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Full-Text Articles in Social and Behavioral Sciences
The Shear Response Of Copper Bicrystals With Σ11 Symmetric And Asymmetric Tilt Grain Boundaries By Molecular Dynamics Simulation, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei
The Shear Response Of Copper Bicrystals With Σ11 Symmetric And Asymmetric Tilt Grain Boundaries By Molecular Dynamics Simulation, Liang Zhang, Cheng Lu, A Kiet Tieu, Xing Zhao, Linqing Pei
Faculty of Engineering and Information Sciences - Papers: Part A
Grain boundaries (GBs) are important microstructure features and can significantly affect the properties of nanocrystalline materials. Molecular dynamics simulation was carried out in this study to investigate the shear response and deformation mechanisms of symmetric and asymmetric Σ11 tilt GBs in copper bicrystals. Different deformation mechanisms were reported, depending on GB inclination angles and equilibrium GB structures, including GB migration coupled to shear deformation, GB sliding caused by local atomic shuffling, and dislocation nucleation from GB. The simulation showed that migrating Σ11(1 1 3) GB under shear can be regarded as sliding of GB dislocations and their combination along the …
Effects Of Grain Boundaries In Oxide Scale On Tribological Properties Of Nanoparticles Lubrication, Xianglong Yu, Zhengyi Jiang, Jingwei Zhao, Dongbin Wei, Cunlong Zhou, Qingxue Huang
Effects Of Grain Boundaries In Oxide Scale On Tribological Properties Of Nanoparticles Lubrication, Xianglong Yu, Zhengyi Jiang, Jingwei Zhao, Dongbin Wei, Cunlong Zhou, Qingxue Huang
Faculty of Engineering and Information Sciences - Papers: Part A
The characters of grain boundaries in oxide layers formed on substrates influence adhesion and friction behaviour, surface fracture and wear during high temperature steel processing. In this work, an electron backscattered diffraction (EBSD) analysis was conducted to investigate the role of surface grain boundary and orientation in magnetite (Fe3O4)/haematite (α-Fe2O3) scale during hot rolling, and further evaluate their effects on tribological properties of water-based nanoparticles lubrication. The results demonstrate that Fe3O4 (100) plane is strongly sensitive to the surface characteristics as the minimisation of surface energy. Coincident site lattice …
Molecular Dynamics Simulation On Σ5 Grain Boundaries Of Copper Bicrystal Under Tensile And Shear Deformation, Liang Zhang, Cheng Lu, A Kiet Tieu
Molecular Dynamics Simulation On Σ5 Grain Boundaries Of Copper Bicrystal Under Tensile And Shear Deformation, Liang Zhang, Cheng Lu, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
Molecular Dynamics simulation are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric Σ5[0 0 1] tilt grain boundaries (GBs) of copper bicrystal under uniaxial tension and shear deformation. Simulation results indicate that the Σ5 asymmetric GBs can facet into their corresponding symmetric GB structures. The maximum tensile stress of symmetric GBs is higher than the asymmetric ones at both 10 K and 300 K, which suggests the symmetric GBs may have a more stable boundary structures. All the Σ5 GBs investigate in this study can migrate under the shear deformation with different velocity. The migration …
Approximate Ordinary Differential Equations For The Optimal Exercise Boundaries Of American Put And Call Options, Marianito R. Rodrigo
Approximate Ordinary Differential Equations For The Optimal Exercise Boundaries Of American Put And Call Options, Marianito R. Rodrigo
Faculty of Engineering and Information Sciences - Papers: Part A
We revisit the American put and call option valuation problems. We derive analytical formulas for the option prices and approximate ordinary differential equations for the optimal exercise boundaries. Numerical simulations yield accurate option prices and comparable computational speeds when benchmarked against the binomial method for calculating option prices. Our approach is based on the Mellin transform and an adaptation of the Kármán–Pohlausen technique for boundary layers in fluid mechanics.
Atomistic Simulation Of Tensile Deformation Behavior Of Σ5 Tilt Grain Boundaries In Copper Bicrystal, Liang Zhang, Cheng Lu, A Kiet Tieu
Atomistic Simulation Of Tensile Deformation Behavior Of Σ5 Tilt Grain Boundaries In Copper Bicrystal, Liang Zhang, Cheng Lu, A Kiet Tieu
Faculty of Engineering and Information Sciences - Papers: Part A
Experiments on polycrystalline metallic samples have indicated that Grain boundary (GB) structure can affect many material properties related to fracture and plasticity. In this study, atomistic simulations are employed to investigate the structures and mechanical behavior of both symmetric and asymmetric ∑5[0 0 1] tilt GBs of copper bicrystal. First, the equilibrium GB structures are generated by molecular statics simulation at 0K. The results show that the ∑5 asymmetric GBs with different inclination angles (φ) are composed of only two structural units corresponding to the two ∑5 symmetric GBs. Molecular dynamics simulations are then conducted to investigate the mechanical response …
Stochastic Recognition Of Closed Object Boundaries In Images, J Helterbrand, Noel A. Cressie
Stochastic Recognition Of Closed Object Boundaries In Images, J Helterbrand, Noel A. Cressie
Faculty of Engineering and Information Sciences - Papers: Part A
Engineering-based edge detection techniques generally use local intensity information to identify whether a pixel location is part of a boundary. Boundaries are presumed present where sharp transitions in the observed intensities occur. Unfortunately, these approaches are sensitive to error and hidden partial boundaries, which hinders the determination of closed object boundaries. In this research, a method to obtain statistically optimal closed object boundaries is presented.