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Herald of Dagestan State Technical University. Technical Sciences

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Vol 40, No 1 (2016)
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https://doi.org/10.21822/2073-6185-2016-40-1

PHYSICAL-MATHEMATICAL SCIENCE

8-14 793
Abstract

The necessity of studying the effect impact of elementary particles impact on the strength and deformation materials properties used in protective constructions nuclear reactors and reactor technology has been stipulated. A nuclear reactor pressure vessel from prestressed concrete, combining the functions of biological protection is to be considered. The neutron flux problem distribution in the pressure vessel of a nuclear reactor has been solved. The solution is made in axisymmetric with the finite element method using a flat triangular finite element. Computing has been conducted in Matlab package. The comparison with the results has been obtained using the finite difference method, as well as the graphs of changes under the influence of radiation exposure and the elastic modulus of concrete radiation deformations have been constructed. The proposed method allows to simulate changes in the deformation properties of concrete under the influence of neutron irradiation. Results of the study can be used in the calculation of stress-strain state of structures, taking into account indirect heterogeneity caused by the physical fields influence.

15-22 685
Abstract
Two types of non-standard relaxation induced impurity photoconductivity (IIP) observed in photoconductors CdS, ZnSe, GaAs and others, depending on the kinetic characteristics of the traps are described. In one case, at the stage of post flashing monotonic decay which is typical for relaxation associated with slow traps (the ratio of the speed of the electron capture to the recombination rate (R << 1), the photo response is experiencing vibrations of low frequency (f =0.03-0.3Hz). Relaxation of the second type characterized by rapid photoelectric traps (R >> 1): measurement alternating signal (f > 20 Hz) relaxation curves take the form of curves usual impurity photoconductivity. Electronic processes responsible for relaxation of non-standard IIP are analyzed. For example, fast-centers, which include the characteristic AIIBVI donor Agi0, for the first time in semiconductors experimentally, investigated the dependence of the cross section of electron capture by traps energy released during localization.

TECHNICAL SCIENCE. POWER, METALLURGICAL AND CHEMICAL MECHANICAL ENGINEERING

23-30 703
Abstract
The necessity of detailed research, relevant consume cal semiconductor heat transfer devices. Distinctive features of thermoelectric devices flow type caused by the change of temperature of streams of coolant along the junctions of termoelectromotoare are identified. Differential equations systems determining the temperature change of the coolants, excluding from them the values of the temperatures of the junctions are used. A mathematical model for parallel flow and counter-flow thermoelectric heat pumps has been constuctucted. A mathematical model of a thermoelectric heat exchanger without any flows of heat in the gaps between the semiconductors has been developed. The cooled and heated liquids temperature dependences at the outlet of the heat exchanger from the heat transfer coefficient to the inner surface of the heat exchanger and reduced heat transfer coefficient from the outer surface of the heat exchanger have been constucted. It is proved that for the same values of heat transfer coefficient to the inner surface of the heat exchanger and reduced heat transfer coefficient from the outer surface of the heat exchanger reducing the temperature of fluid to be cooled significantly more than the increase in the temperature of the heated liquid. The main results obtained by the model are summarized. The analysis is carried out using MathCAD.
31-37 1213
Abstract
It is proved that a prospective direction of electronic power development are intelligent power components: integrated power ICS and modules. Power electronic devices in the field of switched currents up to 50 A are arranged. The results of the semiconductor structures manufacturing technology study, field effect transistor type KP 961 are summarized. The manufacturing technology optimization problem of the transistor structures for power electronics to improve the output characteristics and reliability of the device has been solved. Special attention is paid to the reliability increasing methods, stability and durability of transistors in various modes and operating conditions. To improve the technology some computational model for the stock and the sealing areas formation have been obtained as well as experimental studies have been carried out. Optimised process stages of the transistor structure formation have been proposed. The charts on the structures of transistors grown at the given technology have been made. The manufacturing technology route structure of a field effect transistor of the KP 961 type has been developed.

