bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Student’s Motivation in Pandemic Covid-19 Era Using an Authentic English Learning App
Authors: Putra M T M , Wardani R 
Published: January 2021

Abstract
A habit of the learning process in the classroom where students only receive lessons from the teacher makes students passive in the learning process. Therefore, students learning motivation decreases when it comes to distance learning. The development of Authentic English Learning App aims to motivate and facilitate students during the distance learning process. This system is designed for students to learn English in an authentic context in their surrounding at home. Moreover, students can collaborate with their peers and give feedback to their peers’ work. The App was tested using black box testing before it used by students. Black Box testing show a Very Good performance of the App. Furthermore, The result of this study shows that in the post-motivation, there is a significant difference of learning motivation between students who use Authentic English Learning App (EG) and students who only read a book (CG) (F = 4.664, p < 0.05). Therefore, Authentic English Learning App can motivate students to learn English effectively. Moreover, Technology Acceptance Model (TAM) questionnaire shows a high level of trust in each dimension (M > 4.5), It shows that Authentic English Learning App can facilitate students during Covid-19 in distance learning.
Development of Inverse Kinematics Learning Media Using Hexapod Robot for Robotics Course
Authors: Suprihono H , Mashoedah  
Published: January 2021

Abstract
This study aims to (1) get an inverse kinematic learning media design, (2) find out inverse kinematic learning media performance, (3) find out feasibility level of inverse kinematic learning media using hexapod robot. This type of research is research and development using ADDIE model, with stages: (1) Analysis, (2) Design, (3) Develop, (4) Implement, and (5) Evaluate. The object of research is hexapod robot. The subjects of research are students of Electronic Engineering Education Study Program who took the concentration of Industrial Electronics. Methods of data collection using classroom observation and questionnaires. The data analysis technique is descriptive qualitative analysis. The result of this research and development shows: (1) inverse kinematic learning media design using hexapod robot, (2) the performance through black box testing get result 100%. Each robot’s feet can move with an average axis error percentage x of 7,4%, y of 11,67% and z of 7,87% and produces 14 types of movement, (3) feasibility level of learning media based on the assessment of material expert obtained 94,46% (very feasible), media expert obtained 96,2% (very feasible), and users obtained 80,99% (feasible).
Developing UNYSA Chatbot as Information Services about Yogyakarta State University
Authors: Muhyidin Andri , Setiawan Muhammad Adi Febri , Nurkhamid  
Published: January 2021

Abstract
This study aims to (1) develop chatbot-based public relations communication media that are able to overcome the limitations of service in interacting and providing information about UNY to the public, (2) ensure the quality of software developed with the ISO/IEC 25010 model. The research method used is Research and Development (R&D) with the Agile: Scrum software development model. The results of this study are (1) a chatbot-based PR communication media named UNYSA as an information service about UNY, (2) UNYSA meets ISO/IEC 25010 quality standards on functional suitability characteristics with software developer experts at 0.86 (most features successfully implemented), material experts of 98.82% (Very Eligible), UAT of 83.95% (Very Good); performance efficiency has a latency response of 15 ms (faster than standard speed: 2 seconds); 100% portability (supports all planned frontend apps); usability of 83.81% (Very Eligible); reliability of 92% (Very Feasible), and maintainability with a maintainability index of 83.21 (very easy to maintain).
Development of WeShare As a Knowledge Sharing Platform to Realize the Freedom in Learning
Authors: Setialana Pradana , Fitria Anissa , Atika Riza , Hestiana  , Fadilla Risma Nor , Nurkhamid  
Published: January 2021

Abstract
Education builds a society quality to be creative, innovative. The Ministry of Education and Culture of Indonesia (Kemdikbud) program, “Freedom in Learning”, is expected to be able to create a happy learning atmosphere for the community. It also deals with the innovative Community 5.0 where the community is human-centred and based on technology to improve the human ability to open opportunities for humanity, on the other side to break the sense of stagnation, mutual respect and be able to lead a life active and fun. Therefore, an educational platform “WeShare” was built to promote culture of sharing knowledge to society with the mission of “Together Empowerment”. The research method used Research & Development (RnD) with Waterfall Models such as planning, analysis & design, development, testing, and maintenance programs. The aim of this program is to develop WeShare as a Knowledge Sharing Platform, and to understand the effects and benefits of WeShare program.
Eligibility of Certification Schemes for the Electrical Installation Competency of Electrical Engineering Education Study Program Students
Authors: Hartoyo  , Laras D , Zamtinah  , Sukisno Toto 
Published: January 2021

