ratio and the compliant porosity. We recasted the wave equation in the particle-velocity/stress formulation and solved it by using a time-splitting technique and the Fourier pseudospectral method to compute the spatial derivatives. The algorithm can be used to obtain synthetic wave fields in inhomogeneous media. © 2011 Society of Exploration Geophysicists.

Evans K.-A.,Curtin University Australia | Tomkins A.-G.,Monash University
Earth and Planetary Science Letters | Year: 2011

A number of lines of evidence point to a causal link between oxidised slab-derived fluids, oxidised sub-arc mantle, and the formation of economic concentrations of metals such as Cu and Au that require oxidised magmas. However, trace element evidence from some trace element and isotope data suggests that sub-arc mantle is no more oxidised than mantle elsewhere.A simple analytical model is applied to constrain the evolution of sub-arc mantle oxidation state as a function of redox-budget fluxes from the subducting slab. Influential variables include the solubility of Fe3+ and SO4 2- in slab-derived fluids, the geometry of the infiltration of slab-derived fluids in sub-arc mantle, the coupling between slab-derived and arc-output redox budgets, and the concentration of redox-buffering elements such as Fe and S in the sub-arc mantle.Plausible Archean and Proterozoic redox budget fluxes would not have created oxidised sub-arc mantle without input from ferric iron or sulphate dissolved in non-aqueous fluids such as silicate melts. Aqueous-borne Phanerozoic redox budget fluxes, on the other hand, which are dominated by the sulphate component, could have increased sub-arc fO2 by up to three log10 units. The results are generally consistent with the proposed elevated fO2 for sub-arc mantle, but no resolution was found for the apparent contradiction between high proposed fO2 values derived from iron-based oxybarometry and the lower values inferred from trace element and isotope evidence.Increases in sub-arc mantle fO2 are favoured by focussed fluid infiltration and magma generation, weak coupling between slab and arc-output redox budgets, and restricted redox-buffering in the sub-arc mantle. Fertile arc segments for ore deposits associated with oxidised magmas require fluid chemistry and pressure-temperature gradients that enhance Fe3+ and SO4 2- solubility in aqueous and silica-rich fluids, tectonic stress regimes that favour focussed transfer of components into the sub-arc mantle, and a relatively weak redox buffer for the sub-arc mantle. The paucity of Cu and Au deposits associated with oxidised magmas in Precambrian rocks may be explained as a consequence of a lack of subducted oxidised material, rather than simply as a consequence of preservation potential. Additionally, the reduced nature of subducted material in the Precambrian may have caused S and metal enrichment in the sub-arc mantle. © 2011 Elsevier B.V.

Schoeppe S.,Central Queensland University | Duncan M.J.,Central Queensland University | Badland H.,University of Melbourne | Oliver M.,Auckland University of Technology | Curtis C.,Curtin University Australia
Journal of Science and Medicine in Sport | Year: 2013

Health benefits from children's independent mobility and active travel beyond school travel are largely unexplored. Objectives: This review synthesized the evidence for associations of independent mobility and active travel to various destinations with physical activity, sedentary behaviour and weight status. Design: Systematic review. Methods: A systematic search in six databases (PubMed, Scopus, CINAHL, SportDiscus, PsychInfo, TRIS) for papers published between January 1990 and March 2012 was undertaken, focussing on children aged 3-18 years. Study inclusion and methodological quality were independently assessed by two reviewers. Results: 52 studies were included. Most studies focussed solely on active travel to and/or from school, and showed significant positive associations with physical activity. The same relationship was detected for active travel to leisure-related places and independent mobility with physical activity. An inverse relationship between active travel to school and weight status was evident but findings were inconsistent. Few studies examined correlations between active travel to school and self-reported screen-time or objectively measured sedentary behaviour, and findings were unclear. Conclusions: Studies on independent mobility suggested that children who have the freedom to play outdoors and travel actively without adult supervision accumulate more physical activity than those who do not. Further investigation of children's active travel to leisure-related destinations, measurement of diverse sedentary behaviour beyond simply screen-based activities, and consistent thresholds for objectively measured sedentary behaviour in children wilL clarify the inconsistent evidence base on associations of active travel with sedentary behaviour and weight status. © 2012 Sports Medicine Australia.

Berndt M.C.,Curtin University Australia | Metharom P.,Curtin University Australia | Andrews R.K.,Monash University
Haemophilia | Year: 2014

At the same time as biophysical and omics approaches are drilling deeper into the molecular details of platelets and other blood cells, as well as their receptors and mechanisms of regulation, there is also an increasing awareness of the functional overlap between human vascular systems. Together, these studies are redefining the intricate networks linking haemostasis and thrombosis with inflammation, infectious disease, cancer/metastasis and other vascular pathophysiology. The focus of this state-of-the-art review is some of the newer advances relevant to primary haemostasis. Of particular interest, platelet-specific primary adhesion-signalling receptors and associated activation pathways control platelet function in flowing blood and provide molecular links to other systems. Platelet glycoprotein (GP)Ibα of the GPIb-IX-V complex and GPVI not only initiate platelet aggregation and thrombus formation by primary interactions with von Willebrand factor and collagen, respectively, but are also involved in coagulation, leucocyte engagement, bacterial or viral interactions, and are relevant as potential risk markers in a range of human diseases. Understanding these systems in unprecedented detail promises significant advances in evaluation of individual risk, in new diagnostic or therapeutic possibilities and in monitoring the response to drugs or other treatment. © 2014 John Wiley & Sons Ltd.

Chen D.,Hong Kong University of Science and Technology | Chen D.,Jinan University | Chen C.,Hong Kong University of Science and Technology | Baiyee Z.M.,Hong Kong University of Science and Technology | And 3 more authors.
Chemical Reviews | Year: 2015

The recent advances in the development of nonstoichiometric oxides, ranging from simple oxide, perovskite, layered perovskite, and pyrochlore, for oxygen reduction Reaction (ORR) and oxygen evolution reaction (OER) in metal-air batteries (MABs) and low-temperature fuel cells (LTFCs) are reviewed. These catalysts are characterized to be low cost and earth-abundant, as well as possess relatively high activity and stability under operation conditions. It is expected that these catalysts will be essential to the future development of multiple technologies. It is expected that the development of nonstoichiometric oxides, with the mutual development of system components, will lead to highly stable and efficient MABs and LTFCs in practical applications in the near future. The electrochemical strain microscopy technique may provide a direct visualization of the ORR/OER activation process on the scale of several nanometers and provide nanoscale understanding into local kinetics. An efficient approach to discover new materials with high intrinsic activities is to tune the electronic structure of existing materials.

Petersen A.,Monash University | Seear K.,Curtin University Australia | Munsie M.,University of Melbourne
Sociology of Health and Illness | Year: 2014

The recent growth of so-called stem cell tourism reflects the high optimism that currently surrounds stem cell science. Stem cell treatments for various conditions are increasingly advertised over the Internet as being available at hospitals and clinics around the world. However, most are clinically unproven. Despite numerous warnings from scientists about the dangers posed by such treatments, many individuals are evidently prepared to take the risk, sometimes on more than one occasion. This article explores the dynamics of hope that underpin stem cell tourism. Drawing on ideas from the sociology of hope, as applied to biomedicine, the article explores how hope is constructed and shapes actions in relation to stem cell treatments. Making reference to the findings from an Australian study of patients and carers who travelled overseas to receive stem cell treatments, it is argued that hope has an ambiguous significance in the context of deregulated health care. As we explain, this has implications for patients' and carers' treatment decisions and experiences. The findings are discussed in light of current responses to stem cell tourism. 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

Wang W.,Nanjing University of Technology | Su C.,Curtin University Australia | Wu Y.,Monash University | Ran R.,Nanjing University of Technology | Shao Z.,Nanjing University of Technology
Chemical Reviews | Year: 2013

The article examines progress in solid oxide fuel cells with nickel-based anodes operating on methane and related fuels. Natural gas has already been widely used as an important energy source in numerous applications, including the heating of buildings and cooking by direct combustion, the generation of electricity by gas turbines or steam turbines, and as a fuel for combustion engines in vehicles. Conventional SOFCs employ nickel-based cermet anodes, which exhibit good compatibility with electrolytes composed of stabilized zirconia or doped ceria, high activity toward the electrocatalytic oxidation of hydrogen, and high electronic conductivity. By direct feeding of a nickel cermet anode-based SOFC with methane, the anode may play dual roles: catalyzing the methane reforming reactions and promoting the electrochemical oxidation of hydrogen, carbon monoxide, and methane.

Demichelis R.,Curtin University Australia | Raiteri P.,Curtin University Australia | Gale J.D.,Curtin University Australia | Dovesi R.,University of Turin
Crystal Growth and Design | Year: 2013

For many years the nature of the disordered structure of vaterite, a calcium carbonate polymorph that plays a significant role in biomineralisation, has been debated. In the past year, two independent studies (Angew. Chem., Int. Ed., 51, 7041; CrystEngComm, 14, 44) have proposed new, yet different models on the basis of electron diffraction experiments and ab initio calculations, respectively. Here, it is shown that there are at least three effectively isoenergetic models that are equally likely to describe the vaterite structure at room temperature. These distinct models, each consisting of multiple structures, can explain the disorder of vaterite in terms of different orientations of the carbonate anions, multiple stacking sequences of the carbonate layers, and possible chiral forms. Hence, vaterite is not a single "disordered" structure but should instead be considered as a combination of different forms, each of which can exhibit rapid interchange between multiple structures that exhibit similar average properties. © 2013 American Chemical Society.

Kazem A.,Tafresh University | Sharifi E.,Tafresh University | Hussain F.K.,University of Technology, Sydney | Saberi M.,Islamic Azad University at Tafresh | Hussain O.K.,Curtin University Australia
Applied Soft Computing Journal | Year: 2013

Due to the inherent non-linearity and non-stationary characteristics of financial stock market price time series, conventional modeling techniques such as the Box-Jenkins autoregressive integrated moving average (ARIMA) are not adequate for stock market price forecasting. In this paper, a forecasting model based on chaotic mapping, firefly algorithm, and support vector regression (SVR) is proposed to predict stock market price. The forecasting model has three stages. In the first stage, a delay coordinate embedding method is used to reconstruct unseen phase space dynamics. In the second stage, a chaotic firefly algorithm is employed to optimize SVR hyperparameters. Finally in the third stage, the optimized SVR is used to forecast stock market price. The significance of the proposed algorithm is 3-fold. First, it integrates both chaos theory and the firefly algorithm to optimize SVR hyperparameters, whereas previous studies employ a genetic algorithm (GA) to optimize these parameters. Second, it uses a delay coordinate embedding method to reconstruct phase space dynamics. Third, it has high prediction accuracy due to its implementation of structural risk minimization (SRM). To show the applicability and superiority of the proposed algorithm, we selected the three most challenging stock market time series data from NASDAQ historical quotes, namely Intel, National Bank shares and Microsoft daily closed (last) stock price, and applied the proposed algorithm to these data. Compared with genetic algorithm-based SVR (SVR-GA), chaotic genetic algorithm-based SVR (SVR-CGA), firefly-based SVR (SVR-FA), artificial neural networks (ANNs) and adaptive neuro-fuzzy inference systems (ANFIS), the proposed model performs best based on two error measures, namely mean squared error (MSE) and mean absolute percent error (MAPE). Copyright © 2012 Published by Elsevier B.V. All rights reserved.

Zhou J.-B.,Jilin University | Zhou J.-B.,Curtin University Australia | Wilde S.A.,Jilin University | Wilde S.A.,Curtin University Australia
Gondwana Research | Year: 2013

The basement rocks in parts of NE China constitute a khondalitic sequence of sillimanite- and garnet-bearing gneisses, hornblende-plagioclase gneiss and various felsic paragneisses. Zircon U-Pb dating of garnet-sillimanite gneiss samples from the Erguna, Xing'an, Jiamusi and Khanka blocks indicates that high-grade metamorphism occurred at ~ 500. Ma. Evidence from detrital zircons in Paleozoic sediments from the Songliao Block also indicates the former presence of a ~ 500. Ma component. This uniformity of U-Pb ages across all crustal blocks in NE China establishes a >. 1300. km long Late Pan-African khondalite belt which we have named the 'NE China Khondalite Belt'. This indicates the blocks of NE China were amalgamated prior to ~ 500. Ma, contrary to current belief. One scenario is that this amalgamated terrane had a tectonic affinity to the Siberia Craton, once forming part of the Late Pan-African (~ 500. Ma) Sayang-Baikal orogenic belt extensively developed around the southern margin of the Siberia Craton. This belt was the result of collision between currently unidentified terranes with the Southeastern Angara-Anabar Province at about 500. Ma, where the rocks were deformed and metamorphosed to granulite facies. It appears likely that at sometime after ~ 450. Ma, the combined NE China blocks rifted away from Siberia and moved southward to form what is now NE China. The combined block collided with the North China Craton along the Solonker-Xar Moron-Changchun suture zone at ~ 230. Ma rather than in the end-Permian as previously thought. Local rifting at the eastern extremity of the developing Central Asian Orogenic Belt (CAOB) resulted in the splitting away of the Jiamusi/Khanka(/Bureya) blocks. However, this was only transient and sometime between 210 and 180. Ma, these were re-united with the CAOB by the onset of Pacific plate subduction, which has dominated the tectonic evolution of the region since that time. © 2012 International Association for Gondwana Research.

Li X.-H.,CAS Institute of Geology and Geophysics | Li Z.-X.,Curtin University Australia | Li W.-X.,CAS Guangzhou Institute of Geochemistry | Wang X.-C.,Curtin University Australia | Gao Y.,CAS Institute of Geology and Geophysics
Chemical Geology | Year: 2013

Adakites, or adakitic rocks, in a broad sense, have been used to describe a large range of igneous rocks with the common feature of high Sr/Y and La/Yb ratios that can be achieved though different mechanisms. Among them, the continental, or C-type, adakitic rocks are particularly controversial in terms of their sources and genesis. In this study we revisit both Cu-Au ore-bearing and barren "C-type adakitic rocks" in the Lower Yangtze River Belt (LYRB) of central eastern China, including comprehensive analyses of their in-situ zircon Hf-O isotopes, whole-rock geochemistry and Sr-Nd isotopes. These "C-type adakitic rocks" consist of monzodiorite, granodiorite and quartz monzonite that are classified as shoshonitic to high-K calc-alkaline series according to their chemical compositions. They are characteristically high in potassium (K2O=2.4-4.5%, K2O/Na2O=0.6-1.3), with continental crust-like isotopic compositions, i.e., whole-rock εNd(T)=-3.9 to -7.7, initial 87Sr/86Sr=0.7054-0.7085, zircon εHf(T)=0 to -11, and δ18O=6‰ to 9‰. The ore-bearing and barren rocks are cogenetic. Fractional crystallization of hornblende, titanite, magnetite and apatite played a major role in their chemical variations, with the ore-bearing rocks being more felsic (SiO2=63.3-69.6%) and higher in Sr/Y (41.2-75.6) than the barren rocks (SiO2=57.3-65.0%, Sr/Y=30.4-51.8). All these geochemical and isotopic features, in combination with regional geological data, suggest that the LYRB "C-type adakitic rocks" were unlikely to have been formed by melting of either a thickened and/or delaminated lower continental crust, or an altered oceanic crust as previously thought. These rocks are in general akin in geochemistry and isotopes to the Archean sanukitoids and the Setouchi high-Mg andesites in Japan, and are thus interpreted as being formed by melting of an enriched mantle source metasomatized by dewatering from a delaminated flat-slab. The flat subduction of an oceanic plateau and its subsequent delamination and foundering since the early Mesozoic beneath southeastern China (Li and Li, 2007) thus not only explain the temporal and spatial propagation of widespread Yanshanian igneous rocks regionally since ca. 195Ma, but also the formation of a series of enigmatic "adakitic" rocks in the region, including the LYRB potassium-rich rocks that were inappropriately called the "C-type adakitic rock" by previous workers. © 2013 Elsevier B.V.

Feng H.,Tsinghua University | Soria R.,Curtin University Australia
New Astronomy Reviews | Year: 2011

Ultraluminous X-ray sources (ULXs) are accreting black holes that may contain the missing population of intermediate mass black holes or reflect super-Eddington accretion physics. Ten years of Chandra and XMM-Newton observations of ULXs, integrated by multiband studies of their counterparts, have produced a wealth of observational data and phenomenological classifications. We review the properties of their host galaxies, list popular spectral models and implications for standard and supercritical accretion physics, demonstrate how X-ray timing of these objects places constraints on their masses. We also review multiwavelength studies of ULXs, including the optical emission of the binary system and nebulosity around them. We summarize that three classes of black holes could power ULXs: normal stellar mass black holes (~10M⊙), massive stellar black holes (≲100M⊙), and intermediate mass black holes (102-104M⊙). We collect evidence for the presence of these three types of compact objects, including caveat of each interpretation, and briefly review their formation processes. © 2011 Elsevier B.V.

Yuan W.,Curtin University Australia | Shen P.K.,Sun Yat Sen University | Jiang S.P.,Curtin University Australia
Journal of Materials Chemistry A | Year: 2014

The sluggish water oxidation reaction represents a significant challenge in water splitting for energy storage using hydrogen. We herein report the synthesis of MnO2 nanowires with the ultrasmall diameter and aspect ratio as high as 125 on graphene using a novel in situ polymer-mediated self-assembly approach in aqueous solution and under ambient conditions. The self-assembly process is simple and controllable by the concentration and pH of the polymer solution, in which the polymer serves as a soft template to direct the growth of MnO2 nanowires and also stabilize the structure, forming a unique graphene supported MnO2 nanowire, G@MnO2 NW. This nanostructure shows the most significant improvement of the catalytic activity compared to the graphene supported MnO2 nanoparticle and commercial Pt/C toward water oxidation under both alkaline and neutral conditions, and demonstrates for the first time a remarkable effect of the shape of MnO2 nanostructures on water oxidation catalysis. For example, at 0.7 V, it produces a current density of 5.9 mA cm-2, 14.8 times that of the graphene supported MnO2 nanoparticle (4.0 mA cm-2) and 8.4 times that of Pt/C (0.7 mA cm-2) in alkaline solution. Furthermore, it displays the highest turnover frequency reported among all the Mn oxides used for water oxidation catalysis. The G@MnO2 NW shows great potential as a water oxidation catalyst for energy storage applications. © The Royal Society of Chemistry.

Casassa S.,University of Turin | Demichelis R.,Curtin University Australia
Journal of Physical Chemistry C | Year: 2012

The relative energy of aluminum mono- (boehmite and diaspore) and trihydroxides (gibbsite, bayerite, doyleite, and nordstrandite) was investigated with a periodic local Møller-Plesset second-order perturbative approach, with the aim of providing a reliable trend of stability on the basis of a proper description of both the long-range Coulomb interactions and the short-range correlation effects. These components, disregarded in previous studies based on the density functional theory, turn out to be important for these kinds of systems, where hydrogen bonds and van der Waals forces play a fundamental role in stabilizing the structure. The results are in good agreement with the available experimental evidence. The reasons for the monohydroxides energy difference were investigated, with diaspore showing an electronic structure for oxygen atoms more favorable than that for boehmite. The problem of the nordstrandite structure was reexamined because of the presence of a second minimum energy structure on the energy surface. Both of them are higher in energy than those of the other trihydroxide polymorphs, and the relative stability of one of these structures with respect to gibbsite is in agreement with recent experimental investigations. © 2012 American Chemical Society.

Tang H.,Wuhan University of Technology | Pan M.,Wuhan University of Technology | Jiang S.P.,Curtin University Australia
Dalton Transactions | Year: 2011

A highly ordered inorganic electrolyte based on 12-tungstophosphoric acid (H3PW12O40, abbreviated as HPW or PWA)-silica mesoporous nanocomposite was synthesized through a facile one-step self-assembly between the positively charged silica precursor and negatively charged PW 12O40 3- species. The self-assembled HPW-silica nanocomposites were characterized by small-angle XRD, TEM, nitrogen adsorption-desorption isotherms, ion exchange capacity, proton conductivity and solid-state 31P NMR. The results show that highly ordered and uniform nanoarrays with long-range order are formed when the HPW content in the nanocomposites is equal to or lower than 25 wt%. The mesoporous structures/textures were clearly presented, with nanochannels of 3.2-3.5 nm in diameter. The 31P NMR results indicates that there are (SiOH 2 +)(H2PW12O40 -) species in the HPW-silica nanocomposites. A HPW-silica (25/75 w/o) nanocomposite gave an activation energy of 13.0 kJ mol-1 and proton conductivity of 0.076 S cm-1 at 100 °C and 100 RH%, and an activation energy of 26.1 kJ mol-1 and proton conductivity of 0.05 S cm-1 at 200 °C with no external humidification. A fuel cell based on a 165 μm thick HPW-silica nanocomposite membrane achieved a maximum power output of 128.5 and 112.0 mW cm-2 for methanol and ethanol fuels, respectively, at 200 °C. The high proton conductivity and good performance demonstrate the excellent water retention capability and great potential of the highly ordered HPW-silica mesoporous nanocomposites as high-temperature proton exchange membranes for direct alcohol fuel cells (DAFCs). © 2011 The Royal Society of Chemistry.

Reimers J.R.,University of Sydney | Wang Y.,University of Sydney | Cankurtaran B.O.,University of Technology, Sydney | Cankurtaran B.O.,Curtin University Australia | Ford M.J.,University of Technology, Sydney
Journal of the American Chemical Society | Year: 2010

The superatom model for nanoparticle structure is shown to be inadequate for the prediction of the thermodynamic stability of gold nanoparticles. The observed large HOMO-LUMO gaps for stable nanoparticles predicted by this model are, for sulfur-stabilized gold nanoparticles, attributed to covalent interactions of the metal with thiyl adsorbate radicals rather than ionic interactions with thiolate adsorbate ions, as is commonly presumed. In particular, gold adatoms in the stabilizing layer are shown to be of Au(0) nature, subtle but significantly different from the atoms of the gold core owing to the variations in the proportion of gold-gold and gold-sulfur links that form. These interactions explain the success of the superatom model in describing the electronic structure of both known and informatory nanoparticle compositions. Nanoparticle reaction energies are, however, found not to correlate with the completion of superatom shells. Instead, local structural effects are found to dominate the chemistry and in particular the significanctly different chemical properties of gold nanoparticle and bulk surfaces. These conclusions are drawn from density-functional-theory calculations for the Au102(p-mercaptobenzoic acid)44 nanoparticle based on the X-ray structure (Jadzinsky, P. D.; et al. Science 2007, 318, 430), as well calculations for the related Au102(S*-CH 3)44 nanoparticle, for the inner gold-cluster cores, for partially and overly reacted cores, and for Au(111) surface adsorbates. © 2010 American Chemical Society.

Clark C.,Curtin University Australia | Fitzsimons I.C.W.,Curtin University Australia | Healy D.,University of Aberdeen | Harley S.L.,University of Edinburgh
Elements | Year: 2011

There is widespread evidence that ultrahigh temperatures of 900-1000 °C have been generated in the Earth's crust repeatedly in time and space. These temperatures were associated with thickened crust in collisional mountain belts and the production of large volumes of magma. Numerical modelling indicates that a long-lived mountain plateau with high internal concentrations of heat-producing elements and low erosion rates is the most likely setting for such extreme conditions. Preferential thickening of alreadyhot back-arc basins and mechanical heating by deformation in ductile shear zones might also contribute to elevated temperatures.

Jiang S.P.,Curtin University Australia | Tang H.,Wuhan University of Technology
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

Layer-by-layer (LbL) self-assembly of polyelectrolyte bilayers on the methanol permeability and proton conductivity of Nafion membranes is investigated using polycations PDDA (poly(diallyldimethylammonium chloride)) and PAH (poly(allylamine hydrochloride)) and polyanions PAMP (poly(2-acrylamido-2-methyl-1-propanesulfonic acid)), PAZO (poly(1-(4-(3-carboxy-4-hydroxyphenylazo) benzene sulfonamido)-1,2-ethanediyl, sodium salt)), PSS (poly(sodium styrene sulfonate)) and PAA (poly(acrylic acid)). The formation of polyelectrolyte multilayers on Nafion membranes is confirmed by AFM and UV-visible spectroscopy. The lowest methanol permeability is observed on the self-assembled PDDA-PAA and PAH-PAA bilayers with the exponential growth process. The observed exponential growth process of polyelectrolyte multilayers with PAA polyanion is most likely related to small monomeric block of PAA, resulting in low steric hindrance and high flexibility and mobility of the ionomers and thus promoting the interdiffusion of PAA during the self-assembly. PDDA polycation shows a much better ability to block methanol crossover in comparison with that of PAH polycation. This study shows the importance of LbL self-assembled multilayer structure on the proton conductivity and methanol crossover properties of modified Nafion membranes for application in direct methanol fuel cells (DMFCs). © 2012 Elsevier B.V..

Li X.-H.,CAS Institute of Geology and Geophysics | Li Z.-X.,Curtin University Australia | Li W.-X.,CAS Guangzhou Institute of Geochemistry
Gondwana Research | Year: 2014

The South China Block, consisting of the Yangtze and the Cathaysia blocks, is one of the largest Precambrian blocks in eastern Asia. However, the early history of the Cathaysia Block is poorly understood due largely to intensive and extensive reworking by Phanerozoic polyphase orogenesis and magmatism which strongly overprinted and obscured much of the Precambrian geological record. In this paper, we use the detrital zircon U-Pb age and Hf isotope datasets as an alternative approach to delineate the early history of the Cathaysia Block. Compilation of published 4041 Precambrian detrital zircon ages from a number of (meta)sedimentary samples and river sands exhibits a broad age spectrum, with three major peaks at ~2485Ma, ~1853Ma and ~970Ma (counting for ~10%, ~16% and ~24% of all analyses, respectively), and four subordinate peaks at ~1426Ma, ~1074Ma, ~780Ma and ~588Ma. Five of seven detrital zircon age peaks are broadly coincident with the crystallisation ages of ~1.89-1.83Ga, ~1.43Ga, ~1.0-0.98Ga and ~0.82-0.72Ga for known igneous rocks exposed in Cathaysia, whereas, igneous rocks with ages of ~2.49Ga and ~0.59Ga have not yet been found. The Hf isotopic data from 1085 detrital zircons yield Hf model ages (TDM C) between ~4.19Ga and ~0.81Ga, and the calculated εHf(t) values between -40.2 and 14.4. The Archean detrital zircons are exclusively oval in shape with complicated internal textures, indicating that they were sourced by long distance transportations and strong abrasion from an exotic Archean continent. In contrast, the majority of detrital zircons in age between ~1.9 and ~0.8Ga are euhedral to subhedral crystals, indicative of local derivation by short distance transportations from their sources. The oldest crustal basement rocks in Cathaysia were most likely formed by generation of juvenile crust and reworking of recycled Archean components in Late Paleoproterozoic at ~1.9-1.8Ga, rather than in the Archean as previously speculated. Reworking and recycling of the continental crust are likely the dominant processes for the crustal evolution of Cathaysia during the Mesoproterozoic to Neoproterozoic time, with an intervenient period of significant generation of juvenile crust at ~1.0Ga.Precambrian crustal evolutions of the Cathaysia Block are genetically related to the supercontinent cycles. By comparing detrital zircon data from Cathaysia with those for other continents, and integrating multiple lines of geological evidence, we interpret the Cathaysia Block as an orogenic belt located between East Antarctica, Laurentia and Australia during the assembly of supercontinent Columbia/Nuna at ~. 1.9-1.8. Ga. The Cathaysia Block amalgamated with the Yangtze Block to form the united South China Block during the Sibao Orogeny at ~. 1.0-0.89. Ga. The Laurentia-Cathaysia-Yangtze-Australia-East Antarctica connection gives the best solution to the paleo-position of Cathaysia in supercontinent Rodinia. The significant amount of ~. 0.6-0.55. Ga detrital zircons in Cathaysia and West Yangtze have exclusively high crustal incubation time of >. 300. Ma, indicating crystallisation from magmas generated dominantly by crustal reworking. This detrital zircon population compares well with the similar-aged zircon populations from a number of Gondwana-derived terranes including Tethyan Himalaya, High Himalaya, Qiangtang and Indochina. The united South China-Indochina continent was likely once an integral part of Gondwanaland, connected to northern India by a "Pan-African" collisional orogen. © 2014 International Association for Gondwana Research.

Ntoumanis N.,Curtin University Australia | Ng J.Y.Y.,Chinese University of Hong Kong | Barkoukis V.,Aristotle University of Thessaloniki | Backhouse S.,Leeds Beckett University
Sports Medicine | Year: 2014

Background: There is a growing body of empirical evidence on demographic and psychosocial predictors of doping intentions and behaviors utilizing a variety of variables and conceptual models. However, to date there has been no attempt to quantitatively synthesize the available evidence and identify the strongest predictors of doping. Objectives: Using meta-analysis, we aimed to (i) determine effect sizes of psychological (e.g. attitudes) and social-contextual factors (e.g. social norms), and demographic (e.g. sex and age) variables on doping intentions and use; (ii) examine variables that moderate such effect sizes; and (iii) test a path analysis model, using the meta-analyzed effect sizes, based on variables from the theory of planned behavior (TPB). Data Sources: Articles were identified from online databases, by contacting experts in the field, and searching the World Anti-Doping Agency website. Study Eligibility Criteria and Participants: Studies that measured doping behaviors and/or doping intentions, and at least one other demographic, psychological, or social-contextual variable were included. We identified 63 independent datasets. Study Appraisal and Synthesis Method: Study information was extracted by using predefined data fields and taking into account study quality indicators. A random effects meta-analysis was carried out, correcting for sampling and measurement error, and identifying moderator variables. Path analysis was conducted on a subset of studies that utilized the TPB. Results: Use of legal supplements, perceived social norms, and positive attitudes towards doping were the strongest positive correlates of doping intentions and behaviors. In contrast, morality and self-efficacy to refrain from doping had the strongest negative association with doping intentions and behaviors. Furthermore, path analysis suggested that attitudes, perceived norms, and self-efficacy to refrain from doping predicted intentions to dope and, indirectly, doping behaviors. Limitations: Various meta-analyzed effect sizes were based on a small number of studies, which were correlational in nature. This is a limitation of the extant literature. Conclusions: This review identifies a number of important correlates of doping intention and behavior, many of which were measured via self-reports and were drawn from an extended TPB framework. Future research might benefit from embracing other conceptual models of doping behavior and adopting experimental methodologies that will test some of the identified correlates in an effort to develop targeted anti-doping policies and programs. © 2014, Springer International Publishing Switzerland.

Feng X.,Curtin University Australia | Zhang S.,Jilin University | Lou X.,Curtin University Australia
Colloids and Surfaces B: Biointerfaces | Year: 2013

Photosensitive nanoparticles are useful in developing phototherapeutic agents for targeted cancer therapy. In this paper, core-shell structured titanium dioxide-silica (TiO2-SiO2) nanoparticles, with varying shell thickness, were synthesized. The influence of the silica shell thickness on the photoreactivity, cytotoxicity and photo-killing ability of the TiO2 nanoparticles was investigated. Silica coating reduced the photocatalytic reactivity but improved the cytocompatibility of the TiO2 nanoparticles. This effect was amplified with increasing silica shell thickness. When the silica thickness was about 5.5nm, the coated TiO2 not only retained a high level photodynamic reactivity, comparable to the non-coated TiO2 nanoparticles, but also demonstrated an improved cell compatibility and effective photo-killing ability upon the mouse fibroblast cells (L929). © 2013 Elsevier B.V.

Chi H.-L.,National Taiwan University | Kang S.-C.,National Taiwan University | Wang X.,Curtin University Australia | Wang X.,Kyung Hee University
Automation in Construction | Year: 2013

Augmented reality (AR), a state-of-the-art technology for superimposing information onto the real world, has recently started to affect our daily lives. AR applications are becoming mature and versatile. This paper discusses trends in AR applications for architecture, engineering, construction, and facility management (AEC/FM). This paper specifically focuses on four technologies - localization, natural user interface (NUI), cloud computing, and mobile devices - which have the potential to influence the development of AR applications. Advances in localization technology will enable the deployment of AR in a complex environment. An NUI provides more convenient and intuitive user experiences, which can increase the usability of AR. Cloud computing environments allow users with internet access to ubiquitously retrieve information from almost anywhere. Hence, cloud computing increases the freedom of using AR in AEC/FM applications. Another factor that will lead to the wider usage of AR is that mobile devices are becoming smaller, more powerful, and less expensive. This paper summarizes the results of 101 research efforts, and outlines the research trends and opportunities for applying AR in the fields of AEC/FM. © 2013 Elsevier B.V.

