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.
This paper presents a method and algorithm for finding effective thermal characteristics of composite materials, with complex internal structure by the method of thermal-electrical analogies based on the discrete model that built for the task of analysis of the temperature field 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.
This work reviews the main methods of nitrogen and phosphorus removal from wastewater. The method of simultaneous removal of highly concentrated nitrogen and phosphorus was analyzed by physical and chemical precipitation, forming struvite, a by-product of magnesium ammonium orthophosphate hexahydrate. Laboratory investigations were conducted on the test solutions with the concentrations of ammonium nitrogen, phosphates, ions of magnesium and calcium corresponding to the ones of relevant elements in wastewater of swine complexes located in Lviv region, Ukraine.
The presented article gives a brief overview on the possible use of crushed rubber from waste tires in asphalt mixtures. Advantages, disadvantages and difficulties of its use in road construction are also discussed. The results of sieve analysis and thermal analysis obtained on the samples prepared from waste rubber are discussed. The use of recycled tire rubber in road construction can contribute significantly to the reduction of environmental load.