A novel system of an inductively coupled thermal plasma with a fundamental frequency of 450 kHz has been developed. This system has a capability of modulating the amplitude of the coil current periodically with a cycle of the order of 10 ms, including an inverter power supply rated with a power of 50 kW, an induction plasma torch with a 10 turns coil and vacuum chamber. The controlled modulation of the coil current can lead the plasma to be under various transient state intentionally. A pulse modulated inductively coupled plasma of Ar-H2 plasma was successfully generated at a plasma power of 30 kW under the atmospheric pressure condition. The on-time and off-time of the pulsation was set to 10ms and 5ms, respectively, for a stable pulse modulated plasma establishment, and the ratio of minimum to maximum of the amplitude of the coil current can be set down to 61.7%. In order to investigate the transient behavior of the plasma dynamics in such a pulsing mode, spectroscopic observations of an argon atomic spectral line at a wavelength of 751 nm were made. It was found that the pulse modulated plasma has a characteristic time of the order of 2-5 ms to rise or to decrease. The excitation temperature of Ar atom was estimated from the spectroscopic measurement by the Boltzmann plot method, and it was found to change periodically from 5000 to 10000 K with the pulse modulation of the amplitude of the coil current.

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From comparatively high deNOx efficiency and its compactness, the pulsed-discharge deNOx process is considered to be one of the deNOx processes for combustion gas. However, a clear guidance for optimum electric field, pulse duration, pulse repetitive frequency, and moreover the clear understanding of pulsed-discharge deNOx process have not been presented sufficiently. In this study, we have simulated the pulsed-discharge deNOx process by solving the Boltzmann equation for discharge electron and the deNOx chemical reaction equations simultaneously, and we have shown the time change of chemical species concentration extracting the main deNOx reactions. The simulation shows that the pulsed-discharge deNOx process consists of two processes, one is the reduction of NO to N2 by N radical, and the other is the oxidation of NO to HNO3 and HNO2 by OH and O radicals, and that produced and consumed amounts of radicals are decided by parameters such as electric field, pulse duration, and pulse repitition frequency. In our simulation, such parameters are changed widely to see their quantitative effect on energy consumption, NxOy removal efficiency and reduction ratio in the discharge deNOx process. A preliminary pulsed-discharge deNOx performance is estimated from our simulation resulting that the discharge deNOx process has almost the same performance as the electron-beam deNOx process.

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We have investigated wide band rate repetitive Q-switch pulsed oscillations at the flow type carbon dioxide laser, in which the full reflection mirror of the laser resonator was attached to the ultrasonic vibrator and was vibrated along the axis of the resonator. The pulse shape was nicely reproduced when we calculate to use the three-level rate-equation. The mechanism of the method is interpreted to attribute the changed gain to the vibrated along the axis of the resonator. Good agreements between the observation and the calculation are also obtained in the peak power and the pulse width. At the time of sine wave vibration, the method obtained Q-switch pulse oscillation between 20kHz and 170kHz. But the method can not obtain the Q-switch pulse under 10kHz, because the gain is changed very slowly. Therefore, we vibrated the ultrasonic vibrator by triangle wave so that the gain would be changed faster. We succeed in obtaining the Q-switch pulse between 170kHz and 2.3 kHz.

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We have studied the increase of wettability of polymer surface treated by plasma generated in a low pressure discharge.Many polar groups were introduced by the treatment. A treated surface was analyzed by X-ray photoelectron spectroscopy to determine elements and chemical bonds. However it is difficult to measure simultaneously the surface state during treatment in chamber. In situ measurement technique to detect polar groups on surface of plasma-treated polymer has been required.We have studied photoluminescence (PL) which is a light emission from materials excited with light. An intense fluorescence is observed from polymers including aromatic compound, e.g., Polystyrene (PS) and Polyethylene Terephthalate (PET) irradiated by ultra violet ray. When polar groups are introduced by the surface treatment, the spectrum shape and the intensity of PL should be changed. If the change is sensitive to introduction of polar groups, a PL method may be useful to detect polar groups of plasma-treated layer on polymer surface. Here we observed the PL spectrum of treated PS surface. As the result, it is confirmed that the intensity of new spectrum detected depends on treatment time.

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This paper proposes approximation functions which give the double-exponential function parameters for the given lightning impulse voltage. The functions are derived from the normalised lightning impulse voltage where the double-exponential function is scaled in the time direction so that the number of parameter presenting the function is reduced from two to one, making then treatment of the function much easier. Using the proposed approximation function, one can compute the double-exponential function parameters as precise as 0.03% an error negligible even with a 12bit-recording device. Also in the paper, the Newton method for solving a set of simultaneous non-linear equations quite precisely is discussed.

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Semiconductors such as n-GaAs and n-InP have an N-type bulk negative resistance effect which leads to current oscillation (Gunn oscillation). The oscillation is due to the periodic formation-travelling-disappearance of a high-field domain. In semi-insulating GaAs(ρ_??_10⁷Ω•cm), the oscillation can be generated at room temperature under dc bias and the oscillation frequency is very low due to a slow domain velocity. The detailed mechanism of the low-frequency oscillation has not yet been clarified. To investigate the oscillation mechanism, we tried to observe the domain by a scanning electron microscope (SEM) and could observe it for the first time by the SEM. In order to memorize the moving domain and analyze by a computer afterwards, we introduced a motion picture system and succeeded in capturing of images of the moving domain. This will contribute to clarify the oscillation mechanism and to develop the technique of the visualization of the electromagnetic phenomena.

