bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of peroxiredoxin 2 in cumulus expansion and oocyte maturation in mice
Authors: Jang You-Jee , Kim Jin-Seon , Yun Pu-Reum , Seo Young-Woo , Lee Tae-Hoon , Park Jae-Il , Chun Sang-Young
Published: May 2020

Peroxiredoxin 2 (Prdx2), an antioxidant enzyme, is expressed in the ovary during the ovulatory process. The aim of the present study was to examine the physiological role of Prdx2 during ovulation using Prdx2-knockout mice and mouse cumulus–oocyte complex (COC) from WT mice. Two days of treatment of immature mice (21–23 days old) with equine chorionic gonadotrophin and followed by treatment with human chorionic gonadotrophin greatly impaired cumulus expansion and oocyte maturation in Prdx2-knockout but not wild-type mice. Treatment of COCs in culture with conoidin A (50µM), a 2-cys Prdx inhibitor, abolished epiregulin (EPI)-induced cumulus expansion. Conoidin A treatment also inhibited EPI-stimulated signal molecules, including signal transducer and activator of transcription-3, AKT and mitogen-activated protein kinase 1/2. Conoidin A treatment also reduced the gene expression of EPI-stimulated expansion-inducing factors (hyaluronan synthase 2 (Has2), pentraxin 3 (Ptx3), TNF-α induced protein 6 (Tnfaip6) and prostaglandin-endoperoxide synthase 2 (Ptgs2)) and oocyte-derived factors (growth differentiation factor 9 (Gdf9) and bone morphogenetic protein 15 (Bmp15)). Furthermore, conoidin A inhibited EPI-induced oocyte maturation and the activity of connexins 43 and 37. Together, these results demonstrate that Prdx2 plays a role in regulating cumulus expansion and oocyte maturation during the ovulatory process in mice, probably by modulating epidermal growth factor receptor signalling.
Language policy and the law
Authors: Edwards Alison
Published: May 2020

Universities in the Netherlands are currently faced with finding a balance between the implementation of English-medium instruction and the protection and promotion of Dutch. In this article I analyse university language policy documents from a discursive and critical perspective. I explore the intertextual transformations involved in a multilevel process of policymaking; that is, as policy discourse shifts from the state legislation governing the language of instruction in higher education to the codes of conduct for language of the publicly funded universities. The institutions use various discursive strategies, including intertextuality and recontextualisation, to legitimate their reinterpretation of the basic legal principle ‘Dutch, unless’ as ‘English, unless’ (at master’s level, and increasingly at bachelor’s level too). Although the current law is set to be amended, it appears the proposed new law will simply require universities to do more paperwork while continuing on their current path.
The weakening of intervocalic /d/ in the Spanish of Las Palmas de Gran Canaria
Authors: Samper Padilla José Antonio , Samper Hernández Marta
Published: May 2020

The present paper compares the results obtained from the analysis of intervocalic /d/ in Las Palmas de Gran
Canaria with those of other PRESEEA research groups (four Spanish groups and a Latin American one). The Spanish of the Canary
Islands is placed, as in other phenomena, halfway between Peninsular and Latin American Spanish. In this process of weakening,
interdialectal differences in the degree of deletion of /d/ in participles and the determiner todo stand out,
together with some virtually Panhispanic characteristics. The differences in the weakening of the obstruent in these two contexts
are closely related to the frequency of their use in the different communities.
Convergences and divergences inthe use of the diminutive in Medellin, Caracas and Madrid
Authors: Malaver Irania , Paredes García Florentino
Published: May 2020

This article analyzes the differences and coincidences in the uses of the diminutive found in three varieties of
Spanish. Based on the classification of the pragmatic functions of the diminutive by Reynoso
(2003), and the analysis of 5355 cases of non-lexicalized diminutives, it may be observed that the three varieties
converge greatly in the production of the diminutive forms of -ito. There is some divergence in the variety of
lexical bases that support the diminutive since the people of Madrid use (and listen to) more diminutives than Americans, but they
use (and listen to) them in a smaller number of different words. The social factors contained in the sample have shown a reduced
effect on the functions of the suffix, and a partially differentiating behavior among the three communities: in Caracas, age has a
strong influence on the functions while, in Madrid and Medellin, the level of education is the factor that exerts more influence
on these functions.
Uses and resources of mitigation, in contrast
Authors: Cestero Mancera Ana M.
Published: May 2020

