“Challenges of Science” – 2023

Materials of International Practical Internet Conference “Challenges of Science”

ISSN 2707-9481, ISBN 978-601-323-356-7, 22 November 2023, Issue VI

Title: Bibliometric Analysis of Research Related to Digital Literacy Using the Scopus Database from 2017-2023

Authors: Begimbetova G.A., Retnawati H., Nogaibayeva A.A., Sansyzbayeva D.B., Triyono M.B.

Abstract: This research aimed to carry out a bibliometric analysis of research related to digital literacy using the Scopus-indexed articles database which was published from 2017-2023. To collect data, the author used a document Analysis or documentation instrument, and a sample of collected 665 articles from the Scopus publications was obtained through the application of the saturated sampling technique. The data were analyzed through the R Program Biblioshiny package. The first finding is that a steady rate of publications in the field of digital literacy was observed from 2017 (68 articles) up to 2022 (131 articles). The second finding is that keywords like “e-learning”, “digital literacies”, and “students” have higher bibliographical coupling indexes of 29, 26, and 23 respectively. For the third finding, the concepts of “e-learning” and “information literacy” are very important terms within their network. Besides, authors whose works had much attention have included “e-learning”, “digital storage,” “computer science”, “digital environment”, “education”, “curricula”, and “students” in their words. Based on these findings, the main recommendation is for researchers to make further investigations in order to discover why works including the keywords like “e-learning”, “digital literacies”, and “students” are mostly cited.

Keywords: digital literacy, bibliometric, e-learning, bibliographical coupling, information literacy, students.

Cite this article as: Begimbetova G.A., Retnawati H., Nogaibayeva A.A., Sansyzbayeva D.B., Triyono M.B. (2023). Bibliometric Analysis of Research Related to Digital Literacy Using the Scopus Database from 2017-2023. Challenges of Science. Issue VI, 2023, pp. 5-14. https://doi.org/10.31643/2023.01



Title: Career guidance for Generation Z: modern methods of professional orientation in a stress Period

Authors: Abutalip D., Yesbossyn M., Pertiwi F.D., Suleimen S.B., Kassymova G.K.

Abstract: This article examines the importance of modern career guidance methods for Generation Z, focusing on the methods and tools used to create effective career guidance. The article examines the unique features of Generation Z and how they differ from previous generations and shows the need for individual approaches to professional orientation. It also discusses the advantages of using the Gallup Professional Orientation Test and the DISC personality test to determine individual professional orientation. Additionally, the authors examine Generation Z from a psychological point and found out that they feel stressed; anxious even in the classroom environment. Recently, many Z generation people are university students that suffer from speaking and sharing their points of view. Therefore, overall grades deteriorate noticeably. As a result, cognitive-behavioral therapy is the best method to cope with stress. Overall, this article contains valuable information for educators, career counselors, and professionals working with Gen Z to improve their professional development and future career prospects.

Keywords: Generation Z, career, test, CBT, stress, anxiety, speaking, students.

Cite this article as: Abutalip D., Yesbossyn M., Pertiwi F.D., Suleimen S.B., Kassymova G.K. (2023). Career guidance for Generation Z: modern methods of professional orientation in a stress Period. Challenges of Science. Issue VI, 2023, pp. 15-21. https://doi.org/10.31643/2023.02



Title: Integrating Continuing professional development with Education system reform in Kazakhstan

Authors: Zharylkassyn M.B.

Abstract: In the past few decades, the central position of teachers ensuring the quality of education has become increasingly acknowledged internationally. This article considers the reformation of education policy trends regarding teachers' education in Kazakhstan. State policy in the country recognizes education as a priority for social and economic development, with a focus on strengthening the practical training of teachers. It also addresses the challenges faced by state teachers and examines the significant changes to the structure and delivery of teacher education in Kazakhstan since 2011. The paper concludes with a discussion of the author's concerns and recommendations for the future of initial teacher education, with specific reference to the Kazakhstani education system.

Keywords: Continuing Professional Development, professional development, teacher education, education reforms.

Cite this article as: Zharylkassyn M.B. (2023). Integrating Continuing professional development with Education system reform in Kazakhstan. Challenges of Science. Issue VI, 2023, pp. 22-28. https://doi.org/10.31643/2023.03



Title: Features of the Development of communication skills of younger students in inclusive education

Authors: Lyskova G.T, Safeek N.M., Arpentieva M.R., Ponniah K., Koptyaeva S.V.

Abstract: A teacher working in an inclusive class needs to build communication in such a way as to ensure the inclusion of children with special educational needs (hereinafter referred to as SEN) in communication with normotypical children by developing their communication skills. The purpose of the article is to analyze research on the problem of the formation of communicative skills of younger students in the framework of the educational process in the context of inclusive education. The scientific novelty and theoretical significance of the study lie in the development of the foundations of an integrative approach to the study and formation of communicative skills of younger students in an inclusive class. The methodological basis of the study is a systematic and competence-activity approach to understanding the problems of the formation of communicative skills. Research methods include theoretical and empirical analysis of the problem and reflection of the results of the ascertaining and formative stages of experimental research. The results of the experiment indicate significant and numerous changes in various aspects of the communicative skills of schoolchildren, the need to introduce joint games and other forms of joint activities of schoolchildren from inclusive classes into the educational program, contributing to the harmonization of relations between them, the development of schoolchildren as individuals, partners, and students, improving performance and satisfaction with educational relationships. The prospect of the study is the further development of an integrative approach, the improvement of the system of means and conditions that contribute to the formation of the development of communicative qualities, communicative actions, and speech skills - the communicative skills of students in general, the development of a system of recommendations that allow future and working teachers to increase their aspirations and skills in the sphere of formation of communicative skills of schoolchildren.

Keywords: primary school student, communication skills, inclusive education, inclusive class, a student with SEN, special educational needs.

Cite this article as: Lyskova G.T, Safeek N.M., Arpentieva M.R., Ponniah K., Koptyaeva S.V. (2023). Features of the Development of communication skills of younger students in inclusive education. Challenges of Science. Issue VI, 2023, pp. 29-39. https://doi.org/10.31643/2023.04



Title: Inclusive Health-Saving Education: Ecological Model of Modern Educational Relations

Authors: Stepanova G.A., Kassymova G.K., Arpentieva M.R., Kurmanbai D.B., Lyskova G.T.

