The article discusses the use of mathematical modeling of the transmission of a car in the Simulink environment. Studies of the influence of individual transmission factors on the functional parameters of the KAMAZ 4308 car have been carried out. Differential equations describing the operation of the transmission are solved in a matrix way, allowing to study the dynamics of the car taking into account the moments of inertia of the engine, transmission and individual wheels of the car.

Keywords: transmission, wheeled vehicle, clutch, differential, gear ratio, simulation, maximum speed

In this work, the phonon format of graphane nanoribbons is calculated in the Hamiltonian formulaism. The geometric model is presented in the form of a graphene plane with hydrogen atoms attached to it. The unit cell of graphane contains two carbon atoms from solid graphene and two carbon atoms. The curvature of the graphene plane as a result of attachment to hydrogen atoms and hybridization of the outer electron orbitals of carbon atoms from sp2 to sp3, as well as the interaction between hydrogen atoms, are not taken into account. Analysis of the obtained phonon spectra shows that, for any type and width of graphane nanoribbons, there is a gap between acoustic and optical vibrational modes, in contrast to graphene, which can serve as an indicator for a given structure. Also, for the material under study, the values ​​of the speed of sound and the Debye temperature were calculated.

Keywords: graphene, graphane, nanoribbon, unit cell, vibrational spectrum, dispersion equation

The article deals with modern research in the field of decision support. A model of distributed processing of requests by agents of decision support systems is proposed. The main components of the model are considered. An algorithm is built on the basis of the proposed model. A step-by-step description of the algorithm's actions is given. The main planned results have been identified.

Keywords: decision support systems, intelligent agents, request processing, decision support model

The factors influencing the process of flocculation during aeration are analyzed. It is determined that the effect is due to the damping of small-scale pulsations of water during mixing, accelerated formation of nuclei of solid phases of coagulant hydrolysis products on the surface of air bubbles due to electrostatic and surface forces, as well as the release of excess amounts of carbon dioxide from the water. Theoretical dependences have been obtained showing that the dose of coagulant injected into the mixer with simultaneous aeration of water is proportional to the concentration of heterophase impurities and inversely proportional to the average particle size of contaminants, the gas saturation of the resulting water-air mixture and the velocity gradient.

Keywords: natural water, coagulant, mixer, aeration, coagulant dose, velocity gradient

The article presents the results of comparative tests of samples of connections of wooden elements from glued wood on metal linings using screwed and glued screws, 3 samples of each of 5 types of connections (one glueless and four varieties of glued screwed connection). It has been established that the use of epoxy adhesives increases the strength characteristics of the adhesive-free joint by the criterion of breaking load by 1.46, 1.78, 1.70, 1.59 times, by the criterion of the elastic work of the joint by 1.56, 1.56, 1.82, 1.30 times for glued joints (ED-20 + PEPA, ED -20 + THETA, DER-331 + PEPA, DER-331 + THETA) respectively. Of the glued-in samples, the deformation Dult=2mm was achieved only by samples No. 8 (ED-20 + TETA) and No. 14 (DER-331 + TETA) at loads 1.77, 1.40 times greater than the load in a glueless joint. Full deformations Dp at the same load within the limits of elastic work of joints decrease by 7, 10.61, 10.61 times for glued joints (ED-20 + PEPA, ED-20 + TETA, DER-331 + PEPA), respectively. For samples of compounds (DER-331 + TETA) with a compared load value, the deformations are equal to 0.

Keywords: glued wood, metal linings, testing of joint samples, bearing capacity of the joint, deformability of the joint, upper limit of the elastic work region (URL), total deformation, permanent deformation, elastic deformation, safety factor

The use of high-power thermistors as part of the control gear facilitates a smooth start-up of powerful motors with simultaneous temperature control. When calculating the starting processes, there are a number of limitations on which the nature of starting electric motors with the use of thermistor rheostats depends. The calculated relations describing the mathematical model of the influence of the temperature of overheating of semiconductor thermistors on the process of starting motors with a start-up rheostat are presented in the form of graphic dependences. As a result of modeling the layout of thermistor rheostats, it was determined that it is necessary to pay special attention to the material heating temperature.

Keywords: semiconductor thermistor, starting rheostat, boundary conditions, heating, specific heat, induction motor, starting current, overheating temperature

The construction industry is considered to be one of the most unsafe industries, and as a result, safety in the construction industry is considered a very important factor. To reduce the number of accidents and monitor workers at a construction site, the article suggests integrating new tracking and communication technologies. The authors analyze the existing similar technological solutions, identify their advantages and disadvantages. A method for organizing monitoring of workers at a construction site using mobile devices is proposed, as well as the architecture of a software and hardware complex. The developed method is a smart system for a mobile device. This solution allows you to monitor the location of workers using a GPS tracker and a built-in accelerometer, and, if necessary, notify them of a possible danger.