Mitigation is a highly complex pragmatic phenomenon which has been prioritized as a subject of study in recent decades. However, because of this complexity, there is still neither a convincing definition of exactly what mitigation is nor a definitive list of the linguistic and non-verbal resources through which it is carried out. For this reason, several empirical studies which seek to explain sociopragmatic and geolectal variability in the uses and strategies of mitigation are under way. This is also the aim of our paper, included in theProject for the Sociolinguistic Study of Spanish from Spain and America(PRESEEA). In it, we present relevant data obtained from the comparison of what occurs in Madrid, Valencia, Las Palmas de Gran Canaria and Puebla (Mexico) regarding the frequency of the production of mitigation and its function in transactional interaction, together with the most productive strategies used in each community. This enables us to identify convergences and divergences and pinpoint sociopragmatic and geolectal patterns.
Structural insights into G domain dimerization and pathogenic mutation of OPA1
Authors: Yu Caiting , Zhao Jinghua , Yan Liming , Qi Yuanbo , Guo Xiangyang , Lou Zhiyong , Hu Junjie , Rao Zihe
Published: May 2020

The fusion of mammalian inner mitochondrial membranes (IMMs) is mediated by dynamin-like GTPase OPA1. Mutations in human OPA1 cause optic atrophy, but the molecular basis for membrane fusion and pathogenesis is not clear. Here, we determined the crystal structure of the minimal GTPase domain (MGD) of human OPA1. A three-helix bundle (HB) domain including two helices extending from the GTPase (G) domain and the last helix of OPA1 tightly associates with the G domain. In the presence of GDP and BeF3−, OPA1-MGD forms a dimer, the interface of which is critical for the maintenance of mitochondrial morphology. The catalytic core of OPA1 possesses unique features that are not present in other dynamin-like proteins. Biochemical experiments revealed that OPA1-MGD forms nucleotide-dependent dimers, which is important for membrane-stimulated GTP hydrolysis, and an N-terminal extension mediates nucleotide-independent dimerization that facilitates efficient membrane association. Our results suggest a multifaceted assembly of OPA1 and explain the effect of most OPA1 mutations on optic atrophy.
Structural and optical characteristic features of RF sputtered CdS/ZnO thin films*
Authors: Al-Baradi Ateyyah M , Altowairqi Fatimah A , Atta A A , Badawi Ali , Algarni Saud A , Almalki Abdulraheem S A , Hassanien A M , Alodhayb A , Kamal A M , El-Nahass M M
Published: May 2020

In this study, CdS/ZnO (2:3 mol%) thin films are successfully deposited on quartz substrates by using the sputtering technique. Good images on the structural and optical characteristic features of CdS/ZnO thin films before and after annealing are obtained. The CdS/ZnO thin films are annealed respectively at temperatures of 373 K, 473 K, and 573 K and the structural features are examined by XRD, ATR-FTIR, and FESEM. The optical properties of CdS/ZnO thin films such as refractive indices, absorption coefficients, optical band gap energy values, Urbach energy values, lattice dielectric constants, and high frequency dielectric constants are determined from spectrophotometer data recorded over the spectral range of 300 nm–2500 nm. Dispersion parameters are investigated by using a single-oscillator model. Photoluminescence spectra of CdS/ZnO thin films show an overall decrease in their intensity peaks after annealing. The third-order nonlinear optical parameter, and nonlinear refractive index are also estimated.
Stable soliton propagation in a coupled (2 + 1) dimensional Ginzburg–Landau system*
Authors: Wang Li-Li , Liu Wen-Jun
Published: May 2020

A coupled (2 + 1)-dimensional variable coefficient Ginzburg–Landau equation is studied. By virtue of the modified Hirota bilinear method, the bright one-soliton solution of the equation is derived. Some phenomena of soliton propagation are analyzed by setting different dispersion terms. The influences of the corresponding parameters on the solitons are also discussed. The results can enrich the soliton theory, and may be helpful in the manufacture of optical devices.
A novel training-free recognition method for SSVEP-based BCIs using dynamic window strategy
Authors: Chen Yonghao , Yang Chen , Chen Xiaogang , Wang Yijun , Gao Xiaorong
Published: May 2020

Objective. Filter bank canonical correlation analysis (FBCCA) is a widely-used classification approach implemented in steady-state visual evoked potential (SSVEP)–based brain computer interfaces (BCIs). However, conventional detection algorithms for SSVEP recognition problems, including the FBCCA, were usually based on ‘fixed window’ strategy. That’s to say, these algorithms always analyze data with fixed length. This study devoted to enhance the performance of SSVEP-based BCIs by designing a new dynamic window strategy which automatically finds an optimal data length to achieve higher information transfer rate (ITR). Approach. The main purpose of ‘dynamic window’ is to minimize the required data length while maintaining high accuracy. This study projected the correlation coefficients of FBCCA into probability space by softmax function and built a hypothesis testing model, which took risk function as evaluation of classification result’s ‘credibility’. In order to evaluate the superiority of this approach, FBCCA with fixed data length (FBCCA-FW) and spatial temporal equalization dynamic window (STE-DW) were implemented for comparison. Main results. Fourteen healthy subjects’ results were concluded by a 40-target online SSVEP-based BCI speller system. The results suggest that this proposed approach significantly outperforms STE-DW and FBCCA-FW in terms of accuracy and ITR. Significance. By incorporating the fundamental ideas of FBCCA and dynamic window strategy, this study proposed a new training-free dynamical optimization algorithm, which significantly improved the performance of online SSVEP-based BCI systems.
Chitosan nano film a chemical sensor: Preparation, characterization and application for detection of Nickel ions in aqueous solution
Authors: Moersilah
Published: May 2020

