The loops of the dielectric hysteresis of a soft ceramics based on PZT with Curie temperature TC=210℃ are investigated. The studies were carried out at a frequency of 50 Hz in two modes. In the first of them, the field was switched on by 0.07 seconds, in the second - it operated continuously. The amplitude of the field E_m varied from 2.5 to 25 kV / cm and switched stepwise with an interval of 15 minutes. The coercive field EC and the switchable polarization P_m were determined. The switching polarity in the saturation region turns out to be no more, in contrast to BaTiO3 and other materials, but less than the corresponding values obtained with short-term switching.

Keywords: piezoceramics, piezoelectric material, hot pressing, dielectric hysteresis

The article deals with the development of a mathematical model for reducing the cost of building heat storage tanks by using the refrigerating capacity of liquefied natural gas (LNG)

Keywords: liquefied natural gas, LNG, special fortifications, SPS, full isolation mode, heat storage substance, TAB

The article is devoted to the task of searching for the design solution of the structural coating plate. Structural plates are widely used to cover single-storey structures and have a wide variety of structural and architectural forms. The choice of minimum weight design is based on the VAT control method. As the regulators adopted the location of the columns and the class of steel. Depending on the number and location of the columns on which the structural plate rests, the forces in the structural elements change and accordingly the cross-sectional area and mass of the structure change. Four variants of the arrangement of the columns and three versions of the class of steel were considered. For each design variant, the design was calculated numerically, the cross-section was selected, and the mass was determined. Based on the accepted criterion of the effectiveness of the design solution - metal consumption, the most effective design solution was adopted with the arrangement of columns along the perimeter of the coating in steps of one cell.

Keywords: space grid structures for roofs, regulation of stresses, optimization, metal consumption, criterion of optimality

Flat bending stability problem of constant rectangular transverse section wooden beam, loaded by a concentrated force in the middle of the span is considered. Differential equation is provided for the cases when force is located not in the center of gravity. The solution of the equation is generated numerically by the method of finite differences. For the case of applying a load at the center of gravity, the problem reduces to a generalized secular equation. In other cases, the iterative algorithm developed by the authors is implemented, in the package Matlab. A relationship is obtained between the value of the critical force and the position of the load application point. For this dependence, a linear approximating function is chosen. A comparison of the results obtained by the authors with an analytical solution using the Bessel functions is performed.

Keywords: flat bending stability, secular equation, finite difference method, iteration process

The method of calculation gamma percentage fatigue resource of an arrow shovel excavator. Using this method can most accurately determine the distribution of the extreme members of samples and the corresponding shifts of the Weibull distribution. It was found that to calculate the shifts do not have, you can use only the extreme members of samples.

Keywords: reliability, probability, resource, sample, excavator

The article is devoted to the issues of marketing costs evaluation in the construction project cost's management. The methods of determining the marketing cost in the construction sector within the specifics of the industry are issued.

Keywords: marketing costs, project cost management, methods of marketing costs estimation

In this article, we propose methods for designing fault-tolerant structures for Field Programmable Gate Arrays (FPGAs) by forming an internal structure of macro cells (LUTs), with the possibility of correcting single reversible faults in the circuit’s gates. To improve fault tolerance, the failure tolerance of a typical macro cell was assessed, the most vulnerable areas were identified and the most vulnerable parts of the macrocell were protected by means of triple modular redundancy methods. Depending on the expansion of the protected area, various versions of the built-in redundancy were obtained, and various options for minimizing the built-in redundancy were proposed. Experimental work was carried out to form fault-tolerant ISCAS'85 combinational circuit designs in the basis of fault-tolerant FPGAs.

Keywords: combinational circuit, FPGA, field-programmable gate array, LUT, logic synthesis, increase fault tolerant, computer-aided design (CAD), fault injection, single event transient

In the paper, on the basis of the equation of motion of an incompressible lubricant having the micro-polar properties for the case of a ""thin layer"", the equation of continuity, Darcy and the formula for the energy dissipation rate for determining the function Ф (θ), caused by the molten surface of the bearing bush covered with a low-melting metallic melt of a carrier asymptotic solution by the thermal parameter K. Using a self-similar solution for the zeroth approximation, i.e. without taking into account the melt of the low-melting metallic melt, and for the first approximation, taking into account the low-melting metallic melt, the velocity and pressure fields in the lubricating and porous layers are determined, and the basic performance characteristics of the radial slide bearing are determined. The characteristic permeability of the porous layer and the melt of the surface of the bearing bush, coated with a low-melting metallic melt, on the load capacity and frictional force are estimated.

