thermal analysis

Описано спосіб розрахунку теплофізичних характеристик композитних матеріалів зі складною внутрішньою структурою на основі дискретної моделі, що будується за методом теплоелектричних аналогій.

This paper consider the method of calculation the thermophysical characteristics of composite materials with complex internal structure based on the discrete model that is constructed by the method of thermal-electric analogies.

The filtration method of gradual dehydration of Iron(II) sulfate heptahydrate hase been proposed. Based on the generalization of experimental data of hydrodynamics, the calculated dependence Euзовн=155∙Reзовн-0,55∙Hdч  was obtained, which makes it possible to determine theoreticallypressure losses in the stationary layer of FeSO4·7H2O.According to the results of complex thermal analysis, the regularities of the gradual dehydration process of FeSO4·7H2O have been established in different temperature intervals.

This work reveals a method of complex thermal and chemical activation of natural clinoptilolite from Sokyrnytsky deposit. The chemical activation of a mineral was carried out by HCl solutions treatment at various ratios of liquid-to-solid phases. With the use of thermal and infrared (IR) spectroscopic analyses, the adsorption property of a natural and activated clinoptilolite has been examined for water vapor. The ability of complexly activated clinoptilolite to adsorb direct dyes from their aqua solutions has been investigated.

Biogenic surfactants (rhamnolipid biocomplex, dirhamnolipid and exopolysaccharide) and polyhydroxyalkanoate biopolymer which are the new biosynthesis products of Pseudomonas sp. PS-17 strain have been obtained. The thermal transformation of these products has been studied in the air in the temperature range of 293–1273 K. Thermolysis and IR spectroscopy revealed a formation of rhamnolipid biocomplex between rhamnolipids and exopolysaccharide upon acidification of the culture fluid supernatant to pH = 3. Cellular polymer – polyhydroxyalkanoate – was identified by UV-Vis spectroscopy.

The IR spectroscopy and complex thermal analysis have been used to analyze the adsorption capacity of Transcarpathian clinoptilolite, both naturally occurring and activated, relative to water vapor.

The chemical compositions and properties of glass of different systems for the production of glass ionomer dental cements (GIC) were analyzed. For the synthesis of glass, the basic system 4SiO2–3Al2O3 – xNb2O5 – CaO with the content of Nb2O5 8.8 and 16.2% (wt.) is proposed. High-temperature technology and parameters of glass production for GIC are presented in the article. The properties of synthesized niobium-containing glass were determined and analyzed. The effect of niobium oxide on the crystallization ability of glass was determined by the method of differential thermal analysis.

Based on the complex thermal, titrimetric and UV/Vis spectral analyzes, the structure and the content of functional groups in the molecules of humic acids obtained from different raw materials – coprolite, peat and leonardite – were investigated. The thermal stability of the substances was investigated in the air in the temperature range 20-1000°C. It has been found that the content of the aliphatic component is predominant in humic acids obtained from different raw materials.

The paper describes some approaches for thermal analysis of nano-composites by finite element method.

The paper describes main approaches to thermal analysis of composites in Termet CAE system. Also it describes some principles of FEM implementation in the system.