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  • Modelling and experimental research of duplexer for a decimeter radio station

    There are represented scheme and design of duplexer for the 300-344 MHz radio station. Simulation of duplexer was implemented in Microwave Office environment. Experimental research was executed on the complex transmission coefficient measuring instrument such as “Obzor-103”. There are shown amplitude-frecuency characteristic of receive and transmission channels. Comparison of the simulations results with natural experiment proving the identical.

    Keywords: Filter, duplexer, amplitude-frequency characteristics, receive channel, transmission channel

  • Development of search and ranking algorithm for unstructured information

    The analysis of the used algorithms for the search of unstructured information was carried out, during which it was established that they do not take into account the thematic orientation of the specialized collection of documents. It is proposed to use an annealing simulation algorithm to obtain numerical coefficients used in the information retrieval ranking algorithm system. The results of the standard and modified search algorithm and ranking search results unstructured information. As a result, the value of quality metrics failed improve by an average of 8%, and the average error decreased by 29%

    Keywords: information retrieval, ranking, model, quality metrics, relevance, unstructured information

  • A rational scheme for the control of concrete strength according to GOST 18105

    Offers on the rational organization of control of durability of concrete according to GOST 18105 for modular products, commodity concrete mix and monolithic designs are presented. The concept of "moving analyzed period"is introduced. It is shown that it is not reasonable to use the control scheme for the control of the indirect indicators and the development of rapid methods for assessing the strength of concrete in the control of commercial concrete mixtures. The rational organization of concrete strength control of monolithic structures using direct and indirect methods is proposed. The groundlessness of application of statistical methods of control at control of durability of concrete of monolithic designs is shown.

    Keywords: control of the concrete strength, the analyzed period, the control scheme, the actual concrete strength

  • A study of the directional coupler on the associated strip lines

    A study of the directional coupler range 1-4GHz. The description of the construction on a symmetrical strip line with a lateral connection is given. The amplitude-frequency characteristics were simulated using the Microwave Office package. The model of the directional coupler is experimentally investigated, the following results are obtained: the working attenuation does not exceed 1.7 dB, the transient attenuation does not exceed 10 dB.

    Keywords: Directional coupler, frequency response, flatness, symmetric stripline

  • Efficiency of heat treatment of concrete with polycarboxylate-based superplasticizers

    " The analysis of the influence of superplasticizers based on polycarboxylates on the formation of physical and mechanical properties of concrete under thermal influence. It is established that the high efficiency of the steamed self-compacting concrete with polycarboxylate-based superplasticizers is achieved at low-temperature modes of heat treatment. Rational mode of heat treatment of concrete should be assigned to the quality parameter established by the results of experimental studies. Article is published within implementation of the program of the International Forum «Victorious May, 1945»."

    Keywords: construction materials producing industry, unburnt synthanite, apparatus with vortex layer, innovation, commercial soundness of investments, investment prospects, method of variation of parameters, uncertainty

  • Algorithm of decomposition and coupling of parts of the radio engineering system when adjusting one of the stabilizing parameters

    This article analyzes the possibility of decomposing a radio engineering system into parts, provided that one of the two stabilizing parameters of the coupling scheme is adjusted. An analytical calculation was made (in general), which proves the possibility of adjusting only one stabilizing parameter in the coupling scheme. A numerical example is provided confirming the above idea.

    Keywords: HIL simulation, radio engineering system, decomposition, coupling scheme, stabilizing parameter, coupling two-port network, ideal time delay line, Schur complement, Y-parameters

  • Modeling approach to image compression algorithmization

    The task of creating a file format containing an image having an optimized (compressed) size is considered. The source file is in BMP format. The problem is solved on the basis of optimal interpolation of the data by polynomials of various degrees. The simulation of the algorithmization process was performed in the MATLAB package. The proposed algorithm showed good compression of the initial information.

    Keywords: image, BMP format, compression, algorithm, polynomial regression

  • Underground pedestrian tunnels on the loaded highways

    The article deals with the problem of pedestrian crossings and congestion of highways of the city of Volgograd. It described the situation on the highways and solutions to eliminate congestion on the road. Car traffic was conditionally divided into 3 categories: transit, the transit from the center and the car flow moving into the center. Studied the question of the safety of pedestrians on the road, because, except for pedestrians with the intersection increases their safety. The study and analysis of all previously implemented measures was proposed construction of underground pedestrian tunnels. Several embodiments of tunnel junctions have been considered. Analysis of the current transport situation revealed the busiest places in the city center.It was noted that the construction of underpasses solve the problem of vehicular traffic in the city center and pedestrian safety, and the city will have new underground space.

    Keywords: Сar flow,highway, tunnel transition, transit transport, carriageway, longitudinal,security,road traffic

  • Physical and chemical properties of cobalt catalysts with promoting additives of copper and zirconium

    Physical and chemical properties of cobalt catalysts for Fischer-Tropsch synthesis are investigated. The influence of copper and zirconium oxides on the specific surface area, cobalt concentration, pore volume and size, the degree of reduction of the catalyst Co-Al2O3/SiO2 was studied.

