Showing papers in "Thermochimica Acta in 1991"

TL;DR: In this paper, the limitations and applications of the various nearly ideal binary solvent (NIBS) and modified Wilson models for predicting the thermochemical properties of solutes dissolved in binary solvent mixtures are examined using published solute solubility and infinite dilution activity coefficient data for 72 systems.

TL;DR: In this article, the enthalpies of fusion and melting point temperatures have been gathered from the chemical literature and presented in tabular form according to increasing carbon and hydrogen atom numbers.

TL;DR: In this paper, it was shown that the kinetic compensation effect mathematically results from the exponential form of the rate constant and that a change of activation energy is thus compensated by the same change in temperature or in the logarithm of the pre-exponential factor.

TL;DR: In this article, the influence of the base metal (titanium, tantalum, zirconium, niobium and some of their alloys) on the performance of IrO2-Ta2O5 coated electrodes was investigated.

TL;DR: In this article, the thermal behavior of chitosans with various degrees of deacetylation has been studied and the differential scanning calorimetry curves of the samples exhibit two peaks.

TL;DR: Isothermal calorimetry can be used to examine total metabolic rates of plant samples and to study effects of a wide variety of naturally occurring or artificially added factors on those rates as discussed by the authors.

TL;DR: The application of thermal analysis in the investigation of the role of chemical admixtures in cement hydration is reviewed in this paper, with or without the presence of accelerators, retarders/water reducers and plasticizers.

TL;DR: The Sulphoaluminate belite cement clinker with the main phases C 2 S, C 4 A 3 S and C 4 AF was synthesized from limestone, fly ash and gypsum.

TL;DR: In this article, the thermal decomposition of NTO (3-nitro-1,2,4-triazol-5-one) was studied using DSC, TGA-MS, and ARC.

TL;DR: In this article, a review of the literature on calorimetric measurements carried out in the laboratory under conditions closely resembling those maintained in industrial reactors is presented, followed by a description of a few examples of the results obtained.

TL;DR: In this paper, a simple and consistent method of kinetic analysis of TA data has been developed, which allows one to perform the correct determination of the most suitable kinetic model and subsequent calculation of all kinetic parameters needed for a quantitative description of the studied process.

TL;DR: Syndiotactic polystyrene is a semicrystalline polymer with a melting point between 264 and 272°C as discussed by the authors, and it has a melting capacity of 53.2 J g −1 with typical syntactic poly styrene samples being about 50% crystalline.

TL;DR: In this article, a slow evaporation technique was used to grow single crystals of ammonium dihydrogen phosphate (ADP) from supersaturated aqueous solutions, and the identification of crystal structure for as-grown ADP crystals was achieved.

TL;DR: In this paper, the DSC scans of edible vegetable oils and of lard were measured by heating the samples up to 360 °C in an atmosphere of oxygen, and their extrapolated onset and peak maximum temperatures were determined and used for the assessment of thermal-oxidative stabilities of the samples and for calculation of activation energies.

TL;DR: Besides proteins, lipids are the major constituents of biological membranes and have therefore been the subject of intensive research over the last 20-25 years and show thermotropic and lyotropic phase behaviour.

TL;DR: In this paper, the basic theory underlying this method is discussed and the application of dynamic mechanical analysis (DMTA) to a wide range of materials ranging from solid composites through to polymer melts is considered.

TL;DR: In this article, enthalpies and temperatures of fusion were measured by differential scanning calorimetry for some n -paraffins (docosane, tetracosane and hexacosane), and heat capacity differences between the solid and liquid at the melting point (Δ C pm ) were derived from the experimental results.

TL;DR: In this paper, the thermal decomposition of silver oxalate has been carried out under isothermal conditions using atmospheres of nitrogen, air, oxygen and carbon dioxide, as well as under vacuum.

TL;DR: In this article, the Nb 2 O, Na 2 O and K 2 O systems were re-investigated between 50 and 100 mol% by thermal analysis, dilatometry and X-ray techniques.

TL;DR: In this paper, a DTG and/or TG curve may be produced for direct comparison with experimental curves by assuming values for A and E and using finite difference techniques to produce such a curve.

TL;DR: In this paper, the results showed that both compounds change during heating at different temperatures but that the final products were both MgO. Their Δ H values of dehydration and decomposition were determined by DSC and the thermochemical reactions were given.

TL;DR: Calorimetric investigations of systems of pharmaceutical interest are selectively reviewed and the need for more systematic and quantitative investigations of bioactivity, especially of synergic and antagonistic drug combinations, is drawn.

TL;DR: In this paper, a method for calibrating quantitatively a temperature-programmed decomposition, mass-spectrometric (TPD-MS) system by monitoring the gases evolved during the thermal decomposition of a chemical within the TPD reactor is described.

TL;DR: In this article, a TGA-Fourier transform infrared spectrometer (FTIR) coupled system was used to identify pyrolytic products in the effluent gas as acetic acid for the first-step product.

TL;DR: The principle of emanation thermal analysis, based on the measurement of inert gas released from solids, is given in this article, and the labelling techniques for sample preparation and the mechanisms of the inert gas release are discussed.

TL;DR: In this paper, the authors compare the incremental change in heat capacity in the glass transition temperature range for glassy or freeze-concentrated systems and show that the complex events observed in freeze-conscentrated materials might be considered as the appearance of the transition of their amorphous fraction.

TL;DR: In this article, a commercially available dolomite was split into six different particle size ranges and thermogravimetric and differential thermal analysis was performed on each of these samples.

TL;DR: The mass spectra of the rare earth-thd chelates were very similar to those of the fluorine containing complexes as discussed by the authors, and the strongest peaks in the MS were the following: Pr(hfa)3· H2O and Eu(m 3.5· DMF.

TL;DR: In this article, thermogravimetry-mass spectrometry (TG-MS) analysis of a phenolic resin was carried out recently for the study of the curing of the prepolymer, solvent extraction and carbonization of the polymer at high temperature in an inert atmosphere.