bluuebunny/crossref_metadata_2025_split huggingface dataset:
Current limiting characteristics of a magnetic shielding type Superconducting Fault Current Limiter of REBCO pancake coils
Authors: Sakamoto D , Sakamoto T , Shirai Y 
Published: June 2020

Abstract
Superconducting Fault Current Limiters (SFCLs) are installed in the electric power system, and expected to limit fault current and improve system stability. In this paper, we focus on the transformer magnetic shielding type SFCL made of REBCO wires. This SFCL limits fault current mainly with reactance for small fault current. When fault current gets larger, resistance component is added and a larger impedance is generated. In this time, we fabricated the transformer type SFCL composed of pancake coils and investigated the basic characteristics. The pancake coil type has the advantage that the amount of superconducting wire is less and the size of SFCL becomes smaller than solenoid coil type. As the results of experiment, it was confirmed that SFCL limits fault current with reactance and resistance properly. Regarding the current limiting impedance, it almost agreed with the designed value, and confirmed the current limiting operation as expected.
Experimental study on cabling properties of different REBCO coated tapes
Authors: Xiao G Y , Liu F , Jin H , Zhou C , Qin J G , Liu H J , Li J G , Dai T L , Zhang X T 
Published: June 2020

Abstract
Due to the high current carrying capability, the ReBCO coated tapes are good candidates for magnets operation under a high magnetic field and high current conditions. Cabling the ReBCO conductor tapes on round core (CORC) is one of main cabling concepts. It has the potential to be used for future fusion magnets. However, during the cabling process, the ReBCO tape shall be subjected to strain and stress caused by the combined tension, bending and torsion. It is well known that strain and stress shall reduce the current carrying properties of ReBCO tapes, especially if it is under conditions of normal strain and/or peeling stress. The critical current never returns to its original value once the stress and strain exceed a critical value. Therefore activities were carried out to wound ReBCO tapes with different dimensions on a round core with different diameters. All of the used tapes are from Shanghai Superconductor. The critical current variation of the tape at 77 K and self-field with its thickness, width as well as the used diameter of the round core have been investigated to give guidance for the followed cable design and manufacturing.
Test results of a REBCO superconducting switch for reducing temporal fluctuations in driven-mode
Authors: Iwai S , Otani Y , Miyazaki H , Tosaka T , Nomura S , Ito T 
Published: June 2020

Abstract
High-temperature superconducting magnets are generally driven by a power supply (driven mode), and temporal fluctuations of the power supply unit, such as ripple noise, directly affect the magnetic field stability. A method of suppressing such temporal instability by short-circuiting both ends of the coil with finite low-resistance joints, somewhat similar to a persistent current switch, has been proposed in order to form a closed loop having a large time constant, L/R. In this research, we developed two types of REBCO superconducting switches was constructed with a non-inductive winding using mainly ordinary copper-coated REBCO tapes, and type-B switch used uncoated REBCO tapes toward application to emergency shutdown. For the type-B switch, at the end of the winding, copper-coated REBCO tapes were jointed to prevent degradation by exposure to moisture. The R-T and V-I characteristics of each switch when cooled with liquid nitrogen were tested. The type-A switch was applied to a test REBCO magnet, and the temporal stability of the magnetic field was evaluated under a conduction cooling configuration in the driven mode.
Using of HTS tape coils for the design of a magnetic bearing
Authors: Kurbatova E , Kurbatov P , Kuschenko E , Kulaev Y 
Published: June 2020

Abstract
The use of HTS materials for the construction of magnetic bearings has shown their high efficiency. Currently, more and more research is focused on the use of tape superconductors for magnetic bearings. Application of HTS tapes allows simplifying the manufacturing technology of these devices and improving the specific power characteristics. However, when modelling devices with HTS tapes, computational difficulties arise due to the small thickness of the active layer. The paper considers the possibility of using models for magnetization to describe the properties of HTS tapes in the calculation method based on the integral equations of an electromagnetic field. The features of the proposed models are illustrated by the results of solving simple test tasks and calculations of real designs of magnetic bearings. To confirm the correctness of the simulation, the calculation data are compared with the data of experimental studies.
High Temperature Superconducting (HTS) Cable Application to Ship Deperming Work
Authors: Hirota M 
Published: June 2020

