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Full-Text Articles in Engineering
Editorial: Modelling And Simulation In Health Care Systems, Nagesh Shukla, Pascal Perez, Manoj K. Tiwari, Darek Ceglarek, Joana M. Dias
Editorial: Modelling And Simulation In Health Care Systems, Nagesh Shukla, Pascal Perez, Manoj K. Tiwari, Darek Ceglarek, Joana M. Dias
Faculty of Engineering and Information Sciences - Papers: Part A
Increasingly, changes in population demography, technological and medical advancements, and others, have affected the paradigm of health and social care systems worldwide. These changes have direct effect on organisation and working of health care systems whether they are hospitals, general practitioners or long-term care. An efficient and effective health care system is crucial for high quality of the life in the society. In recent times, major challenges faced by health care systems are accurate diagnosis, operational issues (such as bottlenecks, low throughput, low resource utilisation), hospital redesign, workforce planning and scheduling, streamlining of patient flow, performance management, disease monitoring, and …
Stabilization Of Track Substructure With Geoinclusions- Experimental Evidence And Dem Simulation, Ngoc Trung Ngo, Buddhima Indraratna, Cholachat Rujikiatkamjorn
Stabilization Of Track Substructure With Geoinclusions- Experimental Evidence And Dem Simulation, Ngoc Trung Ngo, Buddhima Indraratna, Cholachat Rujikiatkamjorn
Faculty of Engineering and Information Sciences - Papers: Part A
This article reviews on current knowledge of rail track geomechanics, including several important concepts and topics related to laboratory testing and computational modelling, to study the shear stress-strain and deformation of ballast improved by geosynthetics and recycled rubber mats. The effect that impact loads have on ballast degradation and its mitigation due to resilient synthetic mats (i.e. rubber mats) between the ballast and the subballast is investigated using large-scale impact-testing apparatus. Computational modelling with finite element and discrete element methods are increasingly being used to model ballasted tracks reinforced with geosynthetics to capture the continuum media of formation soils and …
Effect Of Deformation On Microstructure And Mechanical Properties Of Dual Phase Steel Produced Via Strip Casting Simulation, Zhiping Xiong, Andrii Kostryzhev, Nicole Stanford, Elena V. Pereloma
Effect Of Deformation On Microstructure And Mechanical Properties Of Dual Phase Steel Produced Via Strip Casting Simulation, Zhiping Xiong, Andrii Kostryzhev, Nicole Stanford, Elena V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
The strip casting is a recently appeared technology with a potential to significantly reduce energy consumption in steel production, compared to hot rolling and cold rolling. However, the quantitative dependences of the steel microstructure and mechanical properties on strip casting parameters are unknown and require investigation. In the present work we studied the effects of strain and interrupted cooling temperature on microstructure and mechanical properties in conventional dual phase steel (0.08C-0.81Si-1.47Mn-0.03Al wt%). The strip casting process was simulated using a Gleeble 3500 thermo-mechanical simulator. The steel microstructures were studied using optical, scanning and transmission electron microscopy. Mechanical properties were measured …
Organ Doses From Hepatic Radioembolization With 90y, 153sm, 166ho And 177lu: A Monte Carlo Simulation Study Using Geant4, N A A Hashikin, C H Y Yeong, Susanna Guatelli, B J J Abdullah, K H. Ng, Alessandra Malaroda, Anatoly B. Rosenfeld, A C. Perkins
Organ Doses From Hepatic Radioembolization With 90y, 153sm, 166ho And 177lu: A Monte Carlo Simulation Study Using Geant4, N A A Hashikin, C H Y Yeong, Susanna Guatelli, B J J Abdullah, K H. Ng, Alessandra Malaroda, Anatoly B. Rosenfeld, A C. Perkins
Faculty of Engineering and Information Sciences - Papers: Part A
90Y-radioembolization is a palliative treatment for liver cancer. 90Y decays via beta emission, making imaging difficult due to absence of gamma radiation. Since post-procedure imaging is crucial, several theranostic radionuclides have been explored as alternatives. However, exposures to gamma radiation throughout the treatment caused concern for the organs near the liver. Geant4 Monte Carlo simulation using MIRD Pamphlet 5 reference phantom was carried out. A spherical tumour with 4.3cm radius was modelled within the liver. 1.82GBq of 90Y sources were isotropically distributed within the tumour, with no extrahepatic shunting. The simulation was repeated with 153Sm, 166Ho and 177Lu. The estimated …
