Today's Monolithic Silicon Array Detector For Small Field Dosimetry: The Octa,
2019
University of Wollongong
Today's Monolithic Silicon Array Detector For Small Field Dosimetry: The Octa, Giordano Biasi, Khalsa Al Shukaili, Marco Petasecca, Stephanie Corde, Susanna Guatelli, Vladimir Perevertaylo, Tomas Kron, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
The dosimetry of small photon beams is challenging due to detector position uncertainties, dose averaging and lack of electronic equilibrium. Currently only few, single detectors are suitable for measurements in this context, and none is ideal. This study reports on the dosimetric characterization of small fields collimated by fixed cones, performed by a novel 2D monolithic silicon array detector, the Octa.
3d Sensitive Volume Microdosimeter With Improved Tissue Equivalency: Charge Collection Study And Its Application In 12 C Ion Therapy,
2019
University of Wollongong
3d Sensitive Volume Microdosimeter With Improved Tissue Equivalency: Charge Collection Study And Its Application In 12 C Ion Therapy, Benjamin James, Linh T. Tran, David Bolst, Dale A. Prokopovich, Mark I. Reinhard, Michael L. F Lerch, Marco Petasecca, Susanna Guatelli, Marco Povoli, Angela Kok, Naruhiro Matsufuji, Michael A. Jackson, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
No abstract provided.
Characterisations Of A Fibre Optic Dosimetry System For Source Tracking During Hdr Brachytherapy,
2019
University of Wollongong, Taif University, King Faisal Specialist Hospital & Research Centre
Characterisations Of A Fibre Optic Dosimetry System For Source Tracking During Hdr Brachytherapy, Mohammed Al Towairqi, Dean L. Cutajar, Terry Braddock, Enbang Li, S Wadi-Ramahi, Belal Moftah, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
Brachytherapy is a complex treatment procedure where radioactive sources are inserted in or close to the tumours to destroy the cancerous cells. Due to the unique properties of scintillation plastic detectors, this study was aimed to characterise an innovative fibre optic dosimetry system as a quality assurance tool during HDR Brachytherapy. Scintillating plastic fibres with different scintillation lengths were prepared and then optically coupled to non-scintillating fibres for light transmission. A transimpedance photodiode amplifier was used to detect positional sensitivities of different fibre probes placed within a solid-water phantom at varying distances above an 192-Ir brachytherapy source located within the …
Modelling The X-Ray Source For The Australian Mri-Linac,
2019
University of Wollongong, Ingham Institute for Applied Medical Research
Modelling The X-Ray Source For The Australian Mri-Linac, Natalia Roberts, Bradley M. Oborn, U Jelen, B Dong, Jarrad Begg, Armia George, Saree Alnaghy, Trent Causer, Thahabah Alharthi, Lois C. Holloway, Peter E. Metcalfe
Faculty of Engineering and Information Sciences - Papers: Part B
MRI-guided radiotherapy allows real-time imaging during treatment however the magnetic field influences the dose distribution in the patient. An accurate model of the radiation beam and the encompassing magnetic field is important to predict dosimetry changes. The purpose of this work is to develop a Monte Carlo model of the Australian MRI-Linac to be used as input into a dose calculation tool for treatment planning. The Australian MRI-Linac is a 1 T inline system with a 6MV flattening filter free photon beam. Commissioning measurements were undertaken both with and without the magnetic field present, PDDs and profiles were used to …
Characterization Of Prompt Gamma Ray Emission For In Vivo Range Verification In Particle Therapy: A Simulation Study,
2019
University of Wollongong
Characterization Of Prompt Gamma Ray Emission For In Vivo Range Verification In Particle Therapy: A Simulation Study, Melek Zarifi, Susanna Guatelli, Yujin Qi, David Bolst, Dale A. Prokopovich, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
In this paper we investigate the emission and detection characteristics of prompt gamma (PG) rays for in vivo range verification during hadron therapy, using Geant4 simulations. Proton, 4 He and 12 C beams of varying energy are incident on water phantoms. The PG production yield, energy spectral characteristics and spatial correlation with the Bragg Peak (BP) have been quantified. Further, the angular distributions for PG detection with respect to a point-of-reference on the phantom surface have been explored. The temporal properties of PG emission and time-of-flight (TOF) of PG detection have also been investigated in correlation with the changing particle …
