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  • Lateral-torsional buckling of a beam

    Beams are structural elements subjected to bending loads transverse to their longitudinal axis. For steel beams, which compressed flange is not laterally restrained, checking loss of overall stability is often authoritative in determining their section. In engineering practice are known various approaches to verify the assurance of the steel beam against lateral-torsional buckling. In this article the attention is focused to the methods and their characteristics, described in actual version of the European standard EN1993-1-1.

    Keywords: lateral-torsional buckling, steel beams, critical bending force, FEA

  • The Analyisis of the Situations in geopolitically unstable Zones as a specific scientific Procedure: the Scheme of the Second Stage

    This work represents the third article within the cycle devoted to the peculiarities of the analysis of the situations in geopolitically unstable zones of the modern world. This time the author focuses on the second stage of the mentioned scientific procedure. He assumes the analysis of the dynamics of such zones (regions) as multifactorial combinatorics, with the dominance of the conflict nature of interstate relations and the key role (in some cases) of non-regional players. An attempt is made to present unstable regions and the same kind of limitrophic zones as a combination and overlapping of the force fields of a different nature.

    Keywords: modern world, geopolitically unstable zones, separation belts, limitrophic zones, interstate relations, multilateral and vertically organized, conflictness, asymmetrical conflits, international mediation, force fields

  • On the assessment of the particles’ shape factor using results a complex analysis of variance of dispersed dust particles to reduce dust leakage throw out emissions in the dust removal devices of the aspiration schemes at the building construction industr

    The article is devoted to the approach to the development and design of effective dust collectors for the aspiration systems of the construction industry. It was proposed and implemented the study of the particle shape factors that determine the hydrodynamic features of gas flow around dust particles, for example, in the aspiration schemes, which are most spread and applied in the construction industry using the results of complex analysis of variance it this article. It was presented results of implementation hydrodynamic criteria in the output function of the analysis. The values’ meanings of the particle shape factors of the dusts’ particles were gained and obtained at the final stage of experiment. It was obtained regressions for particle shape factors as functions of hydrodynamic criteria. It was proposed dependences to clarify the particle sedimentation-growth velocities taking into account the influence of the particle shape factors of the studied dust samples. It was allowed possibility to assess and obtain ranges of changes in the values’ meanings of particle shape factors. It was obtained more reliable results for determining the sedimentation values’ velocities of dust particle as a determining result of complex analysis of variance of particles also. The research results allow the development and design of dust collecting devices for cleaning emissions in dust removal systems of the aspiration schemes of the construction industry. These dust kinds of collector provides a significant reduction in dust leakage out from dust removal systems of the aspiration. This way become one of the highly effective prevents polluting ways that allows to improve environmental safety of the construction industry.

    Keywords: Dust, building material, dust collector, cleaning, leakage, analysis of variance, velocity, sedimentation, criterion, emission, atmosphere, dust removal, aspiration

  • Studies of dustiness in a residential area located near industrial enterprises with PM10 and PM2.5 particles

    When organizing work on the territory of sanitary protection zones, it is necessary to take into account that the SPZ is already a territory with elevated levels of exposure, which may require the use of additional means of individual and collective protection. Meteorological parameters are important factors affecting the extent of the impact of the work on human health. The article presents a comparative analysis of the concentration of suspended substances in the workplace, depending on meteorological parameters.

    Keywords: sanitary protection zone, hazard class, industrial enterprise, construction, reconstruction, ecology, atmosphere, labor protection, non-stationary workplace

  • Numerical study of the heat sink with a change in the aggregate state of the working substance

    In the article, a numerical study of the heat sink with a change in the aggregate state of the oil is carried out. Simulation was carried out in Ansys Fluent CAD for two modes, static - with constant heating of the oil at 340K and dynamic, at which the heating temperature varied with time from 340K to 270K. Heat transfer in the event of a change in the aggregate state of a substance is widely used in cases where it is necessary to achieve the maximum efficiency of heat exchange. In this case, the energy is expended on the phase transition of the substance, for example, to evaporation from the liquid phase. The advantage of the heat-sink design described in this work is a rather high rate of heat transfer, greater resistance to various influences, including mechanical ones, which is primarily ensured by the simplicity of construction, eliminating the drawbacks of classical designs, which are cumbersome (the presence of an external cooling circuit ) and the limited rate of heat transfer.

    Keywords: heat dissipation, numerical methods, aggregate state, computational experiment, heat exchange efficiency

  • A complex method for measuring the permittivity in the low-frequency and microwave ranges

    In this article, we propose the idea of ​​creating a complex sensor for measuring the dielectric parameters of liquid substances in order to distinguish samples with small changes in the parameters in low-microwave ranges. The measurements are carried out by a capacitive method. For measurement at a low frequency, a capacitor-to-code converter is used; in the microwave method, a vector analyzer is used for the measurement. As a capacitive sensor, a interdigital capacitor is used that has geometrical and electrophysical parameters, in which it is not a radiating structure in the range of controlled frequencies. To combine the low-frequency and microwave methods in one sensor, a frequency-isolation scheme is used. The urgency of the method lies in the absence of the need for separate measurements of the sample with the help of various sensors.

