bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developing proportional reasoning problem like PISA with “choosing services” context
Authors: Utami Sri , Zulkardi  
Published: March 2020

Abstract
This study aims to produce the valid mathematic problems like proportional reasoning in PISA question. The research involved seventh-grade students in one of the junior high school in Palembang. The methodology of this research is a design research with development studies type that consist of preliminary and formative evaluation stage. This article just only discuss validation of problems process and data about student strategies in one to one process. The data collection techniques used walktrough, documentation, observation and interview. The validity of the problems discovered from expert review in validation process. Problems validated based on content, problem has been accord to ratio and proportion learning in seventh-grade, construct, the problem require the student’s proportional reasoning and accord to abilities of the seventh-grade students; and language, the problems use of enhancing spelling, could be understood, and didn’t have variety of meanings. The result show that problems are designed using the context of choosing services can indicate how student’s proportional reasoning. Problems developed indicate that students had different strategies and do not refer to the proportion formula, but with reasoning and the use of a ratio table.
Learning design using PMRI to teach central tendency materials
Authors: Meitrilova A , Putri R I I 
Published: March 2020

AbstractThis study aims to determine the role of activities in learning the central tendency materials (mean, median, and mode), which is expected to be able for helping students understanding the concept of statistical learning in grade VIII. The method used in this study is Validation Studies type Design Research involving students of MTs Negeri 1 Palembang. There are three stages in the design research type of validation studies, namely Preparing for the experiment; The design experiment in the form of a Preliminary Teaching Experiment (Pilot Experiment) and Teaching Experiment; and Retrospective analysis. In this study only that of preliminary teaching experiment is considered. The activity begins with questions about remind the presentation of data in the diagrams, then understanding the concept of the mean, the median, and mode, the question of associating the mean and median to determine the mode. The results of the learning experiment show that through the given questions can support students to understand the concept of the central tendency and know the relevance. Errors in doing activities because students are not careful in reading information on the questions, weak in the ability to count, and don’t remember or not understand about the materials given.
Physics education students’ perception on the use of motion detector in linear motion practicum
Authors: Hariwangsa Panuluh Albertus , Dian Atmajati Elisabeth , Dwi Kristanto Yosep 
Published: March 2020

Abstract
The use of technology in teaching and learning is very common today. In physics learning, practicum has an important role, namely deepening the understanding of concepts and applying concepts. However, it is interesting to know the importance of using technology in practicum. This study aims to know to know the student’s Physics education students’ perception on the use of motion detector in linear motion practicum The present study was descriptive research using a qualitative approach. This research was carried out in mechanics experiment class with 16 students as research subjects. This study used students’ reflection and interview in collecting perception’s of the students. The research found that practicum with motion detector has significant role in results obtained. On the other hand, practicum with motion detector has unsignificant role in the student’s carefullness.
Development of mathematical learning devices based on multimedia on circle materials of grade eighth of junior high school
Authors: Laurens Th , Laamena Ch. M. 
Published: March 2020

Abstract
This study aims to develop multimedia-based mathematical learning tools that are valid and practical in circle material. Learning tools developed are Lesson Plan, Teaching Materials and Student Worksheets. This type of research is development research that uses a 4-D (Four-D) development model developed by Thiagarajan and consists of 4 stages namely define, design, development, and dissemination, but due to time constraints, it is only limited to the development stage. The research subjects were seventh-grade junior high school students at the Angkasa Lanud Pattimura Ambon. The results of the study show that the learning devices developed are valid and practical. This is indicated by the general average validator rating for the three devices is 3.44; practicality of learning 92.98% and mastery of students taught by using the results of the development of 71.42%
Teacher’s questions on mathematics learning based on ELPSA framework
Authors: Rozalia  , Johar R , Duskri M , Khairunnisak C , Zubaidah T 
Published: March 2020

