We observed sea clutter of sea area in the east of the Daini Kaiho sea fort in Tokyo Bay using an X-band Radar, and we obtained the data of 21,996 cells by observation of consecutive 47 times. In order to investigate the statistical properties, we made estimation of parameters by maximum likelihood estimation and a test of goodness of fit by AIC as models for Weibull, log-Weibull, and log-Normal distributions. As a result, the reflected intensity distribution of sea clutter obeyed Weibull distribution better than any other distributions, and so we made a study using shape parameter of Weibull distribution, it was found that sea condition such as swell and wind wave affect the statistical properties of sea clutter.

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Electromagnetic disturbances in vehicle-mounted FM radios are mainly caused by conducted noise currents flowing through wiring-harnesses from printed circuit boards (PCBs) with the slits of ground patterns. To suppress these kinds of noise currents from PCBs, we previously performed the FDTD simulation and measurement using plural simple two-layer PCB models in which the ground patterns were divided into two parts with different widths, and revealed that the both results agreed well with the fact that the cross-talk cannot always be reduced by widening the width of divided ground patters but had the smallest values (dipping point) at specific space between the divided ground patterns. In order to clarify the above result, we calculated cross-talks using a formula developed from a simplified equivalent circuit model consisting of inductances, which were derived from their geometrical mean distance for the traces and ground patterns, and found that the calculation results also had the dipping point however the specific space and cross-talk values were different from the simulations and measurements. In the present study, to improve the calculation accuracy, we considered the non-uniformity of current distribution on the ground patterns instead the uniform current distribution, and obtained the evaluated cross-talk results which agreed better with simulations and measurements.

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A method is proposed for decomposing volatile organic compounds by atmospheric pressure non-thermal plasma with photocatalytic effects. We tried benzene decomposition by using an atmospheric pressure plasma system with an inner electrode made of stainless, titanium, and oxidized titanium. The electrode temperature was controlled typically between 100°C and 300°C. Dry air including benzene with a content of 1000 ppm was introduced into the plasma reactor. The benzene decomposition rate with the titanium electrode was higher than that with the stainless electrode. The benzene decomposition rate with the oxidized titanium electrode was higher than that with the titanium electrode. We consider that the enhanced benzene decomposition reaction with the oxidized titanium electrode is due to the photocatalytic effect of the oxidized layer. A specific energy density below 1800 J/L is required to achieve a benzene decomposition rate of 95%.

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Toward achieving a breakthrough in the self-sustaining electric power generation system consisting of hydrogen energy cycle, we demonstrate the electrostatic induction potential superposed hydrogen electrolyzer to produce stoichiometric H₂-O₂ fuel for fuel cell. This electrolytic system works on the mechanism in which, the total power requirement is given by the product of electrolytic current and additional voltage over the decomposition voltage. In order to achieve the highest energy efficiency for the fuel cell and full sustainability for the fuel, a combined cycle of H₂-O₂ fuel cell and this type of electrolyzer is introduced. Part of the power delivered by the fuel cell is returned to the electrolyzer, and the remaining represents the net power output. According to theoretical calculations, the net power output exceeds 70% of that delivered by the H₂-O₂ fuel cell, without violating the laws of thermodynamics.

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To maintenance power distribution equipment efficiently and to design electrical rooms of factories, office buildings appropriately, it is essential to clarify the complicated factors causing degradation of insulators, which are important in determining the service life of electric installations. We evaluated the effects of the installation environment, the type of insulators, the rated voltage, and the outer air flowed into the interior from the inlet for power distribution equipments on concentration and composition ratio of ions on polyester insulators, phenol insulators, and epoxy insulators. Concentration and composition ratio of ions on insulators had close relations with the exposure of exhaust gas to insulators, but the relation between concentration, composition ratio of ions and the rated voltage could not be identified. Concentration of ions on polyester insulators was the highest. There was a good correlation between the outer air flowed into the interior from the inlet and the degradation of insulators, and the degradation speed of insulators at the upwind in power distribution equipment was faster.

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In this investigation, we attempted to improve the peel strength of PTFE (polytetrafluoroethylene) by nitrogen ion irradiation. Nitrogen ions were irradiated on PTFE-surface at an accelerating voltage of 100, 300, 500, 1000 and 2000 V with its dose ranging from 5×10²⁰ to 1.5×10²² ions/cm². The surface properties of the modified PTFE were characterized by XPS (X-ray photoelectron spectroscopy), AFM (atomic force microscopy), water contact angle and 180 degree peel test. In the result, under condition of accelerating voltage 2000 V and ion dose 1.2×10²² ions/cm², a maximum adhesion force of 1500 N/m was obtained. However, there was no correlation between the adhesive strength and the surface energy, because, the contact angle obtained was affected by the superhydrophobic effect and the net surface energy should not be evaluated. From the observation at the peeled off surface, it was confirmed that the inner PTFE was ripped off. Accordingly, it was ascertained that adhesion strengths between PTFE and epoxy adhesive were higher than the strengths of PTFE.

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In general, a polymer insulator applied high voltage reaches a complete breakdown through a propagation of electrical trees. We showed in previous paper that magnesium hydroxide has a suppressive effect on the growth of an electrical tree and that the lifetime of the polymer insulator can be improved. Hydrated alumina, metal hydroxide, also has the property of releasing crystallization water at a high temperature. Therefore, we have studied the effects of the hydrated alumina on treeing this time. As a result, it was confirmed that the voltage lifetime of epoxy resin with 30 phr of aluminum hydroxide was approximately 100 times longer than that of the neat epoxy resin. Moreover, amorphous part of hydrated alumina was detected by the electron beam diffraction analysis of the fillers located contiguous to electrical tree, and it showed that a endothermic reaction of hydroxide alumina was took place. The suppression of the tree growth by fillers was generally explained by a barrier effect, but the fillers such as hydrated alumina that generated the endothermic reaction have another mechanism for suppression of tree growth.

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The EM absorbing characteristics of the microwave pyramidal-shaped absorbers produced by smoked roof-tile process in the situation placed in outdoor are evaluated. The reflection coefficient dependencies of the pyramid surface water and stain are experimentally considered.

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