COMPUTER SCIENCE, COMPUTER ENGINEERING AND MANAGEMENT

38-45 801
Abstract
The software and hardware development tendency, providing the automated monitoring and control of basic and auxiliary technological processes of gas transportation via system of main gas pipelines has been revealed. The article discusses the stages of creation of the software of system of monitoring corrosion cracking under tension (SCC). The new useful adequate regression models development determining the risk level of LCC is shown. A ranking sections algorithm of main gas pipeline (MG) on the propensity to SCC is presented. Adequate developed regression equation determining the LCC risk level has been developed. To count the main gas pipeline lifetime the variable rank of the danger of SCC (RSCC) on the basis of methods of fuzzy logic is proposed to use. Implementation of the fuzzy model was carried out using the graphical tools developed in MATLAB using the expansion pack Fuzzy Logic Toolbox. The working algorithm of developed program and the screen forms are presented.
46-51 821
Abstract

Methodological aspects of the theory of precision Assembly operations in the manufacture of engineering products. Substantiated the advantage of probabilistic modeling in engineering. Noted that the primary error of engineering products change over time because of wear and tear, as a result of what is happening in the material details of the physical-mechanical processes, and experimental study of the marked character of changes in parameters of the parts does not give the exhaustive information on which to judge those or other reliable regularities of the phenomena. It is noted that the experimental study is very important, as allows to receive multiple implementations, which can be seen on the character of changes of primary errors in particular cases. The features of the use of probabilistic modeling in solving problems of the nonlinear theory of accuracy.

52-61 806
Abstract
It is proved that the navigation system use for direction finding of cell phones will greatly expand the functionality and services of telephone networks mobile operators. The direction-finding system advantages and creation of automated system of direction finding cell phones proposed, which significantly expand the possibilities of services of operators of cellular communication in the cell using standard computer equipment operators themselves have been revelead. The developed system has a modular design, which allows modifying software packages, expanding the functionality. The procedure and algorithm of direction finding, allowing piecewise linear approximation of the graph of the displacement of each subscriber is outlined. The developed direction-finding system application for statistical information and optimization of urban public services processing, choice of speed, route and other activities improving the quality of human life is proposed.
62-70 760
Abstract
The advantages of universal program packages, allowing to solve different types of field tasks are analized. It is proved that the simulation of the magnetic system of the magnetostrictive transducers of level and density in the ELCUT environment is reduced to the two-dimensional tasks solution - plane-parallel and axisymmetric. Issues of the magnetic system modeling of the magnetostrictive transducers of level and density of liquid environments using permanent magnets, in the program ELCUT are developed. Systematic constraints modeling the magnetic system of the magnetostrictive transducers of level and density in the ELCUT environment are revealed. The maps of the axial measurements of the interaction of magnets floats level and density of the brand UHDK40Т8АА. The measurements results of magnetic forces are grouped and graphically presented. The basic magnetic characteristics study results of a single annular magnet are partle given. A mathematical model of the ponderomotive forces of adjacent magnets of the magnetic systems MPUP the ELCUT environment is defined.
71-76 620
Abstract
The concept of crossing or non-crossing sets with objects of different nature. The principles, which give the transformed arrays properties that increase the efficiency of information technology. As the main characteristic defining the relationship on the sets, forming the arrays, we consider the system of indexing of elements of the compared sets. The terms an index of non-crossing array components are. We propose a new class of arrays which components are indexed by disjoint sets, the notion of « non-crossing index sets»; provides methods of forming arrays of different classes. It is proved that any permutation of the elements of arrays are implemented with some regularity, associated with changes in indexing. The developed method of formation of arrays based on cyclic shifts of the rows and columns of the original array for the proposed algorithms. The task of forming arrays with disjoint sets of three types has been solved. The paper analizez the proposed options for building arrays with disjoint components - sets, proving that the properties of non-crossing components are stored for the first type arrays in all permutations of columns.

BUILDING AND ARCHITECTURE

77-84 733
Abstract
The aim of the study is to assess the seismic response of buildings when they are of a different height and stiffness, as well as at different parameters of the system of seismic isolation and seismic forces to determine the efficient application of these systems. It is established that in the technology of the moving belt are main-conductive device is a slip system, including a component of the minimization of friction and the component of the constraints of large horizontal displacements. Computational model of the building with fundamental sliding belt is presented in the form of a cantilever beam with lumped masses. Conducted research of efficiency of application of seismic isolation the moving belt in the buildings of a different height.
85-97 810
Abstract