Abstract
Teacher’s question to encourage students to build their understanding is an essential aspect of mathematics learning. However, teachers show little concern about the quality of questions posed to students. Teachers can implement various strategies in conducting their roles as facilitators in developing students’ understanding. One of which is through questions. ELPSA framework requires teachers to ask questions to help students construct their knowledge. This framework consists of five components: Experience, Language, Pictorial, Symbol, and Application. This study discussed the profile of teacher’ questions based on ELPSA framework. The questions were classified into the types of questions, namely: factual, convergent, divergent, and evaluative questions. This study employed a qualitative research design using an observation sheet as the instrument. The participant of the study was a mathematics teacher from one of the junior high schools in Banda Aceh. The results concluded that the profile of teacher’s questions in Year 8 of one of the junior high schools in Banda Aceh developed for each component of ELPSA framework. These developments were indicated by the suitability of the types of teacher’s questions and the types of questions expected in the components of ELPSA framework.
Website design of Capita Selekta Mathematics Course for mathematics education students
Authors: Thahir Musa , Roza Yenita , Murni Atma 
Published: March 2020

Abstract
This article is based on the use of learning models that are limited to the subjects of Kapita Selekta Mathematics. This article aims to explore the results of the development of a website for learning Kapita Selekta Matematika (KSM) on UIN Suska Riau students that is valid, practical and effective. This research uses a development research model of Borg and Gall. The research instruments used in this article are validation sheets (validity aspects) by involving 6 validator lecturers, lecturer assessment sheets and student assessment sheets (practical aspects) involving 5 students, and student learning outcomes tests (aspects of effectiveness) involving 28 students. The data in this research is analyzed using quantitative and qualitative descriptive. This results in a course learning website which is valid (the average overall aspect of material validation was 4.15 and the average overall aspects of validation technology is 3.98), practicality score is 4.23 with the category “GOOD”, and effective (Sig. 0,000 <Sig (1-tailed) 0.05). Thus, student-learning outcomes after using the learning website are better than before using the learning website. Based on the tests carried out, the development of the overall learning website on the material and technological aspects can be categorized as feasible, while the practical aspects can be categorized as practical, so this learning website can be used as a learning medium to help the learning process.
Javanese calendar as context to learn number pattern and least common multiple
Authors: Zulkardi  , Setiawan M B T 
Published: March 2020

Abstract
This research is about to investigate how Javanese calendar and primbon could be used as context to learn number pattern, least common multiple and modular arithmetic for high school students. This article is the first step for the research, as this research only just reach preliminary stage at this point, which consist of validation on worksheet, one to one and small group to gain data about students’ understandings regarding connection between contexts as student perception with mathematics learning which they had learned. This research using Realistic Mathematics Education (PMRI) approach. The problems which given in this research was based PISA framework. The methodology of this research is using Design Research. This research produce valid and practical problem, worksheet for learning material and support students to understand more about number pattern and least common multiple as basis to learn modular arithmetic even as the learning material itself only just enrichment in national curriculum.
The teachers’ ability in mathematical literacy for space and shape problems on Program for International Student Assessment (PISA) adaptation test
Authors: Julie H , Sanjaya F , Anggoro A Y , Rudhito M A , Putra D P W 
Published: March 2020

Abstract
The teacher’s mathematical ability is one of the factors that influence the achievement of students’ mathematical abilities. In Indonesia, almost all research related to PISA, the subject of research was a student. It is still rare that the subject of research was a teacher. How is the math literacy ability of the teachers? This question will be answered by researchers in this study, especially in the field of space and shape. The subjects were seven Mathematics teachers who taught in junior high schools from seven different schools in Yogyakarta and surrounding areas. In the process of this research, the researcher makes a test adapted from PISA questions. There were 13 questions in the test consisting of three questions in the quantity field, three questions in the uncertainty field, three questions in the field of change and relationship, and four questions in the field of space and shape. In this paper, we will present our result just for the Space and Shape part. The study found that (1) 7 teachers could achieve level 4 for problem 1a, (2) 6 teachers could achieve level 5 for problem 1b, (3) 2 teachers could achieve level 5 for problem 2, (4) 1 teacher could achieve level 5 and 6 for problem 3, and (4) 6 teachers could achieve level 6 for problem 4.
Clinical and radiological assessment of the effect of low level laser therapy on delayed bone fractures healing
Authors: Al Balah Osama , Allam Ahmad , Aid Ghada , Tabl Eslam , Abdelfatah Alaaeldin 
Published: March 2020