Abstract: : An ecological approach to understanding health saving in inclusive educational relationships means that the goal of the teacher and students is to build such relationships and implement such processes and forms of interaction in which “everyone and every one” of the participants wins, a consensus is reached as the point at which they find their best satisfaction. This requires a clear understanding of what is and what is not education and society, what is and what is not a person and society, what is and what is not development and harmony, and what is and what is not transparency and health. The purpose of the study is to analyze the ecological approach to understanding health saving in inclusive educational relations. The research method is a theoretical analysis of the ecological approach to understanding health saving in inclusive educational relations. Inclusive health-saving education is discussed as a part of the ecological model of modern educational relations. Inclusive health-saving education is a part of the ecological model of modern educational relations. Within the framework of exclusive school education, ignoring the tasks of health protection and development, there is a high chance of negative impact, mathetogenesis, and pediogenesis, it is difficult for an individual to become a student, to realize the existence of different strategies, forms, and types of learning activity and learning relationships. Thanks to inclusion, people can experience themselves and the world as different, in different situations. Inclusion allows minimizing (prevention), overcoming (correction and development, or rethinking many problems of an individual or group).

Keywords: inclusiveness, educational relations, health saving, ecological approach to understanding health saving, inclusive educational relations.

Cite this article as: Stepanova G.A., Kassymova G.K., Arpentieva M.R., Kurmanbai D.B., Lyskova G.T. (2023). Inclusive Health-Saving Education: Ecological Model of Modern Educational Relations. Challenges of Science. Issue VI, 2023, pp. 40-52. https://doi.org/10.31643/2023.05



Title: Improving students' cognitive processes to enhance the quality of education

Authors: Bekmurzayeva S., Begimbetova G.A., Karibayeva L., Yuqi F., Hebebci M.T., Leong T.Kh.

Abstract: : This article discusses the problem of improving the quality of students' knowledge by improving their cognitive processes in the educational environment. The purpose and content of the modern educational paradigm are to focus on the free and comprehensive development of future generations, self-education, competitiveness, successful life as a business person, the education of students, their quality of education, and the education of a responsible, humane citizen. Much research is being carried out in this direction. However, the problems of improving students' cognitive processes and improving their knowledge quality require particular study. There are contradictions between the definition of pedagogical conditions for the development of cognitive processes of students and the need to determine their effective ways. The authors found that the concept of cognitive has different meanings. Improving students' cognitive processes at an early age can significantly improve the quality of knowledge. Various research methods were used, including a theoretical analysis of literature, an express questionnaire, and a question-and-answer questionnaire "designed to improve the cognitive processes of students." The studied questions in this article will be helpful for those who are engaged in the education and upbringing of students, including parents and teachers, as well as psychologists and sociologists.

Keywords: Cognition, education, student, learning theory, cognitive processes.

Cite this article as: Bekmurzayeva S., Begimbetova G.A., Karibayeva L., Yuqi F., Hebebci M.T., Leong T.Kh. (2023). Improving students' cognitive processes to enhance the quality of education. Challenges of Science. Issue VI, 2023, pp. 53-61. https://doi.org/10.31643/2023.06



Title: Complex Ni and Co Extraction from Leached Nontronitized Serpentinite via Hydrometallurgical Process at Atmospheric Pressure

Authors: Smailov K.M., Nuruly Ye.

Abstract: The growing significance of mineral processing processes in the contemporary mining and processing industry lies in their aim to augment the concentration of valuable constituents within processed natural raw materials. Predominantly, these processes encompass pyrometallurgy, hydrometallurgy, and electrometallurgy. Each method can extract nickel; however, the high energy demand of pyrometallurgy necessitates a shift toward refining the efficiency of hydrometallurgical procedures. Consequently, optimizing nickel-containing ore processing technologies to yield high-purity nickel and its compounds is a current research concern. This paper investigates the hydrometallurgical processing of nickel and cobalt via leaching, specifically targeting oxidized nickel-cobalt ore. Analytical studies reveal a promising potential for complex extraction of nickel and cobalt, achieving impressive yields of 98.4% and 90.7%, respectively. Our analysis further demonstrates that implementation of this method can notably elevate the extraction degree of targeted metals. Significant energy resource conservation is made possible by conducting extraction at a moderate temperature of 353K and at atmospheric pressure. Importantly, this approach facilitates the extraction of valuable components even from ores containing negligible concentrations. This scientific endeavor enhances our understanding of efficient, sustainable practices in the field of mineral processing, demonstrating the potential of hydrometallurgical methods for nickel and cobalt extraction.

Keywords: Hydrometallurgy, nickel and cobalt extraction, leaching process, energy efficiency, mineral processing.

Cite this article as: Smailov K.M., Nuruly Ye. (2023). Complex Ni and Co Extraction from Leached Nontronitized Serpentinite via Hydrometallurgical Process at Atmospheric Pressure. Challenges of Science. Issue VI, 2023, pp. 62-71. https://doi.org/10.31643/2023.07



Title: Cognitive Abilities of Senior High School Students

Authors: Suryani Y.E., Putro N.H.P.S., Retnawati H., Khamit Zh.

Abstract: The Scholastic Assessment Test is a test used to measure cognitive abilities. The Scholastic Assessment Test predicts prospective students who are able to complete their studies in college well and on time. This study aims to (1) describe the cognitive abilities of high school students through the scores of the Scholastic Assessment Test on Computer-Based Written Examination in 2021; (2) find out the subtest that has the most influence on the Scholastic Assessment Test score. This study uses secondary data, namely the mean score of the SMA/MA Scholastic Assessment Test in the province of Yogyakarta Special Area which is included in the Top 1000 results of the 2021 Computer-Based Written Examination. In the Province of Yogyakarta Special Area, there are 83 schools that fall into the Top 1000 category with details: 28 Senior High Schools in Yogya City, 23 schools in Sleman Regency, 18 schools in Bantul Regency, 7 schools in Gunung Kidul Regency, and 7 schools in Kulon Progo Regency. The data analysis methods used in this study were descriptive statistics and multiple regression analysis. The results of data analysis show that the highest average of students’ cognitive ability in the low group is reading comprehension and writing ability, in the medium group the highest average is reasoning ability, and in the high group, the highest average is quantitative ability. Based on the results of the regression analysis, it can be seen that the reasoning ability subtest has the greatest contribution to the Scholastic Assessment Test scores of high school students in the Special Area of Yogyakarta.

Keywords: Cognitive ability, Computer-Based Written Examination, Scholastic Assessment Test.

Cite this article as: Suryani Y.E., Putro N.H.P.S., Retnawati H., Khamit Zh. (2023). Cognitive Abilities of Senior High School Students. Challenges of Science. Issue VI, 2023, pp. 72-78. https://doi.org/10.31643/2023.08



Title: Stress-strain state of rock mass around pillars and chambers considering the angle of occurrence of the ore body

Authors: Tutanov S.K., Tutanova M.S.

