bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantum dynamics of a planar rotor driven by suddenly switched combined aligning and orienting interactions
Authors: Mirahmadi Marjan , Schmidt Burkhard , Friedrich Bretislav 
Published: May 2021

Abstract
We investigate, both analytically and numerically, the quantum dynamics of a planar (2D) rigid rotor subject to suddenly switched-on or switched-off concurrent orienting and aligning interactions. We find that the time-evolution of the post-switch populations as well as of the expectation values of orientation and alignment reflects the spectral properties and the eigensurface topology of the planar pendulum eigenproblem established in our earlier work (2014 Front. Phys.
2 37, 2017 Eur. Phys. J. D
71 149). This finding opens the possibility to examine the topological properties of the eigensurfaces experimentally as well as provides the means to make use of these properties for controlling the rotor dynamics in the laboratory.
Control problems for the telegraph and wave equation networks
Authors: Alam M , Avdonin S , Avdonina N 
Published: May 2021

Abstract
In this paper we consider control problems for the telegraph equation networks or, in other words, telegraph equations on metric graphs. If a network is homogeneous, i.e. its parameters are the same for all edges of the graph (and in some other cases), the problem can be reduced a control problem for the wave equation. For graphs without cycles, we obtain necessary and sufficient conditions of exact boundary controllability of the telegraph equation network and find the sharp time of controllability.
Visualization of Data Journalism of China’s Mainstream Media in Public Health Emergences: Taking the Data News Section of Xinhua Net as An Example
Authors: Liu Jiahui 
Published: May 2021

Abstract
In the context of Chinese media, the practice of data news visualization during the COVID-19 pandemic presents unique characteristics. In order to explore the visualization mode of China’s data news reports during the epidemic, this article uses the method of content analysis to analyze the data news reports related to the epidemic released by the data news section of Xinhua Net from January 22, 2020 to October 26, 2020. The article discussed the innovations in the application form and narrative characteristics of China’s mainstream media visualization practice from three aspects, and proposed improvements to the deficiencies. The research found that the data news related to the epidemic focus on data analysis in terms of production methods, and use simple and easy-to-understand diagrams for visual design, and use both traditional and advanced infographics; but it also reflects a lack of the richness of data source, mainly including static information charts and insufficient interactivity.
The Investigative Science Learning Environment (ISLE) approach to learning physics
Authors: Etkina E , Brookes D T , Planinsic G 
Published: May 2021

Abstract
In a plenary talk “Investigative Science Learning Environment (ISLE): helping students learn physics by practicing it and be empowered in the process” at the SEA-STEM 2020 conference I (Eugenia Etkina) described the ISLE approach to learning and teaching physics, shared examples of activities and presented evidence of student learning. In this paper I, with my collaborators David T. Brookes and Gorazd Planinsic will briefly summarize my presentation and provide a list of resources for those who wish to learn more about the ISLE approach and to implement it in their physics courses.
Sorption behavior of MgH2-Ti for Hydrogen storage material prepared by high pressure milling
Authors: Malahayati  , Nurmalita  , Ismail  , Machmud M N , Jalil Z 
Published: May 2021

Abstract
Synthesis by reactive ball milling under hydrogen atmosphere is a potential technology for preparation of hydrogen storage materials. In this report we proposed a high pressures reactive milling (hereafter referred as “HPRM”) for preparing the MgH2-Ti. Nanocrystalline materials of MgH2-Ti which is have been synthesized under high pressures hydrogen up to 9 MPa at room temperature. The characterization has been done by X-ray diffraction, scanning electron microscopy for their phase composition and morphology, respectively. Hydrogen storage capacities and the hydriding/dehydriding kinetics measured with gravimetric method. The X-ray diffraction pattern after 12 h of milling showed very broadened peaks, indicating that the crystal size was already in nanometers. It was also observed that the kinetics are fast which works within less than 7 mins for absorption (at 300°C, 10 bar H2) and within 6 mins for desorption (at 350°C, 50 mbar H2), respectively. The hydrogen storage capacity was 2.7 wt%.
Synthesis of TiO2-based photoelectrode and natural dye for dye sensitized solar cell (DSSC)
Authors: Mursal  , Malahayati  , Azmi N , Fatmiyah S 
Published: May 2021

