bluuebunny/crossref_metadata_2025 huggingface dataset:
Shifts in the conflict-coexistence continuum: Exploring social-ecological determinants of human-elephant interactions
Authors: Malley Grace S. , Gorenflo L. J.
Published: March 2023

In Morogoro Region of south-central Tanzania, loss of crops and safety concerns due to elephants compromises livelihoods in many rural communities relying on subsistence agriculture. Using a social-ecological system framework to examine conflict-coexistence between people and elephants, this paper explores drivers that influence human-elephant interaction and subsistence farmer attitudes towards elephants in 10 villages from three different districts. Surveys and interviews document experiences interacting with elephants along with direct and indirect costs incurred in sharing the landscape, revealing different tolerance levels by residents of subject communities towards elephants that have important implications for elephant conservation. Rather than uniformly negative beliefs about elephants, analyses reveal that over the past decade a shift has occurred from largely favorable to unfavorable. The variables influencing attitudes included amounts of crops lost to elephants, perceived benefits from elephants, amounts of crops lost to other causes, perceived trend of human-elephant conflict (HEC) in the past three decades and level of education. Villager tolerance varied by level of income, perception on how the community coexists with elephants, amounts of crops lost to elephants and compensation. The study contributes to understanding how HEC is affecting the relationship between people and elephants, revealing a shift in the conflict-coexistence continuum from positive to broadly negative and identifying characteristics underlying varying tolerance towards elephants in different communities. Rather than a static condition, HEC emerges under specific conditions at particular times and places through varying, uneven interactions between rural villagers and elephants. In communities vulnerable to food insecurity, such conflict exacerbates existing problems of poverty, social inequality, and feelings of oppression. Addressing the causes of HEC, when possible, will be essential to elephant conservation as well as to improving the wellbeing of rural villagers.
Path loss measurement and modeling of 5G network in emergency indoor stairwell at 3.7 and 28 GHz
Authors: Samad Md Abdus , Choi Dong-You , Choi Kwonhue
Published: March 2023

Research on path loss in indoor stairwells for 5G networks is currently insufficient. However, the study of path loss in indoor staircases is essential for managing network traffic quality under typical and emergency conditions and for localization purpose. This study investigated radio propagation on a staircase where a wall separated the stairs from free space. A horn and an omnidirectional antenna were used to determine path loss. The measured path loss evaluated the close-in-free-space reference distance, alpha-beta model, close-in-free-space reference distance with frequency weighting, and alpha-beta-gamma model. These four models exhibited good compatibility with the measured average path loss. However, comparing the path loss distributions of the projected models revealed that the alpha-beta model exhibited 1.29 dB and 6.48 dB for respectively, at 3.7 GHz and 28 GHz bands. Furthermore, the path loss standard deviations obtained in this study were smaller than those reported in previous studies.
Putative avian teeth from the Late Cretaceous of Alberta, Canada, are more likely from crocodilians
Authors: Mohr Sydney R. , Acorn John H. , Currie Philip J
Published: March 2023

Isolated teeth, previously referred to Aves, are more common than other bird fossils from the Late Cretaceous of Alberta. However, there are no known morphological synapomorphies that distinguish isolated bird teeth, and features of these teeth are generally shared with those of non-avian theropods and crocodilians. Here, specimens ranging from Late Santonian to Late Maastrichtian in age are described and qualitatively categorized into morphotypes, most of which strongly resemble teeth of extant juvenile and some fossil crocodilians. Variation within this sample of teeth may therefore reflect the heterodont dentition of crocodilians, rather than avian species diversity. Quantitative analysis Principal Component Analysis was mostly uninformative, with limited overlap between putative avian teeth and those of known Cretaceous birds, crocodilians, and non-avian theropods. The reassignment of these putative avian teeth to Crocodylia has important ramifications for our understanding of the evolutionary history of Cretaceous birds.
ABOUT THE ANOMALOUS PROPERTIES OF BLAST IRON WITHOUT GRAPHITE EMISSIONS
Authors:   Khakass Technical Institute – branch of Siberian Federal University, Sagalakova M.
Published: March 2023

