Netsu Sokutei

Activity Measurements of Zn-Te Alloys by EMF Method

Iwao Katayama, Takeo Inomoto, Yasuyuki Kuwaki, Zensaku Kozuka, Takamic ...

1991 Volume 18 Issue 2 Pages 53-57
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.53

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The e. m. f. of galvanic cells with the solid electrolyte (ZrO₂(+Y₂O₃)) was measured to determine the activity of zinc at the temperatures 839-988K in the two phase regions of zinc-tellurium alloys. The cells used were as follows:
Kanthal|Re|Zn, ZnO|ZrO₂(+Y₂O₃)|ZnTe+Zn, ZnO|Re|Kanthal;
Kanthal|Re|ZnTe-Te, ZnO|ZrO₂(+Y₂O₃)|air, Pt.
The e. m. f. method with fused salt electrolyte was also used for the alloy of ZnTe-Te.
The results were presented by the equations:
loga_Zn=2.365-7419.4/T/K for ZnTe-Te and
loga_Zn=-0.012+9.408/T/K for ZnTe-Zn alloy.
The solubility limit of Zn-Te system at 873K was determined, and the free energy of formation of ZnTe was derived from the data in this study. The result was compared with published ones.

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Enthalpy of Formation of a Solid Soluion in the Cr-S System

Takashi Uchida, Kozue Asakura, Masataka Wakihara, Masao Taniguchi

1991 Volume 18 Issue 2 Pages 58-63
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.58

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Enthalpy changes of combustion (ΔH_c) of nonstoichiometric chromium sulfides; trigonal-Cr₂S₃ (t-Cr₂S₃) and rhombohedral-Cr₂S₃ (r-Cr₂S₃), were measured by using a Tian-Calvet type twin-calorimeter. The enthalpy change of phase transformation from t-Cr₂S₃ to r-Cr₂S₃ (CrS_1.471 to CrS_1.478) was found to be; ΔH_T/kJ·mol^-1=-83.16. In the nonstoichiometric t-Cr₂S₃ phase (CrS_1.402-CrS_1.471), the ΔH_c value stayed unchanged at about-840kJ·mol^-1 in the compositional range of CrS_1.450-CrS_1.471, while it increased with decreasing sulfur composition (x in CrS_x) up to c. a. -420kJ·mol^-1 at CrS_1.402, suggesting that the crystal lattice of CrS_x becomes more stable at lower sulfur compositions in the t-Cr₂S₃ phase. The enthalpies of the foration of solid slution (ΔH^ss)in the t-Cr₂S₃ phase were also estimated by assuming CrS_1.478 (sulfurrich end of the t-Cr₂S₃ phase) as the standard state and that the more sulfur deficient compositions than CrS_1.478 were considered to be formed by the dissolution of Cr atoms into CrS_1.478. ΔH^ss was almost zero in the compositional range of CrS_1.450-CrS_1.471, while it increased with decreasing sulfur composition x in x < 1.450. It went through a maximum of c. a. 370kJ·mol^-1 at CrS_1.440 and then decreased.

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Supercooling and Its Thermal Hysteresis of Pure Metal Liquids

Makoto Kano

1991 Volume 18 Issue 2 Pages 64-70
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.64

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By using a recently developed adiabatic calorimeter, supercooling of gallium, bismuth, tin, lead and indium was measured. It was found that the metals which crystallize in lower symmetries supercooled more deeply and more stably than those which crystallize in the structure of higher symmetry. The degree of supercooling depended on the highest temperature experienced by the sample. This thermal hysteretic effect was examined from the standpoint of nucleation and precursory phenomenon of solidification.

