Wu Z.,University of ManchesterManchester |
McCann H.,University of ManchesterManchester |
Davis L.E.,University of ManchesterManchester |
Hu J.,University of ManchesterManchester |
And 2 more authors.
6th World Congress in Industrial Process Tomography | Year: 2010
Since the 1980’s, electrical tomographic imaging techniques based on low frequency capacitance, resistance or inductance measurements have been developed for the monitoring of various industrial processes, and also in some cases to oil and gas multiphase flows. The research of microwave tomography for oil and gas multiphase flow imaging began in the mid 1990’s even though the basic principle of microwave tomography was reported a decade earlier. Microwave tomography in principle would produce higher resolution images than low-frequency imaging techniques. In addition to multiphase flows, the microwave technique has been investigated over the past two decades for medical imaging with some degree of success. In this paper, an experimental microwave tomography system is described for potential application for oil and gas flow imaging. This includes the laboratory hardware for data acquisition and the iterative algorithm for image reconstruction. The results of using the system for tomographic imaging of oil-gas flow distributions are presented and compared using two different operating frequencies. The quality of the microwave tomographic imaging at different frequencies is then assessed, which shows that better images are reconstructed at the higher frequency. © International Society for Industrial Process Tomography, 2010. All rights reserved.
Bottacin-Busolin A.,University of ManchesterManchester
Water Resources Research | Year: 2015
Average water travel times through a stream network were determined as a function of stage (discharge) and stream network properties. Contrary to most previous studies on the topic, the present work allowed for streamflow velocities to vary spatially (for most of the analyses) as well as temporally. The results show that different stream network mechanisms and properties interact in a complex and stage-dependent manner, implying that the relative importance of the different hydraulic properties varies in space and over time. Theoretical reasoning, based on the central temporal moments derived from the kinematic-diffusive wave equation in a semi-2-D formulation including the effects of flooded cross sections, shows that the hydraulic properties in contrast to the geomorphological properties will become increasingly important as the discharge increases, stressing the importance of accurately describing the hydraulic mechanisms within stream networks. Using the physically based, stage-dependent response function as a parameterization basis for the streamflow routing routine (a linear reservoir) of a hydrological model, discharge predictions were shown to improve in two Swedish catchments, compared with a conventional, statistically based parameterization scheme. Predictions improved for a wide range of modeled scenarios, for the entire discharge series as well as for peak flow conditions. The foremost novelty of the study lies in that the physically based response function for a streamflow routing routine has successfully been determined independent of calibration, i.e., entirely through process-based hydraulic stream network modeling. © 2014. American Geophysical Union. All Rights Reserved.
Qiao J.,Beijing University of Technology |
Qiao J.,Beijing Key Laboratory of Computational Intelligence and Intelligent System |
Li W.,Beijing University of Technology |
Li W.,Beijing Key Laboratory of Computational Intelligence and Intelligent System |
And 3 more authors.
Applied Soft Computing Journal | Year: 2016
This paper proposes a two-phase identification approach to Mamdani fuzzy neural networks. The first phase is the system identification which includes a novel forward recursive input-output clustering method for the structure initialization and the gradient descent algorithm for the parameter initialization. The main advantage of the proposed method is that it fits perfectly the special clustering requirement for system identification: coarser clustering in the regions where the identified system is smoother and finer clustering in the regions where the system is more variable or nonlinear. The second phase is the system simplification which includes the accurate similarity analysis and merging method for similar fuzzy rules and the gradient descent algorithm for the parameter finalization. The accurate similarity analysis developed solves the long standing open problem how to compute the exact (rather than approximate) similarity between fuzzy sets and rules with Gaussian membership functions. Numerical experiments based on well-known benchmark data sets are used to verify the effectiveness and accuracy of the proposed approach. © 2016 Elsevier B.V.