Parametric Characterization Of Penumbra Reduction For Aperture-Collimated Pencil Beam Scanning (Pbs) Proton Therapy,
2019
Seattle Cancer Care Alliance Proton Therapy Center
Parametric Characterization Of Penumbra Reduction For Aperture-Collimated Pencil Beam Scanning (Pbs) Proton Therapy, Dominic Maes, Rajesh Regmi, Phillip Taddei, Charles Bloch, Steven Bowen, Alexander Nevitt, Erick Leuro, Tony Wong, Anatoly B. Rosenfeld, Jatinder Saini
Faculty of Engineering and Information Sciences - Papers: Part B
Recently, a commercial treatment planning system (TPS) has implemented aperture collimators for PBS dose calculations which can serve to reduce lateral penumbra. This study characterized the variation in magnitude of lateral penumbra for collimated and un-collimated PBS fields versus the parameters of air gap, depth, and range shifter thickness. Comparisons were performed in a homogenous geometry between measured data and calculations made by a commercial TPS. Beam-specific target volumes were generated for collimated and un-collimated PBS fields and optimized for various range shifter thicknesses and air gaps. Lateral penumbra (80%-20% distance) was measured across each target volume to characterize penumbra …
Investigating Variable Rbe In A 12c Minibeam Field With Microdosimetry And Geant4,
2019
University of Wollongong
Investigating Variable Rbe In A 12c Minibeam Field With Microdosimetry And Geant4, Emily Debrot, David Bolst, Benjamin James, Linh Tran, Susanna Guatelli, Marco Petasecca, Dale A. Prokopovich, Mark I. Reinhard, Naruhiro Matsufuji, Michael A. Jackson, Michael L. F Lerch, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
An experimental and simulation-based study was performed on a 12C ion minibeam radiation therapy (MBRT) field produced with a clinical broad beam and a brass multi-slit collimator (MSC). Silicon-on-insulator (SOI) microdosimeters developed at the Centre for Medical Radiation Physics (CMRP) with micron sized sensitive volumes were used to measure the microdosimetric spectra at varying positions throughout the MBRT field and the corresponding dose-mean lineal energies and RBE for 10% cell survival (RBE10) were calculated using the modified Microdosimetric Kinetic Model (MKM). An increase in the average RBE10 of ∼30% and 10% was observed in the plateau region compared to broad …
Superconducting Pair-Breaking Under Intense Sub-Gap Terahertz Radiation,
2019
University of Wollongong
Superconducting Pair-Breaking Under Intense Sub-Gap Terahertz Radiation, Jie Tian, Jack Zuber, Sunchao Huang, C Zhang
Faculty of Engineering and Information Sciences - Papers: Part B
We study the effect of a strong and low frequency (ω < Δ, the superconducting gap) electrical field on a superconducting state. It is found that the superconducting gap decreases with the field intensity and wavelength. The physical mechanism for this dependence is the multiphoton absorption by a superconducting electron. By constructing the state of a superconducting electron dressed by photons, we determined the dependence of the superconducting gap on E / ω and temperature. We show that the critical temperature is determined by the parameter E / ω which is distinct from that induced by the heating effect. The result is consistent with experimental findings. This result can be applied to study terahertz nonlinear superconducting metamaterials.
Monte Carlo Investigation Of The Characteristics Of Radioactive Beams For Heavy Ion Therapy,
2019
University of Wollongong, Australian Nuclear Science and Technology Organisation (ANSTO)
Monte Carlo Investigation Of The Characteristics Of Radioactive Beams For Heavy Ion Therapy, Andrew Chacon, Mitra Safavi-Naeini, David Bolst, Susanna Guatelli, Daniel R. Franklin, Yuma Iwao, Go Akamatsu, Hideaki Tashima, Eiji Yoshida, Fumihiko Nishikido, Atsushi Kitagawa, Akram Mohammadi, Marie-Claude Gregoire, Taiga Yamaya, Anatoly B. Rosenfeld
Faculty of Engineering and Information Sciences - Papers: Part B
No abstract provided.