    Keywords: Fischer-Tropsch synthesis, carbonaceous resources, catalyst, active component, silicate carrier, CuO and ZrO2 promoters, elemental analysis, recovery rate, BET method, specific surface area

  • Research of influence of additives on physical and chemical properties of cobalt catalysts of Fischer-Tropsch synthesis

    The study of physical and chemical properties of cobalt catalysts in the synthesis of hydrocarbons by the Fischer-Tropsch method is carried out. The effect of additives promoters NiO, Fe2O3, MnO2, on the specific surface area, pore volume, size of cobalt crystallites, the degree of catalyst reduction is considered

    Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, promoter, carrier, specific surface area, porous structure, catalytic activity, dispersion, cobalt crystallites

  • Features of the calculation of the towers in the form of a mesh hyperboloid

    The article deals with the construction and definition of the stress-strain state of the design scheme of a lattice tower-like structure in the form of a mesh hyperbolic paraboloid. The dependence of the wind load distribution on the characteristics of the form is established, a sectional calculation method for such structures is given.

    Keywords: Hyperbolic paraboloid, finite element method, aerodynamic loads, lattice towers

  • The use of structural membranes in the reconstruction of historic buildings

    This article discusses the basic principles of the use of structural membranes in the reconstruction of buildings and structures. Three principles of intervention in the existing architecture are described in detail. The first is to preserve the historical appearance and character of the building. The second is the scale of the new and old parts of the building. The third is the difference and the possibility of reorganizing new designs. The characteristics of the goals, the achievement of which each of these principles is directed, are given. Using the example of several buildings, we analyzed the use of textile membranes to achieve the main goals of reconstruction, described the positive and negative aspects of restoration using textile membranes. These buildings include: a church on a hill in Corbera d'Ebr, Spain (roof restoration), the central courtyard of the Palacio de Mineria, Mexico (creating coverage over a yard area), Salzburg residence, Austria (sliding roof). In conclusion, conclusions were made about the advantages of using membranes for the preservation of historical heritage and possible prospects for the development of fields of application of this design.

    Keywords: architecture, membranes, reconstruction, restoration, structural structures

  • Features of construction of foundations in permafrost soils

    The article analyzes the natural conditions of the Northern latitudes of Russia, where the main reserves of fossil hydrocarbons and metals are concentrated. It is shown that mining requires the development of the road network and artificial structures on the roads. It is noted that the most difficult stage in the construction of bridge structures is the construction of foundations. The types used in the Northern latitudes of foundations are considered, and their positive and negative qualities, such as weight, method of construction and volume of earthworks, are noted. The paper emphasizes the relevance of the problem of maintaining the stability of permafrost soils in seasonal thawing and loss of their bearing capacity. Methods of maintaining the soil in a solid state can be natural and artificial. The methods of thermal stabilization of soils, as well as machinery and equipment used in these conditions.

    Keywords: permafrost, road network, bridge, polystyrene, superstructure, pile support, Foundation, thermal insulation screen, heat stabilizer

  • Mathematical model of electromagnetic interaction of red blood cells in a narrow capillary

    Red blood cells (RBC) roll like tractor caterpillars along narrow capillaries. On the erythrocyte surface there are charges that, when moving together with the erythrocyte membrane, create a magnetic field in the vicinity of the RBC. Discrete charges are distributed uniformly on the surface of the RBC, their number can reach several million and the charges move together with the RBC membrane. The surface of the RBC is approximated by a truncated cylinder. Discrete charges are located evenly over the surface of the RBC and move along closed curves that are rectangular trapezoids. A mathematical model has been constructed that allows calculating the intensity of the magnetic field produced by mobile charges located on the RBC membrane. According to the Bio-Savart law, the magnetic field strength can be calculated at some point in space if the coordinates and velocity of the charge are known, the distance from the charge to the point and the angle between the velocity vector and the radius vector connecting the charge and the point. If we assume in the first approximation that the medium is isotropic and magnetic currents are absent, then Maxwell's equations can be written out. These equations can be rewritten in the form of equations in finite differences, solving by numerical methods one can obtain distributions of electric and magnetic field strengths in the vicinity of the RBC. Calculations were carried out for different values of input parameters. In the case when the RBCs move through the capillary network, in which the narrow capillaries are located close to each other, the magnetic fields of the RBCs in different capillaries interact, and, as a result, we obtain a new distribution of the magnetic field strength in the vicinity of the capillary network, which varies with time.

    Keywords: mathematical model, algorithm, magnetic field strength, electromagnetic interaction, erythrocyte, narrow capillary

  • Technical and economic assessment of the impact of the structural solution of monolithic floors in the construction of a multi-storey building using caisson slabs

    To date, the construction of the new techniques of construction of buildings and structures, as well as the most advanced durable and lightweight materials with high performance characteristics. All this allows you to build cost-effective, high-quality and aesthetically attractive houses. Depending on the materials used in the construction of multi-storey buildings was considered the effectiveness of ribbed coffered floors. Calculation of the 18-storey monolithic building was made in the program complex "Lira-CAD-2013". Floor slab typical floor is considered in the following schemes: buildings with a step of columns 6m and 12 m, the ceiling is flat and coffered with a 200mm plate 50mm, different beam cross-sections (200х400мм and 200х450мм), step 900х900 mm. analysis of the results showed that the most advantageous use of coffered ceilings in the building with a column grid of 12 m, with the use of high-strength concrete and reinforcement steel class A500.

    Keywords: caisson ceiling, slab, beam, reinforcement, concrete, analysis, consumption, reinforcement, step columns, the cost of construction, structural scheme