Terzija N.,University of ManchesterManchester |
McCann H.,University of ManchesterManchester
6th World Congress in Industrial Process Tomography | Year: 2010
The use of wavelet-based image reconstruction methods is discussed for data inversion of limited path-integral data in hard-field tomography systems. As shown in our previous work, the Landweber iteration method allows stable solution of this tomography problem by incorporating suitable a priori information. We have previously presented a new method that uses a 2-D discrete wavelet transform as a smoothing function. In this paper, the new method is applied to different beam arrays that implement chemical species tomography system using near-IR spectroscopic absorption measurements, and which can be classified as producing severely limited data where both the number of viewing angles and the number of measurements are small. Results are presented for simulated phantoms and for experiments with propane plumes, showing excellent spatial localization and quantification. The improved convergence time of the new iterative algorithm is exploited in application to high-speed experimental data obtained from transient laboratory tests. The potential for the method to be applied to other hard-field tomographic modalities is considered. © International Society for Industrial Process Tomography, 2010. All rights reserved.
Walsh C.,University of ManchesterManchester |
Thornley P.,University of ManchesterManchester
Applied Thermal Engineering | Year: 2013
Low grade heat (LGH) recovery is one way of increasing industrial energy efficiency and reducing associated greenhouse gas emissions. The organic Rankine cycle (ORC) and condensing boiler are two options that can be used to recover low grade heat (<250 °C). This paper assesses the lifecycle greenhouse gas reduction impacts and discounted payback periods associated with both technologies. Generation of electricity through the operation of the ORC saves approximately 11 kt of CO2 annually, but the high carbon intensity of the coking process means this has a negligible influence (<1%) on the overall process lifecycle impacts. However, if the electricity generated offsets the external purchasing of electricity this results in favourable economic payback periods of between 3 and 6 years. The operation of a condensing boiler within a woodchip boiler reduces the fuel required to achieve an increased thermal output. The thermal efficiency gains reduce the lifecycle impacts by between 11 and 21%, and reflect payback periods as low as 1.5-2 years, depending on the condenser type and wood supply chain. The two case studies are used to highlight the difficulty in identifying LGH recovery solutions that satisfy multiple environmental, economic and wider objectives. © 2012 Elsevier Ltd.
Wang L.,University of ManchesterManchester |
Wang L.,China Academy of Space Technology |
Dou R.,China Academy of Space Technology |
Wang G.,China Academy of Space Technology |
And 4 more authors.
Materials Science and Engineering A | Year: 2016
The present study evaluates the fracture strengths and the Weibull modulus of Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) oxygen transport membranes by means of biaxial and uniaxial bending tests at both room temperature (RT) and 800 °C. The fracture strengths obtained from the biaxial bending tests are much lower than those obtained from the uniaxial bending tests while Weibull moduli (m) are similar. By utilising Weibull statistics the uniaxial strengths can be predicted from the biaxial values at both RT and 800 °C. Fracture surfaces at both RT and 800 °C show only a transgranular fracture mode. Failure origins are also determined by scanning electron microscope (SEM) based on the fractographic principles. Most defects determining the fracture strength of this particular material are found to be pores with a relatively large size. © 2016 Elsevier B.V.
Carrillo J.A.,University of ManchesterManchester |
Turner M.L.,University of ManchesterManchester |
Ingleson M.J.,University of ManchesterManchester
Journal of the American Chemical Society | Year: 2016
Thienyl di-N-methyliminodiacetic acid (MIDA) boronate esters are readily synthesized by electrophilic C-H borylation producing bench stable crystalline solids in good yield and excellent purity. Optimal conditions for the slow release of the boronic acid using KOH as the base in biphasic THF/water mixtures enables the thienyl MIDA boronate esters to be extremely effective homo-bifunctionalized (AA-type) monomers in Suzuki-Miyaura copolymerizations with dibromo-heteroarenes (BB-type monomers). A single polymerization protocol is applicable for the formation of five alternating thienyl copolymers that are (or are close analogues of) state of the art materials used in organic electronics. The five polymers were produced in excellent yields and with high molecular weights comparable to those produced using Stille copolymerization protocols. Therefore, thienyl di-MIDA boronate esters represent bench stable and low toxicity alternatives to highly toxic di-trimethylstannyl AA-type monomers that are currently ubiquitous in the synthesis of these important alternating copolymers. © 2016 American Chemical Society.
