IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 127, Issue 2
Displaying 1-12 of 12 articles from this issue
Review
Paper
  • Tadashi Kawamoto, Tadasu Takuma, Hisashi Goshima, Hiroyuki Shinkai, Hi ...
    2007 Volume 127 Issue 2 Pages 59-64
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    This paper analyses the electric field distribution near a wedge-like edge in arrangements consisting of three dielectrics by analytical and numerical methods. The electric potential behaves exponentially as rn (r is distance from the edge) near the edge, leading to an infinitely high field with decreasing r for any cases. The value of analytically derived exponent n agreed well with that obtained from the numerical field calculation. It has been also demonstrated that rounded contact of the spacer with zero contact angle can make the electric field constant without showing an exponential rise near the edge.
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  • Masaaki Tanaka, Yasuyuki Kawagoe, Hisashi Tsukazaki, Kenichiro Yamanis ...
    2007 Volume 127 Issue 2 Pages 65-70
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    We have studied the low pressure silent discharge type active oxygen generator in terms of the application to the formation of oxide thin films. In this paper the oxidation power of active oxygen in the oxide thin film formation is compared with that of oxygen and ozone by forming silicon oxide thin films. It was confirmed that the oxidation power is in turn of active oxygen > ozone > oxygen from the experimental result of the number of x in SiOx thin film. Furthermore we applied active oxygen to the formation of the thin film high temperature super conductor and active oxygen was found to be effective to the formation of the thin film with high performance.
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  • Kotaro Wada, Kosei Tsuji, Hirotaka Muto, Shoji Mizoguchi
    2007 Volume 127 Issue 2 Pages 71-77
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    In inverter drive systems, surge voltage between cable shield and ground (generally 0V in AC drive systems) caused from inverter switching is induced if cable length is longer and dv/dt of the inverter output voltage is much higher. This surge voltage isn't observed under AC drives. This unexpected surge voltage may cause partial discharge at cable sheaths and finally breakdown if the surge voltage exceeds partial discharge inception voltage (PDIV) of the sheaths. Therefore insulating characteristics of cable sheaths under inverter surge should be understood for optimal design of inverter-motor systems. This report states about insulating characteristics of the cable sheath, especially PDIV and V-t characteristics under AC and high dv/dt pulse voltage.
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  • Kazue Kaneko, Takashi Ozaki, Emi Nakane, Yasuo Suzuoki, Teruyoshi Mizu ...
    2007 Volume 127 Issue 2 Pages 78-82
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    Space charge distributions in polyimide (PI) films strongly depend upon electric field, temperature, water content and so on. When a dc field was applied to as-received PI films kept in the atmosphere, whose water contents were ca. 0.9 wt.%, four kinds of space charges were observed, i.e., positive- and negative-homo space charges in the vicinity of the electrodes and negative- and positive-hetero space charges inside the bulk. In water-treated PI films, whose water contents were ca. 2.9 wt.%, positive- and negative-homo space charges were rapidly formed. In dried PI films, the homo space charges were much reduced and hetero space charges were clearly observed. The homo space charge amounts were the largest in as-received PI films among these samples. On the other hand, the dc conduction currents increased almost exponentially with the water content. This suggests that the absorbed water enhanced not only charge injection from the electrode but also mobility of charge carriers. The space charge accumulation and field distortion of PI films are determined by their balance.
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  • Emi Nakane, Kazue Kaneko, Tatsuo Mori, Teruyoshi Mizutani, Hiroshi Tak ...
    2007 Volume 127 Issue 2 Pages 83-88
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    We investigated the space charge and charging current characteristics in polypropylene copolymer films polymerized with metallocene and Ziegler-Natta catalysts, respectively. Positive and negative homo space charges were observed and their amounts showed maxima at 40 °C. Charge carriers injected from the semiconducting (SC) electrode were dominant at 60 °C. The copolymerization of ethylene enhanced the apparent carrier mobility and the charging current. Evaporated Al electrode showed much less carrier injection than Al plate or SC electrode (mechanically-contacted electrode). Carrier injection from SC electrode was dominant than that from Al plate. These suggest that the space charge formation depends on not only electrode materials but also contact conditions.
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  • Takao Kumazawa, Ryouichi Taniguchi
    2007 Volume 127 Issue 2 Pages 89-96
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    It is well known that generation and progress of water tree in XLPE cable are remarkably influenced by inorganic impurities. We have investigated the behavior of them in water tree and reported the experimental results as follows: i) the anomalous increase or decrease in several kinds of inorganic elements was observed in water treed XLPE samples, ii) a distinctive relationship was found for the mass numbers for the elements, iii) the isotopic content of the elements such as Zn deviated over 6% from the natural abundance. These results suggest that water tree is concerned with unknown phenomena e.g., cold fusion or nuclear transmutation in condensed matter. In order to study the relationship between water tree and these phenomena, we attempted to detect neutron, γ-ray or X-ray involving generation and progress of water tree in XLPE samples. For the experiments weak and burst-like radiation seemed to be low energy γ-ray or X-ray was often detected by BF3 and/or CdZnTe counter. The radiation tended to be detected from the samples in which a lot of water trees were generated by supplying inorganic cations abundantly.
