Engineering Commons^™

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.

A Study On The Suitability Of Cable Models To Simulate Switching Transients In A 132 Kv Underground Cable, Muhamad Zalani Daud, P Ciufo, S Perera

Dr Philip Ciufo

Switching transients resulting from the energisation of high voltage cable systems may have a significant effect on both the cables being switched as well as the power system components in the vicinity. The impacts of these transients on such cables are measured based on the stress arising as a result of the voltage and current peaks and the frequency of oscillatory transients. These quantities are typically obtained from a simulation by using a suitable cable model, normally with the capability to predict the transient behaviour in the range up to several 10 kHz. To obtain a cable model that enables …

Calibrating Engineering Graduate Capabilities Against Assessment Tasks: A Preliminary Study, Long Nghiem, Maureen Bell

Long D Nghiem

This paper investigated the connection between assessment tasks and graduate capabilities. Surveys conducted as part of this study revealed differences in planning for the development of, and student achievement of, graduate capabilities and that assessment tasks were valuable tools to guide and facilitate the development of intended graduate capabilities. Drawing from the obtained data, a prototype framework for curriculum design was proposed, allowing for better alignment of assessment tasks and graduate capability development in systematic subject design.

Monte Carlo Study Of The Energy Response And Depth Dose Water Equivalence Of The Moskin Radiation Dosimeter At Clinical Kilovoltage Photon Energies, C Lian, M Othman, D Cutajar, M Butson, Susanna Guatelli, Anatoly Rosenfeld

Susanna Guatelli

Skin dose is often the quantity of interest for radiological protection, as the skin is the organ that receives maximum dose during kilovoltage X-ray irradiations. The purpose of this study was to simulate the energy response and the depth dose water equivalence of the MOSkin radiation detector (Centre for Medical Radiation Physics (CMRP), University of Wollongong, Australia), a MOSFET-based radiation sensor with a novel packaging design, at clinical kilovoltage photon energies typically used for superficial/orthovoltage therapy and X-ray CT imaging. Monte Carlo simulations by means of the Geant4 toolkit were employed to investigate the energy response of the CMRP MOSkin …

Effect Of A Magnetic Field On The Track Structure Of Low-Energy Electrons: A Monte Carlo Study, M Bug, E Gargioni, Susanna Guatelli, S Incerti, H Rabus, R Schulte, Anatoly Rosenfeld

Susanna Guatelli

The increasing use of MRI-guided radiation therapy evokes the necessity to investigate the potential impact of a magnetic field on the biological effectiveness of therapeutic radiation beams. While it is known that a magnetic field, applied during irradiation, can improve the macroscopic absorbed dose distribution of electrons in the tumor region, effects on the microscopic distribution of energy depositions and ionizations have not yet been investigated. An effect on the number of ionizations in a DNA segment, which is related to initial DNA damage in form of complex strand breaks, could be beneficial in radiation therapy. In this work we …

From Imaging To Dosimetry: Geant4-Based Study On The Application Of Medipix To Neutron Dosimetry, M Othman, D Marinaro, M Petasecca, S Guatelli, D Cutajar, M Lerch, Dale Prokopovich, M Reinhard, J Uher, J Jakubek, S Pospisil, Anatoly Rosenfeld

Susanna Guatelli

An application of Medipix2 using a newly developed segmented multiple thickness polyethylene (PE) converter for fast neutron detection is presented. The system has the ability to provide an energy independent response for the dose equivalent for fast neutrons. The application of weighting factors to each defined thickness of PE allows for a flattening of the response of the detector system for dosimetry applications. Six PE converter segments were applied, and their thicknesses and weighting factors were optimised to obtain the required energy independent detector response. The study performed by means of GEANT4. Its suitability for neutron dosimetry was studied with …

Monte Carlo Study Of Mosfet Packaging, Optimised For Improved Energy Response: Single Mosfet Filtration, M Othman, D Cutajar, Nicholas Hardcastle, S Guatelli, Anatoly Rosenfeld

Susanna Guatelli

Monte Carlo simulations of the energy response of a conventionally packaged single metal-oxide field effect transistors (MOSFET) detector were performed with the goal of improving MOSFET energy dependence for personal accident or military dosimetry. The MOSFET detector packaging was optimised. Two different ‘drop-in’ design packages for a single MOSFET detector were modelled and optimised using the GEANT4 Monte Carlo toolkit. Absorbed photon dose simulations of the MOSFET dosemeter placed in free-air response, corresponding to the absorbed doses at depths of 0.07 mm (Dw(0.07)) and 10 mm (Dw(10)) in a water equivalent phantom of size 30 x 30 x30 cm3 for …