Abstract
Synthesis and characterization of Mg and La doped TiO2 photoelectrodes and natural dye have been studied. This study aimed to analyze the effect of Mg and La concentration on the characteristics of Mg and La doped TiO2 and to investigate the characteristic of natural dye extracted from green spinach, red spinach, and mangosteen rind. Mg and La doped TiO2 were synthesize by sol-gel method using titanium (IV) isopropoxide, magnesium acetate and lanthanum (III) acetate as precursors. The concentration of Mg and La were varied from 0 – 4% mol. Mg and La doped TiO2 films were deposited on glass substrate by using doctor blade technique and annealed at 500°C for 1 h. The films were then characterized using X-Ray Diffractometer and UV-Vis spectrometer measurement to investigate its characteristics. The results showed that dopant concentration strongly affected the structural and optical properties of Mg and La doped TiO2. The UV-Vis measurement of the natural dye extracted from green spinach, red spinach, and mangosteen rind showed a different absorption spectrum. However, FTIR measurement of these dyes showed relatively the similar spectrum. This shows that each dye has different optical properties, even though it has relatively the same functional group.
Dye and activated carbon from Canarium ovatum Engl. as photosensitizer and counter electrode for Titania-based dye sensitized solar cell
Authors: Gasga K 
Published: May 2021

Abstract
Natural dye from exocarp and activated carbon from charred shells of Canarium ovatum Engl nut was used in the fabrication of dye sensitized solar cell (DSSC). Anatase titania (titanium dioxide, TiO2) nanoparticles was used as semiconducting layer deposited on a transparent conductive indium tin oxide glass using doctor blade method. TiO2 film thickness and soaking time in dye were varied to show response in terms of fill factor (FF), short circuit current density (Jsc), open circuit photovoltage (Voc), and conversion efficiency (η). In a 2.0 cm2 active surface area tested under solar irradiance, assembled DSSC at optimum conditions garnered 0.768 desirability with FF, Jsc, Voc and n values of 0.601, 6.293 mA/cm2, 0.446 V, and 1.792, respectively.
Fourier Transform Infra-Red spectrophotometry observation to find appropriate wavelength for non-invasive blood glucose level measurement optical device
Authors: Alatas H , Suryana Y , Pambudi S , Widayanti T , Jenie R P , Zaheri R , Aridarma A , Rahayu S K , Riadhie T S , Rahmawaty V , Har N P , Zuhri M , Sumaryada T , Irzaman  
Published: May 2021

AbstractThe appropriate wavelength is essential for non-invasive blood glucose level measurement optical device. We conducted this experimental observation to find the usable wavelength candidate for non-invasive blood glucose level measurement optical device in 1000 nm to 2500 nm range. We run this observation in Prodia Bogor and Food Processing and Crops Technology Lab, Faculty of Agricultural Engineering, IPB University, July 2019. We obtained fasting, 15 mnt postprandial, and 30 mnt postprandial blood sample from 10 randomly selected consenting non blinded healthy adult subjects between 18 to 60 years old. We measured spectrophotometric absorbance for each blood sample. We did the measurement using BUCHI NIR FLEX 500. We compared the result to blood glucose level by standard gold measurement. We also compared the Pearson correlation, and the standard deviation of all samples to then-existing wavelength source LED provided by Thorlabs. We found that the highest absorbance and standard deviation wavelength is at 1939 nm. Wavelength LEDs candidates that represent measuring blood glucose levels is 1200, 1300, 1450, 1750, and 1950 nm. We did not find a severe adverse effect from each participant. Researchers should confirm the trial results with in vivo human observation.
Student’s misconception and thinking style on modern physics course
Authors: Halim A , Nurhasanah  , Zainuddin  , Musdar  , Elisa  , Mahzum E , Irwandi I 
Published: May 2021

