IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 140 , Issue 4
Showing 1-20 articles out of 20 articles from the selected issue
Special Issue on 2019 Annual Conference of Fundamentals and Materials Society
Special Issue Paper
  • Yu Ohtaki, Masashi Ohchi
    2020 Volume 140 Issue 4 Pages 171-178
    Published: April 01, 2020
    Released: April 01, 2020
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    In this research, we have been developed teaching materials for electromagnetics that demonstrate theories using real-world actual applications (capacitors, coils, piezoelectric elements, Wireless Power Transfer(WPT), WiFi, direct-current motor, etc.) presented as animations and video data via Web services. Hypertext Markup Language (HTML) and JavaScript were used to create the Web services for teaching materials. Recently, the lack of academic ability of Japanese engineering course students has become a large social problem at Japanese higher education. In particular, in the field of electrical engineering education, the visualization and mathematical abilities of students have been declining remarkably. In addition, today's teaching materials for educational institutions in Japan tend to reply primarily on rote learning. However, we consider that rote learning is not the primary method for university education. We tested our new developed materials on students learning motivation of electromagnetics and evaluated their effectiveness with some questionnaires. It was clear that the new teaching method has effectiveness for increasing learning motivation of Electromagnetics.

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  • Hiroshi Yamauchi, Yugo Okada, Takashi Tadokoro, Kazuhiro Kudo
    2020 Volume 140 Issue 4 Pages 179-185
    Published: April 01, 2020
    Released: April 01, 2020
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    The electrospray deposition (ESD) method is simple solution process used solution spray formed by electric field between the solution and conductive substrate or insulated electrode. In this study, we fabricated thin films based on 6,13-bis (triisopropyl-silylethynyl) pentacene formed by ESD method. An electric field applied between the nozzle and selected patterned electrodes on the substrate. Moreover, a new droplet size selected vertical ESD method has been proposed. This vertical ESD method allows selecting droplet size by weight itself using this system with horizontal injection on a vertical substrate. We fabricated OFET using this method and measured static electrical characteristics. These results demonstrate that the solution on the selected droplet size by the position of substrate set on vertical.

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  • Shumpei Ogawa, Tatsuya Kuroda, Yasuyuki Katou, Hironori Haga, Hiroki I ...
    2020 Volume 140 Issue 4 Pages 186-192
    Published: April 01, 2020
    Released: April 01, 2020
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    In the improving the characteristics of gate insulating films, the SiN thin films by microwave plasma can obtain a low interface state density. In this investigation, SiO2 thin films on Si substrate were fabricated by microwave plasma in various conditions and evaluated

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  • Takuma Abe, Syohei Oba, Fumihiro Sato, Satoshi Miyahara, Hidetoshi Mat ...
    2020 Volume 140 Issue 4 Pages 193-200
    Published: April 01, 2020
    Released: April 01, 2020
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    The policy of converting vehicles to EV in Europe by 2040 is now spreading around the world. However, in order to promote the EV shift, several problems must be solved. As a major problem, there is a problem of cruising distance caused by the battery capacity and a problem of charging time in the current power supply system. In this study, we propose noncontact power feeding during running as a solution to those problems. It solves the problem of cruising distance and charging time by supplying electricity not only during stoppage but also during driving. In this paper, we proposed an 8 booster coil configuration as a countermeasure against the leakage magnetic field that is a problem in non-contact power feeding system during EV driving. In addition, a small model of 8 booster coils was created and its validity was shown. Using the created scale model, we compared the leakage magnetic field of the existing system and showed its usefulness.

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  • Masatoshi Sekiguchi, Shumpei Ogawa, Tatsuya Kuroda, Hironori Haga, Tom ...
    2020 Volume 140 Issue 4 Pages 201-206
    Published: April 01, 2020
    Released: April 01, 2020
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    In this paper, a colloidal solution of copper nanoparticles was prepared from a Cu ion aqueous solution with the protein casein surfactant by a liquid phase reduction method at low temperature below 353K. For the casein concentration ranging from 6g/L to 75g/L, formation of copper nanoparticle colloid were observed. As a result, the peak was observed at the ranging of 450 to 650 nm corresponding to the copper nanoparticle colloid plasmon absorption. As the surfactant concentration increases, the absorption spectrum tends to blue shift and the particle diameter decreases. Thus, it indicated that the optical property and particle diameter of copper nanoparticle colloidal solution will be controlled by the protein casein surfactant concentration.

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Paper
  • Takeo Shiina, Kenichi Yamazaki
    2020 Volume 140 Issue 4 Pages 207-216
    Published: April 01, 2020
    Released: April 01, 2020
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    We assessed human exposure to radiofrequency (RF) electromagnetic fields used for a wireless communication system installed on a smart meter for communication in the 920 MHz band. In an exposure guideline, the specific absorption rate (SAR) is used as a measure of the thermal effects of human exposure to electromagnetic fields. Although the low-power wireless communication device used for the smart meter inherently complies with the exposure guideline, the assessment of the RF electromagnetic field exposure is useful to deepen our understanding of human safety. For the exposure assessment, firstly, a computational smart meter model was constructed and validated by comparison with the measured data of electric fields around an actual smart meter. Using the computational smart meter model, we calculated the SAR in the head of an anatomical human model that was located very close to the smart meter. The maximum SAR in the head was obtained when the antenna was placed in front of a human eye, which was calculated to be 10.3 mW/kg for an input power of 20 mW. It was shown that the maximum SAR was 200 times smaller than the basic restriction level in the exposure guideline.

