IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 131, Issue 12
Displaying 1-20 of 20 articles from this issue
Special Issue on Space and Earth Environmental Measurement from the International Space Station
Special Issue Paper
  • Takahiro Obara
    2011 Volume 131 Issue 12 Pages 965-970
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Space Environment Data Acquisition equipment with attached payload (SEDA-AP) which was mounted on the Exposed Facility (EF) of the Japanese Experiment Module (JEM, also known as “Kibo”) on the International Space Station (ISS) started to measure the space environment along the orbit of ISS from Sept. 2009. This paper reports the mission objectives, instrumentation, and current status of SEDA-AP.
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  • —Concept and Overview—
    Tomoo Ushio, Mitsuteru Sato, Takeshi Morimoto, Makoto Suzuki, Hiroshi ...
    2011 Volume 131 Issue 12 Pages 971-976
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Global Lightning and sprIte MeasurementS (GLIMS) is a mission on the International Space Station (ISS) to detect and locate optical transient luminous events (TLEs) and associated lightning simultaneously from the non-sun-synchronous orbit. It is scheduled to be launched from Japan in January, 2012 as part of the multi-mission consolidated equipment on the Japanese Exposure Module (JEM). Our mission's goals are (1) to detect and locate lightning and sprites within storm scale resolution over a large region of the Earth's surface along the orbital track of the ISS without any bias, (2) to clarify the mechanism by which sprites are generated, and (3) to identify the conditions under which TLEs occur. To achieve these goals, two CMOS cameras, six Photometers, a VLF receiver and VHF interferometer with two antennas are installed at the bottom of the module to observe the TLEs, as well as causative lightning discharges at nadir direction during day and night time. Though the luminous events' so-called sprites, elves and jets have been investigated by numerous researchers all over the world based mainly on ground observations, some important problems have not been fully understood yet. These include the generation mechanisms of columniform fine structures and horizontal offset of some sprites from the parent lightning discharges. In the JEM-GLIMS mission, observations from our synchronized sensors will shed light on the unsolved problems mentioned above regarding TLEs and causative lightning discharges. In this presentation scientific background, instrumentation, and project summaries are given.
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  • —Gradual Approach to Realize Space-borne VHF Broadband Digital Interferometer—
    Takeshi Morimoto, Hiroshi Kikuchi, Mitsuteru Sato, Makoto Suzuki, Atsu ...
    2011 Volume 131 Issue 12 Pages 977-982
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Global Lightning and sprIte MeaSurements (GLIMS) mission is scheduled on Exposed Facility of Japanese Experiment Module (JEM-EF) of the International Space Station (ISS). This paper introduced an electromagnetic (EM) payload of JEM-GLIMS mission, very high frequency (VHF) broadband digital InTerFerometer (VITF). VITF consists of a pair of VHF broadband antennas and electronics to record EM waveforms from lightning discharges. It is designed to estimate the direction-of-arrival with about 10 km resolution that is equivalent to the scale of a thundercloud. It means that VITF is able to monitor thunderclouds with lightning activities globally. Comprehensive observations with the optical payloads of JEM-GLIMS mission for lightning activities and related transient luminous events (TLEs) are expected to give us many scientific impacts to the field. The developments of VITF are based on the heritage of VHF sensor on Maido-1 satellite.
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  • Takeshi Sakanoi, Yusuke Akiya, Atsushi Yamazaki, Yuichi Otsuka, Akinor ...
    2011 Volume 131 Issue 12 Pages 983-988
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    We present the scientific targets, instrumental design, principle of measurement, and development of the Visible and near-Infrared Spectral Imager (VISI) which will be launched onto International Space Station (ISS) in January 2012. VISI is equipped with fast optics including a grism, and a high-sensitivity CCD to obtain airglow emissions at wavelengths of O (630 nm), OH Meinel band (650 nm) and O2 (0-0) atmospheric band (762 nm). VISI has two field-of-views (FOVs), 45 degrees forward and 45 degrees backward to nadir, to subtract background contaminations. The data acquisition of VISI will be continuously performed with short exposure cycle less than several seconds when ISS is orbiting in the night side of the earth, and then provide the seamless line scanning images of the airglows with a spatial resolution better than 50 km. After manufacturing VISI, we checked its performance though optical and electric function tests as well as environmental tests that are necessary to be launched.
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  • Masayuki Kikuchi, Mitsuteru Sato, Atsushi Yamazaki, Makoto Suzuki, Tom ...