The effects of Dimethyl Glyoxan (DMG) loaded chitosan-nano film (NFCh) chemical sensor for detection Ni+2 ions in aqueous solution were studied. The films, prepared by solvent casting technique with the following compositions of the casting solutions in DMG, chitosan, STPP. The DMG was successfully loaded into NFCh as confirmed by UV–Vis spectrophotometry. Interaction of NFCh with nickel ions provides obvious colorimetric change from red to violet, enabling easy detect with the naked eye. Sensor was exhibited good selectivity with sensitive. In addition, the sensing details were evaluated using UV–Vis spectroscopy. The physico-mechanical properties of NFCh i.e tensile strength, elongation and thicknesses were studied. NFCh with electron withdrawing group at organic ligand showed high selectivity for detection of ion nickel over other interfering anions.
Preparation and characterization of sago (metroxylon sp.) Starch nanoparticles using hydrolysis-precipitation method
Authors: Maryam  , Kasim Anwar , Novelina  , Emriadi
Published: May 2020

at present, the potential for sago starch has not optimally been utilized. The characteristic of this starch is the main problem in using it as industrial raw material. One of efforts to increase the added value of starch is to modify it in the form of starch nanoparticles. Therefore, finding the best and cheapest practice to produce it will a big advantage. One way to do it is by modifying the technique that has already existed. This research is aiming, first to find the best and optimal technique to produce sago starch nanoparticles by combining hydrolysis with precipitation technique and second, calculating the yield and characteristics of sago starch nanoparticles produced from this method. The result showed that hydrolysis−precipitation combination method has succeeded to produce sago starch nanoparticles. The optimum variable was 12 hours hydrolysis, precipitation by ethanol, with produced 25% yield and 21,98 nm particles size. Type of nano particle that is produced is amorf with 41% crystalline. Starch nanoparticle is utilized for reinforcing bioplastic. Eventhough, the results show a potential technique on producing sago starch nanoparticles, but there are still a lot to be done to find the best way to produce it in mass production.
Design and characterization of membrane molecularly imprinted polymer (MIP) as cholesterol absorbent
Authors: Niesa Jihan , Ulianas Alizar
Published: May 2020

Molecularly Imprinted Polymer (MIP) membrane as cholesterol absorbing have succesfull synthesized. MIP membrane can absorb cholesterol molecules because have cavite (pore) and active groups that are selective and sensitive to cholesterol molecules. MIP membranes synthesized from methacrylic acid monomer, cross-linker ethylene glycol dimethacrilate (EGDMA), initiator of the 2-2-dimethoxy-2-phenylacetophenone (DMPP) and cholesterol as a template. MIP membranes are synthesized using photopolynerization irradiated with UV light (UV). Results obtained in the form of leaflets and transparent membrane can be characterized using Fourier Transform Infrared (FTIR). The results obtained by FTIR spectrum showed that the characterization of infrared spectra of MIP membrane-extraction did not reveal any peak absorption by the OH group, whereas MIP-Re-extraction contained absorption peaks in the area of 3540.58 cm-1. This indicates that the MIP membrane selective and sensitive to analyte. Based on the optimum absorption of MIP-cholesterol membrane can absorb the cholesterol molecules in the amount of 0.06 grams of cholesterol composition with a time of 30 minutes and a pH of 8. The average cholesterol absorption MIP membranes-cholesterol in the blood 0.5782mg/dL.
Preliminary research in the development of physics teaching materials that integrate new literacy and disaster literacy
Authors: Mufit F , Asrizal  , Hanum S A , Fadhilah A
Published: May 2020

21st century learning plays an important role in producing quality human resources, in order to have global competitiveness. Among the competencies students must have is new literacy, as an extension of scientific literacy that has been proclaimed by the previous government. New literacy includes data literacy, technology literacy and human literacy. Besides that, students also need to have disaster literacy, because Indonesia is located in an area prone to disasters. This study aims to determine the scientific literacy (conceptual understanding) of students, and knowing the extent of integrating new literacy and disaster literacy into learning in schools. The type of research conducted is survey research. The instruments used were concept tests, learning observation sheets, interview guides for teachers, and textbook analysis sheets. The concept test was given to 78 class XI students from three different schools, and interviews were conducted with 3 physics teachers in the three schools. Book analysis was performed on 5 physics textbooks that are widely used in schools. Data are analyzed quantitatively and qualitatively. The results showed that learning in schools is still traditional or teacher-centered learning. The integration of new literacy and disaster literacy in the learning process and textbooks used is still low. Understanding of student concepts is also low and misconceptions occur. Therefore, the recommendation from this preliminary study is the need to develop physics teaching materials that integrate new literacy and disaster literacy, and can improve students’ understanding of concepts according to the demands of the 21st century.
Analysis of student response to earthquake disaster in high school physics learning
Authors: Ayu Fitrah , Fauzi Ahmad
Published: May 2020

