North-south asymmetry of geomagnetic and tropospheric events

The influences of the solar plasma on geomagnetic and atmospheric phenomena are considered. There are the north-south asymmetry in the reaction of the geomagnetic field, of the geopotential and of the pressure in the magnetically conjugate points relative to the direction of the interplanetary magnetic field. There are the synchronism between direction of the meridinal component of wind at the level of the tropopause and the direction of the interplanetary magnetic field. © 1974

Van der Waals and Graphene-Like Layers of Silicon Nitride and Aluminum Nitride

A systematic study of kinetics and thermodynamics of Si (111) surface nitridation under ammonia exposure is presented. The appeared silicon nitride (8 × 8) structure is found to be a metastable phase. Experimental evidences of graphene-like nature of the silicon nitride (8 × 8) structure are presented. Interlayer spacings in the (SiN)2(AlN)4 structure on the Si (111) surface are found equal to 3.3 Å in SiN and 2.86 Å in AlN. These interlayer spacings correspond to weak van der Waals interaction between layers. In contrast to the widely accepted model of a surface structure (8 × 8) as monolayer of β-Si3N4 on Si (111) surface, we propose a new graphene-like Si3N4 (g-Si3N3 and/or g-Si3N4) model for the (8 × 8) structure. It is revealed that the deposition of Al atoms on top of a highly ordered (8 × 8) structure results in graphene-like AlN (g-AlN) layers formation. The g-AlN lattice constant of 3.08 Å is found in a good agreement with the ab initio calculations. A transformation of the g-AlN to the bulk-like wurtzite AlN is analyzed

Obtaining of Biologically Soluble Membranes Based on Polymeric Nanofibres and Hydroxyapatite of Calcium

In this paper, the possibility of obtaining a synthetic hydroxyapatite of calcium from a biological waste material is shown. The characteristics influencing the synthesis process are studied. Based on the results of the X-ray analysis and the obtained electron microscope images, it can be concluded that the synthesized HAP has a Ca/P ratio of 1.5 and with crystals with an average size of 2 microns. In work, experiments on obtaining biologically soluble films based on nanoscale polymer fibers and calcium hydroxyapatite were carried out. As a result, the main parameters of the process for the electroforming of nano-sized fibers with HAP are determined. The proposed method allows the laying of strictly directed nanofibers from a polymer with a diameter of 50 to 500 nm. The use of different types of electrodes makes it possible to vary the size of nanofibers. The characteristics such as solution viscosity, high voltage and optimum parameters were selected, which allowed obtaining films from biologically soluble polymer nanofibers and HAP. Also, experiments were conducted to introduce medicines into the film structure

Synthesis of Carbon Nanostructures on Iron Nanopowders Obtained by Electrical Explosion of Wires

This work presents the results of experiments on synthesis of carbon nanostructures by the method of thermal chemical vapor deposition using iron nanopowders obtained by the method of electrical explosion of wires as catalysts. To study the process of nucleation and growth of individual carbon nanostructures, experiments were conducted not only on nanopowders, but also on the separated clusters. To determine the optimum conditions of the carbon nanostructures synthesis and lower temperature limit, experiments were performed at different temperatures (300–700 °C) and pressures (100–400 mbar). The experiments have shown that the lower temperature limit for carbon nanostructures synthesis on the iron nanopowders is 350 °C and in this process the growth of carbon nanostructures is not so massive. Stable growth of carbon nanostructures for nanopowders as well as for the separated clusters began from 400 °C during the entire range of pressures. In contrast to the carbon nanostructures on nanopowders, in the case of the separated clusters a strong dependence of their nucleation and growth on temperature and pressure was traced

Soot and Fullerenes Formation in the Premixed Benzene-Oxygen Mixture in Electric Field at Low Pressure

Influence of the direct electric current of different polarity on flame forms, soot yield, parameters of soot samples micro crystals (Lа, Lc and d002) and soot particles sizes in intensity range from 0.5 to 20 kV at electrode systems «needle-plane» at combustion of benzene-oxygen mixture at the ratio С/О = 1.0 with addition of 10% volume of argon at pressure 40 Torr was investigated. It was found that at positive polarity action of electric field rises to such a degree that at U ≥ 10 kV it leads to flame extinction. It is shown that maximum decrease in soot yield is observed at negative polarity. It was found that intensity range of electric field in which soot yield was 10% more soot yield without applying electric field. It was shown that parameters of soot micro crystals on average remain constant irrespective of intensity andpolarity. Fullerenes С60, С70 and PAH were identified in the extracts of soot samples by the method of IR-spectroscopy

НЕСТАЦИОНАРНЫЙ КАПИЛЛЯРНЫЙ ВИСКОЗИМЕТР ДЛЯ КРОВИ

The work is devoted to the development of the theoretical foundations of the processing of measurement results and the algorithm for processing the results for automating measurements for a non-stationary capillary viscometer. The proposed algorithm allows achieving measurement performance and obtaining hemorheological data for diagnostic purposes with a satisfactory degree of accuracy. The results obtained with use of non-stationary capillary viscometer are compared with results achieved with use of rotational viscometer.Работа посвящается разработке теоретических основ обработки результатов измерений и алгоритма обработки результатов для автоматизации измерений для нестационарного капиллярного вискозиметра. Предложенный алгоритм позволяет достичь быстродействия измерений и получить гемореологические данные для диагностических целей с удовлетворительной степенью точности. Приводится сравнение результатов, полученных при использовании нестационарного капиллярного вискозиметра, c результатами, достигнутыми при использовании стандартного ротационного вискозиметра