IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 129, Issue 1
Displaying 1-7 of 7 articles from this issue
Review
  • —EMC emission and TEMPEST Security—
    Hidenori Sekiguchi, Shinji Seto
    2009 Volume 129 Issue 1 Pages 1-6
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    Generally, active electronic devices emit slightly unintentional electromagnetic noise. From long ago, electromagnetic emission levels have been regulated from the aspect of electromagnetic compatibility (EMC). Also, it has been known the electromagnetic emissions have been generated from the ON/OFF of signals in the device. Recently, it becomes a topic of conversation on the information security that the ON/OFF on a desired signal in the device can be reproduced or guessed by receiving the electromagnetic emission. For an example, a display image on a personal computer (PC) can be reconstructed by receiving and analyzing the electromagnetic emission. In sum, this fact makes known information leakage due to electromagnetic emission. “TEMPEST" that has been known as a code name originated in the U. S. Department of Defense is to prevent the information leakage caused by electromagnetic emissions. This paper reports the brief summary of the information security due to electromagnetic emissions from information technology equipments.
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  • Takao Namihira, Douyan Wang, Takao Matsumoto, Sho Okada, Hidenori Akiy ...
    2009 Volume 129 Issue 1 Pages 7-14
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    During the decades, the developments of high power semiconductor switch, magnetic core and etc have allowed us to manufacture the pulsed power source having higher energy transfer efficiency. As the results, the pulsed discharge has been recognized as one of the promised non-thermal plasma to practical use. In this paper, a generation process, electron energy, impedance and a temperature of the pulsed discharge plasma would be explained. In addition, a nano-seconds pulsed discharge plasma would be introduced as the non-thermal plasma processing giving us the highest energy efficiency and be demonstrated it.
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  • Koichi Yasuoka
    2009 Volume 129 Issue 1 Pages 15-22
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    Various types of discharge plasmas in water or along water surface have been studied since 1973 due to the importance of plasma-chemical reactions utilized in the applications of water purification, deactivating microorganisms, material synthesis, and so on. This paper reviews the history and the current status of water-plasma studies, especially for water purification and wastewater treatment.
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Paper
  • Tomio Go, Kyousuke Kanesawa, Nobuyuki Yamazaki, Seiji Mukaigawa, Koich ...
    2009 Volume 129 Issue 1 Pages 23-29
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    Characteristics of inductive energy storage system pulsed power generator with semiconductor opening switch (SOS) diodes are investigated with focusing on an energy transfer efficiency from the generator to the resistive load. Fast recovery diodes VMI K100UF were used as SOS and were connected in series and/or in parallel to realize a large current and a high output voltage. The output voltage increases with increasing circuit inductance L and/or primary capacitor capacitance C. The reverse pumping time also increases with LC value and is saturated to 100 ns at LC=50×10-15 HF. The pulse width of the output voltage increases gradually with increasing value of the LC multiplication. The energy transfer efficiency of the generator to the resistive load has a maximum value of 71% at C=4nF and L=12.6μH when the load resistance is 122 Ω. This value is almost two times larger than 56 Ω of the surge impedance Zs=√L/C and much smaller than impedance of the SOS diodes after interrupting the circuit current. The maximum energy transfer efficiency decreases from 71 to 32% with decreasing LC value from 50×10-15 to 1.2×10-15 HF.
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  • Mrityunjai Kumar Singh, Lei Xu, Akihisa Ogino, Masaaki Nagatsu
    2009 Volume 129 Issue 1 Pages 30-34
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    In this study we investigated the low temperature surface-wave plasma sterilization of directly and indirectly exposed Geobacillus stearothermophilus spores with a large-volume microwave plasma device. The air-simulated gas mixture was used to produce the plasma. The water vapor addition to the gas mixture improved the sterilization efficiency significantly. The effect of ultraviolet photons produced along with plasma to inactivate the spores was studied using a separate chamber, which was evacuated to less than one mTorr and was observed that spores were sterilized within 60 min. The scanning electron microscopy images revealed no significant changes in the actual size of the spores with that of untreated spores despite the survival curve shown that the spores were inactivated.
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  • Nobuaki Ikuta, Akihide Takeda
    2009 Volume 129 Issue 1 Pages 35-40
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    This paper gives a self-evaluation of the Flight Time Integral (FTI) method for solving the Boltzmann equation. The FTI method is featured by taking the flow-in rate distribution of particles as the principal unknown function in place of the velocity distribution. The flow-in rate distribution uniquely converges into a steady form governed by the loop velocity dispersion functions. It assures the continuity of particle flow and establishes the equilibrium velocity distribution for the flying particles.
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  • Junji Mizokami, Hikaru Okuno
    2009 Volume 129 Issue 1 Pages 41-46
    Published: January 01, 2009
    Released on J-STAGE: January 01, 2009
    JOURNAL FREE ACCESS
    Chaos and control of Bloch wall motion is investigated. As for frequency and drive force coefficient, the movement of the magnetic domain wall becomes unstable in the vicinity of 2MHz and 0.2TA/m in this thesis. It is shown that the unstable magnetic domain-wall motion is stabilized and its energy loss is decreased by using the nonlinear feedback control.
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