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Full-Text Articles in Engineering

Effect Of Deformation On Microstructure And Mechanical Properties Of Dual Phase Steel Produced Via Strip Casting Simulation, Zhiping Xiong, Andrii Kostryzhev, Nicole Stanford, Elena V. Pereloma Jan 2016

Effect Of Deformation On Microstructure And Mechanical Properties Of Dual Phase Steel Produced Via Strip Casting Simulation, Zhiping Xiong, Andrii Kostryzhev, Nicole Stanford, Elena V. Pereloma

Faculty of Engineering and Information Sciences - Papers: Part A

The strip casting is a recently appeared technology with a potential to significantly reduce energy consumption in steel production, compared to hot rolling and cold rolling. However, the quantitative dependences of the steel microstructure and mechanical properties on strip casting parameters are unknown and require investigation. In the present work we studied the effects of strain and interrupted cooling temperature on microstructure and mechanical properties in conventional dual phase steel (0.08C-0.81Si-1.47Mn-0.03Al wt%). The strip casting process was simulated using a Gleeble 3500 thermo-mechanical simulator. The steel microstructures were studied using optical, scanning and transmission electron microscopy. Mechanical properties were measured …


Coupled Nonlinear Dynamics Of Geometrically Imperfect Shear Deformable Extensible Microbeams, Mergen H. Ghayesh, Hamed Farokhi Jan 2016

Coupled Nonlinear Dynamics Of Geometrically Imperfect Shear Deformable Extensible Microbeams, Mergen H. Ghayesh, Hamed Farokhi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper aims at analyzing the coupled nonlinear dynamical behavior of geometrically imperfect shear deformable extensible microbeams based on the third-order shear deformation and modified couple stress theories. Using Hamilton's principle and taking into account extensibility, the three nonlinear coupled continuous expressions are obtained for an initially slightly curved (i.e., a geometrically imperfect) microbeam, describing the longitudinal, transverse, and rotational motions. A high-dimensional Galerkin scheme is employed, together with an assumed-mode technique, in order to truncate the continuous system with an infinite number of degrees of freedom into a discretized model with sufficient degrees of freedom. This high-dimensional discretized model …


Effect Of Grain Size On Springback And System Energy In Micro V-Bending With Phosphor Bronze Foil, Zhi Fang, Zhengyi Jiang, Xiaogang Wang, Cunlong Zhou, Xianming Zhao, Xiaoming Zhang, Di Wu Jan 2016

Effect Of Grain Size On Springback And System Energy In Micro V-Bending With Phosphor Bronze Foil, Zhi Fang, Zhengyi Jiang, Xiaogang Wang, Cunlong Zhou, Xianming Zhao, Xiaoming Zhang, Di Wu

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, the effect of grain size on springback in the micro V-bending process of phosphor bronze foil (face-centered cubic structure) is investigated. Grain size effect is expressed by the ratio of material thickness (T) to average grain size (D), and these T/D values are divided into three groups: larger than 1, less than 1, and approximately equal to 1. It has been found that springback angles were the lowest when T/D ≈ 1. Electron backscattering diffraction (EBSD) measurement results show that the twinning boundaries change with the ratios of T/D before and after bending. When T/D > 1, the …


Internal Energy Transfer In Dynamical Behavior Of Slightly Curved Shear Deformable Microplates, Mergen H. Ghayesh, Hamed Farokhi, Gursel Alici Jan 2016

Internal Energy Transfer In Dynamical Behavior Of Slightly Curved Shear Deformable Microplates, Mergen H. Ghayesh, Hamed Farokhi, Gursel Alici

Faculty of Engineering and Information Sciences - Papers: Part A

This paper investigates the internal energy transfer and modal interactions in the dynamical behavior of slightly curved microplates. Employing the third-order shear deformation theory, the microplate model is developed taking into account geometric nonlinearities as well as the modified couple stress theory; the initial curvature is modeled by an initial imperfection in the out-of-plane direction. The in-plane displacements and inertia are retained, and the coupled out-of-plane, rotational, and in-plane motion characteristics are analyzed. Specifically, continuous models are developed for kinetic and potential energies as well as damping and external works; these are balanced and reduced via Lagrange's equations along with …


A Magnetically Actuated Drug Delivery System For Robotic Endoscopic Capsules, Fredy Munoz, Gursel Alici, Weihua Li Jan 2016

