bluuebunny/crossref_metadata_2025_split huggingface dataset:
The investigation of stability of n-CdS/p-Cu2S solar cells prepared by cold substrate method
Authors: Manir Melih , Nevruzoglu Vagif , Tomakin Murat 
Published: January 2021

AbstractIn this study, two different n-CdS/p-Cu2S solar cells were prepared by evaporating Cu at different substrate temperatures (200 K and 300 K) by vacuum evaporation method on a single crystal CdS semiconductor. Field emission scanning electron microscope images showed that the Cu layer obtained at a temperature of 200 K was composed of nanoparticles in accordance with the soliton growth mechanism. Cu film thickness was determined as 395 ∓ 0.76 nm at 300 K substrate temperature and 187 ∓ 0.45 nm at 200 K substrate temperature. The current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the solar cells were examined for 12 weeks in dark and light environments. Open-circuit voltage (Voc), short-circuit current (Isc), maximum power (Pmax), filling factor and efficiency (η) were calculated fromI–Vmeasurements. For the prepared solar cells, the highest efficiency value was obtained in the 7th week (η= 0.1360) at 200 K substrate temperature, while it was obtained in the 5th week (η= 0.0384) at 300 K substrate temperature. FromC–Vmeasurements, donor density (Nd) and barrier potential (Vbi) were calculated. The solar cell produced at 200 K substrate temperature has higher donor density (1st week 2.99 × 1016cm−3) and barrier potential values (12th week 0.411 V). At the end of the 12-week period, the deterioration rate of solar cells created at 200 K and 300 K substrate temperatures was 51% and 94%, respectively.
Impurity dephasing in a Bose–Hubbard model
Authors: Caleffi Fabio , Capone Massimo , de Vega Inés , Recati Alessio 
Published: January 2021

Abstract
We study the dynamics of a two-level impurity embedded in a two-dimensional Bose–Hubbard (BH) model at zero temperature from an open quantum system perspective. Results for the decoherence across the whole phase diagram are presented, with a focus on the critical region close to the transition between superfluid and Mott insulator. In particular we show how the decoherence and the deviation from a Markovian behaviour are sensitive to whether the transition is crossed at commensurate or incommensurate densities. The role of the spectrum of the BH environment and its non-Gaussian statistics, beyond the standard independent boson model, is highlighted. Our analysis resorts on a recently developed method (2020 Phys. Rev. Res.
2 033276) – closely related to slave boson approaches – that enables us to capture the correlations across the whole phase diagram. This semi-analytical method provides us with a deep insight into the physics of the spin decoherence in the superfluid and Mott phases as well as close to the phase transitions.
A comparison of condensate mass of QCD vacuum between Wilson line approach and Schwinger effect *
Authors: Tahery Sara , Chen Xurong , Zou Liping 
Published: January 2021

Abstract
We studied the condensate mass of QCD vacuum through the duality approach via dilaton wall background in the presence of the parameter

, which represents the condensation in a holographic set up. First, from Wilson line calculation, we found

(i.e., the condensate parameter in mixed non-local condensation), whose behavior mimics that of QCD. The value of

that we found by this approach is in agreement with QCD data. Second, we considered the produced mass

via the Schwinger effect mechanism in the presence of the parameter

. We show that vacuum condensation generally contributes the mass dominantly and that the produced mass via Schwinger effect is suppressed by

.
Higgsino asymmetry and direct-detection constraints of light dark matter in the NMSSM with non-universal Higgs masses *
Authors: Wang Kun , Zhu Jingya , Jie Quanlin 
Published: January 2021

Abstract
In this study, we analyze the direct-detection constraints of light dark matter in the next-to minimal supersymmetric standard model (NMSSM) with non-universal Higgs masses (NUHM); we specially focus on the correlation between higgsino asymmetry and spin-dependent (SD) cross section. We draw the following conclusions. (i) The SD cross section is proportional to the square of higgsino asymmetry in dark matter

in the NMSSM-NUHM, and hence, it is small for highly singlino-dominated dark matter. (ii) The higgsino-mass parameter

is smaller than approximately

in the NMSSM-NUHM due to the current muon g-2 constraint, but our scenario with light dark matter can still be alive under current constraints including the direct detection of dark matter in the spin-dependent channel. (iii) With a sizeable higgsino component in the light dark matter, the higgsino asymmetry and SD cross section can also be sizeable, but dark matter relic density is always small; thus, it can escape the direct detections. (iv) Light dark matter in the

- and Z-funnel annihilation channels with sufficient relic density can be covered by future LUX-ZEPLIN (LZ) 7-ton in SD detections. (v) The spin-independent (SI) cross section is dominated by

