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 paper is devoted to problems that arise in practical classes when solving physics tasks for students of engineering majors at the university. Examples of classification of tasks by types are given, taking into account certain criteria. Factors that contribute to the development of students' skills in solving physics tasks are considered. Solutions to the above-mentioned taskss are briefly discussed. A diagram is proposed that shows the main stages of solving a quantitative physics task, as well as feedbacks that seem essential in the course of the solution.

Keywords: physics, engineering direction, practical lesson, task, solution, main stages, problem during solution, mathematical training, mastering the discipline, element of creativity, methodical instructions

The article considers the assessment of the suitability of solar radiation data from ERA5 atmospheric reanalysis for forecasting problems in the northern territories. The experimental site of the Mukhrino station (Khanty-Mansiysk Autonomous Okrug), equipped with an autonomous power supply system, was chosen as the object of analysis. A statistical analysis of the annual array of global horizontal insolation data obtained using the PVGIS platform has been carried out. Seasonal and diurnal features of changes in insolation are considered, distribution profiles are constructed, and emissions are estimated using the interquartile range method. It is established that the data are characterized by high variability and the presence of a large number of zero values due to polar nights and weather conditions. The identified features must be taken into account when building short-term forecasting models. The conclusion is made about the acceptable quality of ERA5 data for use in forecasting energy generation and consumption in heating systems.

Keywords: ERA5, solar radiation, horizontal insolation, the Far North, statistical analysis, forecasting, emissions analysis, renewable energy sources, energy supply to remote areas, time series, intelligent generation management

The paper examines the causes of the decline in the quality of electrical energy in small settlements. A linear multiplicative model for forecasting electrical loads has been developed based on a time series of electricity consumption in one of the small settlements. A posteriori verification of the multiplicative model has been performed, and the efficiency of the developed model for medium-term forecasting tasks has been demonstrated.

Keywords: electricity consumption, small settlement, linear regression model, multiplicative model, forecasting electrical loads, quality of electrical energy

The construction of a mathematical model for solving the problem of planning construction excavation, which is interpreted as a problem with a linear objective function and constraints, is considered. The calculation algorithm is implemented by software in Python using the scipy.optimize.linprog library, which provides effective methods for solving linear programming problems. The developed program visualizes the results, making the allocation of time for the operation of machines. When testing the program, scenarios with different input data were considered, allowing us to conclude that the developed tool helps to make the best decision when planning construction work and analyze the impact of changes in input parameters on the result.

Keywords: organization of construction, linear programming, distribution tasks, optimization, planning, mathematical modeling, simplex method

Establishing relationships between construction and the pristine preservation of the environment, prioritizing what is necessary and sufficient, and balancing requirements and capabilities are a prerequisite for the harmonious development of the planet. But often, high rates of industrialization and local decision-making threaten the stability and harmonious development of the environment. The main problem is the disparity of goals and methods between design specializations. Each employee of a related specialty performs a task in accordance with current regulations, without thinking about the impact of the decision on the future object and its aesthetics. The concept of support and participation meets the requirements of multitasking and encourages an architect to be not only an architect, but also a social worker, engineer, fighter, diplomat, and solve environmental problems. The aim of the authors is to substantiate the need for flexible solutions in engineering and construction design, joint solutions to the problems of creating a favorable environment, and the participation of the architect in all areas of the building's life cycle.

Keywords: environmental well-being, flexible design solution, resource reuse, closed-loop economics, concept of support and participation, sanitary protection zones, invariance, refunctionalization

The authors of the article raise the question of the value of the graphic heritage of famous architects, which they brought when they were sent abroad (on so-called retirement trips) to study architectural monuments, and the significance of these works for their design activities. The development of retirement at the Academy of Fine Arts is briefly considered. Using the example of drawings made by I.A. Monighetti abroad, in order to get acquainted with the world's artistic and architectural monuments, a comparative analysis of measurements preserved in the library's collection with fragments of his specific buildings is carried out. In this publication, for the first time, some of the surviving works of I.A. Monighetti, which are in the collection of the library of St. Petersburg State University, are introduced into scientific circulation. The method of using the studied architectural monuments in the practical works of the master is shown.

