RADIOISOTOPES
Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Volume 14 , Issue 2
Showing 1-19 articles out of 19 articles from the selected issue
  • Takuo ASAI, Sakiko IKEGUCHI
    1965 Volume 14 Issue 2 Pages 73-77
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The present paper describes a new chemical dosimeter utilizing K2Cr2O7⋅H2SO4 system. Decrease of extinction of γ-irradiated K2Cr2O7 were measured in the wavelength of 435 and 350 millimicron. The results obtained are as follows;
    1. Decrease of extinction is proportional to radiation dose and independent of dose rate.
    2. G-Value is 0.446±0.023.
    3. In the dose range of 104r-107r, properly prepared solution of this system can offer reliable results.
    4. The reactions in this system are relatively stable, so the total dose in the divided irradiation is also measurable.
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  • Kiyoshi KODAIRA, Rokuro SHINOHARA
    1965 Volume 14 Issue 2 Pages 78-82
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The following method was established for simultaneous radiochemical determination of 85Sr and 45Ca: 85Sr and 45Ca are precipitated together with calcium oxalate in the presence of 15 mg of Ca in 60 ml of solution (250 ppm) . Radioactivity of 85Sr is obtained directly from scintillation measurement. Using the conversion factor previously determined for single radionuclide of 85Sr, the contribution of radioactivity of 85Sr in the sample to G-M counter is estimated. Radioactivity of 45Ca is obtained by substraction of the estimated counting rate of 85Sr from the total counting rate of G-M measurement.
    Prior to the establishment of the method, coprecipitation yield of Sr in calcium oxalate was examined in terms of Ca concentration. A range of 0.002 to 1 mg of Sr in 60 ml of solution (0.03-17 ppm) was coprecipitated in calcium oxalate, with the yield of 95.0±0.5% in the presence of 15 mg of Ca (250 ppm), and with lower yields at lower concentrations of Ca.
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  • Kentaro MINAMI
    1965 Volume 14 Issue 2 Pages 83-88
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    Investigation of sand movement in the sea, using radioactive tracers, has been carried out widely in several parts of Japanese coast since 1954.
    The G-M detector or scintillation detector which is watertight and is sensitive to γ-rays is used in order to trace the radioactive glass-sands deposited at the definite point on the sea bed.
    It is, therefore, important to know the amount detectable by the measuring system. By knowing this detection level, it become possible to estimate not only the necessary amount of the radioactive glass-sands to be deposited, but also the detectable limit on the area covered by the dispersing glass-sands on the sea-bed.
    A bundle of three G-M tubes was used in a normal run to trace the 60Co labeled glass-sands in the investigations at Niigata and Nakaminato harbours.
    In these measurements, when the background is 85 cpm for 10 minutes counting time, the net count which is distinguished from the background with 95.4% reliability was 22 counts for 1 minute counting time. In this case, the minimum detectable amount determined experimentally was 2.5×10-6μc/cm2.
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  • Seiko OKANOUE, Matsue FUKUTANI, Mizuho SUGIHARA, Isao HASHIDA
    1965 Volume 14 Issue 2 Pages 89-92
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    In previous papers we studied the effects of gamma-ray irradiation on some fruits. In this time authors tried to prevent mold growing and vermin damage on soybean by gamma-ray irradiation. Concerning this theme only a few reports were published and we could not know the details. We wished to determine the optimum dose of gamma-ray irradiation. Soybeans were irradiated by cobalt-60 gamma-rays at the dose of from 0.05×104r to 100.0×104r in about 1/7 mm thick polyethylene film bags. Atmosphere was air or nitrogen. After irradiation samples were storaged at room temperature for about 18 months. Outward appearances, tastes, contents of main nutrient components were estimated. Relations between irradiation doses and these factors were investigated and the optimum dose was determined.
    Results obtained were as follows:
    1) Irradiation at the dose of more than 10.0×104r in air was effective for keeping soybeans from getting moldy, but, on the contrary, irradiation of about 1.0×104r accelerated the mold growing. In nitrogen atmosphere, dose of 1.0×104r gave better results in comparison with control.
