Wollongong, Australia
Wollongong, Australia

The University of Wollongong , abbreviated as UOW, is a public research university located in the coastal city of Wollongong, New South Wales, Australia, approximately 80 kilometres south of Sydney. As of 2014, the University has over 37,000 students enrolled, included over 11,600 international students from 134 countries, an alumni base of over 112,000, and over 2,000 academic related staff. The University has been ranked 9th in Excellence in Research for Australia Australian University Rankings in 2012, among the top 1% for research quality in the world, and among the top 2% of universities in the world. The University ranked 276th in the 2013 QS World University Rankings, 276-300th in the 2013-2014 Times Higher Education World University Rankings and 301-400th in the 2013 Academic Ranking of World Universities.In 1951 a division of the New South Wales University of Technology was established at Wollongong for the conduct of diploma courses. In 1961 the Wollongong University College of the University of New South Wales was constituted and the College was officially opened in 1962. In 1975 the University of Wollongong was established as an independent institution. Since its establishment, the University has conferred more than 100,000 degrees, diplomas and certificates. Its students, originally predominantly from the local Illawarra region, are now from over 140 countries, with international students accounting for more than 30 percent of total.The University of Wollongong has fundamentally developed into a multi-campus institution, three of which are in Illawarra , one in Sydney and two overseas campus in Dubai, United Arab Emirates and Sejong City, South Korea. The Wollongong Campus, the University's Main Campus, is on the original site five kilometres north-west of the city centre, and covers an area of 82.4 hectares with 94 permanent buildings including six student residences. In addition, there are University Education Centres in Bega, Batemans Bay, Moss Vale and Loftus as well as the Sydney Business School in the City of Sydney. The University also offers courses equally based on the Wollongong Campus in collaboration with partner institutions in a number of offshore locations including in Singapore, Malaysia and Hong Kong.The University of Wollongong marked the University's 60th Founding Anniversary in the Year of 2011. Wikipedia.

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Hadi M.N.S.,University of Wollongong | Yuan J.S.,University of Wollongong
Construction and Building Materials | Year: 2017

This paper presents results of an experimental study on the flexural behaviour of a composite beam, which is reinforced with longitudinal tensile steel bars as well as glass fibre reinforced polymer (GFRP) pultruded I-beam encased in concrete. Five beam specimens, including one traditional reinforced concrete (RC) beam and four composite beams, were cast and tested under four-point bending. The variables involved in the composite beams include the type of longitudinal tensile bars (steel bars and GFRP bars) and the location of the I-beam in the cross-section (middle and a shift of 30 mm towards the tension region). The test results presented in this study show that the proposed composite beams have a very ductile response due to the existence of the tensile steel bars, and the yield point of the composite beam is controlled by the tensile steel bars. The ultimate load of the proposed composite beam in this study is higher than the traditional RC beam in this study, and the ultimate load is governed by the encased I-beam. When GFRP bars were used to replace the tensile steel bars to reinforce the composite beams, the brittle failure of GFRP bars caused lack of ductility of the beam members, and both the stiffness and ultimate load were reduced significantly. Compared with steel bars, the slip between the concrete and the I-beam was also increased when GFRP bars were used. The different location of the I-beam has little effect on the flexural response. © 2017 Elsevier Ltd

Wigan M.,University of Wollongong
IEEE Technology and Society Magazine | Year: 2017

Definitions are a key factor when discussing the ethics of brain implants in the military. There is a world of difference between a permanent embedded rewritable chip and an active RFID-managed interface to a nervous system. © 1982-2012 IEEE.

Feng X.,University of Wollongong | Astell-Burt T.,University of Wollongong
International Journal of Environmental Research and Public Health | Year: 2017

Recent reviews of the rapidly growing scientific literature on neighbourhood green space and health show strong evidence for protective and restorative effects on mental wellbeing. However, multiple informants are common when reporting mental wellbeing in studies of children. Do different informants lead to different results? This study utilised nationally representative data on Goodman’s 25-item Strengths and Difficulties Questionnaire reported by 3083 children (aged 12–13 years old), and their parents and teachers. Multilevel models were used to investigate whether similar associations between child mental wellbeing (as measured using the total difficulties score and the internalising and externalising subscales) and neighbourhood green space quantity and quality are obtained regardless of the informant. After adjustment for confounders, higher green space quantity and quality were associated with consistently more favourable child mental wellbeing on all three measures, regardless of the informant. However, associations with green space quantity were statistically significant (p < 0.05) only for the parent-reported total difficulties score and the internalising subscale. Significant associations with green space quality were consistently observed for both parent- and child-reported outcomes. Teacher-reported outcomes were not significantly associated with green space exposure. Future studies of green space and child health should acknowledge when different informants of outcomes could lead to different conclusions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.

Teh L.H.,University of Wollongong | Uz M.E.,Adnan Menderes University
Journal of Structural Engineering (United States) | Year: 2017

This paper examines the accuracy of design equations specified in the North American, European, and Australasian codes for cold-formed steel structures in determining the ultimate tilt-bearing capacity of single-shear bolted connections without washers in flat steel sheets. It points out that all the code equations do not properly distinguish the tilt-bearing failure mode from the conventional bearing failure mode. While the latter takes place downstream of the bolt, the former takes place upstream. Unlike the conventional bearing capacity, the tilt-bearing capacity is affected by the width of the connected sheet and does not vary linearly with either the sheet thickness or the bolt diameter. Furthermore, it is not affected by material ductility. Based on the test results of 156 specimens composed of G2 and G450 sheet steels having various dimensional configurations, this paper proposes a design equation that is dimensionally consistent and that is considerably more accurate than all the code equations. The proposed equation was also verified against single-shear single-row bolted connections tested by independent researchers which failed in the tilt-bearing mode. The verified thicknesses ranged from 0.92 to 3.0 mm, and the bolt diameters ranged from 6.4 to 16 mm. An additional finding is that the tilt-bearing capacity is not significantly affected by the orientation of the bolt head or nut. A resistance factor of 0.75 is recommended for use with the proposed equation for determining the tilt-bearing capacity of single shear single-row bolted connections in cold-reduced steel sheets. © 2016 American Society of Civil Engineers.

De Vet E.,University of Wollongong
Weather, Climate, and Society | Year: 2017

Climates are changing, yet the everyday implications for societies and cultures are unclear. Until recently, weather and climate (change) have been largely represented quantitatively and discussed at broad spatial and social scales. Qualitative weather research is helping to reconnect weather with its diverse local meanings and to explain how climate change may alter future representational and behavioral understands of weather (herein called ''weather-relations'') in the hope of furthering climate change action. Responding to the need for greater research into weather-relations, particularly in industrialized urban areas, this paper examines the role of weather in everyday life in tropical Darwin, Australia. It identifies a willingness among participants to stay ''weather-connected'' despite challenging weather conditions and access to air conditioning. This willingness is driven by desires to remain acclimatized in order to enhance positive weather sensations, retain outdoor lifestyles, and reduce financial and environmental costs associated with resource-intensive technologies. In delving into weather adjustment strategies that facilitate weather-connectedness along with possible climate change implications, greater potential for weather-relations research is recognized. By drawing attention to weather experiences and understandings alongside resource efficient weather responses, this paper uncovered a substantial capacity among participants to respond sustainably to environmental change. These capacities are the outcome of adjustment practices relating to food, clothing, laundering, physical and outdoor activities, and domestic comfort and a previously unrecognized coping strategy expressions of tolerance. Findings suggest that by recognizing and fostering existing adjustment capabilities of societies and cultures and the local values that afford their reproduction, communities would be better placed to adapt to future climate change. © 2017 American Meteorological Society.

Ngo N.T.,University of Wollongong | Indraratna B.,University of Wollongong | Rujikiatkamjorn C.,University of Wollongong
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2017

Railway ballast comprises unbounded discrete grains that are often used to form a load-bearing platform for tracks. Ballast degradation as trains pass over the tracks and infiltration of external fines including slurried (pumped) fine subgrade soils are two of the main reasons for ballast fouling. Fouling causes tracks to settle and also reduces the load-bearing capacity, which is associated with a reduction in internal friction and increased lateral spreading of the ballast layer. This paper presents a study of mobilized friction angle, volumetric behavior, and associated evolutions of contact and fabric anisotropy of fouled ballast subjected to monotonic triaxial loading using a series of large-scale triaxial tests and discrete element modeling. Monotonically loaded and drained triaxial tests were carried out on ballast with levels of clay fouling that varied from 10 to 50% void contamination index (VCI) subjected to three confining pressures of 10, 30, and 60 kPa. The results showed that an increase in the level of fouling decreased the mobilized friction angle and increased the ballast dilation. The discrete element method (DEM) was used to study the mobilized friction angle and fabric anisotropy of fresh and fouled ballast by simulating actual large-scale triaxial tests. Irregular shaped grains of ballast were simulated by clumping bonded circular balls with appropriate sizes and positions together. Ballast fouling was approximately simulated in DEM by adding 1-mm particles into the pore spaces of the fresh ballast. The predicted mobilized friction angles and volumetric changes obtained from the DEM simulations agreed well with those measured in the laboratory, indicating that the peak friction angle of fouled ballast and dilation decreased as the degree of fouling increased. The DEM simulations provided an insight into the distribution of contact force chains, contact orientations, and evolution of fabric anisotropy of fresh and fouled ballast that could not be captured in the laboratory. These observations are important for a better understanding of the load-deformation behavior of fouled ballast from the perspective of micromechanics. © 2016 American Society of Civil Engineers.

Feng X.,University of Wollongong | Astell-Burt T.,University of Wollongong
BMJ Open Diabetes Research and Care | Year: 2017

Aims: The aim was to examine whether a type 2 diabetes mellitus (T2DM) diagnosis increases the odds of psychological distress, a worsening in overall quality of life, and a potential reduction in social contacts. Method: Longitudinal data were obtained from the 45 and Up Study (baseline 2006–2008; 3.4±0.95 years follow-up time). Fixed effects logistic and negative binomial regression models were fitted on a complete case on outcome sample that did not report T2DM at baseline (N=26 344), adjusted for time-varying confounders. The key exposure was doctor-diagnosed T2DM at follow-up. Outcome variables examined included the Kessler Psychological Distress Scale, self-rated quality of life, and four indicators of social contacts. Results: A modest increase in the odds of psychological distress associated with T2DM diagnosis (OR=1.30) was not statistically significant (95% CI 0.75 to 2.25). A T2DM diagnosis was associated with a fivefold increase in the odds of a participant reporting that their quality of life had become significantly poorer (OR 5.49, 95% CI 1.26 to 23.88). T2DM diagnosis was also associated with a reduction in times spent with friends and family (RR 0.88, 95% CI 0.82 to 0.95), contacts by telephone (RR 0.95, 95% CI 0.87 to 1.02), attendance at social clubs or religious groups (RR 0.82, 95% CI 0.73 to 0.91), and the number of people nearby but outside the home that participants felt they could rely on (RR 0.92, 95% CI 0.86 to 0.98). Conclusions: A T2DM diagnosis can have important impacts on quality of life and on social contacts, which may have negative impacts on mental health and T2DM management in the longer term. © 2017, BMJ Publishing Group. All Rights Reserved.

Pourashraf P.,University of Wollongong | Safaei F.,University of Wollongong | Franklin D.R.,University of Sydney
IEEE Journal on Selected Topics in Signal Processing | Year: 2017

This paper reports on the result of a user study to assess the impact of resolution and frame rate of video on the quality of experience of the users, when the video is rendered inside a 3-D virtual space, and consequently viewed from arbitrary perspectives. A mathematical model for video rate is presented that expresses the total rate as the product of separate functions of spatial and temporal resolutions. Results from the user study are combined with the model to predict the rate parameters which will result in perceptually acceptable quality using the 3-D features of the virtual environment. The results show that by exploiting the insensitivity of users to controlled quality degradation, the downstream network load for the client can be significantly reduced with little or no perceptual impact on the clients. © 2016 IEEE.

Machado-Moreira C.A.,University of Wollongong | Taylor N.A.S.,University of Wollongong
Journal of Thermal Biology | Year: 2017

Human eccrine sweat-gland recruitment and secretion rates were investigated from the glabrous (volar) and non-glabrous hand surfaces during psychogenic (mental arithmetic) and thermogenic stimuli (mild hyperthermia). It was hypothesised that these treatments would activate glands from both skin surfaces, with the non-thermal stimulus increasing secretion rates primarily by recruiting more sweat glands. Ten healthy men participated in two seated, resting trials in temperate conditions (25–26 °C). Trials commenced under normothermic conditions during which the first psychogenic stress was applied. That was followed by passive heating (0.5 °C mean body temperature elevation) and thermal clamping, with a second cognitive challenge then applied. Sudomotor activity was evaluated from both hands, with colourimetry used to identify activated sweat glands, skin conductance to determine the onset of precursor sweating and ventilated sweat capsules to measure rates of discharged sweating. From glandular activation and sweat rate data, sweat-gland outputs were derived. These psychogenic and thermogenic stimuli activated sweat glands from both the glabrous and non-glabrous skin surfaces, with the former dominating at the glabrous skin and the latter at the non-glabrous surface. Indeed, those stimuli individually accounted for ~90% of the site-specific maximal number of activated sweat glands observed when both stimuli were simultaneously applied. During the normothermic psychological stimulation, sweating from the glabrous surface was elevated via a 185% increase in the number of activated glands within the first 60 s. The hypothetical mechanism for this response may involve the serial activation of additional eccrine sweat glands during the progressive evolution of psychogenic sweating. © 2017 Elsevier Ltd

Fergusson C.L.,University of Wollongong
Australian Journal of Earth Sciences | Year: 2017

In the late Silurian, the Lachlan Orogen of southeastern Australia had a varied paleogeography with deep-marine, shallow-marine, subaerial environments and widespread igneous activity reflecting an extensional backarc setting. This changed to a compressional–extensional regime in the Devonian associated with episodic compressional events, including the Bindian, Tabberabberan and Kanimblan orogenies. The Early Devonian Bindian Orogeny was associated with SSE transport of the Wagga–Omeo Zone that was synchronous with thick sedimentation in the Cobar and Darling basins in central and western New South Wales. Shortening has been controlled by the margins of the Wagga–Omeo Zone with partitioning along strike-slip faults, such as along the Gilmore Fault, and inversion of pre-existing extensional basins including the Limestone Creek Graben and the Canbelego–Mineral Hill Volcanic Belt. Shortening was more widespread in the late Early Devonian to Middle Devonian Tabberabberan Orogeny, with major deformation in the Melbourne Zone, Cobar Basin and eastern Lachlan Orogen. In the eastern Melbourne Zone, structural trends have been controlled by the pre-existing structural grain in the adjacent Tabberabbera Zone. Elsewhere Tabberabberan deformation involved inversion of pre-existing rifts resulting in a variation in structural trends. In the Early Carboniferous, the Lachlan Orogen was in a compressional backarc setting west of the New England continental margin arc with Kanimblan deformation most evident in Upper Devonian units in the eastern Lachlan Orogen. Kanimblan structures include major thrusts and associated fault-propagation folds indicated by footwall synclines with a steeply dipping to overturned limb adjacent to the fault. Ongoing deformation and sedimentation have been documented in the Mt Howitt Province of eastern Victoria. Overall, structural trends reflect a combination of controls provided by reactivation of pre-existing contractional and extensional structures in dominantly E–W shortening operating intermittently from the earliest Devonian to Early Carboniferous. © 2017 Geological Society of Australia

Cox D.,University of Wollongong | Ecroyd H.,University of Wollongong
Cell Stress and Chaperones | Year: 2017

Protein homeostasis, or proteostasis, is the process of maintaining the conformational and functional integrity of the proteome. Proteostasis is preserved in the face of stress by a complex network of cellular machinery, including the small heat shock molecular chaperone proteins (sHsps), which act to inhibit the aggregation and deposition of misfolded protein intermediates. Despite this, the pathogenesis of several neurodegenerative diseases has been inextricably linked with the amyloid fibrillar aggregation and deposition of α-synuclein (α-syn). The sHsps are potent inhibitors of α-syn aggregation in vitro. However, the limited availability of a robust, cell-based model of α-syn aggregation has, thus far, restricted evaluation of sHsp efficacy in the cellular context. As such, this work sought to establish a robust model of intracellular α-syn aggregation using Neuro-2a cells. Aggregation of α-syn was found to be sensitive to inhibition of autophagy and the proteasome, resulting in a significant increase in the proportion of cells containing α-syn inclusions. This model was then used to evaluate the capacity of the sHsps, αB-c and Hsp27, to prevent α-syn aggregation in cells. To do so, we used bicistronic expression plasmids to express the sHsps. Unlike traditional fluorescent fusion constructs, these bicistronic expression plasmids enable only individual transfected cells expressing the sHsps (via expression of the fluorescent reporter) to be analysed, but without the need to tag the sHsp, which can affect its oligomeric structure and chaperone activity. Overexpression of both αB-c and Hsp27 significantly reduced the intracellular aggregation of α-syn. Thus, these findings suggest that overexpressing or boosting the activity of sHsps may be a way of preventing amyloid fibrillar aggregation of α-syn in the context of neurodegenerative disease. © 2017 Cell Stress Society International

Menary R.,University of Wollongong
Encyclopedia of Consciousness | Year: 2010

Intentionality is usually defined as the directedness of the mind toward something other than itself. My desire for a cold beer is directed at the cold beer in front of me. Much of consciousness is intentional, my conscious experiences are usually directed at something. However, conscious experiences typically have a phenomenal character: there is something it is like for me to see the deep blue of the Pacific Ocean and to feel the warm water lapping over my feet, and to smell the briny breeze. An important question to answer concerning the relationship between intentionality and consciousness is whether all conscious states are intentional? Another question concerns the explanatory priority of intentionality and phenomenal character: Can phenomenal character be explained in terms of intentionality? Or is it the case that intentionality should be understood in terms of phenomenology? Philosophers from the analytic, phenomenological, and naturalistic traditions have all made important contributions to our understanding of intentionality and consciousness. Some philosophers, such as Dretske, think that our phenomenology is intentionally structured. Others, such as Horgan and Tienson think that intentionality is fundamentally determined by our phenomenology. This looks like an impasse; however it may well be resolved by a combination of contemporary accounts of representation combined with an embodied phenomenology. © 2009 Elsevier Inc. All rights reserved.

Menary R.,University of Wollongong
Encyclopedia of Consciousness | Year: 2010

Intentionality is usually defined as the directedness of the mind toward something other than itself. My desire for a cold beer is directed at the cold beer in front of me. Much of consciousness is intentional, my conscious experiences are usually directed at something. However, conscious experiences typically have a phenomenal character: there is something it is like for me to see the deep blue of the Pacific Ocean and to feel the warm water lapping over my feet, and to smell the briny breeze. An important question to answer concerning the relationship between intentionality and consciousness is whether all conscious states are intentional? Another question concerns the explanatory priority of intentionality and phenomenal character: Can phenomenal character be explained in terms of intentionality? Or is it the case that intentionality should be understood in terms of phenomenology? Philosophers from the analytic, phenomenological, and naturalistic traditions have all made important contributions to our understanding of intentionality and consciousness. Some philosophers, such as Dretske, think that our phenomenology is intentionally structured. Others, such as Horgan and Tienson think that intentionality is fundamentally determined by our phenomenology. This looks like an impasse; however it may well be resolved by a combination of contemporary accounts of representation combined with an embodied phenomenology. © 2009 Elsevier Inc. All rights reserved.

Jacobs Z.,University of Wollongong | Roberts R.G.,University of Wollongong
Journal of Human Evolution | Year: 2017

The chronology of the Still Bay (SB) and Howieson's Poort (HP) lithic industries remains an issue of keen interest because of the central role of these two phases of technological and behavioural innovation within the Middle Stone Age of southern Africa. Several dating studies have been conducted on SB and HP sites, including a pair published by the present authors and our colleagues in 2008 and 2013. These reported the results of systematically applying single-grain optically stimulated luminescence (OSL) dating procedures to 10 sites in South Africa, Lesotho and Namibia to constrain the timing of the start and end of the SB and HP and reveal the existence of a gap of several millennia between them. Alternative ages for these two industries have since been proposed by others for one of these South African sites (Diepkloof Rockshelter) and some concerns have been raised about the procedures used in our earlier studies to estimate the beta dose rates for a small number of samples. Here, we provide an update on our chronology for the SB and HP and address the issues raised about the methods that we used previously to estimate the beta dose rates and their associated uncertainties. To test the sensitivity of our new SB and HP ages to different underlying assumptions, we have run the same statistical model as that used in our 2008 and 2013 studies under three different scenarios. We show that the ages for the different samples are insensitive to how we analytically process or statistically model our data, and that our earlier conclusions about timing of the start and end of the SB and the HP and the probability of a gap between them remain true for two of the three scenarios. We conclude by bringing our study into the context of additional chronometric, stratigraphic and lithic technology studies that have been conducted in the intervening decade. © 2017 Elsevier Ltd

Fu X.,University of Wollongong | Cohen T.J.,University of Wollongong | Arnold L.J.,University of Adelaide
Quaternary Science Reviews | Year: 2017

We show with multiple luminescence dating techniques that the sedimentary record for Lake Eyre, Australia's largest lake, extends beyond 200 thousand years (ka) to Marine Isotope Stage (MIS) 7. Transgressive clayey sand and finely laminated clays overlying the Miocene Etadunna Formation in Lake Eyre North document the deep-lake phases of central South Australia in the past. Until now, unresolved chronology has hampered our ability to interpret these sedimentary records, which are important for understanding the timing of the wettest phase of central Australia's late Quaternary climate. In this study, we apply quartz optically stimulated luminescence (OSL) dating, thermally-transferred OSL (TT-OSL) dating and K-feldspar post infrared infrared stimulated luminescence (pIRIR) dating to lake-floor sediments near Williams Point in Madigan Gulf to provide new age constraint for the lacustrine sediments of Lake Eyre. Methodological studies on quartz and K-feldspar demonstrate that these luminescence dating procedures are suitable for the Lake Eyre lacustrine samples and produce consistent replicate ages. A Bayesian model applied to the new dating results provides a chronological model of lacustrine deposition and shows that the transgressive clayey sand were deposited 221 ± 19 ka to 201 ± 10 ka and that the deep-water sediments were laid down in early MIS 6 (191 ± 9 ka to 181 ± 9 ka). We also find evidence for a potential depositional hiatus in mid MIS 6 and the likely formation of a palaeo-playa later in MIS 6 from 158 ± 11 ka to 143 ± 15 ka. In contrast, the MIS 5 sediments are characterised by oscillating deep- and shallow-water lacustrine units deposited 130 ± 16 ka to 113 ± 20 ka. This study is the first of its kind to provide evidence for a wet desert interior in Australia beyond the last glacial cycle using comprehensive numerical dating. Our results show that past deep-lake episodes of central South Australia, which were previously thought to represent peak interglacial conditions, are actually associated with both warm interglacial and cold glacial periods, with all the wettest episodes generally coinciding with the intervening periods between the glacial and interglacial maximums. We assume from these results that orbital forcing is not a first order control for the long-term dynamics of the Lake Eyre basin and the Indo-Australian monsoon. The high lake-level events of Lake Eyre are well correlated with millennial-scale cooling events and stadials of the North Atlantic, and coincide with weakened episodes/events for the East Asia summer monsoon. This may imply an important role for the northern high latitudes in influencing the Indo-Australian monsoon, which may be associated with a southward migration of the Intertropical Convergence Zone (ITCZ) during cooling periods in the North Atlantic. © 2017 Elsevier Ltd

Yang J.,University of Wollongong | Yecies B.,University of Wollongong
Journal of Big Data | Year: 2016

Analysis of online user-generated content is receiving attention for its wide applications from both academic researchers and industry stakeholders. In this pilot study, we address common Big Data problems of time constraints and memory costs involved with using standard single-machine hardware and software. A novel Big Data processing framework is proposed to investigate a niche subset of user-generated popular culture content on Douban, a well-known Chinese-language online social network. Huge data samples are harvested via an asynchronous scraping crawler. We also discuss how to manipulate heterogeneous features from raw samples to facilitate analysis of various film details, review comments, and user profiles on Douban with specific regard to a wave of South Korean films (2003–2014), which have increased in popularity among Chinese film fans. In addition, an improved Apriori algorithm based on MapReduce is proposed for content-mining functions. An exploratory simulation of results demonstrates the flexibility and applicability of the proposed framework for extracting relevant information from complex social media data, knowledge which can in turn be extended beyond this niche dataset and used to inform producers and distributors of films, television shows, and other digital media content. © 2016, Yang and Yecies.

Neuropsychiatric disorders such as schizophrenia are associated with cognitive impairment, including learning, memory and attention deficits. Antipsychotic drugs are limited in their efficacy to improve cognition; therefore, new therapeutic agents are required. Cannabidiol (CBD), the non-intoxicating component of cannabis, has anti-inflammatory, neuroprotective and antipsychotic-like properties; however, its ability to improve the cognitive deficits of schizophrenia remains unclear. Using a prenatal infection model, we examined the effect of chronic CBD treatment on cognition and social interaction. Time-mated pregnant Sprague-Dawley rats (n=16) were administered polyinosinic-polycytidilic acid (poly I:C) (POLY; 4 mg/kg) or saline (CONT) at gestation day 15. Male offspring (PN56) were injected twice daily with 10 mg/kg CBD (CONT+CBD, POLY+CBD; n=12 per group) or vehicle (VEH; CONT+VEH, POLY+VEH; n=12 per group) for 3 weeks. Body weight, food and water intake was measured weekly. The Novel Object Recognition and rewarded T-maze alternation tests assessed recognition and working memory, respectively, and the social interaction test assessed sociability. POLY+VEH offspring exhibited impaired recognition and working memory, and reduced social interaction compared to CONT+VEH offspring (p<0.01). CBD treatment significantly improved recognition, working memory and social interaction deficits in the poly I:C model (p<0.01 vs POLY+VEH), did not affect total body weight gain, food or water intake, and had no effect in control animals (all p>0.05). In conclusion, chronic CBD administration can attenuate the social interaction and cognitive deficits induced by prenatal poly I:C infection. These novel findings present interesting implications for potential use of CBD in treating the cognitive deficits and social withdrawal of schizophrenia.Neuropsychopharmacology advance online publication, 22 March 2017; doi:10.1038/npp.2017.40. © 2017 American College of Neuropsychopharmacology

Ye D.,Swinburne University of Technology | Zhang M.,University of Wollongong | Vasilakos A.V.,Lulea University of Technology
IEEE Transactions on Systems, Man, and Cybernetics: Systems | Year: 2017

This paper surveys the literature over the last decades in the field of self-organizing multiagent systems. Self-organization has been extensively studied and applied in multiagent systems and other fields, e.g., sensor networks and grid systems. Self-organization mechanisms in other fields have been thoroughly surveyed. However, there has not been a survey of self-organization mechanisms developed for use in multiagent systems. In this paper, we provide a survey of existing literature on self-organization mechanisms in multiagent systems. We also highlight the future work on key research issues in multiagent systems. This paper can serve as a guide and a starting point for anyone who will conduct research on self-organization in multiagent systems. Also, this paper complements existing survey studies on self-organization in multiagent systems. © 2013 IEEE.

Kan M.E.,University of Wollongong | Taiebat H.A.,University of New South Wales | Taiebat M.,University of British Columbia
Canadian Geotechnical Journal | Year: 2017

The simplified procedures for evaluation of the earthquake-induced displacement in earth and rockfill dams are widely used in practice. These methods are simple, inexpensive, and substantially less time consuming as compared to the complicated stress–deformation approaches. They are especially recommended to be used as a screening tool, to identify embankments with marginal factor of safety, assuming that these methods always give conservative estimates of settlements. However, recent studies show that application of these methods may not be conservative in some cases, especially when the tuning ratio of a dam is within a certain range. In this paper, the fundamental theory behind the simplified methods is critically reviewed. A case in which the results of the simplified methods are reportedly nonconservative is investigated in detail and possible reasons are discussed. The reliability of the simplified methods is examined here based on the existing thresholds proposed in the literature and accounting for the embankment geometry and type, and for the seismic activity characterization, and a practical framework is proposed accordingly. The effectiveness of this framework is evaluated in the study of seismic behaviour of a rockfill dam where all simplified procedures failed to predict the order of deformation experienced by the dam under a recent earthquake event. © 2017, Canadian Science Publishing. All rights reserved.

Eriksen C.,University of Wollongong | Simon G.,University of Colorado at Denver
Environment and Planning A | Year: 2017

This paper examines vulnerability in the context of affluence and privilege. It focuses on the 1991 Oakland Hills Firestorm in California, USA to examine long-term lived experiences of the disaster. Vulnerability is typically understood as a condition besetting poor and marginalized communities. Frequently ignored in these discussions are the experiences of those who live in more affluent areas. This paper seeks to more closely explain vulnerability at its interface with affluence. The aim is to challenge uncritical explanations of vulnerability. We also offer alternative ways of conceptualizing vulnerability as a material condition and social construct that acknowledges broader cultural, ecological, and economic conditions, which may offset, maintain or deepen true risk exposure. Drawing on in-depth interviews with residents and emergency service managers, the paper presents a suite of vulnerability categories that intersect to create two concomitant and competing conditions. First, vulnerability is variegated between households within communities, including those in more affluent areas. Second, household vulnerability is collectively altered, and oftentimes reduced, by the broader affluent community within which individual households reside. By paying closer attention to the Affluence–Vulnerability Interface the paper reveals a recursive process, which is significant in the context of building more disaster resilient communities. © 2016, © The Author(s) 2016.

Debnath J.C.,Deakin University | Wang J.,University of Wollongong
Physica B: Condensed Matter | Year: 2017

We present a systematic study of the structural, magnetic and electrical properties of La0.7Ca0.3MnO3 (LCMO) and La0.7Ca0.3Mn0.95Co0.05O3 (LCMCO0 perovskite manganites. Most of the work is devoted to the electrical properties with a thorough discussion about different models for both the metallic and insulator states. With a view to understand the conduction mechanism in these materials, the resistivity of both materials was measured over a temperature range 5–300 K and in a magnetic field up to 1 T and the data were analysed by using several theoretical models. It has been observed that the metallic part of the temperature dependent resistivity (ρ) curve fits well with ρ=ρ0 +ρ2⊡5Τ2⊡5, indicating the electron-magnon scattering processes in the conduction of these materials. On the other hand, in the high temperature paramagnetic insulating regime, the adiabatic small polaron and VRH models fit well, thereby indicating that polaron hopping might be responsible for the conduction mechanism. © 2016 Elsevier B.V.

Allen M.S.,University of Wollongong
Journal of Sexual Medicine | Year: 2017

Background: Inflammatory processes underlie biological mechanisms responsible for age-related disease and quality of life. Psychological stress can activate acute-phase reactants associated with inflammation, and sexual activity can assist in the management of stress. Aim: To test whether inflammatory biomarkers (C-reactive protein [CRP], fibrinogen, and white blood cell [WBC] count) would mediate an association between frequency of sexual activity and quality of life in older adulthood. Methods: Older adults from England (N = 4,554; 2,049 men, 2,505 women; mean age = 66.25 ± 8.89 years) provided blood samples and completed self-report questionnaires on sexual activity, quality of life, and health-related behavior. Outcomes: CRP (milligrams per liter), fibrinogen (grams per liter), WBC count (109 cells/L), and quality of life (self-report). Results: Frequency of sexual activity had a negative association with CRP and fibrinogen. An age-moderated effect also showed that frequency of sexual activity had a negative association with WBC count in older participants in the sample (>70 years of age). CRP mediated a positive association between frequency of sexual activity and quality of life. An age-moderated mediation effect also showed that WBC count mediated the association between sexual activity and quality of life in the oldest participants in the sample. All analyses controlled for demographic, anthropometric, and health-related factors. Clinical Translation: More frequent sexual activity might be a useful auxiliary approach to lowering stress-related inflammation and improving quality of life. Strengths and Limitations: Strengths of this study include the large sample and multiple control variables. Limitations include the cross-sectional nature of the data and some loss in sample representativeness. Conclusion: Findings provide evidence that more sexually active older adults exhibit an anti-inflammatory status associated with a perception of higher quality of life. Further research using prospective designs and natural experimental methods is encouraged. Allen MS. Biomarkers of Inflammation Mediate an Association Between Sexual Activity and Quality of Life in Older Adulthood. J Sex Med 2017;XX:XXX-XXX. © 2017 International Society for Sexual Medicine.

Rout J.,University of Wollongong
Journal of Functional Analysis | Year: 2017

We use K-theory to prove an isomorphism theorem for a large class of generalised Bunce-Deddens algebras constructed by Kribs and Solel from a directed graph E and a sequence ω of positive integers. In particular, we compute the torsion-free component of the K0-group for a class of generalised Bunce-Deddens algebras to show that supernatural numbers are a complete invariant for this class. © 2017 Elsevier Inc.

News Article | April 17, 2017
Site: cen.acs.org

By mimicking the way some fishes eat, a new membrane easily separates and collects spilled oil on water without getting clogged (ACS Nano 2017, DOI: 10.1021/acsnano.6b07918). It could be an efficient and cost-effective way to clean up large oil spills, its developers say. Disaster responders typically clean up large oil spills by containing the slick with floating booms and using skimmers to remove it. Many researchers are developing separation membranes that could potentially be faster and cheaper. These are designed to repel water or attract oil, which helps them separate the two liquids. But the membranes’ pores tend to get clogged with oil, which makes them ineffective after a while. Dongliang Tian of Beihang University, Ziqi Sun of the University of Wollongong, and their colleagues designed a new filter inspired by the throat structures of filter-feeding fish. To filter out tiny prey suspended in water, these fish have bony arches in their throats that get narrower and more closely spaced deeper into the throat. Water flows into the throat, gradually seeping out from the spaces between the arches and out through the gills, while food particles collect at the back. To mimic that process, the researchers made a 3-cm-long stainless steel membrane containing five mesh sections with gradually decreasing pore size—from 150 nm to 30 nm—from one end to the other. They coated the membrane with nanosheets of cobalt oxide which intertwine with each other, forming tiny pockets that lock in water, making the membrane water-attracting, or hydrophilic. Then they tilted the membrane so that the large pores were at the bottom and pushed it with a controller attached to the top, emulating how a ship might push the angled membrane, bottom edge first, through the water. When the driving system moves the membrane through an oil-water mixture, the liquids stream up the membrane. Water permeates the membrane and forms a layer along its hydrophilic surface, preventing oil from clogging the pores. The large pores at the bottom, which encounter the highest water flux, allow water to flow through faster, Tian explains, while the water-logged small pores at the top repel oil, allowing it to easily flow over the top of the membrane into a container. Though oil may pass through the large pores on the first pass, the system makes multiple sweeps through a contaminated area, capturing more oil with each pass. The researchers tested the system in a 100-cm-long, 10-cm-wide sink filled with a mixture of water and one of a variety of oils: crude oil, diesel fuel, corn oil, or hydraulic fluid. They were able to continually collect oil at a calculated rate of 50 liters per minute for each meter length of the membrane, pushing the membrane along the sink more than 2,000 times over 100 minutes. The efficiency drops by less than 3% after those uses, and Tian says cleaning the membrane would restore its efficiency. By comparison, when the team tested a conventional setup by pouring an oil-water mixture through a 90-µm pore size membrane, the membrane became clogged and unusable after 50 uses. This novel filtration technique could enable “one-step, fast, continuous, and high-throughput spilled oil collection,” says Lin Feng of Tsinghua University. The technique has promise for use in large-scale oil spills, especially on lakes and quiet seas, she says. Waves could be a challenge since the water could spill over the top of the membrane into the oil-collection vessel and reduce the membrane’s efficiency.

News Article | April 17, 2017
Site: cen.acs.org

A flexible battery made of gauzy silk films could power electronics and then melt away after a preset number of days (ACS Energy Lett. 2017, DOI: 10.1021/acsenergylett.7b00012). The biodegradable battery produces a high enough voltage to power temporary medical implants designed to harmlessly dissolve in the body in a few weeks once their work is done. Scientists have been making rapid progress on medical sensors and devices that could transmit images, stimulate wounds to heal, or deliver drugs for a short while before degrading. Most prototypes of these devices have been powered from an external source so they can only be placed skin-deep. To work deeper in the body, the devices will need an on-board power source. Dissolvable batteries are an ideal solution. Researchers have made such batteries before using natural, biocompatible materials for the electrodes and electrolytes. One team made electrodes out of the skin pigment melanin, while others have used thin foils of magnesium or iron. The electrolytes have typically been solutions of various salts in water, but liquid electrolytes can leak out and degrade battery electrodes, and they make batteries relatively bulky. In a fresh spin on degradable batteries, Caiyun Wang and Gordon G. Wallace of the University of Wollongong and colleagues made electrodes and a solid electrolyte out of silk. The solid electrolyte enables thinner, flatter, and more flexible and robust batteries, says Wang. Silk is ideal for medical electronics because it can be made into thin films, is biocompatible, and is sturdy enough to work in electronic circuitry. The researchers made the thin films that comprise the new battery by first dissolving a fibrous silk protein called fibroin, derived from silkworm cocoons, in water. They spread the solution in a mold and peeled off ultrathin films of silk after the water evaporated. To make the electrolyte, they infused a piece of the silk membrane with the ionic liquid choline nitrate, a molten salt that is excellent at conducting ions, by adding it to the silk fibroin solution. To make electrodes, they deposited a biocompatible magnesium alloy on a piece of the silk film to form an anode and deposited gold on another piece to form a cathode. They assembled the battery by sandwiching the electrolyte between the two electrode films and fusing together the uncoated edges with a sticky, amorphous silk film. The postage-stamp-sized, 170-µm-thick device generated a voltage of 0.87 V and had a power density of 8.7 µW/cm2, which would be enough to power an implantable medical sensor. Placed in a saline buffer solution, the battery showed a stable voltage for about an hour, after which the anode started breaking down. When the researchers added an extra silk film on top of the anode, the voltage remained stable for nearly two hours. Previously reported biodegradable batteries have lasted for about 15 minutes. The device nearly completely decomposed after 45 days in the solution, leaving behind inert gold nanoparticles, which would be cleared by the body. By adjusting the properties of the silk layers encapsulating the battery, Wallace says they could tailor how long it predictably generates power and how quickly it dissolves. The silk-ionic liquid electrolyte improves the performance of magnesium-based decomposable batteries, says Christopher J. Bettinger of Carnegie Mellon University. “These batteries can maintain a pretty high voltage for a relatively long amount of time,” he says. For medical applications it would be important to consider the toxicity of the ionic liquids, he says, but this “could also be a compostable battery for other uses.”

News Article | April 30, 2017
Site: www.techtimes.com

A new study has created a stir among archaeologists. The research claims that ancient humans arrived in the Americas far earlier than previously assumed. The researchers shared that signs of human activity have been found in California between 120,000 and 140,000 years ago. Based on this assertion, the difference between the new claims and the old assumptions of human settlement in the Americas is more than a 100,000 years. The researchers of the new study arrived at this conclusion after dating the archaeological remains at the Cerutti Mastodon site, which has pushed back the arrival of ancient humans to 130,000 years rather than just 15,000 years. "I realize that 130,000 years is a really old date and makes our site the oldest archaeological site in the Americas," Tom Deméré, the study's lead author, told The National Geographic. Human remains have not been found at the site of the new study. However, bones and teeth of ancient animals similar to elephants have been discovered at the site. The animal fossil remains bore signs of modification by human hands, stone hammers, and anvils. Based on the circumstantial evidence, the researchers concluded the presence of humans in California 130,000 years ago. Deméré and his team assume that Cerutti Mastodon was used as a "bone quarry" given the presence of bone flakes, a mastodon skeleton, and several large stones. In ancient times, humans supposedly smashed mastodon bones with the help of stone hammers and anvils to extract bone marrow and raw materials from the skeleton. Although the site of the new study was discovered in 1992, revelations regarding the same came to the fore in 2011 and 2012 due to difficulty in accurately dating the site. Based on the evidence analyzed from Cerutti Mastodon, Deméré and his colleagues arrived at the conclusion that ancient humans arrived 130,000 years ago in California. Richard Fullagar, an archaeologist at University of Wollongong in Australia and also a team member of the controversial study, shared that the rocks bear signs of wear and tear. These appear to be inflicted from ancient stone tools, especially those used for shattering bones. The researchers assert that the stone placement also indicated human presence. The Cerutti Mastodon site was entombed with siltstone. However, bigger rocks displaying the signs of wear are far heavier than the surrounding sedimentary siltstones. This indicated that humans brought the rocks. The archaeologists also revealed that the fractures found on the mastodon bones indicated that they were broken while the bones were still fresh. They also asserted that the bone smashing was a sure result of human activity and not an occurrence of nature. "Discovered in 1992 during construction work to expand an expressway, the bone fragments "show clear signs of having been deliberately broken by humans with manual dexterity," lead author Steve Holen asserted. Several archaeologists are skeptical of the findings, some even dismissed them outright. One of the main criticisms of the study is that it does not conclusively rule out natural causes for the breakage of mastodon bones, presence of stone tools, and breakage patterns on the rock surfaces. Many archaeologists such as Tom Dillehay, from Vanderbilt University shared that the research fails to entirely exclude the possibility of natural processes involved in the movement of the rocks, or creating the wear pattern on the stones. He also noted that these could have taken place easily if the rocks bumped against each other in a stream. However, Holen and Deméré are prepared to answer questions, which they are aware could come up once the controversial study is publicized. "I think we've made a very good case that this is an archaeological site. I think we're quite prepared for the firestorm that's coming," Holen told The National Geographic. The paper has been published in the journal Nature on Wednesday, April 26 © 2017 Tech Times, All rights reserved. Do not reproduce without permission.

