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Full-Text Articles in Engineering

Study, Design And Performance Analysis Of Grid-Connected Photovoltaic Power Systems, Dr. Adel A. Elbaset Sep 2015

Study, Design And Performance Analysis Of Grid-Connected Photovoltaic Power Systems, Dr. Adel A. Elbaset

Dr. Adel A. Elbaset

Solar photovoltaic (PV) is one of the most promising renewable energy resources that converts solar energy into electricity with environment friendly manner. However, it has low efficiency and high relative costs. In order to overcome these drawbacks, a grid-connected PV energy system should be required to satisfy the load demand. The aim of this thesis is to study, design and performance analysis of grid-connected PV system as follows: • System modeling; that is composed of two-diode model to describe the I-V and P-V characteristic curves of PV system performance. Modeling of PV system represents the main goal in the design …


Improved Workflow Modelling Using Role Activity Diagram-Based Modelling With Application To A Radiology Service Case Study, Nagesh Shukla, John Keast, Darek Ceglarek Apr 2015

Improved Workflow Modelling Using Role Activity Diagram-Based Modelling With Application To A Radiology Service Case Study, Nagesh Shukla, John Keast, Darek Ceglarek

Nagesh Shukla

The modelling of complex workflows is an important problem-solving technique within healthcare settings. However, currently most of the workflow models use a simplified flow chart of patient flow obtained using on-site observations, groupbased debates and brainstorming sessions, together with historic patient data. This paper presents a systematic and semi-automatic methodology for knowledge acquisition with detailed process representation using sequential interviews of people in the key roles involved in the service delivery process. The proposed methodology allows the modelling of roles, interactions, actions, and decisions involved in the service delivery process. This approach is based on protocol generation and analysis techniques …


The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld Jan 2015

The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld

Anthony A Espinoza Mr

High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly 192Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 uGy m2/h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the …


A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou Oct 2014

A Comparative Study Of Magnetic Behaviors In Tbni2, Tbmn2 And Tbni2mn, Jianli Wang, M F. Md Din, Shane Kennedy, F Hong, Stewart J. Campbell, A J. Studer, G H. Wu, Zhenxiang Cheng, S X. Dou

Shi Xue Dou

All TbNi2, TbMn2, and TbNi2Mn compounds exhibit the cubic Laves phase with AB2-type structure in spite of the fact that the ratio of the Tb to transition-metal components in TbNi2Mn is 1:3. Rietveld refinement indicates that in TbNi2Mn the Mn atoms are distributed on both the A (8a) and B (16d) sites. The values of the lattice constants were measured to be a = 14.348 Å (space group F-43 m), 7.618 Å, and 7.158 Å (space group Fd-3 m) for TbNi2, TbMn2, and TbNi2Mn, respectively. The magnetic transition temperatures TC were found to be TC = 38 K and TC …


A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop Mar 2014

A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop

Cholachat Rujikiatkamjorn

This paper presents a laboratory study of interface behavior between ballast and geogrid under various degree of fouling by coal fines. The stress-displacement behaviour of fresh and fouled ballast with geogrid was investigated through a series of large-scale direct shear tests where the fouling degree varied from 0% to 95% Void Contamination Index (VCI), at normal stresses ranging from 15kPa to 75kPa. The results showed that geogrid enhances the shear strength and increases apparent angle of shearing resistance, while only slightly reduces the vertical displacement of the composite geogrid-ballast system. However, when ballast was contaminated by coal fines, the influences …


Laboratory Study Of Small-Strain Behavior Of A Compacted Silty Sand, Ana Heitor, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Laboratory Study Of Small-Strain Behavior Of A Compacted Silty Sand, Ana Heitor, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Cholachat Rujikiatkamjorn

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 …


A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop Mar 2014

A Laboratory Study Of Railway Ballast Behaviour Under Various Fouling Degree, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Ngoc Trung Ngo, Matthew Coop