    2) The boiled states and the tastes of the samples were almost unchanged by irradiation of these doses.
    3) The main nutrient components were unchanged by irradiation.
    4) None of blight was found in the storage period.
    5) For the preservation of soybeans it was desirable to irradiate gamma-rays at the dose of 10.0×104r in air or 1.0×104r in nitrogen atmosphere.
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  • Seiko OKANOUE, Matue FUKUTANI, Mizuho SUGIHARA, Isao HASHIDA
    1965 Volume 14 Issue 2 Pages 93-96
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    In the previous report we studied the effects of gamma-ray irradiation on soybeans. In this paper authors tried to prevent mold growing and vermin damage on red beans by gamma-ray irradiation. Concerning this theme either any particular report would not be published or unfortunately we could not know them in detail. We wished to determine the optimum dose of it. Red beans were irradiated by cobalt-60 gamma-rays at the dose of from 0.05×104r to 100.0×104r in about 1/7 mm thick polyethylene film bags. Atmosphere was air or nitrogen. After irradiation, samples were storaged at room temperature for 30 months. Outward appearances, tastes and contents of fats were estimated. Relations between irradiation doses and these factors were investigated.
    Results obtained were as follows :
    1) Immediately after irradiation, outward appearances were remained unchanged. Irradiation at the dose of 1.0×104r could not keep red beans from getting moldy, but, irradiation at the dose of from 10.0×104r to 100.0×104r was effective to suppress the mold growing. Higher dose was more effective.
    2) The boiled states and the tastes of the samples were equally good as against the control in every case.
    3) The contents and the characteristic properties of the fats were almost unchanged by gammaray irradiation.
    4) Vermin were not found during storage.
    5) Therefore it was desirable to irradiate gamma-rays on red beans which contained fats in small quantities and carbohydrates in much quantities at the dose of from 10.0×104r to 100.0×104r in air. This value is larger than the optimum dose for the soybeans which contained fats in much quantities and carbohydrates in small quantities. In the case of the soybeans, irradiation in nitrogen atmosphere gave good results at the dose of only 1.0×104r. But, in the case of the red beans, specially good results were not obtained by irradiation in nitrogen atmosphere.
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  • Seiko OKANOUE, Matsue FUKUTANI, Mizuho SUGIHARA, Isao HASHIDA
    1965 Volume 14 Issue 2 Pages 97-102
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    In the previous report we studied the effects of gamma-ray irradiation on red beans. In this paper authors tried to prevent the mold growing and the vermin damage on rice which has been the most important food in Japan from very early ages. For the prevention of the vermin damage some cereals were irradiated by radial rays, but for the preservation of rice, any systematic research had not been published.
    Rice was irradiated by cobalt-60 gamma-rays at the dose of from 0.5×104r to 400.0×104r in about 1/7 mm thick polyethylene film bags. Atmosphere was air or nitrogen. After irradiation samples were storaged at room temperature for 18 months. Outward appearances, tastes, changes in nutrient components were estimated. Relations between irradiation doses and these factors were investigated and the optimum dose was determined.
    Results obtained were as follows:
    1) Irradiation at the dose of more than 40.0×104r caused the coloration of yellowish brown and its density increased with irradiation dose.
    2) Vermin did not grow when irradiated at the dose of more than 4.0×104r. Irradiataion at the dose of more than 40.0×104r could keep the rice from getting moldy and prevent the vermin damage. In nitrogen atmosphere results were better in some degree.
    3) When irradiated at the dose of less than 4.0×104r, taste of the boiled rice was good, but over 40.0×104r, the boiled rice was not fit for eating and after 6 months' storage this difference became quite remarkable.
    4) Effects of irradiation on the contents of water and fats were not recognized. Acid value was most changeable by irradiation and much increased in the polished rice than in the unpolished one. The specific gravity, refractive index, saponification value and iodine number were almost unchanged until 6 months later, but after 18 months' storage, the acid value increased and both the refractive index and the iodine number decreased with the irradiation dose. These changes were also more remarkable in the polished rice than in the unpolished one.