Wang Z.,CAS Institute of Geology and Geophysics | Wilde S.A.,Curtin University Australia | Wan J.,CAS Institute of Geology and Geophysics
Precambrian Research | Year: 2010

A detailed study of the ∼2.2 Ga Yanmenguan mafic-ultramafic intrusion in the Hengshan area is presented with the aim of clarifying the tectonic history of the Trans-North China Orogen in the North China Craton during the period 2.3-2.1 Ga. SHRIMP U-Pb dating of magmatic zircons from a gabbro indicates emplacement at ∼2193 Ma. The whole rock and mineral geochemistry of this intrusion are akin to Alaskan-type complexes, and are typical of subduction-related magmas. The parental magma likely originated from the depleted mantle wedge above a subduction zone, and experienced fractional crystallization of olivine and clinopyroxene. The continental arc, represented by the mafic-ultramafic intrusions and contemporary granitic and volcanic rocks, together with the Lüliang back-arc basin constitute a marginal arc-back-arc basin system that evolved between 2.3 and 2.1 Ga. Based on geochronological datasets and available data on magmatism, metamorphism and structural deformation, a comprehensive new tectonic model for the evolution of the TNCO during the Neoarchean to Paleoproterozoic is constructed: (1) ∼2.5 Ga intra-oceanic arc-back-arc basin system and its accretion at the end of the Neoarchean; (2) a long hiatus in magmatism and tectonism between ∼2.5 and 2.3 Ga; (3) ∼2.3-2.1 Ga marginal arc-back-arc basin magmatism developed in the accreted Hengshan-Wutai-Fuping arc terranes and the Lüliang terrane; (4) ∼2.1 Ga collision, resulting in closure of the ∼2.3-2.1 Ga Lüliang back-arc basin, accretion of the Lüliang-Hengshan-Wutai-Fuping arc terranes, and their attachment to the Western Block of the North China Craton; (5) the intrusion of ∼1970-1910 Ma post-collisional mafic dykes in an extensional event; (6) final collision between the Western and Eastern Blocks between ∼1.9 and 1.8 Ga, resulting in extensive magmatism, tectonism and metamorphism; and lastly (7) post-1.8 Ga crustal extension. © 2010 Elsevier B.V. All rights reserved.

Zhang S.,China University of Geosciences | Li Z.-X.,Curtin University Australia | Evans D.A.D.,Yale University | Wu H.,China University of Geosciences | And 2 more authors.
Earth and Planetary Science Letters | Year: 2012

The existence of a pre-Rodinia Precambrian supercontinent, variously called Nuna or Columbia, has been widely speculated in the past decade, but the precise timing of its existence and its configuration have been uncertain due to the lack of unequivocal paleomagnetic and geological constraints. Here we report high-quality paleomagnetic results from the well dated ~1780Ma Xiong'er Group in southern North China Block (NCB). A total of 110 paleomagnetic samples from 14 sites were collected and subjected to stepwise thermal demagnetization. After removing a low temperature component (CL) of viscous magnetic remanence acquired in recent geomagnetic field, a high temperature component (CH), carried by hematite and magnetite in redbeds and volcanic samples, has been isolated. It gives a mean direction of (D=18.4°, I=-3.7°, α 95=7.6°, N=14) after bedding correction, and a corresponding paleomagnetic pole at 50.2°N, 263.0°E (A 95=4.5°). The CH passed a reversal test and was interpreted as a primary remanence. This new pole plus three other high-quality poles from the NCB that have been more precisely dated at 1769±3Ma, 1560-1440Ma and 1437±21Ma define a 1780-1440Ma apparent polar wander path (APWP) for the NCB. This, together with an update of global high quality paleomagnetic dataset, allows us to demonstrate that the pre-Rodinia supercontinent Nuna likely existed at least between ~1780Ma and ~1400Ma. Our paleomagnetism-based global reconstruction, for the first time, quantitatively assembles all major cratons together; it encompasses previously proposed regional links including the SAMBA connection between Baltica, Amazonia and Western Africa (Johansson, 2009), connections between Laurentia, Baltica and Siberia at the core of Nuna (Evans and Mitchell, 2011), the proto-SWEAT connection between Laurentia, East Antarctica and Australian blocks (Payne et al., 2009), and the NCB-India connection (Zhao et al., 2011). © 2012 Elsevier B.V.

Hagger M.S.,Curtin University Australia | Luszczynska A.,University of Colorado at Colorado Springs | Luszczynska A.,University of the Humanities
Applied Psychology: Health and Well-Being | Year: 2014

The purpose of this paper is to provide an overview of the literature on two planning intervention techniques in health behaviour research, implementation intentions and action planning, and to develop evidence-based recommendations for effective future interventions and highlight priority areas for future research. We focused our review on four key areas: (1) definition and conceptualisation; (2) format and measurement; (3) mechanisms and processes; and (4) design issues. Overall, evidence supports the effectiveness of planning interventions in health behaviour with advantages including low cost and response burden. There is, however, considerable heterogeneity in the effects across studies and relatively few registered randomised trials that include objective behavioural measures. Optimally effective planning interventions should adopt "if-then" plans, account for salient and relevant cues, include examples of cues, be guided rather than user-defined, and include boosters. Future studies should adopt randomised controlled designs, report study protocols, include fidelity checks and relevant comparison groups, and adopt long-term behavioural follow-up measures. Priority areas for future research include the identification of the moderators and mediators of planning intervention effects. Future research also needs to adopt "best practice" components of planning interventions more consistently to elucidate the mechanisms and processes involved. © 2013 The International Association of Applied Psychology.

Zhang F.,Curtin University Australia | Oganov A.R.,State University of New York at Stony Brook | Oganov A.R.,Moscow State University
Geophysical Research Letters | Year: 2010

The Earth's core is expected to contain around 10 wt % light elements (S, Si, O, possibly C, H, etc.) alloyed with Fe and Ni. Very little is known about these alloys at pressures and temperatures of the core. Here, using the evolutionary crystal structure prediction methodology, we investigate Fe-Si compounds at pressures of up to 400 GPa, i.e. covering the pressure range of the Earth's core. Evolutionary simulations correctly find that at atmospheric pressure the known non-trivial structure with P213 symmetry is stable, while at pressures above 20 GPa the CsCl-type structure is stable. We show that among the possible Fe silicides (Fe3Si, Fe2Si, Fe5Si3, FeSi, FeSi2 and FeSi3) only FeSi with CsCltype structure is thermodynamically stable at core pressures, while the other silicides are unstable to decomposition into Fe + FeSi or FeSi + Si. This is consistent with previous works and suggests that Si impurities contribute to stabilization of the body-centered cubic phase of Fe in the inner core. © Copyright 2010 by the American Geophysical Union.

Ma Z.S.,Xiangtan University | Zhou Y.C.,Xiangtan University | Long S.G.,Xiangtan University | Lu C.,Curtin University Australia
International Journal of Plasticity | Year: 2012

To examine effects of indentation size and substrate on the hardness determination of thin films, two typical types of hard film/soft substrate (Ni/Fe) and soft film/hard substrate (Al/Si and Al/glass) systems are investigated. A simple model is proposed to predict the intrinsic hardness of thin films, which allows a more accurate fitting to empirical data and the estimation of ultimate film hardness. The model can be used to interpret indentation data and extrapolate the indentation depth-hardness curve to an important region where indentation depth lies between 1% to 5 times of film thickness. The results are well consistent with the evolving trend of composite hardness obtained from experiments and numerical results by finite element analysis. © 2012 Published by Elsevier Ltd. All rights reserved.

Zhu W.,Xiangtan University | Yang L.,Xiangtan University | Guo J.W.,Xiangtan University | Zhou Y.C.,Xiangtan University | Lu C.,Curtin University Australia
International Journal of Plasticity | Year: 2015

Determination of interfacial adhesion energies of thermal barrier coatings is important for understanding failure mechanisms and predicting their lifetime. Combined compression test with a cohesive zone finite element model, it is shown that the interfacial adhesion energy is in the range of 100-130 J/m2. Based on the nonlinear delamination theory, the critical interfacial adhesion energy of delamination is 120 J/m2 and the corresponding loading phase angle is -56°. With the increase of the half-length of the crack, the crack propagation tends to be steady with a steady-state interface energy release rate of 150 J/m2, and delamination experiences almost pure mode II. These results obtained from finite element simulations and theoretical analyses are in good agreement with the available values determined by other testing methods reported in the literatures, which confirms the validity of this method. © 2014 Elsevier Ltd.

Yang L.,Xiangtan University | Zhou Y.C.,Xiangtan University | Lu C.,Curtin University Australia
Acta Materialia | Year: 2011

The real-time testing and quantitative assessment of damage evolution in thermal barrier coatings (TBCs) is desirable, but still intractable, especially at elevated temperature. In this paper, the fracture process of TBCs subjected to cyclic heating and cooling is monitored using an acoustic emission method. Based on the wavelet analysis of acoustic emission signals, damage modes in TBCs are discriminated. The results show that, due to thermal stress, vertical cracks tend to occur in the heating stage and interface cracks in the cooling stage. The surface crack density and interface crack length are calculated to obtain the quantitative correlation of damage evolution in TBCs and acoustic emission parameters. The rupture time of TBCs can be predicted from the statistical analysis of acoustic emission signals. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Mao W.G.,City University of Hong Kong | Mao W.G.,Xiangtan University | Shen Y.G.,City University of Hong Kong | Lu C.,Curtin University Australia
Scripta Materialia | Year: 2011

The nanoscale pop-in phenomena in polycrystalline α-Al 2O3 and single crystal α-Al2O 3(0 0 0 1) were comparatively investigated by nanoindentation with Berkovich indenters. It was found that different radii and loading rates have significant effects on the pop-ins formation, stress distributions and dislocation nucleations. Using the Hertzian contact theory and energetic model approach, the pop-in observations and resolved shear stress analysis are consistent with the explanation that the first pop-in corresponds to the nucleation of homogeneous dislocations when the theoretical shear strength is exceeded. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Evans K.A.,Curtin University Australia | Elburg M.A.,Ghent University | Elburg M.A.,University of KwaZulu - Natal | Kamenetsky V.S.,University of Tasmania
Geology | Year: 2012

The subarc mantle is a primary control on the composition of arc magmas and the formation of arc-related ore deposits. Elevated ferric iron contents in arc lavas have been interpreted as a record of subarc mantle that is oxidized relative to mid-oceanic ridge basalt (MORB), but this conclusion is controversial. Measurements of spinel compositions in primitive arc lavas imply an arc magma source 1-4 log units more oxidized than MORB and ocean island basalts analyzed using the same technique. Samples from seven arcs show a significant correlation (P < 0.0005) between redox budget, subduction zone convergence rate, and subduction zone age. These results support the notion of oxidized arc lavas in the mantle source zone, but resolution of contradictory evidence regarding subarc mantle redox state requires further work. © 2012 Geological Society of America.

Bohmann K.,Copenhagen University | Bohmann K.,University of Bristol | Evans A.,Bangor University | Gilbert M.T.P.,Copenhagen University | And 7 more authors.
Trends in Ecology and Evolution | Year: 2014

Extraction and identification of DNA from an environmental sample has proven noteworthy recently in detecting and monitoring not only common species, but also those that are endangered, invasive, or elusive. Particular attributes of so-called environmental DNA (eDNA) analysis render it a potent tool for elucidating mechanistic insights in ecological and evolutionary processes. Foremost among these is an improved ability to explore ecosystem-level processes, the generation of quantitative indices for analyses of species, community diversity, and dynamics, and novel opportunities through the use of time-serial samples and unprecedented sensitivity for detecting rare or difficult-to-sample taxa. Although technical challenges remain, here we examine the current frontiers of eDNA, outline key aspects requiring improvement, and suggest future developments and innovations for research. © 2014 Elsevier Ltd.

Grygolowicz-Pawlak E.,Curtin University Australia | Bakker E.,Curtin University Australia | Bakker E.,University of Geneva
Electrochemistry Communications | Year: 2010

A promising method for the elimination of undesired capacitive currents in view of realizing a potentially calibration free coulometric ion detection system is presented. The coulometric cell is composed of a porous polypropylene tube doped with a liquid calcium-selective membrane and a silver/silver chloride wire as an inner electrode, forming a thin layer sample between wire and tubing. The total charge passed through the system during potential controlled electrolysis of the thin layer sample is indeed found to be proportional to the amount of calcium present, but non-Faradaic processes do contribute to the obtained signal. We introduce here a multi-pulse procedure that allows one to perform a second excitation pulse at the same excitation potential after exhaustive ion transfer voltammetry of calcium has taken place. The intercept of the calibration curve after background subtraction is found as 20.6 ± 0.6 μC, significantly lower than the value of 54.1 ± 0.8 μC for the uncorrected curve. Changes in sample temperature (from 23 °C to 38 °C) did equally not affect the background corrected coulometric readings, supporting that the procedure renders the readout principle more robust. © 2010 Elsevier B.V. All rights reserved.

Zamani A.,Shiraz University | Samiee J.,Shiraz University | Kirby J.F.,Curtin University Australia
Tectonophysics | Year: 2013

We calculated anisotropic wavelet coherence between Bouguer anomaly and topography in order to map the anisotropy of the effective elastic thickness of the Iranian lithosphere (Te). An orthotropic elastic plate model is used for inverting the anisotropic wavelet coherence to compute the mechanical anisotropy through the weak axis of the Te. Anisotropy of the Te-weak axis and the strength of the anisotropic parameter, namely the anisotropic coherence effect over the study area are estimated by restricting the rotated Morlet wavelet (fan wavelet) geometry over an azimuthal range of 90°. Large-scale Te variations have been shown to be associated with phenomena, such as mountain belts, subduction zones, craton boundaries, fault zones, and seismogenic regions. Although the correlation between the major tectonic features of the Iranian lithosphere and the distribution of the Te-weak axis is not general or precise, in some regions, such as the Central Iran Blocks, and the Alborz, Kopeh Dagh, Zagros, and Makran orogenic belts, the weak axis has a uniform or slowly varying pattern which changes over their boundaries. A perpendicular alignment between seismic anisotropy measurements in Iran and the Te-weak directions suggests a lithospheric origin for anisotropy. The correlation between averaged stress directions and the weak axis of the Te in Iran indicates that the present day stress field and the fossil strain are still related. Correlation between these factors suggests vertically coherent deformation of the lithosphere in Iran resulting from the multiply convergent orogenic processes. The complex mechanical anisotropy pattern of the Iranian lithosphere results from the interaction of many pre-existent structures which dominantly control the mechanical anisotropy of the lithosphere. © 2013 Elsevier B.V.

Bateman P.W.,Curtin University Australia | Fleming P.A.,Murdoch University
Behavioral Ecology and Sociobiology | Year: 2014

Most studies examining escape behaviour have considered single approaches and single fleeing responses; few have considered how organisms' response is influenced by persistent pursuit. We explored fleeing behaviour of two grasshopper species to test whether they modified escape behaviour when approached repeatedly. Schistocerca alutacea did not increase flight initiation distance (FID) upon repeated approach but fled farther. Psinidia fenestralis increased its FID on the second approach but decreased its flight distance over successive escapes. Both species showed a bimodal pattern of flight direction, either flying directly away or flying perpendicular to the direction of the observer's approach. Neither species showed a significant pattern of flight direction or change in flight direction with successive escapes. Most (88 %) P. fenestralis initially landed on sand, but after repeated approaches an increasing proportion landed in grass and hid. Both species therefore changed escape behaviour with persistent pursuit but used different tactics, suiting their flight ability or camouflage, and optimised habitat use. Three grasshopper species have now been examined for responses to repeated approach by predators and all show different tactics supporting escape decision theory. Our results emphasise the variety of escape responses across species and how the dynamic nature of escape responses vary according to an animal's situation. Rather than single optimum escape options, each grasshopper species shows a range of responses, which vary with risk from persistent predators. Although grasshoppers provide an excellent model, it would be profitable to examine responses of a range of species according to levels of predation risk. © 2013 Springer-Verlag Berlin Heidelberg.

Korhonen F.J.,Curtin University Australia | Clark C.,Curtin University Australia | Brown M.,University of Maryland University College | Bhattacharya S.,Indian Statistical Institute | Taylor R.,Curtin University Australia
Precambrian Research | Year: 2013

Along the coast of Peninsular India, the Eastern Ghats expose a deep crustal section through a composite Proterozoic orogenic belt. To quantify the late Mesoproterozoic-early Neoproterozoic pressure (P)-temperature (T)-time (t) evolution of the Eastern Ghats Province, new SHRIMP U-Pb zircon and monazite age data from multiple localities are reported and integrated with the results of phase equilibria modelling. Samples of residual granulite, migmatite and enderbite yield a spread of weighted mean 207Pb/206Pb zircon and monazite ages between ca 970 and ca 930Ma. Based on ranges of spot ages from several samples, the late prograde to peak ultrahigh temperature (UHT) metamorphism (counter-clockwise evolution (CCW) to T >950°C at P >8kbar) and initial cooling is interpreted to have occurred between ca 1130 and ca 970Ma. Regionally extensive enderbite and charnockite magmas were emplaced into the hot, suprasolidus crust around the time of peak metamorphism. For the residual granulites and migmatites the retrograde P-T-t path is characterized by close-to-isobaric cooling to the variable but elevated solidi for different samples. Weighted mean ages between ca 970 and ca 930Ma in several samples are interpreted to record the timing of crystallization of melt trapped by the percolation threshold in each of these samples. Two additional weighted mean ages of ca 980Ma (from Korhonen F.J., Saw, A.K., Clark, C., Brown, M., Bhattacharya, S., 2011. New constraints on UHT metamorphism in the Eastern Ghats Province through the application of phase equilibria modelling and in situ geochronology. Gondwana Research 20, 764-781) extend this range back in time by 10My. The variability in the calculated weighted mean ages across the region is interpreted to be due mainly to differences in the temperature of the elevated solidus from sample to sample, suggesting a slow cooling rate of ~1°C/My during the retrograde stage of this long-lived UHT metamorphism. These results demonstrate that the Eastern Ghats Province sustained UHT conditions (T >900°C) for ≫50My, and perhaps for as long as 200Ma from ca 1130 to 930Ma, during a single CCW tectono-metamorphic event. © 2012.

Karkee R.,BP Koirala Institute of Health science | Binns C.W.,Curtin University Australia | Lee A.H.,Curtin University Australia
BMC Pregnancy and Childbirth | Year: 2013

Background: There are several barriers for pregnant women to deliver in a health care facility. This prospective cohort study investigated factors affecting facility delivery and reasons for unplanned place of delivery after implementation of the safer mother programme in Nepal.Methods: Baseline interviews using a validated questionnaire were conducted on a sample of 700 pregnant women representative of the Kaski district in central Nepal. Follow-up interviews of the cohort were then conducted within 45 days postpartum. Stepwise logistic regression analysis was performed to determine factors associated with the facility delivery outcome.Results: Of the 644 pregnant women whose delivery location had been identified, 547 (85%) gave birth in a health care facility. Women were more likely to deliver in a health facility if they were educated especially with higher secondary or above qualification (adjusted odds ratio (OR) 12.39, 95% confidence interval (CI) 5.09 to 30.17), attended 4 or more antenatal care visits (OR 2.15, 95% CI 1.25 to 3.69), and lived within 30 minutes to the facility (OR 11.61, 95% CI 5.77 to 24.04). For the 97 women who delivered at home, 72 (74.2%) were unplanned, mainly due to quick precipitation of labour making it impossible to reach a health facility.Conclusions: It appeared that facility delivery occurs more frequent among educated women and those who live nearby, even though maternity services are now freely available in Nepal. Because of the difficult terrain and transportation problem in rural areas, interventions that make maternity service physically accessible during antenatal period are needed to increase the utilisation of health facility for child birth. © 2013 Karkee et al.; licensee BioMed Central Ltd.

Binns C.W.,Curtin University Australia | Lee M.K.,Murdoch University
Asia Pacific Journal of Clinical Nutrition | Year: 2014

In 2001 the World Health Assembly adopted the infant feeding strategy which included the recommendation for exclusive breastfeeding until 6 months of age with continued breastfeeding while complementary foods are introduced. This recommendation has been endorsed by many national authorities, professional organisations and most countries in the Asia Pacific Region. Reviews by WHO, the US Surgeon General, Agency for Healthcare Research and Quality, US Department of Health and Human Services and others have documented the many benefits of breastfeeding. The introduction of solid foods before six months of age is associated with increased rates of infection, reduced breastmilk production, disruption to the microbiome and possibly obesity. If solids are introduced at around six months (by 26 weeks) there is no evidence of increases in allergic diseases.

Himri Y.,Societe Nationale de iElectricite et du GAZ SONELGAZ | Rehman S.,King Fahd University of Petroleum and Minerals | Agus Setiawan A.,Curtin University Australia | Himri S.,Béchar University
Renewable and Sustainable Energy Reviews | Year: 2012

This paper presents long-term analysis of wind speed data in terms of annual, seasonal and diurnal variations at Tindouf, which is situated on the south west region of Algeria. The wind speed data was collected over a period of 08 years between 1976 and 1984. The study showed that the long-term seasonal wind speeds were found to be relatively higher during September compared to other months. The diurnal change in long-term mean wind speed indicated that higher electricity could be produced during 09:00-18:00 h, which also coincides with higher electricity demand period. The annual wind energy production and capacity factor, obtained using wind speed frequency distribution and wind power curve of 1000 kW wind turbine and RETScreen software were found comparable with each other if unadjusted energy production values calculated by the software were used rather than the renewable energy delivered. Development of wind farm of 30 MW installed capacity at this site could result into avoidance of 23,252 tonnes/year of CO 2 equivalents GHG from entering into the local atmosphere thus creating a clean and healthy atmosphere for local inhabitants. © 2012 Elsevier Ltd. All rights reserved.

Barbhuiya S.,Curtin University Australia | Mukherjee S.,Jadavpur University | Nikraz H.,Curtin University Australia
Construction and Building Materials | Year: 2014

The effects of nano-Al2O3 addition on the early-age microstructural properties of cement paste is reported in this paper. The study was limited to evaluation of properties of cement paste hydrated up to an age of 7 days. Ordinary Portland cement was replaced by nano-Al2O 3 powder at 2% and 4% by weight. The water-binder ratio was fixed at 0.4. No changes were noticed in the early-age compressive strength with nano-Al2O3 addition. XRD analysis confirmed that no new phase developed due to the addition of nano-Al2O3 powder. However, FTIR analysis shows a shift in water associated band to lower frequency mostly with 4% nano-Al2O3 addition. Scanning electron microscopy reveals the formation of much dense microstructure with larger crystals of portlandite within the cement matrix. © 2013 Elsevier Ltd. All rights reserved.

Lee E.A.-L.,Curtin University Australia | Wong K.W.,Murdoch University
Computers and Education | Year: 2014

This study aims to verify the learning effectiveness of a desktop virtual reality (VR)-based learning environment, and to investigate the effects of desktop VR-based learning environment on learners with different spatial abilities. The learning outcome was measured cognitively through academic performance. A quasi pretest-posttest experimental design was employed for this study. A total of 431 high school students from four randomly selected schools participated in this study where they were randomly assigned to either experimental or control groups based on intact classes. Findings indicate a significant difference in the performance achievement between the two groups with students performed better using desktop virtual reality. A possible explanation is that the desktop virtual reality instructional intervention has helped to reduce extraneous cognitive load and engages learners in active processing of instructional material to increase germane cognitive load. A significant interaction effect was found between the learning mode and spatial ability with regard to the performance achievement. Further analysis shows a significant difference in the performance of low spatial ability learners in the experimental and control groups, but no statistically significant difference in the performance of high spatial learners in both groups. The results signify that low spatial ability learners' performance, compared with high spatial ability learners, appeared to be more positively affected by the desktop VR-based learning environment which is supported by the ability-as-compensator hypothesis, and can be explained by the cognitive load theory. © 2014 Elsevier Ltd. All rights reserved.

Lamont B.B.,Curtin University Australia | Lamont B.B.,Murdoch University | Downes K.S.,Curtin University Australia
Plant Ecology | Year: 2011

Data on 386 species with fire-stimulated flowering (fsf) in Australasia and South Africa/Madagascar were collated to show that they occur under a wide range of fire regimes, with 71% confined to the mediterranean-climate regions. About 40% only flower up to 2 years after fire (obligate), while the rest continue at a low rate until the next fire (facultative). Peak flowering occurs 5-18 months after fire in the mediterranean regions but at 1-7 months in savannas. Fsf is recorded in 34 families, headed by terrestrial orchids (45% of species), spread throughout the seed-plant phylogeny from cycads to daisies. Tuberous geophytes (essentially orchids) dominate (51%), but other resprouting growth forms include lignotuberous shrubs and forbs, rhizomatous and bunch grasses, leaf succulents, grasstrees, epicormic trees, and hemiparasites. Most have wind-dispersed diaspores (72%), store their diaspores in the soil (93%), and seeds that do not germinate until the next fire (72%). Fsf in association with resprouting takes advantage of optimal resources and minimal competition for growth and reproduction, conditions that favor wind dispersal and maximize the interval for seed accumulation before the next fire and build-up of fire-tolerant organs. Reduced herbivory has little role in accounting for its benefits. The proximal causes of fsf center around cueing factors (direct effects such as ethylene), resource factors (direct and indirect effects, e. g., extra nutrients), and predisposing factors (circumstantial effects, e. g., fire interval). The evolutionary history of fsf has been explored recently in orchids, proteas, blood roots, droseras, and mistletoes and shown to stretch back over a period of at least 50 million years, indicating that flowering in many groups has a long association with fire as an agent of natural selection. © 2011 Springer Science+Business Media B.V.

McDonald M.C.,ETH Zurich | Oliver R.P.,Curtin University Australia | Friesen T.L.,Cereal Crops Research Unit | Brunner P.C.,ETH Zurich | McDonald B.A.,ETH Zurich
New Phytologist | Year: 2013

Population genetic and phylogenetic studies have shown that Phaeosphaeria nodorum is a member of a species complex that probably shares its center of origin with wheat (Triticum aestivum and Triticum durum). We examined the evolutionary histories of three known necrotrophic effectors (NEs) produced by P. nodorum and compared them with neutral loci. We screened over 1000 individuals for the presence/absence of each effector and assigned each individual to a multi-effector genotype. Diversity at each NE locus was assessed by sequencing c. 200 individuals for each locus. We found significant differences in effector frequency among populations. We propose that these differences reflect the presence/absence of the corresponding susceptibility gene in wheat cultivars. The population harboring the highest sequence diversity was different for each effector locus and never coincided with populations harboring the highest diversity at neutral loci. Coalescent and phylogenetic analyses showed a discontinuous presence of all three NEs among nine closely related Phaeosphaeria species. Only two of the nine species were found to harbor NEs. We present evidence that the three described NEs of P. nodorum were transmitted to its sister species, Phaeosphaeria avenaria tritici 1, via interspecific hybridization. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Korhonen F.J.,Curtin University Australia | Saw A.K.,Indian Statistical Institute | Clark C.,Curtin University Australia | Brown M.,University of Maryland University College | Bhattacharya S.,Indian Statistical Institute
Gondwana Research | Year: 2011

High Mg-Al granulites from the Sunki locality in the central portion of the Eastern Ghats Province record evidence for the high-temperature peak and retrograde evolution. Peak metamorphic phase assemblages from two samples are garnet+orthopyroxene+quartz+ilmenite+melt and orthopyroxene+spinel+sillimanite+melt, respectively. Isochemical phase diagrams (pseudosections) based on bulk rock compositions calculated in the chemical system Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3 (NCKFMASHTO) and Al contents in orthopyroxene indicate peak UHT metamorphic conditions in excess of 960°C and 9.7kbar. Microstructures and the presence of cordierite interpreted to record the post-peak evolution show that the rocks underwent decompression and minor cooling from conditions of peak UHT metamorphism to conditions of ~900°C at ~7.5kbar. In situ U-Pb isotope analyses of monazite associated with garnet and cordierite using the Sensitive High Resolution Ion Microprobe (SHRIMP) yield a weighted mean 207Pb/235U age of ca. 980Ma, which is interpreted to broadly constrain the timing of high-temperature monazite growth during decompression and melt crystallization at ~900-890°C and 7.5kbar. However, the range of 207Pb/235U monazite ages (from ca. 1014Ma to 959Ma for one sample and ca. 1043Ma to 922Ma for the second sample) suggest protracted monazite growth during the high-temperature retrograde evolution, and possibly diffusive lead loss during slow cooling after decompression. The results of the integrated petrologic and geochronologic approach presented here are inconsistent with a long time gap between peak conditions and the formation of cordierite-bearing assemblages at lower pressure, as proposed in previous studies, but are consistent with a simple evolution of a UHT peak followed by decompression and cooling. © 2011 International Association for Gondwana Research.

Lamont B.B.,Curtin University Australia | Lamont B.B.,Murdoch University | He T.,Curtin University Australia
BMC Evolutionary Biology | Year: 2012

Background: Fires have been widespread over the last 250 million years, peaking 60-125 million years ago (Ma), and might therefore have played a key role in the evolution of Angiosperms. Yet it is commonly believed that fireprone communities existed only after the global climate became more arid and seasonal 15 Ma. Recent molecular-based studies point to much earlier origins of fireprone Angiosperm floras in Australia and South Africa (to 60 Ma, Paleocene) but even these were constrained by the ages of the clades examined. Results: Using a molecular-dated phylogeny for the great Gondwanan family Proteaceae, with a 113-million-year evolutionary history, we show that the ancestors of many of its characteristic sclerophyll genera, such as Protea, Conospermum, Leucadendron, Petrophile, Adenanthos and Leucospermum (all subfamily Proteoideae), occurred in fireprone habitats from 88 Ma (83-94, 95% HPD, Mid-Upper Cretaceous). This coincided with the highest atmospheric oxygen (combustibility) levels experienced over the past 150 million years. Migration from non-fireprone (essentially rainforest-climate-type) environments was accompanied by the evolution of highly speciose clades with a range of seed storage traits and fire-cued seed release or germination mechanisms that was diagnostic for each clade by 71 Ma, though the ant-dispersed lineage (as a soil seed-storage subclade) was delayed until 45 Ma. Conclusions: Focusing on the widespread 113-million-year-old family Proteaceae, fireproneness among Gondwanan Angiosperm floras can now be traced back almost 90 million years into the fiery Cretaceous. The associated evolution of on-plant (serotiny) and soil seed storage, and later ant dispersal, affirms them as ancient adaptations to fire among flowering plants. © 2012 Lamont and He; licensee BioMed Central Ltd.

Brown M.,University of Maryland University College | Korhonen F.J.,Curtin University Australia | Siddoway C.S.,Colorado College
Elements | Year: 2011

Melt that crystallizes as granite at shallow crustal levels in orogenic belts originates from migmatite and residual granulite in the deep crust; this is the most important mass-transfer process affecting the continents. Initially melt collects in grain boundaries before migrating along structural fabrics and through discordant fractures initiated during synanatectic deformation. As this permeable porosity develops, melt flows down gradients in pressure generated by the imposed tectonic stress, moving from grain boundaries through outcrop-scale vein networks to ascent conduits. Gravity then drives melt ascent through the crust, either in dikes that fill ductile-to-brittle-elastic fractures or by pervasive flow in planar and linear channels in belts of steep structural fabrics. Melt may be arrested in its ascent at the ductile-to-brittle transition zone or it may be trapped en route by a developing tectonic structure.

Tao P.,Harbin Medical University | Tao P.,Curtin University Australia | Brody S.,University of West of Scotland
Journal of Sexual Medicine | Year: 2011

Introduction. Previous multivariate research in Europe found that sexual satisfaction was associated directly with frequency of penile-vaginal intercourse (PVI) but inversely with masturbation and some aspects of non-PVI partnered sex. Aims. To examine the associations of sexual satisfaction in a sample from the People's Republic of China, including not only frequencies of various sexual behaviors, but also frequencies of orgasm. Methods. Chinese industrial workers (N=158, age over 24 years) completed the sexual satisfaction scale of the Multidimensional Sexuality Questionnaire (MSQ) and a short form of the Marlowe-Crowne social desirability scale, and provided details of the one month frequencies of engaging in, and having an orgasm from, PVI, masturbation, and non-PVI partnered sex. Main Outcome Measures. Multiple regression prediction of sexual satisfaction from age, social desirability responding, and in separate analyses, frequencies of the sexual behaviors or the corresponding orgasm frequencies. Results. For men and women, sexual satisfaction was associated with frequency of PVI and of PVI orgasm (the latter for women only), but not other sexual behavior or orgasm frequency. Similar results were obtained for the MSQ satisfaction scale and for a single satisfaction item. Conclusions. Despite cultural differences (and our smaller, less diverse sample), the positive prediction of satisfaction from only PVI (and in our sample of women, PVI orgasm) frequency-but not other sexual activities-was similar to that in a Swedish sample. Future research might also examine possible occasional avoidance of ejaculation by some Chinese men. © 2010 International Society for Sexual Medicine.

Bartlett P.L.,Murdoch University | Stelbovics A.T.,Curtin University Australia
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

A full four-body implementation of the propagating exterior complex scaling (PECS) method is developed and applied to the electron-impact of helium in an S-wave model. Time-independent solutions to the Schrödinger equation are found numerically in coordinate space over a wide range of energies and used to evaluate total and differential cross sections for a complete set of three- and four-body processes with benchmark precision. With this model we demonstrate the suitability of the PECS method for the complete solution of the full electron-helium system. Here we detail the theoretical and computational development of the four-body PECS method and present results for three-body channels: single excitation and single ionization. Four-body cross sections are presented in the sequel to this article. The calculations reveal structure in the total and energy-differential single-ionization cross sections for excited-state targets that is due to interference from autoionization channels and is evident over a wide range of incident electron energies. © 2010 The American Physical Society.

