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Volume 21 (1994)
- Issue 4 Pages 151-
- Issue 3 Pages 111-
- Issue 2 Pages 55-
- Issue 1 Pages 2-
Volume 21, Issue 4
Displaying 1-5 of 5 articles from this issue
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Tadashi Arii, Takashi Kanaya, Akira Kishi, Nobuyuki Fujii1994 Volume 21 Issue 4 Pages 151-157
Published: October 30, 1994
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSMany of dehydration of inorganic salts are reversible and are influenced by the vapor pressure of water evolved. These reactions greatly depend on the experimental conditions such as the sample size, the nature of the atmosphere, the crucible shape and the heating rate, etc.
Recently, several controlled rate thermal analysis (CRTA) techniques have been actively studied. Here, we propose the dynamic rate control (DRC) method as a high resolution technique that belongs to the CRTA. In this technique, the heating rate of the sample is dynamically and continuously varied in response to the changes in the sample's decomposition rate. The presented data of the dehydration of inorganic salts (CaSO4·2H2O, MgSO4·7H2O and CuSO4·5H2O) show improved resolution as compared with the conventional TG thermograms. At the DRC method, the dehydration proceeds nearly under the equilibrium conditions. Since the beginning of the dehydration shifts to the lower temperature region, the change of DRC curves becomes much more distinct. Also, the reaction clearly occurs in several steps, with a plateau characterizing to the dehydration mechanism. This method is especially proved to be very effective technique in the detection of intermediate products.View full abstractDownload PDF (1012K) -
Naoyoshi Inouchi, Hidetsugu Fuwa1994 Volume 21 Issue 4 Pages 158-161
Published: October 30, 1994
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSGelatinization of endosperm starches isolated from new types of rice grains was characterized by DSC. The starches having higher amylose content showed lower gelatinization temperature and smaller enthalpy.View full abstractDownload PDF (591K) -
Hideo Okazaki1994 Volume 21 Issue 4 Pages 162-170
Published: October 30, 1994
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSIt is reviewed that how the excess heat capacity observed in supeitonic conductors is concerned with its structure and the behaviour of mobile ions distributed in a highly disordered fashion. Superionic conductors are classified into two types according to the number of ions responsible to ionic conduction; in Type I, all ions of one specy in the compound are responsible, such as α-AgI, and in Type II, mobile ions are produced by doping an impurity into insulators and are equal to the number of the impurity introduced, such as YSZ (ZrO2+Y2O3). The crystal structure and the heat capacity of the Type I supeitonic conductors are mainly described, especially on α-AgI, α-Ag2S, and α-RbAg4I5.View full abstractDownload PDF (1160K) -
Keiko Nishikawa1994 Volume 21 Issue 4 Pages 171-179
Published: October 30, 1994
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSIn order to show the contact point of diffraction studies and thermodynamics, structure description by “mixing state” for solutions is presented. The concentration fluctuation and the Kirkwood-Buff parameters are the ones to investigate the mixing state of solutions quantitatively. These parameters are obtained by small-angle X-ray scattering and themodynamic experiments, respectively. As examples of the analysis of the mixing state, the small-angle X-ray scattering studies for ethyl alcohol-water, iso-propyl alcohol-water, n-propyl alcohol-water, and tert-butyl alcohol-water systems and thermodynamic studies of 2-butoxyethanol-water system are presented.View full abstractDownload PDF (1328K) -
Robert N. Goldberg, Ron D. Weir, T. Kimura, H. Suga1994 Volume 21 Issue 4 Pages 180-190
Published: October 30, 1994
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESS
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