    5) Therefore, for the preservation of rice, it was preferable to irradiate at the dose of 10.0 ×104r on unhulled rice and polish it before cooking.
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  • Seiko OKANOUE, Matsue FUKUTANI, Mizuho SUGIHARA, Isao HASHIDA
    1965 Volume 14 Issue 2 Pages 103-110
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    The germination controls of potato and onion were the most important and successful problems in the field of the preservation of foods by gamma-ray irradiation. In the case of sweet potato the same effects would be expected. Therefore authors wished to determine the optimum conditions. After irradiation at the dose from 0.25×104r to 150.0×104r samples were storaged in a temperature and moisture controled room for 4-9 months. Outward appearances, germination, tastes, weights, contents of water, vitamin B1, B2 and C were estimated.
    Results obtained were as follows:
    1) Necessary dose for germination control
    just after harvest…………………1.2×10r
    just before planting…………0.8×104r
    2) Outward appearances
    less than 5.0×104r………unchanged
    more than 20.0×104r………brown spots were appeared
    0.5×104r-1.2×104r……unchanged and better than control (after 4 months)
    3) Generally, the weight changes in the storage period were not influenced by low dose of irradiation and rather small at the dose of 1.2×104r, but over this dose the weights decreased rapidly with increase of irradiation dose.
    4) Immediately after irradiation, samples which were irradiated at the dose of less than 5.0×104r were good to eat, but after 4 months storage this value decreased to 1.2×104r.
    5) Immediately after irradiation, water contents were not influenced by irradiation, but during storage these values were rapidly decreased with increase of irradiation dose.
    6) Vitamin B1 contents were decreased in small quantities by irradiation at the dose of below 20.0×104r. Under the dose of 20.0×104r vitamin B2 contents were not influenced and vitamin C contents were unchanged in any case.
    7) Irradiation under 1.2×104r did not cause any appreciable change in outward appearances, tastes, vitamin contents against the controls.
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  • [in Japanese]
    1965 Volume 14 Issue 2 Pages 111-115
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
  • [in Japanese]
    1965 Volume 14 Issue 2 Pages 116-125
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • H. MIWA, I. MORITA, T. KASAI, U. YAMAMOTO, J. HORIO, N. HINO, U. ASAYA ...
    1965 Volume 14 Issue 2 Pages 126-131
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    This paper is described about the 200 sample-changer liquid scintillation counter with the channel-ratio computer. The device is constructed with an automatic sample-changer for 200 samples, a pulse-height analyzer and an automatic counting system.
    The sample changer, providing a freezer and fitting a special mechanism, is rather compact, moreover, it can reserve numbers of sample. The detecting probe could be improved S/N ratio by means of the current mode connection method. The pulse-height analyzer has the transistorized circuit and the invented graphic pannel, then it's very convenient to operate. The counting system is full automatic, especially it can compute the channel ratio for the counting efficiency, and record the results. The number of channels can be choice freely between one to three channels.
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  • Tetsuo IWAKURA, Yoshihiko KASIDA, Naoko MORISAKI
    1965 Volume 14 Issue 2 Pages 132-136
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    A Method for the determination of the counting efficiency in liquid scintillation counting was studied.
    The ratio of the count rate in two windows which observe different parts of out put pulse spectrum each other vary with quenching degree of scintillator and can be used as an index of the counting efficiency.
    Spectrometer used in this work was TRICARB Model 314 A (Packard Instrument Co.) equipped with three discriminators and two scalers. A number of samples containing same amount of activity of C-14 were quenched to various degree by adding several kinds of solvent as diluter or chemical quencher.
    The lower discriminator: A was set to 10V, middle and upper discriminators: B, C were adjusted, by trial and error, so that the count ratio of one sealer to the another seemed to show linear relationship to the counting efficiency in window A-C.
