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  • Some aspects of the initial modulus of elasticity of concrete compensated shrinkage on tuff aggregates of Kabardino-Balkaria

    The article is devoted to the results of studies of the initial modulus of elasticity of tuffs on natural porous aggregates of Kabardino-Balkaria, with compensated shrinkage with prepared additives, both in quartz and tuff sands. The article presents the results of experiments on determining the initial modulus of elasticity of tuffs of different preparation formulas. The values ​​of the correction coefficients in the well-known formula for the dependence of the initial modulus of elasticity of lightweight concrete on its cubic strength and the volume weight of dry concrete, depending on the formulation of tuffs are proposed.

    Keywords: Modulus of elasticity, tuffs, light concretes, porous aggregates, tuff, tuff sands, compensated shrinkage

  • Thematic Model of Website Rating Based on the Social Importance Criteria

    The model of a numerical estimation of information contents of the Internet sites, based on the thematic analysis of texts is considered. The estimation is made with use of the private qualitative criteria corresponding accepted to "values of a society». On the basis of the expert analysis and sociological interrogations sets of criteria for an estimation of a thematic accessory of Internet sites are formulated. Numerical value of conformity turns out with use of statistical methods of the thematic analysis. For the analysis sets of the linguistic keys corresponding to formulated criteria are used. The received result is used for reception of the generalised rating of the site establishing its social importance.

    Keywords: thematic analysis, site rating, value of a society, ranging, linguistic key

  • Field investigations of traffic flow on the basis of the intensity of the directional microphone

    We describe the design of a directional microphone and a methodology for conducting the tests. In a controlled motion lane highway conducted field observations made by the authors microphone. As a result of the simulation is determined relative measurement error. It is shown that in order to reduce relative error detector transport recommended in 30-100 m behind the traffic lights, since the start of the vehicle the sound coming from the car, increases. Within the measurement error of 12%, a passive acoustic detection of transport, can be applied in the total intensity on the stretch of road that does not exceed 400 vehicles / h.

    Keywords: transport stream, transport noise, passive acoustic detector, directional microphone

  • The additive «Grikol” as an effective means of combating winter slipperiness

    Treatment methods of roadway covering with deicing product, including salt, reducing winter slipperiness, do not provide traffic safety at unpredictable drops in air temperature. Surface distribution of sleetproof materials covering pollutes the environment to a large degree and increases corrosive attack to metal parts of the car. The solution to this problem is the use of asphalt-concrete mixes with deicing properties.

    Keywords: Stone-mastiphiс asphalt, SMA, icing additive, сoated ice adhesion, stabilizing additives, test lottman, national standart

  • Applicatin "Curve method" for building and repairing oil and gas pipelines through natural obstacles

    The problem of complexity and the high economic costs for the construction and repair of pipelines through natural prepyatsviya. A detailed overview of the possibility of applying the "Method curves" during the overhaul, reconstruction and capital construction of underwater crossings of trunk oil and gas pipelines, compared with the traditional method of laying pipe by horizontal directional drilling, given the advantages of this method in terms of both economy and ecology. Detailed description of the general principles of construction works at the construction site with the use of innovative technologies.

    Keywords: pipelines, the method of horizontal directional drilling, underwater passages, pipe bent by cold deformation

  • Finite element modeling of creep of plates of arbitrary shape

    The article proposes the derivation of resolving equations for the bending of triangular finite element of plate with regard to creep. In deriving of the equations we use Lagrange variational principle. The problem is reduced to a system of linear algebraic equations. Creep contributes only to the right side of the system of equations. These equations allow to calculate the plates of arbitrary shape, taking into account the viscoelastic properties of the material. An example of the calculation for a rectangular plate of a secondary polymeric PVC, hinged along the contour and loaded uniformly distributed over the area load is presented. As a law establishing a link between stress and creep deformation we used nonlinear equation of Maxwell-Gurevich. Calculations were performed in Matlab software package. The graphs of change in time of deflection and stresses are presented. Stress during creep vary slightly, a difference between the stresses at the beginning and end of creep process does not exceed 6%. The result of numerical calculation of the maximum deflection value at the end of creep is different from the theoretical on 0.26%.

