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Baskov S.N.,National Research Technological University | Litsin K.V.,Magnitogorsk State Technical University
2015 International Siberian Conference on Control and Communications, SIBCON 2015 - Proceedings | Year: 2015

The article deals with sensorless method for determining the angular position of the rotor of a synchronous motor by means of superimposing a high-frequency signal. The scheme of the laboratory stand for the experiment to determine the angular position without the use of the position sensor was made. A technique for determining the angular position of the rotor with an accuracy of 30°was described. The logic diagram for its implementation was presented. The derivation of the formula for the calculation of the angular position of the synchronous motor rotor was presented. Findings during the experiment for determining the angular position sensorless were analyzed. Conclusions to reduce the cost and size of the drive system and increase its reliability were presented. © 2015 IEEE.

Kekalo I.B.,National Research Technological University | Mogilnikov P.S.,National Research Technological University
Inorganic Materials: Applied Research | Year: 2016

The influence of annealing time on the ductile-brittle transition temperature (embrittlement temperature) Тf in amorphous Co-based alloy Со69Fe3.7Cr3.8Si12.5B11 with extremely low saturation magnetostriction λs (λs < 10–7) is investigated. It is revealed that the embrittlement temperature Тf dependence on annealing time ta can be described by the Arrhenius equation. Embrittlement at annealing temperatures higher and lower than 300°С can be described by different kinetic parameters owing to the different states of the amorphous phase. It is shown that, in the studied alloy, the embrittlement proceeds in a very narrow annealing temperature range, not exceeding 5°С. On the basis of experimental data on the evolution of hysteresis magnetic properties during isochronous annealing and isothermal exposure, the thermal treatment mode is investigated, providing rather high values of permeability μ5 (Н = 5 mOe, f = 1 kHz) of about 50000, without transforming studied alloy into the brittle state. © 2016, Pleiades Publishing, Ltd.

Andreev Y.Y.,National Research Technological University
Protection of Metals and Physical Chemistry of Surfaces | Year: 2012

It has been established that there is a quantitative relationship between the experimental value of hydrogen overvoltage, a =ηH 2 , in the Tafel equation and the surface energy, δU S, of metal with fcc and hcp structure, which is calculated theoretically in metal surface physics. An equation of slow discharge of hydrogen ions on metal is deduced, in which the a value is a linear function of the value δU S/αF where δU S is the minimal surface energy of the specified metal, α = 0.5 is the transition coefficient, and F is the Faraday num-ber. A prevailing tendency toward a decrease in hydrogen overvoltage on polycrystalline surfaces of metals with fcc, hcp, and bcc lattices with an increase in the minimal surface energy related to the appropriate (111), (0001), and (110) facets of these lattices has been observed. Results of analysis of the relationships between ηH 2 and the surface energy of metal are interpreted within the theory of active centers for heterogeneous catalysis with involvement of a thermodynamic model of the metal surface enriched with atom vacancies. © Pleiades Publishing, Ltd., 2012.

Filippov E.S.,National Research Technological University
Russian Physics Journal | Year: 2016

On the basis of the assumption of the electron density fluctuation at the band degradation, a calculation parameter (the radius R) of the half-width of the probability distribution over the coordinate R is identified at the level of the maximum electron density fluctuation (at a maximum of the Gaussian function). Based on an analysis of the crystallization process and high polymorphic transformations bcc → fcc, the reasons for the formation of bcc, fcc, hexagonal, and tetragonal structures from the liquid phase, as well as for the high temperature bcc → hcp transition in the solid phase are established using the calculated parameter (the radius R) in the solid and liquid phases. © 2016, Springer Science+Business Media New York.

Belashchenko D.K.,National Research Technological University
High Temperature | Year: 2015

A multiparticle potential of a new type (EAM-2) including the degree of crystallinity of atoms as a parameter is proposed for metal systems. This potential is based on the potential of the embedded atom model (EAM). The degree of crystallinity of atoms is determined by the expansion of the radius-vectors of neighboring atoms over spherical functions and the calculation of the characteristic q6. The potential EAM-2 describes well the properties of liquid, BCC, and FCC lithium at normal and high pressures. The equilibrium curves of BCC-lithium–liquid and FCC-lithium–liquid are calculated at pressures up to 40 GPa, and good agreement with the experiment including the maximum on the melting curve is obtained. Tables of the pressure and temperature dependences of the density and energy of the models are given. The anomalous behavior of the density of BCC and FCC lithium in the pressure interval of 25–30 GPa (increase in the density during isobaric heating) is noted. © 2015, Pleiades Publishing, Ltd.