Microstructure And Mechanical Properties Of Strip Cast Trip Steel Subjected To Thermo-Mechanical Simulation, Zhiping Xiong, Andrii Kostryzhev, Liang Chen, Elena V. Pereloma
Microstructure And Mechanical Properties Of Strip Cast Trip Steel Subjected To Thermo-Mechanical Simulation, Zhiping Xiong, Andrii Kostryzhev, Liang Chen, Elena V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
Instead of hot rolling and cold rolling followed by annealing, strip casting is a more economic and environmentally friendly way to produce transformation-induced plasticity (TRIP) steels. According to industrial practice of strip casting, rapid cooling in this work was achieved using a dip tester, and a Gleeble 3500 thermo-mechanical simulator was used to carry out the processing route. A typical microstructure of TRIP steels, which included ~0.55 fraction of polygonal ferrite with bainite, retained austenite and martensite, was obtained. The effects of deformation (0.41 reduction) above non-recrystallisation temperature, isothermal bainite transformation temperature and the size of second phase region on …
An Implementation Of Discrete Electron Transport Models For Gold In The Geant4 Simulation Toolkit, D Sakata, Sebastien Incerti, M Bordage, N Lampe, Susumu Okada, Dimitris Emfietzoglou, Ioanna Kyriakou, K Murakami, Takashi Sasaki, H Tran, Susanna Guatelli, V Ivantchenko
An Implementation Of Discrete Electron Transport Models For Gold In The Geant4 Simulation Toolkit, D Sakata, Sebastien Incerti, M Bordage, N Lampe, Susumu Okada, Dimitris Emfietzoglou, Ioanna Kyriakou, K Murakami, Takashi Sasaki, H Tran, Susanna Guatelli, V Ivantchenko
Faculty of Engineering and Information Sciences - Papers: Part A
Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. …
Particle Size Segregation Of Bulk Material In Dustiness Testers Via Dem Simulation, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych
Particle Size Segregation Of Bulk Material In Dustiness Testers Via Dem Simulation, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych
Faculty of Engineering and Information Sciences - Papers: Part A
Dustiness testers are used to quantify the level of dust within a bulk material. The generation of dust can occur as a result of many bulk material handling activities, including filling or discharge from storage bins, during free-fall, material impact on conveyor transfers, or impact with other materials. Dust generation can have a serious impact to the environment as well as workers and nearby communities. This paper presents the findings of a discrete element modeling (DEM) study of the flow behavior of a range of binary granular mixes tested in the European Standard and the Australian Standard dustiness testers. Due …
The Shear Response Of Copper Bicrystals With Σ11 Symmetric And Asymmetric Tilt Grain Boundaries By Molecular Dynamics Simulation, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei
The Shear Response Of Copper Bicrystals With Σ11 Symmetric And Asymmetric Tilt Grain Boundaries By Molecular Dynamics Simulation, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei
Faculty of Engineering and Information Sciences - Papers: Part A
Grain boundaries (GBs) are important microstructure features and can significantly affect the properties of nanocrystalline materials. Molecular dynamics simulation was carried out in this study to investigate the shear response and deformation mechanisms of symmetric and asymmetric Σ11 tilt GBs in copper bicrystals. Different deformation mechanisms were reported, depending on GB inclination angles and equilibrium GB structures, including GB migration coupled to shear deformation, GB sliding caused by local atomic shuffling, and dislocation nucleation from GB. The simulation showed that migrating Σ11(1 1 3) GB under shear can be regarded as sliding of GB dislocations and their combination along the …
Figures Of Merit For Simultaneous Inference And Comparisons In Simulation Experiments, Noel A. Cressie, Sandy Burden
Figures Of Merit For Simultaneous Inference And Comparisons In Simulation Experiments, Noel A. Cressie, Sandy Burden
Faculty of Engineering and Information Sciences - Papers: Part A
2015 John Wiley & Sons, Ltd. This article considers the traditional figures of merit, namely, bias and mean squared (prediction) error, which are typically used to evaluate simulation experiments. We propose functions of them that account for different variables' units; these alternative figures of merit are closely tied to simultaneous multivariate inference on an unknown parameter vector or unknown state vector. Their usefulness is illustrated in a simulation experiment, where the goal is to determine the statistical properties associated with prediction of a multivariate state.