Abstract
We study a system of high electric current cable laid on the seabed for purpose of naval ship magnetic deperming. Moderate magnetic field over 2400 A/m is to be imposed on the volume equivalent of several thousand tons of ship, with alternately changing direction and gradually decreasing intensity. Cable with conventional conductor needs large power source because of the requirements coming from the cable’s resistivity and high decay of magnetic field depending on distance from source. High Temperature Superconducting cable is suitable for this application. We set a requirement of maximum current of the cable as 200 kA and the length as 1200 m set on seabed of 12 m depth. Our recent design of the cable composed of Rare-earth-Barium-Copper-Oxide tape conductor stack, bundled and cooled by helium gas to 50 K. As a next step, cooling to 20 K with the same base concept of cable is shown to mitigate high expense of the tape conductor.
High Temperature Superconducting Halbach Array Topology for Air-cored Electrical Machines
Authors: Zhang Hongye , Li Quan , Ubani Okechukwu , Mueller Markus 
Published: June 2020

AbstractAir-cored electrical machines have attracted increasing attention in applications related to aircraft and wind power because they can eliminate core losses and decrease the total mass. However, the limited magnetic flux in air-cored machines has restricted their power level. In order to improve the power density and efficiency while further reducing the weight of air-cored electrical machines, a novel field winding topology composed of high temperature superconducting (HTS) Halbach Array magnets (HAM) has been proposed in this paper. C-GEN is an innovative multi-stage air-cored generator technology with permanent magnets, which has been demonstrated at laboratory scale. Taking a 1 MW C-GEN generator prototype as the example machine, anH-formulation founded HTSHAM model has been built in COMSOL Multiphysics with the homogenization method. Simulation results show that the proposed HTSHAM C-GEN generator can achieve a power density more than 4 times higher than the conventional design with permanent magnets (PM), with a reduced magnet weight of around half of the previous prototype. The proposed HTSHAM represents a generic approach for the design of fully air-cored superconducting synchronous machines, eliminating heavy ferromagnetic material, and thus provides a useful reference for the design of low-weight air-cored electrical machines with a high power density.
T - formulation based numerical modelling of dynamic loss with a DC background field
Authors: Kails K , Yao M , Zhang H , Machura P , Mueller M , Li Q 
Published: June 2020

Abstract
High-temperature superconducting (HTS) generators offer the advantages of high efficiencies and increased power densities. Most superconducting generator designs feature DC field windings to provide the required magnetomotive force. The superconducting field windings in HTS machines are subject to complex magnetic fields, which lead to dynamic losses occurring in the winding. This magnetic field environment has a large DC background component due to the self-field of the superconducting field windings. This paper investigates the dynamic loss in combination with a DC background field using a T – formulation based numerical model, where the dynamic region is used to identify the dynamic loss. Our double claw pole generator design, which offers a high power density at low superconducting tape requirements, is used as a case study for dynamic loss analysis with a DC background field. Results show that DC background field has a strong effect on the dynamic loss due to the reduced critical current. In addition it was shown that the T – formulation based numerical model in conjunction with the dynamic region requires further research to accurately predict the dynamic loss due to the changing DC current transport region.
The utilization of corncob for the manufacture of charcoal briquette as an alternative fuel
Authors: Rahmawati S , Pathuddin  , Sakung J , Suherman  , Fudholi A , Sushmita L 
Published: June 2020

