Effect of pulse time on surface characteristics and corrosion resistance during pulse electrochemical polishing

Pulse electrochemical polishing (PECP) was used to improve the mechanical properties,such as surface roughness and corrosion resistance,of conductive metallic materials.PECP can provide a smooth,bright,reflective,and deburred surface that exhibits superior corrosion resistance.In this work,stainless steel was used as the anode,and copper was used as the cathode due to their low electrical resistances.The surface roughness of the PECP sample was measured by atomic force microscopy (AFM).A scanning electron microscope (SEM) was used to observe surface characteristics,and an Auger electron spectroscope (AES) was used to analyze the metallurgical composition and thickness of the passive film.The aim of this research was to compare the corrosion resistance rates of the unprocessed and PECP-processed stainless steel.     

High-performance and current crowding-free InGaN-GaNbased LEDs integrated by an electrically-reverse-connected Schottky diode and a Mg-delta doped p-GaN

This work demonstrates high-performance and current crowding-free InGaN/GaN light-emitting diodes (LEDs) using an electrically-reverse-connected Schottky diode (SD) and an Mg-delta (δ) doped layer.Poss...     

Wear of diamond particles for grinding ceramics

The relative wear of a single point diamond, defined in terms of the grinding force, was determined for a group of A1₂O₃ and Si₃N₄. It was found that the wear rate is directly related to the mechanical properties of the workpiece and the grinding environment.     

Knowledge-based robotics†

A major hurdle in the development of intelligent robots is that we still do not possess efficient computational and representational methodologies for emulating knowledge and expectation driven behaviour so basic to human cognition and problem solving. Even if we use techniques such as geometric modelling for representing objects in the robot world, we are still lacking in methods for linking such representations with sensory feedback. In this paper, we have proposed the use of intermediate representations—we call them sensor-tuned representations—for linking CSG based solid modelling with sensory information. We also discuss how sensor-tuned representations are constructed from range data and how object recognition can be done with sensor-tuned representations. Finally, we show results of manipulation experiments produced by the current implementation of the system.     

Location of departmental pickup and delivery points for an AGV system

In this paper, two algorithms are developed for the determination of pickup and delivery point locations for an AGV system. The first algorithm is applicable to general layout configurations and seeks solutions until the local optimum is reached by comparing relative locations of pickup and delivery points. The second algorithm generates solutions with a minimal amount of computational time due to its exploitation of the structural feature of departmental layouts. Computational results are provided to check the quality of solutions from each algorithm.     

Evaluation of microstructure and mechanical properties of Mg-xCe-0.5Zn alloys by nano-indentation

The microstructure and mechanical properties of Mg-xCe-0.5Zn(x=0.5,1.5,2.5,molar fraction,%) alloys were examined using a nano-indentation technique.The alloys were fabricated using a vacuum induction melting method under an argon atmosphere. The microstructures of Mg-xCe-0.5Zn alloys mainly consist ofα-Mg and eutectic Mg12Ce phase.The volume fraction and size of the eutectic Mg12Ce phase increase with increasing Ce contents.Nano-indentation test results show that the indentation hardness and elastic modulus of the eutectic Mg12Ce phase are higher than those of theα-Mg matrix.In addition,the mean indentation hardness and elastic modulus of the Mg-xCe-0.5Zn alloys increase with the Ce addition amount increasing.     

STRESS CONTROLLED FERROELECTRIC (BA0.5Sr0.5)TiO3 THIN FILMS PREPARED ON GD2O3/SRTiO3(001) BY A PULSED LASER DEPOSITION

ABSTRACT

Stress controlled epitaxial ferroelectric Ba_0.5Sr_0.5TiO₃ (BST) films have been deposited on Gd₂O₃/SrTiO₃ by pulsed laser deposition with oxygen background pressure of 200 mTorr at the deposition temperature of 750°C. In order to control the stress in BST films, oxygen pressures for Gd₂O₃ buffer layers have been varied from 0.1 to 100 mTorr, while that of BST films have been fixed at 200 mTorr. It has been found that the lattice parameters of the BST films deposited on Gd₂O₃ were changed. Furthermore, microwave properties of co-planar waveguide (CPW) fabricated on BST films were investigated by a HP 8510C vector network analyzer from 1–20 GHz. Large dielectric tunabilities were observed from the CPW's fabricated on BST films deposited on Gd₂O₃ layers deposited at low and high oxygen pressures, 0.1 and 100 mTorr, respectively.