bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of the residual resource of several buildings and structures as a single object
Authors: Korolkov D I , Bolodyan G I , Gravit M V 
Published: June 2021

Abstract
In this article, the author raises the problem of assessing the residual resource of an object, which consists of several buildings and structures. Four different approaches to solving this problem are presented. The advantages and disadvantages of these approaches are presented. The areas of their application are indicated. Within the framework of these approaches, one can use the direct enumeration method, the combinatorial method, the algebra of logic, the general logical-probabilistic method. The author has developed two possible options for calculating the residual resource of these objects using the general logical-probabilistic method. It is proposed to develop a Methodology for calculating the residual life of such objects before the survey. The author indicates the main points that must be prescribed in the developed Methodology. An example of calculating an object consisting of five buildings is given. The scheme of functional integrity is constructed according to the general logical-probabilistic method. In the program complex “Arbiter” the static and probabilistic-time calculation of the given scheme is performed. Then the calculation of the object as a whole was carried out according to the “2 of 5” system. As a result, the value of the probability of failure-free operation and the residual resource of the object as a whole is shown.
Complex application of ash of hydraulic removal and modified additives such as CMA, CM-2 in the production of non-autoclaved foam concrete
Authors: Dusembinov D S , Lukpanov R E , Tsygulyov D V , Yenkebayev S B 
Published: June 2021

Abstract
The paper presents studies on the use of ash of hydraulic removal in combination with modifier additives in the production of non-autoclaved foam concrete. The research is aimed at obtaining high-quality non-autoclaved foam concrete based on industrial waste with high construction and technical properties. The main objective of the paper is to determine the quality indicators of non-autoclaved foam concrete, according to standard methods, corresponding to the normative and technical documentation. The studies were carried out under laboratory conditions on certified and calibrated test equipment. The industrial waste considered in the paper, the ash of hydraulic removal and food industry waste, are common waste in all countries of the world, which gives high relevance to the research topic within the framework of waste disposal. The conducted studies confirmed the effectiveness of the integrated use of waste, to obtain the best result. As it is known, ash reduces the thermal conductivity, which is a positive effect, but at the same time reduces the strength of the material and frost resistance. In the paper it was proved that with the use of oil processing waste, it is possible to obtain an increase in frost resistance due to volumetric hydrophobization, as well as with the use of alcohol production waste, a significant increase in strength is achieved, due to the plasticizing effect of the casein contained (polymer components) in the composition of alcohol production waste. The obtained results of the study on thermal conductivity, strength and frost resistance confirm the effectiveness of the use of ash in combination with modified additives based on food industry waste CM-2 and CMA-P. In conclusion, a comparative analysis of the effectiveness of the use of industry waste the ash of hydraulic removal in combination with modified CM-2 and CMA-P additives is carried out.
Ensuring environmental safety when using polymer waste in technologies for obtaining building materials
Authors: Pugin K G 
Published: June 2021

Abstract
The production of building materials uses large amounts of primary natural resources. Mineral and organic components of the natural environment are used as raw materials, which leads to degradation and disruption of the habitat of living organisms. One of the possible methods to reduce the consumption of natural resources is the use of industrial and consumer wastes as raw materials, which include polymer waste. The high resource potential of polymer waste as a fuel is shown. Waste can replace coal coke, which is used in ferrous metallurgy technologies. The analysis of several technologies for the use of polymer waste as an inert filler and as a bituminous binder in the production of asphalt concrete and building mixtures has been carried out. The classification of various groups of polymer waste by melting temperature and chemical composition is presented. The analysis of technological processes for the use of polymer waste made it possible to conclude that considerable attention is paid to the extraction of economic benefits without environmental assessment of the safety of the technologies used. An environmental assessment of polymer waste disposal technologies has been proposed, which will allow at the stage of technology development to assess the environmental risks arising from the production and operation of the resulting product. It is proposed to select the temperature range in the technological processes for obtaining secondary products as indicators of the formation of environmental risks when using polymer waste.
Thermal conditions of a single-pipe heating system of an apartment block
Authors: Seminenko A S , Elistratova Y V , Kireev V M , Goncharov I V 
Published: June 2021

