The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
J T Evans - One of the best experts on this subject based on the ideXlab platform.
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the effect of surface roughness Oxide Film thickness and interfacial sliding on the electrical contact resistance of aluminium
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1998Co-Authors: E Crinon, J T EvansAbstract:Contact resistance measurements were made on aluminium alloy sheet with a configuration relevant to electrical resistance spot welding. Previous work has shown that a small amount of sliding is required at the interface to break down contact resistance when the material has a thin, insulating coating. Sliding on a macroscopic scale occurs at the electrode-sheet interface but not at the faying surface. For this reason, the contact resistance at the faying surface is high and its behaviour with applied force is observed to be anomalous. However, local sliding on a microscopic scale can occur at the faying surface, depending on the surface roughness. The effect of surface roughness and Oxide Film thickness was investigated in the present work. In addition, the degree of sliding required to break down contact resistance was quantified in experiments in which relative rotation was induced at the faying surface. It is estimated that a sliding displacement of only about 10 μm is required to produce a dramatic reduction in contact resistance. The results are interpreted in terms of Holm's constriction resistance theory of microscopic spots of metal-to-metal contact within a mechanical contact area largely insulated by the presence of the surface Oxide Films.
Jingying Xie - One of the best experts on this subject based on the ideXlab platform.
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Manganese Oxide Film electrodes prepared by electrostatic spray deposition for electrochemical capacitors from the KMnO4 solution
Journal of Power Sources, 2006Co-Authors: Yang Dai, Jiachang Zhao, Ke Wang, Jingying XieAbstract:Manganese Oxide Film electrodes for electrochemical capacitors were deposited on the polished Pt foils by electrostatic spray deposition (ESD) from KMnO4 precursor solution. The electrochemical properties of electrodes were systematically studied using cyclic voltammetry (CV), constant current charge-discharge tests, and electrochemical impedance spectroscopy (EIS). The specific capacitance (SC) of thick deposited Film was 149 F g-1 at the very high scan rate of 500 mV s-1, in comparison with 209 F g-1 at the low scan rate of 5 mV s-1. The electrode shows good cyclic performance. The initial SC value was 163 F g-1 and 103% of the initial SC can be retained after 10,000 cycles at the scan rate of 50 mV s-1. ?? 2006 Elsevier B.V. All rights reserved.
E Crinon - One of the best experts on this subject based on the ideXlab platform.
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the effect of surface roughness Oxide Film thickness and interfacial sliding on the electrical contact resistance of aluminium
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 1998Co-Authors: E Crinon, J T EvansAbstract:Contact resistance measurements were made on aluminium alloy sheet with a configuration relevant to electrical resistance spot welding. Previous work has shown that a small amount of sliding is required at the interface to break down contact resistance when the material has a thin, insulating coating. Sliding on a macroscopic scale occurs at the electrode-sheet interface but not at the faying surface. For this reason, the contact resistance at the faying surface is high and its behaviour with applied force is observed to be anomalous. However, local sliding on a microscopic scale can occur at the faying surface, depending on the surface roughness. The effect of surface roughness and Oxide Film thickness was investigated in the present work. In addition, the degree of sliding required to break down contact resistance was quantified in experiments in which relative rotation was induced at the faying surface. It is estimated that a sliding displacement of only about 10 μm is required to produce a dramatic reduction in contact resistance. The results are interpreted in terms of Holm's constriction resistance theory of microscopic spots of metal-to-metal contact within a mechanical contact area largely insulated by the presence of the surface Oxide Films.
Satyendra Kumar Mishra - One of the best experts on this subject based on the ideXlab platform.
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Surface plasmon resonance-based fiber optic chlorine gas sensor utilizing indium-Oxide-doped tin Oxide Film
Journal of Lightwave Technology, 2015Co-Authors: Satyendra Kumar MishraAbstract:We report an experimental study on a surface plasmon resonance (SPR)-based fiber optic hydrogen sulphide gas sensor with a thin metal Oxide (zinc Oxide (ZnO)) layer as the additional layer. This zinc Oxide layer is grown over the copper layer to support surface plasmons at the metal–dielectric interface at room temperature. The wavelength interrogation mode of operation has been used to characterize the sensor. The thin Film of zinc Oxide over the copper Film was deposited on the unclad portion of the fiber by the thermal evaporation technique. Experiments were performed for the detection of concentrations of hydrogen sulphide gas varying from 0 to 100 ppm around the probe. The unpolarized light from a polychromatic source is launched from one end of the fiber and the corresponding SPR spectrum is recorded at the other end. The recorded SPR spectrum shows a shift in the resonance wavelength on a change in the hydrogen sulphide gas concentration, which is considered as a detectable signal for the characterization of the sensor. Further, the optimization of the performance of the sensor was achieved by varying the thickness of the zinc Oxide Film. The sensor possesses a very fast response time and high sensitivity. Since the sensor utilizes optical fibers it has additional advantages of remote sensing, online monitoring, light weight and low cost.
D W Shoesmith - One of the best experts on this subject based on the ideXlab platform.
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the impedance properties of the Oxide Film on the ni cr mo alloy 22 in neutral concentrated sodium chloride solution
Electrochimica Acta, 2011Co-Authors: Pellumb Jakupi, Dmitrij Zagidulin, James J Noel, D W ShoesmithAbstract:Abstract The Oxide Film properties on Alloy-22 in the applied potential ( E ) range −600 mV to 600 mV (vs. saturated KCl, Ag/AgCl reference electrode) were characterized by Electrochemical Impedance Spectroscopy (EIS) in near neutral pH, 5 M NaCl solutions, at 30 °C. The impedance properties of the Film were compared to the chromium content of the Film determined by X-ray photoelectron spectroscopy (XPS). The Oxide Film properties on Alloy-22 may be divided into three applied potential (E) ranges: −600 mV ≤ E E ≤ 300 mV, and E > 300 mV. For the range −600 mV ≤ E R Film ) increases with potential accompanied by an increase in Cr 2 O 3 content; in the range −300 mV ≤ E ≤ 300 mV, R Film values and the Cr 2 O 3 content of the Oxide Film achieve their maximum values; for E > 300 mV, a decrease in both R Film and Cr 2 O 3 is observed accompanied by a significant increase in Cr(OH) 3 . Comparison of the impedance properties for Alloy-22 to those of Ni–Cr alloys indicate that the barrier layer Oxide on Alloy-22 contains a lower number of less mobile defects, most likely Cr interstitials. Destruction of the barrier layer for E > 300 mV leads to the formation of a thicker, less protective bilayer, which is high in Mo content.