    2011 Volume 131 Issue 12 Pages 989-993
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    A project to observe lightning and sprites from the International Space Station (ISS), with altitude of 407 km and inclination of 51.6°, is planned for 2012. GLIMS (global lightning and sprite measurements) is an instrument designed for this project, and it includes a CMOS camera, photomultipliers, a VLF receiver, and a VHF interferometer. This is the first project for simultaneous measurements of lightning, sprites, and radiowaves from lightning simultaneously. The sensors used for GLIMS were developed based on previous satellite projects. However, for this project, the sensors used needed to be synchronized, and controlled through the Japanese experiment module (JEM) interface. A science data-handling unit (SHU) was newly developed for this purpose; it included a function for suppressing data traffic using a high-speed lossless compression code (HIREW).
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  • Mitsuteru Sato, Yukihiro Takahashi, Masayuki Kikuchi, Makoto Suzuki, A ...
    2011 Volume 131 Issue 12 Pages 994-999
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Lightning and Sprite Imager (LSI) is a science instrument of JEM-GLIMS to capture images of lightning discharges and upper atmospheric transient luminous events (TLEs), such as sprites, elves and blue jets. LSI consists of two CMOS cameras; one is a wide-band camera named LSI-1 that is equipped with an optical filter whose pass-band ranges from 765nm to 830nm, the other is a narrow-band camera named LSI-2 that is equipped with an optical filter whose transmittance centers at the wavelength of 762nm and has band width of 14nm. From the comparison of LSI-1 images with LSI-2 images the time evolution and spatial distribution of lightning discharges and TLEs can be identified. Since the telemetry speed provided for JEM-GLIMS is limited, LSI images will be acquired not continuously but intermittently according to the onboard event trigger logic. This trigger logic selects only the transient optical flashes caused by lightning discharges or TLEs effectively.
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  • Mitsuteru Sato, Yukihiro Takahashi, Makoto Suzuki, Atsushi Yamazaki, T ...
    2011 Volume 131 Issue 12 Pages 1000-1005
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Six-channel spectrophotometers (PH) are the science instruments of JEM-GLIMS to measure absolute intensity of the emission originated from lightning discharges and upper atmospheric transient luminous events (TLEs). PH unit-1 (PH-U1) consists of four spectrophotometer channels named from PH1 to PH4, while PH unit-2 (PH-U2) two spectrophotometer channels named PH5 and PH6. Optical filters of these spectrophotometers are selected to detect TLE emission lines of N2 1PG, N2 2PG, N2+ 1NG, and N2 LBH. Since the bandwidth of the optical filter of PH2, 3, 5, and 6 is 10 nm and since PH1 measures NUV emission, photomultiplier tubes with high-voltage converters are used as a photon detector. To the contrary, PH4 uses a photodiode as a photon detector because the pass-band of the optical filter is enough wide to detect transient optical emission. Though PH does not equip spatial resolution, it can acquire light curve data with a high time resolution of 50 μs with a 12-bit resolution. Thus, the combinational analysis of PH data and Lightning and Sprite Imager (LSI) data, it is possible to clarify the relationship between TLEs and their parent lightning discharges, the occurrence condition of TLEs, and the energy of the electrons which excite TLE emission.
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  • Ichiro Yoshikawa, Tatsuro Homma, Kouichi Sakai, Go Murakami, Kazuo Yos ...
    2011 Volume 131 Issue 12 Pages 1006-1010
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    At the end of previous century, we succeeded to image the Earth's plasmasphere from the space by EUV spectral range. Then, spacecraft missions were carried out to image the terrestrial EUV emissions. The extreme ultraviolet imagers (EUVIs) on the international space station (ISS) will be launched in 2012. At the altitude of approximately 400 km, two telescopes direct toward the Earth's limb to look the ionosphere and plasmasphere from the inside-out. One telescope detects the terrestrial EUV emission at O+ (83.4 nm), and the other is He+ (30.4 nm). These two EUV emissions are solar-scattered by ionized oxygen and helium, respectively. The maximum spatial and time resolutions are 0.1 degree and 1 minute, respectively. Our observation methods will become standard to probe the Earth's upper atmosphere.
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Paper
  • Tetsuo Fukuchi, Tatsuo Shiina
    2011 Volume 131 Issue 12 Pages 1011-1016
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    An ultraviolet absorption spectroscopy device using light-emitting diodes (LEDs) as the light source was constructed. The measurement cell, light source, transmitting and receiving optics were installed on a breadboard of 30 cm × 30 cm. A measurement optical path length of 1 m was made possible by multireflection optics. The device can mount two LEDs in tandem, and the transmitted light is coupled to an optical fiber, which is connected to a compact spectrometer. Here, two LEDs of center wavelengths 280 nm and 295 nm were used to provide an emission spectrum which covered the peak region of the absorption spectrum of SO2. Experiments confirmed the linearity of the absorption coefficient measured by the device for SO2 concentrations in the range 16-800 ppm.
