電気学会論文誌A(基礎・材料・共通部門誌)
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
127 巻, 10 号
選択された号の論文の18件中1~18を表示しています
論文
  • 志岐 肇, 元木 純平, 滝川 浩史, 榊原 建樹, 西村 芳実, 菱田 茂二, 大川 隆, 大塚 剛史
    2007 年 127 巻 10 号 p. 567-573
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Various materials of the rod electrode were examined in pulsed arc of PEN-Jet (Plasma ENergized-Jet) with working gas of air, which can be used for the surface treatment under atmospheric pressure. The erosion of the rod electrode was measured and it surface was observed. The amount of erosion and surface appearance were found to be different for the materials, input power and energizing time. Tungsten (W) rod electrode was oxidized immediately after starting the discharge and tungsten oxide (WO3) powder was generated over the side surface of electrode tip. This powder contaminated the treating surface. Copper (Cu) rod electrode was also oxidized immediately and CuO/Cu2O multi-layer was formed on the electrode surface. However, the erosion of Cu electrode was quite small. Platinum (Pt) and iridium (20 wt%)-contained-platinum (Pt-Ir) rod electrode were not oxidized and their erosions were significantly small. This indicated that they could be employed for keeping the constant electrode-gap and processing the surface treatment without contamination due to electrode erosion.
  • 曾根 敏文, 門脇 一則, 西本 榮, 木谷 勇
    2007 年 127 巻 10 号 p. 574-580
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Effect of water-surface discharges on inactivation of Bacillus Subtilis ATCC6633 spores was studied using a photographical observation technique and a colony count technique. When a coaxial cable and a coupling condenser at one end of the cable were charged and then directly grounded at the other end of the cable, a reciprocal traveling wave voltage having an oscillation about 106Hz was applied to a point electrode on 3-mm thick water layer. Photographs of transient surface discharge light under atmospheric pressure indicated that many discharge channels repeatedly spread over without breakdown of water. Results in the optical study also showed that repetition of the surface discharge propagation produced by the voltage oscillation was strongly influenced by the cable length. This fact implied that residual charges produced by the first discharge remained on water for several hundred ns, so that the propagation capability of the successive discharge was enhanced. It was confirmed that the discharge light included a UV component due to the emisson of OH excitation. In the test of inactivation of Bacillus Subtilis in water, 20kV reciprocal pulses were applied to the water layer of 1l in volume. The survivor ratio decreased quickly when the test water was irradiated by UV light from a low-pressure Hg lamp. The survivor ratio also decreased with increasing the application time in surface discharge treatment. However, the treatment time for the inactivation using the surface discharge became much longer than that using the UV lamp. The speed for the inactivation using the surface discharge was considerably improved by the combination with the additional H2O2 into the test water.
  • Takashi Uchida, Yasuhiko Abe, Shoji Hashimoto, Yoshizumi Yasuoka
    2007 年 127 巻 10 号 p. 581-585
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    The receiving properties of fabricated parasitic slot antenna arrays on ZnS dielectric substrates for 28-THz-CO2 laser radiation were investigated. When the CO2 laser beam was irradiated on the antennas directly (from the air-side), the E-plane antenna patterns of the parasitic slot antenna arrays became increasing sharper as the number of slots in the array increased from 1to 7. On the other hand, the H-plane antenna patterns did not change with the number of slots because the slot antennas were not arrayed in the H-plane. It was found that the antenna theory based on the transmission line model was applicable at 28 THz. When the CO2 laser beam was irradiated through the substrate (from the substrate-side), rippled antenna patterns were observed due to multiple reflection in the substrate because the thickness of the substrate was much longer than the dielectric wavelength of the CO2 laser. It was also found that the antenna receiving properties were affected by the thickness of the substrate. Furthermore, as expected from the theory, the power gain of the 7-parasitic slot antenna array improved by approximately 7 dB compared to that of the single-slot antenna at 28 THz.
