Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Volume 51, Issue 7
Displaying 1-5 of 5 articles from this issue
Original Paper
  • Kenji Suzuoka, Kazuhiko Katoh, Yasunori Tabira, Isamu Yashima, Motoy ...
    2014 Volume 51 Issue 7 Pages 500-507
    Published: July 10, 2014
    Released on J-STAGE: July 16, 2014
    JOURNAL FREE ACCESS
    The effect of synthesis temperature, pH condition, poly (vinyl alcohol) (PVA) addition and post synthesis treatment by H2O2 on the crystal phase and their electrical resistivity of the powder prepared through the hydrolysis reaction of tin chloride was investigated. A powder that has strong X-ray diffraction (XRD) pattern which corresponds to periodic layered structure and weak Sn3O2(OH)2 signals were obtained when the synthesis condition was controlled to 90℃ and pH=2.4~4.2 with PVA addition. The XRD peak intensity of the layered structure drastically reduced when PVA was not added or the synthesis temperature was below 50℃. It was also found that the Sn3O2(OH)2 phase could be transferred to SnO2-x when the additive content of H2O2 was nearly equivalent to Sn content. Among samples prepared under various pH values and temperatures, it was confirmed that the composite samples with stronger XRD diffraction signals from periodic layered structure possesses lower resistivity.
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  • Hiroshi Nagashima, Toshifumi Ishikura
    2014 Volume 51 Issue 7 Pages 508-518
    Published: July 10, 2014
    Released on J-STAGE: July 16, 2014
    JOURNAL FREE ACCESS
    The smooth transfer of solids from upper stage to lower stage through a downcomer is important for a stable operation of multi-stage spouted beds. Behavior of gas and solids in a moving bed downcomer, which is fitted with an orifice at the bottom, under negative pressure gradient has been investigated experimentally for a spouted bed operation, using Geldart D particles as bed materials. For this study, a downcomer has been installed in a one-stage spouted bed.
    As the results, the limits of operating conditions for a stable operation of a spouted bed with a downcomer were determined experimentally. The limits were influenced by the pressure drop across the spouted bed at the minimum spouting, length of the downcomer and the pressure gradient of the moving bed in the downcomer. Also, the range of the operating conditions for stable operation was extended with decreasing the bed depth of the spouted bed. In addition, based on experimental observation, the moving bed flow pattern changed from stable flow to intermittent flow as the gas pressure gradient in a moving bed downcomer increased and the fact could be explained by the solids discharge model which expresses the gas and the particles flow in the vicinity of the orifice.
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Review
  • Soshu Kirihara
    2014 Volume 51 Issue 7 Pages 519-526
    Published: July 10, 2014
    Released on J-STAGE: July 16, 2014
    JOURNAL RESTRICTED ACCESS
    Ceramics dendrites with spatially ordered micro cavities were successfully fabricated by three dimensional printing of stereolithography. Micro lattices pattern were propagated spatially in computer graphic. Ceramics nanoparticles dispersed photo sensitive liquid resins were spread on a grass substrate, and an ultra violet micro pattern was exposed to create cross sectional solid layer. The composite precursor formed by layer staking processes was dewaxed and sintered. Through this process, alumina photonic crystals with a diamond lattice structure were fabricated to control electromagnetic waves. Subsequently, solid electrolyte dendrites of yttria stabilized zirconia were fabricated for fuel cell miniaturizations.
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Review: Practical Environmental Technology Series
  • Tatsuya Oki
    2014 Volume 51 Issue 7 Pages 527-531
    Published: July 10, 2014
    Released on J-STAGE: July 16, 2014
    JOURNAL RESTRICTED ACCESS
    In the present study, physical separation devices were developed, based on the concept of 'strategic urban mining', in order to establish a new recycling system. First, the optimal separation pattern (system and condition) was selected from two quadrillion possibilities, by means of a simulator developed by the author, using an electronic devices database. Then, the selected system, including an automatic double-tube pneumatic separator, was developed, enabling the recovery of tantalum capacitors from waste printed circuit boards. The system represents the world's first successful means of commercialized tantalum recycling.
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Fundamentals of Powder Technology, 2nd Edition
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