The paper is concerned with relevant stress concentration research in construction elements made of structurally heterogeneous materials. On the base of the physico-mechanical model of structurally heterogeneous body (polycrystal) , with the use of finite elements method, stress distribution in construction elements made of polycrystalline metals with hexagonal lattice (magnesium, titanium, zinc) is investigated at various stress states. Coefficients of stress concentration in plates with circular holes are determined in the case of uniaxial tension, uniform biaxial tension, and pure shear. It is demonstrated that stress concentration coefficients calculated regarding microstructural factors of stress concentration can take values that considerably differ from values for isotropic body, depending on anisotropy of elastic properties of polycrystalline metals and a type of stress state
Keywords: linear and plane stress states, polycrystalline structure, microstructural factors, nonuniformity of stress
In article the qualitative structure of emissions of pollutants in the atmosphere of St. Petersburg is considered and also dynamics of change of volumes of emissions of solid substances on air environment of the city is analyzed
Keywords: emissions of pollutants, atmospheric air, the solid (weighed) substances, stationary sources, non-stationary sources
The paper deals with the results of study on the degrees of stress inhomogeneity caused by interaction between differently oriented crystalline grains in macrovolumes in case of non-uniform uniaxial tension. Calculation of finite element volume consisting of forty grains is performed. It has been revealed that the quantity of forty grains is enough for constituting the smallest body volume, which can be assumed to have the averaged properties of a macrovolume. Directions of crystallographic axes were selected randomly. Calculations were performed for various metals with cubic and hexagonal lattices. Based on the results of calculations, the curves of normal stresses in the central cross-section of the elementary volume were constructed. It has been found that the significant exceedance of normal stress values is possible in comparison to the values calculated for quasi-isotropic fine-grain material. Dependence between the degree of stress inhomogeneity and the degree of anisotropy of elastic properties has been demonstrated
Keywords: microvolume, macrovolume, non-uniform tension, degree of stress inhomogeneity
The abstract briefly describes modern architectural and planning tools to improve the powerefficiency of industrial buildings. The developments of the Soviet industrial architecture and current European trends are recorded. The features of climate in the South of Russia are considered. The perspective tendencies of increase ofpowerefficiency of industrial buildings are formulated. Examples of the use some of constructive methods and means of improvement of territories for increase of powerefficiency of industrial objects are presented
Keywords: industrial architecture, economic factors, energy efficiency, environmental friendliness, flexible planning solutions, functional mobility, additional engineering systems
The developed equipment is being created to increase the cost savings during the construction of the road infrastructure, to improve the quality of temporary winter roads, as well as to build them more quickly and conveniently. This technique replaces two cars in the construction of auto winter roads.
Keywords: auto-wintering, melting, combination, versatility, innovation, snow melting unit, economy, application, design, methods
The developed version of the snow plow plow is created in order to improve the performance of a single unit of equipment when clearing snow on wide streets and to preserve unimpeded movement in a dense stream of cars, as well as the use of technology on narrow streets
Keywords: clearing, productivity, folding, trails, KAMAZ, transportation, costs, area, speed, snow
The article deals with the current stage of modernization of the industrial sector of the economy and development strategies aimed at improving productivity in enterprises in the region. The purpose of the study: identification and analytical review of the main problems of increasing productivity in industrial enterprises of the Rostov region; definition and systematization of strategic directions of problem solving, taking into account the accumulated positive experience of the regional business community. The main methods of research are analysis and synthesis, analysis of statistical data, observation and synthesis.Specific examples of the successful use of the proposed management tools within the industrial enterprises of the largest region of Russia - the Rostov region are given. This region produces about 28% of the industrial output of the entire southern Federal district, while the growth rate of the main indicators of its socio-economic development is higher than the national average. It is concluded that in the region under consideration there are all the prerequisites for the implementation of the regional program "increasing productivity and employment support in the Rostov region" for 2018-2025 on the basis of the introduction of advanced information, innovative management technologies in production.
