The factors affecting the strength of the interlayer bond of 3D concrete, as well as factors affecting the ability of the printer nozzle to produce a controlled concrete thread of a particular composition, which is being investigated in the process of 3D printing technology, the main characteristics of the suitability of compositions for printing on a 3D printer, requirements for rheology, hydration and strength in an uncured form, are considered 3D concrete, the main mechanical test methods for determining the adhesion strength in concrete printed on a 3D printer. The possible shapes and nominal sizes of the samples used in the methods for determining the strength of concrete are given.

Keywords: 3D concrete, anisotropy of mechanical properties, extrusion, cold connection, interfacial coupling, deflocation, thixotropy, initial static viscosity, curing, three-point bending

The article gives an insight into the traditional passive cooling techniques utilized in Mediterranean and hot climate regions, showcasing the effectiveness of natural ventilation and central patios in improving indoor thermal comfort and reducing energy consumption. The integration of these traditional design elements with modern technologies is crucial for creating environmentally friendly and culturally significant architectural solutions for the future. The discussion then transitions to the importance of energy efficiency and environmental sustainability in modern building design, highlighting the use of Ansys Fluent software for modeling natural ventilation in a residential apartment in Yemen. The article emphasizes the need for engineering and architectural solutions to achieve high performance in energy efficiency and environmental safety in contemporary construction practices.

Keywords: natural ventilation, Yemeni houses, Spalart-Allmaras model, civil engineering, Ansys Fluent

The sustainable functioning of the road transport system of any city is inextricably linked with the rational use of road infrastructure. The article deals with the problem of irrational use of road infrastructure and increased transport delays when vehicles are left on the roadway, using the example of Tyumen. In a scientific study, a simulation of traffic flow on a two-lane section of the street was carried out. The PTV Vissim software was used to obtain the results. The dependence of the influence of transport demand on the average delay time when one lane is blocked by stationary vehicles is obtained. The consequences abandonment of unattended cars on the roadway are described. Approaches to solving the problem are proposed. The results can be used by municipalities to effectively manage the process of using road infrastructure, and the results can also be used by scientific organizations for research in the field of traffic management.

Keywords: traffic, simulation, parking, unattended vehicle, lane occupancy

The work is devoted to the development of an information model based on ontological approach in the framework of an educational course. The aim is to reduce the communication time between the participants of the educational process: coordinators, students and tutors. The concept of the solution was formed, namely analysing the activity of the course coordinator in the ‘Telegram’ chats within the course ‘Digital district of electrical networks’ of the network university ‘Energynet’. Based on this, ways to reduce time costs were identified by creating a Telegram bot based on an ontology model. The method reduces the time cost of communication between the coordinator, tutors and students. The results of the study showed that the chatbot built on the ontological model of the educational process within the course ‘Digital district of electrical networks’ helps to significantly reduce time costs of the communication process within the educational model.

Keywords: ontology, networked learning, educational model, chat bot, ontological model, telegram bot, online education, energy, digital university

The purpose of this article is to analyze the atmospheric boundary layer (ABL) models used in computational fluid dynamics packages, which take into account various conditions of atmospheric stratification. The hypothesis of the study is that in this case, the boundary conditions and model parameters should ensure the a horizontally homogeneous flow in the empty computational domain. An overview of works devoted to this topic is given, as well as an example of calculation results obtained using one of the models. The review shows that the considered models used in computational fluid dynamics packages make it possible to include effects associated with atmospheric stratification and obtain horizontally homogeneous vertical profiles of ABL characteristics. It is also possible to identify issues raised by the authors of works in this area, such as modeling of a stable boundary layer, modeling cases of strong convection and stability.

Keywords: atmospheric boundary layer, computational fluid dynamics, CFD modeling, vertical profiles of meteorological parameters, boundary conditions, atmospheric stratification, k-ε-model

The article presents a model for the formation of a thermodiffusion layer on steels. Thermodiffusion coatings on 45 steel and HVG steel were obtained by a chemical-thermal method in a powder mixture. Studies of layered X-ray diffraction phase and microrentgenospectral analysis of the studied coatings have been carried out. on steel. The obtained results of X-ray diffraction and microrentgenospectral analysis of diffusion coatings confirm the correctness of the model of formation of the diffusion layer and the theoretical prerequisites outlined. The results of the study can be used in the preparation of mixtures for thermal diffusion saturation.

Keywords: diffusion layer, diffusion chrome plating, diffusion coating

This article presents the results of a study of the filtration flow in a porous material based on a thrice periodic minimum surface (TPMP) Neovius. The Brinkman model was used to determine the profile of the fluid flow velocity in the channel containing the TPMP insert. Based on computational experiments in ANSYS Fluent, the dependence of the permeability of the medium on its porosity is determined. The results of the study can be used to describe filtration processes in the oil and gas industry, hydrogeology and other fields related to filtration flows in rocks and other media.