Keywords: construction site, accidents, safety in construction, employee monitoring, mobile application, geolocation

Abstract: armor plates made of armored steel or combined armor plates made of hard ceramic material and an aramid or polyethylene substrate are used to provide Br4 and Br5 levels of protection according to GOST 34286-2017 “Armored clothing. Classification and general technical requirements.” The most promising armor plates are those that include a ceramic layer and an aramid substrate. Steel armor plates are currently the most common in the Russian army, however, their heavy weight is a significant drawback. This paper describes the selection of composite structures and the manufacture of their prototypes for ballistic purposes. The paper also presents the results of the ballistic tests.

Keywords: ceramic composite armor panel, Br4 level of protection, Br5 level of protection, armor protection, ballistic protection, aramid fabric

The physicochemical properties of cobalt catalysts on a NaX zeolite support have been studied. The parameters of the specific surface area, reduction of deposited cobalt, and structural properties of the active component of catalytic systems have been determined. To establish these properties, the methods of BET, TPR, TPD-H2, IR spectroscopy were used. It is shown that the preparation procedure has a significant effect on the physicochemical characteristics of the samples.

Keywords: catalysts, cobalt, zeolite, dispersion, specific surface area of the active component

In recent years, municipal solid waste management in developed countries has been based on the principle of recycling and reusing secondary products. The overseas level of sorting and disposal of waste is higher and more detailed, it refers to a higher economic level, cultural level of quality of life, government investment, appropriate policies and the construction of related auxiliary facilities. This article discusses some of the systems and methods for sorting municipal solid waste in order to justify the need to develop a system for object recognition when sorting waste.

Keywords: municipal solid waste, waste sorting problems, waste preparation for sorting, technologies for automatic waste sorting

More than 42 thousand bridges on highways are operated in Russia. Most of the bridge park was built in the past years. Bridges are getting old, accumulating destruction and defects and gradually cease to meet the requirements for safety, durability and load capacity imposed on them. It is necessary to spend a lot of effort and money on maintaining a stable working condition of all operated bridges. The use of modern surveillance tools will save financial and time resources. Such means of monitoring and collecting information can be unmanned aerial vehicles: various types and designs of quadrocopters and drones. A quadrocopter inspection of one of the city's overpasses showed high efficiency and quality of the information received. Based on the data obtained, it is possible to judge the technical condition of the object. Of course, the particularly dangerous defects identified during the inspection should subsequently be examined by a specialist to make a final decision. The article presents the photographic materials obtained by the modern method of data collection, the advantages of using quadrocopters in the survey of bridges and the technical characteristics of the equipment.

Keywords: operation of structures, inspection, bridge structures, quadrocopters, drones, defects, destruction,bridge bed

The aim of the study is to study the features of planning construction production when performing facade work. The theoretical analysis of information and the method of expert assessments were used as research methods. As a result of the study, conclusions were drawn about the factors affecting planning and technical and economic indicators. The analysis of issues related to the planning of construction production and the analysis of the conditions for organizing facade works is carried out. The main issues in this case are the issues of analysis of the initial data, the issues of the choice of means of paving and the selection of the numerical-qualification composition of workers.

Keywords: facade work, construction scaffolds, organizational and technological solutions, technical and economic indicators of work performance, a group of influencing factors, work parameters

Construction work creates a lot of dust and has a significant impact on the air quality in the surrounding area. This article presents the results of studies conducted by foreign and Russian authors to assess the risk of exposure to fine dust from a construction site. The urgency of protecting a person from fine dust and the problems associated with its effect on the human body are shown. The issues of concentration of dust, which are the most dangerous for human health, are considered. Measures are proposed to reduce the impact of RM on humans.

Keywords: Fine dust, PM10, PM2.5, environmental protection, human health, construction, mortality, risk, cardiovascular system, harmful factor, labor, protection

This article provides information that there are different categories of users with different groups of behavioral features. All this data is separated from each other. In the course of this work, it was found that if all data on user models are combined into one method, then the analysis by which information about a virtual person is obtained can lead to improved adaptability of web resources using new technologies.

Keywords: usability, virtual reality, types of virtual personalities, segmentation, socialization, user, Internet

This article proposes the development of a method for transmitting secure messages using a combination of best practices for organizing data exchange and cryptographic instant messaging protocols using end-to-end encryption. It considers ways of organizing an application using a peer-to-peer network and client-server architecture. It analyzes popular instant messaging protocols using end-to-end encryption. The software components of the application based on the developed method are described.

Keywords: messenger, end-to-end encryption, cryptographic protocol, instant messaging, peer-to-peer network, client-server