In this study, the reduction of NO_x was experimentally examined by using the new type of superimposing surface and silent discharges plasma reactor. The new type of plasma reactor consists of double coaxial cylinders. The outer tube is made of ceramics with stripe type surface electrode and coaxial metal electrode immersed inside ceramics. The inner tube is made of glass filled with solutions. AC high voltage was applied to the outer metal electrode and solutions, and the stripe electrode is used as a ground. The phase difference in applied voltages between surface and silent discharges was in phase and out of phase. The NO_x concentration in simulated exhaust gas after it passed through the reactor was measured by a NO_x analyzer.
In this result, reduction rate of NO and NO_x increases with increasing discharge current, discharge power, or resident time, on the other hand, energy yield of NO and NO_x reduction decreases with increasing discharge current, discharge power, or resident time. The most effective condition on the NO_x reduction were found at the gap length larger than 2.5mm and the superimposing discharges. This result shows that superimposing surface and silent discharges is more effective method for the removal of NO_x.

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The localized space charge distribution in electron beam irradiated PMMA was investigated using pulsed electroacoustic method. Using a conventional space charge measurement system, the distribution only in the depth direction (Z) can be measured assuming the charges distributed uniformly in the horizontal (X-Y) plane. However, it is difficult to measure the distribution of space charge accumulated in small area. Therefore, we have developed the new system to measure the three- dimensional space charge distribution using pulsed electroacoustic method. The system has a small electrode with a diameter of 1mm and a motor-drive X-Y stage to move the sample. Using the data measured at many points, the threedimensional distribution were obtained. To estimate the system performance, the electron beam irradiated PMMA was used. The electron beam was irradiated from transmission electron microscope (TEM). The depth of injected electron was controlled using the various metal masks. The measurement results were compared with theoretically calculated values of electron range.

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In order to develop a design method for a laser-beam-forming optical system, we evaluated the error-reduction algorithm as the means of the phase retrieval method. We calculate the phase, profiles for beam transformation from a circular Gaussian beam to a circular uniform beam and a rectangular uniform beam. The calculated phase profiles are almost the same as those calculated by the stationary phase method, and the phase calculation error is equal to about one wavelength. We clarified that the intensity profile error results from the saturation of error reduction of the error-reduction algorithm.

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In this paper, we propose a method to solve the magnetocardiographic inverse problem based on a ventricular excitation model. This method fits a measured magnetocardiogram (MCG) and a simulated MCG during the whole QRS complex. The simulated MCG is derived from a computer model of the propagated excitation on the ventricle. Parameters estimated by the method are the distribution of purkinje fiber. It is also possible to indirectly estimate the excitation fronts during the ventricular depolarization process. We produced a computer simulation to evaluate the noise stability of the method. It was indicated that this method was stable to noise. Next, we estimated the distribution of purkinje fiber and the excitation fronts from the measured MCG. Estimated excitation fronts are presented in this paper, and correspond to excitation of the isolated human .heart measured by Durrer et al. The result estimated by this method has the great influence on predetermined conduction velocity and effect of return current.

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A transition phenomenon to an arc discharge from an uniform glow-like pumping discharge of a KrF excimer laser, is discussed from the view point of the electrical and spectroscopic characteristics. When a bright arc occurs by the transition from a glow-like pumping discharge, a rectangular form of the gap voltage as seen in a high pressure gas discharge, is recognized. The magnitude of the voltage decreases gradually by 40% for 250 to 100V lasting for about 20microseconds. The arc generation also brings a damage of main electrodes by the action of a kind of electro-discharge machining. On the surface of the electrodes, craters appear due to the melting and vaporizing of the electrode material. The emission spectrum of the arc discharge becomes different from that of the glow-like discharge. For the glow-like discharge, only KrI is observed, while in the arc phase, KrII and HeI also appear, of which formation can be seen after 300ns from the termination of the glow-like discharge. Accordingly, the generation of the arc discharge can be decided from the change of the spectrum.

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The authors are taking attention to the relationship between change of γ^p_s and number of metastable states of nitrogen molecules in a discharge space.
Quantitative analysis of polar groups which were produced by two different discharge conditions was carried out by XPS with chemical labeling method. These two conditons are produced by means of UV irradiation into low pressure discharge area and without irradiation to control number density of nitrogen metastable molecules in the discharge space. Results showed that the polar groups introduced on the treated surface by the discharge without UV irradiation are almost twice larger than those by the discharge with UV irradiation. It was confirmed by the chemical labeling method that the introduced polar groups consist of OH and COOH groups.
An absorbance of the irradiated light into the discharge area was also measured in the range from 300 nm to 500nm, and absorption around 337.1nm was detected remarkably. The result means that molecules of B³Π₈ state are pumped up to the C^gΠ_u-state. From the result, it is deduced that number density of metastable molecules are changed by UV irradiation, and this change may introduce the differences on the treated PTFE surface by two different treatment conditions.

