bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Online Conversations for Global Educators
Authors: Guo-Brennan Linyuan
Published: May 2020

Educators in the 21st century need to be globally competent to help students understand the complexity and interdependence of global issues or forces to meet the diverse needs of students from diverse sociocultural, linguistic, and ethnic backgrounds; to effectively integrate educational technology in practices; and to foster active and responsible citizenship for both local and global communities. This chapter discusses the considerations of using critical online conversations as an authentic adult education strategy to develop educators' global perspectives and competences. Informed by the critical global citizenship education, critical online conversations can be a cost-effective approach for creating an open and safe virtual global learning community for educators. Assessing participation in critical online conversations is also discussed as an engagement and evaluation strategy.
Using Student Facilitation and Interactive Tools Within and Beyond the LMS
Authors: Gregg Andrea , Chang Hwei-Kit , Wang Yu , Ward Penny , Clariana Roy B.
Published: May 2020

While dialogue remains a critical component to an online community of inquiry (CoI), challenges regarding engaged student participation persist. This chapter discusses an online graduate course, “Designing Learning Within Course Management Systems” (“Designing Learning”), in which student-student interaction is a key feature and a central component of nearly all of the student activities. This chapter highlights the core pedagogical concepts and theories, including CoI, that form the foundation for the “Designing Learning” course. It then demonstrates the integration of those concepts throughout course design elements, including student facilitation and the use of multiple platforms like VoiceThread and Google Docs for interaction including reflections on both the students' and instructors' experiences of this course. Recommendations are next provided so that the successes of this course can be applied to other online teaching and learning contexts. Lastly, further research directions are identified.
Self-Directed/Community-Supported Learning
Authors: Quintana Rebecca M. , Hearn Catherine S. , Peurach Donald J. , Gabriele Kathryn
Published: May 2020

MOOC designers seeking to address evolving ambitions of MOOCs to support workforce development confront a fundamental design dilemma: on the one hand, the self-paced nature of online learning is efficient for busy learners working alone to acquire new knowledge and capabilities; on the other hand, the self-paced, often-isolated nature of online learning complicates designing MOOCs that motivate and sustain the type of engagement necessary to support learners in mobilizing new knowledge and capabilities in practice contexts and in collaboration with other professionals. The authors offer an account of their efforts to create opportunities for deep learning in large-scale, open-access learning environments through the creation and instantiation of a new instructional model called self-directed/community-supported learning. This model aims to draw diverse learners around the world into a community of discourse and practice through coordinated video content presentations, web-based enrichment activities, scenario-based team practice exercises, and community-wide discussion.
Using an AI-Supported Online Discussion Forum to Deepen Learning
Authors: Butcher Tamarin , Read Michelle Fulks , Jensen Ann Evans , Morel Gwendolyn M. , Nagurney Alexander , Smith Patrick A.
Published: May 2020

Student-to-student interaction is a key element in the learning process, and one that is often missing in online classes. The purpose of this case study is to demonstrate how a technology platform that leverages artificial intelligence (AI) can be used to deepen learning in online discussions by analyzing instructor and student perceptions and examining third-party analytics in two hybrid/blended undergraduate courses. The instructors selected Packback, a third-party online discussion platform, to address some of the engagement issues they encountered in the past when using discussion tools within learning management systems (LMS). Packback increased the depth of student discussions by providing real-time feedback to students on the quality of their posts, thus allowing students to improve the quality of their posts. Packback also allowed for more nuanced evaluation and grading of students' forum posts by instructors.
Argentina's Train Diplomacy
Authors: Baisotti Pablo Alberto
Published: May 2020

The objective of this study is to analyze the impact of the OBOR initiative for Argentina, starting from the premises that Latin America is not considered fundamental for the OBOR initiative and that Argentina played a secondary role in its economic relationship with China. In other words, could Argentina be considered to be on the periphery of the periphery for China and the OBOR initiative? And a more important question, could Argentina escape from that position to which it seems to be historically condemned? To answer these questions, a case study has been selected, the railroad Belgrano Cargas (FBC), because of the importance it represents for Argentine and Chinese interests. Argentina considers it a fundamental means to strengthen the national economy and connect, above all, the interior of the country (Central and Northwest) with Buenos Aires; China, on the other hand, sees in the FBC another means to create a bi-oceanic corridor capable of transporting primary products from Argentina to Chile and from there to China.
Argentina-China 3.0
Authors: Binetti Bruno
Published: May 2020

At this current time of transition, relations between the People's Republic of China (PRC) and the Argentine Republic are 45 years old. After a period of steady progress in trade and diplomatic exchange between 2004 and 2014, the arrival to power of President Mauricio Macri in 2015 posed a challenge for both countries: How would the two sides consolidate their strategic relationship to the point where it would transcend political changes in Buenos Aires? This chapter argues that the arrival of a new government in Argentina, rather than representing an obstacle to greater cooperation, may provide an opportunity for further consolidation of the relationship.
Social Development in the Integral Strategic Association China-Venezuela
Authors: Dias de Barros Jorge
Published: May 2020

