This paper describes partial discharge (PD) characteristics and V-t characteristics of several insulating materials such as liquid crystal polymer, epoxy resins, polyimide and polyethylene-telephthalate (PET) with a needle-plane electrode system at elevated temperature. Life index n for the applied electric field less than 20kV/mm is found to be about 9 and that for more than 20kV/mm is found to be less than 4. PD characteristics changed due to insulating materials. Those V-t characteristics due to PD degradation are similar to those at room temperature except absolute life time.

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Recently ozone is mainly utilized for the sewerage and home equipments. The demand for ozone will increase in the near future. Therefore, it is expected to improve the energy efficiency of ozone generation and to miniaturize an ozonizer.
In this paper, a new ozone generation system is proposed. In this study, the 50Hz three phase voltage is applied to the discharge tube which has three electrodes. And three kinds of discharges, two silent discharges and a surface discharge are superposed in the same space of the ozonizer. There is no discharge-rest-time in this disoharge mode which generates three kinds of discharges with the phase difference of 120 degrees by potential differences among three electrodes. The effects of the three-phase-superposed discharge mode on ozone generation are investigated by compazing with the individual discharge mode.
As a result, the ozone yield efficiency of this discharge mode becomes nearly equal to that of the silent discharge mode. It is supposed that a synergistic effect occurs among the discharges, because the excited-state oxygen molecules are dissociated accumulatively. Moreover, this discharge mode is able to generate high concentration ozone, because this system can increase the discharge power at low applied voltage. Considering the circumstances mentioned above, it is confirmed that this system improves the energy efficiency of the ozone generation and miniaturizes an ozonizer without using a high-frequency power source.

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We propose a novel excimer laser machining using a multiple imaging system employing a holographic optical element (HOE). The multiple imaging system can generate many images from one mask pattern. The HOEs that we used were com-puter generated phase holograms.
We calculated the HOE by with the following three-step optimization using a direct binary search algorithm, 1) high efficiency enhancement step, 2) uniforming step and 3) noise reduction step. By this optimization procedure, a diffraction efficiency over 60% was obtained, the uniformity errors were less than 2%, and noise peak was less than 5% of signal peaks. The optimized HOE pattern was 4-level, and the matrix size was 1024×1024 with 1 micron pixels. To obtain a large HOE area, we tiled the optimized HOE pattern, and manufactured 30×30mm HOEs on a quartz substrate by dry etching.
With the use of this HOE, the 95 holes whose diameter was 0.1mm were drilled in a 10×10mm area. The energy avalil-ability was 19.4%. When a conventional mask-projection system is used, the energy availability is usually less than 1% owing to the small rate of the mask open area, A multiple imaging system using HOE can machine small holes at an efficiency up to 20 times that of conventional mask-projection system.

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Based on Carson's analysis of opposite directional current in a pair of parallel wires, proximity resistance in case of same directional current of high frequencies ranging from 200kHz to 1MHz was investigated analytically by introduction of a new magnetic factor into the the electro-magnetic interaction between two wires. As a result, the ratio of AC to DC resistance was successfully obtained in accordance with experimental values within 10%. Furthermore, current distribution in the cross section of two wires was calculated and drawn on Cassinian ovals diagram.

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Generally, ozone is generated by using silent discharge or surface discharge, however, the energy efficiency of ozone generation by using only one kind of discharge is about 200g/kWh. The energy efficiency of ozone generation is about 1/5 of the theoretical energy efficiency. There is ozone decomposition at the condition of high concentration, heat decomposition and so on. In order to increase ozone generation efficiency, many studies of the ozone generation method have been carried out up to now.
Experiments of ozone generation by using surface discharge and UV rays were carried out. In the experiment of superposing surface discharge and UV rays in the same space, the ozone yield by the superposing mode is lower than each of the ozone yield by surface discharge and by UV rays at the same power. It is supposed that noticeable ozone dissociation by UV rays occurs because high ozone concentration is achieved by the superposing mode. In the case of cascade connection of a surface discharge reactor and UV lamp reactor, the ozone yield of the cascade mode (from UV lamp reactor to surface discharge reactor) is higher than that of the superposing mode at the same power. It is confirmed that cumulative dissociation is an effective reaction on ozone generation.

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Plasma current drive is one of critical problems to be solved in the development of fusion reactors under steady operation of low aspect ratio tokamak. DC helicity injection that has been used for the current drive of spheromak plasmas has also been successfully applied to low A tokamak plasmas. In this paper, the analytical expression of the equilibrium configuration has been derived for low A tokamak plasmas with a rectangler cross section. Two types of electrode configurations for the helicity injection, one the coaxial type, and the other the polar type, are considered. The condition of q profiles that provide the reversal magnetic shear are studied.

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The discharge occurring in a space-charge cloud was investigated by using a cloud of charged droplets. To produce a charged cloud with a difinte space charge density and to cause a reproducible discharge, droplets ejected from an airless nozzle were charged by induction charging and transported by air flow. The transportation of charged droplets by air flow was quite effective to increase the charge quantity of droplets and the charge density of the charged droplets. Corona discharge was observed at a grounded needle electrode inserted into the charged droplet cloud which has a charge density of 13μC/m³ at most. In negatively charged droplets, positive streamer corona was occurred. As the charge density of the cloud increased, the time interval of streamer pulse decreased and shifted to grow corona. In positively charged droplets, the height and the frequency of negative corona pulse increased with the charge density and the velocity of charged droplet cloud.

