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Hovorun T.P.,Sumy State University | Bilous O.A.,Sumy State University | Gaponova O.P.,Sumy State University | Dekhtyaruk L.V.,Kharkiv National University of Construction and Architecture | Chornous A.M.,Sumy State University
Ukrainian Journal of Physics | Year: 2017

The experimental testing of the theoretical concepts of a modified Mayadas–Shatzkes model for the conductivity in thin polycrystalline films with a thin coating has been carried out. It is shown that the deposition of Ni coatings onto Co films increases the specific conductance in bilayer samples with respect to the conductivity in the basic (uncovered) specimen. At the same time, the coating of the Ni films with Cu and of the Cu films with Ni leads to a decrease of the film conductivity. This phenomenon takes place due to the enhancement or worsening of the grain boundary transparency when the coating is deposited. © T.P. HOVORUN, O.A. BILOUS, O.P. GAPONOVA, L.V. DEKHTYARUK, A.M. CHORNOUS, 2017.


Kulyavets Y.,Kharkiv National University of Construction and Architecture | Bogatov O.,Kharkiv National Automobile and Highway University | Ermakova E.,Kharkiv National Automobile and Highway University | Karlash P.,Kharkiv National University of Construction and Architecture | Popov V.,Kharkiv National Automobile and Highway University
EasternEuropean Journal of Enterprise Technologies | Year: 2016

Information excess allows obtaining the resulting estimate by a variety of relatively simple measuring devices and using a minimally sufficient set of primary measurements. At the same time, the estimated parameters are typically associated with the initially measured estimates on the basis of nonlinear functional equations. Therefore, a direct use of the maximum likelihood method makes it necessary to solve a system of nonlinear equations. The use of the linearization method for nonlinear functional correlations allows obtaining explicitly optimal estimates (in this case, the most plausible ones) of the resulting parameter and the correlation matrix of assessment errors. The problem of an optimal use of assessments provided by the same state vector through different simultaneously applied methods can be solved by a consistent application of the estimates' filtering algorithm. However, the weight coefficient matrix in the expression for determining the resulting estimate depends on the measured parameter values, and it is not always known a priori. One of the possible methods of obtaining the estimates of the weight coefficients matrix is to calculate direct estimates of error correlation matrices on the basis of independent discrete samples of estimates for the parameter state vector. Analytical expressions were obtained for mathematical expectation and variance of the assessment components of the error correlation matrix for determining the parameter state vector. The study has shown that the assessment accuracy depends both on the accuracy of the measuring devices and the length of the samples' line taken to determine the error correlation matrix for the parameter evaluation. © Y. Kulyavets, O. Bogatov, E. Ermakova, P. Karlash, V. Popov, 2016.


Shkurdoda Y.O.,Sumy State University | Chornous A.M.,Sumy State University | Loboda V.B.,Sumy State University | Shabelnyk Y.M.,Sumy State University | And 2 more authors.
Journal of Nano- and Electronic Physics | Year: 2016

Structural and phase composition and magnetoresistive properties of three-layer film systems based on permalloy and copper were investigated. The samples were obtained by layer by layer condensation method with followed heat treatment to the 300-700 K temperature range. Shown that the spin-dependent scattering of electrons realizing in the range of layer thicknesses (dCu = 6-15 nm and dPy = 25-40 nm) of the condensed and annealed at 400 K samples. The Maximum GMR observed after annealing the samples at 400 K and annealing to 550 K leads to anisotropic magnetoresistance occurrence. © 2016 Sumy State University.


Korytchenko K.V.,Kharkiv Polytechnic Institute | Poklonskiy E.V.,Kharkiv National University of Construction and Architecture | Vinnikov D.V.,National Science Center Kharkov Institute of Physics and Technology | Kudin D.V.,National Science Center Kharkov Institute of Physics and Technology
Problems of Atomic Science and Technology | Year: 2013

A numerical model of gas-dynamic stage of spark discharge in oxygen that takes into consideration transient processes in an electric circuit and a change in the composition of gas-discharge atmosphere has been presented. The components of e, O, O+, O++ were considered for the conductive channel of a spark. The plasma ionization was neglected in the region beyond the conductive channel and the consideration was given to the components of O2, O. The results of the distribution of thermodynamic parameters, spark channel resistance, radiation losses, and those of expenditure of discharge energy for dissociation and ionization have been given.


