Electrochemical and Specific Heat Measurements on Tellurium-Halogen Systems

1979 ◽  
Vol 34 (8) ◽  
pp. 969-975 ◽  
Author(s):  
J. Haag ◽  
U. v. Alpen ◽  
E. Gmelin ◽  
A. Rabenau

AbstractGibbs free energies of reaction in the systems Te-TeX4 (X = Cl, Br, I) were determined from e.m.f. measurements of solid state galvanic cells using silver halides as auxiliary electrolytes. From the temperature dependence of the e.m.f. the standard entropies and enthalpies of formation S0 (298.15 K) and ⊿Hf0 (298.15 K) have been calculated for α-TeI, TeI4 , Te2 Br, TeBr4 , Te3Cl2 and TeCl4 . The specific heats of α-Tel and Te2Br were determined from 1.5 K to 300 K by adiabatic and differential scanning calorimetry.

1982 ◽  
Vol 60 (14) ◽  
pp. 1853-1856 ◽  
Author(s):  
Eva I. Vargha-Butler ◽  
A. Wilhelm Neumann ◽  
Hassan A. Hamza

The specific heats of five polymers were determined by differential scanning calorimetry (DSC) in the temperature range of 300 to 360 K. The measurements were performed with polymers in the form of films, powders, and granules to clarify whether or not DSC specific heat values are dependent on the diminution of the sample. It was found that the specific heats for the bulk and powdered form of the polymer samples are indistinguishable within the error limits, justifying the determination of specific heats of powders by means of DSC.


2019 ◽  
Vol 61 (4) ◽  
pp. 660
Author(s):  
Л.Т. Денисова ◽  
Л.А. Иртюго ◽  
В.В. Белецкий ◽  
Н.В. Белоусова ◽  
В.М. Денисов

AbstractEr_2Ge_2O_7–Er_2Sn_2O_7 solid solutions have been obtained using solid-state synthesis by burning the stoichiometric mixtures of the initial oxides in air in the temperature range of 1273–1473 K. The effects of temperature and solid solution composition on the specific heat have been examined by differential scanning calorimetry. The Er_2Ge_2O_7 thermodynamic functions have been calculated.


2018 ◽  
Vol 60 (2) ◽  
pp. 262
Author(s):  
Л.Т. Денисова ◽  
Н.В. Белоусова ◽  
Н.А. Галиахметова ◽  
В.М. Денисов ◽  
Е.О. Голубева

AbstractThe TmBiGeO_5 and YbBiGeO_5 compounds have been synthesized from Tm_2O_3 (Yb_2O_3), Bi_2O_3, and GeO_2 oxides by the solid-state synthesis with successive burning at 1003, 1073, 1123, 1143, 1173, and 1223 K. High-temperature specific heat of the oxide compounds has been measured by differential scanning calorimetry. Basing on the experimental dependences C _p = f ( T ), the thermodynamic properties of the oxide compounds, i.e., the enthalpy and entropy variations, have been calculated.


2013 ◽  
Vol 96 (6) ◽  
pp. 1362-1364 ◽  
Author(s):  
Deng-Fwu Hwang ◽  
Tzu-Feng Hsieh ◽  
Shan-Yang Lin

Abstract The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.


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