Abrosimov A.Y.,National Research Technological University | Dvinskikh N.Y.,yb Medical Radiology Center | Sidorin A.V.,yb Medical Radiology Center
Bulletin of Experimental Biology and Medicine | Year: 2016

We studied expression of malignancy markers galectin-3, cytokeratin-19, HBME-1, fibronectin, and cyclin D1 in cells of benign (n=51), malignant (n=87), and borderline (n=53) tumors. The results indicate that 3.9% benign and 41.5% borderline tumors express malignancy markers (specificity 98-100%). Follow up over 1-10 years after surgical treatment for borderline tumors showed no progression of tumor growth. We conclude that some benign and borderline tumors represent low-grade neoplasms with favorable prognosis. © 2016 Springer Science+Business Media New York

Godymchuk A.,Tomsk Polytechnic University | Arzamastseva E.,Tomsk Polytechnic University | Kuznetsov D.,National Research Technological University | Milyaeva S.,National Research Technological University
Journal of Physics: Conference Series | Year: 2011

The dispersion of suspensions based on nanostructured powders (ZrO2 and Y2O3) and the simplest physiological fluids (phosphate buffering saline, glucose solution, water) in terms of their use in ecotoxicological tests was studied. Using the scanning electron microscopy and laser diffraction, an increase in the size of particles and agglomerates in the suspensions in 2-11 times was shown. The particle size distribution in the suspensions was characterized by a single peak, but its magnitude and width varied ambiguously upon standing suspensions in time. It was shown experimentally that the average size of the dispersed phase could rapidly grow in the DW-suspension, could be stabilized in PBS-suspension and might decrease with time in Gl-suspension. By electro-acoustic method it was shown that the Zeta-potential on the solid/liquid boundary in the study varied over a wide range of values from - 200 to + 200, and the nature of change - a jump. This demonstrated the instability of the suspensions based on NP-ZrO2 and NP-Y2O3.

Bokshtein B.S.,National Research Technological University | Khodan A.N.,RAS Research Center Kurchatov Institute | Zabusov O.O.,RAS Research Center Kurchatov Institute | Mal'Tsev D.A.,RAS Research Center Kurchatov Institute | Gurovich B.A.,RAS Research Center Kurchatov Institute
Physics of Metals and Metallography | Year: 2014

In a temperature range of 280-320°C, the mechanism and kinetics of segregation of impurities in steels have yet remained insufficiently studied. Under these conditions diffusion of impurities in the bulk of steel grains practically ceases, and for describing the kinetics of the process it is incorrect to use the Langmuir-McLean equation. In this work we put forward two new approaches to describe the mechanism and kinetics of phosphorus segregation in steels: a model of sequential changes in the state of phosphorus based on first-order reactions and a model of diffusion redistribution of phosphorus between boundaries of carbide precipitates, structure defects, and boundaries of steel grains. A comparative analysis of the suggested models has been conducted, and estimates of the kinetics of segregation based on them have been made; these estimates have been compared with the experimental results obtained in the temperature range of 280-320°C for test times to 20 years. It has been shown that these models fairly well describe the experimental kinetics of phosphorus segregation in boundaries of steel grains. © 2014 Pleiades Publishing, Ltd.

Efimov M.N.,RAS Topchiev Institute of Petrochemical Synthesis | Dzidziguri E.L.,National Research Technological University | Sidorova E.N.,National Research Technological University | Zemtsov L.M.,RAS Topchiev Institute of Petrochemical Synthesis | Karpacheva G.P.,RAS Topchiev Institute of Petrochemical Synthesis
Russian Journal of Physical Chemistry A | Year: 2011

Meta-carbon nanocomposites consisting of a carbon matrix with dispersed nanosize bimetallic Pd-Fe particles were obtained. It was established that at 500-700°C, the bimetallic particles form a solid solution of iron in palladium. It was concluded that raising the intensity of infrared pyrolysis to 800-1100°C leads to the formation of intermetallic compounds whose composition depends on the temperature of nano-composite fabrication. © Pleiades Publishing, Ltd., 2011.

Minaev Yu.A.,National Research Technological University | Alymov M.I.,RAS Institute of Metallurgy
Russian Journal of Physical Chemistry A | Year: 2012

The conditions of the stability of heterophase disperse systems obtained by the exogenous introduction of nanosized solid phases in metal melts were considered by assuming the formation of thick and thin elastic films and disjoining pressure at the contact boundary of particles of disperse phase. The introduced criteria are expressed in the measured interface characteristics, i.e., surface tension and contact angles. The prospects for using a series of compounds of the Periodic system's IV-VI group metals as exogenous modifiers of nickel-based alloys are assessed on the basis of our experimental data. © Pleiades Publishing, Ltd., 2012.

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