The development of modern materials science provides for the constant search for new materials with higher properties. Expensive iron-nickel alloys, the so-called Invars, are currently widely used as such materials. Speaking about the structure and properties of cast iron, the influence of gases (hydrogen, nitrogen and oxygen) on the formation of its structure and properties is most often ignored. In the practice of obtaining cast iron castings, to impart the desired properties to cast iron, the treatment of the melt with various substances is often used. In addition to affecting the chemical composition of the melt, its properties can be changed using other factors. One of the simplest in implementation and efficiency can be a change in the temperature of the melt and residence time at this temperature. To study the effect of thermal cycling on the linear expansion and microstructure of cast iron, two variants of melt processing were carried out. The first one consisted in heating to 1300 °С, holding for 15 minutes and cooling until a hard crust was obtained. The second one is heated to 1550 °С, held for 15 minutes and cooled to a temperature of 1350 °С. Both processes were repeated many times. The performed processing of the melt completely removes the precipitation of free graphite from the cast iron structure. Metallographic analysis of dilatometric samples made it possible to establish that thermal cycling leads to the formation of ledeburite. The effect of heat treatment on the linear expansion and microstructure of blast furnace iron after pretreatment of the melt was studied. The most effective was the chemical-thermal treatment (carburizing in the environment of the Bonduzhsky carburizer) followed by quenching. Carrying out carburizing in the environment of the Bonduzhsky carburizer leads to an increase in the values of the linear expansion coefficient in the region of low and high test temperatures. However, subsequent quenching allows one to obtain rather low values of the coefficient of linear expansion: 3,1·10–6, deg–1 at a temperature of 150 °С and 1,8·10–6, deg–1 at a temperature of 400 °С. Comparing the coefficient of linear expansion of blast furnace iron without precipitation of graphite with the coefficients of linear expansion of Invars in different temperature ranges, it can be seen that the coefficient of linear expansion after preliminary processing takes on rather low values.
THE CHROMIUM AND VANADIUM DISTRIBUTION IN THE DIFFUSION LAYER OF STEEL X35CRNI2-3 DURING THERMОDIFFUSION SATURATION
Authors:   Chelyabinsk Iron and Steel Works, Shaburova Yu. , Shaburova N. ,   South Ural State University, Pashkeev I. ,   South Ural State University
Published: March 2023

Termodiffusion saturation of the surface of alloys with two or more elements remains poorly understood despite the great practical and scientific interest that this method of chemical-thermal treatment represents. The simultaneous introduction of several elements can significantly reduce the processing time of products and obtain a multiphase composition on the surface of the product, which opens up wide opportunities for imparting unique technological and operational properties to products. The article describes the features of the distribution of chromium and vanadium during joint thermal diffusion saturation of steel X35CrNi2-3 at a temperature of 1000 °C. The proposed analysis technique is based on the possibilities of X-ray spectral microanalysis of diffusion layers on transverse microsections of the obtained samples. The elemental composition of the diffusion layer was monitored using a JEOL JSM-6460 LV universal scanning electron microscope. The microstructure was studied on an optical metallographic microscope Axio Observer D1.m. X-ray phase analysis was carried out on a Rigaku Ultima IV diffractometer. The hardness measurement was carried out on an FM-800 microhardness tester at a load of 100 g. Data were obtained on the qualitative and quantitative distribution of chromium and vanadium in the surface layer of steel. It is shown that the emerging diffusion coating has the following structure: a structureless outer layer, consisting mainly of chromium, vanadium carbides → a region of columnar crystals (experiencing γ→α transformation upon cooling), consisting mainly of their Cr1.0V0.4Fe0.3 solid solution → partially decarburized α-phase → base metal. The diffusion coefficients of chromium and vanadium are determined: in the α-phase DCr = 1.3·10–15 m2/s; DV = 1.8·10–14 m2/s; in the γ-phase DCr = 1.13·10–15 m2/s; DV = 1.3·10–15 m2/s. The microhardness of the outer surface layer was 1400–1980 H, the diffusion layer in the base metal was 630–790 HV, and the base metal was about 540–510 HV.
RESEARCH OF THE CHROMIUM DISTRIBUTION IN THE DIFFUSION LAYER DURING CHROMIUM PLATING OF STEEL X35CRNI2-3
Authors:   Chelyabinsk Iron and Steel Works, Shaburova Yu. , Shaburova N. ,   South Ural State University, Pashkeev I. ,   South Ural State University
Published: March 2023

The analysis of scientific literature has shown the diffusion saturation of two and more chemical elements of the surface of alloys remains understudied due to the complexity of sample preparation and subsequent analysis of samples. This remains a relevant objective of modern science. Using of a new technique for determining the concentration of a chemical element during chemical-thermal treatment of alloys will greatly facilitate the theoretical studying of diffusion processes in alloys and the practical application of diffusion saturation. The article describes a new method of determining the concentration of chromium during diffusion chromium plating of steel. The possibilities of the new technique are shown on the example of diffusion saturation with chromium of X35CRNI2-3. The principle of the technique – the obtained samples after chromium plating of steel are cut across the axis, thin sections are made, the diffusion layer is examined from the end of the sample using an electron microscope. In this work the analysis technique is based on the capabilities of scanning electron microscopy, X-ray spectral microanalysis of diffusion layers across a section (local determination of the chemical composition of the material). The chemical composition of the diffusion layer was monitored using a universal scanning electron microscope JEOL JSM-6460 LV. Chromium diffusion saturation of steel X35CRNI2-3 has done. A dense (pore-free) surface layer containing 100 to 2% chromium, to 62 microns thick, has obtained. The diffusion coefficient of chromium has calculated: α-phase – DCr = 6.3·10–14 m2/s, γ-phase – DCr = 3.7·10–15 m2/s. The microhardness of the chromiumplated layer has determined, which averaged 1369 HV300.
STUDY OF CORROSION RESISTANCE OF HIGH ENTROPY ALLOY Al0.5CoCrFeNi1.6Ti0.7 IN SEA WATER
Authors:   South Ural State University, Samoylova O. , Yan’shina E. ,   South Ural State University, Moghaddam A. ,   South Ural State University, Trofimov E. ,   South Ural State University
Published: March 2023