Abstract
Biomass of sweet corncob and birdlime that is much found in society is the garbage that until now have not widely used as a product that have value added. This research aims to use biomass of sweet corncob and the birdlime as an alternative fuel to substitute fossil energy sources. One alternative to make sweet corncob and birdlime as an alternative fuel is process them into charcoal briquettes so it can produces high calorific value. The process to make charcoal briquettes from corncob and birdlime is very easy which includes charcoal raw material drying, preparation of the adhesive, printing and drying the Briquettes. Besides, the testing of briquettes quality of sweet corncob includes: density (0.54 – 0.78 gr/cm3), calorific value (4936.454 cal/gr), water level (6.39%), ash level (3.8%), vaporized substance level (16.72%) and bonded carbon level (79.48%. Whereas, birdlime corncob include: density (0.61 – 1.3 gr /cm3), calorific value (6033.650 cal/gr), water level (6.83%), ash level (4.8%), vaporized substance level (18.41%) and bonded carbon level (76,48%).
Student profile multiple representations skills under the implementation of OBSIM (observation and simulation) model of teaching in improving creative thinking skills
Authors: Ridlo Z R , Sutarto  , Mahardika I K , Indrawati  , Terra I W A , Wardani E 
Published: June 2020

Abstract
The research aims to explore multiple representations under the implementation of the OBSIM model of teaching in the alternating-current circuit course. This research compares the modern class (experimental class) and traditional class with the traditional teaching style. Experiment class applies the OBSIM model of teaching, and Traditional Classroom teaches in traditional style with a direct explanation. Computer simulation also integrated into this research by using Matlab Sofware as part of multiple representations, namely programming representation. This research used triangulation methods. The quantitative methods were applied to analyze student achievement tests according to Creative thinking criteria. The Qualitative method was applied using observation of student activity. Student achievement test followed by a pretest, and post-test quasi-experimental research. The data analysis form pretest and postest analysis indicates a significant value of 0.012 (p ≤ 0.05). Thus, it is a significant value, and the average of student activity in experimental class better than control class. The findings conclude that two classes have differences in terms of student multiple representations and creative thinking skills after implementation of OBSIM model of teaching.
An analysis of olympiad students’ critical thinking in solving National Science Olympiad (OSN) problem on number theory material
Authors: Jatmiko D D H , Fatahillah A , Oktavianingtyas E , Rochmah O A 
Published: June 2020

Abstract
This research aimed at describing the process of the mathematical Olympiad students in solving National Science Olympiad (OSN) problem on number theory material. The subjects of the research were 4 Olympiad students at Pythagoras Development Center of Mathematics and Natural Sciences Jember. The data collection methods used were test and interview. In this case, every student had strengths and weaknesses in solving the problem. All of the students were able to write and explain what was known and asked but they were still lack to model the problem into mathematical form. The students were able to formulate properly but were lack to construct it into various possible answers. All of the students were able to write systematic steps and correct conclusion. All of the students checked all the results, but there were still some students who were not careful in checking, so there were inappropriate answers.
STEM education for pre-service teacher: why and how?
Authors: Nasrudin D , Rochman C , Suhendi HY , Helsy I , Rasyid A , Aripin I , Utami W , Mayasri A 
Published: June 2020

Abstract
The success of STEM implementation in primary and secondary schools is greatly influenced by the role and expertise of the teacher. In the Indonesian context, not many universities have STEM centers yet. This paper wants to describe the STEM education design for pre-service science teachers at Universities. The method used was a Focus Group Discussion from several researchers with backgrounds in physics, chemistry, and biology across universities. The results of the study show the importance of developing STEM education programs in certain subjects, applying STEM learning to pedagogical practices, open courses that specifically train, develop STEM teaching for pre-service teachers and build the STEM center. This study concludes the importance of an integrated program between preparing STEM education at universities and implementing STEM in the field.
The colloid labyrinth media to improve students motivation and learning achievement on chemistry lessons
Authors: Erna M , Susilawati  , Haryati S , Alodia F 
Published: June 2020

