The characteristics of a submersible induction motor are described with sufficient reliability for practice by the theory of multi-motor electric drive. In this case, the classical circuit of a submersible induction motor is a coupled system of several equivalent-T circuits. In turn, this significantly increases its computational complexity and reduces the speed of ACS. It is proposed to construct a mathematical model of the submersible electric motor in the form of polynomials with significantly higher speed using the methods of experiment planning. In the area of applicability, the differences in the estimation of energy performance do not exceed 1.1%, between the proposed models and classical equivalent-T circuits.
Keywords: automated control system, mathematical model, polynomial, mean absolute percentage error, computational complexity, design of experiment, scatter diagram, modal interval, submersible electrical motor, rotor package
The article is devoted to one of the stages of research aimed at studying methodological approaches to urban planning reconstruction of territories in the zone of influence of the railway station. The problem of the research is the existing contradiction between the existing methods of urban development reconstruction and systematised data on the zone of influence of the railway station. The result of the study is the development of a method for identifying common features of territories in the zone of influence of the railway station on the basis of cluster analysis.
Keywords: city planning, city planning zoning, city planning reconstruction, renovation, railway terminal railway terminal, cluster analysis, clustering method
The stability of inorganic ultraviolet pigments synthesized from phosphogypsum in relation to the action of a number of solvents has been studied. It is noted that under the conditions studied, the samples are stable in the presence of water and solutions of organic solvents, and treatment of the samples with concentrated solutions of sulfuric acid and sodium hydroxide leads to a decrease in luminescent properties. The luminescence ability of the samples remains when heated to 800 ° C. Based on the developed pigments, building mixes can be obtained that have luminescent properties when irradiated with ultraviolet light.
Keywords: building mixes, putty, luminescent pigments, phosphogypsum processing, thermal stability, solvent treatment, action of acid and alkali solutions
The article offers examples of simulated processes for creating a digital twin, a monitoring process, and a cargo transportation process. A theory is proposed for calculating a mathematical model based on Petri nets. Models for placing an order and its delivery are proposed, as well as a model of information flows using the example of developing models for the processes of transporting perishable products in a refrigerated container.
Keywords: Business process, modeling, BPMN, IDEF1, DFD, Petri nets, mathematical model, intelligent 3D model
An optimization model has been developed for the minimum required number of employees carrying out transport security measures included in transport security units, taking into account the algorithm for distributing employees, including various groups according to individual functions performed at different security levels, as well as the likelihood of various threats to transport security.
Keywords: transport strategy, digitalization of transport security, cost optimization, transport security units, requirements for ensuring transport security
During the research, a new prestressing system was developed for carbon fiber reinforced polymer plates to reinforce damaged steel beams. A parametric analysis was performed using finite element modeling. The results showed that satisfactory amplification efficiency can be achieved using the new pre-voltage system. The prestressed carbon fiber significantly increased the performance when bending beams at the elastic and elastic-plastic stages due to the use of high-strength carbon fiber plates. In addition, as the pre-voltage level increased, the amplification efficiency increased. A simple increase in the area or modulus of elasticity of the carbon fiber plate slightly improved the hardening efficiency, while the simultaneous application of prestressing clearly increases the hardening efficiency.
Keywords: reinforcement, steel beam, prestressing, new system, carbon fiber plate
The article analyzes approaches to assessing the degree of uniformity in the use of labor resources in the construction sector. The Herfindahl-Hirschman index is proposed as a key tool, which makes it possible to quantify the uniformity of the distribution of labor at various stages of the construction process. The use of this index contributes to more rational planning of labor costs, which helps to reduce downtime, prevent overloading of employees and, as a result, increase the overall efficiency of construction projects.
Keywords: uniformity of labor force use, indicators of uniformity, assessment of uniformity, labor resources, calendar planning
Today in the modern world many architectural solutions are aimed at improving the quality of the environment, increasing energy efficiency by minimising the consumption of artificial light. One of the solutions to these problems is the use of natural light, thanks to which it is possible to reduce the impact of artificial lighting, reduce energy consumption. As it is known in most cases daylight enters the premises through translucent constructions, it is the correct design of windows that makes it possible to increase the flow of sunlight. Depending on the window parameters it is possible to control, distribute the natural light coming into the room. The article considers the influence of the ratio of windows to walls as one of the design options for optimising natural light. The research will be carried out with application of modelling in the software complex for calculation of distribution of daylight.