    Keywords: interdigital capacitor, coaxial probe, frequency isolation circuit, liquid substance, sensor, model, reflection coefficient, electrical capacitance, capacitor-code converter

  • Example of calculation of an oval element of a three-layer construction filler

    In this article, we propose a method for determining the reactive load for an element of the oval rod type with a rectangular or square cross-section, in which the diagrams of the moments of external forces and single loads are rectilinear. In this case, integration can be performed analytically

    Keywords: energy-absorbing element, plot, rod, filler, load, beam, hinge, travel speed, layer

  • A method for improving the convergence of a single-center decomposition of a molecular orbital

    Investigation of the interaction of electromagnetic radiation with molecular systems gives most of the information about their structure and properties. Interpretation of experimental data is directly determined by the knowledge of the structure of energy levels and its change in the transition of these systems to an excited state. A key task of the methods for calculating the molecular orbitals of excited states is to accurately describe the emerging vacancies of the molecular core, leading to radial relaxation of the electron density. A method is proposed for an exact description of the electron density of a molecular system near its nuclei, which provides solutions to the problem of slow convergence of molecular orbitals in a single-center representation. The implementation of the computational procedure is examined using the example of a diatomic hydrogen fluoride molecule. The energy characteristics of the ground and ionized states of the molecule are estimated

    Keywords: single-center method, molecular orbital, excited state, ionized state, deep shell

  • Selection of an environmentally efficient air pollution abatement system for a clay and sand transfer unit at brick factories

    In the article, the groups of parameters of the properties of dust aerosol released into the air pool at the clay and sand transshipment sites of the construction industry, in particular at brick factories, are investigated. The main type of pollutant in the article is considered inorganic dust containing 70-20% silica. The properties of a dust aerosol are presented from the standpoint of the theory of stability of dispersed systems. The main classification feature in the distribution of the parameters of the properties of the groups selected physical nature of the processes and phenomena observed in the dust aerosol. As a result of the construction of a physical model of the process of air pollution, a detailed analysis of the objects involved in the pollution process was conducted.

    Keywords: Atmospheric air, pollutant, overload unit, dust aerosol, parameters of dust aerosol properties, pollution reduction system

  • Floor heating system for residential and industrial premises

    In this article the scheme solution of a heating system by a floor with use of the heat exchanger-supercharger is offered and comparative results of research of a heat transfer coefficient of a surface of heat exchange of the offered system of heating of a floor with traditional are resulted. As a result of the study, the parameters characterizing the operation of the floor heating system were determined. With the established mode of operation of the floor heating system, the heat transfer coefficient of the heat exchange surface is 15% higher than with the traditional one.enterprise.

    Keywords: Underfloor heating, heating, coolant, shock unit, temperature, hydraulic shock, pipeline, air, heat exchanger-blower, pump, leakage

  • Simulation of wave processes in a wall structure with a defect in the form of a crack

    The problem of identification of defects in the construction in the form of a wall element is considered. Numerical simulation of the structure is carried out in the Ansys finite element complex. The investigated model of a wall structure has a defect in the form of a through crack, of a certain length. The edges of the cracks do not interact with each other. The excitation of the structure under pulsed loading is considered. Wave field displacements at control points are analyzed. Identified signs of identification of crack-like defect.

    Keywords: numerical modeling, wall element, defect, crack, identification, finite element modeling, dynamic analysis, oscillations, displacement wave field

  • Investigation of oscillations of a wall structure model with pulsed excitation

    The problem of identification of defects in the construction in the form of a wall element is considered. Numerical simulation of the structure is carried out in the Ansys finite element complex. The investigated model of a wall structure has a defect in the form of a through crack, of a certain length. The edges of the cracks do not interact with each other. The excitation of the structure under pulsed loading is considered. Wave field displacements at control points are analyzed. Identified signs of identification of crack-like defect.

    Keywords: numerical modeling, wall element, defect, crack, identification, finite element modeling, dynamic analysis, oscillations, displacement wave field

  • Stages of formation of the embankment and descents of the city of Rostov-on-Don

    The work is devoted to the stages of the formation of the city embankment. Its evolution from the port-trading and warehouse zone to the recreational. The continuity of the idea of "turning face to the river" of the city passing from project to project before World War II and after, which was realized only in the late 40s. The evolution of the descents to the embankment, originally created for trade needs, later became recreational zones, completed with monumental stairs.

    Keywords: descent, architecture, project, city plan, VN Semenov, Ya. A. Rebain, implementation, restoration, bridge, project

  • Comparison of European countries in the waste industry

    The article is devoted to the study of foreign methods of waste processing and the use of secondary resources. The article also considers the peculiarities of the countries ' legislation in the field

    Keywords: waste, secondary material resources, landscaping, recycling, electrical energy, solid residue, chemicals, leakproofness, incineration, filtration, organic, decomposition, recycling, energy efficiency, emission

  • Application of parametric design in finite element modeling

    The method of parametric modeling and design based on the example of a building is studied, the architectural image of which is a set of circular helical and cylindrical surfaces defined by coordinates through functions of the corresponding surfaces in the SAPPHIRE software. Alternative methods for specifying surfaces in the SAPPHIRE PC, AutoCAD with subsequent export to the LIRA PC for engineering calculations of the frame of the building for various combinations of loads by the finite element method are presented. The object of the study is a 360-meter-high building with a hardness core in the form of a cylindrical shell of revolution. The height of the floor is 3 m. Around the rigid shell there are three circular helical surfaces that "rise" in a spiral upward along with the core of rigidity to a mark of 360 meters from the level of the ground floor. One of the most universal ways to create a surface is to specify it through a formula, because you can easily change the shape and appearance of the surface without manually editing the geometry of the model in the drawing. The development of the parametric architecture calls for the creation of new approaches to the calculation of unique buildings and structures, the improvement of software complexes that implement the finite element method, and the appearance of new varieties of finite elements with curvilinear boundaries.

    Keywords: parametric architecture, surface, shape of the object, shell, curve, model, geometry, program, formula surface, helical surface