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Contacts:

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ivdon3@bk.ru

  • Porous piezocomposite materials based on piezoceramics PKP-12.

    Piezoceramic frames made of PKP-12 material with porosity up to 50% are made. The effect of the total, open and closed porosity on the properties of porous piezoelements on a given piezoelectric material is studied. Hydrostatic tests of porous piezoelements have been performed to determine the pressure at which irreversible changes occur.

    Keywords: piezoceramics, PKP-12, piezocomposites, porous piezoceramics, piezoelectric materials, ferroelectrics, PZT, hydroacoustics, hydrophone

  • Investigation of the structural parameters of promoted Co catalysts on a silicate carrier

    The parameters of the porous structure and the active surface of cobalt catalysts for the synthesis of liquid and solid hydrocarbons (Fischer-Tropsch synthesis) prepared by the method of impregnating a silicate carrier were studied. The effect of additives of oxide promoters on the specific surface, the volume and size of pores, the dispersion and size of crystallites of metallic cobalt on the surface of the Co / SiO2 catalyst was studied.

    Keywords: Fischer-Tropsch synthesis, motor fuel, synthetic hydrocarbons, catalyst, promoter, carrier, specific surface, porous structure, catalytic activity, selectivity

  • To a question on the organisation of concrete works in winter conditions

    The problem of the organisation of civil work during the winter period is studied. Authors inform results of real experience of the organisation of winter concreting in extreme conditions for the Rostov region. Practical recommendations about the organisation of works are made

    Keywords: organization of construction; high-rise housing; reinforced concrete and steel structures

  • A new class of magnetodielectric materials based on manganites

    A new class of materials is proposed that change their dielectric permittivity as a function of the magnetic field strength. Such materials are two-phase composites of composition La0.7Sr0.3MnO3 / I, where I is the isolating phase, Li4P2O7 or GeO2. The ratio of components is close to the percolation threshold: from 10% to 20% by weight. Dielectric properties have been studied in the frequency range of the measuring field from 1 kHz to 1 MHz in magnetic fields from 0 to 15 kOe. Samples have an inductive impedance, their permittivity is negative. In a magnetic field, the permittivity increases in absolute value and at room temperature the values of the magnetodielectric coefficient reach 28%.

    Keywords: lanthanum strontium manganite, composite material, ceramics, one-step synthesis, magnetoresistance, percolation threshold, dielectric constant, barrier layer, tunneling, spin polarization

  • Investigation of the efficiency of the heat sink surface of a volumetric body with an internal heat-loaded source in an aerodynamic flow

    In this work, a study was made of the efficiency of the heat sink surface of a volumetric body with an internal heat source. An electrostatic analog of the distribution of the thermal field is chosen. A model of the convective flow is proposed, under certain initial and boundary conditions, the thermal conductivity of the medium transforming into heat removal. The conclusion is made about the ineffectiveness of the heat-conducting surface in the form of whip, finned and other designs of existing heat sinks, increasing only the mass, technological complexity of manufacture, thermal resistance and temperature of the heat-loaded element.

    Keywords: Temperature field, convective heat transfer, effective heat sink area, electrostatic analog, similarity theory

  • The concept of development of social infrastructure of the Suvorovsky district of Rostov-on-don

    The article deals with the idea of developing the social infrastructure of the new microdistrict "Suvorovsky" of Rostov-on-don. Prospects for the growth of the neighborhood, and the opportunity in the near future to become the core of the agglomerations of the city of Rostov-on-don.

    Keywords: neighborhood, residential complex, state contract, landscaping, social infrastructure, the core of agglomerations, the project activities

  • Investigation of coatings with antifriction properties based on the hydroxide film Al(OH)3 on aluminum with a solid-lubricant coating MoS2

    The article discusses the technological capabilities of application of vibratory mechanical hard lubricant coatings on the basis of MоS2 to improve the surface quality and operational properties of parts made of aluminum with an oxide coating.

    Keywords: vibration treatment, the vibration mechano-chemical coating of solid lubricant, combined methods of treatment

  • Features of the dielectric hysteresis of ferroelectrics-relaxors in a sinusoidally changing electric field

    The loops of the dielectric hysteresis of a soft ceramics based on PZT with Curie temperature TC=210℃ are investigated. The studies were carried out at a frequency of 50 Hz in two modes. In the first of them, the field was switched on by 0.07 seconds, in the second - it operated continuously. The amplitude of the field E_m varied from 2.5 to 25 kV / cm and switched stepwise with an interval of 15 minutes. The coercive field EC and the switchable polarization P_m were determined. The switching polarity in the saturation region turns out to be no more, in contrast to BaTiO3 and other materials, but less than the corresponding values obtained with short-term switching.

    Keywords: piezoceramics, piezoelectric material, hot pressing, dielectric hysteresis

  • Influence of the dielectric properties of the medium on the optical properties of enclosed gold nanoparticles

    In this paper, samples containing gold nanoparticles (NPs) distributed in different optically transparent media have been synthesized and characterized. A liquid (aqueous) and a solid (porous silicate glass and polymer (polyvinylpyrrolidone)) media were used. The samples obtained were characterized by optical spectroscopy and electron microscopy. The position of plasmon resonance band was analyzed depending on the dielectric constant of the medium.