- and

-exchanging channels, which can even cancel each other in some samples, leaving an SI cross section smaller by a few orders of magnitude than that of one individual channel.
Proton radioactivity half-lives with nuclear asymmetry factor
Authors: Soylu A. , Koyuncu F. , Gangopadhyay G. , Dehghani V. , Alavi S. A. 
Published: January 2021

Abstract
The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical formula. Using the single-folding formalism with asymmetry-dependent nuclear radius and surface diffuseness of nuclear matter, the nuclear potential and consequently the half-life are functions of the asymmetry factor. Despite small values of asymmetry in neutron-deficient proton emitters, noticeable changes in the half-lives are observed. The addition of an asymmetry parameter term to the two forms of empirical formulas leads to a reduction in the rms error for ground state and isomeric transitions. A noticeable reduction of about 43% is obtained for isomeric transitions in the second form of the empirical formula. Considering ground state transitions in two categories, odd-even and odd-odd emitters, and adopting deformation and asymmetry-dependent empirical formulas, the rms decreases remarkably. The lowest values of rms errors, viz. 0.1492, 0.2312, and 0.1999, are obtained for the aforementioned empirical formulas for ground state transitions of odd-even and odd-odd emitters and for all isomeric transitions, respectively.
Prediction of electron density and pressure profile shapes on NSTX-U using neural networks
Authors: Boyer M.D. , Chadwick J. 
Published: January 2021

Abstract
A new model for prediction of electron density and pressure profile shapes on NSTX and NSTX-U has been developed using neural networks. The model has been trained and tested on measured profiles from experimental discharges during the first operational campaign of NSTX-U. By projecting profiles onto empirically derived basis functions, the model is able to efficiently and accurately reproduce profile shapes. In order to project the performance of the model to upcoming NSTX-U operations, a large database of profiles from the operation of NSTX is used to test performance as a function of available data. The rapid execution time of the model is well suited to the planned applications, including optimization during scenario development activities, and real-time plasma control. A potential application of the model to real-time profile estimation is demonstrated.
Comparison of SSA and SARIMA in Forecasting the Rainfall in Sumatera Barat
Authors: Fitri F , Rahmat R 
Published: January 2021

Abstract
Rainfall data in West Sumatra in 2001–2018 is assumed to have a seasonal pattern. Several methods can be used to model this data, including SSA and SARIMA. Each method has a different approach but has its own advantages. Therefore, a comparison will be made between the two based on the MAPE. According to the forecasting result, obtained MAPE for SSA is 17% and 22.75% for SARIMA.
Special Probability Distribution In Surah Al Falaq
Authors: Fitria D , Amalita N 
Published: January 2021

Abstract
Learn a subject which is not seem useful in daily life was really not interesting. How if it subject depends on religion, it will increase the motivation to study as worship spirit. All muslim known the Surah Al Falaq and they recite it daily since they were very young. In each verses in this surah tells us the concept of special probability distribution i.e Bernoulli, Binomial, Multinomial and Geometric distribution.
The Effectiveness of Student Worksheet Based on 4’Cs Skills to Improve Higher Order Thinking Skills Students’ SMP Pekanbaru
Authors: Yuanita P , Maimunah  , Arnellis  
Published: January 2021

Abstract
This study aims to determine the effectiveness of Student Worksheet (LKPD) based on 4'Cs skills and its effect on improving higher-order thinking skills of class VIII SMPN 4 Pekanbaru. The design used in this study was pre-experimental with the Static Group Comparison design. The data analysis technique was performed using statistical t-test. The results showed that this LKPD was declared effective as a learning innovation based on indicators of higher-order thinking skills. The effectiveness of the LKPD based on 4'Cs skills is proven to be influential in improving higher-order thinking skills based on the acquisition of results using the difference test.
Analysis of High Order Thinking Skill of Students in Contextual Problems Solving
Authors: Arnellis  , Fauzan A , Arnawa I M , Yerizon  
Published: January 2021

Abstract
This study aims to analyze the high-order thinking skills of students in solving contextual problems in calculus lectures. Currently, students are required to be more creative in solving calculus problems that lead to High Order Thinking Skill (HOTS) thinking, where students apply the knowledge and skills that have been developed during lectures in a new context. This type of research is qualitative, with a descriptive presentation method and a case study approach. The subjects in this study were six students of the January-June 2020/2021 semester mathematics education study program who were selected based on their level of ability to solve contextual questions. The data collection techniques used in this study were observation and written tests presented in contextual problems. Based on the research results, it can be concluded that student HOTS is determined by the student's ability to solve contextual questions, the higher the student's ability to solve contextual questions, the more HOTS indicators are achieved. HOTS students with high abilities are able to meet indicators of analyzing, evaluating, and creating. HOTS students with moderate ability are able to meet the indicators of analyzing and evaluating. HOTS students with low ability are able to only meet the analyzing indicators, The results showed that there were differences in HOT problem solving among students with high, medium and low abilities.
An Initial Observation for Development of Learning Instruction Based on Ethnomathematic at SMP Pembangunan Padang
Authors: Rurisman  , Yerizon  
Published: January 2021

