bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research deformation caused by hydraulic fracturing
Authors: Verisokin A E , Airapetova A A , Zhulina L G , Nazarenko A V , Tkachenko V A 
Published: November 2020

Abstract
The paper discusses problems of tensile loadings affecting a soil layer when conducting hydraulic fracturing. The effect of tensile stress on rocks in a bottomhole formation zone during hydraulic fracturing is studied using numerical methods. A special analysis of the processes of cores deformation under reservoir conditions is carried out in the paper. The article provides formulas to calculate stress-strain state of rocks in bottomhole formation zone. Along with an exact numerical study of the distribution of stresses in bottomhole formation zone, some approximate analytical dependencies reflecting features of the stress-strain state of bottomhole formation zone are obtained with the aim of solving optimization problems. The paper presents the scheme of production layer vertical deformation which shows layer’s roof and bottom displacement caused by increased pressure inrepression cone. Formulas describing the influence of deformation processes in bottomhole formation zone can also be used to study cyclic operation of underground gas storages.
Backfilling for mines
Authors: Zagorodnyuk L H , Chernysh A S , Lesovik V S , Schekina A Yu , Ryzhikh V D , Sumskoy D A , Sinebok D A 
Published: November 2020

Abstract
The article introduces results of studying the problem areas in filling masses of iron ore mining-and-processing enterprise. Some basic study of back filling after the blast hole drilling has been conducted by the authors. The samples picked from the disrupted back filling have been studied for strength. The analysis of the results evidences that all the samples meet the requirements of the strength class but there is a variation of the strength characteristics which evidences about the massif inhomogenuity. The results of chemical, X-ray and fluorescent analyses proved high inhomogenuity of solidified back filling masses in the massif. The microstructure of the back filling samples has inhomogeneous structure, with a great number of various pores. A set of studies showed lack of uniformity and consolidation of the filling solution. It resulted in the loss of strength and durability of the back filling area. The analysis of possible reasons for negative results has been given. The activities to improve the quality and durability of the back filling for mines have been suggested.
Analysis of the current issue of well bore and well bottom cleaning
Authors: Zainagalina L Z 
Published: November 2020

Abstract
The paper considers the problem of insufficient cleaning of oil and gas wells from drill cuttings. The formation of slurry dunes is the main cause of complications and accidents in horizontal well drilling. The task related to the development of high-efficiency equipment for well bottomhole cleaning from drill cuttings is quite relevant. The existing techniques and technologies for borehole bottom cleaning from drill cuttings caused by rotary drilling were analyzed to find a way of improving the efficiency of borehole bottom cleaning. A new technical solution for cleaning vertical, directional and horizontal wells from drill cuttings was developed. The process functional diagram of at-bit sludge chopper during turbine drilling is presented to increase the cleaning efficiency of bottomhole and wellbore of vertical, directional and horizontal wells from drill cuttings during roller boring.
Differential impact on wellbore zone based on hydrochloric-acid simulation
Authors: Zeigman Yu V , Mukhametshin V V , Kuleshova L S 
Published: November 2020

Abstract
On the basis of geologic and statistical modeling in high-viscosity oil deposits of the Tournaisian stage and using the obtained models the paper proposes to carry out forecasting, selection of wells, control and regulation of the impact process in order to reduce the number of inefficient operations and increase technical and economic indicators of fuel and energy complex enterprises.
Research of dependence centrifugal pump efficiency of impeller slit seal design parameters
Authors: Protopopov A , Belov N , Kalugina M , Mukhlaeva A 
Published: November 2020

Abstract
Efficiency and resource are the two main characteristics of a centrifugal pump. In present study, the dependence of these characteristics from impeller sealing wear ring configuration was considered. Range of models with various configurations has been analyzed using numerical flow simulation. Compromise curves nave been obtained as a result. This information allows select an optimal ratio of dimensions of wear ring hydrodynamic slit seal to achieve a balance between efficiency and reliability of centrifugal pump.
Investigation of the dependence of the axial force acting on the rotor of a vertical centrifugal pump on the area of the discharge holes of the impeller
Authors: Protopopov A , Zhestkiy N , Godorozha S , Kalugina M , Mukhlaeva A , Zaitseva A 
Published: November 2020