Abstract
The heating system is one of the life support systems. The discrepancy between the thermal (temperature) conditions of the living quarters is one of the most urgent complaints of residents of apartment blocks in most regions of the Russian Federation. The object of the study is a single-pipe water heating system of a 14-storey apartment block with an overhead distribution, for which the heat output is determined to compensate for heat losses under various initial conditions (outdoor air temperature and infiltration airflow rate). As a result of the calculation of the thermal conditions, deviations in the indoor air temperature of living quarters from the permissible range are determined. To eliminate violations of the microclimate parameters, this paper considers ways to increase the heat transfer of heating appliances by increasing the area of the heating appliance, as well as increasing the flow rate of the heat-transfer agent passing through the appliance. The results of the calculation of the thermal conditions showed the impossibility of eliminating the violation of the thermal conditions by these methods: depending on the temperature of the outdoor air in the living quarters, there is an excess or lack of heat. To eliminate the thermal and hydraulic disarrangement, a mechanical method for adjusting the heat transfer is proposed by switching off the sections of the heating appliance with an increased number of them. Taking into account the recommendations on the need to ensure that the length of the radiator corresponds to 50-70% of the length of the window opening, this method is functional for use.
Research and operating experience of long-burning boilers in the North-East of Russia
Authors: Slobodchikov Egor 
Published: June 2021

Abstract
In Yakutia, there is a tendency to build individual houses in rural areas. Due to the complex geographical location, economic problems and transport and logistics difficulties, it is not possible to connect many settlements to centralized sources of energy supply. Therefore, the demand for efficient autonomous sources of thermal generation due to the use of local solid fuels has recently increased. Practice shows that heat generators of imported and national manufacturers are not adapted to work at low outdoor temperatures. In the climatic conditions of the North-East of Russia, one of the important tasks is to increase the reliability and efficiency of heat generation sources; this is a necessary condition for ensuring comfortable working and living conditions for a person.
The use of waste in the composition of organic-mineral mixtures used in road construction
Authors: Pugin K G , Pugina V K 
Published: June 2021

Abstract
The construction of highways requires a large amount of building materials. Organo-mineral mixtures, which include asphalt concrete, are the main building material for the construction of the upper layers of the road structure. In order to reduce the cost of asphalt concrete, part of the natural mineral raw materials may be replaced by industrial waste. Previous studies show that waste from various industries in terms of their physical and mechanical properties are not inferior to natural raw materials used in road construction. When using the material resource of waste, environmental issues are additionally resolved by reducing the volume of waste disposal at landfills. The studies carried out have shown that the composition of the asphalt concrete mixture, in which drill cuttings are used, as a mineral powder, meet the requirements for asphalt concrete. Studies have shown that waste plastics HDPE and LDPE can be considered as reinforcing and modifying elements in the structure of asphalt concrete. Asphalt concrete, which includes plastic waste, meets the requirements for asphalt concrete used for road construction.
Estimation of deformations of steel constructions of cranes based on photogrammetry
Authors: Yu Ganshkevich A , Shikhov N S , Stoyantsov N M 
Published: June 2021

Abstract
The paper considers the results of the application of photogrammetry to assess the deformations of rod and plate elements of the steel constructions of hoisting machines, the analysis of the main problems arising in their processing and the proposed solutions to ensure the necessary accuracy. The authors, based on their own research and practical experiences application in the use of photogrammetry, carried out accuracy rating the magnitude of deformations. Based on a brief review of normative documents, proposals for rationing the permissible values of measurement errors are given. The paper also considers the problems that may arise in the assessment of the deformed state of design status and proposes approaches to solving these problems. One of the problems solved in the study was to assess the magnitude of the deformation of the rear belt of support of blocks of equalizing polyspast, resulting from an emergency situation during the operation of the crane KPL-16-30. In addition to assessing the overall deformed state of the entire element, the deformation in some sections of the structure was assessed. The application of some approaches to estimating the deformation of rod structure elements based on modeling the shape of the a curved axis of a beam or rod. Also considered the experience of deflection measurement the deflection of the 0.5 t electric hoists guide in the laboratory of hoisting machines. The authors shared their inspecting of the wagon tippler No. 2 examination. In addition to the assessment of transverse deformations, the task was to check the possible torsion of the metal structure of the moving part. In the process of work some problems were also revealed, the solution of which will make it possible to provide the necessary accuracy of measurements. When evaluating the approximation accuracy, the authors propose to use several approaches.
Impact of the stress-strain state of the soil on the stability of the retaining wall
Authors: Kozyukova N V , Zhambakina Z M , Akishev U K , Sarsenbaev N B 
Published: June 2021