Often devastating earthquake struck West Sumatra that have implications for the sustainability of the community. People who do not know the circumstances of how earthquake will aggravate the situation, because the earthquake was a natural disaster but could not be predicted. Communities should be given the socialization and education to reduce the risk caused by the earthquake. Socialization and education about earthquake disaster can be implemented in education institution. The purpose of this study to determine the response of students to the earthquake as the study of the early development of the electronic book. The method used in the study was descriptive method with data collection instruments that is questionnaire learners. The result of questionnaire analysis of students at SMAN 4 Padang obtained information that the interest of students to learn physics, the attention of the students to learn physics, the use of electronic books in the learning process of physics, and leaning through ICT, as well as the responses of learners to disasters earthquake in learning physics is still not optimal. This can be seen from the analysis of the physics learning process questionnaire and student’s response to the earthquake disaster in physics leraning are at simply criteria. Based on the results of questionnaire analysis show that the need to develop an electronic book school physics.
Preliminary analysis of Bukik Chinangkiek edupark’s potential as a learning resource for physics in senior high school at X Koto Singkarak Solok, Indonesia
Authors: Lestari Nila Virgo , Rifai Hamdi
Published: May 2020

“Alam takambang jadi guru” is a Minangkabau philosophy that is suitable implemented in the learning process. Nature tourism in Indonesia is very supportive for the implementation of contextual physics learning, one of which is Bukik Chinangkiek Edupark. Bukik Chinangkiek has natural conditions and rides related to physics for example rotational dynamics but it has not been utilized in physics learning. This study aimed to analyze the potential of Bukik Chinangkiek as an edupark-based learning resource for physics. Analysis was carried out with the Plomp development model at the preliminary analysis phase. The data of this study were obtained from questionnaires and interviews along with teachers and students in high schools throughout X Koto Singkarak Subdistrict, while concepts relevant to physics subject matter were obtained from direct observation of Bukik Chinangkiek Edupark. The technique of data analysis was descriptive percentages. Analysis shows that learning physics has not been integrated into the surrounding natural environment so students have not understood the concept of contextual physics and most students tend to use IT in learning. The results of this study is intended to be used as the basis for developing digital book of edupark (e-book) for high school.
The analysis of senior high school student’s prior knowledge in coastal area to the abrasion
Authors: Azmanita Y , Fauzi A
Published: May 2020

As an archipelago country, Indonesia has many beach lines which are the fourth-longest in the world, and in fact, the coastal areas had damaged by some natural phenomena, such as abrasion. One of the available strategies which would give an understanding of abrasion is integrating this disaster knowledge in a certain lesson at school. Physics is one of the subjects which is suitable to give understanding about abrasion. This is because physics includes various disaster phenomena. The effort to do this is achieved by an e-book. Developing a physics e-book with abrasion theme, it is necessary to analyse the student’s knowledge about abrasion. This study used the descriptive method, and the subjects are those who live near a coastal area, Senior High School 1 Nan Sabaris students. Samples were selected by random sampling techniques. The student’s prior knowledge was tested by a questionnaire that consisted of eleven questions. From the analysis, it can be said that student’s prior knowledge about abrasion can be categorized as a low level, in the C rate (Enough). This result shows that the physics e-book using abrasion theme need to be developed.
Preliminary analysis to develop student worksheet based on inquiry based learning model for 21st century physics learning
Authors: Havid Muhammad , Yulkifli  , Septiani Tri
Published: May 2020

One of the efforts to achieve 21st century skills in learning of physics, student worksheet with the inquiry based learning model that can improve creative thinking skills. Reality in the field still finds learning in schools that have not achieved one of the 21st century skills expected in learning of physics. The aim of this research is to obtain results of the preliminary analysis which became the basis to develop Student Worksheet. Participant of this study were physics teachers and students from several high schools in Padang. Preliminary analysis to develop student worksheet includes Teacher Reform Analysis, Learning Difficulty Analysis and Student Characteristics Analysis by retrieving data obtained through observation sheets and interviews. The data was analyzed using descriptive statistical methods. The result show the student worksheet developing by teacher has not been able to achieve 21st century skills in learning of physics.
Need analysis in development of student books based on STEM approach
Authors: Hizhar Daniel , Ramli Ramli
Published: May 2020