Study Of Shear-Stiffened Elastomers, T Tian, W Li, J Ding, G Alici, H Du

Dr Haiping Du

This paper presents a novel shear-stiffened elastomer (SSE) fabricated with a mixture of silicone rubber and silicone oil. A total of four SSE samples were fabricated in this study. Their mechanical and rheological properties under both steady-state and dynamic loading conditions were tested with a parallel plate rheometer. The effects of silicone oil composition, strain amplitude and angular frequency were summarized. When raising the angular frequency in the dynamic shear test, the storage modulus of conventional silicone rubber shows a small increasing trend with the frequency. However, if silicone oil is selected to be mixed with silicone rubber, the storage …

Monte Carlo Study Of The Energy Response And Depth Dose Water Equivalence Of The Moskin Radiation Dosimeter At Clinical Kilovoltage Photon Energies, C Lian, M Othman, D Cutajar, M Butson, Susanna Guatelli, Anatoly Rosenfeld

Dean Cutajar

Skin dose is often the quantity of interest for radiological protection, as the skin is the organ that receives maximum dose during kilovoltage X-ray irradiations. The purpose of this study was to simulate the energy response and the depth dose water equivalence of the MOSkin radiation detector (Centre for Medical Radiation Physics (CMRP), University of Wollongong, Australia), a MOSFET-based radiation sensor with a novel packaging design, at clinical kilovoltage photon energies typically used for superficial/orthovoltage therapy and X-ray CT imaging. Monte Carlo simulations by means of the Geant4 toolkit were employed to investigate the energy response of the CMRP MOSkin …

Multi-Disciplinary Engineering Research And Development Skills For Mining - A Case Study, C Cook, S Van Duin, Ian Porter

Christopher Cook

This paper discusses how advanced manufacturing technology (AMT), which is fundamentally reliant on and developed via multi-disciplinary skills, has benefitted non-mining industries, and what lessons can be derived from this experience to benefit the mining industry, particularly underground coal mining. Examples of AMT use in 'conventional' industry, some drawn from the more than 25 years experience in many different industries of the Automation and Robotics team at the University of Wollongong, are described to show typical benefits, risks and opportunities expected in using AMT. Applying AMT to mining brings many unique challenges and this paper expands on these and then …

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 …

Quartz Crystal Microbalance Study Of Volume Changes And Modulus Shift In Electrochemically Switched Polypyrrole, Mehrdad Bahrami-Samani, Christopher Cook, John Madden, Geoffrey Spinks, Philip Whitten

Christopher Cook

The performance of conducting polymers as actuators is determined by a complicated series of molecular processes that occur as a result of oxidation and reduction of the polymer. In particular, the amount of actuation strain generated for a given voltage stimulus is determined by the number and type of ions (and solvent) that enter and leave the polymer and changes in the mechanical properties (particularly elastic modulus) of the polymer. In this paper, we present the effects of cyclic voltammetry on the shear modulus and volume of polypyrrole in two different electrolytes: propylene carbonate and an ionic liquid. An electrochemical …

Computer Simulation Study On The Dynamic Behaviour Of An Aeac Mechanical Manipulator, M Ibrahim, Christopher Cook, A Tieu

Christopher Cook

No abstract provided.

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

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

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

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.

Some Comments On The Study Of Metallurgical Coke And Its Use In The Iron Blast Furnace: Understanding Process Fundamentals Through Laboratory Studies, Brian J. Monaghan, Michael Chapman, Sharon A. Nightingale, John G. Mathieson, Robert J. Nightingale

Brian Monaghan

Much of the recent experimental work carried out at by the PYROmetallurgical group at the University of Wollongong has focussed on understanding coke behaviour in the lower zone of the blast furnace. This work has had both fundamental and applied elements and has been carried out with a view to improving coke utilization in the blast furnace and ultimately reducing greenhouse gas emissions.

