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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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Abstract  

Tritium concentrations were measured for river waters on two islands in Japan. Significant difference was observed on the distribution of tritium concentrations on both islands, the river water samples from the northern island had higher concentrations and the average was about twice compared to that from the southern island. Higher tritium concentration in precipitation and the larger area of the northern island would be responsible for higher tritium concentrations in river waters.

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Summary  

Iron(III) spin-crossover complexes [Fe(pap)2]ClO4 . H2O (1), [Fe(pap)2]BF4 . H2O (2), [Fe(pap)2]PF6 . CH3OH (3), [Fe(CH3-pap)2]ClO4 . H2O (4), [Fe0.5Al0.5(pap)2]ClO4 . CH3OH (5) and [Fe0.25Al0.75(pap)2] ClO4 . CH3OH (6)were prepared andthe spin transition behaviors of the complexes have been studied from magnetic susceptibility and Mössbauer spectroscopy measurements. The magnetic properties of light-induced metastable state are measured using Hg-Xe light source. T 1/2is temperature at which the populations of the high-spin and low-spin species are fifty-fifty. Metastable HS is produced by light irradiation at 5 K. T(LIESST) is the temperature at which the populations of the metastable high-spin species decrease to one half and cooperativity factor Cis defined as the parameter which presents the strength of cooperativity. The value of T(LIESST) decreases as T 1/2increases and the plots of T(LIESST) vs. Cshow linear correlation. The effect of cooperativity of the complexes on the relaxations in solid was confirmed for the iron(III) complexes.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Hisamatsu
,
T. Ohmura
,
Y. Takizawa
,
T. Katsumata
,
Y. Inoue
,
M. Itoh
,
K. Ueno
, and
M. Sakanoue

Abstract  

Tritium concentrations are reported for diet and human tissue samples collected in the Akita district of northern Japan. Sixteen separate food group samples and a total diet sample were collected for Akita City during April and May 1987. Six samples of heart and nine samples of kidney tissue were collected from 10 decreased individuals in Akita Prefecture from January to July 1986. Five serum and four blood samples were also obtained in Akita Prefecture from December 1985 to June 1986. Free water3H concentration as well as tissue-bound3H were determined separately. Specific activity ratios of tissue-bound3H to free water3H in the samples were almost between 1.0 and 2.0 and were similar to our previous results for food samples and other tissue samples. The specific activity ratio was also found to be lower than that reported in the U.S.A. and significantly lower than in Europe.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Yagi
,
T. Mitsugashira
,
I. Satoh
,
M. Hara
,
Y. Shiokawa
,
K. Inoue
,
K. Masumoto
, and
S. Suzuki

Abstract  

As a new fact, the neutron emission from the d-d nuclear fusion reaction in a SiO2–D2 system has been confirmed as well as that in the Ti–D2 system. By using a liquid scintillation detector, the neutron emissions from 8 sample materials consisted of SiO2, in which a small amount of deuterium was adsorbed chemically on the surface layer, were measured in the range of temperature between liquid nitrogen temperature and 400 °C. As a result, it was demonstrated that the neutron-emission reactions take place predominantly on the surface layer of sample material.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
K. Takamiya
,
T. Inoue
,
K. Nakanishi
,
A. Yokoyama
,
N. Takahashi
,
T. Saito
,
H. Baba
, and
Y. Nakagome

Abstract  

In order to estimate the deformation rate of fission fragment at the scission point for thermal neutron-induced fission of233,235U and239Pu, double-velocity and double-energy measurements were carried out. As the result of the estimation of the deformation rate, two types of scission point configurations were found. One type is composed of deformed light and heavy fragments, and the other type is a combination of deformed light and spherical heavy fragments. Mass and total kinetic energy distributions were sorted in two distributions by means of the type of configuration.

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Abstract  

The crystal structures of BaTiO3 and PbTiO3 fine particles have been investigated by powder diffraction using synchrotron radiation high energy X-rays. It is revealed that a BaTiO3 fine particle essentially consists of tetragonal and cubic structure components at 300 K, whereas a PbTiO3 fine particle consists of a tetragonal structure. Adopting a structure model for the BaTiO3 particle that a cubic shell covers a tetragonal core, the thickness of cubic BaTiO3 shell is estimated at almost constant irrespective of particle sizes. Successive phase transitions are detected in 100 nm particles of BaTiO3 near the phase-transition temperatures of a bulk crystal. The changes in diffraction profiles are small, but they are apparent for a most up-to-date powder diffractometry.

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Summary A new EGA-MS instrument consisted of a combination of skimmer interface with no change of evolved gaseous species and IAMS (Ion Attachment Mass Spectrometry) with no fragmentation during the ionization has been developed successfully. As its application of evolved gaseous species from PVA as firing process of alumina ceramics binder, the method has indicated detection of gaseous species which have not been detected with Py-GC-MS.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
A. Yokoyama
,
S. Morimoto
,
T. Inoue
,
J. Sanada
,
H. Araki
,
T. Saito
,
H. Baba
,
S. Shibata
,
A. Shinohara
,
T. Muroyama
, and
Y. Ohkubo

Abstract  

Target-like products, that is,191–200Au,185–200Pt, and183–195Ir, from197Au target bombarded with12C ions at the energies of 180, 230, and 400 MeV/u were measured by using off-line gamma-ray spectrometry combined with chemical separation procedures. Spallation systematics by Rudstam reproduces well the measured cross sections for formation of platinum and iridium isotopes. It was found that the cross sections of gold nuclides increase with increase of the incident energy in the range studied and they are enhanced if compared with the reported proton-induced reaction of gold at a similar incident energy. It is suggested that the electromagnetic dissociation process plays a role for production of such gold nuclides.

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Journal of Thermal Analysis and Calorimetry
Authors:
T. Tanaka
,
J. Magoshi
,
Y. Magoshi
,
B. Lotz
,
S.-I. Inoue
,
M. Kobayashi
,
H. Tsuda
,
M. Becker
,
Zh. Han
, and
Sh. Nakamura

Abstract  

The crystal structure, thermal properties and growth rates of spherulites of the Tussah silk fibroin, produced upon drying of the silk taken directly from the lumen which is essentially a poly(L-alanine)polypeptide, are investigated. Depending on casting conditions, spherulites with either αhelical chain conformation or β parallel sheet structure are produced. The growth rates display a strong positive temperature coefficient, with an apparent transition, which however cannot be related with the formation of two different crystal structures at this stage.

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