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
131 巻, 2 号
選択された号の論文の18件中1~18を表示しています
特集:電気技術の継承
特集論文
  • 木村 宰
    2011 年 131 巻 2 号 p. 63-70
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    Developing new renewable energy sources, such as solar photovoltaics (PV), is a key to establishing climate-friendly economy. Japan has been one of the centers of research, development, and diffusion (RD&D) of PV since the 1970's. While it is true that Japan was outnumbered by Germany in installed capacity and by US and Chinese companies in production in recent years, Japan still retains an important position in the world PV market. This paper examines the history of public policies for RD&D of PV in Japan, focusing on two kinds of policies, namely, public support for R&D under the Sunshine Program and various market creation policies in the early 1990's. Based on literature survey and interviews with key persons involved, the paper reveals that those support policies played an indispensable role to accelerate RD&D of PV technology. The Sunshine Program provided stable R&D budgets and space for technology learning throughout the 1980's to 1990's, and contributed to the progress of solar cell efficiency and cost reduction. The various market creation policies in the early 1990's also created regulatory and economic conditions that were necessary to commercialize residential PV systems, and became the direct driver to launch the initial PV market.
  • 今中 健雄
    2011 年 131 巻 2 号 p. 71-77
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    In Japan, energy efficient fluorescent lamp systems which use “rare-earth phosphors” and “electronic ballasts” have shown rapid diffusion since 1990s. This report investigated sources of technological change in the efficiency improvement of fluorescent lamp systems: (i) Fluorescent lamp and luminaires have been under steady technological development for getting more energy efficient lighting and the concepts to achieve high efficiency had been found in such activities; however, it took long time until they realized and become widely used; (ii) Electronic ballasts and rare-earth phosphors add fluorescent lamp systems not only energy efficiency but also various values such as compactness, lightweight, higher output, and better color rendering properties, which have also been expected and have induced research and development (R&D); (iii) Affordable electronic ballasts are realized by the new technology “power MOSFET” which is based on IC technologies and has been developed for large markets of information and communication technologies and mobile devices; and (iv) Rare-earth phosphors became available after rare-earth industries developed for the purpose of supplying rare-earth phosphors for color television.
    In terms of sources of technological change, (i) corresponds to “R&D” aiming at the particular purpose i.e. energy efficiency in this case, on the other hand, (ii), (iii), and (iv) correspond to “spillovers” from activities aiming at other purposes. This case exhibits an actual example in which “spillovers” were the critical sources of technological change in energy technology.
  • 荒川 文生
    2011 年 131 巻 2 号 p. 78-81
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    It is needless to cite the importance of education for succeed of engineering. IEEJ called for the establishment of ICEE in 1994, where the education is thought highly of, though its discussion has not been well working. Generally speaking, education has been one of the most important national strategies particularly at a time of its political and economical development. The science and technology education is, of course, not the exemption. But in these days around 2000 it seems that the public pays little attention on the science and technology, as they are quite day to day matters. As the results, for instance, such engineering as power systems and electric heavy machines are referred to as “endangered”.
    So fur, many engineers have tried not to be involved in social issues. But currently they can not help facing with risks of social issues like patent rights, troubles and accidents due to application of high technology, information security in the use of computers and engineering ethics. One of the most appropriate ways for the risk management is to learn lessons in the past, that is, history, so that the idea suggested in it could be made full use for the risk management. The author cited the global importance of education, particularly of engineering history education for engineering ethics, in the ICEE 2010 held in Bussan, Korea, as the 16th anniversary.
論文
  • 鈴木 進, 伊藤 晴雄
    2011 年 131 巻 2 号 p. 82-88
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    The collisional quenching rate coefficient of metastable nitrogen molecules N2(A3Σu+) by m-xylene (C8H10) is determined experimentally in the Townsend discharge. The diffusion coefficient of N2(A3Σu+), and the reflection coefficient of N2(A3Σu+) at the electrode surface are also determined simultaneously. During the experiment, we find that it is difficult to continue the current measurement necessary to determine the fundamental constants of N2(A3Σu+) for long period. It is considered that any by-product of xylene would be decomposed by N2(A3Σu+) is deposited on the cathode, through repeated experiments, then the current-voltage curves consistently shift to the higher-E/p0 region. For the purpose of clarifying the reason behind this behavior, we confirm that these changes are caused by the current prevention by the decreases of initial photoemission current from the cathode and the decrease in the secondary ionization coefficient γ, because the cathode surface is covered by deposition film of a by-product of decomposed xylene.