Abstract
The objectives of this study were to: (1) know the weaknesses of current certification model, (2) describe a Certification Scheme of Electrical Installation Competency for the Electrical Engineering Education Study Program (EEESP) Students’, Faculty of Engineering, Yogyakarta State University, and (3) know the eligibility of the Certification Scheme for Electrical Installation Competency of Electrical engineering Education Study program Students’. This research was conducted in the Department of Electrical Engineering Education, Faculty of Engineering, Yogyakarta State University from February to September 2020. This research is survey. The data collection used a questionnaire and an assessment of the feasibility of the certification scheme. The research respondents were lecturers, students, assessors, and practitioners in the field of Electrical Installation Competency. The validation of the research instrument was based on expert judgment by calculating the Aiken’s V index. The reliabilities of instrument were measured by Alpha Cronbach and Inter rater using interclass correlation coefficient (ICC). The data analysis technique used quantitative descriptive analysis, namely mean and percentage. The results of the research were as follows: (1) The weaknesses of current certification model were: (a) expensive competency test costs (77%), (b) there is no special certification scheme for the Electrical Engineering Education Study Program students as a prospective teacher (68%), (c) unclear competency test mechanism (52%), (d) inadequate competency test material (51%), and (f) the competency level tested was not suitable (32%); (2) The developed certification scheme is Low Voltage Electrical Installation Engineering Competency for EEESP Students’; (3) The Eligibility of the Electrical Installation Competency Certification Scheme for EEESP Students’ is very eligible with an average score of 3.66 out of 4.00.
Effects of flight altitude on the lift generation of monarch butterflies: from sea level to overwintering mountain
Authors: Sridhar Madhu K , Kang Chang-Kwon , Landrum D Brian , Aono Hikaru , Mathis Shannon L , Lee Taeyoung 
Published: January 2021

Abstract
Aerodynamic efficiency behind the annual migration of monarch butterflies, the longest among insects, is an unsolved mystery. Monarchs migrate 4000 km at high-altitudes to their overwintering mountains in Central Mexico. The air is thinner at higher altitudes, yielding reduced aerodynamic drag and enhanced range. However, the lift is also expected to reduce in lower density conditions. To investigate the ability of monarchs to produce sufficient lift to fly in thinner air, we measured the climbing motion of freely flying monarchs in high-altitude conditions. An optical method was used to track the flapping wing and body motions inside a large pressure chamber. The air density inside the chamber was reduced to recreate the higher altitude densities. The lift coefficient generated by monarchs increased from 1.7 at the sea-level to 9.4 at 3000 m. The correlation between this increase and the flapping amplitude and frequency was insignificant. However, it strongly correlated to the effective angle of attack, which measures the wing to body velocity ratio. These results support the hypothesis that monarchs produce sufficiently high lift coefficients at high altitudes despite a lower dynamic pressure.
Partitioning uncertainty in projections of Arctic sea ice
Authors: Bonan David B , Lehner Flavio , Holland Marika M 
Published: January 2021