Samorodov A.V.,Kharkiv National University of Construction and Architecture | Tabachnikov S.V.,Kharkiv National University of Economics
Soil Mechanics and Foundation Engineering | Year: 2016

A method is proposed for determining the load-bearing capability of drilled piles depending on the effects of upward or downward loading. The validity of the method is confirmed by analysis. © 2016 Springer Science+Business Media New York


Chub I.A.,University of Kharkiv | Novozhylov M.V.,University of Kharkiv | Novozhylov M.V.,Kharkiv National University of Construction and Architecture | Murin M.N.,University of Kharkiv
Cybernetics and Systems Analysis | Year: 2013

The authors consider the mathematical model and solution method for the optimization problem of the allocation of limited resources of a project as a problem of the arrangement of rectangular objects, where objects being placed have variable metric characteristics that are subject to functional dependences. The partial quality criteria and the constraints of the feasible domain of the problem are formalized. © 2013 Springer Science+Business Media New York.


Jurchenko V.A.,Kharkiv National University of Construction and Architecture | Brigada E.V.,Kharkiv National University of Construction and Architecture
Water and Ecology | Year: 2014

According to statistics 75 % of accidents at ferroconcrete water disposal pipelines are caused by biogenic sulfuric corrosion. Till nowadays insufficient information about features of autotrophic bacteria life activity, absence of methods of their operative concentration control have not allowed developing effective ways of suppression of chemosynthesis in these object. The aim of this work is identification of quantitative indexes and mathematical modeling of thiobacilli association development on sewage pipeline upstructure part and process of concrete biogenic corrosion at these objects. On the basis of complex process study presented in the article necessary kinetic constants are defined; mathematical models of extremely acidophilic thiobacilli association development and process of concrete biogenic corrosion are developed. Mathematical model unit «Aerobic chemosynthesis of thiobacilli (oxidation of reducible sulfur compounds to sulfuric acid)» includes substrate diffusion process (H2S) from condensate moisture in biofilm and its consumption, whereas mathematical model unit «Microbiological sulfuric acid corrosion of concrete» includes mathematical description of diffusion of sulphuric acid formed by thiobacilli in concrete and its interaction with concrete hydrates.


Goncharenko D.F.,Kharkiv National University of Construction and Architecture | Bulgakov Ju.V.,Kharkiv National University of Construction and Architecture | Starkova O.V.,Kharkiv National University of Construction and Architecture
Water and Ecology | Year: 2014

The article provides the analysis of the Kharkov sewerage system. The major issues of sewage collector's protection from corrosion are examined; it is showed that the main part in selection of materials for tunnel collector's constructions recovery, apart from other technical and economic characteristics, is assigned to their corrosion resistance. Reliable water disposal is provided by performance of various technical and organizational measures. The most important measure is timely capital repairs and worn out sewage networks recovery. Methods of collectors recovery are considered; underground method of recovery of sewer pipeline in diameter of 1500 mm with the use of polyethylene short pipes in diameter of 1200 mm, implemented at repair of Juzhnaja street in Kharkov, is suggested.


Lutchkovsky I.J.,Kharkiv National University of Construction and Architecture | Samorodov O.V.,Kharkiv National University of Construction and Architecture
Geotechnical Engineering for Infrastructure and Development - Proceedings of the XVI European Conference on Soil Mechanics and Geotechnical Engineering, ECSMGE 2015 | Year: 2015

A method is proposed for defining parameters of an elastic layer of finite thickness for adequately modeling the interaction of buildings and structures with a soil base. © The authors and ICE Publishing: All rights reserved, 2015.


Goncharenko D.F.,Kharkiv National University of Construction and Architecture | Olejnik D.J.,Kharkiv National University of Construction and Architecture | Bondarenko D.A.,Kharkiv National University of Construction and Architecture
Water and Ecology | Year: 2014

The article is dedicated to issues of selection of technologies of corrosion protection and pressure of the groundwater of concrete inspection shafts during their erection on deep-laid automatic flow tanks.Technology solutions of repair and restoration of concrete structures of inspection shafts using panel, ceramic brick and other common and modern building materials are observed.The investigation results on technology solutions and materials for inspection shafts construction on existing deep-laid water disposal networks are presented. The laboratory researches allowed making solutions on applicability of concrete for these purposes containing complex chemical additives as well as technologies with the use of polyethylene sheets.It is found out that the final version of the anticorrosion coat appliance of concrete inspection shafts can be selected in accordance with the specific conditions of construction operations and technical-economic values of observed coat version.

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