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  • Yoshihide Mukoyama, Haruka Kansa, Kaya Nagasawa, Ken Kansa
    2020 Volume 140 Issue 4 Pages 217-223
    Published: April 01, 2020
    Released: April 01, 2020
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    In this paper, we have developed a new method for detoxifying PCBs-use equipment (We used a fluorescent ballast capacitor). In the conventional detoxification treatment, the PCBs-use equipment is finely crushed by manual work etc. as a pretreatment. However, in this study, it was made possible to perform detoxification with pre-treatment by drilling several holes in the PCBs-use equipment. As a result, a significant reduction in the pretreatment process was realized. We focused that the PCBs-use equipment was made of a metal container that can be induction-heated. PCBs-use equipment is installed in a sealed quartz glass tube, and induction heating is performed by a coil outside the glass tube to heat it to about 420 [°C]. As a result, the PCBs inside the equipment was sucked out of the container and vaporized. The vaporized PCBs was detoxified by the Vacuum Induction Heating Decomposition System (previous paper) directly connected to this PCBs-use equipment heating system. By this method, a new technology was established to simultaneously process PCBs-use equipment and separated PCBs.

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  • Makito Osawa, Yuki Kajiuchi, Kyouhei Sawada, Kazumasa Takahashi, Toru ...
    2020 Volume 140 Issue 4 Pages 224-229
    Published: April 01, 2020
    Released: April 01, 2020
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    To improve the acceleration length in laser plasma acceleration, we investigate the discharge plasma waveguide with a magnetic field. The discharge circuit consists of two pulsed-power circuits for preionization and main discharge. Discharges were repeated through the circuit using high-power semiconductor switches. Laser propagation characteristics of discharge plasma waveguide with the external magnetic field was observed. The results show that the reproducibility of waveguide with the external magnetic field is relatively high compared to that without magnetic field. The laser intensity gradually decreases with the strength of external magnetic field. These results suggest that the electron density profile is possible to control using the discharge plasma waveguide with an external magnetic field.

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  • Tomo Tadokoro, Masashi Kotari, Toshiya Ohtaka, Mikimasa Iwata, Yasuhir ...
    2020 Volume 140 Issue 4 Pages 230-240
    Published: April 01, 2020
    Released: April 01, 2020
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    When a fault arc occurs in oil-filled electric power equipment, it generates a flammable pyrolysis bubble. A dynamic pressure rise with the generation of the bubble, may lead to blowout of the oil and a high-temperature flammable gas. This paper presents a numerical model for the analysis of bubble behavior and pressure rise due to the arc in a closed vessel containing air and oil. The model is based on the Rayleigh-Plesset equation which expresses single bubble behavior in liquid to a driving pressure field with consideration of the evaporation/condensation phenomena of the bubble surface and the oil flux. Furthermore, the authors append physical properties of gas and effects of arc energy into the bubble based on measurement and calculation results. The calculated pressure magnitude and frequency of oscillation are similar to the experimental results. The results suggest that the numerical model covered important factors of the bubble behavior and pressure rise phenomena.

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  • Kotaro Ohzuno, Kazuma Abe, Masahiro Kozako, Masayuki Hikita, Nobuhito ...
    2020 Volume 140 Issue 4 Pages 241-246
    Published: April 01, 2020
    Released: April 01, 2020
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    The authors had reported various characteristics of hydrocarbon-based thermosetting resins (HTR) and showed the superiority to conventional epoxy resins. In order to suppress the coefficient of linear expansion, it is necessary to increase the content of inorganic filler, however we had also reported that the increasing filler content caused a decrease in the breakdown strength (Eb). Some of author had reported that Eb of epoxy resin filled with fullerene was increased by about 30% than that of unfilled epoxy resin. In this paper, we describe the results of attempts to improve Eb of HTR by adding fullerene.

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  • Kento Yasuda, Tomohiro Ito, Yutaka Yoshida, Yusuke Ichino, Yuji Tsuchi ...
    2020 Volume 140 Issue 4 Pages 247-252
    Published: April 01, 2020
    Released: April 01, 2020
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    It is necessary to increase the deposition rate in order to reduce the production cost of REBCO coated conductors. The Vapor-Liquid-Solid (VLS) growth technique is a method capable of fabricating a thin film with high-deposition rate and good crystalline orientation owing to a crystal growth through a liquid phase. Increase of oxygen partial pressure (PO2) during the deposition is effective on increase of the deposition rate. However, since melting point of the liquid phase becomes higher with increasing PO2, it is difficult to fabricate a film at the high PO2. In this study, we tried to lower melting point of the liquid phase by adding Ag in the VLS growth technique. By adding Ag to the liquid phase, VLS growth mode in a stable liquid phase became possible even in the high PO2. As a result, we achieved fabrication of a film at a high deposition rate of 26.0 nm/sec with good crystalline orientation and the critical current density (Jc) of the film was improved.

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  • Takenori Nitta, Takayuki Usui, Hiroaki Iino, Akira Ohno, Jun-ichi Hann ...
    2020 Volume 140 Issue 4 Pages 253-258
    Published: April 01, 2020
    Released: April 01, 2020
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    We have designed and synthesized a new liquid crystalline phenylbenzothienobenzothiphene derivative, Ph-BTBT-4S-3, in order to investigate the carrier transport properties in highly ordered smectic liquid crystal phase at a wide temperature range lower than room temperature enough to analyze them. Ph-BTBT-4S-3 exhibits smectic E (SmE) phase, which is the one of highly ordered smectic liquid crystal phases, at the wide temperature range from 200°C to under -130°C. Thanks to its wide temperature range of SmE phase, we could reveal the carrier transport properties in the low temperature range, which were well explained on the basis of Gaussian disorder model having a Gaussian width, s, of 87 meV, which was larger than those of typical non-polar liquid crystals of 40 to 60 meV and was attributed to a thioether group in the side chain.

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