Bartlett P.L.,Murdoch University | Stelbovics A.T.,Curtin University Australia
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The propagating exterior complex scaling (PECS) method is extended to all four-body processes in electron impact on helium in an S-wave model. Total and energy-differential cross sections are presented with benchmark accuracy for double ionization, single ionization with excitation, and double excitation (to autoionizing states) for incident-electron energies from threshold to 500 eV. While the PECS three-body cross sections for this model given in the preceding article are in good agreement with other methods, there are considerable discrepancies for these four-body processes. With this model we demonstrate the suitability of the PECS method for the complete solution of the electron-helium system. © 2010 The American Physical Society.

Venable J.,Curtin University Australia | Pries-Heje J.,Roskilde University | Baskerville R.,Georgia State University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

Evaluation is a central and essential activity in conducting rigorous Design Science Research (DSR), yet there is surprisingly little guidance about designing the DSR evaluation activity beyond suggesting possible methods that could be used for evaluation. This paper extends the notable exception of the existing framework of Pries-Heje et al [11] to address this problem. The paper proposes an extended DSR evaluation framework together with a DSR evaluation design method that can guide DSR researchers in choosing an appropriate strategy for evaluation of the design artifacts and design theories that form the output from DSR. The extended DSR evaluation framework asks the DSR researcher to consider (as input to the choice of the DSR evaluation strategy) contextual factors of goals, conditions, and constraints on the DSR evaluation, e.g. the type and level of desired rigor, the type of artifact, the need to support formative development of the designed artifacts, the properties of the artifact to be evaluated, and the constraints on resources available, such as time, labor, facilities, expertise, and access to research subjects. The framework and method support matching these in the first instance to one or more DSR evaluation strategies, including the choice of ex ante (prior to artifact construction) versus ex post evaluation (after artifact construction) and naturalistic (e.g., field setting) versus artificial evaluation (e.g., laboratory setting). Based on the recommended evaluation strategy(ies), guidance is provided concerning what methodologies might be appropriate within the chosen strategy(ies). © 2012 Springer-Verlag.

Cheng L.,Murdoch University | Cord-Ruwisch R.,Murdoch University | Shahin M.A.,Curtin University Australia
Canadian Geotechnical Journal | Year: 2013

A newly emerging microbiological soil stabilization method, known as microbially induced calcite precipitation (MICP), has been tested for geotechnical engineering applications. MICP is a promising technique that utilizes the metabolic pathways of bacteria to form calcite precipitation throughout the soil matrix, leading to an increase in soil strength and stiffness. This paper investigates the geotechnical properties of sand bio-cemented under different degrees of saturation. A series of laboratory experiments was conducted, including sieve analysis, permeability, unconfined compressive strength, consolidated undrained triaxial, and durability tests. The results indicate that higher soil strength can be obtained at similar CaCO3 content when the treatment is performed under a low degree of saturation. The experimental results are further explained with a mathematical model, which shows that the crystallization efficiency, i.e., actual volume of crystals forming at the contact point where they contribute the most to strength, can be calculated from the degree of saturation and grain size. Fine sand samples exhibited higher cohesion, but lower friction angle than coarse sand samples with similar CaCO3 content. The results also confirm the potential of MICP as a viable alternative technique for soil improvement in many geotechnical engineering applications, including liquefiable sand deposits, slope stabilization, and subgrade reinforcement. The freeze-thaw and acid rain resistance of MICP-treated sand has also been tested.

Rosalie S.M.,Curtin University Australia | Muller S.,Murdoch University
Quarterly Journal of Experimental Psychology | Year: 2014

It is unclear whether perceptual-motor skill transfer is based upon similarity between the learning and transfer domains per identical elements theory, or facilitated by an understanding of underlying principles in accordance with general principle theory. Here, the predictions of identical elements theory, general principle theory, and aspects of a recently proposed model for the transfer of perceptual-motor skill with respect to expertise in the learning and transfer domains are examined. The capabilities of expert karate athletes, near-expert karate athletes, and novices to anticipate and respond to stimulus skills derived from taekwondo and Australian football were investigated in ecologically valid contexts using an in situ temporal occlusion paradigm and complex whole-body perceptual-motor skills. Results indicated that the karate experts and near-experts are as capable of using visual information to anticipate and guide motor skill responses as domain experts and near-experts in the taekwondo transfer domain, but only karate experts could perform like domain experts in the Australian football transfer domain. Findings suggest that transfer of anticipation skill is based upon expertise and an understanding of principles but may be supplemented by similarities that exist between the stimulus and response elements of the learning and transfer domains. © 2013 © 2013 The Experimental Psychology Society.

Ntogramatzidis L.,Curtin University Australia | Ferrante A.,University of Padua
Systems and Control Letters | Year: 2010

In this paper we consider the matrix Riccati differential equation (RDE) that arises from linear-quadratic (LQ) optimal control problems. In particular, we establish explicit closed formulae for the solution of the RDE with a terminal condition using particular solutions of the associated algebraic Riccati equation. We discuss how these formulae change as assumptions are progressively weakened. An application to LQ optimal control is briefly analysed. © 2010 Elsevier B.V. All rights reserved.

Ferrante A.,University of Padua | Ntogramatzidis L.,Curtin University Australia
Automatica | Year: 2014

The purpose of this paper is to investigate the role that the so-called constrained generalized Riccati equation plays within the context of continuous-time singular linear-quadratic (LQ) optimal control. This equation has been defined following the analogy with the discrete-time setting. However, while in the discrete-time case the connections between this equation and the linear-quadratic optimal control problem has been thoroughly investigated, to date very little is known on these connections in the continuous-time setting. This note addresses this point. We show, in particular, that when the continuous-time constrained generalized Riccati equation admits a solution, the corresponding linear-quadratic problem admits an impulse-free optimal control. We also address the corresponding infinite-horizon LQ problem for which we establish a similar result under the additional constraint that there exists a control input for which the cost index is finite. © 2014 Elsevier Ltd. All rights reserved.

Karousis N.,National Hellenic Research Foundation | Suarez-Martinez I.,Curtin University Australia | Ewels C.P.,University of Nantes | Tagmatarchis N.,National Hellenic Research Foundation
Chemical Reviews | Year: 2016

Carbon nanohorns (sometimes also known as nanocones) are conical carbon nanostructures constructed from an sp2 carbon sheet. Nanohorns require no metal catalyst in their synthesis, and can be produced in industrial quantities. They provide a realistic and useful alternative to carbon nanotubes, and possibly graphene, in a wide range of applications. They also have their own unique behavior due to their specific conical morphology. However, their research and development has been slowed by several factors, notably during synthesis, they aggregate into spherical clusters ∼100 nm in diameter, blocking functionalization and treatment of individual nanocones. This limitation has recently been overcome with a new approach to separating these "dahlia-like" clusters into individual nanocones. In this review, we describe the structure, synthesis, and topology of carbon nanohorns, and provide a detailed review of nanohorn chemistry. © 2016 American Chemical Society.

Ferrante A.,University of Padua | Ntogramatzidis L.,Curtin University Australia
IEEE Transactions on Automatic Control | Year: 2012

In this note it is shown that the main result of , concerning a characterization of a pair of structural invariant subspaces associated with the extended symplectic system, is a particular case of a result presented in and within a more general and rigorous context. We also analyse the proof of the main result of , and the way such result is used to accomodate the boundary conditions in the solution of a finite-horizon linear quadratic optimal control problem. © 2006 IEEE.

Sanguinetti L.,University of Pisa | D'Amico A.A.,University of Pisa | Rong Y.,Curtin University Australia
IEEE Journal on Selected Areas in Communications | Year: 2012

The remarkable promise of multiple-input multiple-output (MIMO) wireless channels has motivated an intense research activity to characterize the theoretical and practical issues associated with the design of transmit (source) and receive (destination) processing matrices under different operating conditions. This activity was primarily focused on point-to-point (single-hop) communications but more recently there has been an extensive work on two-hop or multi-hop settings in which single or multiple relays are used to deliver the information from the source to the destination. The aim of this tutorial is to provide an up-to-date overview of the fundamental results and practical implementation issues in designing amplify-and-forward MIMO relay systems. © 2012 IEEE.

Bredin A.,Curtin University Australia | Mullins B.J.,Curtin University Australia | Mullins B.J.,Curtin Health Innovation Research Institute
Separation and Purification Technology | Year: 2012

This study investigated the influence of flow interruptions on the filtration performance of two different multi-layered fibrous filters during liquid aerosol filtration. It was found that both types of filters experienced a significant secondary loading stage, though they had reached a steady state for continuous flow. The filters showed distinctive increases in pressure drop and filter saturation until a second equilibrium state was reached. This second equilibrium state was attributed to a rearrangement of liquid in the filter during the breaks, clogging previously free passages. The ratio of shear and capillary forces was found to determine whether these passages were able to be "cleaned" once airflow was recommenced. Based on these findings, the airflow required to clean fully saturated filters was investigated and a phenomenological model developed to describe this behaviour. Furthermore, it was found that filters could be cleaned and reused, whereby they would return to one of the previous steady states (continuous or discontinuous flow). The experiments conducted in this work represent a more realistic test for oil-mist (or coalescing) filters than typical laboratory testing. Furthermore, it is hoped that they will help to bridge the gap between laboratory and field test results. © 2012 Elsevier B.V. All rights reserved.

Peng T.,CAS Guangzhou Institute of Geochemistry | Peng T.,Curtin University Australia | Wilde S.A.,Curtin University Australia | Fan W.,CAS Guangzhou Institute of Geochemistry | Peng B.,CAS Guangzhou Institute of Geochemistry
Precambrian Research | Year: 2013

Siliceous high-Mg basalt (SHMB) is a rare rock type that occurs mainly at or near the Archean-Proterozoic boundary. It shares some geochemical similarities with Phanerozoic boninites, but there is a clear distinction. Whether the petrogenesis of SHMB resembles that of Phanerozoic boninites or is related to the komatiitic magmatism is controversial. Neoarchean SHMBs are identified for the first time from the Taishan granite-greenstone terrane within the Eastern Block of the North China Craton (NCC). Zircon U-Pb dating indicates that they were emplaced at ∼2.54Ga, contemporaneous with the generation of sanukitoids and adakitic rocks, but later than the eruption of the Late Archean (2.71Ga) komatiites and komatiitic basalts in the area. The high MgO (>8%), high SiO2 (>52%), and Al2O3/TiO2 ratio (12.4-45.0), together with low TiO2 (<0.5%) and HFSE contents and strong enrichment in LREE and LILE in the Taishan SHMBs are comparable with typical Phanerozoic boninites, except for distinct HREE depletion, lack of U-shaped REE patterns and conspicuous positive Zr anomalies. In conjunction with their more depleted Nd isotopic characteristics (e{open}Nd(t=2.54Ga)=+4.42 to +1.05) relative to Late Archean komatiites in the region, it suggests that these SHMBs were derived from partial melting of refractory depleted mantle which experienced earlier basalt extraction and was subsequently enriched in LILE and LREE by subduction-related metasomatization, rather than the products of assimilation-fractional crystallization (AFC) of komatiitic magma. A slab-derived adakitic melt was likely the metasomatizing agent, along with minor aqueous fluids released from the subducting oceanic slab. In combination with regional studies, the generation of these magmas was probably related to slab rollback, which is ascribed to the arrival of an oceanic plateau and/or residual thickened lithospheric keel at the subduction zone at that time. This mechanism might have played a crucial role in the formation of Archean granite-greenstone belts and was an important factor in continental crustal growth, particularly during the Late Archean. © 2013 Elsevier B.V..

Hoang H.G.,Curtin University Australia | Vo B.-N.,Curtin University Australia | Vo B.-T.,Curtin University Australia | Mahler R.,Random Sets LLC
IEEE Transactions on Information Theory | Year: 2015

In this paper, we extend the notion of Cauchy-Schwarz divergence to point processes and establish that the Cauchy-Schwarz divergence between the probability densities of two Poisson point processes is half the squared L2-distance between their intensity functions. Extension of this result to mixtures of Poisson point processes and, in the case where the intensity functions are Gaussian mixtures, closed form expressions for the Cauchy-Schwarz divergence are presented. Our result also implies that the Bhattacharyya distance between the probability distributions of two Poisson point processes is equal to the square of the Hellinger distance between their intensity measures. We illustrate the result via a sensor management application where the system states are modeled as point processes. © 2015 IEEE.

Ntogramatzidis L.,Curtin University Australia | Ferrante A.,University of Padua
IET Control Theory and Applications | Year: 2011

In this study, the authors introduce a range of techniques for the exact design of PID controllers for feedback control problems involving requirements on the steady-state performance and standard frequency-domain specifications on the stability margins and crossover frequencies. These techniques hinge on a set of simple closed-form formulae for the explicit computation of the parameters of the controller in finite terms as functions of the specifications, and therefore they eliminate the need for graphical, heuristic or trial-and-error procedures. The relevance of this approach is (i) theoretical, since a closed-form solution is provided for the design of PID-type controllers with standard frequency-domain specifications; (ii) computational, since the techniques presented here are readily implementable as software routines, for example, using MATLAB®; (iii) educational, because the synthesis of the controller reduces to a simple exercise on complex numbers that can be solved with pen, paper and a scientific calculator. These techniques also appear to be very convenient within the context of adaptive control and self-tuning strategies, where the controller parameters have to be calculated online. Furthermore, they can be easily combined with graphical and first/second-order plant approximation methods in the cases where the model of the system to be controlled is not known. © 2011 The Institution of Engineering and Technology.

Liaw S.-S.,Washington State University | Zhou S.,Washington State University | Wu H.,Curtin University Australia | Garcia-Perez M.,Washington State University
Fuel | Year: 2013

This paper investigates the effect of thermal pretreatment temperatures between 200 and 370 °C on the yield and composition of products (bio-charm gasm water and organics) obtained when Douglas-fir wood was subsequently pyrolyzed in an auger reactor at 500 °C. The yield of products was reported for the pretreatment and pyrolysis steps separately, and for the two steps added. The maximum yield of bio-oils achieved without pretreatment was close to 59 mass%. A decrease in total liquid yield was observed when the biomass was pretreated at 300 °C. At higher temperatures, the yields of Douglas-fir primary degradation products (lignin oligomers, anhydrosugars and alkylated and methoxylated phenols) decreased. The overall water yield increased gradually to 14 mass% at a pretreatment temperature of 290 °C. The yield of lignin oligomers also decreased as the pretreatment temperature increased. A drastic reduction in the yield of methoxylated phenols derived from guaiacyl (G) was observed when the biomass was pretreated at temperatures over 300 °C. This drastic reduction in the yield of methoxylated lignin derivatives can be explained by the formation of liquid intermediates that facilitate the formation of ionic species, enhancing dehydration reactions leading to the production of o-quinone methide intermediates critical for bio-char formation. © 2012 Elsevier Ltd. All rights reserved.

Ristic B.,Defence Science and Technology Organisation, Australia | Vo B.-T.,Curtin University Australia | Vo B.-N.,Curtin University Australia | Farina A.,SELEX Sistemi Integrati
IEEE Transactions on Signal Processing | Year: 2013

Bernoulli filters are a class of exact Bayesian filters for non-linear/non-Gaussian recursive estimation of dynamic systems, recently emerged from the random set theoretical framework. The common feature of Bernoulli filters is that they are designed for stochastic dynamic systems which randomly switch on and off. The applications are primarily in target tracking, where the switching process models target appearance or disappearance from the surveillance volume. The concept, however, is applicable to a range of dynamic phenomena, such as epidemics, pollution, social trends, etc. Bernoulli filters in general have no analytic solution and are implemented as particle filters or Gaussian sum filters. This tutorial paper reviews the theory of Bernoulli filters as well as their implementation for different measurement models. The theory is backed up by applications in sensor networks, bearings-only tracking, passive radar/sonar surveillance, visual tracking, monitoring/prediction of an epidemic and tracking using natural language statements. More advanced topics of smoothing, multi-target detection/tracking, parameter estimation and sensor control are briefly reviewed with pointers for further reading. © 1991-2012 IEEE.

Hamilton L.J.,Defence Science and Technology Organisation, Australia | Parnum I.,Curtin University Australia
Continental Shelf Research | Year: 2011

A fast, simple method is presented to obtain acoustic seabed segmentation from multibeam sonar backscatter data, for situations where processed backscatter curves are already available. Unsupervised statistical clustering is used to classify multibeam sonar backscatter curves in their entirety, with the curves essentially treated as geometrical entities. High variability in the backscatter curves is removed by along-track averaging prior to clustering, and no further preprocessing is required. The statistical clustering method is demonstrated with RESON 8125 multibeam sonar data obtained in two bathymetrically complex environments. These are a sandwave field in Keppel Bay, Queensland, and an area of inter-island sand, reef, seagrass, and rhodolith beds in Esperance Bay, Western Australia. The resulting acoustic charts are visually compelling. They exhibit high spatial coherence, are largely artifact free, and provide spatial context to comparatively sparse grab samples with relatively little effort. Since the backscatter curve is an intrinsic property of the seafloor, the mappings form standalone charts of seafloor acoustic properties. In themselves they do not need ground truthing. Conceptually, use of the full angular backscatter curve should form the primary means of obtaining acoustic seabed segmentation. However, this is dependent on the scale and configuration of seabed backscatter features compared to the dimensions of the averaged swathe used to obtain reliable realisations of the backscatter curve. © 2010.

Suarez-Martinez I.,University of Nantes | Grobert N.,Curtin University Australia | Ewels C.P.,University of Oxford
Carbon | Year: 2012

The guest editorial column of SciVerse ScienceDirect focuses on developing a coherent nomenclature for carbon nanoforms based on their morphological differences and the geometrical transformations that relate one form to another. The column describes that the structurally simplest carbon nanoform is graphene, which is a near planar sheet of sp 2-bonded carbon atoms in a hexagonal network. It can be considered as the final member of the series of fused polycyclic aromatic hydrocarbons, such as naphthalene, anthracene, and coronene. Graphene can also serve as the initial building block for a series of thought experiments, generating other carbon nanoforms by the application of geometrical transformations. Morphological variation in sp 2-based carbon nanoforms is a consequence of curvature, introduction of structural defects, and dangling bonds.

Ferrante A.,University of Padua | Ntogramatzidis L.,Curtin University Australia
Automatica | Year: 2013

This paper investigates the properties of the solutions of the generalised discrete algebraic Riccati equation arising from the classic infinite-horizon linear quadratic (LQ) control problem. In particular, a geometric analysis is used to study the relationship existing between the solutions of the generalised Riccati equation and the output-nulling subspaces of the underlying system and the corresponding reachability subspaces. This analysis reveals the presence of a subspace that plays an important role in the solution of the related optimal control problem, which is reflected in the generalised eigenstructure of the corresponding extended symplectic pencil. In establishing the main results of this paper, several ancillary problems on the discrete Lyapunov equation and spectral factorisation are also addressed and solved. © 2012 Elsevier Ltd. All rights reserved.

Shabala S.S.,University of Tasmania | Godfrey L.E.H.,Curtin University Australia
Astrophysical Journal | Year: 2013

We examine the relationship between source radio luminosity and kinetic power in active galactic nucleus jets. We show that neglecting various loss processes can introduce a systematic bias in the jet powers inferred from radio luminosities for a sample of radio galaxies. This bias can be corrected for by considering source size as well as radio luminosity; effectively the source size acts as a proxy for source age. Based on a sample of Fanaroff-Riley Type II radio sources with jet powers derived from the measured hotspot parameters, we empirically determine a new expression for jet power that accounts for the source size, , where D is source size and L 151 the 151 MHz radio luminosity. By comparing a flux-limited and volume-limited sample, we show that any derived radio-luminosity-jet-power relation depends sensitively on sample properties, in particular the source size distribution and the size-luminosity correlation inherent in the sample. Such bias will affect the accuracy of the kinetic luminosity function derived from lobe radio luminosities and should be treated with caution. © 2013. The American Astronomical Society. All rights reserved.

Oliver R.P.,Curtin University Australia | Friesen T.L.,U.S. Department of Agriculture | Faris J.D.,U.S. Department of Agriculture | Solomon P.S.,Australian National University
Annual Review of Phytopathology | Year: 2012

Stagonospora nodorum is a major necrotrophic pathogen of wheat that causes the diseases S. nodorum leaf and glume blotch. A series of tools and resources, including functional genomics, a genome sequence, proteomics and metabolomics, host-mapping populations, and a worldwide collection of isolates, have enabled the dissection of pathogenicity mechanisms. Metabolic and signaling genes required for pathogenicity have been defined. Interaction with the host is dominated by interplay of fungal effectors that induce necrosis on wheat lines carrying specific sensitivity loci. As such, the pathogen has emerged as a model for the Pleosporales group of pathogens. © 2012 by Annual Reviews. All rights reserved.

Godfrey L.E.H.,Curtin University Australia | Shabala S.S.,University of Tasmania
Astrophysical Journal | Year: 2013

Recent results based on the analysis of radio galaxies and their hot X-ray emitting atmospheres suggest that non-radiating particles dominate the energy budget in the lobes of FR I radio galaxies, in some cases by a factor of more than 1000, while radiating particles dominate the energy budget in FR II radio galaxy lobes. This implies a significant difference in the radiative efficiency of the two morphological classes. To test this hypothesis, we have measured the kinetic energy flux for a sample of 3C FR II radio sources using a new method based on the observed parameters of the jet terminal hotspots, and compared the resulting Q jet-L radio relation to that obtained for FR I radio galaxies based on X-ray cavity measurements. Contrary to expectations, we find approximate agreement between the Q jet-L radio relations determined separately for FR I and FR II radio galaxies. This result is ostensibly difficult to reconcile with the emerging scenario in which the lobes of FR I and FR II radio galaxies have vastly different energy budgets. However, a combination of lower density environment, spectral aging and strong shocks driven by powerful FR II radio galaxies may reduce the radiative efficiency of these objects relative to FR Is and counteract, to some extent, the higher radiative efficiency expected to arise due to the lower fraction of energy in non-radiating particles. An unexpected corollary is that extrapolating the Q jet-L radio relation determined for low power FR I radio galaxies provides a reasonable approximation for high power sources, despite their apparently different lobe compositions. © 2013. The American Astronomical Society. All rights reserved.

Ferrante A.,University of Padua | Ntogramatzidis L.,Curtin University Australia
Automatica | Year: 2013

This note represents a first attempt to provide a definition and characterisation of negative imaginary systems for not necessarily rational transfer functions via a sign condition expressed in the entire domain of analyticity, along the same lines of the classic definition of positive real systems. Under the standing assumption of symmetric transfer functions, we then derive a necessary and sufficient condition that characterises negative imaginary transfer functions in terms of a matrix sign condition restricted to the imaginary axis, once again following the same line of argument of the standard positive real case. Using this definition, even transfer functions with a pole at the origin with double multiplicity, as well as with a possibly negative relative degree, can be negative imaginary. © 2013 Published by Elsevier Ltd.

Foster N.E.,Keele University | Hill J.C.,Keele University | O'Sullivan P.,Curtin University Australia | Hancock M.,Macquarie University
Best Practice and Research: Clinical Rheumatology | Year: 2013

Stratified care for back pain involves targeting treatment to subgroups of patients based on their key characteristics such as prognostic factors, likely response to treatment and underlying mechanisms. It aims to tailor therapeutic decisions in ways that maximise treatment benefit, reduce harm and increase health-care efficiency by offering the right treatment to the right patient at the right time. From being called the 'Holy Grail' of back pain research over a decade ago, stratified care is becoming the zeitgeist in research and clinical practice. In this chapter, we introduce and evaluate the quality and underpinning evidence for three examples of stratified care for back pain to highlight their general principles, research design issues and clinical practice implications. We include consideration of their merits for implementation in practice. We conclude with a set of remaining, key research questions. © 2013 Elsevier Ltd. All rights reserved.

Virolainen S.,Lappeenranta University of Technology | Ibana D.,Curtin University Australia | Paatero E.,Lappeenranta University of Technology | Paatero E.,Outotec Oyj
Hydrometallurgy | Year: 2011

Recovery of indium from LCD screen wastes, which contain indium in the form of indium tin oxide (ITO) as the electrode material, is becoming economically and environmentally justified. Indium is a valuable metal and the present work was aimed to recover indium from ITO as the starting material to study the recovery of indium from waste LCD screens by solvent extraction. The apparent rate of dissolution in acidic media is slow requiring six hours for complete dissolution of the ITO sample in 1 M of either H 2SO 4 or HCl. Complete dissolution in HNO 3 took significantly longer. The acid concentration was found to have a major effect on both the amount and rate of leaching allowing some leaching selectivity. Three solvent systems were chosen to study their selectivity for the separation of indium from tin: TBP, D2EHPA and a mixture of both. With either 1 M of TBP or 0.2 M of D2EHPA + 0.8 M of TBP, tin could be selectively extracted from a 1.5 M HCl solution of this metal. D2EHPA extracts both indium and tin from H 2SO 4 media but indium could be selectively stripped with HCl from the loaded D2EHPA. Based on these results, a scheme for separating and concentrating indium from ITO by solvent extraction is proposed. The scheme includes dissolving ITO into 1 M of H 2SO 4, then extracting indium and tin to D2EHPA followed by selective stripping of indium into 1.5 M of HCl. With this process, HCl solution containing 12.2 g/L of indium could be achieved. © 2011 Elsevier B.V.

Ferrante A.,University of Padua | Ntogramatzidis L.,Curtin University Australia
IEEE Transactions on Automatic Control | Year: 2013

This technical note introduces a new approach to the solution of a very general class of finite-horizon optimal control problems for discrete-time systems. This approach provides a parametric expression for the optimal control sequences, as well as the corresponding optimal state trajectories, by exploiting a new decomposition of the so-called extended symplectic pencil. This decomposition provides an original strategy for a more direct solution of the problem with no need of the system-theoretic hypotheses (including regularity of the symplectic pencil) that have always been assumed in the literature so far. © 1963-2012 IEEE.

Sanguinetti L.,University of Pisa | D'Amico A.A.,University of Pisa | Rong Y.,Curtin University Australia
IEEE Transactions on Vehicular Technology | Year: 2013

In this paper, we focus on the design of linear and nonlinear architectures in amplify-and-forward multiple-input-multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) relay networks in which different types of services are supported. The goal is to jointly optimize the processing matrices to minimize the total power consumption while satisfying the quality-of-service (QoS) requirements of each service specified as Schur-convex functions of the mean square errors (MSEs) over all assigned subcarriers. It turns out that the optimal solution leads to the diagonalization of the source-relay-destination channel up to a unitary matrix, depending on the specific Schur-convex function. © 2012 IEEE.

Wu C.,University of Ballarat | Teo K.L.,Curtin University Australia | Wu S.,National Cheng Kung University
Automatica | Year: 2013

In this paper, a class of min-max optimal control problems with continuous dynamical systems and quadratic terminal constraints is studied. The main contribution is that the original terminal state constraint in which the disturbance is involved is transformed into an equivalent linear matrix inequality without disturbance under certain conditions. Then, the original min-max optimal control problem is solved via solving a sequence of semi-definite programming problems. An example is presented to illustrate the proposed method. © 2013 Elsevier Ltd. All rights reserved.

Hein V.,University of Tartu | Koka A.,University of Tartu | Hagger M.S.,Curtin University Australia
Journal of Adolescence | Year: 2015

We tested a model of the associations between students' perceptions of their physical education teacher's controlling behaviour, perceptions of basic psychological need thwarting, anger and bullying behaviour. School students (N=602; M age=12.88, SD=1.37) from 10 schools completed measures of perceived teachers' controlling behaviour and perceived thwarting of the psychological needs for autonomy, competence, and relatedness in physical education context and self-reported bullying and anger. A well-fitting structural equation model demonstrated that students' perceptions of the negative conditional regard and intimidation exhibited by the teacher had significant indirect effect on students' feelings of anger and bullying behaviour through the perceived psychological need thwarting in physical education. Findings suggest that physical education teachers who avoid the use of negative conditional regard and intimidation in their classes have students who perceive less need thwarting and report less bullying behaviour. © 2015 The Foundation for Professionals in Services for Adolescents.

Moloney N.A.,University College Dublin | Hall T.M.,Curtin University Australia | Doody C.M.,University College Dublin
Journal of Rehabilitation Research and Development | Year: 2012

The use of quantitative sensory testing (QST) has become more widespread, with increasing focus on describing somatosensory profiles and pain mechanisms. However, the reliability of thermal QST has yet to be established. We systematically searched the literature using key medical databases. Independent reviewers evaluated reliability data using the Quality Appraisal for Reliability Studies checklist. Of the 21 studies we included in this review, we deemed 5 to have high methodological quality. Narrative analysis revealed that estimates of reliability varied considerably, but overall, the reliability of cold and warm detection thresholds ranged from poor to excellent, while heat and cold pain thresholds ranged from fair to excellent. The methodological quality of research investigating the reliability of thermal QST warrants improvement, particularly in terms of appropriate blinding. The results from this review showed considerable variability in the reliability of each thermal QST parameter.

Korhonen F.J.,Curtin University Australia | Powell R.,University of Melbourne | Stout J.H.,University of Minnesota
Journal of Metamorphic Geology | Year: 2012

The equilibrium coexistence of sapphirine+quartz is inferred to record temperatures in excess of 980°C, based on the stability of this assemblage in the simplified chemical system FeO-MgO-Al 2O 3-SiO 2 (FMAS) system. However, the potential for sapphirine to contain significant Fe 3+ suggests that the stability of sapphirine+quartz could extend to lower temperatures than those constrained in this ideal system. The Wilson Lake terrane in the Grenville Province of central Labrador preserves sapphirine+quartz-bearing assemblages in highly oxidized bulk compositions, and provides an opportunity to explore the stability of sapphirine+quartz in such rock compositions within the Na 2O-CaO-K 2O-FeO-MgO-Al 2O 3-SiO 2-H 2O-TiO 2-O (NCKFMASHTO) chemical system. Starting with the phase equilibria in FeO-MgO-Al 2O 3-SiO 2-TiO 2-O (FMASTO), expansion into K 2O-FeO-MgO-Al 2O 3-SiO 2-H 2O-TiO 2-O (KFMASHTO) allows the effect of the stability of the additional phases, biotite, K-feldspar and melt, on the stability of sapphirine+quartz to be assessed. These phase relations are evaluated generally using P-T projections, and the ultimate extension into NCKFMASHTO is done with pseudosections. Conditions of peak metamorphism in the Wilson Lake terrane are constrained using P-T pseudosections, and the appropriate H 2O and O contents to use in the modelled compositions are investigated using T-M H2O and T-M O pseudosections. The peak P-T estimates from a sapphirine+quartz-bearing sample are ~960 to 935°C at ~10 to 8.6kbar, similar to estimates from orthopyroxene+sillimanite+quartz±garnet-bearing samples. Whereas the sapphirine+quartz-bearing sample is more Fe-rich than the orthopyroxene+sillimanite-bearing sample on an all-Fe-as-FeO basis, once the oxidation state is taken into account, the former is effectively more magnesian than the latter, accounting for the sapphirine occurrence. © 2011 Blackwell Publishing Ltd.

Van Kranendonk M.J.,University of New South Wales | Van Kranendonk M.J.,Macquarie University | Kirkland C.L.,Geological Survey of Western Australia | Kirkland C.L.,Curtin University Australia
Geology | Year: 2013

The rate of growth of the continental crust is controversial. We present an evaluation of time-constrained analyses of oxygen isotopes in zircon grains and incompatible element (Zr, Th) concentrations in magmatic rocks to test for variations in the degree of crustal recycling through geological time. The data indicate a rise in these geochemical proxies from ca. 3.0 Ga to a statistically significant peak at 1.2-1.1 Ga during the amalgamation of supercontinent Rodinia, and a decrease thereafter. When combined with other geological and geophysical observations, the data are interpreted as a consequence of an unprecedented level of crustal recycling and sediment subduction during Rodinia assembly, arising from a "Goldilocks" (i.e., just right) combination of larger, thicker plates on a warmer Earth with more rapid continental drift relative to modern Earth. The subsequent decrease in 18O, Zr, and Th measurements is interpreted to refl ect decreasing drift rates on a cooling Earth. © 2013 Geological Society of America.

Blyth A.J.,Curtin University Australia | Shutova Y.,University of New South Wales | Smith C.,La Trobe University
Organic Geochemistry | Year: 2013

The determination of δ13C values in speleothems is of considerable importance in palaeoenvironmental research, but has focussed solely on analysis of the carbonate. Here we demonstrate a new method for analysing the δ13C values of organic matter (OM) trapped in speleothems, utilising flow injection liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). Developmental analysis using a homogenised speleothem powder showed that the method is robust, with repeated digests and analyses having an average standard deviation of 0.1‰. Dilution tests with samples of 4-23μg total organic carbon (TOC) show relatively small linearity effects, with the overall standard deviation across a peak response range of 1700-9000mV being 0.2‰. © 2012 Elsevier Ltd.

