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Abstract  

Thermal decomposition of oxalate and nitrate hydrates of transplutonium elements has been studied by differential thermal and X-ray analysis, under heating in helium and oxygen. The formation heats of anhydrous crystalline Am(III) and Cm(III) nitrates were estimated from DTA data. Data of the self-decomposition of244Cm(III) salts under the influence of inherent -radiation were obtained.

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The paper describes the results of statistical analysis of DTA diagrams. A connection is found between the second and third endothermal effects. An analysis of geometrical characteristics of theT, S andh values of DTA diagrams confirms the absence of reliable connections. The rank correlation coefficients are determined according to Spearman. Non-linear programming is formulated to obtain the kinetic dependencies of the process of hydration of cement studied by DTA.

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Attempts were made to apply DTA together with TG for the investigation of asphalt-poly(methyl methacrylate) systems. Compositions were made by photopolymerization of methyl methacrylate in the presence of asphalt or asphalt components.

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Abstract  

The thermal decomposition of iminodiacetic, oxydiacetic, and thiodiacetic acids in helium atmosphere has been studied by means of thermogravimetry (TG), differential thermal analysis (DTA) and temperature-programmed pyrolysis directly coupled with mass spectrometry (TPPy-MS). Evolved gas analysis (EGA) profiles of iminodiacetic and oxydiacetic acids were obtained and compared with TG and DTA profiles. The decomposition of iminodiacetic acid forms water, CO, CO2, CH3CN, HCN and some hydrocarbons. After water evolution a cyclic anhydride is formed, as well as for oxydiacetic acid. Thiodiacetic acid vaporizes without decomposition.

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Theβγ transformation of Ca2SiO4 was investigated with regard to the disintegration of the sinter in alumina manufacturing. DTA was applied to study the effect of the reducing atmosphere upon the course of the polymorphic transitions of Ca2SiO4, and particularly the self-disintegration process. Pure synthetic dicalcium orthosilicate and blends of pure components from the system CaO-Al2O3-SiO2-Fe2O3 were compared with technological mixtures of limestone and fly ash. Data obtained from the DTA runs allowed the specification of technical parameter for both firing and cooling of the sinter.

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