Mariupol, Ukraine

Mariupol State University
Mariupol, Ukraine
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Grankin M.V.,Mariupol State University | Bazhyn A.I.,Donetsk National University | Grankin D.V.,Mariupol State University
Semiconductors | Year: 2014

A kinetic model of semiconductor nanowire growth by gas phase adsorption is developed taking into account, along with the surface equilibrium diffusion of adatoms, the nonequilibrium diffusion of excited (hot) atoms generated by acts of adsorption and their relaxation as a result of excitation-energy accommodation via an electron channel at catalyst droplets. The processes that occur on the surface are simulated using the stochastic Monte Carlo method. It is shown that hot-adatom relaxation can determine the nanowire growth rate. The conditions for nanowire growth by the equilibrium or nonequilibrium diffusion of adatoms are established. It is demonstrated that the nanowire growth rate depends on the diameter of the nanodroplets, the distance between them, and the mean free path of atoms excited by the act of adsorption. © 2014 Pleiades Publishing, Ltd.

Grankin V.P.,Mariupol State University | Grankin D.V.,Mariupol State University
Technical Physics Letters | Year: 2015

A relationship describing the probability of electron excitation in a solid crystal by the energy of a chemical reaction on its surface has been found. It is established that the probability of electron excitation in this reaction exponentially increases with decreasing energy of electron transition in the solid. A method of nonadiabatic chemoelectron energy conversion in heterostructures for hydrogen power engineering based on Schottky diodes is proposed and the efficiency of this method is calculated. © 2015, Pleiades Publishing, Ltd.

Mikhail V.,Mariupol State University
Journal of Security and Sustainability Issues | Year: 2013

Mining and metals production sector (MMPS) of Ukraine is one of the basic for the state's economy. The sector's output, as well as the gradual increase in production, gives reason for taking a favorable view of its development prospects. Until the mid-90s MMPS of Ukraine key representatives were separate companies that operated as independent legal entities. However, during 1999-2004 the MMPS enterprises integration into the structure of major private transnational financial industrial groups took place. Large-scale consolidation of major enterprises that occurred in order to adapt to market conditions contributed to the emergence of business combination referred to as holding company. In the future, Ukrainian iron and steel companies' competitiveness in the world market will be largely determined by the scope of their participation in the global consolidation processes. Their future directly depends on the rate of large corporations' formation and restructuring, including changes in the mechanisms of corporate governance. This is one of the most important ways to improve the efficiency of the national iron and steel industry.

A mathematical model is constructed to describe the coagulation of nonmetallic inclusions and their removal from steel in a large pouring ladle. It is established that the mechanism of flotation by bubbles of inert gas effectively removes only the relatively large inclusions. The feasibility of removing nonmetallic inclusions in steel by treating it with calcium depends on the state of aggregation of the inclusions. In order to efficiently remove calcium aluminates by coagulation and flotation with bubbles of argon or vaporous calcium, the inclusions must be liquid and cannot be covered by a sulfide sheath. © 2010 Springer Science+Business Media, Inc.

Kapustin A.,Mariupol State University
Coordination Chemistry Reviews | Year: 2010

Mercarbide [CHg4O2](OH)2, is a mercury derivative of ethane in which all of the ethane hydrogen atoms are substituted by mercury atoms. Mercarbide exhibits basic and anion exchange properties in addition to showing unique stability towards mineral acids as well as oxidizing and reducing agents. The selectivity of mercarbide towards organic anions shows selectivity dependence on the size and configuration of the pendant hydrocarbon group. Titration of mercarbide with Hammett indicators shows that mercarbide in its hydroxide form is a solid base with sites allocation 7.2 < H0 < 26.5. Studies of the catalytic activity of mercarbide towards alcohol oxyethylation and aldol condensation show that it functions as a homogeneous basic catalyst, but with increased activity owing to the higher basicity of its active sites. The present paper reviews the synthesis, structure, physicochemical, and catalytic properties of mercarbide. © 2009 Elsevier B.V. All rights reserved.

Kolyada Y.E.,Mariupol State University | Fedun V.I.,Mariupol State University
Problems of Atomic Science and Technology | Year: 2015

This paper presents the pulse electrothermal plasma accelerator erosion type. Formation of dense plasma bunches occurs under atmospheric pressure through the development of high-current arc discharge in a cylindrical channel bounded by dielectric walls. Mode of operation accelerator is hydrodynamic. It is demonstrated the possibility use it to obtain microsecond high-current electron beams without vacuum conditions, the synthesis of nanoscale materials, the excitation of elastic pulses in the fluid. © 2015 National Science Center, Kharkov Institute of Physics and Technology. All rights reserved.

Styrov V.V.,Mariupol State University | Simchenko S.V.,Mariupol State University
Revue Roumaine de Chimie | Year: 2011

Generation of a longitudinal electromotive force (e.m.f.) is observed during the reaction of recombination of hydrogen atoms on selenium planar p-n junction with the thin "top" n-layer (chemo e.m.f. or chemo-valve effect). The effect is caused by production of electron-hole pairs due to exoergicity of the surface chemical reaction and its magnitude is a measure of breaking the equilibrium in the electronic system of the catalyst under the reaction conditions. The chemo e.m.f. and chemicurrent is a new means to observe and examine the nonequilibrium electronic processes during heterogeneous chemical reactions.

Grankin V.P.,Mariupol State University | Grankin D.V.,Mariupol State University
Russian Journal of Physical Chemistry A | Year: 2016

The reaction energy transfer to electrons and release of electrons from traps under the action of the recombination of H atoms on the surface of light-sum-storing crystals (Zn2SiO4–Mn, ZnS, ZnS,CdS–Ag) was studied. This effect is associated with the reaction energy accommodation via the electronic channel. The transfer of electronic excitations to the atomic recombination event is independent of the reaction rate, but depends on the electron transition energy in a solid. The possibility of electronic excitation per heterogeneous recombination event of H atoms increased exponentially as the electron transition energy decreased. © 2016, Pleiades Publishing, Ltd.

Styrov V.V.,Berdyansk State Pedagogical University | Simchenko S.V.,Mariupol State University
Journal of Surface Investigation | Year: 2012

The internal emission of hot electrons from a metal (Pd) surface is studied. The electrons gain energy from chemical atomic collisions with the thermal energy hydrogen atoms or with H2 + O2 molecules. A Pd(15 nm)/n-Si(111) nano-Schottky diode is used as a detector of hot electrons in which chemicurrents (and chemo-emf) are generated. The efficiency of entering of chemo-electrons into the external circuit per act of interaction (or per product molecule) is determined. © 2012 Pleiades Publishing, Ltd.

Loza A.V.,Mariupol State University
Steel in Translation | Year: 2015

The influence of dummy-bar defects in continuous-casting machines on accidents at the beginning of casting is analyzed. The stress–strain state of the metal at the head of the dummy bar is investigated. It is shown that residual strain in the head may increase the frictional forces between the ingot and the mold wall and may change the rate of heat transfer, which is a possible source of accidents. © 2015, Allerton Press, Inc.

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