The article is devoted to the construction of domed buildings made of Styrofoam slabs. Positive aspects were noted in the construction and operation of domed buildings. The impact of snow, wind, and seismic loads on the dome building is estimated.
Keywords: construction, building, domes, shaping, energy efficiency, load, snow, wind, seismic
This article raises the issue of designing high-rise monolithic reinforced concrete buildings. Possible applications of the main parts of the building frame to create the optimal structural scheme in accordance with the requirements for providing the building with stiffness, stability, resistance to external forces and resistance to deformations are presented. It also offers a modern method of structural analysis, which allows to ensure durability and all necessary conditions for the safe operation of the building
Keywords: structural scheme, rigidity, stability, reliability, frame, load-bearing element, structural system, "flexible layout", wall systems, finite element method
Often, during the construction of roads in a swampy area, difficulties arise from the adverse conditions of this biome. This becomes a serious problem both at the design stage and at the construction stage. In order for the road to stand the time allotted to it by the project, designers and builders often resort to non-standard solutions, solutions that are rarely used in other conditions. This article will discuss some of them that are most widely used, due to their reliability and effectiveness.
Keywords: road, construction, design, swamp, peat, aggressive environment, geotextiles, geo-piles, concrete, asphalt concrete, retaining walls, armored ground
In the present work optimization of technological process of production of Cabinet furniture at the expense of introduction of system of the automated workplaces (AWP) with application of technology of bar-coding on an example of the concrete enterprise is offered
Keywords: Cabinet furniture, furniture production, automated workplaces, bar-code, bar-coding of details, bar-coding of tasks
The expansion of urban space is carried out through the construction of modern multi-storey buildings located mainly on vacant sites along the perimeter of the existing urban area. It often happens that such sites were previously exposed to various man-made impacts. At the same time, man-made impacts can affect engineering and geological conditions, impairing the natural physical and mechanical properties of the bases. An example is the arrangement of various types of landfills, the movement of the soil and vegetation layer, and the artificial change in hydrogeological conditions. The construction of foundations on such soils is more complex than in normal conditions. The bearing capacity of the bases is reduced, and the geological strata are heterogeneous. The design of foundations requires the fulfilment of calculations, taking into account the above factors. The subsequent implementation of the project requires higher financial and time costs for the preparation of the bases and the construction of foundations, compared with the construction of similar buildings in conditions not previously affected by man-made effects. The article provides examples of the construction of foundations on an artificial basis, in the construction of modern multi-storey residential buildings on the territory of the former aeration fields in Lyubertsy. The results of the work are given and analyzed. The results of the study can be useful in the design and subsequent construction of modern buildings in similar conditions.
Keywords: Foundation, soil, Foundation, sediment, monitoring, construction
Known mechanisms of relaxation of tension in the film at small misfit deformation: the formation of waviness on the initially flat free surface of the film (the instability of the Asaro-tiller-Grinfeld); nucleation of misfit dislocations at the interface film-substrate; a redistribution of atoms near the wavy surface of the film due to the reduction of elastic energy in napylenie on a substrate a semiconductor film; reducing surface energy of the film by increasing its thickness; formation of nanoscale isolated Islands on the surface of the film (Stransky-Krastanov growth); due to the formation of misfit twinning. This paper presents the results of calculations taking into account these factors for different values of the parameters of the film and Islands.The equilibrium conditions of a two-component elastic layer containing mismatch dislocations are investigated. A nanometer-thick SiGe film on a Si substrate and nanometer-sized SiGe Islands on a wetting layer are considered. The uneven distribution of Ge in the sample volume is taken into account. Three-dimensional models of a flat film with dislocation and Islands are constructed. The calculation of elastic deformations is performed using the finite element method. Approximating formulas and iterative algorithm are used to calculate the Ge distribution in the film. According to the results obtained, the uneven distribution of Ge provides relaxation of elastic energy in the alloy, and Ge atoms are concentrated on the protrusions of the disturbed surface of the film and in the vertices of the Islands. Taking into account the heterogeneity of the Ge distribution in the samples has a significant impact on the growth of islets (stable growth occurs with smaller islets) and undulation on the free surface.
Keywords: thin film, heteroepitaxy, Ge, SiGe, misfit dislocations, elastic energy density, finite element method
The article presents the results of research on the morphology of cobalt catalysts for Fischer-Tropsch synthesis on a silicate support with promoting additives of aluminum, manganese and chromium using scanning and transmission electron microscopy. The effect of additives on the surface structure and dimensional characteristics of metallic cobalt was determined.