Abstract
The article describes a vertical centrifugal pump with a bearing Assembly in the upper part of the rotor. It is shown that for certain values of design parameters, the influence of the so-called discharge holes in the impellers can significantly affect the axial force acting on the rotor, and for certain parameters, for example, with a large weight of the rotor, this influence is insignificant and the manufacture of such impellers is impractical.
Profiling of the flat-tool for manufacturing worms with circular eccentric profile by cold forming
Authors: Frumuşanu G , Teodor V , Oancea N 
Published: November 2020

Abstract
The incremental pumps are encountered in pharmaceutical and cosmetics industries. One of the most representative categories of these pumps is formed by the progressing cavity pumps. The helical surfaces with circular profile, eccentrically positioned relative to worm axis, are frequently used in their rotors construction. In this specific case, the constructive dimensions of the worms allow their manufacturing by cold forming, with flat-tools similar to screwing dies. In this paper, an analytical algorithm for profiling such flat-tool is proposed. The algorithm starts from the analytical definition of the helical cylindrical surface with constant pitch of the generated worm, and it lays on the “Minimum distance method”. The equations of the gearing surface between worm and flat-tool are found, and, based on this, the active surface of the tool is determined. A MatLab application developed for implementing the profiling algorithm is presented. The results obtained after running the application in the case of a particular generated surface are also included.
Basic mechanical analysis of biodegradable materials
Authors: Mazurchevici A D , Popa R I , Carausu C , Comaneci R , Mazurchevici S N , Nedelcu D 
Published: November 2020

Abstract
The field of polymeric materials and manufacturing technologies is constantly evolving, offering the possibility to prototype 3D products in a responsible and ecological way, thus aiming to replace on a large scale the filaments of nonbiodegradable synthetic polymers (from fossil resources) with filaments of biodegradable materials, obtained from renewable resources. The paper supports the development mentioned above and follows to characterize biodegradable materials from the mechanical behavior point of view, tensile, bending, and impact tests. Also, the study reflects the influence of the technological parameters on the tensile test obtained results and also aims to optimize the obtained results. The studied materials were Extrudr Green-TEC Anthracite and Extrudr BDP Pearl which according to the obtained basic mechanical results can successfully replace conventional polymers such as Flexible, HIPS, PP and other ones.
Study on the influence of technological parameters on the friction stir butt welding process of pure copper plates
Authors: Constantin M A , Nitu E L , Iordache D M , Badulescu C 
Published: November 2020

Abstract
Friction stir welding - FSW is a relatively new welding process, which is increasingly used in industry, due to the advantages which it has in relation to conventional processes (by melting and adhesions). The advantages of the FSW welding process (as a solid phase welding process) are all the more obvious in the case of joining copper and its alloys, because they have a high melting temperature and high thermal diffusivity. The influence of the technological parameters of the process, the tool rotational speed and the welding feed, on the temperature and the axial force, as well as on the quality of the joint surface is presented. The study shows that the stabilization of the process takes place after a certain time from the beginning of the advance stage and highlighted the major influence of the tool rotational speed on the process temperature, surface defects and the roughness of the joint surface.
Static Structural Analysis Analytical and Numerical of Ball Bearings
Authors: Belabend S. , Paunoiu V. , Baroiu N. , Khelif R. , Iacob I. 
Published: November 2020

Abstract
FEM analysis is a very efficient method for achieving results of stresses at different loading conditions according to forces and boundary conditions applied to the component the static analysis. The purpose of the study is to collect data’s using two different softwares and then to compare them with analytical results. This work aims at analysing the behaviour of the ball bearings under a static load, using Solidworks, ANSYS and MESYS software. The comparison is done between the analytical results using the Hertzian theory, ANSYS and MESYS, for two different cases of loading.
Algorithm for screws profiling of a conical trilobed compressor - analytical solution
Authors: Baroiu N , Costin G A , Teodor V G , Oancea N 
Published: November 2020

