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Full-Text Articles in Science and Technology Studies
Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood
Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood
Faculty of Engineering and Information Sciences - Papers: Part A
Acoustic emission (AE) monitoring has been used to detect split formation during room temperature low blow Charpy impact testing of high strength thick strip steels. The AE signal analysis identified separate signals originating from hammer impact, plastic deformation (verified using Charpy impact testing on mild steel with no splits) and split initiation/growth. The presence of splits was confirmed by sectioning and fractography, and the splits were brittle in nature. A possible correlation between the AE signal features and fracture mode is presented.
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Nonlinear Analysis Of Biaxially Loaded High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Part I: Theory, Qing Quan Liang, Vipulkumar Ishvarbhai Patel, Muhammad N. S Hadi
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a new numerical model for the nonlinear inelastic analysis of biaxially loaded high strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns. The numerical model considers the effects of progressive local buckling, initial geometric imperfections, high strength materials and second order. The accurate fiber element method is used to model the inelastic behavior of composite cross-sections. Theoretical models are developed that simulate the load-deflection responses and strength envelopes of thin-walled rectangular CFST slender beamcolumns under biaxial loads. New computational algorithms based on the M ller's method are developed to adjust the depth and orientation of the neutral …
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
Faculty of Engineering and Information Sciences - Papers: Part A
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 …
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
Faculty of Engineering and Information Sciences - Papers: Part A
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
Faculty of Engineering and Information Sciences - Papers: Part A
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 …
A Low Cost Soft Mapper For Turbo Equalization With High Order Modulation, Licai Fang, Qinghua Guo, Defeng (David) Huang, Sven Nordholm
A Low Cost Soft Mapper For Turbo Equalization With High Order Modulation, Licai Fang, Qinghua Guo, Defeng (David) Huang, Sven Nordholm
Faculty of Engineering and Information Sciences - Papers: Part A
In an MMSE based turbo equalization system, a soft mapper calculates the symbol mean and variance based on extrinsic Log-Likelihood-Ratios (LLRs) information coming from a Soft-Input Soft-Output (SISO) decoder. In this paper, we investigate the complexity of this module, and in particular, we employ a 3-segment linear approximation approach to calculate the mean and variance of data symbols from LLRs. For FPGA and VLSI implementation, we propose novel piecewise linear functions which map LLR to the mean and variance directly without the use of any two-variable-input multipliers. Simulation results for 16-QAM and 64-QAM show that the no multiplier approach has …
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
Faculty of Engineering and Information Sciences - Papers: Part A
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.
Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch
Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch
Faculty of Engineering and Information Sciences - Papers: Part A
Integration of solar photovoltaic (PV) resources into distribution networks changes the normally expected network behaviour by injecting real power into the point of connection. Depending on the characteristics and setup of the PV inverter, reactive power could also be injected into the network. The impact will depend on the control strategy adopted for reactive power injection. Typically, solar PV units are installed at low voltage (LV) level in distribution networks. Cluster based installation of numerous PV inverters in the LV level will impact the operation of both the host LV network and the upstream medium voltage network. With random variations …
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
Faculty of Engineering and Information Sciences - Papers: Part A
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. …
Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack
Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a thermodynamic analysis of a high-yield biochemical process for biofuel production from lignocelluosic biomass based on a previously proposed process. Unlike the standard biochemical process, which ferments sugar intermediates to ethanol, the process under consideration converts sugars to acetic acid which is esterified and hydrogenated to produce ethanol. This process has a significantly higher yield and produces no carbon dioxide. However, we find that the thermodynamic efficiency of the process is not increased in proportion to the yield gain. An additional survey of various biofuel production processes showed no direct correlation between yield and thermodynamic efficiency. This …