Computational and analytical studies of the influence of the duration of operation of nuclear power plants during the extension of their operation on the radiation changes in the concrete of the shaft of water-water power reactors (VVER) on various aggregates have been carried out. The studies were carried out using the existing experimentally tested methods for the analytical determination of radiation changes in concrete and their components. It has been established that during the extension of the operation of nuclear power plants with VVER reactors, the radiation changes in the concrete of the reactor shaft can be commensurate with the allowable changes in concrete or exceed them. It is shown that the radiation changes in the concrete of the reactor shaft increase with an increase in the duration of operation and depend on the power of the reactor (440 or 1000 MW), the thickness of the "dry" shield around the reactor, and the material of the concrete filler used. Radiation changes in all concrete of the NPP shaft with VVER-440 reactors will be more significant than in the concrete of the NPP shaft with VVER-1000 reactors. It has been established that the radiation changes in the concrete of the reactor shaft and the maximum duration of operation when using aggregates from various rocks differ significantly. It is noted which concretes (on which aggregates) have the smallest, largest and intermediate radiation changes. It is shown that with an increase in the operating temperature, the radiation changes in concrete will decrease, and the allowable operating time of the NPP will increase.
Keywords: radiation changes, reactor shaft concretes, concrete aggregates, rocks, water-water power reactors VVER-440 and VVER-1000, extension of NPP operation
The article considers an experimental study of the stress-strain state of radial beam domes. The maximum stress values are fixed in stretched flexible elements with a peak value of 363.6 MPa. With the calculated resistance of the wire material Bp-I Rs = 410 MPa, there is a 12% load-bearing capacity margin. Note the high level of stresses in other flexible elements with values in the range from 141.4 to 274.72 MPa.
Keywords: radial beam dome, experimental studies, loading, strain gages, deformation
In the article, the authors note that current threats, challenges, risks and related global problems, and the urgent need for the use of renewable energy sources is coming to the fore in the life of modern societies. It is highlighted that there is a necessity to treat technological progress in correlation with modern science in Russian society, and it should be noted that nowadays the current policy in the field of ensuring climate agreements is subject to legal uncertainty. The authors conduct cognitive modeling and construct a cognitive model.
Keywords: global problems of modernity, information technologies, cognitive modeling, cyber operations
A monolithic plate is the most reliable type of foundation. The design is selected if the future building or structure will stand on a site with difficult soil. Three variants of organizational and technological solutions are considered - a ribbed foundation plate a solid foundation slab and a box-shaped foundation plate For each technology, two options for reinforcement are considered - steel and fiberglass reinforcement. The analysis of existing technologies for the installation of a monolithic foundation plate carried out in the first section of this work, showed that the use of these technologies is hampered by a number of factors related to the design and technological features of the object being built. The choice of a rational technology for the installation of a foundation plate is carried out by assessing the influence of organizational, technological and design factors. Based on the results of a comparative analysis of the methods for constructing a foundation plate, it was revealed that the most rational in terms of labor intensity and cost for the structure under consideration, a reinforced concrete plate 15.6x544 m, is technology No. 1 - a ribbed foundation plate using MSC formwork and reinforcement with fiberglass reinforcement. The analysis of the dependencies obtained and the calculation of the coefficients showed that the factors affecting the laboriousness of the installation of a monolithic foundation plate can be arranged in the following order in terms of significance: 1) structural characteristics (the presence of ribs, a solid slab or the presence of voids); 2) thickness of the foundation plate; 3) type of reinforcement used for reinforcing the foundation plate; 4) the area of the constructed plates.
Keywords: monolithic foundation plate, steel and fiberglass reinforcement, factorial analysis, labor intensity and cost of construction, work performance
The article presents a review of research on the subject of the special limiting state, which are of interest for the development of theory and practical applications. The results of the main works, which have not lost their relevance, are briefly presented. Perspective directions of development for improvement of the theory of the special limiting state are distinguished: 1) Taking into account in calculations the stiffness of nodal couplings, individual elements of structures. 2) Consideration of joint operation of prefabricated and prefabricated-monolithic structures, including shear stiffness of compound sections. 3) Consideration of temporal and spatial nature of impact. 4) Work on extension of application of the theory beyond calculations for progressive collapse.
