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Abstract  

No-carrier-added 177Lu was produced by the 176Yb(n,)177Yb 177Lu process using enriched 176Yb2O3. The radiochemical separation of the nca 177Lu from the macroscopic ytterbium target was investigated by reversed-phase ion-pair HPLC. Effects of the concentrations of 2-hydroxyisobutyric acid and 1-octanesulfonate in the eluent, the amount of Yb2O3, the type and length of the C18 column on the separation efficiency were examined. Under optimum conditions, the nca 177Lu was obtained in radiochemically pure form from 5 mg of Yb2O3 with a separation yield of 84%.

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Abstract  

Aerosols and source related materials (fly ash from refuse incinerators, vehicle exhaust and soil) were collected in April, 2002 in the northern areas of Jeju-do, Korea, and the Pb isotopic ratios (207Pb/206Pb and 208Pb/206Pb) of the samples were measured in order to estimate the Pb sources of the aerosols. The Pb isotopic ratios of the aerosols were classified into two groups, depending on the sampling date. One group showed similar Pb isotopic ratios with those of the source related materials, suggesting that the contribution of the regional sources to the aerosols was very large. The other showed different Pb isotopic ratios from those of the regional sources and relatively high Pb isotopic ratios compared to the ratios of the first group. The results suggest that in the continental Asia there seems to be a long range transport of Pb with high ratios in desert sands, which are carried by northwest seasonal winds.

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Abstract  

Microwave digestion was applied as pretreatment of environmental samples for the determination of lead isotope ratios by ICP-MS. Microwave digestion decomposed the samples easily and rapidly without lead contamination. The lead isotope ratios could be measured directly by ICP-MS without tedious lead purification, because the influence of the matrix elements on measurements of lead isotope ratios is small enough to be ignored.

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Abstract  

An efficient method to produce [1-14C] benzoic acid within a total time less than 20 min in high chemical and radiochemical yield is described. The procedure we report can be applied for the preparation of [11C]-labeled carboxylic acids suitable for evaluation in the study of human metabolism by positron emission tomography.

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Abstract  

The concentration and size distribution of210Po in particulate matters in the atmosphere were measured around the active volcano, Mt. Sakurajima in Kagoshima prefecture, Japan. The samples were collected eight times at four sampling points for the period from June 1994 to January 1996. The highest concentration of210Po was 2940 μBq/m3 at Akamizu located 2 km away from the crater of Mt. Sakurajima. The210Po concentrations decreased with the increase of distance from Mt. Sakurajima. The size distribution curves of210Po in the particulate matters showed that210Po is usually condensed to fine particles smaller than 2 μm in diameter. In addition, it was suggested that the210Po concentration in particulate matters collected at Akamizu was affected by the wind direction over Mt. Sakurajima.

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Abstract  

For the assessment of a public impact caused by radionuclides released from nuclear facilities, a dynamic compartment model was developed for prediction of behavior of radioiodine in air, paddy field and rice plant system. The transfer coefficients among compartments were determined by some experimental data and assumptions for each chemical form of iodine. A verification of the model was carried out by some case studies.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Shigeta, H. Matsuoka, A. Osa, M. Koizumi, M. Izumo, K. Kobayashi, K. Hashimoto, T. Sekine, and R. Lambrecht

Abstract  

No-Carrier-Added186Re was produced using the186W(p,n)186Re nuclear reaction with 13.6 MeV protons on thick targets of 99.79% isotopically enriched186WO3. The theoretical excitation functions for producing186Re, and possible radionuclidic impurities of182Re,183Re, and184Re were calculated using the ALICE code. Cross-sections of the186W(p,n)186Re reaction were measured up to 20 MeV using the stacked target method with thin foils of natural composition tungsten metal. The experimental and theoretical excitation functions were in good agreement. Targetry used at the TIARA cyclotron, and a radiochemical separation scheme for186Re are described.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: N. Ishioka, H. Matsuoka, S. Watanabe, A. Osa, M. Koizumi, T. Kume, S. Matsuhashi, T. Fujimura, A. Tsuji, H. Uchida, and T. Sekine

Abstract  

The positron emitters11C,13N and18F and their labeled compounds have been produced for studies on plants using a newly developed positron emitting tracer imaging system. Although this system covers, at present, a limited area in a plant, the distribution of the positron emitter fed into the plant can be visualized dynamically. Further development of positron-emitter-labeled compounds is expected to elucidate the physiological function of plants in vivo.

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