bluuebunny/crossref_metadata_2025 huggingface dataset:
An inverse acoustic-elastic interaction problem with phased or phaseless far-field data
Authors: Dong Heping , Lai Jun , Li Peijun
Published: January 2020

Consider the scattering of a time-harmonic acoustic plane wave by a bounded elastic obstacle which is immersed in a homogeneous acoustic medium. This paper is concerned with an inverse acoustic-elastic interaction problem, which is to determine the location and shape of the elastic obstacle by using either the phased or phaseless far-field data. By introducing the Helmholtz decomposition, the model problem is reduced to a coupled boundary value problem of the Helmholtz equations. The jump relations are studied for the second derivatives of the single-layer potential in order to deduce the corresponding boundary integral equations. The well-posedness is discussed for the solution of the coupled boundary integral equations. An efficient and high order Nyström-type discretization method is proposed for the integral system. A numerical method of nonlinear integral equations is developed for the inverse problem. For the case of phaseless data, we show that the modulus of the far-field pattern is invariant under a translation of the obstacle. To break the translation invariance, an elastic reference ball technique is introduced. We prove that the inverse problem with phaseless far-field pattern has a unique solution under certain conditions. In addition, a numerical method of the reference ball technique based nonlinear integral equations is proposed for the phaseless inverse problem. Numerical experiments are presented to demonstrate the effectiveness and robustness of the proposed methods.
Possible quantized charge pump in bilayer and trilayer graphene
Authors: Wang Mei-Juan , Wang Jun , Liu Jun-Feng
Published: January 2020

We report a theoretic study of the two-parameter adiabatic charge pump based on the bilayer and trilayer graphene systems. The two perpendicular time-dependent electric fields with a phase lag between them are taken as the pumping potentials, which induce an instant energy gap in each pumping region. Based on both a continuum model and a lattice model, we show that the pumping results from the bilayer and trilayer graphene systems are very different when the Fermi energy happens to reside in the opened energy gap: there is no pumping current for the bilayer system whereas a quantized charge pumping effect emerges in the trilayer-graphene based pump device. This difference can be accounted for by the different Berry phases of Dirac electrons in the two systems. Our findings may shed a light on developing a quantized charge pumping device.
Fano resonance induced fast to slow light in a hybrid semiconductor quantum dot and metal nanoparticle system
Authors: Chen Hua-Jun
Published: January 2020

We theoretically demonstrate the Fano resonance and the conversion from fast to slow light in a hybrid semiconductor quantum dot (SQDs)-metal nanoparticle (MNPs) with cavity quantum electrodynamics treatment. The absorption spectra of the weak probe field exhibit a series of asymmetric Fano line shapes and their related optical propagation properties, such as fast and slow light effects, are investigated based on the hybrid system for suitable parametric regimes. Further, the transparency windows (i.e. the absorption dip approaches zero) in the probe absorption spectra are accompanied by the rapid steep dispersion of the Fano resonance profile, which promises the slow or fast light effect, and even tunable fast-to-slow light propagation (or vice versa) can be achieved by controlling different parameter regimes. Therefore the investigation may indicate promising applications in quantum information processing based on the hybrid SQD-MNP system.
Surface passivation in n-type silicon and its application in silicon drift detector*
Authors: Wu Yiqing , Tao Ke , Jiang Shuai , Jia Rui , Huang Ye
Published: January 2020

Based on the surface passivation of n-type silicon in a silicon drift detector (SDD), we propose a new passivation structure of SiO2/Al2O3/SiO2 passivation stacks. Since the SiO2 formed by the nitric-acid-oxidation-of-silicon (NAOS) method has good compactness and simple process, the first layer film is formed by the NAOS method. The Al2O3 film is also introduced into the passivation stacks owing to exceptional advantages such as good interface characteristic and simple process. In addition, for requirements of thickness and deposition temperature, the third layer of the SiO2 film is deposited by plasma enhanced chemical vapor deposition (PECVD). The deposition of the SiO2 film by PECVD is a low-temperature process and has a high deposition rate, which causes little damage to the device and makes the SiO2 film very suitable for serving as the third passivation layer. The passivation approach of stacks can saturate dangling bonds at the interface between stacks and the silicon substrate, and provide positive charge to optimize the field passivation of the n-type substrate. The passivation method ultimately achieves a good combination of chemical and field passivations. Experimental results show that with the passivation structure of SiO2/Al2O3/SiO2, the final minority carrier lifetime reaches 5223 μs at injection of 5×1015 cm−3. When it is applied to the passivation of SDD, the leakage current is reduced to the order of nA.
Astrocyte and ions metabolism during epileptogenesis: A review for modeling studies*
Authors: Du Meng-Meng , Li Jia-Jia , Yuan Zhi-Xuan , Fan Yong-Chen , Wu Ying
Published: January 2020