Abstract
The results of the survey and calculation of the stability of retaining walls along highways located near the incline of the slope are presented. The analysis of the results of the numerical solution for modeling the interaction of the slope and the retaining wall shows that the most dangerous areas are the zones of development of maximum horizontal deformations at the retaining walls due to shear deformations. The zone, where shear deformations are spread, covers a large volume of slope soils. Collapsing soils, sinking from their own weight on the slope during water saturation, worsen the initial value of the adhesion, the angle of internal friction, the modulus of deformation, changing the stress-strain state. The trajectories of the movement of particles of collapsing soil when the stress-strain state of the slope on the retaining wall changes show that the movement of soil particles occurs at the boundary of collapsing and non-collapsing loams. Numerical calculations carried out under the PLAXIS program showed that in the water-saturated state, the slope is a landslide. The retaining wall on the incline of the slope, made of collapsing soils, is not stable and the sliding of the soil occurs only in the layers of collapsing soils of the slope.
Investigation of stressed state of shell structure
Authors: Strelnikov V N , Sukov M G 
Published: June 2021

Abstract
The main fundamental difference of wave gears from all other meshing gears is the presence of a flexspline which is implemented in the form of a shell structure, and which, by means of a wave generator located on the input shaft, modifies the rotational motion of the wave generator into permanent elastic wave deformations of the flexspline, which are then transformed in the rotation of the output shaft. The design features of harmonic gear drives provide them with a number of significant advantages, such as smaller dimensions and weight, in comparison with conventional ones, including planetary gear train of the same torque. They have the highest kinematic accuracy, including damping behavior and low level of noise and vibration. A unique feature of harmonic gear drives is the ability to transfer rotation into a sealed space with almost zero fluid leakage. Harmonic gear drives are capable of carrying out large gear ratios in one stage: for steel flexspline, from a minimum of about 60 to a maximum of 300. At the same time, their efficiency is quite high - in the reduction mode of 80 … 90 %, as in planetary gears with the same gear ratio. When operating in the torque multiplication mode, the efficiency noticeably declines. The disadvantage of harmonic gear drives is a relatively low frequency of the wave generator rotation, approximately within the range of 1500 … 3500 min 1 with the radii of small flexspline from 125 to 25 mm, respectively. Therefore, the power of harmonic gear drives, despite the high transmitted torques, is limited to relatively small values - from 0.1 to 48 kW. Their service life is limited to approximately 104 hours; a year and a half with continuous operation throughout the day. Specific weight and cost of harmonic drives is 1.5 +2 times lower than those of planetary type, which represents technical and economic advantages and commercial interest for road and construction machinery.
Dependence of the temperature of the beginning of the heating season on the energy efficiency class of the building
Authors: Svirin M V , Kosilov D M , Seminenko A S 
Published: June 2021

Abstract
The heat supply of most Russian cities is provided by centralized sources of thermal energy. During the operation of buildings, the transition period of the year is not given due attention. The transition periods of the year (before and after the heating season) complicate the task of providing thermal comfort in the rooms of residential and community buildings. The paper deals with the problem of microclimate troubles in multistorey residential buildings during transition periods. The purpose of this work is to test the hypothesis that there is a dependency of the temperature of the beginning of the heating season, depending on its energy efficiency class. For the thermal conditions of the rooms, the classical dependences of the thermal balance, technical thermodynamics and the theory of heat and mass transfer are used. On the example of a nine-storey apartment block, a calculation was carried out, as a result of which the rational temperature of the beginning of the heating season for various energy efficiency classes was determined, as well as the internal air temperature at the outdoor air temperature equal to 8°C (the existing value of the temperature of the beginning and end of the heating season). The results obtained confirm the hypothesis of the study that there is a dependency of the rational temperature of the beginning of the heating season for a particular building, depending on its energy efficiency class. At the temperature of the beginning of the heating season, the internal air temperature of 20°C will be achievable with a deviation of -41.182%, which corresponds to energy efficiency class A (excluding heat gain from solar radiation). It is established that at the current temperature of the beginning of the heating season, the internal air temperature of 20°C will be achievable with a deviation of -41.182%, which corresponds to energy efficiency class A, for buildings of a lower class, the temperature of the beginning of the heating season is not optimal.
Bases of calculation and design of asynchronous diesel generators for autonomous system of power supply
Authors: Absalyamov D R , Avsyukevich D A , Litvinova N B , Druzhinin P V 
Published: June 2021