Abstract
Low level laser has been conducted for treatment of bone fracture on animal and had shown positive results. If laser energy is delivered at optimal dose with appropriate parameters, it might get best results however a little research in the literature has conducted on the effect of low level laser on human bone fracture. The aim of the study was to assess the radiological and clinical difference of the effect of low level laser therapy on the delayed bone healing of patients with different bone fractures. This was a prospective study conducted in Benha university hospital on 33 patients with delayed and non-union of bone fractures via low level laser diode laser with a wavelength 905nm. There were 27 male 5 female patients, mean age group ±34.43 range (24 years to 67 years), the mean delayed of union was ± 6,68 range (3 months to 15 months ). At the end of the study, union is achieved in mean period±1,7( 1 month to 4,1 month)which led to success of about 70% improvement of the treated group, union mean number of sessions used ±23,375 (range 15 sessions to 50 sessions), Mean Visual Analog Scale (VAS) ± 1,3 range from (0 to 6). the present study indicate that Low level laser therapy is an effective modality for treatment of delayed bone fracture, can relieve pain and increase range of motion of the associated stiff joints with no adverse effect provided that adequate patient selection has conducted.
Optothermal response and Tissue Damage analysis during Laser Hair Removal
Authors: Okebiorun Micheal O. , Elgohary Sherif H. 
Published: March 2020

Abstract
Effective design of laser sources is crucial to optimum performance during Laser hair removal. Therefore, the thermal effect of laser sources was evaluated at wavelengths 694, 755, and 1064 nm at different fluence 4.5, 5.5, 10, and 15 J/cm2, respectively. The patient skin models are 3 photo types of a 3-layer 3D model of epidermis, dermis and hypodermis containing the hair shaft and follicle with thickness carefully selected to be in range of a normal human feature. Monte Carlo method, Bio heat transfer and thermal damage analysis using Arrhenius formula were employed. Results show that a laser source of 10-15 J/cm2, at 755 nm wavelength is optimal for light skinned and moderate skinned while 4.5 -10 J/cm2, 755-1064 nm is optimal for dark skinned people for a pulse width of 0.1 sec. This work would assist researchers and manufacturers in the design and development of hair photoepilation devices.
The Effect of Temperature on the Optical and Analytical Properties of PET Polymer Used in Drinking Water Bottles
Authors: Hamdy Omnia , Tawfik Walid 
Published: March 2020

Abstract
Polyethylene Terephthalate (PET) polymer has been utilized in many applications including, optoelectronics, radiology and food packaging due to its resistance to weak acid, organic solvents, and oils, in addition to low density and low cost. However, physical, mechanical and optical properties of PET are highly dependent on some ambient conditions like temperature since its thermal deformation temperature is 76º C. In this work, the effect of increasing the ambient temperature on the PET material used in the fabrication of plastic water bottles was studied optically and analytically. The optical attenuation coefficient was considered at different room temperature ranging from 25 °C to 45 °C emulating hot-sun-days ambient conditions in the laboratory. The elemental composition of the selected polymers was achieved using laser induced plasma spectroscopy (LIPS) technique showing Al emission line at 257.5 nm and CN emission line at 386.1nm in the sample-generated plasma. The optical attenuation coefficient has showed a dramatic increase with the temperature which may lead to leaching of some toxic elements existed in PET polymer into the bottle’s water content during hot weather and cause health problems.
Study of Nonlinear Polymers Operating Parameters for Laser Pulse Chirping
Authors: Nada Y. S. , El-Azab J. M. , Othman H. , Mohamed T. , Maize S. M. A. 
Published: March 2020