Abstract
This study aims to determine the relationship between misconceptions and thinking styles of students in modern physics course and to determine which type of thinking style is more dominant in relation to misconceptions. This type of research is a survey study with a quantitative approach. The samples in this study were 60 students who have followed the modern physics course. Data collection used a two-tier diagnostic test on modern physics and a thinking style questionnaire. The results of the analysis with the correlation test found that the types of thinking style Concrete Sequential (CS), Abstract Sequential (AS), and Random Abstract (RA) are negatively correlated with misconceptions or it can be said that there is almost no correlation with misconceptions, namely (-0.024), (-0.113) and (-0.082). Meanwhile, the type of concrete random thinking style (CT) has a positive correlation with misconceptions, but the relationship is weak (0.303). Based on these results, it can be said that the types of thinking styles of students tend to have no correlation with misconceptions. Even though the correlation between the two is low, it is necessary to pay attention to the thinking style of students in conveying concepts in modern physics.
Increasing critical temperature on BPSCCO superconductors with addition of Al2O3
Authors: Nasution S F , Humaidi S , Imaduddin A , Darsono N , Nugraha H 
Published: May 2021

Abstract
We have investigated the effect of addition of Al2O3 in the manufacture of the BPSCCO superconductors using solid state reaction method. Precursors with consist of Bi2O3, PbO2, SrCO3, CaCO3, and CuO powders were ground using mortar agate for 3 h. The samples were heated at 300°C for 6 h to remove the moisture in the powders, and then ground again for 6 h. Then the samples were calculated at 820°C for 20 h and then Al2O3 (1wt% and 2wt%) were added and ground again. The powders were compacted with a diameter of 10 mm and a thickness of 2 mm and then sintered at 850°C for 30 h. The characterizations were carried out by using Cryogenic Magnet to determine the superconductivity properties, SEM-EDX to analyze the morphology and XRD to determine the phase formed. The resistivity versus temperature results showed the increase of Tc with the addition of Al2O3. Sample with 1wt% Al2O3 has Tconset of 90 K and Tczero of 66 K, when the sample with 2wt% Al2O3 has Tconset of 94 K and Tczero of 73 K. The morphology formed looks less homogeneous, the crystalline granules are melt-shaped, clumpy and there are porosity.
Identification of total suspended solid (TSS) in the Aceh waters from ocean color
Authors: Syawani U , Haditiar Y , Ikhwan M , Wafdan R , Muhammad M , Setiawan I , Jalil Z , Chaliluddin M A , Rizal S 
Published: May 2021

AbstractThe suspended sediment in Aceh waters was analysed from remote Sensing Reflectance of Aqua MODIS resolution 4 km. Two equations from previous studies were used to determine the magnitude and distribution of suspended sediment concentrations in Aceh waters during 2018. The results show the suspended sediment concentrations from the two equations are relatively the same even though they differ spatially (offshore and near the coast of Aceh waters). Based on Zhan et al. equation, the suspended sediment in Aceh waters have a maximum value of 0.786 mg/L and a minimum value of 0.589 mg/L. Meanwhile, based on Zhang et al. equation, the maximum and minimum suspended sediment in Aceh Waters are 0.639 mg/L and 0.271 mg/L, respectively. Based on these two equations, Krueng Kluet estuary located in the western part of Aceh has the highest suspended sediment. In contrast, Krueng Peusangan estuary in the eastern part of Aceh has a low sediment concentration. The highest suspended sediment in Aceh waters occurs in November to December and the low period is in April to September. The heavy rainfall encourages freshwater runoff and high suspended sediment in the mouth of the Aceh waters, especially in the western part of Aceh.
Analysis of students’ ability in completing HOTS-based Basic Physics questions
Authors: Halim A , Mastura I , Soewarno  , Elisa  , Mahzum E , Farhan A , Irwandi I 
Published: May 2021

