Synthesis and properties of SnO prepared from ammoniacal and carbonate suspensions of tin (II) hydroxy compound under microwave radiation

SnO powder was prepared by microwave treatment of ammoniacal and carbonate Sn6O4(OH)4 suspensions. It was shown that the type of the precipitant (aqueous ammonia and sodium carbonate) for Sn(II) hydroxy compound affects the surface properties of the resulting oxide. It is found that SnO powders prepared by homogeneous precipitation of tin(II) hydroxy compound with sodium carbonate, followed by the microwave treatment, have the smaller specific surface area (~0.4 m2 g–1) and contain agglomerates of the larger size (~50 µm) joint together into a “flower.

Zinc oxide films obtained by sol-gel method from film-forming solutions

Thin ZnO films on silicon and quartz substrates were obtained from a film-enriched ethanolic solution based on Zn(NO3)2⋅6H2O and salicylic acid. The effect of salicylic acid on the processes occurring in the film-forming solution was studied by IR spectroscopy, proton-magnetic resonance, and viscometry methods. The formation of zinc salicylate nitrate in an ethanol solution is established, where salicylic acid exhibits a monodentate property in the carboxyl group. Thermal formation of zinc oxide was determined by thermal analysis and X-ray diffraction. The analysis of optical and electrophysical characteristics of ZnO films was carried out using spectroscopy, ellipsometry and also a block for measuring the electrophysical properties of thin-film materials. It was found that ZnO films were semiconductors of the electronic type, characterized by an optical band gap of 2.91–3.21eV, a surface resistance of 109–106 Q. and transparency coefficients in the visible spectral range of 0.80–0.96. It was shown that as the thickness of the ZnO films increased the resistance decreased

Microwave-assisted hydrothermal process for the preparation of SnO from an ammoniacal Sn6O4(OH)4 suspension

SnO powder with a specific surface area of 2 m2/g has been prepared by microwave-assisted hydrothermal processing of an ammoniacal Sn6O4(OH)4 suspension. We have examined the effect of pressure rise rate in a reaction mixture on the surface morphology and photocatalytic activity of SnO. Raising the pressure has been shown to reduce the SnO synthesis time, without influencing the surface morphology of SnO or its photocatalytic activity for methyl orange photodegradation

The composition and structure of iron(III) complex compounds with salicylic acid in ethanol solution and in the solid thin film state

Owing to their properties iron(III) salicylate complexes are interest of for application in biomedicine and environmental monitoring. Recently this complex compounds also are investigated as a potential candidate for preparing Fe2O3 films by sol-gel method from ethanol film-forming solution. Relevance of the work was caused by necessity to determine the structure and composition of iron(III) salicylate complexes in ethanol solution and in the solid film state, which influence on film properties. Nowadays this information is absence in the literature. UV spectroscopy, NMR measurement, methods of isomolar series and thermal analysis were used to analyze the composition of complex in ethanol solution and in the solid state. It was found, that salicylic acid interacts with iron(III) chloride in ethanol solution promotes the formation of [FeC6H4OCOO]+ complex, where salicylate ligand behaves as bidentate ligand. After removal of the solvent from solution iron(III) chloride salicylate crystal hydrate complex of 1:1 stoichiometry was formed in solid state. Thermal decomposition of this compound led to formation α–Fe2O3

New insights into the Weichselian environment and climate of the East Siberian Arctic, derived from fossil insects, plants, and mammals

Multidisciplinary study of a key section on the Laptev Sea Coast (Bykovsky Peninsula, east Lena Delta) in 1998–2001 provides the most complete record of Middle and Late Weichselian environments in the East Siberian Arctic. The 40-m high Mamontovy Khayata cliff is a typical Ice Complex section built of icy silts with a network of large syngenetic polygonal ice wedges, and is richly fossiliferous. In combination with pollen, plant macrofossil and mammal fossils, a sequence of ca 70 insect samples provides a new interpretation of the environment and climate of the area between ca 50 and 12 ka. The large number of radiocarbon dates from the section, together with an extensive 14C database on mammal bones, allows chronological correlation of the various proxies. The Bykovsky record shows how climate change, and the Last Glacial Maximum in particular, affected terrestrial organisms such as insects and large grazing mammals. Both during the presumed “Karginsky Interstadial” (MIS 3) and the Sartanian Glacial (MIS 2), the vegetation remained a mosaic arctic grassland with relatively high diversity of grasses and herbs and dominance of xeric habitats: the tundra-steppe type. This biome was supported by a constantly very continental climate, caused by low sea level and enormous extension of shelf land. Variations within the broad pattern were caused mainly by fluctuations in summer temperature, related to global trends but overprinted by the effect of continentality. No major changes in humidity were observed nor were advances of modern-type forest or forest-tundra recorded, suggesting a major revision of the “Karginsky Interstadial” paradigm. The changing subtypes of the tundra-steppe environment were persistently favourable for mammalian grazers, which inhabited the shelf lowlands throughout the studied period. Mammal population numbers were lowered during the LGM, especially toward its end, and then flourished in a short, but impressive peak in the latest Weichselian, just before the collapse of the tundra-steppe biome. Throughout MIS 3 and MIS 2, the climate remained very favourable for the aggradation of permafrost. No events of regional permafrost degradation were observed in the continuous Bykovsky sequence until the very end of the Pleistocene

