Paper presents a review of scientific works investigating of effect of carbon nanotubes (CNT) concentration on electrical conductivity and pizeresistive properties of concrete. Different values of the percolation threshold for nanomodified concrete obtained by different authors are given. Recommendations for specifying the favorable concentration of nanotubes in composites are considered. As a result of review a need for additional dedicated research for the assessment of relation between favorable CNT concentration and their characteristics, method for the producing of composite and conditions of its application is stated.

Keywords: concrete, sensor, carbon nanotubes, percolation threshold, electrical conductivity, monitoring of stress-strain state

The article describes the principles of the method of x-ray photoelectron spectroscopy. There is described a method for the possible application of the XPS method in fire-technical expertise. There ar given criteria for determining the type of short circuit on electrical products removed from the fire. Depending on the conditions of the occurrence of the circuit of the conductors changes their chemical composition. There are describe of the implementation of existing methods of analysis used in fire laboratories. There given a brief description of the main components of the time-of-flight spectrometer, including an x-ray tube, time-of-flight energy analyzer, and the principles of their operation. Application of the principle of aggregation of spectrometer elements makes it possible to simplify the adaptation of the method of X-ray photoelectron spectroscopy to solving problems in the field of fire safety. There is describe experimental technique in the author’s spectrometer.

Keywords: X-ray spectrometer, x-ray tube, photoelectron spectrum, vacuum system, short circuit, fire-technical expertise, time-of-flight energy analyzer

The paper presents the research results of the influence of materials, which change a phase on the exterior surface of the outer shell, on forming of the heat flow mean value for one year, calculated on change of the exterior temperature per every three hours. The correlation between heat flow and characteristics of the phase-change material was studied. Such materials increase heat lag of the outer shell and allow reducing the amount of electric energy required to keeping of indoor climate. The paper presents the research results of the influence of materials, which change a phase on the exterior surface of the outer shell, on forming of the heat flow mean value for one year, calculated on change of the exterior temperature per every three hours. The correlation between heat flow and characteristics of the phase-change material was studied. Such materials increase heat lag of the outer shell and allow reducing the amount of electric energy required to keeping of indoor climate. Based on the implementation of the method of math planning of experiments the sufficient math model of the dependence of the heat flow density on the material coating thickness, latent heat of transition, heating capacity value and thermal conductivity before and after phase change was made. The mathematical model coefficients were interpreted and best values of very factors based on desirability function were determined. Based on these data the selection of the material with phase-change temperature of about 0 0C for Krasnoyarsk was made.

Keywords: energy efficiency, heat flow, heat saving, heat-storing material, phase-change heat storing, phase-change material

In this article there analyzed the three step approach in a modified spectral characteristics evaluation method using discrete transformations of Walsh and method of parametric spectral analysis of Proni. There briefly described the method based on the method of parametric spectral analysis of Proni, describing the positive and negative qualities. It is also proposed to apply a discrete change of Walsh and Hadamard. There suggested the use of three step procedure. Applying of Walsh discrete transformation will simplify and reduce the computational procedures. When applying these transformations for analysis of mathematical models of processes with similar characteristics, it is proposed to calculate the templates, and then to compare these templates. And templates for each group are invited once to calculate parameters using a modified Prony method or Prony and Berga combined method. Later on using Walsh transforms it is necessary to compare the results obtained with the available templates.

Keywords: modeling, spectral analysis, Proni method, method of Walsh, the model order discretization step response duration

The paper presents the results of studies of the effect of ion-argon bombardment in vacuum on the spectral distribution of the photoconductivity of CdS crystals in the region of the fundamental absorption edge and on the current-voltage characteristic of the semiconductor under study. In the course of research, characteristic changes were found in the spectral distribution of the photoconductivity of a CdS crystal in the edge region of the spectrum and in its current-voltage characteristic at room temperature. It was shown that low-dose ion-argon bombardment leads to an increase in photosensitivity, as well as to a change in the spectral distribution of the photocurrent beyond the absorption edge of a semiconductor. It was found that the exposure of the sample, after exposure to it with argon ions, leads to the relaxation of the photoconductivity spectra of CdS crystals in the direction of the initial distribution. The observed spectral changes are associated with a decrease in the surface concentration of the recombina-tion centers, as well as with an increase in the number of near-surface donor self-defective centers, caused by the action of argon ions on the surface of CdS crystals. Exposure of the CdS crystal under investigation in the air, after exposure to it with argon ions, leads to a reverse increase in the number of recombination centers on the sample sur-face due to the interaction of the surface of the semiconductor with oxygen contained in the air.

Keywords: ion-argon bombardment, photoconductivity spectra, CdS crystals, surface recombination, current-voltage characteristic

Biphasic composite materials were synthesized near the La0.7Sr0.3MnO3-based percolation threshold and the second phase, which is an inorganic or organic compound — polyvinyl acetate, paraffin, carboxymethylcellulose, sucrose, and ultrafine silver particles. For composites with an organic matrix, the magnetoresistance values ​​do not exceed 2%, and for composites with silver particles - 8%. The values ​​of isotropic negative magnetoresistance for ceramic samples of 80% LSMO / 20% GeO2 (mass%) reach 13% in a 15 kOu magnetic field with a sensitivity of about 1% / ke in the low-field region. High chemical and radiation stability of these glass composites should be noted. The magnetoresistive properties of such compounds slightly decreased after 60 days of being in water with a salinity of 35 ppm. Composites of 80% LSMO / 20% GeO2 were exposed to X-rays with a dose of 7 Sv from the Co57 source. The magnetoresistive properties and electrical resistance of these composites did not change after that.