MacLean S.,University of Melbourne | MacLean S.,Center for Alcohol Policy Research | Moore D.,Curtin University Australia
International Journal of Drug Policy | Year: 2014

Background: Young adults from across greater Melbourne are drawn to the city centre night time economy (NTE). There is some evidence that young adults who live in outer-suburbs are involved in higher rates of weekend night time assaults than their inner-urban peers, both as perpetrators and as victims. Using the notion of 'assemblages', this article explores outer-suburban people's participation in the affectively charged spaces of inner-city entertainment precincts to show that trouble in the NTE cannot be attributed to alcohol and other drugs alone. Methods: We provide a narrative analysis of interviews conducted in 2012 with 60 young adult drinkers aged 18-24, half of whom lived in an inner-city area and half in outer-suburbs. Results: More so for young adults from outer-suburbs than those who live closer to the city, going to the city is an event marked out as different from everyday life. Their sense of being 'hyped up' in the inner-city made different sets of practices possible, particularly in relation to drinking and being open to new engagements with friends and sexual partners. Participants also spoke, however, of discomfort, danger and fear. Violence was most likely to occur at points where people felt a dissonance between their heightened affective states and the spaces where they found themselves. Conclusion: In this analysis, outer-suburban young adults' positioning within the assemblages of the city centre NTE makes conflict and violence more likely for them. Efforts to improve NTE safety should maintain a focus on managing alcohol availability. Nonetheless additional strategies to decentralise the NTE, ensure better late night public transport to outer-suburbs or to support people to manage sudden affective shifts in NTE might also play a greater part in the overall effort. © 2014 Elsevier B.V.

Zhang X.,University of Western Australia | Hao H.,Curtin University Australia | Wang Z.,Beijing Institute of Technology
International Journal of Impact Engineering | Year: 2015

Laminated glass panes are widely adopted as blast-resistant glass windows to mitigate the hazard from ejecting fractured glass fragments. The response of laminated glass windows under blast loads is often predicted by equivalent static analysis or simplified equivalent single degree of freedom (SDOF) analysis. The equivalent SDOF and equivalent static analyses are also respectively adopted in UFC and ASTM design guide for glass window designs. Owing to the inherent problems, the SDOF analysis can only predict the global responses of glass windows and the predictions are not necessarily always satisfactory. Therefore the accuracy and applicability of the SDOF analysis is sometimes questioned. Often numerical simulations and/or experimental tests have to be carried out for reliable predictions of laminated glass window responses to blast loads. In this study, experimental tests on laminated glass windows subjected to impact and blast loads were carried out to evaluate the accuracy of available analyses and design methods. Pendulum impact tests were conducted first on laminated panes of various thicknesses. Full-scale field blast tests were performed on laminated glass windows of dimension 1.5 m × 1.2 m. Glass pane deflections were monitored by mechanical linear voltage displacement transducer (LVDT) and high-speed cameras. The responses of the tested windows are compared with the estimations of SDOF models and design standards in this paper. Available blast testing data by other researchers are also included together with the current testing data to evaluate the accuracy of the SDOF and equivalent static analyses defined in the design guides. The adequacy of these simplified approaches in predicting laminated glass window responses to blast loads is discussed. © 2014 Elsevier Ltd. All rights reserved.

Zhang X.,University of Western Australia | Hao H.,Curtin University Australia | Wang Z.,Beijing Institute of Technology
Engineering Structures | Year: 2014

A series of field blasting tests of glass windows to blast loadings have been recently conducted. This is the second paper to report the testing data on monolithic tempered glass windows. While the first paper reports the glass panel response and failure modes, the current paper concentrates on the glass fragments induced by the blast loadings. Thermally tempered glass has been often adopted for monolithic windows to reduce ejecting fragment hazards after window fracture. However, previous blast tests conducted on monolithic tempered glass reported that in addition to small cubic fragments the shattered glass panes could break into large and jagged fragments similar to the cases in annealed glass which poses much more debris threats than expected. A thorough study on tempered glass fragments produced by air blast pressure is therefore necessary for better protection of human safety. In this paper, fragment characteristics of monolithic tempered glass windows observed in blasting tests are analyzed and presented. 1.5. m × 1.2. m monolithic panes of two commonly used thicknesses, i.e. 6. mm and 10. mm, fully clamped onto the opening of an enclosed RC frame were tested with 5-10. kg TNT charge detonated at 4.5-12.3. m stand-off distances. Glass fragment mass and splash distributions both in front of and behind the windows were evaluated with respect to reflected pressure and glass specification. Fragment size and shape were also analyzed. High-speed cameras were used to monitor glass window fracture processes. Fragment velocities were determined by post-processing the high-speed camera images. Fragment ejecting velocities were evaluated with respect to the reflected impulse. Negative pressure was found to significantly influence the fragment ejecting velocity and fragment splash distributions. © 2014 Elsevier Ltd.

Sarker P.K.,Curtin University Australia | Haque R.,SGS Australia | Ramgolam K.V.,Shire of Kalamunda
Materials and Design | Year: 2013

Use of fly ash based geopolymer as an alternative binder can help reduce CO2 emission of concrete. The binder of geopolymer concrete (GPC) is different from that of ordinary Portland cement (OPC) concrete. Thus, it is necessary to study the effects of the geopolymer binder on the behaviour of concrete. In this study, the effect of the geopolymer binder on fracture characteristics of concrete has been investigated by three point bending test of RILEM TC 50 - FMC type notched beam specimens. The peak load was generally higher in the GPC specimens than the OPC concrete specimens of similar compressive strength. The failure modes of the GPC specimens were found to be more brittle with relatively smooth fracture planes as compared to the OPC concrete specimens. The post-peak parts of the load-deflection curves of GPC specimens were steeper than that of OPC concrete specimens. Fracture energy calculated by the work of fracture method was found to be similar in both types of concrete. Available equations for fracture energy of OPC concrete yielded conservative estimations of fracture energy of GPC. The critical stress intensity factor of GPC was found to be higher than that of OPC concrete. The different fracture behaviour of GPC is mainly because of its higher tensile strength and bond strength than OPC concrete of the same compressive strength. © 2012 Elsevier Ltd.

Ahmed S.F.U.,Curtin University Australia | Mihashi H.,Tohoku Institute of Technology
Materials and Structures/Materiaux et Constructions | Year: 2011

Experimental results on the strain hardening and multiple cracking behaviors of polyvinyl alcohol (PVA) fiber reinforced cementitious composites under bending are reported in this paper. Different hybrid combinations of PVA fibers with different lengths and volume fractions are considered to reinforce the mortar matrix. Among different hybrid combinations, the composite containing 2% thicker PVA fibers of 12 mm length and 1% thinner PVA fibers of 6 mm length and the composite containing 2% thicker PVA fibers of 24 mm length and 1% thinner PVA fibers of 6 mm length showed the best performance in terms of highest ultimate load, largest CMOD (crack mouth opening displacement) at peak load and multiple cracking behavior. The effects of four types of light weight sands on the strain hardening and multiple cracking behavior of hybrid fiber composites are also evaluated in this study. It has been observed that the ultimate load and CMOD at peak load for all light weight hybrid fiber composites are almost the same irrespective of volume fractions of light weight sand. The composites containing finer light weight sands exhibited higher ultimate load than those containing coarser light weight sands. It is also observed that the hybrid fiber composite containing normal silica sand exhibited higher ultimate load than the composites with light weight sands. © RILEM 2010.

Aylmore M.G.,Tenova Mining and Minerals Australia Pty Ltd. | Staunton W.P.,Curtin University Australia
Hydrometallurgy | Year: 2014

The effect of some typical oxide and sulfide minerals, as well as activated carbon, on synthetic gold thiosulfate leach solutions was examined. The presences of pyrite and goethite in a synthetic ore slurry have a significant effect on the adsorption and stability of gold, silver, copper and polythionates in ammoniacal thiosulfate solutions. Adsorption of tetrathionate in particular leads to significant gold and silver losses. The adsorption of copper on mineral surfaces inhibited gold and silver losses, even in the presence of tetrathionate. However, goethite was found to strongly adsorb copper(II). It is concluded that gold extraction from natural ores is lower than that obtained with cyanide, partly as a result of sorption or precipitation reactions. Furthermore, the presence of silver in solution catalyses the precipitation of a mixed copper/silver/gold sulfide in ammoniacal thiosulfate solutions containing tetrathionate. © 2014 Elsevier B.V.

Fisher I.,Watervale Systems Pty Ltd | Kastl G.,Level 3 Communications | Sathasivan A.,Curtin University Australia
Water Research | Year: 2011

Maintaining the chlorine residual is a major disinfection goal for many water distribution systems. A suitable general chlorine bulk-decay model is required for simulation of chlorine profiles in networks to assist disinfection planning/management efficiently. The first-order model is unsuitable due to inaccuracy and inability to represent rechlorination. Three potentially suitable, simple, reactant models were compared. The single-reactant model was found to be unsuitable, as it was inaccurate when restricted to using a single set of invariant parameters. The two-reactant model was more suitable than the variable-rate-coefficient model, although both models were accurate under the same restriction. The two-reactant model was then calibrated against datasets consisting of multiple decay tests for five distinctly different waters. It accurately predicted data reserved for validation over the chlorine concentration range of 0-6 mg/L, using a single set of invariant parameters, and is therefore the simplest, generally suitable model for simulating chlorine profiles in distribution system networks. © 2011 Elsevier Ltd.

Newsholme P.,Curtin University Australia | De Bittencourt P.I.H.,Federal University of Rio Grande do Sul | De Bittencourt P.I.H.,National Institute of Hormones and Womens Health
Current Opinion in Clinical Nutrition and Metabolic Care | Year: 2014

Obesity is a chronic inflammatory disease in which the physiological resolution of inflammation is attenuated, leading to low-grade inflammation throughout the body. However, the heat shock response, which is a key component of the physiological response to resolve inflammation, is seriously hampered in adipose tissue and other metabolic organs (e.g. skeletal muscle, liver, pancreatic β-cells) in metabolic diseases. In this review, we hypothesize that adipocyte metabolic stress triggers the onset of fat cell senescence, and companion senescence-Associated secretory phenotype (SASP), and that such a scenario is responsible for attenuating the resolution of inflammation. RECENT FINDINGS: We shall discuss the role of the heat shock response in the context of the resolution of inflammation and the relevance of heat shock response blockade in chronic inflammatory diseases. Sirtuin-1 is responsible for the induction of heat shock transcription factor-1 mRNA expression and for the stabilization of heat shock transcription factor-1 in a high-profile activity state. However, adipose tissue-emanated SASP depress sirtuin-1 expression, leading adipocytes to a perpetual state of unresolved inflammation, due to a dampening of the heat shock response. SUMMARY: The advance of inflammasome-mediated SASP from adipose to other tissues promotes cellular senescence in many other cells of the organism, aggravating obesity-dependent chronic inflammation. Inducers of heat shock response (e.g. heat shock itself, physical exercise and calorie restriction) may efficiently interrupt this vicious cycle and are envisaged as the best and also the most economical treatment for obesity-related chronic diseases.Copyright © Lippincott Williams &Wilkins.

Liang H.,Neuroscience Research Australia | Paxinos G.,University of New South Wales | Watson C.,Curtin University Australia
Brain Structure and Function | Year: 2011

The cells that project from the brain to the spinal cord have previously been mapped in a wide range of mammalian species, but have not been comprehensively studied in the mouse. We have mapped these cells in the mouse using retrograde tracing after large unilateral Fluoro-Gold (FG) and horseradish peroxidase (HRP) injections in the C1 and C2 spinal cord segments. We have identified over 30 cell groups that project to the spinal cord, and have confirmed that the pattern of major projections from the cortex, diencephalon, midbrain, and hindbrain in the mouse is typically mammalian, and very similar to that found in the rat. However, we report two novel findings: we found labeled neurons in the precuneiform area (an area which has been associated with the midbrain locomotor center in other species), and the epirubrospinal nucleus. We also found labeled cells in the medial division of central nucleus of the amygdala in a small number of cases. Our findings should be of value to researchers engaged in evaluating the impact of spinal cord injury and other spinal cord pathologies on the centers which give rise to descending pathways. © Springer-Verlag 2010.

Carlson W.D.,University of Texas at Austin | Gale J.D.,Curtin University Australia | Wright K.,Curtin University Australia
American Mineralogist | Year: 2014

Yttrium and the rare-earth elements (Y+REEs) are incorporated into aluminosilicate garnet as trivalent ions replacing divalent Mg, Fe, Mn, or Ca ("M2+") in dodecahedral sites, which requires some form of coupled substitution to maintain electroneutrality. We compare the energetic costs of competing coupled-substitution schemes, using lattice dynamics calculations to assess defect energies and exchange energies for each scheme. Substitutions with relatively low energetic costs introduce menzerite-like components via the exchange vector [YM-1•(Mg,Fe)Al -1], or alkali components via the exchange vector [Y(Na,Li)M -2]. Substitutions with substantially higher energetic costs introduce a vacancy component via the exchange vector [Y2□M -3], or the yttrogarnet (YAG) component via the exchange vector [YM-1•AlSi-1], or a component with octahedral Li via the exchange vector [Y2M-2•LiAl-1]. Energetic costs decrease significantly as the host-garnet unit-cell dimension expands, decrease very modestly as temperature rises or pressure falls, and decrease substantially with the contraction in ionic radius across the lanthanide series. These results, combined with critical re-examination of arguments cited in favor of each substitution scheme in natural occurrences, suggest that Y+REE incorporation in natural garnet is dominated by coupled substitutions that introduce menzerite and alkali components, that the YAG substitution plays only a subsidiary role, and that the other schemes are likely to be of very minor importance.

Wolf C.,Max Planck Institute for Polymer Research | Li Q.,Curtin University Australia
Langmuir | Year: 2010

Protein microarrays are of great research interest because of their potential application as biosensors for highthroughput protein and pathogen screening technologies. In this active area, there is a lack of techniques that can result in annulus-shaped protein structures (e.g., for the utilization of curved surfaces for enhanced protein-protein interactions and the detection of antigens). We present a new technique employing colloidal templating to yield large-scale (∼cm 2) 2D arrays of antibodies against Escherichia coli K12 and enhanced green fluorescent protein (eGFP) on a versatile glass surface. The antibodies are swept to reside around the templating microspheres during solution drying and physically adsorb onto the glass. After the microspheres are removed, an array of annulus-shaped antibody structures is formed. Wedemonstrate the preserved antibody structure and functionality by binding the specific antigens and secondary antibodies, respectively, which paves the way for the binding of biomolecules and pathogens such as bacteria and viruses. The structures were investigated via atomic force, confocal, and fluorescence microscopy. Operational factors such as the drying time, temperature, and humidity as well as the presence of surfactants in the antibody solution were tuned to obtain a stable antibody structure. © 2010 American Chemical Society.

Zhao G.,University of Hong Kong | Li S.,Ocean University of China | Sun M.,University of Hong Kong | Wilde S.A.,Curtin University Australia
International Geology Review | Year: 2011

Columbia is a Palaeo-Mesoproterozoic supercontinent that was assembled during global 2.0-1.8Ga collisional events, underwent long-lived, subduction-related accretion at key continental margins in the period 1.8-1.3Ga, commenced to fragment ∼1.6Ga ago, and finally broke up at ∼1.3Ga. Similar to most other cratonic blocks (Laurentia, Baltica, Siberia, Amazonia, West African, South Africa, India, Australia, and Antarctica), the North China Craton records the history of assembly, accretion, and break-up of the Columbia supercontinent. New data indicate that the Archaean to Palaeoproterozoic basement of the North China Craton was assembled by microcontinental blocks along three Palaeoproterozoic collisional belts: the Khondalite Belt, the Jiao-Liao-Ji Belt, and the Trans-North China Orogen. The Khondalite Belt was formed by collision between the Yinshan and Ordos blocks and was amalgamated to form the Western Block at ∼1.95Ga. The Eastern Block underwent Palaeoproterozoic rifting at 2.2-1.9Ga to break-up into the Longgang and Nangrim blocks; then the rift basin/incipient ocean closed attending subduction and collision to form the Jiao-Liao-Ji Belt at ∼1.9Ga. Finally, the Western and Eastern blocks collided along the Trans-North China Orogen to form the coherent basement of the North China Craton at ∼1.85Ga. Following this final assembly, the North China Craton underwent subduction-related accretion at its southern margin during the period 1.78-1.45Ga, forming the Xiong'er volcanic belt. At 1.6-1.2Ga, the northern margin of the North China Craton underwent a rifting event that led to separation of the craton from other cratonic blocks of the supercontinent Columbia, forming the 1.6-1.2Ga Zhaertai-Bayan Obo rift zone and associated 1.35Ga mafic sills along the northern margin of the craton. These data indicate that in any configuration of Columbia, the southern margin of the North China Craton must have faced an open ocean, whereas its northern margin was connected to another continental block. © 2011 Taylor & Francis.

Speer M.S.,University of New South Wales | Leslie L.M.,University of Oklahoma | Leslie L.M.,Curtin University Australia | Fierro A.O.,National Oceanic and Atmospheric Administration
Climate Dynamics | Year: 2011

Rainfall on the subtropical east coast of Australia has declined at up to 50 mm per decade since 1970. Wavelet analysis is used to investigate eight station and four station-averaged rainfall distributions along Australia's subtropical east coast with respect to the El Niño-Southern Oscillation (ENSO), the inter-decadal Pacific oscillation (IPO) and the southern annular mode (SAM). The relationships are examined further using composite atmospheric circulation anomalies. Here we show that the greatest rainfall variability occurs in the 15-30 year periodicity of the 1948-1975 or 'cool' phase of the IPO when the subtropical ridge is located sufficiently poleward for anomalous moist onshore airflow to occur together with high ENSO rainfall variability and high, negative phase, SAM variability. Thus, the mid-latitude westerlies are located at their most equatorward position in the Australian region. This maximizes tropospheric interaction of warm, moist tropical air with enhanced local baroclinicity over the east coast, and hence rainfall. © 2009 Springer-Verlag.

Fraser S.,Curtin University Australia | Fraser S.,University of New South Wales
International Journal of Drug Policy | Year: 2013

In the West, most hepatitis C transmission occurs through the sharing of equipment used for injecting drugs, and most sharing occurs between sexual partners. Despite this, little is known about how injecting practice, including equipment use, is managed in these partnerships. This article draws on science studies theorist Bruno Latour's work on technology and ethics (2002), and preliminary data collected for a research project on sexual partners who inject together, to illuminate these issues. Responsibility for avoiding transmission has long been conceived individually, as have measures intended to aid individuals in fulfilling this responsibility, such as the distribution of sterile injecting equipment. This individualising tendency has been criticised for inequitably responsibilising disadvantaged people. This article aims to exceed this individualising approach by proposing a different understanding of agency and a new mode of prevention. Rather than treating hepatitis C in conventional terms, as a bounded, ontologically stable object that pre-exists its encounter with individuals and the material objects they use in injecting, it formulates it as made in its enfolding with other phenomena, including social relationships and technological objects. In turn it sees transmission in new terms; as a question of social relationships and of object design. The article goes on to discuss a new Australian research project that takes this approach as its starting point, aiming to develop two key prevention innovations: (1) new messages aimed at partnerships rather than individuals, and (2) a new injecting pack or 'fitpack' that treats the partnership as a primary unit of resourcing. The article concludes by considering the politics of this shift to an ethics of technology, social relationships and objects. © 2013 Elsevier B.V.

Forbes G.L.,Curtin University Australia | Randall R.B.,University of New South Wales
Mechanical Systems and Signal Processing | Year: 2013

Non-contact measurement of gas turbine rotor blade vibration is a non-trivial task, with no method available which achieves this aim without some significant draw-backs. This paper presents a truly non-contact method to estimate rotor blade natural frequencies from casing vibration measurements at a single engine operating speed. An analytical model is derived to simulate the internal casing pressure in a turbine engine including the effects of blade vibration on this pressure signal. It is shown that the internal pressure inside a turbine contains measureable information about the rotor blade natural frequencies and in-turn the casing vibration response also contains this information. The results presented herein show the residual, pressure and casing vibration, spectrum can be used to determine the rotor blade natural frequencies with validation provided for the analytical model by experimental measurements on a simplified test rig. A simulated blade fault in one of the rotor blades is introduced with successful estimation of the simulated faulty blade natural frequency. © 2012 Elsevier Ltd.

Jourdan F.,Curtin University Australia | Moynier F.,University of Washington | Koeberl C.,University of Vienna | Eroglu S.,University of Tübingen
Geology | Year: 2011

Asteroid impacts play an important role in the evolution of planetary surfaces. In the inner solar system, the large majority of impacts occur on bodies (e.g., asteroids, the Moon, Mars) covered by primitive igneous rocks. However, most of the impacts recorded on Earth occur on different rock types and are poor proxies for planetary impacts. The Lonar crater is a 1.88-km-diameter, Quaternary age crater (Fig. 1) located on the ca. 66 Ma Deccan basaltic traps in Maharashtra (India), and is one of the very few craters on Earth emplaced directly on basaltic lava flows. We carried out 12 40Ar/39Ar step-heating experiments on 4 melt rock samples in order to (1) obtain a precise age for the Lonar crater; (2) study the response of isotopic chronometers during impacts on mafic target rocks; and (3) better understand the dating of extraterrestrial impact craters. We obtained 10 plateau and 9 inverse isochron ages on various aliquots. Combination of selected data into a global inverse isochron yielded an age of 570 ± 47 ka (MSWD = 1.1; P = 0.24). In comparison, previous nonisotopic investigations on rocks thought to be affected by secondary processes yielded a range of much younger ages (ca. 12-62 ka). The measured 40Ar/36Ar trapped values offer a direct comparison with the atmospheric benchmark value and allow us to test the inherited 40Ar * degassing capacity of basaltic impact melt rocks. The 40Ar/36Ar ratio of 296.5 ± 1.7 is indistinguishable from the atmospheric composition and suggests that inherited 40Ar* is absent from the melt rock. This result substantiates diffusion models that predict a near-complete degassing of low-viscosity melt (e.g., basalts) during impact, and demonstrates for the first time that inherited 40Ar* is less problematic for 40Ar/39Ar dating of impact events in basaltic igneous rocks compared to Si-rich rocks. These results provide direct evidence that basaltic melt rocks are excellent candidates for recording the timing of planetary impact events and, as far as dating is concerned, should be the preferred targets of sample recovery by future missions. © 2011 Geological Society of America.

Lewin G.,Curtin University Australia | Vandermeulen S.,Silver Chain
Health and Social Care in the Community | Year: 2010

The Home Independence Program (HIP) is a short-term restorative programme targeted at older home-care clients, who do not have a diagnosis of dementia, when they are first referred for assistance or when they are referred for additional services because their needs have increased. This study compared the outcomes for individuals who participated in HIP with those of individuals who received 'usual' home-care services. The study was conducted in metropolitan Perth, Western Australia, between 2001 and 2003, when HIP was being trialled as a service in just one region. One hundred clients were recruited into each group and were visited at home on three occasions - service start and at 3 months and 1 year. Standardised outcome measures were used to measure functional dependency, morale, confidence in performing everyday activities without falling and functional mobility. Service outcomes were also examined at 3 months and 1 year. The HIP group showed improvements on all personal outcome measures compared with the control group. These improvements were, except for the morale scale, significantly associated with group assignment even when baseline differences between the groups were adjusted for. As regards service outcomes, the odds of the individuals who received HIP still requiring services was 0.07 (95% CI = 0.03-0.15, P < 0.001) times those for the individuals in the control group at 3 months and 0.14 times at 12 months (95% CI = 0.07-0.29, P < 0.001). The results of this study supported the hypothesis that older individuals referred for home care who participated in a programme to promote their independence had better individual and service outcomes than individuals who received usual home care. © 2009 Blackwell Publishing Ltd.

Jahnert R.J.,Curtin University Australia | Jahnert R.J.,Petrobras | Collins L.B.,Curtin University Australia
Marine Geology | Year: 2011

Microbial deposits at Shark Bay, Australia constitute one of the largest and most diverse modern occurrences around the world. The microbial carbonate system has developed in response to environmental change from near open marine into restricted embayment with hypersalinity and high evaporation. Bacterial sediments started depositing at about 2000. years BP, after the Holocene maximum flooding of sea level about 6800. years BP, due to increasing salinity as the sea level fell by about 2.5. m, within the Holocene highstand system tract. The extent and types of subtidal microbial substrate in this World Heritage area have not previously been fully systematically mapped and described. Here we document the importance of subtidal microbial deposits occupying as much as 10 times the occurrence area of the intertidal microbial mats and stromatolites and demonstrate that deeper structures have a cerebroid external morphology with a non laminated internal fabric. Subtidal structures contain consistently different internal fabrics with carbonate grains and fragments interbedded with aragonitic micrite arranged in millimetric laminae or sub-spherical patches, which display fabrics such as well laminated (Smooth), coarse laminated wavy (Colloform), sub-laminar to irregular with voids and biofragments of bivalves (Microbial Pavement), irregular clotted (Pustular) and non-laminated (Cerebroid), constituting carbonate sediment with stromatolitic facies (Smooth and Colloform), thrombolitic facies (Pustular) and cryptomicrobial non-laminated (Cerebroid and Microbial Pavement). Each microbial structure grows in specific settings according to water depth (MSL), with Cerebroid build-ups commonly occurring between -1 and -2.5. m and Microbial Pavement extending as deep as 6. m. Because of the late Holocene sea level fall microbial structures often record in their internal features a shallowing-up carbonate cycle. These newly documented extensive subtidal microbial structures, with distinctive morphologies and fabrics have importance as modern occurrences and provide potential analogues for understanding ancient microbial systems and environments. © 2011 Elsevier B.V.

Yang X.,China University of Mining and Technology | Aldrich C.,Curtin University Australia
International Journal of Mining Science and Technology | Year: 2013

Coal flotation is widely used to separate commercially valuable coal from the fine ore slurry, and is an industrial process with nonlinear, multivariable, time-varying and long time-delay characteristics. The online detection of ash content of products as the operation performance evaluation in the flotation system is extraordinarily difficult because of the low solid content and numerous micro-bubbles in the slurry. Moreover, it is time-consuming by manual analysis. Consequently, the optimal separation is not usually maintained. A novel technique, called the neuro-immune algorithm (NIA) inspired by the biological nervous and immune systems, is presented in this paper for predicting the ash content of clean coal and performing the optimizing control to the coal flotation system. The proposed algorithm integrates the deeply-studied artificial neural network (ANN) and the developing artificial immune system (AIS). A two-layer back-propagation network was constructed offline based on the historical process data under the best system situation, using five parameters: the flow and the density of raw slurry, the input flows of water, the kerosene and the GF oil, as the inputs and the ash content of clean coal as the output. The immune cell of AIS is made up of six parameters above as the antigen. The cytokine based clone selection algorithm is used to produce the relative antibody. The detailed computation procedures about the hybrid neuro-immune algorithm are minutely discussed. The ash content of clean coal was predicted by NIA using the practical process data s: (308.6 174.7 146.1 43.6 4.0 9.4), and the absolute difference between the actual and computed ash content values was 0.0967%. The optimizing control on NIA was simulated considering two different situations where the ash content of clean coal was controlled downward from 10.00% or upward from 9.20% predicted by ANN to the target value 9.50%. The results indicate that the target ash content and the value of controlling parameters are obtained after several control cycles. © 2013 Published by Elsevier B.V. on behalf of China University of Mining & Technology.

Chen X.,Curtin University Australia | Chen X.,CAS Shanghai Institute of Applied Physics | Jiang S.P.,Curtin University Australia
Journal of Materials Chemistry A | Year: 2013

Lanthanum and/or barium strontium cobalt ferrite perovskite oxide materials are highly active cathodes for solid oxide fuel cells (SOFCs) operated at intermediate temperatures of 600-900 °C. However, they are vulnerable to degradation by chromium deposition and poisoning by volatile Cr species from chromia-forming metallic interconnects. Here we report the development of a new mixed ionic and electronic conductor, lanthanum strontium barium cobalt ferrite niobium perovskite, (La0.24Sr0.16Ba0.6)(Co 0.5Fe0.44Nb0.06)O3-δ (LSBCFN), prepared by a novel direct mixing synthesis of (La0.6Sr 0.4)(Co0.2Fe0.8)O3-δ (LSCF) and Ba(Co0.7Fe0.2Nb0.1)O3-δ (BSCN). The electrical conductivity of LSBCFN is 124 S cm-1 at 600 °C, which is significantly higher than 11 S cm-1 measured on BSCN at the same temperature. The new LSBCFN cathode which combines the structural stability and activity of BCFN and the high conductivity of LSCF not only exhibits better electrochemical activity for the O2 reduction reaction than either LSCF or BCFN in the temperature range of 600-900 °C, but most importantly, it shows excellent stability and tolerance toward chromium deposition and poisoning under SOFC operation conditions. A semi-quantitative analysis indicates that the Cr deposition at the electrode is closely related to the surface segregation of Sr and Ba. © The Royal Society of Chemistry 2013.

Joyeux R.,Macquarie University | Ripple R.D.,Curtin University Australia
Energy Journal | Year: 2011

The direction of the causality between energy consumption and income is an important issue in the fields of energy economics, economic growth, and policies toward energy use. The seminal work on the relations between energy consumption and aggregate income is Kraft and Kraft (1978). An extensive literature has followed, but the array of findings provide anything but consensus on either the existence of relations or direction of causality between the variables. The work in this paper extends this research by analysing the cointegrating and causal relations between income and three energy consumption series based on panel data and the latest panel methodologies. These relations are analysed for the 30 OECD countries and 26 non-OECD countries. The results support a finding of causality flowing from income to energy consumption for developed and developing economies, alike. Copyright © 2011 by the IAEE. All rights reserved.

Elhamirad A.H.,Islamic Azad University at Sabzevar | Zamanipoor M.H.,Curtin University Australia
European Journal of Lipid Science and Technology | Year: 2012

In this study, the thermal stability of some phenolic antioxidants including flavonoids (quercetin and catechin) and phenolic acids (gallic acid, tannic acid, ellagic acid and caffeic acid) in tallow olein was investigated. Tallow olein fractionated from sheep tallow fat was used as a medium to study the antioxidant activity at 120, 140, 160 and 180°C. In order to extract tallow olein, a three-stage fractionation method was performed on sheep tallow fat at the constant temperatures of 25, 15 and 5°C using acetone as a solvent. The results suggested that quercetin and ellagic acid had the highest thermal stability amongst others, while gallic acid and caffeic acid exhibited the least thermal stability. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sarma D.S.,CSIR - Central Electrochemical Research Institute | McNaughton N.J.,Curtin University Australia | Belusova E.,Macquarie University | Ram Mohan M.,CSIR - Central Electrochemical Research Institute | Fletcher I.R.,Curtin University Australia
Gondwana Research | Year: 2012

The Western Dharwar Craton in peninsular India comprises a typical Meso- to Neo-Archean granite-greenstone terrain. Detrital zircons from two metagreywackes in a late basin from the Gadag Greenstone Belt preserve at least eight age populations ranging in age from ca 3.34 to 2.55Ga, and grains as old as ca 3.54Ga. The zircon provenances for the two samples appear to be the same up to ca 3.25Ga, with relatively juvenile ε Hf values largely between zero and depleted mantle values. After 3.25Ga, one sample has similar ε Hf values whereas the other has only negative values indicative of Hf-evolution in a crustal environment. After ca 3.25Ga the source regions for the two samples were distinctly different.The detrital zircons reflect the age and evolution of the upper crust of the Western Dharwar Craton. Modeling of Hf isotopic evolution of the detrital zircons suggests two major crust-forming events at ca. 3.6 and 3.36. Ga, and some indication of juvenile addition to the crust at ca 2.6. Ga. The maximum sedimentation age of the greywackes is constrained by the youngest detrital zircon population at 2547 ± 5. Ma. Gold mineralization in the belt is dated at 2522 ± 6. Ma and constrains greywacke sedimentation, deformation and metamorphism to a ca 25. my interval. © 2012 International Association for Gondwana Research.

Jahnert R.J.,Curtin University Australia | Jahnert R.J.,Petrobras | Collins L.B.,Curtin University Australia
Sedimentology | Year: 2013

Microbial deposits at Shark Bay constitute a diverse living microbial carbonate system, developed in a semi-arid, highly evaporative marine setting. Three tidal flats located in different embayments within the World Heritage area were investigated in order to compare microbial deposits and their Holocene evolution. The stressing conditions in the intertidal-subtidal environment have produced a microbial ecosystem that is trapping, binding and biologically inducing CaCO3 precipitation, producing laminated stromatolites (tufted, smooth and colloform), non-laminated thrombolitic forms (pustular) and cryptomicrobial non-laminated forms (microbial pavement). A general shallowing-upwards sedimentary cycle was recognized and correlated with Holocene sea-level variations, where microbial deposits constitute the younger (2360 years bp) and shallower sedimentary veneer. In addition, sediments have been documented with evidence of exposure during the Holocene, from 1040 to 940 14C years bp, when sea-level was apparently lower than present. Filamentous bacteria constitute the dominant group in the blister, tufted and smooth mat types, and coccus bacteria dominate the pustular, colloform and microbial pavement deposit types. In the subtidal environment within colloform and pavement structures, microbial communities coexist with organisms such as bivalves, serpulids, diatoms, green algae (Acetabularia), crustaceans, foraminifera and micro-gastropods, which are responsible for exoskeleton supply and extensive bioturbation. The internal fabric of the microbial deposits is laminated, sub-laminar, scalloped, irregular or clotted, depending on the amount of fine-grained carbonate and the natural ability of microbial communities to trap and bind particles or induce carbonate precipitation. Nilemah tidal flat contains the thickest (1·3 m) and best-developed microbial sedimentary system; its deposition pre-dated the Rocky Point and Garden Point tidal flats, with the most positive isotope values for δ13C and δ18O, reflecting strong microbial activity in a highly evaporative environment. There is an evolutionary series preserved within the tidal flats reflecting relative ages and degree of salinity elevation. © 2012 The Authors. Journal compilation © 2012 International Association of Sedimentologists.

