bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seismic constraints on the internal structure of evolved stars: From high-luminosity RGB to AGB stars
Authors: Dréau G. , Mosser B. , Lebreton Y. , Gehan C. , Kallinger T. 
Published: March 2021

Context. The space-borne missions CoRoT and Kepler opened up a new opportunity for better understanding stellar evolution by probing stellar interiors with unrivalled high-precision photometric data. Kepler has observed stellar oscillation for four years, which gave access to excellent frequency resolution that enables deciphering the oscillation spectrum of evolved red giant branch and asymptotic giant branch stars.
Aims. The internal structure of stars in the upper parts of the red and asymptotic giant branches is poorly constrained, which makes the distinction between red and asymptotic giants difficult. We perform a thorough seismic analysis to address the physical conditions inside these stars and to distinguish them.
Methods. We took advantage of what we have learnt from less evolved stars. We studied the oscillation mode properties of ∼2.000 evolved giants in a model described by the asymptotic pressure-mode pattern of red giants, which includes the signature of the helium second-ionisation zone. Mode identification was performed with a maximum cross-correlation method. Then, the modes were fitted with Lorentzian functions following a maximum likelihood estimator technique.
Results. We derive a large set of seismic parameters of evolved red and asymptotic giants. We extracted the mode properties up to the degree ℓ = 3 and investigated their dependence on stellar mass, metallicity, and evolutionary status. We identify a clear difference in the signature of the helium second-ionisation zone between red and asymptotic giants. We also detect a clear shortage of the energy of ℓ = 1 modes after the core-He-burning phase. Furthermore, we note that the mode damping observed on the asymptotic giant branch is similar to that observed on the red giant branch.
Conclusions. We highlight that the signature of the helium second-ionisation zone varies with stellar evolution. This provides us with a physical basis for distinguishing red giant branch stars from asymptotic giants. Here, our investigation of stellar oscillations allows us to constrain the physical processes and the key events that occur during the advanced stages of stellar evolution, with emphasis on the ascent along the asymptotic giant branch, including the asymptotic giant branch bump.
Direct single-molecule imaging for diagnostic and blood screening assays
Authors: Ruan Qiaoqiao , Macdonald Patrick J. , Swift Kerry M. , Tetin Sergey Y. 
Published: March 2021

Significance
Direct imaging and counting single molecules captured on magnetic microparticles enables diagnostic assays with ultrahigh sensitivities and wide linear detection ranges. The method offers simple assay protocols, short incubation times, minimal reagent consumption, and does not require enzymatic signal amplification. The ratiometric readout, linking the signal and binding area, eliminates the need for strict control over the number of microparticles. Direct imaging provides the sensitivity, flexibility, and simplicity required by rigorous clinical standards. Other benefits of the technique include a seamless transition between digital and analog data analysis modes, scalability, basic consumables, and the reliability to achieve robust implementation in high-throughput automated instruments. HDIA is a versatile tool that can easily be adopted for all receptor–ligand binding assays.
Metastable acceptors in boron doped silicon: evidence of the defects contributing to carrier induced degradation
Authors: Chen Xiaochi , Li Lei , Zhang Jian , Jian Yuan , Yang Guixia , Liu Xuqiang , Zeng Guang , Pang Yuanlong , Yu Xiaofei , Meng Xianfu , Shi Jianmin , Wu Xiaoli 
Published: March 2021

Abstract
This work focuses on the recombination-enhanced reactions of boron related defects in compensated silicon and their impact on the electrical performance of silicon devices. Using deep level transient spectroscopy, we measured the defect spectra in the collector of 14 MeV fusion neutron irradiated p-n-p silicon transistors during forward current injection, as well as the corresponding degradation kinetics of both current gain and leakage current on the same device. Two hole traps at

E

c

+ 0.43 eV and

E

c

+ 0.53 eV are proved to be acceptors in the lower half of the gap with significant recombination enhanced effects. These metastabe acceptors degrade the current gain by changing the space charge distribution in the p-n-p structure and are linked with carrier-induced boron-oxygen complexes responsible for the minority-carrier lifetime degradation of silicon photovoltaics.
Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector
Authors: Nguyen Hung , Riduan Md Foisal Abu , Nguyen Thanh , Dinh Toan , Streed Erik W , Nguyen Nam-Trung , Viet Dao Dzung 
Published: March 2021