Abstract: The task of the study is to determine the parameters of the unstable-deformed state of the rock mass around the targets and the chamber at various angles of occurrence of the ore body. A vertical section of a rock mass is considered. The deformation along the chamber can be neglected and the task is reduced to flat. The number of methodical finite elements is taken as the solution method. To solve the problem, the characteristic conditions of cleaning chambers and tar-gets are modeled. The geometric parameters of the design scheme succeeded with the maximum approximation to real conditions. The characteristic of a solid body and host rocks is given by the modulus of elasticity, Poisson's ratio, and volumetric weight.

Keywords: Rock mass, cleaning chambers, host rocks, tensile stresses, multidimensional mathematical models.

Cite this article as: Tutanov S.K., Tutanova M.S. (2023). Stress-strain state of rock mass around pillars and chambers considering the angle of occurrence of the ore body. Challenges of Science. Issue VI, 2023, pp. 79-83. https://doi.org/10.31643/2023.09



Title: Smart control system for optimal energy use in the oil and gas sector

Authors: Tasmurzayev N.M., Shinassylov Sh.Z., Amangeldy B.S., Nurakhov Ye.S., Bekele S.D.

Abstract: This paper delves into the development of a smart control system for air conditioning and heating within the oil, gas, and energy sectors. It explores techniques for creating an automated sensor monitoring framework and adjusting sensor settings for temperature and air conditioning management. The proposed intelligent HVAC (Heating, Ventilation, and Air Conditioning) system acquires live data from temperature and leak sensors, along with air conditioning units and switches. The paper introduces the system's structure, its operational principles, schematic representations of the control module, and the monitoring and management setup. The core component of the real-time monitoring and management system is realized through the utilization of the SCADA software for the control and supervision of sensor parameters.

Keywords: Industrial Internet of Things, intelligent Control System, sensor network, real-time monitoring system, energy efficiency.

Cite this article as: Tasmurzayev N.M., Shinassylov Sh.Z., Amangeldy B.S., Nurakhov Ye.S., Bekele S.D. (2023). Smart control system for optimal energy use in the oil and gas sector. Challenges of Science. Issue VI, 2023, pp. 84-91. https://doi.org/10.31643/2023.10



Title: Digital Twin of Urban Heat Networks: Optimization of Energy Systems

Authors: Bekibaev T.T., Zhapbasbaev U.K., Ramazanova G.I., Flindt N., Rohde N.

Abstract: The paper discusses the concept and importance of the digital twin of a heat network for modern energy systems. A digital twin is a virtual representation of a real heat network, which allows system operators to efficiently manage and optimize heat supply operations. The advantages of using digital twins are in predicting network efficiency and reducing energy losses. The main stages of creating a digital twin of heat networks are given, as well as the required functionality for thermal-hydraulic calculations. As an example, the process of creating a digital twin for the heating network of Pavlodar city is described.

Keywords: Digital twin, heat network, efficiency optimization, thermal-hydraulic calculations.

Cite this article as: Bekibaev T.T., Zhapbasbaev U.K., Ramazanova G.I., Flindt N., Rohde N. (2023). Digital Twin of Urban Heat Networks: Optimization of Energy Systems. Challenges of Science. Issue VI, 2023, pp. 92-102. https://doi.org/10.31643/2023.11



Title: Modern trends in waste recycling technologies of incinerators

Authors: Shadrunova I.V., Kolodezhnaya E.V.

Abstract: In 2021, the Government of the Russian Federation set the executive authorities the task of decarbonizing Russian industry and developing an action plan for the transition to carbon regulation and sequestration of carbon dioxide emissions. One of the directions of carbon dioxide sequestration is mineral carbonation. The idea of the work is to use mineral carbonation, as an alternative to natural mineral raw materials, slags from the combustion of solid non-combustible waste. The technology of carbon sequestration by mineral carbonation of technogenic raw materials is at the research stage, therefore it is necessary to assess the potential of using waste incinerators. To solve the tasks, the material composition of the slags of one of the incinerators was studied in detail. The possibility of slag enrichment with the production of copper-containing preconcentrate has been established. The content of minerals capable of participating in carbonation was determined, and the carbonation potential was estimated based on the calculated values. The requirements for man-made waste for their use as raw materials for carbonation are formulated. The factors that have a restraining effect on the introduction of mineral carbonation technologies are highlighted.

Keywords: Incinerators, slag from incineration of non-combustible waste, carbon sequestration, carbonation potential, extraction of copper from technogenic raw materials.

Cite this article as: Shadunova I.V., Kolodezhnaya E.V. (2023). Modern trends in waste recycling technologies of incinerators. Challenges of Science. Issue VI, 2023, pp. 103-107. https://doi.org/10.31643/2023.12



Title: RANS modeling of the transition of a non-isothermal flow of a Newtonian fluid to a viscoplastic state in a pipe

Authors: Pakhomov M.A., Zhapbasbayev U.K.

Abstract: A mathematical model of the movement and heat transfer of a turbulent non-isothermal non-Newtonian fluid through a pipe wall with a cold surrounding space has been developed and simulated numerically. Fluid turbulence is described in the framework of the isotropic two-parameter k– model. The Newtonian properties of the fluid in the initial cross-sections of the pipe transformed gradually into a viscoplastic non-Newtonian Bingham-Schwedoff fluid state due to heat transfer through the pipe wall between the heated fluid and a cold environment. The value of its streamwise velocity in the axial zone increased significantly when the fluid moved along the pipe. On the contrary, it decreased in the near-wall zone and the height of the region with a zero fluid velocity increased. This occurred due to the viscoplastic properties of a non-Newtonian fluid. The height of the region with a zero fluid velocity in the pipe increased gradually as the non-Newtonian fluid (waxy crude oil) moved through the pipe. A noticeable increase in the level of turbulent kinetic energy in the axial zone of the pipe and its noticeable decrease in its near-wall region were observed. A significant increase in the average dynamic viscosity and yield stress in the near-wall part of the pipe was shown. The boundary of the area of existence of Newtonian properties of fluid was determined. The height of the region with a zero fluid velocity in the pipe increased gradually as waxy crude oil moved through the pipe and reached y/R ≈ 0.1 at x/D = 15.

Keywords: RANS, Newtonian and non-Newtonian fluids, Bingham-Schwedoff fluid, viscoplastic, yield stress, turbulent flow, heat transfer.

Cite this article as: Pakhomov M.A., Zhapbasbayev U.K. RANS modeling of the transition of a non-isothermal flow of a Newtonian fluid to a viscoplastic state in a pipe. Challenges of Science. Issue VI, 2023, pp. 108-123. https://doi.org/10.31643/2023.13



Title: Intra-school control - as part of the management system of an educational institution

Authors: Uteshkalieva A.M., Madeniyetova Z.A.