Keywords: low-melting metallic melt, porous layer permeability, lubricant with micro-polar properties, sliding bearing

The review of ways of welding of elements of bodies of cars is carried out. Merits and demerits of spot contact welding and a way of welding with use of the high-concentrated power sources are considered. The processes which are taking place in a zone of a welded seam when using laser welding are in details considered.

Keywords: metal welding, welded seam, laser welding

Researches of hardness of various steel grades for the purpose of determination of density of their distribution and distribution of extremes of selections are conducted. Results of the received researches are used for definition of a resource of details with use of a graphic method of transition from selection to set.

Keywords: selection, fatigue resource, population of final volume

The article studies the problems of training of students in construction universities. The actual curricula of training, the possibilities of the educational environment, the requirements for the teaching staff are analyzed. The most acute and important problems are identified in the field of education, primarily in the construction sector

Keywords: training in a construction college, pedagogy, technical specialties

The experience of the research work of the students of the department "Organization of construction" is studied. The main directions of work, problems and ways of the most effective organization of scientific research work are revealed.

Keywords: organization of construction; organization of research work of students

Numerical simulation is becoming more and more widespread when solving the problems of air distribution and inflow air rate. One of the questions of using CFD approaches legitimacy is the possibility of a reliable description of the flow in modern air distribution devices. In the present work, physical and numerical experiments were carried out for the SMK 200 jet nozzle diffuser. Velocity profiles were taken at various distances from the jet nozzle during the physical experiment. Numerical investigation tool was the integrated package STAR-CCM +. Numerical simulation was carried out using various turbulence models. Simulation results showed that the use of the k-ɛ models allows to describe the parameters of the flow with sufficient accuracy. Number of cells required for the correct flow description in modern air distribution device is suitable for practical application.

Keywords: air distribution, numerical simulation, turbulence models, physical experiment, jet nozzle diffuser, STAR-CCM+

The complexity and high cost of multiplexing optical fiber sensors is still the main limitation for the widespread introduction of sensory systems, both distributed and quasi-distributed, and point-like. The article proposes a new multiplexing method that takes advantage of both broadband and two-frequency radio-photon multiplexing systems. The simplest broadband radiator is taken from the first, but a complicated and expensive system of spectrometry is not used to determine the central wavelength of fiber Bragg gratings. From the second, a recording system is used at the beat frequency between two components, but an expensive system for generating two- and polyharmonic probing systems is not used. The multiplexing parameter is determined by the frequency of separation between the transparency windows of a fiber Bragg grating, for example, with two phase π-shifts, which differs by a certain value for each of the sensors. The mechanism of modeling of gratings of the specified type is given, in principle the possibility of multiplexing of various number of sensors is shown. When using sensor networks built on the basis of passive optical, the number of multiplexed sensors can reach 256, with all sensors having the same Bragg wave of the wave, and can be combined into tree, bus and other topologies.

Keywords: fiber Bragg grating, phase inhomogeneity, fiber optic sensor, multiplexing, transparency window, frequency difference between transparency windows, beat frequency

Theoretical studies of the temperature distribution during laser heating of the TiO2 precursor film on the FTO/glass substrate have been carried out. The simulation was performed on the basis of a numerical solution of the heat equation in the Matlab program to determine the energy density of the laser radiation necessary for crystallization of TiO2. It was shown that on the surface of the TiO2 precursor the temperature reaches a maximum value at a time point of 133 ns with the Gaussian temporal form of the laser pulse. The optimum energy density for crystallization of the TiO2 precursor film with the nanosecond pulse duration is 1.3-1.6 J/cm2, when the film thickness temperature corresponds to 400-500 °C. The obtained results of the simulation are consistent with experimental studies.

Keywords: numerical simulation, laser heating, temperature distribution, TiO2 film, solar cell