High-entropy alloys (HEAs) are a relatively new type of alloys and interest is constantly growing. Unlike traditional alloys based on one or two main components, HEAs include five or more components in close to equimolar ratios. It is known that a number of HEAs exhibit a high level of useful properties. Such alloys combine high strength and ductility, increased fatigue resistance, high hardness and wear resistance, and high thermal stability. The development of new compositions and the study of the properties of the obtained high-entropy alloys are currently topical materials science problems. The creation of corrosion-resistant HEAs and the study of their behavior in aqueous solutions of alkalis, acids and salts is justified by the possibility of applying coatings on products operated in aggressive aqueous solutions, including sea water. This work is devoted to the study of the corrosion resistance of the high-entropy alloy Al0.5CoCrFeNi1.6Ti0.7 in an aqueous solution – an analogue of sea water for 93 days in order to determine the long-term stability of this alloy when operating under the conditions of the Northern Sea Route. It is shown that this alloy has a complex multiphase structure, which does not worsen the corrosion resistance when operating in sea water. HEAs Al0.5CoCrFeNi1.6Ti0.7 demonstrates the change in mass according to the parabolic law. During the entire test period, the weight gain was about 2.7 mg/cm2. Most of the surface of the investigated alloy after testing is covered with a thin oxide film; the composition of the film is dominated by oxides of titanium, chromium and nickel.
ANALYSIS OF THE INFLUENCE OF SETTING PARAMETERS WASHING MACHINE ON THE CHANGE OF CASE WALL DIAMETER AND THICKNESS
Authors:   South Ural State University, Vydrin A. , Neroznikov V. ,   TAGMET, Zvonarev D. ,   The Russian Research Institute of the Tube & Pipe Industries (RusNITI), Trubnikov K. ,   TAGMET
Published: March 2023

In the production of seamless pipes, a mass method is the use of billet piercing at helical rolling mills with the first rolling at longitudinal rolling mills. At the same time, increased requirements are imposed on the quality and geometric parameters of finished pipes. Geometric parameters include such as wall thickness, diameter, thickness variation. In this case, the difference in thickness mainly affects the quality of the liner. It is known that the same geometric parameters of the sleeve (diameter and wall thickness) can be obtained at different distances between the rolls, the distance between the holding tool, the extension of the mandrel beyond the clamping. However, in this case, the difference in thickness of the liners will be different. In addition to the tuning parameters, the degree of tool wear, in particular, the mandrel of the piercing mill, also affects the thickness difference. It was found that as the mandrel of the piercing mill wears out, the diameter of the liner monotonically increases, which leads to a redistribution of the liner wall, and, accordingly, the difference in liner thickness. This work is devoted to the search for rational tuning parameters in order to minimize the thickness difference. An experimental plan was developed using modeling in the QForm environment. The obtained sleeves were processed according to the geometric parameters. Based on the data, the mean square error coefficient (RSME) was calculated for various models of regression equations. For the selected model, nomograms of the distribution of thickness variation, wall thickness, and sleeve diameter were constructed depending on the tuning parameters. These nomograms can be used in industrial practice for the operational calculation of geometric parameters when the conditions for piercing workpieces change. As a project, recommendations were developed for obtaining liners with a wall thickness of 17 mm with a minimum thickness difference.
PHASE EQUILIBRIA IN THE Hg–Se SYSTEM DURING VACUUM DISTILLATION
Authors:   Uralelektromed, Korolev A. , Shunin V. ,   Uralelektromed, Timofeev K. ,   Uralelektromed, Technical University of UMMC, Maltsev G. ,   Uralelektromed, Voinkov R. ,   Uralelektromed
Published: March 2023

Abstract. One of the possible ways to recover components from the Hg–Se alloy formed during the processing of copper-electrolyte sludge is vacuum distillation. Object of research: Hg–Se alloys of composition, mol %: 0.01–99.99 Hg; 99.99–0.01 Se, the formation of which is possible during the processing of copper-electrolyte sludge in the production of commercial selenium concentrate. The purpose of the work: calculation of the “gas – liquid” VLE (vapor liquid equilibrium) equilibrium states, including the dependence of the phase composition on temperature (T – x) and pressure (P – x) for the Hg–Se alloy during vacuum distillation. Methods and approaches used. The activity coefficients of the Hg–Se alloy components were calculated using a simplified version of the simple molecular interaction volume model (SMIVM). Phase diagrams of temperature (T – x) and pressure (P – x) are used to pre-select the system temperature and pressure, and to evaluate the efficiency of component separation during vacuum distillation. Novelty: calculation of activity coefficients using a simplified version of the SMIVM model. Main results. In the temperature range of 823‒1073 K, saturated vapor pressures were calculated for Hg (pHg * = 1.418·106‒1.046·107 Pa) and Se (pSe * = 1.42·104‒3,66·105 Pa). High values of the ratio pHg */pSe * = 100.2‒28.6 and the separation coefficient lgβHg = 2.73‒1.01 create theoretical prerequisites for the selective separation of these metals by vacuum distillation, when mercury is enriched in the gas phase (βHg > 1), and selenium – in the liquid phase. The molar fraction of selenium in the gas phase xSe = 0.553–1.43·10‒12 decreases with a decrease in the temperature of 1073‒823 K and the molar fraction of the element in the alloy xSe = 0.99–0.01. For the “liquid – gas” interface of the Hg–Se alloy, the values of changes in the excess Gibbs energy, enthalpy, and entropy are determined ‒ΔGm E = 0.8–3.0 kJ/mol; ‒ΔHm E = 1.86–5.39 KJ/mol; ‒ΔSm E = 0.99–2.94 J/mol.K. Practical significance: reducing the number of time-consuming and expensive installation experiments during the processing of Hg–Se compositions to optimize the temperature and pressure values of the vacuum treatment process distillation in order to obtain Se-containing products of a given composition.
INTERACTION OF CHEMICALLY ACTIVE MELTS WITH CERAMIC MOLD MATERIALS IN VACUUM
Authors:   South Ural State University, Znamenskii L. , Ivochkina O. ,   South Ural State University, Solodyankin A. ,   Chelyabinsk Higher Military Aviation Red Banner School of Navigators
Published: March 2023