In April of 2001, the People's Republic of China under Jiang Zemin and the Bolivarian Republic of Venezuela under Hugo Chavez initiated the first steps towards the construction of the Strategic Alliance for Shared Development between both nations, which has now established over 16 years of their relationship. This relationship could be defined as a set of instruments and mechanisms that have gradually materialized China-Venezuela cooperation, conceived under the three principles that they regulate: graduality, mutual benefit, and perfect planning.
Cuba and the United States in the Configuration of a Foreign Policy for Spain
Authors: Rodríguez Suárez Daniel
Published: May 2020

After the election of the socialist party in 1982, relations between Spain and Cuba entered a channel of greater understanding, as the two nation's traditional commercial and economic relationship found a complementary association in the greater political affinity between Felipe González and Fidel Castro. In the international context, the Cuban leaders had their own vision of the role that Spain might play on the international stage and sensed the possibilities that the young Spanish democracy could open up for the Third World. For Spain there was a need to maintain a neutral international orientation and remain detached from the military pacts with the great powers. This chapter explores Cuba and the United States in the configuration of a foreign policy for Spain.
Redefining Trust and Disinter-Mediation With Blockchain in E-Governance
Authors: Malhotra Jyoti , Jadhav Nagesh N. , Sachdeo-Bedi Rajneeshkaur , Sugandhi Rekha , Sarode Sambhaji
Published: May 2020

Blockchain technology (BCT) is becoming a common language across diverse geographical domains. BCT attempts to solve the fraud issues involved in financial transactions and government operations. E-governance is a convenient platform providing services to all connected citizens and inter-government sectors. Traditional centralization issues are addressed by decentralizing the stakes, keeping the transactions transparent on an open ledger–BCT. It works on the notion of disintermediation eliding the middle layers with the highest trust level. It can contribute to various e-government sectors, namely agriculture, property registrations, supply chain management, tax calculation, etc. BCT application for agriculture supply change management can provide assistance in crop plantation and delivery records. It can bring transparency in land registrations and tax management by maintaining immutable land records and simplified tax management preserving trust between various parties through smart contracts. This chapter focuses on BCT approaches for secured governance.
Blockchain Technology Applications in Government
Authors: Ozsoy Adnan , Gezici Bahar , Bölücü Necva , Bölücü Nurettin
Published: May 2020

Blockchain in government services has a wide range of application areas for various departments from legal document storage and management to healthcare benefits. Decentralized nature opens opportunities for a government that can achieve operations 24/7 and cut back office operations. A Blockchain system for government offers a potential solution to legacy pain points and establishes a secure storage for citizens and businesses. It also reduces intensive paper processes, excessive managing costs, and potential corruption and abuse. Instead, it greatly increases security of digital services and more importantly trust in the government. This chapter provides a detailed review of Blockchain solutions for three major government services: land registry, GDPR, and healthcare. For each service, a state-of-the-art is given, followed with the technical details of use cases and potential improvements for current problems.
Blockchain in the Insurance Industry
Authors: Yıldırım İsmail
Published: May 2020

New technologies that will be developed in the future will determine the place of Blockchain technology in our lives. It is certain that blockchain technology, which has the potential to be used in every field from smart phones to the health sector, will be a technology that will be frequently encountered in the future rather than simply being used in some sectors. What will determine the areas of use of Blockchain technology and how much it can be used depends on what future security, cost, and speed it can do. Blockchain, which can be used in the insurance sector, will help to keep track of accidents, material, and moral losses during the insurance period and keep track of all records very easily. It is expected that this technology, which is expected to be useful in eliminating the minute information problems in the insurance sector, can be very helpful in preventing insurance frauds, and it is expected to have a preventive effect in defrauding insurance and citizens. This chapter discusses how blockchain technologies will transform the insurance sector and their future uses.
Cross-Chain Blockchain Networks, Compatibility Standards, and Interoperability Standards
Authors: Williams Idongesit
Published: May 2020

This chapter explains the role and how interoperability standards and compatibility standards will enable the development of cross-chain blockchain networks. Blockchain currently lacks standardization. There are different initiatives aimed at facilitating interoperability between different blockchains. But if there are no uniform interoperability and compatibility standards, that will cause a problem for the development of cross-chain blockchain networks. In the EU, there is an initiative to facilitate a continental cross-chain blockchain network. Interoperability and compatibility standards are an integral aspect of the initiative. This chapter uses the case of the EU as a basis for explanation on how blockchain service providers can work together to develop these standards.
Story-Telling, Gamification, and Videogames
Authors: Membrive Veronica , Armie Madalina
Published: May 2020

The educational use of gamification in class has been widely explored by research. Theorizations establish a direct relationship between gamification and higher levels of motivation and engagement of students regardless of their educational levels. When teaching English as a second language, gamification becomes a key factor to provide dynamism to lessons and to foster the consolidation of the content taught in class. Moreover, gamification not only promotes the assimilation of vocabulary and grammar, but also the improvement of oral and written comprehension and production. The extensive use of new technologies in class has proved to be very useful for the implementation of the methodology on gamification. One of the tools that has attracted the attention of educators recently is Classcraft, an online virtual game based on digital storytelling. This chapter aims at explaining and assessing the use of Classcraft as a successful technology-based collaborative learning tool in a course on English as a second language at the university level.
Model of Electro-Pulse Processing of Metals Melts
Authors: Shaburova Nataliya , Litvinova E.V. , Naraeva R.R.
Published: May 2020

