The electrical double layer capacitor-electrostatic induction electric power generation system (EDLC-ESIG) undergoes an electric cycle consisting of three steps: energy storage by electrostatic induction, power generation, and initialization by electromechanical coupling. An internally self-sustaining electric power can be generated by repetition of cycles with periods of the order of seconds. The objective of this paper is to show the design of EDLC-cell configuration for practical use to produce constant power output. On the basis of energy densities of the conventional EDLC's for energy storage, the volumetric power density has been estimated to be 450 watt/liter for the discharge time of 10 sec. Possibilities of commercial applications of the EDLC-ESIG system to vehicles and high power generations in central station have been considered with respect to the power densities of the EDLC-cells consolidated into a generation system.

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Japanese style garden is one of the things which representing Japanese history and culture. In this study we try to figure out the optimum color temperature of light sources for the illumination of Japanese gardens at night in order to make them fascinating. We used SD Technique to conduct the digitalization and quantification on the image recognition on the garden lighting when the color temperature is changed. As a result, when the color temperature is 2000K, the activity and the evaluation of the image recognition on garden lighting are both high for all elements (plant, water, stone and object) of the garden. And when it is 10000K, the activity and the evaluation of the image recognition on garden lighting are both low for all elements of the garden. In addition, it is clarified that when color temperature increases, the activity of the image recognition on garden lighting falls down.

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A compact, continuous wave laser was applied to detection of the thermally grown oxide (TGO) layer in thermal barrier coating (TBC) for gas turbine high temperature components by photoluminescence. Experiments were conducted using TBC specimens heated in air to artificially produce a TGO layer. For specimens heated at 1100°C, the photoluminescence intensity increased with heating time, whereas for specimens heated at 1000°C, the photoluminescence intensity did not increase beyond 100 hr. The results indicate that the formation of the TGO layer is strongly dependent on the temperature. In addition, scanning electron microscope (SEM) observations of the specimen cross section confirmed the formation of the TGO layer after 100 hr heating at 1100°C. The applicability of a compact laser to TGO layer detection allows development of a simple TGO detection system, which can be used for screening for detailed inspection of delamination.

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In this study, we propose a new application of the technique for plasma nitriding of steel. The polarity of the applied voltage to a plasma gun was found to significantly affect the plasma formation. When the positive voltage was applied, a relatively large chamber was filled with the nitrogen plasma. The length of insulating capillary tube also affected the emission intensity of nitrogen ion in the plasma. Nitriding experiments of high speed steel showed a considerable improvement of the hardness without forming so-called “white layer (Fe_2-3N)” or damage on the surface. It can be concluded that this technique can be one of the most superior techniques for nitriding steel.

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In this study, we have measured negative ion mobility in high-purity O₂ (99.9999%) and ultrahigh-purity O₂ purified with a gas purifier to remove impurities in cylinder O₂ (99.99995%) for the investigation on the effects of impurities. It is considered that negative ion mobility is strong affected by impurities such as N₂, CO₂ and H₂O at high pressure including atmospheric pressure. However, mobility measurement at high pressure has carried out only a few researchers including our laboratory. Then, we have performed the measurement at atmospheric pressure. An interesting result was obtained from ultrahigh-purity O₂ that is the reduced ion mobility increased to 2.39±0.03 cm²/V·s from the constant value of 2.31±0.03 cm²/V·s obtained in high-purity O₂ at 2.83×10^-2 ≤ E/N ≤ 5.31 Td. The difference of these values 2.31 and 2.39 cm²/V·s was attributed to the impurities that existed in the O₂. The impurity is H₂O contained in the cylinder O₂ which led to a decrease in negative ion mobility. Other impurities such as N₂ and CO₂ are the main constituents of the atmosphere attached on the surfaces of the chamber and electrodes. They led to an increase of ion mobility at high E/N values exceeding 1.77 Td.

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The crystal grain shape of GO (Grain-Oriented steel) sheet is considered by two-dimensional polycrystal magnetic field analysis in which grains grown vertically and grains grown horizontally are compared. Because the grains grown vertically have more adjacent crystal grains in the direction of magnetic flux flow than the grains grown horizontally, they have uniform magnetic flux density distribution and then small iron loss. Therefore, the grains grown vertically are preferable to the grains grown horizontally in order to reduce the iron loss. Since this is the same conclusion as the three dimensional polycrystal model, it is said that the α angle of the crystal grain orientation angle is the main effect for the iron loss in consideration of the crystal grain shape.

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This paper focuses on analyzing the electric field and the temperature distribution in a typical stress grading system used in medium voltage rotating machines under pulse width modulation voltage source conditions. Two analysis models for electric field and heat transfer processes are developed to take into account the nonlinear relationship between the electric field and the electrical conductivity of Silicon Carbide (SiC) semi-conductive tape. The simulation results give a fundamental background to explain the failure of the stress grading system in inverter-driven medium voltage motors.

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The water content in oil-filled electrical equipment is important in connection with evaluation of dielectric strength of insulating oil, deterioration of insulating materials, and the bubble evolution in transformer windings during overload. So the water content and the solubility of water in insulating oil that is represented by saturated water content (Ws), is an essential part of transformer condition monitoring and maintenance. It is well known that the main factors determining Ws are temperature, aromatic content, and acid number. However, changes in acid number cannot explain changes in Ws. It has been reported that in the process of oxidative deterioration of the insulating oil, molecular weight changes. However, the change in molecular weight due to oxidative deterioration has not been considered in evaluation of Ws. In this paper, we have proposed a new estimating equation of Ws considering the changes in molecular weight of the insulating oil. The new estimating equation for Ws includes temperature, acid number, and molecular weight, and it was possible to estimate Ws in insulating oils that have various acid value and aromatic content. And it was found that deviations between the calculated values and the experimental values were less than 10%.

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Advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for water purification through oxidation; therefore, we proposed a useful passing water-type ozonizer, which could generate discharges even on the liquid surface. We first observed optical emissions due to the discharges and then confirmed the existence of O and OH radicals. Next, decomposition of Methylene Blue was examined. When the discharge was generated between a glass electrode and liquid, the AOP was achieved. The obtained results also indicated that various decomposition and treatment would be possible by selecting discharge form for our passing water-type ozonizer.

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