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
136 巻, 1 号
選択された号の論文の20件中1~20を表示しています
特集:2016 年基礎材料分野の研究開発の動向
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論文
  • 豊田 啓孝, 三倉 駿紀, 五百旗頭 健吾
    2016 年 136 巻 1 号 p. 25-32
    発行日: 2016/01/01
    公開日: 2016/01/01
    ジャーナル フリー
    In the modal-equivalent circuit derived from the view of the mode-decomposition technique, mode-conversion sources are placed at the interface where the imbalance factor of the transmission lines changes. In addition, the amount of the mode-conversion sources is proportional to not only the difference in the imbalance factor but also the magnitudes of the normal-mode voltage and the common-mode current at the same position. In this paper, therefore, the suppression of mode conversion from normal mode to common mode is experimentally examined by installing a bypass capacitor to power distribution network. The bypass capacitor helps reduce the normal-mode voltage in the vicinity of a connector on a test board where mode conversion occurs so that the common-mode current flowing a power-line cable and the electric field far from the test board are decreased. In fact, the mode conversion was most suppressed when the bypass capacitor is placed closest to the connector on the test board. Also, it was found that the mode conversion was suppressed by the capacitor installed to the power-line cable in the vicinity of the connector.
  • 根本 大輔, Yudi Kristanto, 賀 婉婷, 松尾 武, 佐藤 直幸, 岡野 一雄, 池畑 隆
    2016 年 136 巻 1 号 p. 33-40
    発行日: 2016/01/01
    公開日: 2016/01/01
    ジャーナル フリー
    We are developing an electrostatic neutralizer operating in an atmosphere without oxygen for the organic electronics fabrication industry. As a part of the study, we investigated ion generation and neutralization characteristics of an ac-corona-discharge-type ionizer in different atmospheric gases such as ambient air, pure nitrogen, mixed N2-O2 and N2-SF6 gases, with changing the partial pressure of O2 and SF6, respectively. The I-V characteristic of the emitter shows that the negative current in nitrogen gas is significantly greater than the positive one; thus the product final voltage VPF gives a significant deviation to a negative value (about -2 kV). However, by introducing SF6 gas by 0.01 %, VPF reduces to about 0 V as that in ambient air. The amount of SF6 needed to improve the ion balance is three orders of magnitude smaller than that of O2, due to higher electronic affinity that a SF6 molecule has.
  • 大久保 智幸, 平谷 多津彦, 尾田 善彦
    2016 年 136 巻 1 号 p. 41-46
    発行日: 2016/01/01
    公開日: 2016/01/01
    ジャーナル フリー
    6.5%Si steel possesses excellent soft magnetic properties, which can be improved by texture control. In this investigation, we report magnetic properties of grain-oriented 6.5%Si steel. The specimens are prepared by cold rolling of grain-oriented 3%Si steel and siliconizing process instead of secondary recrystallization in order to obtain thin and fine-grained specimens to decrease high-frequency iron loss. The grain-oriented 6.5%Si steel shows low iron loss, high flux density and low magnetostriction.
  • 三坂 英樹, 布施 則一, 栗原 隆史, 金神 雅樹, 本間 宏也, 岡本 達希
    2016 年 136 巻 1 号 p. 47-53
    発行日: 2016/01/01
    公開日: 2016/01/01
    ジャーナル フリー
    Flame-retardant ethylene-propylene-diene rubbers were subjected to acceleration aging with simultaneous heat and radiation in the air to evaluate the acceleration factor. Mechanical properties under various dose rates, temperatures, and degradation time (0-1050 Gy/h, 80-120°C, 0-42481 hours) were measured to find the optimal shift factor to minimize the data scattering. The estimated shift factor was applied to the oxygen induction time which may correspond to remaining amount of antioxidants. Obtained aging characteristics were found to suggest that the degradation proceeds after consumption of antioxidants. The present study also revealed that the optimum shift parameter of the degradation process may also be applied to aging characteristics obtained under low oxygen pressure conditions.
  • 土屋 龍平, 村本 裕二, 清水 教之
    2016 年 136 巻 1 号 p. 54-63
    発行日: 2016/01/01
    公開日: 2016/01/01
    ジャーナル フリー
    Electrical insulation system using ice at cryogenic temperature has been studied. Ice has excellent electrical breakdown strength at cryogenic temperature. However, electrical weak points such as voids or cracks are easily formed in ice. Therefore, we tried to suppress the formation of voids or cracks by mixture of alcohol. In this paper, A.C. breakdown voltages of ethylene glycol, 1,3-propanediol, propylene glycol or glycerin of solidified aqueous solutions were observed. The following results were obtained. (1) In many cases, the A.C. breakdown voltages of these solidified alcohol aqueous solutions were higher than that of ice. Average breakdown voltage of ethylene glycol shows the highest value among the tested solutions. It is 1.8 times higher than average value of ice. (2) In order to obtain high breakdown properties, it is necessary to adjust alcohol molar fraction so that solidification goes through sherbet like matter. (3) A.C. breakdown voltages of solidified aqueous solutions have very large dispersion. The breakdown voltage of solidified aqueous solution is clarified to be depending on the solidification state. (4) The solidification state of aqueous solution varies with alcohol concentration, cooling rate and cooling time.
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