Dniprodzerzhynsk State Technical University

www.dstu.dp.ua
Dnipropetrovsk, Ukraine
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Konchits A.A.,Institute of Semiconductor Physics of Ukraine | Shanina B.D.,Institute of Semiconductor Physics of Ukraine | Krasnovyd S.V.,Institute of Semiconductor Physics of Ukraine | Burya A.I.,Dniprodzerzhynsk State Technical University | Kuznetsova O.Y.,Dnipropetrovsk State Agrarian and Economic University
Nanoscale Research Letters | Year: 2017

The evolution of paramagnetic properties of the fullerene soot (FS), fullerene black (FB), and their polymer composites Phenylon C-2/FS, FB has been studied using the electron paramagnetic resonance (EPR) method. For the first time, a drastic growth of the EPR signals in the FB, FS, and composite samples was observed under pumping out at temperatures T = 20 ÷ 300 °C, which is attributed to the interaction between carbon defects and adsorbed gas molecules, mainly oxygen. It is shown that the ensemble of paramagnetic centers in the FB, FS, and the composite is heterogeneous. This ensemble consists of three spin subsystems 1, 2, and 3 related with different structural elements. The subsystems give three corresponding contributions, L1, L2 and L3, into the overall contour of the EPR signal. The most intensive and broad signal L3 is caused by 2D electrons from the surface of carbon flakes. Theoretical calculations of the L3 signal line shape were carried out, and the decay rate of the integral intensity has been obtained for each component L1, L2, and L3 after the contact of the sample with the ambient air. The signal decay process in the bulk composite samples is much slower due to their low gas permeability at room temperature (RT). © 2017, The Author(s).


Byelyanska A.,Dniprodzerzhynsk State Technical University | Voloshyn M.,Dniprodzerzhynsk State Technical University | Karmazina V.,Dniprodzerzhynsk State Technical University
Chemistry and Chemical Technology | Year: 2016

The methods of laboratory studies found the opportunity to intensify the process of methane fermentation which is used in the complex fertilizer technology. To intensify fermentation it was suggested to reprocess the mixture by chemical and mechanical ways that consists in the preliminary dispersion. Thus, the duration of mixture methanation process in mesophilic regime has been reduced by more than a half. The functions have been obtained and can be used to select the method of fermented mixture preprocessing in industry. © 2016. Chemistry & Chemical Technology. All rights reserved.


Maksimenko O.P.,Dniprodzerzhynsk State Technical University | Romanyuk R.Y.,Dniprodzerzhynsk State Technical University
Metallurgical and Mining Industry | Year: 2011

As a result of the developed method for determination of average resultant of horizontal forces it is possible to specify the mechanism of metal balance maintenance in the rolls. The resultant of applied forces is not directed vertically but inclined aside strip motion at simple stable rolling process. Thus the balance in the deformation zone is maintained due to action of opposite force appearing as a result of "opposite" motion of metal. Hence, retracting forces are spent not only on overcoming pushing forces but also on balancing of applied forces. The arm increases at calculation of the moment of deformation in view of inclination of resultant of contact forces. © Metallurgical and Mining Industry, 2011.


Maksimenko O.P.,Dniprodzerzhynsk State Technical University | Romanyuk R.Y.,Dniprodzerzhynsk State Technical University
Metallurgical and Mining Industry | Year: 2010

An average resultant of horizontal forces in the deformation zone that defines stability of rolling process was determined as a result of analysis of experimental contact-stress diagrams. Its value is considerable under stable process and closely related to kinematic parameters, in particular, forward slip. This resultant includes a constituent related to metal strain and dynamic constituent appearing when system of particles accelerates in the area of strip and rolls contact. © Metallurgical and Mining Industry, 2010.


Yashyna K.,Dniprodzerzhynsk State Technical University | Krupnyk O.,Dniprodzerzhynsk State Technical University | Karpenko O.,Kyiv State Maritime Academy named After Hetman Petro Konashevych Sahaydachniy
CEUR Workshop Proceedings | Year: 2016

The article analyzes the spheres of 3D printing and 3D scanning modern technologies application, defines the perspectives of 3D technologies development, and proves the expediency of these technologies application in educational activities of a modern institution of higher education. The authors developed the training course curriculum that allows the students not only to acquire the knowledge and practical skills in the field of 3D printing (scanning), but also to get acquainted with the basics of entrepreneurship and principles of 3D technologies transfer. The article gives the matrix that describes in detail the competences, acquired by the students after getting acquainted with the course materials, developed by the authors. © 2016 by the paper authors.


Lavrinenko V.I.,Ukrainian Academy of Sciences | Sytnyk B.V.,Ukrainian Academy of Sciences | Poltorats'kyi V.G.,Ukrainian Academy of Sciences | Bochechka O.O.,Ukrainian Academy of Sciences | Solod V.Y.,Dniprodzerzhynsk State Technical University
Journal of Superhard Materials | Year: 2014

The authors discuss the application of composites based on finely dispersed cubic boron nitride micron powders as polycrystalline wear-resistant bearing elements in the working layer of diamond abrasive wheels for the purpose of improving the wheel performance in grinding. © 2014, Allerton Press, Inc.


