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Abstract  

99Ru and57Fe-Mössbauer spectroscopic and magnetization measurements were made in order to clarify the magnetic properties of a Huesler alloy, RuFe2Si. The result obtained from99Ru-Mössbauer spectrum leads to the conclusion that Ru atoms were substituted by both Fe[A, C] and Fe[B], but the latter preferentially.

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Abstract  

The proton activation analysis of oxygen was studied in fluoride and chalcogenide glasses used for fiber amplifiers. First, we studied the interfering nuclear reactions from glass matrices to determine the oxygen concentration in these glasses. By using substoichiometric separation for 18F after irradiation, we found that the oxygen concentration was 12 to 204 ppm in InF3-based fluoride glass and 0.04% to 0.7% in chalcogenide glass containing sodium. We also discuss the relation between oxygen concentration and optical properties such as the infrared absorption spectrum and fluorescence lifetime.

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Abstract  

Separation of Au(III) and various carrier-free radionuclides by solvent extraction was investigated using an Au target irradiated by an energetic heavy-ion beam. Percentage extraction of Au(III) and coextraction of the radionuclides were determined with varying parameters such as kinds of solvent, molarity of HCl or pH, and Au concentration. Under the conditions where Au(III) was effectively extracted, namely extraction with ethyl acetate or isobutyl methyl ketone from 3 mol·dm–3 HCl, carrier-free radionuclides of many elements were found to be more or less coextracted. Coextraction of radionuclides of some elements was found to increase with an increase in the concentration of Au(III). This finding is ascribed to the formation of strong association of the complex of these elements with chloroauric acid. In order to avoid serious loss of these elements by the extraction, lowering of the Au(III) concentration or the use of a masking agent such as sodium citrate is necessary. Gold(III) was shown to be effectively back extracted with a 0.1 mol·dm–3 aqueous solution of 2-amino-2-hydroxymethyl-1,3-propanediol. Thus, a radiochemical procedure has been established for preparing a carrier-free multitracer and an Au tracer with carrier form from an Au target irradiated with a heavy-ion beam. Both tracers are now used individually for chemical and biological experiments.

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We investigated the effects of resistance exercise combined with essential amino acid supplementation on psoas major muscle (PMM) hypertrophy and walking ability in elderly individuals. Twenty-nine healthy elderly individuals were assigned to 3 groups: (1) E (exercise), (2) A3 (exercise combined with 3.0 g of essential amino acid supplementation), and (3) A6 (exercise combined with 6.0 g of essential amino acid supplementation). To evaluate walking ability, the participants underwent the following 3 types of tests: the (1) 10-meter walk (10-W), (2) 10-meter walk involving crossing of obstacles (10-W + O), and (3) 6-minute walk (6M-W) tests. The 6-month training program resulted in significant PMM hypertrophy in all groups independent of amino acid supplementation. The extent of hypertrophy in the participants who took amino acids was dose-dependent, although the differences were not significant. Groups A3 and A6 demonstrated improvements in the 10-W and 10-W + O tests, whereas no improvement was observed in group E, regardless of PMM hypertrophy. Furthermore, group A6 showed an improvement in the 6M-W test. These results suggest that our training program causes PMM hypertrophy, whereas the training program combined with essential amino acid supplementation improves walking ability.

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Abstract  

Quantitative determination of ppb-order 10B was carried out in a small number of cultured tumor cells by particle tracks by the 10B(n,)7Li reactions using solid state nuclear track detector (SSNTD) for boron neutron capture therapy research. The detection limit of 10B concentration in tumor cells is less than 1·10-3 ppm under our experimental conditions which permits the quantitative determination of 10B in a small number of boronated tumor cells (105/ml = ca. 0.1 mg). Boron quantities in tumor cells determined were well compatible with the tumor cell killing effects of boron neutron capture therapy.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: S. Ambe, S. Chen, Y. Ohkubo, Y. Kobayashi, H. Maeda, M. Iwamoto, M. Yanokura, N. Takematsu, and F. Ambe

Abstract  

We established Multitracer, a new versatile radiotracer technique, for simultaneous tracing of a number of elements in various chemical, environmental, and biological systems. Metal foil targets (typically Au, Ag, Ge, Cu and Fe) are irradiated with C, N, or O ions accelerated up to 135 MeV/nucleon by RIKEN Ring Cyclotron. Radiochemical procedures have been developed to remove the target material leaving the nuclides as Multitracer solutions containing various radionuclides of Be, Na, Mg, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Te, I, Ba, Ce, Pm, Eu, Gd, Tb, Tm, Yb, Lu, Hf, W, Re, Os, Ir, Pt, and Hg. Multitracers enable efficient tracing of a number of elements, and comparison of their behavior under strictly identical experimental conditions. Such features will be demonstrated by means of an example of application to a model experiment for the study of removal mechanism of various elements from the ocean.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: W. Sato, K. Sueki, K. Kikuchi, K. Kobayashi, S. Suzuki, Y. Achiba, H. Nakahara, Y. Ohkubo, F. Ambe, and K. Asai

Abstract  

Time-differential perturbed angular correlation method was applied to Ce@C82 in order to investigate the electronic properties of the encaged Ce atom. The nuclear quadrupole frequency of the nuclear spin of the Ce was successfully determined as ωQ = 6.5(3)·107 rad/s, which is much greater than what has already been estimated for Ce4+ and La3+ in other compounds. By comparing the present value with the values for the Ce4+ and La3+, it was inferred that the valence state of the encaged Ce atom is trivalent.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: K. Tanoi, H. Matsue, H. Iikura, T. Saito, Y. Hayashi, Y. Hamada, H. Nishiyama, N. Kobayashi, and T. Nakanishi

Abstract  

We carried out instrumental neutron activation analysis (INAA) as well as k 0-based prompt gamma-ray analysis (k 0-PGA) to measure the amount of the elements in onions and studied whether the onions collected from different sites can be categorized based on the elemental concentration profile. Six elements (Na, Mg, Cl, K, Ca, Mn) and 3 elements (B, S, Cl) were measured by INAA and PGA in the onions grown in two districts, Hokkaido and Saga, in Japan, respectively. After principal component analysis, it was found that Cl was an important element to feature the producing districts of onions.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: K. Kobayashi, M. Kuwano, K. Sueki, K. Kikuchi, Y. Achiba, H. Nakahara, N. Kananishi, M. Watanabe, and K. Tomura

Abstract  

Advantages and uniqueness of radiochemical techniques in fullerene studies are pointed out. Some experimental data are presented on metallofullerenes production yields, HPLC elution behaviors of Y, La, Gd containing fullerenes, encapsulation of a new metal in the carbon cage, stability of the carbon cage against recoil energy, and the distribution of metallofullerenes among various organs of rats.

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Journal of Thermal Analysis and Calorimetry
Authors: T. Tanaka, J. Magoshi, Y. Magoshi, S. ichi Inoue, M. Kobayashi, H. Tsuda, M. Becker, and Sh. Nakamura

Abstract  

The thermal properties of liquid silk from domestic and wild silkworms are investigated. Liquid silks obtained from the silk gland of the domesticated silkworm, Bombyx mori and four wild silkworms, Samia cynthia ricini, Dictyoploca japonica, Antheraea pernyi and Antheraea yamamai were used. The DSC curves for the liquid silk from the domestic silkworm have weak endothermic peaks corresponding to the breaking of hydrogen bonds in the β-form or to the untangling of physical network. The DSC curves for the wild silkworm silks, however, show clear exothermic peaks corresponding to a phase transition from the α-helix conformation to the β-form. Liquid silk from all the different silkworms undergoes a characteristic irreversible phase transition.

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