Abstract: This article provides an explanation of intra-school control as part of the management system of an educational institution. The pedagogical activity of any school is characterized by comprehension of the accumulated work experience, the search for new ideas, the achievement of a high level of pedagogical excellence in the organization of educational activities, the emergence and dissemination in the pedagogical, parental, and managerial environment. and a new understanding of the values of education, when education becomes a priority in the lives of the younger generation. And in every school, one of the real levers for such development is the apparatus of intra-school control. In-school observation should be motivated and stimulating, based on knowledge of the capabilities and interests of all participants in the educational process. On the one hand, its result is a qualitative improvement in relations within a certain group and between them, on the other hand, it contributes to the degree of professional growth and achievements of teachers and students.

Keywords: Intra-school control, forms, types, forms, methods, principles of intra-school control.

Cite this article as: Uteshkalieva A.M., Madeniyetova Z.A. Intra-school control - as part of the management system of an educational institution. Challenges of Science. Issue VI, 2023, pp. 124-129. https://doi.org/10.31643/2023.14



Title: Investigation of the structural properties of amorphous films obtained by high-frequency magnetron sputtering

Authors: Tursyn Ye.

Abstract: This article presents a study of amorphous films obtained using the high-frequency magnetron sputtering (HFMS) method and their potential applications in various industries. Materials play a crucial role in the modern world, and the development of new materials with unique structural and functional properties has become a paramount task in the scientific and engineering community. HFMS is a powerful method for synthesizing amorphous materials with high structural purity and controllable properties. The article commences with a description of the experimental setup and methods for obtaining amorphous films using HFMS, including the operational principles of the equipment, the selection of materials for sputtering, and process parameters. Special attention is given to the magnetron as a key component of the setup. Subsequently, the article explores various fields of application for amorphous films obtained through HFMS, including integrated circuits, sensors, solar cells, medical devices, optical coatings, and more. HFMS provides the capability to create materials with specific characteristics, making it an essential tool for developing novel materials and enhancing existing technologies. The study of amorphous films and their applications in diverse industries constitutes a significant area of scientific research, and this article offers an overview of synthesis methods and potential material applications.

Keywords: Amorphous films, high-frequency magnetron sputtering (HFMS), structural properties, material applications, synthesis methods.

Cite this article as: Tursyn Ye. (2023). Investigation of the structural properties of amorphous films obtained by high-frequency magnetron sputtering. Challenges of Science. Issue VI, 2023, pp. 130-132. https://doi.org/10.31643/2023.15



Title: Studying the influence of electrolyte composition on the structure and properties of the surface layer of aluminum alloys during plasma-electrolytic processing

Authors: Kydyrmolla M.K., Smagulov D.U., Ybyraiymkul D.T.

Abstract: Plasma electrolytic oxidation (PEO) is a new processing process used primarily to produce a thick and dense surface layer of metal oxides, especially light metals, to improve wear and corrosion resistance. If we compare the surface layers obtained by the PEO method with the surface layers obtained by conventional anodic oxidation, then, first of all, they are more resistant to wear and corrosion. It is widely used in mechanical engineering, petrochemical, and biomedical industries. Many studies have been carried out to determine the characteristics of surface layers obtained by PEO. This review attempts to summarize and explain some fundamental aspects of the PEO process, the formation mechanism of the surface layer, the processing conditions affecting the process, the main characteristics of the process, and the mechanical and tribological properties. In addition, recent developments in nanocomposite surface layers and their applications are discussed with examples. It also highlights the importance of this process, its current trends, and the scope of future work. In this case, pay attention to the breakdown of dielectrics, which appears several times on the surface of the workpiece. These discharges play a central role in the process since it is mainly due to the associated plasma that the substrate is oxidized and the coating is formed. The details are complex because discharge characteristics are affected by a number of processing parameters. The relationship between electrical conditions, electrolyte composition, surface microstructure, and rate of discharge performance has become clearer in recent years, and these improvements in understanding are summarized here. There is a significant opportunity to more effectively control the process with specific objectives in terms of coating performance and energy efficiency, and efforts are being made to identify the key factors that contribute to this.

Keywords: Plasma electrolytic oxidation, electrolyte composition, aluminum alloys, oxidation process, surface layer, corrosion resistance, mechanical properties, sulfuric acid, chromic acid, oxalic acid, wear resistance.

Cite this article as: Kydyrmolla M.K., Smagulov D.U., Ybyraiymkul D.T. (2023). Studying the influence of electrolyte composition on the structure and properties of the surface layer of aluminum alloys during plasma-electrolytic processing. Challenges of Science. Issue VI, 2023, pp. 133-144. https://doi.org/10.31643/2023.16



Title: Numerical simulation of turbulent airflow in a room using the OpenFOAM package

Authors: Abdimutalipova Z.K., Kurbanaliev A.Y.

Abstract: The results of numerical modeling of turbulent airflow in a room using the computational fluid dynamics approach to solve the Reynolds-averaged Navier-Stokes equation for a fluid are presented. First, a two-dimensional model was studied; the focus is on mesh refinement, the effect of mesh topology, and the influence of the turbulence model. The structured grid results were found to be in better agreement with available experimental measurements. Dimensionless velocities for various turbulence models are presented and compared: standard k-ε, standard k-ω, RNG k-ε, k-ω SST. The results explain that all turbulence models produce almost identical results.

Keywords: Plain jet, turbulence models, RNG k-ε, k-ω SST, ventilation.

Cite this article as: Abdimutalipova Z.K., Kurbanaliev A.Y. (2023). Numerical simulation of turbulent airflow in a room using the OpenFOAM package. Challenges of Science. Issue VI, 2023, pp. 145-150. https://doi.org/10.31643/2023.17



Title: Exploring Pre-service Teacher’s Knowledge of Content and Teaching (KCT) and Computational Thinking: The Case of Addition and Subtraction

Authors: Rakhmawati Y., Retnawati H., Sugiman S., Kassymova G.K., Kudyarova G.