Abstract
Single-crystalline silicon carbide (3C-SiC) has been attracting significant attention in recent years due to its cost-effectiveness and high crystalline quality, mature fabrication techniques on Si-substrate and outstanding mechanical, chemical, and optoelectronic characteristics. Taking advantage of its large built-in potential, a promising application of 3C-SiC on Si (3C-SiC/Si) heterostructure is to develop position-sensitive detectors (PSDs) based on the lateral photovoltaic effect. The lateral photovoltage is generated under non-uniform illumination due to the asymmetry diffusion of photo-induced charge carriers. However, the full potential of 3C-SiC/Si heterojunction-based PSDs has not been elucidated yet. In this study, we investigate the influence of photogenerated hole and its diffusion path length on the sensing performance of the devices in attempts to obtain an optimal design and further pushing the limit of the PSD. Devices with different electrode spacings are fabricated on the 3C-SiC/Si heterostructure, and experiments are conducted under different illumination conditions to determine the position-sensitivity. Devices with short electrode spacings are found to have excellent position-sensitivity with the highest sensitivity of 470 mV mm−1 obtained in a device spacing of 300 µm under 980 nm (1000 µW) laser illumination. The physic mechanism underneath the experimentally observed behaviors are explained based on the generation and separation of electron–hole (e–h) pairs under the illumination, and charge carrier diffusion theory. The findings of this work will provide insights to design highly sensitive PSDs and explore its full potentials.
Origami-based adjustable sound-absorbing metamaterial
Authors: Jiang Pingting , Jiang Tianxi , He Qingbo 
Published: March 2021

Abstract
Broadband acoustic absorption at deep sub-wavelength has become a research hotspot, while current methods still suffer from thick structures and narrow bandwidth. This study proposes an origami-based foldable sound absorber based on micro-perforated resonators. The origami acoustic absorber is composed of six different channels. The resonance frequency of each channel can be easily tuned by origami process under the deep sub-wavelength thickness. When the structure is folded, the thickness is only 20 mm to 30 mm. The operating bandwidth can be tuned from 55 Hz to 80 Hz in the frequency range of 305 Hz to 540 Hz, where the average sound absorption coefficient is beyond 80%. Effective absorption can be realized via a design whose average thickness is only 1/34.4

λ

for the resonance frequency. This study broadens the sound absorption bandwidth and improves the low-frequency sound absorption ability, which provides an avenue for flexible low-frequency noise control.
SEIR order parameters and eigenvectors of the three stages of completed COVID-19 epidemics: with an illustration for Thailand January to May 2020
Authors: Frank T D , Chiangga S 
Published: March 2021

AbstractBy end of October 2020, the COVID-19 pandemic has taken a tragic toll of 1150 000 lives and this number is expected to increase. Despite the pandemic is raging in most parts of the world, in a few countries COVID-19 epidemics subsided due to successful implementations of intervention measures. A unifying perspective of the beginnings, middle stages, and endings of such completed COVID-19 epidemics is developed based on the order parameter and eigenvalue concepts of nonlinear physics, in general, and synergetics, in particular. To this end, a standard susceptible-exposed-infected-recovered (SEIR) epidemiological model is used. It is shown that COVID-19 epidemic outbreaks follow a suitably defined SEIR order parameter. Intervention measures switch the eigenvalue of the order parameter from a positive to a negative value, and in doing so, stabilize the COVID-19 disease-free state. The subsiding of COVID-19 epidemics eventually follows the remnant of the order parameter of the infection dynamical system. These considerations are illustrated for the COVID-19 epidemic in Thailand from January to May 2020. The decay of effective contact rates throughout the three epidemic stages is demonstrated. Evidence for the sign-switching of the dominant eigenvalue is given and the order parameter and its stage-3 remnant are identified. The presumed impacts of interventions measures implemented in Thailand are discussed in this context.
Determination of refractive index on three mediums based on the principle of refraction of light
Authors: Malik A , Mardianti D , Nurlutfiah D , Izzah D W , Mulhayatiah D , Nasrudin D , Suhendi H Y 
Published: March 2021

AbstractThis study aims to develop a tool to determine the refractive index and height of objects in three media based on the principle of light refraction. The method used was an experimental method. The results showed the refractive index values of the three media were quite accurate when compared to the absolute refractive index. The relationship of the angle of the incident ray was directly proportional to the angle of the refractive ray. The angle of light produced will be greater if the value of the given beam angle was greater. Thus, the set of refractive index laboratory tools developed is said to be good and suitable to be implemented in schools to explain the concept of the refractive index of light.
Experiential learning using STEM approach in improving students’ problem solving ability
Authors: Lestari I F 
Published: March 2021

Abstract
This study aims to explore the increase of students’ problem solving ability as the impact of the application of experiential learning using STEM approach. This study use a pre experiment method that is applying the one group pretest-posttest learning design. The participants are 40 students (18 male and 22 female) of second grade Science program in one high school in Province of West Java. The selection of the participants is using random class sampling technique. The data are collected based on the questions that are given to the participants. The questions are divided into five indicators of problem solving ability in Pascals’ principle learning material. According to the result of this study, that using normalized gain, it shows the increase of students’ problem solving ability that can be categorized in high level. The highest score for the students’ problem solving ability is in describing problem and planning a solution, whereas the lowest score is in giving evaluation for the solution of the problem. The result of this study shows that the experiential learning using STEM approach can be used as an alternative to improving students’ problem solving ability, especially in Pascals’ principle.
Spring oscillator as case based learning (CBL) device
Authors: Uskenat K , Iswanto B H , Indrasari W 
Published: March 2021