Questions of influence of nanosecond electromagnetic impulses on melts of metals are considered in the article. The analysis of action of impulses on electromagnetic hashing and thermal conditions of a melt showed their small influence. Mechanical (acoustic) action is chosen as the main one. Formulas and values for coefficients of transformation of electromagnetic field to the acoustic one for a number of metals are given. The transformation model in the form of the wave of current running on the radiator is offered. Comparison of action of electromagnetic impulses on melts showed that emergence of acoustic vibrations is the main thing. The theory of contactless transformation of electromagnetic waves in acoustic ones is considered. Comparison with experiments is given. The model of contact electro-pulse processing of metal melts in the form of transition of an electromagnetic wave to acoustic is offered. Acoustic waves change structure of a melt, condition of a crystallization of a melt and improve properties of the hardened metal.
Research on Obtaining Silica Xerogels from Nepheline and Study of some of their Physical and Chemical Properties
Authors: Velyaev Yuriy , Maiorov Dmitry , Kometiani Ilona
Published: May 2020

The article presents a method to obtain silica xerogels with developed specific surface based on nepheline concentrate acid decomposition in C2H5OH-H2SO4 system. It was found that the use of ethanol instead of water produces stable and steady silica gels. It is proved that the use of ethanol results in almost complete deposition of soda alum and aluminum potassium sulphate out of nepheline decomposition solution without its additional cooling, due to their extremely low solubility in alcohol solution. The morphology, structural and surface properties of synthesized xerogel sample with ~600 m2/g specific surface area (based on the analysis) were investigated; its mixed micro-and mesoporous structure was established. Electron probe microanalysis showed chemical purity of the resulting SiO2.
The Research of Service Characteristics of Up-to-Date Packaging Material for Metal Products
Authors: Kolyada Lyudmila G. , Tarasyuk Elena V. , Ponomarev Anton P.
Published: May 2020

Every year corrosion of metals leads to huge losses. Solving this problem is a very important task. The use of packaging materials with corrosion inhibitors is an innovative method to protect metal products from corrosion during transportation and storage. Polypropylene laminated fabrics have a number of advantages: durability, increased mechanical strength, they don’t rot, they are easy to be welded and sewed together, they are proof against water. Barrier and mechanical properties of polypropylene laminated fabric with and without volatile corrosion inhibitor are investigated in this research. The protective ability of polypropylene laminated fabrics for zinc-coated wire has been evaluated. It was found that polypropylene laminated fabric with corrosion inhibitor has higher mechanical properties and better protective ability against corrosion.
Kinetics of Structural Changes in Strontium Hexa-Ferrite Powder during Milling in Beater Mill
Authors: Egorov Ivan N. , Egorov Nikolay Ya. , Kryzhanovsky Viktor P.
Published: May 2020

The paper presents the results of experimental studies of strontium hexa-ferrite average particle size and structural characteristics changes during milling process. Coarse strontium hexaferrite was milled in beater mill, without and with electromagnetic effect. Electromagnetic effect was produced by constant and alternating gradient magnetic fields with mutually perpendicular induction lines. Particle sizes were measured by microscopic methods, and structural characteristics were calculated by processing of X-ray diffractograms. Diffraction studies showed that during milling process, both with and without electromagnetic effect, the most intensive changes of coherent scattering region (CSR) sizes, dislocation densities and relative deformation of particulate material occur at earlier stage of milling. At this stage the speed of average particle size decrease is maximal. At later stage both average particle size and structural characteristic changes correlate and have asymptotic character.
Thermodynamic Modeling of Phase Equilibria in the FeO-Al2O3-Cr2O3 and MgO-Al2O3-Cr2O3 Systems
Authors: Mikhailov Gennady G. , Makrovets Larisa A. , Samoilova Olga V.
Published: May 2020

Thermodynamic modeling of phase equilibria and further construction of a full projection of the liquidus surface in the FeO–Al2O3–Cr2O3 and MgO–Al2O3–Cr2O3 systems were carried out. Theories of sub-regular ionic solutions, regular ionic solutions and ideal ionic solutions were used for calculation. Values of energy parameters of the used thermodynamic models were obtained in the course of the research. These values might be applicable for further modeling of more complex oxide slag systems which are formed in the process of manufacture of chromic steels. Calculated phase diagrams for the FeO–Al2O3–Cr2O3 and MgO–Al2O3–Cr2O3 systems were compared with available data from literature sources.
Features of Tri-Calcium Silicate Formation Suppression by Sulphur and Possible Ways of its Preventing
Authors: Sheshukov O.Yu. , Nekrasov I.V. , Egiazaryan Denis K.
Published: May 2020