To obtain precise castings from chemically active melts, a special method of precision cas¬ting according to removable models is traditionally used, consisting in the manufacture of ceramic molds on an ethyl silicate binder and further filling with melt in vacuum. At the same time, when forming castings of a responsible purpose by pouring titanium and heat-resistant nickel alloys in a vacuum, the current technology causes a high defect due to the identification of various surface casting defects that are unacceptable when working parts under the action of repeatedly repeated temperature changes and alternating mechanical loads. The analysis showed that the main reason for this defect is the lack of thermochemical resistance of ceramic corundum molds on an ethyl silicate binder to interaction with poured titanium and heat-resistant nickel al-loys in vacuum. The possibility of obtaining high-quality castings from chemically active alloys is reduced to the use as a binder of ceramic forms of materials that are resistant to thermal dissociation in vacuum at heating temperatures of 1913–1973 K. For this purpose, it is proposed to use a silica-free binder – an aqueous solution of aluminum phosphate concentrate. The composition of the mold made according to the proposed technology, in which there is no silica, excluded the harmful effect of oxidation processes in vacuum on the quality of castings from chemically active alloys. Ceramic electrocorundum molds based on aluminum phosphate concentrate are resistant to thermal dissociation and interaction with chemically active metals poured in vacuum. This will reduce defects in non-metallic inclusions and improve the quality of precision castings made of titanium and heat-resistant nickel alloys.
OPTIMIZATION OF THE CHEMICAL COMPOSITION OF SUPERMARTENSITIC STAINLESS STEEL USING THERMODYNAMIC CALCULATIONS
Authors:   Ural Federal University named after the first President of Russia B.N. Yeltsin, Lobanova L. , Lobanov M. ,   Ural Federal University named after the first President of Russia B.N. Yeltsin
Published: March 2023

Supermartensitic steels have a unique complex of chemical and mechanical properties, so pipes made of these steels have found their application in the oil and gas industry. However, these steels tend to form a banding structure. The banding structure is the cause of the products properties anisotropy and in addition can lead to the semi-finished products destruction at the production stage. In this work, the steel of the supermartensitic class 10Kh13N3MFB was investigated for its tendency to form a defect “banding” in the structure. For this, thermodynamic calculations and mathematical modeling were carried out using the Thermo-Calc-3.01 software. The following program functions were used: calculation of phase equilibria for the average chemical composition, as well as for compositions with a maximum of austeniteforming elements with a minimum of ferrite-forming elements and with a maximum of ferrite-forming ones with a minimum of austenite-forming elements. An constructed thermodynamic equilibria analysis showed that steel 10Kh13N3MFB tends to form a banded structure. To reduce the likelihood of banding, it is necessary to carry out crystallization and hot rolling of steel only in single-phase states (δ-ferrite and austenite, respectively). Therefore, further calculations in Thermo-Calc were aimed at determining the steel chemical composition, at which the alloy crystallizes in the single-phase δ-region, excluding the appearance of phase segregation, and establishing the temperature range of hot deformation. After analyzing the data obtained, the optimal chemical composition of the steel melting was proposed and the temperature ranges of hot rolling were determined for the average chemical composition with different contents of Ni – 2, 3, 4 wt. %.
KINETICS OF CONTINUOUS COOLING TRANSFORMATIONS OF AUSTENITE IN HIGH-CHROMIUM IRON ALLOYS
Authors:   South Ural State University, Okishev K. , Savushkina E. ,   South Ural State University, Kulikov V. ,   Karaganda Technical University, Kvon Sv. ,   Karaganda Technical University, Sozykina A. ,   South Ural State University, Omarova A. ,   Karaganda Technical University, Atambaev Zh. ,   Karaganda Technical University
Published: March 2023

