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Full-Text Articles in Physical Sciences and Mathematics

An Integrated Centrifugo-Opto-Microfluidic Platform For Arraying, Analysis, Identification And Manipulation Of Individual Cells, Robert Burger, D Kurzbuch, Robert Gorkin Iii, Gregor Kijanka, Macdara Glynn, C Mcdonagh, Jens Ducree Jun 2015

An Integrated Centrifugo-Opto-Microfluidic Platform For Arraying, Analysis, Identification And Manipulation Of Individual Cells, Robert Burger, D Kurzbuch, Robert Gorkin Iii, Gregor Kijanka, Macdara Glynn, C Mcdonagh, Jens Ducree

Robert Gorkin III

In this work we present a centrifugal microfluidic system enabling highly efficient collective trapping and alignment of particles such as microbeads and cells, their multi-colour fluorescent detection and subsequent manipulation by optical tweezers. We demonstrate array-based capture and imaging followed by "cherry-picking" of individual particles, first for fluorescently labelled polystyrene (PS) beads and then for cells. Different cell lines are discriminated based on intracellular as well as surface-based markers.


Optical Sensing System Based On Wireless Paired Emitter Detector Diode Device And Ionogels For Lab-On-A-Disc Water Quality Analysis, Monika Czugala, Robert Gorkin Iii, Thomas Phelan, Jennifer Gaughran, Vincenzo Curto, Jens Ducree, Dermot Diamond, Fernando Benito-Lopez Jun 2015

Optical Sensing System Based On Wireless Paired Emitter Detector Diode Device And Ionogels For Lab-On-A-Disc Water Quality Analysis, Monika Czugala, Robert Gorkin Iii, Thomas Phelan, Jennifer Gaughran, Vincenzo Curto, Jens Ducree, Dermot Diamond, Fernando Benito-Lopez

Robert Gorkin III

This work describes the first use of a wireless paired emitter detector diode device (PEDD) as an optical sensor for water quality monitoring in a lab-on-a-disc device. The microfluidic platform, based on an ionogel sensing area combined with a low-cost optical sensor, is applied for quantitative pH and qualitative turbidity monitoring of water samples at point-of-need. The autonomous capabilities of the PEDD system, combined with the portability and wireless communication of the full device, provide the flexibility needed for on-site water testing. Water samples from local fresh and brackish sources were successfully analysed using the device, showing very good correlation …


Centrifugal Microfluidics For Cell Analysis, Robert Burger, Daniel Kirby, Macdara Glynn, Charles E Nwankire, Mary O'Sullivan, Jonathan Siegrist, David Kinahan, Gerson Aguirre, Gregor Kijanka, Robert Gorkin Iii, Jens Ducree Jun 2015

Centrifugal Microfluidics For Cell Analysis, Robert Burger, Daniel Kirby, Macdara Glynn, Charles E Nwankire, Mary O'Sullivan, Jonathan Siegrist, David Kinahan, Gerson Aguirre, Gregor Kijanka, Robert Gorkin Iii, Jens Ducree

Robert Gorkin III

Over the past two decades, centrifugal microfluidic systems have successfully demonstrated their capability for robust, high-performance liquid handling to enable modular, multipurpose lab-on-a-chip platforms for a wide range of lifescience applications. Beyond the handling of homogeneous liquids, the unique, rotationally controlled centrifugal actuation has proven to be specifically advantageous for performing cell and particle handling and assays. In this review we discuss technologies to implement two important steps for cell handling, namely separation and capturing/counting.


Quantitative Analysis Of Structure And Bandgap Changes In Graphene Oxide Nanoribbons During Thermal Annealing, Yu Zhu, Xianyu Li, Qinjia Cai, Zhengzong Sun, Gilberto Casillas, Miguel Jose-Yacaman, Rafael Verduzco, James Tour May 2014

Quantitative Analysis Of Structure And Bandgap Changes In Graphene Oxide Nanoribbons During Thermal Annealing, Yu Zhu, Xianyu Li, Qinjia Cai, Zhengzong Sun, Gilberto Casillas, Miguel Jose-Yacaman, Rafael Verduzco, James Tour