Scientists have known for over a decade that the West Antarctic Ice Sheet has been losing mass and contributing to sea level rise. Its eastern neighbour is, however, ten times larger and has the potential to raise global sea level by some 50 metres. Despite its huge size and importance, conflicting results have been published on the recent behaviour of the East Antarctic Ice Sheet. A study led by a group of NASA scientists, that was published in 2015, suggested that this part of Antarctica was gaining so much mass that it compensated for the losses in the west. Determining what the largest ice sheet on the planet is doing is vital for our understanding of the factors that are influencing present day, and future, sea level rise. To address this question, a team of scientists led by the University of Bristol and including the University of Wollongong, Australia have studied the problem by combining different satellite observations within a statistical model that is able to separate the processes related to ice mass changes over the continent. Professor Jonathan Bamber from the Bristol Glaciology Centre which is part of the School of Geographical Sciences, said: "We used similar data sets to the NASA team but added other satellite data from a mission called the Gravity Recovery And Climate Experiment (GRACE) to help solve for mass gains and losses. "We then conducted different experiments, using similar assumptions made in the NASA study but found that in every experiment, mass loss from the west always exceeded gains in the east." The researchers concluded that over the study period, 2003-2013, Antarctica, as a whole, has been contributing to sea level rise and that the gains in East Antarctica were around three times smaller than suggested in the 2015 study.

News Article | April 20, 2017
Site: www.eurekalert.org

A new study on UHT milk is helping scientists to better understand Alzheimer's, Parkinson's and type 2 diabetes, opening the door to improved treatments for these age-related diseases. About 500 million people worldwide suffer from these diseases, which cause millions of deaths each year. Co-lead researcher, ANU Professor John Carver, said that two unrelated proteins aggregate in UHT milk over a period of months to form clusters called amyloid fibrils, which cause the milk to transform from a liquid into a gel. He said the same type of protein clusters are found in plaque deposits in cases of Alzheimer's and Parkinson's. "Parkinson's, dementia and type 2 diabetes are big problems for the ageing population in Australia and many other countries around the world," said Professor Carver from the ANU Research School of Chemistry. "Our interest in milk proteins led to a discovery of the reason for this gelling phenomenon occurring in aged UHT milk." "The research does not suggest UHT milk can cause these age-related diseases." Professor Carver said milk proteins changed structurally when heated briefly to around 140 degrees to produce UHT milk, causing the gelling phenomenon with long-term storage. He said normal pasteurised milk did not form amyloid fibrils. ANU worked with CSIRO, University of Wollongong and international researchers on the study, which is published in the journal Small. Watch a video interview with Professor John Carver about the study.

News Article | April 17, 2017
Site: www.newscientist.com

It’s a drone of the deep. A soft-bodied robot that swims like a manta ray has been engineered to spy on underwater creatures without disturbing them. The mostly transparent robot has no motor or other rigid machinery and is much faster than other soft robotic fish. The goal is to use the robot to explore underwater areas, says Tiefeng Li at Zhejiang University in Hangzhou, China. It could be used to investigate a submerged ship or plane wreck, or survey coral reefs. “The soft body will make it easy for the robot to sneak through reefs without damaging them,” he says. Robots are increasingly being constructed from soft, stretchy materials to make them more resilient and more compatible with living beings. However, powering them without traditional hard-edged circuit boards and motors is a challenge. To get around using a motor in the manta-ray-inspired robot, Li and his colleagues made artificial fin muscles from a flexible polymer called dielectric elastomer. A silicone-encased lithium battery supplies a cyclic voltage that squeezes and releases that material, causing the muscles to bend up and down. This flaps the ray’s fins, made of a thin silicone film, so that it moves through the water. The rest of the remotely controlled robot – which weighs 90 grams and has a wing span of 22 centimetres – is made of a silicone body and tail for steering. All components are transparent, except for the small battery pack and two electromagnets that help to manoeuvre the tail. At top speed, the robot can swim 6 centimetres per second. This beats the previous record for soft, untethered underwater robots by 3 centimetres per second, but is still significantly slower than similar-sized fish. The researchers showed that the electronic ray can tolerate temperatures between 0.4°C and 74°C, swim for 3 hours with a single battery charge, and carry a small video camera to monitor its surroundings. The flexibility and transparent disguise of the robot ray should allow it to monitor underwater environments without disturbing or damaging them, says Li. “Ocean creatures will feel more comfortable with it than hard, non-transparent robots,” he says. The underwater electronics do not pose an electrocution risk to ocean life because the robot’s circuitry is set up so the surrounding water functions as the grounding electrode – the end that dissipates electrical energy. “This is a very good idea,” says Gursel Alici at the University of Wollongong in Australia. Although other types of robotic swimmers have been made using soft parts – including ones that mimic octopuses, fish and jellyfish – the manta ray is a unique take on this concept, says Alici. It remains to be seen whether it will have practical applications, he says.

News Article | April 17, 2017
Site: www.newscientist.com

A new 4D-printing technique that creates complex structures in minutes could be used to make temperature-activated cardiac stents, drug capsules and flat-pack furniture. 4D printing creates 3D objects that change their shape over time in response to stimuli such as heat, moisture or light. It is useful for making structures that can adapt to their environment, but is often a laborious process. The most common materials used in 4D printing, shape-memory polymers, normally require at least five steps to make them into adaptable objects. Hydrogels are simpler to use, but too soft to fashion into rigid structures. Zhen Ding at the Singapore University of Technology and Design and his colleagues have now developed a way to rapidly print rigid 4D objects with a commercial 3D printer and a heat source. They created a variety of objects, including a delicate flower that closes its petals, a flat star shape that morphs into a dome, and lattices that contract and elongate. The structures were made from flat 3D-printed strips that were then heated to make them curve. The strips, which can be printed in less than a minute, are made from layers of a stiff shape-memory polymer paired with a rubbery elastomer – a polymer with elastic properties. When heated to 45°C, the shape-memory polymer component relaxes and allows the elastomer to bend. As the strip cools, the shape-memory polymer stiffens again and locks the object into its new, curved configuration. One limitation to the technique is that it permanently fixes the structure in place after one heating cycle, says Geoff Spinks at the University of Wollongong in Australia. “This rules out applications that require reversible shape changes, like artificial muscles for robots and prosthetics,” he says. But the method could be used to make complex structures that don’t require such shape-shifting, says Spinks. For example, compact cardiac stents – tubes for placing in blood vessels to keep them open – could open up in an artery in response to body temperature. By fine-tuning the temperature transition point, medicine capsules could also be designed to bend and break open when body temperature rises with infection. And flat-pack furniture could assemble itself when heated. Moreover, the technology could easily be used by people with other ideas, says Spinks. “No new chemistries, materials or equipment are involved, so it’s ready for anyone to start using immediately.”

News Article | April 26, 2017
Site: www.cnet.com

The remains of a 130,000-year-old mastodon found in southern California show signs of being bashed by humans around the time of its demise. The discovery is amazing because, until now, it was believed that the first humans to migrate over an ancient land bridge from Asia to North America showed up only about 15,000 years ago. The fossil site was discovered in San Diego County during a freeway construction project all the way back in 1992. The ancient animal's bones, tusks and teeth had been broken and buried along with large stones that appear to have been used by someone as hammers and anvils to do the breaking. "Which poses a puzzle," explains Dr. Tom Deméré from the San Diego Natural History Museum in the below video. "The remains of this mastodon were found in a silt layer and geological processes that would deposit silt are not going to be depositing or carrying rocks of this size... what makes sense to us, although it's out there, is the hypothesis suggesting that humans brought these rocks to the site." Deméré is a co-author of a paper on the discovery published in Thursday's issue of the journal Nature. If the broken Mastodon bones really are evidence of a prehistoric tool-making or marrow buffet site, it would be the oldest such archaeological site on the continent by as much as 100,000 years. Radiocarbon dating of the site has not been possible, but recent technological advances made it possible to use uranium-thorium dating on multiple bone specimens to determine their age. "This discovery is rewriting our understanding of when humans reached the New World. The evidence we found at this site indicates that some hominin species was living in North America 115,000 years earlier than previously thought," said Judy Gradwohl, president and CEO of the San Diego Natural History Museum, in a release. But the conclusion that some broken mastodon bones are a clear indication of human activity in North America millennia ahead of the more generally understood migration schedule is being met with some skepticism. "Until we actually find a skeleton at this site or at a site of a comparable age in the Americas, it's all open to speculation and we just don't know," says John McNabb of the University of Southampton. In a conference call with reporters, lead author Dr. Steve Holen from the Center for American Paleolithic Research, said he's confident that the surrounding geology of the site, the placement of the apparent tools and the way the bones were broken all point to a human presence. His team went so far as to use similar rock tools on comparable elephant bones to see if they broke in the same way. "It's understandable that it might be difficult to get your head around the nature of this evidence," added co-author Richard Fullagar from the University of Wollongong. "But Steve is absolutely right... the evidence is truly incontrovertible." If there were human ancestors in North America ten times earlier than previously thought, it brings up many more questions. Exactly who were they? Where did they come from? Why is there a 100,000 year gap in the evidence we've found for their existence? And of course, where the heck did they go? The scientists behind the discovery concede that they have no solid answers for these big questions just yet. But if the findings hold up, we may need to revise the accepted answer to the question of just how long we've been wandering around the "New World," which suddenly seems a little less new. Technically Literate: Original works of short fiction with unique perspectives on tech, exclusively on CNET.

News Article | April 26, 2017
Site: www.newscientist.com

An extraordinary chapter has just been added to the story of the First Americans. Finds at a site in California suggest that the New World might have first been reached at least 130,000 years ago – more than 100,000 years earlier than conventionally thought. If the evidence stacks up, the earliest people to reach the Americas may have been Neanderthals or Denisovans rather than modern humans. Researchers may have to come to terms with the fact that they have barely scratched the surface of the North American archaeological record. “We often hear statements in the media that a new study changes everything we knew,” says Chris Stringer at the Natural History Museum in London. “If this result stands up to scrutiny, it does indeed change everything we thought we knew about the earliest human occupation of the Americas.” The evidence comes from a coastal site in San Diego County, California. In the early 1990s, routine highway excavations exposed fossil bones belonging to a mastodon, an extinct relative of the elephant. Researchers moved in to examine the site, and they soon decided that this was no ordinary mastodon fossil. Many of the bones and teeth were fragmented, some with “spiral” fractures that may be produced when humans break open fresh bone. Alongside the broken bones and teeth, the researchers found stone cobbles that had evidence of impact marks on their surfaces. Two were particularly large – about 15 centimetres in diameter – and each was surrounded by small bone and teeth fragments. Taken together, the evidence points to one scenario, says team member Steven Holen at the Center for American Paleolithic Research in South Dakota. A group of early humans stumbled upon a fresh mastodon carcass and then removed bones and broke them open using stones as simple hammers – with the two larger cobbles serving as makeshift anvils. “The distribution of fractured pieces of bone right around the anvils is fairly conclusive evidence,” he says. The mastodon bones would have been a good source of nutritious bone marrow. Alternatively, the early humans might have broken the bones to use as raw material – bone can be worked and sharpened to create tools. None of this would be particularly controversial except for one final detail. Holen’s colleague – James Paces at the United States Geological Survey in Colorado – has used uranium-thorium isotope dating to age the mastodon fossils. The results suggest the remains are 131,000 years old, give or take 10,000 years. The current consensus view is that humans first reached the Americas much more recently, perhaps just 15,000 years ago. “We believe we have a robust and defensible age for early humans being in America more than 100,000 years earlier than people had imagined,” says Paces. Exactly who those people were is impossible to say as there were no human fossils at the Californian site. “But there are a range of possibilities,” says team member Richard Fullagar at the University of Wollongong in Australia. “They could have been Neanderthals or Denisovans.” Both of these groups were probably present in Siberia more than 130,000 years ago. Holen says sea levels were low and a land bridge existed between Siberia and North America just before 130,000 years ago. Either group could in theory have wandered across. Alternatively, it might have been modern humans – Homo sapiens – that made it to the New World 130,000 years ago, says Fullagar. Recent archaeological evidence suggests our species was in China 120,000 years ago, which is far earlier than once thought. Perhaps modern humans were in East Asia even earlier than the Chinese fossils suggest, and moved into the Americas from there. However, given that genetic studies strongly suggest that indigenous populations in North America trace their routes to much later episodes of colonisation, it would seem likely that whoever arrived there 130,000 years ago didn’t survive very long. “The claims are extraordinary and the potential implications staggering,” says Jon Erlandson at the University of Oregon. Dennis Jenkins, also at the University of Oregon, simply describes the work as “mind-boggling”. But both researchers – and many others – express extreme caution about the conclusions. “Broken bones and stones alone do not make a credible archaeological site in my view,” says Erlandson. He singles out the supposed stone hammers and anvils as a particular weak point in the analysis. By 130,000 years ago, hominins elsewhere in the world were making elaborate stone tools. Nothing this complicated was found near the mastodon. “I would expect to find more sophisticated tools and behaviour,” says María Martinón-Torres at University College London, who works on the early archaeological record of China. Simple stone tools of a similar age have been found in only one place: Homo floresiensis, the “hobbit”, left a record of relatively simple stone tools on the Indonesian island of Flores. But even these tools show a level of complexity not seen at the mastodon site, says Adam Brumm at Griffith University in Queensland, Australia, who works on the Flores archaeological record. “If these are indeed humanly modified artefacts they make the typical hobbit tool look like an iPhone,” he says. Brumm’s general reaction to the new study is scepticism. “Most archaeologists will simply never believe it – the dates are too old, the ‘tools’ too untool-like and the implications too mind-boggling.” Fullagar isn’t disheartened by such scepticism, though. “I’ve spent about four years looking at these artefacts and the team has been looking at the evidence for about 24 years,” he says. “It’s understandable that it might be difficult to get your head around the nature of this evidence in a couple of days.” And the reaction to the new evidence isn’t universally sceptical. Gerrit van den Bergh was already aware of the research because he works at the University of Wollongong alongside Fullagar. “I think the team has very strong arguments and good evidence,” he says. Stringer is also prepared to be open-minded. “The paper has come through thorough peer review,” he says. “[But] many of us will want to see supporting evidence of this ancient occupation from other sites before we abandon the conventional model.”

Jalalifar H.,Shahid Bahonar University of Kerman | Aziz N.,University of Wollongong
Rock Mechanics and Rock Engineering | Year: 2010

The load transfer capacity and failure mechanism of a fully grouted bolt installed across a joint in shear is investigated, both experimentally and numerically, in five types of bolt. The double-shearing testing of bolts were studied in concrete blocks of 20, 40 and 100 MPa strengths, subjected to different pretension loads of 0, 5, 10, 20, 50 and 80 KN, respectively. The parameters examined include: shear resistance, shear displacement, induced strains and stresses during the bolt-bending process, and its ultimate failure across the sheared joint planes. The conclusions drawn from the study were that the strength of the concrete, bolt profile configuration and bolt pretension load played a significant influence on the shear resistance, shear displacement and failure mechanism of the reinforced medium. Experimental and numerical simulations showed that the failure occurs as a result of the induced axial and shear stresses acting between the hinge point distances in the vicinity of the shear joint plane. © 2009 Springer-Verlag.

Bradstock R.A.,University of Wollongong | Collins L.,University of Wollongong | Price O.,University of Wollongong
Landscape Ecology | Year: 2010

The effects of weather, terrain, fuels on fire severity were compared using remote sensing of the severity of two large fires in south-eastern Australian forests. The probability of contrasting levels of fire severity (fire confined to the understorey vs. tree canopies consumed) was analysed using logistic regression. These severities equate to extremes of fire intensity (<1,500 vs. >10,000 kW m-1), consequent suppression potential (high vs. nil) and potential adverse ecological impacts on vertebrate fauna and soils (low vs. high). Weather was the major influence on fire severity. Crown fire was absent under nonextreme weather and but more likely under extreme weather, particularly on ridges in vegetation unburnt for >10 years. Crown fire probability was very low in recently burnt vegetation (1-5 years) and increased at higher fuel ages. In all cases, fire severity was lower in valleys, probably due to effects of wind protection and higher fuel moisture in moderating fire behaviour. Under non-extreme weather, fires are likely to be suppressible and burn heterogeneously, due to the influence of topographic position, slope and fuel load. Under extreme weather, fires are influenced only by fuel and topographic position, and probability of suppression on accessible ridges will be low except in recently burnt (i. e. 1-5 year old) fuels. Topographically imposed variation may mitigate adverse ecological effects on arboreal fauna and soil erosion potential. © Springer Science+Business Media B.V. 2009.

Baowan D.,Mahidol University | Thamwattana N.,University of Wollongong
Microporous and Mesoporous Materials | Year: 2013

The selective separation of biomolecules is a critical process in food, biomedical and pharmaceutical industries. Due to its size and properties, mesoporous silica offers many advantages as a separation media for biomolecules such as proteins and enzymes. In this paper, we investigate mathematically the separation of proteins trypsin and lysozyme using mesoporous silica materials. These proteins are modelled as densely packed spheres, while the silica pore is assumed to have a cylindrical structure. The Lennard-Jones potential together with a continuum approximation is employed to determine the interaction among the proteins and the interaction between a protein and a silica pore. For these systems, the total interaction energies are obtained analytically as functions of the protein size and the pore dimensions. We find that the pore radii which give rise to the maximum adsorption energies for trypsin and lysozyme are 21.74 Å and 17.74 Å, respectively. Since the binding energy between any two protein molecules is found to be three orders of magnitude lower than the adsorption energy of the protein into the silica pore, proteins prefer to be separated and stay inside the pore. Further, we find that using silica pores with radii in the range between 17.23 Å and 21.24 Å allows the entrance of only lysozyme, as such separating lysozyme from trypsin. These results agree with previous experimental study, confirming that mesoporous silica pores may be used to separate trypsin-lysozyme mixture. © 2013 Elsevier Inc. All rights reserved.

Sheppard Brennand H.,University of Sydney | Soars N.,University of Sydney | Dworjanyn S.A.,Southern Cross University of Australia | Davis A.R.,University of Wollongong | Byrne M.,University of Sydney
PLoS ONE | Year: 2010

Background: As the oceans simultaneously warm, acidify and increase in PCO2, prospects for marine biota are of concern. Calcifying species may find it difficult to produce their skeleton because ocean acidification decreases calcium carbonate saturation and accompanying hypercapnia suppresses metabolism. However, this may be buffered by enhanced growth and metabolism due to warming.Methodology/Principal Findings: We examined the interactive effects of near-future ocean warming and increased acidification/PCO2 on larval development in the tropical sea urchin Tripneustes gratilla. Larvae were reared in multifactorial experiments in flow-through conditions in all combinations of three temperature and three pH/PCO2 treatments.Experiments were placed in the setting of projected near future conditions for SE Australia, a global change hot spot. Increased acidity/PCO2 and decreased carbonate mineral saturation significantly reduced larval growth resulting in decreased skeletal length. Increased temperature (+3°C) stimulated growth, producing significantly bigger larvae across all pH/PCO2 treatments up to a thermal threshold (+6°C). Increased acidity (-0.3-0.5 pH units) and hypercapnia significantly reduced larval calcification. A +3°C warming diminished the negative effects of acidification and hypercapnia on larval growth.Conclusions and Significance: This study of the effects of ocean warming and CO2 driven acidification on development and calcification of marine invertebrate larvae reared in experimental conditions from the outset of development (fertilization) shows the positive and negative effects of these stressors. In simultaneous exposure to stressors the dwarfing effects of acidification were dominant. Reduction in size of sea urchin larvae in a high PCO2 ocean would likely impair their performance with negative consequent effects for benthic adult populations. © 2010 Sheppard Brennand et al.

Eckermann S.,University of Wollongong | Karnon J.,University of Adelaide | Willan A.R.,University of Toronto
PharmacoEconomics | Year: 2010

Value of information (VOI) methods have been proposed as a systematic approach to inform optimal research design and prioritization. Four related questions arise that VOI methods could address. (i) Is further research for a health technology assessment (HTA) potentially worthwhile? (ii) Is the cost of a given research design less than its expected value? (iii) What is the optimal research design for an HTA? (iv) How can research funding be best prioritized across alternative HTAs?Following Occams razor, we consider the usefulness of VOI methods in informing questions 14 relative to their simplicity of use. Expected value of perfect information (EVPI) with current information, while simple to calculate, is shown to provide neither a necessary nor a sufficient condition to address question 1, given that what EVPI needs to exceed varies with the cost of research design, which can vary from very large down to negligible. Hence, for any given HTA, EVPI does not discriminate, as it can be large and further research not worthwhile or small and further research worthwhile. In contrast, each of questions 14 are shown to be fully addressed (necessary and sufficient) where VOI methods are applied to maximize expected value of sample information (EVSI) minus expected costs across designs.In comparing complexity in use of VOI methods, applying the central limit theorem (CLT) simplifies analysis to enable easy estimation of EVSI and optimal overall research design, and has been shown to outperform bootstrapping, particularly with small samples. Consequently, VOI methods applying the CLT to inform optimal overall research design satisfy Occams razor in both improving decision making and reducing complexity. Furthermore, they enable consideration of relevant decision contexts, including option value and opportunity cost of delay, time, imperfect implementation and optimal design across jurisdictions.More complex VOI methods such as bootstrapping of the expected value of partial EVPI may have potential value in refining overall research design. However, Occams razor must be seriously considered in application of these VOI methods, given their increased complexity and current limitations in informing decision making, with restriction to EVPI rather than EVSI and not allowing for important decision-making contexts. Initial use of CLT methods to focus these more complex partial VOI methods towards where they may be useful in refining optimal overall trial design is suggested. Integrating CLT methods with such partial VOI methods to allow estimation of partial EVSI is suggested in future research to add value to the current VOI toolkit. © 2010 Adis Data Information BV. All rights reserved.

Keeley J.E.,U.S. Geological Survey | Keeley J.E.,University of California at Los Angeles | Rundel P.W.,University of California at Los Angeles | Bond W.J.,University of Cape Town | Bradstock R.A.,University of Wollongong
Trends in Plant Science | Year: 2011

Traits, such as resprouting, serotiny and germination by heat and smoke, are adaptive in fire-prone environments. However, plants are not adapted to fire per se but to fire regimes. Species can be threatened when humans alter the regime, often by increasing or decreasing fire frequency. Fire-adaptive traits are potentially the result of different evolutionary pathways. Distinguishing between traits that are adaptations originating in response to fire or exaptations originating in response to other factors might not always be possible. However, fire has been a factor throughout the history of land-plant evolution and is not strictly a Neogene phenomenon. Mesozoic fossils show evidence of fire-adaptive traits and, in some lineages, these might have persisted to the present as fire adaptations. © 2011.

Indraratna B.,University of Wollongong | Nimbalkar S.,University of Wollongong | Neville T.,Australian Rail Track Corporation Ltd
Proceedings of the Institution of Civil Engineers: Ground Improvement | Year: 2014

In coastal Australia, high population density and increased traffic volumes have promoted rapid expansion of urban transportation infrastructure including railways. Coastal soft clays pose significant construction challenges. Therefore, the search for innovative ground improvement techniques imperative for more resilient and sustainable transport infrastructure has become an obvious priority in research and development. Use of artificial inclusions such as polymeric geosynthetics and energy-absorbing shock mats is described in this paper as a suitable alternative for reducing unacceptable track degradation and for ensuring sustainable track alignment. An extensive monitoring programme was undertaken on fully instrumented track sections constructed near Singleton, New South Wales, Australia. Four types of geosynthetics were installed at the ballast-capping interface of track sections located on different types of subgrades. It was found that geogrids could decrease the vertical settlement of the ballast layer with the obvious benefits of improved track stability and decreased cost of maintenance. It was also found that the effectiveness of reinforcing geogrids is greater when the subgrade is soft.

Wang X.,Beijing Normal University | Wang H.,Beijing Normal University | Brown H.R.,University of Wollongong
Soft Matter | Year: 2011

The fabrication of hydrogels with well-defined structure and high mechanical strength has become a challenging and fascinating topic. The aim of this study is to develop a new method for fabricating hydrogels with high mechanical strength by utilizing the well-developed structure of biological gels. We firstly studied the mechanical properties and microstructure of a biological gel - the mesogloea of edible jellyfish Rhopilema esculenta Kishinouye (JF gel). JF gel has much higher mechanical strength than normal synthetic hydrogels due to its layered porous structure with pore walls consisting of nano-structured layers and fibers. We have also synthesized hydrogels by radiation-induced polymerization and crosslinking and found that they are distinctly stronger than those produced by the classical thermal polymerization using a crosslinking agent. When a synthetic gel is incorporated into JF gel by the radiation-induced polymerization and crosslinking of a hydrophilic monomer, a novel type of hybrid hydrogel with very high mechanical strength results. The compressive and tensile strengths of the hybrid hydrogels are generally several times to more than ten times higher than those of JF gel and the corresponding component synthetic gels. The hybrid gels combine the well-developed structure of biological jellyfish gel and the unique microstructure of the synthetic gel produced by the radiation method, and strong interactions between the two networks are formed. © 2011 The Royal Society of Chemistry.

Liang J.,University of Queensland | Zheng Y.,University of Queensland | Chen J.,University of Wollongong | Liu J.,University of Queensland | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2012

Honeycomb catalysis: A facile oxygen reduction reaction has been observed on a graphitic C 3N 4/carbon catalyst with three-dimensional interconnected macropores (see picture with SiO 2 template). This material not only shows catalytic activity that is comparable to that of commercial Pt/C, but also has much higher organic-fuel tolerance and long-term stability. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wang L.,University of Wollongong | Zhou L.,University of Wollongong | Shen C.,University of Adelaide | Liu L.,University of Wollongong | Liu H.,Arizona State University
IEEE Transactions on Pattern Analysis and Machine Intelligence | Year: 2014

In image recognition with the bag-of-features model, a small-sized visual codebook is usually preferred to obtain a low-dimensional histogram representation and high computational efficiency. Such a visual codebook has to be discriminative enough to achieve excellent recognition performance. To create a compact and discriminative codebook, in this paper we propose to merge the visual words in a large-sized initial codebook by maximally preserving class separability. We first show that this results in a difficult optimization problem. To deal with this situation, we devise a suboptimal but very efficient hierarchical word-merging algorithm, which optimally merges two words at each level of the hierarchy. By exploiting the characteristics of the class separability measure and designing a novel indexing structure, the proposed algorithm can hierarchically merge 10,000 visual words down to two words in merely 90 seconds. Also, to show the properties of the proposed algorithm and reveal its advantages, we conduct detailed theoretical analysis to compare it with another hierarchical word-merging algorithm that maximally preserves mutual information, obtaining interesting findings. Experimental studies are conducted to verify the effectiveness of the proposed algorithm on multiple benchmark data sets. As shown, it can efficiently produce more compact and discriminative codebooks than the state-of-the-art hierarchical word-merging algorithms, especially when the size of the codebook is significantly reduced. © 2014 IEEE.

Lv B.,Peking University | Zhang C.,University of Wollongong | Ma Z.,Peking University
Physical Review Letters | Year: 2012

We reveal that the recently discovered specular Andreev reflection (SAR) [C. W. J. Beenakker, Phys. Rev. Lett. 97, 067007 (2006)PRLTAO0031-900710.1103/ PhysRevLett.97.067007] can occur in semiconductors where the spin-orbit coupling is finite. We demonstrate this finding in the hybrid of a two-dimensional electron gas with Rashba spin-orbit coupling and a superconductor. In the limit of low density or a strong spin-orbit coupling, specular Andreev reflection is finite. We also show that unit electron-hole conversion is possible in a specular Andreev reflection due to the different topological structures of the equal-energy surface between electrons and holes. The SAR in the semiconductor is determined by the relative orientation of wave vector to group velocity, which can be analyzed by ray equations. © 2012 American Physical Society.

Gordon R.,University of Wollongong | Heim D.,University of Central Lancashire | MacAskill S.,University of Stirling
Public Health | Year: 2012

Objectives: This paper presents the synthesis of findings from a literature review study of drinking cultures across five West European countries (France, Germany, Spain, Sweden and the UK), examining the nature and features of drinking typologies before proposing a new dimensional approach. Study design: The study incorporated a systematic literature search covering the period 1980-2010 for literature from each of the five countries. Methods: Researchers reviewed abstracts and selected relevant material, leading to the inclusion of 203 articles from database searches plus 26 records from other sources. A summary of key findings are presented here. Intercoder reliability checks were performed to ensure consistency in inclusion in the review according to pre-ordained selection criteria. The review was further supplemented by the inclusion of gray literature including policy documents obtained from a range of sources. Results: It was found that sociocultural contexts have a major influence on drinking cultures, and this is an area in which there have been dramatic changes over the past 30 years. Differences were found between the countries in terms of drinking cultures, the way in which alcohol is viewed, and how alcohol-related policy and practice operates. However, there seems to be an increasing homogenization of drinking cultures across many countries, strongly influenced by Anglo-US cultural zeitgeist. Modern drinking patterns have emerged, offering a complex and often overlapping schema of drinking typologies. Conclusions: The study suggests that the wet-dry dichotomy is no longer relevant and that a revised version of a more recent dimensional approach featuring three dimensions - hedonism, function and control - may be better placed to describe and measure contemporary drinking cultures. © 2011 The Royal Society for Public Health.

Chen L.,Peking University | Ma Z.,Peking University | Zhang C.,University of Wollongong
Applied Physics Letters | Year: 2010

We show that for graphene with any finite asymmetry in the on-site energy between the two sublattices (Δ), the optical absorption edge is determined by the Δ. The universal conductance will be broken and the conductance near the band edge varies with frequency as 1/ ω2. The onset conductance is σc =2 σ0 =π e2 /2h, independent of the size of the band gap. The total integrated optical response is nearly conserved despite of the opening of the band gap. Moreover, near the band edge, there is a change over of the electrical resistivity from temperature independent to a linear temperature dependence. © 2010 American Institute of Physics.

Wang S.,University of Wollongong | Meng Q.,National University of Singapore
Computers and Operations Research | Year: 2014

It is crucial for a liner shipping company to design its container shipping network. Given a set of port-to-port container shipment demands with delivery deadlines, the liner shipping company aims to design itineraries of portcalls, deploy ships on these itineraries and determine how to transport containers with the deployed ships in order to maximize its total profit. In this paper we first demonstrate NP-hardness of this problem and subsequently formulate it as a mixed-integer non-linear non-convex programming model. A column generation based heuristic method is proposed for solving this problem. Numerical experiments for container shipping on the Asia-Europe trade lane show that the proposed solution algorithm is efficient to find good quality solutions. © 2013 Elsevier Ltd.

Naderi M.,Khorramshahr Marine Science and Technology University | Wong M.Y.L.,University of Wollongong | Gholami F.,Islamic Azad University at Yasuj
Aquatic Toxicology | Year: 2014

In the recent years, there has been a growing concern about the production and use of bisphenol-A substitute, namely bisphenol-S (BPS). Due to its novel nature, there have been few studies addressing the ability of BPS to disrupt the endocrine system of animals. In the present study, zebrafish (Danio rerio) embryos were exposed to and reared in various concentrations of BPS (0, 0.1, 1, 10 and 100. μg/l) for 75 days. Then adult males and females were paired in spawning tanks for 7 days in clean water and the consequent effects on fish development, reproduction, plasma vitellogenin (VTG), sex steroids and thyroid hormone levels were investigated as endpoints. After 75 days of exposure, there was a skewed sex ratio in favor of females. The results also showed that body length and weight significantly decreased in males exposed to 100. μg/l of BPS. Gonadosomatic index was significantly reduced in fish at ≥10. μg/l. Hepatosomatic index exhibited a significant increase in both male and female fish. At ≥1. μg/l of BPS, plasma 17β-estradiol levels were significantly increased in both males and females. However, plasma testosterone showed a significant reduction in males exposed to 10 and 100. μg/l of BPS. A significant induction in plasma VTG level was observed in both males and females at ≥10. μg/l of BPS. Plasma thyroxine and triiodothyronine levels were significantly decreased at 10 and 100. μg/l of BPS in males, and at 100. μg/l in females. Egg production and sperm count were also significantly decreased in groups received 10 and 100. μg/l of BPS. Moreover, once time to hatching and hatching rates were calculated for fertilized eggs the postponed and decreased rates of hatching were observed. Taken together, these results suggest that developmental exposure to low concentrations of BPS has adverse effects on different parts of the endocrine system in zebrafish. © 2014.

Liu Z.,Monash University | Meng Q.,National University of Singapore | Wang S.,University of Wollongong
Transportmetrica A: Transport Science | Year: 2014

A major objective of the practical implemented cordon-based congestion pricing schemes is to maintain the traffic conditions within the cordon area, which is rarely considered in most of the existing studies. Thus, this paper addresses the optimal toll charge pattern that can restrict the total inbound flow of each cordon to a predetermined threshold. The toll charges on all the entry links of one cordon are required to be identical, for the ease of implementation and users' recognition. The users' route choice behaviour is assumed to follow stochastic user equilibrium (SUE) with asymmetric link travel time functions. It is shown that such an optimal toll charge pattern can be attained by solving a SUE problem with side constraints. A variational inequality (VI) model is first proposed for the optimal toll pattern, where the monotone property of this model is rigorously proved. Then, a convergent self-adaptive prediction and correction method can be adopted for solving the VI model. It is shown that when used in practice, the solution method only needs traffic counts on entry links of each cordon. © 2013 © 2013 Hong Kong Society for Transportation Studies Limited.

Lee J.A.,Hanyang University | Shin M.K.,Hanyang University | Kim S.H.,Hanyang University | Cho H.U.,Hanyang University | And 7 more authors.
Nature Communications | Year: 2015

Flexible, wearable, implantable and easily reconfigurable supercapacitors delivering high energy and power densities are needed for electronic devices. Here we demonstrate weavable, sewable, knottable and braidable yarns that function as high performance electrodes of redox supercapacitors. A novel technology, gradient biscrolling, provides fastion-transport yarn in which hundreds of layers of conducting-polymer-infiltrated carbon nanotube sheet are scrolled into ∼20 μm diameter yarn. Plying the biscrolled yarn with a metal wire current collector increases power generation capabilities. The volumetric capacitance is high (up to ∼179 F cm-3) and the discharge current of the plied yarn supercapacitor linearly increases with voltage scan rate up to ∼80 Vs-1 and ∼20Vs-1 for liquid and solid electrolytes, respectively. The exceptionally high energy and power densities for the complete supercapacitor, and high cycle life that little depends on winding or sewing (92%, 99% after 10,000 cycles, respectively) are important for the applications in electronic textiles. © 2013 Macmillan Publishers Limited. All rights reserved.

Chen T.Y.,Swinburne University of Technology | Tse T.H.,University of Hong Kong | Zhou Z.Q.,University of Wollongong
IEEE Transactions on Software Engineering | Year: 2011

We present an integrated method for program proving, testing, and debugging. Using the concept of metamorphic relations, we select necessary properties for target programs. For programs where global symbolic evaluation can be conducted and the constraint expressions involved can be solved, we can either prove that these necessary conditions for program correctness are satisfied or identify all inputs that violate the conditions. For other programs, our method can be converted into a symbolic-testing approach. Our method extrapolates from the correctness of a program for tested inputs to the correctness of the program for related untested inputs. The method supports automatic debugging through the identification of constraint expressions that reveal failures. © 2011 IEEE.

Liu Z.,Monash University | Meng Q.,National University of Singapore | Wang S.,University of Wollongong
Transportation Research Part C: Emerging Technologies | Year: 2013

The cordon-based Electronic Road Pricing (ERP) system in Singapore adopts the average travel speed as an index for evaluating the traffic congestion within a cordon area, and the maintenance of the average travel speed within a satisfactory range is taken as the objective of the toll adjustment. To formulate this practical speed-based toll design problem, this paper proposes a mathematical programming with equilibrium constraint (MPEC) model with the objective of maintaining the traffic condition in the cordon area. In the model, the network users' route choice behavior is assumed to follow probit-based stochastic user equilibrium with elastic demand, asymmetric link travel time functions and continuous value-of-time. A distributed revised genetic algorithm is designed for solving the MPEC model. Finally, a network example based on the ERP system is adopted to numerically validate the proposed models and algorithms, and further indicates that the computation speed can be improved greatly by using a distributed computing system. © 2013 Elsevier Ltd.

Gallagher S.,University of Memphis | Gallagher S.,University of Hertfordshire | Gallagher S.,University of Wollongong | Varga S.,University of Memphis
World Psychiatry | Year: 2015

The philosophical and interdisciplinary debate about the nature of social cognition, and the processes involved, has important implications for psychiatry. On one account, mindreading depends on making theoretical inferences about another person's mental states based on knowledge of folk psychology, the so-called "theory theory" (TT). On a different account, "simulation theory" (ST), mindreading depends on simulating the other's mental states within one's own mental or motor system. A third approach, "interaction theory" (IT), looks to embodied processes (involving movement, gesture, facial expression, vocal intonation, etc.) and the dynamics of intersubjective interactions (joint attention, joint action, and processes not confined to an individual system) in highly contextualized situations to explain social cognition, and disruptions of these processes in some psychopathological conditions. In this paper, we present a brief summary of these three theoretical frameworks (TT, ST, IT). We then focus on impaired social abilities in autism and schizophrenia from the perspective of the three approaches. We discuss the limitations of such approaches in the scientific studies of these and other pathologies, and we close with a short reflection on the future of the field. In this regard we argue that, to the extent that TT, ST and IT offer explanations that capture different (limited) aspects of social cognition, a pluralist approach might be best. © 2015 World Psychiatric Association.

Kirby D.S.,University of Wollongong | Ward P.,Australian Bureau of Agricultural and Resource Economics and science ABARES
Marine Policy | Year: 2014

Mitigating the environmental impact of commercial fishing, by avoiding, minimizing and compensating for adverse effects, is core business for fisheries management authorities globally. The complex interplay of ecological, economic, and social considerations has often resulted in bycatch management being reactive, confrontational and costly. In many cases it has been difficult to demonstrate success and to establish whether bycatch management has been efficient or effective. This article proposes standards for bycatch management following reviews of literature, international agreements and Australian domestic fishery management policies, and consideration by many technical experts and several stakeholder representatives. The standards have been developed using Australian Commonwealth fisheries - and the international fisheries agreements to which Australia is party - as a baseline, but should be applicable to both domestic and regional/international governance systems. The proposed standards involve quantifying fisheries bycatch, agreeing on operational objectives, assessing the effects of fishing on bycatch populations, establishing the cost-effectiveness of mitigation measures, and evaluating performance. The standards encourage domestic management measures that are consistent with the guidance and requirements of international agreements and regional fisheries management organisations. The importance of engaging stakeholders throughout the process is recognised. The standards provide a framework for measuring performance and a checklist of actions for managing bycatch at a fishery level. They have the potential to facilitate the development of more strategic and effective approaches to bycatch management, with defined goals, monitoring systems, and adaptive decision-making. This review of past bycatch management, including the application of the proposed standards to the mitigation of shark bycatch in an Australian longline fishery, demonstrates that the proposed standards are operationally feasible but that they have not always been applied. Specifically, monitoring the performance of bycatch management measures has not always followed their implementation. © 2013.

Liu T.-C.,National Central University | Lin Y.-C.,National Central University | Tsai M.-J.,National Taiwan University of Science and Technology | Paas F.,Erasmus University Rotterdam | Paas F.,University of Wollongong
Computers and Education | Year: 2012

This study investigated split-attention and redundancy effects in a mobile learning environment on leaf morphology of plants as a function of different combinations of media. Eighty-one fifth-grade students were randomly assigned to the following three conditions: texts with pictures embedded in the mobile device (TP condition); texts embedded in the mobile device and real objects that are outside of the mobile device (TO condition); and texts with pictures embedded in the mobile device and real objects that are outside of the mobile device (TPO condition). Differences in performance on comprehension tests and learning efficiency were examined across conditions. The TP condition was expected to perform better than the TO condition due to a split-attention effect. The TP and TO conditions were expected to perform better than the TPO condition due to a redundancy effect. The results indicated no difference between the TP and the TO condition in comprehension and learning efficiency, but the TP and TO conditions performed better than the TPO condition on both measures. The implications of the results for research and design of mobile learning environments are discussed. © 2011 Elsevier Ltd. All rights reserved.

Beckman R.C.,National University of Singapore | Schofield C.H.,University of Wollongong
International Journal of Marine and Coastal Law | Year: 2014

In the face of seemingly intractable territorial and maritime disputes in the South China Sea, the article examines how the 1982 United Nations Convention on the Law of the Sea (LOSC), sets out what maritime claims States can make in the South China Sea and how it establishes a framework that will enable States to either negotiate maritime boundary agreements or negotiate joint development arrangements (JDAs) in areas of overlapping maritime claims. It provides an avenue whereby the maritime claims of the claimants can be brought into line with international law, potentially allowing for meaningful discussions on cooperation and maritime joint development based on areas of overlapping maritime claims defined on the basis of the LOSC. © koninklijke brill nv, leiden, 2014.

Moritz M.A.,University of California at Berkeley | Batllori E.,University of California at Berkeley | Bradstock R.A.,University of Wollongong | Gill A.M.,Australian National University | And 7 more authors.
Nature | Year: 2014

The impacts of escalating wildfire in many regions-the lives and homes lost, the expense of suppression and the damage to ecosystem services-necessitate a more sustainable coexistence with wildfire. Climate change and continued development on fire-prone landscapes will only compound current problems. Emerging strategies for managing ecosystems and mitigating risks to human communities provide some hope, although greater recognition of their inherent variation and links is crucial. Without a more integrated framework, fire will never operate as a natural ecosystem process, and the impact on society will continue to grow. A more coordinated approach to risk management and land-use planning in these coupled systems is needed. © 2014 Macmillan Publishers Limited. All rights reserved.

Hardy L.L.,University of Sydney | Reinten-Reynolds T.,University of Sydney | Espinel P.,University of Sydney | Zask A.,University of Sydney | And 2 more authors.
Pediatrics | Year: 2012

OBJECTIVE: To describe the demographic and health-related characteristics of school-aged children with low competency in fundamental movement skills (FMS). METHODS: Cross-sectional representative school-based survey of Australian elementary and high school students (n = 6917) conducted in 2010. Trained field staff measured students' height, weight, and assessed FMS and cardiorespiratory endurance (fitness). Information on students'demographics and physical activity was collected by questionnaire. RESULTS: Overall, the prevalence of students with low motor skill competency was high. Girls with low socioeconomic status (SES) were twice as likely to be less competent in locomotor skills compared with high SES peers. Among boys, there was a strong association between low competency in FMS and the likelihood of being from non-English-speaking cultural backgrounds. There was a clear and consistent association between low competency in FMS and inadequate cardiorespiratory fitness. For boys, there was a clear association between low competency in object-control skills and not meeting physical activity recommendations. Conversely, the odds of being inactive were double among girls who had low competency in locomotor skills. CONCLUSIONS: Low competency in FMS is strongly associated with lower cardiorespiratory fitness and physical activity levels in children and adolescents. The characteristics of students with competency in FMS differ by gender and skills types and show that interventions need to target girls from low SES backgrounds and boys from non-Englishspeaking cultural backgrounds. The high prevalence of low competency in FMS among Grade 4 students indicates that FMS interventions need to start during the preschool and early school years. Copyright © 2012 by the American Academy of Pediatrics.