Keywords: morphology, electron microscopy, catalysts, Fischer-Tropsch synthesis, promoters
A hydroacoustic waveguide is considered as a linear system with parameters distributed over dis-tance. A method is proposed for modeling the impulse response of a waveguide. The fields of indi-vidual normal modes at fixed frequencies are calculated so that discretization theorems are satisfied. By performing the inverse Fourier transform of the fields of all modes separately, the time realiza-tions are restored. Then, summing the mode fields, the impulse response of the waveguide is calcu-lated. This approach allows you to "turn off" the fields of individual modes, add, if necessary, the fields of higher modes, or to study all fields separately, simulating the operation of mode selection. The impulse response is considered as a tool for solving the problems of inverting the acoustic characteristics of the seabed and modeling the propagation of signals in waveguides. The impulse response of the first mode of the Pekeris waveguide with the bottom in the form of an intermediate layer and half-space is restored, its wave attributes are revealed: ground wave, water wave, Airy wave. The frequency dependences of the group velocity of normal modes and the multimode im-pulse response are restored. Low-pass filtering of the impulse response makes it possible to reveal the Airy phase of the first mode.
Keywords: normal modes, seabed, attenuation coefficient, group velocity, impulse response, intramode dispersion, intermode dispersion
The article presents the results of research of the physical and chemical properties of cobalt catalysts on a zeolite support. Methods of BET, thermoprogrammed reduction, thermoprogrammed hydrogen desorption and IR-spectroscopy were used for study. The influence of the support nature on the structural (specific surface area, dispersion of metallic cobalt, size of metal crystallites) and chemical (degree of cobalt reduction) properties of catalysts was established.
Keywords: Fischer-Tropsch synthesis, catalysts, zeolite, hydrocarbon synthesis, structural properties
In the framework of ensuring a high level of products and in order to increase its competitiveness, the development and implementation of quality management systems at the enterprise can be considered an urgent task. Among the main processes of the QMS, a special place is taken by corrective and preventive actions. Management of this process, in turn, requires regular evaluation of the effectiveness of these activities. The article provides a methodology for evaluating the effectiveness of corrective and preventive actions in the production of solid medicines.
Keywords: corrective actions, preventive actions, unplanned non-conformities, non-conforming products, efficiency analysis
The article proposes a method of automatic recognition of the type of building for an environmental monitoring system. based on convolutional neural networks. To train the neural network, the Keras library was chosen, containing numerous implementations of the main components of neural networks, such as layers, target and transfer functions, optimizers, and many tools to simplify working with images and text. The processes of network implementation using the Google Colab cloud platform, the preparation of a training set, the training of a constructed neural network, and its testing during training are described. The result of this work is a convolutional neural network model, capable of determining with accuracy of the order of 90-92 percent what type of buildings is shown on the cartographic image, which allows us to automate this process and use it as a subsystem for the environmental monitoring system of atmospheric air.
Keywords: environmental monitoring system for air, building type recognition, convolutional neural networks, machine learning, computer vision
A large number of power receivers with non-linear current-voltage characteristics with a pulsed mode of operation appeared in residential buildings, which leads to the generation of 0.38 kV higher harmonic current components into the electric network, large values of these harmonics lead to a deterioration in the shape of the network voltage curve. The purpose of the work is to study the harmonics of current generated by electrical receivers of residential buildings, and their influence on the coefficient of non-sinusoidality of the network voltage of 0.38 kV. It has been established that the greatest negative impact on the electric network is exerted by electronic devices with switching power supplies, such as PCs, laptops and netbooks, as well as dishwashers and LED lamps with a socle E14 and E27, whose total harmonic current component coefficient is 85% ≤ THDI ≤ 205%. In the Matlab Simulink program, a simulation model of a 0.38 kV network of a residential building is simulated, which allows the study of the total distortion coefficient of the current KI and voltage KU in the ASU. With the installed non-linear load power more than double the linear load, the coefficient of non-sinusoidality of the voltage in the network of 0.38 kV may exceed the values established by GOST 32144-2013.