The work develops the models of two principal diffusional transformations in high-chromium iron alloys on continuous cooling, viz. precipitation of secondary carbides (Cr, Fe)7C3 from aus-tenite and pearlitic decomposition of the latter. Literature experimental data for alloys of various composi-tion were used for analysis. Chemical composition of austenite by the end of austenitizing holding was de-termined using previously developed models, and then the exact expression describing isothermal precipita-tion of carbides from supercooled austenite was found based on the general equation following from the ki-netic theory of phase transformations. It was found out that the time exponent n in that expression equals to 3/2, which corresponds to the case of preferred precipitation of very fine carbide particles. For transition to the continuous cooling condition the C-curve of isothermal carbide precipitation was approximated by a square parabola. This permitted to find the relation between cooling rate and the amount of precipitated car-bide phase by means of the Scheil–Steinberg integral. Further comparison with the experimentally observed increase of martensitic point allowed to determine the numerical parameters of the model and their depend-ence on carbide composition of a given alloy. For the pearlitic transformation, a previously developed mod-el describing the parameters of temperature dependence of the Avrami equation coefficients on austenite composition was employed. That model was generalized for the continuous cooling case in the same was as above. As a result, CCT diagrams of diffusional austenite transformations in high-chromium alloys were calculated, that in general corresponded well the experimental ones.
THE CHROMIUM AND TUNGSTEN DISTRIBUTION IN THE DIFFUSION LAYER OF STEEL X35CrNi2-3 DURING THERMОDIFFUSION SATURATION
Authors:   South Ural State University, Shaburova N. , Pashkeev I. ,   South Ural State University
Published: March 2023

Chemical-thermal treatment (CHT) of structural parts operating under conditions of wear, friction, shock loads make it possible to obtain a unique combination of surface and core properties of the product. However, such traditional CTO methods as carburizing and nitriding, while improving the mechanical characteristics of the surface, are not suitable for all types of steels. Diffusion metallization methods, in particular, thermal diffusion chromium plating, are more effective in terms of the achieved set of properties. Currently, chromium plating is carried out both by saturation of the metal with one element – chromium, and by multi-element mixtures. The article describes the technology of thermal diffusion saturation of steel X35CrNi2-3 with chromium and tungsten at a temperature of 1000 °С. A technique for analyzing the obtained coating is presented, based on the possibilities of X-ray spectral microanalysis (XMS) of the diffusion layer on transverse microsections of the obtained samples. The elemental composition of the diffusion layer was monitored using a JEOL JSM-6460 LV universal scanning (scanning) electron microscope. The microstructure was studied on an optical metallographic microscope Axio Observer D1.m. X-ray phase analysis was carried out on a Rigaku Ultima IV diffractometer. The hardness measurement was carried out on an FM-800 microhardness tester at a load of 100 g. Data were obtained on the qualitative and quantitative distribution of chromium and tungsten in the surface layer of steel. It is shown that the resulting thermal diffusion coating consists of a substitutional solid solution based on Cr–Fe with a bcc lattice, chromium and tungsten carbides. The depth of the outer coating on the sample was about 20 μm, the depth of the diffusion layer in the base metal was 50–55 μm. The absence of a decarburized area in the surface layer of the base metal was noted. The average diffusion coefficients of chromium in the α-phase of chromium were determined to be DCr = 3,58·10–13 m2/s; in the γ-phase of iron DCr = 2,83·10–15 m2/s. The microhardness of the outer surface layer was 1800–2000 HV, the diffusion layer in the base metal was 1300–550 HV, and the base metal was about 540–510 HV.
PHYSICAL EQUATION OF COMPACTED ELASTIC-VISCOUS MEDIUM
Authors:   South Ural State University, Chaplygin B. , Shirokov V. ,   South Ural State University
Published: March 2023

Experienced information about the rheological properties of materials used in the manufacture of abrasive mixtures for the subsequent technology of manufacturing wheel blanks by rolling, pressing and punching made it possible to classify it as a heterogeneous compacted elastoviscous, characterized by deformation and rate hardening, a significant proportion of elastic deformation, elastic aftereffect and relaxation phenomena. This, in turn, made it possible to approach the derivation of the defining physical equation. The conclusion that defines the physical equation in the entirety of the parameters included in it is a difficult task. At the same time, the creation of an exact theory of physical equations is one of the main problems. There are various approaches to the construction of defining physical equations. Some of them claim to be a deep study of the essence of phenomena, lead to rather complex constitutive physical equations, and are difficult to use in applied problems. The article proposes a variant of constructing the defining physical equation, which is based on plastometric curves, their approximation by polynomials, a step-by-step procedure for processing experimental data, the choice of a mechanical analogue and the derivation of a physical equation in a differential form for a small time interval, the determination of the constants of a physical equation by the least squares method, and as a result, obtaining the dependence of the modulus of elasticity and the coefficient of viscosity on the deformation conditions. The presence of a defining physical equation makes it possible to proceed to the solution of applied problems.
ELASTIC TORQUE OBSERVER OF A TWO-MASS ELECTROMECHANICAL SYSTEM
Authors:   South Ural State University, Chelyabinsk, Russia, Karandaev A.S. , Loginov B.M. ,   South Ural State University, Chelyabinsk, Russia, Khramshin V.R. ,   Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia, Bodrov E.G. ,   JSC “KONAR”, Chelyabinsk, Russia, Samodurova M.N. ,   South Ural State University, Chelyabinsk, Russia
Published: March 2023