Yin Z.,China Pharmaceutical University | Yin Z.,University of Wollongong | Song Y.,Shanghai University | Rehse P.H.,Shanghai Medicilon Inc.
ACS Chemical Biology | Year: 2013

Phosphorylation-dependent protein-protein interaction has rarely been targeted in medicinal chemistry. Thymoquinone, a naturally occurring antitumor agent, disrupts prephosphorylated substrate recognition by the polo-box domain of polo-like kinase 1, a key mitotic regulator responsible for various carcinogenesis when overexpressed. Here, crystallographic studies reveal that the phosphoserine/phosphothreonine recognition site of the polo-box domain is the binding pocket for thymoquinone and its analogue poloxime. Both small molecules displace phosphopeptides bound with the polo-box domain in a slow but noncovalent binding mode. A conserved water bridge and a cation-π interaction were found as their competition strategy against the phosphate group. This mechanism sheds light on small-molecule intervention of phospho-recognition by the polo-box domain of polo-like kinase 1 and other phospho-binding proteins in general. © 2012 American Chemical Society.

Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: ENV.2009. | Award Amount: 8.23M | Year: 2010

Fire regimes result from interactions between climate, land-use and land-cover (LULC), and socioeconomic factors, among other. These changed during the last decades, particularly around the Mediterranean. Our understanding of how they affected fire regime in the past is limited. During this century temperatures, drought and heat waves will very likely increase, and rainfall decrease. These and further socioeconomic change will affect LULC. Additional areas will be abandoned due to being unsuitable for agriculture or other uses. Fire danger and fire hazard are very likely to increase, affecting fire regimes. FUME will learn from the past to understand future impacts. Mod. 1 we will study how LULC and socioeconomics changed and how climate and weather affected fire in dynamically changing landscapes. Fires will be mapped throughout Europe to determine hazard burning functions for LULC types. Since climate has changed, an attempt to attribute (sensu IPCC) fire regime change to climate, differentiating it from socioeconomic change, will be made. Mod. 2 will produce scenarios of change (climate, including extremes, land-use land-cover, socioeconomics, vegetation) for various emissions pathways and three time-slices during this century. With these and results from Mod.1, models and field experiments projected impacts on fire-regime and vegetation vulnerabilities will be calculated, including climate extremes (drought, heat-waves). Mod. 3 will investigate adaptation options in fire- and land-management, including restoration. Fire prevention and fire fighting protocols will be tested/developed under the new conditions to mitigating fire risks. A company managing fire will be a key player. Costs and policy impacts of changes in fire will be studied. Research will focus on old and new fire areas, the rural interface, whole Europe and the Mediterranean, including all Mediterranean countries of the world. Users will be involved in training and other activities.

Hutto D.D.,University of Wollongong | Hutto D.D.,University of Hertfordshire | Kirchhoff M.D.,University of Wollongong | Myin E.,University of Antwerp
Frontiers in Human Neuroscience | Year: 2014

Radical enactive and embodied approaches to cognitive science oppose the received view in the sciences of the mind in denying that cognition fundamentally involves contentful mental representation. This paper argues that the fate of representationalism in cognitive science matters significantly to how best to understand the extent of cognition. It seeks to establish that any move away from representationalism toward pure, empirical functionalism fails to provide a substantive "mark of the cognitive” and is bereft of other adequate means for individuating cognitive activity. It also argues that giving proper attention to the way the folk use their psychological concepts requires questioning the legitimacy of commonsense functionalism. In place of extended functionalism—empirical or commonsensical—we promote the fortunes of extensive enactivism, clarifying in which ways it is distinct from notions of extended mind and distributed cognition. #x00A9; 2014 Hutto, Kirchhoff and Myin. All Rights Reserved.

Gallagher S.,University of Memphis | Gallagher S.,University of Hertfordshire | Gallagher S.,University of Wollongong
Frontiers in Human Neuroscience | Year: 2014

In cognitive psychology, studies concerning the face tend to focus on questions about face recognition, theory of mind (ToM) and empathy. Questions about the face, however, also fit into a very different set of issues that are central to ethics. Based especially on the work of Levinas, philosophers have come to see that reference to the face of another person can anchor conceptions of moral responsibility and ethical demand. Levinas points to a certain irreducibility and transcendence implicit in the face of the other. In this paper I argue that the notion of transcendence involved in this kind of analysis can be given a naturalistic interpretation by drawing on recent interactive approaches to social cognition found in developmental psychology, phenomenology, and the study of autism. © 2014 Gallagher.

Agency: GTR | Branch: EPSRC | Program: | Phase: Research Grant | Award Amount: 5.75M | Year: 2013

We propose an End Use Energy Demand (EUED) Centre focused on Energy Epidemiology to be located at the multidisciplinary UCL Energy Institute (UCL-Energy), which undertakes research on energy demand and energy systems. Energy Epidemiology uses data and modelling to study energy use in the real world, with the aim of understanding the interactions of policy, technology, infrastructure, people and culture. The Centre for Energy Epidemiology (CEE) will: undertake primary data collection; advise on data collection; provide secure and ethical curation of a wealth of administrative, commercial and research data; link, develop and use innovative research methods; and support a structured research programme on energy demand intended to achieve a major reduction in UK carbon emissions. CEE will provide key research and policy insights at city, regional, national and international levels. It will support UK academics, policymakers and industry to research energy demand, by providing a cost-effective, secure and ethical bureau service for energy and related data. It will work closely with the new cross-government Energy Efficiency Deployment Office (EEDO) of DECC, the Energy Saving Trust, UK Energy Research Centre (UKERC) and the new Open Data Institute (ODI) to marshal and maximise the value of existing and very large future sources of energy-related data (big data), ensuring the greatest impact for evidence-based energy demand research. The Centre will initiate and be a key player in an international network of energy epidemiologists, sharing research methods and undertaking cross-cultural comparisons of policies and technologies to reduce energy demand and to help the UK to meet its carbon targets. UCL-Energy: - has a clear focus on energy demand and its interaction with energy supply systems - this has been the core focus of UCL-Energy since its launch, with full UCL support, 35 months ago. - is multi- and interdisciplinary with lawyers, economists, social scientists, engineers, physicists, psychologists, architects, mathematicians and policy analysts co-located in open plan offices facilitating collaborative work. It has successfully worked with researchers from anthropology, English literature and history on energy demand problems. - makes an impact by supporting policy makers and industry to both set and achieve UK carbon targets. Examples of such support include the Green Deal, CCC budgets, smart meter rollout, and the development of products for reducing energy demand. UCL-Energy is the only university centre that has officially advised DECCs new EEDO, whose focus is squarely on EUED. - undertakes research of the highest quality; its staff were recognised as world leading by two successive EPSRC Platform Grant reviews. Roughly half its staff were submitted in the Built Environment UoA (30), for which UCL received the highest percentage (35%) of internationally leading staff (4*) in the UK. It holds the grant for the only Centre for Doctoral Training in energy demand. - is not sector-specific; it covers all energy uses and applies methods across sectors e.g. transport and buildings. - is managed as a coherent centre - this is facilitated by placing all staff under a single budget centre with a clear management structure. UCL-Energy is advised and guided by a prestigious International Advisory Board with CEOs and directors from leading companies around the world. - has leveraged a wide range of funding. From an initial UCL investment of £680k, it has so far raised £10m of external funding, including £2m from industry. - has strong leadership - its Director, Professor Tadj Oreszczyn has established a new academic department at UCL in less than 3 years, advises government at senior level, is on the boards of key organisations and has written several strategic papers on the future direction of energy demand research. - has critical mass and sustainability: UCL-Energy has 80 staff and PhD students

News Article | October 5, 2016
Site: www.materialstoday.com

In recent years, researchers at the University of Texas at Dallas and colleagues at the University of Wollongong in Australia have put a high-tech twist on the ancient art of fiber spinning, using modern materials to create ultra-strong, powerful, shape-shifting yarns. In a new perspective article in the Proceedings of the National Academy of Sciences, scientists at UT Dallas’ Alan G. MacDiarmid NanoTech Institute describe the path to developing a new class of artificial muscles made from highly twisted fibers of various materials. These range from exotic carbon nanotubes to ordinary nylon thread and polymer fishing line. Because the artificial muscles can be made in different sizes and configurations, potential applications range from robotics and prosthetics to consumer products such as smart textiles that change porosity and shape in response to temperature. “We call these actuating fibers ‘artificial muscles’ because they mimic the fiber-like form-factor of natural muscles,” said Carter Haines, associate research professor in the NanoTech Institute and co-lead author of the article, together with research associate Na Li. “While the name evokes the idea of humanoid robots, we are very excited about their potential use for other practical applications, such as in next-generation intelligent textiles.” Spinning animal fur and plant fibers to make thread and yarn goes back thousands of years. Aligning the fibers and then twisting them into yarn provides the yarn with strength. By exploiting this concept, and adding 21st century science, the UT Dallas researchers have produced actuating muscle yarns that, like their woolly counterparts, can be woven, sewn and knitted into textiles. For example, carbon nanotubes are tiny, hollow tubes that are super-strong and electrically conductive. In 2004, a team led by Ray Baughman, director of the NanoTech Institute at UT Dallas, developed a method to draw ‘forests’ of nanotubes out into sheets of aligned fibers – much like carded wool – and then twist these sheets into yarns. Next, the group turned to polymer fibers such as nylon sewing thread and fishing line, which consist of many individual molecules aligned along the fiber’s length. Twisting the thread or fishing line orients these molecules into helices, producing torsional – or rotational – artificial muscles that can spin a heavy rotor at more than 100,000 revolutions per minute. When these muscles are so highly twisted that they coil like an over-twisted rubber band, they can produce tensile actuation, where the muscle dramatically contracts along its length when heated, and returns to its initial length when cooled. This research, published in 2014, showed that simple, low-cost muscles made from fishing line can lift 100 times more weight and generate 100 times higher mechanical power than a human skeletal muscle of the same length and weight. “The success of our muscles derives from their special geometry and the fact that we start with materials that are anisotropic – when they are heated, the materials expand in diameter much more than they expand along their length,” said Baughman, senior author of the perspective. This anisotropy is an intrinsic property of high-strength polymer fibers, and is the same principle that drives powerful artificial muscles the researchers discovered in 2012, which they made by adding a thermally responsive ‘guest’ material within a carbon nanotube yarn. “When these fibers are then twisted and coiled, their internal geometry changes so that when they are heated, that diameter expansion results in a change in length,” Baughman said. “The fiber’s diameter only has to expand by about 5% to drive giant changes in length.” In their most recent experiments, described for the first time in the article, Haines and Li added a new twist to their artificial muscles. “The coiled artificial muscles we initially made from fishing line and nylon sewing thread were limited in the amount they could expand and contract along their length,” Haines said. “Because of their geometry – like a phone cord – they could only contract so far before the coils began to collide with one another.” “The advantage to the spiral shape is that now our muscle can contract into a flat state, expand out in the other direction, and return to its original length, all without getting stuck on itself,” Li said. “Our experiments to date have been proof-of-concept, but have already shown that we can use heating and cooling to drive this back-and-forth motion across a giant range. This type of telescoping actuator can produce over an 8600% change in length, compared to around 70% for our previous coils.” Li said that one potential application for the spiral-shaped coil might be thermally-responsive clothing. Instead of a down-filled jacket, a coat that incorporates many small coils could change the loft and insulating power of the garment in response to temperature. In the laboratory, Haines and Li have produced spools of coiled polymer muscle threads suitable for sewing. “We have shown that these thermally responsive fibers can be used in conventional machines, such as looms, knitting machines and sewing machines,” Li said. “As we move forward with our research, and scale it up, we hope to incorporate our ideas into functional fabrics and textiles for a variety of purposes, from clothing to environmentally responsive architecture to dynamic art sculptures.” This story is adapted from material from the University of Texas at Dallas, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

News Article | November 10, 2016
Site: www.sciencedaily.com

A team of Norwegian, French and Australian researchers is the first in the world to succeed in quantifying the effects of radiation on individual cancer cells. This means that radiation therapies can now be tailored to individual tumours and thus be more effective. The recently developed sensor is the first of its kind and can measure radiation doses at the level of the individual cell in mixed radiation fields (e.g. measuring all type of radiation at the same time). It enables doctors to obtain a complete picture of how much damage each cell has incurred following treatment. "This technology means that doctors can monitor and control radiation doses to make sure that only cancer cells are destroyed, with only minimal damage to surrounding healthy tissue," explains physicist and SINTEF researcher Angela Kok. Kok has been leading the work to develop the sensor as part of her day-to-day research looking into microsystems and nanotechnology. Until now, quantification of the radiation dose absorbed by an individual cancer cell has been regarded as a very difficult task. Firstly, each cell is very small, and there may be as many as about a million cells in a single cubic millimetre of tissue. For this reason, and to ensure that the resulting data are correct, a sensor designed to measure radiation has to be as small as the cell itself. In other words, there has to be space for a million sensors in a single cubic millimetre of cancer tissue. The second problem is that the cells themselves "perceive" the radiation dose in an entirely different way to the sensors. This is why, until now, no sensor has been able to quantify the actual degree of damage caused to cells by a radiation dose. But the international research team has now succeeded in solving both of these problems. The sensor size issue has been addressed simply by developing a sensor that is as small as a cancer cell. This has been achieved using a technology called semiconductor processing. The second problem, addressing the different ways in which cells and sensors perceive radiation doses, represented a major challenge. But researchers solved this problem by encapsulating the sensors in a plastic material that mimics human tissue. In this way, the radiation dose measured by the sensors is almost identical to that absorbed by real cancer cells. The measuring instrument contains microsensors placed alongside each other in a way that creates a "sheet" of sensors mounted on the silicon base. Dispersal across a given area enables the sensors to provide an image of the location within the cell that absorbs the highest levels of radiation. "In simple terms, we can say that the sensors are used to map variations in radiation intensity absorbed across the exposed cell," explains Kok. The most important component of the new sensor is the element silicon, which is a semiconductor with radiation detection properties. "When radiation counteracts with silicon the energy is converted into a measurable electrical signal," explains Kok. "The magnitude of the signal indicates the intensity of the radiation," she says. The very first sensor prototype saw the light of day at SINTEF's microsystems and nanotechnology lab following a major multinational project involving researchers in the field of medical radiation physics. It was tested recently at the European Synchrotron Radiation Facility (ESRF*) in Grenoble with outstanding results. It has also been tested by Australian researchers at the Australian Nuclear Science and Technology Organisation. "This project is a little unusual because our research has resulted in new and fundamental knowledge about what happens in a volume of silicon that has the same dimensions as a typical cell," says Senior Research Scientist Kari Schjølberg-Henriksen, who has been working with quality assurance on this project. "We've taken this knowledge further and have seen it applied in practice after only four years," she says. Research scientist Marco Povoli has been working on this project both as a SINTEF employee and as part of his post-doctoral studies at the University of Oslo. He believes that this innovation may be good news for the future development of cancer treatments using proton therapy. (Read the fact box) "It appears that proton therapy produces better outcomes for some types of cancer than traditional radiotherapies," he says. "This is why the University of Wollongong, with which we collaborate, has been working for some time to develop sensors designed for use in proton therapy. There currently exist no sensors (microdosimetry tools, Ed. note) capable of measuring radiation of this kind, but we realised that our technology could be adapted to develop sensors with the right specifications," says Povoli. The team based their work on a technology originally applied to develop sensors for tracking nuclear particles as part of experiments using the particle accelerator at CERN. The technology was used to make the silicon structures that now mimic the effects of radiation on human tissue. "The fabrication process required more development to optimise the reliability of the results, but we overcame this challenge within a few months," says Povoli. The sensor has now been tested with excellent results. According to the research team, it is capable of measuring the true values of radiation doses absorbed by tissue, and with a better spatial resolution than existing equipment. The team is now hoping to be able to contribute towards the future development of radiation therapies for cancer. This can be achieved by providing a more precise quantification of the radiation doses absorbed by cancer tissue, while at the same time reducing the damage incurred by healthy tissue.

News Article | January 27, 2016
Site: phys.org

Research co-led by Eureka Prize winner Professor Dayong Jin at UTS, in collaboration with colleagues at Macquarie University, the University of Wollongong and the National University of Singapore, has taken a huge step closer to the engineering of nanoscale devices to aid the delivery of life-saving drug treatments. A renowned biomolecular scientist, Professor Jin said such minute devices have the potential to be engineered to efficiently and more safely deliver drug treatments directly to the location of diseased cells while helping avoid harm to healthy cells that fall victim to toxic drugs administered by conventional means. "Treatment for aggressive cancers by with radiation or chemical drugs might kill cancer cells, but can also kill up to 70 to 90 per cent of healthy cells," Professor Jin said. "We see similar problems in the treatment of neurological diseases. There are many drugs available, however the blood-brain barrier protecting the brain from infection also blocks drug treatments – often the drug circulates through the blood stream without reaching the brain to fight a disease." Ground-breaking work by Professor Jin and his colleagues over the past three years has produced a library of 800 different and uniquely shaped nanocrystals, formed from ordered atom clusters. The differently shaped "hybrid" nanocrystals act as new tools or molecular tags that enable and aid targeted drug delivery. Professor Jin said the new types of nanocrystal could also assist in the development of clearer diagnostic bio-imaging such as MRI scans and X-rays. "Hybrid nanocrystals are multifunctional and able to do different things simultaneously," he said. "For example, one can design a super nanoparticle that has optical, magnetic and chemical responses which allows for multiple modality imaging of a disease and in-time super high-resolution images. "Having precise diagnostics is essential for enabling surgeons to operate. They need to understand exactly where the tumour is. If higher resolution imaging can more easily show a precise boundary between healthy cells and tumor cells, better outcomes can be achieved for patients. "Now nanoparticles can be precisely controlled to create different shapes and sizes, we can investigate whether they have an impact on the transportation of drugs within the body. Ongoing research in collaboration with medical researchers will focus on further tailoring the design of such particles to deliver positive results." This research can be viewed at Nature Communications. More information: Deming Liu et al. Three-dimensional controlled growth of monodisperse sub-50 nm heterogeneous nanocrystals, Nature Communications (2016). DOI: 10.1038/ncomms10254

News Article | October 28, 2015
Site: www.nature.com

High tide left its mark on the houses like a dirty ring in a bathtub. The flood crept into the village of Teaoraereke under the cover of darkness, sending filthy seawater sloshing through pigsties and shallow graves, and into people's homes. Teaoraereke residents scrambled to retreat, hoisting sleeping children, sodden bedding and other belongings to higher ground. But some stayed put, including Rerema Kauria, a 63-year-old grandmother who was marooned just inches above the floodwaters on a raised platform bed. She was still there by mid-morning as the water receded, her possessions tucked into the rafters of her traditional house of wooden poles and thatch. She knew that when high tide returned that afternoon it would bring more flooding, but she gave a roaring laugh when asked if she had considered leaving. “Where would I go?” The uncertain future of people such as Kauria has drawn attention to a collection of atolls in the central Pacific Ocean that make up the Republic of Kiribati (pronounced Keer-re-bahs). The average height of the country's 33 islands is little more than 2 metres above the ocean, which makes Kiribati acutely vulnerable to climate change. By the end of the century, melting polar ice and the thermal expansion of warmer seawater is expected to raise global ocean levels by perhaps 1 metre. That upsurge would, according to some predictions, displace many from Kiribati and millions of others around the world — and the water will keep going up. For years, Kiribati President Anote Tong has sounded the alarm over his nation's plight, warning that residents would soon have to abandon their homeland. The flooding that hit Teaoraereke last year reinforces those dire predictions. Although it is impossible to know how much, if at all, climate change contributed to the flooding, village residents say that they have never before seen such inundation. To some of them, it seemed as if the swelling seas were starting to consume Kiribati and the end of the atoll might come sooner than they had thought. But researchers who study Kiribati say that the situation is not a simple story of rising seas swallowing low-lying islands. In fact, some coastal experts dispute the idea that Kiribati will soon sink beneath the waves like a modern Atlantis. They have gathered evidence that many of these islands have been gaining ground in recent decades by capturing sediments from surrounding coral reefs. “It's just plain wrong to assume that all atolls are washing away,” says Arthur Webb, a coastal geomorphologist affiliated with the University of Wollongong in Australia who has spent two decades living and working in the Pacific Islands. “It's also wrong to sugar-coat the sobering facts that rising sea levels will ultimately seal the fate of low-lying islands and their limited soils and groundwater. The confusion isn't surprising. It's just more complicated than many expect.” Even if Kiribati does not drown in the near future, its residents may soon need an exit strategy. Poverty, overcrowding and poor sanitation are galloping ahead of rising seas to deplete the islands' resources, especially their supply of clean fresh water. And residents' habits of altering the shoreline and removing coastal protections can magnify the impacts of the swelling oceans, leaving villages more exposed to flooding. The story playing out on these tiny islands shows how difficult it is to tease out the impact of climate change from other human and environmental pressures. And what happens to the Kiribati people has implications for the hundreds of millions in low-lying coastal areas across the globe who will be threatened with flooding and displacement in coming decades. But unlike the residents of Miami, Guangzhou or Mumbai, the Kiribati people have no option of retreating inland or up-slope as their vulnerable flyspecks of land become uninhabitable. As Kauria says: where would they go? From the air, Kiribati's Tarawa atoll emerges from the Pacific as narrow strands of land that join to form a wispy V shape. On the outside of the V is the deep blue of the ocean; inside are the aquamarine and turquoise waters of the shallow lagoon. Tarawa is the capital of Kiribati, which is one of the most remote countries on Earth, located on the equator about halfway between Australia and Hawaii. Its atolls are scattered across a patch of the Pacific the size of India, and yet they have a total of just 811 square kilometres of land, about half the size of Greater London. When a plane lands on Tarawa, a crowd gathers at the airport, drawn by the excitement of the jet making the three-hour flight from Fiji. Aside from occasional freighters bringing canned food, this twice-weekly Fiji Airways flight provides the primary connection to the outside world. The airport was built on relatively high ground, an elevation of 3 metres, in one of the atoll's widest sections. It happens to sit above the main subsurface reservoir, a freshwater layer floating on top of the seawater that presses against the porous island from all sides. Although the sea presents an existential threat, the more immediate problem is not too much water, but too little — of the fresh, clean kind. A dozen of Kiribati's islands are deserted, too arid to support human habitation. Without enough replenishing rains, their thin lenses of groundwater turned brackish. On Tarawa, groundwater is heavily overdrawn and contaminated by the local practice of defecating on the beach or in the bushes. With little land, residents bury their relatives and raise pigs next to their homes, which also contributes to groundwater pollution. Next to the road leading to the airport, a buried white plastic pipe that carries fresh water from the reservoir has been exposed in places, owing to erosion by waves and tides. Public workers have fought back by using old tyres filled with concrete to hold it in place. They have had less success keeping locals from tapping illegally into the waterline, directing the flow into hand-dug wells for their homes. Water supplies are so limited that authorities turn on the airport's groundwater pumps for only a couple of hours every other day. The perils of water, both sweet and salty, are intertwined with Tarawa's history, says George Fraser, high commissioner to Kiribati from Australia, which is the biggest provider of international support to the developing nation. In one of the bloodier clashes in the Pacific during the Second World War, US commanders misjudged the tides and landing craft got stuck on the reef, forcing marines to wade through chest-deep water under heavy Japanese fire. Fraser deconstructs that infamous battle as he takes a tour of the island the day before the king tide that flooded Teaoraereke. A fast and confident driver, Fraser weaves his small sport utility vehicle around wobbly wheeled trucks, dodging potholes. In narrow spots, the atoll's main road is soaked with seawater and he swerves to avoid a wave splashing over a concrete berm. “Some people use calendars to get through the week,” he says. “We use tide charts.” The road is the only paved one on the atoll. It crosses a series of causeways that have been battered by wheels and waves; road crews repair cavities, stuffing them with as much concrete and sand as possible to slow the decay. The Australian government has bankrolled much of a repaving project along the length of South Tarawa. As Australia's top representative, Fraser has a keen sense of the various challenges that this poor country faces in coming decades, and how they stack up. “If you look at rising sea levels as the train coming down the track, it's a couple of kilometres away,” he says. “If you look at what's 100 metres down the track, it's no water, and right behind it is no food.” More than half of Kiribati's 110,000 residents live on Tarawa, and their numbers are rapidly increasing as more arrive from outer islands seeking jobs, cash and better schools. Many were subsistence fishers and farmers on their home islands, struggling with depleted fisheries and poor soil damaged by periodic over-wash of salt water. When they get to Tarawa, they often end up jobless or underemployed. The Kiribati culture is communal, with families accustomed to bedding down together on woven mats on the floor. It is taboo to refuse the request of a relative, so households often pack dozens of extended family members from other islands under one roof. That has made South Tarawa one of the most densely packed places in the Pacific; its clusters of shanties resemble slums in the poorest capitals of Africa and Asia. Factoring in high birth rates and ongoing urbanization, the government projects that the population of the island will almost double in 15 years. The new Battle of Tarawa will be over where all these people will live. Today's scientific debate about whether Kiribati is growing or shrinking can be traced to Charles Darwin — who first worked out how coral atolls form. While sailing the Pacific on the HMS Beagle in the 1830s, he theorized that these curiously shaped sand islands are produced by coral reefs that sprouted on the slopes of volcanic islands and have continued to grow as the volcanoes sink into the abyss. He was proved right a century later, when scientists drilled into an atoll and hit volcanic rock. Over the millennia, the exoskeletons of millions of tiny coral animals fuse with coralline algae and the shells of molluscs and other sea creatures to form limestone reefs, often arranged in a circle with a shallow lagoon in the middle. Living corals grow on the fringes of these limestone platforms. As the crest of the living reef reaches close to the ocean surface, waves break some of it into rubble and sand that gets deposited on the dead limestone platform to form land. The atolls that exist today are the survivors, ones in which coral reefs kept pace with rising seas and the subsidence of the undersea volcano. The pressing issue is, what will become of those atolls as sea levels start rising faster? Researchers wonder whether corals can keep up, given the host of environmental problems they face. In many places, overfishing and nutrient pollution have triggered the growth of coral-killing bacteria and algae. Abnormally warm seawater is causing 'bleaching' die-offs throughout the tropics, and as ocean water takes up more carbon dioxide and acidifies, it will be harder for coral polyps to build rugged exoskeletons. Around Tarawa, the coral reefs are in particularly poor shape, says Simon Donner, a climatologist at the University of British Columbia in Vancouver, Canada, who has done diving surveys. “Coral cover is lower than you'd expect around the island,” he says. “That's the legacy of pollution, sewage mostly, and frequent bleaching events in the past 20 years.” To help predict how corals may fare in the future, Dennis Hubbard, a geologist at Oberlin college in Ohio, and his colleagues have been peering into the past, amassing a database of sediment core samples obtained by drilling into limestone beneath coral reefs. With carbon dating, they can determine how quickly these reefs have grown: in yet-to-be-published work, they have found that more than half of the world's coral reefs grew more slowly over the past 10,000 years than sea levels are rising today. Extrapolating forward, those results suggest that only half of all atolls in existence today have a chance of keeping pace with rising seas under the best of conditions, he says. “Given that this was in a time with no human impact, we feel this is the most optimistic scenario possible.” Kiribati and other low-lying island nations have long been held up as the countries most susceptible to the ravages of rising seas. In 2001, the Intergovernmental Panel on Climate Change (IPCC) highlighted1 predictions that two-thirds of Kiribati and the nearby Marshall Islands would be inundated by a sea rise of 80 centimetres. But the idea that these atolls will disappear any time soon has been challenged by Paul Kench, a coastal geomorphologist at the University of Auckland. He and his colleagues have pored over satellite images, comparing new and old aerial photographs to see how such islands have changed. In a 2010 study, he and Webb determined2 that 23 out of 27 atoll islands scattered across Kiribati, Tuvalu and the Federated States of Micronesia had either increased in area or remained stable in recent decades. The results, they reported, “contradict widespread perceptions that all reef islands are eroding in response to recent sea level rise”. The researchers concluded that these islands are more “resilient landforms” than previously thought. The study created a media stir in the region and beyond. It has been widely cited by climate-change sceptics seeking to punch holes in research on global warming and its impacts. Kench recognizes the powerful forces of climate change but complains that too many scientists and activists focus solely on rising sea levels while ignoring the other part of the equation: how the land responds. “There are a lot of claims that islands are passive geological entities that will sit there and drown,” he says. “Our work shows that they are anything but static. They are dynamic. They move around and they can grow. So just because sea level is rising, it doesn't mean doom and gloom for all atolls.” He also believes that most scientists make a mistake by tethering the fate of atoll islands to the health of surrounding coral reefs. Even if reefs die, he says, they can provide sufficient sediment to maintain islands for a century or more. But Hubbard considers Kench's views shortsighted. “If you run out of reefs, you run out of sediment, and once you run out of sediment, you run out of islands,” he says. “A lot of this is a semantics issue, challenging when the reef island is going to be physically underwater. Those reef islands are going to be abandoned long before that because they are uninhabitable.” On Tarawa and other Kiribati islands (see 'Isolated islands'), most people do not dwell on such matters, going about their daily lives just like residents of other countries. But their president has earned international recognition for speaking out on the threats of climate change. In an interview, Tong dismisses those who suggest that atolls are resilient to rising seas, saying that they have the luxury of “talking from the top of a mountain” and not putting their lives on the line. “These people are not living here. Their grandchildren will not be living here. If they believe that, let them come here,” he says, pounding his fist on a chair armrest for emphasis. “I'd rather plan for the worst and hope for the best.” Tong has told his people that they must prepare to leave, seeding the idea of an early “migration with dignity”, rather than fleeing as refugees when storm-generated waves wash over the islands. Last year, his government completed an US$8-million purchase of 22 square kilometres of hilly land in Fiji, to grow food and provide possible refuge for some of his people — although it will not accommodate all of them. He does not know when people will need to migrate, but he wants to purchase more land in Australia and New Zealand, saying that it is much cheaper than trying to build sea walls and other defences. “If we build up these lands, it's going to cost billions of dollars,” he says. “We might as well be buying land for millions of dollars elsewhere.” For nearly a week after Teaoraereke flooded, resident Matua Kamori worked alongside his neighbours to build a makeshift sea wall where the high tide had breached a sand berm on the beach. Villagers piled up chunks of coral scavenged from the shore and grouted them together with cement donated by a local church. Kamori, 33, lives in the village with his wife and 4 kids on a small parcel of land given to him by his wife's uncle in exchange for looking after one of his sons. To prepare the land, Kamori spent months scouring sand and coral gravel off the beach and hauling it to the site with nothing more than a rice sack. Over time, he fashioned a building pad half a metre high and constructed a hand-hewn traditional house of wood and thatch on it. Such beach mining is rampant on Tarawa, according to household surveys. Government studies3 show that it increases the likelihood of flooding by lowering the protective sand berm that keeps the highest tides at bay. In the case of the recent inundation, Kamori says that he fared better than most: the water reached calf-deep in his house, rather than thigh-high. But nothing could be done to stop the briny stew of salt water, mixed with human and animal waste, from polluting his well or killing his garden of vegetables and banana and papaya trees. Kamori says that he settled on the land because he had nowhere else to go. As crowding increases, new settlements are pushing into vulnerable lowlands, places they historically would have avoided. The individual actions of settlers such as Kamori are only part of the problem on Tarawa. Large-scale construction projects over the years have also exacerbated flooding and erosion, says Naomi Biribo, Kiribati's secretary of fisheries and marine resources development. Biribo earned a PhD in Australia by examining the impact of the sea walls and other human structures on Tarawa. The construction of causeways, rather than bridges, to connect the islets had the effect of closing channels and disrupting the flow of sediment that normally resupply some eroding coastlines, she found4. Reclamation projects that create new land are another problem: although such efforts have added hundreds of hectares to Tarawa, they accelerate erosion elsewhere, says Biribo. For Tarawa residents, she says, the thin ribbons of land leave little room to move. “In many places on Tarawa, you can stand in the middle and you can see the ocean on one side and still see lagoon on the other side,” she says. “If we retreat from the ocean side, and institute a setback, we will fall into the lagoon.” Biribo's work suggests that sea-level rise may be having a small influence on the shoreline changes happening today, but nothing compared to human activities and the seasonal variations in erosive tides and waves in the Pacific that come with the El Niño periods of warming and La Niña cooling. Donner agrees that climate change has been dwarfed by other factors so far. “You cannot blame the flooding on sea-level rise,” he says. “At least not yet.” Where does this leave residents of Kiribati? Webb has long wrestled with that question. He is married to a woman from Tarawa, and they own a house there, where they live with their children for part of the year. Webb was also a lead author of the small-islands chapter5 of the IPCC's fifth assessment report in 2014, which found that rising seas present “severe sea flood and erosion risks for low-lying coastal areas and atoll islands”. It highlighted one projection6 that a 50-centimetre rise in sea level could displace 1.2 million people from low-lying islands in the Caribbean Sea and the Indian and Pacific oceans; that number almost doubles if the sea level rises by 2 metres. And yet, the latest assessment steered clear of the IPCC's previous assertion that an 80-centimetre rise would inundate two-thirds of Kiribati. Scientific understanding of atoll geology has sharpened since that earlier projection. Webb expects some remnants of Tarawa to remain a century or two from now, but probably no more than some wave-washed gravel banks — and by that point, everyone will have long gone. The geological evidence does not get to the key human question about the destiny of these Pacific islanders. That leaves Webb facing a difficult question — one he hears from his own Kiribati-born teenagers. “How long do we have?” they ask. To that, he replies: “Your children will not grow old in the atolls.”

News Article | January 27, 2016
Site: www.cemag.us

Development of effective new treatments for cancer, dementia, Parkinson's disease, and other brain conditions is becoming possible from breakthrough discoveries being made in nanotechnology. Research co-led by Eureka Prize winner Professor Dayong Jin at University of Technology Sydney, in collaboration with colleagues at Macquarie University, the University of Wollongong, and the National University of Singapore, has taken a huge step closer to the engineering of nanoscale devices to aid the delivery of life-saving drug treatments. A renowned biomolecular scientist, Jin says such minute devices have the potential to be engineered to efficiently and more safely deliver drug treatments directly to the location of diseased cells while helping avoid harm to healthy cells that fall victim to toxic drugs administered by conventional means. "Treatment for aggressive cancers by with radiation or chemical drugs might kill cancer cells, but can also kill up to 70 to 90 percent of healthy cells," Jin says. "We see similar problems in the treatment of neurological diseases. There are many drugs available, however the blood-brain barrier protecting the brain from infection also blocks drug treatments – often the drug circulates through the blood stream without reaching the brain to fight a disease." Ground-breaking work by Jin and his colleagues over the past three years has produced a library of 800 different and uniquely shaped nanocrystals, formed from ordered atom clusters. The differently shaped "hybrid" nanocrystals act as new tools or molecular tags that enable and aid targeted drug delivery. Jin says the new types of nanocrystal could also assist in the development of clearer diagnostic bio-imaging such as MRI scans and X-rays. "Hybrid nanocrystals are multifunctional and able to do different things simultaneously," he says. "For example, one can design a super nanoparticle that has optical, magnetic and chemical responses which allows for multiple modality imaging of a disease and in-time super high-resolution images. "Having precise diagnostics is essential for enabling surgeons to operate. They need to understand exactly where the tumor is. If higher resolution imaging can more easily show a precise boundary between healthy cells and tumor cells, better outcomes can be achieved for patients. "Now nanoparticles can be precisely controlled to create different shapes and sizes, we can investigate whether they have an impact on the transportation of drugs within the body. Ongoing research in collaboration with medical researchers will focus on further tailoring the design of such particles to deliver positive results." This research can be viewed at Nature Communications. Release Date: January 27, 2016 Source: University of Technology Sydney

News Article | March 30, 2016
Site: www.sciencenews.org

Hobbits disappeared from their island home nearly 40,000 years earlier than previously thought, new evidence suggests. This revised timeline doesn’t erase uncertainty about the evolutionary origins of these controversial Indonesian hominids. Nor will the new evidence resolve a dispute about whether hobbits represent a new species, Homo floresiensis, or were small-bodied Homo sapiens. Hobbits vanished about 50,000 years ago at Liang Bua Cave on Flores, an island situated between Borneo and Australia’s northern coast, say archaeologist Thomas Sutikna of the University of Wollongong, Australia, and his colleagues. Cave sediment dating to about 12,000 years ago, which lies just above soil that yielded H. floresiensis remains, provided an initial estimate of when these diminutive hominids died out. But that sediment washed into the cave long after H. floresiensis was gone, covering much older, hobbit-bearing soil, the researchers report in the March 31 Nature. Using the initial age estimate, researchers had previously concluded that hobbits survived for tens of thousands of years after Homo sapiens passed through Indonesia and reached Australia around 50,000 years ago. It now appears that hobbits instead hit an evolutionary dead end around that time, Sutikna’s group says. The centerpiece of hobbit finds, a partial skeleton, comes from an individual who lived well before then, the scientists add. Measurements of the decay of radioactive elements in an arm bone from the partial skeleton indicate that the find dates to between 86,900 and 71,500 years ago. Until now, researchers suspected these bones were only about 18,000 years old. Based on the new dates, “there was possibly no overlap or interactions between H. floresiensis and H. sapiens on Flores,” says paleoanthropologist Richard Potts of the Smithsonian Institution in Washington, D.C. Hobbits disappeared before the earliest skeletal evidence of humans on Flores, says paleoanthropologist and study coauthor Matthew Tocheri of Lakehead University in Thunder Bay, Canada. H. sapiens bones date to around 11,000 years ago on the Indonesian island. That undermines a controversial argument that a partial hobbit skeleton comes from a human with a developmental disorder (SN: 11/18/06, p. 330), Tocheri says. Paleoanthropologist Russell Ciochon of the University of Iowa in Iowa City agrees. H. floresiensis probably descended from a large-bodied Asian Homo erectus group that reached Flores roughly 1 million years ago, he says. On islands, large-bodied mammals tend to become smaller, presumably in response to limited food sources and other factors. But in a joint e-mail to Science News, two researchers who regard hobbits as humans — and the partial hobbit skeleton as displaying signs of Down syndrome — stick to their guns. Regardless of the new dates from Liang Bua Cave, hobbit bones fall within the range of skeletal sizes and shapes observed in people today, assert Robert Eckhardt of Penn State and Maciej Henneberg of the University of Adelaide in Australia. H. sapiens could have reached Flores and nearby islands (SN: 2/6/16, p. 7) when Sutikna’s group says hobbits were alive, they claim. It’s not known whether humans or other Asian hominids, such as Denisovans (SN Online: 3/17/16), reached Flores more than 50,000 years ago at a time of lowered sea levels and possible drought on the island, Potts says. If they did, intruding species might have pushed an already reeling hobbit population to extinction. Liang Bua Cave excavations also suggest that other Flores animals, including vultures, giant marabou storks and an extinct elephant relative, vanished around the same time that the hobbits did. Annual excavations from 2007 through 2014 clarified how sediment accumulated in the cave. A thick soil deposit containing hobbit remains had substantially eroded before being covered by soil layers that washed into the cave starting around 20,000 years ago. Techniques for dating soil, rock, volcanic ash and bone indicated that hobbits’ skeletal remains ranged in age from 100,000 to 60,000 years ago. Stone tools probably made by hobbits dated to between around 190,000 and 50,000 years ago. Liang Bua Cave preserves a late slice of H. floresiensis life on an island probably reached by toolmaking hobbit ancestors around 1 million years ago (SN: 6/3/06, p. 341), Tocheri says. Researchers don’t know what happened during the roughly 800,000 years between hobbit ancestors’ arrival on Flores and hobbits’ last evolutionary stages. “If there was a book that chronicled the evolutionary history of H. floresiensis, we would have only a few tattered and torn pages with the rest missing,” Tocheri says. Editor’s Note: This story was updated April 4, 2016, to clarify the description of hobbits and the scientific discipline of one of the researchers.

Kirchmajer D.M.,University of Wollongong | Watson C.A.,University of Wollongong | Ranson M.,University of Wollongong | Panhuis M.I.H.,University of Wollongong
RSC Advances | Year: 2013

The synthesis of genipin cross-linked gelatin (Gelapin) hydrogel materials is presented. Gelapin hydrogels were comprehensively characterised through chemical, mechanical and physical analysis techniques. It was found that the hydrogels could be cross-linked to up to 90% using a genipin concentration of 24.4% (w/w). The hydrogels reach a stable swollen state and cease leaching of residual starting materials after 72 h in phosphate buffered saline solution at 37 °C. The proteolytic degradation of Gelapin by collagenase is tuneable through manipulation of the material composition with the rate of degradation ranging from 60 mg per day up to 500 mg per day. The mechanical characteristics (at 37 °C) are controllable through adjustment of the gelatin and genipin concentrations resulting in compressive stress-at-failure values ranging from 26 kPa to 300 kPa. Gelapin gels were found to become more elastic and ductile during proteolytic degradation up to 70% mass loss. The ability for vascularisation of these hydrogels was demonstrated using a chick embryo chorioallantoic membrane assay method. This journal is © The Royal Society of Chemistry 2013.