    Keywords: creep, finite element method, bending of plates, polymers, Maxwell-Gurevich equation, long cylindrical rigidity

  • Basis for the creation of natural-technical systems (PTS) "The natural environment – object of activity – population" in the use of water resources

    The use of water resources to economic activity that is determined a necessity in human existence, all living beings and in almost all technological processes of industrial and agricultural production, fuel and energy complex and other industries, and other activities. At the modern stage of society development at the global level of the system ""Nature–Society–Man"" and the local level of basin geosystems, within which are formed the water resources, there is a strong tendency of the limited water resources within the bounding conditions for further development. Use of water within the local basin geosystems of the southern and Northern Caucasus the river Kuban, Terek and the Upper don, where more than 23 million people. (16.3 per cent of the total population of the Russian Federation)provided by the existing and newly built water system (WS) that in-basin and inter-basin regulation, redistribution of runoff (surface, underground), the selection of a water source and transportation of the estimated costs of water to a particular water user. The aim of the study is to develop a methodology basics of technical theory title of ""environment – Object of activity – Population"" existing in the composition of the WS, in which the main component is man-made hydraulic structures (HS), amending the natural processes of interaction between biotic and abiotic components, requiring a system of quantitative and qualitative assessment.

    Keywords: water resources of the basin geosystems, water systems, natural and technological systems, monitoring, environmental safety, the object of activity, ecological conditions, the zone of influence

  • Samouplotnyayushchiesya fine-grained fibrobetony with the application of withdrawals of lithotrity

    Are given the results of studies on the creation of samouplotnyayushchikhsya fine-grained fibrobetonov on the withdrawals of lithotrity with the application of a polyfunctional additive D -5. Are developed the compositions of samouplotnyayushchikhsya fine-grained fibrobetonov with the application of a basaltic fibre, which make it possible to considerably decrease the expenditure of cement and to improve the characteristics of fine-grained concrete mixture and concrete. The use of a polyfunctional additive D -5 in the mixtures makes it possible to increase the strength properties of fine-grained fibrobetonov with a simultaneous improvement in the rheological characteristics of concrete mixtures. The replacement of cement to 10 % from the mass by ashes of fraction d0,14 mm in the fine-grained concrete mixtures does not cause noticeable reduction in the strength properties of concrete. Developed samouplotnyayushchiesya fine-grained fibrobetony possess the increased strength properties and have low prime cost due to the use of local raw material and withdrawals of lithotrity

    Keywords: cement, the withdrawals of lithotrity, ashes, polyfunctional additive D -5, basaltic fiber, samouplotnyayushchiysya fine-grained fibrobeton, strength for the bend and the compression, the mobility of mixture, the plan of the experiment

  • Modelling and experimental research of path filter of C range

    Modelling and experimental research of path filter of C range on opposing rods was made. In the paddband from 4 to 8 GHz losses were not more than 1.5 dB. Blocking at tuning downwards per 1 GHz was not less than 50 dB. Blocking at tuning upwards per 2 GHz was not less than 70 dB. There is a false passband 16.6 - 21.5 GHz.

    Keywords: filter on opposing rods, modelling, experiment, wave centimetre range

  • Technical and economic perspectives of import substitution of forest harvesting machines

    The paper presents a technical-economic analysis of the perspective of development of domestic forestry machine-building in the conditions of import substitution. The authors substantiate and prove the prospects of using domestically produced harvesting machines in logging works, particularly the machines based on caterpillar tractors OTZ-300 and OTZ-400, fitted with modern foreign (in prospect - domestic) technological equipment. Using logging machines made by “Amkodor” company during cutting operations is also economically justifiable. In particular, in difficult natural-manufacturing conditions (the third category of soil) vehicle operating costs on a work cycle of machine complexes by the company “Ponsse” make 1081,7 rouble/m³, of machines by the company “Amkodor” – 848,4 rouble/m³, and of machines based on caterpillar tractors by LLC “OTZ” the costs make 407,7 rouble/m³ on the average. Specific capital costs are 2862, 1215,2 and 560,5 rouble/m³, respectively. Hence, we can draw a conclusion that machines and machine complexes based on caterpillar tractors of cross-country capacity provide stable productive work with high technical-and-economic indexes in difficult natural conditions.