Brown G.,University of ManchesterManchester
Pattern Recognition Letters | Year: 2015
Abstract We study a dichotomy of scientific styles, unifying and diversifying, as proposed by Freeman J. Dyson. We discuss the extent to which the dichotomy transfers from the natural sciences (where Dyson proposed it) to the field of Pattern Recognition. To address this we must firstly ask what it means to be a "unifier" or "diversifier" in a field, and what are the relative merits of each style of thinking. Secondly, given that Dyson applied this to the sciences, does it also apply in a field known to be a blend of science and engineering? Parallels are drawn to Platonic/Aristotelian views, and to Cartesian/Baconian science, and questions are asked on what drives the Kuhnian paradigm shifts of our field. This article is intended not to marginalise individuals into categories (unifier/diversifier) but instead to demonstrate the utility of philosophical reflection on our field, showing the depth and complexities a seemingly simple idea can unearth. © 2015 The Authors.
Adank P.,University College London |
Adank P.,University of ManchesterManchester |
Nuttall H.E.,University College London |
Banks B.,University of ManchesterManchester |
Kennedy-Higgins D.,University College London
Frontiers in Human Neuroscience | Year: 2015
The recognition of unfamiliar regional and foreign accents represents a challenging task for the speech perception system (Floccia et al., 2006; Adank et al., 2009). Despite the frequency with which we encounter such accents, the neural mechanisms supporting successful perception of accented speech are poorly understood. Nonetheless, candidate neural substrates involved in processing speech in challenging listening conditions, including accented speech, are beginning to be identified. This review will outline neural bases associated with perception of accented speech in the light of current models of speech perception, and compare these data to brain areas associated with processing other speech distortions. We will subsequently evaluate competing models of speech processing with regards to neural processing of accented speech. See Cristia et al. (2012) for an in-depth overview of behavioral aspects of accent processing. © 2015 Adank, Nuttall, Banks and Kennedy-Higgins.
PubMed | Wageningen University, University Utrecht, University of Nottingham and University of ManchesterManchester
Type: | Journal: Frontiers in plant science | Year: 2016
Seed dormancy is a genetically controlled block preventing the germination of imbibed seeds in favorable conditions. It requires a period of dry storage (after-ripening) or certain environmental conditions to be overcome. Dormancy is an important seed trait, which is under selective pressure, to control the seasonal timing of seed germination. Dormant and non-dormant (after-ripened) seeds are characterized by large sets of differentially expressed genes. However, little information is available concerning the temporal and spatial transcriptional changes during early stages of rehydration in dormant and non-dormant seeds. We employed genome-wide transcriptome analysis on seeds of the model plant Arabidopsis thaliana to investigate transcriptional changes in dry seeds upon rehydration. We analyzed gene expression of dormant and after-ripened seeds of the Cvi accession over four time points and two seed compartments (the embryo and surrounding single cell layer endosperm), during the first 24 h after sowing. This work provides a global view of gene expression changes in dormant and non-dormant seeds with temporal and spatial detail, and these may be visualized via a web accessible tool (http://www.wageningenseedlab.nl/resources). A large proportion of transcripts change similarly in both dormant and non-dormant seeds upon rehydration, however, the first differences in transcript abundances become visible shortly after the initiation of imbibition, indicating that changes induced by after-ripening are detected and responded to rapidly upon rehydration. We identified several gene expression profiles which contribute to differential gene expression between dormant and non-dormant samples. Genes with enhanced expression in the endosperm of dormant seeds were overrepresented for stress-related Gene Ontology categories, suggesting a protective role for the endosperm against biotic and abiotic stress to support persistence of the dormant seed in its environment.