Abstract
Junior high school student learning outcomes are still low, especially problem solving abilities. This happens because the existing equipment does not match the characteristics of students. Good learning instruction will lead students to have good problemsolving abilities. Initial observations aim to find, analyze and explain (1) students' mathematical problem solving abilities (2) the conditions of learning tools (LKPD) used and developed by the teacher (3) as a basis for continuing ethnomatematic based development research to develop problem solving abilitiesof students. This is a descriptive study research with a qualitative approach. The results of the observations made at the UNP Laboratory Development Junior High School, it can be concluded that the learning tools still not connect the material with the environment and student culture, so the learning experienced by students is less meaningful. The LKPD used are still general and does not match the characteristics of students.
Development of Problem-Based Learning (PBL) Instrument to Improve Mathematical Communication
Authors: Putri M E , Yerizon  , Khaidir C 
Published: January 2021

Abstract
The purpose of the research is to develop students' worksheet with valid, practical, and effective PBL-based for the second semester of VIII grade students of SMP / MTs to improve mathematical communication. This research was conducted in class VIII of MTsN 7 Tanah Datar. This research was using Plomp model development, which consists of three phases, namely preliminary research, prototyping, and assessment. The instruments used in this research were LKPD validation sheets, questionnaires, interview guidelines, and tests. Before using the tool to collect data, the tool has been validated by the validator. The results showed that the designed LKPD is valid, practical, and effective.
Application of the E-Learning with Adaptive Theory Information Model in English for Mathematics Lectures
Authors: Jamaan E Z , Arnellis  
Published: January 2021

Abstract
After the emergence of the Covid-19 outbreak, the education system began to look for the latest innovations to form an effective lecture process with a learning model that was suitable for students in distance learning using the E-Learning learning model which was been adaptive additional information was needed. It;s known as the Elita model. The purpose of this research is to produce profile information about Elita's users who are categorized, in student's achievement and student's preferences in English for Mathematics lectures. This type of research is a mixture of qualitative and quantitative. Quantitative data were obtained from tests, and qualitative data were obtained from interviews and observations. The population is students of Mathematics Education, Universitas Negeri Padang. The sample was 43 students from January to June 2020 semesters. The instruments used were interview guides, field notes, and tests. The results obtained were the achievement of student's achievement in understanding the EFM lecture material, an increase in the average score, while the results of student’s preference in the EFM lecture process with the Elita model was moderate.
Development of an Android-Based for Math E-Module by using Adobe Flash Professional CS6 for Grade X Students of Senior High School
Authors: Ilmi R , Arnawa I M , Yerizon  , Bakar N N 
Published: January 2021

Abstract
Learning in the industrial revolution 4.0 requires the optimal use of technology in the learning, one of which is by learning to use mathematical e-modules that can be operated on smartphones using an android operating system. This study aimed to create valid, practical, and effective android-based e-modules. This research was research and development (R&D) with the Plomp development model, which consists of the preliminary research phase, the development or prototyping phase, and the assessment phase. The subjects of this study were students of grade X in SMA N 5 Pekanbaru. The results of this study were the android-based e-module was valid, practical, and effective. The validity of e-modules was classified based on the results of the experts' evaluation. The practicality of the e-module was classified based on the questionnaire responses of teachers and students, who can use the e-module well, can help students in understanding the material, and interested in using it. The effectiveness of e-modules was classified by the percentage of student's completeness learning after using e-modules more than 70%.
Primarily research on the mathematical problem-solving abilities of grade X Vocational High School students for Computer and Network Engineering Competencies
Authors: Oktari A , Permana D 
Published: January 2021

Abstract
Computer and network engineering are one of the skill competencies in Vocational high school. Graduates of this major are expected to have problem-solving abilities to be able to compete in the working world. Mathematics is a subject that can develop mathematical problemsolving abilities. This study aimed to see, review and describe the mathematical problem-solving abilities of students and draw conclusions about these things as the phenomena found and to review the conditions of the learning devices used and developed by the teacher. This research used descriptive quantitative research methods. The data was collected through interviews, observations, and giving tests. Data analysis techniques used descriptive techniques for the results of observation and interview data, and scoring rubrics for mathematical problem-solving abilities for test result data. The results showed that the students' mathematical problem-solving abilities were still not relatively low. Some of the factors that cause this are 1) the learning was still using the lecturing method so that learning became meaningless, 2) students were accustomed to copying and memorizing formulas given by the teacher without understanding them, 3) the learning tools used were the same for each skill program, 4) a mathematics learning approach had not led students to be actively involved in the learning process and had not guided students to construct their knowledge in improving mathematical problem-solving abilities. Based on these results, further action is needed in the form of research on the development of constructivism-based learning tools to improve the mathematical problem-solving abilities of students in the Vocational High School for Computer and Network Engineering Competencies.
Development of learning media based on to improve the mathematical problem solving abilities of grade 11 senior high school student
Authors: Fikriah E , Arnawa I M , Yerizon  , Asmar A , Bahri S 
Published: January 2021