As a large group of cells in a central nervous system, astrocytes have a great influence on ion and energy metabolism in a nervous system. Disorders of neuronal ion and energy metabolism caused by impaired astrocytes play a key role in the pathogenesis of epilepsy. This paper reviews the existing computational models of epileptogenesis resulting from impaired astrocytes and presents several open perspectives with regard to ion and energy metabolism-induced epileptogenesis in a neuron-astrocyte-capillary coupled model.
The implementation of guided inquiry model on the subject matter harmonious vibration
Authors: Arifuddin M , Aslamiah M , Misbah M , Dewantara D
Published: January 2020

The low level of science process skills and scientific attitudes of students is because students are accustomed to getting information from teachers and learning that takes place only in one direction. Therefore, this study aims to improve students’ scientific attitudes and process skills through a guided inquiry model. The specific purpose of this study was to describe the implementation of lesson plans, science process skills, scientific attitudes, and learning outcomes of students. This study was a class action research model Kemmis and Mc Taggart consisting of 2 cycles. The subjects of this study were 34 students of class X-3 SMA Negeri 4 Banjarmasin. Data obtained through observation, tests, and documentation. The results showed: 1) the implementation of the lesson plan was categorized very well with a percentage of 90% and 96%; 2) students’ science process skills increase from an average score of 2.60 with a skilled category to 3.28 with a highly skilled category; 3) the scientific attitude of students also increased from an average score of 2.04 with a good category to 2.63 with a very good category; 4) student learning outcomes increase from classical completeness 50% to 85%. It was concluded that the science process skills and scientific attitudes of students increased after applied guided inquiry learning models on harmonious vibration material.
Higher-order thinking (HOT) oriented learning: exploration of mathematics teachers’ perception
Authors: Fajriah N , Sari A , Suryaningsih Y
Published: January 2020

Teacher is one of the factors of the success in implementing high-order thinking oriented learning so that students can think at a higher level. In fact, students’ high-order thinking skills are still low, so teachers’ perceptual information is needed. This study aims to describe the perception of mathematics teachers on HOT-oriented learning from the aspects of (1) curriculum, (2) books, (3) training, and (4) learning activities carried out. The research method used was a survey with a quantitative descriptive approach. The population of this study was 29 state junior high school mathematics teachers in North Banjarmasin Subdistrict. Data was collected through questionnaires and analyzed using a Likert scale, percentage, and mode. The results obtained showed that mathematics teachers had the following perceptions: (1) positive for the 2013 curriculum, (2) positive for books that were with HOT oriented but negative for examples in textbooks easily understood by students, (3) positive for training material that had been followed, (4) positive that planning is needed to construct HOT criteria, increase questioning activities, express opinions, foster creativity, and students’ critical thinking skills, but negatively increase the activity of observation, student experimentation, and scheduled timelines.
Critical thinking skill of prospective mathematics teachers in solving the two-dimensional geometry problem
Authors: Ansori H , Hidayanto T , Noorbaiti R
Published: January 2020