The article is dedicated to the peculiarities of the internal space composition in architecture of Central Asia. There are some main distinguishing features of artistic and aesthetic functions of this direction considered. The purpose of the article is to find forms of ancient cultures interpretation in modern interiors, given the growing tendency of the traditional style use in architecture and design. There are some examples of tourism service facilities in the historic centers of the region with elements of national architecture given. Currently there is an increasing tendency of applying the traditional style in architecture and design using modern building materials. This makes the objects attractive for people interested in different cultures. Entire cities are becoming a modern interpretation of ancient cultures. In the case of designing tourist complexes near the monuments of culture, the direct study of their space-planning structure makes possible to identify the characteristics of the objects architecture, which will recreate the atmosphere of the cultural epoch of that time in a modern style.

98-107 859
Abstract

We consider the problems associated with the development of high-efficient binders. It was found that the mortars and concretes important indicator is the ratio of binding properties of cements with a so-called ”specific consumption of aggregates. ” It was found that the activity of Portland cement in the past decade has increased slightly and is 50-55 MPa; physical and technical characteristics of high-quality graded fine and coarse aggregates remained unchanged. It substantiates the relevance of the development of new types of cements for high-strength and high-quality concrete with active mineral additives and an effective superplasticizers. It is proved that the use of the obtained cements of low water through the use of active mineral additives of different origin, allows to obtain high-quality concrete with strength class from B60 to B100, reduce the need for water-mortar and concrete mixtures of 25-30% for equal mobility.

108-118 875
Abstract
It is proved that for the majority of building structures characterized by different damping elements. The goal of constructing matrix hysteretic damping that takes into account the internal friction in the material. The study is based on generalized hypothesis of E. S. Sorokin on the proportionality of the matrices of damping and stiffness elements of the structure. The methods of accounting for damping in the evaluation of the earthquake resistance of structures. The exact and approximate methods of decomposition of the motion equations for the mode shapes are considered. It is established that the empirical criterion of the approximate method applicability of accounting for damping and its refinement on the basis of the initial approximation can serve as the correlation coefficients of waveforms. It is shown that for non-proportional damping it is possible to approximate the decomposition of movements according to oscillations forms of non-damped system, if the forms are weakly correlated.
119-132 784
Abstract

The article touches upon the theoretical and experimental studies of the influence of the various components of road conditions to reduce the stability of the vehicle, which lead to skidding and rollover. The resulting research material will improve traffic safety on the roads of the Republic of Dagestan. We give formulas for calculating the critical speed cornering with cross gradients and sharp change in direction, in which the skid and rollover is not excluded, due to the appearance of additional transverse forces of inertia. It is explained that a significant impact on the stability of the car has a «side pull». We give graphs of the lateral force from the vehicle slip angle of tires and tire tread wear of the impact on the quality of grip at different speeds and the amount of coating roughness obtained experimentally. Effect on the skid and rollover car road surface irregularities is marked. In such traffic conditions, the technical condition of the vehicle and in particular the shock absorbers are essential. The schedule damper effect on driving conditions, obtained experimentally.

ECONOMIC SCIENCE

133-142 865
Abstract
It is proved that the pricing of the construction is different from the pricing system in the industry and other branches of economy, because it has different methodological and organizational approaches. It has been determined that the cost of construction is set on the stage of its design, in the process of concluding investment contracts (construction contracts), as well as directly during construction, major repairs of objects of capital construction, reconstruction and the implementation of certain types of construction and installation works. It has been found that the pricing mechanism in construction is based on the detailed legal and reference documents regulating material consumption rates and prices, taking into account sectoral, territorial and seasonal features of building production. It has been found that under inflation conditions the price index calculation of construction products for investment purposes is of great importance. Mandatory approval of all stakeholders of the construction production method for determining the price of the construction site is proposed.
143-151 755
Abstract
The paper touches upon some topical issues of effective management of the use and development of the building enterprise production potential. The main characteristics of the production capacity of the construction enterprise are specified. It is established that the interchangeability of the elements of production potential should not be understood mechanically, although some technical and technological peculiarities of production are in its basis. The interchangeability of the elements of production potential is an economic problem to a greater extent. We identify and classify the typical features of the construction enterprise productive capacity. Taken in into account, different approaches to managing the effective use and development of productive capacity in an unstable economic environment are proposed.


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ISSN 2073-6185 (Print)
ISSN 2542-095X (Online)