Keywords: permeability, filtration, porous medium, minimum surface, TPMP, ANSYS, Brinkman model, numerical modeling, boundary value problem, velocity profile

The above study is aimed at calculating the market value of a land plot free from development, located in the city of Vsevolozhsk, Leningrad region. The authors consider a comparative approach to the assessment of the object, its positive sides and disadvantages are indicated. The features of the implementation of the method of comparative sales and the construction of regression models are noted. The dependence of the cost of land plots on the distance from the local center in the territory of elite cottage development was revealed. Vsevolozhsk. The conclusion is formulated about the influence of a set of factorial features and the method of their accounting on the reliability and compliance of the result with the current situation in the real estate market.

Keywords: comparative approach, comparative sales method, correlation and regression analysis, real estate market, market information, price-forming factor, analogue object, real estate object, land plot, individual housing construction

Modeling the behavior of cylindrical shell structures weakened by holes when applying a load evenly distributed over the surface, taking into account geometric nonlinearity in the finite element software package ANSYS Mechanical APDL 2022R. Models of cylindrical shell structures with various hole arrangements have been created, and an analysis of the behavior of structures with an increase in the magnitude of the acting external uniformly distributed load has been carried out. Material type: isotropic, steel. Load-deflection graphs are obtained. The values of the critical load at which the structure loses stability are found. The values of internal stresses arising in structures under the influence of a critical load are found. The values of the displacement of the nodes are found: central and quarter under the influence of a critical load.

Keywords: Shell structures, stress-strain state, loss of stability, finite element method, deflection, supercritical behavior, geometric nonlinearity, step-by-step application of load, load–deflection dependence graph, isotropic material

This article discusses the theoretical and practical aspects of controlling a frequency converter through a programmable logic controller, and also analyzes the main methods and technologies used in analyzing the operating time of a controlled asynchronous motor. The possibility of organizing remote and multiple control of several frequency converters from one PLC (programmable logic controller) in large production areas is considered. If complex control with the exchange of large amounts of data, diagnostics and monitoring of drive operation in real time has been analyzed, it is preferable to use the RS-485 interface, which allows integration with more complex automation systems that require software control of various parameters.

Keywords: industrial controllers, frequency converter, analog control

The article presents the results of a comprehensive assessment of the deformability of a frame one-story, single-span building, the load-bearing structures of which are made of laminated wood. Constant and short-term loads were applied to the frame elements, the duration fraction was identified, the standard value was clarified, and the values of vertical displacements of the structural units were obtained. An assessment was made of the maximum deflections of the circuit elements from the standard load values with the maximum permissible valuese considered - on columns and in floor beams.

Keywords: one-story single-span building, permanent loads, short-term loads, standard load values, laminated board package, spacer system, boundary conditions, modulus of elasticity, stiffness, stress, displacement, CAD

The influence of secondary crushed stone on the strength and shrinkage of concrete was studied. The results showed that when granite coarse aggregate is replaced with crushed recycled concrete, the compressive strength of concrete is reduced by an average of 20% and the flexural strength by 3-10%. Concrete on recycled crushed stone has a high shrinkage. The shrinkage of concrete with a minimum consumption of recycled aggregate differs slightly from the shrinkage of concrete on granite crushed stone.

Keywords: demolition waste, concrete scrap, recycling, recycled aggregate, compressive strength, flexural strength, shrinkage

The advantages of simulation models are presented. A computer simulation model of an automated warehouse is considered and a solution to the model optimization problem of warehouse management is given. The model is implemented in the AnyLogic system using multi-agent modeling tools. These models can be used for clustering.

Keywords: modeling, simulation, digital twin, inventory management, AnyLogic, clustering

The article presents the results of the effect of replacing a part of cement with volcanic ash on the strength of cement stone in building mortars. Pozzolan additives have hydraulic properties. Volcanic ash from Kabardino-Balkaria deposits can be used in building mortars and concrete mixtures as an active mineral additive.

Keywords: volcanic ash, active mineral additive of natural origin, building mortars with active mineral additives, cement stone, flexural and compressive strength

Reliable and safe operation of oil and gas pipelines in the conditions of the Far North and Siberia is an urgent task facing the Russian Federation. It has the most important economic and strategic importance. The climatic and geological conditions of these regions suggest a high degree of risk associated largely with seasonal temperature fluctuations and oil pumping technologies, leading to freezing or thawing of the soil, the appearance of thawed permafrost waters. The purpose of our study was to analyze the influence of extreme natural and operational conditions on the design and spatial position of pipelines during the operation of the section of the CPS-2 - NPS Urengoyskaya highway. It was found out that the studied section of the oil pipeline has a predisposition to failures due to unfavorable conditions: meltwater, heaving soils, swampy territory. Technological calculations allowed us to conclude that at this stage the pipeline route meets all the conditions of strength and stability, i.e. the reliability of the pipeline is ensured.

Keywords: hydrocarbons, pipeline, melt water, underground laying, strength calculation, stability calculation, permafrost soils, spatial location