Critical thinking is one of the 21st-century skills that a person needs to have. However, the critical thinking skills of prospective mathematics teachers are relatively low. This study analyzed the critical thinking phase of prospective mathematics teachers in solving a two-dimensional geometry problem, i.e. problem analysis, exploration, drawing conclusions, clarification, and resolution phase. The subjects in this descriptive study were 35 prospective mathematics teachers. In the problem analysis phase, while some prospective mathematics teachers were able to identify what was known or asked in detail, some others were not. In the exploration phase, some prospective mathematics teachers presented ideas in solving problems in one way while others did it in various ways. The subject, who presented the idea of solving the problem in only one way, gave the final conclusion immediately. However, the subject that presented problem-solving in several ways and reviews from various perspectives can provide clarification of the problem and even convey resolution to the problem. This clarification and resolution arose because of cognitive conflicts that occur in the mind of the subject. Cognitive conflict arose because of the contradiction of the solutions to the problem when the subject used problem-solving from a different perspective.
Developing a computer simulation to minimize misconceptions in motion concept
Authors: Saehana S , Darsikin  , Haeruddin  , Kasim S
Published: January 2020

In this paper, we report the effort to minimize the students’ misconception in motion concept by developing a computer simulation. This research and development are applied with Borg and Gall methods. In developing a computer simulation, Forced Concept Inventory (FCI) with Certainty Responses Index (CRI) scale is used to detect misconceptions of the students.

The steps to develop a computer simulation are: (1) detecting misconception (pre-test), (2) designing and making a computer simulation, (3) validating simulation by an expert, (4) giving a chance to students on giving their opinion to a computer simulation, (5) trying the simulation in physics learning; the last step is (6) committing students’ conception test (post-test). Based on the FCI test, it was found that good conception of the students was 40%; less conception of the students was 20%; misconception of the students was 40%. According to our identification, the misconceptions were found in some motion concept i.e. linear motion, free fall, and parabolic motion. Then, a computer simulation was developing by designing it using Borland Delphi 7.0. After that, it was evaluated by material and media experts. The students gave their opinion about the computer simulation. Finally, a computer simulation was used in physics learning on the students of SMAN 2 Palu. It is found that students’ misconception is decreased about 25% after the computer simulation is applied.
Building students’ problem-solving skill in the concept of temperature and expansion through phenomenon-based experiential learning
Authors: Santhalia P W , Yuliati L , Wisodo H
Published: January 2020

This research is aimed to describe students’ problem-solving skill in phenomenon-based experiential learning especially in the subtopics of temperature and expansion. The problem-solving skill is one of the vital skills in physics learning that should be applied in measuring students’ understanding level. This research used a mixed-method approach with research design of an embedded experimental model for 32 eleventh graders of State Senior High Schools in Malang, East Java, Indonesia. The data were collected by pretest and posttest using tests and interview. The result shows that there is an improvement of students’ problem-solving skill after being taught by using phenomenon-based experiential learning. The calculation result of the N-Gain score showed the improvement of students’ problem-solving skill on a moderate category and the calculation result of d-Cohen effects size in on strong category. Meanwhile, the result of the qualitative calculation showed that students’ problem-solving skill is improved from beginner category to expert category that is 62.5%. The students’ problem-solving skill should be intensively trained by using contextual scientific problems in daily life.
The analysis of heat - temperature misconception and integration with Al Quran
Authors: Sofianto E W N , Irawati R K , Akmalia H A , Apriani R R
Published: January 2020

This research analyzed the misconception of heat and temperature material integrated with Al Quran on senior high school students in Banjarmasin. This research used qualitative method. Subjects of the research are student eleventh grade of science program in 16 senior high school of Banjarmasin. Every school was taken one class became subject of the research. This misconception has been analyzed using four tier test. Misconception that identified by four tier test and integrated with Al Quran on senior high school science students in Banjarmasin is the concept of heat transfer, changes in form, heat capacity, and expansion factor. Those concepts have been found not well understood among science students, especially on Black’s Principle, changes in form, and expansion factor.
Using three-tier diagnostic test to asses students’ misconception of simple harmonic oscillation
Authors: Susilowati E , Suyidno  , Mayasari T , Winarno N
Published: January 2020

