"n this article, the influence of the physical state of chemical additives at the moment of their introduction into a gas-concrete mixture on the kinetics of gas evolution and the gas diffusion coefficient is considered. To test the working hypothesis, two compounds were designed and manufactured. As a part of С№1 chemical additives were entered in the form of a colloidal solution. A comparative analysis of the results of physical and mechanical tests of the aerated concrete samples of the tested compositions showed that the introduction of chemical additives in the form of a colloidal solution lowers the average density in the dry state due to a more intensive course of the gas evolution reaction without significantly reducing the compressive strength. At the same time, the average density increases in the composition of CN2.

Keywords: kinetics of gas evolution, gas diffusion coefficient, aerated concrete mixture, reactivity, expansion of aerated concrete mixture, colloidal solution

This article considers the effect of the introduction of a partially hydrated aerated concrete mixture on the intensity of gas evolution, the reactivity of a disperse gas generator, and the physical and mechanical properties of aerated concrete. To test the working hypothesis, two compounds were designed and manufactured. The pure dispersed gas generator was introduced into composition C№1, and a mixture of a gas generator with a partially hydrated gas-concrete mixture was introduced into the composition C№2. A comparative analysis of the results of physical and mechanical tests of the aerated concrete samples of the tested compositions showed that its introduction increases the compressive strength, while reducing the density of aerated concrete. At the same time in the composition of С№1 there is a higher density and a drop in strength

Keywords: Partially hydrated mixture, gas generator, aluminum powder PAP-1, reactivity, device PGV-2, kinetics of gas evolution, average density in the dry state, compressive strength

The article proposes some innovative technical solutions to build a multistory substructure for residential and public buildings. To erect a building, it is proposed to construct a system of interconnected rail runways at a first storey level along which travelling gantry cranes and special platforms will move. To descend the machines, building materials, instruments to the design level, during the underground space development, it is proposed to employ travelling gantry cranes. In order to quickly relocate loads and machines from one work zone to another, an additional system of rails is mounted along which special platforms are moving. The management of the gantry cranes and special platforms movement is done by the remote operating panels. The superstructure is built in the traditional way using a tower crane, track mounted, for example. The application of the proposed designs when building multistory substructures will enable to improve the technological processes of building the substructures. The proposed technology will help to use it in all the climatic areas of our country.

Keywords: construction of a multistory substructure, slurry wall, process of excavation, bored pile, substructure

The article presents the physical essence of the method of hydrodynamic reduction of air pollution by foam method as the most effective technology palisadian open for extended sources. The mathematical description taking into account the physico-chemical properties of dust and a bubble of foam, and the parameters of the return to technological raw materials dust particles due to the different physical mechanisms of their capture. Parametric dependence of the efficiency of dust removal as a result of setting foaming method of palisadian provides the ability to forecast its calculation for the considered technology implementation process palisadian air bearing features of the interaction of dust with a layer of foam.

Keywords: Palisadian, dust particles, method foam, foam layer, the efficiency of palisadian, belt conveyors

In the article the modern approach to the assessment of the acoustic impact on the adjoining residential zone under construction or reconstruction of airport complexes. While the features of sources of acoustic impact as ground handling and flight operations. Assessment of acoustic impact on the adjoining residential zone under construction or reconstruction of airport complexes, according to the authors, involves several stages. The implementation proposed by the authors of the stages of the assessment of acoustic impact will allow to identify the zones of acoustic discomfort and plan a set of measures aimed at reducing noise in those areas and thus enhance environmental validity under construction or reconstruction of airport complexes.

Keywords: assessment of acoustic impact of the construction of the airport complex, adjacent residential zone, the zone of acoustic discomfort

A home-made heating accessory for UV-Vis cells was developed and tested in both DLS and UV-Vis in-situ measurements. The device is designed to be placed in a measurement chamber of the two-beam spectrophotometer (SHIMADZU UV-2600). It is made of aluminum, and contains four ceramic resistors for the simultaneous uniform heating of two standard UV-Vis cells. The outer thermal emittance is minimized by a wooden thermo-insulating shield. The accessory is painted matte black to minimize beam dispersion of the spectrophotometer. DC power supply allows to maintain temperature of the UV-Vis cells in the interval from 30 to 120 °C. The optical probe of the DLS can be immersed into heated liquid sample in a standard UV-Vis cell. The reaction of the formation of gold nanoparticles in heating accessory was in-situ monitored by simultaneous measurements with SHIMADZU UV-2600 and Microtrac Nano-flex particle size analyzer as an example.