Keywords: special limitstate, special effects, reinforced concrete, deformability, special limit state criteria
In modern conditions, the healthcare system is going through a stage of active implementation of information and analytical tools. In the regions contaminated with radionuclides as a result of the accident at the Chernobyl nuclear power plant, activities for the prevention, detection and management of cases of thyroid diseases are of particular importance. Modern formalized methods of analysis, such as methods for searching for association rules, clustering using self-organizing maps, have sufficient functionality and effectiveness to be introduced as sources of new knowledge about the signs of thyroid diseases. In this paper, the authors consider the stages and results of developing a software package for information and analytical support for the process of examining the thyroid gland using ultrasound.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
The article considers the possibilities of using a large fraction of coal industry enrichment waste in road construction. The use of waste rock as a large aggregate in the composition of road concrete is proposed, because the enrichment waste is not disposed of properly, but is sent to the tailings dump. These dumps occupy large areas of land, thereby causing damage to the environment. The fractional composition of coal waste from the enrichment of the Gukovo-Zverevsky coal-bearing area is analyzed. From the results of sieving, it was seen that the structural composition satisfies the size of the fractions of a large aggregate for the concrete mixture. Analytical studies of the composition of the concrete coating were carried out. Based on the analysis of the composition of the concrete mixture, we came to the conclusion that tailings waste can be used as a major substitute. A comparative characteristic of the requirements put forward for the resulting mixture is presented. In our work, one of the main qualities of the road concrete pavement was tested - strength. The results of experimental strength tests of control samples of concrete with various types of aggregate are presented. Based on the results obtained, it is possible to draw a positive conclusion about the possibility of using enrichment waste as a large aggregate of concrete mixture in road construction according to technical and economic criteria.
Keywords: road construction, concrete mix, enrichment waste, coal rock
Тhe article provides a detailed analysis of the work under load structures of clamp scaffolding and systematizes the features of taking into account loads and impacts when performing strength calculations. The article analyzes the stress-strain state of free-standing forests. An algorithm for calculating free-standing forests is proposed, taking into account the features of structural schemes of blocks that are not specified in the normative literature. Based on the results of the analysis of data from a series of numerical experiments, constructive measures are proposed to ensure the load-bearing capacity, rigidity and stability against overturning of spatial blocks of free-standing forests, which will allow installing blocks with a height-to-size ratio exceeding 3,5:1 in open areas (outside buildings and structures) without attachment to existing structures.
Keywords: steel scaffolding, yoke scaffolding, stress-strain state, structural solutions, stability, load-bearing capacity, nonlinear calculation, spatial free-standing block, dismounting, off-center coupling of elements
The article is devoted to the actual problem of automating the life support processes of the system “intelligent building”, through the introduction of telemetry modules, in order to comply with the requirements of high-quality supervision, control and precautionary measures, in particular, in the areas of maintenance of water networks, responsibility for the operation of engineering networks and facilities between suppliers and consumers, ensuring water quality analysis. An analysis of the automated dispatching control and management system (on the example a water intake unit) shows that a lot of works (both Russian and foreign researchers) are devoted to the issues of control and distribution of water supply in the city, but narrowing the object of study to a complex of an automated sodium hypochlorite dosing system, the possibility of its optimization, taking into account the specific states of the system. The formulas given in the work for calculating the working dose and the amount of active chlorine, well as the number of strokes the dispenser pumps and the formulas for determining the actual working dose of the disinfection process, open up the possibility of clearly monitoring the actual dose and adjusting it, analyzing in detail the main parameters of the disinfection system. At the same time, the automatic control of the complex is carried out by a controller and PC, and the relevance lies in the use of telemetry control modules for organizing uninterrupted, remote operation of the dispatch service. Thanks to telemetric means of dispatching control and management of the state of water supply facilities, the process reaches a new qualitative level. The functionality of the water intake unit is expanding due to the introduction of telemetry and telecontrol system in the form of separate technological modules. The developed modules (through spatial and time series models) provide the performance of additional functions, such as: water quality control (residual chlorine, accounting for a number of random pollution factors), support for the route technology of the dispatching system, remote control of actuators with the possibility of automatic control, self-diagnostics of the software and hardware complex, as well as planning preventive measures. repair and restoration works of engineering systems. As a result of operational monitoring of water quality (using a telemetry module), optimal ratios of chlorine entering the water are automatically provided in the chlorination room. At the same time, the author convincingly proves that the use of the proposed method for monitoring and transmitting data makes it possible to perform continuous remote diagnostics (of communication channels, the performance of all systems) and, importantly, there is no need to send specialists directly to the object each time (parameterization and calibration of devices is carried out remotely). Quick setting of limit levels and modes of operation allows you to flexibly control the production process, reconfigure it according to changing tasks and re-equip it (if necessary).
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
This paper presents the results of a study of the nature of lifting the tail lift of a truck with a hydraulic drive that supplies the working fluid to the cylinders in series for two positions of the center of gravity of the load on the lifting platform. A diagram of a hydraulic drive is presented, which supplies the working fluid to the hydraulic cylinders in series. Mathematical models describing the operation of the hydraulic drive are compiled according to the scheme. Simulation modeling was carried out using the MATLAB Simulink environment.