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  • Norihito Yanagita, Tatsuro Kato, Toshiaki Rokunohe, Takeshi Iwata, Hir ...
    2011 Volume 131 Issue 12 Pages 1017-1023
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Insulation design with discharge simulation based on physics phenomena is used in designing electrical instruments to facilitate their miniaturization and get high insulation reliability. We developed a partial discharge inception calculation model in a non-uniform air gap based on theories of electron avalanche and streamer phenomena. The calculated and experimental PDIVs were compared under a constant humidity condition, and we confirmed these agreed well with each other within about 10 %. Furthermore, we built a relationship between negative ions and humidity into the model, and confirmed the calculated and experimental PDIVs (Partial Discharge Inception Voltage) agreed within about 15 %. Therefore, this model was judged as a method for predicting changes in PDIV when the humidity changes.
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  • Yoshikuni Hirano, Keiji Ishii, Takenobu Usui, Yukio Murakami, Masahiko ...
    2011 Volume 131 Issue 12 Pages 1024-1030
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    We propose a new arrayed plasma simulation method in which discharge and circuit simulation are coupled to investigate the display characteristics of a plasma display panel (PDP). In the new method, the PDP is described an equivalent circuit model as a set of impedance models for electrodes and capacitance models for the panel, in which a discharge simulation evaluates the discharge currents of the PDP cells. Further, the new method estimates variability of the applied voltage waveform distortion and then the luminescence uniformity of the high resolution PDP. In this paper, we describe the new method and its effectiveness.
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  • Amir Izzani Mohamed, Michiyasu Morimoto, Takashi Akagi, Kazunori Kadow ...
    2011 Volume 131 Issue 12 Pages 1031-1036
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Positive charges packet is frozen inside the bulk of a low-density polyethylene(LDPE) film after subjecting to 1.5MV/cm of DC electric field. In this paper, simultaneous measurements of space charge dynamics and external current through LDPE are carried out by using a pulsed electroacoustic (PEA) method in order to understand this phenomenon. By carrying these measurements simultaneously, we can understand further about the physical process during the freezing period. External current shows an increase as the electric field is up to 5MV/cm though the velocity of the charges decreases. This implies that, beside the charges packet, there are also moving charges in the freezing region. 3 type of samples, LDPE neat sample, LDPE with paraffin sample and LDPE with polyisobutylene sample are prepared. In comparison with LDPE neat sample, the LDPE with paraffin sample tends to suppress the positive charges penetration hence showing a lower current flow. On the other hand, LDPE with polyisobutylene sample shows a relatively fast positive charges packet penetration and a higher current flow.
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  • Atsushi Shimizu, Yasuhiro Hattori
    2011 Volume 131 Issue 12 Pages 1037-1040
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    A copper and gallium alloy is easily produced through contact of liquid gallium and copper metal. A combination of CuGa2 and silver was investigated as a new electrical contact. The resistivity of the alloy is 1.1×10-5 Ωcm at room temperature. Oxide film on the alloy was suppressed during heat treatment in air. Due to mutual immiscibility without oxygen, adhesive wear of the silver during abrasion against the alloy was reduced less than that against silver itself. With exclusion of oxygen using a lubricant, the combination is a prospect for electrical contacts.
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  • Mayumi Hyuga, Toshikatsu Tanaka, Yoshimichi Ohki, Takahiro Imai, Miyuk ...
    2011 Volume 131 Issue 12 Pages 1041-1047
    Published: December 01, 2011
    Released on J-STAGE: December 01, 2011
    JOURNAL FREE ACCESS
    Effects of addition of nano-sized and micro-sized fillers into epoxy resin on its mechanical and dielectric relaxation phenomena were examined. The glass transition temperature (Tg) decreases when a small content of nanoclay modified by octadecylamine was added, while the decrease in Tg is suppressed when the nanoclay was modified by dimethyldodecylamine. On the other hand, Tg increases when microsilica was added abundantly. At temperatures above Tg, both mechanical and dielectric relaxations are accelerated in samples with octadecylamine-modified nanoclay, while the acceleration does not occur in samples with nanoclay modified by dimethyldodecylamine. Both relaxations are restricted in composites with abundant microsilica. Therefore, co-addition of dimethyldodecylamine-modified nanoclay and abundant microsilica is adequate in order to make an epoxy resin composite with a high Tg and low dielectric loss.
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