Molecular Dynamics Simulation On Generalized Stacking Fault Energies Of Fcc Metals Under Preloading Stress, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei, Guillaume Michal
Molecular Dynamics Simulation On Generalized Stacking Fault Energies Of Fcc Metals Under Preloading Stress, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei, Guillaume Michal
Faculty of Engineering and Information Sciences - Papers: Part A
Molecular dynamics (MD) simulations are performed to investigate the effects of stress on generalized stacking fault (GSF) energy of three fcc metals (Cu, Al, and Ni). The simulation model is deformed by uniaxial tension or compression in each of [111], [11-2], and [1-10] directions, respectively, before shifting the lattice to calculate the GSF curve. Simulation results show that the values of unstable stacking fault energy (γusf), stable stacking fault energy (γsf), and unstable twin fault energy (γutf) of the three elements can change with the preloaded tensile or compressive stress in different directions. The ratio of γsf/γusf, which is related …
A Round-Robin Test With Thermal Simulation Of The Welding Haz To Draw Cct Diagrams: A Need For Harmonized Procedures And Microconstituent Terminologies, Americo Scotti, Huijun Li, Rosa M. Miranda
A Round-Robin Test With Thermal Simulation Of The Welding Haz To Draw Cct Diagrams: A Need For Harmonized Procedures And Microconstituent Terminologies, Americo Scotti, Huijun Li, Rosa M. Miranda
Faculty of Engineering and Information Sciences - Papers: Part A
Thermal simulations of heat affected zone (HAZ) have been widely used. This is an economic expedite process for phase transformation evaluations in steels when subjected to weld thermal cycles as well as to draw continuous cooling transformation (CCT) diagrams. Different approaches for the simulation and parameter settings have been used by several researchers, yet leading to not always even results. Thus, it was proposed a round-robin test trial performed by different laboratories, aiming to evidence potential sources of error or inadequacy of the approaches. A High Strength Low Alloy (HSLA) steel was used as a case study. Despite the limited …
A Combined Experimental And Simulation Method For Appraising The Energy Performance Of Green Roofs In Ningbo's Chinese Climate, Georgios Kokogiannakis, Jo Darkwa, Kate Yuan
A Combined Experimental And Simulation Method For Appraising The Energy Performance Of Green Roofs In Ningbo's Chinese Climate, Georgios Kokogiannakis, Jo Darkwa, Kate Yuan
Faculty of Engineering and Information Sciences - Papers: Part A
A passive means of lowering the energy demand of buildings is the application of green roofs. The complexity between heat and moisture exchanges in green roof layers and the large variations of green roof types make the need for experimental or simulation assessments necessary for quantifying the energy benefits from green roofs. The current treatment of green roofs in simulation programs is either over-simplistic, for example by ignoring heat and moisture exchanges such as evapotranspiration, or the more advanced models have limitations and require inputs that are rarely available in practice. In this paper a combination of experimental and modelling …
Optimisation Of Size-Controllable Centroidal Voronoi Tessellation For Fem Simulation Of Micro Forming Processes, Liang Luo, Zhengyi Jiang, Haina Lu, Dongbin Wei, Kezhi Linghu, Xianming Zhao, Di Wu
