[in Japanese]

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Instrumentation and measurement technology is essential for establishment of standards, evaluation and diagnostics of equipment, development of disaster mitigation strategies based on understanding of natural phenomena, and other needs which span our society. The IEEJ Technical Committee on Instrumentation and Measurement has explored key technologies in this field through technical meetings and research committees. Its recent activities and some leading research results are presented.

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Activities of the technical committee on light application and visual science (TC-LAV) have been covering various kinds of application of optical engineering in the wavelength region from far-infrared (THz-wave) to extreme ultraviolet and fields of information processing of visual sense.

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The main objective of HEE is to examine the direction in which electrical engineering should move in the years ahead by studying the past. Electrical engineering history constitutes the basis of technologies that we should develop. It is the starting point from which we should approach the future. This paper introduces recent activities of the committee.

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This article reports some recent research topics presented in the 43rd Symposium on Electromagnetic Theory (EMT). The symposium on EMT is an annual symposium organized by Technical Committee on Electromagnetic Theory in IEEJ, and The Technical Committee on Electromagnetic Theory in IEICE (The Institute of Electronics, Information and Communication Engineers). By reviewing the research topics in the symposium on EMT, we overlook the trend of research and development in electromagnetic theory.

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Establishment background and past research activities of the Technical Committee on Electromagnetic Compatibility (EMC), and activities of current technical subcommittees were reported.

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This is a review of the 46^th Symposium on Electrical and Electronic Insulating Materials and Applications in Systems (SEEIMAS) hosted by Technical Committee on Dielectrics and Electrical Insulation (TC-DEI) in IEEJ in order to overview the research trend in this specific field. The proceedings booklet in Japanese, with English abstract and figure captions for each presentation, will be available at the IEEJ office.

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In this report, recent activities were introduced of the Technical Committee on Plasma Science and Technology (TC-PST), IEEJ. The field of this committee includes researches and investigations on fundamentals and applications of various plasmas over wide ranges of their density, temperature, ionization degree such as nuclear fusion, plasma processing, and plasma chemistry. The TC-PST usually provides technical meetings on the above topics three or four times a year for scientists and engineers as well as students.

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In this paper we will introduce future technologies based on superconducting materials and devices, which will dramatically improve our social life in the future. It will be shown that what are the key superconducting technologies to realize the future technologies and in which status these technologies are.

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Resent topics on electrical-discharge-related technologies along with the research activities of the Technical Committee on Electrical Discharges (TC-ED) of IEEJ are briefly presented. Following the introduction of major research subjects and aims of TC-ED, and the recent activities of TC-ED, such as Technical Meetings, International Conferences, Investigation Committees are presented.

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The activities in magnetics committee in the institute of electrical engineers of Japan from April, 2012 to March, 2015 were summarized and reported. The main topics are applied magnetics technologies for high efficiency energy conversion in (1) dc-dc converter, (2) AC energy conversion, (3) Electro-mechanical energy conversion, (4) energy harvest, and (5) wireless power transfer, and (6) material technology.

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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.

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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 V_PF gives a significant deviation to a negative value (about -2 kV). However, by introducing SF₆ gas by 0.01 %, V_PF 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.

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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.

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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.

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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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Advanced oxidation process (AOP) with hydroxyl radicals (OH) is considered to be useful for sterilization; therefore, we have proposed an underwater plasma source with a porous glass membrane which functioned in bubble supply and the formation of micro-discharges. In this study, we first examined whether B. subtilis spores could be sterilized by the underwater plasma of which operating gas was argon. Next, similar experiment was conducted by using mannitol, and the numbers of colonies were compared. The obtained results showed that OH radicals generated at gas-liquid interface were responsible for the sterilization.

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