Yu Zhu

Graphene oxide nanoribbons (GONRs) are wide bandgap semiconductors that can be reduced to metallic graphene nanoribbons. The transformation of GONRs from their semiconductive to the metallic state by annealing has attracted significant interest due to its simplicity. However, the detailed process by which GONRs transform from widebandgap semiconductors to semimetals with a near zero bandgap is unclear. As a result, precise control of the bandgap between these two states is not currently achievable. Here, we quantitatively examine the removal of oxygen-containing groups and changes in the bandgap during thermal annealing of GONRs. X-ray photoelectron spectroscopy measurements show the progressive removal …


Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona Jul 2013

Texture Analysis Using Gabor Wavelets, Golshah Naghdy, Jianli Wang, Philip Ogunbona

Jianli Wang

Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for …


Mpeg-7 Visual Descriptors And Discriminant Analysis, Jun Zhang, Lei Ye, Jianhua Ma Dec 2012

Mpeg-7 Visual Descriptors And Discriminant Analysis, Jun Zhang, Lei Ye, Jianhua Ma

Dr Lei Yi

No abstract provided.


A Fundamental Analysis Of Continuous Flow Bioreactor Models With Recycle Around Each Reactor Governed By Contois Kinetics. Iii. Two And Three Reactor Cascades, Rubayyi Alqahtani, Mark Nelson, Annette Worthy Dec 2012

A Fundamental Analysis Of Continuous Flow Bioreactor Models With Recycle Around Each Reactor Governed By Contois Kinetics. Iii. Two And Three Reactor Cascades, Rubayyi Alqahtani, Mark Nelson, Annette Worthy

Associate Professor Annette Worthy

The steady-state treatment of industrial wastewaters in a cascade reactor with recycle is analyzed. A number of cascades with alternative arrangements of the settling units are considered. Specifically, we consider the case when the recycle stream leaving a settling unit which is placed around a reactor goes back into the feed stream for that reactor. The Contois kinetic model is used to study the degradation of biodegradable organic materials. The steady-states for the model are found and their stability determined as a function of the total residence time in the cascade. Asymptotic solutions in the limit of large total residence …


Analysis Of A Chemostat Model With Variable Yield Coefficient: Contois Kinetics., Rubayyi Alqahtani, Mark Nelson, Annette Worthy Dec 2012

Analysis Of A Chemostat Model With Variable Yield Coefficient: Contois Kinetics., Rubayyi Alqahtani, Mark Nelson, Annette Worthy

Associate Professor Annette Worthy

Food processing wastewaters and slurries typically contain high concentrations of biodegradable organic matter. Before the wastewater can be discharged, the pollutant concentration must be reduced. One way to achieve this is by using a biological species (biomass) that consumes the organic matter (substrate). We investigate an unstructured kinetic model for a bioreactor with a variable yield coefficient, taking into account the death rate of the microorganisms. The growth rate is given by a Contois expression, which is often used to model the growth of biomass in wastewaters containing biodegradable organic materials. The analysis shows that the system has natural oscillations …


The Analysis Of Utility Voltage Sag Data, Victor Gosbell, D Robinson, Sarath Perera Dec 2012

The Analysis Of Utility Voltage Sag Data, Victor Gosbell, D Robinson, Sarath Perera

Dr Duane Robinson

No abstract provided.


A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Non-Competitive Product Inhibition. Ii. Exponential Inhibition, Mark Nelson, Wei Xian Lim Dec 2012

A Fundamental Analysis Of Continuous Flow Bioreactor And Membrane Reactor Models With Non-Competitive Product Inhibition. Ii. Exponential Inhibition, Mark Nelson, Wei Xian Lim

Associate Professor Mark Nelson

The steady-state production of a product produced through the growth of microorganisms in a continuous flow bioreactor is presented. A generalised reactor model is used in which both the classic well-stirred bioreactor and the idealised membrane bioreactor are considered as special cases. The reaction is assumed to be governed by Monod growth kinetics subject to non-competitive product inhibition. Inhibition is modelled as a decaying exponential function of the product concentration. This reaction scheme is well documented in the literature, although a stability analysis of the governing equations has not previously been presented. The performance of a well-stirred bioreactor with microorganisms …


Analysis Of A Chemostat Model With Variable Yield Coefficient: Contois Kinetics., Rubayyi Alqahtani, Mark Nelson, Annette Worthy Dec 2012

Analysis Of A Chemostat Model With Variable Yield Coefficient: Contois Kinetics., Rubayyi Alqahtani, Mark Nelson, Annette Worthy