Keywords: natural light, natural light factor, translucent structures, optimisation, area, modelling, walls, working surface, illuminance, vertical expansion, horizontal expansion, recommendations, model, energy efficiency
Currently, bitumen-polymer roofing materials are used in the construction of various types of buildings and structures, which have sufficient strength characteristics, wear resistance, water resistance and are convenient for installation. The mechanical properties of bitumen-polymer materials are significantly affected by the operating temperature. Of scientific interest is the analysis of the possibility of restoring the integrity of bitumen-polymer roofing materials at elevated temperatures, damaged as a result of mechanical stress at subzero temperatures. The article presents the results of testing the flexibility of samples of roofing bitumen-polymer materials at subzero temperatures. The samples that were damaged during the test were subjected to subsequent heating in a temperature chamber in order to identify the possibility of restoring the integrity of the material and the temperature at which the restoration would occur. The analysis of the test results showed the possibility of restoring the integrity of the material and the direct dependence of the quality of restoration of integrity on the heating temperature of the material.
Keywords: restoration of integrity, bitumen-polymer materials, roofing materials, flexibility, influence of temperature
This article examines the use of a dual-circuit closed-loop system for pulsation combustion of solid fuel in agricultural services. The results of research on gas self-oscillations during wood waste combustion in a Helmholtz resonator-type installation are presented. It has been established that with certain geometric characteristics of the installation, a significant sound pressure level (up to 165 dB) can be achieved in the combustion chamber while maintaining a low noise level (up to 65 dB), which contributes to increased combustion efficiency and meets environmental requirements. Potential applications of this technology are proposed, including agricultural waste utilization, drying of agricultural products, and heating of greenhouse complexes and livestock facilities.
Keywords: Pulsation combustion, Helmholtz resonator, solid fuel, agricultural waste, energy efficiency, biomass utilization, agro-industrial complex.
In this article, the focus shifts to an in-depth study of the effect of bending deformation on the change in the refractive index of the optical fiber core. The developed module will allow analyzing trends in this indicator, which will provide a more detailed understanding of the internal processes occurring in the fiber under the influence of deformation.
Keywords: mathematical modeling, optical fiber, bending deformation, modeling of deformed fiber behavior, software
The paper considers the choice of the optimal technology for the construction of tongue-and-groove fencing based on the hierarchy analysis method. Decision-making in construction practice requires consideration of many factors, including internal (cost, reliability, speed of work) and external local conditions (risk of interruptions in the supply of materials, the influence of weather conditions, work in cramped conditions). The hierarchy analysis method makes it possible to formalize the decision-making process by structuring the task in the form of a hierarchy and comparing alternatives in pairs. In the course of the study, a comparative analysis of the technologies of hammering, vibration immersion and static indentation of sheet piles was carried out. Priority vectors for each criterion were calculated, and the consistency of the matrices was checked. The final choice of technology is justified based on the integration of internal and external factors. The results obtained allow us to recommend the optimal technology that takes into account the technical and organizational features of the construction process.
Keywords: tongue-and-groove fencing, technology selection, hierarchy analysis method , selection criteria, construction technologies, pairwise comparison, priority vectors
The article deals with the distribution of air flow velocities for cities of compact configuration on the example of the city of Stavropol. The verification of the implementation of Weibull's law for different wind flow velocities in its various directions has been carried out.
Keywords: wind flow direction and velocity, atmospheric air, distribution law, Weibull's law, mixed Gaussian distribution, change in air flow velocities, time of day, compact city
The work is devoted to the development of eco-industrial parks in the Southern Federal District. They represent the territory allocated for sewage treatment plants (CBS). Examples of CBS using bioreactors with a ruff nozzle at denitrification, nitrification and wastewater treatment plants are given, which have a sanitary protection zone of 15-50 m for closed pavilions, allowing them to be placed directly in residential buildings. The economic parameters of the eco-industrial park are given depending on the productivity of CBS m3/day. The result of the work is a technological scheme developed by the authors for completing an eco-industrial park at the KOS site, a scheme of an eco-industrial park with an area of no more than 8 hectares is presented.
Keywords: eco-industrial parks, sewage treatment plants, wastewater, bioreactor, waste
On the basis of the analysis of tourist infrastructure objects location the influence of tourist flow seasonality on the number of temporary population of resort towns is shown. The relationship between the level of urban infrastructure development and seasonality of tourist flows is revealed.
Keywords: urban planning objects, engineering and transportation infrastructure, temporary population, tourist flow, seasonality, types of tourism