Synthesis of the portland cement clinker in the presence of a significant amount of SO3 is difficult, due to the tri-calcium silicate formation suppression. Since some technogenic formations contain a significant amount of SO3, it is hard to obtain the portland cement clinker from it. The analysis of the SO3 influence on the clinker-formation thermodynamic process allowed to reveal a number of regularities of their occurrence and to propose a method for the raw mix composition calculating and its preparation, to ensure a stable portland cement clinker synthesis.
Investigation of CaSO4-KPO3-Na2B4O7 System as a Basis for Synthesis of Low-Melting Glasses Used as a Glass-Solder Material
Authors: Stolbovsky Alexey V. , Murzinova Svetlana , Vyatchina Vita
Published: May 2020

The possibility of using the compositions of CaSO4-KPO3-Na2B4O7 system as a glass-solder material is shown. A glass formation region has been established in ternary system. The concentration dependences of linear thermal expansion coefficient, the softening temperature and the glass transition temperature are determined and discussed.
The Influence of Temperature and Deformation Ratio on Structure Formation and Physico-Mechanical Properties of Powder Materials
Authors: Ryabicheva Lyudmila , Dyadichev Valery V. , Nikitin Yu.N. , Dyadichev A.V.
Published: May 2020

The paper presents the materials on researching the use of current conductor copper waste for getting new functional materials. The changes of maximum deformation ratio, density, microstructure and hardness of powder copper preforms at different temperatures and deformation rates have been studied. The result is that the value of the maximum deformation ratio depends on kinetics of dynamic weakening processes. The change of the microstructure depending on the temperature and deformation ratio has been scrutinized. It has been established that the most fine-grained structure was got at the temperatures of dynamical recovery and recrystallization. The temperature intervals of stamping for manufacturing products by pressing are recommended. On the basis of experimental researches a resource-saving manufacturing method of producing axisymmetric details of high density from powder copper material with the use of maximum deformation ratios has been elaborated.
Surface Electric Arc Hardening of Low-Carbon Steels
Authors: Safonov E.N. , Mironova M.V.
Published: May 2020

Examined geometric characteristics, microhardness and features of structure formation in the heat affected zone of steels 09G2, 20L, 20FL. These studies were carried out after surface quenching by a magnetically controlled (scanning) DC electric arc in a protective argon atmosphere. It is shown that electric arc hardening forms on the treated surface of the steel a thin layer of martensitic-austenitic structure with varying composition and hardness. A ferrite-austenitic structure is formed in the region of transition from the base metal to the heat-strengthened metal. This structure contains crushed ferrite grain and winding boundaries between the structural components. On the periphery of austenitic grains martensitic layer is observed. Repeated heating, occurring during heat treatment of the adjacent surface area, is accompanied by a partial decay of martensite and austenite of a pre-hardened structure with the formation of bainite-and sorbitol-like tempering structures. On the surface, experienced repeated heating, the volume fraction of austenite increases. The dependences allowing to control the structural state and depth of the hardening zone are established.
The Chemical Reactivity Comparison of High-Modulus and High-Strength Carbon Fibers
Authors: Gomzin A.I. , Gallyamova Rida , Zaripov N.G. , Galyshev S.N. , Musin F.F.
Published: May 2020

In this study two types of PAN-based continuous carbon fibers were compared: high-modulus UMT-430 and high-strength UMT-49. The dynamics of carbon fibers oxidation at a temperature of 600°C with an exposure from 1 to 6 hours was evaluated. It was found that high-strength fibers burn out faster than high-modulus. The surface of the fibers in the initial state and after annealing was investigated. Composite samples with an Al-6Mg alloy matrix, reinforced with these types of carbon fibers, were tested for three-point bending. It was found that the strength of the composite with high-modulus fiber was more than 2 times higher than strength of the composite with high-strength fiber. The samples fracture surfaces of Cf/Al composites after mechanical tests are investigated.
Research for the Processing of Stale Slag from the Ural Region by the Pyro-Metallurgical Method
Authors: Malzev K.Y. , Kolmachikhina O.B. , Polygalov S.E.
Published: May 2020

Pyro-metallurgical copper production is characterized by the formation of a large amount of slags. The copper content in the smelt slag is 0.5-2 %, in the vessel slag - about 5%, which often exceeds the copper content in the mined ores (about 1%). This makes depletion of slag a necessary operation in the pyro-metallurgical production of copper. In addition, about 110 million tons of copper slags have been accumulated in the dumps of copper factories in the Urals. The processing of these slags which contain up to 2.5% Cu is a very important task, the solution of which will allow extracting copper and reducing the areas occupied by the dumps.
Examining of Solid and Liquid Industrial Copper Blanks with Purpose for Quality Control in Respect of Defects of Technological Origin
Authors: Tkachuk G.A. , Maltsev V.A. , Chikova O.A.
Published: May 2020

