In the article, the authors carried out a computer experiment in Ansys Fluent CAD to study the efficiency of a heat sink surface in terms of reducing the temperature of a heat-loaded source. Providing optimal thermal conditions for electronic products is one of the most important problems in the design of radio electronic equipment. Increasing the temperature of electronic products significantly reduces the reliability of their work. The work is devoted to numerical modeling of the heat sink surface efficiency of a pin radiator with an internal heat source. A conclusion is drawn about the ineffectiveness of performing a heat sink pin surface, not the entire surface is equally effective.

Keywords: thermal mode of equipment, pin heat sink, numerical methods, aerodynamic flow

In this paper, we consider the application of the optical heterodyning method for signal processing of a receiving device. The simulation of the developed scheme was carried out in the environment of OptiSystem. Also presented are the results of modeling, explaining the principle of operation of this scheme.

Keywords: optical heterodyning, radio frequency, L-band, signal spectrum

The absorbing apparatus serves to extinguish the impact when the wagons cohere and move. Most of the energy, about 80%, in this system is absorbed by a friction unit consisting of a friction wedge and a fixed plate. Absorption of energy in this system occurs due to the work of frictional forces arising during longitudinal motion of the pressure wedge with respect to the friction plate. Due to the large shock-frictional loads, intensive wear and destruction of the cermet cake occurs, which adversely affects the energy capacity of the absorbing apparatus. To eliminate these shortcomings, studies were conducted to create a new material. After numerous experiments, a composition was obtained with the optimum content of components, which maximally satisfies the working conditions of the friction unit and the requirements imposed on these devices.

Keywords: absorbing apparatus, friction unit, cermet, wear resistance, friction plate, powder material, sintering technology

The analysis of the projects for securing the soil foundations, which are part of the new construction projects of educational institutions in the Rostov region in 2016-18, is carried out. On the example of the construction of schools in the cities of Rostov-on-Don, Taganrog, Shakhty, Novocherkassk, Aksai and the village of Chaltyr, the main technical and technological solutions for soil consolidation are considered, depending on the engineering and geological conditions of the construction sites

Keywords: cementation, injector, soil, consolidation, foundation, soil piles, retaining walls, sediment, subsidence, deformation

The article gives an overview of the ways to utilize the heat of the boiler exhaust gases. In conditions of actualization (both technical and economic expediency) of application of technologies for fuel economy and environmental protection, the use of aggregates based on the internal combustion engine and microturbines with the utilization of the heat of the cooling system and exhaust gases has found application. Deep cooling of combustion products of natural gas both in boilers (condensing boilers) and in special condensing heat exchangers (utilizers) makes it possible not only to organize the full utilization of the physical heat of the flue gases (the lowest heat of combustion of the fuel), but also to select the latent heat of condensation Water vapor. The coefficient of efficiency of the boiler-aggregate will be increased in this mode by 8-12%, provided that the boiler operates in the optimal mode. Cooling of combustion products also reduces the content of nitrogen oxides in flue gases, incl. With the use of heat pump plants. The efficiency of the implementation of projects for the installation of condensing heat exchangers depends to a large extent on the number of hours of operation at maximum capacity in the mode of deep utilization. In this connection, we propose a variant of optimization of the boiler room thermal scheme with the heat recovery of the flue gases.

Keywords: Heat recovery boiler, boiler house thermal scheme, optimization, boiler, flue gases, heat generating unit

The problem of identification of defects in the construction in the form of a wall element is considered. Numerical simulation of the structure is carried out in the Ansys finite element complex. The investigated model of a wall structure has a defect in the form of a through crack, of a certain length. The edges of the cracks do not interact with each other. The excitation of the structure under pulsed loading is considered. Wave field displacements at control points are analyzed. Identified signs of identification of crack-like defect.

Keywords: numerical modeling, wall element, defect, crack, identification, finite element modeling, dynamic analysis, oscillations, displacement wave field

The problem of identification of defects in the construction in the form of a wall element is considered. Numerical simulation of the structure is carried out in the Ansys finite element complex. The investigated model of a wall structure has a defect in the form of a through crack, of a certain length. The edges of the cracks do not interact with each other. The excitation of the structure under pulsed loading is considered. Wave field displacements at control points are analyzed. Identified signs of identification of crack-like defect.

Keywords: numerical modeling, wall element, defect, crack, identification, finite element modeling, dynamic analysis, oscillations, displacement wave field

The article is devoted to the study of the problem of determining the mechanical properties of vibrating centrifuged concrete with a combined aggregate and fibrous additive, which was basalt fiber. Experimentally obtained data on the optimal consumption of disperse fiber. The dependence of the strength properties of concrete with a combined aggregate on the amount of fiber additive added is graphically presented. Also graphically shows the increase in the speed of the passage of an ultrasonic wave in the body of concrete when determining the prismatic strength. It was found that the presence of porous particles in a concrete mixture facilitates the directed distribution of mineral fibers along the section of the concrete ring. This, in turn, leads to an increase in the fracture toughness of the material. The conclusion is made that the joint introduction of porous and fibrous additives into the concrete mix determines the production (at the same cement costs) of high-strength concretes with an increased crack resistance, as evidenced by the data on the displacement of the boundaries of microcracks formation in the direction of their increase.

Keywords: structures and products of annular section, centrifuged concrete, vibrocentrifuging, mechanical properties of vibrating centrifuged concrete, combined aggregate, fiber additive, basalt fiber, prismatic strength

An experimental device designed for the detection of peripheral veins during the injection and infusion was developed on the basis of recording the difference in the intensity of the optical signal reflected from the vessels and surrounding tissues. The device allows to perform the detection of the locations of vessels, to determine their projection, to confidently distinguish veins and arteries. The effectiveness of the application is shown in tests on healthy people and patients with diabetic angiopathy. The device is very compact, has a simple design and low cost.