A Magnetically Actuated Drug Delivery System For Robotic Endoscopic Capsules, Fredy Munoz, Gursel Alici, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

There is an increasing need to incorporate an actively controlled drug delivery system (DDS) into the next generation of capsule endoscopy in order to treat diseases in the gastrointestinal tract in a noninvasive way. Despite a number of attempts to magnetically actuate drug delivery mechanisms embedded in endoscopic capsules, longer operating distances and further miniaturization of on-board components are still drawbacks of such systems. In this paper, we propose an innovative magnetic system that consists of an array of magnets, which activates a DDS, based on an overly miniaturized slider-crank mechanism. We use analytical models to compare the magnetic fields …


Analysis Of Micro Flexible Rolling With Consideration Of Material Heterogeneity, Feijun Qu, Zhengyi Jiang, Haina Lu Jan 2016

Analysis Of Micro Flexible Rolling With Consideration Of Material Heterogeneity, Feijun Qu, Zhengyi Jiang, Haina Lu

Faculty of Engineering and Information Sciences - Papers: Part A

This paper establishes a finite element model to numerically study the springback in thickness direction during micro flexible rolling process, in which 3D Voronoi tessellation has been applied to describe grain boundary and generation process of grain in the workpiece. To reflect material heterogeneity, nine kinds of mechanical properties defined by nine types of heterogeneity coefficients are selected and assigned to Voronoi polyhedrons as per the statistical distribution of hardness of grains identified by micro hardness testing. Initial workpiece thicknesses of 100, 250 and 500 μm with reduction changing from 20% to 50% are respectively considered in the numerical simulation …


Analysis Of Laminated Crack Defect In The Upsetting Process Of Heavy Disk-Shaped Forgings, Minting Wang, Dongying Li, Fan Wang, Xinliang Zang, Xuetong Li, Hong Xiao, Fengshan Du, F C. Zhang, Zhengyi Jiang Jan 2016

Analysis Of Laminated Crack Defect In The Upsetting Process Of Heavy Disk-Shaped Forgings, Minting Wang, Dongying Li, Fan Wang, Xinliang Zang, Xuetong Li, Hong Xiao, Fengshan Du, F C. Zhang, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

Using nonlinear finite element method, a thermo-mechanical coupled simulation model for the formation mechanism of the laminated crack defect has been established in the upsetting of heavy disk-shaped forgings. Through numerical simulation, the distributions of stress, equivalent strain and strain rate were analysed. Meanwhile the distribution diagram of stress state evolution was obtained, and the uncoordinated deformation, under tri-lateral compression, is determined as the main reason leading to laminated crack defect. To reveal the characteristics of the uncoordinated deformation, the variations of each variable and its gradient in numerical simulation were presented, and a combined prediction model of laminated crack …


Acetylated Bacterial Cellulose Coated With Urinary Bladder Matrix As A Substrate For Retinal Pigment Epithelium, Sara Goncalves, Ines P. Rodrigues, J Padrão, J P. Silva, Vitor Sencadas, Senentxu Lanceros-Méndez, Henrique Girao, F M. Gama, F Dourado, L R. Rodrigues Jan 2016

Acetylated Bacterial Cellulose Coated With Urinary Bladder Matrix As A Substrate For Retinal Pigment Epithelium, Sara Goncalves, Ines P. Rodrigues, J Padrão, J P. Silva, Vitor Sencadas, Senentxu Lanceros-Méndez, Henrique Girao, F M. Gama, F Dourado, L R. Rodrigues

Faculty of Engineering and Information Sciences - Papers: Part A

This work evaluated the effect of acetylated bacterial cellulose (ABC) substrates coated with urinary bladder matrix (UBM) on the behavior of retinal pigment epithelium (RPE), as assessed by cell adhesion, proliferation and development of cell polarity exhibiting transepithelial resistance and polygonal shaped-cells with microvilli. Acetylation of bacterial cellulose (BC) generated a moderate hydrophobic surface (around 65°) while the adsorption of UBM onto these acetylated substrates did not affect significantly the surface hydrophobicity. The ABS substrates coated with UBM enabled the development of a cell phenotype closer to that of native RPE cells. These cells were able to express proteins essential …


Fundamentals And Applications Of Inertial Microfluidics: A Review, Jun Zhang, Sheng Yan, Dan Yuan, Gursel Alici, Nam-Trung Nguyen, Majid Ebrahimi Warkiani, Weihua Li Jan 2016