Abstract
This research aims to: (1) develop and find out the feasibility of a spring oscillator practicum; and (2) practice the spring oscillator tool developed. The research method was the research & development method with the ADDIE development model. The study was conducted at SMAN 1 Indramayu in July-August 2019. The instrument was developed using a laser distance sensor type VL53lX as a distance gauge, a vibrator made from a coil as a spring and LCD system shaker and a laptop to display the results of the experiment. The control system uses Arduino Nano. The study was conducted in March-May 2019 at the Physics Laboratory, FMIPA, Jakarta State University. The experimental results of measuring the spring constant get an average value of 6.527 N / m. The second experiment obtained an average value of the natural frequency of the system at 1.672 Hz. The third experiment obtained a maximum amplitude value of 4.8 cm and a period of 0.59 s. The results of expert validation from media experts, and material experts were 85.16% and 90.04%, respectively. The trial of practicum tools was carried out at SMAN 1 Indramayu, West Java, as many as 20 students with a percentage of 86.66% achievement. Based on the data it is concluded that the spring oscillator practicum tool developed is suitable for use as a learning medium.
Rural and urban students’ attitudes toward physics: a comparative study using Rasch analysis
Authors: Ringo S S , Kuswanto K , Samsudin A , Setiawan A 
Published: March 2021

Abstract
Physics education researchers have put out a large number of papers about attitudes. Yet, only few papers employed Rasch model to analyze data of attitudes. This paper reports a comparative study of students’ attitudes toward physics from rural and urban high schools (n=130). In order to collect data of attitudes toward physics, the Colorado Learning Attitudes about Science Survey (CLASS) was administered online to participated students. Obtained data were analyzed by using Rasch model and t-test. Prior Rasch analysis revealed that all items of the CLASS were fitted the Rasch model and had good psychometric properties. The present research found that there were no significant differences between rural and urban students in terms of attitudes toward physics. This result was in line with some earlier finding, but contrary to other previous result. One of variables probably affecting this outcome was teachers’ unawareness of technology usage and other school facilities to enhance teaching quality.
Evaluation of critical thinking skills of class x high school students on the material of Newton’s laws
Authors: Febriana R , Sinaga P 
Published: March 2021

Abstract
This study aims to determine of critical thinking skills of class X high school students in the material of Newton’s laws. The research subjects used 36 students consist of 18 males and 18 females with their average age 15 years old of class X at one of the high schools in Duri City. The research instrument used is the problem description which was constructed using indicators of critical thinking skills proposed by Ennis. Data analysis is based on the percentage of critical thinking skills. The results of total number of students, aspect of critical thinking skills providing simple explanations worth 49%, aspects of basic skills in making decisions, 39.5% of students were able to work on problems in skills Inference aspects worth 59.3%, aspects of advanced clarification skills worth 56.5%, and on aspects of strategy and tactic skills worth 57%. The results of these data indicate that students’ critical thinking skills are still low. The results of this study can provide teachers as an educator with information and illustration about the condition of students’ critical thinking skills. Teachers can make various efforts in improving students’ critical thinking skills in accordance with the demands of the curriculum in the 21st century.
Introducing physics in early childhood: logic, language, and literacy
Authors: Nasrudin D , Fitriyanti N , Muhtar SN , Dalimunthe R N R P , Nandang A , Hidayat W , Kurnia A 
Published: March 2021

Abstract
Physics is an important subject matter for everyone to learn. Therefore, introducing physics from an early age is a necessity. This paper wants to uncover various thoughts about efforts to introduce physics to early childhood. The method used is a Focus Group Discussion (FGD), which involves experts from physics education, linguists, management, and early education. There are several important points that became the result of the FGD, including (1) physics logic must be made simpler that is easy to understand (2) Mathematical formula which becomes a symbol language does not need to be introduced first. Language skills are needed to understand physics and communicate it (3) Through the right approach, method and media, learning that is delivered by the teacher will make early childhood more literate with physics. This research concludes that physics is possible to be taught in early childhood. We, therefore, recommend that early childhood teachers collaborate with physics teachers in planning, implementing, and evaluating physics learning.
Measuring collaborative problem-solving skills (CPSS) of vocational high school students using web-based assessment
Authors: Azura A , Suwarma I R , Efendi R 
Published: March 2021