  • 堺 健司, 平木 聖大, 吉門 進三
    2007 年 127 巻 10 号 p. 586-592
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    It has been found that if magnetic materials isolate in dielectric medium, permeability of composite material doesn't obey Lichtenecker's law, which is well known to explain permeability and permittivity of composite material. This characteristic leads to absorption of electromagnetic wave above 1 GHz. We proposed isolated model to simulate the frequency dispersion of permeability and developed composite electromagnetic wave absorber made of ferrite-SiO2 or permalloy-polystyrene system in which magnetic materials are isolated. The mechanical milling is employed to isolate magnetic materials in the dielectric medium. Ni-Zn ferrite could be isolated in the SiO2 medium and measured values of the complex permeability were close to simulated ones. As a result, this absorber can absorb electromagnetic wave in the frequency range near 2 GHz. Permalloy particles were insulated by molten polystyrene. Permalloy-polystyrene absorber showed good absorption characteristics in the frequency range between 3 and 8 GHz.
  • 高橋 紹大, 栗原 隆史, 武田 敏信, 熊田 亜紀子, 松岡 成居, 日高 邦彦
    2007 年 127 巻 10 号 p. 593-598
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Electromagnetic waves are named depending on their wavelength range. For many years, the generation methods, detection methods and applications of almost all electromagnetic waves have been investigated. However, there remains an unveiled range owing to a lack of appropriate generation methods. This wavelength range is from several tens to several hundreds of micrometers, and has a frequency range from one to several tens of THz. Generally, waves in this range are called the THz waves. Some generation methods for THz waves have been developed recently, the characteristics of these waves are still under investigation, but some applications have been proposed. One of the important properties of THz waves is their high transmissivity in opaque dielectric materials. Generally, insulating materials are opaque to visible light, and it is difficult to observe internal defects externally. However, if THz waves show sufficient transmissivity and proper interaction with internal physical quantities, they are expected to be a useful measurement tool for insulating materials. In this study, polyethylene, which is a typical insulating material, is choosen as the measurement target, and void interfaces and mechanical strain are detected using THz waves.
  • Keigo Imanishi, Osamu Kumagai, Seiji Mukaigawa, Koichi Takaki, Tamiya ...
    2007 年 127 巻 10 号 p. 599-604
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    A magnetically driven carbon shunting arc discharge was generated in nitrogen gas circumstance and amorphous carbon nitride (a-CNx) films were prepared using plasma-based ion implantation technique. A silicon substrate was immersed into the plasma, and a series of pulse voltage was applied to the substrate synchronizing with an ignition of the shunting arc with a peak current of 2.1 kA. The ambient nitrogen gas pressure was varied from 0.02 to 2 Pa. The shunting arc plasma was successfully produced and was accelerated along carbon rails. Rod heating energy to generate the shunting arc had the minimum value for variation of the ambient gas pressure. A spectroscopic measurement from the plasma light emission showed that the produced plasma contained nitrogen particles in ambient nitrogen gas circumstance. X-ray photoelectron spectroscopy analysis showed that the prepared carbon films contained nitrogen and was obtained to be N/C ratio of 0.35 at 2 Pa nitrogen gas pressure.
  • 高野 啓, 名雪 琢弥, 大石 祐嗣, 藤井 隆, 早田 敬太, 高嶋 隆太, 長谷川 秀一, 堀田 栄喜, 根本 孝七
    2007 年 127 巻 10 号 p. 605-610
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    We developed a compact laser electron source which can be used as an X-ray source for nondestructive diagnosis instead of radio isotopes. High energy electrons were generated by an ultrashort laser pulse focused on a thin tape target. The laser energy was only 15 mJ. Pulse duration and beam diameter of the laser beam were 140 fs and 10 mm, respectively. We got over 1 MeV energetic electrons with this compact laser electron source.