Fundamentals And Applications Of Inertial Microfluidics: A Review, Jun Zhang, Sheng Yan, Dan Yuan, Gursel Alici, Nam-Trung Nguyen, Majid Ebrahimi Warkiani, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

In the last decade, inertial microfluidics has attracted significant attention and a wide variety of channel designs that focus, concentrate and separate particles and fluids have been demonstrated. In contrast to conventional microfluidic technologies, where fluid inertia is negligible and flow remains almost within the Stokes flow region with very low Reynolds number (Re < 1), inertial microfluidics works in the intermediate Reynolds number range (~1 < Re < ~100) between Stokes and turbulent regimes. In this intermediate range, both inertia and fluid viscosity are finite and bring about several intriguing effects that form the basis of inertial microfluidics including (i) inertial migration and (ii) secondary flow. Due to the superior features of high-throughput, simplicity, precise manipulation and low cost, inertial microfluidics is a very promising candidate for cellular sample processing, especially for samples with low abundant targets. In this review, we first discuss the fundamental kinematics of particles in microchannels to familiarise readers with the mechanisms and underlying physics in inertial microfluidic systems. We then present a comprehensive review of recent developments and key applications of inertial microfluidic systems according to their microchannel structures. Finally, we discuss the perspective of employing fluid inertia in microfluidics for particle manipulation. Due to the superior benefits of inertial microfluidics, this promising technology will still be an attractive topic in the near future, with more novel designs and further applications in biology, medicine and industry on the horizon.


Mechanical Recoverability And Damage Process Of Ionic-Covalent Paam-Alginate Hybrid Hydrogels, Hai Xin, Hugh Ralph Brown, Sina Naficy, Geoffrey M. Spinks Jan 2016

Mechanical Recoverability And Damage Process Of Ionic-Covalent Paam-Alginate Hybrid Hydrogels, Hai Xin, Hugh Ralph Brown, Sina Naficy, Geoffrey M. Spinks

Faculty of Engineering and Information Sciences - Papers: Part A

Hydrogels consisting of interpenetrating networks of ionically and covalently crosslinked polymers showed high toughness and mechanical recoverability as a result of the dissociation and re-formation of ionic crosslinks. The present investigation aimed to provide a quantitative study on the mechanical recoverability and damage process of an example hybrid gel of calcium crosslinked alginate and covalently crosslinked polyacrylamide. Three series of load/unload tests were performed sequentially with the mechanical properties of the gel fully retrieved between the 2nd and 3rd load/unload series while only the partial recovery of mechanical properties was evident from the 1st to 2nd series. The load/unload curves …


Nonlinear Dynamical Behavior Of Axially Accelerating Beams: Three-Dimensional Analysis, Mergen H. Ghayesh, Hamed Farokhi Jan 2016

Nonlinear Dynamical Behavior Of Axially Accelerating Beams: Three-Dimensional Analysis, Mergen H. Ghayesh, Hamed Farokhi

Faculty of Engineering and Information Sciences - Papers: Part A

The three-dimensional (3D) nonlinear dynamics of an axially accelerating beam is examined numerically taking into account all of the longitudinal, transverse, and lateral displacements and inertia. Hamilton's principle is employed in order to derive the nonlinear partial differential equations governing the longitudinal, transverse, and lateral motions. These equations are transformed into a set of nonlinear ordinary differential equations by means of the Galerkin discretization technique. The nonlinear global dynamics of the system is then examined by time-integrating the discretized equations of motion. The results are presented in the form of bifurcation diagrams of Poincare maps, time histories, phase-plane portraits, Poincare …


Analytic Performance Model For State-Based Mac Layer Cooperative Retransmission Protocols, Brett Hagelstein, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei, Wei Ni Jan 2016

Analytic Performance Model For State-Based Mac Layer Cooperative Retransmission Protocols, Brett Hagelstein, Mehran Abolhasan, Daniel R. Franklin, Farzad Safaei, Wei Ni

Faculty of Engineering and Information Sciences - Papers: Part A

Cooperative retransmission can significantly improve link reliability over lossy and time-varying wireless links. However, comparing retransmission protocols is challenging, and generally requires simplistic assumptions specific to each protocol. In this paper, we develop a general model to evaluate cooperative retransmission protocols with distributed, slot-based contention algorithms. Specifically, we propose to calculate the relay time-out probabilities at a MAC time-slot scale, formulate retransmission outcomes as functions of the time-out probabilities, and derive the probability of a retransmission process for every data frame. We also propose a Markov extension of our model to characterise the dependency between retransmissions of multiple frames. This …