Abstract
In this study, the optimization of the operating parameters of nonlinear polymers for self-phase modulation is reported. The effect of delocalization length and adding function groups (donor-acceptor groups) on the nonlinear refractive index are investigated. Based on nonlinear Schrödinger equation, the pulse chirping factor, for a set of nonlinear polymers, at different operating conditions, is studied. The comparison between laser pulse chirping factor resulting from saturated and conjugated polymers is presented. It is noticed that the chirping factor that evolved from conjugated polymers is greater than its equivalent in saturated polymers. Moreover, laser pulse chirping factor is increased with increasing of delocalization length. Therefore, this study may initiate the synthesis of new nonlinear polymers in order to produce appropriate nonlinear optical properties for high broadening materials in laser compression systems.
Three-Dimensional Holographic Reconstruction of Brain Tissue Based on Convolution Propagation
Authors: Abdelazeem Rania M. , Youssef Doaa , El-Azab Jala , Hassab-Elnaby Salah , Agour Mostafa 
Published: March 2020

Abstract
In this study, a dynamic holographic projection system for brain tissue and its anatomical structures extracted from Magnetic Resonance (MR) plane slice is reported. Computer holograms are calculated using a modified Gerchberg-Saxton (GS) iterative algorithm where the projection is based on the plane wave decomposition. First, brain anatomy includes white matter (WM), grey matter (GM) and brain tissue are extracted. Then, phase holograms using the proposed method are generated. Finally, single-phase hologram for the whole brain anatomy is generated and is optically reconstructed by a phase-only spatial light modulator (SLM) at different depths. The obtained results revealed that the three-dimensional holographic projection of MR brain tissue can aid to provide better interpretation of brain anatomical structure to achieve better diagnostic results.
Research on Floor Response Spectrum of Shielded Building Structure under Seismic Loading
Authors: Chen Yang , Xiong Cheng , Ma Tengfei , Zeng Wenlin , Wang Juan 
Published: March 2020

Abstract
As a clean energy source, nuclear power has broad prospects for development. It is of great significance to study the seismic response of nuclear power plants. PLAXIS software is used to establish the whole finite element model of AP1000 nuclear power plant shielding plant structure. Considering the foundation embedding and soil-structure interaction, the seismic response analysis of nuclear power plants on different inclined soft rock sites was carried out under seismic loading. By analyzing and comparing the calculated results of the floor response spectrum amplification factor, the peak frequency of the floor response spectrum at the important position is smaller than the peak frequency of the design response spectrum, the inclination of the inclined site will affect the peak frequency and cause the amplification effect.
Estimation on stress concentration factor of remanufacturing notch for TC4 titanium alloy
Authors: Ding Mingchao , Zhang Yuanliang , Xian Hongwei 
Published: March 2020

Abstract
Remanufacturing notch would be produced after crack polishing in remanufacturing pre-treatment. In the present study, stress concentration of remanufacturing notch was investigated by a series of semi-elliptical notch models using finite element analysis. Comparing with notch width, notch depth has a critical effect on stress concentration. An equation to estimate stress concentration factor (SCF) has been modified to be suitable for remanufacturing notch. Based on the pre-estimation of stress concentration for remanufacturing notch, references on crack polishing plan can be provided in the remanufacturing field.
Synthesis and Photophysical Properties of Small Molecule Donor Materials Based on Indacenodithieno[3, 2-b]Thiophene Core for Organic Solar Cells
Authors: Zhang Chao , Liu Kai-Kai , Zhang Han-Jian , Wang Jin-Liang 
Published: March 2020