Keywords: wheel tyre, suspension module, wheeled vehicle, MATLAB Simulink, mathematical model, modeling
The results of studies of the effect of mineral additives of natural and man-made origin on some properties of fine-aggregate concrete with the introduction of a mineral additive from 10 to 25% of the cement weight instead of either a part of cement with an increase in the value of W/ C, or a part of sand with a constant value of the value of W / C are presented. A slight, up to 3%, change in the average density of concrete was revealed. A decrease in the E-modulus from 4 to 14% was recorded when replacing a part of cement, while an increase in the flexural strength, depending on the dosage, was up to 26% (marshallite) and 6% (chemical water treatment sludge), and a decrease in the compressive strength was from 10 to 22%. When replacing part of the sand, an increase of up to 10% of the E-modulus, the flexural strength from 19 to 38% (marshallite) and up to 11% (chemical water treatment sludge) was recorded. The increase in the compressive strength, depending on the type and dosage of the additive, ranged from 8 to 20%. No significant effect of additives on the porosity of cement stone was revealed.
Keywords: mineral additive, fine-aggregate concrete, flexural strength, E-modulus, shrinkage, water absorption
The article is devoted to the study of curves that are not representable by the intersection of two surfaces. In modern architectural practice, they very often depart from classical forms, replacing them with complex surfaces. Recently, there has been the development of such an architectural style as architectural bionics or bio-tech. Faced with the challenges of sustainable development and its impact on the environment, the construction sector faces the necessary need for innovation. Architecture is presented as one of the promising areas of knowledge use based on biological research. And it is able to respond to current environmental problems. Indeed, many species of animals and plants know how to apply adaptation strategies to the environment and its transformations, forming together with it a sustainable ecosystem. Technological advances in very small-scale observation allow for deeper knowledge of how nature works and offer a new source of knowledge and inspiration for architecture.
Keywords: architecture, spatial curves, axonometric projections of curves, narrowed curves, bionics, biomimicry, eco-innovation
The increase in the population of large cities leads to the need for residential buildings, office space, leisure facilities, etc. leads to an increase in new construction. The city cannot constantly develop in terms of space as it is limited by the territory allocated to it in the framework of the cadastral division of the territory and it cannot grow indefinitely in breadth. That is why there are various programs for urban development, such as renovation, redevelopment of industrial areas and reconstruction of existing buildings. Also in recent years it has become popular to use different environmental standards in the design and construction of new or reconstructed buildings. This article will focus on the redevelopment of industrial areas with the development of underground space from the perspective of Fitwel ecological standard.
Keywords: Fitwel, green standard, redevelopment, industrial areas, renovation, industrial buildings, industrial facilities, new construction, development of underground space, integrated development of the territory
The influence of the content of the zeolite component in the composition of cobalt catalysts for the synthesis of hydrocarbons on their physico-chemical properties is investigated. The catalysts were obtained by impregnation of a zeolite-containing carrier with subsequent heat treatment. The obtained samples with a concentration of ZVM zeolite of 30-70% were characterized by the methods of BET, TPR, TPD H2. The results of the analysis show that an increase in the concentration of the zeolite component of the catalyst contributes to an increase in the specific surface area, dispersion and a decrease in the recovery temperature of the deposited cobalt.
Keywords: applied catalyst, cobalt, zeolite, dispersion, specific surface area, active component, synthetic fuel, degree of reduction
The article presents the results of a study of the photoelectric response of cobalt-containing ferroelectric ceramics (1-x)Ва0.95Pb0.05TiO3+xCo2O3, synthesized at the Institute of Solid State Physics of the University of Latvia using conventional ceramic technology. Ceramics was exposed to optical radiation at room temperature. Before applying light radiation to the cellular electrode of the ceramic sample located in the measuring cell, zero current was recorded for 0.5 minutes in the absence of illumination using a high sensitivity digital electrometer. Then, the photoresponse was recorded during the time until its value remained constant (since the anomalous photovoltaic effect manifests itself in the form of constant currents flowing along the polar directions) and only then the light flux was turned off. A significant effect of the concentration of cobalt oxide on the value of the photovoltaic current is shown, which manifests itself in a decrease in the value of the stationary current with an increase in the content of the impurity of cobalt oxide. It is assumed that a possible reason for the decrease in the stationary current is deep charge traps, which is due to an increase in the cobalt concentration in the ceramic. The influence of the incident radiation wavelength, as well as the aging factor on the photoelectric response for ceramics with the highest concentration of cobalt oxide, is established.
Keywords: mobile robots, polarization, depolarization, ferroelectrics, polarization current, remanent polarization, dielectric losses, electrical load, domain structure, electrical breakdown, mechanical failure