Abstract
The article discusses the characteristics of diesel generator sets currently used in autonomous power supply systems. The modes of operation of synchronous generators and their overload capacity are analyzed. The overloading capacity of diesel generator sets (DGS) can be significantly increased when used as an electromechanical energy converter of asynchronous generators (AG). The initial algorithm for their selection involves calculating the optimal value of the rotor speed and choosing the range of rotation frequency. The value of the optimal value of the rotational speed is determined depending on the method of maintaining the constancy of the current frequency when calculating the parameters of an autonomous asynchronous semiconductor cascade, which is understood as an AG together with its excitation and control system. The dependences of individual terms of electrical power losses on the operating mode of an autonomous asynchronous semiconductor stage are considered. After determining the optimal speed, the possible AG power is selected. Then, from a number of powers, its nominal power is selected. After determining the rated power, the minimum and maximum values of the rotational speed, it is possible to determine the optimal operating modes of the diesel generator set with the AG. As a criterion of optimality, the specific effective fuel consumption of the diesel generator set is taken. This approach to the choice of the type of diesel generator set when designing autonomous power supply systems requires a detailed consideration of the technical and economic characteristics of the units. The proposed design principles can ensure the most complete use of the positive properties of a diesel engine and an electromechanical energy conversion system, as a result of which to improve the technical and economic characteristics of autonomous power supply systems.
Research of aerodynamic properties of some building models
Authors: Gadaborsheva T B , Torgashina S N , Stepanova I E , Chicherov K O 
Published: June 2021

Abstract
The paper provides a brief analysis of the history of urban development, depending on the consideration of natural and climatic conditions, in particular, the movement of air masses. The construction practice is taken into account when accounting wind conditions, which primarily involves the effective placement of industrial enterprises, sanitary break zones, residential development and public space. Theoretical studies of the aerodynamic properties of two models of buildings of simple shape, based on some experimental data, are presented. Comparing the flow directions calculated theoretically with the directions measured experimentally by different authors, it is confirmed that the proposed theoretical methods well reflect the actual picture of the flow around a rectangular profile by an air flow. For the considered models No. 1 and No. 2, according to the test results, it was determined that the pressure on the windward planes (walls) of different heights depends on the ratio between the thickness of the boundary layer and the height of the building, respectively, buildings of small height are almost entirely located in the boundary layer, i.e. in the layer of air, which, touching the surface of the earth, is slowed down due to the roughness of the underlying surface, as the speed of air movement decreases as it approaches the surface of the earth, and on the surface it is zero.
Effect of low-level jet on turbine aerodynamic blade loading using large-eddy simulations
Authors: Gadde Srinidhi N. , Liu Luoqin , Stevens Richard J. A. M. 
Published: June 2021

Abstract
Low-level jets (LLJs) are winds with high-shear and large wind energy potential. We perform large-eddy simulations (LES) with actuator line modeling of a turbine operating in a moderately stable boundary layer in the presence of LLJs. We find that the turbine tip and root vortices break down quickly when the LLJ is above the turbine rotor swept area. In contrast, the wake recovery is slow, and the vortices are stable when the LLJ is in the middle or even below the rotor swept area. The LLJ shear causes significant azimuthal variation in the external aerodynamic blade loading, increasing fatigue loading on the turbines. We observe that both tangential and axial forces on the blades are highest when the blade directly interacts with the LLJ. Azimuthal variation in the tangential forces on the blades is the highest when the LLJ is above the rotor swept area, i.e. when the turbine operates in the positive shear region of LLJ, with the blade tip interacting with the LLJ.
Validation of wind turbine wakes modelled by the Meso-NH LES solver under different cases of stability
Authors: Jézéquel E , Cathelain M , Masson V , Blondel F 
Published: June 2021

Abstract
In wind farms, the wakes of upstream turbines impact the downstream ones in terms of power production, loads, and fatigue. The wake properties depend on many parameters such as the stratification, Coriolis force, large-scale forcing and orography. To simulate this interdependence, the actuator line method (ALM) has been implemented in the atmospheric code Meso-NH, which is an LES research code developed by the French weather services. This implementation has already been validated for the blade force distribution on the NewMexico case (uniform inflow in a wind tunnel) and for the interaction with the atmosphere on the Horns Rev photo case. The work presented here aims at completing the validation in a realistic atmospheric boundary layer (ABL), with a focus on velocity deficit and wake meandering. It is based on the international SWiFT benchmark which compares the results of many numerical models with LiDAR measurements in the wake of a single turbine for three cases of atmospheric stability: neutral, unstable and stable. The good results show the capacity of Meso-NH/ALM to generate realistic wakes in a representative ABL.