Abstract
As it was found in many schools, the learning media have not helped educators in facilitating students in supporting an effective learning process. Learning tools which consist of a syllabus, lesson plans, teaching materials and learning outcomes tests that were used do not involve students actively. One effort that can be used is through discovery learning methods that are valid, practical and effective. Where this method was implemented by connecting the concept of learning with problems in everyday life and aimed to improve students' problem-solving abilities and teaching them how to solve problems until new knowledge was discovered by students. The aimed of this development was to produce a learning media based on discovery learning by using GeoGebra on valid and practical for second semester topic. This type of research was a development research using the Plomp development model which consists of three phases where the initial investigation, the development phase and the assessment phase. The research subjects were students of class grade 11 in Senior High School Number 2 Pulau Punjung. The results of the validity of the data analysis indicated the ddiscovery learning were in valid criteria in terms of content and validity of lesson plan with a percentage of 86.78% and the validity of worksheet was 82.24%. Practicality of learning media, attractiveness, comfort and time efficiency were 95% based on teacher questionnaire responses and 85.30% questionnaire responses for student learning media with discovery leaning method and the affectivity of discovery learning in term of completeness was 83. 87%.
Mathematical Problem Solving Ability Package A Elementary School Equivalents In PKBM Kasih Bundo Bukittinggi
Authors: Bayu E P S , Fauzan A , Armiati  
Published: January 2021

Abstract
Good learning can maximize the potential of students through various active and fun activities. No exception for equality education in the form of the package A equivalent elementary school program. But in reality learning in the Package A program still experiences various problems, especially in problem-solving abilities that apply mathematical concepts through higher levels of thinking. It can be seen from the low it results that the achievement of problem-solving ability averages less than 20%. This finding is supported by the lack of understanding of educators in terms of implementation, age diversity students, and the content standard is quite dense while learning activities are less than optimal providing meaningful experiences. For this reason, one form of learning that can be done with the right learning approach, one of which is RME. This approach will integrate mathematical problem solving abilities into its application.
Development of constructivism-based mathematics learning tools for eleventh graders
Authors: Hidayati F , Arnawa I M , Bahri S 
Published: January 2021

Abstract
Critical thinking skills are complex thinking abilities, so they can determine what students must believe and do. An attempt to improve the critical thinking skill is by applying the constructivist approach to the learning tools. The learning device was tested on students’ class XI of SMA N 2 Lubuk Basung. This research is development research that implements Plomp design. There are three stages that should be done. The first stage is the initial investigation stage (preliminary research). Next is the development stage (development or prototyping stage). Last is the assessment stage. This research is only limited to one to one stage because it is in the COVID-19 period. Three eleventh graders of SMA N 2 Lubuk Basung become the subject of this research. There are three instruments used in this study: validation sheets, student questionnaire responses, and interview sheets with teachers and students. If the learning tools satisfy content and construct validities, they are considered valid. The results of the validation of the RPP and LKPD experts were 0.95 and 0.96 with a valid category. The conclusion based on the research finding is that the constructivism-based mathematics learning tools for eleventh graders of SMA N 2 Lubuk Basung can be declared valid.
The Influence of Using Computers in Mathematics Learning to Students Mathematical Ability
Authors: Ulfa M , Yerizon  , Arnawa I M 
Published: January 2021

AbstractThe use of technology has entered all aspects of human activities, belonging education. The use of computer-based media in the learning process is very useful. This study aims to describe the results of various studies on the use of computers in the learning of mathematics. The method used is descriptive research. The aspects seen are the various types of software used and their effects on mathematics learning. Based on the results of the research, it can be concluded that the use of computers can help students visualize and understand mathematics material.
Research on the method of determining satellite state vector based on Kepler orbital parameters
Authors: Shao Changguo 
Published: January 2021

Abstract
to simplify the process of satellite orbit determination, can use limited conditions known to the calculation of satellite orbit dynamic state vector to determine satellite position to implement the standardization of satellite orbit, this paper introduces the satellite state vector at any time using the Kepler orbital parameters method, the calculation method of Kepler orbit parameters are mostly only for satellite without disturbing force movement. This paper is based on the three-point method which is used to calculate the orbit parameters of Kepler satellite in the case of satellite unphotographed.