Associate Professor Mark Nelson

Food processing wastewaters and slurries typically contain high concentrations of biodegradable organic matter. Before the wastewater can be discharged, the pollutant concentration must be reduced. One way to achieve this is by using a biological species (biomass) that consumes the organic matter (substrate). We investigate an unstructured kinetic model for a bioreactor with a variable yield coefficient, taking into account the death rate of the microorganisms. The growth rate is given by a Contois expression, which is often used to model the growth of biomass in wastewaters containing biodegradable organic materials. The analysis shows that the system has natural oscillations …


A Fundamental Analysis Of Continuous Flow Bioreactor Models And Membrane Reactor Models To Process Industrial Wastewaters, Mark Nelson, Xiao Dong Chen, Easwaran Balakrishnan, Harvinder Sidhu Dec 2012

A Fundamental Analysis Of Continuous Flow Bioreactor Models And Membrane Reactor Models To Process Industrial Wastewaters, Mark Nelson, Xiao Dong Chen, Easwaran Balakrishnan, Harvinder Sidhu

Associate Professor Mark Nelson

No abstract provided.


A Fundamental Analysis Of Continuous Flow Bioreactor Models With Recycle Around Each Reactor Governed By Contois Kinetics. Iii. Two And Three Reactor Cascades, Rubayyi Alqahtani, Mark Nelson, Annette Worthy Dec 2012

A Fundamental Analysis Of Continuous Flow Bioreactor Models With Recycle Around Each Reactor Governed By Contois Kinetics. Iii. Two And Three Reactor Cascades, Rubayyi Alqahtani, Mark Nelson, Annette Worthy

Associate Professor Mark Nelson

The steady-state treatment of industrial wastewaters in a cascade reactor with recycle is analyzed. A number of cascades with alternative arrangements of the settling units are considered. Specifically, we consider the case when the recycle stream leaving a settling unit which is placed around a reactor goes back into the feed stream for that reactor. The Contois kinetic model is used to study the degradation of biodegradable organic materials. The steady-states for the model are found and their stability determined as a function of the total residence time in the cascade. Asymptotic solutions in the limit of large total residence …


A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark Nelson, Annette Worthy Dec 2012

A Mathematical Model For The Biological Treatment Of Industrial Wastewater In A Reactor Cascade, Rubayyi Turki Alqahtani, Mark Nelson, Annette Worthy

Associate Professor Mark Nelson

Many industrial processes, particularly in the food industry, produce slurries or wastewaters containing high concentrations of biodegradable organic materials. Before these contaminated wastewaters can be discharged the concentration of the biodegradable organic pollutant must be reduced. One way to do this is to pass the wastewater through a bioreactor containing biomass which grows through consumption of the pollutant. Anaerobic conditions are often favoured for the processing of waste materials with high levels of biodegradable organic pollutants as these can be removed with low investment and operational costs. We investigate the steady state effluent concentration leaving a cascade of two reactors. …


Mathematical Analysis Of Self-Heating In Compost Piles, Harvinder Sidhu, Mark Nelson, Nadeem Ansari, Xiao Dong Chen Dec 2012

Mathematical Analysis Of Self-Heating In Compost Piles, Harvinder Sidhu, Mark Nelson, Nadeem Ansari, Xiao Dong Chen

Associate Professor Mark Nelson

We model the increase in temperature in compost piles or landfill sites due to micro-organisms undergoing exothermic reactions. The model incorporates the heat release due to biological activity within the pile and the heat release due to the oxidation of cellulosic materials. The heat release rate due to biological activity is modelled by a function which is a monotonic increasing function of temperature over a particular range and followed by a monotone decreasing function of temperature. This functionality represents the fact that micro-organisms die or become dormant at high temperatures. The heat release due to the oxidation reaction is modelled …


Regression Analysis Under Probabilistic Multi-Linkage, Gunky Kim, Raymond Chambers Dec 2012

Regression Analysis Under Probabilistic Multi-Linkage, Gunky Kim, Raymond Chambers

Dr Gunky Kim

"Linkage errors can occur when probability-based methods are used to link records from two distinct data sets corresponding to the same target population. Current approaches to modifying standard methods of regression analysis to allow for these errors only deal with the case of two linked data sets and assume that the linkage process is complete, that is, all records on the two data sets are linked. This study extends these ideas to accommodate the situation when more than two data sets are probabilistically linked and the linkage is incomplete."