Weng B.,University of Wollongong | Shepherd R.,University of Wollongong | Chen J.,University of Wollongong | Wallace G.G.,University of Wollongong
Journal of Materials Chemistry | Year: 2011

We chemically synthesized inkjet printable polypyrrole (PPy) nanoformulations with reasonable conductivity for the first time in the presence of gemini surfactants 9BA-4-9BA (6,6′-(butane-1,4-diylbis(oxy)) bis(3-nonylbenzenesulfonic acid)) and 9B-4-9B (6,6′-(butane-1,4- diylbis(oxy)) bis(3-nonylbenzenesulfonic sodium)). Different oxidants and surfactants were investigated to optimize the surface tension, viscosity and conductivity of PPy dispersions to make it suitable for inkjet printing. Finally, a nanoformulation (maximum particle size < 200 nm) with low viscosity (9.4 mPa s), low surface tension (30.8 mN m-1) and reasonable cast conductivity (1.26 S cm-1) was obtained. This nanoformulation was printed successfully on different substrates and SEM images of a printed film on PVDF indicate that the size of the particles in the dispersion is 50 ± 5 nm. The conductivity of printed PPy/GA films on glass slides was as high as 0.7 S cm-1. © 2011 The Royal Society of Chemistry.

Amin K.A.M.,University of Wollongong | Panhuis M.I.H.,University of Wollongong
Carbohydrate Polymers | Year: 2011

The formation of polyelectrolyte complexation (PEC) films by dipping free-standing films of either gellan gum (GG) or chitosan (CH) into solutions of opposite charge is reported. It was shown that the composition and mechanical characteristics depend on pH, and the order in which the biopolymers were added, i.e., dipping CH into GG, or dipping GG into CH. Toughness, tensile strength, extensibility and density values of PEC films prepared by immersing CH films into GG solutions increased with increasing CH:GG ratio. This was not observed for PEC films prepared by dipping GG into CH. The observed behaviour is attributed to the difference in their film compositions, i.e., films prepared by dipping GG into CH solution consist of an inner CH layer and two outer GG layers. In contrast, GG appears to diffuse into the CH layer for films prepared by dipping CH into GG. © 2011 Elsevier Ltd All rights reserved.

Li L.,University of Wollongong | Seng K.H.,University of Wollongong | Liu H.,University of Wollongong | Nevirkovets I.P.,University of Wollongong | Guo Z.,University of Wollongong
Electrochimica Acta | Year: 2013

Well-crystallized Mn3O4-anchored reduced graphene oxide (rGO) nanocomposites have been successfully synthesized via a facile, effective, energy-saving, and scalable microwave hydrothermal technique for potential application as supercapacitor material. Integrating these nanostructures resulted in a strong synergistic effect between the two materials, consequently leading to a hybrid composite with higher specific capacitance compared to the bare Mn3O4 nanoparticles. The results from different sorts of characterization indicate that the Mn 3O4 particles were deposited and anchored on graphene sheets. The capacitance value of the rGO(31.6%)-Mn3O4 nanocomposite reached 153 F/g, much higher than that of the bare Mn 3O4 (87 F/g) at a scan rate of 5 mV/s in the potential range from -0.1 V to 0.8 V. More importantly, a 200% increase in capacitance was observed for the nanocomposite with cycling at 10 mV/s due to electrochemical activation and the oxidization of Mn(II,III) to Mn(IV) during cycling, as verified by X-ray photoelectron spectroscopy. There is no observable capacitance fading up to 1000 cycles. The facile synthesis method and good electrochemical properties indicate that the nanocomposite could be an electrode candidate for supercapacitors. © 2012 Elsevier Ltd.

Ciarrochi J.,University of Wollongong | Fisher D.,University of Wollongong | Lane L.,Wollongong Hospital
Psycho-Oncology | Year: 2011

Objective: This study investigated the relationship between cancer patient's values and cancer related distress. Method: A total of 107 patients with cancer diagnoses completed an anonymous questionnaire. Results: Less self-regulating motivation for health values was significantly related to poorer well-being. Greater success at living one's values was significantly related to improved well-being and distress-related outcomes. Sex difference analysis suggested that success at friendship values was linked to less cancer-related distress among women, but not men, whereas success at romantic relationship values was linked to less distress among men, but not women. Conclusion: The results have important implications for values focused interventions, highlighting the importance of facilitating success at valued living and attending to sex differences among cancer patients. © 2010 John Wiley & Sons, Ltd.

Zhong C.,University of Wollongong | Wang J.,University of Wollongong | Chen Z.,University of Wollongong | Liu H.,University of Wollongong
Journal of Physical Chemistry C | Year: 2011

SnO 2-graphene composites have been synthesized by an ultrafast and environmentally friendly microwave autoclave method. From field emission scanning electron microscopy and transmission electron microscopy, it can be determined that the SnO 2 nanoparticles, around 4-5 nm in diameter, are uniformly sandwiched between graphene nanosheets containing only a few layers. The successful synthesis demonstrates that in situ loading of SnO 2 nanoparticles can be an effective way to prevent graphene nanosheets from being restacked during the reduction. The Li-cycling properties of the materials have been evaluated by galvanostatic discharge-charge cycling and impe- dance spectroscopy. Results show that the SnO 2-graphene composite with a graphene content of 33.3 wt % exhibits a very stable capacity of about 590 mA h g -1 without noticeable fading for up to 200 cycles. © 2011 American Chemical Society.

Fosso Wamba S.,University of Wollongong | Fosso Wamba S.,France Business School
Journal of Medical Systems | Year: 2012

In this paper, a comprehensive review of articles published between 1997 and 2011 in the Journal of Medical Systems (JMS) on RFID technology is presented. A total of 22 papers are analyzed using a classification framework that has three dimensions: RFID-enabled healthcare applications, RFID-enabled healthcare issues, and RFID-enabled healthcare benefits. In addition, an invitation sent to all authors of the papers accepted for the special issue on RFID for the JMS allows them to position their various papers within the classification framework. Finally, a list of future research directions is presented. © 2011 Springer Science+Business Media, LLC.

Li B.,University of Wollongong | Roberts R.G.,University of Wollongong | Jacobs Z.,University of Wollongong | Li S.-H.,University of Hong Kong
Quaternary Geochronology | Year: 2014

It has been shown previously that the 'sensitivity' of the post-infrared infrared stimulated luminescence (post-IR IRSL or pIRIR) signal-that is, the intensity of the test dose signal (Tx)-can retain a 'memory' of the pre-dose received in nature, but can be reset by sunlight bleaching. Based on this observation, we describe here a single-aliquot regenerative-dose (SAR) multiple elevated temperature (MET) pIRIR dating procedure for K-feldspar that differs in one important respect from the conventional SAR MET-pIRIR procedure. Instead of using a high temperature IR bleaching step between each SAR cycle-as in the conventional procedure-our modified procedure uses a solar simulator bleach for 2h to reset the dose-dependent pIRIR signal sensitivity before each regenerative SAR cycle. We show that the De can be obtained directly from either the Tx signal or the sensitivity-uncorrected signal (Lx) using the modified procedure. Both of these signals saturate at a higher dose than the sensitivity-corrected signal (Lx/Tx) and, hence, can be used to date older sediments than is feasible using conventional IRSL or pIRIR methods. We have tested our new procedure on 10 sediment samples from different regions of Europe (France and Italy) and Asia (China, Georgia and India), including samples with independently known ages of between ~48 and ~470ka. Based on these external comparisons of age, and on internal (dose recovery) validation tests of the performance of this new pre-dose MET-pIRIR (or pMET-pIRIR) SAR procedure, we conclude that it can potentially measure natural doses of up to ~1500Gy in K-feldspar and produce reliable ages for Late and Middle Pleistocene sediments. © 2013 Elsevier B.V.

Xu D.,Zhengzhou University | Xu Q.,Zhengzhou University | Wang K.,Zhengzhou University | Chen J.,University of Wollongong | Chen Z.,Zhengzhou University
ACS Applied Materials and Interfaces | Year: 2014

A hierarchical high-performance electrode with nanoacanthine-style polyaniline (PANI) deposited onto a carbon nanofiber/graphene oxide (CNF/GO) template was successfully prepared via an in situ polymerization process. The morphology analysis shows that introducing one-dimensional (1D) CNF could significantly decrease/inhibit the staking of laminated GO to form an open-porous CNF/GO architecture. Followed with in situ facial deposition of PANI, the as-synthesized PANI modified CNF/GO exhibits three-dimensional (3D) hierarchical layered nanoarchitecture, which favors the diffusion of the electrolyte ions into the inner region of active materials. The hierarchical free-standing electrodes were directly fabricated into sandwich structured supercapacitors using 1 M H2SO4 as the electrolyte showing a significant specific capacitance of 450.2 F/g at the voltage scan rate of 10 mV/s. The electrochemical properties of the hierarchical structure can be further improved by a reduction procedure of GO before the deposition of PANI. © 2013 American Chemical Society.

Parletta N.,University of South Australia | Milte C.M.,Deakin University | Meyer B.J.,University of Wollongong
Journal of Nutritional Biochemistry | Year: 2013

The important role of diet in cardiometabolic health is generally well recognised; for mental health, it is not so well understood. However, lifestyle risk factors for poor physical health are the same risk factors for mental illness, including poor diet. This is reflected by the high level of poor physical health in people with mental illness. Mediterranean, whole food diets have been associated with reduced risk for chronic disease, but very little research has investigated their mental health benefits. We provide a model for the pathways by which food components provided by a Mediterranean-style diet can facilitate healthy brain function. We then review evidence for the role of selected nutrients/food components - antioxidants, omega-3 fatty acids and B vitamins - in the brain and, hence, modulation of cognitive function and mental health. Converging evidence indicates multiple pathways by which these nutrients can assist in brain function, drawing from studies investigating them in isolation. There is very little work done on synergistic actions of nutrients and whole diets, highlighting a need for human intervention studies investigating benefits of Mediterranean-style diets for mental, as well as cardiometabolic health. © 2013 Elsevier Inc.

Abbott S.K.,University of Wollongong | Else P.L.,University of Wollongong | Atkins T.A.,University of Wollongong | Hulbert A.J.,University of Wollongong
Biochimica et Biophysica Acta - Biomembranes | Year: 2012

In one of the most extensive analyses to date we show that the balance of diet n-3 and n-6 polyunsaturated fatty acids (PUFA) is the most important determinant of membrane composition in the rat under 'normal' conditions. Young adult male Sprague-Dawley rats were fed one of twelve moderate-fat diets (25% of total energy) for 8 weeks. Diets differed only in fatty acid (FA) profiles, with saturate (SFA) content ranging 8-88% of total FAs, monounsaturate (MUFA) 6-65%, total PUFA 4-81%, n-6 PUFA 3-70% and n-3 PUFA 1-70%. Diet PUFA included only essential FAs 18:2n-6 and 18:3n-3. Balance between n-3 and n-6 PUFA is defined as the PUFA balance (n-3 PUFA as % of total PUFA) and ranged 1-86% in the diets. FA composition was measured for brain, heart, liver, skeletal muscle, erythrocytes and plasma phospholipids, as well as adipose tissue and plasma triglycerides. The conformer-regulator model was used (slope = 1 indicates membrane composition completely conforming to diet). Extensive changes in diet SFA, MUFA and PUFA had minimal effect on membranes (average slopes 0.01, 0.07, 0.07 respectively), but considerable influence on adipose tissue and plasma triglycerides (average slopes 0.27, 0.53, 0.47 respectively). Diet balance between n-3 and n-6 PUFA had a biphasic influence on membrane composition. When n-3 PUFA < 10% of total PUFA, membrane composition completely conformed to diet (average slope 0.95), while diet PUFA balance > 10% had little influence (average slope 0.19). The modern human diet has an average PUFA balance ~ 10% and this will likely have significant health implications. © 2012 Elsevier B.V. All rights reserved.

Ren T.,University of Wollongong | Wang Z.,University of Wollongong | Cooper G.,Tecpro Australia
Tunnelling and Underground Space Technology | Year: 2014

To mitigate dust contamination in the mine intake roadway, Computational Fluid Dynamics (CFD) study was first conducted to understand the ventilation and respirable dust flow behaviour above the bin. Based on the modelling results, two possible solutions were proposed for dust control, one is modifying the ventilation system to dilute the respirable dust particles, and the other is using water mist dust droppers to suppress and capture the majority of the dust particles. Modelling results indicated that respirable dust particles could be significantly diluted at the operators' breathing level by increasing the ventilation volume from the horizontal air intake, where 10-13m3/s of air flow rate was suggested to be a preferable quantity. The mechanism of respirable dust capture using water mist was investigated from classical theory and two phase flow theory, respectively, both of which demonstrated a good dust mitigation effect was achievable. CFD models were employed to investigate the flow behaviour of water mists when sprays were oriented at different directions above the bin. An innovative design of dust control system employing water mist technology with four nozzles was proposed and subsequently built for field implementation. An independent field dust evaluation demonstrated that a reduction up to 68% of respirable dust particles has been achieved in the vicinity of the underground bin, and an average of 40% respirable dust reduction along the belt roadway. The successful application of the new dust mitigation system also demonstrates its potential use in underground longwall faces, roadway development and subsurface tunnel excavations by roadheader. © 2014 Elsevier Ltd.

Stress conditions can destabilize proteins, promoting them to unfold and adopt intermediately folded states. Partially folded protein intermediates are unstable and prone to aggregation down off-folding pathways leading to the formation of either amorphous or amyloid fibril aggregates. The sHsp (small heatshock protein) αB-crystallin acts as a molecular chaperone to prevent both amorphous and fibrillar protein aggregation; however, the precise molecular mechanisms behind its chaperone action are incompletely understood. To investigate whether the chaperone activity of αB-crystallin is dependent upon the form of aggregation (amorphous compared with fibrillar), bovine αB-lactalbumin was developed as a model target protein that could be induced to aggregate down either off-folding pathway using comparable buffer conditions. Thus when α-lactalbumin was reduced it aggregated amorphously, whereas a reduced and carboxymethylated form aggregated to form amyloid fibrils. Using this model, αB-crystallin was shown to be a more efficient chaperone against amorphously aggregating α-lactalbumin than when it aggregated to form fibrils.Moreover, αB-crystallin forms high molecular mass complexes with α-lactalbumin to prevent its amorphous aggregation, but prevents fibril formation via weak transient interactions. Thus, the conformational stability of the protein intermediate, which is a precursor to aggregation, plays a critical role in modulating the chaperone mechanism of αB-crystallin. © The Authors Journal compilation © 2012 Biochemical Society.

Wong J.,University of Wollongong | Garner B.,University of Wollongong
Biochemical and Biophysical Research Communications | Year: 2012

Tropomyosin receptor kinase B (TrkB) is best known as the receptor for brain-derived neurotrophic factor (BDNF). In humans, three major isoforms of TrkB, the full-length receptor (TrkB-TK+) and two C-terminal truncated receptors (TrkB-TK- and TrkB-Shc) are expressed in various tissues. In comparison to TrkB-TK+ and TrkB-TK-, TrkB-Shc is less well characterized. In this study, we analyzed the biological function of the TrkB-Shc receptor in response to exogenous BDNF treatment. In experiments transiently overexpressing TrkB-Shc in CHOK1 cells, we found that TrkB-Shc protein levels were rapidly decreased when cells were exposed to exogenous BDNF. When we assessed the functional impact of TrkB-Shc on TrkB-TK+ activity, we found that phosphorylated TrkB-TK+ protein levels were significantly decreased in the presence of TrkB-Shc and moreso following BDNF exposure. Interestingly, while the reduction of phosphorylated TrkB-TK+ protein was more pronounced in the presence of TrkB-Shc following BDNF exposure, the stability of TrkB-Shc protein itself was increased. Our findings suggest that cells may increase TrkB-Shc protein levels in response to exogenous BDNF exposure to regulate TrkB-TK+ activity by increasing degradation of activated receptor complexes as a means to prevent overactivation or inappropriate temporal and spatial activation of BDNF/TrkB-TK+ signaling. © 2012 Elsevier Inc.

Gibson C. Negotiating regional creative economies: academics as expert intermediaries advocating progressive alternatives, Regional Studies. Academics who research the creative economy document and analyse the creative economy while participating in and promoting the creative economy itself. With this in mind, what role is there for academics as expert intermediaries in advocating for progressive alternatives? What kind of creative economy is being implicitly or explicitly promoted? This concluding article draws together threads of research towards a reflection about the role of academics as expert intermediaries. What matters less is that academics are expert intermediaries, and more that this position of privilege is acknowledged and productively negotiated. In the more intimate moments of narrative intermediation, researchers are active agents in making the creative economy 'known', drawing boundaries around the regional context, and translating discourses for and with policy-makers. This is a crucial point of intervention. © 2014 © 2014 Regional Studies Association.

Feng Z.,University of Wollongong | Shi D.,University of Wollongong | Dou S.,University of Wollongong
Solid State Communications | Year: 2011

(001)-oriented 0.67PbMg13Nb23O30. 33PbTiO3 thin films with a pure perovskite crystalline phase were deposited on LaNiO3-coated SiO2Si substrates by the rf magnetron sputtering technique. We found that the as-grown thin films with (001)-oriented texture possess not only excellent dielectric and ferroelectric properties but also a large electrocaloric effect (14.5 K in 12 V, i.e., 1.21 K/V) which is attributed to the large polarization and entropy change during the ferroelectricparaelectric phase transition at a high electric field. The discovery of the large electrocaloric effect in highly textured ferroelectric thin films widens their potential applications, such as in solid-state electrical refrigeration. © 2010 Elsevier Ltd. All rights reserved.

Pamungkas D.S.,University of Wollongong | Ward K.,University of Wollongong
2013 IEEE/ASME International Conference on Advanced Intelligent Mechatronics: Mechatronics for Human Wellbeing, AIM 2013 | Year: 2013

Tactile feedback from a remotely controlled robotic arm can facilitate certain tasks by enabling the user to experience tactile or force sensations from the robot's interaction with the environment. However, equipping both the robot and the user with tactile sensing and feedback systems can be complex, expensive, restrictive and application specific. This paper introduces a new tele-operation haptic feedback method involving electro-tactile feedback. This feedback system is inexpensive, easy to setup and versatile in that it can provide the user with a diverse range of tactile sensations and is suitable for a variety of tasks. We demonstrate the potential of our electro-tactile feedback system by providing experimental results showing how electro-tactile feedback from a tele-operated robotic arm equipped with range sensors can help with avoiding obstacles in cluttered workspace. We also show how interactive tasks, like placing a peg in a hole, can be facilitated with electro-tactile feedback from force sensors. © 2013 IEEE.

Sayeef S.,University of Wollongong | Foo G.,University of New South Wales | Rahman M.F.,University of New South Wales
IEEE Transactions on Industrial Electronics | Year: 2010

The performance of a speed sensorless variable structure direct-torque-controlled interior permanent magnet synchronous motor drive at very low speeds including standstill is investigated in this paper. The rotor position and speed are estimated using a high-frequency (HF) signal injection algorithm at low speeds and a sliding observer at medium to high speeds. The changeover between these two algorithms is performed using a weighting function which smoothly hands over the estimated rotor position information for stator flux and torque estimation purposes. Experiments were performed to test the effectiveness of the proposed HF signal injection algorithm, and results show that the sensorless drive is capable of accurately estimating the position and speed at very low speeds including standstill. The implementation of the changeover algorithm to switch between the two observers at low and high speeds has enabled sensorless operation of the drive from zero to base speed. © 2010 IEEE.

Prior T.,ETH Zurich | Eriksen C.,University of Wollongong
Global Environmental Change | Year: 2013

The consequences of wildfires are felt in susceptible communities around the globe on an annual basis. Climate change predictions in places like the south-east of Australia and western United States suggest that wildfires may become more frequent and more intense with global climate change. Compounding this issue is progressive urban development at the peri-urban fringe (wildland-urban interface), where continued infrastructure development and demographic changes are likely to expose more people and property to this potentially disastrous natural hazard. Preparing well in advance of the wildfire season is seen as a fundamental behaviour that can both reduce community wildfire vulnerability and increase hazard resilience - it is an important element of adaptive capacity that allows people to coexist with the hazardous environment in which they live. We use household interviews and surveys to build and test a substantive model that illustrates how social cohesion influences the decision to prepare for wildfire. We demonstrate that social cohesion, particularly community characteristics like 'sense of community' and 'collective problem solving', are community-based resources that support both the adoption of mechanical preparations, and the development of cognitive abilities and capacities that reduce vulnerability and enhance resilience to wildfire. We use the results of this work to highlight opportunities to transfer techniques and approaches from natural hazards research to climate change adaptation research to explore how the impacts attributed to the social components of social-ecological systems can be mitigated more effectively. © 2013 Elsevier Ltd.

Jones H.A.,University of Wollongong | Charlton K.E.,University of Wollongong
BMC Public Health | Year: 2015

Background: The low-income Pacific Island nation of Vanuatu is experiencing a double burden of diet-related disease whereby micronutrient deficiencies and underweight occur at the same time as obesity related non-communicable diseases. Increasing intakes of nutrient dense, energy dilute foods such as fruits and vegetables will be important to address this issue. However, reduced access to agricultural land in urban areas provides limited opportunities for traditional subsistence fruit and vegetable production. Set in Port Vila, Vanuatu's capital and main urban centre, this study aimed to determine the cost and affordability of meeting international recommendations to consume at least 400 g of non-starchy fruits and vegetables (NSFV) per person per day, and assess the adequacy of households' NSFV expenditure. Methods: NSFV prices from the 2010 Vanuatu Consumer Price Index (n∈=∈56) were used to determine the minimum monthly cost of purchasing 400 g of local NSFV per person, after accounting for wastage. The 2010 Vanuatu Household Income and Expenditure Survey (n∈=∈578 households) was analysed to determine the proportion of households' total and food budget required to purchase 400 g of local NSFV for all household members. Household NSFV costs were also compared against actual household expenditure on these items. Consumption of own-produce and gifts received were included within estimates of food expenditure. Results: The minimum cost of purchasing the recommended amount of local NSFV was 1,486.24 vatu (16.60 US) per person per month. This level of expenditure would require an average of 9.6% (SD 6.4%) of households' total budget and 26.3% (SD 25.8%) of their food budget. The poorest households would need to allocate 40.9% (SD 34.3%) of their total food budget to NSFV to purchase recommended amounts of these foods. Twenty-one percent of households recorded sufficient NSFV expenditure while 23.4% recorded less than 10% of the expenditure required to meet the NSFV recommendations. Conclusions: Achieving recommended intakes of local NSFV in Port Vila is largely unaffordable, and expenditure on these foods was inadequate for most households in Port Vila in 2010. Addressing fruit and vegetable affordability will be an important consideration in prevention of non-communicable diseases in the Pacific region. © 2015 Jones and Charlton; licensee BioMed Central.

Fordyce-Voorham S.,University of Wollongong
Journal of Nutrition Education and Behavior | Year: 2011

Objective: To identify the food skills deemed essential to include in skill-based healthful eating programs in secondary schools. Methods: Fifty-one food experts including home economics educators, chefs, nutritionists and dietitians, community educators, homemakers, and young people were recruited by invitation, mail, and advertising. Data were obtained by interviewing these food experts over 3 months. Results: The identification of food skills forms the preliminary data for the first study of 3 in the design of programs in secondary schools. The data were reviewed for emerging themes and were coded by applying content analysis procedures. Conclusions and Implications: Food skills required for young people were described under 4 themes as the areas of expertise required for young people to live independently. Understanding these skills would support teachers in designing programs that would address behavioral capabilities to improve young people's food preparation and eating behaviors. © 2011 Society for Nutrition Education.

Foroughi J.,University of Wollongong | Spinks G.M.,University of Wollongong | Wallace G.G.,University of Wollongong
Journal of Materials Chemistry | Year: 2011

Electrically conducting, robust fibres comprised of both an alginate (Alg) biopolymer and a polypyrrole (PPy) component have been produced using reactive wet-spinning. Using this approach polypyrrole-biopolymer fibres were also produced with single-walled carbon nanotubes (CNTs), added to provide additional strength and conductivity. SEM images of the PPy-Alg composite fibres clearly show the tubular multifilament form of the alginate fibre impregnated with PPy nanoparticles. The fibres produced containing CNTs show a 78% increase in ultimate stress and 25% increase in elongation to break compared to PPy-alginate fibre. Young's modulus obtained for the PPy-Alg-CNT fibres showed a 30% increase compared to the PPy-alginate fibre. The fibres produced were electrochemically active and capable of electromechanical actuation with a strain of 0.7% produced at a scan rate of 100 mV s-1 of the potential. © 2011 The Royal Society of Chemistry.

Yu P.,University of Wollongong
Studies in Health Technology and Informatics | Year: 2010

Systematic evaluation of the introduction and impact of health information systems (HIS) is a challenging task. As the implementation is a dynamic process, with diverse issues emerge at various stages of system introduction, it is challenge to weigh the contribution of various factors and differentiate the critical ones. A conceptual framework will be helpful in guiding the evaluation effort; otherwise data collection may not be comprehensive and accurate. This may again lead to inadequate interpretation of the phenomena under study. Based on comprehensive literature research and own practice of evaluating health information systems, the author proposes a multimethod approach that incorporates both quantitative and qualitative measurement and centered around DeLone and McLean Information System Success Model. This approach aims to quantify the performance of HIS and its impact, and provide comprehensive and accurate explanations about the casual relationships of the different factors. This approach will provide decision makers with accurate and actionable information for improving the performance of the introduced HIS. © 2010 IMIA and SAHIA. All rights reserved.

McNamee P.,University of Aberdeen | Mendolia S.,University of Wollongong
Social Science and Medicine | Year: 2014

Chronic pain is associated with significant costs to individuals directly affected by this condition, their families, the healthcare system, and the society as a whole. This paper investigates the relationship between chronic pain and life satisfaction using a sample of around 90,000 observations from the first ten waves of the Household, Income and Labour Dynamics of Australia Survey (HILDA), which is a representative survey of the Australian population that started in 2000. We estimate the negative impact on life satisfaction and examine the persistence of the effect over multiple years. Chronic pain is associated with poor health conditions, disability, decreased participation in the labour market and lower quality of life. We calculate the compensating income variation of chronic pain, based on the measurement of chronic pain, the life satisfaction of individuals and the income of households. Panel data models with random and fixed effects are used to control for characteristics of individuals that do not vary over time. Further, we investigate whether individuals who experience chronic pain exhibit adaptation and recovery in life satisfaction after 3 years. Overall, we find that chronic pain has a large negative association with life satisfaction, and that the compensating income variation is substantial (around 640 US$ per day). © 2014 Elsevier Ltd.

Jalili R.,University of Wollongong | Razal J.M.,University of Wollongong | Innis P.C.,University of Wollongong | Wallace G.G.,University of Wollongong
Advanced Functional Materials | Year: 2011

A simplified wet-spinning process for the production of continuous poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) fibers is reported. Conductivity enhancement of PEDOT:PSS fibers up to 223 S cm -1 has been demonstrated when these fibers are exposed to ethylene glycol as a post-synthesis processing step. In a new spinning approach it is shown that by employing a spinning formulation consisting of an aqueous blend of PEDOT:PSS and poly(ethlylene glycol), the need for post-spinning treatment with ethylene glycol is eliminated. With this approach, 30-fold conductivity enhancements from 9 to 264 S cm-1 are achieved with respect to an untreated fiber. This one-step approach also demonstrates a significant enhancement in the redox properties of the fibers. These improvements are attributed to an improved molecular ordering of the PEDOT chains in the direction of the fiber axis and the consequential enrichment of linear (or expanded-coil like) conformation to preference bipolaronic electronic structures as evidenced by Raman spectroscopy, solid-state electron spin resonance (ESR) and in situ electrochemical ESR studies. A facile one-step fiber wet-spinning process to fabricate continuous and highly conducting fibers from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)-poly(ethylene glycol)(PEDOT:PSS-PEG) blend is described. Improvements in electrical conductivity and electrochemical properties are due to the improved molecular ordering of the PEDOT chains in the direction of the fiber axis and the consequential enrichment of linear (or expanded-coil-like) conformation to preference bipolaronic electronic structures. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Salari M.,University of Wollongong | Konstantinov K.,University of Wollongong | Liu H.K.,University of Wollongong
Journal of Materials Chemistry | Year: 2011

The many applications of high energy storage devices have forged an increasing interest in research areas related to electrochemical capacitors. Here, in this work, we present a facile method for the fabrication of self-organized titania nanotubes grown by anodic oxidation of titanium foil with different subsequent heat-treatment regimes for use as binder-free working electrodes in supercapacitor applications. The capacitance of these highly ordered titania nanotubes, when exposed to a reductive atmosphere during annealing, was determined to be well above 900 F cm-2, confirming that the capacitance contribution was pseudocapacitive in nature. The behaviour of oxygen depleted titania in the anatase to rutile (A → R) phase transformation and also in electrochemical charge storage has been studied in detail. It was found that upon the reduction of Ti4+ to Ti 3+, with oxygen depletion of the structure, the A → R phase transformation was promoted. In addition, the fabricated electrodes showed highly reversible charge-discharge stability. © The Royal Society of Chemistry 2011.

Cox D.,University of Wollongong | Carver J.A.,Australian National University | Ecroyd H.,University of Wollongong
Biochimica et Biophysica Acta - Molecular Basis of Disease | Year: 2014

Protein homeostasis, or proteostasis, is the process of maintaining the conformational and functional integrity of the proteome. The failure of proteostasis can result in the accumulation of non-native proteins leading to their aggregation and deposition in cells and in tissues. The amyloid fibrillar aggregation of the protein α-synuclein into Lewy bodies and Lewy neuritis is associated with neurodegenerative diseases classified as α-synucleinopathies, which include Parkinson's disease and dementia with Lewy bodies. The small heat-shock proteins (sHsps) are molecular chaperones that are one of the cell's first lines of defence against protein aggregation. They act to stabilise partially folded protein intermediates, in an ATP-independent manner, to maintain cellular proteostasis under stress conditions. Thus, the sHsps appear ideally suited to protect against α-synuclein aggregation, yet these fail to do so in the context of the α-synucleinopathies. This review discusses how sHsps interact with α-synuclein to prevent its aggregation and, in doing so, highlights the multi-faceted nature of the mechanisms used by sHsps to prevent the fibrillar aggregation of proteins. It also examines what factors may contribute to α-synuclein escaping the sHsp chaperones in the context of the α-synucleinopathies. © 2014.

Liney G.P.,Ingham Institute for Applied Medical Research | Liney G.P.,University of Wollongong | Moerland M.A.,University Utrecht
Seminars in Radiation Oncology | Year: 2014

Magnetic resonance imaging (MRI) has a number of benefits for the planning of radiotherapy (RT), but its uptake into clinical practice has often been restricted to specialist research sites. There is often a lack of detailed MRI knowledge within the RT community and an apprehension of geometric distortions, both of which prevent its best utilization and merit the introduction of a standardized approach and common guidelines. This review sets out to address some of the issues involved in acquiring MRI scans for RT planning in the context of a number of clinical sites of interest and concludes with recommendations for its best practice in terms of imaging protocol and quality assurance. The article is of particular interest to the growing number of cancer therapy centers that are embarking on MRI simulation on either existing systems or their own dedicated scanners. © 2014 Elsevier Inc.

Seyedin M.Z.,University of Wollongong | Razal J.M.,University of Wollongong | Innis P.C.,University of Wollongong | Wallace G.G.,University of Wollongong
Advanced Functional Materials | Year: 2014

It is a challenge to retain the high stretchability of an elastomer when used in polymer composites. Likewise, the high conductivity of organic conductors is typically compromised when used as filler in composite systems. Here, it is possible to achieve elastomeric fiber composites with high electrical conductivity at relatively low loading of the conductor and, more importantly, to attain mechanical properties that are useful in strain-sensing applications. The preparation of homogenous composite formulations from polyurethane (PU) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) that are also processable by fiber wet-spinning techniques are systematically evaluated. With increasing PEDOT:PSS loading in the fiber composites, the Young's modulus increases exponentially and the yield stress increases linearly. A model describing the effects of the reversible and irreversible deformations as a result of the re-arrangement of PEDOT:PSS filler networks within PU and how this relates to the electromechanical properties of the fibers during the tensile and cyclic stretching is presented. Conducting elastomeric fibers based on a composite of polyurethane (PU) and PEDOT:PSS, produced by a wet-spinning method, have high electrical conductivity and stretchability. These fibers can sense large strains by changes in resistance. The PU/PEDOT:PSS fiber is optimized to achieve the best strain sensing. PU/PEDOT:PSS fibers can be produced on a large scale and integrated into conventional textiles by weaving or knitting. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Haque M.E.,University of Tasmania | Negnevitsky M.,University of Tasmania | Muttaqi K.M.,University of Wollongong
IEEE Transactions on Industry Applications | Year: 2010

This paper presents a novel control strategy for the operation of a direct-drive permanent-magnet synchronous-generator-based stand-alone variable-speed wind turbine. The control strategy for the generator-side converter with maximum power extraction is presented. The stand-alone control is featured with output voltage and frequency controller that is capable of handling variable load. The potential excess of power is dissipated in the dump-load resistor with the chopper control, and the dc-link voltage is maintained. Dynamic representation of dc bus and small-signal analysis are presented. Simulation results show that the controllers can extract maximum power and regulate the voltage and frequency under varying wind and load conditions. The controller shows very good dynamic and steady-state performance. © 2010 IEEE.

Larkin T.A.,University of Wollongong | Mcandrew D.J.,University of Wollongong
Anatomical Sciences Education | Year: 2013

Changes in medical education have affected both curriculum design and delivery. Many medical schools now use integrated curricula and a systemic approach, with reduced hours of anatomy teaching. While learning anatomy via dissection is invaluable in educational, professional, and personal development, it is time intensive and supports a regional approach to learning anatomy; the use of prosections has replaced dissection as the main teaching method in many medical schools. In our graduate-entry medical degree, we use an integrated curriculum, with prosections to teach anatomy systemically. However, to not exclude dissection completely, and to expose students to its additional and unique benefits, we implemented a short "Dissection Experience" at the beginning of Year 2. Students attended three two-hour anatomy sessions and participated in dissection of the clinically relevant areas of the cubital fossa, femoral triangle, and infraclavicular region. This activity was voluntary and we retrospectively surveyed all students to ascertain factors influencing their decision of whether to participate in this activity, and to obtain feedback from those students who did participate. The main reasons students did not participate were previous dissection experience and time constraints. The reasons most strongly affecting students' decisions to participate related to experience (lack of previous or new) and new skill. Students' responses as to the most beneficial component of the dissection experience were based around practical skills, anatomical education, the learning process, and the body donors. We report here on the benefits and practicalities of including a short dissection experience in a systemic, prosection-based anatomy course. Anat Sci Educ 6: 225-231. © 2013 American Association of Anatomists.

Hanich Q.,University of Wollongong
Marine Policy | Year: 2012

The Western and Central Pacific Ocean is home to the world's most productive tuna fisheries, with the majority of tuna catches occurring inside the exclusive economic zones (EEZs) of the region's developing coastal States. It is important that these fisheries are managed effectively throughout their range, both within and between EEZs and on the high seas. Unrestrained exploitation in a particular EEZ or on the high seas has the potential to significantly impact on catches elsewhere with potentially devastating consequences for developing coastal States, some of which have few alternate resources. The Western and Central Pacific Fisheries Commission (WCPFC) was established in 2004 to manage the region's highly migratory tuna fisheries. However, the WCPFC has since repeatedly failed to adopt conservation and management measures that are sufficient to meet the WCPFC's conservation and sustainable use objectives. This paper analyses catch data from the WCPFC and suggests that the weak position of bigeye (in a strategic political context), the unwillingness of members to compromise their interests and the lack of a transparent framework for distributing the burden of conservation are key factors in the WCPFC's failure to adopt sufficiently strong conservation and management measures. © 2011 Elsevier Ltd.

Kelly G.,University of Wollongong
Renewable and Sustainable Energy Reviews | Year: 2011

Many years before greenhouse gas emission reduction became a major driver for renewable energy development, New Zealand was an early adopter of several alternative energy technologies, particularly hydroelectricity and geothermal energy. It has achieved a level of 60% of total electricity generation from such sources, and is now pursuing a target of 95% of electricity generation from renewable energy, to be achieved in fifteen years. In recent years, however, the development of renewables has lagged that of other countries, particularly in fields such as wind power. The paper reviews the history, current status and potential of the major renewable energy technologies in New Zealand, and suggests what may be current barriers to development. It is seen that the likely major contributors to replacing fossil fuel based energy are likely to be wind power and expanded geothermal energy use, with biomass, marine and solar energy sources likely to play a lesser role. The barriers to development include environmental issues, the opportunity cost of biomass feedstocks, and a policy environment offering less incentive to RE development than is the case in many other countries. © 2011 Elsevier Ltd. All rights reserved.

Hinwood J.B.,Monash University | Mclean E.J.,University of Wollongong
Pure and Applied Geophysics | Year: 2013

On 11 March 2011 a subsea earthquake off the north-eastern coast of Honshu Island, Japan generated a huge tsunami which was felt throughout the Pacific. At the opposite end of the Pacific Ocean, on the south-east coast of Australia, multiple reflections, scatterings and alternate pathways lead to a prolonged and complicated response. This response was largely unaltered in crossing the continental shelf but was then transformed by bay resonances and admittances. These effects are described using data from tide recorders sparsely spread over 1,000 km of the coast. Some new adaptations and applications of time-series analysis are applied to separate tsunami waves that have followed different pathways but contain the same spectral components. The possible types of harbour response are classified and illustrated. Despite its small height in this region, the tsunami put several swimmers at serious risk and generated strong harbour oscillations, which should be considered when generating future warnings. © 2012 Springer Basel AG.

Rashad A.A.,University of Wollongong | Mahalingam S.,Griffith University | Keller P.A.,University of Wollongong
Journal of Medicinal Chemistry | Year: 2014

Chikungunya virus is an emerging arbovirus that is widespread in tropical regions and is spreading quickly to temperate climates with recent epidemics in Africa and Asia and documented outbreaks in Europe and the Americas. It is having an increasingly major impact on humankind, with potentially life-threatening and debilitating arthritis. There is no treatment available, and only in the past 24 months have lead compounds for development as potential therapeutics been reported. This Perspective discusses the chikungunya virus as a significant, new emerging topic for medicinal chemistry, highlighting the key viral target proteins and their molecular functions that can be used in drug design, as well as the most important ongoing developments for anti-chikungunya virus research. It represents a complete picture of the current medicinal chemistry of chikungunya, supporting the development of chemotherapeutics through drug discovery and design targeting this virus. © 2013 American Chemical Society.

Rahman M.M.,University of Wollongong | Wang J.-Z.,University of Wollongong | Hassan M.F.,University of Wollongong | Wexler D.,University of Wollongong | Liu H.K.,University of Wollongong
Advanced Energy Materials | Year: 2011

This work introduces an effective, inexpensive, and large-scale production approach to the synthesis of a carbon coated, high grain boundary density, dual phase Li 4Ti 5O 12-TiO 2 nanocomposite anode material for use in rechargeable lithium-ion batteries. The microstructure and morphology of the Li 4Ti 5O 12-TiO 2-C product were characterized systematically. The Li 4Ti 5O 12-TiO 2-C nanocomposite electrode yielded good electrochemical performance in terms of high capacity (166 mAh g -1 at a current density of 0.5 C), good cycling stability, and excellent rate capability (110 mAh g -1 at a current density of 10 C up to 100 cycles). The likely contributing factors to the excellent electrochemical performance of the Li 4Ti 5O 12-TiO 2-C nanocomposite could be related to the improved morphology, including the presence of high grain boundary density among the nanoparticles, carbon layering on each nanocrystal, and grain boundary interface areas embedded in a carbon matrix, where electronic transport properties were tuned by interfacial design and by varying the spacing of interfaces down to the nanoscale regime, in which the grain boundary interface embedded carbon matrix can store electrolyte and allows more channels for the Li + ion insertion/extraction reaction. This research suggests that carbon-coated dual phase Li 4Ti 5O 12-TiO 2 nanocomposites could be suitable for use as a high rate performance anode material for lithium-ion batteries. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sun B.,University of Technology, Sydney | Chen Z.,University of Wollongong | Kim H.-S.,Korea Electrotechnology Research Institute | Ahn H.,Gyeongsang National University | Wang G.,University of Technology, Sydney
Journal of Power Sources | Year: 2011

MnO/C core-shell nanorods were synthesized by an in situ reduction method using MnO2 nanowires as precursor and block copolymer F127 as carbon source. Field emission scanning electron microscopy and transmission electron microscopy analysis indicated that a thin carbon layer was coated on the surfaces of the individual MnO nanorods. The electrochemical properties were evaluated by cyclic voltammetry and galvanostatic charge-discharge techniques. The as-prepared MnO/C core-shell nanorods exhibit a higher specific capacity than MnO microparticles as anode material for lithium ion batteries. © 2010 Elsevier B.V. All rights reserved.

Cho Y.H.,University of Queensland | Aminorroaya S.,University of Wollongong | Liu H.K.,University of Wollongong | Dahle A.K.,University of Queensland
International Journal of Hydrogen Energy | Year: 2011

The inexpensive fabrication technique of casting is applied to develop new Mg-Ni based hydrogen storage alloys with improved hydrogen sorption properties. A nanostructured eutectic Mg-Mg2Ni is formed upon solidification which introduces a large area of interfaces along which hydrogen diffusion can occur with high diffusivity. After a few cycles of hydrogenation and dehydrogenation, an ultrafine porous structure formed in the eutectic Mg-Mg 2Ni and some cracks developed along the interface between the eutectic and the α-Mg matrix. This indicates that hydrogen atoms introduced into the alloys preferentially migrate along the interfaces in the nanostructured eutectic which enables effective short-range diffusion of hydrogen. Furthermore, transition metals (TMs) such as Nb, Ti and V in the range 240-560 ppm are added directly to molten Mg-10 wt% Ni alloys and are found to form intermetallic compounds with Ni during solidification. The alloys can store 5.6-6.3 wt% hydrogen at 350 °C and 2 MPa. TM-rich intermetallics distributed homogeneously in the cast alloys appear to play a key role in accelerating the nucleation of Mg from MgH2 upon dehydrogenation. This leads to a significant improvement in the hydrogen desorption kinetics. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Burrows A.D.,University of Bath | Hunter S.O.,University of Wollongong | Mahon M.F.,University of Bath | Richardson C.,University of Wollongong
Chemical Communications | Year: 2013

Direct heating of a metal-organic framework provides a simple, controllable way of effecting a covalent post-synthetic modification. Herein we report that an allyloxy-tagged zinc metal-organic framework undergoes a thermally-promoted aromatic Claisen rearrangement through which the framework connectivity and porosity are maintained. © The Royal Society of Chemistry 2013.