Abstract
This study describes an online method for measuring students’ collaborative problem-solving skills individually using two interactive web-based assessment on the webcps program, with students working in pairs. The method used in this research is a qualitative method of case studies of vocational high school students on dynamic electric material. Process flow data was taken from 30 students (17 of them male students and 13 female students) who completed the assignment at one of the vocational high schools in Riau province. Data is transformed into indicators of collaborative problem-solving skills and is categorized based on four levels namely beginner (level 1), emerging (level 2), intermediate (level 3), and advanced (level 4). The results show that students are at various levels with different characteristics in both the social domain and cognitive domain in CPS skills. The assessment used in this study can be used as a measurement tools electrical circuit and as an instrument of measurement for collaborative problem-solving skills.
Promoting the model introducing, connecting, applying reflecting, and extending using Rasch analysis (ICARE-R) to improve students’ critical thinking skills on physics concepts
Authors: Sa’diyah L H , Siahaan P , Samsudin A , Suhendi E , Riani V R , Fatima W O 
Published: March 2021

Abstract
Critical thinking skills are important in physics learning because in physics learning comparable with examination actions on focuses reaching since detecting, formulating complications, collecting data, processing and considering data, and finishing. This study purposes on promoting of the ICARE model to improve students’ critical thinking skills on physics concepts using Rasch Analysis. The research method used a pre-experimental method with one group pretest-posttest design for 21 eleventh grade students (10 males and 11 females) and using Rasch analysis to measure the person reliability. Data were collected by pretest and posttest to measure of the ICARE model and person reliability on students’ critical thinking skills. The results showed that ICARE model persuaded critical thinking skills by the average score of 0.62, categorized as medium. It can be concluded that the ICARE model as one of the learning models that can influence and enhance students’ critical thinking skills.
The impact of PhET virtual lab worksheets on student learning outcomes on sound wave materials
Authors: Halim A , Farhan  , Ahyuni A , Susanna  , Andriani W , Irwandi  
Published: March 2021

Abstract
The need for students’ worksheets is felt urgent and very necessary, especially when the covid-19 pandemic. Therefore, through this research a Student Worksheet (SW) will be developed and the application to increase the understanding of the Sound Wave concept in Middle School students. The development of SW uses a Research and Development approach through the ADDIE model. SW limited trials were conducted on high school students. This research was conducted in 2 cycles of 4 meetings, each of which consisted of 4 stages: planning, implementation, observation and reflection. In addition, the feasibility of the learning tools used, the feasibility of learning, classroom management and students’ responses to learning were examined. Trials on limited samples, test student learning outcomes, teacher skills and student responses. Data analysis method used is descriptive method. Results that being analyzed with descriptive statistics it was found that the use of Lab Virtual PhET SW can improve student learning outcomes and teacher skills in the learning process in each cycle.
Experiments of the law of conservation of mechanical energy using video tracker in high school learning
Authors: Fahrunnisa S A , Rismawati Y , Sinaga P , Rusdiana D 
Published: March 2021

Abstract
Props have been made to prove the law of conservation of mechanical energy using a video tracker, a miniature road Roller Coaster is a teaching aid that will be used for experiments. Through this learning media, it is hoped that it can help the physics learning process of Covid-19. The learning implementation is carried out in one of the high schools in West Bandung Regency in the even semester of the 2019/2020 school year. Determination of the research area using the method of the purposive sampling area, which means the area was chosen deliberately based on specific objectives and considerations. The population in this study were all students of class X MIPA. Using a video tracker is very helpful in the experiential process, the results of the implementation of this learning media can be implemented well as indicated by the results of the achievement of student indicators.
Pedagogical and professional physics teacher training: why hybrid learning is important?
Authors: Mulhayatiah D , Sinaga P , Rusdiana D , Kaniawati I , Suhendi H Y 
Published: March 2021

Abstract
Teacher professional development is inseparable from the process of increasing teacher competency that can be trained through training activities. Training held to improve the pedagogic and professional competence of physics teachers both by the training organizers and the deliberation of subject teachers is generally still conducted face-to-face, even though the teacher has limited time and place in following it. This happens because the teacher also has to carry out his main task of teaching, so we need a training strategy that can be accessed by teachers anywhere and anytime. The purpose of this study is to find out the reasons why in the process of developing pedagogic and professional teachers need learning strategies that are based on hybrid learning. This research method is descriptive qualitative using data collection techniques in the form of interviews, documentation studies, and questionnaires for teacher needs in the implementation of training. The results obtained based on interviews with the training providers showed that the implementation of the pedagogical and professional teacher improvement training was still conducted face-to-face. Meanwhile, the results of the questionnaire distributed to 45 physics teachers showed that most of the teachers stated that they needed training to improve pedagogic and professional competencies, which facilitated the teacher’s training in the form of combining face-to-face and online. This can be done by implementing a hybrid learning training strategy, because in hybrid learning we can combine face-to-face and online training.