Abstract
The colloid labyrinth media is a game media that can be used in learning chemistry topics taught in high school. The type of this research was experiment research with design randomized control group pretest-posttest design. This research object is students of SMA 8 Pekanbaru. The sample of this research consisted of 32 students of XI IPA 9 as the experiment group and 35 students of XI IPA 10 as the control group at the 2016/2017 academic year which were determined randomly after conducting normality and homogeneity test. The experiment class was treated with the use of labyrinth media while the control class without the use of labyrinth media. The data analysis was using the analysis of descriptive statistic and t-test. Based on analysis of the data obtained tcount > ttable is 2.63 > 1.67, it’s mean that the use of labyrinth media can improve students learning outcomes on the subject of colloid in XI IPA SMA Negeri 8 Pekanbaru. Based on the data analysis, it is obtained students motivation in experiment groups (66.14%) than control group (40.95%), means that the use of labyrinth media can improve students motivation on the subject of colloid in XI IPA SMA Negeri 8 Pekanbaru. The category improvement of students learning achievement at experiment group was high category with N-gain normalized is 0.8633.
Science textbook based on Socio-Scientific Issues (SSI) for environmental pollution to increase student science literacy in junior high school
Authors: Anggraini S D , Indrawati  , Wahyuni D 
Published: June 2020

Abstract
21st century learning leads to problem solving, social emotional skills to face the challenges of RI 4.0 and it will have an influence scientific understanding. This scientific understanding is still low in analyzing and applying the concept of a problem that has an impact on the ability of science literacy. Science literacy is related ability to think scientifically by using knowledge and identifying natural phenomena. The results of the distribution of questionnaires for 18 junior high schools in Jember middle region of 89% stated the concept of science literacy of students was still lacking. Science literacy has a close relationship with Socio-Scientific Issues (SSI) which are described as social problems with a scientific context that connects students with scientific issues that are developing in society to be explored such as environmental pollution problems. This research used quasi-pretest-posttest experiment without control class. Data analysis using the mixed-method, and were analyzed quantitatively.The sample used was 33 students junior high school in VII C class room. The result obtained from pretest and posttest with open questions following aspect of science literacy and showed that students experienced an increase in science literacy by 0,75 in the high categories.
The application of Lesson Study for LearningCommunity (LSLC)- based collaborative learning - integrated Realistic Mathematics Education (RME) to improve the students’ mathematical reasoning ability class IX D of MTSN 5 Jember on quadratic equation material
Authors: Kusumawati R 
Published: June 2020

Abstract
Students in each level of education are required to have mathematical reasoning ability. Students’ mathematical reasoning abilities were very low. Therefore, this research investigated the application of lesson study for learning community-based collaborative learning-integrated realistic mathematics education to improve the students’ mathematical reasoning ability. The method used was classroom action research and the material was quadratic equation in class IXD of MTsN 5 Jember in odd semester in 2019/2020 academic year. Mathematical reasoning was assessed through essay test. The data were obtained from the results of learning achievement test, conducting the observation, interview and observation of activity results of the teacher and students during the learning through lesson study for learning community-based collaborative learning-integrated realistic mathematics education. The mean result of pre-test on the students’ mathematical reasoning ability was around 42.50. While the mean result of post-test on the students’ mathematical reasoning ability improved as much as 88.13. This means that in the cycle I, the students’ mathematical reasoning improved. This indicated that lesson study for learning community-based collaborative learning-integrated realistic mathematics education improved the students’ mathematical reasoning ability.
Adiwiyata School: An environmental care program as an effort to develop Indonesian students’ ecological literacy
Authors: Febriani R , Farihah U , Nasution N E A 
Published: June 2020

