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Документ A study of initial stages for formation of carbon condensates on copper(PC тесhnology сеntеr, 2018) Dai, Yu.; Kolupaev, I. N.; Sоbоl, O. V.In the CVD method, samples of carbon condensates were obtained under special conditions (low substrate temperature and short growth times). The use of special technological conditions makes it possible to study the initial stages of growth of graphene layers. To analyze the influence of the microinhomogeneities of the copper substrate on growth conditions, various modes of its electrochemical polishing were used in the study. The structural state of the surface was studied using computer processing of digital images of a surface with color segmentation. A metallographic analysis of more than 70 samples was carried out and three main structural elements of the initial stage of growth of graphene layers were identified on the basis of computer image processing during condensation. These are graphene layers, sections of a copper substrate and a cluster of atoms with a structural state different from the graphene (presumably amorphous). It has been established that preparation of the substrate surface should be attributed to the most important technological operations for obtaining a high-quality graphene coating. It has been found that the use of multicomponent electrolytes during the polishing of the copper substrate makes it possible to increase the uniformity in the dimensions of the structural elements of the surface roughness. This leads to an increase in the surface area of the formation of graphene layers already during the initial stages of growth (at a relatively low process temperature of 700 °C). The obtained results testify to the prospects of using multistage image analysis (using the clustering method) to optimize the technological regimes for obtaining the “carbon condensate/substrate” systems, taking into account the initial roughness of the latter.Документ Polygraphene Coatings on Copper: Mechanisms of Nucleation and Growth(Sumy State University, 2018) Kolupaev, I. N.; Murakhovski, A. V.; Koltsova, T. S.; Sobol, V. O.; Dai, Yu.Samples of polygraphene layers on a copper substrate were obtained using CVD technology. For the preparation, a gaseous mixture of methane, hydrogen and argon was used. To analyze the degree of filling and the specific area of the polygraphene formed on a copper substrate, we used optical microscopy (with specialized computer image processing) in combination with Raman spectroscopy and atomic force microscopy. It is proposed to use the approach based on the double structure model (transparent regions of graphene and copper) for evaluating the morphological parameters of the coating of polygraphene on a copper substrate. This approach is used for the primary optimization of the production process of polygraphene formation. The mechanism of initial stages of polygraphene growth on copper is proposed.Документ Use of computer processing by the method of multi-threshold cross sections for the analysis of optical images of fractal surface microstructure(PC тесhnology сеntеr, 2016) Kolupaev, I. N.; Sobol, O. V.; Murakhovski, A. V.; Koltsova, T. S.; Kozlova, M. V.; Sobol, V. O.Multi-threshold slices of an intensity of the optical images of the surface were used for a quantitative assessment of physical and chemical processes on the covering. Computer analysis was applied for testing the real relief by correlation of the image intensity with a geometrical profile representation (axis Z is accepted as optical microscopy intensity scale). The multithreshold method of image analysis proposed and applied in the present study is based on an assessment of the fractal dimension of relief elements rather than the entire surface “as a whole”, which makes the processing procedure effective in the images of any origin (not only optical microscopy data, but also scanning electron microscopy). It is shown that the replacement of full-profile analysis with the analysis of the series arrays of the sections along the axis of the intensity makes the determination of the fractal dimension of complex surface topography formed under nonequilibrium conditions quite simple. The effect of the thickness and the stress-strain state of ion-plasma diboride's layers formed as the fractal dimension surface structure was considered. The use of colour optical image analysis techniques and assumption about the existence of the four components of the graphene layer on copper, opens the way to carry out morphological analysis of islands of each type and propose the model of stages of formation of the graphene coating.Документ Electrochemical Production of Tungsten Powders from Tungsten Hardmetal Waste(Springer Science, 2020) Tulskiy, Gennadiy; Liashok, L. V.; Osmanova, M. P.; Kolupaev, I. N.Hardmetals intended to perform in harsh operating conditions are developed with the use of metallic powders, in particular, tungsten powders. The growing consumption of tungsten in industry necessitates the improvement of techniques employed to produce it from industrial waste. The objective of this research effort was to reduce metallic tungsten (as a powder) from chloride and chloride–fluoride melts and determine the factors influencing its particle size. The starting material was tungsten oxide (WO3) produced electrochemically from processed raw material (VK-6 tungsten carbide pseudoalloy). The melts were KCl–NaCl–CsBr and NaCl–KCl–CsBr–Na3WO3F3 eutectic mixtures. When the melt with a high WO2F42– content was subjected to electrolysis, tungsten precipitated as a superfine powder. The precipitate morphology showed that the tungsten particl esize was dependent on electrolysis conditions. A relatively inexpensive and effective method of producing tungsten powders was developed upon the research.