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Full-Text Articles in Engineering
Vibration-Induced Aerodynamic Loads On Large Horizontal Axis Wind Turbine Blades, Xiong Liu, Cheng Lu, Shi Liang, Ajit R. Godbole, Yan Chen
Vibration-Induced Aerodynamic Loads On Large Horizontal Axis Wind Turbine Blades, Xiong Liu, Cheng Lu, Shi Liang, Ajit R. Godbole, Yan Chen
Faculty of Engineering and Information Sciences - Papers: Part A
The blades of a large Horizontal Axis Wind Turbine (HAWT) are subjected to significant vibrations during operation. The vibrations affect the dynamic flow field around the blade and consequently alter the aerodynamic forces on the blade. In order to better understand the influence of blade vibrations on the aerodynamic loads, the dynamic stall characteristics of an S809 airfoil undergoing translational motion as well as pitching motion were investigated using Computational Fluid Dynamics (CFD) techniques. Simulation results indicated that both the out-of-plane and in-plane translational motions of the airfoil affect the unsteady aerodynamic forces significantly. In order to investigate the effects …
Retained Austenite: Transformation-Induced Plasticity, Elena V. Pereloma, Azdiar A. Gazder, Ilana B. Timokhina
Retained Austenite: Transformation-Induced Plasticity, Elena V. Pereloma, Azdiar A. Gazder, Ilana B. Timokhina
Faculty of Engineering and Information Sciences - Papers: Part A
The deformation-induced phase transformation of metastable austenite to martensite is accompanied by macroscopic plastic strain and results in significant work hardening and the delayed onset of necking. Steels that exhibit such transformation-induced plasticity (TRIP) effect possess high strength-ductility ratios and improved toughness. Since the stability of the retained austenite (RA) phase is the rate controlling mechanism for the TRIP effect, the factors affecting the chemical and mechanical stability of RA in CMnSi TRIP steels are discussed. It was suggested that chemical stability plays a more important role at low strains, whereas other factors become responsible for RA behavior at higher …
The Effect Of Respiratory Induced Density Variations On Non-Tof Pet Quantitation In The Lung, Beverley F. Holman, Vesna Cuplov, Brian F. Hutton, Ashley M. Groves, Kris Thielemans
The Effect Of Respiratory Induced Density Variations On Non-Tof Pet Quantitation In The Lung, Beverley F. Holman, Vesna Cuplov, Brian F. Hutton, Ashley M. Groves, Kris Thielemans
Faculty of Engineering and Information Sciences - Papers: Part A
Accurate PET quantitation requires a matched attenuation map. Obtaining matched CT attenuation maps in the thorax is difficult due to the respiratory cycle which causes both motion and density changes. Unlike with motion, little attention has been given to the effects of density changes in the lung on PET quantitation. This work aims to explore the extent of the errors caused by pulmonary density attenuation map mismatch on dynamic and static parameter estimates. Dynamic XCAT phantoms were utilised using clinically relevant 18F-FDG and 18F-FMISO time activity curves for all organs within the thorax to estimate the expected parameter errors. The …
Induced Molecular Dissociations As A Radiation Damage Descriptor (Nanodosimetry), A Traore, L Ellis-Gibbings, Alexey Verkhovtsev, K Krupa, A Munoz, Fernando Blanco, Gustavo Garcia
Induced Molecular Dissociations As A Radiation Damage Descriptor (Nanodosimetry), A Traore, L Ellis-Gibbings, Alexey Verkhovtsev, K Krupa, A Munoz, Fernando Blanco, Gustavo Garcia
Faculty of Engineering and Information Sciences - Papers: Part A
We present a nanodosimeter software based on Monte Carlo, termed: Low Energy Particle Track Simulation. For medical applications purposes, we propose bond breakings to describe the energy deposited taking water as an example. This tool aims to improve current treatment planning approach based on absorbed dose.