Development Of A Novel Multi-Layer Mre Isolator For Suppression Of Building Vibrations Under Seismic Events, Jian Yang, Shuaishuai Sun, Tongfei Tian, Weihua Li, Haiping Du, Gursel Alici, Masami Nakano Jan 2016

Development Of A Novel Multi-Layer Mre Isolator For Suppression Of Building Vibrations Under Seismic Events, Jian Yang, Shuaishuai Sun, Tongfei Tian, Weihua Li, Haiping Du, Gursel Alici, Masami Nakano

Faculty of Engineering and Information Sciences - Papers: Part A

Protecting civil engineering structures from uncontrollable events such as earthquakes while maintaining their structural integrity and serviceability is very important; this paper describes the performance of a stiffness softening magnetorheological elastomer (MRE) isolator in a scaled three storey building. In order to construct a closed-loop system, a scaled three storey building was designed and built according to the scaling laws, and then four MRE isolator prototypes were fabricated and utilised to isolate the building from the motion induced by a scaled El Centro earthquake. Fuzzy logic was used to output the current signals to the isolators, based on the real-time …


Nano-Enhanced Phase Change Materials For Improved Building Performance, Zhenjun Ma, Wenye Lin, Mohammed I. Sohel Jan 2016

Nano-Enhanced Phase Change Materials For Improved Building Performance, Zhenjun Ma, Wenye Lin, Mohammed I. Sohel

Faculty of Engineering and Information Sciences - Papers: Part A

Nano-enhanced phase change materials (PCMs) have attracted increasing attention to address one of the key barriers (i.e. low thermal conductivity) to the wide adoption of PCMs in many industrial applications. This paper discusses the generic problem and key issues associated with appropriately using this new class of materials in buildings for effective thermal management and improved energy performance. An overview on major recent development and application of nano-enhanced PCMs as thermal energy storage media is provided. A case study based on a PCM ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors is then performed to evaluate the potential …


New Configuration Of Transverse Reinforcement For Improved Seismic Resistance Of Rectangular Rc Columns: Concept And Axial Compressive Behavior, D H. Jing, T Yu, X D. Liu Jan 2016

New Configuration Of Transverse Reinforcement For Improved Seismic Resistance Of Rectangular Rc Columns: Concept And Axial Compressive Behavior, D H. Jing, T Yu, X D. Liu

Faculty of Engineering and Information Sciences - Papers: Part A

Columns are considered to be critical members of moment-resisting structural systems. In seismically active regions, it is important to improve the ductile deformation capacity and energy dissipation capacity of columns so that the entire structure can endure severe ground motion and dissipate a considerable amount of seismic energy. Against this background, this paper presents the idea of a new transverse reinforcement configuration (TRC) for improved seismic performance of rectangular (including square) reinforced concrete (RC) columns. The novel features of the new TRC compared to conventional TRCs using rectangular hoops and cross ties mainly include the use of additional small circular …


Bacterial Community Dynamics In An Anoxic-Aerobic Membrane Bioreactor - Impact On Nutrient And Trace Organic Contaminant Removal, Hop V. Phan, Faisal I. Hai, Ren Zhang, Jinguo Kang, William E. Price, Long D. Nghiem Jan 2016

Bacterial Community Dynamics In An Anoxic-Aerobic Membrane Bioreactor - Impact On Nutrient And Trace Organic Contaminant Removal, Hop V. Phan, Faisal I. Hai, Ren Zhang, Jinguo Kang, William E. Price, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

The bacterial community in different redox regimes of an anoxic-aerobic MBR under different operating conditions was investigated using pyrosequencing. With internal recirculation (IR) between the anoxic and aerobic reactors, the bacterial communities in these reactors were highly similar in structure and phylogenetic relationship, indicating IR as a key driving force shaping the bacterial communities that are responsible for the core function in the system. Without IR, each redox condition sustained the growth of distinct bacterial communities according to their oxygen requirement, and the anoxic community presented a low capacity of nutrient and trace organic contaminant (TrOC) removal. Higher bacterial diversity …


An Efficient Quantum Scheme For Private Set Intersection, Run-Hua Shi, Yi Mu, Hong Zhong, Jie Cui, Shun Zhang Jan 2016

An Efficient Quantum Scheme For Private Set Intersection, Run-Hua Shi, Yi Mu, Hong Zhong, Jie Cui, Shun Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Private Set Intersection allows a client to privately compute set intersection with the collaboration of the server, which is one of the most fundamental and key problems within the multiparty collaborative computation of protecting the privacy of the parties. In this paper, we first present a cheat-sensitive quantum scheme for Private Set Intersection. Compared with classical schemes, our scheme has lower communication complexity, which is independent of the size of the server's set. Therefore, it is very suitable for big data services in Cloud or large-scale client-server networks.