Zhang G.,Tianjin University | Liu W.,Curtin University Australia
IEEE Transactions on Automatic Control | Year: 2011

The problem of impulsive mode elimination for descriptor systems via a structured output proportional and derivative (P-D) feedback is investigated in this technical note. The motivation of solving this problem arises from an observation that the impulse behavior for some descriptor systems can not be eliminated completely by a parameterized output P-D feedback, but it can be removed by a structured P-D feedback elegantly designed. In order to explain this phenomenon explicitly, a concept of the structured P-D feedback is first introduced, then an explicit necessary and sufficient condition is constructively derived for the closed loop systems to be regular and impulse-free by the structured P-D feedback. The main result is represented in terms of the original system parameters instead of decomposed subsystem parameters. Finally, an example is provided to illustrate the effectiveness of the proposed result. © 2006 IEEE.

Jiang S.P.,Curtin University Australia | Chen X.,CAS Shanghai Institute of Applied Physics
International Journal of Hydrogen Energy | Year: 2014

Intermediate temperature solid oxide fuel cells (IT-SOFCs) using chromia-forming alloy interconnect requires the development of cathode not only with high electrochemical activity but also with the high resistance or tolerance towards Cr deposition and poisoning. This is due to the fact that, at SOFC operating temperatures, volatile Cr species are generated over the chromia scale, poisoning the cathodes such as (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) and causing a rapid degradation of the cell performance. Thus, a fundamental understanding of the interaction between the Fe-Cr alloys and SOFC cathode is essential for the development of high performance and stable SOFCs. The objective of this paper is to critically review the progress and particularly the work done in the last 10 years in this important area. The mechanism and kinetics of the Cr deposition and Cr poisoning process on the cathodes of SOFCs are discussed. Chromium deposition at SOFC cathodes is most likely dominated by the chemical reduction of high valence Cr species, facilitated by the nucleation agents on the electrode and electrolyte surface and/or at the electrode/electrolyte interface, i.e., the nucleation theory. The driving force behind the nucleation theory is the surface segregation and migration of cationic species on the surface of perovskite oxide cathodes. Overwhelming evidences indicate that the surface segregation plays a critical role in the Cr deposition. The prospect of the development in the Cr-tolerant cathodes for SOFCs is presented. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Singh S.P.,Curtin University Australia | Singh S.P.,National Agri Food Biotechnology Institute NABI | Singh Z.,Curtin University Australia
Postharvest Biology and Technology | Year: 2012

Storage atmosphere composition is an important factor affecting potential storage life, susceptibility to physiological disorders and overall quality of fruit. We investigated the effects of controlled/modified atmospheres (CA/MA) on fruit quality, lipid peroxidation, and enzymatic and non-enzymatic antioxidative system in 1-MCP treated Japanese plums cv. 'Blackamber' during cold storage. Commercially mature fruit pretreated with 1-MCP (0.6μLL -1 for 12h) were stored for 5 and 8weeks at 0-1°C in different storage atmospheres, viz. normal air, 1% O 2 and 3% CO 2 (CA-1), 2.5% O 2 and 3% CO 2 (CA-2) and modified atmospheres (∼10% O 2 and 3.8% CO 2) generated through packaging in low density polyethylene bags. The results showed that storage under CA-1 and CA-2 was beneficial in delaying fruit ripening, retarding lipid peroxidation and reducing incidence and severity of chilling injury (CI) during 5 and 8 weeks of storage compared to normal air and MAP. The activities of enzymes involved in ascorbate-glutathione (AA-GSH) cycle were determined to explain the redox status of ascorbate and glutathione as influenced by storage atmospheres. CA conditions were favourable for the glutathione pool and the enzymes related to restoration of glutathione in the AA-GSH cycle, but the effects of CA on the ascorbate pool were not favourable. The data suggested that the enzymatic and non-enzymatic antioxidative systems were efficiently operating under low O 2 atmospheres to scavenge reactive oxygen species produced in response to long-term chilling and gas stresses. CA conditions appeared to be limiting oxidative processes to some extent resulting in reduced oxidative damage. In conclusion, the development of CI, which is a manifestation of oxidative damage to the fruit tissue, can be significantly reduced through synergistic beneficial effects of CA and pretreatment with 1-MCP in Japanese plums. © 2012 Elsevier B.V.

Chamhuri N.,National University of Malaysia | Batt P.J.,Curtin University Australia
Journal of Retailing and Consumer Services | Year: 2013

Differences in retail store choice behaviour are examined for the purchase of fresh meat and fresh fruit and vegetables in Malaysia. In purchasing fresh meat, cluster analysis identified two groups of respondents who purchased the majority of the fresh meat they consumed from either modern retail stores or the traditional market. However, with regard to the purchase of fresh fruit and vegetables, cluster analysis identified three groups of respondents (modern retail shoppers, transient shoppers and traditional market shoppers). Although the clusters were labelled using similar terms, several similarities and differences were identified in the respective clusters for each food item. The findings indicate that store choice preference was based on the food product that the consumer intended to purchase. © 2013 Elsevier Ltd.

Li J.,Curtin University Australia | Shui B.,ACEEE
Journal of Cleaner Production | Year: 2015

This article is concerned with a comprehensive analysis of building energy efficiency policies in light of improvements in energy performance, living standards and climate change mitigation in China's built environment. In recent years, China has added about 1.7 billion square meters of new floor space in both urban and rural areas on an annual basis. In 2010, the total area of existing buildings in China was approximately 48.6 billion square meters, nearly twice the total of existing buildings areas in the European Union. How to improve energy efficiency in the soaring number of new buildings and accelerate the retrofit of the huge number of existing buildings are two daunting challenges currently facing China in terms of energy security and climate change mitigation at a global level. China has gradually altered the building energy efficiency policy portfolio, from a purely regulatory approach with a mandatory building code at the initial stage to voluntary green buildings initiatives. This paper is structured as a critical assessment of building energy efficiency policies for new and existing buildings. Both strengths and weaknesses of the implemented energy efficiency policies are detailed in each of the studied areas. It also discusses the dilemma of public games in green and sustainable buildings production in the context of Chinese economic development and societal transition. The analysis emphasises the importance of guaranteeing the consistency between policies in the current regulatory framework to maximise the effectiveness of energy efficiency policies in the built environment in China. For this, it is necessary to articulate building energy efficiency policies implementation and broader energy and climate policies. This integrative study provides both a retrospective assessment and prospective direction of building energy efficiency policy development in China. © 2014 Elsevier Ltd.

Jahnert R.J.,Curtin University Australia | Jahnert R.J.,Petrobras | Collins L.B.,Curtin University Australia
Marine Geology | Year: 2012

The distribution, nature and extent of microbial deposits in Hamelin Pool, Shark Bay have been investigated and mapped with emphasis on the occurrence, external morphologies, internal fabrics, constructional mechanisms, microbial communities, growth rates and sediment associations in the intertidal and previously little researched subtidal zone.Detailed georeferenced substrate mapping revealed extensive subtidal microbial deposits occupying approximately 300km 2 of the total Holocene 1400km 2 area of Hamelin Pool. The Microbial Pavement covers 227km 2 of the subtidal substrate that together with columnar structures reveals a subtidal microbial habitat which occupies an area 10 times larger than the area of the intertidal deposits. Microbial carbonate is composed of aragonite (80-98%) that reveals high positive values of δ 13C (+4.46 to +5.88) and δ 18O (+3.06 to +3.88) as a characteristic of the highly evaporative environment with extensive microbial activity. Oldest dated heads are 1915 and 1680 14Cyears BP, and the overall system was deposited in two stages; the first between 2000 and 1200 and the last from 900years BP to the present. Slow growth rates vary from less than 0.1mm/year to 0.5mm/year.Different internal fabrics were constructed according to their position in relation to the littoral zone by distinct microbial communities, and lateral fabric relations have been established. Evidence of shallowing-upward fabric sequences of microbial origin reflects relative falling sea levels during the late Holocene and is likely useful in ancient environmental interpretation. A sequence of events and mechanisms are described emphasizing differences between the stromatolitic, thrombolitic and cryptomicrobial deposits in Shark Bay. The new substrate map and depositional history for this distinctive and peculiar microbial habitat establish the significance of subtidal structures and emphasize the geoscientific importance of Hamelin Pool, especially with respect to early life studies and ancient analogues for understanding microbial activity, deposit characteristics, fenestral fabrics and distribution. © 2012 Elsevier B.V.

Mukhamedzhanov A.M.,Texas A&M University | Kadyrov A.S.,Curtin University Australia
Physical Review C - Nuclear Physics | Year: 2010

Future exact many-body theory will allow us to calculate nuclear reactions based on the adopted NN and many-body nuclear potentials. But NN potentials are not observable and there are an infinite number of the phase-equivalent NN potentials related via finite-range unitary transformations. We show that asymptotic normalization coefficients, which are the amplitudes of the asymptotic tails of the overlap functions, are invariant under finite-range unitary transformations but spectroscopic factors are not. We prove also that the exact amplitudes for the (d,p),(d,pn), and (e,e′p) reactions determining the asymptotic behavior of the exact scattering wave functions in the corresponding channels, in contrast to spectroscopic factors, are invariant under finite-range unitary transformations. Moreover, the exact reaction amplitudes are not parametrized in terms of the spectroscopic factors and nuclear reactions in the exact approach cannot provide a tool to determine spectroscopic factors which are not observable. © 2010 The American Physical Society.

Herzog G.,Tyndall National Institute | Nolan M.-T.,Tyndall National Institute | Arrigan D.W.M.,Curtin University Australia
Electrochemistry Communications | Year: 2011

The electrochemical behaviour of haemoglobin denatured using different concentrations of urea was investigated at the liquid-liquid interface. The reverse peak current varied with the concentration of urea, allowing the building of the unfolding curve, which compares well with UV-Vis absorbance results. Thermodynamic parameters, such as the change in free energy of folding in water, ΔG w, and the index of the compactness of the protein, m, were extracted from the experimental data. The work here presents a simple electrochemical method for the study of protein unfolding by electrochemistry at the liquid-liquid interface. © 2011 Elsevier B.V. All rights reserved.

Dong C.,Curtin University Australia | Takagi H.,Tokushima University
Composites Part B: Engineering | Year: 2014

A study on the flexural properties of environmentally friendly "green" composites made from starch-based, dispersion-type biodegradable resin and cellulose nanofibres is presented in this paper. Models were developed for correlating the flexural modulus and flexural strength with voids and fibre length-diameter ratio due to processing. It shown voids and fibre length-diameter ratio have large effect on the flexural modulus. The flexural modulus decreases with increasing void content and increases with fibre length-diameter ratio. Thus, the flexural modulus can be increased by choosing the processing method. This study shows the stirrer mixing process yields the highest average fibre length-diameter ratio. Flexural strength decreases as expected with increasing void content. The stirrer mixing process yields the highest overall flexural strength, which is due to the lowest void content and enhanced uniform dispersion of nanofibres. It can be derived from the regression model that flexural strength is dependent on the average fibre length-diameter ratio, and the critical fibre length-diameter ratio for reinforcing the matrix is about 80. The sensitivities of the flexural strength to voids were also studied, and it was found that the stirrer-treated composites were least sensitive to voids. © 2013 Elsevier Inc. All rights reserved.

Hu P.J.-H.,University of Utah | Hui W.,Curtin University Australia
Decision Support Systems | Year: 2012

We examine students' learning effectiveness and satisfaction in technology-mediated learning by analyzing how it influences the underlying learning process, with a focus on the role of learning engagement. We propose a structural model that explains students' learning effectiveness and satisfaction, and then empirically test that model and the associated hypotheses with an experiment involving 212 university students learning Adobe Photoshop. Our experimental data show that the effects of technology-mediated learning are mostly mediated by learning engagement. In particular, the use of preprogrammed video contents to deliver learning materials negatively affects learning engagement, which in turn reduces perceived learning effectiveness and satisfaction. However, technology-mediated learning appears to have no significant effects, direct or moderating, on learning effectiveness or satisfaction. These findings have several important implications for technology-mediated learning research and practice. © 2012 Elsevier B.V. All rights reserved.

Rasmussen B.,Curtin University Australia | Krapez B.,Curtin University Australia | Meier D.B.,University of Leeds
Bulletin of the Geological Society of America | Year: 2014

Banded iron formations (BIFs) are central to interpretations about the composition of the Precambrian ocean, atmosphere, and biosphere. Hematite is an important component of many BIFs, and its presence has been used as evidence for the former presence of hydrous ferric oxyhydroxides that formed from the oxidation of dissolved ferrous iron in seawater. However, textural evidence for the origin of hematite is equivocal. New petrographic results show that hematite in unmineralized BIF from the ca. 2.5 Ga Dales Gorge Member of the Brockman Iron Formation, Hamersley Group, Western Australia, including morphologies previously interpreted to represent ferric oxyhydroxide precipitates, formed via fluid-mediated replacement of iron-silicates and iron-carbonates along sedimentary layering. The lateral transition from stilpnomelane- and sideriterich laminae to hematite-dominated laminae is interpreted to reflect progressive stages of in situ alteration of reduced mineral assemblages by oxygen-bearing fluids rather than changes in the chemistry of the water column during deposition. Although morphologies previously ascribed to "primary" hematite are present, they are related to mineral replacement reactions, raising doubts about the petrographic criteria used to identify original hematite. Hematite replacement in unmineralized BIF postdated deposition and possibly metamorphism, and predated modern weathering. From a regional perspective, it appears to be a distal signature of the processes that were responsible for iron-ore mineralization, which involved the deep infiltration of oxygen-bearing meteoric fluids. The mineral replacement reactions recorded in the Dales Gorge Member are unlikely tobe unique and probably occurred in BIFs elsewhere at some point in their history. The observation that at least some of the hematite in unmineralized BIF did not form directly from ferric oxyhydroxides implies that hematite is not a reliable proxy for the composition of the precursor sediment or the redox chemistry of the ocean. The oxidation of ferrousrich phases after deposition suggests that the precursor sediments of BIF originally had a more reduced bulk composition. This raises the possibility that, in an ocean with negligible molecular oxygen and elevated Si and Fe, the growth of iron-rich clay minerals was favored over hematite. © 2014 Geological Society of America.

Moses P.S.,Curtin University Australia | Masoum M.A.S.,Curtin University Australia | Toliyat H.A.,Texas A&M University
IEEE Transactions on Energy Conversion | Year: 2011

This paper investigates the stability domain of ferroresonance in asymmetric three-phase three-leg transformers considering magnetic couplings and hysteresis effects of the core. A newly developed and accurate time-domain transformer model capable of simulating dynamic and transient operating conditions is implemented in this study. The model is based on electromagnetic circuit theory and considers dynamic hysteresis effects (major and minor loops) as well as core topology, asymmetry, and magnetic flux cross-coupling interactions of the core legs. Unbalanced switching with series and shunt capacitances, which is known to increase the risk of ferroresonance, is studied with the developed model. The validity of the model under ferroresonant conditions is confirmed by comparisons with extensive experimental data. The main contribution is a new analysis of (a)symmetric three-phase transformer ferroresonance behavior with an accurate core model capable of predicting ferroresonance modes. © 2010 IEEE.

Moses P.S.,Curtin University Australia | Masoum M.A.S.,Curtin University Australia | Toliyat H.A.,Texas A&M University
IEEE Transactions on Energy Conversion | Year: 2010

A new dynamic model of a three-phase three-leg transformer for steady-state and transient operating conditions is proposed in this paper. With very few exceptions, the existing models oversimplify the magnetic interactions in multileg core topologies and employ single-value nonlinear functions for modeling core nonlinearities. Unfortunately, this does not provide sufficient accuracy for a wide range of dynamic disturbances such as dc bias, ferroresonance, and inrush. For this purpose, a new time-domain model based on magnetic-circuit theory is developed to include dynamic-hysteresis behavior (major and minor loops) in asymmetric three-leg core topologies. Furthermore, a new analysis is performed to study the impacts of hysteresis on no-load and transient inrush current behavior in three-phase transformers. Simulation results have been successfully compared with measurements to verify the accuracy of the proposed model. © 2006 IEEE.

Bray I.,Curtin University Australia | Fursa D.V.,Curtin University Australia | Kadyrov A.S.,Curtin University Australia | Stelbovics A.T.,Curtin University Australia | And 2 more authors.
Physics Reports | Year: 2012

The past decade has seen extraordinary theoretical progress in the field of fully kinematically resolved atomic electron-impact ionisation, and its closely related field of double photoionisation. These processes were challenging to calculate due to formal and computational difficulties associated with break-up problems involving the long-range Coulomb potential. Presently, however, these processes can be calculated accurately for simple targets such as atomic hydrogen and helium, irrespective of the kinematics considered or the geometry of detectors. We report on the computational progress, and how it has resulted in a deeper understanding of the formalism of Coulomb few-body problems. © 2012 Elsevier B.V.

Brewer M.L.,Curtin University Australia | Stewart-Wynne E.G.,Royal Perth Hospital
Journal of Interprofessional Care | Year: 2013

Royal Perth Hospital, in partnership with Curtin University, established the first interprofessional student training ward in Australia, based on best practice from Europe. Evaluation of the student and client experience was undertaken. Feedback from all stakeholders was obtained regularly as a key element of the quality improvement process. An interprofessional practice program was established with six beds within a general medical ward. This provided the setting for 2- to 3-week clinical placements for students from medicine, nursing, physiotherapy, occupational therapy, social work, pharmacy, dietetics and medical imaging. Following an initial trial, the training ward began with 79 students completing a placement. An interprofessional capability framework focused on the delivery of high quality client care and effective teamwork underpins this learning experience. Quantitative outcome data showed not only an improvement in students' attitudes towards interprofessional collaboration but also acquisition of a high level of interprofessional practice capabilities. Qualitative outcome data from students and clients was overwhelmingly positive. Suggestions for improvement were identified. This innovative learning environment facilitated the development of the students' knowledge, skills and attitudes required for interprofessional, client centred collaborative practice. Staff reported a high level of compliance with clinical safety and quality. © 2013 Informa UK Ltd.

Fakhoury M.,McGill University | Negrulj R.,Curtin University Australia | Mooranian A.,Curtin University Australia | Al-Salami H.,Curtin University Australia
Journal of Inflammation Research | Year: 2014

Inflammatory bowel disease (IBD) is defined as a chronic intestinal inflammation that results from host-microbial interactions in a genetically susceptible individual. IBDs are a group of autoimmune diseases that are characterized by inflammation of both the small and large intestine, in which elements of the digestive system are attacked by the body's own immune system. This inflammatory condition encompasses two major forms, known as Crohn's disease and ulcerative colitis. Patients affected by these diseases experience abdominal symptoms, including diarrhea, abdominal pain, bloody stools, and vomiting. Moreover, defects in intestinal epithelial barrier function have been observed in a number of patients affected by IBD. In this review, we first describe the types and symptoms of IBD and investigate the role that the epithelial barrier plays in the pathophysiology of IBD as well as the major cytokines involved. We then discuss steps used to diagnose this disease and the treatment options available, and finally provide an overview of the recent research that aims to develop new therapies for such chronic disorders. © 2014 Fakhoury et al.

Yaw L.K.,Royal Perth Hospital | Robinson J.O.,Royal Perth Hospital | Robinson J.O.,Curtin University Australia | Ho K.M.,Royal Perth Hospital | Ho K.M.,University of Western Australia
The Lancet Infectious Diseases | Year: 2014

Background: Findings from previous studies have suggested that outcomes after meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia are worse than after meticillin-sensitive S aureus (MSSA) bacteraemia. We assessed whether patients who had MRSA bacteraemia had a higher risk of death and recurrent infections than those who had MSSA bacteraemia. Methods: For this observational cohort study, we assessed data from the microbiology laboratory database at the Royal Perth Hospital (WA, Australia). Data were for all patients who had an episode of MRSA bacteraemia between July 1, 1997, and June 30, 2007, and, by use of a computer-generated randomisation sequence, a randomly selected subgroup of patients who had an episode of MSSA bacteraemia (patients with one or more set of blood cultures positive for S aureus). The primary outcomes were survival time and subsequent infection-related hospital readmissions, analysed by Cox proportional hazards regression with adjustment for important prognostic factors. Findings: Of the 583 patients who had an episode of MRSA or MSSA bacteraemia, we used data for the 582 who had complete data linkage: 185 patients who had MRSA bacteraemia and 397 patients who had MSSA bacteraemia. The crude survival time of patients after MRSA bacteraemia was shorter than it was for patients with MSSA bacteraemia (14 months [IQR 1-86] vs 54 months [3-105]; hazard ratio 1·46, 95% CI 1·18-1·79; p=0·01). The adverse association between MRSA and all-cause mortality (0·98, 0·77-1·30; p=0·87) or infection-related mortality (1·22, 0·89-1·69; p=0·22) were not statistically significant after adjustment for important prognostic factors including age, comorbidities, severity of acute illness, metastatic infections, and long-term care facility resident status. After adjustment for these confounding factors, we saw no difference in infection-related hospital readmissions between patients who had MRSA bacteraemia and those who had MSSA bacteraemia (odds ratio 0·95, 95% CI 0·59-1·53; p=0·83). Interpretation: Long-term outcomes after MRSA bacteraemia were worse than those after MSSA bacteraemia through its confounding associations with other prognostic factors. Our findings might have implications for management strategies to control MRSA colonisation. Funding: The Medical Research Foundation of Royal Perth Hospital. © 2014 Elsevier Ltd.

Erbe C.,Curtin University Australia | MacGillivray A.,JASCO Applied science | Williams R.,University of St. Andrews
Journal of the Acoustical Society of America | Year: 2012

Including ocean noise in marine spatial planning requires predictions of noise levels on large spatiotemporal scales. Based on a simple sound transmission model and ship track data (Automatic Identification System, AIS), cumulative underwater acoustic energy from shipping was mapped throughout 2008 in the west Canadian Exclusive Economic Zone, showing high noise levels in critical habitats for endangered resident killer whales, exceeding limits of good conservation status under the EU Marine Strategy Framework Directive. Error analysis proved that rough calculations of noise occurrence and propagation can form a basis for management processes, because spending resources on unnecessary detail is wasteful and delays remedial action. © 2012 Acoustical Society of America.

Swartz D.A.,NASA | Soria R.,Curtin University Australia | Tennant A.F.,NASA | Yukita M.,University of Alabama
Astrophysical Journal | Year: 2011

One hundred seven ultraluminous X-ray sources (ULXs) with 0.3-10.0keV luminosities in excess of 1039ergs-1 are identified in a complete sample of 127 nearby galaxies. The sample includes all galaxies within 14.5Mpc above the completeness limits of both the Uppsala Galaxy Catalogue and the Infrared Astronomical Satellite survey. The galaxy sample spans all Hubble types, a four-decade range in mass, 7.5 < log (M/M·) < 11.4, and in star formation rate, 0.0002 < SFR(M· yr -1) ≤ 3.6. ULXs are detected in this sample at rates of one per 3.2 × 1010 M·, one per 0.5 M ·yr-1 star formation rate, and one per 57Mpc 3 corresponding to a luminosity density of 2 × 10 37ergs-1Mpc-3. At these rates we estimate as many as 19 additional ULXs remain undetected in fainter dwarf galaxies within the survey volume. An estimated 14 objects, or 13%, of the 107 ULX candidates are expected to be background sources. The differential ULX luminosity function shows a power-law slope α -0.8 to -2.0 with an exponential cutoff at 20 × 1039ergs-1 with precise values depending on the model and on whether the ULX luminosities are estimated from their observed numbers of counts or, for a subset of candidates, from their spectral shapes. Extrapolating the observed luminosity function predicts at most one very luminous ULX, LX 1041ergs-1, within a distance as small as 100Mpc. The luminosity distribution of ULXs within the local universe cannot account for the recent claims of luminosities in excess of 2 × 1041ergs-1, requiring a new population class to explain these extreme objects. © 2011 The American Astronomical Society. All rights reserved.

Long J.A.,Natural History Museum of Los Angeles County | Trinajstic K.,Curtin University Australia | Trinajstic K.,Perth Cultural Center
Annual Review of Earth and Planetary Sciences | Year: 2010

The Gogo Formation of Western Australia preserves a unique Late Devonian (Frasnian) reef fauna. The exceptional three-dimensional preservation of macrofossils combined with unprecedented soft-tissue preservation (including muscle bundles, nerve cells, and umbilical structures) has yielded a particularly rich assemblage with almost 50 species of fishes described. The most significant discoveries have contributed to resolving placoderm phylogeny and elucidating their reproductive physiology. Specifically, these discoveries have produced data on the oldest known vertebrate embryos; the anatomy of the primitive actinopterygian neurocranium and phylogeny of the earliest actinopterygians; the histology, radiation, and plasticity of dipnoan (lungfish) dental and cranial structures; the anatomy and functional morphology of the extinct onychodonts; and the anatomy of the primitive tetrapodomorph head and pectoral fin. Copyright © 2010 by Annual Reviews. All rights reserved.

Pearce W.M.,James Cook University | Williams C.,Curtin University Australia
International Journal of Speech-Language Pathology | Year: 2013

Speech-language pathologists experience uncertainty about how to interpret standardized assessment results for Indigenous Australian children. There are risks for inappropriate diagnosis: both over- and under-diagnosis of language impairment may occur due to a convergence of linguistic features which causes difficulty in distinguishing between impairment and difference. While the literature suggests that standardized assessments are inappropriate for Indigenous Australian children, there is an absence of empirical documentation to show how Indigenous children perform on standardized tests of language ability. This study examined the performance of 19 Indigenous Australian children, aged 8;01-13;08, from one school on the Clinical Evaluation of Language Fundamentals, Fourth Edition, Australian Standardized Edition. Standardized scores were compared with teacher ratings of children's oral language skills. Analysis showed poor alignment between teacher ratings and language assessment, and assessment scores were negatively influenced by features of Aboriginal English. Children rated with above average language skills presented with different linguistic profiles from the children rated with average and below average language abilities. The inappropriateness of current standardized language assessments for Indigenous children and the need for further research to guide appropriate assessment are discussed. © 2013 The Speech Pathology Association of Australia Limited.

Dhami N.K.,Thapar University | Sudhakara Reddy M.,Thapar University | Mukherjee A.,Curtin University Australia
Frontiers in Microbiology | Year: 2014

Since ages, architects and artists worldwide have focused on usage of durable stones as marble and limestone for construction of beautiful and magnificent historic monuments as European Cathedrals, Roman, and Greek temples, Taj Mahal etc. But survival of these irreplaceable cultural and historical assets is in question these days due to their degradation and deterioration caused by number of biotic and abiotic factors. These causative agents have affected not only the esthetic appearance of these structures, but also lead to deterioration of their strength and durability. The present review emphasizes about different causative agents leading to deterioration and application of microbially induced calcium carbonate precipitation as a novel and potential technology for dealing with these problems. The study also sheds light on benefits of microbial carbonate binders over the traditional agents and future directions. © 2014 Dhami, Reddy and Mukherjee.

Norman M.D.,Lunar and Planetary Institute | Norman M.D.,Australian National University | Nemchin A.A.,Curtin University Australia
Earth and Planetary Science Letters | Year: 2014

A sharp rise in the flux of asteroid-size bodies traversing the inner Solar System at 3.9 Ga has become a central tenet of recent models describing planetary dynamics and the potential habitability of early terrestrial environments. The prevalence of ~3.9Ga crystallization ages for lunar impact-melt breccias and U-Pb isotopic compositions of lunar crustal rocks provide the primary evidence for a short-lived, cataclysmic episode of late heavy bombardment at that time. Here we report U-Pb isotopic compositions of zirconolite and apatite in coarse-grained lunar melt rock 67955, measured by ion microprobe, that date a basin-scale impact melting event on the Moon at 4.22 ± 0.01Ga followed by entrainment within lower grade ejecta from a younger basin approximately 300 million yr later. Significant impacts prior to 3.9 Ga are also recorded by lunar zircons although the magnitudes of those events are difficult to establish. Other isotopic evidence such as 40Ar-39Ar ages of granulitic lunar breccias, regolith fragments, and clasts extracted from fragmental breccias, and Re-Os isotopic compositions of lunar metal is also suggestive of impact-related thermal events in the lunar crust during the period 4.1-4.3 Ga. We conclude that numerous large impactors hit the Moon prior to the canonical 3.9 Ga cataclysm, that some of those pre-cataclysm impacts were similar in size to the younger lunar basins, and that the oldest preserved lunar basins are likely to be significantly older than 3.9 Ga. This provides sample-based support for dynamical models capable of producing older basins on the Moon and discrete populations of impactors. An extended period of basin formation implies a less intense cataclysm at 3.9 Ga, and therefore a better opportunity for preservation of early habitable niches and Hadean crust on the Earth. A diminished cataclysm at 3.9 Ga suggests that the similarity in the age of the oldest terrestrial continental crust with the canonical lunar cataclysm is likely to be coincidental with no genetic significance. © 2013 Elsevier B.V.

Singh Z.,Curtin University Australia | Singh R.K.,CSIR - Central Electrochemical Research Institute | Sane V.A.,CSIR - Central Electrochemical Research Institute | Nath P.,CSIR - Central Electrochemical Research Institute
Critical Reviews in Plant Sciences | Year: 2013

Mango is one of the choicest fruits in the world and popular due to its delicate taste, pleasant aroma and nutritional value. Mango is indigenous to north-east India and north Burma, but now grown in over 90 countries. In the past two decades, mango production has increased appreciably with international trade jumping approximately four-fold valued close to US$ 950 million. Mango belongs to the category of climacteric fruits and its ripening is initiated and proceeded by a burst in ethylene production and a dramatic rise in the rate of respiration. Although there are a few hundred mango cultivars grown in the Indian subcontinent and other parts of the world, the most popular cultivars are generally highly perishable and ripen within 7 to 9 days of harvest at ambient temperature. Currently, the export potential and international trade of mango is limited due to several factors such as its perishable nature, disease and pest infestation, and susceptibility of certain premium cultivars to chilling injury when stored at low temperatures. Efforts are ongoing to develop technologies for improved storage and packaging, and overcome limitations encountered during storage and transit. Controlled atmosphere (CA) and hypobaric storage of mango are powerful means to overcome its perishable nature. The composition of CA varies among cultivars to ensure its original taste, flavor and aroma. Edible coating on the fruit skin may further cut down the rate of deterioration. Recently, significant advances have been made in understanding ripening characteristics of mango at the molecular level. Candidate genes related to ethylene biosynthesis and signalling, cell wall modification, aroma production and stress response have been cloned and characterized for future use in mango improvement. Efforts are also being made to establish a suitable transformation and plant regeneration system so that transgenic mango with added value and increased shelf life for long distance transportation could be developed. © 2013 Copyright Taylor and Francis Group, LLC.

Bauer I.,James Cook University | Bauer I.,Curtin University Australia
Travel Medicine and Infectious Disease | Year: 2012

Financially comfortable, with ample spare time and much better health, older people travel more than ever and to more adventurous destinations. Taking Australian senior adventure travellers to Peru as an example, travel health preparations need to take into account the phenomenon 'senior traveller', the destination with its attractions and challenges, and age-related changes and restrictions. The need for routine travel health advice, vaccinations and prophylaxis remains unchanged. However, more emphasis should be placed on locality-specific issues so that age-appropriate advice and preparations maximize the chances for a safe and memorable travel experience.

Sharma S.,Thapar University | Mukherjee A.,Curtin University Australia
Cement and Concrete Composites | Year: 2015

Durability and strength of mature concrete can be judged a great deal from its properties when it is freshly poured. This paper demonstrates an ultrasonic in-situ monitoring technique for freshly poured concrete. The solidification and curing of freshly poured concrete is monitored through the propagation of ultrasonic waves in waveguides such as steel reinforcing bars. As concrete solidifies and cures, more wave energy escapes into the surrounding concrete resulting in signal attenuation. RC beam specimens are monitored with carefully selected ultrasonic signal patterns during the first 24 h of setting of concrete. Destructive tests such as bar pull out and compressive strength are also performed at different stages of setting of concrete. The ultrasonic signals have been calibrated for determination of early age concrete properties. © 2014 Elsevier Ltd.