Keywords: Heating cell, DLS, Uv-vis, in-situ analysis,gold nanoparticles

The aim of this work is determination of regularities that determine the operation parameters of the fan in a thermally non-stationary ventilation system contains a heater located along the air flow after the fan. It is established that the ventilation system, containing the heater, has two characteristics aerodynamic resistance related to the volumetric air flow at the sections of the network before and after the heater. It is proved that when using the superposition method, P-L characteristics to determine the parameters of the fan in the system, you must apply the P-L characteristic of the network is related to the volumetric air flow to the heater. The obtained dependences determine the parameters of the fan depending on its aerodynamic characteristics and the location of the heater in the system.

Keywords: the ventilation system is in a thermally transient mode, fan, heater, energy efficiency, energy conservation

the design of a new object presupposes not only the functional aspect, but an important factor is the location of the building or structure. The choice of location is one of the fundamental criteria: it is necessary to take into account the infrastructure and architectural appearance of the selected area, the needs of the district or region in the projected facility.

Keywords: constructivism, the architectural appearance, the blue line, multi-center, prototype, monuments, cultural centers, the Great Patriotic war

In the scientific article, the problem of instrumental and methodological support of works on a special assessment of working conditions is considered. The paper presents an approach to the selection of measuring equipment for the measurement of harmful production factors, which is based on the method of expert assessments. The results of studies of the application of the expert method for determining the possibility of using a group of instruments for the assessment of physical and chemical factors for conducting a special assessment of working conditions at workplaces of a machine building enterprise are presented. Recommendations are presented for equipping the laboratory with laboratories that carry out special assessment work in the conditions of machine building enterprises.

Keywords: labor protection, instrumentation, measuring equipment, special assessment of working conditions, method of expert evaluation

Discusses the problems of effective management of the firm. we study the question of decentralization and delegation of authority to field offices. Seem positive and negative sides of this approach in the light of modern researches of employees of the don state technical University. The conclusion is based on the efficient organization of work units from the creative activity of managers Executive managers

Keywords: organization of construction; personnel management; methods of management of the company

In the article the distinctive features of the cargo car service are compared with the service servicing cars. Questions of an optimum term of carrying out of diagnostics of brake system of the lorry and qualification of the personnel of car-care center are raised. A comparative analysis of three types of stands for the diagnosis of the brake system of a car is carried out.

Keywords: Car, maintenance, diagnostics, car service, braking system, bench tests

In this paper, the temperature distribution from a point source of heat under convective heat transfer is studied. The Navier-Stokes equation describing the steady two-dimensional laminar motion of a fluid is solved numerically. The distribution of the temperature field of a heat-loaded point source is obtained under appropriate boundary conditions, supplemented by the boundary conditions for the flow velocity to equal zero on the paraboloid walls by numerical integration using the control volume method.

Keywords: Radiator protrusion shape, thermal conductivity, thermal apparatus mode, the temperature of the heat source

In the paper, based on the linear equations of motion of an electrically conductive liquid lubricant for the case of a "thin layer", the continuity equation and Darcy, the exact self-similar solution of the problem of hydrodynamic calculation of a radial bearing with an electrically conductive lubricant is given. A field of velocities and pressures in the lubricating and porous layers was found in the work, in the following, analytical dependences were obtained for the main operating characteristics of a bearing with a two-layer porous coating on the shaft surface. An estimate is also given of the effect of the electrically conductive properties of the lubricant, the presence of a porous layer on the main operating characteristics of the bearing.

Keywords: Electroconductive liquid lubricant, radial bearing, permeability of porous layers, electromagnetic field

The results of a computational experiment performed in the Lira-SAPR environment are considered in the article. The purpose of the experiment is modal analysis of various structural schemes of multi-storey reinforced concrete frame under pulsating and seismic influences. The considered design schemes differ in the ratio of the frame and diaphragm components of the frame. It was calculated three series of samples, differing by the ratio of rigidity. The stiffness ratio varied from 20% to 65.9%. Within each series calculations were performed for seismicity of 7, 8 and 9 points. For each variant of seismicity, the soils of the 1st, 2nd and 3rd seismicity categories were considered. It is established that when the role of the frame part increases, the distribution of the modal masses shifts towards the lower forms of oscillations, and the numerical values of their frequencies decrease. Accelerations of the nodes of the coating from the ratio of rigidity do not depend. They increase with increasing seismicity of the site. The ratio of stiffness affects the total consumption of the reinforcement of slabs. This influence is significant in the range of values of the ratio from 20.5% to 42.5%. Further increase in the ratio of stiffness to the consumption of reinforcement influences slightly.

Keywords: seismicity, category of soils by seismic properties, modal analysis, rigidity, selection of fittings, PC Lira-SAPR

In the article the analysis of the market of services of a car-care center of an average city is carried out. A selection of popular car repair shops is given. The market is estimated by the number of required posts and the market share of the services in the city.

Keywords: Car, maintenance, repair, market of services of car-care center, working post