Keywords: management, socio-economic system, modernization, industrial sector, labor productivity, region, strategies, management models, management tools
The article presents the analysis of the properties of local fine aggregates, their influence on the characteristics of the concrete, and also presents the impact of screening crushing when it is introduced into the mixture in various proportions on the strength of concrete
Keywords: Concrete, screenings of crushing, construction sand, experiment, grain composition, concrete strength, small aggregates
Structurally heterogeneous materials, in particular polycrystalline materials, have wide application in construction and technics. The higher values of local microstress in comparison to the average values of stress lead to the faster exhaustion of bearing capacity and destruction. Therefore, nonuniformity of microstress and microstrain depending on structure, physical and mechanical properties, should be taken in consideration when estimating bearing capacity, especially for the elements of construction with different stress concentrators. On the base of the physico-mechanical model of structurally heterogeneous body stress concentration for small-scale plates , made of polycrystalline materials with hexagonal lattice, with circular holes, at the case of uniaxial stress state, is investigated. It is shown that coefficients of stress concentration depending on anisotropy of elastic properties of polycrystalline materials can take values which considerably differ from values for isotropic body. Physico-mechanical model developed for structurally heterogeneous body allows studying local microstress in the construction elements at various stress states, with different forms and kinds of stress concentrators, which is the subject of the further research
Keywords: stress distribution, structural heterogeneity of the material, polycrystalline metals,microstress and microstrain, stress concentration
In the article the scheme of the measuring stand of the device model for determining the part of the energy distributed from the generator, the scheme of the measuring stand of the model for measuring the standing water coefficient (VSWR) and the measurement of the transient resistance are presented. The best results are obtained by a partition consisting of two metal plates overlapping the path both above and below the clay layer. So, with a clay humidity of 4%, the total attenuation was 14.4 dB (-6.1 dB without a partition), and at a humidity of 16% -35 dB (-18.4 dB without a partition). There is an increase in attenuation of approximately two times compared to the case without a partition for both dry and wet clay, but the amount of attenuation is insufficient. To increase the attenuation in model 2, two consecutive resonators were created. But the attenuation in this case increased insignificantly in comparison with one resonator. It is obvious that two resonators are upset because of mutual influence on each other. Therefore, it is proposed in a real installation between these two resonators to place a section of a waveguide of nonresonant length with an absorber that will eliminate the coupling between the resonators.
Keywords: measuring stand, super-high-frequency installation, brick, drying, firing, power, structure, electrodynamic modeling, experimental setup
The mechanical stresses measuring methods analysis is showing in that paper. The purpose of that paper is to choosing the practical method of the measuring mechanical stresses in polymer glasses during its using. The calculation of the piezoelectric effect on the polycarbonate is considering in that paper. It is showing that this effect can be used for measuring the mechanical stress in polymer glasses during its using. So, it is showing the advantages of that method.
Keywords: polymer glasses, mechanical stresses, polycarbonate, piezoelectric effect, possibility of applying, comparative analysis of the methods
When organizing work on the territory of sanitary protection zones, it is necessary to take into account that the SPZ is already a territory with elevated levels of exposure, which may require the use of additional means of individual and collective protection. Meteorological parameters are important factors affecting the extent of the impact of the work on human health. The article presents a comparative analysis of the concentration of suspended substances in the workplace, depending on meteorological parameters.
Keywords: sanitary protection zone, hazard class, industrial enterprise, construction, reconstruction, ecology, atmosphere, labor protection, non-stationary workplace
The article discusses the features of the climatic conditions of St. Petersburg, affecting the formation of the ecological situation in the city, including the content of fine dust particles in the atmospheric air.
Keywords: fine dust, temperature, relative humidity, wind speed, wind rose, air pollution
The article analyzes the adaptation contour, which is an integral level of management of the body's hematopoietic system, aimed at optimal maintenance of the body's metabolism as a whole. It is indicated that for complex measurement problems it is advisable to use the principles of constructing measuring systems, formulated in terms of system functions using the fractal-categorical approach. It is concluded that the functorial and category maps make the analysis of the hematopoiesis process more complete and visual, and the possibility of further decomposition allows the researcher to carry out more detailed research, visually displays the processes of adaptation of the organism under external influences and naturally contributes to the construction of automated measuring systems for which the adaptive The contour is a model of the bioconverter of information on the processes of hematopoiesis included in composition of bioinstrumental measuring system
Keywords: structural and analytical method, information-measuring system, information flows, hematopoietic system, category diagram, functors, adaptation contour, bioinstrumental information-measuring system, control signal, measurements
The paper presents an analysis of the processes of formation and processing of vegetable waste. An assessment is given to the existing ways of processing woodworking wastes and their inefficiency is justified. A new kind of resource and energy-saving grinding set of disk mills is proposed. On the basis of the analysis of the results of experimental research, the effectiveness of the use of the proposed method for the production of wood fiber is substantiated.
Keywords: abrasive set, grinding, efficiency, wood-fiber semi-finished product, specific fiber surface, wood pulp, defibrator, refiner, refiner, knife grinding