Buddhima Indraratna

This paper presents a laboratory study of interface behavior between ballast and geogrid under various degree of fouling by coal fines. The stress-displacement behaviour of fresh and fouled ballast with geogrid was investigated through a series of large-scale direct shear tests where the fouling degree varied from 0% to 95% Void Contamination Index (VCI), at normal stresses ranging from 15kPa to 75kPa. The results showed that geogrid enhances the shear strength and increases apparent angle of shearing resistance, while only slightly reduces the vertical displacement of the composite geogrid-ballast system. However, when ballast was contaminated by coal fines, the influences …


Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng Mar 2014

Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng

Buddhima Indraratna

This study is an attempt to investigate the effectiveness of a prefabricated vertical drain (PVD) installed in remoulded soft clay, where a large-scale cyclic triaxial process simulation rig was employed to simulate cyclic loading representing a track environment. The experimental data show that PVD successfully prevents excessive accumulation of pore water pressure during cyclic loading, and their dissipation continues to occur after the load is removed. The findings of this study have direct significance to rail track environments, e.g. in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently adopted.


Laboratory Study Of Small-Strain Behavior Of A Compacted Silty Sand, Ana Heitor, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Laboratory Study Of Small-Strain Behavior Of A Compacted Silty Sand, Ana Heitor, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Buddhima Indraratna

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 …


Microstructures Of Conducting Polymers: Patterning And Actuation Study, Babita Gaihre, Bo Weng, Syed A. Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace Mar 2014

Microstructures Of Conducting Polymers: Patterning And Actuation Study, Babita Gaihre, Bo Weng, Syed A. Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace

Gordon Wallace

The conducting polymers exhibit electrochemically driven expansion and shrinkage due to ingress and egress of dopant ions in response to potential applied. In this paper, we report on patterning of microdots and microsquares of polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,3-dihexyl-3-4-dihydro-2H-thieno[3,4b][1,4]-dioxepine PProDOT(Hx) 2 and their behaviour under voltage change. Stainless steel mesh was used to deposit microdots and inkjet-printed cellulose girds were used to deposit microsqures of the conducting polymers on the ITO surface. It was found that PPy showed distinct actuation in the z direction while colour change was prominent in the case of PEDOT and PProDOT(Hx)2.


Aging Effect Evolution During Ferroelectric-Ferroelectric Phase Transition: A Mechanism Study, Zuyong Feng, Zhenxiang Cheng, Dongqi Shi, S X. Dou Mar 2014

Aging Effect Evolution During Ferroelectric-Ferroelectric Phase Transition: A Mechanism Study, Zuyong Feng, Zhenxiang Cheng, Dongqi Shi, S X. Dou

Shi Xue Dou

Aging can significantly modify the dielectric, piezoelectric, and ferroelectric performance of ferroelectrics. However, little attention has been paid to the aging effect during ferroelectric-ferroelectric phase transitions that is essentially correlated with real applications. In this letter, the authors report the aging effect evolution between two ferroelectric phases in an acceptor-doped piezoceramics. The results show that aging-induced double hysteresis loops were exhibited in different ferroelectric phases, but disappeared during ferroelectric-ferroelectric phase transitions, suggesting the mechanism that the intrinsic restoring force for the reversible switching of domains caused by the alignment of defect dipoles was weakened due to ferroelectric dipole reorientation.


Neutron Diffraction Study Of Mnniga2 - Structural And Magnetic Behaviour, Jianli Wang, L Ma, M Hofmann, M Avdeev, S J. Kennedy, S J. Campbell, M F. Md Din, M Hoelzel, G H. Wu, S X. Dou Mar 2014

Neutron Diffraction Study Of Mnniga2 - Structural And Magnetic Behaviour, Jianli Wang, L Ma, M Hofmann, M Avdeev, S J. Kennedy, S J. Campbell, M F. Md Din, M Hoelzel, G H. Wu, S X. Dou

Shi Xue Dou

MnNiGa2 crystallizes in the L21 (Heusler) structure and has a ferromagnetic ordering temperature TC ∼ 192 K. Rietveld refinement of the neutron diffraction patterns indicates that the Ga atoms occupy the equivalent 8c position, while Mn and Ni share the 4a (0, 0, 0) and 4b (0.5, 0.5, 0.5) sites with a mixed occupancy of Mn and Ni atoms. It is found that that ∼83% of Mn and ∼17% Ni are located at the 4a site while ∼83% of Ni and ∼17% Mn occupy the 4b site. There is no evidence of a magneto-volume effect around TC. In agreement with …