Abstract: This research discusses the knowledge of content and teaching (KCT) and computational thinking (CT) of pre-service elementary school teachers on student work results. How much do pre-service teachers deepen students' thinking about the concepts of addition and subtraction? This research aims to get an overview of pre-service teachers' thinking about KCT and CT so that the results can be used to determine educational policies for developing human resource capabilities in elementary schools. The subjects of this research were three pre-service teachers at elementary school that selected by purposive sampling. The criteria for pre-service teachers are those who have taken basic concepts of mathematics, mathematics education, and mathematics development. The subjects in the low, medium, and high categories from state universities with A accreditation in Yogyakarta, Indonesia. The type of research is a case study. The research instruments namely the results of elementary school students ' work about addition and subtraction, then interview instruments to give an idea of how deeply they think about the material. The KCT’s findings are that pre-service teachers do not understand the Van De Walle concept of addition and subtraction, do not understand the prerequisites for addition and subtraction material, and pre-service teachers find unique ways of learning from students. In the CT component, there are two components that appear in them, namely pattern recognition and decomposition. An interesting finding was that pre-service teachers only learned about the Van de Walle technique after seeing the results of the work carried out by students. This means that previously they did not use those techniques at all. This picture shows that pre-service teachers' KCT and CT is still not optimal, so further, and in-depth research is needed to explore their understanding.

Keywords: Knowledge of content and teaching (KCT), computational thinking, pre-service teacher, mathematics, addition and subtraction.

Cite this article as: Rakhmawati Y., Retnawati H., Sugiman S., Kassymova G.K., Kudyarova G. (2023). Exploring Pre-service Teacher Knowledge of Content and Teaching (KCT) and Computational Thinking: The Case of Addition and Subtraction. Challenges of Science. Issue VI, 2023, pp. 151-159. https://doi.org/10.31643/2023.18



Title: Crystal Plasticity Finite Element Method (CPFEM): state-of-the-art

Authors: Ahmad Gemeal

Abstract: A brief discussion is given for crystal plasticity finite element method, reasons of its importance and its microscopic and macroscopic applications. Also, discussions were made for its primary engineering objectives and its further related applications. Chronological brief of evolution of its two legs: finite element method and crystal plasticity was also captured. Chronological brief of necessities and developments of new models was also tracked.

Keywords: Crystal plasticity, Twinning, Indentation, Multiphase steel, Anisotropy.

Cite this article as: Ahmad Gemeal (2023). Crystal Plasticity Finite Element Method (CPFEM): state-of-the-art. Challenges of Science. Issue VI, 2023, pp. 160-175. https://doi.org/10.31643/2023.19



Title: On the feasibility of producing locally modified metallic materials with controlled gradient of properties

Authors: Chumanov I., Anikeev A., Sedukhin V.

Abstract: Metallurgy and engineering endeavours to develop and implement advanced technologies to save metal and create new metallic materials with improved characteristics. These scientific and technological activities include improvements to existing materials as well as the development of new materials by various methods. One such method is the creation of iron-based materials with a gradient of properties along the cross-section, obtained by locally modifying a given volume of the formed billet by filling the structure with heat-resistant, high-strength, dispersed phases. This paper describes the course and results of a number of experiments on the formation of a gradient of properties in steel castings of various compositions, and analyses the results of experiments on the creation of such materials.

Keywords: metal melts; dispersed particles; centrifugal casting; dispersed hardening; microstructure; properties.

Cite this article as: Chumanov I., Anikeev A., Sedukhin V. (2023). On the feasibility of producing locally modified metallic materials with controlled gradient of properties. Challenges of Science. Issue VI, 2023, pp. 176-179. https://doi.org/10.31643/2023.20



Title: About economic efficiency of electroslag refining process of iron-rich raw material

Authors: Chumanov I., Anikeev A., Sergeev D.

Abstract: The question of efficiency of use of metalized pellets for production of consumable electrodes subjected to electroslag remelting process in order to obtain metal pure in phosphorus and impurities of non-ferrous metals is considered. Analytical estimation of the processes occurring during the interaction "pellet - ligature" has been made, which allowed to obtain optimal parameters for the formation of consumable electrode from ligature and metallized pellets. The experimental estimation of temperature interval of pellets preheating 300...500 °C was carried out. The optimum temperature of pellets preheating is determined, which is 400 °C. The obtained prototypes are investigated and it is established that pellet preheating up to 400 °C allows to obtain fusion of pellet surface layers with ligature. The technology of formation of expendable electrodes from metalized pellets by pouring liquid ligature into a special liner with a polystyrene rod pre-installed in it has been developed.

Keywords: iron, raw material, slag, refining process, costs of production.

Cite this article as: Chumanov I., Anikeev A., Sergeev D. (2023). About economic efficiency of electroslag refining process of iron-rich raw material. Challenges of Science. Issue VI, 2023, pp. 180-183. https://doi.org/10.31643/2023.21



Title: Analysis of numeracy ability test item characteristics grade VIII students with mixed model item response theory (IRT) approach

Authors: Alan Rifqi Kamal, Edi Istiyono

Abstract: Basic knowledge of mathematics is essential for solving problems contextually. Mathematics has a function for the development of the ability to calculate, measure, find, and use mathematical formulas that can provide students with an understanding of concepts related to life phenomena. One ability that is synonymous with understanding problems contextually is numeracy ability. Numeration has a main focus, namely the ability of students to formulate, apply, and be able to interpret mathematics in various contexts that include mathematical reasoning and using mathematical concepts, methods, facts, and auxiliary media, explaining, and predicting phenomena in everyday life. This study aims to determine the construct of numeracy ability test instruments for class VIII public junior high school students in Pekalongan Regency, determine the quality of numeracy ability test instruments for class VIII public junior high school students in Pekalongan Regency, and determine the numeracy ability profile of class VIII public junior high school students in Pekalongan Regency. This research method approaches quantitatively by developing instruments using CFA and IRT mixed models. This research was conducted at the junior high school level within the scope of the education office of Pekalongan Regency, Central Java Province, by taking 6 schools as samples. Content validity using Aiken V and Cronbach Alpha reliability as well as item characteristics with mixed IRT and descriptive analysis. The results of this study, namely (1) Construction of numeracy ability instruments for grade VIII State Junior High School students, which are related to the content of algebra, numbers, geometry, and measurement, as well as data and uncertainty. In addition, using personal, socio-cultural, and scientific contexts, using cognitive levels of understanding, application, and reasoning, (2) The quality of numeracy ability instruments is declared valid and reliable, and in construct validity all items are fit as seen from the Loading Factor Standardized Solution value of more than 0.3 and p-value < 0.05 and the reliability of the high category and the estimated characteristics of the items show that the question items are included in the category both in terms of difficulty, and (3) The numeracy ability of junior high school students in Pekalongan Regency shows that there are 36 students out of 599 students classified as proficient with a percentage of 6%, 139 students out of 599 students classified as proficient with a percentage of 23%, 390 students out of 599 students classified as basic with a percentage of 65%, and 34 students out of 599 students classified as needing special intervention with a percentage of 6%.

Keywords: Item Characteristics, Numeracy Ability, Mixed Model Item Response Theory (IRT).