To reduce the accident rate and increase the service life of electromechanical systems with shock load changes, the monitoring of elastic moments in mechanical gears is necessary. This task is relevant for the main lines of stands of hot rolling mills. The implementation of monitoring systems based on physical measuring devices is inefficient due to their complexity and low operational reliability. As an alternative, a relatively simple elastic moment observer is proposed, which is a fragment of an industrial controller software. The structure of the observer is presented and its advantages in comparison with known analogues are shown. The adequacy of the measured and reconstructed elastic moment signals is proved using the example of electromechanical systems of the stand of the thick-sheet mill 5000. A quasi-experimental analysis of emergency modes is substantiated, which allows the processing of signals stored in the form of data arrays. Based on this approach, an assessment of the dynamic moments in the emergency shutdown mode of the crate with metal in the rolls is given. The expediency of creating an online monitoring system for overloads of spindles and methods for calculating their resource is emphasized.
METHODOLOGY FOR COMPARING THE ENERGY EFFICIENCY OF METHODS FOR REGULATING THE PERFORMANCE OF A BLOWER STATION
Authors:   Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia, Vecherkin M.V. , Sarvarov A.S. , Romanova I.P. , Bogacheva I.Yu. , Oskolkov S.V.
Published: March 2023

This article presents a method for comparing the energy efficiency of different methods of regulating the total productivity of a blower station. The basic principles for the electrical modeling of duct networks are shown for a mathematical description of their properties. The results of a comparison of the energy efficiency of regulating methods for a single fan and a group of five fans operating on a common line are presented. There is higher energy efficiency combining start-stop control with stepless control using axial guide vanes for a five-fan blower station compared to the simultaneous frequency control of five fans.
VECTOR CONTROL OF AN ELECTRIC DRIVE BASED ON A THYRATRON MOTOR WITH DISCRETE WINDING COMMUTATION
Authors:   South Ural State University, Chelyabinsk, Russia, Voronin S.G. , Klinachev N.V. ,   South Ural State University, Chelyabinsk, Russia, Kuleva N.Yu. , Chernyshev A.D.
Published: March 2023

The article considers the possibility of implementing phase vector control (FVU) of a synchronous motor with permanent magnets in the thyratron motor mode. The characteristics of the FVU with three methods of discrete commutation of the three-phase winding are considered: six-stroke 120- and 180-degree and twelve-stroke 150-degree. A comparative assessment of the efficiency of the PVF is carried out in terms of expanding the range of implemented mechanical coordinates and energy indicators, both with different methods of discrete switching and with respect to sinusoidal power supply. It is shown that 120-degree switching is the most advantageous in terms of energy indicators. However, with it, the values of the maximum achievable speeds and moments weakly depend on the angle of commutation θ, therefore, operation is recommended at a constant θ = 0, corresponding to the efficiency value close to the maxi­mum in a wide range of speeds. With 180-degree commutation, the FVU allows you to adjust both the maximum speed and the maximum torque. However, with small values of the relative inductance of the winding, which refers to the ratio of inductive resistance to active, this method of regulation is ineffective due to low efficiency and is inferior in this indicator to both 120-degree commutation and the case of sinusoidal power supply. As the relative inductance increases, the difference between the case of sinusoidal power supply and 180-degree switching decreases. The use of 150-degree commutation allows, on the one hand, to increase efficiency while maintaining the ability to adjust coordinates, on the other hand, reduces the pulsation of the motor torque, expanding the possible scope of the drive.
DEVELOPMENT OF A SYNCHRONOUS REACTIVE MACHINE WITH HIGH SPECIFIC INDICATORS FOR INDUSTRIAL ECLETRIC DRIVES
Authors:   South Ural State University, Chelyabinsk, Russia, Savosteenko N.V. , Maksimov N.M. , Blagov M.S. , Posadnov A.E.
Published: March 2023

The use of an energy efficient electric drive affects various areas of production. The relevance is growing every year, thus replacing old equipment with modern is a matter of time and pace of modernization. So in the industrial production of shipbuilding, there is a question of modernizing propulsion plants by using an electric drive with high specific performance. Very tough conditions are imposed on this power plant: a fairly high efficiency and high power, with relatively small weight and size indicators. Thus, the choice fell on the use of a synchronous reluctance motor using high-temperature superconductors. To maintain the superconducting state of HTSC elements, a cryogenic facility is required. With the conditions of operation and operation of cargo ships and icebreakers, the installation should be simple, and the material for cooling should be available. In this case, liquid nitrogen (77 K) has good qualities, because to create it, only access to air from the environment is necessary. The HTSC elements on which the SRM is designed must pass into the superconducting state at the boiling point of liquid nitrogen. This design of the electric drive will allow not only to reduce the weight and dimensions of the propulsion unit (the Azipod power plant system), but also to maintain the overload capacity, ensuring reliable operation of the drive over the entire period of time and modes of operation of the vessel.
University as a Place for Personal Renaissance: Future-teachers’ University Experiences as Agents for Learning and Teaching Peace
Authors: ERDEN-BASARAN Ozlem , GURSEL-BİLGİN Gulistan
Published: March 2023