Abstract
Screw compressors, as rotary machinery, are capable of working with high compression ratios for gas compression. They transform the mechanical work done by an electric motor or turbine into the potential energy of a gas, by reducing its volume and increasing the pressure. The essential elements of these compressors are the two helical rotors with lobes, mounted in a housing. Existing rotors in the construction of compressors are working bodies whose composite profiles include circle arcs, line segments and cycloidal curves, while also often including non-analytical curves. Such geometry of profiles gives the gear processes superior characteristics, in the sense of reducing friction and improving sealing conditions. This paper analyses, by analytical approach, the possibility of constructing a multilobated conical screw compressor with a number of lobes Z, Z + 1, of the male and female rotor. The parametric equations of the contained worm and the kinematics of the working process of the conical screw compressor shall be defined. The theory of surface wrapping comprises analytical methods of study, which were developed on the basis of the fundamental theorems on wrapping of known surfaces in differential geometry and the kinematics laws on rotor movements. Thus, this paper proposes an algorithm based on the approach to the problems analyzed under the “virtual focal points theorem” between the complex surfaces of the conical surface lobes, which constitute the active lobes of the male and female rotors. Normal to active surfaces are defined, and also the speed in relative movement, in the “gear” process of the conical screw compressor. Regarding rotors in conical screw compressors, the circular pitch of the teeth is constant. Also, the screw pitch of the conical compressor rotors is a constant value. In these conditions, the rotors of the screw compressors are acknowledged as active surfaces, conical screw surfaces with constant axial screw pitch. The cross section (in the normal plane to the driving rotor axis) determines a plane gear. This defines the specific winding condition, and the shape of the conical screw surface of the female rotor.
Comparison of the Strength Properties of Heat-Resistant Titanium Alloys at Elevated Temperatures
Authors: Davydenko L V , Egorova Yu B , Mamonov I M 
Published: November 2020

Abstract
The results of statistical studies of the strength properties of rods made of heat-resistant titanium alloys at test temperatures of 20-600 °C are represented. The initial data for the research were the results of experiments published in various sources from the 1960s to 2019.The chemical composition of the alloys has been compared by aluminum and molybdenum equivalents and tensile strength at various temperatures. With an increase in the degree of alloying with a-stabilizers and neutral hardeners, the heat-resistant properties of alloys increase and remain at higher temperatures. However, this may reduce the thermal stability of alloys with an aluminum equivalent of more than 9.0%. The highest strength properties while maintaining thermal stability have alloys with aluminum equivalents of 8.5-9.0% and molybdenum of 1.0-4.5%. Regression dependences of the average values of strength properties on the test temperature, silicon content, and aluminum and molybdenum equivalents of alloying elements and impurities have been determined.
Choosing the Rational Heat Treatment Conditions for High-Strength Cold-Resistant Weldable Steel with Yield Strength of more than 600 N/mm2
Authors: Poletskov P P , Kuznetsova A S , Nikitenko O A 
Published: November 2020

Abstract
Rational heat treatment conditions for the new weldable cold-resistant steel grade 20G2SMRA ensuring a guaranteed yield strength σ0,2 ⩾ 600 N/mm2 combined with the lowtemperature impact strength KCV-60 ⩾ 50 J/cm2 have been searched. The effect of various quenching and tempering conditions on the steel microstructure parameters, hardness, and impact strength at a temperature of -60 °C has been studied. The dependencies of the microstructure parameters, hardness (HV1), and impact strength (KCV-60) on the quenching and subsequent tempering temperature are represented. Rational heat treatment conditions have been found for a new weldable cold-resistant steel with high yield strength.
Electromagnetic Properties of Composite Materials Based on Nd-Compound Modified Fe-Si-Al Alloy
Authors: Goryachko A I , Ivanin S N , Yu Buz’ko V 
Published: November 2020

