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Mashchenko V.A.,Rivne State Humanitarian University | Sadovenko I.O.,National Mining University
Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu | Year: 2014

Purpose. To analyze the influence of structural and morphological, and elastic characteristics of defects on the features of the structure and deformation of some sandstones based on the modeling approach and interpretation of experimental data of velocity of longitudinal and transverse acoustic waves. Methodology. We have involved a series of experimental studies of density, porosity, and determination of the velocity of propagation of longitudinal and transverse acoustic waves in samples of sandstone with different structural organization. Findings. The elastic parameters of defects of solid structure were calculated based on the velocities of propagation of acoustic waves for sandstones with different effective Poisson's ratio. The normal and tangential compliances with the effective Poisson's ratio of sandstone were comparatively analyzed. Poisson's ratio of the medium matrix was calculated based on the variations of the velocities of propagation of acoustic waves under the influence of external pressure. Originality. The deformation behavior of sandstones was considered on the basis of the model of microinhomogeneous medium as an elastic matrix and planar defects inclusions. Theoretical estimates of the parameters of defects, based on the elastic constants of linear elasticity theory, indicate the adequacy of the model to describe the strain state of imperfectly elastic rock. The possibility of the existence of negative Poisson's ratio in sandstones with high normal compressibility and the contribution of the contact interactions were theoretically justified. Practical value. Theoretical estimates of the parameters of defects, based on the elastic constants of linear elasticity theory, indicate the adequacy of the model to describe the strain state of imperfectly elastic rock. There were obtained the relations for evaluation of normal and tangential compliance on the basis of effective elastic moduli microinhomogeneous medium, elastic moduli and the Poisson's ratio of the matrix medium. It is shown that the concentrations of defects in their compliance and effective Poisson's ratio have an inverse relationship, which determines the strain-elastic properties of the medium of propagation of acoustic waves. Source


Kolupaev B.B.,Ukrainian Academy of Sciences | Klepko V.V.,Ukrainian Academy of Sciences | Lebedev E.V.,Ukrainian Academy of Sciences | Kolupaev B.S.,Rivne State Humanitarian University
Polymer Science - Series A | Year: 2010

Phonon relaxation and internal friction in kaolin-and bentonite-filled PVC composites are studied. By varying the temperature and/or content of the ultrafine mineral filler in the PVC, one can control the contribution from phonon viscosity, damping force, and the effect of viscosity into the energy dissipation of ultrasonic oscillations in the MHz frequency interval. The dynamic character of the measurements makes it possible to differentiate between relaxation phenomena in the composites and to suggest methods for their controlled changes. © Pleiades Publishing, Ltd., 2010. Source


Danilevska N.B.,Rivne State Humanitarian University | Moroz M.V.,National University of Water management and Nature resources use | Nechyporuk B.D.,Rivne State Humanitarian University | Novoseletskiy N.E.,Rivne State Humanitarian University | Yukhymchuk V.O.,Institute of Semiconductor Physics of Ukraine
Journal of Nano- and Electronic Physics | Year: 2016

The effect of concentration of sodium thiosulfate and the temperature of the electrolyte in the process of obtaining cadmium sulfide nanocrystals electrolyte method using cadmium electrodes. X-ray diffraction studies were used to determine the size of the nanocrystals using the Debye-Scherrer formula and method of Williamson-Hall. Comparison of the results of XRD studies the results of Raman spectroscopy and differential thermal analysis. © 2016 Sumy State University. Source


Danilevskaya N.B.,Rivne State Humanitarian University | Moroz N.V.,National University of Water management and Nature resources use | Nechyporuk B.D.,Rivne State Humanitarian University | Rudyk B.P.,National University of Water management and Nature resources use
Journal of Nano- and Electronic Physics | Year: 2016

The possibility of obtaining zinc oxide and sulfide nanocrystals by electrolytic method using sodium thiosulfate solution as the electrolyte is given. Received samples were examined by methods of X-ray diffraction analysis and absorption spectrometry. The size of nanoparticles is defined by Williamson-Hall and Debye-Scherrer methods. Found that the nanocrystals data of substances are in tension, which affect the value of the broadening of x-ray peaks. © 2016 Sumy State University. Source


Krivtsov V.V.,Rivne State Humanitarian University | Malinovsky Y.V.,Rivne State Humanitarian University
Journal of Nano- and Electronic Physics | Year: 2014

Electretic state and radiation absorption of nanocomposites consisting of polymer matrix and metal particles filler obtained in result of electric explosion are investigated. Stable thermoelectrets of polymer metal-filled systems that have better electert properties than traditional polymer materials are obtained. Suggested method of composite polymer system creation enables to obtain shielded materials with better radiative absorption, resistant to external actions, cost-efficient. © 2014 Sumy State University. Source

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