Cite this article as: Alan Rifqi Kamal, Edi Istiyono (2023). Analysis of numeracy ability test item characteristics grade VIII students with mixed model item response theory (IRT) approach. Challenges of Science. Issue VI, 2023, pp. 184-195. https://doi.org/10.31643/2023.22



Title: Analysis of the distractor of the multiple-choice test using classical test theory (CTT) and item response theory (IRT)

Authors: Ihda Mutimmatul Fitriyah, Heri Retnawati

Abstract: This study aimed to analyzed the functional distractor based on the results of the multiple-choice test using CTT and IRT. Data obtained mathematics test at one of the junior high schools (grade 7) in Sidoarjo in the 2021-2022 academic year. The test consists of 20 items, which are a collection of questions that have been standardized in the school curriculum. One hundred examinees attending this mathematics test. The analysis used Iteman 4.3 software for analysis distractor using CTT, and R program for analysis pseudo-guessing’s parameter using 3PL IRT model. The result showed that all items have distractors well function it (Prop. > 0,05) in CTT. Meanwhile, with IRT, 8 of the 20 questions were not good because the pseudo-guessing index was > 0.25. The result of this study provided important information for future study to examine the ability estimate when a test's fixed feature is the item-specific characteristic utilized for pseudo-guessing.

Keywords: Distractor, Pseudo-guessing, classical test theory, item response theory.

Cite this article as: Ihda Mutimmatul Fitriyah, Heri Retnawati (2023). Analysis of the distractor of the multiple-choice test using classical test theory (CTT) and item response theory (IRT). Challenges of Science. Issue VI, 2023, pp. 196-203. https://doi.org/10.31643/2023.23



Title: Trends and Network Analysis of Data Literacy in Various Fields: Bibliometric Analysis

Authors: Rina Safitri, Syahri Ramadan, Rugaya Tuanaya, Heri Retnawati

Abstract: Data literacy has emerged as a key aspect in meeting the challenges of the evolving digital age. However, existing bibliometric analyses related to this topic are scarce. To fill the gap, this study uses a bibliometric approach to conduct a comprehensive review spanning nearly seven decades in order to assess the research landscape, progress, and emerging trends in data literacy. This article presents a new review of scientific production through an in-depth bibliometric analysis of the Scopus database using two software packages namely VOSviewer and RStudio. The article presents a synthesis of 2896 peer-reviewed articles from 1956 to 2023. Using keyword and co-occurrence analyses to identify key trends and relationships in research on this topic. Researchers highlighted the most researched concepts and the most important relationships between different publications. The analysis process was conducted by presenting the publication time, disciplinary area, scientific publications on data literacy, prolific authors, most cited publications, productive scientific countries, and keyword co-occurrence analysis on this topic.

Keywords: Bibliometrics, data literacy, scientific research.

Cite this article as: Rina Safitri, Syahri Ramadan, Rugaya Tuanaya, Heri Retnawati (2023). Trends and Network Analysis of Data Literacy in Various Fields: Bibliometric Analysis. Challenges of Science. Issue VI, 2023, pp. 204-212. https://doi.org/10.31643/2023.24



Title: Academic Research of the Protective Ability of Zinc-Filled and Epoxy Polyamide Paint Coatings against Atmospheric and Soil Corrosion

Authors: Duysembaev I.S., Sharipov R.Kh., Zhambakin D.K., Didukh A.G., Ivashov N.A., Abdukhalykov D.B. El-Sayed Negim

Abstract: Currently, zinc-filled coatings capable of providing protection against corrosion through a barrier and tread mechanism are becoming increasingly widespread. When exposed to an aggressive environment, the coating prevents steel corrosion by “healing” the damage. In this way, the corrosion process slows down, and the by-products formed during the activation of zinc are able to fill the space left by the defect. The article presents a description of the principle of “healing” with such coatings, as well as the results of laboratory and field tests carried out in order to study data on the effectiveness of protective characteristics in comparison with the traditionally used epoxy polyamide coating with parallel operation of electrochemical protection. It was noted that laboratory tests confirmed the “restorative ability” of the zinc-filled coating to prevent the formation of corrosion in places of applied defects.

Keywords: corrosion, paint and varnish coatings, corrosion protection, steel, zinc-filled coating.

Cite this article as: Duysembaev I.S., Sharipov R.Kh., Zhambakin D.K., Didukh A.G., Ivashov N.A., Abdukhalykov D.B. El-Sayed Negim (2023). Academic Research of the Protective Ability of Zinc-Filled and Epoxy Polyamide Paint Coatings against Atmospheric and Soil Corrosion. Challenges of Science. Issue VI, 2023, pp. 213-219. https://doi.org/10.31643/2023.25



Title: Thermodynamic studies of the binary system of magnesium with the alloying metal – beryllium

Authors: Nitsenko A., Linnik X.

Abstract: The results of studies to obtain thermodynamic constants of condensed and vapor phases of binary systems of magnesium with beryllium are presented in this paper, and liquid-vapor phase transitions at atmospheric pressure and in vacuum are also constructed. Mg - Be alloys of a given composition were prepared as a result of this work. The partial pressures of magnesium over binary alloys with beryllium were determined with the use of the boiling point method (isothermal variant). The partial vapor pressure of beryllium was found by numerical integration of the Gibbs-Duhem equation. The partial pressures of magnesium and beryllium are represented by temperature-concentration dependences. The boundaries of melt and vapor coexistence fields of magnesium-beryllium system at atmospheric pressure and in vacuum of 1.33 kPa are calculated and plotted on the state diagram. It is established that the separation of magnesium-beryllium system alloys does not involve technological difficulties.

Keywords: magnesium, beryllium, metal, alloy, diagram of state.

Cite this article as: Nitsenko A., Linnik X. (2023). Thermodynamic studies of the binary system of magnesium with the alloying metal – beryllium. Challenges of Science. Issue VI, 2023, pp. 220-224. https://doi.org/10.31643/2023.26



Title: Physical Properties of Liquid Slag, their Influence on the Basic Parameters of Technological Processes

Authors: Khursanov A., Hasanov A., Tolibov B.

Abstract: In this article given physical properties of liquid slag, their influence on the basic parameters of technological processes in Almalyk mining and metallurgical plant. The physical properties of melts directly affect the main parameters of pyrometallurgical processes, as well as the design and operation features of equipment. The physical properties of melts (F) are functions of the composition of the phase under study (Xij) and external parameters that determine the state of the system. These properties reflect the structure of the melt, i.e., they are structure-sensitive properties. The physical properties of the liquid phase should also be understood as its properties that are not associated with changes in its material composition or chemical properties, or are associated to an insignificant extent.

Keywords: slag, matte, copper, temperature, density, viscosity, surface layer, electrical conductivity, interfacial properties, double electrical parameters, crystallization, thermal conductivity, separation, smelting, furnace.