Keywords: lanthanum strontium manganite, ceramic two-phase material, one-step synthesis, radiation exposure, magnetoresistance, percolation threshold, dielectric constant, barrier layer, spin-dependent tunneling, spin polarization

The article considers the modeling of wind impact on the objects of parametric architecture. To determine the optimal shape of the surface, the evolution of the analytical surface shaping, formed by congruent curves in parallel planes, obtained by the rotation of the reulault triangle with a plane perpendicular to the axis of rotation, is studied. Based on the results of a numerical experiment using the finite element method, the rational analytical surface of the object of parametric architecture, resistant to wind, is determined. The dynamic characteristics of the object of parametric architecture are obtained. Recommendations are given to clarify the methods of determining the wind load for buildings and structures of complex geometric shape.

Keywords: parametric architecture; wind load; modal analysis; pulsation component; building frame; finite element method

The problem of designing and construction of objects of various purposes of an eco-sustainable type in urbanized areas is currently extremely topical. Directions and techniques used in theory and practice to improve the quality of the urban environment, still remain the subject of many scientific disputes and professional discussions. In their article, the authors propose to act in accordance with a number of environmental principles in order to solve urban-planning tasks of this kind on the territory of complex development. According to the authors, with an integrated approach to solving the problem, architectural and town-planning activities, modified according to the principles listed in the article, should ultimately contribute to the development of natural processes. In this case there will be a significant increase in the level of construction development of the territories in terms of the quality of the processes performed and an increase in the level of environmental safety.

Keywords: environmental safety, urbanized areas, urban environment, environmental principles, sustainable construction, comprehensive assessment

The influence of grain composition and active mineral addition of microsilicasuspension on properties of dry concrete mix was considered. The selection of the method of production of paving slabs with allowance for technological modes of vibropressing technology was made. The optimum dose of microsilicasuspension, having positive effect on the concrete quality, was defined.

Keywords: grain composition, dry mix, process of hydration, microsilica, paving slabs, heavy concrete, compressive breaking strength, abrasion capacity

In the article the features of application of logistic approaches of the organization of movement of the cable cars, as well as the method of selecting the cable car and the slopes at various characteristics of the operation of the complex. The results of experimental research on the network of cable cars of the mountain resort "Rosa Khutor"are offered. The paper uses the methods of monitoring the movement of passengers on cable cars by means of identification by ski pass and GPS

Keywords: transport mobility, route network, public transport, automated monitoring of passenger traffic, logistics approach, cable car, monitoring of cable car congestion on-line, traffic volume, digital transport management system

The article proposed a method for determining the geometric parameters of surface roughness using the Gwyddion computer program and a Canon Lide 220 flatbed scanner. Using the method, surface roughness samples were investigated. Analysis of the obtained results showed low values ​​of the absolute error of measurement of roughness parameters.

Keywords: Bavykin O.B., Krivozubova E.V.

The paper proposes a mathematical model for evaluating the effectiveness of measures aimed at anticipating competitors in the market. The model is based on the theory of Markov random processes. It allows you to assess the probability of pre-emption in the implementation of commercial projects by one party over the other in a competitive environment. The dependences of probabilities of pre-emption of the parties from time to time. It is shown that these probabilities depend on the average project execution time of each competitor and have a maximum characterizing the most effective lead time. The obtained theoretical dependences allow us to analyze the possible outcomes of competition in market conditions.

Keywords: competition, market relations, advance, efficiency, commercial project, mathematical modeling, conflict of parties, random process, probability of state, time dependence

The electrical properties of composites based on La0.7Sr0.3MnO3 (LSMO) synthesized at the percolation threshold have been studied: LSMO / Li4P2O7, LSMO / Sb2O3, LSMO / GeO2. The activation energies of these compounds have been determined. New ceramic materials with silver interlayers between LSMO manganite crystallites have been synthesized. The current-voltage characteristics for the LSMO / GeO2 series are given. The nonlinearity of the characteristics is most pronounced for compositions near the percolation threshold, 85% LSMO / 15GeO2.

Keywords: lanthanum strontium manganite, composite material, ceramics, one-step synthesis, magnetoresistance, percolation threshold, dielectric constant, barrier layer, tunneling, spin polarization

The relevance of the study of two-dimensional periodic graphene gratings in the terahertz range is described. The structure under study and the results of calculation of scattering and reflection diagrams of multilayer structures are presented.The relevance of the study of two-dimensional periodic graphene gratings in the terahertz range is described. The structure under study and the results of calculation of scattering and reflection diagrams of multilayer structures are presented.

Keywords: Golovacheva E.V., Ivanova I.N., Gribnikova E.I., Makhno V.V.

The paper contains information about a stationary model of coordination of private and public interests in the allocation of resources. The study is conducted in a game setting, taking into account the hierarchy in the relations between the subjects. Take into account the subjects of management on two levels: the supervisor and the agents. Between agents occurs non-antagonistic game in which the Nash equilibrium.When modeling the interaction between the supervisor and agents, the Stackelberg equilibrium is constructed. Algorithms for solving the problem are specified, simulation experiments for a number of characteristic input data are carried out. The analysis of the obtained results is given.

Keywords: supervisor, agent, Nash equilibrium, hierarchical system, Stackelberg equilibrium, subject of management, private interests, public interests