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Volume 19 (1992)
- Issue 4 Pages 151-
- Issue 3 Pages 103-
- Issue 2 Pages 57-
- Issue 1 Pages 2-
Volume 19, Issue 4
Displaying 1-7 of 7 articles from this issue
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Shirou Shimada1992 Volume 19 Issue 4 Pages 151-155
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe dehydration and thermal decomposition of NaClO4·H2O were studied by using a home-made simultaneous AE-DTA apparatus. It was found that the heating of powdered NaClO4·H2O samples gives rise to the low- and high-temperature AE peaks in a range 70-300°C and 450-575°C, respectively, the latter consisting of six peaks a-f. The origins of both the low- and high- temperature AE peaks were suggested by the high temperature microscopic observation of the samples under the heating. The influence of the resonant frequency of the sensor (140kHz to 1.5MHz) on both the peaks was examined. The power spectra with a peak at 80 or 140kHz characteristic of bubble formation were obtained, which results from oxygen generation due to the decomposition.View full abstractDownload PDF (1438K) -
Takayuki Tsuji, Toshimasa Hashimoto1992 Volume 19 Issue 4 Pages 156-162
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSA simple non-steady state method using a temperature wave method has been developed for measuring the thermal diffusivity of organic material including solid and liquid state. This method is based on the acJoule heating at the front surface of flat film shaped sample and the observation of the temperature oscillation at the rear surface. A sputtered gold layer on both surfaces was used as the heater and sensor. When the temperature wave diffuses to the rear surface, it takes a short time for the heat flow. Then a phase shift is produced between the heater and the sensor. This phase shift depends on the thermal diffusivity and the thickness of the sample plate. We described the thermal diffusivity for some normal alkans as a function of temperature including the rotational phase transition temperature and melting point. It is found from the measurements for alkans that the thermal diffusivity was rapid fall-off at the first order transition points and the odd-even effect of carbon number in molecular chain was recognized in the temperature dependence.View full abstractDownload PDF (1032K) -
Michiko Kodama, Shinji Takebayashi, Shun-ichi Kidokoro, Hatsuho Uedair ...1992 Volume 19 Issue 4 Pages 163-169
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe thermal denaturation (N-D transition) of fatty acid-containing and defatted (fatty acid-free) bovine serum albumin (BSA) at pH 7.00 was investigated by differential scanning microcalorimetry. The enthalpy change (ΔHcal) associated with the thermal transition from the native to the denatured state for the fatty acid-free BSA was about 30% lower than that for the fatty acid-containing BSA. The calorimetric data of two BSA's were analyzed on the basis of a double deconvolution method proposed by S. Kidokoro et. al. (Biopolymers 26, 231 (1987)). By this method, the thermal transition of the defatted BSA was analyzed to be a three-state transition, while the thermal transition of the fatty acid-containing BSA was estimated to be a four-state transition, corresponding to a three-domain structural model for this protein.View full abstractDownload PDF (1475K) -
Takafumi Matsumoto, Harumi Yokokawa1992 Volume 19 Issue 4 Pages 170-173
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSAn algorithm for searching the minium point of G, Gibbs energy of the system, by successively projecting the gradient vector of G into the space which satisfies mass balance equations, has been developed. A PC-based software implementing this algorithm has precisely determined the equilibrium points of numerous solid-gas systems. Since this algorithm neither needs any estimated initial point other than the point given as the quantities of input materials, nor passes unreasonable point such as negatives, it features high stability of the solution. The same algorithm can be applied for searching the minimum point of Helmholtz energy.View full abstractDownload PDF (609K) -
Kiyoshi Takeda1992 Volume 19 Issue 4 Pages 174-181
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSRecent calorimetric studies of the enthalpy relaxation in simple molecular glasses were summerized from the viewpoint of the entropy theory. Especially, enthalpy relaxations of some gglasses formed by unconventional techniques were described. From the qantitative experiments with high precision, the differences were discussed in the relaxational behavior of non-crystalline samples formed by liquid-quenching and other techniques. The utility and limitations of the Adam-Gibbs theory have been clarified.View full abstractDownload PDF (1080K) -
T. Arii, Y. Takata, T. Senda, A. Kishi1992 Volume 19 Issue 4 Pages 182-185
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (497K) -
K. Amita, H. Matsui, H. Okamoto, G. Hashizume1992 Volume 19 Issue 4 Pages 186-191
Published: October 30, 1992
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (1397K)
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