Cite this article as: Khursanov A., Hasanov A., Tolibov B. (2023). Physical Properties of Liquid Slag, their Influence on the Basic Parameters of Technological Processes. Challenges of Science. Issue VI, 2023, pp. 225-232. https://doi.org/10.31643/2023.27



Title: Impact of aluminum content upon the microstructure of Ni-Cr-Al gradient coatings

Authors: Maulet Meruyert, Wojciech Wieleba

Abstract: Studied the aluminium concentration in the composite powder NiCr-Al influences the structure of NiCr-Al gradient coatings. Gradient coatings based on NiCr-Al were obtained by detonation spraying, with a phased reduction in the barrel filling volume with acetylene-oxygen gas mixture from 50% to 25%. The coatings' microstructure was analyzed across different aluminum concentrations: 15%, 20%, and 30%. By adjusting the aluminum concentration in the powder mix, we achieved coatings with a gradient formation. The findings indicated that the phase composition of the gradient coating is significantly influenced by the Al mass percentage. The findings suggest a powder composition of 80%NiCr and 20%Al to produce NiCr-Al coatings with a good gradient structure.

Keywords: Ni-Cr-Al coating, gradient coating, detonation spraying, microstructure, XRD.

Cite this article as: Maulet Meruyert, Wojciech Wieleba (2023). Impact of aluminum content upon the microstructure of Ni-Cr-Al gradient coatings. Challenges of Science. Issue VI, 2023, pp. 233-236. https://doi.org/10.31643/2023.28



Title: Investigation of vibrational properties of carbon films obtained by magnetron sputtering method

Authors: Baitimbetova B., Kydirbai G.

Abstract: In the present work, thin carbon films and nanofibers of different morphologies were obtained by magnetron sputtering on a modernized VUP-2 unit. Information of vibrational properties of carbon films and nanofilaments was obtained by Raman spectroscopy. Carbon nanofilaments were obtained in the G band region 1580-1595 cm-1, which is in good agreement with the known literature data. Apparently, the most fascinating results were achieved when steel-3 was used as a substrate. This is probably due to the presence of carbon in steel-3, which serves as a condensation center for the formation of carbon structures, including carbon tubes. The study of amorphous films and their applications in diverse industries constitutes a significant area of scientific research, and this article offers an overview of synthesis methods and potential material applications.

Keywords: Сarbon thin films, magnetron sputtering, vibrational properties, material applications, synthesis methods.

Cite this article as: Baitimbetova B., Kydirbai G. (2023). Investigation of vibrational properties of carbon films obtained by magnetron sputtering method. Challenges of Science. Issue VI, 2023, pp. 237-239. https://doi.org/10.31643/2023.29



Title: Investigation of the possibility of introducing yttrium oxide by vacuum induction melting to produce nickel-free stainless steel

Authors: Popov F.E., Panichkin A.V., Lutchenko N.A., Arbuz A.S.

Abstract: The possibility of smelting an oxide-dispersed strengthening steel alloy using five different approaches involving the introduction of finely dispersed Y2O3 particles into liquid Fe-13Cr steel alloy under vacuum conditions has been investigated. To achieve the objective, five series of experiments were carried out, each differing in the conditions and process of the experiments. Two series of melting, were performed to evaluate the possibility of mechanical introduction of yttrium oxide into the melt under different conditions of introduction. The subsequent three series, were carried out to study the possibility of oxidation of metallic yttrium in the melt with the formation of yttrium oxide particles. In these experiments such parameters as duration of melt holding time and residual pressure in the furnace chamber were varied. When the obtained ingots were analysed by X-ray fluorescence (XRF), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and energy dispersive X-ray spectroscopy (EDS), it was found that a significant amount of yttrium oxide was not successfully incorporated into the steel volume. A method using oxidation of metallic yttrium in the melt by reduction of added iron oxide was found to be the most promising.

Keywords: ODS steel, yttrium oxide, induction furnace, nickel-free steel.

Cite this article as: Popov F.E., Panichkin A.V., Lutchenko N.A., Arbuz A.S. (2023). Investigation of the possibility of introducing yttrium oxide by vacuum induction melting to produce nickel-free stainless steel. Challenges of Science. Issue VI, 2023, pp. 240-244. https://doi.org/10.31643/2023.30



Title: Validity and Reliability Analysis of Character Instruments for High School Students in Coastal Areas of Maluku

Authors: Rugaya Tuanaya, Edi Istiyono, Widihastuti, Haryanto

Abstract: The research is a development of character assessment instrument for high school students in coastal areas in Maluku. This study aims to test the quality of character assessment instrument of high school students in coastal areas of Maluku which consists of content validity, construct validity and reliability. The sample in this study amounted to 56 students with the sampling technique using random sampling technique. Content validity used is Aiken's V, while Confirmatory Factory Analysis is used to prove construct validity. Reliability analysis using Cronbach Alpha. The results of the analysis show that the content validity of the character assessment instrument of coastal high school students in Maluku all items have met the valid criteria, construct validity with CFA provides evidence that there are 18 items that do not fit, while the reliability coefficient is 0.9 with a very high category.

Keywords: Character education, Character of coastal students, Instrument quality.

Cite this article as: Rugaya Tuanaya, Edi Istiyono, Widihastuti, Haryanto (2023). Validity and Reliability Analysis of Character Instruments for High School Students in Coastal Areas of Maluku. Challenges of Science. Issue VI, 2023, pp. 245-250. https://doi.org/10.31643/2023.31



Title: How do Indonesia and New Zealand facilitate their students in learning statistics? A comparative study on the intended mathematics curriculum

Authors: Ibnu Rafi, Heri Retnawati

Abstract: Students’ learning outcomes can be influenced by the intended curriculum as the main guidelines for teachers in facilitating their students to learn. Comparative study can be conducted to evaluate to what extent the intended curriculum of a country is designed to give an opportunity for students to learn compared to the other countries. The present comparative study was aimed at describing the similarities and differences between Indonesia and New Zealand in facilitating their students in learning statistics. To gain this objective, the official documents of curriculum of those Countries were analyzed qualitatively. The analysis was focused on the expected competence. The results show that New Zealand provides more facilities for their students in learning statistics through statistical investigation and literacy than Indonesia. At the particular level, both Indonesia and New Zealand give the same content but the depth of the discussions given to their students is different. These results could be beneficial for both countries as well as the others as the consideration to improve the quality of their curriculum.

Keywords: comparative study, Indonesia and New Zealand, intended curriculum, statistics.