Curriculum-2013 was developed by perfecting critical learning patterns. The implementation of learning, including Physics, needs to emphasize the process of developing students attitudes, knowledge and skills through various approaches, such as STEM (Science, Technology, Engineering, and Mathematics) that integrates four scientific disciplines. Through STEM, students are expected to have skills to think critically, creatively, innovatively, and be able to communicate and collaborate. Furthermore, books as teaching materials and learning resources are seen as important in determining the success of physics learning. A preliminary analysis was conducted at SMAN 1 Luhak Nan Duo and SMAN 2 Pasaman about the characteristics of students, teacher competencies and student books. This Analysis uses the Plomp’s Development Model. Data is taken from results of questionnaires and interviews with teachers and students. It shows that teachers have not used books based on STEM yet, only use common textbooks and worksheets. Some teachers still use lecture method so that students have not received learning that guides them to think critically. Students are less interested in reading and have difficulty understanding Physics concepts from textbooks. This is used as the basis to developing student books based on the STEM approach to improve critical thinking skills.
Meta analysis the use of e-modules based on research based learning models
Authors: Hadianto Andrye , Festiyed
Published: May 2020

This study aims to analyze the use of E-MODUL based on research based learning on student learning outcomes. The method of this study is a meta-analysis with a sample of 10 articles in national journals. Research meta-analysis shows that the effect of using E-MODUL based on reasear based learning on student learning outcomes is more effective. The results showed that the effect size on the effect of learning outcomes was carried out on 10 national journal samples categorized as medium. This means that the influence of the use of E-MODULES can improve student learning outcomes greater than using conventional learning.
Preliminary analysis development of interactive student worksheets using inquiry based learning model for 10th grade senior high school
Authors: Samudra Elmi Yanto Adhar , Yulkifli Yulkifli , Widestra Rahmi Agustia
Published: May 2020

Physics learning emphasizes the giving of direct experience to students to foster the ability to think critical, creative, innovative, collaborative, and communicative. However, students are still difficult to understand and find the concept of physics, because learning is not yet fully centered on students, the existing teaching materials in the form student worksheets of are not interactive and the learning model has not been implemented optimally. This study aims to conduct an initial analysis of interactive student worksheet using the inquiry based learning model. This research is a descriptive study carried out through direct observation at senior high school (SMA N 15 Padang) with a sample of research is students of grade 10th. The initial analysis of the development of interactive student worksheet includes analysis of students, analysis of teaching materials, media analysis, and analysis of learning activities with instruments in the form of questionnaires and interviews. Based on the analysis of the data from the teaching materials obtained results of 65.8 and media analysis obtained results of 62.4. Therefore, it is necessary to develop interactive student worksheet using the inquiry based learning model for grade 10th senior high school.
Increasing students’ creative thinking skills at 11th grade of mathematics and natural sciences 5, Senior High School 42 Jakarta on subject of Temperature and Heat by applying discovery learning model
Authors: Serevina V , Sarah A L , Risniawati M , Andriana W
Published: May 2020

The purpose of this research is to increase the student’s creative thinking skills by applying Discovery Learning on subject of Temperature and Heat subject. This research was done by July 2018 to November 2018. The method used on this research is Class Action Research (CAR) method which was done within two cycles with Planning, Acting, Observing, and Reflecting stages. The aspects that measured on this research are the creative thinking skill which covering the aspect of Fluency, Flexibility, Elaboration, and Originality. Syntax of discovery learning model that applied in this research is stimulation, problem statement, data collection, data processing, verification, and generalization. The total score of creative thinking skill in cycle 1 was 54,35%, in cycle 2 was 60,65%. So, the average score of the skill to think creatively was 57,5%, refer to table 1, the student’s way in thinking creatively were “enough creative”. The pretest was been held obtained that average results of students score was 55 and the posttest results was 73. On post test results 73 known that student has been reached minimal completeness of physics subject as big as 70 refer to the rules from Senior High School 42 Jakarta. It can be concluded that students’creative thinking skills has increased by applying Discovery Learning model on temperature and heat subject..
Analysis of factors affecting thesis work of physics students in digital era
Authors: Fendriani Yoza , Zakirman
Published: May 2020

Thesis is one of the mandatory requirements to complete education at the university level. The conditions in that process indicate that many factors influence the completion of student thesis, especially in the Physics department. Physics students are currently in the digital age, so the rapid development of technology contributes to the completion of thesis. The purpose of this study is to describe the results of the analysis of factors that influence the successful completion of thesis Physics students in the digital era. This type of research is descriptive, with samples35 Physics students covering undergraduate, master and doctoral level. Based on the results of this study, it was found that there are several factors that influence the success of student thesis in the digital era, namely: internet browsing preferences, quality of guidance, desire to graduate on time, want to boast of parents, ability to write articles, pressure from family, motivation from friends, availability of references on campus, availability laboratorytools, campus internet access, using of chat applications on smartphones, internet network quality, intensity of attending peer sessions and proficiency in technology.
A meta-analysis of the effects of using PhET interactive simulations on student’s worksheets toward senior high school students learning result of physics
Authors: Chotimah C , Festiyed
Published: May 2020