Abstract
Improved knowledge of the contributing sources of uncertainty in projections of Arctic sea ice over the 21st century is essential for evaluating impacts of a changing Arctic environment. Here, we consider the role of internal variability, model structure and emissions scenario in projections of Arctic sea-ice area (SIA) by using six single model initial-condition large ensembles and a suite of models participating in Phase 5 of the Coupled Model Intercomparison Project. For projections of September Arctic SIA change, internal variability accounts for as much as 40%–60% of the total uncertainty in the next decade, while emissions scenario dominates uncertainty toward the end of the century. Model structure accounts for 60%–70% of the total uncertainty by mid-century and declines to 30% at the end of the 21st century in the summer months. For projections of wintertime Arctic SIA change, internal variability contributes as much as 50%–60% of the total uncertainty in the next decade and impacts total uncertainty at longer lead times when compared to the summertime. In winter, there exists a considerable scenario dependence of model uncertainty with relatively larger model uncertainty under strong forcing compared to weak forcing. At regional scales, the contribution of internal variability can vary widely and strongly depends on the calendar month and region. For wintertime SIA change in the Greenland-Iceland-Norwegian and Barents Seas, internal variability contributes 60%–70% to the total uncertainty over the coming decades and remains important much longer than in other regions. We further find that the relative contribution of internal variability to total uncertainty is state-dependent and increases as sea ice volume declines. These results demonstrate that internal variability is a significant source of uncertainty in projections of Arctic sea ice.
Friction: from Leonardo da Vinci to modern nanotechnologies
Authors: Makarov A V 
Published: January 2021

Abstract
The review paper presents an outstanding contribution of Leonardo da Vinci to the science of friction, which is the heart of modern nanotechnologies. It demonstrates a significant role of nanocrystalline friction structures (NCFS) in the formation of the tribological properties of metal alloys and in the implementation of deformation-induced nanostructuring techniques for metal alloy surface processing. Inherent in the very nature of friction, the ability to obtain an NCFS can be effectively used for targeted nanostructuring of product surface layers in order to increase their resistance to wear, corrosion, mechanical loads, and high temperatures. This can be achieved by using simple frictional and ultrasonic impact-frictional surface treatments, as well as combined methods based on the chemical modification of the formed NCFS. It is proposed to use nanostructuring frictional pretreatment and the industrial technology of nanostructuring burnishing in combined methods for surface preparation of structural stainless steels, including those produced by additive laser technology, for applying high-strength nanocomposite thin-film coatings.
Microstructure and mechanical properties of a nickel-base superalloy heavily alloyed with substitution elements
Authors: Zainullin R I , Ganeev A A , Shakhov R V , Mukhtarov S K , Imayev V M , Imayev R M 
Published: January 2021

Abstract
The present work is devoted to a study of the microstructure and mechanical properties of a new heat resistant nickel-base superalloy Ni-14(Al, Ta)-30.7(Co, Cr, W, Hf) (wt.%) intended for using as a die material. The superalloy contains about 70 vol.% of the γ′(NÎ3AI) phase and a small amount (about 3 vol.%) of carbides and topologically close-packed phases. Compression tests were carried for the new superalloy at 1000-1200°C. The superalloy showed the yield stress values at 1100-1200°C comparable with those obtained for the Russian VKNA-superalloys based on the γ′(NÍ3Al) phase. Tensile tests were performed for the cast and heat treated and wrought conditions of the superalloy. The tensile properties show that the new superalloy can be considered as an advanced disc material for gas turbine engines as well.
Effect of post-forging heat treatment on the microstructure and mechanical properties of a nickel-base superalloy SDZhS-15
Authors: Mukhtarova K S , Shakhov R V , Ganeev A A , Mukhtarov S K , Logunov A V , Imayev V M 
Published: January 2021

Abstract
The newly designed ingot-metallurgy Ni-base superalloy SDZhS-15 intended for disc applications was subjected to multiple heat treatment and forging in the temperature range (Ts-70)-Ts, where Ts is the γ’ solvus temperature, followed by solid solution treatment and ageing. A fine-grained microstructure was attained in the forged condition as a result of recrystallization processes occurring during processing. It was revealed that solution treatment at T>(Ts-50) led to a fast γ grain growth, which in turn led to a decrease in strength and ductility of the superalloy. At the same time, the solution treatment at slightly lower temperatures, at (Ts-60)-(Ts-50), allowed to save fine γ grains (d
γ
= 10-20 μm) and to provide the formation of secondary γ′ precipitates with a mean size of about 0.1 The superalloy in the forged and heat treated condition showed superior mechanical properties as compared with those of other disc superalloys.
Structure and properties of Cu-based alloys diluted by Pd and Ag
Authors: Volkova E G , Novikova O S , Kostina A E , Glukhov A V , Volkov A Yu 
Published: January 2021

