Видання зареєстровані авторами шляхом самоархівування
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Item Determination of the Company's Value under the Influence of Various Factors(Qazvin Islamic Azad University, 2021) Ignatyuk, A.; Dikiy, A.; Shevtsiv, L.; Petlenko, Y.; Klymash, N.; Зайцев, Олександр Васильович; Зайцев, Александр Васильевич; Zaitsev, Oleksandr VasylovychThe authors studied and analyzed various concepts and approaches to company value management. They described the advantages and disadvantages of the leading traditional approaches to assessing the value of an enterprise and proposed a model of the dynamics of the company's value, taking into account the ownership structure, explaining the mechanism of the influence of the company's ownership structure on the capital structure. Using an example, we examined the change in the company's value by individual factors and identified which factors have the most significant positive and negative impact.Item Infuence of the thermal annealing on the morphological and structural propertie(Springer Nature, 2020) Доброжан, Олександр Анатолійович; Доброжан, Александр Анатольевич; Dobrozhan, Oleksandr Anatoliiovych; Пшеничний, Роман Миколайович; Пшеничный, Роман Николаевич; Pshenychnyi, Roman Mykolaiovych; Vorobiov, S.; Курбатов, Денис Ігорович; Курбатов, Денис Игоревич; Kurbatov, Denys Ihorovych; Komanicky, V.; Опанасюк, Анатолій Сергійович; Опанасюк, Анатолий Сергеевич; Opanasiuk, Anatolii SerhiiovychIn this work, ZnO flms were deposited onto fexible polyimide substrates by ink-jet printing nanoinks containing polyolsynthesized nanocrystals. ZnO flms were annealed at 200–400 °C for 10 min and 60 min under the ambient atmosphere. The morphological (shape, size, size distribution, surface roughness), structural (phase composition, crystal structure), optical (band gap, transmission coefcients) properties and the chemical composition of the synthesized nanocrystals and the obtained flms were studied. X-ray difraction analysis, transmission and scanning electron microscopies, atomic force microscopy, Fourier-transform infrared (FTIR) and optical spectroscopies, and energy-dispersive X-ray spectroscopy (EDS) were used to study the properties of obtained ZnO materials. The flms, annealed at Ta=400 °C for ta=60 min, and nanocrystals, synthesized for tg=120 min, have the good fundamental characteristics for application in the microelectronic devices, especially in solar cells and thermoelectric generators.Item Structural Features of Nanostructured Copper Oxide Thin Films, Synthesized by Spray Pyrolysis Technique(Sumy State University, 2015) Опанасюк, Анатолій Сергійович; Опанасюк, Анатолий Сергеевич; Opanasiuk, Anatolii Serhiiovych; Salohub, A.O.; Д`яченко, Олексій Вікторович; Дьяченко, Алексей Викторович; Diachenko, Oleksii Viktorovych; Hnatenko, Yurii Pavlovych; Гнатенко, Юрий Павлович; Гнатенко, Юрій Павлович; Cheong, H.; Nam, D.In the present study, the properties of copper oxide thin films prepared by spray pyrolysis were investigated at different substrate temperatures (573 – 723 К) and at constant spraying volume of precursor. The compositions, structural and morphological properties of the films were investigated by field emission scanning electron microscopy, atomic force microscopy and Raman spectroscopy.Item Physical and Mechanical Properties of (Ti-Zr-Nb)N Coatings, Fabricated by Vacuum-Arc Deposition(Sumy State University, 2015) Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Belovol, K.O.; Maksakova, O.V.; Beresnev, V.M.; Sobol, O.V.; Grankin, S.S.; Nyemchenko, U.S.; Novikov, V.Yu.; Eskermesov, D.K.The coatings based on (Ti-Zr-Nb)N were fabricated by vacuum-arc deposition of the Ti+Zr+Nb cathodes in the nitrogen atmosphere. Their physical and mechanical properties as well as tribological characteristics have been studied. The coatings are characterized by a columnar structure, their hardness reaches 44.57 GPa. The adhesion strength of coatings reaches 66.77 GPa, the friction coefficient of the «cover – Al2O3» is 1.1. It has been determined, that the hardness of the investigated coatings significantly depends on the pressure of the reaction gas. The coatings are promising as protective coatings for friction pairs and cutting tools.Item Modeling of the Mechanism of Phase Transitions in ZrO2 with Small Additions of In2O3 at High Temperatures in a Vacuum(Sumy State University, 2014) Solovyova, A.E.In the work were considered the models and analytical study crystallographic sequence of the phase transition in zirconium dioxide at heated. It has been shown, that mechanism of the transformation of monoclinic phase in tetragonal modification takes place at a move of two atoms of oxygen from of three in positions of the structure. At that a move is form a nodal anion vacancies, which are elements of the structure. The accumulation of such vacancies and the appearance of new anion vacancies, which form at evaporation of the oxygen from the lattice zirconium dioxide lead to the appearance zirconium cations of different valence. The transformations of phase of zirconium dioxide upon heating had : tetragonal – cubic, type C - cubic, type F, occur by shifting of the certain concentrations of anion vacancies in the non-structural position. The sequence of phase confirmed experimentally by heating in the temperature range 25 -1600oC in vacuum, samples of zirconium dioxide with addition 5 mol.