AbstractThis study aims to determine students’ higher order thinking skills in solving HOTS-based Basic Physics questions. The research method used is descriptive method with a quantitative approach. The research subjects were 23 students of the second semester of the Physics Education Study Program. The data collection technique used was a test by giving questions consisting of three questions covering questions to analyse, evaluate and create. Based on the results of data analysis, it is known that students’ high-order thinking skills in solving HOTS-based Basic Physics questions are in the poor category with the following details: The percentage of students who have high-order thinking skills is very good category is 15%, good category is 10%, category 25% enough, 35% less category and 15% very poor category. The inference from these results is that in the evaluation of the Basic Physics subject, it is necessary to add more high-level standard questions.
Binary logistic regression for identification of high school student interest in Banda Aceh city in continuing study at Universitas Syiah Kuala
Authors: Nurhasanah  , Rusyana A , Fitriana A R 
Published: May 2021

Abstract
Universitas Syiah Kuala is the oldest university in Aceh. The campus has the nickname of the jantong hate campus to the Acehnese people, which of course can be interpreted as the campus of pride of the Acehnese people. Universitas Syiah Kuala increased its accreditation status from C to A accreditation awarded by the research, technology and higher education ministry. This showed a very significant quality of improvement. With this condition a study was conducted on the interest of high school students in the Banda Aceh City in choosing Universitas Syiah Kuala as a place to study. This study aims to determine the factors that influence the interest of Banda high school students in continuing their studies to Universitas Syiah Kuala and get a model of interest in the Banda Aceh city students through a binary logistic regression approach. The results show that the factors that influence students’ interest in continuing their studies at Universitas Syiah Kuala are the ability to be affiliated with others, goals, and expectations. With the binary logistic regression model obtained, it can be seen the tendency of students to continue their studies at Universitas Syiah Kuala.
The challenges experienced by teachers in online workshop during the COVID-19 pandemic
Authors: Johar R , Elizar E , Annisa D , Mailizar M 
Published: May 2021

Abstract
COVID-19 pandemic has changed many aspects of our everyday life, including education. Schools and universities are closed, so that teaching and learning activities must be modified from traditional face-to-face to online learning. Also, professional development programs are affected. However, online program does not always run smoothly and the participants may encounter some challenges. This study investigates the challenges experienced by mathematics teachers in online workshops on Realistic Mathematics Education. This qualitative research involved 11 mathematics teachers in Banda Aceh, Indonesia, joined the online workshop voluntarily. The instrument used in this study was an interview sheet. The results of the interview regarding the challenges during the online workshop showed four categories of challenges: technical issues, facilities, cooperation between groups, and collaboration with facilitators. The finding of the study is expected to provide insight on how to improve future online workshop.
Mathematical creative thinking level on polyhedron problems for eight-grade students
Authors: Junaedi Y , Wahyudin  , Juandi D 
Published: May 2021

Abstract
Mathematical creative thinking is needed by students in addition to other abilities because it can provide broad thinking to get new ideas or new solution of mathematical problemsolving. The aim of this research is to describe mathematical creative thinking level on polyhedron problems for eight-grade students. This research was conducted at a senior secondary school in Indonesia with a total of 35 students in year 8. This type of research is a case study with inductive data analysis techniques which include: data reduction, data display, drawing conclusions and verification. The research instrument consisted of 4 test descriptions based on the aspects of mathematical creative thinking ability, interview guidelines and documentation. The result of this research concluded that students with a high level of mathematical creative thinking ability tend to solve polyhedron problems in the aspects of originality, fluency, flexibility, and elaboration. Students with a medium level of mathematical creative thinking ability tend to give one overall correct answer to polyhedron problems in the aspects of originality, fluency, flexibility, and elaboration. Students with low level mathematical creative thinking ability tend to give incorrect answers to polyhedron problems in the aspects of originality, fluency, flexibility, but in the elaboration aspect, it gives one correct answer even though it is not detailed.
Prospective mathematics teachers’ concept image on the limit of a function
Authors: Sulastri R , Suryadi D , Prabawanto S , Cahya E , Siagian M D , Tamur M 
Published: May 2021