Microstructure of ingot and industrial blanks made of copper M2 was examined for quality control. Microstructure was examined by means of traditional metallographic analysis methods. Exogenous nonmetal inclusions and pores in microstructure were found. The transition from exogenous inclusions and pores, which were not removed in initial processing stage, to the crack, which leads to billet destruction on one of last processing stages, is shown. Without quality control of copper blanks by a metallographic method, it is impossible to provide guarantee of reliable operation of machines and responsible purpose constructions. A comparative study of the temperature dependences of the viscosity of the melts of charge materials and finished ingots for copper M2 was carried out. The study of the viscosity of copper melts M2 was carried out with the aim of quality control in the chain of "charge-melt-ingot" at the foundry stage.
The Metallurgical Characterization of Iron-Containing Concentrate
Authors: Myrzaliev B.M. , Nogaeva Kulgamal A. , Kolmachikhina E.B.
Published: May 2020

The expediency of processing iron-containing concentrate with low iron content, increased content of manganese and copper is considered in the article. To process such a concentrate, a metallization process is proposed to produce sponge iron with a reducing agent - carbon. It was found that in solid-phase reduction at 1150 °C iron is reduced to a greater extent, as well as small particles with a copper content of about 95%, manganese is not recovered. The simulation process of metallization with carbon at a temperature of 1250 °C shows that iron is mainly distributed in the metallic phase, to a lesser extent in slag phases, manganese is distributed in two phases - metal and slag, copper is presented as a separate phase of metallic copper in the composition with iron alloys, and also composes a part of iron alloys. The reduction degree from concentrate to the metallic part is 80 - 91% for iron and 95 - 98% for copper. The presence of metallized particles of various sizes, representing phases of iron with manganese and copper was found in the slags.
Kinetics of the Natural Wolframite Interaction with Sodium and Potassium Carbonates
Authors: Selivanov E.N. , Pikulin K.V. , Gulyaeva R.I. , Galkova L.I.
Published: May 2020

The kinetics and mechanism of the natural wolframite interaction with sodium and potassium carbonate, when they are heated in the air, are studied. Using X-ray phase and X-ray structure microanalysis, it was established that the initial single crystal wolfram consists of Fe0.5Mn0.5WO4 and Fe0.3Mn0.7WO4. The method of differential thermal and subsequent phase analysis of products has shown that the interaction of wolframite with sodium and potassium carbonates begins above 450-470 °C with the formation of tungstate and ferrites of sodium and potassium, iron and manganese oxides. Conducting the model experiments on sintering with the subsequent removal of water-soluble compounds (alkalization) made it possible to follow the change in the structure of wolframite. Unit cells parameters of wolframites in solid products (cakes) of leaching do not change if sintering is carried out in the range up to 600 °С. In samples, the preparation of which is coupled with heating to 700–800 °C, the atomic ratio of Fe/Mn in wolframite decreases to 0.2. This allows to specify the mechanism of the process and judge the greater reactivity of wolframites with an increased proportion of iron. Thermal analysis with data processing using the methods of non-isothermal kinetics has established that the studied interactions proceed according to a two-stage mechanism, which in the first stage is limited by diffusion. The appearance of a low-melting eutectic Na2WO4 – Na2CO3 и K2WO4 – K2CO3 in the system contributes to the process transition to the autocatalytic mode.
Study of Sulphatizing Roasting Process Using Iron Sulphates for the Treatment of Zinc Leach Residue
Authors: Grudinsky Pavel , Podjelnikova Ekaterina , Dyubanov Valery
Published: May 2020

The paper presents the results of the investigation of zinc leach residue (ZLR) processing by sulphatizing roasting with iron sulphates FeSO4 and Fe2(SO4)3 followed by water leaching. The elemental and phase compositions of ZLR of JSC "Chelyabinsk Zinc Plant" were studied. Based on the thermodynamic calculations using HSC Chemistry 9.9 software, the temperature ranges of the sulphatizing roasting and the required amounts of iron sulphate additives for the sulphation of zinc and copper were determined. Subsequent experiments showed that recovery rates of zinc and copper reached 99.5% and 89.1% respectively, while iron remained in the leached residue. The results have indicated a high efficiency of sulphatizing roasting to transform zinc and copper contained in ZLR from ferrite to water-soluble sulphate.
Use of Nonferrous Metallurgy Waste: Clayey Portion of the Zircon-Ilmenite Ore Gravity Tailings and Pyrite Cinders in Tile-Making
Authors: Kairakbaev A.K. , Abdrakhimova E. S. , Abdrakhimov V.Z.
Published: May 2020

Studies have shown that using nonferrous metallurgy waste in the ceramic mixture for the making of roof tiles improves the final product quality; one can use the clayey portion of the zircon-ilmenite ore gravity tailings as the clay, pyrite cinders as leaners and sintering intensifier, and wollastonite as an agent to reduce shrinkage and prevent deformation-related buckling. The common method of linear regression was used to study the dependency of the basic physico-mechanical properties of tiles on how much clay from the zircon-ilmenite ore gravity tailings, pyrite cinders, and wollastonite is used in manufacture. The resultant mathematical model takes into account the combined effects these components have on the physico-mechanical properties of tiles; it matches well the experimental data.
Single Pellet Heating in Natural Gas Combustion Products in Mixture with Air and Oxygen
Authors: Voronov German V. , Glukhov Il'ya V.
Published: May 2020