Waitt G.,University of Wollongong
Social and Cultural Geography | Year: 2014

A growing body of work in social and cultural geography is concerned with examining food to explore ethical, civic and social concerns. I build on the critiques by engaging with the visceral. Drawing on the theoretical work of Elspeth Probyn, I argue that eating reveals the fundamental ambiguity of embodiment, allowing us to attend to visceralities of difference as understood within the context of power geometries that shape and reshape food politics. This analysis is promoted by the Australian Commonwealth Government's endorsement of suggestions by environmental scientists that households' meals should substitute kangaroo for farmed livestock to lower greenhouse gas emissions. I investigate appetites for kangaroo as discussed while plating-up, and sometimes digested, by white bodies in kitchens and dining rooms within thirty households in Wollongong, New South Wales. To explain where kangaroo is rendered inedible, or edible, I use the recognition that the visceral realm-narrated through the aromas, tastes and touch-offers insights to place, subjectivity, embodied skills and food politics. © 2014 Taylor & Francis.

Cheng Z.,University of Wollongong | Wang H.,Macquarie University
Habitat International | Year: 2013

Rural-to-urban migrant workers have contributed enormously to the Chinese economy and society in the past three decades. Many of them have concentrated in disadvantaged neighbourhoods and physically and socially suffered from poor residential environment. However it is unclear how the neighbourhoods-as the provision of shelter, social and public service, and community organizing-influence migrant workers' labour market outcomes. To fill this gap, this paper researches the way in which urban neighbourhoods have affected migrant workers' wages. Factors such as housing quality, social interaction and trust, and neighbourhood organization and participation were examined. Results show that five of eight neighbourhood characteristics had statistically significant effects on wages. Robustness tests were conducted to address endogeneity problems of self-selection and unobserved individual ability. Test results demonstrated that our main findings were generally robust, and thus the causality was solid. © 2012 Elsevier Ltd.

Szabo K.,University of Wollongong
Journal of Archaeological Science | Year: 2012

Hermit crabs are ever alert for more suitable shells to inhabit, but what this may mean for coastal shell middens has rarely been considered. Here, the impact of the most landward-based of hermit crab families, the tropical Coenobitidae, upon archaeological shell-bearing deposits is assessed using a case study: the Neolithic Ugaga site from Fiji. At Ugaga, hermit crabs were found to have removed the majority of shells from the midden and had deposited their old, worn shells in return. The behavioural ecology of genus Coenobita suggests a mutualistic interaction whereby humans make available shell and food resources to hermit crabs, which in turn provide a site cleaning service by consuming human and domestic waste. Diagnostic indicators of terrestrial hermit crab wear patterns on gastropod shells are outlined and the conditions under which extensive 'hermitting' of shell midden deposits may occur are investigated. The ability to recognise hermit crab modification of shells is considered not only important for archaeomalacologists analysing tropical shell deposits, but also for field archaeologists wishing to select suitable shell samples for radiocarbon dating. © 2011 Elsevier Ltd.

Wang J.Z.,University of Wollongong
Chemistry (Weinheim an der Bergstrasse, Germany) | Year: 2011

Fe(3)O(4)-graphene composites with three-dimensional laminated structures have been synthesised by a simple in situ hydrothermal method. From field-emission and transmission electron microscopy results, the Fe(3)O(4) nanoparticles, around 3-15nm in size, are highly encapsulated in a graphene nanosheet matrix. The reversible Li-cycling properties of Fe(3)O(4)-graphene have been evaluated by galvanostatic discharge-charge cycling, cyclic voltammetry and impedance spectroscopy. Results show that the Fe(3)O(4)-graphene nanocomposite with a graphene content of 38.0wt% exhibits a stable capacity of about 650mAh g(-1) with no noticeable fading for up to 100cycles in the voltage range of 0.0-3.0V. The superior performance of Fe(3)O(4)-graphene is clearly established by comparison of the results with those from bare Fe(3)O(4). The graphene nanosheets in the composite materials could act not only as lithium storage active materials, but also as an electronically conductive matrix to improve the electrochemical performance of Fe(3)O(4). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kaplan R.M.,University of Wollongong
Australasian Psychiatry | Year: 2012

Objective: To explore the life and contributions of Reginald Spencer Ellery (1897-1955), one of the most eminent psychiatrists in Australia between the wars.Conclusions: Ellery pioneered malariotherapy and psychoanalysis, mixed with leading intellectuals, including Max Harris, John and Sunday Reed, was a member of the Communist Party, wrote poetry and published widely on a wide range of topics. Ellery was talented, innovative, driven and highly energetic, managing a range of activities aside from his work without difficulty. While his writing talent was questioned by some, there is no doubting his influence on painters such as Albert Tucker and Sidney Nolan and his standing in the intellectual life of Melbourne. Ellery was uncompromising in his public stand on issues such as communism and psychoanalysis, but by the end of his life he was deeply disillusioned. Ellery's autobiography, The Cow Jumped Over the Moon, confirms the impression of a restless and creative mind reluctant to be constrained by conventional orthodoxy, the most eminent Australian psychiatrist of his time. His diverse achievements and talent, now largely forgotten, deserve recognition from a profession that is rapidly losing its links with the historical past. © 2012 The Royal Australian and New Zealand College of Psychiatrists.

Gibbs L.M.,University of Wollongong
Environment and Planning A | Year: 2013

Australian water politics is marked by conceptual and bureaucratic separation of water as discrete matter. The source of this politics of separation is colonial relations with water and the Australian continent. Yet, analysis of the materiality of water illuminates the agency of water as part of an assemblage. This paper seeks to unsettle the treatment of water as separate, discrete matter. It asks how political responses to the public problem of water would change were we to take seriously the vitality of nonhuman bodies. In order to investigate this question, the paper presents an analysis of six objects from the inland deserts of eastern central Australia-two bottles, two bores, and two boats-derived from field and archival research. The analysis draws on recent material approaches and a broadly postcolonial literature to argue that 'taking seriously' the matter of water might provide a productive means of reframing the politics of water, by using the concept of the 'agency of assemblages' to replace the notion of water as separate. Furthermore, paying greater attention to local Indigenous knowledge provides an alternate epistemology upon which to base decision-making, which both unsettles the separation of water and contributes to an ongoing process of decolonisation. © 2013 Pion and its Licensors.

Sense A.J.,University of Wollongong
International Journal of Project Management | Year: 2013

Drawing on a longitudinal action research case study analysis of project-based learning, this paper seeks to advance a deeper understanding of a project sponsor's impact on practice-based learning activity within a project. It represents a first case examination of the interface between a sponsor and practice-based learning phenomenon within projects. The reported findings argue for the project sponsor role to be acknowledged as dynamic and interactive and a dramatic influence on project practice-based learning. It also implies that a sponsor confronts some significant dilemmas in successfully stewarding such learning. Moreover, through such endeavour, the sponsor may also become an agent for organizational learning. The findings generated also encourage further investigations into the nexus between the sponsor and other social phenomenon within projects. © 2012 Association for Project Management and the International Project Management Association and Elsevier Ltd.

Zhang Z.,University of Wollongong | Nemcik J.,University of Wollongong
Journal of Hydrology | Year: 2013

The presence of fracture roughness, isolated contact areas and the occurrence of nonlinear flow complicate the fracture flow process. To experimentally investigate the fluid flow regimes through deformable rock fractures, water flow tests through both mated and non-mated sandstone fractures were conducted in triaxial cell under changing confining stress from 1.0. MPa to 3.5. MPa. For the first time Forchheimer's nonlinear factor b describing flow in non-mated fractures under variable confining stress has been quantified. The results show that linear Darcy's law holds for water flow through mated fracture samples due to high flow resistance caused by the small aperture and high tortuosity of the flow pathway, while nonlinear flow occurs for non-mated fracture due to enlarged aperture. Regression analyses of experimental data show that both Forchheimer equation and Izbash's law provide an excellent description for this nonlinear fracture flow process. Further, the nonlinear flow data indicate that for smaller true transmissivity, the appreciable nonlinear effect occurs at lower volumetric flow rates. The experimental data of both mated and non-mated fracture flow show that the confining stress does not change the linear and nonlinear flow patterns, however, it has a significant effect on flow characteristics. For mated fracture flow, the slope of pressure gradient versus flow rate becomes steeper and the transmissivity decreases hyperbolically with increase of confining stress, while for non-mated fracture flow, the rate of increase of the nonlinear coefficient b used in Forchheimer equation steadily diminishes with the increase of confining stress. Based on Forchheimer equation and taking 10% of the nonlinear effect as the critical state to distinguish between linear and nonlinear flow, the critical Reynolds number was successfully estimated by using a nonlinear effect coefficient E. This method appears effective to determine critical Reynolds numbers for specific flow cases. © 2012 Elsevier B.V.

Sun Z.,University of Wollongong | Kim J.H.,University of Wollongong | Zhao Y.,University of Wollongong | Attard D.,University of Wollongong | Dou S.X.,University of Wollongong
Chemical Communications | Year: 2013

Morphology-controlled bilayer TiO2 nanostructures consisting of one-dimensional (1D) nanowire bottom arrays and a three-dimensional (3D) dendritic microsphere top layer were synthesized via a one-step hydrothermal method. These novel 1D-3D bilayer photoanodes demonstrated the highest energy conversion efficiency of 7.2% for rutile TiO2 dye-sensitized solar cells to date, with TiCl4 post-treatment. © The Royal Society of Chemistry 2013.

Sharma N.,Australian Nuclear Science and Technology Organisation | Guo X.,CAS Institute of Physics | Du G.,University of Wollongong | Guo Z.,University of Wollongong | And 3 more authors.
Journal of the American Chemical Society | Year: 2012

Lithium-ion batteries power many portable devices and in the future are likely to play a significant role in sustainable-energy systems for transportation and the electrical grid. LiFePO 4 is a candidate cathode material for second-generation lithium-ion batteries, bringing a high rate capability to this technology. LiFePO 4 functions as a cathode where delithiation occurs via either a solid-solution or a two-phase mechanism, the pathway taken being influenced by sample preparation and electrochemical conditions. The details of the delithiation pathway and the relationship between the two-phase and solid-solution reactions remain controversial. Here we report, using real-time in situ neutron powder diffraction, the simultaneous occurrence of solid-solution and two-phase reactions after deep discharge in nonequilibrium conditions. This work is an example of the experimental investigation of nonequilibrium states in a commercially available LiFePO 4 cathode and reveals the concurrent occurrence of and transition between the solid-solution and two-phase reactions. © 2012 American Chemical Society.

Perlman D.J.,University of Wollongong
Physical Education and Sport Pedagogy | Year: 2015

Background: A major goal within physical education is to develop a student who will engage in a lifetime of physical activity. A concept deemed critical and strongly associated with engagement in physical activity is motivation. As such, a number of research studies have been focused on elements that facilitate student motivation in physical education. An area of limited inquiry has been focused on those students with extremely low levels of motivation, also termed amotivated. Therefore, the aim of this study was to examine the impact of teacher instruction, based within self-determination theory (SDT), on the motivational responses of amotivated students.Purpose: The purpose of this study was to examine how different forms of teacher instruction, based within SDT, can influence amotivated students' motivational responses within secondary physical education. Participants and settings: Forty-eight (Male = 18; Female = 30) amotivated students engaged in a compulsory Year-9 sport-based physical education class. Participants were randomly assigned to one of two treatment groups (autonomy-supportive or control).Data collection: Participants' motivational responses were collected using a pretest/posttest design. Teacher data were collected through the observation and coding of specific behaviors.Data analysis: Data were analyzed through a set of (2 × 2) (Group × Time) Repeated Measures analysis of variances (ANOVAs). Significant ANOVA calculations were placed on a chart to illustrate where the significance was located.Results: Analysis of data indicated that amotivated students engaged in the autonomy-supportive classes reported significantly higher levels of self-determined motivation and support for relatedness compared with the control group.Conclusions: Findings from this study provide empirical support for the infusion of autonomy-supportive teaching within physical education. Previous SDT-based instructional studies have reported that teachers who are more supportive have students who report positive experiences and are more physically active. This study extends the SDT body of knowledge by demonstrating the positive motivational change for students with extremely low forms of motivation. Specifically, amotivated students engaged in the autonomy-supportive classes reported significantly higher levels of self-determined motivation and support for relatedness. © 2013, © 2013 Association for Physical Education.

Trani L.D.O.,University of Wollongong | Indraratna B.,University of Wollongong
Geotechnique | Year: 2010

The hydraulic conductivity (k) of a fully saturated granular material can be predicted by the well-known Kozeny-Carman formula, and its slightly different variations, based on the porosity (n) and effective diameter (deff). Most variations of the Kozeny-Carman formula compute the parameter deff based on a given conventional particle size distribution by mass (PSDm), where the validation would normally be carried out by comparing against laboratory permeability tests conducted on soils having an average coefficient of uniformity (Cu) of about 3. Knowing that the Kozeny-Carman formula was originally developed for uniformly graded materials, inevitable limitations are inherited when it is applied to increasingly graded soils. This study proposes to convert the PSDm into its equivalence in surface area (PSDsa) conforming to the fundamental geometric assumption by which the Kozeny-Carman equation was originally formulated. The estimated deff based on this proposed PSDsa method appears implicitly to incorporate the size, shape and angularity of the natural grains which were traditionally represented by the shape coefficient (α). The results presented in this paper show that the suggested method is capable of predicting k for fully saturated granular soils with Cu of up 20.

Suebsuk J.,Suranaree University of Technology | Horpibulsuk S.,Suranaree University of Technology | Liu M.D.,University of Wollongong
Computers and Geotechnics | Year: 2010

This paper presents a generalised constitutive model for destructured, naturally structured and artificially structured clays that extends the Structured Cam Clay (SCC) model. This model is designated as " Modified Structured Cam Clay (MSCC) model" The influence of structure and destructuring on the mechanical behaviour of clay can be explained by the change in the modified effective stress, which is the sum of the current mean effective stress and the additional mean effective stress due to structure (structure strength). The presence of structure increases the modified mean effective stress and yield surface, enhancing the cohesion, peak strength and stiffness. The destructuring begins when the stress state is on the virgin yield surface. After the failure (peak strength) state, the abrupt destructuring occurs as the soil-cementation structure is crushed; hence the strain softening. The soil structure is completely removed at the critical state when the yield surface becomes identical to the destructured surface. The destructuring law is proposed based on this premise. In the MSCC model, the yield function is the same shape as that of the Modified Cam Clay (MCC) model. A plastic potential is introduced so as to account for the influence of structure on the plastic strain direction for both hardening and softening behaviours. The required model parameters are divided into those describing destructured properties and those describing structured properties. All the parameters have physical meaning and can be simply determined from the conventional triaxial tests. Thus, the MSCC model is a useful tool for geotechnical practitioners. The capability of the model is verified by the test results of destructured, natural structured and artificially structured clays. © 2010 Elsevier Ltd.

The Lachlan Fold Belt of southeastern Australia developed along the Panthalassan margin of East Gondwana. Major silicic igneous activity and active tectonics with extensional, strike-slip and contractional deformation have been related to a continental backarc setting with a convergent margin to the east. In the Early Silurian (Benambran Orogeny), tectonic development was controlled by one or more subduction zones involved in collision and accretion of the Ordovician Macquarie Arc. Thermal instability in the Late Silurian to Middle Devonian interval was promoted by the presence of one or more shallow subducted slabs in the upper mantle and resulted in widespread silicic igneous activity. Extension dominated the Late Silurian in New South Wales and parts of eastern Victoria and led to formation of several sedimentary basins. Alternating episodes of contraction and extension, along with dispersed strike-slip faulting particularly in eastern Victoria, occurred in the Early Devonian culminating in the Middle Devonian contractional Tabberabberan Orogeny. Contractional deformation in modern systems, such as the central Andes, is driven by advance of the overriding plate, with highest strain developed at locations distant from plate edges. In the Ordovician to Early Devonian, it is inferred that East Gondwana was advancing towards Panthalassa. Extensional activity in the Lachlan backarc, although minor in comparison with backarc basins in the western Pacific Ocean, was driven by limited but continuous rollback of the subduction hinge. Alternation of contraction and extension reflects the delicate balance between plate motions with rollback being overtaken by advance of the upper plate intermittently in the Early to Middle Devonian resulting in contractional deformation in an otherwise dominantly extensional regime. A modern system that shows comparable behaviour is East Asia where rollback is considered responsible for widespread sedimentary basin development and basin inversion reflects advance of blocks driven by compression related to the Indian collision. © 2010 Geological Society of Australia.

At a time when climate change is being defined and grappled with around the world as a looming large-scale environmental crisis, low-lying Pacific islands are being publicized in a range of practices as 'disappearing islands', and their inhabitants as future 'climate refugees'. This paper is concerned with the disappearing island as a space in which new intersections between environmentalism and tourism can be explored. It analyzes specifically western representational practices associated with climate change imperatives on Tuvalu, an atoll state in the central Pacific. New phenomena are emerging there such as climate change tourism and the transformation of the islands into showcases of renewable energy. These phenomena are analyzed in order to understand how climate change meanings are being shaped by various participants in the debate. I argue that Pacific islanders are heroized as climate change saviours when environmentalists attempt to locate ethnocentric notions of environmentally harmonious, 'traditional' culture on disappearing islands. Further, islanders are objectified in the rhetoric of climate change tourism. Imagined destinies for atoll dwellers as climate saviours are sited uncomfortably alongside voyeuristic gazes turned towards inundated islands. Competing forces of compassion and voyeurism produced in the name of the Tuvaluan indigene are entrenching an iconic role for the Tuvaluan atoll dweller as climate change hero/victim. © 2010 The Author. Journal compilation © 2010 Department of Geography, National University of Singapore and Blackwell Publishing Asia Pty Ltd.

Brennan-Horley C.,University of Wollongong
Journal of Maps | Year: 2010

Cultural researchers are increasingly turning to Geographical Information Systems (GIS) technologies for visualising spatially-oriented qualitative data. This paper discusses one example, where mental maps have been employed in interviews with creative industry workers and the results accumulated in a GIS for visualisation and analysis. This technique extends on participatory and qualitative methods that counteract overtly economic and empiricist techniques regularly employed in creative industry mapping studies. Collating together creative workers' mental maps within a GIS provides a means for exposing 'high traffic' areas - hot spots of creative activity - and other hidden geographies that comprise the 'creative city'. Key spaces, known within creative communities but understood by researchers only anecdotally, can be visualised with a GIS. The methodology was carried out in Darwin, the capital city of Australia's Northern Territory, which has sought to re-imagine itself as a creative city. Results from two mental mapping questions form the focus of this paper: on where 'creative epicentres' and 'spaces of inspiration' exist in Darwin. The former tend to centre on popular suburban sites and inner city spaces while the latter privileges open space and iconic harbourside settings. The differences and similarities between responses to interview questions are best revealed through 3D visualisation. Outputs from this method incorporate vernacular voices into policy-making, and can henceforth inform spatial planning, allowing for the development of more spatially literate creative city policies that reflect creative workers' actual spatial proclivities.

Dippenaar R.,University of Wollongong
Materials Science Forum | Year: 2010

The automotive industry is increasingly utilizing advanced high-strength steels, primarily to reduce the mass of motor vehicles. However, many of these steels fall within the peritectic composition range, which are notoriously difficult to cast by continuous casting techniques. Against this background, a brief review is given of our current understanding of the peritectic reaction as such and the subsequent peritectic phase transformations. © (2010) Trans Tech Publications.

Phillips C.,University of Wollongong
Environment and Planning A | Year: 2013

In this paper, informed by more-than-human and biosecurity literatures, I attend a neglected nonhuman considered a serious agricultural pest: the fruit fly. In addressing what it takes to live without fruit flies, biosecurity is theorised as ongoing, enacted achievement sustained (or not) by everyday and eventful interactions of heterogeneous spaces, strategies, and participants-human and nonhuman. Relations of fruits, flies, and people are explored through one vital attempt to biosecure life: Australia's Fruit Fly Exclusion Zone (FFEZ), a tristate pest-free area established to protect commercial horticulture from the fruit fly. Fruit flies become problematised as their appetites and mobilities confound fruit production and marketing, and affiliated biosecurity controls. Making fruit safe enrolls policy and agricultural sectors, but also more dispersed agents (travellers, residents, trees) and management sites (primarily off-farm). Since its introduction, the FFEZ's ongoing biosecuring normalised, with only occasional outbreak events. However, recent unprecedented outbreaks evoke questions about the FFEZ's future status. In such eventful times, it is worth reflecting on what kinds of living are possible in biosecurity zones-for flies, for resident human communities, and for agrifood networks.

Slater L.,University of Wollongong
Environment and Planning D: Society and Space | Year: 2013

In 2005 the Australian Queensland state government passed the Wild Rivers Act to preserve the natural heritage of rivers. My interest is not with all Wild Rivers but rather with those in Cape York where the public debate has been fierce and divisive. Prominent Cape York Aboriginal leaders and organisations condemned the bill. A coalition of north Queensland Traditional Owners support the policy and call for the 'proper Indigenous management of country' and the right people to speak for country. The conflict is an example of the argument put forward by some scholars that Cape York politics is being reconfigured: there is a schism between regionally focused visions of Indigenous futures and locally focused traditionalist visions held by community leaders 'living on country'. Analysing the Wild Rivers debate in conjunction with Holmes's and Smith's findings, one is struck by the emerging political ecology: rivers are becoming political actors. By bringing the postcolonial into relation with more-than-human praxis, I want to prise open this debate to consider what the public controversy conceals, what political practices are emerging, and what this demands of scholarship. When rivers become political actors the concept and practice of social justice are potentially reconfigured. What happens when we take seriously rivers as actors in a multirealist world? We know that rivers sustain and reproduce life, but which life worlds are being considered? © 2013 Pion and its Licencors.

Atchison J.,University of Wollongong | Head L.,University of Wollongong
Environment and Planning D: Society and Space | Year: 2013

It is increasingly acknowledged that invasive plant management, although a significant global issue, is a matter of coexistence rather than control. Nevertheless an adversarial rhetoric dominated by discourses of war and winning persists. This paper focuses on the bodies of plants, the animals with which they become entangled, and the humans who are charged with eradicating them. Plants help to rethink bodily difference beyond the human, extending feminist theories that have contributed to increased recognition of nonhuman difference. Bodies are a barely acknowledged scale of invasive plant management, which is usually conceptualised in landscape terms. Our empirical focus is the eradication of three species in northwestern Australia: Mimosa (Mimosa pigra), Gamba Grass (Andropogon gayanus), and Neem (Azadirachta indica). By paying attention to plant difference and illuminating the experience of invasive plant managers, we show how eradication manages the intersecting timespaces of different bodies in order to stop plants becoming collectives. We identify contradictions in the regulation and application of borders, which are less permeable for some animals than for all humans. We also draw attention to the questions of risk-for humans and others-in the process of killing plants. For embodied geographies, a plant perspective opens up new ways of thinking about bodily boundaries: in particular the individual/collective divide. The implication for invasive plant management is that, even at the eradication end of the spectrum, effective management is an uncertain process that involves living in association with invasive plants rather than living separately from them.

Trani L.D.O.,Coffey Geotechnics | Indraratna B.,University of Wollongong
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2010

This paper presents an investigation into the seepage hydraulics of a layer of subballast filter subjected to cyclic loading in a fully saturated environment. A multilayer mathematical approach was used to predict the time-dependent permeability of this filter, with a reduction in porosity as a function of compression under cyclic loading, and the amount of base soil (<150 μm) trapped within the filter voids being the two main aspects of this proposed model. Laboratory test results conducted on a novel cyclic loading permeameter apparatus were used to validate the proposed model. The family of equations that are an integral part of the proposed model are then presented in the form of compact visual guidelines anticipated to provide a more practical tool for railway design practitioners. © 2010 ASCE.

Davies G.,University of Wollongong | Woodroffe C.D.,University of Wollongong
Earth Surface Processes and Landforms | Year: 2010

In order to better understand the relations between tidal estuary shape and geomorphic processes, the width profiles of 79 tidal channels from within 30 estuaries in northern Australia have been extracted from LANDSAT 5 imagery using GIS. Statistics describing the shape and width convergence of individual channels and entire estuaries (which can contain several channels) are analysed along with proxies for the tidal range and fluvial inputs of the estuaries in question. The width profiles of most individual channels can be reasonably approximated with an exponential curve, and this is also true of the width profiles of estuaries. However, the shape of this exponential width profile is strongly related to the mouth width of the system. Channels and estuaries with larger mouths generally exhibit a more pronounced 'funnel shape' than those with narrower mouths, reflecting the hydrodynamic importance of the distance over which the channel or estuarine width converges. At the estuarine scale, this 'convergence length' also tends to be higher in estuaries which have larger catchments relative to their size. No clear relation between the estuarine width convergence length and tidal range could be discerned within the Northern Australian estuaries although, when these data are combined with data from other studies, a weak relationship emerges. © 2010 John Wiley & Sons, Ltd.

Kenchington R.,University of Wollongong
Bulletin of Marine Science | Year: 2010

Responses by management to an increasing range of human uses and impacts on marine ecosystems are a recent phenomenon. They are developing alongside traditional sectoral management of fisheries, shipping, and coastal land uses. Many regimes have been developed for approaching the tasks of integrating management of coastal and marine ecosystems. The role of marine protected areas and conservation agencies in such regimes is often a matter of contention. The application of International Union for the Conservation of Nature (IUCN) protected-area categories to marine ecosystems can cover the broadest range of management regimes, from strict nature reserves with no fishing or collecting to multiple, verifiably environmentally sustainable, levels of use and impact. Here, I address the roles that protected areas and other management categories can play in relation to the multiple scales and strategic objectives for management of marine ecosystems. I draw on experiences of planning, management, and community response to the Great Barrier Reef Marine Park to discuss the opportunities and challenges of using protected-area categories and other strategies in management for conservation and reasonable multiple use at the ecosystem scale. © 2010 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

Jansen J.D.,University of Glasgow | Jansen J.D.,University of Stockholm | Nanson G.C.,University of Wollongong
Journal of Geophysical Research: Earth Surface | Year: 2010

Water and sediment flux interactions are examined in Magela Creek, an alluvial (anabranching) sand bed river in the northern Australian tropics. Dense riparian vegetation stabilizes the channels and floodplains thereby preventing erosional instability at flow depths up to 6.2 times bankfull and discharges up to 15 times bankfull. Narrow anabranching channels characterize >92% of the alluvial reach and transport bed load more efficiently than short reaches of wide single-channels, yet overall 29 ± 12% of the bed load is sequestered and the average vertical accretion rate is 0.41 ± 0.17 mm yr -1 along the 12 km study reach. The most effective discharge for transporting sediment (40-45 m3 s-1) is consistent at all 5 stations (10 channels) examined and is equivalent to the channel-forming discharge. It has an average recurrence interval of 1.01 years, occurs for an exceptionally long portion (13-15%) of the annual flow duration, and averages a remarkable 2.1 times bankfull. The high flow efficiency (i.e., bed load transport rate to stream power ratio) of the anabranches is facilitated by low width/depth channels with banks reinforced by vegetation. Colonnades of bank top trees confine high-velocity flows overbed (i.e., over the channel bed) at stages well above bankfull. At even larger overbank flows, momentum exchange between the channels and forested floodplains restrains overbed velocities, in some cases causing them to decline, thereby limiting erosion. Magela Creek exhibits a complicated set of planform, cross-sectional and vegetative adjustments that boost overbed velocities and enhance bed load yield in multiple channels while restraining velocities and erosion at the largest discharges. Copyright 2010 by the American Geophysical Union.

Horpibulsuk S.,Suranaree University of Technology | Liu M.D.,University of Wollongong | Liyanapathirana D.S.,University of Western Sydney | Suebsuk J.,Suranaree University of Technology
Computers and Geotechnics | Year: 2010

In this paper, the mechanical properties of cemented clay are studied. The theoretical framework of the Structured Cam Clay (SCC) model is extended to describe the behaviour of cemented clay. The SCC model is modified to take into account special features of the behaviour of cemented clay. The widely used mean effective stress parameter is modified to include the influence of cementation on the strength and the plastic deformation of cemented clay. A new destructuring function is also suggested to represent the removal of the cementation structure, especially in the formation of the final failure state for artificially strongly cemented clay. The revised model is then employed to simulate and predict the behaviour of cemented clay with various degrees of cementation and confining stresses. The main features of the complicated behaviour of cemented clay can be reasonably represented well by the theoretical framework of the SCC model. Finally, the influence of cementation on the model parameters is discussed, and empirical equations are proposed to determine some of the key model parameters for engineering practice. © 2009 Elsevier Ltd.

Cordner L.,University of Wollongong
Journal of the Indian Ocean Region | Year: 2010

The Indian Ocean Region is moving to the centre of the global geostrategic agenda. Resource competition and energy security, environmental and economic issues exacerbated by climate change; the involvement of external powers like China, and the emergence of regional powers like India underscore a heightened need for attention to this region. Concomitantly, Indian Ocean sea lines of communication are becoming increasingly important to global and regional commerce. Related security issues largely converge in the maritime domain. There is little history of region-wide security cooperation and a lack of regional institutions in the Indian Ocean Region. Non-conventional threats posing collective security risks to common interests present the most realisable prospects, at least initially, for the development of collective security dialogue and mechanisms. Such arrangements need to involve both regional and extra-regional powers that have interests to protect and capacities to assist. Given geography and the diverse nature of the region, maritime security offers the most compelling area for cooperation in the Indian Ocean Region. Efforts to facilitate collective security dialogue and establish maritime security cooperative mechanisms and habits need to be urgently progressed at official, non-official and operational levels. © 2010 Indian Ocean Research Group.

Oliveira D.A.F.,University of Wollongong | Indraratna B.,University of Wollongong
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2010

One important component in the design of tunnels in urban areas is a correct assessment of the interaction between the underground excavation with other structures in the vicinity. In this sense a correct stress-strain response by the model representing the rock mass behavior is essential. The shear and normal displacement of rock discontinuities and their shear and normal stiffness control the distribution of stress and displacement within a discontinuous rock mass. In conditions where an equivalent continuum based approach is not applicable, the joint material model should be able to describe important mechanisms such as asperity sliding and shearing, post-peak behavior, asperity deformation, and the effect of soft infilling. The distinct element code UDEC was used to simulate the direct shear tests on a natural joint profile, and the prediction of two existing models of discontinuity strength and deformation were then compared with a new soil-infilled joint model and with experimental data for clean and soil-infilled rock joints. A numerical modeling of a cavern excavated in a jointed medium is also presented to illustrate the response of different models. The proposed soil-infilled joint model described more comprehensively the occurrence of dilation and compression with lateral displacements and also better represented the double peak shearing in relation to the adopted squeezing mechanism that could not be captured by the two existing models. © 2010 ASCE.

Brennan-Horley C.,University of Wollongong
Australian Geographer | Year: 2010

This paper attempts to further spatial understandings of creative work by focusing on the inherent topology linking workplaces together. Topographical approaches to creative employment are advanced by reflecting on how creative activity is linked and enacted across space. Everyday realities of creative work mean that multiple locations are used (for rehearsal, exhibition, for networking or for performance). It is difficult to ascertain relationships between these places using conventional methods such as mapping census data. Instead, I draw on workplace data taken from a creative industry research project conducted in Darwin, a remote city in Australia's Northern Territory, where qualitative interviews and mental maps were combined. The analysis proffers two key advances. First, mental map interviews conducted with creative workers can yield, on average, a fivefold increase over census data in the number of important, everyday work sites reported by creative practitioners. This means more detail and subtlety can be woven into analysis. Second, a hierarchy of important intra and inter-suburban linkages can be mapped, revealing the city's creative topology and furthering breakdown of the 'creative inner/uncreative outer' urban binary. A topological approach reveals that rather than being CBD (central business district)-centric (which static readings of raw workplace counts per neighbourhood show) creativity is highly interconnected across the city. Such findings bolster the case for reimagining suburbs as vital and functional parts of the creative city. Rather than being typified as secondary to internal-CBD milieus, outer suburbs are highly connected, performing specialised roles in Darwin's creative topology. © 2010 Geographical Society of New South Wales Inc.

Warren A.,University of Wollongong | Evitt R.,University of Wollongong
Australian Geographer | Year: 2010

This paper discusses the creative and contemporary performances of young Indigenous hip-hoppers in two seemingly disparate places (Nowra, NSW, and Torres Strait Islands, QLD). Visiting two Indigenous hip-hop groups from these places-and drawing on interviews and participant observation-we explore the way in which emerging technologies, festivals, programs and online networking have helped enable unique forms of music making. In contrast to racist discourses depicting Indigenous youth as idle or inactive, our research participants demonstrated musical aspiration, creativity and a desire to express love of country and culture. Rather than assume cities and urban centres are hubs for creativity, hip-hop production is geographically mobile, operating in locations removed from large population centres. Indigenous hip-hop links up-and-coming with more experienced performers in what amounts to a semi-formal, political, transnational and anti-colonial creative industry. Geographical distance remains an ongoing challenge, but more than this, wider patron discourses framing what is expected from 'proper' Indigenous performance are the more profound coalface of marginalisation. © 2010 Geographical Society of New South Wales Inc.

Ma Y.,University of Wollongong
Resources Policy | Year: 2013

To examine the impact of the change in forward pricing mechanism on the volatility of iron ore spot prices, we model the iron ore daily price of Platts IODEX from October 7, 2008 to September 21, 2012. The identified iron ore spot price tends to be less volatile after the introduction of quarterly pricing mechanism. Our main approaches are as follows: (i) to decompose the spot price of Platts IODEX into two subsamples and relate the result of the structural break to the date of the switch in the iron ore forward pricing mechanism; (ii) to apply the EGARCH (1, 1) model to simultaneously capture the long memory and the asymmetric effect on the volatility of the iron ore spot price; and (iii) to delineate the news impact curve to further interpret the asymmetric effect. © 2013 Elsevier Ltd.

Xie M.,University of Wollongong | Nghiem L.D.,University of Wollongong | Price W.E.,University of Wollongong | Elimelech M.,Yale University
Water Research | Year: 2013

The impact of humic acid fouling on the membrane transport of two pharmaceutically active compounds (PhACs) - namely carbamazepine and sulfamethoxazole - in forward osmosis (FO) was investigated. Deposition of humic acid onto the membrane surface was promoted by the complexation with calcium ions in the feed solution and the increase in ionic strength at the membrane surface due to the reverse transport of NaCl draw solute. The increase in the humic acid deposition on the membrane surface led to a substantial decrease in the membrane salt (NaCl) permeability coefficient but did not result in a significant decrease in the membrane pure water permeability coefficient. As the deposition of humic acid increased, the permeation of carbamazepine and sulfamethoxazole decreased, which correlated well with the decrease in the membrane salt (NaCl) permeability coefficient. It is hypothesized that the hydrated humic acid fouling layer hindered solute diffusion through the membrane pore and enhanced solute rejection by steric hindrance, but not the permeation of water molecules. The membrane water and salt (NaCl) permeability coefficients were fully restored by physical cleaning of the membrane, suggesting that humic acid did not penetrate into the membrane pores. © 2013.

Biribo N.,University of Wollongong | Woodroffe C.D.,University of Wollongong
Sustainability Science | Year: 2013

Low-lying reef islands on atolls appear to be threatened by impacts of observed and anticipated sea-level rise. This study examines changes in shoreline position on the majority of reef islands on Tarawa Atoll, the capital of Kiribati. It investigates short-term reef-island area and shoreline change over 30 years determined by comparing 1968 and 1998 aerial photography using geographical information systems. Reef islands have substantially increased in size, gaining about 450 ha, driven largely by reclamations on urban South Tarawa, accounting for 360 ha (~80 % of the net change). Widespread erosion and high average accretion rates appear to be related to disjointed reclamations. In rural North Tarawa, most reef islands show stability, with localised changes in areas such as embayments, sand spits and beaches adjacent to, or facing, inter-island channels. Shoreline changes in North Tarawa are largely influenced by natural factors, whereas those in South Tarawa are predominantly affected by human factors and seasonal variability associated with El Niño-Southern Oscillation (ENSO). However, serious concerns are raised for the future of South Tarawa reef islands, as evidence shows that widespread erosion along the ocean and lagoon shorelines is primarily due to human activities and further encroachment onto the active beach will disrupt longshore sediment transport, increasing erosion and susceptibility of the reef islands to anticipated sea-level rise. Appropriate adaptation measures, such as incorporating coastal processes and seasonal variability associated with ENSO when designing coastal structures and developing appropriate management plans, are required, including prohibiting beach mining practices near settlements. © 2013 Springer Japan.

Farbotko C.,University of Wollongong | McGregor H.V.,University of Wollongong
Australian Geographer | Year: 2010

The Pacific island nation-state of Tuvalu featured significantly at the Copenhagen Conference of Parties (COP) 15 climate change negotiations, where the vulnerability of Tuvalu to sea level rise and emotional outpourings of the Tuvaluan delegation contributed to the nation's prominence. In this paper we discuss the likely impacts for Tuvalu of a 1.5°C versus 2°C global warming target and explore sadness and discomfort surrounding discussion of these targets during COP 15. We highlight tensions between science and emotion, arguing that affective encounters can be significant in climate change decision-making. Weeping by a member of the Tuvalu delegation evoked discomfort in the conference plenary. This discomfort briefly unsettled the apparently stable boundaries of convention and protocol that seek to separate emotion from science and politics. We argue that possibilities for change arise when emotions enter climate change negotiations, even though (or perhaps because) these are arenas that privilege rational exchange. Our conclusion urges that more attention be paid to how climate science and emotion are intertwined in climate change politics. © 2010 Geographical Society of New South Wales Inc.

Guo W.D.,University of Wollongong
International Journal for Numerical and Analytical Methods in Geomechanics | Year: 2016

This paper develops a three-layer model and elastic solutions to capture nonlinear response of rigid, passive piles in sliding soil. Elastic solutions are obtained for an equivalent force per unit length ps of the soil movement. They are repeated for a series of linearly increasing ps (with depth) to yield the nonlinear response. The parameters underpinning the model are determined against pertinent numerical solutions and model tests on passive free-head and capped piles. The solutions are presented in non-dimensional charts and elaborated through three examples. The study reveals the following: On-pile pressure in rotationally restrained, sliding layer reduces by a factor α, which resembles the p-multiplier for a laterally loaded, capped pile, but for its increase with vertical loading (embankment surcharge), and stiffness of underlying stiff layer: α=0.25 and 0.6 for a shallow, translating and rotating piles, respectively; α=0.33-0.5 and 0.8-1.3 for a slide overlying a stiff layer concerning a uniform and a linearly increasing pressure, respectively; and α=0.5-0.72 for moving clay under embankment loading. Ultimate state is well defined using the ratio of passive earth pressure coefficient over that of active earth pressure. The subgrade modulus for a large soil movement may be scaled from model tests. The normalised rotational stiffness is equal to 0.1-0.15 for the capped piles, which increases the pile displacement with depth. The three-layer model solutions well predict nonlinear response of capped piles subjected to passive loading, which may be used for pertinent design. © 2016 John Wiley & Sons, Ltd.

O'Gorman E.,University of Wollongong
Journal of Australian Studies | Year: 2013

Within the context of contemporary concerns about ecological degradation and debates about water use for irrigation, this article examines how and why commercial rice growing began in the Murrumbidgee River region, New South Wales. It focuses on the crop's establishment and rapid expansion from approximately 1900 to 1960 and concentrates on three events, which each significantly shaped commercial rice growing: the problems faced by the Murrumbidgee Irrigation Area during its first years of operation, the introduction of Californian varieties of rice, and World War II. This history of rice growing reveals some of the changing connections between regional, state, national, and global concerns about food and water. The analysis builds on Marnie Haig-Muir's 1996 examination of the economic forces that influenced rice growing in Wakool, located in the Murray River valley, during World War II, taking a different geographical perspective, a broader temporal view, and emphasising the importance of considering the cultural dimensions of the establishment of rice growing. It expands previous histories of water management and irrigation in Australia by examining historical agricultural publications related to rice. This history is relevant to contemporary issues around rice farming and the Murray-Darling Basin, and this article explores the ways in which the history of rice has shaped the contemporary political and physical landscape. © 2013 International Australian Studies Association.

Perlman D.,University of Wollongong
Journal of Teaching in Physical Education | Year: 2015

The purpose of this study was to examine the influence of an intervention grounded in Self-Determination Theory on preservice teachers' instructional behaviors and the motivational responses of their students. A total of 62 preservice physical education teachers enrolled in a secondary physical education content and methods course were randomly assigned to either a treatment (n = 31) or a control group (n = 31). The study employed a pretest/posttest design and data were collected through: (a) observation of preservice teachers' instruction, (b) a survey measuring preservice teachers' perceptions of their autonomy support, and (c) a survey measuring secondary students' motivation. Data analysis used repeated-measures ANOVAs to examine differences between the groups. Results indicated significant changes in autonomy-support for both teachers and students exposed to the intervention. © 2015 Human Kinetics, Inc.

Flood M.,University of Wollongong
Culture, Health and Sexuality | Year: 2015

This paper provides a critical assessment of efforts to involve men in the prevention of men's violence against women. Although there is a substantial evidence base attesting to the effectiveness of at least some strategies and interventions, this field is also limited in important ways. Violence prevention efforts often have focused on changing men's attitudes, rather than also seeking to transform structural and institutional inequalities. While feminist and queer scholarship has explored diversities and pluralities in the organisation of sexuality, much violence prevention work often assumes a homogenously heterosexual male constituency. Too often this work is conceptually simplistic with regard to gender. Against this background, this paper contests and complicates several assumptions that are part of an emerging consensus in men's violence prevention: first, that it is in men's interests to support progress towards non-violence and gender equality; second, that the best people to engage and work with men are other men; and finally, the strengths and limitations of inviting and drawing on ‘real men’. A critical assessment of the field's working assumptions is vital if it is to contribute to the future prevention of men's violence against women. © 2015 Taylor & Francis.

Salari M.,University of Wollongong | Aboutalebi S.H.,University of Wollongong | Konstantinov K.,University of Wollongong | Liu H.K.,University of Wollongong
Physical Chemistry Chemical Physics | Year: 2011

We report the synthesis of self-organized titania nanotubes and nanocrystalline titania powders employing an alternative and novel approach. Integrating these nanostructures in a binder-free working electrode improved the capacitance up to 911 μF cm-2, which is around one to two orders of magnitude higher than the conventional electric double layer capacitors. © the Owner Societies 2011.

