bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of the Flow on No-Load Breaking of SF6 Circuit Breaker Based on Lattice Boltzmann Method
Authors: Gui Meijing , Gao Fei , Zhang Junmin 
Published: December 2019

Abstract
In the simulating breaking of SF6 circuit breaker with the finite difference method and finite element method, there are some disadvantages such as a long calculation time and a complex calculation procedure. In this paper, a new method which is based on the lattice Boltzmann method (LBM) is presented to simulate the breaking process in an SF6 circuit breaker. And the model of nozzle arc is established by the lattice Boltzmann method. The flow in the arc-extinguishing chamber is calculated with the LBM. The pressure and velocity fields of the upstream and throat of the nozzle in the chamber are obtained by the simulation. Compared with the test data, they are good agreement. The results show the feasibility and correctness of the lattice Boltzmann method in studying the evolution of gas flow of nozzle during the breaking.
Analysis of Influence of Inverter New Energy Transient Short-Circuit Current Harmonic Component on Transformer Differential Protection
Authors: Huang Yuyuan , Zong Wei , Zhang Bo 
Published: December 2019

Abstract
The second harmonic braking protection is the key to the differential excitation inrush current of the transformer and the quick action of the differential protection. In this paper, it is verified that the large-scale inverter type power supply may affect the second harmonic braking protection of the transformer. The mechanism of generating the second harmonic component of the current during the short-circuit fault of the inverter-type power supply is analyzed. Further analysis of the secondary harmonic current generated by the inverter-type power supply during the fault in the transformer zone may cause the second harmonic braking component of the transformer. Finally, the correctness of the analysis is verified based on the PSCAD/EMTDC transient electromagnetic simulation software.
Improvement of Digital Guidance for Tracking of the Last Stage of a Shipborne Unmanned Antenna
Authors: Yang Liu , Jing He 
Published: December 2019

Abstract
This paper proposes its background from an unmanned antenna needs digital guide to lead it to accomplish getting the target to existing digital guide for initiative Aerospace measurement has a poor accuracy. Then the principles of three major errors of digital guide namely time difference, visual difference and delaying accumulation error are explained and thus each method to each error has been given.
Features of change in strength and modulus of elasticity of various layers of vibrocentrifuged fiber-reinforced concrete columns of annular section
Authors: Shcherban’ E M , Stel’makh S A , Prokopov A Yu 
Published: December 2019

Abstract
Upon carrying out the studies, the authors identified the features of strength and elastic modulus variation of different layers of vibration centrifuged fiber-concrete tubular columns. They provide rationalization for the variational nature of test structures, i.e. combinations of layers, the properties and characteristics of which are different. To reveal the trends of changes in the physical and mechanical properties of a structure by layers, the authors performed a through ultrasonic scanning using a Pulsar 2.2 device. The authors verified the applicability of the described technique for the variational vibration centrifuged structures. Three test cubes used for compression strength determination were produced from each the inner, middle, and outer layers. Confirming theoretical data on centrifugal molding, the authors revealed that the outer layer of the structure, which experienced the maximum centrifugal force, had the greatest strength, and the inner layer had the minimal strength. Substantiation of the fact that the variational vibration centrifuged structure is three-layered was confirmed experimentally.
Modifying additive for dry building mixtures
Authors: Loganina V I , Frolov M V 
Published: December 2019

AbstractIt is proposed to use limy finishing compositions with a modifying additive in thermal insulation. Such additives are obtained in two-stage synthesis technology. The mineralogical composition of the additive is represented by a mixture of synthesized hydrosilicates and calcium aluminosilicates. The method of lime absorption from lime solution was used to find out the additive pozzolanic activity. The authors estimate the efficiency of using additives in the composition of calcareous dry mortars. The compressive strength and the content of free lime in lime composites are determined. Further, the paper provide the feasibility of the adopted two-stage synthesis technology. Finally, the authors obtain the crack resistance of coatings based on a heat-insulating calcareous dry mortar intended for finishing aerated concrete.
Fine-aggregate concrete with polymer and basalt fiber
Authors: Perfilov V A 
Published: December 2019

Abstract
The article covers the results of research and experimental studies aimed at determination of the impact of polymer and basalt fibre as well as plasticizing agents on the properties of fine-aggregate concrete. The authors identified the physical and mechanical properties of fine-aggregate fibre-reinforced concrete depending on the amount of basalt and polymer fibres. The article also dwells on the impact of different plasticizing agents on the properties of fine-aggregate fibre-reinforced concrete. It was determined that the optimal concentration of polymer and basalt fibre is 0.9-1.0 kg/m3 when maximum compression strength and tension in bending have been reached. The authors managed to select efficient superplasticizing agents Sika ViscoCrete 5-800 and POLIPLAST SP-4 which provided maximum increase in strength of fine-aggregate concrete. It was determined that the use of polymer and basalt fibres ensures increase in strength and crack resistance of the obtained fire-aggregate concrete compositions.
The effect of aluminosilicate modifying additive on the deformation properties of adhesive dry building mixtures
Authors: Zhegera K V , Pyshkina I S 
Published: December 2019