Abstract
The investigation of microstructure, optical and electromagnetic properties of powder prepared from Nd-compound doped Al6Si9Fe85 (Alsifer) alloy. The result of energy-dispersive X-ray spectroscopy is an evidence that the complementary Nd-containing Nd-Fe phase is on the surface of Alsifer particles. The magnetic particles distribution histogram in powder after mechanical treatment was plotted and analyzed. The electromagnetic properties (components magnetic permeability and dielectric permittivity) for produced composites with Nd-compound doped Alsifer powder with 50-90% (wt.) was studied. The nonlinear concentration dependence of magnetic and dielectric permittivity versus concentration Nd-compound doped Alsifer particles was observed. The magnetic resonance in composites was detected that shifted in low frequencies with increased magnetic filler concentration. The resonance field, absorption linewidth, g-factor and microwave absorption ability of Nd-compound doped Alsifer powder were determined from FMR experiment.
Aperiodic Schrodinger Crystals
Authors: Malkov V B , Chemezov O V , Malkov A V 
Published: November 2020

Abstract
In 1945, E. Schrödinger predicted the possibility of the existence of “aperiodic crystals,” that is, more and more increasing crystalline aggregates, but without a simple lattice repetition mechanism. In the present work, such structures are experimentally prepared using selenium as an example. By thermal gradient treatment of the amorphous selenium film, we have obtained nano-thin spatial dissipative structures (SDS) of hexagonal selenium, the lattice of which undergoes non-uniform rotational curvature around, in the general case, three mutually perpendicular directions. The formation of these nano-thin SDS of hexagonal selenium occurs as a result of cooperative rotations of selenium macromolecules around, in general, three mutually perpendicular directions. Since nano-thin SDS after hardening in air have all the features of crystals each of the above nano-thin SDS of hexagonal selenium obtained at different annealing temperatures corresponds to the concept of “aperiodic crystals” Thus, “aperiodic crystals” were obtained experimentally, the possibility of the existence of which was predicted by E. Schrödinger.
Synthesis, Structure and Properties of Zn0.3Ni0.7-xCoxFe2O4 Ferrite
Authors: Sherstyuk D P , Yu Starikov A , Zhivulin V E 
Published: November 2020

Abstract
The article presents the results of a study of ferrite Zn0.3Ni0.7-xCoxFe2O4, where x = 0 – 0.6 in increments of 0.2. The samples were obtained by solid-phase synthesis in a tube furnace with silicon carbide heaters at a temperature of 1150 °C for 5 hours. X-ray phase analysis showed that all the samples obtained are monophasic and have a spinel structure. X-ray structural analysis revealed that the substitution of cobalt atoms for nickel atoms leads to a monotonic increase in the parameters (a and V) of the unit crystal lattice. The elemental composition of the synthesized samples was monitored using an energy dispersive analyzer installed on a Jeol JSM 7001F scanning electron microscope. The aim of this work was to obtain new monophasic samples using previously developed technology.
Formation of Impurity Inclusions in Silicon when Smelting in Ore-Thermal Furnaces
Authors: Nemchinova N V , Hoang V V , Tyutrin A A 
Published: November 2020

Abstract
Silicon production by carbon reduction of silica-containing raw materials is performed in ore-thermal furnaces. The process proceeds at high temperatures (above 2,000°C). Consumers place high demands on the chemical purity of the silicon smelted, but the finished product contains a negligible amount of impurities. We have analyzed the causes for the impurity inclusions in silicon forming in smelting based on the data on the behavior of various elements penetrating the process with quartzite and reducing agent ashes. The chemical composition of furnace slag and silicon samples from the Silicon JSC of RUSAL (Russia) has been analyzed using various techniques, i.e. metallographic, X-ray fluorescence, X-ray diffraction, and X-ray spectral microanalysis. It has been established that the main source of non-metallic inclusions in silicon are furnace slag particles enmeshed in the melt when it is released from the tap. Due to the high degree of iron passing into the melt when smelting, the main metal inclusions are metal aluminum solutions based on iron, silicon, and other elements: FeSi2Al0,3, FeSi1,5Al0,3, and FeSi2Ti. The main way to improve the smelted silicon quality is to select feed with a minimum amount of impurities and conduct the process at optimal temperatures in the quartzite melting zone.
Mathematical Modelling of the Thermal State of a Ladle During Arc Heating of the Melt
Authors: Agapitov E B , Sokolova M S , Lemeshko M A 
Published: November 2020