Abstract
The microstructure, mechanical and electrical properties of Cu-Pd alloys (with Pd content not more than 8 at.%) and triple Cu-Pd-Ag alloys with 5 at.%Ag were studied. It was established that the strength and the recrystallization temperature of the Cu-Pd alloys increased with palladium content. A comparison of the electrical properties of these alloys when Pd content was increased from 0 to 8 at.%Pd was done. An anomaly was revealed in the Cu-5.9Pd and Cu-8Pd alloys: the plastic deformation does not lead to an increase in the electrical resistivity. It is due to the destruction of short range atomic order in the quenched Cu-Pd alloys under deformation. The alloying with silver leads to a further increase in strength with a constant electrical conductivity. It was found that annealing of the deformed Cu-Pd-Ag alloys at 200-300°C led to an increase in strength. It was shown that the effect was not related to the Pd-content and was due to silver only.
Effect of accumulative high-pressure torsion on the structure of steel 10
Authors: Ramazanov I A , Gunderov D V , Astanin V V , Sitdikov V D , Zakiryanova G T , Sharafutdinov A V 
Published: January 2021

Abstract
The effect of processing by accumulative high-pressure torsion on the structure of steel 10 is investigated. It is found that after processing by accumulative HPT, a stronger structure refinement takes place in steel 10 as compared to regular HPT processing for the same number of revolutions.
High density of shear bands in the Vitreloy bulk metallic glass subjected to high-pressure torsion
Authors: Astanin Vasily , Gunderov Dmitry , Qiang Ren Zhi , Valiev Ruslan , Wang Jing Tao 
Published: January 2021

Abstract
Plastic deformation by high-pressure torsion allows one to achieve high strains of bulk metallic glasses without their failure. It is shown that inclusions of the primary crystalline phase in the Vit105 alloy provoke the formation of cracks, and shear bands themselves have a complex composite structure and are prone to branching and merging during the development of deformation. The density of the bands reaches 1.76 μm−1, with a distance between them 80-120 μm.
Calculation of hardening contributions of the TiNi alloy undergoing martensitic transformations in a free state
Authors: Churakova A A , Gunderov D V , Tolstov N E , Magomedova D K 
Published: January 2021

AbstractThe paper reports on the studies of the effect of thermal cycling on the microstructure of the Ti - 50.8 at. % Ni alloy in coarse-grained and ultrafine-grained states, mechanical properties, and calculation of contributions to hardening in the studied states. The comparison of the calculated and experimental values of the yield stress in the TiNi alloy was carried out.
Influence of free torsion deformation modes on the microstructure and mechanical properties of commercially pure copper
Authors: Kodirov I S , Aleshin G N , Raab A G 
Published: January 2021

Abstract
The paper investigates the effect of the free torsion rate of cylindrical specimes of commercially pure copper (grade M1) on their deformed state, microstructure, and mechanical properties. The study of the microstructure was carried out by means of transmission electron microscopy and X-ray diffraction analysis in the central region and at the periphery of the deformed rod. The mechanical properties were evaluated by measuring the microhardness. It was found that an increase of the torsion rate, other things being equal, promotes more intensive strengthening and refinement of the microstructure.
Structure of copper-containing nanocomposites obtained by electrochemical synthesis
Authors: Isaeva I Yu , Ostaeva G Yu , Odinokova I V , Eliseeva E A , Busko V I 
Published: January 2021

Abstract
The properties of copper nanocomposites obtained by electrochemical reduction in an aqueous-alcohol electrolyte solution (CUSO4) with the addition of poly(N-vinylpyrrolidone) were investigated. Electrolysis was carried out at direct current using copper electrodes: the anode is made as a hollow cylinder, and the cathode in the form of a bundle of insulated wires with open cross sections, placed inside the cylinder with a working solution. The stabilizing properties of the polymer and the influence of the cathode on the electrochemical deposition processes were shown. The composition, morphology and size characteristics of synthesized copper-containing nanocomposites were determined. The resulting nanoparticles have a crystal cut, and also a high copper content.
Effect of the structural elements size of crumpled graphene on hydrogen sorption: atomistic simulation
Authors: Apkadirova N G , Krylova K A 
Published: January 2021