Abstract
In line with the increase of complexity in environmental problems as a result of over-exploitation, it is necessary to care for the environmental program. Ecological literacy education needs to be realized in the programs of environmental care. This study aims to determine the importance of Adiwiyata school program in an effort to improve students’ ecological literacy. The method used in this research is qualitative descriptive with interview, observation and documentation as data collection techniques. Ecological literacy is a collective action which needs togetherness to produce a positive impact to the environment. The application of ecological literacy at schools requires awareness from all teachers, students and other school community. Adiwiyata program in SMAN 5 Jember, Indonesia can increase students’ ecological literacy by establishing a caring attitude and environment on students. This is evidenced by the behaviour of students who dispose of waste in place, sort out the types of garbage, recycling of waste, making hydroponics plants are free of pesticides, and composting. It can be concluded that inveronmental care program (Adiwiyata) is one way to improve the literacy of students in the school about ecology by observing the effectiveness of Adiwiyata program.
Factors behind the implementation of STEM education in Bangladesh
Authors: Chowdhury S A , Arefin ASM S , Ahmed F 
Published: June 2020

Abstract
In this world of ever growing challenges; Science, Technology, Engineering, and Mathematics (STEM) has gained momentum in global education systems. Unfortunately, Bangladesh as a country is yet to be on board with this advanced education system. No research has been published related to STEM education in Bangladesh. Hence, the aim of this study was to explore the key factors and major challenges behind the implementation of STEM education system in Bangladesh. The design of the study followed mixed method approach. Undergraduate students of the University of Dhaka were selected as sample using non-random purposive sampling technique. Data were collected from the participants through semi-structured questionnaire and focus group discussion. According to the primary findings, more than 80% of the respondents agreed that infrastructure and resources as well as professional development are the key factors to implement STEM in Bangladesh. In addition, inadequate scientific laboratory facilities, lack of financial resources, lack of training for trainers and large class size have been identified as the major challenges behind the implementation of STEM. Keeping these factors and challenges in mind, an effective STEM based education system can be developed and successfully implemented in phase by phase from primary to tertiary levels. This study has, therefore, implications for policy makers, educationists and stakeholders in both private and public sectors to increase the country’s global competitiveness as well as boost the national economy via providing the STEM based skills and capacity to the learners.
The analysis of dyscalculia that referred to the learning style of fleming and mills theory on matrix materials of MAN 1 Metro students
Authors: Jannah T M , Bharata H 
Published: June 2020

Abstract
This study aims to: (1) Investigate the learning problems from students, (2) To know the learning styles of students, (3) To identifies the dyscalculia experienced by students on matrix based on their learning styles of Flaming and Mills Theory. The subject of research are students of MIA 6 MAN 1 Metro grade XI, in the 2018-19 Academic Year. The research uses descriptive qualitative method. The results of this research are: (1) the students of class XI MIA 6 had four difficulties of learning mathematics such as (a) spatial disruption: not describing the steps of operating on the answers done, (b) the difficulty of understanding the concept: not making the problem answer correctly, (c) the difficulty of understanding the formulas or symbols: the incomplete of writing formulas the use of false step and the use of wrong formulas and symbols, and (d) the difficulty in calculation: the lack of students accuracy during the operation of the work; (2) students of class XI MIA 6 have four styles (VARK) they are Visual (V): 8 students, Audiotori (A): 13 students, Read-Write (R): 7 students, and Kinesthetic (K): 8 Students, and found students who have combined learning styles of Audiotori and Read-Write (AR): 2 students, Audiotori, Read-Write and Kinestetik (ARK): 1 student, and Visual, Audiotori, Read-Write and Kinestetik (VARK): 1 student; (3) The difficulties of learning mathematics experienced by students are also attributed to their V-A-R-K learning style; Visual students (V): spatial disruption and difficulty of understanding formulas or symbols. Audiotori Students (A): spatial disruption, the difficulty of understanding concepts, and calculations. Read-Write student (R): spatial disruption and the difficulty of understanding formulas or symbols. And Kinesthetic students (K): spatial disruption, the difficulty of understanding concepts, formulas or symbols and calculations.