The purpose of this study was to analyze the effect of the use of PhET Interactive Simulations student worksheets on students learning outcomes. The method used is the meta-analysis method. Meta-analysis is a technique used to summarize a variety of quantitative research results by finding the value of effect size using a sample of 10 articles in national journals. The results showed average effect size of 1, 117 with a standard deviation of 181,1. The resulting effect size is categorized as medium. Means that the influence of the use of PhET Interactive Simulations student worksheets can improve student learning outcomes by 32,73%.
Validity of science student books with the theme of energy in life based integrated local materials using integrated models for 21st century learning
Authors: Hidayat Zaitul , Sarmi Rahima Syabrina , Ratnawulan  , Desnita
Published: May 2020

Science student’s book should be in accordance with 21st century learning with assessments that are relevant to the characteristics of the learning. Where in the 21st century learning that is demanded are critical thinking skills and problem solving, creative and innovative skills, communication skills and collaborative skills. Where the four skills will aim to develop the potential in developing character, talent, competency, interest and literacy. To make use of this science student’s book, then need to be validated. The purpose of the validation is to know the validation science student’s books with the theme of energy in life based integrated local materials using integrated models for 21st century learning to use Aiken’s V with 5 validator is three experts and two practitioners composed. The questionnaire used the data of collection method. The result by 3 experts composed of content validation, construct validation, validation and then the graphical language with a valid validation category. While practitioners composed from same 2 with 3 experts composed is content validation, construct validation, validation and then the graphical language with a valid validation category. Conclusion, overall the science student’s books with the theme of energy in life based integrated local materials using integrated models for 21st century learning Be avowed valid and it can to be use in school.
Validation of integrated science teacher book integrated mode with scene life energy in the regional local content based sijunjung for 21st century skills
Authors: Sarmi Rahima Syabrina , Hidayat Zaitul , Ratnawulan  , Desnita
Published: May 2020

Prior to the development of integrated science teacher book-type integrated with the energy theme in the lives of local content based Sijunjung area to improve the skills of the 21st century, it is necessary to do the validation. Validation is done teacher book aims to examine the content validity and construct validity. Content validity with respect to the content and format of the book the teacher developed, while the construct validity with respect to the structure and characteristics of teacher-developed book. In addition to content validity and construct validity, it is also necessary to test the validation language to see the use of the language used in the book of teachers in accordance with the correct EYD and also carried out a validation test graphics. Validation of Integrated Science teacher book-type integrated with the energy theme in the lives of local content based on the area Sijunjung performed using validator Aikens V with 5 of them 3 experts and two practitioners. Collecting data using questionnaires. From the results of research by five people validator, then book the type of integrated science teacher integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills considered valid. In conclusion, the type of integrated science teacher book integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills have been developed and used by teachers in schools. From the results of research by five people validator, then book the type of integrated science teacher integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills considered valid. In conclusion, the type of integrated science teacher book integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills have been developed and used by teachers in schools. From the results of research by five people validator, then book the type of integrated science teacher integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills considered valid. In conclusion, the type of integrated science teacher book integrated with the energy theme in the lives of local content based Sijunjung area to improve 21st century skills have been developed and used by teachers in schools.
The development of physics learning tools in vocational high school based constructivism approach using learning cycle 5E model
Authors: Fatimah Iim
Published: May 2020

Teachers should be able to develop a learning tools that can improve the students’s ability to build knowledge and formulate their own concepts in the learning process. One of learning models that can support these purpose is learning based contructivism approach using learning cycle 5 E model. The type of research is research and development using 4-D model consist of define, design, development and disseminate. The research instrument used was a questionnaire (RPP validation, validation module, validation worksheets, assessment and response validation teacher) and RPP feasibility sheet. The data analysis technique used is descriptive statistics to obtain an average value and the percentage of the validity and practicality of learning tools. Based on the analytical validation of data is known that the developed learning tools considered valid. Based on the data analysis of the test results is known that the learning tools developed practical and effective category. From these results it can be concluded that the learning tools of physics based contructivism approach using learning cycle 5 E model at class XI TITL SMK Negeri 1 Rao Selatan developed are valid, practical and effective and it can enhance student competence.
Development of mathematics learning device based on guided discovery of program of international student assessment model orientation (preliminary research)
Authors: Afrilia C , Yerizon  , Permana D , Armiati
Published: May 2020