Abstract
The effect of the size of carbon flakes of crumpled graphene on the physical hydrogen sorption is considered using molecular dynamics simulation. Hydrogenated crumpled graphene was subjected to hydrostatic compression up to ε = 0.77, hydrogen dynamics in the dense structure is studied at 77 and 300 K. It has been found that the hydrogen sorption of crumpled graphene depends on its specific surface area. The highest sorption capacity was observed for crumpled graphene with carbon nanoflakes 20 nm in diameter. The difference in volumetric sorption capacity of flakes with the diameters of 9.5 and 20 nm was about 10% for a compression strain of ε = 0.77 at 20 ps at 77 K.
Molecular dynamics simulation of crumpled graphene filled with Ni nanoparticles
Authors: Safina L R , Murzaev R T , Krylova K A 
Published: January 2021

Abstract
Graphene-nickel composites are novel structures with improved properties intensively studied in the last decades. In the present work, molecular dynamics simulation is used to study the process of formation of a composite obtained from well-known crumplec graphene mixed with Ni nanoparticles on the atomistic level. To obtain the composite from initially separated structural units, hydrostatic compression at elevated temperatures is applied. As it is found, the composite structure can be obtained only at high temperatures ir 1200 < T < 1500 K range. Numerical tensile tests showed that the higher is the temperature during hydrostatic compression, the smaller is the pore size at the final stage of tension. Compression at high temperature leads to the formation of new chemical bonds between graphene flakes, supports the spread of Ni atoms inside the graphene structure and results in a formation of an excellent composite structure.
Contribution of structural parameters to the strength and electrical conductivity of Cu-0.5%Cr alloy subjected to ECAP and cold rolling
Authors: Sarkeeva E A , Alexandrov I V 
Published: January 2021

Abstract
The effect of cold rolling with a reduction rate of 95% at room temperature and subsequent aging on the evolution of the microstructure, strength properties and electrical conductivity of the Cu-0.5Cr alloy (wt.%), which is widely used in the electrical industry in the form of strips and ribbons, has been studied. The cold rolling and aging of the alloy was carried out in coarse-grained and ultrafine-grained states after equal-channel angular pressing. The regularities found were used to assess the contribution of various structural parameters to the level of strength properties as well as the electrical conductivity of the alloy in the obtained states.
Influence of rolling modes and the level of accumulated deformation on the mechanical and plastic properties of stainless austenitic steel AISI 304L
Authors: Raab A G , Raab G I , Dobatkin S V , Tokar A A , La P 
Published: January 2021

Abstract
The paper presents the results of studies of rolling modes (direct, reverse, cross ones) at 500°C for samples of stainless steel AISI 304L and their influence on mechanical and plastic properties of the material. The stress-strain state was investigated using a numerical simulation program and the deformation parameters of processing were established. The mechanical properties were studied by microhardness measuring and tensile testing methods. The results of the experiment were analyzed and discussed, and conclusions were drawn. The regularities of the effect of strength parameters depending on the modes of processing and accumulated deformation during rolling have been established.
Features of the formation of a diffusion layer and the mechanism of diffusion during boronizing of steels
Authors: Guryev A.M. , Ivanov S. G. , Guryev M. A. , Mei S. , Lygdenov B.D. 
Published: January 2021

Abstract
The paper presents the results of studies on the formation of a diffusion layer during the boriding of steel with a carbon content of 0.38 wt%. The study of diffusion coatings by SEM and TEM methods allows one to more clearly determine the mechanisms of diffusion of boron atoms and the formation of diffusion boride coatings. Diffusion of boron in the processes of diffusion boriding of iron-carbon alloys proceeds by a mixed mechanism: the delivery of active boron atoms to the diffusion front proceeds along the grain and phase boundaries. The reaction mechanism is realized by a gradual substitution of carbon with boron in iron carbides. Due to the continuous diffusion of boron, the reaction boundary is constantly moving in the direction from the surface to the core of the saturated material. In this case, as the diffusion proceeds, the concentration of carbon atoms under the boride layer constantly increases. This provides resistance to diffusion of boron atoms by the atomic mechanism and provokes diffusion by the reaction mechanism.