    Keywords: import substitution, logging machines, technical-economic analysis, perspectives

  • The criterion for assessing the quality of repair work for electricity pilons of transmission line

    The article presents the quality assessment of repair work for electricity pilons of transmission line performed by the method of vibration diagnostics. The suggested criterion for assessing the quality of the repair is relative adhesion of repair layers to the base of the stand. Modeling of structural oscillations strut mount, transmission lines and calculations in the finite-element complex Ansys. The dependence of the parameters own frequency of fluctuations of the value of damage at different values of the space adhesion. The resulting equations based on changes in natural frequencies on the magnitude of adhesion. The calculation of the relative adhesion of the repair composition to the concrete model of the design. The material presented can be used for assessing the quality of repair work of different structures of the core type reinforced concrete structures.

    Keywords: vibration diagnostics, quality, repair of structures, defect, adhesion, natural frequencies

  • Method of complex estimation of investment projects in construction based on fuzzy logic

    Expediency of creating a method of complex estimation of investment projects in construction is substantiated in the article. The necessity of the accounting internal and external factors, their importance and trends, and also an inertance of manifestation factors are proved. The method is recommended to use for complex estimation of created and already realized investment projects in construction.

    Keywords: investment project, complex estimation, efficiency, multicriteria optimization, fuzzy logic, construction

  • Theoretical work basis and design philosophy of highcurrent coaxial type termoresistors

    Thermoresistors nowadays are used not only as parts of temperature sensors and flowmeters but they are used as components of starting and control devices. Use of low-powered thermoresistors as starting and control devices parts needs a lot of devices that reduces equipment reliability. Current step-up running through motor-starting devices simplifies control circuit. For using thermoresistors in electric circuits with high-discharge rate it is necessary to use special constructions in order not to let termoresistor body be overheated. Thermoresistor expansion results in changing of thermal fields distribution pattern inside this semiconductor. The authors show calculated characteristics which let determine proportions and shapes of semiconductor subject to thermoresistor temperature.

    Keywords: high power thermoresistors, thermoresistors of coaxial type, current density, temperature, analogy criterion, thermal conductance, temperature gradient, thermal field, stability criterion

  • Recommendations on the selection of bearing parts in order to increase the service life of a bridge structure

    One of the most important elements of the bridge, from which the service life of this structure directly depends, is the supporting part. It provides the movement and rotation of span structures, as well as the transfer of all loads from the forces acting on them to the supports. The task of the designer is to select such support parts, that could be allowed maximum reducing of the forces, acting at the ends of the beams and having a minimum resistance to their free movement. It is necessary in each case to select the support part, which will most closely meet the requirements. To solve this problem, the author structured and tabulated the kinds of support parts. And also an analysis of the main characteristics of some of them.

    Keywords: bearing part, exothermia, bridge structure, durability, service life, transfer of loads and displacements, deforming systems, sliding systems, rolling systems

  • Simulation design of silicon solar cells using the program PC1D

    Created single-stage model of silicon solar cell using PC1D v.5.9 program, designed to simulate the photovoltaic devices. In the process of simulation change the level of doping and thickness of the n + type layer of the front, as well as applied texturing the front surface. The influence of the doping level and the thickness of the n + type layer in the photovoltaic solar cell characteristics. It was determined that with the increase of the doping level and the thickness of the front n + -layer a decrease in the efficiency of solar cells. It was found that the use of texturing the front surface leads to an increase in efficiency and is associated with reduced reflection losses and an increase in the photocurrent.

    Keywords: Silicon solar cell thickness, doping levels, texturing, current-voltage characteristic