Student’s mathematical problem solving ability has optimal yet, this is due to school learning fail to get students used to work on problem solving PISA questions model. The purpose of this research is to produce mathematics learning device based on guided discovery of PISA model orientation in order to improve student’s problem solving ability. This is a development research. Development model of this research is Plomp model which consists of three phases, namely, preliminary research, development or prototyping phase, and assessment phase. The results of data analysis on preliminary research are: 1) Teacher has yet to be able to develop the learning device to improve students’ mathematical ability. 2) Learning resources used by the students are optimal yet to be able to draw student’s interest to learn. 3) Students are expecting for the attractive worksheet display and small number of the questions. 4) Students are expecting worksheet to discuss more on the use of mathematics in the society real life and problems related with their personal activities. 5) Students who are living in the remote area tend to be less motivated and less willing the learning process. 6) Students prefer group learning to individual learning.
Analysis of student’s understanding about Newton’s laws, in terms of perceptions to learning in senior high school
Authors: Putra A , Heriyanto
Published: May 2020

The results of student’s analysis of physics mastery of class X in several high schools in the city of Padang, showed the lowest value found in Newton‘s laws of motion. This shows that students experience various obstacles in mastering this material. One of them is the factor of the perception of students towards learning physics. This study aims to reveal the tendency of students’ perceptions of learning physics in Newton‘s law material, student mastery, their relationship and the factors of difficulty in learning Newton’s laws of motion, in terms of student perception. This study included descriptive correlational study in high school in Padang city in semester from January to June 2019. With stratified random sampling technique obtained by 60 students as samples to represent a clever student, medium and less, which is derived from 4 SMA and one private school. The instrument used to obtain data, in the form of 60 items of perception questionnaires and 24 items of mastery of material compiled based on a grid combination of 4 dimensions of knowledge and 6 levels of cognitive processes refers to Bloom’s revised taxonomy. The instrument used has fulfilled its validity and reliability. The results showed that a) the perception of students towards learning the laws of Newton at the high category, b) mastery of physics students are on the low category, c) There are positive correlation between the perceptions of teaching physics with students mastery to the material laws Newton‘s motion, with 36.2% contribution. b) The proportion of understanding dimensions of students’ knowledge: factual, conceptual, procedural, and metacognitive respectively, are 51.42 %, 36.88 %, 13.96 %, and 4,54 %. c) the proportion of mastery of cognitive process levels for the ability to remember, understand, apply, analyse, evaluate and create are: 54.44 %, 33.56 %, 38.75 %, 14.44 %, 13.19 % and 5.81 %. d) study difficulties were found in learning Newton’s law materials according to the perceptions of students, in terms of factors: students individual; properties inherent in physical matter; and student learning conditions created by the teacher.
A topology and sizing optimization method for frame structures combined with an orthogonal-maximin Latin hypercube design(LHD) method
Authors: Fu Jiayi , Huang Hai
Published: May 2020

This work presents a new strategy for improving the global searching capability of the two-level approximation method. By using an orthogonal-maximin latin hypercube design (LHD) method, five initial designs reflecting more information of the feasible domain can be generated. Due to their good representation for the feasible domain of the five latin hypercube designs, it is more likely to obtain a global optimum or a near global optimum which is better than before. Numerical examples of frame structures are established to illustrate the effectiveness of this method. From the results, it can be seen that a series of better optimal solutions can be obtained by using the strategy of orthogonal-maximin LHD method and the number of structure analysis required in the optimization process is dozens of times or fewer, even comparable to size-variable optimization.
Finite Element Analysis of an Acoustic Metamaterial Plate Incorporating Tunable Shape Memory Cantilever Absorbers
Authors: Wu Y T , Hu H L , Lee C Y
Published: May 2020

Metamaterials are materials having artificially tailored internal structure and unusual physical and mechanical properties. Due to their unique characteristics, metamaterials possess great potential in engineering applications. This study proposes a tunable metamaterial for the applications in vibration or acoustic isolation. For the state-of-the-art structural configurations in metamaterial, the geometry and mass distribution of the crafted internal structure is employed to induce the local resonance inside the material. Therefore, a stopband in the dispersion curve can be created because of the energy gap. For the conventional metamaterial, the stopband is fixed and unable to be adjusted in real-time once the design is completed. Although the metamaterial with distributed resonance characteristics has been proposed in the literature to extend its working stopband, the efficacy is usually compromised. In this study, the incorporation of tunable shape memory materials (SMM) via phase transformation into the metamaterial plate is proposed. Its theoretical finite element formulation for determining the dynamic characteristics is established. The effect of the configuration of the SMM cantilever absorbers on the metamaterial plate for the desired stopband in wave propagation is simulated by using finite element model and COMSOL Multiphysics software. The result demonstrates the tunable capability on the stopband of the metamaterial plate under different activation controls of the SMM absorbers, and shows the ability to trap the vibration at the designed frequency and prevent vibration wave from propagating downstream in different absorber arrangement and alloy phase. To conclusion, this study should be beneficial to precision machinery and defense industries which have desperate need in vibration and noise isolation.
Application of intelligent algorithm in trajectory optimization of hypersonic vehicle
Authors: Liu L H
Published: May 2020