This phenomenological study aims to understand how future-teachers’ university setting has become a personal awakening place to reflect on their past schooling experiences and build plans as peace agents. In other words, this study argues that university experience, if meaningfully constructed to promote peace, equips future-teachers with the necessary skills to teach peace, and it could help future teachers about critically reflecting their past learnings upon the negative peace and violence. It transforms these learnings into positive peace in the end. Drawing from Freire’s (1970) critical consciousness and Giroux’s (1981,1988, 2010) conceptualization of teachers as transformative intellectuals, the findings suggest that universities by building inclusive, peaceful, democratic, and diverse communities, can help their students to gain the awareness of systematic oppression and structural violence (re)produced by patriarchal, political and social discourses, and it develops motivation to incorporate peace (education) in their professional practices.
ARSITEKTUR NABATI : RESPON RUANG PASKA PANDEMI COVID-19 DI INDONESIA
Authors: Sekarlangit Nimas , Satwiko Prasasto
Published: March 2023

Pandemi COVID-19 tahun 2020 memaksa seluruh penduduk bumi, termasuk Indonesia untuk menjalani kebiasaan hidup baru. Para ahli yang berkompeten menyatakan bahwa pandemi zoonosis yang terus berulang terkait erat dengan konsumsi manusia pada hewan liar dan ternak. Sebenarnya sumber pangan nabati telah terbukti dapat memenuhi kebutuhan nutrisi lengkap manusia. Arsitektur nabati nusantara adalah bentuk arsitektur yang menggabungkan wadah aktivitas manusia dengan tanaman pangan dalam konteks lokal. Arsitektur nabati menawarkan pemecahan terpadu dan komprehensif terhadap masalah pencegahan berulangnya pandemi zoonosis, pencukupan nutrisi, keanekaragaman hayati, serta kualitas lingkungan hidup perkotaan. Tulisan ini menggunakan metode terbaru dengan menggali informasi terkini yang berhubungan dengan COVID 19 dan membahas benang merah antara pandemi dan desain arsitektur nabati. Sebagai objek studi yaitu karya mahasiswa dan arsitek profesional dalam menanggapi ide pertanian perkotaan. Hasil pembahasan menemukan bahwa Arsitektur Nabati mampu menjadi upaya mitigasi awal terhadap bencana pandemi dengan memberikan kualitas udara dan pencahayaan yang baik bagi ruang dan mampu menyehatkan penghuninya serta memberikan ketahanan pangan akibat keterbatasan lahan
Pułapka „ciepłych portretów”. Wybrane przykłady ukraińskich heteroobrazów w literaturze i kinie polskim na początku XXI wieku
Authors: Kupidura Ryszard
Published: March 2023

The expressions of Polish solidarity with Ukrainians after the aggression of the Russian Federation on February 24, 2022 was absolutely unprecedented. Undoubtedly, such a radical historical breakthrough would not have been possible without the contribution of Ukrainian migration diplomacy, implemented, often unknowingly, by hundreds of thousands of migrants who, through direct contact with Poles, reduced the conflict-causing potential of Ukrainian-Polish history. The aim of this paper is to examine the evolution of Ukrainian heteroimages appearing in Polish cinema and literature at the beginning of the 21st century, e.g. Lady from Ukraine by Paweł Łoziński, Ukrainian girl by Barbara Kosmowska and reportages written by Marta Mazuś and Monika Sobień-Górska. The author also focuses attention on the migration counter-discourse in Guest Worker Literature, the role of the Polish-Ukrainian theater and the intercultural perspective for future literary and artistic searches.
Nonlinear elliptic–parabolic problem involving p-Dirichlet-to-Neumann operator with critical exponent
Authors: Deng Yanhua , Tan Zhong , Xie Minghong
Published: March 2023

We consider the nonlinear elliptic–parabolic boundary value problem involving the Dirichlet-to-Neumann operator of p-Laplace type at the critical Sobolev exponent. We first obtain the existence and asymptotic estimates of the global solution, and the sufficient conditions of finite time blowup of the solution by using the energy method. Second, we improve the regularity of solution by Moser-type iteration. Finally, we analyze the long-time asymptotic behavior of the global solution. Moreover, with the help of the concentration compactness principle, we present a precise description of the concentration phenomenon of the solution in the forward time infinity.
RFID supply chain data deconstruction method based on artificial intelligence technology
Authors: Zhang Huiying , Li Ze
Published: March 2023

Radio frequency identification (RFID) is a broad rapidly evolving skill in the past few years. It is characterized by non-contact identification, fast read and write speed, small label size, large data storage capacity, and other technical advantages. RFID technology for goods movement has completely changed the traditional supply chain management, greatly improved the operational efficiency of enterprises, and has become an important method for the development of supply chain logistics. This work mainly studies and analyzes the RFID supply chain, introduces the development and application of RFID supply chain sector technology, and discusses the operation of the supply chain in detail. Then, according to the existing RFID supply chain, a RFID supply chain artificial intelligence (AI) based approach to technology is proposed, and the data analysis of RFID supply chain is introduced in detail. In this work, through the research experiment of AI technology RFID supply chain data analysis, the experimental data show that there are several time-consuming links in the supply chain system. The time consumed in the AI RFID system is 9.9, 3.4, 3.5, and 29.9 min, respectively, while each link in the original system takes 13.4, 4.9, 4.9, and 34.9 min. It can be seen from the above data that the amount of time in each system link of the AI RFID supply chain system is less than that of the original supply chain system, which shortens the entire product passing cycle and greatly improves work efficiency.
Approximation via statistical measurable convergence with respect to power series for double sequences
Authors: Narrania Devia , Raj Kuldip
Published: March 2023