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For the optimum design of photovoltaic power generation system, it is necessary to accurately estimate their annual power output. However the output of thin film solar cell (in this paper, layered tandem a-Si and CdS/CdTe) varies with the spectral distribution of solar radiation as well as with Staebler-Wronski Effect. Changes in the spectral distribution of solar radiation are caused by variations in air mass movement and water vapor content of the atmosphere. The output of thin film solar cells is seriously effected because of their narrow spectral response band. S. W Effect is a phenomenon where the photo conductivity degrades by light irradiation and recovers by heating. Since several factors can affect the output in such away it makes it difficult to accurately estimate the power output of thin film solar cells for an entire year.
In this paper, we will show a method for calculating power output from the spectral distribution of solar radiation. We will also attempt to clarify the degradation and recovery due to S. W Effect by make a comparison between the conversion efficiency calculated by this method and the conversion efficiency obtained from measured data. The results revealed that the initial degradation of conversion efficiency of layered tandem a-Si and CdS/CdTe solar cells are 22% and 15% (including the degradation due to dirt 6-7%), and the recovery are 5% and 10%.

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This paper describes on deterioration diagnosis of silicone rubber housing of polymer insulators by Infrared spectroscopy. The insulators investigated were tested by corona discharge test in a fog-chamber, and used in fields. Aluminum nitride which generated corona discharge and moisture, and it deposited on the surfaces of the specimens could easily analyzed with infrared spectroscopy, because aluminum nitride had some peaks of absorption spectrum at different wavenumber comparing to the peaks of silicone rubber. Corona deterioration index was set based on the deposited amount of aluminum nitride. The index of line side was larger than earth side. This means corona discharge tend to occurred line side than earth side. Corona deterioration index of the polymer insulators tested in fog-chamber showed good correlation with test period. Polymer insulators used in fields were analyzed by this technique and the results were compared with the results obtained the fog-chamber test. There will be possibilities to predict of the life time of polymer insulators by studying of the determination of deterioration modes, setting of the deterioration indexes, and comparing the indexes of the specimens tested by artificial aging and fields.

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We have investigated the relation between the molecular weight distribution (MWD) of diffusible species and the recovery rate of hydrophobicity of room-temperature vulcanizing (RTV) silicone rubber (SIR) using solvent extraction at various temperatures. Using gel permeation chromatography (GPC), we confirmed that the extract had a MWD ranging from a few hundreds to hundreds of thousands, and the average molecular weight (MW) of the extract having MW over 3000 increased with the increase of extraction temperature. By measuring the infrared (IR) absorption of siloxane migrating to the extracted SIR surface through a thin carbon coating, the aspect of migration of diffusible species was observed as a real time plot, and the time constant of the migration was calculated. According to the time dependence of IR-absorbance, the time constant was increased with the increase of MW of the extracts. It was found that the recovery rate of hydrophobicity of SIR was related to the MWD of the diffusible species.

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Previously, authors developed a novel linear actuator with flat-ring-shaped metal magnets and applied it to a pump. Because the actuator can transfer energy with the magnetic field of very low frequency through a non-magnetic wall such as a human skin, the pump has a possibility to be used as an artificial heart. We made a new pump driven by a newly developed actuator with more powerful and larger metal magnets than used before. Also, we proposed a new driving method for the actuator in order to obtain larger power than before. As a result, the pump output power of 0.3W and the actuator output power of 0.77W are obtained on the condition that the water pressure for the pump and the driving frequency for the actuator are 132mmHg and 1.1Hz, respectively. The experimental system worked out for evaluating the output characteristics of the actuator and the pump is also shown in this paper.

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An RF radiated immunity test method using an electromagnetic (EM) field of low speed rotation (rotating field) and its basic characteristics have been studied. In this method, the EM field to illuminate equipment under test (EUT) rotates two-dimensionally at an arbitrary and extremely low speed. By applying the ro-tating field to the EUT, the radiated immunity characteristics of EUT can be made clear two-dimensionally and continuously. A generation method of wide-band rotating field using double balanced mixers is studied and the basic characteristics of the generated field are measured to check the performance of our trial setup. The immunity test of a rectangular cavity with a slit is conducted as an example. The results show that the immunity characteristics of the EUT is measured in detail and automatically, and besides, this method is time-saving.

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Leakage current levels of various types of polymeric materials able to be used in HV outdoor insulation are evaluated using salt-fog chamber test. Silicone rubbers could resist leakage current development during this test. Larger leakage current is allowed on non-silicone polymeric materials than hydrophilic glass materials. The reduction magnitudes of the hydrophobicity of material surfaces and their recover rates during a restoration are in agreement with the levels of leakage current and subjected damages. Hydrophobic stability of silicone rubbers seems to be a key to suppress leakage current in polluted environments. It is suggested that hydrophobic behavior of polymeric materials in the early stage of their installations affect their electrical performances and aging levels.

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