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Enthalpy and Entropy Changes on Molecular Inclusion of 1-Butanol into α-and β-Cyclodextrin Cavities in Aqueous Solutions

Masao Fujisawa, Takayoshi Kimura, Sadao Takagi

1991 Volume 18 Issue 2 Pages 71-76
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.71

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Enthalpy of dilution of dilute aqueous solution of 1-butanol and those of transfer of 1-butanol from dilute aqueous solution to dilute aqueous α-and β-cyclodextrin solutions have been determined by microcalorimetry. The molar enthalpies, entropies, and Gibbs energies of inclusion as well as the equilibrium constants of 1:1 inclusion-complex formation and ratios of included 1-butanol at infinite dilution at 298.15K have also been determined. The dependences of enthalpies and entropies of inclusion on the number of carbon atoms in the alkyl radicals of alcohol molecules are discussed.

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Differential Scanning Calorimetric Study of the Thermal Denaturation of Glucoamylase

Akiyoshi Tanaka

1991 Volume 18 Issue 2 Pages 77-80
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.77

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The thermal unfolding of Rhizopus glucoamylase (EC 3.2.1.3) was studied at pH7 by high-sensitivity differential scanning calorimetry (DSC). The DSC curve showed a single irreversible asymmetric peak having the temperature of maximal excess specific heat, t_p, at around 57°C. The curve was resolved into two components according to the model of independent two-state processes. In the presence of SGI (5-amino-1, 5-dideoxy D-glucopyranose), a sugar inhibitor of the enzyme, t_p increased with increasing concentration of SGI. Analysis of the DSC data of the enzyme-SGI complex suggests two independent domains with dissociation of SGI in the second component.

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Role of Water Molecules in a Formation of Molecular Assemblies of Amphiphile Compounds: Surfactant and Phospholipid

Michiko Kodama, Syûzô Seki

1991 Volume 18 Issue 2 Pages 81-88
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.81

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The role of water molecules in an appearance of amphiphile molecular assemblies was investigated on the binary systems of surfactant-, and phospholipid-water. The thermal characterization of the water structure in these systems ravealed that the amount of interlamellar structural water increases in the order coagel < gel < micelle for the surfactant-water system and in the order bilayer crystal < Lβ' gel < Pβ' gel < liguid crystal for the phospholipid-water system. The phase transitions of the two systems were discussed from a change in the aggregation state of the water molecules, focusing on two kinds of interaction, hydration and electrostatic, operating in the polar head groups of amphiphile molecules.

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Flow-Injection Calorimetry of Heavy Metal Ions Using Apoenzyme-Reactors

Ikuo Satoh

1991 Volume 18 Issue 2 Pages 89-96
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.89

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A novel calorimetric flow-injection analysis for cofactors with use of immobilized metalloenzymes and thermistors was proposed. The biosensing system was assembled with a combination of the enzyme-reactor and the thermistor probe for monitoring the enzymatic activity. Heavy metal ions ranging from micromolar to millimolar levels were calorimetrically determined through its activation of the immobilized metal-free enzyme (apoenzyme) reactor. The overview of the apoenzyme reactivation microassay for heavy metal ions was described.

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 97a-100
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.97a

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[title in Japanese]

[in Japanese], [in Japanese]

1991 Volume 18 Issue 2 Pages 97
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.97

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 100-102
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.100

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 102-104
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.102

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[title in Japanese]

[in Japanese], [in Japanese]

1991 Volume 18 Issue 2 Pages 104-105
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.104

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 105-107
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.105

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 107-109
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.107

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[title in Japanese]

[in Japanese]

1991 Volume 18 Issue 2 Pages 109-111
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.109

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Combustion Rate Analysis of Solid Fuels by Thermogravimetric Analysis

M. Kaya, H. Matsuda

1991 Volume 18 Issue 2 Pages 112-115
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.112

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Thermal Analysis of Industrial Materials

-Opinions of a Practical Thermal Analyst-(Summary)

M. Todoki

1991 Volume 18 Issue 2 Pages 116-118
Published: April 30, 1991
Released on J-STAGE: September 07, 2009

DOIhttps://doi.org/10.11311/jscta1974.18.116

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