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Abstract  

DSC was used for heat capacity measurements of pure RuO2 in the temperature range from 300 to 1170 K of solid solutions corresponding to the compositions of (Ti1−x Rux )O2 (x ≤0.15 and x ≥0.85) and in the temperature range from 300 to 1550 K of pure TiO2. The analysis of experimental data obtained within 2% of accuracy has shown that the characteristic temperatures representing the harmonic lattice vibrations do not strongly depend on the chemical composition x . It was demonstrated that non-harmonic heat capacity is strongly correlated to x. The existence of additional excess heat capacity was observed with the mixed oxide solid solution samples of low Ru content and explained by the defect formation model.

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Abstract  

A novel system using a potassium aluminosilicate electrolyte under applied potential that is able to split H2O (or OH) into H2 and 1/2O2 (or O2 2-) with higher yields than the value deduced from Faraday"s law is presented. There were three steps by which H2 and O2 were generated stoichiometrically, and it was predicted that the high yields were due to the occurrence of chemically endothermic reactions: dehydration of the catalytic cell at a temperature below 100C (step I), disproportionation of KOH (2KOH→H2+K2O2) at a temperature around 200C (step II), and disproportionation of K2O (2K2O→K2+K2O2) at a temperature above 500C (step III). So-called Nemca might be caused in the course of step III, since the rate of H2 was ca 102 times larger than the value deduced from Faraday"s law.

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Abstract  

The preparation of rutile type solid solutions in (TiO2)x -(RuO2)1−x system in the 0≤x ≤0.7 concentration range is described. The single phase solid solutions are formed by controlled nanocrystallization of amorphous gels prepared by the sol-gel method. The kinetics of this crystallization process has been analyzed. It was found that the crystallization does not correspond to the Johnson-Mehl-Avrami model and it can be described by the two-parameter Šestk-Berggren kinetic model.

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Simulation of the atmospheric dispersion of 85Kr from a reprocessing plant over a coastal area

Performance examination of an emergency environmental radiation dose evaluation code system, SIERRA-II

Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Takeyasu
,
T. Iida
,
H. Watanabe
,
M. Takeishi
, and
A. Yamamoto

Abstract  

The performance of the computer code system, SIERRA-II, for calculating the environmental radiation dose due to an accident was assessed over a coastal area, using the environmental monitoring data around the coastally located Tokai Reprocessing Plant (TRP) when 85Kr was discharged during its operation. The agreement within a factor of 5 between the calculated and observed air concentrations of 85Kr in areas of a few km from the TRP was achieved in 57% of the comparison data, disregarding the internal boundary layer. The mean fraction bias was −0.6, which meant a slight overestimation. According to the vertical profile of the atmospheric temperatures, the internal boundary layer was modeled with the SIERRA-II and the agreement became better than when the internal boundary layer was not considered.

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Abstract  

Coprecipitation methods with SmF3 and BaSO4 were developed in order to evaluate the radioequilibrium of natural decay nuclides series in high purity silica and lead. The present study revealed that228Th,230Th, and231Pa in silica and210Po, probably210Pb, in lead were enriched in much higher concentrations than their precursor nuclides.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Watanabe
,
N. Ishioka
,
T. Sekine
,
A. Osa
,
M. Koizumi
,
H. Shimomura
,
K. Yoshikawa
, and
H. Muramatsu

Abstract  

Ion implantation was applied to the production of endohedral 133Xe-fullerene. Using an isotope separator, 133Xe ions were implanted into a fullerene target of C60 and C70 produced by vacuum evaporation on a Ni backing. An HPLC analysis following dissolution of the fullerene targets in o-dichlorobenzene corroborated the formation of 133Xe@C60 and 133Xe@C70, showing a strong correlation between C60/C70 and 133Xe. The observed tailing following 133Xe peaks in the elution curves suggests a possibility of the isolation of endohedral 133Xe-fullerene from empty fullerene.

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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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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Y. Kobayashi
,
Y. Tsuruoka
,
M. Kubo
,
H. Nonaka
,
Y. Yamada
,
Y. Sakai
,
H. Shoji
,
W. Sato
,
A. Shinohara
,
Y. Watanabe
, and
H. Matsue

Abstract  

In order to investigate the physical and chemical effects of neutron capture reaction, a neutron in-beam Mössbauer spectroscopic study on two isomorphs of iron disulfide: pyrite and marcasite, were carried out with a parallel plate avalanche counter at room temperature. In both compounds only two major products accounted for the obtained spectrum: one with Mössbauer parameters close to the parent compound and the other one considered to be a new product. The yield of the parent-like species was different in the two isomorphs.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
W. Sato
,
H. Ueno
,
H. Watanabe
,
H. Ogawa
,
H. Miyoshi
,
N. Imai
,
A. Yoshimi
,
K. Yoneda
,
D. Kameda
,
Y. Kobayashi
, and
K. Asahi

Abstract  

A new 19F probe disintegrated from short-lived 19O has been developed for the first time for time-differential perturbed angular correlation method. The angular correlation coefficient for the relevant cascade has been experimentally estimated to be A22 = -0.17±0.01. As the first application of this technique to condensed matter physics, the probe was implanted in polycrystalline fullerene C60. We have observed two contrastive perturbations acting on the probe nuclei, which reflect electrostatic and dynamic interactions with the extranuclear field.

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Acta Physiologica Hungarica
Authors:
Kenichi Watanabe
,
R. Thandavarayan
,
N. Gurusamy
,
S. Zhang
,
A. Muslin
,
K. Suzuki
,
H. Tachikawa
,
M. Kodama
, and
Y. Aizawa

Cardiovascular disease is a leading cause of death worldwide. Diabetes mellitus is a well-known and important risk factor for cardiovascular diseases. The occurrence of diabetic cardiomyopathy is independent of hypertension, coronary artery disease, or any other known cardiac diseases. There is growing evidence that excess generation of highly reactive free radicals, largely due to hyperglycemia, causes oxidative stress, which further exacerbates the development and progression of diabetes and its complications. Diabetic cardiomyopathy is characterized by morphologic and structural changes in the myocardium and coronary vasculature mediated by the activation of various signaling pathways. Myocardial apoptosis, hypertrophy and fibrosis are the most frequently proposed mechanisms to explain cardiac changes in diabetic cardiomyopathy. Mammalian 14-3-3 proteins are dimeric phosphoserine-binding proteins that participate in signal transduction and regulate several aspects of cellular biochemistry. 14-3-3 protein regulates diabetic cardiomyopathy via multiple signaling pathways. This review focuses on emerging evidence suggesting that 14-3-3 protein plays a key role in the pathogenesis of the cardiovascular complications of diabetes, which underlie the development and progression of diabetic cardiomyopathy.

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