The problem of flexible vibrations of a rectangular orthotorque plate clamped along the contour is considered. The general solution of the problem, which satisfies the vibartion equation identically, is constructed on the basis of the superposition method in the form of two Fourier series. Clamped boundary conditions lead to a homogeneous infinite system of linear algebraic equations with respect to unknown coefficients in the general solution. The uniqueness of a bounded non-trivial solution of an infinite system for the natural frequency is proved, the asymptotics of the unknowns are found, and an effective solution algorithm is constructed. Examples of the numerical implementation of the developed algorithm for calculating the natural frequencies and natural modes of the plate vibrations are given.

Keywords: plate, vibrations, natural frequencies, planar forces, superposition method, infinite system of linear equations, asymptotics

The construction and substantiation of a finite element model of the capillary tube running-in process, which was obtained by drawing on a fixed mandrel, are considered. The rolling rolls are cylindrical and absolutely rigid. The condition for performing the work is a comparison of the resulting gap between the pipe and the mandrel and the facet formed during deformation. The solid-state model of the process is described by an adaptive grid. Under these conditions, an informative model was obtained, which was used in parametric analysis.

Keywords: drawing with a mandrel, capillary tube, extraction, rolling, model construction, compression selection, pipe size tolerance

In this work, an experimental model of a circuit diagram with pulsating circulation of a liquid coolant in a heated circuit of a plate heat exchanger was assembled and tested. As a result of hydraulic and energy calculations of the circuit, the optimal parameters for flow, pressure, and temperature of the coolant were selected at maximum efficiency of the impact unit. It has been established that with an increase in the operating frequency of the impact unit, the heat transfer coefficient of the heat exchanger first decreases and reaches a minimum of 452.47 W/(m2*0C) at a frequency of 0.5 Hz, and then begins to increase and reaches a maximum of 482.31 W/(m2* 0C) at a frequency of 2 Hz, after which it gradually decreases. It has also been experimentally established that the temperature at the outlet of the heat exchanger of the heated circuit increases with increasing frequency of the shock unit and reaches a maximum at a frequency of 2 Hz, after which it begins to gradually decrease. It has been established that the change in temperature at the outlet of the heat exchanger of the heated circuit exceeds the change in temperature at the outlet of the heat exchanger of the heating circuit at operating frequencies above 1 Hz, which is due to the stronger influence of cavitation at these frequencies.

Keywords: heat exchanger, heat transfer coefficient, impact unit, frequency, heat transfer

Polyethylene pipes are widely used for the construction of gas distribution networks. The disadvantage of pipes is their low mechanical strength. When crossing various artificial obstacles in pipes, unacceptable stresses may arise, causing destruction along the pipe body. To make a decision on the installation of a casing in such areas, it is necessary to determine the stability criteria for the circular cross-section of polyethylene gas pipelines. The article reveals that of the two equations proposed by SP 42-103-2003 for the critical value of external pressure of polyethylene gas pipelines, in practice only one can be used, for which the criterion value is always minimal.

Keywords: polyethylene gas pipelines, dynamic load, stability of the circular cross-section, external pressure

The article presents studies of a computer simulation statistical model between the characteristics of flows in terms of linear density and the proportion of components in a mixed flow. The results of evaluating the effect of the filling fraction of the component on the average and standard deviation of the fraction of the 1st component in the mixture are presented, the type of autocorrelation functions of the linear density of the mixed stream and the fraction of the 1st component in the mixed stream are determined, estimates of the spectral density of dispersion for the linear density of the mixed stream and the fraction of the 1st component in the mixed stream are shown.

Keywords: fiber mixing, linear density, component fraction, autocorrelation function, spectral density of dispersion, standard deviation

The modern cycle of creating simulation models is not complete without analysts, modelers, developers, and specialists from various fields. There are numerous well-known tools available to simplify simulation modeling, and in addition, it is proposed to use large language models (LLMs), consisting of neural networks. The article considered the GPT-4 model as an example. Such models have the potential to reduce costs, whether financial or time-related, in the creation of simulation models. Examples of using GPT-4 were presented, leading to the hypothesis that LLMs can replace or significantly reduce the labor intensity of employing a large number of specialists and even skip the formalization stage. Work has been conducted comparing the processes of creating models and conducting experiments using different simulation modeling tools, and the results have been formatted into a comparative table. The comparison was conducted based on the main simulation modeling criteria. Experiments with GPT-4 have successfully demonstrated that the creation of simulation models using LLMs is significantly accelerated and has great perspective in this field.

Keywords: Simulation modeling, large language model, neural network, GPT-4, simulation environment, mathematical model

The problem of waste disposal is becoming increasingly relevant in the modern world. The huge volumes of solid and organic waste that accumulate every day require efficient and environmentally friendly methods of recycling. One of the most effective and promising solutions in this area is pyrolysis technology. The article discusses pyrolysis as a method of recycling solid municipal waste. It is noted that it is most effective when processing its organic component. Types of pyrolysis depending on temperature are considered.

Keywords: municipal solid waste, waste management methods, waste recycling, pyrolysis

Currently, crop production faces such problems as a decrease in soil quality, untimely detection of weeds, pests and diseases of cultivated crops, irrational use of fertilizers, pesticides, and water resources. This leads to an increase in production costs due to overspending of resources (fertilizers, pesticides, and water) and a shortage of crops due to inefficient decision-making in conditions of limited information, which causes the need for the introduction of innovative intellectual solutions in the cultivation of crops. Internet of Things (IoT) technologies have significant potential for a solution to the above problem. However, to date, these technologies have not been widely used, even in countries with a high level of information and communication technology development. The purpose is to identify the factors limiting the development of the Internet of Things in crop production and to determine ways to solve the identified problems. It is shown that the limiting factor in the development of the Internet of Things in crop production is the need to install a significant number of heterogeneous sensors, the lack of Internet and mobile communications in remote areas, as well as, in some cases, the problem of organizing effective data transfer from sensors to platforms for storage, processing, and analysis, or commands in the opposite direction to actuators. In crop production, an Internet of Things technology can be realized through the use of unmanned aerial vehicles as an IoT device and as communication technologies.

Keywords: Internet of Things, structure, informational management system, unmanned aerial vehicle, crop production

The article disrible a lot of novel patents in Civil Engineering, more of them from China

Keywords: patent's description, civil Engineering

Steel roof trusses are the main type of load-bearing structures used in the roofing of industrial buildings. Among them, trusses of the “Molodechno” type have become widespread, in which closed bent-welded profiles of square and rectangular cross sections are used as rods. The use of this type of rolled product makes it possible to create structures without gussets and connecting strips, with a maximum degree of process automation, which significantly reduces labor intensity and reduces the cost of their production. Another feature of the coatings under consideration is their non-running solution. The trusses are located in 4m increments, supported by rafter structures. However, in such a situation, the loads on the truss and the forces in the elements are small, and therefore, and also taking into account the limited range of bent-welded profiles, understressing of the truss elements and excessive consumption of metal are likely. Three variants of coatings with different pitches of trusses were considered, and the metal consumption per square meter of coating was determined. It has been proven that with increasing pitch of trusses, the metal consumption of coatings decreases.

Keywords: "Molodechno", rafter truss, sub-rafter truss, continuous purlin, lattice purlin, truss pitch, metal consumption