The article presents a numerical simulation of energy separation (thermal stratification) in a Leontiev tube, conducted using STAR-CCM+ software. The study focuses on a comparative analysis of two different tube designs, each intended to create temperature differences in gas flows. The simulation revealed that the supersonic flow passing through the tube significantly increases in temperature at the outlet, while the subsonic flow, on the contrary, shows a noticeable decrease in temperature. Detailed profiles of gas velocity and temperature are provided for both designs, demonstrating the effectiveness of each Leontiev tube variant in creating distinct areas of gas with different temperatures without the need for additional external heat exchange. The results obtained are of practical significance for improving the efficiency of gas distribution stations, enabling more effective management of thermal flows and preventing the formation of gas hydrates, as well as for use in other technological processes where temperature separation in flows is required without external heating or cooling.
Keywords: Leontiev tube, numerical simulation, STAR-CCM+, thermal stratification, gas flow
The article deals with the peculiarities of the results of tests carried out to determine the characteristics of the contact zone organized by stamping on a steel plate. During the test, the specimen was in the steel mold in which it was manufactured. The steel form was used to prohibit horizontal movement of the steel thin plates and minimize the effect of uneven slippage of the steel gouge in the direction perpendicular to the shear force. The considered tests were carried out according to a specially developed methodology, which took into account the specifics of the contact zone shear operation, the applied tooling and took into account the set objectives of the study.
Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite design
The application of orthogonal matrices in information processing and transformation systems is considered. A method is proposed for assessing the results of protective masking of audio information using Walsh-structured quasi-orthogonal Mersenne matrices.
Keywords: orthogonal matrix, message masking, masking/unmasking algorithm, amplitude-frequency response, white noise, root mean square error, signal-to-noise ratio
The article discusses the method of constructing a horizontal protective screen made of large-diameter steel pipes used for the construction of tunnel-type structures using a closed method. The factors influencing the choice of this method are analyzed - features of the construction site, economic and time indicators. As an example, a project for constructing a protective screen made of large-diameter pipes for the construction of a two-section transport tunnel under railway tracks is considered. Diagrams are provided that provide basic information about the construction project, its main parameters are considered: geometric shape and dimensions, location of structural elements with an indication of their sizes. The sequence of construction work is presented, consisting of six main stages, starting with the construction of auxiliary working pits and ending with the construction of the internal structures of the tunnel. Such construction of tunnels in dense urban areas requires taking into account and minimizing their impact on existing structures and transport routes in the construction area. The article presents the results of numerical calculations of stabilized movements of the soil mass, confirming the effectiveness of this method.
Keywords: horizontal protective screens, tunnel-type structures, large-diameter pipes, soil deformations
The article presents a way to increase the load-bearing capacity of a reinforced concrete column due to metal clips from the corners with an increase in the load on it. To ensure the joint operation of the existing column and the metal cage, the corners are subjected to prestressing, which is achieved by compressing the corners with jacks.
Keywords: reinforced concrete column, column reinforcement, metal cage, prestressing of the cage
The article thoroughly explores cloud, fog, and edge computing, highlighting the distinctive features of each technology. Cloud computing provides flexibility and reliability with remote access capabilities, but encounters delays and high costs. Fog computing focuses on data processing at a low level of infrastructure, ensuring high speed and minimal delays. Edge computing shifts computations to the data source itself, eliminating delays and enhancing security. Applications of these technologies in various fields are analyzed, and their future development is predicted in the rapidly evolving world of information systems.
Keywords: cloud computing, fog computing, edge computing, cloud technologies, data processing infrastructure, scope of application, hybrid computing, Internet of Things, artificial intelligence, information systems development
This article deals with the problem of analyzing and recognizing human emotions using sound data processing. In view of the increase in the scope of application, which is largely caused by the difficult epidemiological situation in the world, the solution of the described problem is an urgent issue. The main stages are described: the audio data stream is recorded and, in accordance with the “sound fingerprinting” approach, is converted into an image that is a spectrogram of the sound data set. The stages of training a convolutional neural network on a pre-prepared set of sound data are described, and the structure of the algorithm is also described. To validate the neural network, a different set of audio data was selected, not participating in the training. As a result, graphs were constructed demonstrating the accuracy of the proposed method.
