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  • Author or Editor: A. Yamazaki x
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Large amounts of rice husk ash (RHA) are discharged from rice husk power plants, and the development of an effective system for recycling this RHA waste would be desirable. In the current study, the silica component of RHA obtained from a rice husk power plant in Myanmar was successfully used as raw material for the synthesis of the aluminosilicate nanotube (ASNT) material. The RHA used contained over 90 wt% of silica. The synthesized ASNT had a web-like structure formed of fi brous bundles, each containing many individual ASNT.

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Authors: Y. Inoue, O. Tochiyama, H. Yamazaki and A. Sakurada

Abstract  

A model for treating the sorption of metal ions on hydrous metal oxides was established based on the assumptions that these materials are weakly acidic cation exchangers and have a discrete exchanger phase. The experimental results of the sorption of metal ions on the hydrous niobium(V) and tin(IV) oxides are found to be consistent with the formulas derived from the model by considering that the charge balance and the mass action law hold in the exchanger phase and cations are sorbed by the distribution between this phase and the bulk aqueous phase.

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Authors: A. Yamazaki, Y. Inoue, M. Koike, T. Sakamoto and R. Otsuka

Abstract  

Thomsonite with ideal chemical composition and with an ordered framework structure was synthesised hydrothermally from zeolite Na−A, which was ground to X-ray amorphous, with 0.05 mol dm−3 CaCl2 solution at 200°C. The dehydration behaviour of the prepared thomsonite was examined by TG-DTA. It was revealed that thomsonite lost most of zeolitic water below 450°C in three steps at about 180°, 340° and 390°C. The peak profiles of, the two higher-temperature endotherms were sharp and similar, and the weight loss at each step was approximately equal.

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Authors: K. Kaneiwa, J. Adachi, M. Aoki, T. Masuda, A. Midorikawa, A. Tanimura and S. Yamazaki

Abstract  

In this paper,Nature andScience, the two distinguished multi-disciplinary scientific journals were compared placing emphasis on their internationality. The items investigated were as follows. A general comparison: 1. number of authors per article, 2. distribution of countries to which first authors' institutions belong, 3. distribution of main discplines studied by first authors, 4. time-lag between the date of receipt of an article by the editor and the date of its publication. B. the position with regard to Japanese author: 1. number of Japanese authors, 2. relationship between the ranking of a Japanese author in the list of authors' names and the country where his institution is located, 3. relationship between the time-lag stated in A-4 and the items stated in B-2. As a result, it can be said thatNature is a more highly international journal thanScience.

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Authors: S. Miyamoto, M. Sutoh, A. Shiomoto, S. Yamazaki, K. Nishimura, C. Yonezawa, H. Matsue and M. Hoshi

Abstract  

Boron concentration of plasma, feces, urine and body tissues from sheep fed with borated water (100 mg B/l) and tap water were determined by neutron-induced prompt gamma-ray analysis to elucidate boron metabolism. The B level in plasma and urine increased rapidly and the B content of feces increased greatly. The B concentrations in body tissues (liver, kidney, spleen, thyroid and muscle) of B dosed sheep were ten times higher than those of tap water administered sheep.

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Authors: N. K. Labhsetwar, V. Balek, S. Rayalu, T. Terasaka, A. Yamazaki, J. Šubrt, H. Haneda and T. Mitsuhashi

Summary Studies on ruthenia-titania based materials have been attractive because of their catalytic properties as well as due to the possibility of solid solution formation. Samples of pure ruthenia and ruthenia containing various amounts of titania (10-70 mol%) were investigated during heating of their hydroxide precursors from 20 to 800°C in air using emanation thermal analysis (ETA), thermogravimetry (TG), and differential thermal analysis (DTA). The resulting mixed oxide type materials were characterized by X-ray diffraction (XRD), which indicate the presence of three ruthenia-titania phases. The onset temperature of the crystallization of materials was identified by ETA results, whereas DTA effects characterized the crystallization in bulk of the samples. A good agreement was found between the ETA results and other characterization techniques used. ETA results, indicating the microstructural changes in surface and subsurface of ruthenia-titania based catalytic materials, can be used for optimization of their synthesis protocols to achieve the better physical properties.

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