Abstract
The paper analyzes energy losses in the ladle furnace. In particular, the authors focus on electrical losses, namely total energy losses of the electric arc, conditionally including radiation losses of a part of the arc uncovered by slag. Managing these flows creates conditions for increasing the efficiency of heating. The calculations given in the paper showed that electrical losses decreased, during prolonged heating (about 8-12 minutes) with a sufficient amount of slag. This mode provides a reduction in heat loss by 4-5 %. By selecting options of changes in a sequence of stages and their duration, the proposed mathematical model makes it possible to apply a new technology to process molten steel in the ladle furnace characterized by lower power consumption.
Research of Possibility of Processing of Oxidized Nickel Ore by Chloride Sublimation Roasting Technology
Authors: Kolmachikhina O B , Polygalov S E , Lobanov V G 
Published: November 2020

Abstract
Oxidized nickel ores (ONO) contain most of the world’s nickel reserves. However, choice of a cost-effe nickel ore processing technology is difficult due to the dispersed distribution of nickel compounds in refractory minerals, low nickel content, presence of a large amounts of consuming host rocks, and impossibility of beneficiation by conventional physicochemical methods. The paper presents studies on the ONO processing technology by means of chloride sublimation roasting. Sodium and calcium chlorides were used as chlorinating agents both individually and in various ratios. It has been shown that roasting allows for nickel and cobalt conversion into chloride form followed by selective distillation of the resulting compounds into the gas phase by 89 – 90% at a roasting temperature of 1100 °C.
Oxidized Nickel Ore and Galvanic Sludge Combined Treatment Investigation
Authors: Boshnyak M V , Kolmachikhina O B , Kolmachikhina E B 
Published: November 2020

Abstract
Galvanic sludges have been accumulated in large quantities in Ural region. These materials contain low concentration of non-ferrous metals (nickel, zinc, chromium) and iron, and are not being processed. Another difficult for treatment nickel containing materials are oxidized nickel ores, deposits of which are located in Ural. However, the nickel ores aren’t processed due to low economic efficiency. In this article simultaneous treatment of oxidized nickel ore and galvanic sludge was investigated. The proposed technology includes nickel ore sulfatization at high temperature in presence of sulfuric acid and further water leaching. Therefore, maximum nickel extraction in solution at leaching of oxidized nickel ore after sulfatization was 82 %. Solutions after leaching are neutralized by nickel containing galvanic sludge. Due to partial nickel chromite dissolution in sulfuric acid a total nickel concentration has been substantially increased. Selective nickel extraction from such solutions is possible by sorption methods, and further metal nickel obtaining – by electrowinning.
Heat Exchange in High-Power Arc Steel Furnace when the Height of the Slag Layer Changes
Authors: Makarov A N , Krupnov A V 
Published: November 2020

Abstract
Calculation results and analysis of changes in thermal radiation density of arcs by wall height for hundred-ton arc furnaces at different slag layer height and at equal arc power are presented. It was found that with an increase in the height of the slag layer from 70 to 300 mm, that is, with an increase in the depth of the arcs in the slag, the density of thermal radiation flows of the arcs in the most heat-loaded part of the walls decreases by 2 times. The efficiency of arcs increases with the increase in the depth of arcs in the slag and increases by 1.61 times when fully buried.
Study of the Principles for Ensuring the Accuracy of CCM Design Parameters
Authors: Sotnikov A L , Sholomitskii A A , Strichenko S M 
Published: November 2020

Abstract
It is established that the defining factor of accuracy of the designing parameters of S-type billet continuous casting machine (CCM) is relative difference of curvature of the adjacent arc-like sections, which form process axis of strand. An analysis of the local radius change of CCM ingot path curvature is carried out. In the process of CCM equipment alignment, it is necessary to ensure alignment of its curvature centers under condition of curvature value equality for minimization of its relative difference. Developed technology of position control and CCM equipment alignment allows meeting this requirement. The developed technology is based on the use of “Vizir 3D” a high-precision measurement system built on the base of electronic total station. Practical experience of alignment showed the efficiency of geodesic and combined method of equipment alignment on both billet and slab CCM.