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171.
The comparative studies of methanol, ethanol, 2-propanol and 2-butanol electrooxidation were carried out on carbon-ceramic electrode (CCE) potentiostatically modified with Pd nano-particles. The Characterization of catalytic layer by Scanning electron microscope (SEM), Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) indicated that well-dispersed catalytic particles with high density have been formed on CC substrate. Voltammetry, Chronoamperometry (CA), Polarization study and electrochemical impedance spectroscopy (EIS) were used to investigate the alcohols oxidation reactions. The relevant parameters such as the Tafel slope and activation energy (Ea) were determined. This study upholds the fact that 2-propanol is a promising fuel candidate for a direct alkaline alcohol fuel cell.  相似文献   
172.
Parkinson's disease is a growing and chronic movement disorder, and its diagnosis is difficult especially at the initial stages. In this paper, movement characteristics extracted by a computer using multilayer back propagation neural network mapping are converted to the symptoms of this disease. Then, modulation of three classifiers of C4.5, k‐nearest neighbors, and support vector machine with majority voting are applied to support experts in diagnosing the disease. The purpose of this study is to choose appropriate characteristics and increase the accuracy of the diagnosis. Experiments were performed to demonstrate the improvement of Parkinson's disease diagnosis using this method.  相似文献   
173.
A two-stage, fully differential amplifier is presented in this work. The proposed amplifier enjoys from an intrinsic common-mode feedback scheme, which eliminates the extra common-mode circuitries that are essential in typical fully differential circuits. Besides, the proposed architecture introduces a left-half-plane zero which can be adjusted to cancel out the dominant pole and thus to extend the structure’s bandwidth. The simulation results with TSMC 180 nm standard CMOS technology shows the 92.2 dB DC gain and 49 MHz gain bandwidth product with 89° of phase margin. The amplifier consumes 0.45 mW from 1.8 V power supply.  相似文献   
174.
A novel multi mode low pass hybrid continuous/discrete time delta sigma modulator which is suitable for low power wide band applications is presented in this article. The proposed topology can adapt itself for operating in various signal bandwidths as well as different signal to noise plus distortion ratios (SNDRs). The novelty of the proposed modulator lies in the fact that several techniques have been employed simultaneously that not only can reduce the power consumption, but also it can increase the performance of the modulator. Continuous time integrator is utilized to alleviate the specs for the first stage op-amp. The modulator employs an op-amp sharing technique, which decreases the power consumption dramatically due to elimination of the power hungry adder before the quantizer in the feed forward topology. Another attractive advantage of the proposed modulator is using the noise-shaping enhancement technique which can increase the performance of the modulator without using analog active blocks. The unused block of the modulator can be made inactive to achieve less power dissipation. Behavioral simulations in MATLAB environment show the SNDR of 91/86/73 dB over 0.2/2/20 MHz signal bandwidth.  相似文献   
175.
176.
This paper presents the results of an investigation into the behaviour and ultimate strength characteristics of imperfect steel plates used in ships and other related marine structures. The analysed plates are suffering from general corrosion on their both surfaces and subjected to uniaxial in-plane compression. A series of elastic and elastic–plastic large deflection finite element analyses is performed on the both-sides randomly corroded steel plates. The effects of general corrosion are introduced into the finite element models using a specially developed random thickness surface model. The effects of random thickness reduction on the plate strength characteristics as a result of systematic variation of the involved parameters are evaluated.  相似文献   
177.
Journal of Failure Analysis and Prevention - Chemical process plants, especially the oil and gas plants operating under severe processing conditions and dealing with hazardous materials, are...  相似文献   
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