Optimisation Of Size-Controllable Centroidal Voronoi Tessellation For Fem Simulation Of Micro Forming Processes, Liang Luo, Zhengyi Jiang, Haina Lu, Dongbin Wei, Kezhi Linghu, Xianming Zhao, Di Wu
Faculty of Engineering and Information Sciences - Papers: Part A
Voronoi tessellation has been employed to characterise material features in Finite Element Method (FEM) simulation, however, a poor mesh quality of the voronoi tessellations causes problems in explicit dynamic simulation of forming processes. Although centroidal voronoi tessellation can partly improve the mesh quality by homogenisation of voronoi tessellations, small features, such as short edges and small facets, lead to an inferior mesh quality. Further, centroidal voronoi tessellation cannot represent all real micro structures of materials because of the almost equal tessellation shape and size. In this paper, a density function is applied to control the size and distribution of voronoi …
Molecular Dynamics Simulation On Σ5 Grain Boundaries Of Copper Bicrystal Under Tensile And Shear Deformation, Liang Zhang, Cheng Lu, A Kiet Tieu
Molecular Dynamics Simulation On Σ5 Grain Boundaries Of Copper Bicrystal Under Tensile And Shear Deformation, Liang Zhang, Cheng Lu, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
Molecular Dynamics simulation are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric Σ5[0 0 1] tilt grain boundaries (GBs) of copper bicrystal under uniaxial tension and shear deformation. Simulation results indicate that the Σ5 asymmetric GBs can facet into their corresponding symmetric GB structures. The maximum tensile stress of symmetric GBs is higher than the asymmetric ones at both 10 K and 300 K, which suggests the symmetric GBs may have a more stable boundary structures. All the Σ5 GBs investigate in this study can migrate under the shear deformation with different velocity. The migration …
Transmob: An Agent Based Simulation Of Transport Demand And Residential Mobility In South East Sydney, Pascal Perez, Nam N. Huynh, Vu Lam Cao, Rohan Wickramasuriya, Matthew J. Berryman
Transmob: An Agent Based Simulation Of Transport Demand And Residential Mobility In South East Sydney, Pascal Perez, Nam N. Huynh, Vu Lam Cao, Rohan Wickramasuriya, Matthew J. Berryman
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents an agent-based simulation, called TransMob, of transport demand and residential mobility in South East Sydney, Australia. In this model, each agent represents an individual resident of the study area. Each agent is given an initial travel diary. Agents are grouped in various types of household which generate social interdependencies and additional constrains on travel diaries. This initial synthetic population is then allowed to evolve for 20 years, driven by natural growth parameters, social bonding and migration rates. A micro-simulation component calculates daily traffic conditions and individual travel times, allowing for multi-modal journeys. The transport mode choice component …
An Agent Based Model For The Simulation Of Road Traffic And Transport Demand In A Sydney Metropolitan Area, Nam N. Huynh, Vu Cao, Rohan Wickramasuriya Denagamage, Matthew Berryman, Pascal Perez, Johan Barthelemy
An Agent Based Model For The Simulation Of Road Traffic And Transport Demand In A Sydney Metropolitan Area, Nam N. Huynh, Vu Cao, Rohan Wickramasuriya Denagamage, Matthew Berryman, Pascal Perez, Johan Barthelemy
Faculty of Engineering and Information Sciences - Papers: Part A
No abstract provided.