Hydrostatic Pressure Induced Transition From Δtc To Δℓ Pinning Mechanism In Mgb2, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, S X. Dou, Feixiang Xiang
Hydrostatic Pressure Induced Transition From Δtc To Δℓ Pinning Mechanism In Mgb2, Babar Shabbir, Xiaolin Wang, Shaban Reza Ghorbani, S X. Dou, Feixiang Xiang
Faculty of Engineering and Information Sciences - Papers: Part A
The impact of hydrostatic pressure up to 1.2 GPa on the critical current density (Jc) and the nature of the pinning mechanism in MgB2 have been investigated within the framework of the collective theory. We found that the hydrostatic pressure can induce a transition from the regime where pinning is controlled by spatial variation in the critical transition temperature (δTc ) to the regime controlled by spatial variation in the mean free path (δℓ). Furthermore, critical temperature (Tc) and low field Jc are slightly reduced, although the Jc drops more quickly at high fields than at ambient pressure. We found …
An In-Situ Neutron Diffraction Study Of A Multi-Phase Transformation And Twinning-Induced Plasticity Steel During Cyclic Loading, Ahmed A. Saleh, Donald W. Brown, Elena V. Pereloma, Bjorn Clausen, Christopher H. J Davies, Carlos N. Tome, Azdiar A. Gazder
An In-Situ Neutron Diffraction Study Of A Multi-Phase Transformation And Twinning-Induced Plasticity Steel During Cyclic Loading, Ahmed A. Saleh, Donald W. Brown, Elena V. Pereloma, Bjorn Clausen, Christopher H. J Davies, Carlos N. Tome, Azdiar A. Gazder
Faculty of Engineering and Information Sciences - Papers: Part A
In-situ neutron diffraction during cyclic tension-compression loading (þ3.5% to 2.8%) of a 17Mn-3Al-2Si-1Ni-0.06C steel that exhibits concurrent transformation and twinning -induced plasticity effects indicated a significant contribution of intragranular back stresses to the observed Bauschinger effect. Rietveld analysis revealed a higher rate of martensitic transformation during tension compared to compression. Throughout cycling, a0-martensite exhibited the highest phase strains such that it bears an increasing portion of the macroscopic load as its weight fraction evolves. On the other hand, the e-martensite strain remained compressive as it accommodated most of the internal strains caused by the shape misfit associated with the c!e …
Defects Induced Ferromagnetism In Plasma-Enabled Graphene Nanopetals, Zengji Yue, Donghan Seo, Kostya Ostrikov, Xiaolin Wang
Defects Induced Ferromagnetism In Plasma-Enabled Graphene Nanopetals, Zengji Yue, Donghan Seo, Kostya Ostrikov, Xiaolin Wang
Faculty of Engineering and Information Sciences - Papers: Part A
Ferromagnetism in graphene is fascinating, but it is still a big challenge for practical applications due to the weak magnetization. In order to enhance the magnetization, here, we design plasma-enabled graphene nanopetals with ultra-long defective edges of up to 105 m/g, ultra-dense lattice vacancies, and hydrogen chemisorptions. The designed graphene nanopetals display robust ferromagnetism with large saturation magnetization of up to 2 emu/g at 5 K and 1.2 emu/g at room temperatures. This work identifies the plasma-enabled graphene nanopetals as a promising candidate for graphene-based magnetic devices. 2014 AIP Publishing LLC.
The Effect Of Processing Parameters On The Microstructure And Mechanical Properties Of Low-Si Transformation-Induced Plasticity Steels, Fayez Alharbi, Azdiar A. Gazder, Andrii Kostryzhev, Bruno C. De Cooman, Elena Pereloma
The Effect Of Processing Parameters On The Microstructure And Mechanical Properties Of Low-Si Transformation-Induced Plasticity Steels, Fayez Alharbi, Azdiar A. Gazder, Andrii Kostryzhev, Bruno C. De Cooman, Elena Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
A base low Si, high-A1 transformation-induced plasticity (TRIP) steel and one with 0.03Nb and 0.002Ti (wt percent) additions were subjected to thermo-mechanical processing (TMP) and galvanising simulations. T
Design And Development Of A Novel Displacement Differential Self-Induced Magnetorheological Damper, Guoliang Hu, Yi Ru, Weihua Li
Design And Development Of A Novel Displacement Differential Self-Induced Magnetorheological Damper, Guoliang Hu, Yi Ru, Weihua Li
Faculty of Engineering and Information Sciences - Papers: Part A
This article presents the development of a novel magnetorheological damper which has a self-sensing ability. In this study, a linear variable differential sensor, which was based on the electromagnetic induction mechanism, was integrated with a conventional magnetorheological damper. The working principle, configuration, and prototype of the displacement differential self-induced magnetorheological damper based on the integrated linear variable differential sensor technology were presented. A mathematical model of the proposed displacement differential self-induced magnetorheological damper was established. The finite element model was built with two-dimensional Maxwell software and the magnetic simulations were presented. With this approach, the influence of the flux leakage, …