The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld Feb 2014

The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld

Stéphanie Corde

High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly 192Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 uGy m2/h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the …


Similarity-Based Search For Model Checking: A Pilot Study With Java Pathfinder, Elmin Ibrahimov, Jixing Wang, Zhiquan Zhou Jan 2014

Similarity-Based Search For Model Checking: A Pilot Study With Java Pathfinder, Elmin Ibrahimov, Jixing Wang, Zhiquan Zhou

Dr Zhiquan Zhou

When a model checker cannot explore the entire state space because of limited resources, model checking becomes a kind of testing with an attempt to find a failure (violation of properties) quickly. We consider two state sequences in model checking: (i) the sequence in which new states are generated, and (ii) the sequence in which the states generated in sequence (i) are checked for property violation. We observe that neighboring states in sequence (i) often have similarities in certain ways. Based on this observation we propose a search strategy, which generates sequence (ii) in such a way that similar states …


Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson Dec 2013

Dynamic Characteristics Of A Hybrid Microgrid With Inverter And Non- Inverter Interfaced Renewable Energy Sources: A Case Study, A V. Jayawardena, L G. Meegahapola, S Perera, D A. Robinson

Dr Lasantha G Meegahapola

Microgrids are becoming important constituents of electric power distribution networks. Microgrids are typically comprised of both inverter interfaced (e.g. double-fed induction generator (DFIG), solar-photovoltaic (PV) system) and non-inverter interfaced (e.g. synchronous generator) renewable energy generators (REGs), hence their dynamic characteristics are significantly different from the conventional grids comprised of centralised synchronous generators. Different inherent characteristics of REGs, power dispatch levels, relative REG capacities, and external grid characteristics are some of the important features of significant interest in relation to microgrid dynamic behaviour. For this study a microgrid model was developed in DIgSILENT Power Factory based on the IEEE-13 bus system …


The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld Nov 2013

The Feasibility Study And Characterziation Of A Two-Dimensional Diode Array In “Magic Phantom” For High Dose Rate Brachytherapy Quality Assurance, A Espinoza, B Beeksma, M Petasecca, I Fuduli, C Porumb, D L. Cutajar, S Corde, M A. Jackson, M Lf Lerch, Anatoly B. Rosenfeld

Michael L.F. Lerch

High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly 192Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 uGy m2/h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the …


Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld Nov 2013

Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld

Michael L.F. Lerch

Silicon microdosimeters for the characterisation of mixed radiation fields relevant to the space radiation environment have been under continual development at the Centre for Medical Radiation Physics for over a decade. These devices are useful for the prediction of single event upsets in microelectronics and for radiation protection of spacecraft crew. The latest development in silicon microdosimetry is a family of large-area n-SOI microdosimeters for real-time dosimetry in space radiation environments. The response of n-SOI microdosimeters to 2 MeV H and 5.5 MeV He ions has been studied to investigate their charge collection characteristics. The studies have confirmed 100% yield …


The Study Of Flood Hydraulics Before The Building Of Maroon Dam By Hec-Ras, Maskingam And Muskingum - Cunge Method, Mohammad Hossein Naghshine, Farhad Fakheri Raof, Ali Khoshrftar Sep 2013

The Study Of Flood Hydraulics Before The Building Of Maroon Dam By Hec-Ras, Maskingam And Muskingum - Cunge Method, Mohammad Hossein Naghshine, Farhad Fakheri Raof, Ali Khoshrftar

Farhad Fakheri Raof

Routing of rivers which flow through the important areas is from the important river engineering measures. In this research, flood routing in the Maroon River has been studied bases on hydrometric stations between Behbahan and Chamnezam. Todays, numerical computer methods are developed for the Cent and Nante equations. The HEC-RAS software and Muskingum and Muskingum - corners methods are used for this work. HEC-RAS model with solving of dynamic equations motion simulates unsteady flow in the form of onedimensional flow in open channels. After calibration and testing, the results of these methods were compared.So, the HEC-RAS model results considerably better …


Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld Jun 2013

Large Area Silicon Microdosimeter For Dosimetry In High Let Space Radiation Fields: Charge Collection Study, Jayde Livingstone, Dale A. Prokopovich, Michael L. F Lerch, Marco Petasecca, Mark I. Reinhard, Hiroshi Yasuda, Marco Zaider, James F. Ziegler, Vincent L. Pisacane, John F. Dicello, Vladimir L. Perevertaylo, Anatoly B. Rosenfeld

Anatoly Rozenfeld

Silicon microdosimeters for the characterisation of mixed radiation fields relevant to the space radiation environment have been under continual development at the Centre for Medical Radiation Physics for over a decade. These devices are useful for the prediction of single event upsets in microelectronics and for radiation protection of spacecraft crew. The latest development in silicon microdosimetry is a family of large-area n-SOI microdosimeters for real-time dosimetry in space radiation environments. The response of n-SOI microdosimeters to 2 MeV H and 5.5 MeV He ions has been studied to investigate their charge collection characteristics. The studies have confirmed 100% yield …


Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou Jun 2013

Neutron Diffraction Study Of The Magnetic Order In Ndmn2ge1.6si0.4, Jianli Wang, Stewart J. Campbell, John M. Cadogan, A J Studer, Rong Zeng, S. X. Dou

Shi Xue Dou

Here we report a detailed investigation of NdMn2Ge1.6Si0.4; this forms part of our investigation of the magnetic order across the NdMn2Ge2−xSix (x = 0–2.0) series by magnetometry, x-ray diffraction and neutron diffraction over the temperature range 6–465 K. On decreasing the temperature from 465 K, NdMn2Ge1.6Si0.4 exhibits four magnetic transitions: (i) from paramagnetism to intralayer antiferromagnetism AFl at TIntraN ~ 430 K; (ii) AFl to canted ferromagnetism Fmc at TInterC ~ 330 K; (iii) Fmc to conical magnetic ordering of the Mn sublattice Fmi at Tcc ~ 178 K and (iv) Fmi(Mn) to Fmi(Mn)+F(Nd) at TNdC ~ 72 K.


A Study On The Charge-Discharge Mechanism Of Co3o4 As An Anode For The Li Ion Secondary Battery, Yong-Mook Kang, Min-Sang Song, Jin-Ho Kim, Hyun-Seok Kim, Min-Sik Park, Jai-Young Lee, Hua-Kun Liu, S X. Dou Jun 2013

A Study On The Charge-Discharge Mechanism Of Co3o4 As An Anode For The Li Ion Secondary Battery, Yong-Mook Kang, Min-Sang Song, Jin-Ho Kim, Hyun-Seok Kim, Min-Sik Park, Jai-Young Lee, Hua-Kun Liu, S X. Dou

Shi Xue Dou

Co3O4 has shown acceptable electrochemical properties as the anode material of Li secondary batteries. In detail, its capacity reached about 700 mAh/g, twice as high as graphite, and 93.4% of initial capacity was retained after 100 cycles. EIS (electrochemical impedance spectroscopy) analyses revealed that after the 1st cycle, the insertion or extraction of Li ions in Co3O4 can occur homogeneously and reversibly (randless-like behavior, homogeneous mixture: Co + Li2O (in the state of Li insertion), Co3O4 (in the state of Li extraction)). In fact, the coulombic efficiency of Co3O4 was almost 100% except for the 1st cycle. According to P. …


A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish May 2013

A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish

Nathan Larkin

In this study, the continuous cooling phase transformation behaviour of a quenched and tempered armour steel was investigated. A continuous cooling transformation diagram was constructed providing valuable information for predicting microstructural evolution and mechanical properties at different cooling rates during actual welding fabrication. Welding trials were carried out utilising flux-cored arc welding technique in combination with an austenitic stainless steel consumable. The effect of various preheat and interpass temperatures on cooling rate and consequently on the heat affected zone microstructure and mechanical properties of multipass welds were investigated.