Single pellet heating was considered at natural gas combustion product movement with oxidant flow coefficient of α=1.0 with air and oxygen in unconstrained volume. Physical parameters (density, dynamic and kinematic viscosity) and heat transfer properties (temperature, heat capacity, thermal conductivity, thermal diffusivity) of combustion products correspond to the average composition of gas delivered to the Ural region. Iron-ore pellet average properties were evaluated, based on major pellet plant data. Convection and radiant heat transfer coefficients were determined at pellet heating in natural gas combustion products in a mixture with air and oxygen. It was noted that, at switching to gas burning with oxygen radiant heat transfer to the pellet surface increases significantly, as compared to the convection one.
Specific Features of Thermal Performance of the Arc Steel Furnace in Unstable Properties Conditions of Burden Materials
Authors: Voronov German V. , Glukhov Il'ya V.
Published: May 2020

In the production of steel in a state-of-the art arc furnace, there are two serious issues, resulting from a decrease in bulk density of burden materials, and an increase in non-ferrous metals concentration. The paper presents the analysis results of changes in the chemical composition of iron-containing materials related with an increase in the content of non-ferrous metals: copper, tin, lead, antimony and unspecified metals in a given steel grade and a decrease in the bulk density of burden materials. A method of reducing impurities by means of using pellets produced from natural raw materials, that are pure in terms of impurities, is presented. A method of setting up charging of burden materials with different bulk density, using the filling coefficient of the furnace operating volume, is proposed. Combined burden materials that include various types of scrap and non-ferrous metals of iron-ore pellets, that are pure in terms of impurities, will ensure high-quality steel production.
Forming and Utilizing Ferrochromium Production Waste
Authors: Kascheev Ivan D. , Zhuchkov Vladimir I. , Zayakin Oleg V.
Published: May 2020

Analysis of forming chromium-bearing ferroalloys production waste in Russian Federation was performed. Chemical, phase, fractional compositions and physico-chemical, technological properties of high-carbon ferrochromium slag were defined. Physico-chemical, thermo-mechanical and thermo-physical properties of fire-resistant materials, obtained from ferrochromium production slag and dust, were researched. It was shown that researched waste may be utilized as raw for fire-resistant materials production. Because of their chemical and phase composition, researched materials may be utilized for production of forsterite-spinel-based and forsterite-spinel-periclase-based fire-resistant materials. Technological properties of researched materials allow obtaining dense strength fire-resistant materials. Such fire-resistant materials are promising in the field of ferrous metallurgy (lining up furnaces, ladles and overflow launders in ferroalloys production).
Reduction Smelting of Iron-Manganese-Ree Ores of the Tomtor Deposit
Authors: Zinoveev Dmitry , Dyubanov Valery , Delitsyn Leonid
Published: May 2020

The chemical and phase composition of iron-manganese rare-earth ores of the Tomtor deposit were investigated. It is shown that the ores contain a large amount of iron, manganese and rare earth metals. The thermodynamic calculation of reduction smelting was carried out. The reduction smelting of the ores at 1650 °C was investigated. The phase and chemical composition of the obtained slag and the alloy were studied. It is showed that obtained alloy is ferromanganese with a high content of carbon and phosphorus, and obtained slag has high content of REM.
Anodic Dissolution of Non-Ferrous Metals in a Glycerate-Alkali Electrolyte
Authors: Valnev Vladimir A. , Lobanov Vladimir G. , Lubnin Lev A.
Published: May 2020

Studies have been conducted to assess the possibility of refining a lead collector containing precious metals, with the aim of obtaining lead using an economically viable technology. Studied the patterns of anodic oxidation of lead and impurities in alkaline-water-glycerate electrolytes, depending on the concentration of sodium hydroxide and glycerol in the electrolyte, the potential sweep rate.
Structural Changes in the Aluminum - Magnesium System Alloy
Authors: Illarionov I.E. , Gilmanshina T.R. , Kovaleva A.A.
Published: May 2020

The purpose of this work is to study the structure and mechanical properties of an aluminum – magnesium system alloy after various types of heat treatment (quenching and ageing). The microstructure of an alloy has been studied by means of Zeiss OBSERVER.D1m microscope combined with a camera and image display on a monitor screen. Micro X-ray spectral analysis was performed by means of Carl Zeiss EVO 50 scanning electron microscope. The micro-hardness of the samples has been measured on prepared metallographic sections by means of DM8 micro-hardness meter. In the course of the process it has been found that quenching the Al-12,78% Mg alloy from temperatures of 430–440 ° C does not lead to the formation of a single-phase solid solution. Ageing at 100 ° C enables the formation of secondary phases. It was noted that with an increase in the quenching temperature, the micro-hardness increases slightly. An increase in the exposure time doesn’t influence greatly the micro-hardness of the alloy, while the structure remains practically unchanged.
Development of Cryptocrystalline Graphite Desulfurization Methods
Authors: Gilmanshina T.R. , Koroleva G.A. , Lytkina S.I.
Published: May 2020