Keywords: infrared light, optical pair, photodiode, LED, introscopy, vascular detection, complicated intravenous access, peripheral vein, photoplethysmography, angiopathy

The article deals with the effectiveness of high-strength concrete for the design of concrete columns on the example of 20-storey residential building in Rostov-on-Don. The results of the ground floor columns calculations for different types of concrete strength are presented. The columns are presented in two variations. The first variation is 600x600 B25 from the second underground floor to the tenth floor and 500x500 B25 from the eleventh to twenty-fifth floor. The second one is 500x500 B60 from the second underground floor to the seventh floor, 400x400 B60 from the eighth to the eleventh and 400x400 B25 from the twelfth to the twentieth floor. The analysis of the study results showed the technical and economic efficiency of the use of high-strength concrete (in particular, concrete class B60) due to increasing the strength characteristics of the compressed elements. This is also due to reducing the cross-sectional size and weight of the columns, saving reinforcement, causing a reduction in the cost of elements as a whole.

Keywords: high-strength concrete, compressed elements, construction of tall buildings, columns, Lira-SAPR, calculation of structures

The low-Thickness aeration zone in the loess soils of Rostov-on-Don is favorable for underflooding. Active civil engineering in the groundwater discharge zone generates a delayed geological risk of seepage and underflooding. To increase the reliability of hydrogeological forecasts, the materials of engineering and geological surveys have been analyzed and summarized, and a conceptual hydrogeological model of the near-river part of the Temernik River has been developed. The model describes the geological structure, boundary conditions of geofiltration, ranges of changes in soil filtration properties. To refine the hydrogeological parameters and reduce the uncertainty of the model, multivariate numerical modeling is planned.

Keywords: underflooding, geological risk, subsidence ground, modeling, conceptual model, hydrogeological conditions

The oil and gas industry is life-supporting for almost all branches of the national economy and forms the basis of the country's economy, while forming the volume of construction production, depending on the amount of oil and gas produced and consumed. Construction in the oil and gas industry has a specific nature, and the arrangement of oil and gas fields differs from industrial construction by a number of features.The main features can be considered: significant volumes of construction and its duration, the scattered nature of oil and gas field facilities on a large territory of the country's regions, linking oil production facilities to oil and gas fields and settlements, and high energy costs for oil and gas fields. Generalized in this study, the organization of construction of oil and gas facilities are aimed at identifying opportunities to use rational and efficient methods of conducting work, increasing the pace of organization of construction of oil and gas facilities in extreme conditions and improving their technical and economic indicators.

Keywords: organization of construction, oil and gas facilities, climatic conditions of construction, technological processes of construction

In the article results of approbation of the experimental devices designed for visualization of blood vessels developed by the authors are presented. Experimental device number one is an emitter of infrared light, the experimental device number two is a emitter of visible red light. Devices can be recommended for use in patients with no factors impeding vascular imaging and in patients with elevated body mass index.

Keywords: infrared radiation, optical pair, photodiode, LED, introscopy, visible red light, vascular detection, complicated intravenous access, peripheral vein

Erythrocyte, when moving through a narrow capillary, stretches out and rolls like a tractor's caterpillar. Charges located on the surface of the erythrocyte, move together with the membrane and generate a magnetic field in the vicinity of the erythrocyte membrane, which can affect both elements of blood flow outside the erythrocyte, and its contents, in particular, the iron atoms that make up the hemoglobin. A three-dimensional model of the erythrocyte is constructed. The shape of the erythrocyte is approximated by a truncated cylinder of radius r with generators L1 and L2. It is assumed that all charges on the surface of the erythrocyte are the same and evenly distributed over the surface of the erythrocyte. Charges move along with the membrane along closed curves (trapezoids). Moving charge creates a magnetic field, the strength of which depends on the magnitude and speed of the charge. On the erythrocyte membrane there are several charges and each of them at some selected point creates a magnetic field. The total strength of the magnetic field is defined as the vector sum of the strains created by each of the charges. The following parameter values ​​were used in the calculations. The charge of the erythrocyte is 20 million elementary charges. The number of charges on the erythrocyte membrane is 38594. The rotation frequency of the erythrocyte membrane is 20 revolutions per second. The erythrocyte radius is 2 μm. The erythrocyte volume is 94 μm3. The erythrocyte surface area is 135 μm2, the lengths of the truncated cylinder forming are 3.4 μm and 11.5 μm. The erythrocyte speed is 100 μm / sec. The step along the space is 0.1 μm. The performed calculations of the magnetic field strength H have shown that the rotation of the erythrocyte membrane with the charges placed on it leads to a significant redistribution of the magnetic field in the vicinity of the erythrocyte. And with an increase in the frequency of rotation of the erythrocyte membrane, the heterogeneity of H increases significantly and can lead to a change in hemodynamics in the microcirculation system.

Keywords: mathematical model, erythrocyte, narrow capillary, magnetic field, microcirculation

The article studies the power divider of 10-centimeter range. A description of the scheme and design of the power divider on the air-strip transmission line. The analysis of the amplitude-frequency characteristics of the power divider in the forward and lateral shoulders with the help of the Microwave Office package is carried out. The model of the power divider is experimentally studied, the following results are obtained: in the band from 2.4 to 3.7 GHz, losses do not exceed 4.3 dB, and the unevenness does not exceed 1.7 dB.

Keywords: power Divider, directional coupler, plume bridge, amplitude-frequency characteristic, losses, unevenness