Sharma S.,Thapar University | Mukherjee A.,Curtin University Australia
Structural Control and Health Monitoring | Year: 2015

This paper reports a non-contact, in-situ and non-destructive corrosion monitoring methodology for submerged plates using ultrasonic guided waves. Specific surface sensitive and core sensitive guided wave modes are utilized for monitoring plates undergoing accelerated impressed current corrosion in the presence of chlorides. A combination of the selected guided wave modes could effectively discern various corrosion mechanisms occurring in plates. Along with the ultrasonic signals, mass loss, stress-strain behaviour and tensile strength of the plates at different stages of corrosion have been monitored. Algebraic relationships between the ultrasonic readings and other parameters have been developed. This investigation should be useful in developing a non-destructive technique for monitoring progressive corrosion in plates and assessing their deterioration in strength, stiffness and mass loss that would help in the estimation of residual life. Copyright © 2014 John Wiley & Sons, Ltd.

Tang J.,Japan National Institute of Materials Science | Tang J.,Waseda University | Liu J.,Curtin University Australia | Torad N.L.,Japan National Institute of Materials Science | And 4 more authors.
Nano Today | Year: 2014

The ideal catalyst support toward development of high-performance electrodes for fuel cells should possess advantageous structural and chemical features concerning accessibility to framework surfaces and electrochemical stability of conducting frameworks. In order to satisfy these requirements for the design of fuel cells by using nanoporous carbon electrodes, a great deal of efforts has been devoted to the functionalization of nanoporous carbon electrodes. In this review, the recent developments of nanoporous carbon materials synthesis are summarized with introduction of their potentials in fuel cells. The focuses are placed on precise controls of porosity, crystallinity, and morphology, combined with the designs of surface structure, framework composition, and encapsulation of metal and metal oxide nanoparticles. Finally, some perspectives are provided for future developments and directions of the synthesis and functionalization of nanoporous carbon materials for fuel cell design. © 2014 Elsevier Ltd.

Konovalov D.A.,James Cook University | Bray I.,Curtin University Australia
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The J-matrix approach to electron-atom scattering is applied to ionization processes. We consider the Temkin-Poet model of e-H ionization. Convergence issues are studied with greater detail than previously possible using other close-coupling methods. The numerical strengths of the technique are emphasized with the long-term goal of application to ionization-plus-excitation processes. © 2010 The American Physical Society.

Bauer I.L.,James Cook University | Bauer I.L.,Curtin University Australia
Travel Medicine and Infectious Disease | Year: 2014

Background Love, sex and the female traveller: romance tourism or female sex tourism? The phenomenon of women travelling in search of relationships with local men in developing countries has been studied for the last 20 years. However, it appears little known in travel medicine. Methods Relevant literature was found through PubMed, Science Direct, ProQuest and Google Scholar. The reference lists of selected articles identified further sources. Results Historical records of women travellers to far-away countries abound. Then, as now, women not only searched for the erotic 'other' but made romance and sex the purpose of their trip. Today, increasing numbers of women travel to destinations in developing countries where sex with local men is the main attraction. This pastime raises concerns not only for the women themselves but for the local men involved as well as their sex partners and the local communities. Conclusions Although more research is necessary, comparing the criteria that describe men travelling for sex and relationships and women travelling for sex and relationships appears to suggest that there is very little difference between the two, regardless of what the pursuit is called. Women looking for sex with local men are sex tourists, too. Recognition of this fact needs to influence the pre and post travel care of female travellers. © 2013 Published by Elsevier Ltd.

Kalaugher E.,University of Waikato | Bornman J.F.,Curtin University Australia | Clark A.,DairyNZ | Beukes P.,DairyNZ
Environmental Modelling and Software | Year: 2013

The development of effective climate change adaptation strategies for complex, adaptive socio-ecological systems such as farming systems, requires an in-depth understanding of both the dynamic nature of the systems themselves and the changing environment in which they operate.To date, adaptation studies in the New Zealand dairy sector have been either bottom-up, qualitative social research with farmers and communities, or top-down, quantitative biophysical modelling. Each of these approaches has clear benefits as well as significant limitations. This review considers concepts and approaches that support the potential for different disciplines to complement each other in developing a more in-depth understanding of farming systems and their adaptive potential. For this purpose, a Mixed Methods Framework is presented, using examples from a pilot study of a New Zealand dairy farm to illustrate the complementarities between the two current approaches.By presenting this methodology in a specific context, the review provides the theoretical basis for a practical way to integrate quantitative and qualitative research for climate change adaptation research. © 2012 Elsevier Ltd.

Yu X.,RMIT University | Cecati C.,University of L'Aquila | Dillon T.,Curtin University Australia | Simes M.G.,Colorado School of Mines
IEEE Industrial Electronics Magazine | Year: 2011

The power grid is a massive interconnected network used to deliver electricity from suppliers to consumers and has been a vital energy supply. To minimize the impact of climate change while at the same time maintaining social prosperity, smart energy must be embraced to ensure a balanced economical growth and environmental sustainability. Therefore, in the last few years, the new concept of a smart grid (SG) became a critical enabler in the contemporary world and has attracted increasing attention of policy makers and engineers. This article introduces the main concepts and technological challenges of SGs and presents the authors views on some required challenges and opportunities presented to the IEEE Industrial Electronics Society (IES) in this new and exciting frontier. © 2011 IEEE.

Sang H.M.,Curtin University Australia | Fotedar R.,Curtin University Australia | Filer K.,Pacific Biosciences
Aquaculture Nutrition | Year: 2011

The aim of this experiment was to determine the effects of dietary supplementation of Bio-Mos® as a source of mannan oligosaccharide (MOS) on the growth, survival, immunity and digestive enzyme activity of freshwater crayfish, Cherax destructor (yabby). A basal diet and another diet with 0.4% of Bio-Mos® supplemented to the basal diet were formulated. Each diet was provided to eight yabbies (35.14±0.48g, initial weight) replicated 3 times in individual 250-L plastic cylindrical tanks for a duration of 56days. Each tank was provided with an independent recirculating water system filtered with a biological filtration. Growth parameters such as weight, specific growth rate and average weekly gain of Bio-Mos®-fed yabbies were higher (P<0.05) than yabbies fed the control diet. Total haemocyte count, granular cells and semi-granular cells were also higher in the yabbies fed Bio-Mos® diet. Protease activity was higher in hepatopancreas, and amylase activity was higher in the guts of yabbies fed Bio-Mos® diet. The results implies that supplementation of MOS through Bio-Mos® can effectively improve growth and immunological condition of yabbies. © 2010 Blackwell Publishing Ltd.

White R.W.,University of Mainz | Powell R.,University of Melbourne | Holland T.J.B.,University of Cambridge | Johnson T.E.,University of Mainz | And 2 more authors.
Journal of Metamorphic Geology | Year: 2014

New activity-composition (a-x) relations for minerals commonly occurring in metapelites are presented for use with the internally consistent thermodynamic dataset of Holland & Powell (, Journal of Metamorphic Geology, 29, 333-383). The a-x relations include a broader consideration of Fe2O3 in minerals, changes to the formalism of several phases and order-disorder in all ferromagnesian minerals where Fe-Mg mixing occurs on multiple sites. The a-x relations for chlorite, biotite, garnet, chloritoid, staurolite, cordierite, orthopyroxene, muscovite, paragonite and margarite have been substantially reparameterized using the approach outlined in the companion paper in this issue. For the first time, the entire set of a-x relations for the common ferromagnesian minerals in metapelitic rocks is parameterized simultaneously, with attention paid to ensuring that they can be used together to calculate phase diagrams of geologically appropriate topology. The a-x relations developed are for use in the Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-O2 (NCKFMASHTO) system for both subsolidus and suprasolidus conditions. Petrogenetic grids in KFMASH and KFMASHTO are similar in topology to those produced with earlier end-member datasets and a-x relations, but with some notable differences. In particular, in subsolidus equilibria, the FeO/(FeO + MgO) of garnet is now greater than in coexisting staurolite, bringing a number of key staurolite-bearing equilibria into better agreement with inferences from field and petrographic observations. Furthermore, the addition of Fe3+ and Ti to a number of silicate phases allows more plausible equilibria to be calculated in relevant systems. Pseudosections calculated with the new a-x relations are also topologically similar to equivalent diagrams using earlier a-x relations, although with many low variance fields shifting in P-T space to somewhat lower pressure conditions. © 2013 John Wiley & Sons Ltd.

Lim F.P.L.,Curtin University Australia | Dolzhenko A.V.,Curtin University Australia | Dolzhenko A.V.,University of Selangor
European Journal of Medicinal Chemistry | Year: 2014

Purines can be considered as the most ubiquitous and functional N-heterocyclic compounds in nature. Structural modifications of natural purines, particularly using isosteric ring systems, have been in the focus of many drug discovery programs. Fusion of 1,3,5-triazine ring with pyrrole, pyrazole, imidazole, 1,2,3-triazole or 1,2,4-triazole results in seven bicyclic heterocyclic systems isosteric to purine. Application of the isosterism concept for the development of new compounds with therapeutic potential in areas involving purinergic regulation or purine metabolism led to significant advances in medicinal chemistry of the azolo[1,3,5]triazines. These 1,3,5-triazine-based purine-like scaffolds significantly increase level of molecular diversity and allow covering chemical space in the important areas of medicinal chemistry. Some of these azolo[1,3,5]triazine systems have become privileged scaffolds in the development of inhibitors of various kinases, phosphodiesterase, xanthine oxidase, and thymidine phosphorylase, antagonists of adenosine and corticotropin-releasing hormone receptors, anticancer and antiviral agents. © 2014 Elsevier Masson SAS.

Hirt C.,Curtin University Australia | Kuhn M.,Curtin University Australia | Featherstone W.E.,Curtin University Australia | Gtotl F.,Deutsches Geodtisches Forschungsinstitut
Journal of Geophysical Research: Solid Earth | Year: 2012

We use gravity implied by the Earth's rock-equivalent topography (RET) and modeled isostatic compensation masses to evaluate the new global gravity field models (GGMs) from European Space Agency (ESA)'s Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) satellite gravimetry mission. The topography is now reasonably well-known over most of the Earth's landmasses, and also where conventional GGM evaluation is prohibitive due to the lack (or unavailability) of ground-truth gravity data. We construct a spherical harmonic representation of Earth's RET to derive band-limited topography-implied gravity, and test the somewhat simplistic Airy/Heiskanen and Pratt/Hayford hypotheses of isostatic compensation, but which did not improve the agreement between gravity from the uncompensated RET and GOCE. The third-generation GOCE GGMs (based on 12 months of space gravimetry) resolve the Earth's gravity field effectively up to spherical harmonic degree ∼200-220 (∼90-100 km resolution). Such scales could not be resolved from satellites before GOCE. From the three different GOCE processing philosophies currently in use by ESA, the time-wise and direct approaches exhibit the highest sensitivity to short-scale gravity recovery, being better than the space-wise approach. Our topography-implied gravity comparisons bring evidence of improvements from GOCE to gravity field knowledge over the Himalayas, Africa, the Andes, Papua New Guinea and Antarctic regions. In attenuated form, GOCE captures topography-implied gravity signals up to degree ∼250 (∼80 km resolution), suggesting that other signals (originating, e.g., from the crust-mantle boundary and buried loads) are captured as well, which might now improve our knowledge on the Earth's lithosphere structure at previously unresolved spatial scales. Copyright 2012 by the American Geophysical Union.

El-Mowafy A.,Curtin University Australia | Hu C.,Tongji University
Journal of Applied Geodesy | Year: 2014

This study presents validation of BeiDou measurements in un-differenced standalone mode and experimental results of its application for real data. A reparameterized form of the unknowns in a geometry-free observation model was used. Observations from each satellite are independently screened using a local modeling approach. Main advantages include that there is no need for computation of inter-system biases and no satellite navigation information are needed. Validation of the triple-frequency BeiDou data was performed in static and kinematic modes, the former at two continuously operating reference stations in Australia using data that span two consecutive days and the later in a walking mode for three hours. The use of the validation method parameters for numerical and graphical diagnostics of the multi-frequency BeiDou observations are discussed. The precision of the system's observations was estimated using an empirical method that utilizes the characteristics of the validation statistics. The capability of the proposed method is demonstrated in detection and identification of artificial errors inserted in the static BeiDou data and when implemented in a single point positioning processing of the kinematic test. © 2014 by Walter de Gruyter Berlin/Boston.

Jiang X.-D.,Ocean University of China | Li Z.-X.,Curtin University Australia
Nature Communications | Year: 2014

The spectacular topography of the Tibetan Plateau is the result of collision between India and Eurasia over some 50Myr, but how the plateau grew to its present size remains a topic of debate. Work along its eastern margin suggests a two-stage uplift (thus growth of the plateau) since 30-25Myr. Here we report high-resolution seismic reflection and drill core results from the southern Tarim Basin that indicate a similar pattern for the northern margin of the plateau. The data suggest that uplift in northern Tibet started at ∼23Myr from near sea level, with the first episode finished by ∼10Myr, followed by a post-5-Myr episode of rapid uplift along the present plateau margin. The growth of the Tibetan Plateau after the Eocene thus appears to have been episodic in nature, and near-synchronous along both eastern and northern margins. © 2014 Macmillan Publishers Limited. All rights reserved.

Migliari S.,University of Barcelona | Miller-Jones J.C.A.,Curtin University Australia | Russell D.M.,University of Amsterdam
Monthly Notices of the Royal Astronomical Society | Year: 2011

We investigate the role of the compact object in the production of jets from neutron star X-ray binaries. The goal is to quantify the effect of the neutron star spin, if any, in powering the jet. We compile all the available measures or estimates of the neutron star spin frequency in jet-detected neutron star X-ray binaries. We use as an estimate of the ranking jet power for each source the normalization of the power law which fits the X-ray/radio and X-ray/infrared luminosity correlations Lradio/IR∝LΓ X (using infrared data for which there is evidence for jet emission). We find a possible relation between spin frequency and jet power (Spearman rank 97 per cent), when fitting the X-ray/radio luminosity correlation using a power law with slope 1.4; Γ= 1.4 is observed in 4U 1728-34 and is predicted for a radiatively efficient disc and a total jet power proportional to the mass accretion rate. If we use a slope of 0.6, as observed in Aql X-1, no significant relation is found. An indication for a similar positive correlation is also found for accreting millisecond X-ray pulsars (Spearman rank 92 per cent), if we fit the X-ray/infrared luminosity correlation using a power law with slope 1.4. While our use of the normalization of the luminosity correlations as a measure of the ranking jet power is subject to large uncertainties, no better proxy for the jet power is available. However, we urge caution in over-interpreting the spin-jet power correlations, particularly given the strong dependence of our result on the (highly uncertain) assumed power-law index of the luminosity correlations (which span less than 3 orders of magnitude in X-ray luminosity). We discuss the results in the framework of current models for jet formation in black holes and young stellar objects and speculate on possible different jet production mechanisms for neutron stars depending on the accretion mode. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.

Saxton C.J.,University College London | Soria R.,Curtin University Australia | Wu K.,University College London | Kuin N.P.M.,University College London
Monthly Notices of the Royal Astronomical Society | Year: 2012

We studied the X-ray timing and spectral variability of the X-ray source Sw J1644+57, a candidate for a tidal disruption event. We have separated the long-term trend (an initial decline followed by a plateau) from the short-term dips in the Swift light curve. Power spectra and Lomb-Scargle periodograms hint at possible periodic modulation. By using structure function analysis, we have shown that the dips were not random but occurred preferentially at time intervals ≈(2.3, 4.5, 9) × 10 5s and their higher order multiples. After the plateau epoch, dipping resumed at ≈(0.7, 1.4) × 10 6 s and their multiples. We have also found that the X-ray spectrum became much softer during each of the early dips, while the spectrum outside the dips became mildly harder in its long-term evolution. We propose that the jet in the system undergoes precession and nutation, which causes the collimated core of the jet briefly to go out of our line of sight. The combined effects of precession and nutation provide a natural explanation for the peculiar patterns of the dips. We interpret the slow hardening of the baseline flux as a transition from an extended, optically thin emission region to a compact, more opaque emission core at the base of the jet. © 2012 The Author Monthly Notices of the Royal Astronomical Society © 2012 RAS.

Fisher I.,Watervale Systems Pty Ltd | Kastl G.,Level Inc | Sathasivan A.,Curtin University Australia
Water Research | Year: 2012

Maintaining a chlorine residual is a major disinfection goal in many water distribution systems. A suitable general model of chlorine decay in the transported bulk water is an essential component for efficiently modelling chlorine concentration in distribution systems. The two-reactant model meets basic suitability criteria, including accurate prediction of chlorine residual over hundreds of hours, commencing with chlorine concentration 0-4 mg/L. This model was augmented with an equation that increases the decay coefficients with temperature according to Arrhenius theory. The augmented model was calibrated against decay-test data sets to obtain a single invariant set of parameters for each water. Model estimates of chlorine residuals over time closely matched decay-test data, over the usual operating ranges of initial chlorine concentration (1-4 mg/L) and temperature (3.5-28 °C). When the augmented model was fitted to partial data sets, it also predicted the data reserved for validation very well, suggesting that this model can accurately predict the combined effect of initial chlorine concentration and temperature on chlorine bulk decay in distribution systems, using a single set of invariant parameters for a given source water. © 2012 Elsevier Ltd.

Wang S.,Nanyang Technological University | Jiang S.P.,Curtin University Australia | Wang X.,Nanyang Technological University | Guo J.,Nanyang Technological University
Electrochimica Acta | Year: 2011

In this work, Pt nanowire networks supported on high surface area carbon (Pt NWNs/C) are synthesized as electrocatalysts for direct methanol fuel cells (DMFCs). The electrocatalytic behavior of Pt NWNs/C catalysts for the methanol and adlayer CO oxidation reactions is investigated and the results are compared with the Pt nanoparticles (NPs) supported on carbon (Pt NPs/C). The results indicate that Pt NWNs are characterized by interconnected nanoparticles with large number of grain boundaries, downshifted d-band center and reduced oxophilicity, which results in the enhanced surface mobility of oxygen-containing species such as COads and OHads. The enhanced surface mobility of COads and OHads in turn facilitates the removal of intermediate CO species during the methanol oxidation. The activity of the Pt NWNs/C electrocatalyst for the methanol oxidation reaction and electrooxidation of adsorbed CO is also evaluated by cyclic voltammetry, CO stripping, and kinetic analysis. The results show that Pt NWNs/C catalysts have a significantly higher electrocatalytic activity for the methanol oxidation reaction as compared to Pt NPs/C catalysts. The enhanced electrocatalytic activity of Pt NWNs/C catalysts is mainly due to the existence of large number of the grain boundaries of the interconnected nanoparticles of the unique Pt NWN structure. © 2010 Elsevier Ltd. All rights reserved.

Wang S.,Nanyang Technological University | Jiang S.P.,Curtin University Australia | Wang X.,Nanyang Technological University
Electrochimica Acta | Year: 2011

An effective synthesis strategy of hybrid metal (PtRu)/metal oxide (SnO2) nanoparticles on graphene nanocomposites is developed using a microwave-assisted one-pot reaction process. The mixture of ethylene glycol (EG) and water is used as both solvent and reactant. In the reaction system for the synthesis of SnO2/graphene nanocomposite, EG not only reduces graphene oxide (GO) to graphene, but also results in the formation of SnO 2 facilitated by the presence of a small amount of water. On the other hand, in the reaction system for preparation of PtRu/graphene nanocomposites, EG acts as solvent and reducing agent for reduction of PtRu nanoparticles from their precursors and reduction of graphene from graphene oxide. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) characterizations confirm the feasibility of the microwave-assisted reaction system to simultaneously reduce graphene oxide and to form SnO2 or PtRu nanoparticles. The as-synthesized SnO2/graphene hybrid composites show a much higher supercapacitance than the pure graphene, and the as-prepared PtRu/graphene show much better electrocatalytic activity for methanol oxidation compared to the commercial E-TEK PtRu/C electrocatalysts. © 2011 Elsevier Ltd. All rights reserved.

Mullins B.J.,Griffith University | Mullins B.J.,Curtin University Australia | Braddock R.D.,Griffith University
International Journal of Heat and Mass Transfer | Year: 2012

The modified Washburn equation has been further developed in this work, to examine capillary rise in porous media which are being immersed in liquid at a continuous rate. The capillary rise rate and/or properties of the media can be determined by a series of differential equations which govern the processes. The model was applied to oleophillic and oleophobic porous, fibrous media with generally good results, however it was found that the model needed to be fitted separately to the initial rise phase and to the longer-term (near-constant slope) phase. It was also found that a good agreement between the theory and experiment could be found if the porous media was contained inside a glass tube so that inflow could only occur from below and not from the sides of the filter. In order to model the insertion of media without this tube, a combination of a horizontal and a vertical capillary model was needed. The model could not be easily fitted to very thin, oleophillic media, and reasons for this are discussed; one likely reason being the inflow of liquid from the sides of the media. However, good agreement between the model and experiment could be found for equivalent media with an oleophobic coating and the same oil. © 2012 Elsevier Ltd. All rights reserved.

Richards R.G.,Griffith University | Mullins B.J.,Curtin University Australia | Mullins B.J.,Griffith University
Ecological Modelling | Year: 2013

The remediation of leachate from (municipal) landfills and disposal of hypersaline effluent (from desalination plants) are becoming an increasing challenge for many government authorities and practitionersThere is mounting interest in using bioremediation as a means of stripping contaminants from these waste streams and in the potential for lipid production using microalgaeWe present a system dynamics approach to exploring the efficacy of using mixed microalgae populations to treat leachate-hypersaline waterThis model evaluates the temporal evolution of metal removal and lipid production using four common marine microalgae species: Nanochloropsis, Pavlova lutheri, Tetraselmis chuii and Chaetoceros muelleriThe uptake kinetics of the metals (removal from the leachate) are modelled using basic adsorption kinetics and the model is primarily parameterised from data obtained through an experimental study where two photobioreactors were dosed with composite leachate-hypersaline solution and seeded with the four microalgae speciesAfter a 10-day period, the microalgae population was found to have removed over 95% of the metals from the solutionMicroalgae growth was dominated by Nanochloropsis gaditana and Cmuelleri, which are the two species with the highest lipid contentsOverall, this study indicated that the use of microalgae-based bioremediation is a viable method for treating waste streams and lipid-production. © 2012 Elsevier B.V.

Zeng J.,Curtin University Australia | Zeng J.,Nanyang Technological University | Jiang S.P.,Curtin University Australia
Journal of Physical Chemistry C | Year: 2011

The synthesis and characteristics of high-temperature proton-exchange membranes based on mesoporous silica nanocomposite functionalized with phosphotungstic acid (HPW) were investigated in detail for applications in protonexchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). The HPW-meso-silica nanocomposites were characterized by small-angle X-ray scattering (SAXS), FTIR spectroscopy, Raman spectroscopy, TGA, N 2 absorption isotherm, water uptake, TEM, conductivity, and fuel cell performance. The spectroscopy results indicate interactions between the Keggin anions of HPW and meso-silica and the possible formation of (≡SiOH 2 +)(H2PW12O40 -) species. The results show that the proton conductivity of the HPW-mesosilica nanocomposites depends strongly on the content of HPW. The threshold for the proton conductivity of the nanocomposite is ∼10 wt %. The best proton conductivity is 0.07 S cm-1 at 25 °C under 100% relative humidity (RH) with an activation energy of ∼14 kJ mol-1, obtained on HPW-meso-silica nanocomposites with 67-83% HPW. A PEMFC based on a HPW-meso-silica membrane produced a power output of 308 mW cm-1 at 80 °C and 80% RH in H2/O2, 206 mW cm-2 at 80 °C and 80% RH in H2/air, and 134 mW cm-2 at 160 °C in methanol/air without external humidification. The high tolerance of HPW-meso-silica nanocomposites toward RH fluctuations demonstrates the unique high water retention capability of HPW-meso-silica nanocomposites. The results indicate that HPW-meso-silica forms a promising proton-exchange membrane for PEMFCs and DMFCs operating at high temperatures. © 2011 American Chemical Society.

Khandaker M.R.A.,University College London | Rong Y.,Curtin University Australia
IEEE Transactions on Wireless Communications | Year: 2014

In this paper, we consider a multicasting multiple-input multiple-output (MIMO) relay system where multiple transmitters multicast their own messages to a group of receivers over multiple hops, and all nodes are equipped with multiple antennas. The joint transmit and relay precoding design problem has been investigated for multicasting multiple data streams based on min-max mean-squared error (MSE) criterion. We aim at minimizing the maximal MSE of the signal waveform estimation among all receivers subjecting to power constraints at the transmitters and all the relay nodes. This problem is highly nonconvex with matrix variables and the exactly optimal solution is very hard to obtain. We develop an iterative algorithm to jointly optimize the transmitter, relay, and receiver matrices by solving convex subproblems. By exploiting the optimal structure of the relay precoding matrices, we then propose a low complexity solution for the problem under some mild approximation. In particular, we show that under (moderately) high signal-to-noise ratio assumption, the min-max optimization problem can be solved using the semidefinite programming technique. Numerical simulations demonstrate the effectiveness of the proposed algorithms. © 2014 IEEE.

Wang S.,Nanyang Technological University | Wang X.,Nanyang Technological University | Jiang S.P.,Curtin University Australia
Physical Chemistry Chemical Physics | Year: 2011

Pt and Au nanoparticles with controlled Pt :Au molar ratios and PtAu nanoparticle loadings were successfully self-assembled onto poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene (PDDA-G) as highly effective electrocatalysts for formic acid oxidation in direct formic acid fuel cells (DFAFCs). The simultaneously assembled Pt and Au nanoparticles on PDDA-G showed superb electrocatalytic activity for HCOOH oxidation, and the current density associated with the preferred dehydrogenation pathway for the direct formation of CO2 through HCOOH oxidation on a Pt1Au8/PDDA-G (i.e., a Pt :Au ratio of 1 : 8) is 32 times higher than on monometallic Pt/PDDA-G. The main function of the Au in the mixed Pt and Au nanoparticles on PDDA-G is to facilitate the first electron transfer from HCOOH to HCOOads and the effective spillover of HCOOads from Au to Pt nanoparticles, where HCOOads is further oxidized to CO2. The Pt :Au molar ratio and PtAu nanoparticle loading on PDDA-G supports are the two critical factors to achieve excellent electrocatalytic activity of PtAu/PDDA-G catalysts for the HCOOH oxidation reactions. © the Owner Societies 2011.

Standing S.,Edith Cowan University | Standing C.,Edith Cowan University | Love P.E.D.,Curtin University Australia
Decision Support Systems | Year: 2010

Electronic marketplaces are an important research theme on the information systems landscape. In this paper we examine twelve years of research on electronic marketplaces in leading information systems journals. The research articles are classified according to five conceptual high level groupings: electronic markets theory; system perspective with a focus on the technology or functionality with the system; adoption and implementation issues; organisational implications; and broader e-commerce issues. The findings show an increase in electronic marketplace (e-marketplace) research over the twelve years. The analysis of the literature highlights two distinct issues that researchers in the information systems discipline need to address. The first is the lack of research on the fundamental questions on the nature of electronic markets and their efficiency. If information systems research does not address this question then it will not be seen as tackling critical issues by those outside of the discipline. The second is the relative lack of articles on the organisational implications of adopting and managing electronic marketplaces. These include, the organisational benefits, costs and risks of trading through e-marketplaces and strategies and methodologies for managing organisational participation. Both issues can be addressed by increasing the number of macro studies examining efficiencies in electronic markets. © 2009 Elsevier B.V. All rights reserved.

Chan K.Y.,Curtin University Australia | Dillon T.S.,Curtin University Australia | Kwong C.K.,Hong Kong Polytechnic University
Information Sciences | Year: 2011

In this paper, an effective particle swarm optimization (PSO) is proposed for polynomial models for time varying systems. The basic operations of the proposed PSO are similar to those of the classical PSO except that elements of particles represent arithmetic operations and variables of time-varying models. The performance of the proposed PSO is evaluated by polynomial modeling based on various sets of time-invariant and time-varying data. Results of polynomial modeling in time-varying systems show that the proposed PSO outperforms commonly used modeling methods which have been developed for solving dynamic optimization problems including genetic programming (GP) and dynamic GP. An analysis of the diversity of individuals of populations in the proposed PSO and GP reveals why the proposed PSO obtains better results than those obtained by GP. © 2011 Elsevier Inc. All rights reserved.

Mattiussi A.,University of Udine | Rosano M.,Curtin University Australia | Simeoni P.,University of Udine
Decision Support Systems | Year: 2014

A framework for an energy supply decision support system (DSS) for sustainable plant design and production is presented in this paper, utilising an innovative use of multi-objective and multi-attribute decision-making (MODM, MADM) modelling together with impact assessment (IA) of the emission outputs. The mathematical model has been applied within an eco-industrial park (EIP) setting and includes three steps. First, an assessment of the total EIP emissions' inventory and impacts is conducted; the second step, focusing on the sustainability benefits of combined heating and power (CHP) plants and photovoltaic technologies, developed a multi-objective mathematical model including both economic and environmental objectives in a Pareto-frontier optimisation analysis. Four different scenarios involving combinations of CHP plants (internal combustion engine, gas turbine, micro-turbines and fuel cells) and two types of PV plant (monocrystalline and polycrystalline) were evaluated. The third step utilises a MADM methodology - the analytic hierarchy process (AHP) - for selecting the best alternative among the Pareto-frontier efficient solutions. This model has been applied to a case study of an EIP located in Perth (Kwinana Industrial Area - KIA), Western Australia. © 2013 Elsevier B.V.

Cheng A.S.K.,Hong Kong Polytechnic University | Lee H.C.,Curtin University Australia
Transportation Research Part F: Traffic Psychology and Behaviour | Year: 2012

The purposes of this study were to identify the relationships between the risk-taking behavior, response inhibition, and risky motorcycle riding behavior of commuter motorcyclists with different levels of impulsivity, and to examine how these behaviors contribute to motorcycle accidents. A total of 255 Chinese commuter motorcyclists were recruited for this study. Their levels of impulsivity were classified according to the Chinese Barratt Impulsiveness Scale version 11th. Their risk-taking behavior was assessed by the Balloon Analogue Risk Task and their response inhibition was assessed by the Chinese version of the Stroop test Victoria version. The Chinese Motorcycle Rider Driving Violation Scale was used to assess risky motorcycle riding behaviors. Results showed that impulsivity was associated with risk-taking behavior and risky motorcycle riding. Highly impulsive motorcyclists carry out more risk-taking behaviors and are less able to inhibit responses than those with low impulsivity. Motorcyclists with medium impulsivity (OR, 4.74; 95% CI, 1.91-11.39) and those with high impulsivity (OR, 4.91; 95% CI, 2.34-10.24) were about 5 times more likely to be actively involved in motorcycle accidents than those with low impulsivity. Postlicense motorcycle riding experience and risky motorcycle riding behavior were two significant predictors of motorcycle traffic accidents after controlling for other sociodemographic variables. These results can facilitate the development of interventions, including the training and testing of motorcyclists, public education, and mass media messages about traffic risk. © 2012 Elsevier Ltd. All rights reserved.

Chan K.Y.,Curtin University Australia | Dillon T.S.,Curtin University Australia | Kwong C.K.,Hong Kong Polytechnic University
IEEE Transactions on Industrial Informatics | Year: 2011

Modeling of manufacturing processes is important because it enables manufacturers to understand the process behavior and determine the optimum operating conditions of the process for a high yield, low cost and robust operation. However, existing techniques in modeling manufacturing processes cannot address the whole common issues in developing models for manufacturing processes: a) manufacturing processes are usually nonlinear in nature; b) a small amount of experimental data is only available for developing manufacturing process models; c) outliers often exist in experimental data; d) explicit models in a polynomial form are often preferred by manufacturing process engineers; and e) models with satisfactory prediction accuracy are required. In this paper, a modeling algorithm, namely, the particle swarm optimization-based fuzzy regression (PSO-FR) approach, is proposed to generate fuzzy nonlinear regression models, which seek to address all of the common issues in developing models for manufacturing processes. The PSO-FR first employs the operations of particle swarm optimization to generate the structures of the process models in nonlinear polynomial form, and then it employs a fuzzy coefficient generator to identify outliers in the original experimental data. Fuzzy coefficients of the process models are determined by the fuzzy coefficient generator in which the experimental data excluding the outliers is used. The effectiveness of the PSO-FR approach is evaluated by modeling the manufacturing process liquid epoxy molding process which is a commonly used technology for microchip encapsulation in electronic packaging. Results were compared with those based on the commonly used modeling methods. It was found that PSO-FR can achieve better goodness-of-fitness than other methods. Also, the prediction accuracy of the model developed based on the PSO-FR is better than the other methods. © 2006 IEEE.

Lun Y.H.V.,Hong Kong Polytechnic University | Quaddus M.A.,Curtin University Australia
Expert Systems with Applications | Year: 2011

In this study, we examine the relationship between firm size and the use of electronic commerce (EC) by container transport operators in Hong Kong and their performance implications. Using data collected from a sample of container shipping operators in Hong Kong, we identified internal and external drivers that affect the use of EC by container transport operators. Our findings indicate that large firms tend to adopt EC at a higher level of sophistication. This study also investigates the relationship between the use of EC and firm performance. Our results show that sales growth is positively related to the use of EC and firm size. To understand how firm size affects firm performance, we use a structural equation model (SEM) to examine their structural relationships. Our findings indicate that firm size positively influences sales growth. On the other hand, sales growth affects the profitability of a firm. Although customer satisfaction does not have a direct impact on profitability, our SEM suggests that customer satisfaction is a significant variable that affects the sales growth of firms. © 2010 Elsevier Ltd. All rights reserved.