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The chaotic character of discharge luminescence in time series during AC electrical tree propagation is investigated using PMMA and EVA specimens. The attractors of discharge luminous intensity in time series were embedded in 3D phase space using Takens embedding theorem and the fractal dimensions of their attractors were evaluated with a box counting method. Furthermore, the largest Lyapnov exponents of luminous intensity in time series were estimated. The results show that the time series of discharge luminescence during AC electrical tree propagation in PMMA and EVA specimens have chaotic characters.

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This paper describes the influence of sample temperatures on tracking breakdown of organic insulating materials by IEC Publ. 112 Method. Trackuig phenomenon is a kind of surface deterioration of organic insulating materials. The mechanism of tracking is not intensively investigated under conditions such as higher temperature environments. According to spread of the systems of transmission and supplying electricity, many electrical and electronic apparatus have been used at higher temperature environments. in this research, phenolic-paper laminates and polycarbonate with and without flame-retardant have been employed to study the influence of test condition on tracking failure. Tests have been carried out in the temperature range of 25 to 150°C with brass electrodes. The results of phenolic-paper laminates and polycarbonate show that with increasing the amount of flame-retardant, the comparative tracking index(CTI)are getting smaller. When sample temperatures are raised higher, the difference of CTI values becomes gradually samll.

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The YBCO superconductors prepared by the Melt- Powder-Melt-Growth (MPMG) process exhibit high critical current density over 30, 000A/cm² at 77K and 1T. Because these are expected to be applied to various fields such as magnetic bearing, magnetic levitation, magnetic shielding, and etc. In such applications in order to design applied high-T_c superconductors it is important that assessment methods of magnetic property should be developed. Especially, in real applications it is necessary to assess quench property of the superconductors. So we measured AC quench property of the YBCO ring specimen under the AC magnetic field with the frequency of 50Hz. We got the experimental results that the superconductor results in the quench by the heat under the some AC magnetic field, and that the quench property of ring specimen is ruled by its weak link.

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Cubic barium titanate (BaTiO₃) thin films have been successfully prepared in situ on the substrate of Al/SiO₂/Si(100) or SiO₂/Si(100) by intense, pulsed, ion-beam evaporation technique without heating the substrate. The energy of the ion beam used was typically 1.3 MeV with the power density of 0.6GW/cm². The deposition rate was observed to be 0.6μm/shot on the substrate placed at the distance, 4cm, from the target. The films prepared were cubic polycrystals and the composition are equivalent to that of the target. The specific dielectric constant was typically observed to be 40 at 1kHz. Relaxation time of dielectric palarization was found to distribute ln the range of 0.3-0.0003s.

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Noise produced by a transformer core has been reduced by improving material and design of the, core. Further reduction is required for the trend toward amenity. The comprehension of the mechanism producing noise is necessary and one of the measures is detail investigation of core vibration. We developed the vibration measuring system utilizing a laser Doppler vibration meter and we measured the vibration of a 3-phase 3-limb transformer core. The vibration on the front and the back of the core was two or three times higher than the other surfaces. The vibration occurred mainly in the limbs of the core and the vibration direction was perpendicular to the core surface. The vibration waveforms were out of phase between the center limb and the both side limbs. These results reveal that it is resonant vibration of the core. In the upper surface of the yoke the vibration was higher on the both sides and the center. It is supposed that the vibration on the both sides is derived from the magnetostriction of the limb and the vibration in the center is produced by the magnetostriction under the condition of the rotational induction which occurs in the T-joint of the core.

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We have investigated the partial discharge (PD) due to electrical treeing degradation in polyethylene. It was found that the magnitude of PD due to an electrical tree is proportional to the instantaneous voltage, while the PD occurrence is governed by the time derivative of the applied voltage (dv/dt). Based on the results, a model for electrical treeing discharge was proposed. By utilizing the model, the Monte Carlo computer-simulation was carried out for sinusoidal and triangular applied voltages. The simulated PD patterns were similar to the experimental results, suggesting the validity of the proposed model. The simulation revealed that the tree discharge path length and its distribution determined the PD pattern. The so called wing-like pattern from a treelike tree was obtained for long discharge path and broad distribution, while the PD pattern from a bush-like tree was obtained for long discharge path and narrow distribution. This indicates the potential of PD pattern recognition for diagnosis of treeing degradation.

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