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  • Tomoari Nishio, Makoto Takahashi, Shinpei Wada, Toshiyuki Miyauchi, Ko ...
    2007 Volume 127 Issue 2 Pages 97-102
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    In-doped n-CdTe thin films have been electrodeposited at -0.35V vs. Ag/AgCl from a nitric acid solution of pH 1 containing 0.05 mol/dm3 (M) Cd(NO3)2, 0.5mM TeO2, and various concentration In(NO3)3. Deposited films were annealed at 350°C under N2 flow. The films were characterized with X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscope(SEM), and a reflectance meter. The conductivity and the carrier concentration of the films were measured using the van der Pauw method and Hall effect measurement at room temperature. This is the first study to investigate the effect of the In(NO3)3 concentration on the composition, the crystallinity, and the electric properties of In doped CdTe films prepared by electrodeposition. The conductivity of the CdTe films linearly increases from 9.3 to 27.4 S/cm-1and the electron concentration [log(n/cm3)] increases from 3.9×1018 to 2.8×1019 cm-3 as the In(NO3)3 concentration rises from 1×10-2 to 1×10-1 M .
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  • Mitsuharu Nogaku
    2007 Volume 127 Issue 2 Pages 103-107
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    We propose to instruct engineering exercise in the part of information processing including electric engineering, mathematics, information basics, and experiments. We give first year students four themes for exercise; (1) the trigonometric function, (2) the solving equations, (3) Fourier series, and (4) the model of electric field in the dielectric materials. The used software is Microsoft Excel on Windows XP. At the fourth theme, all the students are arranged as lattice points of a model case, and work together to calculate voltage values by desk calculators. The results from their handwork are compared to simulated values of the Excel software. In each theme, the graphical method of simulated values leads students to understandings of theories and phenomena.
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  • Yasumitsu Ebinuma, Noriaki Masui
    2007 Volume 127 Issue 2 Pages 108-114
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    Recently the measurement of residual charge has been studying as insulation deterioration diagnosis of XLPE insulated cables. Authors have studied the measurement process and the charge characteristic. The specimens are XLPE sheets of 1mm which are degraded with water-trees. There are four processes of charge removal, charge injection, ground and charge release in the measurement.
    The process of charge removal was introduced to measure a little charge successfully. In the process of charge injection, it was confirmed that the relation between the applied dc voltage and the charge was examined, and the higher dc voltage was, more the charge was. In addition, it has been showed that the applied process of the dc voltage greatly influences the measured charge. In the process of ground, the grounding period is changed and the charge is measured. It has been showed that the grounding period doesn't influence the measured charge greatly. In the process of charge release, the frequency and the period of applied ac voltage were changed and the charge was measured. It has been showed that neither the frequency nor the period of ac voltage greatly influence the charge measured. In addition, the dc voltage was superimposed to ac voltage, and the charge was measured. It has been showed that the charge measured changes greatly even if the dc voltage is low. The method of the insulation deterioration measurement of cable was examined from these results, and the measurement conditions and a newer method were suggested.
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  • Yuya Yamaguchi, Nao Uchibori, Yoshimichi Ohki
    2007 Volume 127 Issue 2 Pages 115-120
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    Three kinds of biodegradable polymers, poly-L-lactic acid (PLLA), polybutylene succinate (PBS), and polybutylene succinate adipate (PBSA), and low-density polyethylene (LDPE) as a reference were irradiated for 30 minutes by ultraviolet (UV) photons from a KrCl excimer lamp. It has become clear that the three biodegradable polymers are far more susceptible to UV photons than LDPE since they absorb UV photons very intensely in the vicinity of the irradiated surface. Space charge distribution profiles show that charge carriers are trapped near the irradiated surface. The conduction current increases by the UV-irradiation in all the biodegradable polymers. Instrumental analyses show that the samples were decomposed by photoinduced oxidation. Furthermore, the absorption spectra indicate the appearance of conjugated double bonds. Such structural changes induced seem to be responsible for the higher conductivity and the charge trapping.
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  • Yoshiaki Yamano, Katsuhiko Shutoh, Masaaki Kando, Katsuhiro Okamoto
    2007 Volume 127 Issue 2 Pages 121-127
    Published: 2007
    Released on J-STAGE: May 01, 2007
    JOURNAL FREE ACCESS
    The flashover voltages (FOVs) between foil conductors across a narrow gap on a printed wiring board with or without backing electrode were measured by four institutions using the same testing boards. The experiments were carried out in air at a room temperature and 40-55%RH. FOVs with two different configurations of the foil conductors on the board were measured. The gap distances studied ranged from 20μm to 200μm, and the thickness of the foil conductor on the board was 6μm or 18μm. The board thicknesses studied were from 60μm to 800μm. FOV was measured under the impulse voltage application (1.2/50μs). The dependences of FOV upon gap distance, polarity of applied voltage, the board thickness and foil thickness were clarified and discussed mainly comparing with calculated results of electric field. The following results are obtained commonly by the four institutions: When the gap distance is smaller than 50μm, FOV is almost independent of the existence of the backing electrode and the board thickness; FOV is independent of the thickness of the foil conductors; When the board thickness is 60μm, FOV is almost unchanged with the increase in the gap distance; FOV at positive voltage application is higher than that at the negative application.
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