Abstract
The concept of limit is one of the prerequisite subjects in studying calculus. Previous studies indicate that the use of the limit concept in learning that is not in accordance with the limit concept in mathematics. This study aims to describe the concept image of prospective mathematics teachers on the concept of limit functions and the causes of the concept image. This qualitative study used the phenomenology approach, involving seven mathematics students in the fifth semester at a university in Bandung, Indonesia, who were selected based on the results of a written test. The data were obtained from the results of written tests on the concept of limit function and interviews and analysed descriptively. The results showed that students understood the concept of limit function in the same way that limit is an unreachable function. This causes the definition of limit formally using ε-δ is not properly understood. In this case, a comprehensive study of the limit function is needed at the beginning of calculus learning and should be an important concern for lecturers of calculus.
An analysis of students’ mathematical literacy skills assessed from students’ learning style
Authors: Sakinah M , Avip P B 
Published: May 2021

AbstractThis study aims to determine students’ mathematical literacy skills based on their learning styles. This descriptive research used a learning style questionnaire, a students’ mathematical literacy test to determine students’ mathematical skills, and interviews to complement the data. The data analysis included analyzing the learning style and mathematical literacy tests with data validity using the triangulation method. This study revealed several results: 1) The mathematical literacy skills of students with visual, auditory, and kinesthetic learning styles were still deficient, where only 14% of students answering the mathematical literacy questions correctly; 2) The mathematical literacy skills of students with a kinesthetic learning style were better than students’ with visual and auditory learning styles; 3) Students with a visual learning style had been able to formulate the given mathematical problems, while the use of mathematical concepts and interpreting mathematical problems were still lacking; 4) Students with an auditory learning style had the lowest skills in formulating mathematical problems so that they mistakenly used basic mathematical concepts; and 5) Students with a kinesthetic learning style were able to formulate and use mathematical concepts properly and correctly despite still lack of interpreting mathematical problems.
Error analysis in solving the linear equation system of three variables using Polya’s problem-solving steps
Authors: Wiyah R B , Nurjanah  
Published: May 2021

Abstract
Recently, students still often have difficulties and share common mistakes in solving the linear equation system of three variables. This qualitative descriptive research describes the errors and causes of students’ errors in solving the linear equation system of three variables using Polya’s problem-solving steps. The subjects were 33 students of Grade 10 Science at one of the Senior High School in Indralaya. The data collection techniques used observation, student worksheets, and interviews. The results showed there were several students’ errors and the causes of students’ errors in solving the problems. These errors are errors in identifying the known and asked information, errors in making mathematical models of problems, errors in calculations, errors in arranging the linear equation system of three variables, and errors in giving valid reasons for their answers. The causes of these errors are the limited time for understanding the problem, careless in doing calculations, forgetting the formulas, and lacking understanding of variables concept.
Improving students’ mathematical identity using games as learning media during the Covid-19 pandemic
Authors: Hima L R , Nusantara T , Hidayanto E , Rahardjo S , Murniasih T R 
Published: May 2021

AbstractDuring the COVID-19 pandemic, Indonesia has applied digital learning methods for all school levels. It is undeniable that digital learning also brings out boredom for students. This saturation decreases student motivation to learn, coupled with anxiety about the uncertain pandemic situation. Decreased motivation and increased anxiety are related to the mathematical identity possessed by students. As a result of this decline, the mathematical identity of the students is also not good. This research was conducted to improve student mathematical identity by using games as learning media. Data were collected from two fifth-grade elementary school students who have a low-category mathematical identity. This research is qualitative research using a case study approach. The results showed that the games used as learning media succeeded in improving students’ mathematical identities. Other findings indicate that the circumstances around students, such as a pandemic, reduce students’ mathematical identity. Therefore, it is hoped that teachers’ creativity in developing students’ mathematical identities is expected because the development of students’ mathematical identities strongly depends on the treatment of the environment around them, such as teachers, friends, and even the learning media they use.