  • 三輪 紘睦, 平田 晃正, 藤原 修, 長岡 智明, 渡邊 聡一
    2011 年 131 巻 2 号 p. 89-94
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    We previously showed that a strong correlation exists between the absorption cross section and the body surface area of a human for 0.3-2GHz far field exposure, and proposed a formula for estimating whole-body-average specific absorption rates (WBA-SARs) in terms of height and weight. In this study, to evaluate variability in the WBA-SARs in infants based on their physique, we derived a new formula including Kaup indices of infants, which are being used to check their growth, and thereby estimated the WBA-SARs in infants with respect to their age from 0 month to three years. As a result, we found that under the same height/weight, the smaller the Kaup indices are, the larger the WBA-SARs become, and that the variability in the WBA-SARs is around 15% at the same age. To validate these findings, using the FDTD method, we simulated the GHz-band WBA-SARs in numerical human models corresponding to infants with age of 0, 1, 3, 6 and 9 months, which were obtained by scaling down the anatomically based Japanese three-year child model developed by NICT (National Institute of Information and Communications Technology). Results show that the FDTD-simulated WBA-SARs are smaller by 20% compared to those estimated for infants having the median height and the Kaup index of 0.5 percentiles, which provide conservative WBA-SARs.
  • 本山 卓大, 濱田 奈那子, 田中 康寛, 前野 恭
    2011 年 131 巻 2 号 p. 95-101
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    Space Charge behavior in polyimide film under dc stress with visible light irradiation was investigated out using a newly developed measurement system of the pulsed electro-acoustic (PEA) method. The PEA method has been widely used to observe a space charge distribution in various solid insulating materials. We applied the method to investigate the influence of visible light irradiation on space charge formation in insulating materials under DC stress. It is well known that a property of the conduction in insulating materials is affected by the irradiation of light. However the relationship between the space charge and the irradiation of light has not been clear yet. So, we have observed the effect of the light irradiation on the space charge distribution in polyimide film. In this research, we have found that the space charge formation and the decrease of breakdown strength depends on chemical structure and fundamental absorption of the polyimide.
  • 日高 啓昭, 坂口 裕二郎, 末永 寛, 田島 大輔, 大坪 昌久
    2011 年 131 巻 2 号 p. 102-108
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    The purpose of this research is to design a structure of membrane electrode assembly (MEA) for reduction of a platinum amount considering with a reaction surface area, a various polarizations and a max power density by changing structure of catalyst layer numbers of MEA. Firstly, an operation of the multi-layered MEA was evaluated. As the result, the reaction surface area increases and the activation polarization decreases as increasing the number of catalyst layers in anode and cathode. In addition, the max power density increases with increasing the reaction surface area and the max power density increases with decreasing the activation polarization. However, a tendency of increasing of the reaction surface area and decreasing of the activation polarization saturated and the max power density decreased in the five-layered MEA. It was thought that flooding occurred by excessive stacking of the catalyst layers on cathode. Therefore, the optimal structure of multi-layered MEA was four-layered structure. In this study, it was clearly understood that multi-layered MEA was effective in increase of reaction surface area of the platinum catalyst, reduction of activation polarization and improvement of maximum output density. In addition, fuel cell module with multi-layered MEA was effective for reducing platinum amount.
  • 西中 英文
    2011 年 131 巻 2 号 p. 109-118
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    Currently, the resistive voltage divider (Fluke 752A) has been using as the instrument for extending the voltage range at most of the advanced industrial metrology laboratories. The voltage ratios belonging to this divider can be calibrated by the self-calibration or the external standard. However, the self-calibration is somewhat difficult to need the accomplished technique. Therefore, the calibration of the voltage ratios has planed the method based on a Josephson Junction Array Voltage Standard developed at the NMIJ or a Zener voltage reference (Fluke 732B) as the external standards. A Zener voltage reference used at here is the modified one for obtaining a 1V output. This paper describes how to calibrate the voltage ratios using two external standards and reveals the source of the calibration uncertainty.
  • 辻 拓朗, 高 義礼, 藤原 修, 山本 典央
    2011 年 131 巻 2 号 p. 119-124
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    International Electrotechnical Commission (IEC) prescribes immunity tests (IEC61000-4-2) of electronic equipment against electrostatic discharge (ESDs), and specifies indirect discharges of an ESD-gun onto a vertical coupling plane (VCP) in the vicinity of equipment under test (EUT) for simulating personal discharges to conductive materials being adjacent to the EUT. According to IEC 61000-4-2 2001-04, the VCP shall be placed at a distance of 0.1m from the EUT, and the indirect discharges of an ESD-gun should be conducted to the centre of a vertical edge of the VCP, while the reference arrangement of EUT is not specifically determined. In the present study, by using a magnetic field probe and a half-wavelength dipole antenna in lieu of EUT, we measured their induced voltages due to electromagnetic fields spatially induced for indirect discharges of an ESD-gun onto a VCP, and investigated variations in peaks and waveform energies with respect to the measurement positions. As a result, we found that positions close to the ESD-gun provide variations by 1.46 (4.0) and 3.4 (27) times in peaks (waveform energies) of the induced voltages due to magnetic and electric fields, respectively, while positions away from the ESD-gun suppress their variations by 0.6 (0.4) and 0.2 (0.34) times, and discharges onto a vertical edge from the back side of a VCP could be expected to further reduce the above-mentioned variations.