Physicochemical Study Of Spiropyran-Terthiophene Derivatives: Photochemistry And Thermodynamics, Michele Zanoni, Simon Coleman, Kevin J. Fraser, Robert P. Byrne, Klaudia K. Wagner, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace, D Diamond Mar 2013

Physicochemical Study Of Spiropyran-Terthiophene Derivatives: Photochemistry And Thermodynamics, Michele Zanoni, Simon Coleman, Kevin J. Fraser, Robert P. Byrne, Klaudia K. Wagner, Sanjeev Gambhir, David L. Officer, Gordon G. Wallace, D Diamond

Gordon Wallace

The photochemistry and thermodynamics of two terthiophene (TTh) derivatives bearing benzospiropyran (BSP) moieties, 1-(3,3''-dimethylindoline-6'-nitrobenzospiropyranyl)-2-ethyl 4,4''-didecyloxy-2,2':5',2''-terthiophene-30-acetate (BSP-2) and 1-(3,3''-dimethylindoline-6'- nitrobenzospiropyranyl)-2-ethyl 4,4''-didecyloxy-2,2':5',2''-terthiophene-30-carboxylate (BSP-3), differing only by a single methylene spacer unit, have been studied. The kinetics of photogeneration of the equivalent merocyanine (MC) isomers (MC-2 and MC-3, respectively), the isomerisation properties of MC-2 and MC-3, and the thermodynamic parameters have been studied in acetonitrile, and compared to the parent, non-TTh-functionalised, benzospiropyran derivative, BSP-1. Despite the close structural similarity of BSP-2 and BSP-3, their physicochemical properties were found to differ significantly; examples include activation energies (Ea(MC-2) = 75.05 kJ mol-1, Ea(MC-3) = 100.39 …


Comparative Displacement Study Of Bilayer Actuators Comprising Of Conducting Polymers, Fabricated From Polypyrrole, Poly(3,4- Ethylenedioxythiophene) Or Poly(3,4-Propylenedioxythiophene), Babita Gaihre, Syed Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace Mar 2013

Comparative Displacement Study Of Bilayer Actuators Comprising Of Conducting Polymers, Fabricated From Polypyrrole, Poly(3,4- Ethylenedioxythiophene) Or Poly(3,4-Propylenedioxythiophene), Babita Gaihre, Syed Ashraf, Geoffrey M. Spinks, Peter C. Innis, Gordon G. Wallace

Gordon Wallace

The stress gradient generated due to electrochemical oxidation/reduction of a conducting polymer in a bilayer actuator causes a bending movement. Here we report a comparative study of the displacement of bilayer actuators prepared using different conducting polymers. The effects of conducting polymers obtained from electrochemical or chemical synthesis route: different polymers (polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) PEDOT and poly(3,3-dihexyl-3-4-dihydro-2H-thieno[3,4b][1,4]-dioxepine [PProDOT(Hx) 2]); and different electrolytes (0.1 M lithium trifluromethanesulfonate/propylenecarbonate (LiTFSI/PC) and 1-ethyl-3-methyl imidazolium trifluromethanesulfonate (EMITFSI)) on the displacement amplitude and displacement patterns of these actuators were investigated and compared. The results indicate that the bilayer actuator consisting of an electrochemically synthesized conducting polymer …


Simulation Study Of Quadrupole Dielectrophoretic Trapping, Weihua Li, J Sun, B Liu, X Z. Zhang Feb 2013

Simulation Study Of Quadrupole Dielectrophoretic Trapping, Weihua Li, J Sun, B Liu, X Z. Zhang

Professor Weihua Li

This paper presents a numerical study of particle trapping using quadrupole microfludic dielectrophoretic device. By taking into account the dielectrophoreis, viscous drag, the trajectory of particles flowing through the quadrupole device was obtained. Simulation results show that the device is effective for negative trapping, where particles are effectively trapped at the device centre. The device geometry is optimized by maximizing the dielectrophoretic force.


