Showing papers in "Thermochimica Acta in 1979"

TL;DR: In this paper, the polymorphism of Bi2O3 has been studied by means of differential thermal analysis and electrical conductivity measurements, thermogravimetry, high temperature X-ray powder diffraction, and differential scanning calorimetry.

TL;DR: In this paper, data generated from selected model expressions for solid-state kinetics have been analysed in terms of expressions of closely-related form to test distinguishability of the models on which the expressions are based.

TL;DR: In this paper, the influence of the preparation history of α-Fe2O3 on its reactivity has been investigated in the context of hydrogen reduction of the metal ion Cu2+, Ni2+, and Ti4+ in a stream of oxygen, air or nitrogen at temperatures of 500-1200°C for one hour.

TL;DR: In this article, the authors determined the difference between the enthalpies of fusion and of solidification for several salt hydrates by means of differential scanning calorimetry (DSC).

TL;DR: In this paper, a model was proposed to explain the decomposition mechanism integratedly throughout the various partial pressures of carbon dioxide; the formation of the intermediate governed the decarbonation rate and the crystallization of MgCO 3 from the amorphous lower carbonate at ∼500°C.

TL;DR: In this article, a technique has been developed for rapid determination of thermal conductivity of solid materials using a commercial differential scanning calorimeter, which is constructed without modification of the original instrument.

TL;DR: In this paper, the formation enthalpies of solid alloys in the Fe, Co, Ni, and Ni binary systems have been determined with the aid of a solution calorimeter using liquid tin as solvent.

TL;DR: The suitability of the SETARAM high temperature calorimeter for the determination of mixing enthalpies of liquid metallic alloy systems has been investigated in this article, where several methods of calibration were investigated as well as the dependence of the calibration factor on total mass in the crucible and volume of a crucible occupied.

TL;DR: In this paper, a general method for the determination of enthalpy changes in solution for systems containing an unlimited number of components, that can give rise to mononuclear, polynuclear, protonated, hydroxo and mixed species was set up.

TL;DR: In this article, the thermal stabilities of 33 polynitroaromatic compounds and their derivatives were determined using non-isothermal differential thermal analysis (DTA), and the results obtained are discussed from a molecular structural point of view.

TL;DR: The Nomenclature Committee of the International Confederation for Thermal Analysis (ICTA) and its Sub-Committees have been well received and have been accepted by such international and national bodies as IUPAC8, ISO9, ASTM10 and AFNOR11 as mentioned in this paper.

TL;DR: In this article, isothermal and non-isothermal decomposition of hydromagnesite 4 MgCO3 · Mg(OH)2 · 4 H2O was studied thermogravimetrically.

TL;DR: In this article, the thermal behavior of crystalline titanium or zirconium bismonohydrogen orthophosphate dihydrate, Ti(HPO4)2·2H2O (γ-titanium phosphate) and Zr(H 2 O 2 O )2· 2H 2O and their sodium-and strontium-exchanged forms have been investigated.

TL;DR: In this article, the first two stages of the thermal decomposition of calcium oxalate monohydrate have been established from non-isothermal thermogravimetric studies, and the rate-controlling processes are phase boundary reactions; the dehydration step assumes spherical symmetry whereas the decomposition step follows cylindrical symmetry.

TL;DR: In this paper, the authors show that the heat of adsorption of ammonia on a protonated ZSM zeolite at 416 K, plotted as a function of surface coverage, passes through a maximum which is explained by the unusual conjunction of immobile adsorptions, mass transfer limitations, and preferential location of the most energetic acid sites in the internal pores of the zeolites structure.

TL;DR: In this article, a compensation effect was observed for the thermal decomposition of manganese(II) carbonates, prepared in the presence of Al 3+ and Na + ions. And the mechanism of decomposition was found to follow first order kinetics.

TL;DR: In this paper, general relationships are developed for obtaining non-isothermal (dynamic) rate equation from a knowledge of the isothermal kinetics of the system, and applications to several important specific forms of isothermal rate expressions are given.

TL;DR: The basic principles of the description and processing of thermal analysis (TA) curves are examined in this article, where a rational approach is used to investigate the limits of the validity of phenomenological thermodynamics under non-isothermal conditions.

TL;DR: In this paper, a least square curve-fitting method was developed for the following thermo-analytical problem: "find the kinetic parameters and the unknown initial amounts of the reactants from non-isothermal thermoanalytical curves in the case of two or more independent or quasi-independent thermal reactions".

TL;DR: In this article, a computer model of tobacco pyrolysis has been constructed which can calculate the gas formation rate/temperature profile from a given set of reaction parameters, and a generalised kinetic mechanism for the thermal decomposition of tobacco was developed.

TL;DR: In this paper, a number of M(CO) 6− x L x complexes were shown to undergo both disproportionation and substitution in a CO atmosphere, when heated on a thermobalance using a DSC.

TL;DR: In this paper, the molar heat capacity at constant pressure, C P, of the two binary liquid mixtures 1,2-dichloroethane + cyclohexane and 1, 2-Dichloromethane + methylcycloenhexane were determined at 298.15 K from measurements of the volumetric heat capacity, C p / V, in a Picker flow microcalorimeter.

TL;DR: In this paper, a critical survey of the apparatus used and of the reactions studied has determined the working under which the measures must be carried out, and a conduction microcalorimeter fitted with an inertia corrector can be used.

TL;DR: In this paper, the thermal analysis of n-long chain alcohols CH3(CH3)n-1-OH, designated as Cn-OH (n = 16, 18, 20 and 22), and corresponding alkoxy ethanols CH 3(CH2)n1-OCH2CH2

TL;DR: In this article, a comparative study of Avrami-Erofeev and diffusion-controlled reactions has been carried out using thermoanalytical data, calculated by assuming a quasi-isothermal heating technique.

TL;DR: In this paper, the thermal dehydrations of formate dihydrates of Mg(II), Mn(II, Fe, Co, Ni, Cu, Zn, and Cd(II) were studied by means of thermogravimetry, differential thermal analysis and differential scanning calorimetry in air.

TL;DR: In this paper, two methods, Reich-Stivala (R-S) and double-log (D-L), were employed to distinguish one mechanism from among 15 theoretical possibilities for heterogeneous solid-state reactions using theoretical TG data.

TL;DR: An exothermic phenomenon and a simultaneous rapid evolution of a small amount of carbon dioxide at −500°C during thermal decomposition of hydromagnesite 4 MgCO3 · Mg(OH)2 · 4 H2O was studied by isothermal DSCTG in a carbon dioxide atmosphere.