The Suspension Of A Graph, And Associated C⁎-Algebras,
2019
University of Wollongong
The Suspension Of A Graph, And Associated C⁎-Algebras, Aidan Sims
Faculty of Engineering and Information Sciences - Papers: Part B
Given a directed graph E, we construct for each real number l a quiver whose vertex space is the topological realisation of E, and whose edges are directed paths of length l in the vertex space. These quivers are not topological graphs in the sense of Katsura, nor topological quivers in the sense of Muhly and Tomforde. We prove that when l=1 and E is finite, the infinite-path space of the associated quiver is homeomorphic to the suspension of the one-sided shift of E. We call this quiver the suspension of E. We associate both a Toeplitz algebra and a …
Performance Analysis Of The Activated Sludge Model (Number 1),
2019
University of Wollongong
Performance Analysis Of The Activated Sludge Model (Number 1), Mark Nelson, Harvinder S. Sidhu, Simon D. Watt, Faisal I. Hai
Faculty of Engineering and Information Sciences - Papers: Part B
The activated sludge process is widely used to treat both municipal sewage and a variety of industrial wastewaters. We investigate the steady-state behaviour of an activated sludge process. We use the activated sludge model number one, an internationally accepted model, to describe the biochemical, biological, and physical-chemical phenomena that occur inside the bioreactor. The treatment configuration consists of a single aerated reactor attached to a settling unit. Continuation methods are used to determine the steady-states of the model as a function of the hydraulic residence time. From these solutions we construct important operational parameters including the chemical oxygen demand, total …
We Can Halve Train Travel Times Between Our Cities By Moving To Faster Rail,
2019
University of Wollongong
We Can Halve Train Travel Times Between Our Cities By Moving To Faster Rail, Philip G. Laird
Faculty of Engineering and Information Sciences - Papers: Part B
The Melbourne-Sydney air corridor is now the second-busiest in the world. That's true for either the number of passenger planes flying between the two airports or by counting actual passenger numbers, now over 9 million passengers a year. That's an increase of 28% since 2009. On an average day, some 12,330 people get on a plane in Sydney to fly to Melbourne. A similar number make the reverse journey. Most passengers will have taken some time to get the airport and waited well over half an hour at the airport just to get on the plane. Once on board, the …
Constructing Kms States From Infinite-Dimensional Spectral Triples,
2019
Chalmers University of Technology
Constructing Kms States From Infinite-Dimensional Spectral Triples, Magnus Goffeng, Adam C. Rennie, Alexandr Usachev
Faculty of Engineering and Information Sciences - Papers: Part B
We construct KMS-states from Li1-summable semifinite spectral triples and show that in several important examples the construction coincides with well-known direct constructions of KMS-states for naturally defined flows. Under further summability assumptions the constructed KMS-state can be computed in terms of Dixmier traces. For closed manifolds, we recover the ordinary Lebesgue integral. For Cuntz-Pimsner algebras with their gauge flow, the construction produces KMS-states from traces on the coefficient algebra and recovers the Laca-Neshveyev correspondence. For a discrete group acting on its Stone-Čech boundary, we recover the Patterson-Sullivan measures on the Stone-Čech boundary for a flow defined from the Radon-Nikodym cocycle.
Microstructure And Mechanical Properties Of Thin Varying Thickness Strips With Different Transition Zones Produced By Micro Flexible Rolling,
2019
University of Wollongong, University of Science and Technology Liaoning
Microstructure And Mechanical Properties Of Thin Varying Thickness Strips With Different Transition Zones Produced By Micro Flexible Rolling, Mingshuai Huo, Jingwei Zhao, Haibo Xie, Shengli Li, Hongmei Zhang, Zhiping Hu, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part B
In order to better understand transition zones with a variety of structural features that affect thin varying thickness strips, 6061 aluminium alloy thin strips were flexibly rolled into different thickness ratios and transition zone lengths, using an innovative micro rolling mill. The microstructure and mechanical properties of the thin varying thickness strips produced by micro flexible rolling were systematically investigated and the mechanisms were analysed. The results indicate that a thin varying thickness strip with either a larger thickness ratio or a shorter transition zone length will present a relatively high slope of the transition zone during micro flexible rolling. …
Quantification Of Texture-Induced Ridging In Ferritic Stainless Steels 430 And 430lr During Tensile Deformation,
2019
University of Wollongong
Quantification Of Texture-Induced Ridging In Ferritic Stainless Steels 430 And 430lr During Tensile Deformation, Xiaoguang Ma, Jingwei Zhao, Wei Du, Xin Zhang, Laizhu Jiang, Zhengyi Jiang
Faculty of Engineering and Information Sciences - Papers: Part B