  • 水野 勉, 鈴木 貴之, 朝比奈 孝, 野田 真裕, 榎木 茂実, 品川 宏樹, 植原 精作, 北沢 弘
    2007 年 127 巻 10 号 p. 611-620
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Coil resistance is broken down into DC resistance, resistance due to the skin effect and resistance due to the proximity effect. Most of the coil resistance is composed of resistance due to the proximity effect in the high-frequency range. Thus, the resistance due to the proximity effect, which is equal to the eddy current loss, must be reduced. The eddy current loss in a magnetoplated wire is smaller than that in a copper wire. The magnetoplated wire is a copper wire whose circumference is plated with a magnetic thin film. The eddy current losses in magnetoplated wire can be analyzed using the finite element method. However, the analysis time is long and there is a memory capacity restriction when using the finite element method. In this study, we derive the expressions of the skin effect and eddy current loss in a magnetoplated wire for ease of calculation. The result shows that eddy current loss in the magnetoplated wire is reduced to a factor of 0.25 or less in comparison with that in copper wire, and that the resistance of the magnetoplated wire can be reduced due to the proximity effect.
  • 高田 雅之, 吉門 進三
    2007 年 127 巻 10 号 p. 621-628
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    The effects of SnO2 additon on the electrical degradation characteristics of Bi2O3-MnO2-Co3O4-added ZnO varistors were investigated by field-emission scanning electron microscopy (FE-SEM), energy dispersion X-ray spectroscopy (EDX), X-ray diffraction (XRD), voltage-current (V-I) characteristics, and capacitance-voltage (C-V) characteristics. The microstructure containing both twins of ZnO and Zn2SnO4-type spinel particles was observed at the grain boundary similar to Bi-Mn-Co-Sb2O3-added ZnO varistors. Spinel particles began to appear by the addition of SnO2 over approximately 0.5mol%. Before electrical degradation, value of nonlinearity index α of V-I characteristic for Bi-Mn-Co-SnO2-added samples was approximately 50 and varistor voltage was 120∼140V/mm. Varistor voltage increased with increasing the amount of SnO2. Value of α after the electrical degradation showed local maximum at approximately 0.1mol% with the increase of the amount of SnO2 and then showed local minimum at approximately 0.5mol% similar to the relative integral intensity of XRD diffraction peak for (004) plane at small amount of SnO2. It is suggested that the diffusion of oxygen ions through the grain boundary is affected by the change of crystal orientation of ZnO grains at the grain boundary by addition of small amount of SnO2. It is found that the increase of the varistor voltage by addition of SnO2 is due to the increase of the barrier height of Schottky barriers.
  • 長田 昭義, 西本 彰文
    2007 年 127 巻 10 号 p. 629-634
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Solid oxygen fuel cell (SOFC) having yttria-stabilized zirconia (YSZ) electrolyte film thickness of 12-3μm, which was grown on the Ni-YSZ cermet substrate using as the fuel electrode by RF magnetron sputtering, has been studied on the operating property until lower temperature of 700°C. A single SOFC having YSZ electrolyte film thickness of 3μm could be well operated at 800°C and that could performed the V-I property of 700mV-300mA/cm2 indicating the development index of the cell. The open circuit voltage (OCV) of the cell gave nearly the same value as the theoretical electromotive force. However, the OCV drop became larger as making thin YSZ film, because the grain boundary and pore were caused in the film in consequence of a surface roughness on the substrate. The voltage drop of the cell was mainly occupied by the resistance loss in YSZ film and its percentage increased as the operating temperature decreased. Moreover, the film conductivity at the operating temperature of 800°C became smaller by two figures than the theoretical conductivity of the bulk electrolyte.