Abstract
We synthesized a small molecule donor material based on IDTT for solar cells, named C6S2ThBSeIDTT, which was obtained by IDTT-2SnMe3 and a capping fragment by a simple Stiller coupling reaction. Its structure and properties were HNMR. C6S2ThBSeIDTT was confirmed that it exhibited good solubility in conventional organic solvent. It can be found that strong intermolecular charge transfer (ICT) exists in the D-A-D-A-D conformation. It has been found to have broad and strong absorption by absorption spectroscopy with a medium wide band gap of 1.70 eV, and will well agree with fullerene acceptors such as PC60BM and PC71BM for efficient bulk heterojunction solar cells.
Dynamic characteristic analysis of double-column machine bridge of spillway gate
Authors: Sun Naidong , Yang Lingqiang , Wang Zhenyu 
Published: March 2020

Abstract
The machine bridge has problems in many earthquake cases, such as cracking at the end of the column, excessive local displacement, and even severe damage. To improve the seismic property of the machine bridge, a new design method is proposed, namely the double-column machine bridge. The finite element analysis is used to analyze the dynamic time history of the structure, and the stress and displacement of the structure during the earthquake action are studied. In addition, the collision analysis between the machine bridges is carried out, which is based on the results of the three-dimensional finite element calculation. The results show that the double-column machine bridge has better seismic performance. Compared with the ordinary machine bridge, the displacement and stress of the new structure under the large earthquake are obviously reduced. By optimizing the structure, the collision between structures can be effectively avoided.
Review of biogas models and key challenges in the further development in China
Authors: Chen Lihong , Frederiksen Pia , Li Xin , Shu Bangrong 
Published: March 2020

Abstract
This paper provides an overview of biogas models and key challenges of further biogas development in China. A review of the biogas models aim to highlight the complexity of biogas development in China, and thereby draw attention to some easily neglected issues in China’s biogas development. China’s biogas development had stagnated in recent years, and while household biogas projects have always been the leading force of biogas production in China, their proportion declines year on year. “3 in 1”, “4 in 1” and “5 in 1” models are the most common models used in China, but Medium and Large-scale Biogas Projects (MLBPs) increasingly play a significant role. By comparison, MLBPs perform better than household biogas projects in some aspects. On the other hand, household projects have their advantages and are essential aspects of energy system development, particularly in more remote rural areas. This paper strongly recommends paying more attention to the practical application of household biogas models and providing the necessary support to skill development and digester maintenance. Moreover, this paper argues that biogas policies need to be based on scientific evidence.
The effect of thickness on properties of three-phase piezocomposites
Authors: Xu Junan , Wang Likun , Zhong Chao 
Published: March 2020

Abstract
In this study, three-phase piezocomposite is fabricated on the basis of the 1–3 composite structure and the cutting–filling method. The 1–3 piezocomposite is used with PZT-5A as the piezoelectrics and epoxy/silicone rubber as the matrix. The relationships between the performance parameters of the 1–3 composites and different thicknesses are analyzed via finite element simulation and experimental measurement. Composite samples with thickness of 3mm-10mm are prepared through an experiment and tested using an impedance analyzer. Simulation results agree well with experiment results, thereby indicating that the composites have a high electromechanical coupling coefficient.
Research on EP reinforced by nanoSiO2/Al2O3/ZrO2 and its mechanism
Authors: Xu Xuefeng , Cai Yuebo 
Published: March 2020

Abstract
Epoxy resin is modified by nanoSiO2, nanoAl2O3 and nanoZrO2 dispersed by dispersing agent by combining the means of high-speed mechanical stirring and ultrasonic cavitation. It aims at studying the influences of different nanometer-particles types and its dosages on the properties of composite. Research results show that the optimum dosages of nanoSiO2, nanoAl2O3 and nanoZrO2 are 1%, 3% and 5% separately. The tensile strengths of three kinds of composites are similar when it is added by its optimum dosages. The mechanisms of reinforcing epoxy resin caused by nanometer-particles are investigated by combining the SEM.