Increasing demands on the quality of graphite cause carrying out detailed studies of its desulfurization. Combined sulfur present in natural graphite reduces the heat transfer coefficient, increases the heat energy consumption, pollutes the atmosphere with harmful emissions in the process of their application in various branches of industry. The technology and deepness of desulfurization is determined by the total content and ratio of various sulfur compounds in graphite. Previously, a number of technologies for cryptocrystalline graphite enrichment had been developed by the authors. However, the use of these technologies does not effectively reduce the sulfur content in the graphite composition. Therefore, the aim of this work is to develop activation methods that can reduce effectively the sulfur content in the composition of cryptocrystalline graphite. In order to reduce the total sulfur content, mechanical and electro-explosive-pulsing activation were tested. Mechanical activation of graphite was carried out in АGО-2, DCM, D-100 activator mills in different environments and at different activation time. To implement electric-explosive-pulsing activation, special equipment was used. In the process of the research it has been found that the use of mechanical activation and electric-explosive-pulsing activation does not reduce the sulfur content below 0.25 wt.%. Mechanical activation of graphite in different modes enables more intensive release of sulfide minerals from aggregate graphite formations and their intensive oxidation.
Improving the Quality of Production of Sand Core on Core Shooting Machines
Authors: Korotchenko A.Yu. , Khilkov D.E. , Khilkova A.A. , Tverskoy M.V.
Published: May 2020

The article is devoted to the study of the method of modeling the core shooting process of manufacturing core from cold hardening mixtures (CHM) in the software package Flow-3D, as well as consideration of recommendations on the parameters of the core shooting process, to ensure quality castings of cast iron and steel. This technology of production of cores belongs to technologies which are widely used in foundry production.
Shot Blasting Process Schematization for Rollers Using Slip-Line Method
Authors: Ogarkov Nikolay N. , Zvyagina Elena U. , Antropova Lyudmila I.
Published: May 2020

The considered theoretical analysis of the roughness parameters formation of the rolling face of the pinch pass mills, when they are indented with shot, allows to obtain more adequate and convenient theoretical results for use in practice. The formation of a rough layer on the rolling working surface of the pinch pass mill is determined by the impact and penetration of the shots into its surface. When this occurs, the elastic and plastic deformation of the roll materials and shot with the dimple formation and the displacement of a portion of the deformed roll material on the edges of this dimple takes place. The obtained results allow using the mathematical dependencies to control purposefully the process of shot blasting and correct it when texturing the working rolling faces of the pinch pass mills.
The Ways of Reaching the Specified Mode of Testing Samples for Torsion with Variable Strain Rate
Authors: Erpalov Mikhail , Pavlov Dmitry
Published: May 2020

The paper is devoted to the practical implementation of the new torsion testing method for studying rheological properties of materials in a hot state. This method involves the testing of cylindrical samples in the grips of a test setup, the angular velocity of which changes exponentially. The testing mode allows you to restore the hardening curves of a material according to the test results. This article aims to formulate the requirements for possible ways to implement the proposed testing method, and presents two different ways to obtain the specified exponential testing mode. The experience of their use on the test setup in the Ural Federal University indicates the feasibility of the new testing method, as well as the possibility of a smooth transition to the specified testing mode.
Kinematic and Dynamic Conditions in Metal Rolling of Porous Materials
Authors: Barkov Leonid A. , Samodurova Marina N. , Nevraeva O.A.
Published: May 2020

Mathematical modeling of plastic deformations in rolling consists in a consequent combination of the general energetic relationship in plasticity and the variation inequality expressed the principle of minimum of entire deformation energy. A real deformation state in a plastic zone beneath rolls and corresponding kinematic and dynamics conditions on the contact surface are considered as a limited one for the consequent approximate deformation states and are found out by the method of approximated approach. Any realization of this method on personal computers requires a rational construction of a kinematic-possible velocity field in the spatial domain on plastic flow. Using the ordinary propositions and a new assumptions the authors have constructed a simple kinematic-possible velocity field in the plastic zone beneath rolls. On the base of the consequent approach in which the general energetic relationship and the variation inequality are interrelated the authors have been able to find out the geometric, kinematic and dynamics characteristics of plastic deformation’s states in metal rolling.
Research the Effect of Stress-Pulse Regulation on the Process of Manual Arc Welding Technological Plates Made of AMg6 Alloy Sheet Material 4mm Thickness
Authors: Mikheev Vladimir A. , Demidova Marina M. , Alvarenga Roberto de , Zarembo Victor I.
Published: May 2020

The result of the effect of stress-pulse regulation on the process of manual arc welding with the connection of pulse generator is presented. Technology of stress-pulse regulation is accessible and easy to use: the equipment is so small that it can be applied in any convenient place. At the same time, there is a practical alignment of the microhardness of the zone of the base metal of the welded plates, the transition zone and the zone of the weld, which indicates the absence of residual stresses of the welded parts. The results of the research confirm the effectiveness and prospects stress-pulse regulation in any production.
Development of Technology for Welding Repair of Steel Housings Using a Combination of Ultrasonic Vibrations and Forced Cooling
Authors: Fatkullin Marat R. , Fayrushin Ayrat M. , Rizvanov Rif G.
Published: May 2020

