The article presents the results of a study of the physicochemical and catalytic properties of cobalt catalysts on a mixed zeolite-containing carrier. Samples of catalysts containing 10% cobalt and from 30 to 70% high-silica zeolite ZVM were prepared by impregnation with subsequent heat treatment. Methods of IR spectroscopy, scanning electron microscopy (SEM) in combination with energy dispersion analysis (EMF) were used to study the physicochemical properties of catalysts. The catalytic properties were studied in a reactor with a fixed layer at a temperature of 240 °C, a pressure of 20 MPa, a volumetric gas velocity (OSG) of 1000 h-1, H2 / CO = 2. As a result of IR spectroscopy, the presence of Si-O, Al–OH, Co–O, etc. functional groups was detected, SEM–EMF images confirmed the uniform distribution of cobalt on the surface of catalysts. The dependences of the catalytic characteristics depending on the content of zeolite were established, the maximum activity was recorded for a sample containing 70% of ZVM zeolite.

Keywords: catalysts, Fischer-Tropsch synthesis, cobalt, zeolite, carrier, IR spectroscopy

The method of numerical calculation of the parameters of the river channel in the arms is given. The method of nonlinear programming for analysis of dissipative systems with concentrated parameters is used. The technique is focused on computer modeling in the environment of engineering package MathCad. The results of the experiment are given.

Keywords: Distribution of water flow, calculation method, multi-node sections of rivers, water flow

The increasing problem of the formation of ash dumps in the Rostov region dictates the need to search for environmentally friendly methods of waste disposal in the heat and power sector. In this article, the ash and slag waste of the Novocherkassk GRES is considered. We analyzed the chemical and fractional compositions of the ash-slag mixture formed at a coal-fired thermal power plant and proposed the use of ash waste with a size of 10-100 microns in road construction as a micro-filler. To study the strength of the road surface using ash microparticles, we manufactured and tested cubes of modified concrete mixture for compression using a press machine. The obtained result showed that the use of ash as a micro-filler in concrete does not affect its strength in any way. The tests of control samples with the use of ash wastes showed an improvement in the water resistance and frost resistance of concrete while maintaining its strength.

Keywords: ash and slag waste, micro-filler, concrete mix, road construction

The paper discusses the use of machine learning in relation to natural language processing (sentiment analysis, semantic proximity analysis) to build a recommendation system for the choice of perfumery products. The topic of the work is relevant in view of the growth of the range of manufactured perfumery products and the complexity of its choice by consumers and promotion by manufacturers. The proposed approaches are relevant for solving this problem due to the accumulated textual reviews and reviews of perfumery products on various websites, including online stores.

Keywords: machine learning, natural language, sentiment analysis, distributive semantics, word2vec, recommender systems

Many sources of environmental pollution affect human health. The concentration of harmful substances constantly changes during the day when the weather conditions change in different parts of the territory. Residents can repeatedly enter and leave areas of increased pollution without noticing it with their senses when moving around the city. The authors analyzed the existing solutions for monitoring the quality of atmospheric air, as well as key sources of pollution and their distribution in the air. The interrelation of distribution of pollutants with weather conditions is noted. Preparation of data on the presence of harmful substances on the example of the city of Volgograd has been carried out. A method for organizing monitoring of harmful substances in the atmosphere using a software and hardware complex is proposed. The developed method was applied to create a specialized web application. The implemented solution allows to monitor the state of the environment using sensors and build routes around areas with a high concentration of harmful substances.

Keywords: environment, air quality, air pollution, ecology, monitoring, web application, eco-route, spatial data, route building, cartographic visualization

The paper presents an evaluation of the efficiency of the use of road trains for transporting fuel chips during operation in real natural and industrial conditions through the variability of the coefficient of adhesion weight (kst). The authors of the paper note that the transport and transposing aspect of the technological process is especially important in the formation of efficient technological chains for the production of biofuels and, in particular, wood chips for energy purposes. The analysis showed that it is rational to use wood chip trucks based on all-wheel drive vehicles (6x6) to ensure movement in all modes when operating in complicated and challenging conditions on road surfacing in an unsatisfactory condition. Vehicles for transporting wood chips for energy purposes, manufactured in Russia and Belarus, are at the level of foreign analogues in terms of the main technical and economic indicators, and in some cases surpass them.

Keywords: forest bioenergy, transportation of fuel chips, wood chip trucks, cohesive weight coefficient, cross-country ability

The application of the results of hardness measurements and its modeling in CAD as a 3D model is considered. Different welding modes were applied and electrodes CT-15, OZL-8 and CL-11 were used as consumables. The test material is a hot-rolled pipe with a diameter of 159 mm made of corrosion-resistant steel 12X18N10T with a thickness of 6 mm. The electrodes were fused to half its length and removed from the electrode holder, after cooling the remainder of the electrode, it was reused. For scanning measurement of microhardness of samples with a load of 100 g, the scanning step was applied 0.5 mm. The use of modern software was able to more accurately simulate the test results on a 3D model. The samples are welded with CT-15 electrodes at a maximum current of 100 A. the hardness is over 450-550 HV, regardless of what the passage was. Similarly, when welding with OZL-8 brand electrodes, but only at low currents, the hardness exceeds 450 HV. In both electrodes, the hardness is increased. When using OZL-8 electrodes, samples welded at high currents have less hardness than at low currents. When welding with these electrodes, it is possible to use them in certain passages, for example, when surfacing the root layer of the seam. In the case of full penetration in high-current modes with CT-15 electrodes, the result differs little as in low modes.

