RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 55 , Issue 11
Showing 1-6 articles out of 6 articles from the selected issue
  • Koji OGAWA, Kazushige YODA, Shigeru IWANAMI, Tadashi NOZAKI
    2006 Volume 55 Issue 11 Pages 665-669
    Published: November 15, 2006
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    It has been proved that 99mTc can be obtained from the generator in a solution free from evaporation residue by the following procedure: (1) elution with aqueous NaNO2 solution instead of physiological saline, (2) leading of the effluent into a column of cation exchange resin in NH4- form for Na+ to NH4+ exchange, (3) collection of 99mTc-containing portion of the effluent, and its heating for complete decomposition of NH4NO2 into N2 and H2O. The resultant solution can be evaporated to dryness, leaving the 99mTc without any visible residue. Necessity and usefulness of this procedure are discussed and exemplified by the preparation of 99mTc-labeled carbon aerosols.
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  • Toshiya YAMANO, Yusuke KOBAYASHI, Masaki HARA, Yoshiyuki SHIRAKAWA
    2006 Volume 55 Issue 11 Pages 671-678
    Published: November 15, 2006
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    A conventional monitoring post is the equipment useful for check of leakage of radiation or radioactive substance from a nuclear facility. This device regularly offers the data of radiation dose rate (μSv/h, nGy/h) and counting rate (cpm, cps) . We have developed a new one which can also measure an incoming direction of gamma ray flux for early discovery of a nuclear accident or adequate interpretation of abnormal data caused from other reasons. This detector is composed of three kinds of scintillators, NaI (Tl), CsI (Tl), and BGO with a photomultiplier tube. The measurement principle is based on the relative change of photoelectric peak counts made by each scintillator depending on the incident direction. This principle in the middle energy range has already been proven by the experiment using 137Cs (662 keV) . Then, here the characteristics of the directional sensitivity for low energy (241Am, 60 keV), middle energy (133Ba, 356 keV) and high energy gamma rays (60Co, 1250 keV) have been simulated by using Electron Gamma Shower Program (EGS4), and evaluated by experiments. As a result, this detector has been confirmed to measure the incident direction in a wide energy range.
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  • Yukinori NARAZAKI, Yumi YASUOKA, Masaki SHINOGI, Tetsuo ISHIKAWA, Shin ...
    2006 Volume 55 Issue 11 Pages 679-686
    Published: November 15, 2006
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    High radon concentrations have been found in potable water originating from groundwater. Radon in potable water presents a possible health risk to humans. For the purpose of reducing the health risk due to radon in water, the following methods were investigated in order to remove radon from potable water: the use of softeners and purifiers, heating, aeration and leaving water standing in bottles. (1) Domestic softeners and purifiers : When grainy activated carbon is used as filtration material, the increase of radon removal ratio is certain, if for a short term, but the removal ratio is lowered with increase of water quantity to be treated. (2) Heating : The radon concentration in water decreased depending on the water temperature. Radon was almost completely removed when the water was thoroughly boiled. (3) Aeration : Radon was efficiently removed when water was aerated. The removal ratio of radon increased exponentially as the volume of aeration increased. (4) Leaving water standing in bottles : The concentration of radon in bottled water where the lid was not closed decreased gradually. The removal ratio of radon depended on the shape, depth of the bottle and the contact area between the water and air. The water-air interface was intensely disturbed by boiling, aeration, and bubbling, and these methods demonstrated an effective removal of radon.
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  • Atsushi SAKUMA, Miho NAKAYAMA
    2006 Volume 55 Issue 11 Pages 687-690
    Published: November 15, 2006
    Released: March 01, 2011
    JOURNALS FREE ACCESS
    Radiation hormesis was studied for salad rocket plant (Eruca vesicaria sp.sativa), using different energies of X-ray (100 kV and 10 MV) . To get the optimum dose for plant to provide the highest growth, the dose for the seeds was changed from 0 to 3 000 mGy using 100 kV of X-ray. The highest growth of the plant was found for the dose of 600 mGy. When the seeds were irradiated to 600 mGy with 100 kV and 10 MV X-rays, in both cases, the growth of the irradiated seeds was higher than those without irradiation, where P-values were 0.0112 and 0.0214, respectively. In the case of 600 mGy irradiation, there was not any significant change in the plant growth between the seeds irradiated with 10 MV and 100 kV X-ray (P=0.862) .
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  • Kazuhisa KOMURA
    2006 Volume 55 Issue 11 Pages 691-697
    Published: November 15, 2006
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Technical Committee of Ultralow Level
    2006 Volume 55 Issue 11 Pages 699-707
    Published: November 15, 2006
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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