Aiming at the application problem of intelligent algorithm in trajectory optimization of hypersonic vehicle, the basic theoretical framework to solve this problem is discussed. Based on the flight characteristics of hypersonic flight vehicle, the demand for intelligent algorithm application is put forward. According to the principle of intelligent optimization, the key problems such as initial selection of trajectory optimization, intelligent algorithm and parallel computation are discussed. On this basis, the system application framework of intelligent algorithm is designed, which optimizes trajectory and guidance synchronously, and provides a new typical application mode for flight vehicle intelligent control technology.
Modelling and Control of Quad Hybrid Engine Levitating Platform
Authors: Hou Y J , Chen T L
Published: May 2020

This research aims to develop trajectory controls for a levitation platform which is powered by rocket fuel. This control task is to regulate the platform for 3D trajectory followings and suspension in the air, which is different from that of the most rocket systems. To cope with the challenges of slow thrust response and coupled vehicle dynamics, we proposed a control system that consists of 4 independent loops for the height, yaw angle, x-position, y-positions, respectively. The developed controllers include 4 PID compensators for the flow rate throttling system, and four double phase lead and two lead-lag compensators for the vehicle dynamics. According to the simulation results, the levitation platform can follow a designated trajectory well when there exist external torques disturbance. (both 1 N-m step inputs and 0.1 N-m Gaussian distributed input) and 2% thrust force oscillations.
Temperature Compensation Method of Lamb waves on Composite Plate using First Arrival Wave
Authors: Gong I. C. , Jun Y. U. , Park J. S.
Published: May 2020

There are two basic methods of temperature compensation on isotropic plates, Optimal Baseline Selection(OBS) and Baseline Signal Stretch(BSS). The OBS method compensates the temperature using multiple baseline signals, while the BSS method using one baseline signals and stretch factor. However, in composite materials, the velocity of lamb waves differs from one direction to another. In this paper, a temperature compensation algorithm is proposed using the First Arrival Wavepacket(FAW) factor considering the propagation direction of lamb waves in composite plates. The proposed algorithm consists of two parts. First, Fast Fourier Transform (FFT) was used to filter the response signal in the space domain. Second, the signal was compensated by using the FAW factor for each separated signal. And the accuracy of the algorithm was improved by considering the group velocity and phase velocity of the numerical value of the lamb waves. The numerical value is calculated by using the stress-strain relation and the equation of motion for particles in the composite. Finally, the error of the signals was calculated using the Maximum Error of the Subtracted Signal(MESS). Also, the temperature compensation method using the proposed algorithm was verified by comparing the existing OBS/BSS method. Also, the compensated signal was compared with the experimental signal.
Numerical Simulation on the Cavity-Induced Boundary Layer Transition
Authors: Guo Peixu , Gao Zhenxun , Jiang Chongwen , Lee Chun-Hian
Published: May 2020

The boundary layer transition can be triggered in either natural or forced way. In this paper, a Mach 3 cavity-induced boundary layer transition is simulated using the implicit large eddy simulation, in order to study the transition caused by the surface gap on the vehicles in the real condition. One of the characteristics of this paper is that no disturbance is imposed in the inflow condition such that the boundary layer transition is triggered by the self-sustained fluctuation in the upstream cavity. Results show that the transition appears in the natural scenario and the stage of the linear instability seems to be followed by the process of the secondary instability. Linear stability analyses are also utilized to show the development of the unstable modes.
A modified active disturbance rejection control for fast steering mirror in aerospace application
Authors: Zheng Xintao , Huang Hai , Li Weipeng
Published: May 2020

Active disturbance rejection control (ADRC) has proved to be an effective tool in dealing with engineering problems related to the plant along with dynamic uncertainties, disturbances, nonlinearities. A modified active disturbance rejection control (MADRC) method is proposed to design the Fast Steering Mirror (FSM) controller. The modified extended state observer (ESO) incorporate with identified plant information is employed to reject the disturbances, nonlinear factors and modelling errors which meant to constraint the plant to a nominal form. Therewith, an well-designed analytical method is introduced to calculate the parameters of a feedback loop to force the plant response like a pre-designed model. Besides, a Lead-Leg Controller (LLC) consisting of two Tracking-Differentiator (TD) is designed to improve the performance of the controller. LLC generates a filtered output based on the expected plant dynamics to increase the FSM bandwidth, and LLC can also help to improve the stability of the system by restricting the tracking error in a limited range when there is an abrupt command input. The MADRC strategy is proven an effective solution for FSM. Simulation results show that the MADRC method can achieve a excellent performance without tedious tuning work. The experiment results proved the validation in practical application.