  • 皆川 正寛, 新保 一成, 加藤 景三, 金子 双男
    2007 年 127 巻 10 号 p. 635-641
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    Organic Electroluminescent device (OLED) was fabricated using a vacuum evaporation method and thermal properties were investigated. The OLED has an Indium Tin Oxide (ITO)/ N,N'-diphenyl-N,N'- bis(3-methylphenyl) 1- 1'biphenyl- 4,4'-diamine (TPD)/ tris- (8-hydroxyquinoline) aluminum (Alq)/ Lithium fluoride (LiF)/ aluminum (Al) structure. An electron dominant device of an Al/ Alq/ LiF/ Al structure, or a hole dominant device of an ITO/ TPD/ Al structure was also fabricated in order to study the carrier behavior in the OLEDs. The current density vs. voltage (J-V) properties with various thickness of organic layers were investigated in the both electron and hole dominant devices, and the thermal dependence of J-V properties was observed in the devices. At room temperature, conductions in large current region were considered to be due to space-charge-limited current for all the devices. Especially, for the Al/ Alq/ LiF/ Al device and the OLED, J∝Vm+1 relationships were observed across wide current region. At low temperature, tunnel currents were estimated for the ITO/TPD/Al device. For the Al/ Alq/ LiF/ Al device and the OLED, J∝Vm+1 relationships were observed across wide current region at low temperature.
  • 一柳 龍伸, 早川 朝康
    2007 年 127 巻 10 号 p. 642-646
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    We measured the temperature of a polyethylene film exposed to partial discharge using an X-ray diffractometer based on the fact that thermal vibration of the polyethylene molecules attenuates the diffracted intensity exponentially. Polyethylene (PE) resin is known to be a crystalline polymer that can adopt a folded chain conformation. In bulk, PE is composed of amorphous and crystalline regions. With increased temperature, the molecular chains move and the PE transforms from the crystalline state that exists before heating. When a film temperature was at less than 60 degrees above room temperature, the diffracted intensity was at the same value as at room temperature.
    Parallel plate electrodes (two glass plates with an aperture in between) were attached to the goniometer of the X-ray diffractometer to generate partial discharge. Discharge by the electrodes only did not change the diffracted intensity. As such, the effect of X-ray dispersion by the electric field or discharge-generated gas was considered. A discharge was generated by applying a PE film to each glass plate electrode and the change in diffracted intensity was recorded. After the discharge had stopped, the PE film was heated to determine the temperature which gave the same diffracted intensity as that obtained by discharge. The discharge was found to increase the temperature of the PE film by 16 degrees above room temperature. This temperature rise is considered an average value resulting from penetration of the PE film by X-rays.
  • 和田 耕太郎, 粟野 悠平, 辻 孝誠, 武藤 浩隆
    2007 年 127 巻 10 号 p. 647-653
    発行日: 2007/10/01
    公開日: 2007/10/01
    ジャーナル フリー
    In inverter-fed motor systems, output voltage of the inverter has a rectangular waveform with rise time of a few tens of nanoseconds, and consequently a motor suffers from repetitive surge pulses which may have adverse effect on motor insulation. Therefore it is very important to know partial discharge (PD) characteristics during inverter operation especially if there were insulation defects. We have investigated the PD characteristics under inverter surge during actual motor operation, especially about the dependence of PD pulse count rate on inverter DC bus voltage when PD defect exists at phase-phase or phase-ground at motor terminal. As a result, we found that the characteristics of PD pulse count rate depend on DC bus voltage considerably and differs whether the PD defect is at phase-phase or phase-ground. When PD defect is at phase-phase, the PD pulse count rate reaches immediately twice of the power frequency above the PD inception voltage and become constant even if the DC bus voltage is increase, and when the DC bus voltage is further increased, PD pulse count rate starts to increase again. On the other hand, when PD defect is at phase-ground, the PD pulse count rate has increased monotonously with the DC bus voltage until PD pulse count rate has reached twice of carrier frequency. This difference is caused by the difference of the voltage waveform between phase-phase voltage and phase-ground voltage under inverter drives. Therefore, we concluded that it is possible to distinguish whether the PD source is at phase-phase or phase-ground by the dependence of PD pulse count rate on the DC bus voltage.
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