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  • On the behavior of an elastoplastic disk under the action of a thermal source

    The steps of constructing an algorithm for calculating the stressed and strained state of a thin circular disk experiencing thermal and force effects are discussed. A homogeneous temperature field is created in the central part of the disk. Within the framework of the theory of the flow of an ideal elastoplastic body, conditions of general plasticity are considered. It is assumed that the plasticity limit for uniaxial tension is common for all plasticity conditions. Dependencies between the disk radius, the temperature of the central region of the disk and the external pressure, which determine the appearance of plastic regions, are established. For piecewise-linear plasticity conditions of general form, analogous dependences are defined, when singular plasticity regimes are realized at elastoplastic boundaries. For different values ​​of the input parameters of the problem, the stresses, equivalent stresses and the hodograph of the stress vector are given.

    Keywords: mathematical modeling, elastoplastic body, plane stress state, piecewise linear plasticity conditions, plastic flow theory, thermoelastic plasticity

  • New directions of research and development in the field of nanotechnology for the creation and application of inorganic composite materials Part II

    In the paper, we give a brief overview of the main developments made personally and under the direct supervision of the professor, academician RANS andIAELPS P. Kudryavtsev. These developments are devoted to the use of sol-gel processes in various branches of science and technology. Using this process, new composite heat-resistant materials, highly disperse materials and thin filmswere created. These developments have made it possible to create new efficient catalysts and highly selective inorganic ion-exchange materials. Based on inorganic ion-exchange materials, a technology was developed to extract lithium from natural brines, which are poor in lithium content. On the basis of sol-gel technology, new composite matrix-isolated flocculants-coagulants were created. These reagents are designed for the treatment of natural and wastewater in order to remove impurities of oil products and heavy metals.

    Keywords: Nanomaterials, Sol-Gel Technology, Nanostructured Materials, Composite Materials, Highly Dispersed Materials, Thin Films, Catalysts, Highly Selective Inorganic Ion Exchangers, Extraction of Lithium, Composite Flocculants-Coagulants

  • Flicker noise in a simulated time dependences of amperage in polarization of the ferroelectric

    The main maintenance of a diversification of production as activity of subjects of managing is considered. being shown in purchase of the operating enterprises, theIn this work, we carried out computer simulations of the equilibrium polarization in the ferroelectric noise within the two-dimensional model Ishibashi in the case of deposits and intra-parietal areas. We considered different configurations influence of thermal noise. The analysis revealed flicker noise in the simulated time dependence of the current strength.

    Keywords: simulation, polarization current, domain walls, the noise, Ishibashi model, intra-region, parietal region

  • 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