RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 53 , Issue 2
Showing 1-7 articles out of 7 articles from the selected issue
  • Teruyuki HAKODA, Hiromi SUNAGA, Haruki TAKIZAWA, Koichi HIROTA, Takuji ...
    2004 Volume 53 Issue 2 Pages 59-69
    Published: February 15, 2004
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    Electron beams (EBs) at energies of 300 keV or lower have a potential to be utilized for purification of polluted waste gases. Such low-energy electrons are scattered in waste gases, and consequently in the state having nonuniform distribution of absorbed dose rate. Dosimetry in the gas is, therefore, necessary for designing the efficient treatment system of waste gas using EBs. In the present work, the dosimetry study for 300 keV electron beams was performed in ambient air of irradiation vessel (or in an irradiation vessel filled with ambient air) using two kinds of polymer film dosimeters for dose rate measurement, a prototype totalabsorption aluminum calorimeter for energy fluence measurement, and semi-empirical calculation using EDMULT code for depth-dose distribution estimation. The four results were compared concerning dose rate distribution or energy fluence as a function of depth in gas. As a result, the depth-dose rate distribution results obtained by the polymer film dosimeters were in good agreement with the EDMULT code calculation results considering electrons scattering in air. Energy fluence measured by a prototype calorimeter was 8-11 % lower than that estimated by both two different polymer film dosimeters. The difference is reasonably small, considering the experimental errors. These results demonstrate that polymer film dosimeters can be used for dosimetry in low-energy EB irradiation field when they are calibrated against this simple calorimeter under practical irradiation condition.
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  • Hideyuki SAKAI, Hiroshi IMAIZUMI, Tomohiro MURATA, Naoki KANO
    2004 Volume 53 Issue 2 Pages 71-75
    Published: February 15, 2004
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    In order to clarify the reactivity of normal chain diols, the hydrogen-isotope exchange reaction (T-for-H exchange reaction) between solid poly (vinyl alcohol) labeled with tritium and each normal chain diol dissolved in 1, 4-dioxane has been observed in the range of 30 to 70 °C (or 90 °C) . The observed data was analyzed with the A″-McKay plot method, and the following three matters are consequently found. (1) The greater the number of methylene groups in a diol is, the smaller is the reactivity of the diol. (2) A significant difference in the reactivity is found between diols having even number of methylene groups and those having odd number of ones, and the reactivity of the former is larger than that of the latter. (3) As to the ratio of the decrease of the reactivity of the diols having increasing number of methylene groups, the ratio of diols having even number of methylene groups is greater than the ratio of diols having odd number of ones.
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  • Tarek ELNIMR
    2004 Volume 53 Issue 2 Pages 77-84
    Published: February 15, 2004
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    Results of a survey of 222Rn concentration using direct measurement in 834 Cairo houses are reported. Although the study was not random with respect to population or land area, it was useful in identifying areas at risk and locating several houses having elevated indoor 222Rn air concentrations. Approximately 22% of the houses tested exceeded 37 Bq/m3, with 2.4% exceeding 70 Bq/m3. Several Cairo regions had larger fractions of houses exceeding 49 Bq/m3, such as Madinat Al-Muquattam (44%), Manshiyyat Nasir (31 %), Al-Abbasiyyah (29%) and Hadiak Al-Qubbah (17%), Elevated 222Rn concentrations were measured for a variety of house types having different construction materials. The effect of water was identified as a potentially significant source of 222Rn in Madinat Al-Muquattam homes. This survey is the first by this method in Egypt (a hot region) . The indoor concentration of 222Rn were measured in homes, in different locations within the flat, also the concentration of radon has been shown to decrease with the increase of the distance of room investigated from ground level with different heights in a tall building during the winter and summer seasons. Indoor radon concentration ranged from 6.32 Bq/m3 to 97.68 Bq/m3 and averaged value with standard deviation was 21.77±7.85 Bq/m3. The concentrations of radon in the unoccupied flats were observed to be considerably higher than those occupied one.
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  • Tadayuki TAKAHASHI
    2004 Volume 53 Issue 2 Pages 85-94
    Published: February 15, 2004
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Masami ANDO, Hiroshi SUGIYAMA, Dingchang XIAN
    2004 Volume 53 Issue 2 Pages 95-105
    Published: February 15, 2004
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Yoshio HINO
    2004 Volume 53 Issue 2 Pages 106
    Published: February 15, 2004
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Yoshio HINO, Nobuhisa TAKATA
    2004 Volume 53 Issue 2 Pages 107-113
    Published: February 15, 2004
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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