Continuous Manipulation And Separation Of Particles Using Combined Obstacle-And Curvature-Induced Direct Current Dielectrophoresis, Ming Li, Shunbo Li, Weihua Li, Weijia Wen, Gursel Alici
Continuous Manipulation And Separation Of Particles Using Combined Obstacle-And Curvature-Induced Direct Current Dielectrophoresis, Ming Li, Shunbo Li, Weihua Li, Weijia Wen, Gursel Alici
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a novel dielectrophoresis-based microfluidic device incorporating round hurdles within an S-shaped microchannel for continuous manipulation and separation of microparticles. Local nonuniform electric fields are generated due to the combined effects of obstacle and curvature, which in turn induce negative dielectrophoresis forces exerting on the particle that transport throughout the microchannel electrokinetically. Experiments were conducted to demonstrate the controlled trajectories of fix-sized (i.e. 10 or 15x μm) polystyrene particles, and size-dependent separation of 10 and 15 μm particles by adjusting the applied voltages at the inlet and outlets. Numerical simulations were also performed to predict the particle trajectories, …
Microstructure And Texture Evolution In A Twinning-Induced-Plasticity Steel During Uniaxial Tension, Ahmed A. Saleh, Elena V. Pereloma, Azdiar A. Gazder
Microstructure And Texture Evolution In A Twinning-Induced-Plasticity Steel During Uniaxial Tension, Ahmed A. Saleh, Elena V. Pereloma, Azdiar A. Gazder
Faculty of Engineering and Information Sciences - Papers: Part A
A combination of electron back-scattering diffraction and X-ray diffraction was used to track the evolution of the microstructure and texture of a fully recrystallized Fe-24 Mn-3 Al-2 Si-1 Ni-0.06 C twinning-induced-plasticity steel during interrupted uniaxial tensile testing. Texture measurements returned the characteristic double fibre texture for face-centred cubic materials, with a relatively stronger 〈1 1 1〉 and a weaker 〈1 0 0〉 partial fibre parallel to the tensile axis. The interaction with the stable 〈1 1 1〉 oriented grains results in preferential plastic flow in the unstable 〈1 1 0〉 oriented grains. Consequently, the grains oriented along the 〈1 1 …
Ebsd Observations Of Recrystallisation And Tensile Deformation In Twinning Induced Plasticity Steel, Ahmed A. Saleh, Azdiar A. Gazder, Elena Pereloma
Ebsd Observations Of Recrystallisation And Tensile Deformation In Twinning Induced Plasticity Steel, Ahmed A. Saleh, Azdiar A. Gazder, Elena Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
The microstructure evolution of cold-rolled and isochronally annealed Fe-24Mn-3Al-2Si-1Ni-0.06C twinning induced plasticity steel was investigated by electron back-scattering diffraction (EBSD). Deformation behaviour of a fully recrystallised sample was tracked in a selected area as a function of the true strain using a combination of interrupted tensile testing and EBSD. The results show that the cold rolled microstructure contained a large fraction of primary and secondary twins as well as remnants of annealing twins carried over from the prior hot rolling stage. A novel deconstruction technique was applied to a partially recrystallised sample in order to separate the microstructure into deformed, …
Image Guidance During Breast Radiotherapy: A Phantom Dosimetry And Radiation-Induced Second Cancer Risk Study, A Quinn, L Holloway, Peter Metcalfe
Image Guidance During Breast Radiotherapy: A Phantom Dosimetry And Radiation-Induced Second Cancer Risk Study, A Quinn, L Holloway, Peter Metcalfe
Faculty of Engineering and Information Sciences - Papers: Part A
Imaging procedures utilised for patient position verification during breast radiotherapy can add a considerable dose to organs surrounding the target volume on top of therapeutic scatter dose. This study investigated the dose from a breast kilovoltage cone-beam CT (kV-CBCT), a breast megavoltage fan-beam CT (MV-FBCT), and a TomoDirectTM breast treatment. Thermoluminescent dosimeters placed within a female anthropomorphic phantom were utilised to measure the dose to various organs and tissues. The contralateral breast, lungs and heart received 0.40 cGy, 0.45 cGy and 0.40 cGy from the kV-CBCT and 1.74 cGy, 1.39 cGy and 1.73 cGy from the MV-FBCT. In comparison to …
Prediction Of Earthquake-Induced Liquefaction For Level And Gently Sloped Ground, G Chiaro, J Koseki
Prediction Of Earthquake-Induced Liquefaction For Level And Gently Sloped Ground, G Chiaro, J Koseki
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents a simplified procedure for predicting earthquake-induced level and sloped ground failure, namely liquefaction and shear failure. It consists of a framework where cyclic stress ratio (CSR), static stress ratio (SSR) and undrained shear strength (USS) are formulated considering simple shear conditions, which simulate field stress during earthquakes more realistically.
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
Faculty of Engineering and Information Sciences - Papers: Part A
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.
Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar
Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar
Faculty of Engineering and Information Sciences - Papers: Part A
Strain-induced phase transformation studies have been conducted in a Ti-6Al-2Sn-4Zr-6Mo alloy. This alloy was subjected to b sub-transus deformation upon slow cooling from the b-phase field and the effect of strain on the extent and morphology of the phase transformation during hot-deformation was determined. In addition, the transformation kinetics and the morphology of the newly formed a-phase were studied following deformation under different cooling conditions. By applying strain, the rate of the b-to-a phase transformation increased significantly during deformation as well as during slow cooling following deformation. This increase in the kinetics of the b-to-a transformation can be ascribed to …
Effect Of Microstructure On The Stability Of Retained Austenite In Transformation-Induced-Plasiticity Steels, I B. Timokhina, P D. Hodgson, E V. Pereloma
Effect Of Microstructure On The Stability Of Retained Austenite In Transformation-Induced-Plasiticity Steels, I B. Timokhina, P D. Hodgson, E V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
Two Fe-0.2C-1.55Mn-1.5Si (in wt pct) steels, with and without the addition of 0.039Nb (in wt pct), were studied using laboratory rolling-mill simulations of controlled thermomechanical processing. The microstructures of all samples were characterized by optical metallography, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural behavior of phases under applied strain was studied using a heat-tinting technique. Despite the similarity in the microstructures of the two steels (equal amounts of polygonal ferrite, carbide-free bainite, and retained austenite), the mechanical properties were different. The mechanical properties of these transformation-induced-plasticity (TRIP) steels depended not only on the individual behavior of all …
A Systematic Study Of Radio-Induced X-Ray Cavities In Clusters, Groups, And Galaxies, L Birzan, D A. Rafferty, B R. Mcnamara, M W. Wise, Paul E. J Nulsen
A Systematic Study Of Radio-Induced X-Ray Cavities In Clusters, Groups, And Galaxies, L Birzan, D A. Rafferty, B R. Mcnamara, M W. Wise, Paul E. J Nulsen
Faculty of Engineering and Information Sciences - Papers: Part A
We present an analysis of 16 galaxy clusters, one group, and one galaxy drawn from the Chandra Data Archive. These systems possess prominent X-ray surface brightness depressions associated with cavities or bubbles that were created by interactions between powerful radio sources and the surrounding hot gas. The central galaxies in these systems harbor radio sources with luminosities ranging between ∼2 × 10 38 and 7 × 10 44 ergs s -1. The cavities have an average radius of ∼10 kpc, and they lie at an average projected distance of ∼20 kpc from the central galaxy. The minimum energy associated with …
Effect Of Deformation Schedule On The Microstructure And Mechanical Properties Of A Thermomechanically Processed C-Mn-Si Transformation-Induced Plasticity Steel, I B. Timokhina, P D. Hodgson, E V. Pereloma
Effect Of Deformation Schedule On The Microstructure And Mechanical Properties Of A Thermomechanically Processed C-Mn-Si Transformation-Induced Plasticity Steel, I B. Timokhina, P D. Hodgson, E V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties …
Regularity Of Induced Representations And A Theorem Of Quigg And Speilberg, Astrid An Huef, Iain Raeburn
Regularity Of Induced Representations And A Theorem Of Quigg And Speilberg, Astrid An Huef, Iain Raeburn
Faculty of Engineering and Information Sciences - Papers: Part A
Mackey's imprimitivity theorem characterizes the unitary representations of a locally compact group G which have been induced from representations of a closed subgroup K; Rieffel's influential reformulation says that the group C*-algebra C*(K) is Morita equivalent to the crossed product C0(G/K)×G [14]. There have since been many important generalizations of this theorem, especially by Rieffel [15, 16] and by Green [3, 4]. These are all special cases of the symmetric imprimitivity theorem of [11], which gives a Morita …
Naturality And Induced Representations, Siegfried Echterhoff, S Kaliszewski, John Quigg, Iain Raeburn
Naturality And Induced Representations, Siegfried Echterhoff, S Kaliszewski, John Quigg, Iain Raeburn
Faculty of Engineering and Information Sciences - Papers: Part A
We show that induction of covariant representations for C*-dynamical systems is natural in the sense that it gives a natural transformation between certain crossed-product functors. This involves setting up suitable categories of C*-algebras and dynamical systems, and extending the usual constructions of crossed products to define the appropriate functors. From this point of view, Green's Imprimitivity Theorem identifies the functors for which induction is a natural equivalence. Various special cases of these results have previously been obtained on an ad hoc basis.
Induced C*-Algebras, Coactions And Equivariance In The Symmetric Imprimitivity Theorem, Siegfried Echterhoff, Iain Raeburn
Induced C*-Algebras, Coactions And Equivariance In The Symmetric Imprimitivity Theorem, Siegfried Echterhoff, Iain Raeburn
Faculty of Engineering and Information Sciences - Papers: Part A
The symmetric imprimitivity theorem provides a Morita equivalence between two crossed products of induced C*-algebras and includes as special cases many other important Morita equivalences such as Green's imprimitivity theorem. We show that the symmetric imprimitivity theorem is compatible with various inflated actions and coactions on the crossed products.
Induced C*-Algebras And Landstad Duality For Twisted Coactions, John C. Quigg, Iain Raeburn
Induced C*-Algebras And Landstad Duality For Twisted Coactions, John C. Quigg, Iain Raeburn
Faculty of Engineering and Information Sciences - Papers: Part A
No abstract provided.