Lie Group Symmetry Analysis Of Transport In Porous Media With Variable Transmissivity, James Hill, Maureen Edwards, A P S Selvadurai Dec 2012

Lie Group Symmetry Analysis Of Transport In Porous Media With Variable Transmissivity, James Hill, Maureen Edwards, A P S Selvadurai

Dr Maureen Edwards

We determine the Lie group symmetries of the coupled partial differential equations governing a novel problem for the transient flow of a fluid containing a solidifiable gel, through a hydraulically isotropic porous medium. Assuming that the permeability ($K^*$) of the porous medium is a function of the gel concentration ($c^*$), we determine a number of exact solutions corresponding to the cases where the concentration-dependent permeability is either arbitrary or has a power law variation or is a constant. Each case admits a number of distinct Lie symmetries and the solutions corresponding to the optimal systems are determined. Some typical concentration …


It Governance Silo In The Firm: An Analysis Of Governance Research Literature, Akemi Chatfield, Padmaharsha Wanninayaka Dec 2012

It Governance Silo In The Firm: An Analysis Of Governance Research Literature, Akemi Chatfield, Padmaharsha Wanninayaka

Dr Akemi Chatfield

No abstract provided.


The Analysis Of Stratified Multiple Responses, Ivy Liu, Thomas Suesse Dec 2012

The Analysis Of Stratified Multiple Responses, Ivy Liu, Thomas Suesse

Dr Thomas Suesse

Surveys often contain qualitative variables for which respondents may select any number of the outcome categories. For instance, for the question “What type of contraception have you used?” with possible responses (oral, condom, lubricated condom, spermicide, and diaphragm), respondents would be instructed to select as many of the outcomes that apply. This situation is known as multiple responses. When the data includes stratification variables, we discuss two approaches: (1) the “GEE” approach which uses logit models directly applying the generalized estimating equations (GEE) method (Liang and Zeger, 1986); and (2) the “GMH” approach which extends the generalized Mantel–Haenszel type estimators …


Unravelling Ecological Analysis, David Steel, Mark Tranmer, D Holt Dec 2012

Unravelling Ecological Analysis, David Steel, Mark Tranmer, D Holt

Professor David Steel

No abstract provided.


A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis Dec 2012

A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis

Dr Alison Smith

The statistical analysis of late-stage variety evaluation trials using a mixed model is described, with one- or two-stage approaches to the analysis. Two sets of trials, from Australia and the UK, were used to provide realistic scenarios for a simulation study to evaluate the different methods of analysis. This study showed that a one-stage approach gave the most accurate predictions of variety performance overall or within each environment, across a range of models, as measured by mean squared error of prediction or realized genetic gain. A weighted two-stage approach performed adequately for variety predictions both overall and within environments, but …


Enhanced Diagnostics For The Spatial Analysis Of Field Trials, Katia Stefanova, Alison Smith, Brian Cullis Dec 2012

Enhanced Diagnostics For The Spatial Analysis Of Field Trials, Katia Stefanova, Alison Smith, Brian Cullis

Dr Alison Smith

We report an analysis of a series of uniformity field trials using the technique proposed by Gilmour, Cullis, and Verbyla. In particular, we clarify the role of the sample variogram and present a range of enhanced graphical diagnostics to aid the spatial modeling process.We highlight the implications of the presence of extraneous variation related to commonly used agronomic practices, such as serpentine harvesting.


Research Methods And The Relevance Of The Is Discipline: A Critical Analysis Of The Role Of Methodological Pluralism, Rajeev Sharma Dec 2012

Research Methods And The Relevance Of The Is Discipline: A Critical Analysis Of The Role Of Methodological Pluralism, Rajeev Sharma

Associate Professor Rajeev Sharma

No abstract provided.


The Analysis Of Utility Voltage Sag Data, Victor Gosbell, D Robinson, Sarath Perera Nov 2012

The Analysis Of Utility Voltage Sag Data, Victor Gosbell, D Robinson, Sarath Perera

Associate Professor Sarath Perera

No abstract provided.