Westerveld M.F.,Griffith University | Claessen M.,Curtin University Australia
International Journal of Speech-Language Pathology | Year: 2014

A national online survey was used to investigate spontaneous language sampling and analysis practices by speech-language pathologists working with children and adolescents. A total of 257 responses were received from clinicians around Australia. Results indicated that spontaneous language samples are collected on a routine basis in elicitation contexts deemed appropriate to the clients' age or developmental stage. However, language samples were generally short, often not recorded, and analysed informally. Consistent with previous research into language sampling practices, the main barrier to more detailed language sample analysis appears to be the time needed for transcription. Despite rapid technological advances in the last two decades, only 12.5% of the respondents reported using computer-assisted transcription and analysis procedures. Suggestions are made on how to promote change in clinical practice to ensure spontaneous language samples are transcribed and analysed in more detail. By transcribing the samples, detailed analysis of children's language performance can be undertaken, allowing for effective goal-setting and assisting in objective progress measuring during and following intervention. © 2014 The Speech Pathology Association of Australia Limited.

Liu Y.,Curtin University Australia | Strutwolf J.,University of Tübingen | Arrigan D.W.M.,Curtin University Australia
Analytical Chemistry | Year: 2015

In this work, the ion-transfer voltammetric detection of the protonated -blocker propranolol was explored at arrays of nanoscale interfaces between two immiscible electrolyte solutions (ITIES). Silicon nitride nanoporous membranes with 400 pores in a hexagonal arrangement, with either 50 or 17 nm radius pores, were used to form regular arrays of nanoITIES. It was found that the aqueous-to-organic ion-transfer current continuously increased steadily rather than reaching a limiting current plateau after the ion-transfer wave; the slope of this limiting current region was concentration dependent and associated with the high ion flux at the nanointerfaces. Electrochemical data were examined in terms of an independent nanointerface approach and an equivalent microdisc approach, supported by finite element simulation. In comparison to the larger interface configuration (50 nm radius), the array of 17 nm radius nanoITIES exhibited a 6.5-times higher current density for propranolol detection due to the enhanced ion flux arising from the convergent diffusion to smaller electrochemical interfaces. Both nanoITIES arrays achieved the equivalent limits of detection, 0.8 μM, using cyclic voltammetry. Additionally, the effect of scan rate on the charging and faradaic currents at these nanoITIES arrays, as well as their stability over time, was investigated. The results demonstrate that arrays of nanoscale liquid-liquid interfaces can be applied to study electrochemical drug transfer, and provide the basis for the development of miniaturized and integrated detection platforms for drug analysis. © 2015 American Chemical Society.

Gagnon M.M.,Curtin University Australia | Hodson P.V.,Queen's University
Marine Pollution Bulletin | Year: 2012

Significant efforts are invested in field studies using fish, and it is important to optimize the number of organisms collected to evaluate the possible impacts of contamination. This paper provides ecotoxicologists with the approximate numbers of fish needed to identify statistically significant differences among samples using physiological indices and biochemical markers of fish health. The numbers of fish to collect are reported for ethoxyresorufin-o-deethylase (EROD); ethoxycoumarin-o-deethylase (ECOD), serum sorbitol dehydrogenase (sSDH), stress proteins, gonadosomatic index, liver somatic index, condition factor, and biliary metabolites of polycyclic aromatic hydrocarbons. The number of fish to collect was as few as four for ECOD activity (with a power of 80%), but as high as 106 for CF (with a power of 95%). Achieving statistical significance between sites does not help in the interpretation of the biological significance of a parameter, but well-planned field samplings will maximize the chances of correctly identifying areas of concern. © 2012 Elsevier Ltd.

Vo B.-T.,Curtin University Australia | Vo B.-N.,Curtin University Australia | Hoseinnezhad R.,RMIT University | Mahler R.P.S.,Lockheed Martin
IEEE Journal on Selected Topics in Signal Processing | Year: 2013

In Bayesian multi-target filtering knowledge of parameters such as clutter intensity and detection probability profile are of critical importance. Significant mismatches in clutter and detection model parameters results in biased estimates. In this paper we propose a multi-target filtering solution that can accommodate non-linear target models and an unknown non-homogeneous clutter and detection profile. Our solution is based on the multi-target multi-Bernoulli filter that adaptively learns non-homogeneous clutter intensity and detection probability while filtering. © 2007-2012 IEEE.

Lin R.M.,Nanyang Technological University | Lu C.,Curtin University Australia
Mechanical Systems and Signal Processing | Year: 2010

Carbon nanotube-based composite is becoming increasingly popular and offers great potential for highly demanding practical high strength and high damping applications. The excellent damping capacity of CNTs is primarily due to the interfacial friction between carbon nanotubes and polymer resins and the extremely large interfacial surface area over a given specific mass (specific area). In this paper, damping characteristics of carbon nanotube-based composites have been investigated, with an objective of developing an effective and accurate analytical model, which can be used as a design tool for the damping design of such materials. Based on the interfacial slips between the resin and nanotubes and between the nanotubes themselves, a micro stick-slip damping model has been developed. Such a physically derived model is believed to be appropriate and representative of the actual complex damping mechanism of the material system. The model, developed for the first time, is analytical and relates explicitly the material properties of the resin and nanotubes and the processing parameters to the overall material damping loss factor and hence it offers the possibility for material engineers to possibly optimize the damping for required applications. Due to the nonlinear forcedisplacement relationship derived under the micro stick-slip, a harmonic linearization method, the Describing Function method, has been employed to analyse its vibration characteristics and to derive the required damping loss factors. From the analytical formula, it can be seen that the damping loss factor of the material system depends on the individual material properties of the resin and the nanotubes, structural deformation, nanotube volume fraction and the critical shear stresses at which interfacial slips take place. By taking careful considerations of these design parameters, optimized carbon nanotube-based composites for advanced damping applications can be developed. Extensive numerical simulations have been carried out to establish the practical applicability of the proposed analytical model. Based on realistic material properties of carbon nanotubes and polymer resins, damping characteristics have been predicted which compare well with existing results from open literature. The results have shown that for a volume fraction as small as 1%, a damping loss factor as high as 20% can be achieved which is adequate for most practical applications. The model has been further developed to deal with bending vibrations where different parts of the material are subject to different vibration strain levels. A practical case of cantilevered beam vibration has been employed to demonstrate the practical application of the proposed model. © 2010 Published by Elsevier Ltd.

Rajakaruna S.,Nanyang Technological University | Rajakaruna S.,Curtin University Australia | Jayawickrama L.,Parsons Brinckerhoff
IEEE Transactions on Industrial Electronics | Year: 2010

All possible steady states of a Z-source inverter are identified and analyzed with the objective of deriving design guidelines for the symmetrical impedance network. This paper shows that, in addition to the desired three dynamic states, an operating cycle can contain another three static states that do not contribute to the power conversion process. These three static states can be avoided by selecting suitably large capacitors and inductors. By using the equations derived in the steady-state analysis, this paper presents guidelines to design the impedance network accurately for the case where the inverter is operated only in active and shoot-through states. The proposed design method can also be used to predict the critical values of capacitance and inductance below which static states appear during the operating cycle. Computer simulations and laboratory experiments are used to verify the design method and to demonstrate the appearance of static states when the capacitors and inductors are sized lower than their critical values. © 2010 IEEE.

Hosseini S.,Curtin University Australia | Ahmed K.,Ceramic Fuel Cells Ltd. | Tade M.O.,Curtin University Australia
Journal of Power Sources | Year: 2013

A fully coupled CFD model of a direct internal reforming single cell SOFC stack previously designed by Ceramic Fuel Cell Ltd (CFCL) has been developed. In this model, an innovative solution technique for accelerating finite volume treatment of the electrodes as two distinct layers, a diffusion layer and a catalyst layer, is taken to analyse the combined effects of the macro/microstructural parameters on distribution of fields and each of the reactions involved in the process. To assess the simulation results, the model is not only evaluated with the CFCL experimental data that was reported from the similar geometry, but it is also assessed for the effects of the reforming and water gas shift reactions. It is found that a 3D model is more representative of the global reforming reaction rate. Furthermore, distributions of the key parameters along different spatial domains disclose the complex interaction between the anode flow field design and microstructural parameters of the anode diffusion layer. In fact, an optimal set of the anode microstructure that promotes the reforming reaction rate will not automatically result in improved SOFC performance. The developed model is a powerful tool to study complex fuel cell related problems and to optimize fuel cells' structure. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

Ling S.K.,Curtin University Australia | Wang S.,Curtin University Australia | Peng Y.,Beijing University of Technology
Journal of Hazardous Materials | Year: 2010

Dye degradation using advanced oxidation processes with Co2+/H2O2 and Co2+/peroxymonosulfate (PMS) systems has been investigated. Two types of dyes, basic blue 9 and acid red 183, were employed. Several parameters affecting dye degradation such as Co2+, PMS, H2O2, and dye concentrations were investigated. The optimal ratio of oxidant (PMS, H2O2)/Co2+ for the degradation of two dyes was determined. It is found that dye decomposition is much faster in Co2+/PMS system than in Co2+/H2O2. For Co2+/H2O2, an optimal ratio of H2O2 to Co2+ at 6 is required for the maximum decomposition of the dyes. For Co2+/PMS, higher concentrations of Co2+ and PMS will increase dye degradation rate with an optimal ratio of 3, achieving 95% decolourisation. For basic blue 9, a complete decolourisation can be achieved in 5min at 0.13mM Co2+, 0.40mM PMS and 7mg/l basic blue 9 while the complete degradation of acid red 183 will be achieved at 30min at 0.13mM Co2+, 0.40mM PMS and 160mg/l of acid red 183. The degradation of acid red 183 follows the second-order kinetics. © 2010 Elsevier B.V.

Soria R.,University College London | Soria R.,Curtin University Australia
Astronomische Nachrichten | Year: 2011

I discuss some differences between the observed spectral states of ultraluminous X-ray sources (ULXs) and the canonical scheme of spectral states defined in Galactic black holes. The standard interpretation of ULXs with a curved spectrum, or a moderately steep power-law with soft excess and high-energy downturn, is that they are an extension of the very high state, up to luminosities ≈1-3L Edd. Two competing models are Comptonization in a warm corona, and slim disk; I suggest bulk motion Comptonization in the radiatively-driven outflow as another possibility. The interpretation of ULXs with a hard power-law spectrum is more problematic. Some of them remain in that state over a large range of luminosities; others switch directly to a curved state without going through a canonical high/soft state. I suggest that those ULXs are in a high/hard state not seen in Galactic black holes; that state may overlap with the low/hard state at lower accretion rates, and extend all the way to Eddington accretion rates. If some black holes can reach Eddington accretion rates without switching to a standard-disk-dominated state, it is also possible that they never quench their steady jets. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cui Z.,Nanyang Technological University | Li C.M.,Nanyang Technological University | Jiang S.P.,Curtin University Australia
Physical Chemistry Chemical Physics | Year: 2011

A simple self-assembly approach has been developed to functionalize carbon nanotubes (CNTs) with chitosan (CS) and heteropolyacids (HPAs) of phosphomolybdic acid (H 3PMo 12O 40, HPMo) and phosphotungstic acid (H 3PW 12O 40, HPW). The non-covalent functionalization method, which introduces homogenous surface functional groups with no detrimental effect on graphene structures of CNTs, can be carried out at room temperature without the use of corrosive acids. The PtRu nanoparticles supported on HPAs-CS-CNTs have a uniform distribution and much smaller size as compared to those of the PtRu nanoparticles supported on conventional acid treated CNTs (PtRu/AO-CNTs). The onset and peak potentials for CO ad oxidation on PtRu/HPAs-CS-CNTs catalysts are more negative than those on PtRu/AO-CNTs, indicating that HPAs facilitate the electro-oxidation of CO. The PtRu/HPMo-CS-CNTs catalyst has a higher electrocatalytic activity for methanol oxidation and higher tolerance toward CO poisoning than PtRu/HPW-CS-CNTs. The better electrocatalytic enhancement of HPMo on the PtRu/HPAs-CS-CNTs catalyst is most likely related to the fact that molybdenum-containing HPAs such as HPMo have more labile terminal oxygen to provide additional active oxygen sites while accelerating the CO and methanol oxidation in a similar way to that of Ru in the PtRu binary alloy system. © 2011 the Owner Societies.

Hill-Haas S.V.,University of Western Australia | Dawson B.,University of Western Australia | Impellizzeri F.M.,Neuromuscular Research Laboratory | Impellizzeri F.M.,University of Verona | Coutts A.J.,Curtin University Australia
Sports Medicine | Year: 2011

Small-sided games (SSGs) are played on reduced pitch areas, often using modified rules and involving a smaller number of players than traditional football. These games are less structured than traditional fitness training methods but are very popular training drills for players of all ages and levels. At present, there is relatively little information regarding how SSGs can best be used to improve physical capacities and technical or tactical skills in footballers. However, many prescriptive variables controlled by the coach can influence the exercise intensity during SSGs. Coaches usually attempt to change the training stimulus in SSGs through altering the pitch area, player number, coach encouragement, training regimen (continuous vs interval training), rules and the use of goalkeepers. In general, it appears that SSG exercise intensity is increased with the concurrent reduction in player number and increase in relative pitch area per player. However, the inverse relationship between the number of players in each SSG and exercise intensity does not apply to the time-motion characteristics. Consistent coach encouragement can also increase training intensity, but most rule changes do not appear to strongly affect exercise intensity. The variation of exercise intensity measures are lower in smaller game formats (e.g. three vs three) and have acceptable reproducibility when the same game is repeated between different training sessions or within the same session. The variation in exercise intensity during SSGs can also be improved with consistent coach encouragement but it is still more variable than traditional generic training methods. Other studies have also shown that SSGs containing fewer players can exceed match intensity and elicit similar intensities to both long- and short-duration high-intensity interval running. It also appears that fitness and football-specific performance can be improved equally with SSG and generic training drills. Future research is required to examine the optimal periodization strategies of SSGs training for the long-term development of physiological capacity, technical skill and tactical proficiency. © 2011 Adis Data Information BV. All rights reserved.

Zhang Y.,Nanyang Technological University | Sunarso J.,Deakin University | Liu S.,Curtin University Australia | Wang R.,Nanyang Technological University
International Journal of Greenhouse Gas Control | Year: 2013

Carbon dioxide (CO2) is a greenhouse gas found primarily as a main combustion product of fossil fuel as well as a component in natural gas, biogas and landfill gas. The interest to remove CO2 from those gas streams to obtain fuel with enhanced energy content and prevent corrosion problems in the gas transportation system, in addition to CO2 implications to the climate change, has driven the development of CO2 separation process technology. One type of technology which has experienced substantial growth, breakthroughs and advances during past decades is membrane-based technology. The attractive features offered by this technology include high energy efficiency, simplicity in design and construction of membrane modules and environmental compatibility. The objective of this review is to overview the different types of membranes available for use including their working principles, current status and development which form the primary determinants of separation performance and efficiency. The emphasis is toward CO2/CH4 separation, considering its substantial and direct relevance to the gas industry. To this end, discussion is made to cover polymeric gas permeation membranes; CO2-selective facilitated transport membranes, hollow fiber gas-liquid membrane contactors, inorganic membranes and mixed matrix membranes.The market for CO2 separation is currently dominated by polymeric membranes due to their relatively low manufacturing cost and processing ability into flat sheet and hollow fiber configurations as well as well-documented research studies. While there have been immensely successful membrane preparation and development techniques with consequential remarkable performance for each type of membrane. Each type of membrane brings associated advantages and drawbacks related to the characteristic transport mechanism for specific application conditions. Inorganic membranes, for example, are very suitable for high temperature CO2 separation in excess of 400°C while all other membranes can be applied at lower temperatures. The recent emergence of mixed matrix membranes has allowed the innovative approach to combine the advantages offered by inorganic and polymeric materials. © 2012 Elsevier Ltd.

Slatyer S.,Edith Cowan University | Williams A.M.,Edith Cowan University | Michael R.,Curtin University Australia
International Journal of Nursing Studies | Year: 2015

Background: Hospital patients experience significant pain, which can delay healing and increase the risk of developing chronic pain. Nurses are affected by patients' ongoing pain and may cope with consequent anxiety and helplessness by distancing themselves from such patients. Understanding nurses' responses to patients in severe pain will inform strategies to support their coping, their patients and, ultimately, their retention in the nursing workforce. Objectives: The aim of the study was to develop a substantive theory explaining the hospital nurse's perspective of caring for patients in severe pain. Design: The study used grounded theory method. Settings: Data were collected on four acute care wards in a 610 bed Australian hospital. Participants: The sample included 33 nurse participants and 11 patient participants. Selection criteria for nurse participants were those who worked in the four study wards, cared for patients who experienced severe pain, and consented to be included. Selection criteria for patient participants were those who self-reported pain at intensity of seven or more on a scale of 0-10, were aged 18 years or older, could speak and read English, and consented to be included. Methods: Theoretical sampling directed the collection of data using semi-structured interviews with nurses and participant observation, including structured observations of nurses who cared for patients in pain. Data were analysed using constant comparison method. Results: Nurse participants encountered a basic psychosocial problem of feelings of disempowerment when their patients experienced persisting severe pain. In response, they used a basic psychosocial process of seeking empowerment to provide comfort in order to resolve distress and exhaustion associated with disempowerment. This coping process comprised three stages: building connections; finding alternative ways to comfort; and quelling emotional turmoil. Conclusions: The substantive theory proposed a link between the stress of nurses' disempowerment and a coping response that provides direction to support nurses' practice. Strategies indicated include enhanced communication protocols, access to advanced practice nurses, use of nonpharmacological comfort measures, utilization of ward-based pain resource nurses, and unit-specific pain management education. Further research to verify and extend the substantive theory to other settings and nursing populations is warranted. © 2014 Elsevier Ltd.

Wang S.,Curtin University Australia | Peng Y.,Beijing University of Technology
Chemical Engineering Journal | Year: 2010

Natural zeolites are abundant and low cost resources, which are crystalline hydrated aluminosilicates with a framework structure containing pores occupied by water, alkali and alkaline earth cations. Due to their high cation-exchange ability as well as to the molecular sieve properties, natural zeolites have been widely used as adsorbents in separation and purification processes in the past decades. In this paper, we review the recent development of natural zeolites as adsorbents in water and wastewater treatment. The properties and modification of natural zeolite are discussed. Various natural zeolites around the world have shown varying ion-exchange capacity for cations such as ammonium and heavy metal ions. Some zeolites also show adsorption of anions and organics from aqueous solution. Modification of natural zeolites can be done in several methods such as acid treatment, ion exchange, and surfactant functionalisation, making the modified zeolites achieving higher adsorption capacity for organics and anions. © 2009 Elsevier B.V. All rights reserved.

Ruebsam W.,University of Kiel | Munzberger P.,Geological Survey Luxembourg | Schwark L.,University of Kiel | Schwark L.,Curtin University Australia
Earth and Planetary Science Letters | Year: 2014

Early Toarcian (Jurassic; ~183 Ma) sediments recorded profound environmental changes, including mass extinction, global warming, marine transgression as well as widespread bottom water anoxia and organic matter accumulation on the Western Tethyan shelf. Enhanced organic matter accumulation was accompanied by a positive carbon isotope excursion (CIE) in pelagic carbonate, which marks the Toarcian Oceanic Anoxic Event. These environmental changes were accompanied by a major perturbation of the global carbon cycle, expressed by negative CIE, interrupting the positive trend. The duration of the carbon cycle perturbation is still debated, with estimates for the negative CIE range from ~200 to ~600 kyr. Here we present ultra high-resolution (<1 kyr) measurements of magnetic susceptibility and sediment color from a marine section located in the Lorraine Sub-Basin (NE Paris Basin) documenting Milankovitch-controlled fluctuations in depositional conditions that occurred superimposed onto the overall sea level evolution. Differences in the wavelength of the sedimentary cycles indicate variable sediment accumulation rates that mainly resulted from rapid sea level fluctuations. The most pronounced sea level rise that took place within the uppermost tenuicostatum zone resulted in a strong condensation of the basal Schistes Carton formation. Strong condensation can explain the discrepancy between durations previously calculated for the CIE placed at this stratigraphic interval. Our data support durations of ~900 kyr and ~600 kyr for the positive and negative CIE, respectively. The cyclostratigraphy-based timescale further proposes a duration of >555 kyr for the tenuicostatum zone and 1310 kyr for the serpentinum zone. The durations of the elegantulum and falciferum subzones can be estimated to ~790 kyr and ~520 kyr, respectively. A change in the orbital response from eccentricity- to obliquity-forcing, evident from other locations, is well-expressed in the Lorraine Sub-Basin and occurred within the CIE interval. The strong impact of the obliquity component in post-event deposits hints to processes most effective at high latitudes, such as the waxing and waning of polar ice. Paleogeographic features of the Western Tethyan shelf supported the tele-connection of higher to lower latitude processes via water exchange through the Viking Corridor. © 2014 Elsevier B.V.

Souders A.K.,Memorial University of Newfoundland | Sylvester P.J.,Memorial University of Newfoundland | Myers J.S.,Curtin University Australia
Contributions to Mineralogy and Petrology | Year: 2013

Isotopic analyses of ancient mantle-derived magmatic rocks are used to trace the geochemical evolution of the Earth's mantle, but it is often difficult to determine their primary, initial isotope ratios due to the detrimental effects of metamorphism and secondary alteration. We present in situ analyses by LA-MC-ICPMS for the Pb isotopic compositions of igneous plagioclase (An75-89) megacrysts and the Hf isotopic compositions of BSE-imaged domains of zircon grains from two mantle-derived anorthosite complexes from south West Greenland, Fiskenæsset and Nunataarsuk, which represent two of the best-preserved Archean anorthosites in the world. In situ LA-ICPMS U-Pb geochronology of the zircon grains suggests that the minimum crystallization age of the Fiskenæsset complex is 2,936 ± 13 Ma (2σ, MSWD = 1. 5) and the Nunataarsuk complex is 2,914 ± 6. 9 Ma (2σ, MSWD = 2. 0). Initial Hf isotopic compositions of zircon grains from both anorthosite complexes fall between depleted mantle and a less radiogenic crustal source with a total range up to 5 εHf units. In terms of Pb isotopic compositions of plagioclase, both anorthosite complexes share a depleted mantle end member yet their Pb isotopic compositions diverge in opposite directions from this point: Fiskenæsset toward a high-μ, more radiogenic Pb, crustal composition and Nunataarsuk toward low-μ, less radiogenic Pb, crustal composition. By using Hf isotopes in zircon in conjunction with Pb isotopes in plagioclase, we are able to constrain both the timing of mantle extraction of the crustal end member and its composition. At Fiskenæsset, the depleted mantle melt interacted with an Eoarchean (~3,700 Ma) mafic crust with a maximum 176Lu/177Hf ~0. 028. At Nunataarsuk, the depleted mantle melt interacted with a Hadean (~4,200 Ma) mafic crust with a maximum 176Lu/177Hf ~0. 0315. Evidence from both anorthosite complexes provides support for the long-term survival of ancient mafic crusts that, although unidentified at the surface to date, could still be present within the Fiskenæsset and Nunataarsuk regions. © 2012 Springer-Verlag.

Aoun S.M.,Curtin University Australia | Nekolaichuk C.,University of Alberta
Journal of Pain and Symptom Management | Year: 2014

The adoption of evidence-based hierarchies and research methods from other disciplines may not completely translate to complex palliative care settings. The heterogeneity of the palliative care population, complexity of clinical presentations, and fluctuating health states present significant research challenges. The aim of this narrative review was to explore the debate about the use of current evidence-based approaches for conducting research, such as randomized controlled trials and other study designs, in palliative care, and more specifically to 1) describe key myths about palliative care research; 2) highlight substantive challenges of conducting palliative care research, using case illustrations; and 3) propose specific strategies to address some of these challenges. Myths about research in palliative care revolve around evidence hierarchies, sample heterogeneity, random assignment, participant burden, and measurement issues. Challenges arise because of the complex physical, psychological, existential, and spiritual problems faced by patients, families, and service providers. These challenges can be organized according to six general domains: patient, system/organization, context/setting, study design, research team, and ethics. A number of approaches for dealing with challenges in conducting research fall into five separate domains: study design, sampling, conceptual, statistical, and measures and outcomes. Although randomized controlled trials have their place whenever possible, alternative designs may offer more feasible research protocols that can be successfully implemented in palliative care. Therefore, this article highlights "outside the box" approaches that would benefit both clinicians and researchers in the palliative care field. Ultimately, the selection of research designs is dependent on a clearly articulated research question, which drives the research process. © 2014 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Hoseinnezhad R.,RMIT University | Vo B.-N.,Curtin University Australia | Vo B.-T.,Curtin University Australia
IEEE Transactions on Signal Processing | Year: 2013

This correspondence presents a novel method for simultaneous tracking of multiple non-stationary targets in video. Our method operates directly on the video data and does not require any detection. We propose a multi-target likelihood function for the background-subtracted grey-scale image data, which admits multi-target conjugate priors. This allows the multi-target posterior to be efficiently propagated forward using the multi-Bernoulli filter. Our method does not need any training pattern or target templates and makes no prior assumptions about object types or object appearance. Case studies from the CAVIAR dataset show that our method can automatically track multiple targets and quickly finds targets entering or leaving the scene. © 1991-2012 IEEE.

Asadi M.S.,Baker Hughes Inc. | Rasouli V.,Curtin University Australia | Barla G.,Polytechnic University of Turin
Rock Mechanics and Rock Engineering | Year: 2012

Different failure modes during fracture shearing have been introduced including normal dilation or sliding, asperity cut-off and degradation. Attempts have been made to study these mechanisms using analytical, experimental and numerical methods. However, the majority of the existing models simplify the problem, which leads to unrealistic results. With this in mind, the aim of this paper is to simulate the mechanical behaviour of synthetic and rock fracture profiles during direct shear tests by using the twodimensional particle flow computer code PFC2D. Correlations between the simulated peak shear strength and the fracture roughness parameter DR1 recently proposed by Rasouli and Harrison (2010) are developed. Shear test simulations are carried out with PFC2D and the effects of the geometrical features as well as the model micro-properties on the fracture shear behaviour are studied. The shear strength and asperity degradation processes of synthetic profiles including triangular, sinusoidal and randomly generated profiles are analysed. Different failure modes including asperity sliding, cut-off, and asperity degradation are explicitly observed and compared with the available models. The DR1 parameter is applied to the analysis of synthetic and rock fracture profiles. Accordingly, correlations are developed between DR1 and the peak shear strength obtained from simulations and by using analytical solutions. The results are shown to be in good agreement with the basic understanding of rock fracture shear behaviour and asperity contact degradation. © Springer-Verlag 2012.

Chaudhary D.S.,Curtin University Australia | Adhikari B.P.,University of Ballarat | Kasapis S.,RMIT University
Food Hydrocolloids | Year: 2011

Two plasticizers namely, glycerol and xylitol, based on their similar molecular size (6.3 Å) but different molecular weights (Glycerol-92; Xylitol-152) were selected for studying the glass-transition behaviour (rubber like behaviour) in multi-plasticized starch biopolymer with about 70% amylopectin structure. In the calorimetry measurements, glass-transition temperatures (onset temperature for bulk viscous flow) of plasticized samples were higher than non-plasticized samples at low water activities, thus showing typical antiplasticization behaviour. However, when plasticizer concentration was increased up to 15% and 20% wt, all plasticized samples showed significant reduction in glass-transition temperature. We used a modified Gordon-Taylor model to understand the competitive plasticization of glycerol and xylitol in presence of water, and suggest that competitive plasticization exists and occurs at a threshold amount of matrix free water content, due to strong three-way interactions: starch-plasticizer, plasticizer-plasticizer/water and starch-water. This competitive interaction is significant in determining the onset temperature for viscous flow behaviour; at higher matrix water content, the Gordon-Taylor constant was relatively unaffected by the plasticizer amount, and water was the dominant plasticizer. A new interaction parameter that separates the starch-plasticizer interaction in a starch-plasticizer-water system is also discussed. © 2010 Elsevier Ltd.

Zhang X.,Yantai University | Liu L.,Qufu Normal University | Liu L.,Curtin University Australia | Wu Y.,Curtin University Australia
Mathematical and Computer Modelling | Year: 2012

Let D0+α be the standard Riemann-Liouville derivative. We discuss the existence of multiple positive solutions for the following fractional differential equation with a negatively perturbed term {-D0+αu(t)=p(t)f(t,u(t))-q(t),0

Mumby K.,Northumbria University | Whitworth A.,Curtin University Australia
International Journal of Language and Communication Disorders | Year: 2012

Background: Despite recognition of the need for increased long-term support for people with aphasia following stroke, there remains limited evidence for effective service-level interventions. Aims: To evaluate the outcomes and experiences of people participating in the Communication Hub for Aphasia in North Tyneside (CHANT), a 2-year partnership project between health, local authority and third-sector services, shaped by people with aphasia, which provided a coordinated programme of support and interventions for people with long-term aphasia following stroke. Methods & Procedures: Quantitative and qualitative methods were used in the evaluation. Thirty-nine participants with aphasia were recruited to the 12-month study as they became part of CHANT, with 20 completing all measures at the end of the study. Participants had no other speech and language therapy during the study. Quantitative measures (before and after intervention) were used for quality of life, self-report outcomes and goal attainment. Three of the participants with aphasia and three further people involved in the service (carer, volunteer, public sector worker) each agreed to a series of five semi-structured interviews over a 9-month period. A total of 28 interviews were collected using neutral interviewers; these were transcribed and analysed by a team within NVivo8 software, based on interpretive principles from grounded theory. Thematic analysis of the narratives explored the experience of engaging with CHANT, and the barriers and facilitators affecting quality of life. Outcomes & Results: People with aphasia made significant gains in quality of life (in particular, in communication and psychosocial adjustment to stroke) and self-report measures of change. A total of 82% of real-life goals set as part of intervention were fully or partially achieved at follow-up. Five core themes emerged from the narratives: 'Quality of life', 'Barriers', 'Facilitators', 'Types of CHANT activity' and 'Effectiveness'. The intervention was evaluated through the theme of 'Effectiveness' in relation to the other themes, encapsulating emerging participant views (including the type and timeliness of activity, expectations of outcomes, resources and perceived value). The impact of the intervention was also analysed in terms of identifying barriers and providing facilitators. Conclusions & Implications: The quantitative and qualitative (narrative) findings were complementary in demonstrating the effectiveness of the CHANT service delivery model. Moreover, the narratives, through a longitudinal perspective, provided evidence about people's experience of intervention for long-term aphasia. The findings provide foundations for further work into long-term recovery, intervention and adjustment to aphasia post-stroke. © 2012 Royal College of Speech and Language Therapists.

Gibson S.,St John of God Hospital | McConigley R.,Curtin University Australia
Supportive Care in Cancer | Year: 2016

Aim: The aim of this study was to identify the incidence, causes, risk factors and interventions for cancer patients requiring unplanned admissions within 14 days of discharge at a large metropolitan private hospital without a co-located emergency department. Methods: Retrospective data were collected on cancer patients who had an unplanned admission within 14 days of discharge during the period December 1, 2011 and May 31, 2012. Data were collected from the inpatient bed administration database and medical record review. Variables collected included demographics, cancer diagnosis, reasons for admission, interventions, and length of stay. Results: A total of 133 oncology patients required 206 unplanned admissions (UPAs). The most common cancer diagnoses associated with unplanned readmission were upper gastrointestinal (25.4 %), colorectal (19.6 %), gynaecological (18.8 %) and breast (13.8 %) cancers. The symptoms most commonly associated with unplanned re-admission were pain (16 %); infection not associated with neutropaenia (15.5 %); fever and febrile neutropaenia (14.6 %); nausea, vomiting and dehydration (13.6 %); dyspnoea (8.3 %) and altered neurological status (7.8 %). The median length of stay (LOS) was 6 days. Length of stay during UPA was decreased for patients with a partner and for those who had a palliative care consult. The need for psychological supports was related to a longer LOS during UPA. Conclusion: Cancer patients are at a significant risk of requiring unscheduled care and admission. Strategies and services to limit the burden on patients and the health care system should be reviewed to minimise the incidence of unplanned admission. © 2015, Springer-Verlag Berlin Heidelberg.

