Stepper motors are often used in automated laser cutting systems. The control circuit of a stepper motor requires a special electronic device - a driver, which receives logical signals as input and changes the current in the motor windings to provide motion parameters. This research study evaluated stepper motor drivers to determine the feasibility of their use - PLDS880, OSM-42RA, OSM-88RA. To control the system, software code was written, which was connected to the controller via a link board. With each driver, in different modes, optimal parameters were selected (initial speed, final speed and acceleration), that is, the movement of the carriage without stalling for ten passes with a minimum travel time. The results of the experiments are presented in the form of tables.

Keywords: laser, laser cutting, automation, technological process, stepper motor, performance, driver, controller, control circuit, optimal parameters

Stepper motors are often used in automated laser cutting systems. The control circuit of a stepper motor requires a special electronic device - a driver, which receives logical signals as input and changes the current in the motor windings to provide motion parameters. This research study evaluated stepper motor drivers to determine the feasibility of their use - PLDS880, OSM-42RA, OSM-88RA. To control the system, software code was written, which was connected to the controller via a link board. With each driver, in different modes, optimal parameters were selected (initial speed, final speed and acceleration), that is, the movement of the carriage without stalling for ten passes with a minimum travel time. The results of the experiments are presented in the form of tables.

Keywords: laser, laser cutting, automation, technological process, stepper motor, performance, driver, controller, control circuit, optimal parameters

The article presents a way to increase the load-bearing capacity of a reinforced concrete column due to metal clips from the corners with an increase in the load on it. To ensure the joint operation of the existing column and the metal cage, the corners are subjected to prestressing, which is achieved by compressing the corners with jacks.

Keywords: reinforced concrete column, column reinforcement, metal cage, prestressing of the cage

The analysis of accidents on the main gas pipelines was carried out. The mathematical dependences of the volume of gas located in a gas pipeline of various diameters are determined. A nomogram is proposed to determine the volume of natural gas located in certain sections of the gas distribution network.

Keywords: gas pipelines, accident rate, degassing, gas bleeding. gas compressibility factor

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 article discusses various mechanisms of self-healing of concrete used in the construction of buildings and structures designed for certain operating conditions and the environment, which saves resources and time during maintenance and repair of objects for various purposes. Types of self-healing of concrete: With hollow fibers; Microcapsulation; Expanding additives; Bacteria. Conclusions. Today, progress has been made in understanding the relationship between the structure of materials and their properties. Thanks to the knowledge gained about the structure of materials, the possibility of designing materials of directional quality was considered, which guarantees their compliance with certain operating conditions and the environment.

Keywords: concrete, destruction, self-healing, hollow fibers, microcapsulation, expanding agent, bacteria

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

The article considers the possibility of improving the physical, mechanical and environmental properties of polymer concrete by changing their component composition depending on the requirements for the operational characteristics of the construction object. Currently, the research of scientists is aimed at the development and implementation in construction practice of compositions of light building materials, the range of densities of which varies depending on the tasks set. Such an additive as glass, changing the physical properties of the material, significantly improves its characteristics, there are the following types of such concrete: glass concrete with fiber, concrete with optical fiber, with cullet, and also a solution where glass is used as a binding element. Liquid glass, when added to concrete, helps to improve the stability and strength of plaster and concrete structures. When using this material, you can find a lot of positive things. The environmental friendliness of the material expands the scope of its use, which is very important at the present time. The new material is easy to obtain, is made from affordable materials, has improved physical and mechanical characteristics, which makes it competitive among a wide range of products on the global construction market.

Keywords: polymer concrete, liquid glass, glass concrete, optical fiber, cullet, modification, strength, composite material, glass fiber concrete, secondary raw materials

The purpose of this work is to develop an algorithm for recognizing shrinkage defects on metal alloys. The steps for image processing are described. When analyzing the algorithm, a description is presented for each step, followed by a software implementation. The final step, after using the methods of the algorithm, is to count the contours of the defects. To demonstrate the functionality of the software, random photos of the metal body in the section were taken, where defects in the form of gas pores can be directly observed. The software, with the correct selection of input data, processes the image with high accuracy, minimizing errors in calculating defects. Using the proposed algorithms reduces the diagnostic time. The article presents a comparative description of the manual and automated methods, showing the effectiveness of the second method in comparison with the first. To write the software, the Python 3.7 programming language was used, as well as the OpenCV computer vision algorithms library.

Keywords: defect detection, computer vision algorithms, OpenCV, metal defects, shrinkage defects

The analysis is made of the use of expanded clay gravel in cement-sand mortar in order to reduce ice at the boundary between the pile and the mortar. The application of expanded clay concrete in block-modular buildings is considered. Lightweight design and reduced heatloss are proven.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

The article conentrates on the problem of synchronization the pseudo-noise sequence in direct sequence spread spectrum systems. Authors propose a method for transmitting information and synchronizing signals on a single carrier frequency, which allows data transmission in complex coditions in radio channel. A brief review of existing solutions for time synchronization direct sequence spread spectrum systems is carried out. The proposed solution is considered in terms of data transmission in broadband systems in the conditions of negative signal-to-noise ratio, while the limitations of the usage of this solution are also considered. A simulation of the scheme that implements the proposed synchronization method is carried out, and the requirements for the signal-to-noise ratio in the information and synchronization channels are determined. The proposed method can find application in systems with code division multiplexing, including modern IoT systems.

Keywords: time synchronization, direct sequence spread spectrum, broadband communication systems, Internet of Things, BER

The possible ways of research and development of management of ultra-high-frequency technological complex for the treatment of solids and liquids accumulated in waste storage on horse and livestock farms. Given a classification assessment of existing and proposed integrated model thermoelectrochemical approaches that account for physico-chemical composition of the treated medium. The results of laboratory experiments on drying of processed substances for the justification of integrated management and development of real microwave technological complex are presented.

Keywords: dielectric, dielectric permittivity, microwave heating, humidity, waste, physicochemical composition, mathematical models, technological complex

the article presents experimental studies of a low-power boiler with a furnace of a high-temperature fluidized bed with recirculation of outgoing gases in stationary and transient modes of operation. The experimental installation of the boiler KVP-1,74 WKS with recirculation of outgoing gases is represented and described. The results of experimental studies of the dependences of the coefficient of excess oxygen at of the volume of the recirculation of exhaust gases of the boiler KVP-1,74 VTX at nominal and partial loads, based on the percentage of fuel saving of the boiler from the amount of recirculation of exhaust gases of the boiler KVP-1,74 VTX at nominal and partial loads boilers, graphs of transient processes in boiler "KVP-1,74-VTX" with recirculation of flue gas when changing the fuel consumption, GRAPHS of the comparison of transients in the boiler "KVP-1,74-VTX" with recirculation of flue gas when changing fuel consumption.

Keywords: high temperature fluidized bed, exhaust gas recirculation, experimental studies, automation system

Criteria and approaches to the new business choosing for investing and developing being used by contemporary Russian specialists are discussed in the paper. Advantages and shortcomings of different approaches being used in practical management are analyzed. Different approaches used by specialists of different profiles are discussed as well as a two-step method of the new business choosing.

Keywords: business choosing, criteria, investing, business attractiveness, resource capacity