  • 若林 秀昭, 山北 次郎
    2011 年 131 巻 2 号 p. 125-131
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    Surface-relief and index modulated dielectric gratings can be approximated by uniform equivalent permittivity when the periodicity is very small compared with a wavelength. In plane gratings, equivalent anisotropic effects of surface resistance will also appear when the periodicity is very small. In this paper, a versatile uniform approximation of equivalent resistance is proposed in the three-dimensional electromagnetic scattering problem of plane gratings with periodic surface resistance illuminated by linearly and circularly polarized incidence. Scattering properties are obtained by the equivalent resistance from our proposed uniform approximation. Scattering by plane gratings with various periodic surface resistance are analyzed rigorously by the Galerkin method based on the mixed form of current expansions in the spectral and spatial domains. By investigating the difference between the equivalent resistance and the numerical values corresponding to the surface resistance of plane gratings, the applicable condition of the uniform approximation is directly cleared. And the equivalent anisotropic effects of various resistance distributions are compared.
  • 吉武 勇一郎, 尾畑 功治, 榎本 裕治, 岡部 義昭
    2011 年 131 巻 2 号 p. 132-138
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    To increase the power density of motors in a wide range of fields from home appliance to power industry, we proposed two new high thermal conductive insulation systems for the motors. They were a glass cross insulation system and a resin coated insulation system without forced cooling devices such as a cooling fan. Their thermal and insulation characteristics were measured and analyzed, and optimum thermal conductive structures for claw teeth motors were discussed through robust design and thermal network analysis. Experiment on prototype motors with the highest thermal conductive epoxy resin (5 W/mK) and the proposed systems, revealed that the temperature rise of motor coils was decreased; their temperature reached 73 % of that of the motor coils with standard insulation and normal resin (0.6 W/mK). Furthermore, partial discharge inception voltage (PDIV) and breakdown voltage (BDV) were measured, and we verified that resin coated insulation motors could withstand as high a voltage as normal insulation motors.
  • 柳田 太一郎, 田上 英人, 神谷 雅男, 須田 善行, 滝川 浩史, 瀧 真, 長谷川 祐史, 石川 剛史
    2011 年 131 巻 2 号 p. 139-144
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    Electromagnetically pulled-out gas plasma (EPOP) gun was developed, which will be applied to the filtered arc deposition system in order to enhance the nitriding of preparing thin film under medium vacuum. A hot cathode of tungsten (W) filament was employed and DC discharge was generated between the cathode and anode (SUS304). The distance of electrodes was 100 mm. Electromagnetic coils were placed around the cathode, anode and plasma pulled-out duct, separately. Experimental pressure was 0.1 Pa. The following results were obtained. Ignition voltage became lower when the same direction magnetic field was axially applied to the cathode and anode. Minimum voltage for sustaining the discharge became lower when the magnetic filed was applied to the anode. With increasing discharge voltage, the discharge current increased dramatically for the discharge voltage less than 50 V and increased gradually for the voltage more than that. The plasma between the cathode and anode was able to be pulled out to the process chamber by applying magnetic field perpendicular to the discharge axis. The amount of pulled-out plasma increased with increasing the filament current and magnetic flux density for plasma pulling-out.
  • 前田 義隆, 戸高 孝, 榎園 正人
    2011 年 131 巻 2 号 p. 145-150
    発行日: 2011/02/01
    公開日: 2011/02/01
    ジャーナル フリー
    In order to develop higher torque, lower weight and smaller sized magnetic actuators for driving electrical vehicles and robot arms, designing under high magnetic field and high exciting voltage is most effective. It is therefore very important to understand vector magnetic properties in electrical steel sheets under high magnetic flux density conditions. The vector magnetic properties mean the relationship between the magnetic flux density vector and the magnetic field strength vector and it is very difficult to measure the each component under high magnetic flux density conditions because of the magnetic saturation and the magnetic anisotropy. In this paper, accurate measurement techniques of the vector magnetic properties over 1.5T and measured vector magnetic properties are reported and discussed.
研究開発レター
部門記事
feedback
Top