Hot Enough For You? A Spatial Exploratory And Inferential Analysis Of North American Climate-Change Projections, Noel A. Cressie, Emily L. Kang Jan 2016

Hot Enough For You? A Spatial Exploratory And Inferential Analysis Of North American Climate-Change Projections, Noel A. Cressie, Emily L. Kang

Faculty of Engineering and Information Sciences - Papers: Part A

Climate models have become the primary tools for scientists to project climate-change into the future and to understand its potential impact. Continental-scale General Circulation Models (GCMs) oversimplify the regional climate processes and geophysical features such as topography and land cover. The consequences of local/regional climate change are particularly relevant to natural resource management and environmental-policy decisions, for which Regional Climate Models (RCMs) have been developed. RCMs simulate, for example, three-hourly "weather" over long time periods, from which long-run averages (e.g., over 30 years) are commonly computed to estimate a region's future climate. With anthropogenic forcings incorporated, RCMs provide a means …


Fault-Tolerant Control Of Electric Vehicles With In-Wheel Motors Using Actuator-Grouping Sliding Mode Controllers, Boyuan Li, Haiping Du, Weihua Li Jan 2016

Fault-Tolerant Control Of Electric Vehicles With In-Wheel Motors Using Actuator-Grouping Sliding Mode Controllers, Boyuan Li, Haiping Du, Weihua Li

Faculty of Engineering and Information Sciences - Papers: Part A

Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and …


Secure Multiparty Quantum Computation For Summation And Multiplication, Run-Hua Shi, Yi Mu, Hong Zhong, Jie Cui, Shun Zhang Jan 2016

Secure Multiparty Quantum Computation For Summation And Multiplication, Run-Hua Shi, Yi Mu, Hong Zhong, Jie Cui, Shun Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

As a fundamental primitive, Secure Multiparty Summation and Multiplication can be used to build complex secure protocols for other multiparty computations, specially, numerical computations. However, there is still lack of systematical and efficient quantum methods to compute Secure Multiparty Summation and Multiplication. In this paper, we present a novel and efficient quantum approach to securely compute the summation and multiplication of multiparty private inputs, respectively. Compared to classical solutions, our proposed approach can ensure the unconditional security and the perfect privacy protection based on the physical principle of quantum mechanics.


Online Coordinated Voltage Control In Distribution Systems Subjected To Structural Changes And Dg Availability, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi Jan 2016

Online Coordinated Voltage Control In Distribution Systems Subjected To Structural Changes And Dg Availability, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The responses of multiple DG units and voltage regulating devices such as tap changers and capacitor banks for correcting the voltage may lead to operational conflicts and oscillatory transients, where distribution systems are subjected to network reconfiguration and changes in availability of the DG units. Therefore, coordinated voltage control is required to minimize control interactions while accounting for the impact of structural changes associated with the network. This paper proposes a strategy for coordinating the operation of multiple voltage regulating devices and DG units in medium voltage (MV) distribution systems, under structural changes and DG availability, for effective voltage control. …


Mitigating Tap Changer Limit Cycles In Modern Electricity Networks Embedded With Local Generation Units, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi, Md Jan E Alam Jan 2016

Mitigating Tap Changer Limit Cycles In Modern Electricity Networks Embedded With Local Generation Units, Dothinka Ranamuka Rallage, Ashish P. Agalgaonkar, Kashem M. Muttaqi, Md Jan E Alam

Faculty of Engineering and Information Sciences - Papers: Part A

Cascaded on-load tap changers (OLTCs) are widely used for coarse control of voltages in largely interconnected elec- tric power systems. There could be interactions between load dynamics and OLTC control under certain system operating conditions which may lead to the OLTC limit cycle phenomena, thereby resulting into long-term voltage oscillations in the system. In recent years, renewable and nonrenewable local generation (LG) units have been getting interconnected in modern power systems. The existence of OLTC limit cycles in the presence of LG has not been addressed in the literature in greater details. In this paper, the OLTC limit cycle phenomenon, …