    Keywords: gold nanoparticles, colloidal solution, polymer, porous glass

  • Evaluation of the efficiency of wet dust collectors

    The article deals with topical issues related to the need to improve the efficiency of dust collection systems, the correct choice of the method of purification of emissions and the design of industrial filters linking the operating modes of devices with the properties of the captured dust. A method of complex treatment of emissions with a wet dust collector built into the process line is proposed.

    Keywords: wet dust collectors, efficiency, system efficiency, optimization, emissions, ecology, dust collection

  • Studying the work of the panel from a tree under the action of a shear load

    This article describes the operation of panels from wood, sheathing from sheets and under the conditions of shear fixing in the form of ribs, an examination of the energy method that allows to determine the shear deformations of panels made of wood. Could get dependencies that determine the effort. They occur on each nail, nailed to the contour and to the inner edges of the panel. Proceeding from this, we developed a computer program that determines the numerical values of the angles by the method of successive approximations.

    Keywords: wood panels, plywood coatings, shear forces and deflections, energy method, computer program

  • The problem of ice on the wires of the overhead lines of the railway power supply system

    Overhead contact system is a part of electric traction network which doesn’t have safety margin of a construction that’s why its using in winter becomes much difficult. The most heavy overhead contact system work is the operating regime in wind and ice loading because of wind and increasing not only on wires and suspension strands but on supporting structures. Ice loading on wires makes current-collecting conditions much worse and taking into account operational factors it can be a cause of a traffic accident and trains stop. The authors examine some methods of ice prevention, their efficiency effect and the capacity of their combining. In connection with this it is very important to trace ice load as early as possible. Equipment set for thermodynamic method instantiation and its fixing variant are represented.

    Keywords: traction power system, overhead contact system, contact wire line, ice loading, loading, testing methods

  • The problem of determining the imaging error of the generalized criteria management

    In the article we have considered the actual problem of determining the error in visualization of generalized control criteria. It is indicated that the most common nonlinear interaction of parameters in technical systems is the multiplicative interaction of measured physical quantities. Based on the fact that the physical elements of the processor measuring channel have linear dynamic characteristics, it is concluded that the application of nonlinear transformations for quantitative estimates of the properties of monitoring systems requires linearization, the errors of which undoubtedly affect the accuracy of the final mathematical model and its magnitude may be is estimated and attributed to the methodological error of visualization. The process of linearization is considered for the example of the multiplicative interaction P of measured physical quantities. As a result of the analysis of the properties of many industrial control objects under the conditions of steady-state technological processes, it was found that they are characterized by small fluctuations with respect to the mathematical expectation (no more than 10%), which makes it possible to apply the obtained mathematical models of errors arising in the process of linearizing the measurement equations for control criteria, for design and research works.

    Keywords: control objects, measuring system, programmable logic controllers, visualization error, mathematical expectation, adaptive control, linearized measurement equation, measurement error

  • Structural model of adaptive contours of bioinstrumental information-measuring system

    The article deals with the question of constructing an analytical model in assessing a person's functional state. It is indicated that for complex measurement problems it is advisable to use the principles of constructing measuring systems, formulated in terms of system functions using the fractal-categorical approach; the technique is applicable in the design and analysis of complex medical complexes, and the resulting system function of a complex medical complex is the basis for further analysis within the selected method; The structural-analytical method for constructing complex systems makes it possible, by analyzing the requirements and constraints of the system, to optimize the functions of transferring control actions, to build blocks, parts of the structure on their basis, and to optimize inter-unit communications. The approach described in the article to the process of hematological research makes it possible to analyze the adaptive response of the body's hematopoietic system to external influences of a different nature and intensity.

    Keywords: structural and analytical method, information-measuring system, information flows, hematopoietic system, category diagram, functors, adaptation contour, bioinstrumental information-measuring system, control signal, measurements.

  • Model for optimizing the tuning coefficients of a firmware measuring channel

    When developing large information-measuring and control systems, special attention must be paid to the interaction of various blocks of the system with each other. For example, the structure of a software-hardware measuring channel consists of four consecutively connected elements: primary converter; analog-to-digital converter; software dynamic converter; digital to analog converter. To find the parameters of the measurement channel error, mathematical models were constructed for each of the blocks. Simulation modeling of the measuring channel was carried out. As the input signal, the first-order aperiodic link model is taken. To generate the interference signal, a random number generator with a noise level of 0.5 is used. The error for the measuring channel is found. The suggested mathematical model allows to find the tuning coefficients of the software of the measuring channel, which ensure the minimum information loss in the software-hardware measuring channel. The resulting model can be used in automatic control systems for the current identification of regulator settings.

    Keywords: model of measuring channel, model of primary converter, adjustment of coefficients, error of measuring channel