Assessment Of Distributed Generation Impacts On Distribution Networks Using Unbalanced Three-Phase Power Flow Analysis, Md Jan-E- Alam, Kashem Muttaqi, Danny Sutanto Nov 2012

Assessment Of Distributed Generation Impacts On Distribution Networks Using Unbalanced Three-Phase Power Flow Analysis, Md Jan-E- Alam, Kashem Muttaqi, Danny Sutanto

Associate Professor Kashem Muttaqi

Impacts of Distributed Generation (DG) resources on distribution networks have been studied. A Newton-Raphson algorithm based three phase unbalance power flow program has been developed to incorporate the effects of system unbalance and single phase DG injection. Power flow equations have been formulated and solved in phase coordinated form. Effects of substation load-tap changer, voltage regulator, shunt capacitor and different type of load models have been considered in the development of the program. Phase asymmetry of distribution networks has been treated by modifying the Jacobian matrix. The proposed technique has been tested on IEEE 34 bus distribution test system for …


Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky Nov 2012

Dynamic Modelling Of Hydroelectric Turbine-Generator Unit Connected To A Hvdc System For Small Signal Stability Analysis, Yin Chin Choo, Ashish Agalgaonkar, Kashem Muttaqi, Sarath Perera, Michael Negnevitsky

Associate Professor Kashem Muttaqi

This paper presents the linearised small-signal dynamic modelling of hydroelectric turbine-generator (TG) unit with CIGRE first high-voltage direct current (HVDC) benchmark system in the synchronously rotating D-Q reference frame for small-signal stability analysis. The interaction behaviour between the hydroelectric unit and the dynamics and control of HVDC system is investigated utilising eigen-analysis,participation factor analysis and by conducting sensitivity studies. The computation of eigenvalues and eigenvectors for small signal stability analysis provides an invaluable insight onto the power system dynamic behaviour by characterising the damping and frequency of the system oscillatory modes. Theconsequences of different operating conditions, such as active and …


The Analysis Of Pattern Change In Intron Sequences, Jinda Kongcharoen, Yan-Xia Lin, Rachel Caldwell, Yiren Yang, Ren Zhang Nov 2012

The Analysis Of Pattern Change In Intron Sequences, Jinda Kongcharoen, Yan-Xia Lin, Rachel Caldwell, Yiren Yang, Ren Zhang

Associate Professor Yan-Xia Lin

The Generalized Bernoulli Modeling approach is used to analyze the pattern change in intron sequences of a model plant species Arabidopsis thaliana. The influence of the intron length and the number of GC on the intron sequence pattern changes is examined. Two other gene properties, the gene expression level and the protein function encoded are also assessed. Among the random sampled intron sequences,10.71% of them have been identified to have sequence pattern change. Our study shows that the number of GC and the intron length significantly influence the intron pattern change while the gene expression level and the protein function …


Automated Change Impact Analysis For Agent Systems, Aditya Ghose, Hoa Dam Nov 2012

Automated Change Impact Analysis For Agent Systems, Aditya Ghose, Hoa Dam

Dr Hoa Dam

Intelligent agent technology has evolved rapidly over the past few years along with the growing number of agent systems in various domains. Although a substantial amount of work in agent-oriented software engineering has provided methodologies for analysing, designing and implementing agent-based systems, recent studies have highlighted that there has been very little work on maintenance and evolution of agent-based systems. A critical issue in software maintenance and evolution is change impact analysis: determining the potential consequences of a proposed change. There has been a proliferation of techniques proposed to support change impact analysis of procedural or object-oriented systems, but to …


The Analysis Of Longitudinal Data Using Mixed Model L-Splines, S. Welham, Brian Cullis, M. Kenward, R Thompson Nov 2012

The Analysis Of Longitudinal Data Using Mixed Model L-Splines, S. Welham, Brian Cullis, M. Kenward, R Thompson

Professor Brian Cullis

L-splines are a large family of smoothing splines defined in terms of a linear differential operator. This article develops L-splines within the context of linear mixed models and uses the resulting mixed model L-spline to analyze longitudinal data from a grassland experiment. In the spirit of time-series analysis, a periodic mixed model L-spline is developed, which partitions data into a smooth periodic component plus smooth long-term trend.


A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis Nov 2012

A Comparison Of Analysis Methods For Late-Stage Variety Evaluation Trials, Sue Welham, Beverley Gogel, Alison Smith, Robin Thompson, Brian Cullis

Professor Brian Cullis

The statistical analysis of late-stage variety evaluation trials using a mixed model is described, with one- or two-stage approaches to the analysis. Two sets of trials, from Australia and the UK, were used to provide realistic scenarios for a simulation study to evaluate the different methods of analysis. This study showed that a one-stage approach gave the most accurate predictions of variety performance overall or within each environment, across a range of models, as measured by mean squared error of prediction or realized genetic gain. A weighted two-stage approach performed adequately for variety predictions both overall and within environments, but …