Maksimenko O.P.,Dniprodzerzhynsk State Technical University | Izmailov M.K.,Dniprodzerzhynsk State Technical University | Loboyko D.I.,Dniprodzerzhynsk State Technical University
Metallurgical and Mining Industry | Year: 2015

The paper proposes a new friction model for determining the shear stresses in the roll pass. With its application a method of estimating of longitudinal strip stability in rolls when rolling with tension is developed. On the basis of the developed method analyses of the tension influence of strips on the kinetic and strength rolling parameters was carried out. It showed that when tension composite longitudinal force increases, the absolute value decreases, and hence the stability of the rolling process is reduced.


Iashyna K.,Dniprodzerzhynsk State Technical University
Proceedings of the 2015 IEEE 8th International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications, IDAACS 2015 | Year: 2015

This article describes synthesis and software implementation of electric arc furnace (EAF) electrodes motion control system. The controlling system, developed by the author, has been made a good use while the automation process with the controlling operation of EAF to reduce the aggregate power consumption at the constant quality of the productions. © 2015 IEEE.


Kalambet S.V.,Dniprodzerzhynsk State Technical University | Zolotariova O.V.,Dniprodzerzhynsk State Technical University | Pivniak Y.V.,Dniprodzerzhynsk State Technical University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2016

Purpose. Identifying the impact of households' finances in Ukraine on their mobility in the labour market, social and economic indicators, indicators of fiscal sector and monetary market. Methodology. The study was done with the help of the following methods: a systematic approach for a comprehensive study of such a complex research object as households' finances as a single integrated system; method of grouping in the formation of uniform indicators groups (households' mobility in the labour market, social and economic indicators, indicators of the fiscal sector and monetary market) for association of the studied units in a partial entity; correlation analysis to study the interdependence of the indicators selected for analysis (households' finances and the above mentioned groups of indicators) and establish causal links between them; dynamic analysis to characterize the change of the selected parameters to analyse and identify major trends and patterns of development. Findings. Based on a detailed analysis of the structure of income and expenditure of households, it was found that, firstly, the primary source of the money income of households in Ukraine is wages, secondly, the dynamics of households' expenditures show that there is an increase in consumptive use of revenues, while their structure is sub-optimal because of excessively big share of food expense and too low non-consumptive expenses; thirdly, households are characterized by a low level of mobility, irrational behaviour, limited investment potential of savings. It is proved that the amount and structure of household's finance dynamics produces influence on the parameters selected for analysis (mobility, socio-economic, fiscal sector and monetary market), and it is inverse regarding indicators of mobility in the labour market and the consumer price index, but directly proportional to other selected indicators. The presence of mostly strong and very strong correlation is confirmed by socio-economic indicators, indicators of the fiscal sector and the monetary market. The proposed state reforms in the context of addressing the identified issues should concern: the active involvement of households into the investment process by strengthening the level of trust and ensuring their rights, comprehensive promotion and development of self-employment and entrepreneurship; employment through optimization of regional labour markets, increasing investment in education and training; creating conditions for the return of skilled emigrants into the country; development of national and regional models of alignment and depolarization of the employment conditions of the various categories of workers and types of economic activity; coordination of the state tax policy and the policy of wages level regulation, differentiation of work payment according to the area of employment and the region. Originality. Theoretical concepts have been supplemented, firstly, by ideas about the essence of household finances by defining specific difference between household, state and commercial finances as reflected in methods of forming incomes and financial resources, as well as in the areas and structure of their spending and saving. Secondly, ideas about household mobility have been developed, which is understood as transformation of professional, social, and geographic affiliations of the household members resulting from the response to inner motivation and regulatory impact of institutional environment via selection of the specific forms and lines of mobility. The necessity to shift priorities in the state regulation system from general support of socially unprivileged strata of the society to developing mechanisms of stimulating population mobility has been further substantiated. The authors suggest using a certain arrangement of parameters which allow clarifying the influence of household finances on characteristics of their mobility and tendencies of social and economic development of Ukraine. Practical value. If public authorities take into close account conclusions and recommendations presented in the paper, it will promote economic growth in Ukraine, which requires immediate changes in the regulation of households' finance and shift from the support of socially vulnerable population to stimulation of economic activity and household mobility. © Kalambet S. V., Zolotariova O. V., Pivniak Yu. V., 2016.


Lavrinenko V.I.,Ukrainian Academy of Sciences | Solod V.Yu.,Dniprodzerzhynsk State Technical University | Sytnyk B.V.,Ukrainian Academy of Sciences | Nikitin Yu.I.,Ukrainian Academy of Sciences
Journal of Superhard Materials | Year: 2011

A study is performed to find ways for efficient use of bearing elements in the form of layered compacts or milled Kiborite in the working layer of superabrasive wheels in order to improve the wheel performance in grinding processes. © 2011 Allerton Press, Inc.

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