Andresen R.,University of Wollongong | Caputi P.,University of Wollongong | Oades L.G.,University of Wollongong
Psychiatry Research | Year: 2010

There is an international call for mental health services to become recovery-oriented, and also to use evidence-based practices. Addressing this call requires recovery-oriented measurement of outcomes and service evaluation. Mental health consumers view recovery as leading as meaningful life, and have criticised traditional clinical measures for being too disability-oriented. This study compares three measures of consumer-defined recovery from enduring mental illness: the Recovery Assessment Scale, the Mental Health Recovery Measure and the Self-Identified Stage of Recovery, with four conventional clinical measures. Correlational analyses supported the convergent validity of the recovery measures, although certain subscales were unrelated to each other. More importantly, little relationship was found between consumer-defined recovery and the clinical measures. Analyses of variance revealed that scores on the recovery measures increased across self-identified stage of recovery, but scores on most clinical measures did not improve consistently across stage of recovery. The findings demonstrate the qualitative difference between the two types of measures, supporting the claim by consumers that clinical measures do not assess important aspects of recovery. There is a need for further research and refinement of recovery measurement, including assessment of stages of recovery, with the aim of including such measures as an adjunct in routine clinical assessment, service evaluation and research. © 2010 Elsevier Ireland Ltd.

Brown S.H.J.,University of Wollongong | Mitchell T.W.,University of Wollongong | Blanksby S.J.,University of Wollongong
Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids | Year: 2011

Recent developments in analytical technologies have driven significant advances in lipid science. The sensitivity and selectivity of modern mass spectrometers can now provide for the detection and even quantification of many hundreds of lipids in a single analysis. In parallel, increasing evidence from structural biology suggests that a detailed knowledge of lipid molecular structure including carbon-carbon double bond position, stereochemistry and acyl chain regiochemistry is required to fully appreciate the biochemical role(s) of individual lipids. Here we review the capabilities and limitations of tandem mass spectrometry to provide this level of structural specificity in the analysis of lipids present in complex biological extracts. In particular, we focus on the capabilities of a novel technology termed ozone-induced dissociation to identify the position(s) of double bonds in unsaturated lipids and discuss its possible role in efforts to develop workflows that provide for complete structure elucidation of lipids by mass spectrometry alone: so-called top-down lipidomics. This article is part of a Special Issue entitled: Lipodomics and Imaging Mass Spectrom. © 2011 Elsevier B.V.

Price O.F.,University of Wollongong
Austral Ecology | Year: 2015

Fire management attempts to coerce fire into a desired regime using three primary strategies: prescribed burning, fire suppression and ignition management. The West Arnhem Land Fire Abatement project (WALFA), where prescribed Early Dry Season burning is used to reduce unplanned Late Dry Season burning, is heralded as model for prescribed burning. However, a previous analysis found that Late Dry Season area burnt in WALFA had been reduced further than would be expected based purely on the Early Dry Season treatment area. This study investigated whether treatment has reduced the number and size of unplanned fires. Daily burnt area mapping from MODIS satellite sensors was used to identify individual fires to compare fire activity before and after management was introduced in WALFA (2005) and in a control region in East Arnhem Land. Late Dry Season area burnt reduced after treatment in WALFA but also in the control region. The number of fires in August-October increased after treatment. There is a period from early August until late September when human ignitions can cause huge fires. Late Dry Season area burnt was strongly influenced by the size of the largest single fire and only weakly by the number of ignitions. Early Dry Season area burnt had modest effects on both the number and maximum size of Late Dry Season fires. Eliminating the largest fire in each 1600km2 sample block would have halved the total Late Dry Season area burnt. A similar reduction could be obtained from a 14% annual treatment with Early Dry Season fire, but this may not reduce the overall area burnt. If overall fire frequency is the main threat to biodiversity in the savannas, then the best solution will be to prevent the small subset of fires that have the potential to become very large. © 2015 Ecological Society of Australia.

Ye D.,University of Wollongong | Zhang M.,University of Wollongong | Sutanto D.,University of Wollongong
IEEE Transactions on Power Systems | Year: 2011

This paper presents a hybrid multiagent framework with a Q-learning algorithm to support rapid restoration of power grid systems following catastrophic disturbances involving loss of generators. This framework integrates the advantages of both centralized and decentralized architectures to achieve accurate decision making and quick responses when potential cascading failures are detected in power systems. By using this hybrid framework, which does not rely on a centralized controller, the single point of failure in power grid systems can be avoided. Further, the use of the Q-learning algorithm developed in conjunction with the restorative framework can help the agents to make accurate decisions to protect against cascading failures in a timely manner without requiring a global reward signal. Simulation results demonstrate the effectiveness of the proposed approach in comparison with the typical centralized and decentralized approaches based on several evaluation attributes. © 2006 IEEE.

Simon A.,University of Wollongong | Price W.E.,University of Wollongong | Nghiem L.D.,University of Wollongong
Separation and Purification Technology | Year: 2013

The aim of this study was to evaluate the changes in membrane surface properties and solute separation by a nanofiltration membrane during repetitive membrane fouling and chemical cleaning. Secondary treated effluent and model fouling solutions containing humic acids, sodium alginate, or silica colloids were used to simulate membrane fouling. Chemical cleaning was carried out using a commercially available caustic cleaning formulation. Carbamazepine and sulfamethoxazole were selected to examine the filtration behaviour of neutral and negatively charged organic compounds, respectively. Results show that the impact of membrane fouling on solute rejection is governed by pore blocking, modification of the membrane surface charge, and cake enhanced concentration polarisation. Caustic cleaning was effective at controlling membrane fouling and membrane permeability recovery was slightly more than 100%. In good agreement with the literature, the high membrane permeability recovery observed here suggests that caustic cleaning could lead to temporary enlargement of the membrane pores. In addition, microscopic observations based on scanning electron microscopy and energy dispersive spectroscopy revealed some irreversible fouling on the chemical cleaned membrane. Thus caustic cleaning did not completely remove all foulants from the membrane surface and the membrane surface hydrophobicity and zeta potential changed correspondingly. The temporary enlargement of the membrane pores due to caustic cleaning subsequently led to notable changes in the rejection of inorganic salts (measured by conductivity) and carbamazepine. By contrast, the impact of chemical cleaning on the rejection of the negatively charged sulfamethoxazole was negligible. This is because the rejection of sulfamethoxazole is predominantly governed by electrostatic repulsion between the compound and the negatively charged membrane surface and thus is not significantly influenced by any enlargement of the membrane pores. © 2013 Elsevier Ltd. All rights reserved.

Ranson N.J.,University of Wollongong | Byrne M.K.,University of Wollongong
Journal of Autism and Developmental Disorders | Year: 2014

This study evaluated the effects of an eight-session female higher-functioning autism anti-stigma program on the knowledge, attitudes and behavioural intentions of adolescent girls. Participants were seventh-, eighth- and ninth-grade students (N = 273) in a mainstream school. Two-eighth-grade classes were randomly allocated to the intervention condition. The remaining students were either allocated to the no-intervention peer or no-intervention non-peer condition. The anti-stigma program positively influenced knowledge, attitudes and to a lesser extent behavioural intentions towards peers with higher-functioning autism within the intervention condition. Some degree of attitudinal improvement occurred across all conditions following the program suggesting some spill over effects. Overall, findings provide preliminary evidence supporting the efficacy of an anti-stigma program tailored to support females with higher-functioning autism. © 2014, Springer Science+Business Media New York.

Jones S.C.,University of Wollongong | Kervin L.,University of Wollongong
Public Health Nutrition | Year: 2011

Objective The present study sought to determine the feasibility of an experimental research design to investigate the effects of exposure to magazine advertising on children's food choices.Design Children were randomized to read either a magazine with food advertisements or a magazine with no food advertisements. They then chose two food items from the intervention 'store- to eat after the session. Data were also collected on attitudes to advertising and snack food preferences. Finally, participants- parents were provided with a self-completion survey on food choices and other variables (n 24).Setting Three vacation care centres in regional New South Wales, Australia.Subjects Children aged 5-12 years (n 47).Results Children in the experimental condition were more likely to choose advertised foods than those in the control group. Interestingly, the majority reported taste and healthiness as the most important factors in snack food choices; however, when faced with the actual food choice, they predominantly chose unhealthy foods (eighty-two unhealthy and only twelve healthy items were chosen).Conclusions This was the first study to assess the effects on children of exposure to food advertising within the context of reading a child-targeted magazine. Importantly, even with the small sample size and venue limitations, we found that exposure to magazine advertising influenced food choices. Children's magazines are an under-researched and poorly regulated medium, with considerable potential to influence children's food choices. The present study shows that the methodology is feasible, and future studies could replicate this with larger samples. © 2010 The Authors.

Varese F.,Bangor University | Varese F.,University of Liverpool | Barkus E.,University of Wollongong | Bentall R.P.,Bangor University | Bentall R.P.,University of Liverpool
Psychological Medicine | Year: 2012

Background It has been proposed that the relationship between childhood trauma and hallucinations can be explained by dissociative processes. The present study examined whether the effect of childhood trauma on hallucination-proneness is mediated by dissociative tendencies. In addition, the influence of dissociative symptoms on a cognitive process believed to underlie hallucinatory experiences (i.e. reality discrimination; the capacity to discriminate between internal and external cognitive events) was also investigated.Method Patients with schizophrenia spectrum disorders (n=45) and healthy controls (with no history of hallucinations; n=20) completed questionnaire measures of hallucination-proneness, dissociative tendencies and childhood trauma, as well as performing an auditory signal detection task.Results Compared to both healthy and non-hallucinating clinical controls, hallucinating patients reported both significantly higher dissociative tendencies and childhood sexual abuse. Dissociation positively mediated the effect of childhood trauma on hallucination-proneness. This mediational role was particularly robust for sexual abuse over other types of trauma. Signal detection abnormalities were evident in hallucinating patients and patients with a history of hallucinations, but were not associated with pathological dissociative symptoms.Conclusions These results are consistent with dissociative accounts of the trauma-hallucinations link. Dissociation, however, does not affect reality discrimination. Future research should examine whether other cognitive processes associated with both dissociative states and hallucinations (e.g. deficits in cognitive inhibition) may explain the relationship between dissociation and hallucinatory experiences. © Cambridge University Press 2011.

Han J.,University of Wollongong | Li H.,University of Wollongong | Xu H.,Baosteel
Materials and Design | Year: 2014

The microstructure, including grain size and precipitation, tensile strength and Charpy impact toughness of (Nb. +. V) 18Cr-2Mo ferritic stainless steel heavy plates with/without Ti were investigated by means of optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and standard tensile strength and Charpy impact toughness testing. It was found that for 18Cr-2Mo heavy plate, a good combination of Nb-V stabilized method without Ti induces refinement of grain sizes due to the precipitation of amounts of fine Nb carbonitrides and V nitrides. Meanwhile, the mechanical testing results indicate that optimal transformation of grain size, precipitation that Nb-V composition system brings to 18Cr-2Mo heavy plate is beneficial to improvement of strength and impact toughness. © 2014 Elsevier Ltd.

McGhee D.E.,University of Wollongong | Steele J.R.,University of Wollongong
Medicine and Science in Sports and Exercise | Year: 2010

Purpose: The aim of this study was to investigate whether a sports bra designed to both elevate and compress the breasts could decrease exercise-induced breast discomfort and bra fit discomfort experienced by women with large breasts relative to a standard encapsulation sports bra. Methods: Breast kinematic data, bra fit comfort, exercise-induced breast discomfort, and bra rankings in terms of preference to wear during running were compared in 20 women with large breasts who ran on a treadmill under three bra conditions: an experimental bra that incorporated both breast compression and elevation, an encapsulation sports bra, and a placebo bra. Subjective data were collected immediately before and after the treadmill running trials. Results: Exercise-induced breast discomfort (P < 0.01) and bra discomfort (P < 0.01) were significantly less for the experimental bra condition relative to the sports bra and placebo bra. This reduction in discomfort was achieved through greater breast elevation (P < 0.01) and compression, with no difference found in vertical breast displacement (P = 0.12) or vertical breast velocity (P = 0.06). Conclusions: The design features of greater breast elevation and compression provided significantly increased breast and bra comfort compared with a standard encapsulation sports bra during physical activity for women with large breasts. Copyright © 2010 by the American College of Sports Medicine.

Ang Y.S.,University of Wollongong | Sultan S.,University of Wollongong | Zhang C.,University of Wollongong
Applied Physics Letters | Year: 2010

We demonstrate that the nonlinear optical response in bilayer graphene is among the strongest, especially in the important frequency regime of terahertz to far-infrared. Furthermore, we show that both the single frequency and frequency tripled nonlinear response become comparable to the linear response at very moderate electric field. The field strength for the onset of nonlinear effect in bilayer graphene is well within the experimental achievable range in laboratories. Our result suggests that bilayers are preferred structures for developing graphene-based nonlinear photonics and optoelectronics devices. © 2010 American Institute of Physics.

Li L.,University of Wollongong | Guo Z.,University of Wollongong | Du A.,University of Queensland | Liu H.,University of Wollongong
Journal of Materials Chemistry | Year: 2012

A nanocomposite of Mn 3O 4 wrapped in graphene sheets (GSs) was successfully synthesized via a facile, effective, energy-saving, and scalable microwave hydrothermal technique. The morphology and microstructures of the fabricated GS-Mn 3O 4 nanocomposite were characterized using various techniques. The results indicate that the particle size of the Mn 3O 4 particles in the nanocomposite markedly decreased to nearly 20 nm, significantly smaller than that for the bare Mn 3O 4. Electrochemical measurements demonstrated a high specific capacity of more than 900 mA h g -1 at 40 mA g -1, and excellent cycling stability with no capacity decay can be observed up to 50 cycles. All of these properties are also interpreted by experimental studies and theoretical calculations. © 2012 The Royal Society of Chemistry.

Kelly B.,University of Wollongong | Flood V.M.,University of Wollongong | Yeatman H.,University of Wollongong
Health and Place | Year: 2011

Reliable and valid measures of local food environments are needed to more fully understand the relationship between these environments and health and identify potential intervention points to improve access to, and the availability of, healthy foods. These measures also inform policy making, including the zoning of food outlets and food labelling/information requirements. A literature review was undertaken using health, behavioural and social sciences, nutrition and public health databases and grey literature, to determine available information on the measurement of local food environments. Included articles were those measuring aspects of food environments published from 2000 to 2010. A range of tools and methods are available to measure different components of food environments. Those focusing on community nutrition environments record the number, type and location of food outlets. The tools that focus on the consumer nutrition environment incorporate other factors, such as available food and beverage products, their price and quality, and any promotions or information to prompt consumers to make purchasing decisions. A summary and critique of these measures are provided. © 2011.

Su D.,University of Technology, Sydney | Dou S.,University of Wollongong | Wang G.,University of Technology, Sydney | Wang G.,Nanjing University of Aeronautics and Astronautics
Chemistry of Materials | Year: 2015

Amorphous TiO2@C nanospheres were synthesized via a template approach. After being sintered under different conditions, two types of polyphase TiO2 hollow nanospheres were obtained. The electrochemical properties of the amorphous TiO2 nanospheres and the TiO2 hollow nanospheres with different phases were characterized as anodes for the Na-ion batteries. It was found that all the samples demonstrated excellent cyclability, which was sustainable for hundreds of cycles with little capacity fading, although the anatase TiO2 presented a capability that was better than that of the mixed anatase/rutile TiO2 or the amorphous TiO2@C. Through crystallographic analysis, it was revealed that the anatase TiO2 crystal structure supplies two-dimensional diffusion paths for Na-ion intercalation and more accommodation sites. Density functional theory calculations indicated lower energy barriers for the insertion of Na+ into anatase TiO2. Therefore, anatase TiO2 hollow nanospheres show excellent high-rate performance. Through ex situ field emission scanning electron microscopy, it was revealed that the TiO2 hollow nanosphere architecture can be maintained for hundreds of cycles, which is the main reason for its superior cyclability. © 2015 American Chemical Society.

Healthy food baskets have been used around the world for a variety of purposes, including: examining the difference in cost between healthy and unhealthy food; mapping the availability of healthy foods in different locations; calculating the minimum cost of an adequate diet for social policy planning; developing educational material on low cost eating and examining trends on food costs over time. In Australia, the Illawarra Healthy Food Basket was developed in 2000 to monitor trends in the affordability of healthy food compared to average weekly wages and social welfare benefits for the unemployed. It consists of 57 items selected to meet the nutritional requirements of a reference family of five. Bi-annual costing from 2000-2009 has shown that the basket costs have increased by 38.4% in the 10-year period, but that affordability has remained relatively constant at around 30% of average household incomes. © 2010 by the authors.

Cao M.,Beihang University | Ju J.,CAS Beijing National Laboratory for Molecular | Li K.,CAS Beijing National Laboratory for Molecular | Dou S.,University of Wollongong | And 2 more authors.
Advanced Functional Materials | Year: 2014

Although clean drinking water is a basic human need, freshwater scarcity has been identified as a major global problem of the 21st century. Nature has long served as a source of inspiration for human beings to develop new technology. The cactus in the desert possesses a multifunctional integrated fog collection system originating from the cooperation of a Laplace pressure gradient and the wettability difference. In this contribution, inspired by the cactus, an artificial fog collector on a large scale is first fabricated through integrating cactus spine-like hydrophobic conical micro-tip arrays with the hydrophilic cotton matrix. The novel cactus-inspired fog collector can spontaneously and continuously collect, transport, and preserve fog water, demonstrating high fog collection efficiency and promising applications in the regions with drinking water scarcity. Furthermore, the present approach is simple, time-saving and cost-effective, which provides a potential device and new idea to solve the global water crisis. Inspired by the fog-harvesting behavior of the cactus, a novel fog collector in large scale is first fabricated through integrating cactus spine-like hydrophobic conical micro-tip arrays with a hydrophilic cotton matrix, which can spontaneously and continuously collect, transport, and preserve fog water. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ledo L.,University of Wollongong | Kosasih P.B.,University of Wollongong | Cooper P.,University of Wollongong
Renewable Energy | Year: 2011

Building-integrated micro-wind turbines are promising low-cost renewable energy devices. However, the take-up of micro-wind turbines in high density suburban environments is still very limited due to issues such as: a) low wind speeds; b) high turbulence intensity; and c) the perception of potentially high levels of aerodynamic noise generated by the turbines. The wind flow field above the roof of buildings in this environment is different to that over flat terrain or around isolated buildings. The effect of the local suburban topology on the wind speed and turbulence intensity fields in a given locality is therefore an important determinant of the optimal location of micro-wind turbines. This paper presents a numerical study of above roof wind flow characteristics in three suburban landscapes characterized by houses with different roof profiles, namely: pitched roofs, pyramidal roofs and flat roofs. Computational Fluid Dynamic (CFD) technique has been used to simulate the wind flow in such environments and to find the optimum turbine mounting locations. Results show how the wind flow characteristics are strongly dependent on the profile of the roofs. It is found that turbines mounted on flat roofs are likely to yield higher and more consistent power for the same turbine hub elevation than the other roof profiles. © 2010 Elsevier Ltd.

Jalili R.,University of Wollongong | Razal J.M.,University of Wollongong | Wallace G.G.,University of Wollongong
Journal of Materials Chemistry | Year: 2012

In order to exploit the inherent properties of carbon nanotubes (CNT) in any polymer composite, systematic control of carbon nanotube loading and protocols that mitigate against CNT bundling are required. If such composites are to be rendered in fiber form via wet-spinning, then CNT bundling during the coagulation process must also be avoided. Here we have achieved this by utilizing highly exfoliated single walled carbon nanotubes (SWNT) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonicacid) (PEDOT:PSS) to obtain wet-spinnable composite formulations at various nanotube volume fractions (Vf). The addition of only 0.02 Vf of aggregate-free and individually dispersed SWNT resulted in a significant enhancement of modulus, tensile strength, electrical conductivity and two cell electrode specific capacitance of PEDOT:PSS-SWNT composite fibers to 5.2 GPa, 200 MPa, 450 S cm-1 and 59 F g-1 by the rate of dY/dVf = 89 GPa, dσ/dVf = 3.2 GPa, dS/dVf = 13 300 S cm -1 and 6 folds, respectively. © 2012 The Royal Society of Chemistry.

Chou S.-L.,University of Wollongong | Wang J.-Z.,University of Wollongong | Liu H.-K.,University of Wollongong | Dou S.-X.,University of Wollongong
Journal of Physical Chemistry C | Year: 2011

Li4Ti5O12 microspheres composed of nanoflakes were synthesized within 1 h by a combination of a microwave-assisted hydrothermal method and a microwave postannealing process. The Li 4Ti5O12 microspheres were characterized by X-ray diffraction, Brunauer-Emmett-Teller N2 adsorption, scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy. Sodium carboxymethyl cellulose (CMC) was also investigated as a low-cost green binder. The electrochemical tests, including constant current charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy, demonstrated that the electrode using CMC as binder had better high-rate capability than the one with polyvinylidene fluoride (PVDF) binder. The electrode using CMC and PVDF as binder had the same lithium diffusion coefficient. The electrode using CMC as binder showed much lower charge transfer resistance, lower apparent activation energy, and lower apparent diffusion activation energy than for the electrode using PVDF as the binder. Apparent activation energies of Li 4Ti5O12 microsphere electrodes using CMC and PVDF as binder were calculated to be 26.8 and 33.6 kJ mol-1, respectively. © 2011 American Chemical Society.

Aboutalebi S.H.,University of Wollongong | Chidembo A.T.,University of Wollongong | Salari M.,University of Wollongong | Konstantinov K.,University of Wollongong | And 3 more authors.
Energy and Environmental Science | Year: 2011

We report the synthesis of graphene oxide/multi-walled carbon nanotube (MWCNT) composites employing an alternative and novel approach for possible application as supercapacitor materials in energy storage devices. Integrating these nanostructures resulted in a strong synergistic effect between the two materials consequently leading to a robust and superior hybrid material with higher capacitance compared to either graphene oxide or MWCNTs. Specific capacitances of 251, 85 and 60 F g-1 were obtained for graphene oxide-multi-walled carbon nanotubes, MWCNTs and graphene oxide, respectively, in a potential range from -0.1 to 0.5 V. Most importantly, a 120% increase in capacitance was observed with increasing cycle number at 20 mV s-1. The ease of synthesis and the exceptional electrochemical properties make the use of this nanostructure an attractive, alternative way of designing future supercapacitors in both conventional fields and new emerging areas. © The Royal Society of Chemistry 2011.

Zhang P.,University of Wollongong | Guo Z.P.,University of Wollongong | Huang Y.,Xinjiang University | Jia D.,Xinjiang University | Liu H.K.,University of Wollongong
Journal of Power Sources | Year: 2011

Porous nanowires of Co3O4/Carbon composite have been synthesized by using a simple and inexpensive electrospinning technique. The as-prepared materials were investigated by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the composite have been characterized using cyclic voltammetry and galvanostatic methods. The results show a remarkably improved electrochemical performance in term of reversible capacity, rate capability, and cycling performance. © 2010 Elsevier B.V. All rights reserved.

Hemmerich A.,University of Cape Town | Van Der Merwe W.,Sports Science Orthopaedic Clinic | Batterham M.,University of Wollongong | Vaughan C.L.,University of Cape Town
American Journal of Sports Medicine | Year: 2011

Background: While single-bundle anterior cruciate ligament reconstruction reduces anterior-posterior laxity, studies have demonstrated residual rotational instability. Improved pivot-shift results have been shown with the double-bundle graft; however, no study has compared rotational laxity outcome of these surgical techniques in vivo under quantified, isolated torsional loading. Hypothesis: The anterior cruciate ligament-deficient knee exhibits greater rotational laxity than the contralateral uninjured knee. The double-bundle reconstruction restores rotational joint stability to a greater extent than single-bundle surgery. Study Design: Controlled laboratory study. Methods: Rotational laxity of 32 patients with unilateral anterior cruciate ligament injury was assessed in both knees at full extension and 30° of flexion using a magnetic resonance imaging-compatible torsional loading device. Patients were randomly allocated either a single- or double-bundle reconstruction and reassessed 5 months after surgery. Results: The anterior cruciate ligament-deficient knees demonstrated greater laxity to internal rotational torque in the extended position, but not in the 30° flexed position. No significant differences in rotational laxity were found between single- and double-bundle reconstructions. In extension, excessive internal rotational laxity of injured compared with contralateral knees was reduced by anterior cruciate ligament reconstruction. The single-bundle reconstruction did not affect internal rotation compared with contralateral or preoperative groups. In response to internal rotational torque in the flexed knee position, the double-bundle reconstruction reduced laxity to 10.8° from the pre-operative value of 15.3° (P =.058); postoperative rotation was also significantly less than the contralateral laxity of 16.4° (P =.022). Conclusion: The ruptured anterior cruciate ligament resulted in increased internal rotational laxity only in the extended position. The single-bundle reconstruction did not affect rotational restraint compared with contralateral or preoperative groups. The double-bundle procedure significantly reduced internal laxity in the flexed position when compared with normal. Clinical Relevance: As the anterior cruciate ligament is not the primary restraint to rotation, its contribution to joint stability is limited under isolated torsional load. While the double-bundle graft demonstrates superior rotational constraint, this may be excessive for isolated anterior cruciate ligament rupture. © 2011 The Author(s).

Daeneke T.,Monash University | Uemura Y.,Japan National Institute of Advanced Industrial Science and Technology | Uemura Y.,University of Tsukuba | Duffy N.W.,CSIRO | And 5 more authors.
Advanced Materials | Year: 2012

Solar energy conversion efficiencies of over 4% have been achieved in DSCs constructed with aqueous electrolytes based on the ferricyanide-ferrocyanide redox couple, thereby avoiding the use of expensive, flammable and toxic solvents. This paradigm shift was made possible by the use of a hydrophobic organic carbazole dye. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Osmond B.,University of Wollongong | Osmond B.,Australian National University
Annual Review of Plant Biology | Year: 2014

This is a tale of a career in plant physiological ecology that enjoyed the freedom to address photosynthetic physiology and biochemistry in leaves of plants from diverse environments. It was supported by block funding (now sadly a thing of the past) for research at the Australian National University, by grants during appointments in the United States and in Germany, and by Columbia University. It became a "career experiment" in which long-term, high-trust support for curiosity-driven plant biology in Australia, and at times in the United States, led to surprisingly innovative results. Although the rich diversity of short-term competitive grant opportunities in the United States sustained ongoing research, it proved difficult to mobilize support for more risky long-term projects. A decade after the closure of the Biosphere 2 Laboratory, this article highlights the achievements of colleagues in experimental climate change research from 1998 to 2003. Copyright © 2014 by Annual Reviews.

Hulbert A.J.,University of Wollongong | Kelly M.A.,University of Wollongong | Abbott S.K.,University of Wollongong
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology | Year: 2014

Fatty acids are essential for life because they are essential components of cellular membranes. Lower animals can synthesize all four classes of fatty acids from non-lipid sources, but both omega-6 and omega-3 cannot be synthesized de novo by 'higher' animals and are therefore essential components of their diet. The relationship between normal variation in diet fatty acid composition and membrane fatty acid composition is little investigated. Studies in the rat show that, with respect to the general classes of fatty acids (saturated, monounsaturated and polyunsaturated) membrane fatty acid composition is homeostatically regulated despite diet variation. This is not the case for fatty acid composition of storage lipids, which responds to diet variation. Polyunsaturated fatty acids are important determinants of physical and chemical properties of membranes. They are the substrates for lipid peroxidation and it is possible to calculate a peroxidation index (PI) for a particular membrane composition. Membrane PI appears to be homeostatically regulated with respect to diet PI. Membrane fatty acid composition varies among species and membrane PI is inversely correlated to longevity in mammals, birds, bivalve molluscs, honeybees and the nematode Caenorhabditis elegans. © 2013 Springer-Verlag Berlin Heidelberg.

Paine M.R.L.,University of Wollongong | Barker P.J.,Bluescope Steel Ltd. | Blanksby S.J.,University of Wollongong
Analytica Chimica Acta | Year: 2014

The purpose of this review is to showcase the present capabilities of ambient sampling and ionisation technologies for the analysis of polymers and polymer additives by mass spectrometry (MS) while simultaneously highlighting their advantages and limitations in a critical fashion. To qualify as an ambient ionisation technique, the method must be able to probe the surface of solid or liquid samples while operating in an open environment, allowing a variety of sample sizes, shapes, and substrate materials to be analysed. The main sections of this review will be guided by the underlying principle governing the desorption/extraction step of the analysis; liquid extraction, laser ablation, or thermal desorption, and the major component investigated, either the polymer itself or exogenous compounds (additives and contaminants) present within or on the polymer substrate. The review will conclude by summarising some of the challenges these technologies still face and possible directions that would further enhance the utility of ambient ionisation mass spectrometry as a tool for polymer analysis. © 2013 Elsevier B.V.

Skropeta D.,University of Wollongong | Wei L.,University of Wollongong
Natural Product Reports | Year: 2014

Covering: 2009 to 2013. This review covers the 188 novel marine natural products described since 2008, from deep-water (50->5000 m) marine fauna including bryozoa, chordata, cnidaria, echinodermata, microorganisms, mollusca and porifera. The structures of the new compounds and details of the source organism, depth of collection and country of origin are presented, along with any relevant biological activities of the metabolites. Where reported, synthetic studies on the deep-sea natural products have also been included. Most strikingly, 75% of the compounds were reported to possess bioactivity, with almost half exhibiting low micromolar cytotoxicity towards a range of human cancer cell lines, along with a significant increase in the number of microbial deep-sea natural products reported. This journal is © the Partner Organisations 2014.

Spronk I.,Wageningen University | Kullen C.,HQ Forces Command | Burdon C.,University of Sydney | Burdon C.,University of Wollongong | O'Connor H.,University of Sydney
British Journal of Nutrition | Year: 2014

The present systematic review examined the relationship between nutrition knowledge and dietary intake in adults (mean age ≥ 18 years). Relevant databases were searched from the earliest record until November 2012. Search terms included: nutrition; diet or food knowledge and energy intake; feeding behaviour; diet; eating; nutrient or food intake or consumption. Included studies were original research articles that used instruments providing quantitative assessment of both nutrition knowledge and dietary intake and their statistical association. The initial search netted 1 193 393 potentially relevant articles, of which twenty-nine were eligible for inclusion. Most of them were conducted in community populations (n 22) with fewer (n 7) in athletic populations. Due to the heterogeneity of methods used to assess nutrition knowledge and dietary intake, a meta-analysis was not possible. The majority of the studies (65·5 %: community 63·6 %; athletic 71·4 %) reported significant, positive, but weak (r< 0·5) associations between higher nutrition knowledge and dietary intake, most often a higher intake of fruit and vegetables. However, study quality ranged widely and participant representation from lower socio-economic status was limited, with most participants being tertiary educated and female. Well-designed studies using validated methodologies are needed to clarify the relationship between nutrition knowledge and dietary intake. Diet quality scores or indices that aim to evaluate compliance to dietary guidelines may be particularly valuable for assessing the relationship between nutrition knowledge and dietary intake. Nutrition knowledge is an integral component of health literacy and as low health literacy is associated with poor health outcomes, contemporary, high-quality research is needed to inform community nutrition education and public health policy. © 2014 The Authors.

Taylor N.A.S.,University of Wollongong | Tipton M.J.,University of Portsmouth | Kenny G.P.,University of Ottawa
Journal of Thermal Biology | Year: 2014

Despite previous reviews and commentaries, significant misconceptions remain concerning deep-body (core) and skin temperature measurement in humans. Therefore, the authors have assembled the pertinent Laws of Thermodynamics and other first principles that govern physical and physiological heat exchanges. The resulting review is aimed at providing theoretical and empirical justifications for collecting and interpreting these data. The primary emphasis is upon deep-body temperatures, with discussions of intramuscular, subcutaneous, transcutaneous and skin temperatures included. These are all turnover indices resulting from variations in local metabolism, tissue conduction and blood flow. Consequently, inter-site differences and similarities may have no mechanistic relationship unless those sites have similar metabolic rates, are in close proximity and are perfused by the same blood vessels. Therefore, it is proposed that a gold standard deep-body temperature does not exist. Instead, the validity of each measurement must be evaluated relative to one's research objectives, whilst satisfying equilibration and positioning requirements. When using thermometric computations of heat storage, the establishment of steady-state conditions is essential, but for clinically relevant states, targeted temperature monitoring becomes paramount. However, when investigating temperature regulation, the response characteristics of each temperature measurement must match the forcing function applied during experimentation. Thus, during dynamic phases, deep-body temperatures must be measured from sites that track temperature changes in the central blood volume. © 2014 Elsevier Ltd.

Chen J.,University of Wollongong | Iverson D.,University of Wollongong
Cancer Causes and Control | Year: 2012

Obesity is associated with the increased incidence of colon cancer. Many cancer risk factors have been identified including increased blood levels of insulin, leptin, interleukin-6, interleukin-17, tumor necrosis factoralpha, and decreased blood levels of adiponectin. However, the role of blood levels of estrogen in obesity-associated colon cancer is controversial. Evidence showed that obesity affected men more strongly than women in the carcinogenesis of colon cancer, indicating protective effect of estrogen which is increased in obesity. However, an epidemiological study has also shown that endogenous estradiol level is an independent risk factor for colon cancer, positively associated with colon cancer after normalizing insulin, IGF-1. The controversial opinions may be caused by different effects of ER-alpha and ER-beta. ER-alpha can increase colon cancer cell proliferation and increase cancer incidence. ER-beta has the opposite effect to ER-alpha, and it causes apoptosis of colon cancer cells. The normal colonocytes mainly express ER-beta. Therefore, increased estrogen in obesity may have protective effect via ER-beta in obesity-associated colon cancer. However, with the development of colon cancer, ER-alpha is increased and ER-beta is decreased. In the late stage of colon cancer, estrogen may promote cancer development via ER-alpha. The different effects and expression of ER-alpha and ERbeta may explain the different results observed in several epidemiological studies as well as several animal experiments. Therefore, manipulation of estrogen-caused signal pathways to inhibit ER-alpha and stimulate ER-beta may have preventive and therapeutic effect for obesity-associated colon cancer. © 2012 Springer Science+Business Media B.V.

Seng K.H.,University of Wollongong | Park M.-H.,Ulsan National Institute of Science and Technology | Guo Z.P.,University of Wollongong | Liu H.K.,University of Wollongong | Cho J.,Ulsan National Institute of Science and Technology
Nano Letters | Year: 2013

GeO2/Ge/C anode material synthesized using a simple method involving simultaneous carbon coating and reduction by acetylene gas is composed of nanosized GeO2/Ge particles coated by a thin layer of carbon, which is also interconnected between neighboring particles to form clusters of up to 30 μm. The GeO2/Ge/C composite shows a high capacity of up to 1860 mAh/g and 1680 mAh/g at 1 C (2.1 A/g) and 10 C rates, respectively. This good electrochemical performance is related to the fact that the elemental germanium nanoparticles present in the composite increases the reversibility of the conversion reaction of GeO2. These factors have been found through investigating and comparing GeO2/Ge/C, GeO2/C, nanosized GeO2, and bulk GeO2. © 2013 American Chemical Society.

Magee C.A.,University of Wollongong | Caputi P.,University of Wollongong | Iverson D.C.,University of Wollongong
Sleep Medicine | Year: 2011

Objective: To determine whether sleep duration is associated with self-rated health and quality of life in adults residing in New South Wales, Australia. Methods: Cross-sectional data from the 45 and Up Study were used. Sleep duration, self-rated health, quality of life and other health-related variables were assessed using a self-report questionnaire. Multinomial logistic regression models were used to examine whether sleep duration predicted self-rated health and quality of life. Results: The sample included 63,408 adults aged 45-95. years. After controlling for a range of covariates, <6. h sleep (OR. =1.49, 95% CI 1.31-1.70), 6. h sleep (OR. =1.28, 95% CI 1.17-1.38) and ≥9. h sleep (OR. =1.56, 95% CI 1.46-1.67) were associated with poorer self-rated health. Similarly, <6. h sleep (OR. =1.80, 95% CI 1.57-2.07), 6. h sleep (OR. =1.36, 95% CI 1.24-1.49) and ≥9. h sleep (OR. =1.41, 95% CI 1.30-1.53) were associated with poorer quality of life. Conclusion: Short and long sleep were significantly associated with poor self-rated health and lower quality of life in this large sample of middle aged and older Australian adults. While cross-sectional, these results add weight to recent data emphasising the importance of adequate sleep in physical and mental health. © 2011.

Chandra H.,Indian Agricultural Research Institute | Chambers R.,University of Wollongong
Biometrical Journal | Year: 2016

Survey data often contain measurements for variables that are semicontinuous in nature, i.e. they either take a single fixed value (we assume this is zero) or they have a continuous, often skewed, distribution on the positive real line. Standard methods for small area estimation (SAE) based on the use of linear mixed models can be inefficient for such variables. We discuss SAE techniques for semicontinuous variables under a two part random effects model that allows for the presence of excess zeros as well as the skewed nature of the nonzero values of the response variable. In particular, we first model the excess zeros via a generalized linear mixed model fitted to the probability of a nonzero, i.e. strictly positive, value being observed, and then model the response, given that it is strictly positive, using a linear mixed model fitted on the logarithmic scale. Empirical results suggest that the proposed method leads to efficient small area estimates for semicontinuous data of this type. We also propose a parametric bootstrap method to estimate the MSE of the proposed small area estimator. These bootstrap estimates of the MSE are compared to the true MSE in a simulation study. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Taylor N.A.S.,University of Wollongong
Comprehensive Physiology | Year: 2014

In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation. © 2014 American Physiological Society.

Bradstock R.A.,University of Wollongong
Global Ecology and Biogeography | Year: 2010

Aim: Patterns of fire regimes across Australia exhibit biogeographic variation in response to four processes. Variations in area burned and fire frequency result from differences in the rates of 'switching' of biomass growth, availability to burn, fire weather and ignition. Therefore differing processes limit fire (i.e. the lowest rate of switching) in differing ecosystems. Current and future trends in fire frequency were explored on this basis. Location: Case studies of forests (cool temperate to tropical) and woodlands (temperate to arid) were examined. These represent a broad range of Australian biomes and current fire regimes. Methods: Information on the four processes was applied to each case study and the potential minimum length of interfire interval was predicted and compared to current trends. The potential effects of global change on the processes were then assessed and future trends in fire regimes were predicted. Results: Variations in fire regimes are primarily related to fluctuations in available moisture and dominance by either woody or herbaceous plant cover. Fire in woodland communities (dry climates) is limited by growth of herbaceous fuels (biomass), whereas in forests (wet climates) limitation is by fuel moisture (availability to burn) and fire weather. Increasing dryness in woodland communities will decrease potential fire frequency, while the opposite applies in forests. In the tropics, both forms of limitation are weak due to the annual wet/dry climate. Future change may therefore be constrained. Main conclusions: Increasing dryness may diminish fire activity over much of Australia (dominance of dry woodlands), though increases may occur in temperate forests. Elevated CO2 effects may confound or reinforce these trends. The prognosis for the future fire regime in Australia is therefore uncertain. © 2010 Blackwell Publishing Ltd.

Yue B.,University of Wollongong | Yue B.,Donghua University | Wang C.,University of Wollongong | Ding X.,Donghua University | Wallace G.G.,University of Wollongong
Electrochimica Acta | Year: 2012

Wearable electronics offer the combined advantages of both electronics and fabrics. Being an indispensable part of these electronics, lightweight, stretchable and wearable power sources are strongly demanded. Here we describe a daily-used nylon lycra fabric coated with polypyrrole as electrode for stretchable supercapacitors. Polypyrrole was synthesized on the fabric via a simple chemical polymerization process with ammonium persulfate (APS) as an oxidant and naphthalene-2,6-disulfonic acid disodium salt (Na 2NDS) as a dopant. This material was characterized with FESEM, FTIR, tensile stress, and studied as a supercapacitor electrode in 1.0 M NaCl. This conductive textile could endure 1000 stretching cycles with 100% strain applied, and still retained its electrical conductivity and electrochemical properties. Interestingly, we also found that this material showed improved electrochemical properties when it was being stretched. © 2012 Elsevier Ltd. All rights reserved.

McGregor H.V.,University of Wollongong | Fischer M.J.,Australian Nuclear Science and Technology Organisation | Gagan M.K.,Australian National University | Fink D.,Australian Nuclear Science and Technology Organisation | And 3 more authors.
Nature Geoscience | Year: 2013

Earth's interannual climate variability is dominated by El Niño/Southern Oscillation (ENSO). Palaeoclimate records indicate a lower ENSO variance during the middle Holocene compared with today; however, model simulations have not reproduced the full magnitude of the changes, and whether external forcing drives large intrinsic ENSO variability is therefore a matter of considerable debate. Here we present a 175-year-long, monthly resolved oxygen isotope record, obtained from a Porites coral microatoll located on Kiritimati (Christmas) Island, in the NINO3.4 region of the central equatorial Pacific. Our quantitative record of ENSO variability about 4,300 years ago shows that ENSO variance was persistently reduced by 79%, compared with today, and it exhibits a dominant annual cycle. Season-specific analysis shows that El Niño events were damped during their September-November growth phase, and delayed relative to the climatological year. We suggest that the higher boreal summer insolation at the time strengthened the tropical Pacific zonal winds as well as the gradients in sea surface temperature, and thereby led to an enhanced annual cycle and suppressed ENSO. As the weak ENSO is subject to interdecadal amplitude modulation, we conclude that amplitude modulation is likely to remain robust under altered climates. Our findings show that ENSO is capable of responding to external forcing.