Christou A.,Curtin University Australia | Thompson S.C.,University of Western Australia
BMC Public Health | Year: 2012

Background: Indigenous Australians are significantly less likely to participate in colorectal cancer (CRC) screening compared to non-Indigenous people. This study aimed to identify important factors influencing the decision to undertake screening using Faecal Occult Blood Testing (FOBT) among Indigenous Australians. Very little evidence exists to guide interventions and programmatic approaches for facilitating screening uptake in this population in order to reduce the disparity in colorectal cancer outcomes. Methods. Interviewer-administered surveys were carried out with a convenience sample (n=93) of Indigenous Western Australians between November 2009-March 2010 to assess knowledge, awareness, attitudes and behavioural intent in regard to CRC and CRC screening. Results: Awareness and knowledge of CRC and screening were low, although both were significantly associated with exposure to media advertising (p=0.008; p<0.0001). Nearly two-thirds (63%; 58/92) of respondents reported intending to participate in screening, while a greater proportion (84%; 77/92) said they would participate on a doctors recommendation. Multivariate analysis with logistic regression demonstrated that independent predictors of screening intention were, greater perceived self-efficacy (OR=19.8, 95% CI=5.5-71.8), a history of cancer screening participation (OR=6.8, 95% CI=2.0-23.3) and being aged 45 years or more (OR=4.5, 95% CI=1.2-16.5). A higher CRC knowledge score (medium vs. low: OR=9.9, 95% CI=2.4-41.3; high vs. low: 13.6, 95% CI=3.4-54.0) and being married or in a de-facto relationship (OR=6.9, 95% CI=2.1-22.5) were also identified as predictors of intention to screen with FOBT. Conclusions: Improving CRC related knowledge and confidence to carry out the FOBT self-screening test through education and greater promotion of screening has the potential to enhance Indigenous participation in CRC screening. These findings should guide the development of interventions to encourage screening uptake and reduce bowel cancer related deaths among Indigenous Australians. © 2012 Christou and Thompson; licensee BioMed Central Ltd.

Leahy M.F.,University of Western Australia | Mukhtar S.A.,Curtin University Australia
Internal Medicine Journal | Year: 2012

The ageing population in developed countries, including Australia, is putting increasing demands on blood transfusion services. With a falling donor pool there is likely to be a shortage of blood and blood products in the next 20 to 30years unless there are significant changes in medical practice. The National Health and Medical Research Council/Australasian Society of Blood Transfusion Clinical Practice Guidelines on the Use of Blood Components from 2001 are being redeveloped by the National Health and Medical Research Council/Australian and New Zealand Society of Blood Transfusion as evidence-based patient-focused Patient Blood Management guidelines with the aim of improving patient outcomes by reducing inappropriate blood and blood product use and targeting therapies for improving the management of anaemia and coagulopathies. © 2012 The Authors. Internal Medicine Journal © 2012 Royal Australasian College of Physicians.

Hardcastle S.J.,University of Brighton | Taylor A.H.,University of Exeter | Bailey M.P.,University of Brighton | Harley R.A.,University of Brighton | Hagger M.S.,Curtin University Australia
International Journal of Behavioral Nutrition and Physical Activity | Year: 2013

Background: Intensive diet and physical activity interventions have been found to reduce cardiovascular disease (CVD) risk, but are resource intensive. The American Heart Association recently recommended motivational interviewing (MI) as an effective approach for low-intensity interventions to promote health-related outcomes such as weight loss. However, there is limited research evaluating the long-term effectiveness of MI-based interventions on health-related outcomes associated with CVD risk. The current research evaluated the effectiveness of a six-month low-intensity MI intervention in a UK primary-care setting in maintaining reductions in CVD risk factors at12 months post-intervention.Methods: Primary-care patients were randomised to an intervention group that received standard exercise and nutrition information plus up to five face-to-face MI sessions, delivered by a physical activity specialist and registered dietician over a 6-month period, or to a minimal intervention comparison group that received the standard information only. Follow-up measures of behavioural (vigorous and moderate physical activity, walking, physical activity stage-of-change, fruit and vegetable intake, and dietary fat intake) and biomedical (weight, body mass index [BMI], blood pressure, cholesterol) outcomes were taken immediately post-intervention and at a 12-month follow-up occasion.Results: Intent-to-treat analyses revealed significant differences between groups for walking and cholesterol. Obese and hypercholesterolemic patients at baseline exhibited significant improvements in BMI and cholesterol respectively among those allocated to the intervention group compared to the comparison group. Post-intervention improvements in other health-related outcomes including blood pressure, weight, and BMI were not maintained.Conclusions: The present study suggests that a low-intensity MI counselling intervention is effective in bringing about long-term changes in some, but not all, health-related outcomes (walking, cholesterol levels) associated with CVD risk. The intervention was particularly effective for patients with elevated levels of CVD risk factors at baseline. Based on these findings future interventions should be conducted in a primary care setting and target patients with high risk of CVD. Future research should investigate how the long-term gains in health-related outcomes brought about by the MI-counselling intervention in the current study could be extended to a wider range of health outcomes. © 2013 Hardcastle et al.; licensee BioMed Central Ltd.

Baur O.,Austrian Academy of Sciences | Kuhn M.,Curtin University Australia | Featherstone W.E.,Curtin University Australia
Journal of Geodesy | Year: 2013

Present-day continental mass variation as observed by space gravimetry reveals secular mass decline and accumulation. Whereas the former contributes to sea-level rise, the latter results in sea-level fall. As such, consideration of mass accumulation (rather than focussing solely on mass loss) is important for reliable overall estimates of sea-level change. Using data from the Gravity Recovery And Climate Experiment satellite mission, we quantify mass-change trends in 19 continental areas that exhibit a dominant signal. The integrated mass change within these regions is representative of the variation over the whole land areas. During the integer 9-year period of May 2002 to April 2011, GIA-adjusted mass gain and mass loss in these areas contributed, on average, to -(0. 7 ± 0. 4) mm/year of sea-level fall and + (1. 8 ± 0. 2) mm/year of sea-level rise; the net effect was + (1. 1 ± 0. 6) mm/year. Ice melting over Greenland, Iceland, Svalbard, the Canadian Arctic archipelago, Antarctica, Alaska and Patagonia was responsible for + (1. 4±0. 2) mm/year of the total balance. Hence, land-water mass accumulation compensated about 20 % of the impact of ice-melt water influx to the oceans. In order to assess the impact of geocentre motion, we converted geocentre coordinates derived from satellite laser ranging (SLR) to degree-one geopotential coefficients. We found geocentre motion to introduce small biases to mass-change and sea-level change estimates; its overall effect is + (0. 1 ± 0. 1) mm/year. This value, however, should be taken with care owing to questionable reliability of secular trends in SLR-derived geocentre coordinates. © 2012 Springer-Verlag.

Schmieder M.,University of Western Australia | Schmieder M.,Curtin University Australia | Jourdan F.,Curtin University Australia
Geochimica et Cosmochimica Acta | Year: 2013

An in-depth approach of 40Ar/39Ar dating of the ~23km Lappajärvi impact structure (Finland) was performed using carefully selected single-grain aliquots of optically fresh, clast-poor, impact melt rock and recrystallized K-feldspar melt particles separated from impact-metamorphosed granite pegmatite. Step-heating analysis yielded a set of 13 statistically robust plateau ages obtained on six melt rock and seven K-feldspar samples. The melt rocks yielded fully concordant ages with a weighted mean of 76.37±0.46Ma. Dating of the K-feldspar melt particles resulted in a series of younger plateau ages ranging from 75.11±0.36 to 76.11±0.35Ma. The melt rock results combined with the oldest syn-melt rock K-feldspar age and including all sources of uncertainties yielded a weighted mean age of 76.20±[0.29]Ma (2σ; MSWD=1.02, P=0.41), which is interpreted to represent the best-estimate age of the Lappajärvi impact. The age spread of at least 1.1±0.5Ma between the crystallization of the impact melt rocks and the K-feldspar melt particles warns against the use of single 40Ar/39Ar analysis to derive a meaningful impact age. In turn, the age offset monitors both rapid cooling of the Lappajärvi melt sheet versus slow cooling and impact-induced hydrothermal circulation within the crater basement, most likely driven by long-lasting heat flow from the hot central uplift of the impact structure. This interpretation is in line with the grain-size dependent argon diffusion parameters and apparent closure temperatures of ~230-410°C determined for various domain sizes of K-feldspars observed in this study. Our study shows that even in comparatively small impact craters post-impact hydrothermal activity can be estimated to last between ~600ka and ~1.6Ma and is technically resolved by means of the 40Ar/39Ar dating technique. Therefore, the longevity of hydrothermal systems in medium-sized impact craters might be an order of magnitude longer than previously estimated. Prolonged post-impact heat flow in medium-sized craters, in analogy to Lappajärvi, might have played an important role in the emergence of life on early Earth and possibly Mars. © 2013 Elsevier Ltd.

Pidgeon R.T.,Curtin University Australia | Nemchin A.A.,Curtin University Australia | Cliff J.,University of Western Australia
Contributions to Mineralogy and Petrology | Year: 2013

Zircons from Archean granites from the Darling Range Batholith in the Yilgarn Craton of Western Australia have been shown to have complexly discordant U-Pb systems with a strong component of zero age disturbance. The only geological event that has affected the granites in recent times is the pervasive regional weathering. Our aim in this study was to investigate the effects of weathering on the U-Pb and oxygen systems of the zircons, and to this end, we report secondary ion mass spectrometry (SIMS) results of OH, oxygen and U-Pb isotope systems of six typical zircons from a sample of the granite. These results confirmed the presence of OH in highly radiation-damaged parts of the zircons, demonstrating fluid interaction within grains. The presence of OH was accompanied by significant changes in the 18O/16O ratios. The data suggest trends where δ18O values in individual grains both increase and decrease with increasing OH. SIMS measurements showed the U-Pb systems are variably and unsystematically discordant in radiation-damaged parts of the zircons, particularly those with elevated OH contents. The complex U-Pb systems are interpreted in terms of multiple disturbance events between 450 and 0 Ma involving low-temperature fluid-induced movement of radiogenic Pb, decoupled from parent U and Th, within the radiation-damaged zircons, together with some Pb loss. © 2013 Springer-Verlag Berlin Heidelberg.

Cooper C.E.,Curtin University Australia | Withers P.C.,University of Western Australia
Physiological and Biochemical Zoology | Year: 2010

Strict criteria have been established for measurement of basal metabolic rate and standard evaporative water loss to ensure that data can be compared intra- and interspecifically.However, data-sampling regimes vary, from essentially continuous sampling to interrupted (switching) systems with data recorded periodically at more widely spaced intervals. Here we compare one continuous and three interrupted sampling regimes to determine whether sampling regime has a significant effect on estimation of basal metabolic rate or standard evaporativewater loss. Compared to continuous 20-s sampling averaged over 20 min, sampling every 6 min and averaging over 60 min overestimated basal metabolic rate and evaporative water loss, sampling every 3 min and averaging over 21 min underestimated basal metabolic rate, and sampling every 12 min and averaging over 36 min showed no difference in estimates. Increasing the period over which the minimum mean was calculated significantly increased estimates of physiological variables. Reducing the frequency of sampling from 20 s to a longer interval of 3, 6, or 12 min underestimated basal metabolic rate but not evaporative water loss. This indicates that sampling frequency per se influences estimates of basal metabolic rate and that differences are not just an artifact of differences in the period over which the mean is calculated. Sampling regime can have a highly significant influence on estimation of standard physiological variables, although the actual differences between sampling regimes were generally small (usually <5%). Although continuous sampling is the preferred sampling regime for openflowrespirometry studies, if time and cost are prohibitive, then use of an appropriate switching system will result in smaller errors than measuring individuals continuously for shorter periods. © 2010 by The University of Chicago. All rights reserved.

Fisher C.,University of Western Australia | O'Connor M.,Curtin University Australia
Cancer Nursing | Year: 2012

Background: Breast cancer is the most commonly diagnosed cancer among women in Western Australia, with negative psychological impacts exacerbated for younger women. Many women survive 5 years following diagnosis, suggesting more young women and their families will be living with its ongoing effects for longer periods. Diagnosis and treatment impact a woman's identity as a mother, but limited research exists from the women's perspective. Objective: The aim of the study was to explore the impact of breast cancer on the identities of young women as "mothers." Methods: A qualitative research design using conversational in-depth interviews and guided by a social constructivist paradigm was used. In-depth interviews were undertaken with 8 young women who were living with breast cancer and had dependent children. Interviews were audiotaped, transcribed, and analyzed. Results: Biographical disruption as described by Bury provided the analytical framework for interpretation of data. Four themes, "diagnosis and disruption," "maintaining normality," "continuing the mothering role," and "experiencing survivorship," reflect women's experiences of identity reconstruction in the context of living with breast cancer. Conclusions: A breast cancer diagnosis precipitates complex changes in a woman's identity as a mother. A woman's postdiagnosis identity invariably integrates a changed prediagnosis identity and that of "breast cancer patient" and "survivor." The relationship between the 3 is dynamic and in constant tension. Implications for Practice: Routine practice should include acknowledgement that an identity as mother exists alongside "patient." Questions to women about children and any concerns and issues they may have should also be routine. Copyright © 2012 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.

Dam H.H.,Curtin University Australia | Cantoni A.,University of Western Australia
Signal Processing | Year: 2015

This paper proposes a new computational procedure for solving the optimal zero-forcing beamforming problem in multiple antenna channels that maximizes user achievable rate with restriction on the per-antenna element power constraints. An interior point method with optimal step size procedure is developed in which the step size for the line search in the Newton search direction is calculated exactly for each iteration. This significantly enhances the efficiency associated with the line search. Design examples show that the proposed algorithm converges rapidly to the optimal solution with low computational complexity. © 2014 Published by Elsevier B.V. All rights reserved.

Vleeshouwers V.G.A.A.,Wageningen University | Oliver R.P.,Curtin University Australia
Molecular Plant-Microbe Interactions | Year: 2014

One of most important challenges in plant breeding is improving resistance to the plethora of pathogens that threaten our crops. The ever-growing world population, changing pathogen populations, and fungicide resistance issues have increased the urgency of this task. In addition to a vital inflow of novel resistance sources into breeding programs, the functional characterization and deployment of resistance also needs improvement. Therefore, plant breeders need to adopt new strategies and techniques. In modern resistance breeding, effectors are emerging as tools to accelerate and improve the identification, functional characterization, and deployment of resistance genes. Since genome-wide catalogues of effectors have become available for various pathogens, including biotrophs as well as necrotrophs, effector-assisted breeding has been shown to be successful for various crops. "Effectoromics" has contributed to classical resistance breeding as well as for genetically modified approaches. Here, we present an overview of how effector-assisted breeding and deployment is being exploited for various pathosystems. © 2014 The American Phytopathological Society.

Rieck A.,Curtin University Australia | Pettigrew S.,University of Western Australia
Quality in Primary Care | Year: 2013

Background Community pharmacists (CPs) have been changing their role to focus on patient-centred services to improve the quality of chronic disease management (CDM) in primary care. However, CPs have not been readily included in collaborative CDM with other primary care professionals such as physicians. There is little understanding of the CP role change and whether it affects the utilisation of CPs in primary care collaborative CDM. Aim To explore physician and CP perceptions of the CP's role in Australian primary care and how these perceptions may influence the quality of physician/CP CDM programmes. Methods Data were collected from physicians and CPs using semi-structured interviews. A qualitative methodology utilising thematic analysis was employed during data analysis. Qualitative methodology trustworthiness techniques, negative case analysis and member checking were utilised to substantiate the resultant themes. Results A total of 22 physicians and 22 CPs were interviewed. Strong themes emerged regarding the participant perceptions of the CP's CDM role in primary care. The majority of interviewed physicians perceived that CPs did not have the appropriate CDM knowledge to complement physician knowledge to provide improved CDM compared with what they could provide on their own. Most of the interviewed CPs expressed a willingness and capability to undertake CDM; however, they were struggling to provide sustainable CDM in the business setting within which they function in the primary care environment. Conclusions Role theory was selected as it provided the optimum explanation of the resultant themes. First, physician lack of confidence in the appropriateness of CP CDM knowledge causes physicians to be confused about the role CPs would undertake in a collaborative CDM that would benefit the physicians and their patients. Thus, by increasing physician awareness of CP CDM knowledge, physicians may see CPs as suitable CDM collaborators. Second, CPs are experiencing role conflict and stress in trying to change their role. Strengthening the service business model may reduce these CP role issues and allow CPs to reach their full potential in CDM and improve the quality of collaborative CDM in Australian primary care. © 2013 Radcliffe Publishing.

Lentillon-Kaestner V.,University of Lausanne | Hagger M.S.,Curtin University Australia | Hardcastle S.,University of Brighton
Scandinavian Journal of Medicine and Science in Sports | Year: 2012

The protection of the health of athletes is one of the three criteria taken into account when registering a substance in the World Anti-Doping Agency prohibited list. Nevertheless, in elite-level cycling, banned substance use is widespread. The present research adopted a psychological approach to examine how or whether perceived health risks influence elite-level cyclists' decisions to use banned substances. Sixteen semi-structured interviews were conducted with cyclists hoping to join a professional team (n=6), neo-professional cyclists (n=2), and former professional cyclists (n=8). Although an evolution was observed in the organization of doping and perceptions of doping over the last decade, the perceived health hazards did not influence, most of the time, decisions to use banned substances among the sample of cyclists. There was a systematization of exogenous substance use in the cycling environment and a trivialization of the side effects of the banned substances. Finally, younger cyclists were not concerned about the long-term health consequences of banned substances; they were more focused on the short-term performance-enhancing benefits. There is a need to implement more effective preventive programs to change athletes' attitudes toward doping and its health risks. © 2011 John Wiley & Sons A/S.

Williams M.E.,Curtin University Australia | Thompson S.C.,University of Western Australia
Journal of Immigrant and Minority Health | Year: 2011

With large numbers of refugee arrivals and numerous barriers to accessing services it is especially important that resources are efficiently and effectively directed to address the health needs of refugees. Ten databases were utilised to conduct the review, returning 156 titles which were assessed for validity based on specified criteria. The 14 critically appraised articles included in this review consist of experimental research and discussions on best practice. Articles consistently demonstrated the benefit of community-based mental health service in improving mental health outcomes. Themes of cultural awareness, language, setting, and post-migration stressors emerged across the articles. In addition, the studies also point to the gaps in research of a longitudinal nature and ones that deal with scattered populations post migration. Communitybased interventions proved valuable for improving the mental health of refugees. However, additional interventions and evaluations are required to draw consistent and conclusive judgments on best practice in dealing with refugee mental health issues. © Springer Science+Business Media, LLC 2010.

Gucciardi D.F.,Curtin University Australia | Jackson B.,University of Western Australia
Journal of Science and Medicine in Sport | Year: 2015

Objectives: Fostering individuals' long-term participation in activities that promote positive development such as organised sport is an important agenda for research and practice. We integrated the theories of planned behaviour (TPB) and basic psychological needs (BPN) to identify factors associated with young adults' continuation in organised sport over a 12-month period. Design: Prospective study, including an online psycho-social assessment at Time 1 and an assessment of continuation in sport approximately 12 months later. Methods: Participants (N=. 292) aged between 17 and 21 years (M=. 18.03; SD. =. 1.29) completed an online survey assessing the theories of planned behaviour and basic psychological needs constructs. Bayesian structural equation modelling (BSEM) was employed to test the hypothesised theoretical sequence, using informative priors for structural relations based on empirical and theoretical expectations. Results: The analyses revealed support for the robustness of the hypothesised theoretical model in terms of the pattern of relations as well as the direction and strength of associations among the constructs derived from quantitative summaries of existing research and theoretical expectations. The satisfaction of basic psychological needs was associated with more positive attitudes, higher levels of perceived behavioural control, and more favourable subjective norms; positive attitudes and perceived behavioural control were associated with higher behavioural intentions; and both intentions and perceived behavioural control predicted sport continuation. Conclusions: This study demonstrated the utility of Bayesian structural equation modelling for testing the robustness of an integrated theoretical model, which is informed by empirical evidence from meta-analyses and theoretical expectations, for understanding sport continuation. © 2013.

Reuter S.,University of Ulm | Vo B.-T.,Curtin University Australia | Vo B.-N.,Curtin University Australia | Dietmayer K.,University of Ulm
IEEE Transactions on Signal Processing | Year: 2014

This paper proposes a generalization of the multi-Bernoulli filter called the labeled multi-Bernoulli filter that outputs target tracks. Moreover, the labeled multi-Bernoulli filter does not exhibit a cardinality bias due to a more accurate update approximation compared to the multi-Bernoulli filter by exploiting the conjugate prior form for labeled Random Finite Sets. The proposed filter can be interpreted as an efficient approximation of the δ-Generalized Labeled Multi-Bernoulli filter. It inherits the advantages of the multi-Bernoulli filter in regards to particle implementation and state estimation. It also inherits advantages of the δ-Generalized Labeled Multi-Bernoulli filter in that it outputs (labeled) target tracks and achieves better performance. © 2014 IEEE.

Lindwall M.,Gothenburg University | Larsman P.,Gothenburg University | Hagger M.S.,Curtin University Australia
Health Psychology | Year: 2011

Objective: The aim of this prospective study was to investigate the reciprocal nature of the physical activity-depressive symptoms relationship in 17,593 older adults from 11 European countries older adults (M age = 64.07, SD = 9.58) across two-year follow-up. Also, gender and age were examined as potential moderators of this relation. Method: A two-wave cross-lagged panel design and latent change score models with structural equation modeling was used to analyze data. Depressive symptoms were measured at baseline (T1) and follow-up (T2) using the EURO-D scale, capturing the two factors of affective suffering and motivation. Physical activity was measured at T1 and T2 as frequency of moderate physical activity and vigorous physical activity. Results: Cross-sectional latent variable analyses revealed that higher levels of physical activity at T1 and T2 were associated with lower levels of affective suffering and motivation at T1 and T2. Physical activity at T1 was significantly associated with affective suffering and motivation at T2. The relations of depressive symptoms at T1 with physical activity at T2 were not significant. However, a cross-lagged model showed best model fit, supporting a reciprocal prospective relationship between physical activity and depressive symptoms in older adults. Latent change in depressive symptoms factors was related to latent change in physical activity indicating complex and dynamic associations across time. Conclusions: Regular physical activity may be a valuable tool in the prevention of future depressive symptoms in older adults, and depressive symptoms may also prevent older adults from engaging in regular physical activity. © 2011 American Psychological Association.

Ebert J.R.,University of Western Australia | Smith A.,Curtin University Australia | Wood D.J.,University of Western Australia | Ackland T.R.,University of Western Australia
American Journal of Sports Medicine | Year: 2013

Background: Patient-reported outcome (PRO) instruments are employed to assess outcomes after matrix-induced autologous chondrocyte implantation (MACI), although the PRO most responsive to change after surgery remains unknown. Purpose: To compare the responsiveness of 4 commonly used PRO instruments at 5 years after MACI. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The Knee Injury and Osteoarthritis Outcome Score (KOOS), the Lysholm score, the Tegner activity scale, and the 36- item Short Form Health Survey (SF-36) were administered to 104 patients before and at 5 years after MACI knee surgery. The Selfadministered Patient Satisfaction Scale was employed at 5 years to investigate each patient's overall level of satisfaction as well as satisfaction with relieving pain and improving the ability to perform daily activities, partake in recreational activities, and participate in sport. The effect size (ES) and standardized response mean (SRM) were used to compare PRO responsiveness. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the extent to which PRO changes were associated with satisfaction. The minimal clinically important difference (MCID) according to the criterion of patient satisfaction was identified as the PRO instrument change score maximizing classification accuracy. Results: The most responsive PRO measures were the KOOS sport/recreation (ES, 1.63; SRM, 1.43) and quality of life (QOL) (ES, 1.37; SRM, 1.18) subscales. The least responsive were the SF-36 mental component summary (MCS) (ES, 0.38; SRM, 0.40) and the Tegner activity scale (ES, 0.91; SRM, 0.59). Of the 104 patients, 54 (51.9%) reported being "very satisfied," 38 (36.5%) "somewhat satisfied," 8 (7.7%) "somewhat dissatisfied," and 4 (3.9%) "very dissatisfied." A ROC curve analysis was performed using "very satisfied" as the responder criterion. The strongest association was between the change in KOOS sport/recreation with satisfaction in improving the ability to perform recreational activities (area under the curve, 0.756; 95% confidence interval, 0.663-0.849), and the change score maximizing prediction accuracy (MCID) was 40 (sensitivity, 69%; specificity, 76%). Conclusion: The KOOS sport/recreation and QOL subscales were the most responsive PRO measures and were most predictive of satisfaction. This information will provide a guide as to the improvements required in pertinent PRO measures to produce a satisfied patient, while allowing researchers to better structure trials in these patients using the most relevant PRO instruments. © 2013 The Author(s).

Cairney J.,McMaster University | Rigoli D.,Curtin University Australia | Piek J.,Curtin University Australia
Developmental Review | Year: 2013

There is a growing literature connecting poor motor coordination to physical and mental health outcomes in children and adolescents. These studies suggest that children with disorders such as developmental coordination disorder (DCD) are at greater risk for depression and anxiety, as well as obesity, and poor physical fitness. With regard to internalizing problems (symptoms of depression and anxiety), there is also evidence to suggest that the environment may play an important role in the etiology of psychological distress in this population. Cairney, Veldhuizen, & Szatmari, 2010 used the phrase "environmental stress hypothesis" to highlight the role that negative exposure to personal and interpersonal stressors might play in accounting for higher rates of internalizing symptoms in children with DCD. In this paper, we elaborate further on this basic premise, offering a model linking DCD to internalizing problems based on Pearlin's stress process framework. In addition to stressors (risk) and protective factors, we incorporate both physical activity and obesity into our stress model. Next, we review the existing literature to see if there is evidence supporting specific components (pathways) of the model. In doing so, areas in need of further research are identified. Implications for intervention are also provided. © 2013 Elsevier Inc.

Nguyen T.L.,University of Western Australia | Do K.D.,Curtin University Australia | Pan J.,University of Western Australia
Journal of Sound and Vibration | Year: 2013

The aim of this paper is to design a boundary controller for global stabilization of two-dimensional marine risers under environmental disturbances. Based on the energy approach, equations of motion including bending couplings for the risers are derived. Due to the couplings, the riser dynamics exhibit mutual effects between transverse motions. The Lyapunov direct method is used to design the boundary controller. Proof of the existence and uniqueness of the solutions of the closed-loop system is provided based on the Galerkin approximation method. Stability analysis of the closed-loop system is carried out using the Lyapunov stability theory. Numerical simulations illustrate the results. © 2013 Elsevier Ltd.

He T.,Curtin University Australia | He T.,University of Western Australia | Lamont B.B.,Curtin University Australia | Downes K.S.,Curtin University Australia
New Phytologist | Year: 2011

Historical evidence of recurrent fire in many of the world's biomes suggests that fire may have had profound evolutionary influences on their extant floras. However, the role of fire as a selective force in the origin and evolution of plant traits remains controversial. Using Bayesian Monte-Carlo-Markov-Chain procedures and calibration points from the fossil record, we generated a dated phylogeny for the iconic Australian genus Banksia, and reconstructed the evolutionary/chronological position of five putatively fire-related traits. The fire-dependent trait, on-plant seed storage (serotiny), and associated fire-enhancing trait, dead floret retention, co-originated with the first appearance of Banksia 60.8million yr ago (Palaeocene). Whether nonsprouting or resprouting is ancestral was indeterminable, but the first banksias were nonclonal. Derived traits, such as dead leaf retention (fire-enhancing) and clonality (underground budbanks; fire-avoiding), first appeared 26-16million yr ago (Miocene) with the onset of seasonal drought and thus more frequent fire, and culminated in dead florets/bracts completely covering the persistent fruits in some species. Thus, fire may have been a selective force in the very origin of Banksia 40million yr before the onset of climate seasonality in the Miocene, and continued to have an impact on the direction of evolution, favouring traits consistent with adaptation to an increasingly (sometimes less) fire-prone environment. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Norman P.E.,University of Western Australia | Spilsbury K.,Curtin University Australia | Semmens J.B.,Curtin University Australia
Journal of Vascular Surgery | Year: 2011

Background Studies of the population trends for abdominal aortic aneurysms (AAAs) in the period 1970 to 2000 all indicated that the incidence of AAAs was increasing. It is not known whether this increase has continued. We hypothesized that the incidence of AAAs has begun to fall in Australia. Methods Age-standardized national trends in mortality from AAAs were estimated for the period 1999 to 2006, and hospital separations (deaths or discharges) for AAAs were estimated for the period 1999 to 2008. Poisson regression models were constructed to estimate the relative change over time. Results The age-standardized mortality rate from AAAs fell by an average of 6.0% (95% confidence interval [CI], 4.7-7.3) per annum in men and 2.9% (95% CI, 1.0-4.7) in women. After adjusting for age, hospital separations for men decreased by an average of 2.3% (95% CI, 1.4-2.7) per annum for nonruptured AAAs, and 5.9% (95% CI, 5.0-6.6) for ruptured AAAs and for women decreased by an average of 2.2% (95% CI, 1.4-3.0) per annum for nonruptured AAAs, and 5.1% (95% CI, 3.7-6.5) for ruptured AAAs. Ruptured, compared with nonruptured, AAAs were proportionally more common in women compared with men. The age-specific trends in separations from hospital were all downward apart from nonruptured AAAs in individuals aged 80 years and over. Conclusions The rates of separation from hospital and mortality for AAAs in Australia have fallen since 1999. This suggests a true fall in incidence of AAAs. Although the reasons for this are unknown, it has implications for policy decisions about screening. © 2011 Society for Vascular Surgery.

Webster J.,Northumbria University | Whitworth A.,Curtin University Australia
International Journal of Language and Communication Disorders | Year: 2012

Background: In recent years there has been significant interest in the differential processing of nouns and verbs in people with aphasia, but more limited consideration about whether the differences have implications for therapy. It remains unclear whether verbs can be treated in a similar way to nouns or should be treated using approaches that recognize the relationship between verb retrieval and sentence production. Aims: This paper reviews studies focusing on therapy for spoken verb retrieval, considering the impact of therapy on treated and untreated verbs, sentence production and connected speech. It explores whether there are differential gains across therapy paradigms and whether verbs respond to therapy in the same way as nouns. Method & Procedures: Studies were identified using a systematic search. A total of 26 studies were reviewed and classified under four headings: (1) studies that treated verbs in a single-word context, (2) studies that compared treatment for nouns and verbs, (3) studies that treated verbs in a sentence context, and (4) studies that treated verb retrieval and argument structure. Main Contribution: Findings from the review demonstrate that verb therapy, irrespective of whether verbs are treated within a single-word or sentence context, is effective in improving the retrieval of treated verbs, but with limited generalization to untreated verbs. Verbs respond very similarly to nouns when treated using the same techniques, but improving verb retrieval may be harder to achieve than improving noun retrieval. The impact on sentence production is more varied. The gains in sentence production are discussed in relation to the different therapy types, the rationale for therapy and the presence of co-occurring sentence difficulties. Conclusions: The review highlights the need for more systematic evaluation of different types of verb therapy, measuring the impact of therapy on verb retrieval, sentence production and connected speech. Only through the judicious assessment and monitoring of change across different contexts will an understanding of how verbs respond to therapy be developed and what generalization patterns can be predicted. This will lead to increased confidence in the selection of therapy approaches for people with verb difficulties in aphasia. © 2012 Royal College of Speech and Language Therapists.

Gebauer D.,University of Konstanz | Kellermeier M.,University of Konstanz | Gale J.D.,Curtin University Australia | Bergstrom L.,University of Stockholm | Colfen H.,University of Konstanz
Chemical Society Reviews | Year: 2014

Crystallisation is at the heart of various scientific disciplines, but still the understanding of the molecular mechanisms underlying phase separation and the formation of the first solid particles in aqueous solution is rather limited. In this review, classical nucleation theory, as well as established concepts of spinodal decomposition and liquid-liquid demixing, is introduced together with a description of the recently proposed pre-nucleation cluster pathway. The features of pre-nucleation clusters are presented and discussed in relation to recent modifications of the classical and established models for phase separation, together with a review of experimental work and computer simulations on the characteristics of pre-nucleation clusters of calcium phosphate, calcium carbonate, iron(oxy)(hydr)oxide, silica, and also amino acids as an example of small organic molecules. The role of pre-nucleation clusters as solute precursors in the emergence of a new phase is summarized, and the link between the chemical speciation of homogeneous solutions and the process of phase separation via pre-nucleation clusters is highlighted. This journal is © the Partner Organisations 2014.

Yao Z.T.,Hangzhou Dianzi University | Yao Z.T.,Zhejiang University | Xia M.S.,Zhejiang University | Xia M.S.,State Oceanic Administration | And 2 more authors.
Fuel | Year: 2014

Coal fly ash, an industrial by-product, is derived from coal combustion in thermal power plants. It is one of the most complex and abundant of anthropogenic materials, and its improper disposal has become an environmental concern and resulted in a waste of recoverable resources. Coal fly ash is rich in alumina, making it a potential substitute for bauxite. With the diminishing reserves of bauxite resources as well as the increasing demand for alumina, recovering alumina from fly ash has attracted extensive attentions. The present review first describes the alumina recovery history and technologies, and then focuses on the recovery status in China. Finally, the current status of fly ash recycling and directions for future research are considered. © 2013 Elsevier Ltd. All rights reserved.

Orlando L.,Copenhagen University | Orlando L.,University Paul Sabatier | Gilbert M.T.P.,Copenhagen University | Gilbert M.T.P.,Curtin University Australia |