From Imaging To Dosimetry: Geant4-Based Study On The Application Of Medipix To Neutron Dosimetry, M Othman, D Marinaro, M Petasecca, S Guatelli, D Cutajar, M Lerch, Dale Prokopovich, M Reinhard, J Uher, J Jakubek, S Pospisil, Anatoly Rosenfeld

Dean Cutajar

An application of Medipix2 using a newly developed segmented multiple thickness polyethylene (PE) converter for fast neutron detection is presented. The system has the ability to provide an energy independent response for the dose equivalent for fast neutrons. The application of weighting factors to each defined thickness of PE allows for a flattening of the response of the detector system for dosimetry applications. Six PE converter segments were applied, and their thicknesses and weighting factors were optimised to obtain the required energy independent detector response. The study performed by means of GEANT4. Its suitability for neutron dosimetry was studied with …

Monte Carlo Study Of Mosfet Packaging, Optimised For Improved Energy Response: Single Mosfet Filtration, M Othman, D Cutajar, Nicholas Hardcastle, S Guatelli, Anatoly Rosenfeld

Dean Cutajar

Monte Carlo simulations of the energy response of a conventionally packaged single metal-oxide field effect transistors (MOSFET) detector were performed with the goal of improving MOSFET energy dependence for personal accident or military dosimetry. The MOSFET detector packaging was optimised. Two different ‘drop-in’ design packages for a single MOSFET detector were modelled and optimised using the GEANT4 Monte Carlo toolkit. Absorbed photon dose simulations of the MOSFET dosemeter placed in free-air response, corresponding to the absorbed doses at depths of 0.07 mm (Dw(0.07)) and 10 mm (Dw(10)) in a water equivalent phantom of size 30 x 30 x30 cm3 for …

A Study Of The Strength Of Lime Treated Soft Clays, Martin D. Liu, Stephen Pemberton, Buddhima Indraratna

Buddhima Indraratna

In this paper, a comprehensive study of the strength of lime treated soft clays is made. There are three major factors that affect the strength of the soils; they are the lime content, curing time, and curing temperature. The variations of soil strengths with the three factors are analysed and quantified via proposed empirical equations. These equations are verified against experimental data. Finally, a general strength criterion, unifying the influence of all the three factors into a single equation, is proposed. The capacity of the general equation is also demonstrated. It is seen that the proposed strength equations can provide …

Modeling Of Bolted Joint Behaviour Under Constant Normal Stiffness Conditions - Laboratory Study, Buddhima Indraratna, Najdat I. Aziz, A Dey

Buddhima Indraratna

The shear behaviour of grouted joints has been studied in the recent past using the conventional direct shear apparatus, where the normal load on the joint plane is kept constant during testing. The Constant Normal Stiffness (CNS) condition is adopted in this study of shear behaviour of bolted joints, as the CNS condition represents a better approximation of the deformation behaviour of grouted joints in underground excavations as compared to the conventional Constant Normal Load (CNL) condition. A series of tests were conducted to study the behaviour of these stabilised joints under constant normal stiffness condition at an initial normal …

Microbeam Radiation Therapy: A Monte Carlo Study Of The Influence Of The Source, Multislit Collimator, And Beam Divergence On Microbeams, Heidi Nettelbeck, George Takacs, Michael Lerch, Anatoly Rosenfeld

George Takacs

Microbeam radiation therapy (MRT) is a new oncology method currently under development for the treatment of inoperable pediatric brain tumors. Monte Carlo simulation, or the computational study of radiation transport in matter, is often used in radiotherapy to theoretically estimate the dose required for treatment. However, its potential use in MRT dose planning systems is currently hindered by the significant discrepancies that have been observed between measured and theoretical dose and the PVDR (peak to valley dose ratio). The need to resolve these discrepancies is driven by the desirability of making MRT available to humans in the next few years. …

Sediment Control At Water Intakes Along Sand Bed Rivers, Fred L. Ogden

Fred L. Ogden

Results from five physical hydraulic model studies of riverside water intakes situated along the Missouri River reach between Sioux City, Iowa, and St. Louis, Missouri, are presented. Movable-bed, undistorted Froude-scale models are used to determine the effectiveness of structural modifications in the vicinity of the intake to limit the influx of bed-load sediments. Solutions developed in each case include a series of submerged flow-turning vanes located on the riverward side of the intake. A sediment-barrier wall between the vanes and intake ...

Distribution Of Interactions In Binary Polymer Mixtures: A Monte Carlo Simulation Study, William Macknight, P. Cifra, F. E. Karasz

William MacKnight

Problems In Compatibility Studies, William Macknight, F. E. Karasz

William MacKnight

No abstract provided.