    The same procedure was applied to tritium. These plots are shown in Fig. 2-Fig.6. The linearlity of curve was slightly impaired when either setting of B was not optimum or photomultiplier voltage was higher than the balance point of A-C window.
    A conclusion was obtained that several types of quencher, i, e. diluter, mild quencher and strong quencher, gave the same effect on discriminator ratio-efficiency relation.
    Recent application of this method to the measurement of natural C-14 level in essential oil: p-cymene, was also reported.
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  • Keishi SHIMOKAWA, Zenzaburo KASAI
    1965 Volume 14 Issue 2 Pages 137-141
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
    1. Determination of ethylene-14C evolved by plant tissue using liquid scintillation counter was studied.
    For the determination of radioactivity, addition of the following scintillation solution to 0.1 M methanol solution of mercuric acetate absorbed ethylene-14C gives the highest counting efficiency (59%) .
    Toluene: ethylcellosolve: dioxane (1: 1: 1), containing 0.4% PPO, 0.01% POPOP, and 10.0% naphthalene.
    2. For the quantitative absorption of ethylene and elimination of 14CO2 contamination, the following procedure was adopted. Ethylene-14C evolved by plant tissue is absorbed in 0.25 M mercuric perchlorate, from which ethylene is released by addition of 4 N lithium chloride, and the ethylene-14C released is reabsorbed by 0.1 M methanol solution of mercuric acetate. By adoption of this two step absorption, it is found that the contamination of 14CO2 to ethylene -14C could be prevented at a level of 0.02% of total 14CO2.
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  • Keiichi KUSAMA
    1965 Volume 14 Issue 2 Pages 142-145
    Published: March 15, 1965
    Released: September 07, 2010
    JOURNALS FREE ACCESS
    For the purpose of measuring aqueous solutions of biological compounds, especially nucleic acids and nucleotides, a very convenient Hyamine-water-toluene system was developed.
    The composition of this counting mixture is:
    10 ml of toluene scintillator (4 grams of PPO, and 0.1 grams of POPOP in 1 liter of toluene)
    0.5 ml of 1M Hyamine 10-X chloride in ethanol up to 0.3 ml of aqueous sample solution when 1.0ml of Hyamine is added, the system can contain up to 0.4ml of aqueous solution.
    Maximum efficiency for 3H is 18.3% and 14C is 53%. Efficiencies of aqueous solution of 3H- and 14C-UMP, uridine and uracil are compared with four different solvent systems, that is Hyamine-water-toluene, 70% toluene-30% ethanol-PPO-POPOP, dioxane-naphthalene-PPO-POPOP, and so-called“Bray solution”, at -8°C and 10°C. The best results are obtained for this Hyamine-water-toluene system described above.
    1M Hyamine Cl in ethanol only has an effect as a solubilizing agent of aqueous solution with toluene scintillator. Commercial 1M Hyamine hydroxide in methanol, 1M Hyamine Cl in methanol, 1/2M in ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, or 2/3M in npropanol has no effect at -8°C. Higher alcohol than propanol can not dissolve Hyamine as 1M solution.
    Quenching per cent for 0.1 ml of 1N HCl, 0.5N KOH, and 0.5M KCl are 2.5, 6, and 5%, respectively, in the case of 1 ml of 1M Hyamine Cl ethanolic solution is added. Even when 10 mg/0.2 ml of nucleic acid, UMP, uridine solution or 6 mg/0.1 ml of threonine solution is added, no precipitate or no quenching is observed.
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese]
    1965 Volume 14 Issue 2 Pages 146-147
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    1965 Volume 14 Issue 2 Pages 148-151
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese], [in Japanese]
    1965 Volume 14 Issue 2 Pages 152-165
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • [in Japanese]
    1965 Volume 14 Issue 2 Pages 166-168
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • 1965 Volume 14 Issue 2 Pages 169-192
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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  • 1965 Volume 14 Issue 2 Pages A445-A128
    Published: March 15, 1965
    Released: July 21, 2010
    JOURNALS FREE ACCESS
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