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Faculty of Engineering and Information Sciences - Papers: Part A

Micro

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Full-Text Articles in Science and Technology Studies

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 Jan 2013

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.


Self-Assembly Of Hierarchical Star-Like Co3o4 Micro/Nanostructures And Their Application In Lithium Ion Batteries, Li Li, Kuok Hau Seng, Zhixin Chen, Zaiping Guo, Hua-Kun Liu Jan 2013

Self-Assembly Of Hierarchical Star-Like Co3o4 Micro/Nanostructures And Their Application In Lithium Ion Batteries, Li Li, Kuok Hau Seng, Zhixin Chen, Zaiping Guo, Hua-Kun Liu

Faculty of Engineering and Information Sciences - Papers: Part A

A novel hierarchical star-like Co3O4 was successfully synthesized from self-assembled hierarchical Co(OH)F precursors via a facile hydrothermal method and subsequent annealing in air. The morphological evolution process of the Co(OH)F precursors was investigated by examining the different reaction times during synthesis. First, hexagonal plates are formed, and then nanodiscs grow on the surface of the plates. Subsequently, dissolution and regrowth of Co(OH)F occur to form the star-like hierarchical structures. Co3O4 obtained from thermal decomposition of the Co(OH)F precursor in air at 350 °C exhibited high reversible capacity as an anode material in lithium ion batteries. The specific charge capacity of …


Analysis Of Axisymmetric Cup Forming Of Metal Foil And Micro Hydroforming Process, Hideki Sato, Kenichi Manabe, Dongbin Wei, Zhengyi Jiang Jan 2013

Analysis Of Axisymmetric Cup Forming Of Metal Foil And Micro Hydroforming Process, Hideki Sato, Kenichi Manabe, Dongbin Wei, Zhengyi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

A novel forming method "micro hydromechanical deep drawing (MHDD)" is focused to improve the tribological property and forming limit. In this study, a theoretical model for MHDD is developed to investigate the size effect on deformation behavior in micro hydromechanical deep drawing. The effects of fluid pressure, the difference of friction coefficients at inner pockets and outer pockets are considered in the investigation on the size effect of tribological property. The friction force decreases as the scale factor decreases in MHDD process. It is also found that the tribological property in micro scale can be improved by applying the fluid …


Simulation Of Defects In Micro-Deep Drawing Of An Aluminium Alloy Foil, Syamsul Hadi, Hai-Liang Yu, Kiet Tieu, Cheng Lu Jan 2013

Simulation Of Defects In Micro-Deep Drawing Of An Aluminium Alloy Foil, Syamsul Hadi, Hai-Liang Yu, Kiet Tieu, Cheng Lu

Faculty of Engineering and Information Sciences - Papers: Part A

Micro-forming refers to the application of conventional forming processes to manufacture products from ultra-thin sheet materials. While attempting to meet the increasing demand for cost-effective manufacturing of micro-formed components, it is very important to reduce the defects in the products. In this paper, we report a number of Finite Element (FE) simulations of the micro-deep drawing process with various sample thicknesses and eccentric distances. The simulations indicated that when the sample thickness is nearly equal to the gap between the plunger and the die, the sample is likely to develop fractures at the bottom corner. When the sample thickness is …


Study On The Influence Of Temperature On The Surface Asperity In Micro Cross Wedge Rolling, H N. Lu, D B. Wei, Z Y. Jiang, D Wu, X M. Zhao Jan 2013

Study On The Influence Of Temperature On The Surface Asperity In Micro Cross Wedge Rolling, H N. Lu, D B. Wei, Z Y. Jiang, D Wu, X M. Zhao

Faculty of Engineering and Information Sciences - Papers: Part A

When the common deformation processes are scaled down to micro/meso dimensions, size effect is the particular phenomena in microforming, which is related to the dominant influence of single grains inside the micropart. The conventional cross wedge rolling (CWR) is introduced into the micro scale in order to take the advantages of CWR. The micro cross wedge rolling (MCWR) has to confront with the phenomena of size effect that occurs in the common microforming processes inevitably. One of the approaches to compensate size effect is to increase the deforming temperature. An increased formability is achieved because more slip systems of polycrystal …


An Image-Based Approach For Classification Of Human Micro-Doppler Radar Signatures, Fok Hing Chi Tivive, Son Lam Phung, Abdesselam Bouzerdoum Jan 2013

An Image-Based Approach For Classification Of Human Micro-Doppler Radar Signatures, Fok Hing Chi Tivive, Son Lam Phung, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

With the advances in radar technology, there is an increasing interest in automatic radar-based human gait identification. This is because radar signals can penetrate through most dielectric materials. In this paper, an image-based approach is proposed for classifying human micro-Doppler radar signatures. The time-varying radar signal is first converted into a time-frequency representation, which is then cast as a two-dimensional image. A descriptor is developed to extract micro-Doppler features from local time-frequency patches centered along the torso Doppler frequency. Experimental results based on real data collected from a 24-GHz Doppler radar showed that the proposed approach achieves promising classification performance.