Monte Carlo Study Of The Potential Reduction In Out-Of-Field Dose Using A Patient-Specific Aperture In Pencil Beam Scanning Proton Therapy, Stephen J. Dowdell, Benjamin Clasie, Nicolas Depauw, Peter E. Metcalfe, Anatoly B. Rosenfeld, Hanne M. Kooy, Jacob B. Flanz, Harald Paganetti Sep 2012

Monte Carlo Study Of The Potential Reduction In Out-Of-Field Dose Using A Patient-Specific Aperture In Pencil Beam Scanning Proton Therapy, Stephen J. Dowdell, Benjamin Clasie, Nicolas Depauw, Peter E. Metcalfe, Anatoly B. Rosenfeld, Hanne M. Kooy, Jacob B. Flanz, Harald Paganetti

Anatoly Rozenfeld

This study is aimed at identifying the potential benefits of using a patientspecific aperture in proton beam scanning. For this purpose, an accurate Monte Carlo model of the pencil beam scanning (PBS) proton therapy (PT) treatment head at Massachusetts General Hospital (MGH) was developed based on an existing model of the passive double-scattering (DS) system. The Monte Carlo code specifies the treatment head at MGH with sub-millimeter accuracy. The code was configured based on the results of experimental measurements performed at MGH. This model was then used to compare out-of-field doses in simulated DS treatments and PBS treatments. For the …


Study Of Actuator Technologies For A Miniature Distributed, Fazel Naghdy, P Wong, P Carter, N Laszlo, Christopher D. Cook Aug 2012

Study Of Actuator Technologies For A Miniature Distributed, Fazel Naghdy, P Wong, P Carter, N Laszlo, Christopher D. Cook

Christopher Cook

Disnibuted Manipulation Environment (DME), is a concept based on the overall modularity of a manufacturing system including actuation, sensing, control, computing hardware and software. The basic building block of DME is the Manipulation Module (MM). Each MM may consist of up to three units including processing the unit, actuating unit and sensory unit. The emphasis of this paper is on the actuating unit of the Manipulation Modules used in DME. The generic features of the actuators suitable for this application are discussed and a review of the motion producing characteristics of the following actuator technologies is presented: electrostatic, electromagnetic, fluid …


Viscoelastic Study Of Conducting Polymers Using Quartz Crystal Microbalance, Mehrdad Bahrami Samani, Philip G. Whitten, Geoffrey M. Spinks, Christopher David Cook Aug 2012

Viscoelastic Study Of Conducting Polymers Using Quartz Crystal Microbalance, Mehrdad Bahrami Samani, Philip G. Whitten, Geoffrey M. Spinks, Christopher David Cook

Christopher Cook

Application of conducting polymers has been growing widely in different fields such as batteries, solar cells, capacitors and actuators. Mechanical properties of conducting polymers like flexibility, high power to mass ratio and high active strain make them potentially applicable to robotic and automation industries. Obviously, a dynamic model of the actuation phenomenon in conducting polymers is needed to study its controllability and also to optimize the mechanical performance. De Rossi and colleagues suggest treating the mechanical behaviour of conducting polymers separately from the viscoelastic structural model and electrochemical actuation[1]. But it has been observed that the effects of electrochemical actuation …


Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng Jan 2012

Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng

Cholachat Rujikiatkamjorn

This study is an attempt to investigate the effectiveness of a prefabricated vertical drain (PVD) installed in remoulded soft clay, where a large-scale cyclic triaxial process simulation rig was employed to simulate cyclic loading representing a track environment. The experimental data show that PVD successfully prevents excessive accumulation of pore water pressure during cyclic loading, and their dissipation continues to occur after the load is removed. The findings of this study have direct significance to rail track environments, e.g. in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently adopted.


Comparative Study Of Oxide Inclusion Dissolution In Cao-Sio2-Al2o3 Slag, Brian J. Monaghan, Liang Chen, J. Sorbe Jan 2012

Comparative Study Of Oxide Inclusion Dissolution In Cao-Sio2-Al2o3 Slag, Brian J. Monaghan, Liang Chen, J. Sorbe

Brian Monaghan

The dissolution of alumina, spinel and zirconia inclusions in a liquid CaO–SiO2–Al2O3 slag has been investigated using laser scanning confocal microscopy. Over the experimental temperature range 1477–1577uC it is found that alumina inclusions have a slower dissolution rate than that of spinel, and that zirconia inclusions form gas bubbles at the inclusion surface during dissolution. The results have been analysed assuming mass transfer control in the slag phase, and the slower rate of dissolution of the alumina inclusions is explained by the observation that they have a greater mass of aluminium oxide, the rate controlling species, than that of spinel.