Keywords: neural network; human emotion recognition; convolutional neural network; sound fingerprinting; Tenserflow; Keras; Matlab; Deep Network Toolbox
In most countries of the world, the construction industry is one of the main sources of air pollution in urban areas and agglomerations. One of the most dangerous pollutants are fine dust particles PM2.5 and PM10, formed from the production of dusty construction processes. Due to the optimal location of administrative facilities on the construction site, it is possible to reduce the concentration of dust emissions of particles PM2.5 and PM10. In addition, the cost of the dust control method is of concern to contractors, as it leads to an increase in the cost of construction. Therefore, reducing overall transportation costs is another optimization goal. To solve several tasks at once, the study uses multi-purpose optimization using the particle swarm method (MRF) algorithm to find an optimized construction site layout that can simultaneously reduce both the level of pollution from dust emissions and transportation costs.
Keywords: environmental safety, environmental monitoring, atmospheric air protection, ecology in construction, dust suppression, feasibility study, dust collection systems, labor protection in construction
We have considered the improvement of analytical formulas for the determination of bending moments in a single-span beam with semi-rigid nodes. We have obtained analytical relationships for deflections, angles of rotation, bending moments and shear forces in a single-span beam with semi-rigid nodes. A convenient coefficient from 0 to 1 is used to specify the intermediate stiffness node. The coefficient characterizes the fraction of possible rotation of the support node. When we derived the formulas, we used the assumption of constant bending stiffness of the beam along its length and linear deformation of the beam material under load. We did not consider the cases of loading the beam with concentrated forces and concentrated bending moments in the span. We realize the complexity and necessity of calculating beams with semi-rigid nodes, so we have created a table for easy calculation. In the table you will find the values of the supporting moments depending on the degree of possible angle rotation. With the information about the bearing moments, you can load the hinged beam with them and construct a bending moment diagram. The upper left and lower left values from the table are used to determine the bending moments at the supports. The upper right and lower right values of the table are used to determine the bending moments in the beam span.
Keywords: semi-rigid nodes, multilayer structures, calculation methods, contact zone, wooden beams, reinforcement, wood, reinforcement, environmental friendliness
This paper analyzes the shortcomings of the existing organizational and technological documentation, namely the construction organization project and the project of work production. It is concluded that the main task of organizational-technological documentation is to minimize construction risks at the earliest stage, to increase knowledge about the project and to transfer the process of development and decision-making to an earlier stage of construction. As a solution to these problems, it is proposed to consider the use of building information modeling technologies (BIM) in construction, and move to the development of digital construction organization project (4D model of the construction process), which is a digital information model of the capital construction object (3D model), the elements of which are interconnected with the work on construction production. Two projects where the building information modeling technology was applied and a digital construction organization project was developed are considered: construction of an underground tunnel and reconstruction of a power unit of a combined heat and power plant. The advantages of using a digital construction organization project are proved, which makes it possible to forecast the planned duration of works, as well as the duration of works, taking into account the occurrence of risk events, necessary resources and equipment.
Keywords: digital project of construction organization, 4D model, building information modeling, project of construction organization, capital construction object
The article deals with the peculiarities of the study objectives and test methodology for characterization of different contact zones organized in different ways and requiring different methodological approach for specimen fabrication and testing. The steel plate-concrete contact zone organized by stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone between the steel plate and the concrete, organized by the stamping on the steel plate requires the use of steel molds to prohibit horizontal movement. The contact zone of two wooden bars organized by epoxy glue with reinforcing fabric placed between the layers of glue is tested for shear without organizing the prohibition of horizontal movement. The contact zone formed at the connection of a steel plate and incompletely gained strength concrete, with the association of steel bars has features of fixing the actual strength of the concrete part of the specimen. The considered methods have both a number of common features and differences, which are taken into account in the proposed methods of fabrication and testing.
