Advanced Materials Research Vol. 1040

Abstract: In this paper for investigation of the medicine «Lactobacterin» containing lactic acid bacteria was used luminescence method. It is shown, that spectrum of the Lactobacilli has 3 peaks from different substances. It is shown that during 2 hours the bacterial cells are alive.

Abstract: The possibility of aromatic petroleum resin liquidphase oxidation was investigated. The influence of various factors on the modification process and properties oxidized samples was studied. The optimal parameters of the oxidation processes with hydrogen peroxide using interphase catalysis mechanisms, with peracetic acid, and with the electrogenerated oxidants complex of peroxide nature.

Abstract: A method of oxidative mineralization of the salicylic acid and its derivatives as well as medicinal products containing salicylic acid as the active ingredient was investigated. Destruction of the organic compounds is possible both in the electrolyte under the oxidant, electrochemically formed in situ in the sulphuric acid solutions, and at the anode so. Simultaneously, at the cathode, reduction of the zinc ions, contained in a number of medicinal products, is possible. Final products of the oxidation are simple non-toxic organic compounds, carbon dioxide, and water. This process is the most effective in the 40% sulphuric acid at the current density of 0.5–0.8 A/cm² and the temperature of 30–50 °C.

Abstract: In this article we provide results on the preparation of starch-based block copolymer with polyacrylic acid by radical polymerization. Starch was pregelatinized and then reacted with acrylic acid in the presence of radical polymerization initiator. Resulting mixture was used to prepare cast-films. Structure of the polymer films was investigated by gel filtration chromatography, FTIR and DCS analysis. It was found that structure of the films represents starch-graft-polyacrylic acid dispersed in a starch matrix. Results of DCS and FTIR suggested that polyacrylic acid acts as additional plasticizer for starch films.

Abstract: It was shown that Ba (BrF₄)₂ acts like a highly-active brominating agent in case of interaction with p-nitrotoluene, the pure 3-bromo-nitrotoluene is formed. It was shown, that typical electrophilic bromination of aromatic compound with electron-donating and electron-accepting substituents occurs without any catalysts and hard conditions.

Abstract: The application of NF90 membrane was shown to be the most effective for the removal of silicon and iron ions and organic substances from natural water. In this case, the membrane retention capacity amounts to ~ 86.0 % for silicon ions. The application of GR81PP and GR95PP membranes was shown as the most effective for the removal of iron ions and organic substances from natural water. In this case, the membrane retention capacity amounts to ~ 86.0 % for organic substances and 99.8% for iron ions. Therefore, the processes of ultra- nanofiltration can be used as a post-treatment step for groundwater of Western Siberia.

Abstract: One of the promising directions of quality improvement of building materials (based on various binders) is to use hydrosilicates of calcium and barium. In particular, it is known that the application of calcium hydrosilicates can improve the compression strength in two or three times; the fracture toughness can be increased in two times and more. Prospects of using barium hydrosilicates in cement systems are due to the similarity of the chemical composition (with calcium hydrosilicates) and advantages of barium cements compared to traditional cements. It is advisable to synthesize the barium hydrosilicates by means of low-temperature technology. To investigate the influence of the curing agent (barium chloride) to the properties of the reaction products in the present study the IR spectroscopy and differential scanning calorimetry (DSC) are used. Analysis of the results allowed to state that the main reaction product is a crystalline silicate phase. Reducing the amount of curing agent leads to an increase of the content of silicic acid. DSC results show that dehydration of barium hydrosilicates takes place in two stages. It is typical for systems BaO•SiO₂•6H₂O. Increasing the content of silicic acid is accompanied by an endothermic effect in temperature range of 120...130 °C. Joint analysis of the results of IR spectroscopy and DSC leads to the conclusion that there is a reaction of barium carbonate and silicic acid. In general case, reduction of the amount of the curing agent contributes to increase of content of the silica acid and barium carbonate. Therefore, it is advisable to use compositions prepared with reduced amount of BaCl₂ in systems capable of interacting with the silica acid and forming the insoluble products.

Abstract: Radiation safety of the rooms with X-ray sources often achieved by means of creating protective coatings. Such coatings are made of special mortar containing barite. There is the alternative for barite – barium hydrosilicates. It is advisable to synthesize barium hydrosilicates from available components – sodium hydrosilicates and soluble salts of barium. To improve the effectiveness of the protective coatings the composition and technology of the shielding material is recommended. In this work the synthesis was carried out by means of precipitation the barium hydrosilicates from solution of sodium hydrosilicates and barium chloride. It is found that composition of the synthesized product obtained by precipitation of sodium hydrosilicates with barium chloride contains barium hydrosilicates, barium carbonate and silicic acid. This is due to technological processes: intensive mixing of solutions leads to air entrapment. The properties of the composite binder made of portland cement and barium hydrosilicates are examined. It is shown that optimal composition for X-ray-protective binder comprises 20-30% of barium hydrosilicates synthesized with precipitant amount close to stoichiometric.

Abstract: This study presents the research of water-alcohol solution phase transition by permittivity changing. Complex permittivity was measured by open-end-coaxial method in frequency range 500 MHz – 40 GHz. We varied temperature from 240 K to 310 K and ethanol content from 10 % to 80 %. Temperature dependencies of permittivity for water-alcohol solutions were obtained and the patterns of variation of those solidification temperatures were established.

Abstract: Review of the widely known isotope separation techniques where the isotope effect is caused by electron interactions is presented in this paper. An assumption that isotope effects are based on spin interactions can be made.