Vitebsk State Technological University

www.vstu.by
Vitebsk, Belarus

Vitebsk State Technological University is an entire academic-scientific-production complex, which trains specialists with higher education for the light industry and other branches of national economy, prepares highly qualified scientific personnel, provides qualification improvement and employees retraining in different spheres, implements fundamental and applied scientific research on broad aspects, manufactures light industry products, develops international cooperation with higher educational establishments and enterprises. The University provides the high level of professional training of specialists which is located in Vitebsk, Belarus. Wikipedia.


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Khodasevich I.A.,National Academy of Sciences of Belarus | Kornienko A.A.,Vitebsk State Technological University | Dunina E.B.,Vitebsk State Technological University | Grabtchikov A.S.,National Academy of Sciences of Belarus
Optics and Spectroscopy (English translation of Optika i Spektroskopiya) | Year: 2013

We present data from an investigation of the properties of the blue (475 nm) and green (520-560 nm) emissions that arise from KGW and YVO4 crystals upon excitation into the transmission band of the medium by continuous infrared laser radiation the power density of which is in the kilowatt range. As distinct from standard luminescence, the two emissions are narrowband, have a structure, and show a nonlinear character. In the case of blue emission, it is noted that, simultaneously with laser radiation, the crystal experiences a significant action of Raman generation. We demonstrate the excitation of the blue emission by the laser radiation alone and present its dynamic characteristics, showing that its intrinsic time differs from the corresponding times of the Raman and laser generations. Our results show that the green emission has an up-conversion nature with the several photons excitation of residual low-concentration erbium ions. We report that the band intensity ratio of the upconversion luminescence of erbium sharply changes with increasing excitation intensity. The nonlinear interaction that is developed in KGW is accompanied by transformation of the transmission. It is concluded that the investigated processes develop in undoped KGW and YVO4 crystals as a result of a prolonged exposure of the medium to the laser radiation, which leads to a change in its properties. © 2013 Pleiades Publishing, Ltd.


Dyagilev A.S.,Vitebsk State Technological University | Kogan A.G.,Vitebsk State Technological University
Izvestiya Vysshikh Uchebnykh Zavedenii, Seriya Teknologiya Tekstil'noi Promyshlennosti | Year: 2015

Proposed a method for the investigation and simulation of physical and mechanical properties of textile fibers. On the basis of the proposed method a study of physical and mechanical properties of cottonized flax fibers. © 2015 r.


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2016

Methods of processing of experimental data on the drying of thin materials with the use of generalized variables of the drying kinetics are considered. Empirical computational equations for the main parameters of the drying kinetics are presented. © 2016 Springer Science+Business Media New York


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2013

This paper presents methods for calculating the integral-average temperature of the material for the period of decreasing drying rate on the basis of generalized variables of the process. © 2013 Springer Science+Business Media New York.


Jezhora A.A.,Vitebsk State Technological University | Navumenka A.M.,Vitebsk State Technological University
Russian Journal of Nondestructive Testing | Year: 2011

The model of an attachable electrocapacitance screened transducer was considered. The direct and inverse problems were solved and the inspection zones of a transducer and also its optimal construction parameters that provide a high sensitivity to anisotropy in the dielectric properties of orthotropic materials were determined. The effective dielectric permittivity of a flax fiber was studied at different humidities depending on the frequency of an electromagnetic field oriented along or across the fiber. A dielectrometric method for evaluating the quality of a flax fiber was developed. © Pleiades Publishing, Ltd., 2011.


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2013

The kinetics of drying of porous ceramics has been investigated by the Dokuchaev-Smirnov method. A procedure for processing of experimental data for the calculation of the drying curve has been presented. Equations for determination of the basic parameters of the kinetics of drying of porous ceramics have been obtained. © 2013 Springer Science+Business Media New York.


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2013

Equations for calculation of the basic parameters of the kinetics of drying in the period of a dropping rate have been established. A graphoanalytical method of calculating the process of drying in the second period has been presented. © 2013 Springer Science+Business Media New York.


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2016

The results of investigations of the drying kinetics of porous ceramics on the basis of the regular regime theory are presented. The influence of the main heat and mass transfer criteria on the drying process of porous ceramics has been considered. The main thermophysical characteristics of porous ceramics have been determined. © 2016 Springer Science+Business Media New York


Ol'shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2014

Results of investigation of the drying of plane samples of different capillary-porous materials by the method of regular heat regime are presented. Experimental empirical dependences defining the kinetics of drying of these materials have been obtained. The dependences of the rate of heating of a moist capillary-porous material and the rate of decrease in the moisture content in it on different factors determining the drying process were investigated. The influence of these factors on the rate of heating of such a material and the rate of removal of moisture from it were determined. © 2014, Springer Science+Business Media New York.


Ol'Shanskii A.I.,Vitebsk State Technological University
Journal of Engineering Physics and Thermophysics | Year: 2014

Heat transfer in the process of drying of moist materials has been calculated from the experimental data on moisture transfer. Equations for computation of the average temperature of the materials, the heat fluxes in them, and the time of their drying in the second period have been presented. Numerical values of the drying parameters obtained by calculation from the formulas have been compared to the corresponding experimental data. © 2014 Springer Science+Business Media New York.

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