Clinoptilolite/Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>: a magnetic sorbent for removing <Superscript>90</Superscript>Sr from aqueous media

The ability of a magnetic sorbent prepared by modification of clinoptilolite with magnetite to take up ⁹⁰Sr was studied. ⁹⁰Sr is sorbed most efficiently at pH in the range 6–9. At the sorbent dosage of 5 g dm^–3 and sorption time of 24 h, the degree of ⁹⁰Sr sorption from aqueous solution is as high as 99.8%.     

Modification of the organic matter of brown coals with nitrous oxide

The results of the treatment of brown coals from the Kansk-Achinsk Basin in an atmosphere of nitrous oxide are given. It was established that the main products of nitrous oxide interaction with the organic matter of brown coal are soluble low-molecular-weight products (ketones and aromatic acids) and oxodiazoline structures in a coal matrix. The thermal-oxidative degradation of terminal oxygen-containing groups, which accompanied this process, facilitated the formation of strong crosslinks and the strengthening of a supramolecular structure.     

Diffusion welding of 12Cr18Ni10Ti steel to palladium alloy foil

The special features of the method of diffusion welding of corrosion-resisting steel with a palladium foil using an intermediate layer made of nickel are presented. The method can be used for producing full-strength and vacuum-tight welded joints.     

High-temperature oxidation of nickel-based alloys and estimation of the adhesion strength of resulting oxide layers

The kinetics of isothermal oxidation (1100°C) of commercial nickel-based alloys with different content of sulfur (0.22–3.2 wt ppm) is studied. The adhesion strength in a metal/oxide system is estimated as a function of sulfur content and duration of high-temperature exposure. The scratch-test technique is proposed to quantitatively estimate the work of adhesion of resulting oxide films. It is found that the film microstructure is composed of an inner α-Al₂O₃ layer and an outer NiAl₂O₄ spinel layer, which are separated by discrete inclusions of TiO₂. Residual stresses in the oxide film are experimentally determined by X-ray diffraction.     

Unstrained epitaxial InxGa1−x As films obtained on porous GaAs

Epitaxial layers of InGaAs solid solutions were grown on porous GaAs(100) substrates by liquid-phase epitaxy. A comparison between the compositions and thicknesses of these epitaxial layers with those of layers obtained under the same conditions on normal monolithic GaAs substrates suggests that the crystallization of epitaxial layers on porous substrates may be considered as the growth of free unstrained films. Pis’ma Zh. Tekh. Fiz. 25, 15–20 (November 12, 1999)     

A Thermogravimetric Analysis Study of the Kuzbass Coals of Different Ranks

The coals of different ranks from the Kuznetsk Coal Basin were studied by thermogravimetric analysis in inert and oxidizing atmospheres. Correlations between thermal decomposition characteristics [maximum decomposition temperatures (T_max, °C), maximum rates of decomposition (Vmax, %/min), and sample weight losses in different temperature ranges (Δm, %)] and proximate analysis [yields of volatile substances (Vdaf, %)] and petrographic analysis [vitrinite reflectance (R_o)] data and NMR-spectroscopic data [aromaticity factor ( fa)] as the characteristics of the degree of maturity of the test coals were established.     

The vitamin allowance of the pupils in a rural vocational and technical school and their prophylactic vitaminization]

The actual nutrition and providing with vitamins C and B1 was studied in boys aged 16-17 years, students of a rural trade school (Volsk of Saratov Province). Although the caloric value of their ration was high enough the content of animal proteins was only 42-48 g/day. The content of ascorbic acid in the ration comprised 48%, in the spring of 1987 it was 17%, and of 1988-29% of the recommended standard, vitamin B1 levels did not show seasonal differences. Vitamin C and B1 deficiencies in the spring were proved by their low excretion levels in urine, and by a low concentration of vitamin C and decreased activity of B1-dependent enzyme transketolase in the blood. Intake of "Undevitum" (1 dragee/day) during 4 months was conductive to the improvement of the student providing with vitamins.     

Thermal dissolution of oil shale in benzene with an ethanol additive under supercritical conditions

The results of the thermal dissolution of oil shale from some deposits in Russia in a benzene solvent under supercritical conditions in a semiflow system are reported. It was found that the addition of ethanol significantly increased the yield of liquid products due to the hydrogenating and alkylating properties of the alcohol.     

Domestic Technologies, Materials, and Equipment for Decorative Coatings

Methods for the application of decorative coatings to bottles are described. Possibilities of servicing customers are shown, using decoration of bottles as an example.