A comparative study has been carried out to assess the effect of rolling and annealing processes on ridging generation of ferritic stainless steels (FSSs) 430 and 430LR after tensile deformation. The results show that FSS 430LR has better ridging resistance owing tothe refinement of microstructure and crystallographic texture optimisation. A 30% reduction of ridging height can be achieved using FSS 430LR compared to FSS 430 after tension.Optimal reduction during cold rolling benefits the microstructural refinement and surface quality improvement of FSSs 430 and 430LR. Both theoretical calculations and experimental results indicate that the (1 1 2) and the (0 0 …
Numerical And Experimental Studies On A New Variable Stiffness And Damping Magnetorheological Fluid Damper,
2019
Fuzhou University
Numerical And Experimental Studies On A New Variable Stiffness And Damping Magnetorheological Fluid Damper, Hui Huang, Shuaishuai Sun, Shumei Chen, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part B
This article describes a new magnetorheological fluid damper; its damping and stiffness are variable and controllable through the compact structure of two damping units and a spring. The ability of variable stiffness and damping enables it to be used for more effective vibration control in wide-band excitation wave occasions. First, the effective stiffness and output damping force are calculated in theory. Then, the magnetic field is simulated by finite element analysis. After the prototype of the new magnetorheological fluid damper is developed and machined, the damper's performances are tested in a hydraulic actuated MTS machine, including stiffness variability and damping …
Rapid, One-Step Preparation Of Sers Substrate In Microfluidic Channel For Detection Of Molecules And Heavy Metal Ions,
2019
Chongqing University, The Hong Kong University of Science And Technology
Rapid, One-Step Preparation Of Sers Substrate In Microfluidic Channel For Detection Of Molecules And Heavy Metal Ions, Sheng Yan, Fangjia Chu, Haiyun Zhang, Yuan Yuan, Yingzhou Huang, Anping Liu, Shuxia Wang, Weihua Li, Shunbo Li, Weijia Wen
Faculty of Engineering and Information Sciences - Papers: Part B
On-chip fabrication of surface-enhanced Raman spectroscopy (SERS)-active materials enables continuous, real-time sensing of targets in the microfluidic chip. However, the current techniques require the time-consuming, complicated process and costly, bulky facilities. In this work, we present a novel method for synthesis of Ag nanostructures in a microfluidic channel via one-step electroless galvanic replacement reaction. The whole reaction could be achieved <10 >mins, while the traditional methods take hours. The microfluidic channel has a Cu base, which can reduce Ag ions to Ag nanoparticles in the presence of AgNO3 solution. The new technique enables the label-free sensing of chemical molecules (i.e., …
A Secure And Efficient Data Sharing And Searching Scheme In Wireless Sensor Networks,
2019
Shandong University
A Secure And Efficient Data Sharing And Searching Scheme In Wireless Sensor Networks, Binrui Zhu, Willy Susilo, Jing Qin, Fuchun Guo, Zhen Zhao, Jixin Ma
Faculty of Engineering and Information Sciences - Papers: Part B
Wireless sensor networks (WSN) generally utilize cloud computing to store and process sensing data in real time, namely, cloud-assisted WSN. However, the cloud-assisted WSN faces new security challenges, particularly outsourced data confidentiality. Data Encryption is a fundamental approach but it limits target data retrieval in massive encrypted data. Public key encryption with keyword search (PEKS) enables a data receiver to retrieve encrypted data containing some specific keyword in cloud-assisted WSN. However, the traditional PEKS schemes suffer from an inherent problem, namely, the keyword guessing attack (KGA). KGA includes off-line KGA and on-line KGA. To date, the existing literature on PEKS …
A Comparison Of Methods For Poverty Estimation In Developing Countries,
2019
Shahjalal University of Science and Technology, University of Wollongong, Maastricht University
A Comparison Of Methods For Poverty Estimation In Developing Countries, Sumonkanti Das, Stephen Haslett
Faculty of Engineering and Information Sciences - Papers: Part B
Small area estimation is a widely used indirect estimation technique for micro-level geographic profiling. Three unit level small area estimation techniques-the ELL or World Bank method, empirical best prediction (EBP) and M-quantile (MQ) - can estimate micro-level Foster, Greer, & Thorbecke (FGT) indicators: poverty incidence, gap and severity using both unit level survey and census data. However, they use different assumptions. The effects of using model-based unit level census data reconstructed from cross-tabulations and having no cluster level contextual variables for models are discussed, as are effects of small area and cluster level heterogeneity. A simulation-based comparison of ELL, EBP …
Conditionally Integrable Nonlinear Diffusion With Diffusivity 1/U,
2019
La Trobe University, University of Wollongong
Conditionally Integrable Nonlinear Diffusion With Diffusivity 1/U, Philip Broadbridge, Joanna M. Goard
Faculty of Engineering and Information Sciences - Papers: Part B
An explicit mapping is given from the space of general complex meromorphic functions to a space of special time-dependent solutions of the 1 + 2-dimensional nonlinear diffusion equation with diffusivity depending on concentration as D = 1/u. These solutions have constant-flux boundary conditions. Some simple examples are constructed, including that of a line source enclosed by a cylindrical barrier. This has direct application to electron diffusion in a laser-heated plasma.