Keywords: stages, architectural education, Academy of fine Arts, retirement, graphic heritage, projects, architect, Hippolyte Monighetti

We conducted experimental studies to determine the thermal conductivity of polyurethane foams with different structural parameters, such as cell type and size. The purpose of the study was to investigate the contribution of radiant heat exchange to the thermal conductivity of polyurethane foams. The studies were conducted using the ITP-MG4 thermal conductivity meter in two distinct versions. In the first instance, the thermal conductivity of polyurethane foam was measured without the inclusion of a foil layer, whereas in the second instance. The results of the studies demonstrated that, depending on the morphology of the foam, the contribution of radiant heat exchange to thermal conductivity ranges from 5.88% to 15.87%.

Keywords: cellular materials, thermal insulation, polyurethane foam, thermal conductivity, radiation, morphology

The presented article reveals the issue of using waste from the automotive industry of rubber products as one of the possible ways to improve the quality of asphalt pavement and, accordingly, reduce the number of repair activities and material costs for their implementation and increase the service life of the roadway. The tests carried out show that the asphalt-concrete mixture using a modifier based on active rubber powder demonstrates the best mechanical and operational characteristics. The strength and elasticity of asphalt concrete increases, as well as the abrasion resistance decreases, which leads to a longer use time of this web. Such changes in the characteristics of the roadway have a positive effect on the economic side of the issue. Improving the quality of the finished product increases the time intervals between repair actions, which reduces material and resource costs. The adhesion of the road to the rubber of cars is improved.

Keywords: asphalt concrete, asphalt mix, automobile waste, rubber crumb, modifier, active rubber powder

Using the example of the Burzyanskaya SES (Republic of Bashkortostan), operating in an autonomous mode from the power grid, the possibilities of using renewable energy sources (RES) and energy storage systems (ESS) are described. The tasks of ESS in the power system are considered: stabilization of frequency and voltage, optimization of load, reduction of electricity losses. An analysis of the economic efficiency of the implementation of ESS is carried out.

Keywords: electric power grids, renewable energy sources, energy storage systems, isolated systems, power supply

The article discusses a methodology for predicting global horizontal radiation for the day ahead, based on the concept of characteristic days – typical daily profiles of global horizontal insolation. The method is aimed at use in the absence of operational meteorological information and is intended as an alternative (backup) method of short-term forecasting in autonomous energy systems. As a test case, data from the Murino station (Khanty-Mansiysk Autonomous Okrug), obtained from the PVGIS service based on ERA5 reanalysis, was used. The average and median characteristic days for each month are constructed and the accuracy of forecasts using the RMSE, MAE, MdAE and R2 metrics is compared. It is shown that median profiles provide more stable results in conditions of increased weather variability. The method can be used for approximate planning of photovoltaic installations in remote and northern regions with limited access to meteorological data.

Keywords: solar radiation, global horizontal insolation, ERA5, statistical forecasting methods, forecasting in energy systems, forecasting horizon, forecasting for the day ahead, methods for constructing characteristic days, average and median profiles

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.

A study of heat transfer in porous heat exchangers with a sediment of dust particles was carried out. The influence of heat exchanger length and the presence of sediment on the Nusselt number was studied. It was revealed that increasing the length of the heat exchanger from 5 to 30 mm leads to an increase in the Nusselt number by 39.72-81.35% depending on the Reynolds number. The formation of sediment on the surface of the heat exchanger leads to a decrease in the Nusselt number by 2.8-6.6%.

Keywords: heat transfer, hydrodynamics, calculation, Nusselt number, Reynolds number, mathematical modeling, sediment formation, microelectronics, cooling systems, radiator

More attention is being paid to the transition to domestic software with the digitalisation of the construction industry and import substitution. At each stage of construction, additional products are needed, including CAD and BIM. The experience of integration of Russian-made systems for the tasks of information modeling of transport infrastructure and road construction is considered. Within the framework of the work the integration of Vitro-CAD CDE and Topomatic Robur software system was performed. Joint work of the construction project participants in a single information space was organized. The efficiency of work of the project participants was determined due to the release from routine operations. Integration experience has shown that the combination of Vitro-CAD and Topomatic Robur allows to manage project data efficiently, store files with version tracking, coordinate documentation and issue comments to it.

Keywords: common data environment, information space, information model, digital ecosystem, computer-aided design, building information modeling, automation, integration, import substitution, software complex, platform, design documentation, road construction

The paper proposes and specifies the engineering mathematical model of the drive using a block of ferrofluid couplings and, within the framework of preliminary design, studies its dynamic properties, in the course of which transient characteristics are obtained, allowing to assess the qualitative performance of such a drive and to outline measures for their improvement.

Keywords: uninterruptible power supply system, automatic regulation, relay voltage regulator, relay system modeling.