Strategies For The Development Of Three Dimensional Scaffolds From Piezoelectric Poly(Vinylidene Fluoride), Daniela M. Correia, Clarisse Ribeiro, Vitor Sencadas, L Vikingsson, M Oliver Gasch, J L. Gomez Ribelles, Gabriela Botelho, Senentxu Lanceros-Méndez Jan 2016

Strategies For The Development Of Three Dimensional Scaffolds From Piezoelectric Poly(Vinylidene Fluoride), Daniela M. Correia, Clarisse Ribeiro, Vitor Sencadas, L Vikingsson, M Oliver Gasch, J L. Gomez Ribelles, Gabriela Botelho, Senentxu Lanceros-Méndez

Faculty of Engineering and Information Sciences - Papers: Part A

Cell supports based on electroactive materials, that generate electrical signal variations as a response to mechanical deformations and vice-versa, are gaining increasing attention for tissue engineering applications. In particular, poly(vinylidene fluoride), PVDF, has been proven to be suitable for these applications in the form of films and two-dimensional membranes. In this work, several strategies have been implemented in order to develop PVDF three-dimensional scaffolds. Three processing methods, including solvent casting with particulate leaching and three-dimensional nylon, and freeze extraction with poly(vinyl alcohol) templates are presented in order to obtain three-dimensional scaffolds with different architectures and interconnected porosity. Further, it is …


A Dual Deformation Mechanism Of Grain Boundary At Different Stress Stages, Liang Zhang, Cheng Lu, Jie Zhang, A Kiet Tieu Jan 2016

A Dual Deformation Mechanism Of Grain Boundary At Different Stress Stages, Liang Zhang, Cheng Lu, Jie Zhang, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

Molecular dynamics (MD) simulation with embedded-atom method (EAM) potential was carried out to study the structure and shear response of an asymmetric tilt grain boundary in copper bicrystal. A non-planar structure with dissociated intrinsic stacking faults was observed in the grain boundary. Simulation results show that this type of structure can significantly increase the ductility of the simulation sample under shear deformation. A dual deformation mechanism of the grain boundary was observed; the grain boundary can be a source of dislocation emission and migrate itself at different stress stages. The result of this study can provide further information to understand …


Computational Fluid Dynamics Simulation Of Carbon Dioxide Dispersion In A Complex Environment, Bin Liu, Xiong Liu, Cheng Lu, Ajit R. Godbole, Guillaume Michal, A Kiet Tieu Jan 2016

Computational Fluid Dynamics Simulation Of Carbon Dioxide Dispersion In A Complex Environment, Bin Liu, Xiong Liu, Cheng Lu, Ajit R. Godbole, Guillaume Michal, A Kiet Tieu

Faculty of Engineering and Information Sciences - Papers: Part A

In order to quantitatively evaluate the risk associated with the Carbon Capture and Storage (CCS) technology, a deeper understanding of CO2 dispersion resulting from accidental releases is essential. CO2 is a heavier-than-air gas. Its dispersion patterns may vary according to local conditions. This study focuses on CO2 dispersion over complex terrains. Computational Fluid Dynamics (CFD) models were developed to simulate the CO2 dispersion over two hypothetical topographies: (1) a flat terrain with an axisymmetric hill and (2) a simplified model of an urban area with buildings. The source strength, wind velocity and height of the buildings were varied to investigate …


Dynamic Response Of Symmetrical And Asymmetrical Sandwich Plates With Shear Thickening Fluid Core Subjected To Penetration Loading, Z. H. Tan, L Zuo, Weihua Li, L S. Liu, Peng Zhai Jan 2016

Dynamic Response Of Symmetrical And Asymmetrical Sandwich Plates With Shear Thickening Fluid Core Subjected To Penetration Loading, Z. H. Tan, L Zuo, Weihua Li, L S. Liu, Peng Zhai

Faculty of Engineering and Information Sciences - Papers: Part A

Symmetrical and asymmetrical sandwich plates with a shear thickening fluid (STF) core were designed to be penetrated by a cylindrical projectile at various impact velocities. These STFs consist of SiO2/PEG400, and the volume fractions of SiO2 nano-particles are 54% and 56%, respectively. Failure mode of the rear face sheet of the symmetrical sandwich plate is petal perforation, but the rear face sheet of the asymmetrical sandwich plate failed in plug perforation mode at the velocity of less than 80 m/s and in the petal perforation mode at the velocity faster than 90 m/s. The results showed that both the face …