A Study Of Plastic Deformation Behavior During High Pressure Torsion Process By Crystal Plasticity Finite Element Simulation, Peitang Wei, Cheng Lu, A K. Tieu, Guanyu Deng
A Study Of Plastic Deformation Behavior During High Pressure Torsion Process By Crystal Plasticity Finite Element Simulation, Peitang Wei, Cheng Lu, A K. Tieu, Guanyu Deng
Faculty of Engineering and Information Sciences - Papers: Part A
High pressure torsion (HPT) is an efficient technique of producing ultrafine grained materials with exceptional small grain size. In this study, a crystal plasticity finite element method (CPFEM) model has been developed to investigate the plastic deformation behavior of pure aluminum single crystal during the HPT process. The simulation results show that, the distribution and evolution of the macroscopic plastic strain and the accumulative shear strain are similar. The value increases with the increase of the distance from the center as well as the number of revolution. The simulation is capable of reflecting the anisotropic characteristics of HPT deformation, a …
Concept And Simulation Study Of A Novel Localization Method For Robotic Endoscopic Capsules Using Multiple Positron Emission Markers, Trung Duc Than, Gursel Alici, Steven Harvey, Hao Zhou, Weihua Li
Concept And Simulation Study Of A Novel Localization Method For Robotic Endoscopic Capsules Using Multiple Positron Emission Markers, Trung Duc Than, Gursel Alici, Steven Harvey, Hao Zhou, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
Purpose: Over the last decade, wireless capsule endoscope has been the tool of choice for noninvasive inspection of the gastrointestinal tract, especially in the small intestine. However, the latest clinical products have not been equipped with a sufficiently accurate localization system which makes it difficult to determine the location of intestinal abnormalities, and to apply follow-up interventions such as biopsy or drug delivery. In this paper, the authors present a novel localization method based on tracking three positron emission markers embedded inside an endoscopic capsule. Methods: Three spherical 22Na markers with diameters of less than 1 mm are embedded in …
Atomistic Simulation Of Tensile Deformation Behavior Of Σ5 Tilt Grain Boundaries In Copper Bicrystal, Liang Zhang, Cheng Lu, A Kiet Tieu
Atomistic Simulation Of Tensile Deformation Behavior Of Σ5 Tilt Grain Boundaries In Copper Bicrystal, Liang Zhang, Cheng Lu, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
Experiments on polycrystalline metallic samples have indicated that Grain boundary (GB) structure can affect many material properties related to fracture and plasticity. In this study, atomistic simulations are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric ∑5[0 0 1] tilt GBs of copper bicrystal. First, the equilibrium GB structures are generated by molecular statics simulation at 0K. The results show that the ∑5 asymmetric GBs with different inclination angles (φ) are composed of only two structural units corresponding to the two ∑5 symmetric GBs. Molecular dynamics simulations are then conducted to investigate the mechanical response …
Dem Simulation Of The Behaviour Of Geogrid Stabilised Ballast Fouled With Coal, Ngoc Trung Ngo, Buddhima Indraratna, Cholachat Rujikiatkamjorn
Dem Simulation Of The Behaviour Of Geogrid Stabilised Ballast Fouled With Coal, Ngoc Trung Ngo, Buddhima Indraratna, Cholachat Rujikiatkamjorn
Faculty of Engineering and Information Sciences - Papers: Part A
Geogrids are commonly used in railway construction for reinforcement and stabilisation. When railway ballast becomes fouled due to ballast breakage, infiltration of coal fines, dust and subgrade soil pumping, the reinforcement effect of geogrids decreases significantly. This paper presents results obtained from Discrete Element Method (DEM) to study the interface behaviour of coal-fouled ballast reinforced by geogrid subjected to direct shear testing. In this study, irregularly-shaped aggregates (ballast) were modelled by clumping together 10-20 spheres in appropriate sizes and positions. The geogrid was modelled by bonding a large number of small spheres together to form the desired grid geometry and …
Cellular Automaton Simulation Of Hot Deformation Of Trip Steel, Ying Zhi, Xianghua Liu, Hailiang Yu
