Application of controlled switching to 500-kV shunt reactor current interruption

To suppress reignition overvoltages caused when a 500-kV shunt reactor current is interrupted by a 550-kV one-break circuit breaker (CB), a study was carried out on controlled switching. Using a full-scale test circuit, reactor current interruption tests were carried out to obtain the relation between opening phase angle and generation of reignition. The results showed that even with the dispersion of CB operations taken into account, there were contact separation points free from high reignition overvoltages. It was also proved that no voltage escalations were caused by reignition and high-frequency arc extinction, and that overvoltages due to current chopping were at a safe level in terms of equipment insulation.     

A tentative plan of measuring the amount of the stretch of the skin using origin on body surface

The present study was made to search for the origin on human dorsal surface, which is available for a correct grasp of a change of body surface (skin surface) with human activities and to try to re-evaluate, using the above origin, quantitative skin deformation of human dorsal surface on raising arms. The following results were obtained: 1) X. examination in standing (static) and arm-raising (dynamic) positions revealed a site with inter-positional difference, as zero, in slippage on dorsal median line. This site was supposed to be the origin and was confirmed to be Th10 and Th12. The palpation of the site of, Th10 and Th12 on dorsal median line was thought to be simple and effective in searching for a site with the least bone and skin slippage, thus in presuming the origin. 2) Based upon the origins on dorsal median line and scapular line parallel thereto in sitting position, 5 cm phi-correct circles were stamped up and down, then arm raising action was taken. The utilization of the origin enabled us to determine the length, directional angle, theta, and area, S, of the slippage between correct and distorted circles as obtained by these actions. 3) For arm raising, the skin slipped up and down on median line for lower and higher sites than the origin, respectively, with the angle theta on scapular line indicating the + direction, while and theta appeared greater and smaller for a nearer site to the origin, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultralow specific on resistance UMOSFET with trench contacts for source and body regions realised by selfaligned process

An ultralow on resistance power UMOSFET having a refined contact structure has been fabricated by a selfaligned process. The most important feature of this UMOSFET is its great increment of channel width per unit area, which leads to a noticeable reduction in the on resistance. A 50 V UMOSFET with a specific on resistance of 0.58 m Omega cm/sup 2/ has been achieved despite employing a relatively thick (520 mu m) substrate with a resistivity of 8 m Omega cm.<>     

Field experiments of narrowband digital FM transmissions withdiversity reception at 1.45 GHz carrier frequency

Field experimental results of narrowband digital FM signal transmissions at 1.45 GHz carrier frequency was reported. A 16 kbit/s Gaussian-filtered MSK (GMSK) was employed for the modulation scheme. Transmitted signals were received by a two branch space diversity receiver using improved frequency-detection schemes. The measured bit-error rates (BERs) are presented     

Growth of silicon nanowires on H-terminated Si {111} surface templates studied by transmission electron microscopy

We have studied the growth of silicon nanowires (SiNWs) by means of transmission electron microscopy. SiNWs are grown from nanocatalysts via the Vapor-Liquid-Solid (VLS) mechanism using silane (SiH4) gas as a source gas. The nanocatalysts are prepared on a hydrogen (H)-terminated Si surface. We have examined the formation mechanism of nanocatalysts on H-terminated surface and have observed several structural variants of SiNWs. According to the study we have suggested that many structural variations of SiNWs are possible, which modify the structural properties of SiNWs to great extents.