RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 13 , Issue 6
Showing 1-14 articles out of 14 articles from the selected issue
  • C. TAKEI
    1964 Volume 13 Issue 6 Pages 435-438
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    Since beta-ray fluorescence of anthracene crystal is strong, one can determine activity of the beta-rays by leading the fluorescence through a light-pipe to photomultiplier. Previously the author measured beta-activity of the radio-phosphorus deposited in a human body cavity which is accessible to an acryl light-pipe. The present paper deals with fundamental investigations about effects of the length and diameter of light-pipe on counting-efficiency and pulseheight distributions.
    Counting-efficiency is as large as 80±5 % even when the acryl light-pipe is as long as 30 em. Pulse-height analysis of the fluorescence which reaches photomultiplier through light-pipe shows that with increasing length and decreasing diameter of the light-pipe, the amount of higher pulses decreases and that of lower pulses increases.
    Lowering of pulse-heights of the fluorescence by transmission through light-pipe is apparently due to incomplete smoothness of the totally reflecting surface of the light-pipe used.
    Acryl light-pipe dose not absorb lights of specific wave-length. As compared with acryl rod a glass fiber would be better suited for light-pipe because of the latter's flexibility and smoothness of totally reflecting surface.
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  • Daisaku MIYATANI, Toyosaburo TAKEUCHI
    1964 Volume 13 Issue 6 Pages 439-443
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The relation between the bond strength of adsorbed hydrogen and the reactivity of the hydrogen for ethylene was investigated by using tritium as tracer. Hydrogen (or tritium) was adsorbed first on a powdered nickel at -78°C and tritium (or hydrogen) was subsequently adsorbed, then ethylene was added. The adsorption of hydrogen was made by changing thecoverage, i.e., 0.08 and 0.2 for the nickel reduced at 200°C, and 0.03 and 0.2 for the nickel reduced at 400°C. After a certain time, hydrogen and the mixture of ethane and ethylene were drawn off successively from the reaction vessel and separated. The assay of tritium in each fraction of gas was then made. The result on the nickel reduced at 200°C indicated that neither the hydrogen very strongly adsorbed nor that weakly adsorbed reacts with ethylene. The result on the nickel reduced at 400°C indicated that the hydrogen weakly adsorbed does not react with ethylene. These results suggest that the very strong sites for the adsorption of hydrogen, which are inactive for the hydrogenation reaction would diminish by the elevation of the reduction temperature.
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  • Tomihisa KAMBARA, Kunihiko HASEGAWA, Masayuki ISHIKAWA, Masahiko URATA
    1964 Volume 13 Issue 6 Pages 444-449
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The 59Fe (III) dissolved in sulfuric acid solution was reduced with the zinc-amalgam reduction method. The reduction yields for several conditions were investigated. It was found that the effects of sulfuric acid concentrations on these yields were not so remarkable as compared with those of Fe (II) carrier concentrations.
    The 59Fe (II) thus obtained was kept for standing at 25°C and the per cent decreases of 59Fe (II) were measured with the lapse of the reaction time. From all the experiments linear relations were obtained by plotting the logarithms of the per cent of 59Fe (II) remained versus the time elapsed. The effects of the sulfuric acid concentrations, the specific activity concentrations and chloride ion concentrations were investigated. The conversion mechanisms of 59Fe (II) to 59Fe (III) were concluded to depend upon the radiation induced electron exchange process.
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  • Yoshio KODA, Motoharu TANAKA, Tsu-Chang HUNG
    1964 Volume 13 Issue 6 Pages 450-454
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    A rapid method of separation and determination of radio-ruthenium is proposed. The method is highly selective and allows the separation of radio-ruthenium from mixtures of fission products. When a large amount of sample water has to be treated as in the determination of radio-ruthenium in natural waters, ruthenium is preferably coprecipitated with hydrous ferric oxide prior to the final extraction step. The procedure is briefly given below: 5 mg of ferrous iron and 10 ml of 3 % hydrogen peroxide solution are added to every 1 liter of sample water, and pH of the solution is adjusted to about 6 using bromocresol purple as an indicator. The resulted hydrous ferric oxide is filtered through a glass filter. The precipitate is then dissolved in hot 1 N sulfuric acid. The solution is cooled and about 0.4 g of argentic oxide is added. After 10 minutes' standing at room temperature, the oxidation of ruthenium to the octavalent state is quantitative. Ruthenium tetroxide thus formed is then extracted with 0.1% nitrobenzene solution of polyvinyl chloride. Radionuclides such as 36Cl, 90Sr, 50Y, 99Tc and 74As are not extracted, distribution of these nuclides in favor of organic phase being very low. The over-all recovery of ruthenium of more than 98% is attainable. Ruthenium separated from mixtures of fission products shows a γ-ray spectrum identical to that of pure 106Ru-106Rh. Distribution ratio of ruthenium tetroxide between 1N sulfuric acid and the nitrobenzene solution of polyvinyl chloride is as high as 1, 000. Distribution ratios of ruthenium tetroxide between 1N sulfuric acid and some other organic solvents are also given.
