The article analyzes the elements of recursion and methods of its optimization, gives a name to the elements of the structure of recursion, an analysis is carried out, a pseudocode is shown. The relevance of using a recurrent approach when conducting inspection activities in order to ensure transport security is revealed. Algorithms of actions of transport security units based on recursion are specified.

Keywords: recursion, transport security, inspection, memoization, segmentation, transport security zone

At various stages of the life cycle - during manufacture, transportation, installation and operation, defects and damages may occur that affect the stress-strain state of structures. Some examples of survey the technical conditions of load-bearing structures of enterprises in the city of Ivanovo are given in the article. Defects and damages in operated bending structures are revealed. The results of experimental studies of reinforced concrete beams with initial cracks are presented. The tables show: the beam loading scheme, defect parameters, the location of initial cracks, the main characteristics of materials, as well as experimental data in the form of the relative moment Mult / Mtest, where Mult is the breaking moment of a beam with initial cracks, Mtest is the breaking moment of a similar beam without defects. The degree of influence of defects on the bearing capacity of beams is determined. Empirical coefficients are calculated that take into account the type and parameters of cracks, the cross-section reinforcement coefficient and concrete strength of the beams. A formula for determining stresses in concrete compression zones for beams with cracks is derived based on the theory of destruction mechanics and using experimental coefficients. A method for calculating of reinforced concrete bending structures bearing capacity with defects and damages is proposed. An analysis of experimental and theoretical studies confirming the correctness of this technique is made.

Keywords: reinforced concrete bending elements, beams with cracks, load-bearing capacity, calculation method

This article presents the results of a research work devoted to the use of ultrafiltration membranes in the technology of purification of natural waters and wash waters of a contact clarifier unit, as well as design proposals developed on their basis for the reconstruction of existing water treatment plants.

Keywords: membrane technology, ultrafiltration, membrane module, natural water treatment technology, flushing water treatment technologywater treatment facilities, patent research

As part of the proper maintenance of a number of infrastructure facilities (right-of-way for roads and railways, protected zones of power lines, gas pipeline routes, etc.), work is being carried out on their territory to remove growing unwanted vegetation. The article discusses the features of determining the values ​​of capital investments for the formation of a system of machines, mechanisms and used mechanized and manual equipment for cleaning these territories from unwanted vegetation, shows an example of their calculation using specific brands of machines, mechanisms and equipment used in production, formulates a conclusion about the feasibility of introducing of the considered method into the production process of enterprises and organizations responsible for the maintenance of the indicated territories of linear infrastructure facilities.

Keywords: territory, unwanted vegetation, removal, mechanization, equipment, definition, capital investment

Recently, the main principles in the field of municipal solid waste management are recycling and reuse of secondary resources. Information technologies are widely used in modern waste management technologies. Problematic is the issue of recognition of the sorting object on the waste conveyor. There are various robotic systems for automated separation of sorting objects. The article provides a description of the system in the process of "recognition - capture - movement" of a sorting object on a common conveyor. A group of sensors is used to identify objects on the conveyor, while simultaneously fixing the coordinates of each identified object on the surface of the conveyor belt. Information about the coordinates and properties of each identified object is transmitted over the communication line to the control panel by manipulators, which capture individual identified objects and mix them into special containers.

Keywords: sorting, waste, automation, recognition systems, sensors, manipulators

The key parameter of any cooling system is the heat transfer coefficient. The article deals with the issue of studying the dependence of the thermal resistance of the heat exchanger of a liquid cooling system based on ferrofluids and the heat transfer coefficient on the parameters of the fluid flow and the magnetic field in the heat exchanger. The study was carried out by numerical simulation and thermophysical experiment. A feature of the considered cooling system is the coolant. A ferromagnetic liquid based on Fe3O4 magnetites and propylene glycol is used as a coolant. As a result, a numerical model for calculating the heat transfer coefficient for an experimental liquid cooling system is obtained. The influence of the magnetic field on the thermal resistance of the system and the heat transfer coefficient of the wall-liquid at various magnitudes of the magnetic field strength is estimated. An experimental dependence has been obtained showing an increase in the heat transfer coefficient up to 12.5% when a magnetic field is applied.

Keywords: numerical model of heat transfer, liquid cooling system, Laplace equation, thermal management, CPU, ferrofluid, percolation, heat transfer coefficient, nanofluid, magnetic field, electronics cooling

This paper presents an information model of a relational database developed by the authors, designed to take into account the teachers workload of an educational organization. The identification of the subject area entities, their decomposition and the relationships identification between them are carried out. The constructed database model was brought to the Boyes - Codd normal form. Based on the designed database schema, its physical implementation and filling with test data was carried out. The results of test queries showed the developed model adequacy and the its practical applicationp ossibility. It is currently in trial operation at the Department of Information Systems and Computer Modeling, Volgograd State University. With minimal changes, the developed database schema can be applied to account for the teachers workload in various educational organizations.

Keywords: database, information modeling, "entity-relationship" diagram, decomposition, information system, educational organization

The article provides a consideration of the prospects of replacing the lateral stability stabilizer with a pneumatic balloon in the suspension together with body level sensors relative to the road surface.

Keywords: public transport, bus, spring - air suspension, body level sensor

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