Development of national production through integration of machine building enterprises into industrial park structures

The article studies organizational & economic peculiarities of functioning of domestic industrial enterprises which consist in transformation of corporate vertically integrated structures into inter-company production associations. It is suggested to create industrial parks, as a main tool of development of territorial inter-company productive networks in machine building complex. Expedience of creation of industrial parks on the basis of large machine building enterprises is substantiated. Such initiatives are aimed at development of production of component base for structural industrial enterprises. Principles of creation of industrial parks are based on identified motivating and suppressing factors of integration of machine building enterprises into network production structures. Targeted indicators of monitoring of effectiveness of industrial parks functioning are offered. It suggested to use the following indicators as basic ones, for conduct of monitoring of indicators: level of import substitution of component production for enterprise-integrator; growth of total investments at enterprises-residents of park; indicator of growth of production of innovational products in total volume of products manufactured by park; indicator of growth of jobs in park’s structure; indicator of growth of the number of SME in park’s structure.peer-reviewe

ABOUT SELF-STUDY OF PHYSICAL CULTURE DURING THE EXAMINATIONS AS A CRITERION OF STUDENTS’ READINESS TO PROFESSIONAL ACTIVITIES

Purpose of the study: The relevance of the research is conditioned by the contradiction between the social and state need to form the positive attitude to healthy lifestyle (including extracurricular time) in student youth and the underestimation of the potential of students' self-study activities aimed at increasing of physical activity and development of readiness for physical culture in specified group of youth. The article is aimed at the study of the student’s readiness for independent physical education during the examinations as a manifestation of independence in general, as well as at the study of the significance of independent physical education of students during the examinations in the process of future specialist formation. Methodology: The leading approach to the study of this problem was the theory of the activity approach in the development of personality and independent activities of students which allowed to substantiate the place of readiness of university students for independent physical training during the examinations in the process of future specialist training. Results: Of all the types of special readiness, the readiness of university students for independent physical training during examinations is of particular importance, the specificity of which is that this type of readiness contains features of types of readiness for professional activity, as well as readiness to act in problem situations, in which connection the readiness for independent physical training during the examinations is an indicator of the future specialist's readiness to problem professional situation. Applications of this study: The results of the study allow specialists who study the quality of university graduates to use the assessment of the development of student’s readiness for independent physical training during the examinations as an indicator of the future specialist’s readiness to act in a problem situation. Novelty/Originality of this study: The authors note that this problem cannot be solved by simply increasing the hours envisaged by the curriculum for independent work in the framework of the subject “Physical Education”, i.e. increase in quantity. A qualitative change in the approach to independent work of students, an appropriate system of actions in her organization and planning are necessary to achieve the desired effect

Modulation of network activity and induction of homeostatic synaptic plasticity by enzymatic removal of heparan sulfates

Heparan sulfates (HSs) are complex and highly active molecules that are required for synaptogenesis and long-term potentiation. A deficit in HSs leads to autistic phenotype in mice. Here, we investigated the long-term effect of heparinase I, which digests highly sulfated HSs, on the spontaneous bioelectrical activity of neuronal networks in developing primary hippocampal cultures. We found that chronic heparinase treatment led to a significant reduction of the mean firing rate of neurons, particularly during the period of maximal neuronal activity. Furthermore, firing pattern in heparinasetreated cultures often appeared as epileptiform bursts, with long periods of inactivity between them. These changes in network activitywere accompanied by an increase in the frequency and amplitude of miniature postsynaptic excitatory currents, which could be described by a linear up-scaling of current amplitudes. Biochemically, we observed an upregulation in the expression of the glutamate receptor subunit GluA1, but not GluA2, and a strong increase in autophosphorylation of a and b Ca2\ufe/calmodulin-dependent protein kinase II (CaMKII), without changes in the levels of kinase expression. These data suggest that a deficit in HSs triggers homeostatic synaptic plasticity and drastically affects functional maturation of neural network

Copolymer of chitosan with acrylamide: electron beam stimulated synthesis, structure and properties

The aim of this research was to obtain the grafted copolymer of chitosan with acrylamide using the electron beam irradiation. Radiation dose was varied from 6 to 160 kGy. The highest yield of the product was observed at radiation dose of 12–40 kGy. Further increase in the dose caused a decrease in the product yield as well as its solubility in water. Using gel permeation chromatography, it was confirmed that unreacted chitosan remained in the product. NMR study of the water-soluble part of the product obtained under the doses of 6, 12, and 20 kGy showed that the length of the side chains of grafted acrylamide was about 2 elementary units. Investigation of chitosan solutions by means of dynamic light scattering revealed the presence of chitosan agglomerates in the solution. The possibility of obtaining dense films was demonstrated. Mechanical treatment of the copolymer in the ball mill caused an increase in the solubility of the samples obtained even at radiation doses of 80 and 160 kGy. It was determined by means of chromatographic methods that there were no products with low molecular weight in the ball-milled product, and unreacted chitosan did not undergo mechanocracking during the mechanical treatment