In this paper, we introduce and study a new type of convergences using statistical convergence via the power series method and measurable convergence. We also study their relationship with other convergences. Further, we demonstrate Korovkin-type approximation theorems for double sequences of positive linear operators using these newly specified convergences, and we also provide illustrations that demonstrate how our proven theorems are better than their classical counterparts. Finally, we have determined rates of statistical product measurable convergence using the power series approach and the modulus of continuity.
Modelling of the exploding wire technique, a novel approach utilized for the synthesis of nanomaterials
Authors: Singh Surendra , Goswami Navendu
Published: March 2023

Of late, the exploding wire technique (EWT) is being popularly utilized for high yield synthesis of diverse nanomaterials. In this paper, we propose an equivalent electrical circuit-based model of this technique when the explosion of wire against a metallic plate takes place in the presence of aqueous medium. The wire transforms into plasma state immediately after explosion and formation of liquid-vapour mixed phase is imminent in this process. We elucidate the conversion of metallic wire into partially ionized plasma by a set of semi-empirical mathematical equations. We propose a mathematical electrical conductivity model for analysing complex behaviour of wire explosion in a liquid medium. The present work results are restricted to one-dimension but could be extended to two- and three-dimensional codes associated with the dynamics of z-pinch or x-pinch.
Guided domino lithography for uniform fabrication of single-digit-nanometer scale plasmonic nanoantenna
Authors: Oh Dong Kyo , Kim Yeseul , Kim Jaekyung , Kim Inki , Rho Junsuk
Published: March 2023

Single-digit-nanometer scale plasmonic nanoantenna platforms are widely used in optical sensors, quantum plasmonics, and other applications. Uniform and reliable fabrications with a single-digit-nanometer resolution are desirable for diverse quantum nanophotonic device applications, but improving the process yield and uniformity of the shape of the nanoantenna over the entire fabrication area remains a challenge. Here we report the guided domino lithography fabrication method for uniform ultra-sharp nanoantenna arrays. We use a collapsing of unstable photoresist nanostructures with a guide structure to uniformly fabricate ultra-sharp bowtie photoresist masks. We directly compare the yields of the conventional and the guided domino lithography under the optimized electron beam exposing and development conditions. Furthermore, we conduct a rigorous analysis to verify the electric field enhancement effect from ultra-sharp bowtie nanoantennas fabricated with different geometry. We believe that guided domino lithography can be a promising solution toward a practical manufacturing method for single-digit-nanometer plasmonic nanoantennas.
Robustness of lateral tongue bracing under bite block perturbation
Authors: Liu Yadong , Luo Sophia , Łuszczuk Monika , Mayer Connor , Shamei Arian , de Boer Gillian , Gick Bryan
Published: March 2023

Lateral tongue bracing is a lingual posture in which the sides of the tongue are held against the palate and upper molars, and has been observed cross-linguistically. However, it is unknown whether lateral bracing makes adjustments to external perturbation like other body postures. The present study aims to test the robustness of lateral tongue bracing with three experiments. The first baseline experiment was an analysis of an electropalatogram database and the results showed lateral bracing being continuously maintained. The second experiment applied an external perturbation during speech production. A bite block was held between participants’ teeth while intra-oral video was used to record contact between the sides of the tongue and upper molars during speech. The results indicated that lateral bracing was maintained most of the time during speech. The third experiment included simulations investigating the activation of tongue muscles relevant to lateral bracing at different degrees of jaw opening. The results show that bracing requires higher activation of bracing agonists and lower activation of bracing antagonists as jaw opening increases. Our results suggest that lateral tongue bracing is actively maintained and robust under external perturbation and further indicate it serves as an essential lingual posture during speech production.
Numerical modelling of 1-dimensional silicon photonic crystal sensor for hydrostatic pressure measurement
Authors: Gowda Ranjith B. , Sharan Preeta , Khamar Saara
Published: March 2023

In this work, a highly sensitive hydrostatic pressure sensor using one-dimensional (1D) photonic-crystal (PC) is designed and analyzed numerically for its sensing performance. The device design has silicon (Si) sensing layer at the top to sense the applied pressure. The proposed sensor performance has been studied for its pressure sensing, by applying boundary load on the sensing layer. The structure is designed, simulated and analyzed using an FEM tool. As the applied pressure is varied from 0 MPa to 10 MPa, resonant mode shifts towards the higher wavelength region. The effect of defect cavity length and the number of periods are also analyzed to choose the optimized value which enhances the sensor performance parameters. Simulation result shows that the proposed sensor has a very high sensitivity of 250 nm/GPa and Q-factor of 11,120 with the transmission of 99.99%.