Barnes R.S.K.,University of Queensland | Hamylton S.,University of Wollongong
Estuarine, Coastal and Shelf Science | Year: 2013

The nature of the transition from one contrasting macrobenthic assemblage to another across interfaces between intertidal seagrass and unvegetated sand was investigated in the subtropical Moreton Bay Marine Park, eastern Australia, via six two-dimensional core lattices. The same pattern of transition was manifested in each lattice. Macrofaunal abundance, species density (both observed and estimated total) and assemblage composition did not vary with distance away from the interface within the 0.75m wide marginal bands of each habitat type. Neither were there significant differences in assemblage metrics or composition between the marginal and non-edge regions of either habitat. There were, however, very marked differences in assemblage composition, abundance and species density across the 25cm wide strip on either side of the actual interface, the interacting assemblages reacting symmetrically. All these differences therefore took place over an ecotone distance of only 0.5m at most. Spatial trends in assemblage metrics across the boundary zone were captured accurately by second and third order polynomial regression models. It also appeared that edge effects on individual species within the seagrass were a variable local response not a consistent effect of closeness to the bare sand. © 2013 Elsevier Ltd.

Fergusson C.L.,University of Wollongong | Nutman A.P.,University of Wollongong | Kamiichi T.,Hiroshima University | Hidaka H.,Hiroshima University
Gondwana Research | Year: 2013

The Early Palaeozoic Ross-Delamerian orogenic belt is considered to have formed as an active margin facing the palaeo-Pacific Ocean with some island arc collisions, as in Tasmania (Australia) and Northern Victoria Land (Antarctica), followed by terminal deformation and cessation of active convergence. On the Cambrian eastern margin of Australia adjacent to the Delamerian Fold Belt, island arc and backarc basin crust was formed and is now preserved in the Lachlan Fold Belt and is consistent with a spatial link between the Delamerian and Lachlan orogens. The Delamerian-Lachlan connection is tested with new zircon data. Metamorphic zircons from a basic eclogite sample from the Franklin Metamorphic Complex in the Tyennan region of central Tasmania have rare earth element signatures showing that eclogite metamorphism occurred at ~. 510. Ma, consistent with island arc-passive margin collision during the Delamerian(Tyennan) Orogeny. U-Pb ages of detrital zircons have been determined from two samples of Ordovician sandstones in the Lachlan Fold Belt at Melville Point (south coast of New South Wales) and the Howqua River (western Tabberabbera Zone of eastern Victoria). These rocks were chosen because they are the first major clastic influx at the base of the Ordovician 'Bengal-fan' scale turbidite pile. The samples show the same prominent peaks as previously found elsewhere (600-500. Ma Pacific-Gondwana and the 1300-1000. Ma Grenville-Gondwana signatures) reflecting supercontinent formation. We highlight the presence of ~. 500. Ma non-rounded, simple zircons indicating clastic input most likely from igneous rocks formed during the Delamerian and Ross Orogenies. We consider that the most probable source of the Ordovician turbidites was in East Antarctica adjacent to the Ross Orogen rather than reflecting long distance transport from the Transgondwanan Supermountain (i.e. East African Orogen). Together with other provenance indicators such as detrital mica ages, this is a confirmation of the Delamerian-Lachlan connection. © 2013 International Association for Gondwana Research.

Guo W.D.,University of Wollongong
Computers and Geotechnics | Year: 2013

Elastic-plastic, closed-form solutions were developed recently by the author, to capture the nonlinear response of laterally loaded rigid piles. Presented in compact form, the solutions are convenient to use, and sufficiently accurate despite using only two input parameters of the net limiting force per unit length pu along the pile, and a subgrade modulus k. Nevertheless, piles may be subjected to limited cap-restraints or loading below ground surface, which alter the response remarkably.This paper provides explicit expressions for estimating loading capacity of anchored piles and develops new solutions for lateral piles with cap-rotation by stipulating a constant pu or a linear increasing pu (Gibson pu) with depth. Lateral loading capacity Ho (at the tip-yield state and yield at rotation point state) and maximum bending moment Mm (at the tip-yield state) are presented against loading locations, and in form of the lateral capacity Ho-. Mo (applied moment) locus. The capacity is consistent with available solutions for anchored piles, and caissons with either pu profile, allowing a united approach from lateral piles to anchored piles. The new solutions are also presented in charts to highlight the impact of rotational stiffness of pile-cap on nonlinear response, offering a united approach for free-head piles through fixed-head piles.Several advantages of the solutions are identified against the prevalent p-. y curve based approach. To estimate the key parameter pu, values of the resistance factor Np (=ratio of pile-soil limiting resistance over the undrained shear strength su) are deduced using the current expressions against available normalised pile capacity involving the impact of gapping (between pile and soil), pile movement mode, pile slenderness ratio, inclined loading angle (anchored piles) and batter angles (lateral piles). The Np is characterised by: (i) An increase from 5.6-8.6 to 10.14-11.6, as gapping is eliminated around lateral piles and caissons, and from 1.0-6.1 to 2.8-9.8, as translation is converted into rotation mode of footings. (ii) Similar variations with slenderness ratio between anchors and caissons (without gapping), and among anchors, caissons and pipelines (with gapping). And (iii) A reduction with loading angles (anchors) resembling that with batter angles (piles). © 2013 Elsevier Ltd.

Zhang Z.,University of Wollongong | Nemcik J.,University of Wollongong
Rock Mechanics and Rock Engineering | Year: 2013

Fluid flow through rock joints occurs in many rock engineering applications. As the fluid flows through rough-walled rock fractures, pressure head loss occurs due to friction drag of the wall and local aperture changes. In this study, the friction factor was experimentally investigated by performing flow tests through sandstone fractures with joint roughness coefficient ranging from 5.5 to 15.4 under changing normal stress from 0.5 to 3.5 MPa. According to the experimental results, the friction factor was formulated as a function of two-independent variables - Reynolds number and relative roughness. Relative roughness is defined as the ratio of maximum asperity height to equivalent hydraulic aperture. The experimental results show that the proposed predictor of the friction factor fits the data with a coefficient of determination R 2 > 0.93. Sensitivity analyses indicate that in general, the proposed friction factor increases with the relative roughness of confined fractures. The large difference of friction factor induced by relative roughness occurs when the Reynolds number is lower than unity, especially for Re < 0.2. For Reynolds numbers greater than unity, the difference of friction factor induced by relative roughness is smaller. Inclusion of joint roughness in calculating the friction resistance to fluid flow in rough rock joints and the influence of normal stress to the joints is a major step towards more accurate predictions for fluid flow in underground joint networks. This study provides a significant improvement in fundamental understanding of fluid flow in the jointed strata. © 2012 Springer-Verlag Wien.

Rodrigo M.R.,University of Wollongong
Journal of Forensic Sciences | Year: 2016

The problem of time of death (TOD) estimation by body cooling is revisited by proposing a nonlinear least squares approach that takes as input a series of temperature readings only. Using a reformulation of the Marshall-Hoare double exponential formula and a technique for reducing the dimension of the state space, an error function that depends on the two cooling rates is constructed, with the aim of minimizing this function. Standard nonlinear optimization methods that are used to minimize the bivariate error function require an initial guess for these unknown rates. Hence, a systematic procedure based on the given temperature data is also proposed to determine an initial estimate for the rates. Then, an explicit formula for the TOD is given. Results of numerical simulations using both theoretical and experimental data are presented, both yielding reasonable estimates. The proposed procedure does not require knowledge of the temperature at death nor the body mass. In fact, the method allows the estimation of the temperature at death once the cooling rates and the TOD have been calculated. The procedure requires at least three temperature readings, although more measured readings could improve the estimates. With the aid of computerized recording and thermocouple detectors, temperature readings spaced 10-15 min apart, for example, can be taken. The formulas can be straightforwardly programmed and installed on a hand-held device for field use. © 2016 American Academy of Forensic Sciences.

Yeh C.H.,University of New South Wales | Zhang G.,University of Wollongong
International Journal of Mineral Processing | Year: 2013

The commercial technologies for aluminium production include production of alumina from bauxite and smelting of alumina to produce aluminium. The current technology is energy intensive, and a major source of greenhouse gas emissions and harmful fluoride emissions. Carbothermal reduction of bauxite is a promising alternative technology for aluminium and aluminoalloy production. Western Australia and Queensland bauxite ores were carbothermally reduced in steps in argon. Experiments were performed in a high temperature vertical tube furnace, and the off-gas composition was monitored using an infra-red gas analyser. The phase composition of reduced samples was characterised by XRD. Oxygen and carbon contents in reduced samples were determined by LECO analysers. The morphology of the surface and intersections was observed by SEM. The chemical compositions of the phases in the reduced samples were detected by EDS. The results of this study have proved the concept of stepwise reduction of bauxite ores in solid state by appropriate control of reduction temperature. Below 1100 C, only iron oxides were reduced to metallic iron. A ferroalloy phase was formed at 1200 C and above. The products in the bauxites reduced to 1600 C include a ferroalloy of silicon and aluminium, carbides of titanium, silicon and aluminium, and unreacted alumina. © 2013 Elsevier B.V.

Saintilan N.,NSW Office of Environment and Heritage | Rogers K.,University of Wollongong | Mazumder D.,Australian Nuclear Science and Technology Organization | Woodroffe C.,University of Wollongong
Estuarine, Coastal and Shelf Science | Year: 2013

Estimates of carbon store and carbon accumulation rate in mangrove and saltmarsh are beset by issues of scale and provenance. Estimates at a site do not allow scaling to regional estimates if the drivers of variability are not known. Also, carbon accumulation within soils provides a net offset only if carbon is derived in-situ, or would not otherwise be sequestered. We use a network of observation sites extending across 2000km of southeastern Australian coastline to determine the influence of geomorphic setting and coastal wetland vegetation type on rates of carbon accumulation, carbon store and probable sources. Carbon accumulation above feldspar marker horizons over a 10-year period was driven primarily by tidal range and position in the tidal frame, and was higher for mangrove and saltmarsh dominated by Juncus kraussii than for other saltmarsh communities. The rate of carbon loss with depth varied between geomorphic settings and was the primary determinant of carbon store. A down-core enrichment in δ13C was consistent with an increased relative contribution of mangrove root material to soil carbon, as mangrove roots were found to be consistently enriched compared to leaves. We conclude that while surface carbon accumulation is driven primarily by tidal transport of allocthonous sediment, in-situ carbon sequestration is the dominant source of recalcitrant carbon, and that mangrove and saltmarsh carbon accumulation and store is high in temperate settings, particularly in mesotidal and fluvial geomorphic settings. © 2013 Elsevier Ltd.

Indraratna B.,University of Wollongong | Hussaini S.K.K.,University of Wollongong | Vinod J.S.,University of Wollongong
Geotextiles and Geomembranes | Year: 2013

Ballast being an unbounded granular medium spreads laterally when subjected to high-frequency cyclic loading. To reduce lateral movement of ballast and to optimize track performance, rail tracks can be reinforced with geogrid. In this study, a novel large-scale process simulation test (PST) apparatus that can capture the lateral strain variation upon loading is described. Laboratory tests were conducted to explore the deformation and degradation response of both unreinforced and reinforced ballast under high-frequency cyclic loading. Fresh Latite basalt having an average particle size (D50) of 35mm, and geogrids with different aperture sizes were tested. The laboratory experimental results reveal that the ballast deformation (both lateral and vertical) and the breakage during cyclic loading are influenced by the geogrid type and its placement location. Moreover, the lateral strain profiles along the ballast depth have been measured and the geogrid influence zone (GIZ), defined as the distance to which the effect of geogrid in arresting the lateral displacement of ballast exists, has been determined. The GIZ is found to vary from 160mm (4.60D50) to 225mm (6.45D50) depending on the location of the geogrid. In addition, the optimum geogrid position in the track has been identified to be 65mm above the subballast. The test results also exemplify the ability of geogrid to arrest lateral displacement of ballast, reduce settlement and minimize particle degradation under high-frequency cyclic loading. © 2013 Elsevier Ltd.

Indraratna B.,University of Wollongong | Tennakoon N.,University of Wollongong | Nimbalkar S.,University of Wollongong | Rujikiatkamjorn C.,University of Wollongong
Geotechnique | Year: 2013

Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail ballast of volcanic origin, commonly used in Australia. Consolidated drained triaxial tests were conducted under three different levels of confining pressure and varying degrees of clay fouling. Stress-strain degradation characteristics are discussed in detail. This paper also describes the non-linear strength envelope and a novel empirical relationship to capture the detrimental effects of clay fouling on the performance of ballasted tracks.

Kane-Maguire L.A.P.,University of Wollongong | Wallace G.G.,University of Wollongong
Chemical Society Reviews | Year: 2010

This critical review describes the preparation and properties of a relatively new class of chiral macromolecules, namely chiral conducting polymers. It focuses in particular on examples based on polypyrrole, polythiophene and polyaniline. They possess remarkable properties, combining not only chirality with electrical conductivity but also the ability to undergo facile redox and pH switching. These unique properties have opened up a range of exciting new potential applications, including as chiral sensors, as novel stationary phases for chiral separations, and as chiral electrodes for electrochemical asymmetric synthesis (153 references). © 2010 The Royal Society of Chemistry.

Shenouda A.Y.,Central Metallurgical Research and Development Institute | Liu H.K.,University of Wollongong
Journal of the Electrochemical Society | Year: 2010

Lithium copper tin silicon oxide was prepared from their precursor compounds using Brij surfactant and different sources of Si such as SiO 2, SiC, and Si3 N4. A hydrothermal autoclave method was used in the first stage of the preparation. X-ray diffraction characterization revealed that the crystal structures of these compounds were tetragonal. Scanning electron microscope investigation showed that the particle size morphology of Li2CuSnSiO6 is larger than that of Li2CuSnO4. Electrochemical impedance spectroscopy explained that the cell prepared from the Li2CuSnSiO6 electrode using Si3N4 precursor had a lower charge-transfer resistance (38 ω) than that of Li2CuSnO 4 (Rct =2936 ω). Furthermore, the reversible specific discharge capacity of the Li2CuSnSiO6 cell was 870 mAh/g in comparison with 780 mAh/g for the Li2CuSnO4 cell after 100 cycles. © 2010 The Electrochemical Society.

Wang X.-L.,University of Wollongong | Dou S.X.,University of Wollongong | Zhang C.,University of Wollongong
NPG Asia Materials | Year: 2010

Electrons carry both charge and spin. The processing of information in conventional electronic devices is based only on the charge of the electrons. Spin electronics, or spintronics, uses the spin of electrons, as well as their charge, to process information. Metals, semiconductors and insulators are the basic materials that constitute the components of electronic devices, and these have been transforming all aspects of society for over a century. In contrast, magnetic metals, half-metals, magnetic semiconductors, dilute magnetic semiconductors and magnetic insulators are the materials that will form the basis for spintronic devices. Materials having a zero-energy band gap are a special class of these materials that exhibit some fascinating and superior electronic properties compared to materials with a non-zero energy gap. This article reviews a range of materials with zero-gap band structures, focusing on materials with quadratic and linear symmetrical dispersions, disorder-induced linear dispersions, asymmetrical linear dispersions and topological insulating states. These materials all have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors. © 2011 Tokyo Institute of Technology.

Chou S.-L.,University of Wollongong | Pan Y.,University of Wollongong | Wang J.-Z.,University of Wollongong | Liu H.-K.,University of Wollongong | Dou S.-X.,University of Wollongong
Physical Chemistry Chemical Physics | Year: 2014

Li and Na batteries are very important as energy storage devices for electric vehicles and smart grids. It is well known that, when an electrode is analysed in detail, each of the components (the active material, the conductive carbon, the current collector and the binder) makes a portion of contribution to the battery performance in terms of specific capacity, rate capability, cycle life, etc. However, there has not yet been a review on the binder, though there are already many review papers on the active materials. Binders make up only a small part of the electrode composition, but in some cases, they play an important role in affecting the cycling stability and rate capability for Li-ion and Na-ion batteries. Poly(vinylidene difluoride) (PVDF) has been the mainstream binder, but there have been discoveries that aqueous binders can sometimes make a battery perform better, not to mention they are cheaper, greener, and easier to use for electrode fabrication. In this review, we focus on several kinds of promising electrode materials, to show how their battery performance can be affected significantly by binder materials: anode materials such as Si, Sn and transitional metal oxides; cathode materials such as LiFePO4, LiNi1/3Co1/3Mn1/3O2, LiCoO2 and sulphur. © the Partner Organisations 2014.

Indraratna B.,University of Wollongong | Athukorala R.,University of Wollongong | Vinod J.,University of Wollongong
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2013

This paper describes a theoretical model to capture the rate of erosion of a silty sand based on the principle of conservation of energy. Erosion is considered to begin when the interparticle bonds between grains are broken by hydrodynamic stresses exerted on the soil particles. These detached particles are then suspended and transported by the flow of eroding fluid. It is further assumed that once the particles are fully suspended and have reached the flow velocity, resettlement does not take place. Stabilization of soil particles because of lignosulfonate (LS) treatment is represented by the increased strain energy required to break the interparticle bonds. The equation proposed in this study is based on the shear stress-strain characteristics, mean flow velocity, mean particle diameter, and the packing arrangement of particles. The result of the proposed study is presented in the form of erosion rate versus the hydraulic shear stress. The model is validated with a series of laboratory erosion tests using the Process Simulation Apparatus for Internal Crack Erosion (PSAICE) for different percentages of LS. The model results are in good agreement with the experimental observations. © 2013 American Society of Civil Engineers.

Guo W.D.,University of Wollongong
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2013

The response of a laterally loaded pile is normally dominated by the limiting force per unit length profile (LFP, pu) mobilized along the pile to the depth of the plastic zone (e.g., maximum slip depth, max xp) and depends on pile-soil relative rigidity (via the subgrade modulus of elasticity k). The values of pu and the shear modulus (G, thus k) were deduced extensively against the measured response of 32 and 20 piles tested in situ in clay and sand, respectively. In this paper, simplified closed-form solutions are presented for the design of laterally loaded piles. The parameters of the pu and the G obtained previously are utilized to examine the impact of loading eccentricity on piles and to assess the validity of existing pu-profiles. Expressions are also explored and provided regarding determinations of the pu-profiles, the modulus of the subgrade reaction k (via G), the ranges of the plastic zone (max xp), and the depth of elastic influence (via the critical pile length Lcr), along with the correlations between the shear modulus of soil G and undrained shear strength (su) and/or the standard penetration test blow count (N). It is noted that the popularly adopted LFPs (such as Matlock's LFP, Reese's LFP, and American Petroleum Institute code methods) are not sufficiently accurate for 60-85% of the 52 piles investigated herein, especially for those with a diameter > 1.5 m. © 2013 American Society of Civil Engineers.

Zhang W.,University of Wollongong | Sherrell P.,University of Wollongong | Minett A.I.,University of Wollongong | Razal J.M.,University of Wollongong | Chen J.,University of Wollongong
Energy and Environmental Science | Year: 2010

Catalyst support materials exhibit great influence on the performance and durability of proton exchange membrane (PEM) fuel cells. This minireview article summarises recent developments into carbon nanotube-based support materials for PEM fuel cells, including the membrane electrode assembly (MEA). The advantages of using CNTs to promote catalyst performance and stability, a perspective on research directions and strategies to improve fuel cell performance and durability are discussed. It is hoped that this minireview will act as a conduit for future developments in catalyst supports and MEA design for PEM fuel cells. © The Royal Society of Chemistry 2010.

Li B.,University of Wollongong | Roberts R.G.,University of Wollongong | Jacobs Z.,University of Wollongong
Quaternary Geochronology | Year: 2013

The infrared (IR) stimulated luminescence (IRSL) and post-IR IRSL (pIRIR) signals from K-feldspar can, for convenience, be divided into two components, bleachable and 'non-bleachable', where the latter corresponds to the 'residual' signal observed in sunlight-bleached samples. In this paper, we examine the non-bleachable component of IRSL of K-feldspar for several sedimentary samples from across Eurasia. We observed a large variability in the residual doses among these samples after prolonged exposure to sunlight. By employing multiple elevated temperature (MET) IR stimulations at 50-300°C, we show that the residual dose increases systematically with stimulation temperature, attaining values as high as ~50Gy at 300°C, even after several hours to tens of hours of exposure to unfiltered sunlight. We examined two samples in detail and found that the bleachable and non-bleachable components produced different dose response curves. Pulse annealing studies showed that the non-bleachable component is more stable than the bleachable component, suggesting that a preheat procedure cannot eliminate the non-bleachable component. Additional experiments revealed that the non-bleachable component is dose dependent. Owing to this dose dependency, we demonstrate mathematically and empirically that the simple subtraction of a residual dose from the measured equivalent dose (De) - which is the most common approach employed (if any residual dose is subtracted at all) - will result in underestimation of the actual De. We present a method to correct for the dose dependency of the residual dose, which can improve the accuracy of either MET-pIRIR or pIRIR age estimates for samples in which the non-bleachable component represents a significant fraction of the measured signals. © 2013 Elsevier B.V.

Yu H.,University of Wollongong | Griffiths T.M.,University of Wollongong
Physical Chemistry Chemical Physics | Year: 2014

Glycoside hydrolase families 33 and 34 catalyse the hydrolysis of terminal sialic acid residues from sialyl oligosaccharides and glycoconjugates with a net retention of the stereochemistry at the anomeric centre. It is generally believed that the conserved aspartic acid in the active site functions as a general acid to protonate the hydroxyl group of the departing aglycone during glycosylation, and then as a general base to facilitate the nucleophilic attack of the water molecule on the intermediate state during the deglycosylation reaction. The dual role of the general acid/base places specific demands upon its protonation state, and thus pKa values. However, it is not fully understood how this catalytic residue can achieve such pKa cycling during catalysis. We present both MM and combined QM/MM simulations to characterise the pKa values of the proposed catalytic general acid/base in the glycoside hydrolase families 33 and 34. Collectively, our study suggests that the binding of anionic substrates and the local solvation properties along with the neutralisation of the nearby glutamic acid upon glycosylation modulate the electrostatic environment around the general acid/base to achieve its proper protonation states. © 2014 the Owner Societies.

Heitor A.,University of Wollongong | Indraratna B.,University of Wollongong | Rujikiatkamjorn C.,University of Wollongong
Canadian Geotechnical Journal | Year: 2013

Small-strain behavior is a key indicator for assessing the performance of compacted fills. Compaction conditions, i.e., initial moisture content and applied energy, govern compaction effectiveness and thus, the structure and matric suction of compacted soil. This paper presents an experimental study of the small-strain behavior of compacted silty sand prepared with different compaction conditions. Specimens with varying initial moisture contents and compaction energies were tested with bender elements to determine the small-strain shear modulus (G0), while the post-compaction matric suction was measured using the filter paper method and tensiometer. The experimental data suggest a pronounced relationship between G0 and the degree of saturation (Sr) of the as-compacted soil specimens. X-ray computed tomography (CT) scans were performed to examine structural changes of selected specimens upon compaction. The laboratory results are also examined in light of common end-product specifications, which show that it is beneficial to compact the soil slightly dry of optimum moisture content from the modulus point of view.

Abdullah M.A.,University of Wollongong | Muttaqi K.M.,University of Wollongong | Agalgaonkar A.P.,University of Wollongong
Renewable Energy | Year: 2015

Electricity generation using renewable energy generation technologies is one of the most practical alternatives for network planners in order to achieve national and international Greenhouse Gas (GHG) emission reduction targets. Renewable Distributed Generation (DG) based Hybrid Energy System (HES) is a sustainable solution for serving electricity demand with reduced GHG emissions. A multi-objective optimisation technique for minimising cost, GHG emissions and generation uncertainty has been proposed in this paper to design HES for sustainable power generation and distribution system planning while considering economic and environmental issues and uncertainty in power availability of renewable resources. Life cycle assessment has been carried out to estimate the global warming potential of the embodied GHG emissions from the electricity generation technologies. The uncertainty in the availability of renewable resources is modelled using the method of moments. A design procedure for building sustainable HES has been presented and the sensitivity analysis is conducted for determining the optimal solution set. © 2014 Elsevier Ltd.

Bailey R.C.,University of Wollongong | Grenyer B.F.S.,University of Wollongong
Harvard Review of Psychiatry | Year: 2013

Background: A major feature of personality disorders is significant impairment in interpersonal functioning, which may create challenges in close relationships. This article aims to systematically review the experience of carers of persons with personality disorders. Method: The PRISMA systematic review method was followed, and empirical studies written in English, published between 1996 and 2011, and cited in major electronic databases were searched. Studies meeting the following selection criteria were included: (1) carers or families of persons with personality disorders; (2) intervention involving the carers or families; (3) burden or related construct used. Studies were required to meet either criteria 1 and 3 or criteria 2 and 3. Reference lists were scanned, and experts were consulted for further studies. Results: Six studies met inclusion criteria, representing data on 465 carers. Five of the six studies focused on carers of persons with borderline personality disorder. The findings indicated that carers experience elevated objective and subjective burden, grief, impaired empowerment, and mental health problems, including depression and anxiety. Scores on objective and subjective burden were half a standard deviation above the mean compared to carers of inpatients with other serious mental illnesses. Conclusions: This study is the first to report data on a large, aggregated sample of carers of persons with personality disorders. Significant gaps in the literature remain, and it is recommended that future research focus on the burden and support needs of carers of persons across different personality disorders, that attention be paid to the gender balance of patients, and that data be reported in a way to allow meta-analysis. © 2013 President and Fellows of Harvard College.

Yu P.,University of Wollongong
Electronic Journal of Health Informatics | Year: 2012

This paper reviews the development of aged care IT innovations in Australia in the past decade. It starts with a brief description of the establishment of the Aged Care eConnect project by the Commonwealth Department of Health and Ageing to promote aged care IT. This is followed by a snapshot of the aged care associations' and research groups' promotional activities. The roles of government, industry peak bodies, aged care providers, aged care IT application providers and researchers for the diffusion of aged care IT innovations are analysed.

Zhao J.,University of Wollongong | Jiang Z.,University of Wollongong | Lee C.S.,Pohang University of Science and Technology
Materials and Design | Year: 2013

In the present work, the effects of hot forging and post-forging heat treatment on the impact fracture toughness and tensile properties of a microalloyed cast steel were investigated. Mechanical tests were used to evaluate the room temperature impact fracture toughness and tensile properties of the steel. The resulting microstructures were analysed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The extraction replica technology was used to investigate the characterisation of complex precipitates formed during heat treatment. The obtained results showed that the coarse-grained microstructure of the forged specimen was significantly refined after post-forging heat treatment. Presence of complex precipitates had a favourable effect on the formation of refined austenite grains, and consequently refined final microstructure. Hot forging was beneficial to enhance the impact fracture toughness and tensile properties of the microalloyed cast steel. After 920. °C-treatment followed by air cooling, the impact energy of the forged specimen was significantly increased from 19.3 to 208.3. J, and further enhancement in tensile properties was obtained. The enhanced impact fracture toughness and tensile properties of the microalloyed cast steel after hot forging and post-forging heat treatment were closely related to the refined and homogenised ferritic-pearlitic microstructure. © 2012 Elsevier Ltd.

Hastie D.B.,University of Wollongong
Chemical Engineering Science | Year: 2013

The coefficient of restitution (COR) is one of the fundamental particle properties needed in the setup of discrete element modelling (DEM) simulations. The more accurate the input parameters for DEM are, the more accurate the resulting simulation outputs will be. The determination of the COR for spherical particles is a relatively straightforward process, however, when considering irregular shaped particles, the unpredictable behaviour of particles after impact makes the analysis of the COR more involved. This paper presents an experimental method to determine the COR using high-speed video in a three-dimensional environment to capture the random behaviour of irregular shaped polyethylene pellets. The angular displacement and angular velocity of particles are experimentally determined and the process used to determine the coefficient of restitution using various equations is presented. © 2013 Elsevier Ltd.

Moulton S.E.,Intelligent Polymer Research Institute | Wallace G.G.,University of Wollongong
Journal of Controlled Release | Year: 2014

Drug delivery from 3-dimensional (3D) structures is a rapidly growing area of research. It is essential to achieve structures wherein drug stability is ensured, the drug loading capacity is appropriate and the desired controlled release profile can be attained. Attention must also be paid to the development of appropriate fabrication machinery that allows 3D drug delivery systems (DDS) to be produced in a simple, reliable and reproducible manner. The range of fabrication methods currently being used to form 3D DDSs include electrospinning (solution and melt), wet-spinning and printing (3-dimensional). The use of these techniques enables production of DDSs from the macro-scale down to the nano-scale. This article reviews progress in these fabrication techniques to form DDSs that possess desirable drug delivery kinetics for a wide range of applications. © 2014 Elsevier B.V.

Sampson J.A.,University of Wollongong | Donohoe A.,Fire and Rescue NSW | Groeller H.,University of Wollongong
Journal of Science and Medicine in Sport | Year: 2014

Objectives: Mechanical and neuromuscular benefits arise during ballistic stretch-shortening cycle muscle activation, yet resistance training regimens are typically non-ballistic, and in contrast to ballistic movement, require a concentric deceleration phase. Design: Twelve healthy males performed a unilateral, six repetition maximum non-ballistic elbow flexion-extension task during; (i) rapid shortening (RS), (ii) stretch-shortening cycle (SSC) and (iii) a 2-s eccentric and 2-s concentric control (C). Methods: A load cell and shaft encoder recorded respectively force and velocity. Surface electromyographic root mean square amplitude (EMGRMS) was recorded in the biceps and triceps brachii, and is reported as the relative (%) difference, normalised to control (C). Results: The average lengthening and shortening velocity of SSC (0.57±0.03ms-1; 0.43±0.02ms-1) was significantly greater than RS (0.22±0.01ms-1; 0.35±0.01ms-1), and C (0.17±0.00ms-1, 0.20±0.00ms-1). Peak eccentric force was increased (P<0.0001) and in the first 5% of concentric movement during SSC, in the first and last repetitions respectively (194.7±8.4N, 164.1±7.5N) when compared to RS (163.3±8.9N, 152.4±7.5N) and C (155.9±8.5N, 152.2±8.7N). Eccentric EMGRMS in the biceps brachii was significantly increased during the first three and final repetitions of SSC (31.9±10.9%, 46.7±12.4, 69.3±13.6%, 92.0±16.4%), and the third and last repetitions of RS (35.9±7.4%, 50.3±10.9%), compared to C (0.00%, 15.8±4.0%, 23.7±4.1%, 39.2±8.6%). Conclusions: In the current study, eccentric limb velocity potentiated eccentric and concentric force, concentric velocity, and eccentric EMG amplitude during non-ballistic exercise. © 2013.

Klair D.K.,University of Wollongong | Chin K.-W.,University of Wollongong | Raad R.,University of Wollongong
IEEE Communications Surveys and Tutorials | Year: 2010

RFID technologies have revolutionized the asset tracking industry, with applications ranging from automated checkout to monitoring the medication intakes of elderlies. In all these applications, fast, and in some cases energy efficient, tag reading is desirable, especially with increasing tag numbers. In practice, tag reading protocols face many problems. A key one being tag collision, which occurs when multiple tags reply simultaneously to a reader. As a result, an RFID reader experiences low tag reading performance, and wastes valuable energy. Therefore, it is important that RFID application developers are aware of current tag reading protocols. To this end, this paper surveys, classifies, and compares state-of-the-art tag reading protocols. Moreover, it presents research directions for existing and future tag reading protocols. © 2005 IEEE.

Stefanic N.,University of Wollongong | Caputi P.,University of Wollongong | Iverson D.C.,University of Wollongong
Supportive Care in Cancer | Year: 2014

Purpose: Physical symptoms associated with breast cancer and its treatment can substantially interfere with functional outcomes and quality of life. The present study seeks to delineate the relationship between physical symptom burden and cancer-related goal interference in early-stage breast cancer patients. Methods: Self-report questionnaires were administered to 43 eligible female patients at four time-points in the 6 months following surgery for early-stage breast cancer. Physical symptoms, cancer-related goal interference, and psychological distress were assessed at each time-point. K-means cluster analysis and independent sample t tests evaluated the relationships of interest. Results: Women with a higher physical symptom burden experienced significantly higher goal interference and psychological distress than those with a lower burden at multiple time-points following surgery. Conclusions: This study provides preliminary evidence that physical symptom burden can interfere with important goal pursuit in early-stage breast cancer patients. Breast cancer survivors with ongoing challenging symptoms may require targeted psychosocial support to cope with possible goal interference and associated distress. © 2013 Springer-Verlag.

Whitehead A.,Lancaster University | Beck E.J.,University of Wollongong | Tosh S.,Agriculture and Agri Food Canada | Wolever T.M.S.,University of Toronto
American Journal of Clinical Nutrition | Year: 2014

Background: Health claims regarding the cholesterol-lowering effect of soluble fiber from oat products, approved by food standards agencies worldwide, are based on a diet containing ≥3 g/d of oat b-glucan (OBG). Given the number of recently published randomized controlled trials (RCTs), it is important to update the findings of previous meta-analyses.Objective: The objective was to quantify the effect of >3 g OBG/d on serum cholesterol concentrations in humans and investigate potential effect modifiers.Design: A meta-analysis was performed on 28 RCTs comparing ≥3 g OBG/d with an appropriate control. Systematic searches were undertaken in PubMed, AGRICOLA, and Scopus between 1 January 1966 and 6 June 2013, plus in-house study reports at CreaNutrition AG. Studies were assessed with regard to inclusion/exclusion criteria, and data were extracted from included studies by reviewers working independently in pairs, reconciling differences by consensus. Estimates of the mean reduction in serum cholesterol from baseline between the OBG and control diets were analyzed by using random-effects meta-analysis models and meta-regression.Results: OBG in doses of >3 g/d reduced low-density lipoprotein (LDL) and total cholesterol relative to control by 0.25 mmol/L (95% CI: 0.20, 0.30; P , 0.0001) and 0.30 mmol/L (95% CI: 0.24, 0.35; P , 0.0001), respectively, with some indication of heterogeneity (P = 0.13 and P = 0.067). There was no significant effect of OBG on high-density lipoprotein (HDL) cholesterol or triglycerides and no evidence that dose (range across trials: 3.0-12.4 g/d) or duration of treatment (range: 2-12 wk) influenced the results. LDL cholesterol lowering was significantly greater with higher baseline LDL cholesterol. There was a significantly greater effect for both LDL and total cholesterol in subjects with diabetes compared with those without (although based on few studies).Conclusions: Adding >3 g OBG/d to the diet reduces LDL and total cholesterol by 0.25 mmol/L and 0.30 mmol/L, respectively, without changing HDL cholesterol or triglycerides. © 2014 American Society for Nutrition.

Anurans exhibit a greater reproductive diversity than any other vertebrate order. However, studies investigating the effects of the external fertilisation environment on fertilisation success are limited to aquatic-breeding species. This study investigated the effects of fertilisation medium osmolality, sperm concentration and short-term oocyte storage on fertilisation success in a terrestrial-breeding anuran, Pseudophryne guentheri. Split-clutch experimental designs were used to determine optimal fertilisation conditions. To determine the effect of short-term sperm storage, sperm viability was assessed using fluorescence microscopy and percentage sperm motility and velocity quantified with a computer-assisted sperm analysis system. Fertilisation success was highest in media ranging in osmolality from 25mOsmkg-1 to 100mOsmkg-1, representing a broader range and higher optimal osmolality than previously reported for aquatic breeders. High rates of fertilisation (>75%) were achieved in relatively low sperm concentrations (2.5×104mL-1). Oocytes stored in isotonic solutions (200mOsmkg-1) retained fertilisation capacity (32%) after 8h of storage, while sperm suspensions maintained motility (≥26%) for 13 days. Additional studies on terrestrial-breeding anurans will be required to ascertain whether the optimal fertilisation conditions reported reflect adaptations to achieve fertilisation in a terrestrial environment. © 2013 CSIRO.

Price O.,University of Wollongong | Bradstock R.,University of Wollongong
PLoS ONE | Year: 2013

Previous investigations into the factors associated with house loss in wildfires have focused on the house construction and its immediate environment (e.g. gardens). Here, we examine how nearby native forest and other houses can influence house loss. Specifically, we used a sample of 3500 houses affected by the Victorian bushfires of February 7th 2009 to explore how the amount of forest, proportion of forest burned by crown fire and the number of nearby houses affected house loss and how far from the house this influence was exerted. These fires were the most destructive in Australian history and so represent the extreme of fire risk. Using generalized linear modeling we found that the probability of house loss increased with forest extent and the proportion burnt by crown fire and this relationship was strongest for forest measured 1 km from the houses. Houses were more likely to be destroyed if there were other houses within 50 m and if they were on a slope. A model containing these variables predicted house loss with 72% accuracy. Our findings have three important implications: i) management to change the occurrence of crown fire will be effective in reducing house loss; ii) this management may be required up to 1 km away from houses in some situations (a much larger zone than is currently used); iii) high density of houses may increase risk of loss. Given the potentially large width of this management zone and the hazard from nearby houses, it may be more sensible to concentrate on modification of buildings to reduce their vulnerability. © 2013 Price et al.

Tu K.L.,University of Wollongong | Chivas A.R.,University of Wollongong | Nghiem L.D.,University of Wollongong
Desalination | Year: 2013

Boron rejection by nanofiltration (NF) and reverse osmosis (RO) membranes in the presence of glycerol, mannitol and sorbitol was investigated as a function of feed solution pH and boron:polyol molar ratio. In the presence of polyols, significant boron rejection improvement was obtained and the extent of the impact was directly related to the stability constant of the boron-polyol complex. Polyols could complex with boron in either the boric acid or borate anion forms; however the complexation between polyol and boric acid appeared to be incomplete. With and without the presence of polyols, boron rejection was strongly pH dependent. The increase in boron rejection due to polyol addition was higher for the NF membrane compared to the RO membrane. A boron:polyol molar ratio of 1:1 appeared to be adequate. The presence of polyols did not cause any observable membrane fouling. Results reported here suggest that the addition of polyols could allow NF membranes to be effectively used for boron removal. © 2012.

Hadi M.N.S.,University of Wollongong | Tran T.M.,University of Wollongong
Construction and Building Materials | Year: 2014

This paper introduces a new method for retrofitting reinforced concrete (RC) exterior beamcolumn T joints, using segmental circular concrete covers together with Carbon Fibre Reinforced Polymer (CFRP). Two RC T connections without transverse reinforcement at the joints were cast and tested. The first connection (Strengthened specimen, TS) was glued with the concrete covers around the column at the joint area to modify it from a square to a circular section and then it was wrapped with CFRP to strengthen its capacity. A load was first applied on the second connection (Repaired specimen, TR) to cause a serious failure then it was repaired. The repair scheme of the second connection was identical to the first connection. Results of testing the two connections have shown that the performances of both the strengthened and the repaired connections were improved significantly. The glued concrete covers worked well with the existing concrete to resist shear load. Moreover, the wrap on the modified circular sections helped in increasing the effectiveness of CFRP by increasing the confinement effect on the concrete and reduce the possibility of debonding of CFRP at the joints. © 2014 Elsevier Ltd. All rights reserved.

Pham T.M.,University of Wollongong | Hadi M.N.S.,University of Wollongong
Construction and Building Materials | Year: 2014

This study establishes a confinement model for FRP confined normal- and high-strength concrete circular columns. A new column parameter was suggested for estimating the compressive strength of FRP confined concrete. The proposed model is able to predict the ultimate condition of FRP confined concrete columns that have similar unconfined concrete strength and confining pressure but significant differences in the jacket stiffness. The proposed model was then verified using a database of 574 FRP confined concrete circular columns with different types of FRP. This database covers unconfined concrete strength between 15 MPa and 170 MPa and specimens with a diameter ranging from 51 mm to 406 mm. Furthermore, this database includes specimens with a variety of FRP types: carbon FRP (CFRP), glass FRP, high-modulus carbon FRP, aramid FRP (AFRP), CFRP tube, ultra-high-modulus CFRP tube, and AFRP tube. Finally, the model's prediction fits the experimental results very well by verifying the proposed model with the extensive database. © 2014 Elsevier Ltd. All rights reserved.

Li W.,University of Wollongong | Chou S.-L.,University of Wollongong | Wang J.-Z.,University of Wollongong | Kim J.H.,University of Wollongong | And 2 more authors.
Advanced Materials | Year: 2014

Sn4+xP3 @ amorphous Sn-P composites are a promising cheap anode material for sodium-ion batteries with high capacity (502 mA h g-1 at a current density of 100 mA g-1), long cycling stability (92.6% capacity retention up to 100 cycles), and high rate capability (165 mA h g-1 at the 10C rate). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Al-Rifai J.H.,University of Wollongong | Khabbaz H.,University of Technology, Sydney | Schafer A.I.,University of Edinburgh
Separation and Purification Technology | Year: 2011

A detailed investigation was carried out to evaluate the occurrence, persistence and fate of a range of micropollutants at different processing points at a full-scale water recycling plant (WRP) in Queensland, Australia. The WRP, which combines an advanced water treatment plant (AWTP) with a wastewater treatment plant (WWTP), produces high quality recycled water for industrial users. The concentrations of 11 pharmaceuticals from various therapeutic categories and two endocrine disrupting chemicals were examined in full-scale microfiltration and reverse osmosis membrane facilities. Salicylic acid was the most abundant analyte in the WWTP influent, with a concentration range of 11-38 μg/L, followed by bisphenol A with concentrations ranging from 6 to 23 μg/L. The concentration of all analytes decreased on average by one order of magnitude following primary and secondary treatment. Gemfibrozil, primidone and carbamazepine were found to have lower removal efficiencies (74-78%) than other compounds during these stages, which could indicate lower biodegradability. The microfiltration and reverse osmosis systems were found to further lower the pollutant concentrations by an order of magnitude. The overall removal efficiencies in the final recycled water were above 97%, resulting in product water concentrations of lower than 0.1 μg/L for most compounds. An exception to this finding was observed for bisphenol A, which was detected in concentrations up to 0.5 μg/L in the final recycled water. © 2010 Elsevier B.V. All rights reserved.