Cite this article as: Ibnu Rafi, Heri Retnawati (2023). How do Indonesia and New Zealand facilitate their students in learning statistics? A comparative study on the intended mathematics curriculum. Challenges of Science. Issue VI, 2023, pp. 251-258. https://doi.org/10.31643/2023.32



Title: Trend Research Sustainable Developments Goals in Indonesia within ASEAN Nations from 2015 to 2023: A Bibliography Analysis

Authors: Nabilah N., Ulwiyah S., Rifqiyah F., Pusporini W.

Abstract: This study aims to identify and analyze the development of research related to sustainable development goals (SDGs) in Indonesia from 2015 to 2023 using bibliometric analysis methods. The SDGs represent a global commitment in addressing various social, economic, and environmental challenges faced by the world today. This study focuses on the main trends developing in SDGs research in Indonesia, including research productivity, collaboration between researchers, and dominant research themes. Bibliometric methods were used to collect and analyze data from various sources, such as scientific journals and reviews available in the Scopus database. The data analysis process involved the use of keyword visualization tools such as VoS Viewer, as well as R-studio Biblioshiny bibliometric analysis software. The results of the analysis show that sustainable development is a trending topic and peaks in 2020-2023. In addition, the evolution of research over a certain half-life (2017-2023) revealed that water sanitation, biodiversity, and food security became the main focus in SDGs-related publications. For almost the past decade, Indonesia has been the country that produced the highest number of SDGs-related articles in the Scopus database. This bibliometric study provides a comprehensive understanding of the development of SDGs research in Indonesia and can be a reference for other researchers to understand the growing trends and fictions in efforts to achieve development goals in Indonesia.

Keywords: Sustainable Development, Bibliometrics, Indonesia, Analysis, Trend.

Cite this article as: Nabilah N., Ulwiyah S., Rifqiyah F., Pusporini W. (2023). Trend Research Sustainable Developments Goals in Indonesia within ASEAN Nations from 2015 to 2023: A Bibliography Analysis. Challenges of Science. Issue VI, 2023, pp. 259-270. https://doi.org/10.31643/2023.33



Title: A Visualized Bibliometric Analysis for Mapping Research Trends of Machine Learning in Academic Research

Authors: Ibrahim Z. S., Rifqiyah F., Sultan J., Retnawati H.

Abstract: This study aims to conduct a comprehensive bibliometric analysis of machine learning research within the academic research from 2013 to 2023. The goals include comprehending how publication trends have changed over time, pinpointing important fields of interest, and clarifying how machine learning and scholarly research interact. This study's methodology combines a bibliometric framework with a qualitative descriptive approach. The data were collected from Scopus database, which consist of 4.655 documents for analysis. The analysis is executed using R studio and Biblioshiny. The result shows that the rise of machine learning in academic research between 2013 and 2023 suggests that this field of study will continues to be a trending area for academic exploration.

Keywords: Bibliometric Analysis, Machine Learning, Academic Research, Machine Learning in Education.

Cite this article as: Ibrahim Z. S., Rifqiyah F., Sultan J., Retnawati H. (2023). A visualized Bibliometric Analysis for Mapping Research trends of Machine Learning in Academic Research. Challenges of Science. Issue VI, 2023, pp. 271-279. https://doi.org/10.31643/2023.34



Title: Application of Critical Thinking in Mathematics Education: Bibliometric Analysis (1991-2023)

Authors: Zafrullah, Xu Wenxin, Atika Miftah Ramadhani, Anugrah Arya Bakti, Abzal Kuanyshuly

Abstract: Critical thinking is an important skill in the 21st century and plays a major role in learning. This bibliometric research evaluates previous academic work on the use of Critical Thinking in mathematics education. Through Scopus analysis, research uses RStudio Biblioshiny and VosViewer to map research trends and search for new keywords. The results show an increase in publications of approximately 10.58% annually, reflecting growing interest in this topic. The Indonesian University of Education stands out as a productive research center in this field, with more than 25 related articles. "Journal of Physics: Conference Series" and "International Journal of Instruction" stand out as the most prolific publications, with "Soter et al. (2008)" having the highest number of citations, reaching 217 citations. Keywords such as systematic reviews, critical mathematics education, science technologies, and e-learning stand out as key trends, providing potential for further exploration in future research. This underscores the importance of continued research in applying Critical Thinking in mathematics education, indicating growing interest as well as areas requiring further focus for the development of critical skills in this context.

Keywords: Critical Thinking, Mathematics Education, Bibliometrics

Cite this article as: Zafrullah, Xu Wenxin, Atika Miftah Ramadhani, Anugrah Arya Bakti, Abzal Kuanyshuly (2023). Application of Critical Thinking in Mathematics Education: Bibliometric Analysis (1991-2023). Challenges of Science. Issue VI, 2023, pp. 280-289. https://doi.org/10.31643/2023.35



Title: Assessment of the flux composition effect on the removal efficiency of non-metallic inclusions in high-chromium cast iron

Authors: Panichkin A.V., Kshibekova B.B.

Abstract: The problem to refine high-chromium cast iron melts obtained with the use of a large proportion of scraped metal and scrap is considered herein. Since fluxes containing calcium fluoride are currently considered to be environmentally polluting, it is required to reduce the use of fluorides, or completely replace them. It was shown that a decrease in the melting point of the flux can be achieved with the use of a mixture of calcium and magnesium fluorides or by the introduction of boron oxide into the composition of the fluxes. However, the efficiency of these fluxes, as well as silicocalcium additives and vacuum remelting in the high-chromium cast iron melting when a high proportion of scrap in the charge is used, has not been previously considered. In this regard, the effect of these refining methods on the removal of non-metallic inclusions in high-chromium cast iron of Grade 340Х18HML was experimentally assessed. Thermodynamic calculations were performed for the interaction of magnesium and calcium fluorides with non-metallic oxide inclusions typical of high-chromium cast irons and with oxides used for neutral lining of induction furnaces. It has been shown that fluxes based on boron oxide, magnesium and calcium fluorides and their mixtures effectively remove oxide and sulfide non-metallic inclusions; however, they have a destructive effect on the lining of furnaces, significantly reducing its service life. The addition of silicocalcium reduces the content of sulfides but does not affect the content of non-metallic inclusions in the form of oxides and nitrides. Vacuum remelting effectively reduces the number of nitride inclusions.

Keywords: high chromium cast iron, HCCI, flux, calcium and magnesium fluorides, boron oxide, non-metallic inclusions

Cite this article as: Panichkin A.V., Kshibekova B.B. (2023). Assessment of the flux composition effect on the removal efficiency of non-metallic inclusions in high-chromium cast iron. Challenges of Science. Issue VI, 2023, pp. 290-297. https://doi.org/10.31643/2023.36