Cellular Automaton Simulation Of Hot Deformation Of Trip Steel, Ying Zhi, Xianghua Liu, Hailiang Yu
Faculty of Engineering and Information Sciences - Papers: Part A
The recrystallization process of hot deformed austenite of TRIP steel was predicted using Cellular Automaton (CA) combined with the principles of physical metallurgy. A model was developed for prediction of the dynamic and static recrystallization microstructure evolution and properties of hot deformed austenite for TRIP steel. The theoretical modeling of recrystallization was based on dislocation density. The microstructure evolution of austenite recrystallization of TRIP steel (such as the grain shape and size, volume fraction, kinetics curve of recrystallization) was predicted both visually and quantitatively. The distribution and variation of the dislocation density and flow stress were also obtained, and the …
Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod
Behavior Of Fresh And Fouled Railway Ballast Subjected To Direct Shear Testing: Discrete Element Simulation, B Indraratna, N T Ngo, C Rujikiatkamjorn, J S. Vinod
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents the three-dimensional discrete element method (DEM) that was used to study the shear behaviour of fresh and coal fouled ballast in direct shear testing. The volumetric changes and stress-strain behaviour of fresh and fouled ballast were simulated and compared with the experimental results. 'Clump logic' in Particle Flow Code (PFC3D) incorporated in a MATLAB Code was used to simulate irregular shaped particles in which groups of ten to twenty spherical balls were clumped together in appropriate sizes to simulate ballast particles. Fouled ballast with various Void Contaminant Index (VCI), ranging from 20%VCI to 70%VCI, were modelled by …
Benchmarking And Validation Of A Geant4-Shadow Monte Carlo Simulation For Dose Calculations In Microbeam Radiation Therapy, Iwan Cornelius, Susanna Guatelli, Pauline Fournier, Jeffrey C. Crosbie, Manuel Sanchez Del Rio, Elke Brauer-Krisch, Anatoly Rosenfeld, Michael Lf Lerch
Benchmarking And Validation Of A Geant4-Shadow Monte Carlo Simulation For Dose Calculations In Microbeam Radiation Therapy, Iwan Cornelius, Susanna Guatelli, Pauline Fournier, Jeffrey C. Crosbie, Manuel Sanchez Del Rio, Elke Brauer-Krisch, Anatoly Rosenfeld, Michael Lf Lerch
Faculty of Engineering and Information Sciences - Papers: Part A
Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including …
Development Of Databases For Facilitating Green Roof Energy Simulation Assessments, Aloysius Decruz, Georgios Kokogiannakis, Jo Darkwa, Kate Yuan, Paul Strachan
Development Of Databases For Facilitating Green Roof Energy Simulation Assessments, Aloysius Decruz, Georgios Kokogiannakis, Jo Darkwa, Kate Yuan, Paul Strachan
Faculty of Engineering and Information Sciences - Papers: Part A
Assessments of the energy performance of green roofs have traditionally been performed with experimental and modelling procedures. Experimental green roof energy studies have significant disadvantages (expensive, time-consuming, cannot be generalised, etc.). On the other hand, modelling studies are often done with over-simplified models (for example, by ignoring the effect of moisture flows in the green roof layers) or with detailed models that require inputs which are often difficult to be obtained in practice and may involve a certain degree of uncertainty. This paper describes the methodologies for the development of databases that include data inputs that could be used within …
Monte Carlo Simulation Of The Transit Dosimetric Response Of An A-Si Electronic Portal Imaging Device, Samuel J. Blake, Aimee Mcnamara, Philip Vial, Lois Holloway, Peter Greer, Zdenka Kuncic
Monte Carlo Simulation Of The Transit Dosimetric Response Of An A-Si Electronic Portal Imaging Device, Samuel J. Blake, Aimee Mcnamara, Philip Vial, Lois Holloway, Peter Greer, Zdenka Kuncic
Faculty of Engineering and Information Sciences - Papers: Part A
Amorphous silicon (a-Si) electronic portal imaging devices (EPIDs) are x-ray detectors frequently used in radiotherapy imaging and dosimetry applicatioins. EPIDs employ a copper plate and gadolinium oxysulfide phosphor screen with an array of a-Si photodiodes to indirectly detect incident radiation. In this study, a previously developed Mote Carlo (MC) model of an a-Si EPID has been extended for transit dosimetry.
