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Volume 10 (1983)
- Issue 4 Pages 127-
- Issue 3 Pages 91-
- Issue 2 Pages 43-
- Issue 1 Pages 2-
Volume 10, Issue 1
Displaying 1-5 of 5 articles from this issue
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Kimio Isa, Masahiro Nogawa1983 Volume 10 Issue 1 Pages 2-7
Published: January 20, 1983
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThermal decomposition of magnesium sulfate heptahydrate was studied by TG-DTG-DTA under various sealed atmospheres (open, quasi-sealed, and completely sealed). In the case of open system, stable hexahydrate was obtained, and in the case of quasi-sealed system (29.8μm∅ and 130μm∅ tungsten wires), stable tri-, di-, and mono-hydrate were obtained. However in the case of completely sealed system, mono-hydrate was only obtained. Concerning the condition of completely sealed system, there is some relation between the results of MgSO4·7H2O and CaSO4·2H2O. In the case of CaSO4·2H2O, the hemihydrate was obtained under completely sealed system. The results explain directly that self-generated atmosphere plays an important role of dehydration reaction. The intermediate stages of dehydration were easily obtained by this method.View full abstractDownload PDF (554K) -
Yasutoshi Saito, Kurima Kobayashi, Toshio Maruyama1983 Volume 10 Issue 1 Pages 8-14
Published: January 20, 1983
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe phase transition in Na2SO4 was studied by differential scanning calorimetry (DSC). In the undoped Na2SO4, the enthalpy changes of the III→I, I→II and II→III transitions were 6.50, -4.85 and -2.15kJmol-1, respectively. When the reheating was started in the course of the II→III transition, the absolute value of the enthalpy change of the II→I transition increased with an increase in the starting temperature of the reheating, whereas that of the III→I transition decreased. The doping of yttrium up to about 0.7 at.% decreased the transition temperature and the enthalpy changes of the III→I transition. The entropy change of the II→I transition in the undoped Na2SO4 was found to be 8.30Jmol-1K-1 from the calculation with the enthalpy change and the transition temperature. It suggested that the transition was characterized by the configurational change of 3.View full abstractDownload PDF (843K) -
Jun Oishi1983 Volume 10 Issue 1 Pages 15-21
Published: January 20, 1983
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThis report describes the some problems mainly on the experimental apparatus and procedures encountered in the measurements of the heats of formation of metal fluorides, especially of lanthanide trifluorides by the fluorine bomb calorimetry, which were carried out by us in the past nine years.
There involved are the handling of fluorine gas, the effects of the impurities contained in the metal samples and their states of combination, the handling of the metal samples in ambient and fluorine gas atmospheres, the method of burning of the metal samples, and the handling of the combustion products.
The comparison of our experimental results with those by the other methods of measurement is discussed. The application of the fluorine bomb calorimetry is refered to, and it is concluded that the fluorine bomb calorimetry is a very promising and useful method only if careful safty considerations are given to the handling of fluorine gas.View full abstractDownload PDF (1086K) -
(I) Principles of calorimetryM. Sakiyama1983 Volume 10 Issue 1 Pages 22-31
Published: January 20, 1983
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (1426K) -
T. Ozawa1983 Volume 10 Issue 1 Pages 35
Published: January 20, 1983
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (148K)
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