Wild C.Y.,University of Wollongong | Steele J.R.,University of Wollongong | Munro B.J.,University of Wollongong
Medicine and Science in Sports and Exercise | Year: 2013

PURPOSE: Women sustain more anterior cruciate ligament (ACL) ruptures than men, and this gender disparity is apparent from pubertal onset. Although the hamstring muscles play a vital role in ACL protection during landing by restraining anterior tibial motion relative to the femur, it is unknown whether hamstring strength affects landing biomechanics during a functional movement. This study aimed to determine whether pubescent girls with lower hamstring strength displayed different lower limb biomechanics when landing from a leap compared with girls with higher hamstring strength. METHODS: Thirty-three healthy girls, age 10-13 yr, in Tanner stage II (pubertal onset) and 4-6 months from their peak height velocity were recruited. The concentric and the eccentric isokinetic strength of the hamstring and quadriceps muscles were assessed. On the basis of peak concentric hamstrings torque, participants were divided into a lower (peak torque < 45 N·m) and higher (peak torque > 60 N·m) strength group. Participants performed a functional landing movement, during which ground reaction forces (1000 Hz), lower limb electromyography (1000 Hz), and kinematic data (100 Hz) were collected. RESULTS: Girls with lower hamstring strength displayed significantly (P < 0.05) greater knee abduction alignment, reduced hip abduction moments, and greater ACL loading at the time of the peak anteroposterior ground reaction forces compared with their stronger counterparts. CONCLUSIONS: Girls with reduced hamstring strength appear to have a decreased capacity to control lower limb frontal plane alignment. This reduced capacity appears to contribute to increased ACL loading and, in turn, increased potential for injury. Copyright © 2013 by the American College of Sports Medicine.

Remennikov A.M.,University of Wollongong | Uy B.,University of New South Wales
Journal of Constructional Steel Research | Year: 2014

This paper describes the blast loading trials on steel tubular members with and without concrete infill. The standoff distances considered in this trial were selected to demonstrate the response of these steel sections to contact and very close-range detonations of high explosive (HE). The main objective of the trials was to investigate the effects of contact and near-field explosions on steel square tubular members and to demonstrate the effect of standoff variations on the mode of response and failure of steel square sections. The experimental data collected during these trials can be used for verification of theoretical and numerical models of response of steel tubular columns subjected to contact and close-range blasts. Due to difficulties with collecting quantitative data (displacements, blast pressures, etc.) in the close proximity of a detonating HE charge, analysis of the steel tubes in this paper is confined mostly to qualitative assessment based on visual observations of the structural damage and limited numerical simulations of the blast-structure interaction using LS-DYNA aimed at clarifying some important phenomena that were not available to be obtained directly from the explosive tests. A new simplified approach to predicting the dynamic response of square tubular steel members subjected to the near-field airblast loading is proposed. The comparison of the analytically predicted dynamic response parameters of the concrete-filled steel tubular members with the experimental data shows very good agreement with the predicted failure mechanism and level of damage of the structural element. © 2014 Elsevier Ltd.

Mackay A.,University of Wollongong | Stewart B.A.,University of Michigan | Chase B.M.,Montpellier University | Chase B.M.,University of Bergen
Journal of Human Evolution | Year: 2014

The later Pleistocene archaeological record of southernmost Africa encompasses several Middle Stone Age industries and the transition to the Later Stone Age. Through this period various signs of complex human behaviour appear episodically, including elaborate lithic technologies, osseous technologies, ornaments, motifs and abstract designs. Here we explore the regional archaeological record using different components of lithic technological systems to track the transmission of cultural information and the extent of population interaction within and between different climatic regions. The data suggest a complex set of coalescent and fragmented relationships between populations in different climate regions through the late Pleistocene, with maximum interaction (coalescence) during MIS 4 and MIS 2, and fragmentation during MIS 5 and MIS 3. Coalescent phases correlate with increases in the frequency of ornaments and other forms of symbolic expression, leading us to suggest that population interaction was a significant driver in their appearance. © 2014 Elsevier Ltd.

Pham T.M.,University of Wollongong | Pham T.M.,HCMC University of Technology | Hadi M.N.S.,University of Wollongong
Journal of Composites for Construction | Year: 2014

The paper uses the membrane hypothesis to formulate the confining behavior of fiber-reinforced polymer (FRP) confined rectangular columns. A model was developed to calculate the strength of FRP confined rectangular concrete columns. The model was verified using a database of 190 FRP confined rectangular concrete columns. The database covers unconfined concrete strength between 18.3 and 55.2 MPa, and specimens with dimensions ranging from 79-305 mm and 100-305 mm for short and long sides, respectively. The performance of the proposed model shows a very good correlation with the experimental results. In addition, the strain distribution of FRP around the circumference of the rectangular sections was examined to propose an equation for predicting the actual rupture strain of FRP. The minimum corner radius of the sections is also recommended to achieve sufficient confinement. © 2013 American Society of Civil Engineers.

Seng K.H.,University of Wollongong | Park M.-H.,Ulsan National Institute of Science and Technology | Guo Z.P.,University of Wollongong | Liu H.K.,University of Wollongong | Cho J.,Ulsan National Institute of Science and Technology
Angewandte Chemie - International Edition | Year: 2012

Simple and powerful: Two germanium/carbon nanostructures were synthesized through a facile self-assembly method. Controlling the size of the precursor germanium nanoparticles produces cluster and non-clustered nanostructures. The cluster-Ge/C sample showed better capacity retention and an exceptionally high rate performance (see picture; Q=charge capacity and V=voltage). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spinks G.M.,University of Wollongong
Angewandte Chemie - International Edition | Year: 2012

Pump it: Materials that show intriguing shape changes induced by simple light exposure are emerging as candidates for artificial muscles. Recent examples are highlighted to illustrate the various molecular conformational changes induced by irradiation. Assemblies of these photoresponsive molecules are now being prepared that show functions that resemble real muscle. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bennett S.,University of Wollongong | Maton K.,University of Sydney
Journal of Computer Assisted Learning | Year: 2010

The idea of the 'digital natives', a generation of tech-savvy young people immersed in digital technologies for which current education systems cannot cater, has gained widespread popularity on the basis of claims rather than evidence. Recent research has shown flaws in the argument that there is an identifiable generation or even a single type of highly adept technology user. For educators, the diversity revealed by these studies provides valuable insights into students' experiences of technology inside and outside formal education. While this body of work provides a preliminary understanding, it also highlights subtleties and complexities that require further investigation. It suggests, for example, that we must go beyond simple dichotomies evident in the digital natives debate to develop a more sophisticated understanding of our students' experiences of technology. Using a review of recent research findings as a starting point, this paper identifies some key issues for educational researchers, offers new ways of conceptualizing key ideas using theoretical constructs from Castells, Bourdieu and Bernstein, and makes a case for how we need to develop the debate in order to advance our understanding. © 2010 Blackwell Publishing Ltd.

Flexer V.,University of Queensland | Chen J.,University of Wollongong | Donose B.C.,University of Queensland | Sherrell P.,University of Wollongong | And 2 more authors.
Energy and Environmental Science | Year: 2013

Bioelectrochemical systems encompass a range of electrochemical systems wherein microorganisms are used as biocatalysts. These range from classical microbial fuel cells to novel microbial electrosynthesis processes. The future of practical applications relies on increased performance. In all cases the development of new electrode materials is essential to overcome the low current densities of bioelectrochemical systems. Here we describe a new biocompatible, highly conductive three-dimensional scaffold electrode, NanoWeb-RVC, with a hierarchical porous structure, synthesized by direct growth of carbon nanotubes on a macroporous substrate. The nanostructure of these electrodes enhances the rate of bacterial extracellular electron transfer while the macrostructure ensures efficient mass transfer to and from the electrode surface. NanoWeb-RVC electrodes showed a current density of (6.8 ± 0.3) mA cm-2, almost three times higher than a control electrode with the same macroporous structure but lacking the nanostructure. This current density is among the highest reported to date for a microbial bioanode. This journal is © The Royal Society of Chemistry 2013.

Swamy N.K.,University of Wollongong | Yazici A.,University of Wollongong | Pyne S.G.,University of Wollongong
Journal of Organic Chemistry | Year: 2010

The CuX (X = I, Br, Cl, CN)-mediated cyclization-halogenation and cyclization-cyanation reactions of β-hydroxyalkynes and o-alkynylphenol and -aniline derivatives give rise to 3-halo- and 3-cyanofuro[3,2-b]pyrroles, 3-iodo-, 3-bromo-, and 3-cyanobenzofurans, and 3-cyanoindoles, respectively. © 2010 American Chemical Society.

Liu M.D.,University of Wollongong | Indraratna B.N.,University of Wollongong
International Journal of Geomechanics | Year: 2011

The strengths of geomaterials and their variation under different factors are investigated in this paper. First, a general isotropic variation of a strength criterion is proposed for describing the critical state and peak strengths of geomaterials. Second, the proposed criterion is extended to describe the effect of anisotropy on the peak strength. After an analysis of experimental data, the hypothesis is made that the failure of an element of geomaterial generally occurs in a particular plane when the applied shear stress in that plane reaches the shear resistance of the material. Therefore, the variation of the peak strength of anisotropic materials should be described in terms of the stress tensor applied, a vector parameter defining the position of the potential failure plane of the material, and the material properties. A general failure criterion for geomaterials with cross anisotropy is obtained then from the proposed isotropic strength criterion. The proposed criterion is demonstrated to well represent both the isotropic and anisotropic strengths of various geomaterials. Finally, a general anisotropic criterion is introduced. © 2011 American Society of Civil Engineers.

Alam M.J.E.,University of Wollongong | Muttaqi K.M.,University of Wollongong | Sutanto D.,University of Wollongong
IEEE Transactions on Smart Grid | Year: 2013

Future distribution networks with increasing level of solar PV penetration will be managed using smart grid technologies capable of producing appropriate and timely response during normal and abnormal operational events. Distribution feeder loads vary throughout the day according to the trend of consumption of the customers. Solar PV outputs fluctuate in proportion to irradiance level of sun. Simultaneous occurrence of both of these variations would result in various operating conditions that may lead to unexpected events, and would require a large amount of network data to be processed and analyzed for decision making. It is envisaged that such data will be available in the future grids with the availability of smart technologies and advanced communication in residential dwellings, commercial buildings and industrial complexes. In this paper, an advanced intelligent computational tool is developed to characterize and analyze the large amount of data associated with wide variations in network behavior using SAX (Symbolic Aggregate Approximation) and pattern recognition. The proposed tool is capable of dealing with network asymmetry, load unbalance, single-phase solar PV integration and their impacts on upstream networks and will assist in making right and timely decision to mitigate adverse impacts of solar PV. The proposed tool has been tested with a practical three-phase distribution system in Australia and can provide an extensive assessment with less computational efforts and time. © 2010-2012 IEEE.

Le L.-S.,University of Wollongong | Wegmann A.,Ecole Polytechnique Federale de Lausanne
Computer Standards and Interfaces | Year: 2013

Modeling Enterprise Architecture (EA) requires the representation of multiple views for an enterprise. This could be done by a team of stakeholders that essentially have different backgrounds. One way to do this is to structure the model into hierarchical levels each of which can be of interest to just some, not all, stakeholders. Due to the multidisciplinary nature of EA, stakeholders simply cannot choose a single modeling approach, even a widely-recognized one, to build their enterprise model and make it viewable and understandable to the whole team. Developing a modeling framework that can be applied uniformly throughout the entire enterprise model and that can be used by all stakeholders is thus challenging. We based our work on the RM-ODP (Reference Model of Open Distributed Processing) - a standardization effort that defines essential concepts for modeling distributed systems, as well as ODP-related international standards/recommendations, to develop such a modeling framework that we call SeamCAD. This framework consists of a computer-aided tool and a language behind the tool for modeling EA in a hierarchical manner. SeamCAD makes RM-ODP applicable in the context of multi-level EA and consolidates the SEAM - a family of methods for seamless integration between disciplines. © 2012 Elsevier B.V.

Zhao Z.,SAS Institute | Wang L.,University of Wollongong | Liu H.,Arizona State University | Ye J.,Arizona State University
IEEE Transactions on Knowledge and Data Engineering | Year: 2013

In the literature of feature selection, different criteria have been proposed to evaluate the goodness of features. In our investigation, we notice that a number of existing selection criteria implicitly select features that preserve sample similarity, and can be unified under a common framework. We further point out that any feature selection criteria covered by this framework cannot handle redundant features, a common drawback of these criteria. Motivated by these observations, we propose a new 'Similarity Preserving Feature Selection framework in an explicit and rigorous way. We show, through theoretical analysis, that the proposed framework not only encompasses many widely used feature selection criteria, but also naturally overcomes their common weakness in handling feature redundancy. In developing this new framework, we begin with a conventional combinatorial optimization formulation for similarity preserving feature selection, then extend it with a sparse multiple-output regression formulation to improve its efficiency and effectiveness. A set of three algorithms are devised to efficiently solve the proposed formulations, each of which has its own advantages in terms of computational complexity and selection performance. As exhibited by our extensive experimental study, the proposed framework achieves superior feature selection performance and attractive properties. © 1989-2012 IEEE.

Dam H.K.,University of Wollongong | Winikoff M.,University of Otago
Science of Computer Programming | Year: 2013

Numerous methodologies for developing agent-based systems have been proposed in the literature. This proliferation creates a challenge to practitioners who need to select a methodology to adopt. This situation is analogous to that of object-oriented methodologies and notations pre-UML, and we argue that the time is ripe to begin the development of a next generation agent-oriented software engineering (AOSE) methodology, leading ultimately towards a unified AOSE methodology. This paper proposes process and models for a next generation AOSE methodology. Our proposal is based on a comparative analysis of seven prominent AOSE methodologies, which identified strengths, weaknesses, commonalities and differences. © 2012 Elsevier B.V. All rights reserved.

D'Ambra J.,University of New South Wales | Wilson C.S.,University of New South Wales | Akter S.,University of Wollongong
Journal of the American Society for Information Science and Technology | Year: 2013

Increasingly, e-books are becoming alternatives to print books in academic libraries, thus providing opportunities to assess how well the use of e-books meets the requirements of academics. This study uses the task-technology fit (TTF) model to explore the interrelationships of e-books, the affordances offered by smart readers, the information needs of academics, and the "fit" of technology to tasks as well as performance. We propose that the adoption of e-books will be dependent on how academics perceive the fit of this new medium to the tasks they undertake as well as what added-value functionality is delivered by the information technology that delivers the content. The study used content analysis and an online survey, administered to the faculty in Medicine, Science and Engineering at the University of New South Wales, to identify the attributes of a TTF construct of e-books in academic settings. Using exploratory factor analysis, preliminary findings confirmed annotation, navigation, and output as the core dimensions of the TTF construct. The results of confirmatory factor analysis using partial least squares path modeling supported the overall TTF model in reflecting significant positive impact of task, technology, and individual characteristics on TTF for e-books in academic settings; it also confirmed significant positive impact of TTF on individuals' performance and use, and impact of using e-books on individual performance. Our research makes two contributions: the development of an e-book TTF construct and the testing of that construct in a model validating the efficacy of the TTF framework in measuring perceived fit of e-books to academic tasks. © 2012 ASIS&T.

Kautz K.,University of Wollongong | Jensen T.B.,Copenhagen Business School
Information and Organization | Year: 2013

The notion of 'sociomateriality' has recently gained in popularity among information systems (IS) scholars in their search for providing new ways of investigating and theorizing about IS in organizations and society at large. While some scholars put forward arguments and research accounts that lead to new insights concerning the concept, others expose a cursory treatment and partial appreciation of the idea. In addition, sociomateriality as a new worldview has been criticized for introducing yet more academic jargon monoxide. Although existing research and debates show some potential for progressing the theorizing of 'man-machine' reconfigurations, we point to the necessity of a deeper exploration of the term. Inspired by the Alternative Genres Track at the European Conference on Information Systems 2012, the purpose here is to take a fresh look, to evoke new insights and to gain deeper understanding of the notion of sociomateriality and its use in the IS discipline. We invite the reader to attend a prolonged monologue - characterized by honesty, frank observations and wit - at the royal court of IS. The monologue is delivered by the court jester and directed to the two sovereigns who, based on their conceptual contributions, have played a decisive role in the spreading of the idea of sociomateriality in IS. The intention is to contribute with a stimulating debate about sociomateriality that builds on open-minded questions in the pursuit of key reflections to inform our research discipline. Throughout the monologue, the jester uncovers some contradictions and limitations in and between the sovereigns' writings and points to some possible resolutions. © 2013 Elsevier Ltd.

Thanh Nguyen D.,University of Wollongong | Ogunbona P.O.,University of Wollongong | Li W.,University of Wollongong
Pattern Recognition | Year: 2013

Motivated by the discriminative ability of shape information and local patterns in object recognition, this paper proposes a window-based object descriptor that integrates both cues. In particular, contour templates representing object shape are used to derive a set of so-called key points at which local appearance features are extracted. These key points are located using an improved template matching method that utilises both spatial and orientation information in a simple and effective way. At each of the extracted key points, a new local appearance feature, namely non-redundant local binary pattern (NR-LBP), is computed. An object descriptor is formed by concatenating the NR-LBP features from all key points to encode the shape as well as the appearance of the object. The proposed descriptor was extensively tested in the task of detecting humans from static images on the commonly used MIT and INRIA datasets. The experimental results have shown that the proposed descriptor can effectively describe non-rigid objects with high articulation and improve the detection rate compared to other state-of-the-art object descriptors. © 2012 Elsevier Ltd.

Price O.F.,University of Wollongong | Bradstock R.A.,University of Wollongong
International Journal of Wildland Fire | Year: 2010

We investigated the effect of fuel age on the truncation of spread of unplanned fires using a set of 1473 patches in the Sydney region of Australia. Twenty-two percent of patches derived from prescribed fire experienced a subsequent unplanned fire within 5 years, compared with 42% of patches derived from unplanned fires. Among those encounters, the subsequent unplanned fire stopped at the leading edge of 18% of prescribed patches and 11% of unplanned patches. In comparison, the subsequent fire stopped somewhere in the patch for 44% of both prescribed and unplanned fires. Overall, there was a 10% chance that a prescribed burn patch would experience an unplanned fire that stops within the patch. Statistical modelling revealed that the presence of a road barrier was the best predictor of the likelihood of stopping on the leading edge, but fuel age and weather also had an influence. Stopping on the trailing edge was less influenced by the variables analysed. In extreme weather, even 1-year-old patches have a low likelihood of stopping unplanned fires. Fuel age had little influence on the spread of unplanned fires. Consequently, prescribed fires will be most effective when sited at the urban interface where resultant reduced unplanned fire intensity will be a benefit. © 2010 IAWF.

Hinkley T.,Deakin University | Salmon J.,Deakin University | Okely A.D.,University of Wollongong | Hesketh K.,Deakin University | Crawford D.,Deakin University
American Journal of Preventive Medicine | Year: 2012

Background: Physical activity is important for children's health, and identifying factors associated with their physical activity is important for future interventions and public health programs. Purpose: This study sought to identify multidimensional correlates of preschool children's physical activity. Methods: The social-ecological model (SEM) was used to identify constructs potentially associated with preschool children's physical activity. Data were collected from 1004 preschool children, aged 3-5 years, and parents in 2008-2009, and analyzed in 2010-2011. Physical activity was measured over 8 days using ActiGraph accelerometers. Parents completed a comprehensive survey. Generalized linear modeling was used to assess associations between potential correlates and percentage of time spent in physical activity. Results: Correlates of physical activity were found across all the domains of the SEM and varied between boys and girls and week and weekend days. Age was the only consistent correlate, with children spending approximately 10% less time in physical activity for each advancing year of age. Some modifiable correlates that were related to more than one physical activity outcome were rules restricting rough games inside and usual daily sleep time for boys. For girls, a preference to play inside/draw/do crafts rather than be active, and child constraints, was associated with more than one of the physical activity outcomes. A novel finding in this study is the counterintuitive association between parental rules restricting rough games inside and boys' higher physical activity participation levels. Conclusions: Potential strategies for promoting children's physical activity should seek to influence children's preference for physical activity and parent rules. Gender-specific strategies also may be warranted. © 2012 American Journal of Preventive Medicine.

Jalalian A.,KTH Royal Institute of Technology | Jalalian A.,University of Wollongong | Grishin A.M.,KTH Royal Institute of Technology
Applied Physics Letters | Year: 2012

Dense homogeneous textile composed from continuous bead-free sodium potassium niobate (NKN) nanofibers 100 μm long and 50-200 nm in diameter was sintered by sol-gel calcination assisted electrospinning. High resolution electron microscopy and x-ray diffraction revealed preferential cube-on-cube growth of fibers in [001] direction. Raman spectrum of NKN fibers contains all the features characteristic to electrically poled orthorhombic phase. In contrast to polycrystalline ceramics, it shows relative enhancement of the Raman cross section of isotropic A 1g(v 1) mode compared with polar axis defined F 2g(v 5) and E g(v 2) vibrations. We interpret this as an evidence for superparaelectric state of NKN nanofibers. Spontaneous polarization inside highly crystalline nanofiber exists at room temperature though big distance between fibers prevents the settling of a net macroscopic polarization. © 2012 American Institute of Physics.

de Leede-Smith S.,University of Wollongong | Barkus E.,University of Wollongong
Frontiers in Human Neuroscience | Year: 2013

Over the years, the prevalence of auditory verbal hallucinations (AVH) has been documented across the lifespan in varied contexts, and with a range of potential long-term outcomes. Initially the emphasis focused on whether AVHs conferred risk for psychosis. However, recent research has identified significant differences in the presentation and outcomes of AVH in patients compared to those in non-clinical populations. For this reason, it has been suggested that auditory hallucinations are an entity by themselves and not necessarily indicative of transition along the psychosis continuum. This review will examine the presentation of auditory hallucinations across the life span. The stages described include childhood, adolescence, adult non-clinical populations, hypnaogogic/hypnopompic experiences, high schizotypal traits, schizophrenia, substance induced AVH, AVH in epilepsy and AVH in the elderly. In children, need for care depends upon whether the child associates the voice with negative beliefs, appraisals and other symptoms of psychosis. This theme appears to carry right through to healthy voice hearers in adulthood, in which a negative impact of the voice usually only exists if the individual has negative experiences as a result of their voice(s). This includes features of the voices such as the negative content, frequency and emotional valence as well as anxiety and depression, independently or caused by voices presence. It seems possible that the mechanisms which maintain AVH in non-clinical populations are different from those which are behind AVH presentations in psychotic illness. For example; the existence of maladaptive coping strategies in patient populations is one significant difference between clinical and non-clinical groups which is associated with a need for care. Whether or not these mechanisms start out the same and have differential trajectories is not yet evidenced. Future research needs to focus on the comparison of underlying factors and mechanisms that lead to the onset of AVH in both patient and non-clinical populations. © 2013 De_leede-smith and Barkus.

Naficy S.,University of Wollongong | Razal J.M.,University of Wollongong | Spinks G.M.,University of Wollongong | Wallace G.G.,University of Wollongong | Whitten P.G.,University of Wollongong
Chemistry of Materials | Year: 2012

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4- ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm -1. This conductivity is the highest yet reported for hydrogel materials of high swelling ratios. These hydrogels may be useful as soft strain sensors because their electrical resistance changed significantly when cyclically loaded in compression. © 2012 American Chemical Society.

Hooi M.Y.S.,University of Sydney | Raftery M.J.,University of New South Wales | Truscott R.J.W.,University of Sydney | Truscott R.J.W.,University of Wollongong
Investigative Ophthalmology and Visual Science | Year: 2012

PURPOSE. Long-lived proteins are widespread in man, yet little is known about the processes that affect their function over time, or their role in age-related diseases. METHODS. Racemization of two proteins from normal and cataract human lenses were compared with age using tryptic digestion and LC/mass spectrometry. Asp 151 in aA crystallin and Asn 76 in cS crystallin were studied. RESULTS. Age-dependent profiles for the two proteins from normal lenses were different. In neither protein did the modifications increase linearly with age. For aA crystallin, racemization occurred most rapidly during the first 15 years of life, with approximately half of L-Asp 151 converted to D-isoAsp, L-isoAsp, and D-Asp in a ratio of 3:1:0.5. Values then changed little. By contrast, racemization of Asn 76 in cS crystallin was slow until age 15, with isoAsp accounting for only 5%. Values remained relatively constant until age 40 when a linear increase (1%/year) took place. When cataract lenses were compared with age-matched normal lenses, there were marked differences in the time courses of the two crystallins. For aA crystallin, there was no significant difference in Asp 151 racemization between cataract and normal lenses. By contrast, in cS crystallin the degree of conversion of Asn 76 to isoAsp in cataract lenses was approximately double that of normals at every age. CONCLUSIONS. Modification of Asn and Asp over time may contribute to denaturation of proteins in the human lens. An accelerated rate of deamidation/racemization at selected sites in proteins, such as cS crystallin, may contribute to cataract formation. © 2012 The Association for Research in Vision and Ophthalmology, Inc.

Piper A.,University of Wollongong | Safavi-Naini R.,University of Calgary
IET Information Security | Year: 2013

Semi-fragile watermarks are used to detect unauthorised changes to an image, whereas tolerating allowed changes such as compression. Most semi-fragile algorithms that tolerate compression assume that because compression only removes the less visually significant data from an image, tampering with any data that would normally be removed by compression cannot affect a meaningful change to the image. Scalable compression allows a single compressed image to produce a variety of reduced resolution or reduced quality images, termed subimages, to suit the different display or bandwidth requirements of each user. However, highly scaled subimages remove a substantial fraction of the data in the original image, so the assumption used by most semi-fragile algorithms breaks down, as tampering with this data allows meaningful changes to the image content. The authors propose a scalable fragile watermarking algorithm for authentication of scalable JPEG2000 compressed images. It tolerates the loss of large amounts of image data because of resolution or quality scaling, producing no false alarms. Yet, it also protects that data from tampering, detecting even minor manipulations other than scaling, and is secure against mark transfer and collage attacks. Experimental results demonstrate this for scaling down to 1/1024th the area of the original or to 1/100th the file size. © 2013 The Institution of Engineering and Technology.

Howard S.K.,University of Wollongong
Technology, Pedagogy and Education | Year: 2013

Teachers who do not integrate technology are often labelled as 'resistant' to change. Yet, considerable uncertainties remain about appropriate uses and actual value of technology in teaching and learning, which can make integration and change seem risky. The purpose of this article is to explore the nature of teachers' analytical and affective risk perceptions, and how these influence decisions to integrate technology in their teaching practice. These ideas are explored through an in-depth qualitative analysis of teacher interviews focusing on experiences with, and beliefs about, technology and teaching. Results suggest decisions to integrate technology in teaching are influenced by negative affective responses to technology, general risk-aversion in teaching, and the perceived value of technology in teaching. The risk analysis framework and findings presented in this paper can be used to support communication with teachers to minimise perceived risks and, where appropriate, help support future technology use. © 2013 Copyright Association for Information Technology in Teacher Education.

Li W.,University of Wollongong | Zhang Z.,Microsoft | Liu Z.,Microsoft
2010 IEEE Computer Society Conference on Computer Vision and Pattern Recognition - Workshops, CVPRW 2010 | Year: 2010

This paper presents a method to recognize human actions from sequences of depth maps. Specifically, we employ an action graph to model explicitly the dynamics of the actions and a bag of 3D points to characterize a set of salient postures that correspond to the nodes in the action graph. In addition, we propose a simple, but effective projection based sampling scheme to sample the bag of 3D points from the depth maps. Experimental results have shown that over 90% recognition accuracy were achieved by sampling only about 1% 3D points from the depth maps. Compared to the 2D silhouette based recognition, the recognition errors were halved. In addition, we demonstrate the potential of the bag of points posture model to deal with occlusions through simulation. © 2010 IEEE.

Ogie R.,University of Wollongong
IEEE Consumer Electronics Magazine | Year: 2016

As organizations constantly strive to improve strategies for ICT management, one of the major challenges they must tackle is bring your own device (BYOD). BYOD is a term that collectively refers to the related technologies, concepts, and policies in which employees are allowed to access internal corporate IT resources, such as databases and applications, using their personal mobile devices like smartphones, laptop computers, and tablet PCs [1]. It is a side effect of the consumerization of IT, a term used to describe the growing tendency of the new information technologies to emerge first in the consumer market and then spread into business and government organizations [2]. Basically, employees want to act in an "any-devices, anywhere" work style, performing personal activities during work and working activities during personal time [2]. There are several risks associated with BYOD [3, p. 63], and the big gaps in BYOD policies adopted by today's organizations [4, p. 194] show that the solution to BYOD is not well understood. This article establishes a background to understand BYOD risks by considering conditions that increase the occurrence of these risks and the consequences of the risks occurring. It then aims to present the most commonly adopted BYOD solutions, their limitations, and remedies, as well as important policy considerations for successfully implementing them. © 2012 IEEE.

Michael K.,University of Wollongong
IEEE Consumer Electronics Magazine | Year: 2016

If you were born before 1985, then there is a good chance you watched Looney Tunes on a Saturday morning and followed the exploits of the Elmer Fudd, Bugs Bunny, and Daffy Duck hunting episodes with anticipation but no element of surprise. Poor old Daffy Duck, at times disguised as a rabbit, just couldn't outwit Bugs during rabbit season! And Elmer Fudd was one of those hunters you felt sorry for-a thousand shots fired, some on target, but he never really could finish off his rival. © 2012 IEEE.

Hayes A.,University of Wollongong
IEEE Consumer Electronics Magazine | Year: 2016

I came into the consumer electronics industry as a wearable-technology reseller and educator with a background in e-learning and flexible delivery. My interests in location-enabled, wearable video technologies began in 2003, culminating over the ensuing years in national and international projects with industry, policing, national security, and social research, including the impact on the Australian vocational education and training sector [1]. © 2012 IEEE.

Zhang C.,University of Wollongong | Zhang C.,Nanyang Technological University | Chen Z.,University of Wollongong | Guo Z.,University of Wollongong | Lou X.W.,Nanyang Technological University
Energy and Environmental Science | Year: 2013

A facile synthesis of novel 3D porous V2O5 hierarchical microspheres has been developed, based on an additive-free solvothermal method and subsequent calcination. Due to their unique structure, these V2O5 microspheres display a very stable capacity retention of 130 mA h g-1 over 100 cycles at a current rate of 0.5 C, and show excellent rate capability with a capacity of 105 mA h g-1 even at the 30 C rate. The good electrochemical performance suggests that this unique hierarchical V2O5 material could be a promising candidate as a cathode material for lithium-ion batteries. © 2013 The Royal Society of Chemistry.

Hinkley T.,University of Wollongong | Salmon J.,Deakin University | Okely A.D.,University of Wollongong | Crawford D.,Deakin University | Hesketh K.,Deakin University
Medicine and Science in Sports and Exercise | Year: 2012

PURPOSE: Little evidence exists about the prevalence of adequate levels of physical activity and of appropriate screen-based entertainment in preschool children. Previous studies have generally relied on small samples. This study investigates how much time preschool children spend being physically active and engaged in screen-based entertainment. The study also reports compliance with the recently released Australian recommendations for physical activity (≥3 h•d -1) and screen entertainment (≤1 h•d -1) and the National Association for Sport and Physical Education physical activity guidelines (≥2 h•d -1) and American Academy of Pediatrics screen-based entertainment recommendations (≤2 h•d -1) in a large sample of preschool children. METHODS: Participants were 1004 Melbourne preschool children (mean age = 4.5 yr, range = 3-5 yr) and their families in the Healthy Active Preschool Years study. Physical activity data were collected by accelerometry during an 8-d period. Parents reported their child's television/video/DVD viewing, computer/Internet, and electronic game use during a typical week. A total of 703 (70%) had sufficient accelerometry data, and 935 children (93%) had useable data on time spent in screen-based entertainment. RESULTS: Children spent 16% (approximately 127 min•d -1) of their time being physically active. Boys and younger children were more active than were girls and older children, respectively. Children spent an average of 113 min•d in screen-based entertainment. Virtually no children (<1%) met both the Australian recommendations and 32% met both the National Association for Sport and Physical Education and American Academy of Pediatrics recommendations. CONCLUSIONS: The majority of young children are not participating in adequate amounts of physical activity and in excessive amounts of screen-based entertainment. It is likely that physical activity may decline and that screen-based entertainment may increase with age. Compliance with recommendations may be further reduced. Strategies to promote physical activity and reduce screen-based entertainment in young children are required. © 2012 by the American College of Sports Medicine.

Toyoda T.,Tokai University | Zhang C.,University of Wollongong
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

A Hall resistivity formula for the 2DES in graphene is derived from the zero-mass Dirac field model adopting the electron reservoir hypothesis. The formula reproduces perfectly the experimental resistivity data [K.S. Novoselov, et al., Nature 438 (2005) 201]. This perfect agreement cannot be achieved by any other existing models. The electron reservoir is shown to be the 2DES itself. © 2011 Elsevier B.V. All rights reserved.

Hooi M.Y.S.,University of Sydney | Raftery M.J.,University of New South Wales | Truscott R.J.W.,University of Wollongong
Experimental Eye Research | Year: 2013

Racemisation of amino acids is one of the most abundant modifications in long-lived proteins. In this study racemisation of Asp 58 in the small heat shock protein, αA crystallin, was investigated. In normal human lenses, levels of l-isoAsp, d-isoAsp and d-Asp increased with age, such that by age 70 they accounted for approximately half of the total Asp at this site. Levels of d-isoAsp were significantly higher in all cataract lenses than age-matched normal lenses. The introduction of d-isoAsp in αA crystallin could therefore be associated with the development of cataract. Its more rapid formation in cataract lenses may represent an example of accelerated protein aging leading to a human age-related disease. © 2012.

Ranjbartoreh A.R.,University of Wollongong | Wang G.,University of Wollongong
Journal of Nanoparticle Research | Year: 2010

In this article, mechanical properties of single-walled carbon nanotubes (SWCNTs) with various radiuses under tensile, compressive and lateral loads are considered. Stress-strain curve, elastic modulus, tensile, compressive and rotational stiffness, buckling behaviour, and critical axial compressive load and pressure of eight different zigzag and armchair SWCNTs are investigated to figure out the effect of radius and chirality on mechanical properties of nanotubes. Using molecular dynamic simulation (MDS) method, it can be explained that SWCNTs have higher Young's modulus and tensile stiffness than compressive elastic modulus and compressive stiffness. Critical axial force of zigzag SWCNT is independent from the radius, but that of armchair type rises by increasing of radius, also these two types show different buckling modes. © Springer Science+Business Media B.V. 2009.

Palmisano S.A.,University of Wollongong | Kim J.,University of Sydney | Freeman T.C.A.,University of Cardiff
Journal of Vision | Year: 2012

Previous research has shown that vection can be enhanced by adding horizontal simulated viewpoint oscillation to radial flow. Adding a horizontally oscillating fixation target to purely radial flow induces a superficially similar illusion of self-motion, where the observer's perceived heading oscillates left and right as their eyes pursue the moving target. This study directly compared the vection induced by these two conditions for the first time. Adding fixation point oscillation and simulated viewpoint oscillation to radial flow were both found to improve vection (relative to no oscillation control displays). Neither vection advantage could be explained in terms of differences in perceived scene rigidity or motion adaptation. Our findings also provided little support for the notion that pursuit eye-movements were essential for the simulated viewpoint oscillation advantage for vection (since observers successfully fixated a stationary, centrally- placed target during these conditions in the current experiments). The strongest support was found for the proposal that fixation point oscillation and simulated viewpoint oscillation both improve vection by increasing the observer's global retinal motion. © 2012 ARVO.

Ghayesh M.H.,University of Wollongong | Farokhi H.,McGill University
International Journal of Engineering Science | Year: 2015

In this paper, the nonlinear dynamics of a microplate is investigated based on the modified couple stress theory. The von Kármán plate theory is employed to model the system by retaining in-plane displacements and inertia. The equations of motion are derived via an energy method based on the Lagrange equations, yielding a set of second-order nonlinear ordinary differential equations with coupled terms. These equations are recast into a set of first-order nonlinear ordinary differential equations and the resulting equations are solved by means of the pseudo-arclength continuation technique. The nonlinear dynamics is examined through plotting the frequency-response and force-response curves of the system. The influence of system parameters on the resonant responses is highlighted. The differences in the response amplitude of the system modelled based on the modified couple stress theory and the classical one are discussed. © 2014 Elsevier Ltd. All rights reserved.

Cook S.M.,University of Wollongong | Skora A.,University of Wollongong | Gillen C.M.,University of Queensland | Walker M.J.,University of Queensland | Mcarthur J.D.,University of Wollongong
Molecular Microbiology | Year: 2012

Streptococcus pyogenes (group A streptococcus, GAS) secretes streptokinase, a potent plasminogen activating protein. Among GAS isolates, streptokinase gene sequences (ska) are polymorphic and can be grouped into two distinct sequence clusters (termed cluster type-1 and cluster type-2) with cluster type-2 being further divided into sub-clusters type-2a and type-2b. In this study, far-UV circular dichroism spectroscopy indicated that purified streptokinase variants of each type displayed similar secondary structure. Type-2b streptokinase variants could not generate an active site in Glu-plasminogen through non-proteolytic mechanisms while all other variants had this capability. Furthermore, when compared with other streptokinase variants, type-2b variants displayed a 29- to 35-fold reduction in affinity for Glu-plasminogen. All SK variants could activate Glu-plasminogen when an activator complex was preformed with plasmin; however, type-2b and type-1 complexes were inhibited by α2-antiplasmin. Exchanging skatype-2a in the M1T1 GAS strain 5448 with skatype-2b caused a reduction in virulence while exchanging skatype-2a with skatype-1 into 5448 produced an increase in virulence when using a mouse model of invasive disease. These findings suggest that streptokinase variants produced by GAS isolates utilize distinct plasminogen activation pathways, which directly affects the pathogenesis of this organism. © 2012 Blackwell Publishing Ltd.

Saltzman K.,Gothenburg University | Head L.,University of Wollongong | Stenseke M.,Gothenburg University
Journal of Rural Studies | Year: 2011

Within the now extensive recent literature on cultures of nature, agriculture has received less attention than might have been expected given its threshold role in transforming human relations with the earth and with plants and animals. The concept and practice of agriculture can be understood as central to the emergence and maintenance of the culture/nature dichotomy within Western thought and practice. In this paper we use the comparative cases of Sweden and Australia to examine the differential and contingent positioning of agriculture with respect to that which is understood as nature. Broadly speaking, some parts of agriculture are understood to belong to nature in Sweden through a long history. This is not the case in Australia, where the short agricultural history is positioned in contrast to nature. This affects the way in which biodiversity and environmental protection takes place - in Sweden as part of farming, - in Australia in spite of it. We argue that these cultural differences have been more important than generally recognised in debates over multifunctional agriculture. We discuss the environmental management implications of the two different models in a context made more dynamic by climate change. © 2010 Elsevier Ltd.

Liu L.,Australian National University | Wang L.,Australian National University | Wang L.,University of Wollongong | Liu X.,Australian National University | Liu X.,National University of Defense Technology
Proceedings of the IEEE International Conference on Computer Vision | Year: 2011

In object recognition, soft-assignment coding enjoys computational efficiency and conceptual simplicity. However, its classification performance is inferior to the newly developed sparse or local coding schemes. It would be highly desirable if its classification performance could become comparable to the state-of-the-art, leading to a coding scheme which perfectly combines computational efficiency and classification performance. To achieve this, we revisit soft-assignment coding from two key aspects: classification performance and probabilistic interpretation. For the first aspect, we argue that the inferiority of soft-assignment coding is due to its neglect of the underlying manifold structure of local features. To remedy this, we propose a simple modification to localize the soft-assignment coding, which surprisingly achieves comparable or even better performance than existing sparse or local coding schemes while maintaining its computational advantage. For the second aspect, based on our probabilistic interpretation of the soft-assignment coding, we give a probabilistic explanation to the magic max-pooling operation, which has successfully been used by sparse or local coding schemes but still poorly understood. This probability explanation motivates us to develop a new mix-order max-pooling operation which further improves the classification performance of the proposed coding scheme. As experimentally demonstrated, the localized soft-assignment coding achieves the state-of-the-art classification performance with the highest computational efficiency among the existing coding schemes. © 2011 IEEE.

Hardy L.L.,University of Sydney | Barnett L.,Deakin University | Espinel P.,University of Sydney | Okely A.D.,University of Wollongong
Medicine and Science in Sports and Exercise | Year: 2013

PURPOSE: The objective of this study is to describe 13-yr trends in children's fundamental movement skill (FMS) competency. METHODS: Secondary analysis of representative, cross-sectional, Australian school-based surveys was conducted in 1997, 2004, and 2010 (n = 13,752 children age 9-15 yr). Five FMS (sprint run, vertical jump, catch, kick, and overarm throw) were assessed using process-oriented criteria at each survey and children's skills classified as competent or not competent. Covariates included sex, age, cardiorespiratory endurance (20-m shuttle run test), body mass index (kg·m), and socioeconomic status (residential postcode). RESULTS: At each survey, the children's FMS competency was low, with prevalence rarely above 50%. Between 1997 and 2004, there were significant increases in all students' competency in the sprint run, vertical jump, and catch. For boys, competency increased in the kick (primary) and the overarm throw (high school), but among high school girls, overarm throw competency decreased. Between 2004 and 2010, competency increased in the catch (all students), and in all girls, competency increased in the kick, whereas competency in the vertical jump decreased. CONCLUSIONS: Overall, students' FMS competency was low especially in the kick and overarm throw in girls. The observed increase in FMS competency in 2004 was attributed to changes in practice and policy to support the teaching of FMS in schools. In 2010, competency remained low, with improvements in only the catch (all) and kick (girls) and declines in vertical jump. Potentially, the current delivery of FMS programs requires stronger positioning within the school curriculum. Strategies to improve children's physical activity should consider ensuring children are taught FMS to competency level, to enjoy being physically active. Copyright © 2013 by the American College of Sports Medicine.

Ferris C.J.,University of Wollongong | Gilmore K.G.,University of Wollongong | Wallace G.G.,University of Wollongong | In Het Panhuis M.,University of Wollongong
Applied Microbiology and Biotechnology | Year: 2013

The development of cell printing is vital for establishing biofabrication approaches as clinically relevant tools. Achieving this requires bio-inks which must not only be easily printable, but also allow controllable and reproducible printing of cells. This review outlines the general principles and current progress and compares the advantages and challenges for the most widely used biofabrication techniques for printing cells: extrusion, laser, microvalve, inkjet and tissue fragment printing. It is expected that significant advances in cell printing will result from synergistic combinations of these techniques and lead to optimised resolution, throughput and the overall complexity of printed constructs. © 2013 Springer-Verlag Berlin Heidelberg.