Now, one of the most pressing issues in the development of petroleum engineering is increasing the efficiency of apparatus and machines, as well as reducing material, energy and labor resources. During operation, oil-refining equipment over time destroyed by welded joints due to the impact of power and temperature loads, corrosion, and other factors. The cause of damage in welded joints of oil and gas equipment can be justified by the occurrence in them of structural heterogeneity and residual stresses during and after welding. Today manual arc welding is almost the only applicable in the repair of equipment for oil and gas processing, which require welding operations. The high temperature source of energy and the difference in deformation properties of parts are the cause of the occurrence of substantial residual stresses, which cause a change in shape, a significant decrease in strength, a decrease in the corrosion resistance of the metal, which adversely affects the durability and reliability of the structure. At present, the technology of repair with due to manual arc welding with the concomitant heating of the defective area and subsequent heat treatment is used. A complex of simultaneously proceeding processes accompanies the welding process: thermal effects on the metal in the heat-affected zone, metallurgical processes in the weld pool and crystallization of the metal in the weld pool. The repair technology presented by us, which consists in a combination of ultrasonic shock vibrations and forced cooling during the welding process, allows to improve the mechanical properties of the welded joint, as well as to refuse to carry out heating during welding and subsequent heat treatment.
The Selection of Parameters for Automatic Welding of the Nuclear Reactors Pipelines
Authors: Ngo Gia Viet
Published: May 2020

In this paper, the author selected the optimal welding parameters, which allow to achieve a stable production of high-quality welded joints and gave the calculation method of welding parameters depending on the spatial position of the weld pool.
Changes in the Structure of Steel during Quenching in a Magnetic Field
Authors: Pustovoit Viktor N. , Dolgachev Yuri V. , Aref'eva L.P.
Published: May 2020

The structure of martensite obtained by quenching steel under the action of a constant magnetic field was studied. The kinetic changes of the martensitic transformation, caused by the action of a magnetic field, are expressed in the structure by an increase in the dispersity of the transformation products. Samples of steels C45, 100CrMn6 and 30HGSA were investigated. Dispersity was evaluated statistically in images obtained on light and electron microscopes. The specific surface area was measured and the parameters of the surface relief caused by martensitic transformation were studied. Experimental data show that after quenching in a magnetic field, a decrease in the volumetric strain of the transformation, an increase in the dispersity of packets of martensitic crystals and components of the packets are observed. It is concluded that an increase in dispersion and a fragmentation of the structure of martensite are mainly the result of multiplicative nucleation.
Research of Electrolyte Plasma Treatment Impact on Wear Resistance and Roughness of 18HN3MA-SH Steel
Authors: Satbayeva Zarina A. , Bayatanova Lyaila B. , Kozhanova R.S.
Published: May 2020

This work provides the results of research of the wear resistance of the surface of samples of low carbon structural of 18HN3MA-SH steel, subjected to electrolytic-plasma treatment by nitriding and carbonitriding. The effect of the structure on the surface wear resistance of steel is shown. Changes in abrasive wear and dry friction characteristics were studied depending on temperature and processing time. The results of studies of tribological tests show that after electrolytic-plasma nitriding, the wear resistance of steel 18HN3MA-SH increases by 1.5–2 times compared with the initial state. The observed effects can be explained by the flowing surface modification - the formation of a modified surface layer with the formation of hardening phases. The nature of changes in the surface roughness Ra of steel samples after cementation, carbonitriding and nitriding was studied.
Influence of the Powder Particle Size on the Denudated Zone Width at Selective Laser Melting
Authors: Khmyrov Roman Sergeevich , Ableyeva R.R. , Tarasova Tatiana Vasilievna , Gusarov A.V.
Published: May 2020

Mass transfer in the laser-interaction zone at selective laser melting influences the quality of the obtained material. Powder particles displacement during the formation of the single bead is experimentally studied. The so-called denudated zone was visualized by metallography. It was determined that increasing the powder particle size leads to widening the denudated zone. This can signify that the adhesion forces between powder particles prevail over the friction forces.
Investigation of Mechanical Properties of Anisotropic Materials Used in Rapid Prototyping Technologies
Authors: Perepelkina Svetlana , Makhmudova Karina , Kovalenko Pavel
Published: May 2020

In this paper, the tensile tests were carried out for the samples made of polylactic acid (PLA) with the use of fused deposition modeling (FDM) with various filling factors. The results of the study showed that the ultimate strength of 3D-printed parts non-linearly depends on the filling factor. In addition, the thermal analysis of the 3D printing process using a thermal camera was performed. The obtained results could be used for medical purposes, e.g. PLA parts can be used as implants in maxillofacial surgery. That kind of temporary implants should have cellular structure and enough strength to sustain external and internal loads.