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1.
The effects of inter-electrode insertion on the performance of a hollow-electrode plasma torch have been investigated by numerical analysis. Simulation results revealed that when inter-electrodes are inserted, the arc voltages and plasma powers increase due to the increase in the arc length. In addition,it was predicted that thermal efficiency can be improved with the increase in plasma power by injecting plasma gases through the gaps between inter-electrodes. These unique effects of inter-electrode insertion are a result of the plasma temperatures adjusting themselves to increase arc voltages when the arc column is contracted radially by increasing gas-flow rate or decreasing inter-electrode diameter. 相似文献
2.
S. H. WONG MS BSc CBiol MIBiol C. C. CHOI BSc CEng MIChE MAIChE MHKIE 《Water and Environment Journal》1989,3(1):75-81
A n existing aetated lagoon treating piggery waste was converted into an aerobic sequencing batch reactor (SBR). After the commissioning period, the SBR plant treated piggery wastewater containing BOD and suspended solids (SS) concentrations of 2881 mg/l and 1419 mg/1 respectively, producing an effluent having an average BOD and SS of 18.7 mg/1 and 12.3 mg/1 respectively. The volumetric loadings on the SBR and the process were similar. However, the SBR process operated at a lower mixed liquor suspended solids (MLSS) concentration and shorter sludge retention period. Although the capital and operating costs of the SBR are higher than for the aerated lagoon, the simplicity of operation, the high BOD and SS removal efficiency, and the small land requirement make this type of process an attractive treatment option, particularly in places where land supply is limited and expensive. 相似文献
3.
Although milling is one of the most common chip metal removal processes, little has been done to aid in identifying the optimum operational conditions for milling processes. In this paper, a mathematical model for milling operations is developed and the five primary control variables identified. The model is then decomposed and an efficient optimization procedure developed for control variable identification. 相似文献
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Jae Sung YOON Tae-Jin JE Doo-Sun CHOI Sung Hwan CHANG Kyung-Hyun WHANG 《中国有色金属学会会刊》2011,(Z1):100-103
A novel fabrication process for micro patterns with curvature was introduced. The curved structures were made by compensating rectangular micro structures with liquid photoresist layer. Because of the surface tension of the liquid in micro scale, various shapes of meniscus can be made on the micro channels. The micro channels were made on the silicon substrate in advance, and then the liquid layer was coated on the micro channels. From the nature of liquid behavior, the curved patterns with smooth surface are obtained, which cannot be made easily with the conventional mechanical machining, as well as with the microfabrication processes, such as wet and dry etching. With this principle, it is expected that the smooth and curved surfaces can be made by simple processes and the results can be applied widely, such as optical patterns. 相似文献
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Young Su HONG Se Hun KWON Tiegang WANG Doo-In KIM Jihwan CHOI Kwang Ho KIM 《中国有色金属学会会刊》2011,(Z1):62-67
Cr-Al-Si-N coatings were deposited on SUS 304 substrate by a hybrid coating system. A Cr interlayer was introduced between Cr-Al-Si-N coating and SUS 304 substrate to improve the coating adherence. The effects of Cr interlayer on the microhardness, adhesion, and tribological behavior of Cr-Al-Si-N coatings were systematically investigated. The results indicate that the microhardness of the Cr-Al-Si-N coatings gradually deceases with increasing thickness of Cr interlayers. The adhesion between Cr-Al-Si-N and SUS 304 substrate is improved by addition of the Cr interlayers. A peak critical load of ~50 N is observed for the coating containing Cr interlayer of 60 nm as compared ~ 20 N for the coating without Cr interlayer. The thicker Cr interlayers result in reduced critical load values. Moreover, the wear resistance of the Cr-Al-Si-N coatings is greatly enhanced by introducing the Cr interlayer with thickness of 60 nm in spite of the decreased microhardness. The friction coefficient of the coating system is also moderately reduced. 相似文献
7.
The use of repeater for the support of high rate data transmission and the extension of cell coverage is imperative for the Wibrc system,which based on the IEEE 8M.16e standardization.Generally,if the separation between transmitting and receiving antennas isnot sufficient,the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be ocerur.Hence,the Interference Cancellation System(ICS)should be implemented as the important part of the repeater system far the mobile cellular systems in order to eliminate unwanted signals from the corruptW signals in the receiver.In this paper,we propose an adaptive technique for the Least Mean Square(LMS)-based interference cancellation methods by changing the step size according to the variation of channel environment in order to improve the performance degradation which oceuurs by using the fixed step size approach.Simrlatim results show that the proposed sclxme attains a little lower Berafor Rate(BER)performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques.The proposed scheme can be applied to other Orthogonal Frequency Division Multiple(OFDM)-based cellular systems and also be expected to achieve a similar performance improvement to W17-advanced system,which is called as the next generation mobile communication standards. 相似文献
8.
The new measurement scheme of IP performance metrics is proposed for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes (MNs) inside the mobile network needs to understand the condition of multiple communication paths outside the mobile network, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the presence or absence of measurement functionality. At the same time, the proposed scheme does not require the MN to be involved in measuring IP performance metrics. The Multihomed Mobile Router (MMR) with heterogeneous wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP performance metrics from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and battery power since MNs don't measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injected testing traffic are reduced. 相似文献
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