A Molecular Dynamics Simulation Of Fracture In Nanocrystalline Copper, Linqing Pei, Cheng Lu, Kiet Tieu, Hongtao Zhu, Xing Zhao, Kuiyu Cheng, Liang Zhang
A Molecular Dynamics Simulation Of Fracture In Nanocrystalline Copper, Linqing Pei, Cheng Lu, Kiet Tieu, Hongtao Zhu, Xing Zhao, Kuiyu Cheng, Liang Zhang
Faculty of Engineering and Information Sciences - Papers: Part A
A large-scale molecular dynamics simulation was used to investigate the propagation of cracks in three dimensional samples of nanocrystalline copper, with average grain sizes ranging from 5.34 to 14.8 nm and temperatures ranging from 1K to 500 K. It was shown that intragranular fracture can proceed inside the grain at low temperature, and plastic deformation around the tip of the crack is accommodated by dislocation nucleation/emission; indeed, both fully extended dislocation and deformation twinning were visible around the tip of the crack during fracture. In addition, due to a higher concentration of stress in front of the crack at a …
Impact Of Patient Rotational Errors On Target And Critical Structure Dose In Imrt: A 3d Simulation Study, S Arumugam, A Xing, P Vial, A Scotti, R Stirton, G Goozee, Lois Holloway
Impact Of Patient Rotational Errors On Target And Critical Structure Dose In Imrt: A 3d Simulation Study, S Arumugam, A Xing, P Vial, A Scotti, R Stirton, G Goozee, Lois Holloway
Faculty of Engineering and Information Sciences - Papers: Part A
The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30 to +30 was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to …
Simulation Of Defects In Micro-Deep Drawing Of An Aluminium Alloy Foil, Syamsul Hadi, Hai-Liang Yu, Kiet Tieu, Cheng Lu
Simulation Of Defects In Micro-Deep Drawing Of An Aluminium Alloy Foil, Syamsul Hadi, Hai-Liang Yu, Kiet Tieu, Cheng Lu
Faculty of Engineering and Information Sciences - Papers: Part A
Micro-forming refers to the application of conventional forming processes to manufacture products from ultra-thin sheet materials. While attempting to meet the increasing demand for cost-effective manufacturing of micro-formed components, it is very important to reduce the defects in the products. In this paper, we report a number of Finite Element (FE) simulations of the micro-deep drawing process with various sample thicknesses and eccentric distances. The simulations indicated that when the sample thickness is nearly equal to the gap between the plunger and the die, the sample is likely to develop fractures at the bottom corner. When the sample thickness is …
Effect Of Particle Properties On The Discrete Element Simulation Of Wall Friction, Andrew Grima, Peter Wypych
Effect Of Particle Properties On The Discrete Element Simulation Of Wall Friction, Andrew Grima, Peter Wypych
Faculty of Engineering and Information Sciences - Papers: Part A
Modelling the interaction between particles and boundaries is of great interest and importance in many Discrete Element Method (DEM) applications where boundary failure conditions dictate the flow behaviour and velocity gradients of a bulk material. Bulk wall friction angles in DEM models are dependent on the mechanical properties of the particles and boundary material as well as the constraints of the contact models used, especially the tangential and rolling torque components. This paper examines the parameters determined from the calibration inclination test by conducting direct wall shear tests to validate the accuracy of the calibration parameters and the sensitivity of …
The Simulation Of Particle Flow Mechanisms In Dustiness Testers, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych
The Simulation Of Particle Flow Mechanisms In Dustiness Testers, Sathaphon Wangchai, David B. Hastie, Peter W. Wypych
Faculty of Engineering and Information Sciences - Papers: Part A
Dust generation is a common result of many bulk handling and mining applications and has potentially serious consequences to the surrounding environment as well as workers and nearby community. Companies need to know how much and what type of dust is being generated so they can find ways to reduce this dust. Dustiness testers can be used for this purpose. This paper investigates the rotating drum testers used for dustiness testing of bulk solids and the subsequent discrete element method (DEM) simulation of the particle mechanisms. Preliminary comparisons of the rotating drum designs were undertaken using particle/bulk parameters of a …