Tribological Behavior In Micro-Sheet Hydroforming, Hideki Sato, Kenichi Manabe, Dongbin Wei, Zhengyi Jiang, Sergei Alexandrov Jan 2016

Tribological Behavior In Micro-Sheet Hydroforming, Hideki Sato, Kenichi Manabe, Dongbin Wei, Zhengyi Jiang, Sergei Alexandrov

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, the tribological behavior and its size effects in micro-hydromechanical deep drawing (MHDD) are theoretically and experimentally investigated. It is found that a required fluid pressure for hydrodynamic lubrication significantly increases with scaling down micro-scale due to a high sealablity at small relative punch diameter to minimum thickness. Moreover, the opposite tribological size effect from a conventional microforming appears in MHDD in which the fluid medium can be kept in open lubricant pockets (OLPs) by applying a fluid pressure and, the friction coefficient decreases as a specimen size decreases. Thus, MHDD can induce the hydrodynamic lubrication and lubrication …


A Comparative Study Of Fluid Flow And Mass Transfer In A Trumpet-Shaped Ladle Shroud Using Large Eddy Simulation, Jiangshan Zhang, Jingshe Li, Yi Yan, Zhixin Chen, Shufeng Yang, Jingwei Zhao, Zhengyi Jiang Jan 2016

A Comparative Study Of Fluid Flow And Mass Transfer In A Trumpet-Shaped Ladle Shroud Using Large Eddy Simulation, Jiangshan Zhang, Jingshe Li, Yi Yan, Zhixin Chen, Shufeng Yang, Jingwei Zhao, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

The advantages of trumpet-shaped ladle shrouds (TLS) have been frequently demonstrated over conventional straight-bore ladle shrouds (CLS) with respect to production efficiency and molten steel quality in continuous casting practices. The present study is to shed some lights on why the TLS are better than the CLS design by examining the fluid dynamics and mass transfer using large eddy simulation. The obtained numerical results were validated with particle imaging velocimetry experiments. Flow velocity, deformation, turbulent energy dissipation, and mixing kinetics of tracer were discussed. The results showed that the entering jet of the CLS flowed straight down into the tundish …


Effect Of Sterilization Methods On Electrospun Poly(Lactic Acid) (Pla) Fiber Alignment For Biomedical Applications, T A. M Valente, D M. Silva, P S. Gomes, M H. Fernandes, J D. Santos, Vitor Sencadas Jan 2016

Effect Of Sterilization Methods On Electrospun Poly(Lactic Acid) (Pla) Fiber Alignment For Biomedical Applications, T A. M Valente, D M. Silva, P S. Gomes, M H. Fernandes, J D. Santos, Vitor Sencadas

Faculty of Engineering and Information Sciences - Papers: Part A

Medically approved sterility methods should be a major concern when developing a polymeric scaffold, mainly when commercialization is envisaged. In the present work, poly(lactic acid) (PLA) fiber membranes were processed by electrospinning with random and aligned fiber alignment and sterilized under UV, ethylene oxide (EO), and γ-radiation, the most common ones for clinical applications. It was observed that UV light and γ-radiation do not influence fiber morphology or alignment, while electrospun samples treated with EO lead to fiber orientation loss and morphology changing from cylindrical fibers to ribbon-like structures, accompanied to an increase of polymer crystallinity up to 28%. UV …


A Review Of Topologies Of Three-Port Dc-Dc Converters For The Integration Of Renewable Energy And Energy Storage System, Neng Zhang, Danny Sutanto, Kashem M. Muttaqi Jan 2016

A Review Of Topologies Of Three-Port Dc-Dc Converters For The Integration Of Renewable Energy And Energy Storage System, Neng Zhang, Danny Sutanto, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The application of renewable energy such as solar photovoltaic (PV), wind and fuel cells is becoming increasingly popular because of the environmental awareness and advances in technology coupled with decreasing manufacturing cost. Power electronic converters are usually used to convert the power from the renewable sources to match the load demand and grid requirement to improve the dynamic and steady-state characteristics of these green generation systems, to provide the maximum power point tracking (MPPT) control, and to integrate the energy storage system to solve the challenge of the intermittent nature of the renewable energy and the unpredictability of the load …