Abstract
The article provides information about the possibility of using amorphous aluminosilicates as a modifying additive for dry building mixtures. The data on the synthesis of the additive, its chemical and physical properties are given. A recipe for adhesive dry building mixtures with the use of amorphous aluminosilicates is proposed synthesized by the proposed method. The technical and physical properties of tile adhesives made using amorphous aluminosilicates as a modifying additive are considered. The deformative properties of tile adhesive made on the basis of the proposed recipe are considered. The elastic modulus of the coating, shrinkage deformation, ultimate tensile strength, axial tensile strength and crack resistance coefficient are calculated. According to the results obtained, appropriate conclusions were made.
Structurization of cement systems with nanodispersed silica stabilized with acetate ions
Authors: Lukuttsova N P , Golovin S N 
Published: December 2019

Abstract
The influence of a modifying additive in the form of silica sol stabilized with acetate ions on the structure and properties of cement stone has been studied. The mechanism of structure formation in the system of “cement-nanodispersed silica (NDS) stabilized with acetate ions” is proposed. It includes two aspects. In the initial period of hydration the crystallization of calcium hydroacetoaluminates occurs, the rate of their formation being higher than the rate of ettringite formation. Their crystals have some micro-reinforcing effect on cement stone, increasing its density and strength. The nanodisperse silica in combination with the calcium hydroacetoaluminates is directly involved in the structurization of cement stone, colmataging the pores. Si4+ atoms, building-in in the structure of portlandite phases, increase the impermeability of cement stone. The generation of calcium hydroacetoaluminates leads to the formation of the primary carcass, providing the strength development of cement stone in the early stages of hardening. It is established that adding the modifier results in pore redistribution in size: a decline in the amount of macropores and an increase in the quantity of the gel pores and submicropores (5-0.1 µm) at a constant micropore volume (0.1-20 µm).
Lightening of ceramic bricks based on red-burning clay
Authors: Pavlova I A , Sapozhnikova M A , Farafontova E P 
Published: December 2019

Abstract
To determine the possibility of using a mineral pigment based on the rutile form of titanium dioxide in the production of volume-colored ceramic brick in order to obtain lighter brick tones the studies are conducted. The previously studied low-melting clay of the Tyumen deposit was used as a basis. It was established that significant lightening of the brick does not occur even with the introduction of 8% of the specified pigment, although some lightening is appeared. In addition, with the pigment introduction, an increase in water absorption of bricks is observed, which leads to a decrease in the sample strength. Increasing the firing temperature to 950°C does not lead to an improvement in the quality characteristics of the samples, and even vice versa makes them worse. Thus, the use of a white pigment under investigation does not give a significant effect of lightening of ceramic red-burning clay.
Influence of high-frequency cyclic loading on mechanical and structural characteristics of rail steel under extreme conditions
Authors: Loktev A A , Korolev V V , Gridasova E A 
Published: December 2019

Abstract
In this paper topical issues of change of a microstructure and microhardness in steel at high-frequency vibration influence which is observed in technological pipelines, connected to the pump and compressor equipment. To study the micro-structures of samples after influence of high-frequency loading, the authors used optical microscopy and microhardness testing. Relevant and timely is the task of modelling and subsequent design and construction of railways, taking into account a wide range of geometric and mechanical characteristics, which is most in demand in the construction of artificial structures in the Arctic, due to the large temperature difference and differences in temperature coefficients of materials. The purpose of this work is to study the mechanical and structural characteristics of 40X steel under high-frequency loading conditions. For mechanical and structural studies the authors prepared the samples from a rod of 40X steel with a diameter of 12 mm. The strength properties of steel was evaluated by tension testing, fatigue testing, then structural analysis (metallographic studies) and microhardness testing.
Method of determining electrotechnical characteristics of concrete
Authors: Pogorelov S N , Semenyak G S , Kolmogorova A O 
Published: December 2019

Abstract
The main characteristics of concrete working under the influence of electricity are considered. In this regard, concretes can be divided into two main groups: electrically conductive and electrically insulating. Both of them have the right to exist, as the development of science and technology predetermines their necessity. Various attempts were made to determine the electrotechnical properties of concrete. The article presents a fundamentally new way to study the electrotechnical properties of concrete and mortars: the “voltmeter-ammeter” method. It is proved that the measurement of the specific resistance at frequencies of 1 … 5 kHz should be considered the most appropriate for carrying out the measurements. The experiments showed that this method has the right to exist, and is one of the simplest and does not require expensive equipment.
Computer technology of designing of optimum road constructions made of local materials
Authors: Aleksikov S V , Leskin A I , Gofman D I 
Published: December 2019