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In the paper, GMRES is applied to various large matrices appearing in the 3D field analyses. By changing the condition of the matrices, effective pre-conditioning of the matrix is to be searched for. Also studied is a relationship between the residual norm and the precision evaluated during GMRES. The paper clarified the residual norm, which is indirectly computed in GMRES and has so far been used as a measure of precision, cannot be used as an indicator of solution's accuracy. After reasoning a deterioration of the precision, GMRES (ml), which solves matrix with a modified iterative scheme, is proposed. It is to be confirmed that GMRES(ml) is faster and more accurate than any of GMRES and its modified version, GMRES (m).

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The authors have proved that ethylene-propylene rubber (EPR) is suitable for the solid electrical insulating material of superconducting and cryoresistive cables due to its excellent mechanical and good electrical properties. It is imperative to study the treeing resistivity of EPR in view of long term reliability as a cable insulator.
The objectives of this paper are to establish an AC treeing test method of opaque EPR samples with fillers and to examine the treeing resistivity of EPR at both liquid nitrogen and room temperatures and the effect of fillers on treeing resistivity. It was found that EPR has enough resistance to AC treeing at liquid nitrogen temperature and that fillers improve AC treeing resistivity slightly. High reliability of EPR insulation is expected during the long term operation at cryogenic temperature.

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Below the melting point, polyethylene forms a structure in which crystalline part and amorphous part exist together. Therefore, polyethylene is not homogeneous. It is thought that generation of a crack by the maxwell stress is one of the tree initiation causes. The crack is generated easier in a unhomogeneous stracture than in a homogeneous stracture. Above the melting point, the homogeneity may increase because all crystalline part melts into amorphous part. In order to examine the homogeneity of polyethylene and the relation to the generation of electrical tree, polyethylenewas heated up to 180°C. The relation between the superstructure and the electrical tree initiation voltage at varioustemperatures was examined.

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Non-cleaning method is the most preferable among the CFCs alternative methods from the environmental and the cost performance points of view.
In performing non-cleaning method, non-cleaning flux are used because they are supposed to feature high insulation reliability without after soldering cleaning process.
However, even non-cleaning flux might effect on the insulation reliability, and it is thought that the metal ions released from electrode metal by the remaining flux activators (organic acids) are the main cause of the insulation error.
In this study, the effects of some chelating organic acids on the insulation reliability was examined, assuming that the insulation reliability was expected to be improved by utilizing organic acids as flux activators which can trap the released metal ions and form metal complexes with them.
In the evaluation of dicarboxyl acids, succinic acid-applied printed circuit board kept insulation reliability on Cu electrode, on which metal complex (succinic acid copper salt) was created by the reaction of succinic acid and CuO. On the other hand, succinic acid caused insulation error on soldering metal (Sn/Pb) electrode, on which metal complexes were not formed due to poor chelating ability of succinic acid against typical metals (Sn and Pb) compared with transition metal (Cu). It suggested that organic acids for highly reliable non-cleaning flux need to have high chelating ability against Sn and Pb as well as Cu.
In the case of aminocarboxyl acids, anthranilic acid was found to keep insulation reliability on Cu electrode as well as Sn/Pb electrode because anthranilic acid formed metal complexes on both Cu electrode and Sn/Pb electrode. Iminodiacetic acid, however, brought about insulation error on both electrodes despite metal complexes were formed on each electrode. From the fact that iminodiacetic acid salts are dissoluble in water while anthranilic acid ones are not, it was thought that iminodiacetic acid turned to ionic compounds by absorbing water and caused migration reaction.
Consequently, the organic acids which create water-insoluble metal complexes with Cu and soldering metals are found to keep insulation reliability.
Therefore it was cleared that high reliable non-cleaning flux can be developed by prescribed organic acids and their solvents.

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In this paper, we try an improvement of the resistive sheet type mm-wave absorber at 94GHz, which consists of spacer (polycarbonate) and resistive sheet (polyethylene terephtalate deposited with Indium Tin Oxide). First, the sheet resistance of the resistive sheet and the permittivity of polycarbonate are estimated by the least-squares method using the absorption which is measured at 85-100GHz frequency band. Second, we describe a design and manufacturing of the wave absorber for 94GHz band using these data. As a result, measured frequency characteristics of the reflection loss indicates that the peak absorption of 34-46dB is attained at 95-96GHz.

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Carbon film has been prepared by irradiation of pulse YAG laser (wave length 1064nm) to polyimide film under N₂ or ordinary atmosphere. By laser irradiation polyimide were transferred to carbon film, with low degree of crystallinity, The room temperature electrical resistivities are about 0.1Ω•Cm, and their temperature dependencies are similar to those of amorphous or turbostratic carbons with negative temperature coefficient. Carbon as well as electroplated circuit by Ni was successfully prepared in finer pattern than those formed by conventional printing method of conducting paint.

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