% In2O3, prepared with hot pressure. The existence in nature is of compounds Zr2O3, with a cubic modification type C – pyrochlore, theoretically and experimentally confirmed.Item Nanostructure Formation in Superior Quality Rails(Sumy State University, 2014) Gromov, V.E.; Volkov, K.V.; Morozov, K.V.; Konovalov, S.V.; Alsaraeva, K.V.; Fefilova, A.A.; Semina, O.A.Using transmission electron microscopy methods the layer by layer analysis of the bulk hardened superior quality rails is carried out and the quantitative parameters of structure, phase state and defect substructure gradients are established. The gradient character of changing of structure-phase states and dislocation substructure along the cross section of rail head is revealed. The oil bulk hardening of superior quality rails is accompanied by the formation of morphologically different structure, being produced according to the shear and diffusion of γ-α transformation. The base structure volume is formed by the diffusion mechanism and is consisted of plate pearlite grains, free ferrite grains and grains of ferrite-carbide mixture. The presence of the bend extinction contours testifying to curvature-torsion of crystal lattice is revealed on electron microscope images. The analysis of far acting internal field stresses created by interfaces of cementite plates of pearlite grains and interfaces of pearlite and ferrite grains is carried out. It is shown that the interface boundaries globular cementite particles-matrix are the possible places of microcracks initiation.Item Structure Transformation in Fullerenes C60 at High Temperature Treatment(Sumy State University, 2013) Rud, A.D.; Kiryan, I.M.; Nikonova, R.М.; Ladyanov, V.I.; Bilyi, N.M.; Merzlyakova, M.A.The changes in the local structure of the fullerenes C60 are studied after high-temperature annealing. Based on the model of atomic configurations obtained by reverse Monte Carlo, the quantitative character-istics of the topological order are founded for the C60 in initial state and after annealing. It is shown that the critical temperature of the beginning of the destruction of the structure of molecular lattice of fuller-enes is 900° C (30 min). At this temperature, a partial breakage of the fullerene molecules occurs. At tem-perature of 1600° C, fully breakage of fullerene molecules and formation of amorphous carbon takes place. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35439Item Features of the Phase Composition and Structure of Eu Doped Y2O3 Submicrospheres(Sumy State University, 2013) Bezkrovnyi, O.S.; Yermolayeva, Yu.V.; Matveevskaya, N.A.; Vovk, O.M.; Tolmachev, A.V.Polycrystalline, non-agglomerated nanopowders based on monosized (Y1-xEux)2O3 submicrospheres were prepared. It was shown that the annealing temperature strongly influences on the structure, mor-phology and composition of the spherical (Y1-xEux)2O3 phosphors obtained. It was found that the concentra-tion quenching effects of Eu3+ luminescence in the (Y1-xEux)2O3 spheres with 70-280 nm diameter is shifted to lower Eu3+ concentrations (x =0,02; 0,05 for 70 and 280 nm spheres respectively) compared with the mi-crocrystalline powders with similar composition (x = 0,09). The reason of this phenomenon probably is for-mation of inhomogeneous phase of (Y1-xEux)2O3 solid solution in the nanopowders with the primary location of bigger Eu3+ ions in the surface area due to active diffusion processes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35217Item Electric Discharge Plasmochemical Synthesis of Carbon Nanomaterials(Sumy State University, 2012) Rud, A.D.; Kuskova, N.I.; Boguslavskii, L.Z.; Kiryan, I.M.; Petrichenko, S.V.; Nazarova, N.S.; Rodionova, V.N.High-energy electric discharge technologies (electric breakdown and HF volume discharge in organic media) for a large scale synthesis of amorphous carbon (AC) are developed. A destruction of hydrocarbon molecules into separate fragments occurs during such processing of organic media, what results in AC formation in the process of ultra-fast cooling of the clusters. To investigate the influence of chemical nature of working media, organic liquids and gases from the class of arenes with sp2-hybridisation of carbon atoms in molecule and alkanes with sp3-hybridisation were used. Performed XRD, HRTEM and Raman studies showed that produced powders are typical amorphous materials with significant degree of disorder. But only in the case of electric breakdown of alkanes, carbon nanomaterials with complex core-shell structure were discovered. Individual particles of onion-like carbon (OLC) consist of ~ 5 nm core surrounded by graphitic shell of 5-6 layers. Synthesized OLC is used as antifriction additives to industrial oils and as material for electromagnetic waves shielding. The statistical analysis of the atomic structure of the synthesized materials using reverse Monte Carlo and Voronoi-Delaunay methods was performed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35099Item Structural Properties of ZnO Thin Films Obtained by Chemical Bath Deposition Technique(Sumy State University, 2012) Бересток, Таїсія Олександрівна; Бересток, Таисия Александровна; Berestok, Taisiia Oleksandrivna; Курбатов, Денис Ігорович; Курбатов, Денис Игоревич; Kurbatov, Denys Ihorovych; Опанасюк, Надія Миколаївна; Опанасюк, Надежда Николаевна; Opanasiuk, Nadiia Mykolaivna; Манжос, Олексій Павлович; Манжос, Алексей Павлович; Manzhos, Oleksii Pavlovych; Danilchenko, S.M.Zinc oxide thin films have been deposited onto glass substrate from zinc sulfate, ammonia and thiourea aqueous solution by chemical bath deposition. In the work this were specified solution preparation procedure and optimized the composition of the solution and content of component in it. X-ray difraction and high-resolution scanning electron microscopy were used to characterize structure formation of obtaining ZnO films. As a result of investigation was determined the effect of time deposition on the structural and substructural properties such as lattice parameters, texture quality, coherent scattering domain size. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35076