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  • Masao TAKIZAWA, Kugao KODA, Shigetane UEHARA, Akio HIROKAWA
    1964 Volume 13 Issue 6 Pages 455-461
    Published: November 15, 1964
    Released: December 13, 2010
    JOURNALS FREE ACCESS
    Natural clay in rod of 1 mm dia. × 2-5 mm was prepared from a predominately Ca saturated montmorillonite (100%), which is a commercial bleaching earth from Omi, Niigata prefecture, with polyvinyl acetate (10%) as a binder. Portions of the natural clay in rod were converted to Na- and H-forms by treating with 1N solutions of the corresponding chloride. Through a column (2 cm dia.) of 20 g of natural, H-, or Na-clay in rod, the test solutions containing 137Cs 1.0×10-2 μc/ml were percolated at a flow rate of 10 ml/min at room temperatures. The cesium capacities of the three clay columns were measured by the effluent volume (ml/g of clay) at a specific activity ratio (C/ C0) of 0.05. Na-Clay column was incomparatively superior in cesium capacity to natural and H-clay columns, and the pH value of the feed most suitable for 137Cs removal on Na-clay was a range of 6 to 9, as was also indicated for 90Sr removal. Comparative effects of competing various rations on the cesium capacity of Na-clay column are in the order: K+ >Na+ >Ba2+ ( >Al3+ (pH 2.3) ) >Ca2+ >Sr2+ for neutral 1, 0×10-1N aqueous solutions of the corresponding chloride, because the effluent volume values at C/C0 of 0.05 for the above systems in the presence of these cation were found to be 30, 170, 440, 770 (pH 2. 2), 2, 400 and 3, 900 ml/g, respectively. Effects of increasing K, Na and Ca concentrations on the cesium capacity of Na-clay column can be expressed as the linear relations between the effluent volume in ml/g at C/C0 of 0.05, x, and log (the initial concentration of the corresponding chloride in N, y) :
    log y=log (1.07×10-1) - (2.58×10-3) x, for 0.01-0.1N KCl, neutral;
    log y=log (1. 06×10-1) - (1.48×10-4) x, for 0.05-0.1N NaCl, neutral;
    log y=log 1.32- (4.66×10-4) x, for 0.1-0.5 N CaCl2, neutral.
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  • Yoshiki WADACHI, Shunichi MIYASAKA
    1964 Volume 13 Issue 6 Pages 462-464
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The excellent coating surface of hot area has a low susceptibility and a high decontami-nability to the radioactive contamination. In order to survey such excellent coatings, 27 species of coatings which are Japanese commercial products were examined their susceptibilities and decontaminabilities to radioactive isotopes, that is, 60CoCl2 and fission products. Also 5 species of floor materials were examined these properties in the same measurements. Results obtained show that some vinyl chloride resin coatings are excellent for the wall surface and some unsaturated polyester resin coatings are suitable for the floor surface of hot area.
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  • Takami KOYANAGI, Isao KIMURA
    1964 Volume 13 Issue 6 Pages 465-471
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The absorption characteristics of radiations in the materials are the base of the radioactive thickness gage. To make the basis firm, the absorption curves of six kinds of metallic materials (Al, Fe, Ni, Cu, Sn, Pb) and six nonmetallic materials (vinyl, celluloid, polyethylene and three kinds of paper) are obtained experimentally, using 90Sr+90Y as the β-ray source. Two kinds of detector, scintillation detector and ionization air chamber are used. The gists may be pointed as follows:
    (1) The absorption curves are affected by the experimental arrangements for thinner absorbers than a maximum range of the β-rays, especially with small field size.
    (2) The absorption curves are changed by the kinds of material, namely the absorption of β-rays increases with increasing atomic number. These two phenomena can be explained by the scattering of β-rays.
    (3) For the materials thicker than a maximum range, the effects of Bremsstrahlung are remarkable, when the scintillation detector is used.
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  • Hikoyuki YAMAGUCHI, Md. Abdul Jalil MIAH
    1964 Volume 13 Issue 6 Pages 472-476
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The comparative effects of ionizing radiations (X-and γ-rays) and ethylene imine of relatively low doses were studied, using dry seeds of variety Kinmaze in rice. There was a linear relationship between the mutation frequency and the dose of X- and γ-rays, and a significant difference of the mutation yield was not found within the two types of radiation used. For the materials irradiated with sufficiently low dose and treated with ethylene imine, the segregation ratios in X1-ear-branch showed a strong deficit of recessives. With higher doses, however, the segregation ratios came nearer to the expected ratio of 0.25. The results are interpreted to indicate that two types of mutation, fractional and whole, are produced by mutagenie agents.
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  • Teruo NAGAI, Takeshi IINUMA, Tomio ISHIHARA
    1964 Volume 13 Issue 6 Pages 477-483
    Published: November 15, 1964
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The purpose of the presented paper is to use the total body potassium content measured with a human whole body counter as an index of aging process, and to analyse chronologic change of gross body composition. 189 normal volunteers ranging age 6 to 89 years were assayed for K-40 in the large plastic scintillator human counter. The results obtained appear to suggest some interesting possibility for the study of gross body composition. The method reported here seems to be worthy of further study as a practical method of evaluating the aging process in large population groups.
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  • [in Japanese], [in Japanese]
    1964 Volume 13 Issue 6 Pages 484-487
    Published: November 15, 1964
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese]
    1964 Volume 13 Issue 6 Pages 488-490
    Published: November 15, 1964
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • Kenjiro KIMURA, Fumio YAMASAKI, Seizo OKAMURA, Masao KATO, Masatoshi K ...
    1964 Volume 13 Issue 6 Pages 491-502
    Published: November 15, 1964
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 13 Issue 6 Pages 502
    Published: 1964
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • 1964 Volume 13 Issue 6 Pages A619-A96
    Published: November 15, 1964
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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