Keywords: power supply system, electric network, quality of electric energy, voltage harmonics, current harmonics, electromagnetic compatibility, power receiver
This article focuses on solving the urgent task of forecasting hazardous mining zones by determining the position of local centers of tension in a processed coal seam. The relevance of this task is confirmed by the fact that the intensification of mining processes inevitably leads to an increase in the risk of hazardous production situations, such as rock blows, sudden coal and rock emissions, etc. The most dangerous for the manifestation of rock strikes are the protrusions of the edge sections of the coal seam, intersection and pairing workings. Shockproof activities regulated by the normative documents, are not always sufficiently effective. To solve this problem, authors propose an approach that allows you to quickly determine the position of local centers of tension, taking into account the influence of the worked out space. The authors developed an integration grid, in the construction of which the division of the entire area into elementary sections is performed in such a way that the influence of the weight of the roof rocks over each section is the same. To implement this approach, the influence function of the worked out space is introduced in the form of the equation of the reference rock pressure diagram. Based on the results of numerical simulation of the stress-strain state of the geomassiv, an exponential dependence is obtained, which allows one to determine the concentration coefficient of vertical stresses for points on the plot of reference rock pressure. According to the values of vertical stresses calculated for each point of the integration grid, it is possible to predict the stress-strain state of the geomassiv and justify the need for shockproof measures. The application of the proposed approach will allow the rapid forecasting of hazardous areas and significantly reduce the cost of shockproof measures.
Keywords: modeling, geomassive, coal seam, integration grid, forecasting, vertical stresses
A method for remote determination of the angular velocity of rotation of the blades of a wind generator based on digital processing of the video stream of this wind generator is considered. The main problems that are encountered with this method of measuring angular velocity are analyzed. The considered method for determining the rotation speed of the blades of a wind generator is possible provided that the frame rate is several times greater than the determined rotation frequency. The minimum possible error of this measurement method was found; the real error of measuring the angular velocity was calculated on a specific example.
Keywords: digital processing of the video stream, image stabilization of the wind generator, finding the contours of the rotor blades, estimation of the angular speed of rotation of the rotor
The article presents theoretical calculations and studies of the possibility of parametric oscillations and parametric resonance arising in a polymer self-supporting thermoplastic pipe "Furanflex". The Furanflex thermoplastic, polymer liner is offered as a variant of a separate gas exhaust trunk during the reconstruction of boiler rooms and thermal power plants by heat generating companies.The article provides a detailed description and analysis of the occurrence of parametric oscillations. Examples of symmetric and asymmetric parametric oscillations are considered.Information and conclusions of the presented work are intended for a different range of readers, teachers, designers, students of construction specialties.This article should be of interest to utility managers and heat generating companies .
Keywords: chimney, ventilation duct, corrosion, repair, restoration of the chimney, condensate,protection of the chimney, lining, furanflex, thermoplastic liner,perimetric oscillation
Updating and expanding the road network, even with good funding, is not keeping pace with the ever-growing number of vehicles. One of the ways to solve this problem is to develop a direction in the field of creating intelligent transport technologies. In the work, the operability of the road regulation method was checked based on the analysis of the influence area of the delay point when working on the road network, the conditions for minimizing the delay points on the road network were identified. And also presents the logical design of an automated system for traffic management based on the proposed method of road regulation.
Keywords: delay points, influence area of the delay point, simulation, traffic control, traffic, mathematical model, ITS
The article presents a methodology for solving the problems of integrated quality management of production processes at enterprises for the production of food products. For a general assessment of product quality, it is advisable to calculate the criteria of correctness and accuracy with the subsequent determination of the G. Taguchi “signal-to-noise” ratio. To calculate the criteria of correctness and accuracy, a comparative assessment of product quality indicators was carried out in comparison with the standard sample.
Keywords: quality management, G. Taguchi methods, product quality, generalized indicator
The work is devoted to the study of the main aspects of the use of expert systems in the metallurgy industry. An overview of current production problems is given, as well as prospects for the development of automatic decision-making systems based on formalized expert knowledge using modern data processing tools
Keywords: production processes, metallurgy, control actions, expert systems, technological personnel, production indicators, software implementation, modeling, interference, training complexes
The work is devoted to the consideration of problems and the state of use of alternative energy sources. The description of various types of refrigerating machines using solar energy for air conditioning systems of administrative and residential buildings is given.
Keywords: solar energy, secondary heat sources, absorption refrigeration machines, lithium-methanol bromide mixture.
The construction of social infrastructure is an integral part of improving the quality of life. The study systematized the main problems faced by the developer and the state in the construction of social infrastructure, provides an approximate list of measures that can improve the situation.
Keywords: social infrastructure, state, developer, economy, residential complex, public-private sector, housing construction, state, operation
The influence of road transport on the formation of noise along highways is considered. The proposed options for protecting against noise from the roads.
Keywords: linear city, noise, vehicles, main roads, road categories, noise control