Abstract
This article considers the principles of formation and support of the database management system (DBMS) in design of optimum road designs made of local road-building materials. The principle of multilevel representation of information bases, which are connected by relational communications, is the basis for design. Databases contain separate information files on administrative or territorial regions of area or the region, technical parameters of highways, soil and geological conditions and also data on the available road-building materials of the region and their specific expense. Contact between the separate DBMS files is kept constantly by means of the uniform codifier. Management of databases is carried out by the AD application program written in the FoxPro language, allowing one to run for search of optimum roadbed designs depending on the area of construction, technical category of the road and type of soil of a roadbed with their subsequent check on durability.
Strength and stiffness of wood structures for compounds of gang nail plate “Steelcap”
Authors: Isupov S A , Chaganov A B 
Published: December 2019

Abstract
The article is devoted to research of strength and stiffness properties of wood structures on a new type of gang nail plates. The relevance of the study is due to the need to meet the requirements of modern design standards SP64.13330.2017 with respect to new types of wood structures. In this regard, the purpose of this article is to determine the estimated carrying capacity and stiffness of joints of wooden structures “Steelcap”. The main method of studying this problem is the analysis of experimental data on the basis of short test compounds with the gang nail plate at the angle of 0°, 45° and 90° the fibers of wood.
On micro-level vulnerability of concrete surface layer in process of crystallization of hydrating Portland cement and upon mechanical load
Authors: Akhmetzyanov F Kh , Radaykin O V , Ibragimov R A 
Published: December 2019

Abstract
The target of this research is to make a system of data on discontinuity of the cement stone microstructure in concrete. To achieve this, the following issues have to be addressed: a) a justification for the presence of dislocations in cement stone and definition of their type needs to be provided; b) the source of the considered material weakness has to be identified; c) an explanation of formation and propagation of micro cracks starting at the surface and going deeper into the concrete needs to be given; d) an educated guess has to be made for the opening/depth ratio of micro cracks; e) information about the distances between micro cracks in the capillary walls of the cement stone should be obtained; e) binding energy in the calcium silicate crystalline hydrate has to be determined. The research results show that the mechanical properties of crystals and polycrystals in the cement stone (concrete) depend on the ratio of small-angle (θ≤10…150) and large-angle boundaries. Due to a relatively small number of large-angle boundaries, intergranular and plastic flow deformations are dampened under straining, resulting in cleavage in the areas where stress-raisers are found (pores, capillaries, submicrocracks, etc.).
On potentiality and practicability of installing flooring suspended in geodesic domes by means of cable system
Authors: Romanovich A , Kleshcunov Y , Vlasov A 
Published: December 2019

Abstract
The article considers the potentiality and practicability of installing flooring suspended in the geodesic domes by means of a cable system. Such design consideration will allow using the interior space of the geodesic domes more rationally and ramp up the rentable area of the building dramatically. The literature review revealed that the question of the possibility of embedding a flooring in a geodesic dome remains unexplored at present. The stress-strain state of the geodesic dome with worked in flooring was studied in the course of the investigation. Further, the authors conducted comparative analysis of the investigated structure with a test version has been carried out. The efficiency of the investigated test model was confirmed. Solutions for the elimination of stress and strain raisers in the model elements were proposed. Reliability of the results of the obtained data for the analysis of the investigated model was ensured by the accuracy of the finite element method. The practical significance of the paper lies in the development of methods for calculating and constructing geodesic domes with the worked in flooring.
Study on characteristics of fatigue strength of ARALL composite in constructive elements
Authors: Adegova L , Frolova V , Losev S 
Published: December 2019

Abstract
Due to Fatigue Testing fatigue life of specimens made of various materials and with various flange types was estimated. Specimens with dish-shaped and ring-shape flanges were tested. Specimens were made of aluminum alloy D16chATV sheets (thickness 1.2 mm) and of ARALL with a thickness of 1.2 mm based on aluminum layers of 0.5 mm thickness. Specimens were tested under 3 levels of cyclic stress: σmax=120, 100, 80 MPa with minimum stress of σmin=20 MPa. Some of ARALL specimens were tested only under σmax=100 MPa stress level. Under each stress level were tested 5 – 6 specimens. According to the results of all specimen tests the authors plotted plotted fatigue curves. Using the Finite Element Method the stress state of specimens during cyclic stress tests was analyzed. Calculations of fatigue life of specimens were made on the basis of the offered method. Full-element and numerical experiments revealed that fatigue resistance of monolithic alloy specimens with dish-shaped flange under all stress levels is higher than of specimens with a ring-shaped flange. ARALL specimens with dish-shaped and ring-shaped flanges both according to test results have a higher fatigue resistance than monolithic alloy specimens.
Influence of pre-stressing over parameters of diagram of static-dynamic deformation of RC elements
Authors: Fedorova N V , Iliushchenko T A 
Published: December 2019

