RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 42 , Issue 12
Showing 1-10 articles out of 10 articles from the selected issue
  • Jun SATO, Toshihiro NAKAMURA
    1993 Volume 42 Issue 12 Pages 667-675
    Published: December 15, 1993
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    Leaching efficiency of radon from rock was observed with fresh and weathered granites. Portions of 500 g of samples were brought into contact with a 2l of water, respectively, for the period of 1 month or more. Radon was determined by the liquid scintillation counting The observed radon concentrations ranged from 0.3 to 1.0Bq/l. The leaching efficiencies from the fresh granite were around 2%, while those from the weathered around 6%, indicating that weathering accounts significantly for the enhancement of the leaching efficiency. Microscopic surface areas of the weathered granite were larger than that of the fresh one, and a positive, but not adequate, correlation between the leaching efficiency of radon and the microscopic surface area was observed.
    Depletion of 210Pb in the weathered granite was estimated to be attributed to the escape of radon into the atmosphere and the meteoric water from the outcrop during a long period of time, together with possible leaching of 210Pb itself.
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  • Akira YAMADERA, Eunju KIM, Takamoto MIYATA, Takashi NAKAMURA
    1993 Volume 42 Issue 12 Pages 676-682
    Published: December 15, 1993
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    An applicability of imaging plate to personal dosimeter was investigated by irradiating bremsstrahlung X rays and 60Co and 137Cs gamma rays on UR type imaging plate.
    For imaging plate attached with filters of 0.8 mm Sn, 0.4 mm Pb, and 1.8 mm plastic, the sensitivities were 212 PSL/mm2⋅mSv and 1 150 PSL/mm2⋅mSv for 60Co γ-ray and 140 keV X rays respectively. The linearity between 1 cm dose equivalent and PSL density was observed for very wide range of 1μSv to 10 mSv.
    It was found out that the imaging plate detector is useful as a new type wide range personal dosimeter.
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  • Hideo SUGIYAMA, Hiroshi TERADA, Kimio ISOMURA, Hirofumi TSUKADA, Hisas ...
    1993 Volume 42 Issue 12 Pages 683-690
    Published: December 15, 1993
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    Concentrations of 137Cs and stable Cs in wild mushrooms, cultivated mushrooms and those substrates were measured by gamma-ray spectrometry and neutron activation analysis.
    The average concentration of 137Cs in 80 wild mushrooms in Japan was 87.5Bq/kg (wet wt.), and concentration of 137Cs in mycorrhizal mushrooms was higher than that of saprophytic mushrooms. High concentrations of 137Cs were found in Pleurotus ostreatus (Fr.) Kummer Y-1, saprophytic mushrooms, cultivated in culture substrates containing high 137Cs. Clear correlations with 5% level of significance were found between wild mushroom-to-substrate ratios (wet/dry) of 137Cs concentration and those of stable Cs. Cultivated P. ostreatus-to-culture substrate ratios (wet/wet) of 137Cs concentration were stable in the order of 100 when the culture substrate was containing 10000Bq/kg (wet wt.) of 137Cs or 1000mg/kg (wet wt.) of stable Cs. The ratios of 137Cs concentration in cultivated mushrooms were about equal to those in wild mushrooms. Higher concentration of 137Cs in culture substrate after sampling P. ostreatus was observed at the upper layer where mycelium density was high.
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  • Shigeki NAGAMACHI, Hiroaki HOSHI, Seishi JINNOUCHI, Takashi OHNISHI, S ...
    1993 Volume 42 Issue 12 Pages 691-695
    Published: December 15, 1993
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    Regional cerebral blood flow (γ-CBF) of 10 pregnant women were quantified by 133Xe SPECT study with inhalation method before and after artificial abortion. During pregnancy, value of γ-CBF in each region except occipital lobe was significantly higher than that of the post abortion.
    Arterial blood gas was analyzed after SPECT procedure. PCO2 concentration increased significantly after artificial abortion.
    Although its mechanism is unknown, our preliminary work demonstrates that γ-CBF increased by pregnancy.
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  • Masatake HONDA
    1993 Volume 42 Issue 12 Pages 696-705
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Kenichi IJIRI
    1993 Volume 42 Issue 12 Pages 706-718
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1993 Volume 42 Issue 12 Pages 719-720
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1993 Volume 42 Issue 12 Pages 721-722
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese]
    1993 Volume 42 Issue 12 Pages 723-724
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese]
    1993 Volume 42 Issue 12 Pages 725-726
    Published: December 15, 1993
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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