The issues of optimization of ribbed reinforced concrete slabs with prestressing of reinforcement, taking into account geometric, strength and cost indicators, are considered. The study was car-ried out on the basis of an analysis of the sales market for building materials, the basics of rein-forced concrete resistance and the provisions of regulatory documents, design activities in the Russian Federation, as well as the works of domestic and foreign scientists. The research method is structural-analytical analysis taking into account the relationships of the factors under study. Analytical and graphic materials are presented, revealing the regularities between the geometric dimensions and the cost of components. The proposed method for determining the efficiency of a structure, taking into account the cost indicators of materials, indicates the feasibility of its ap-plication in design practice. Recommendations for design are given to ensure that structures of the minimum cost are obtained and that meet the requirements of strength and durability.

Keywords: reinforced concrete, strength, structure, reinforcement, diameter, price, cost, efficiency, dimen-sions, analysis, element

The article proposes a method for assessing the risk of a possible stay of an automated special-purpose information system in a critical state, based on the synthesis of two heterogeneous mathematical models, one of which allows taking into account the intensity of DDOS attacks and the intensity of application processing, based on Markov processes, and the second is one of the forms of a formal description of protection systems, with complete overlap, in which the interaction of the "threat area", "protected area" is considered – areas of resources of an automated information system for special purposes, and "protection systems" – security mechanisms of an automated information system. The developed method makes it possible to simulate the information security tools included in the automated information system for special purposes, under the influence of DDOS attacks, taking into account both the empirical values obtained as a result of measurements or modeling, and the theoretical base of parameters specified by input data. In the synthesis of the two models, the lack of uncertainty of some of the input parameters, taking into account the values based on expert estimates, was eliminated.

Keywords: automated information system, security assessment, queuing system, risk

A method of selecting admixtures for the production of dry building mixes is proposed based on the results of an expert assessment of the complex indicator of the workability of application (connectivity, continuity when pulling with a toothed trowel, elasticity, quality of rollers) on a 100-point scale and the strength of adhesion to the concrete base, followed by the calculation of the specific cost of admixtures in the mixture per ton of products, respectively, by one point of workability of application and 1 MPa of adhesion strength, developed as a result of studies of adhesive mixtures made using 4 different cements, 5 water-retaining additives and 12 redispersible polymer powders. The possibility of obtaining adhesive compositions of adhesion class C 2 using redispersible polymer powders of domestic production is shown.

Keywords: dry building mix, adhesion strength to the base, unit cost, processability of application

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

This article analyzes the calculated fire curve in accordance with the ignition heat source in the compartment. To predict the calculated fire curve, the exponential equation proposed in the previous study was compared with the heat release rate measured in a fire experiment. The lag index, which is the main factor used to predict the time it will take to reach the maximum heat release rate, has decreased in proportion to the ignition heat source.

Keywords: fire calculation curve, pipe insulation, ignition heat source, deceleration index, heat release rate

In this article, we investigate the effectiveness of using multiple pipes for heat dissipation. The study assumes laminar flow under steady-state conditions. Various mixtures are numerically investigated at different flow rates. Various nanofluids flowing through multiple parallel pipes have been numerically investigated to study the effects of temperature rise. Thanks to the benefits they bring to the cooling process, nanofluids have opened up a new way to improve the performance of thermal systems. A typical nanofluid consists of a base fluid, which is usually water, and nanoparticles.

Keywords: heat exchanger, flow tube, nanofluid, bottom heating, coefficient of friction, pressure drop

The article studies the dependence of the temperature of a heat-loaded element of microelectronics on the parameters of the shape of the heat-removing body. Numerical modeling of the study of the efficiency of the heat-removing surface in terms of reducing the source temperature was carried out in the Ansys Fluent CAD system. The advantage of the heat sink design described in the work is considered to be a fairly high intensity of heat removal from the thermally active region and a small weight, which is provided by the simplicity of the heat sink system and the increased heat transfer rate, which makes it economically advantageous to calculate the use of material and time costs for the manufacture of the product. The increased temperature of electronic equipment elements significantly affects the reliability of their operation. In this paper, the task is to ensure the normal temperature regime of the housing of a heat-loaded microelectronics element using a passive cooling system of a specially designed shape.

Keywords: heat sink, efficiency of the heat-removing structure, thermal resistance, temperature regime, heat transfer, thermal resistance, heat dissipation, heat-loaded element

The article considers the improvement of the centralized heat supply system (SCT) from Saransk CHP-2 by optimizing the calculated quantitative and qualitative parameters of the hydraulic regime due to circuit solutions (optimization of the thermal circuits of the CTP and etc.), including the distribution of thermal loads; the use of devices (installations) providing the expansion of the temperature schedule of heat supply to the network. This event will allow: to create the technical possibility of technological connection of a promising thermal load; to reduce specific fuel consumption by increasing the share of combined power generation at Saransk TPP-2; will ensure an increase in the utilization rate of the installed thermal capacity of Saransk TPP-2 to 45-50%.

Keywords: temperature chart; hydraulic mode; combined production; central heating point

The work is devoted to the application of modern information technologies in the socio-economic systems of control of forces and means of operational rescue units. Using the Google Earth interface with integrated data from the Mapinfo program, it is possible to track and coordinate the forces and means of rescue units to the scene in real time.

Keywords: information technology, Google Earth, MapInfo, visualization, fire development, forces and means, operational rescue units, interface, socio-economic system

The article discusses the improvement of overhead power line supports (OHPL) by optimizing them and automating the design, including the creation of a OHPL design model as a single system and an algorithm for solving it. Performed the stress-strain state analysis and the optimization of structural forms of support poles, taking into account the requirements of efficiency and manufacturability. Created a system of automated one-stage design of overhead transmission line supports.

Keywords: overhead power line, optimal design, lattice support, design model

The development of a methodology for the formation of an estimate of a construction object on the basis of its information model is considered, taking into account the state of development of software systems for BIM modeling and the peculiarities of regulatory regulation of the construction of construction projects in Russia. The factors that limit the possibility of drawing up estimate documentation for the information model have been identified. Taking into account the identified limitations, a set of operations necessary for the formation of an estimate for a construction object based on its information model is presented.

Keywords: BIM, 5D BIM-model, estimate documentation, civil and industrial construction

The design of internal combustion engine (ICE) control system for an unmanned aerial vehicle (UAV), providing reduced fuel consumption and stable operation of ICE at an altitude above 5000 m above sea level, has been created. A system of remote adjustment of the internal combustion engine parameters in real time during the flight of the UAV was developed and manufactured.

Keywords: unmanned, aircraft, control system, internal combustion engine, remote adjustment, radio channel

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 paper presents the results of a study of the possible fight against snow drifts in the Murmansk region on the example of an auto-approach to the village of Teriberka. The volume of snowfall is calculated, recommendations are given on climatic data for the region, recommendations are given on possible options for dealing with snow in the Far North regions.

Keywords: snow drift, snow transport, road climatology, motor road, protection against snow drifts, drifting road sections, permanent and temporary snow protection

The choice of a method for transporting hydrocarbons from the shelf of the northern seas is an urgent task, necessary for the economic justification of a project for the development of an offshore field. A comparative analysis of existing transportation schemes allows us to take into account both the advantages and disadvantages of possible options, namely, the natural and climatic features of the region, the technical capabilities of contractor organizations, the cost of field development facilities and vehicle rental.

Keywords: hydrocarbons, continental shelf, transport scheme, analysis, tanker, gas and oil pipeline, onshore infrastructure, offshore infrastructure