Keywords: steel 12X18N10T, multi-pass welding, welding of austenitic steels, pipe, coated electrodes, welding modes, mechanical properties, macrostructure. Excel, Autodesk Inventor, CT-15, OZL-8, CL-11, amperage

The results of clinical trials are the main source of information in the implementation of medical activities in accordance with the principles of evidence-based medicine. At the moment, there are no information systems that would allow a doctor to select clinical studies within the framework of nosology that best match the profile of a particular patient, in order to further analyze their results and select therapy. The aim of the study was to improve the existing process of searching for clinical trials by using the prioritization method according to the inclusion criteria set by the doctor during the selection. To achieve this goal, the following tasks were implemented, namely, the process of selecting and searching for clinical trials by doctors was studied and the method of searching for clinical trials by doctors and the allocation of the necessary criteria was worked out. The team of authors proposed an algorithm for searching for clinical trials according to inclusion criteria, which in turn will significantly increase the effectiveness and reduce the time for searching and choosing therapy.

Keywords: clinical studies, criteria search algorithms, criteria search methods, including factors, search for the nearest class, services

The seismic activity of the zones through which the pipelines are laid has always caused serious concern. The analysis of emergency situations on pipeline systems caused by an earthquake revealed factors affecting their stability: longitudinal and transverse displacement of the soil, the effect of soil liquefaction, faults resulting in open cracks and shear deformations. To prevent damage to pipelines during seismic impact, it is necessary to take into account the nature of the impact on the pipeline structure, the required level of safety for this seismic impact. Currently, special attention is paid to structural solutions and materials from which pipelines are made. The conducted studies allow us to form an approach to assessing the operability of polyethylene and steel pipelines in earthquake-prone areas, and on the basis of a comparative analysis of their stability, to make recommendations on the use of pipelines under specified conditions.

Keywords: hydrocarbons, analysis, pipeline, reliability, seismic impact, deformation, composite materials

This work is devoted to modeling the absorption of microwave electromagnetic field energy in a device for milk pasteurization. Using CAD FEKO, a 3D model of the device was built and its operation was simulated. A study was made of the influence of the tilt angle of quartz tubes on the distribution of the electromagnetic field in the waveguide. The influence of the diameter and material of the tubes is also considered. The distributions of the electric field and the specific power absorbed per kg of dielectric in the waveguide are obtained. The accuracy of the results was assessed.

Keywords: pasteurization, microwave, heat treatment of dielectrics

The article considers the possibility of replacing a monolithic frame with a precast-monolithic frame during the construction of a residential apartment building. The variety of structural systems erected in the Russian Federation for residential and public buildings is given. The positive and negative aspects of each of the proposed methods are considered. An economic justification for replacing a monolithic frame with a precast-monolithic one is given. Based on the results obtained, conclusions were drawn about the effectiveness of the use of prefabricated monolithic systems for the construction of civil buildings.

Keywords: construction, construction technology, monolithic frame, prefabricated monolithic frame, prefabricated structures, construction period, construction cost

The article discusses the geological aspects of the existing and designed anti-landslide protection system of the central part of the Karasan landslide on the Crimean peninsula, where the reconstructed Oryol boarding house is located.

Keywords: landslide, anti-landslide protection system, pile protection wall, retaining wall, Crimea, reconstruction, bored piles

The question of creating an automated accompaniment is still an undisclosed part within the current automation of the musical field. The construction of accompaniment is used not only in the musical field, but also in related ones. Automatically generated accompaniment is used in audio and video studios for advertising, by people with and without musical education. In this paper, the existing methods for constructing automated accompaniment, audio file formats will be considered, and the developed algorithm and method for automatic accompaniment generation will be described.

Keywords: accompaniment, auto generated accompaniment, auto accompaniment, melody, MIDI

This paper presents the results of a study of the interaction of the wheel tire with the support surface of the support-running module during the movement of the wheeled vehicle. The creation of a mathematical model of the movement of the wheel on the support base of the support-running module is given. For this, a design scheme for the movement of the wheel along the supporting surface of the support-running module was presented, and the following equations were given: the dynamics of the drive wheel; normal reaction and reaction vector of the interaction of the wheel tire with the support base; partial slip friction coefficient for cohesive soils and slip coefficient. Simulation modeling was carried out using the MATLAB Simulink environment, which allows, on the basis of a given mathematical model, to study the system being developed. When using this system, there is a reduction in the cost of expensive physical prototypes and an increase in the quality of products, as a result of an increase in the accuracy of calculations.

Keywords: wheel tyre, suspension module, wheeled vehicle, MATLAB Simulink, mathematical model, modeling

The article presents an analysis of the problems of diagnosis and restoration of the human respiratory system after diseases, including COVID-19. The review of analogues of small-sized spirometers is carried out. On the basis of which an individual small-sized device has been developed for effective training of the respiratory system. The functional scheme of the pneumatic trainer is described and the main simulator-game scenarios for achieving a therapeutic effect are analyzed.

Keywords: respiratory system, COVID-19, pneumatic trainer, portable device, pressure sensor, MEMS technology