Abstract
The stress-strain state in RC elements of statically indeterminate structural systems under sudden restructuring is considered in this article. The solution of the problem on determining the parameters of a static-dynamic deformation diagram of prestressed RC elements was obtained on the energy basis excluding the structure dynamics instrument the problem. The deformation dependences for the pre-stressed flexural RC element are determined using the diagram method presented in the research of. For the possibility of obtaining an analytical expression of the desired moment convenient for practical application of the construction of the “moment-curvature” diagram for the pre-stressed element is performed using the simplest deformation dependence. The calculation analysis of the deformation of such a structural systems was performed using the level of primary and secondary design models.
Tools development for estimated cost management of construction and assembly works
Authors: Gureev K A , Aftakhova U V , Gladkikh V S 
Published: December 2019

Abstract
In general, construction costs are governed by the federal law № 44-FZ CONCERNING THE PROCUREMENT CONTRACT SYSTEM OF GOODS, WORKS AND SERVICES FOR STATE AND MUNICIPAL NEEDS (in force 05 April 2013) and the federal law №223-FZ CONCERNING THE PROCUREMENT OF GOODS, WORKS AND SERVICES BY SEPARATED TYPES OF ENTITIES (in force 18 July 2011) as well. A method, which is more applicable in practice, and presented in the laws mentioned above – is the calculation of estimated working costs. In order to calculate total costs and economic effects for an enterprise correctly, it is possible to use such tools, as complex estimation, active examination and cost modelling processes. It is important to add specific costs which are peculiar to this particular object into calculation of total costs and effectiveness. Modelling will be applied well for calculation of capital construction cost. A positive economic effect from the application of new methods and approaches is expected due to the accuracy of the cost estimates and cost projections will increase.
Actual aspects of modeling method application in organization of construction management
Authors: Pesotskaya E , Selyutina L , Egorova L 
Published: December 2019

Abstract
The possibility of using the modeling method in the organization of construction management is analyzed in the article. It reveals the specifics of the methodology for forecasting and strategic planning in the investment and construction complex, as well as the principles and methods for implementing a universal expert method applicable to any research tasks. Particular attention is paid to the methodology of engineering forecasting as an analytical tool suitable for use in multi-factor models. The methodological foundations of managing the competitiveness of investment and construction complex subjects and methods for its assessment are studied. The importance of competitive factors and the need to take them into account when developing options of model constructions are also emphasized.
Experimental studies of pneumatic impulse booster when unloading cement from metal tanks
Authors: Burak E E , Zherlykina M N , Vorobyeva Y A 
Published: December 2019

Abstract
The paper is devoted to solving the problem of increasing the efficiency of discharging powdered cement from metal tanks using an air-pulsed booster. The results of research on the experimental facility and the method of transition from them to production tanks, which are most common in mortar-concrete installations and inventory warehouses of cement, are presented. The scheme of the experimental stand developed by the authors is given. The authors obtain experimental dependences of the effectiveness of cement collapse on the power in the system of pulsed air supply and the effectiveness of its collapse on the size of the gap. Further, the paper establishes the nature of the outflow and the formation of cement hang at the bottom of the tank. Based on the results of experimental studies using the similarity theory and dimensional analysis, the parameters of the system of cement collapse in real tanks are determined.
Target focusing of innovation activity in building construction
Authors: Matveeva M V 
Published: December 2019

Abstract
In case of modernizing a building construction complex in overall structure of the national economy, searching and analysis of the problems of a current state of building construction business and determination of innovative development perspectives for that economy sector are important scientific and practical issues. At the same time, designing and including innovations in the building construction area is currently one of the actively developing directions of the scientific and technological activity. The author consider the features characterizing the building construction area as an important factor of innovation technologies introduction. The main cause of lack of innovation is the market structure of the building and construction trade. Companies see no need to initiate innovation programmes; the market structure is not conducive to innovation. Today target focusing of innovation activity in building construction allows the companies to get competitive benefits. Based on this, it’s important to determine the features of project portfolio of an investment and construction sphere for providing proper cooperation with an outside area, supporting a stable growth and ability of restructuring, developing and diversification of business. It will be paramount for construction companies to learn, master and harness these technologies and techniques so that their construction businesses can remain competitive and relevant in the face of an ever-increasing list of demands from clients.