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Full-Text Articles in Social and Behavioral Sciences
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
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 …
Dynamic Testing Of Tekseal High Yield Grout To Provide An Orepass Plug Designed For Impact, I V. S Mutton, Alexander Remennikov, D Pateman
Dynamic Testing Of Tekseal High Yield Grout To Provide An Orepass Plug Designed For Impact, I V. S Mutton, Alexander Remennikov, D Pateman
Alex Remennikov
Significant wear in orepasses particularly in the brow and chute areas is proportional to the tonnage throughput with increased wear associated with running orepasses empty. During planned shutdowns it may be necessary to isolate maintenance crews from objects falling from orepasses. In the last 15 years grout orepass plugs that can later be easily removed have been poured above chute maintenance areas. These provide protection from high energy impact and isolating workers from the hazard. Construction and removal methods will be briefly explained. Since it is not feasible to investigate the problem of orepass plug impact response using full-scale experimental …
Development Of Safe Optimized Welding Procedures For High Strength Q&T Steel Welded With Austenitic Consumables, Lenka Kuzmikova, Huijun Li, John Norrish, Zengxi Stephen Pan, Nathan Larkin
Development Of Safe Optimized Welding Procedures For High Strength Q&T Steel Welded With Austenitic Consumables, Lenka Kuzmikova, Huijun Li, John Norrish, Zengxi Stephen Pan, Nathan Larkin
zengxi pan
High strength quenched and tempered (Q&T) steels offer obvious economic benefits originating from their advantageous strength to price and weight ratios. These steels are usually welded using ferritic consumables and for this combination the risk of hydrogen assisted cold cracking (HACC) is high. The use of austenitic stainless steel (ASS) consumables has great potential to significantly improve this issue. Yet, there are no guidelines for determination of safe level of preheat for welding ferritic steels with ASS consumables. For this reason manufacturers adopt this parameter from procedures developed for conventional ferritic consumables thus significantly limiting the benefits ASS consumables are …
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
zengxi pan
In this study, the feasibility of hybrid laser-gas metal arc welding process for replacement of conventional flux-cored arc welding procedure for welding high strength quenched and tempered steel was investigated. Experimental work focused on optimisation of process parameters to produce joint with desired properties. Hardness of the weld heat affected zone produced by both processes has been measured. Productivity and cost effectiveness of both processes were compared. It was concluded that hybrid laser-gas metal arc welding process is suitable for welding high strength quenched and tempered steel.
A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld
A Real-Time In Vivo Dosimetric Verification Method For High-Dose Rate Intracavitary Brachytherapy Of Nasopharyngeal Carcinoma, Zhen-Yu Qi, Xiao-Wu Deng, X Cao, Shao-Min Huang, Michael L. Lerch, Anatoly B. Rosenfeld
Anatoly Rozenfeld
Purpose: A real-time in vivo dosimetric verification method using metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters has been developed for patient dosimetry in high-dose rate (HDR) intracavitary brachytherapy of nasopharyngeal carcinoma (NPC). Methods: The necessary calibration and correction factors for MOSFET measurements in 192Iridium source were determined in a water phantom. With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system. Results: Five MOSFETs were independently calibrated with the HDR source, yielding calibration factors of 0.48 ± 0.007 cGymV. …
Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome
Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome
Anatoly Rozenfeld
Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed "Super Sampling" involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances receiving …
Very High Data Rate Mb-Ofdm Uwb Systems With Transmit Diversity Techniques, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei
Very High Data Rate Mb-Ofdm Uwb Systems With Transmit Diversity Techniques, Ngoc Phuc Le, Le Chung Tran, Farzad Safaei
Professor Farzad Safaei
In this paper, the application of space time block codes in a very high data rate multiband-OFDM ultra-wideband (VHDR MB-OFDM UWB) system, where the Modified Dual Carrier Modulation (MDCM) scheme and Low Density Parity Check codes are deployed, is investigated. First, we present a new table-based mapping approach and derive soft-demapping expressions for the MDCM scheme. We then propose a space-time-frequency coded VHDR MB-OFDM UWB system by incorporating space time block codes into the conventional VHDR MB-OFDM UWB system. Numerical simulations of the system supporting a data rate of 1Gbps over the IEEE 802.15.3a channel models are implemented. The simulation …
Double Space-Time Transmit Diversity For Very High Data Rate Mb-Ofdm Uwb Systems, Ngoc P. Le, Le C. Tran, Farzad Safaei
Double Space-Time Transmit Diversity For Very High Data Rate Mb-Ofdm Uwb Systems, Ngoc P. Le, Le C. Tran, Farzad Safaei
Professor Farzad Safaei
In this paper, we investigate a multiband-orthogonal frequency division multiplexing ultra-wideband (MB-OFDM UWB) system with very high data rates (VHDR) of several gigabits per second (Gbps). We propose a DSTTD-based VHDR MB-OFDM UWB system by incorporating a double space-time transmit diversity (DSTTD) scheme into the conventional MB-OFDM UWB system. At the receiver, an efficient soft-demapper that takes into consideration the noise enhancement due to a zero-forcing equalization is developed. Numerical simulations of the proposed system at a very high data rate of 2.Gbps over the IEEE 802.15.3a channel models are implemented. The simulation results show that this system could achieve …
Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou
Graphene Micro-Substrate Induced High Electron-Phonon Coupling In Mgb2, W X. Li, X Xu, K S. B De Silva, F X. Xiang, S X. Dou
Shi Xue Dou
Electron-phonon coupling strength was studied in graphene-MgB2 composites to explore the possibilities for a higher superconducting transition temperature (Tc). For the first time in the experimental work on MgB2, the Raman active E2g mode was split into two parts: a softened mode corresponding to tensile strain and a hardened mode attributed to the carbon substitution effect. The tensile strain effect is suggested to improve Tc of graphene-MgB2 composites because it increases the electron-phonon coupling strength of MgB2.
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
Investigation Into Feasibility Of Hybrid Laser-Gmaw Process For Welding High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Nathan Larkin, Zengxi Pan, Mark Callaghan, Huijun Li, John Norrish
Nathan Larkin
In this study, the feasibility of hybrid laser-gas metal arc welding process for replacement of conventional flux-cored arc welding procedure for welding high strength quenched and tempered steel was investigated. Experimental work focused on optimisation of process parameters to produce joint with desired properties. Hardness of the weld heat affected zone produced by both processes has been measured. Productivity and cost effectiveness of both processes were compared. It was concluded that hybrid laser-gas metal arc welding process is suitable for welding high strength quenched and tempered steel.