Keywords: contact zone, contact characteristics, test methodology, shear tests, stamping, composite construction
The paper describes the composition of a wireless sensor network for agricultural purposes, including a sensor node, an actuator node and a coordinator node. Based on the IEEE 802.15.4 standard, a hybrid network architecture with node synchronization via a time slot mechanism is proposed. The WSN model is proposed, which includes the forming functions of nodes, which makes it possible to abandon the matrix of energy characteristics and describe the elements of the network in a simplified form.
Keywords: wireless sensor network, sensor node, coordinator node, network structure, wireless node architecture, wireless network parameters, network model
The loads on the power floors and column foundations of modern logistics centers can reach 6-9 t/m2 and 1000 t, respectively. At the same time, the step of the grid of exploration wells in the mined areas does not allow reflecting on the geological sections the exact geometry of the occurrence of weak, untreated soils of backfilling pits. The use of a method for strengthening man-made soils by pressing in prefabricated prismatic piles made it possible to compensate for the missing information from engineering and geological surveys by controlling the forces of indentation and thus determining the occurrence marks of more durable foundation soils.
Keywords: engineering and geological surveys, the territory being worked on, man-made soils, soil reinforcement with piles, geological section
The paper proposes a hybrid method of packet routing in a wireless sensor network based on a genetic algorithm that allows you to build a routing table taking into account restrictions on the maximum number of transmissions through each node of the network and, as a result, increase its energy efficiency. The results of experimental studies on BSS with a random configuration of nodes in space are presented and it is shown that the congestion of data packet relay nodes is reduced by 30-40% with an increase in the total length of routes by 10%.
Keywords: wireless sensor network, sensor node, coordinator node, network structure, packet routing, energy efficiency of a wireless network, network model
Modern domestic calculation methods and developed countries for determining the bearing capacity of monolithic reinforced concrete slabs for punching do not fully take into account all factors of design solutions and operating conditions. The available design provisions are made for the static operation of structures and there are no recommendations for taking into account the features of the dynamic impact on the overlap and the nature of the work of the node interfaces. The accepted empirical assumptions of the calculation, based on numerous experimental data, do not take into account the features of the stress-strain state of the coupling of the overlap with the column during destruction according to the punching scheme. This is due to the lack of computational models in which all the acting internal forces ensuring the resistance of the interface to penetration would be considered comprehensively. The complexity of the problem is due to the fact that the sections of the nodal interface are in an inhomogeneous stressed state. The stress-strain state of plates for punching under dynamic load is currently little studied. This article proposes a method for determining the bearing capacity of a symmetrical nodal coupling of a column with an overlap for punching under static and short-term dynamic loading. The proposed design model of the punching strength is based on the following prerequisites: the resistance to punching of a monolithic reinforced floor consists of the shear resistance along the surface of the reduced punching pyramid formed by the height of the compressed concrete zone; the strength of the concrete shear resistance increases due to volumetric compressive forces on the surface of the reduced punching pyramid; the angle of inclination of the faces of the punching pyramid depends on the loading speed. The obtained theoretical dependences are applicable under static and dynamic loading and are in satisfactory agreement with experimental data.problems in the field of video analytics. Numerous studies have shown that, despite the dynamism of processes in the field of information technology and the introduction of various tools and methods, the task of object maintenance still remains relevant and requires further improvement of previously developed algorithms in order to eliminate some inherent disadvantages of these algorithms, systematization of techniques and methods and the development of new systems and approaches. The presented article describes the process of step-by-step development of an algorithm for tracking human movements in a video stream based on the analysis of color groups. The key stages of this algorithm are: the selection of certain frames when dividing the video stream, the selection of the object under study, which is further subjected to a digital processing procedure, the basis of which is to obtain information about color groups, their average values and percentages of their occupancy relative to the object under study. This information is used for the procedure of searching, detecting and recognizing the selected object with an additional function of predicting the direction of movement on video frames, the result of which is the formation of the entire picture of the movement of the person under study. The materials presented in this paper may be of interest to specialists whose research focuses on issues related to the automated acquisition of certain data in the analysis of various images and videos.
Keywords: coupling of a monolithic floor with a column, static and dynamic load, punching pyramid, tangential stresses, concrete shear strength, punching strength