This examination includes the advancement of a three-level analytic test to gauge understudies’ comprehension of simple harmonic oscillation. The Simple Harmonic Oscillation Test (SHOT) is a 10-items three-level demonstrative test comprising of three-level things for surveying understudies’ understanding of simple harmonic oscillation concepts. The SHOT was controlled to 50 understudies in the control class and 50 understudies in the experimental class. Cronbach alpha unwavering quality lists for the SHOT were assessed to be .73 and .85 for the control and experimental class, individually. Point-biserial coefficients went from .22 to .67, a normal of .42 for the control class and with a normal of .44 for experimental class. The results research showed that a three-tier diagnostic test able to reduce the misconception of simple harmonic oscillation. There is requirement for more investigations to create three-level tests in other branches of knowledge.
Anubias (Anubias sp.) propagation trough hydroponic culture technique
Authors: Sholichah L , Yamin M , Ginanjar R , Meilisza N
Published: January 2020

Anubias, water ornamental plants (Anubias sp) are exotic water ornamental plants from Africa that have a high economic value. Apart from its potential economic value, there are still many obstacles faced in the process of aquaculture. One of them is related to the propagation and a slow growth rate. This research was conducted to find the most suitable planting media for the propagation and growth of Anubias through hydroponic techniques. The hydroponic culture was carried out with four treatments in the form of planting media which consisted of: (1) husk charcoal; (2) sand (pasir Malang); (3) gravel; (4) Rockwool; all treatments were carried out by floating / NFT (nutrient film technic) technique. The design used in this study was a completely randomized design, where each treatment was given three replications. Parameters observed and measured included root length, plant height, number of leaves and number of new shoots. The sand as a planting media provides better growth when compared to the other three growing media.
An analysis of mathematical literacy of state junior high school students in Kupang
Authors: Fointuna D W , Kaluge A H , Fernandez A J
Published: January 2020

This survey was conducted to describe the mathematical literacy of state junior high school students in Kupang, East Nusa Tenggara province. Not only was it done due to the low performances of Indonesian 15-year-old students in PISA but also since there was not any research studies that had been done before to map the mathematical literacy of 15-year-old students in Kupang. This study used two-stage cluster randomized sampling to choose six-state junior high schools representing six sub-districts around Kupang. A total of 377 ninth-grade students were selected to become the respondents in this survey. They were tested using fifteen mathematical literacy problems directly adopted from PISA 2012 and some development researches items. The results showed that the mathematical literacy of state junior high school students in Kupang generally was in a low category. When we looked into three process domains as well as four content domains, the math literacy of students was also classified as either a low or a very-low-category. The results of this study can provide valid and actual data for society and the government regarding the math literacy of students in Kupang.
The effect of collaborative based science learning model on enhancing students’ critical thinking skills and responsibility
Authors: Isnawati  , Ibrahim M , Tjandrakirana  , Suyidno  , Rusmansyah  , Kusuma A E
Published: January 2020

The Collaborative Based Science Learning (CBSL) model was a learning model collaborative based science that integrates Critical Thinking Skills (CTS) and student responsibility. This study aims to analyze the effect of the CBSL model in enhancing the CTS and the responsibility of junior high school students. This study employed a quasi-experimental study with one group pre-test and post-test design. One hundred and seventy students of the eighth grade of Public Junior High School 6 Banjarmasin, Indonesia were involved and classified into five groups. The data was collected through the Critical Thinking Skills Test, a questionnaire on student responsibility, and an in-depth interview. The collected data were analyzed by using paired t-test / Wilcoxon test and n-gain. The results of the study in group-1, group-2, group-3, group-4, and group-5 indicate that the obtained of the sig. (2-tailed) CTS of students is 0.00 (p = < 0.05), and n-gain is 0.74-0.87, showing that it is significant in high criteria. In addition, the obtained sig. (2-tailed) student responsibility is 0.00 (p = <0.05) and n-gain is 0.55-0.67; showing significant result in the criteria of moderate. It is concluded that the CBSL model is effective. This study implies that the CBSL model can be used as an alternative to maximize students’ CTS and responsibility in science learning at schools as well as equip success in students’ life and future career.
The various type of microalgae in lentic habitats
Authors: Amintarti S , Utami N H , Ajizah A
Published: January 2020

Microalgae are unicellular algae living in freshwater. Algae were carbon fillers and biomass generators, so they have an important function to balance the environment. Lentic habitats can change rapidly, especially the existence of various activities such as sedimentation, pollution of various pollutants originating from domestic and industrial activities. This research aims to identify various types of microalgae in lentic habitats. Sampling was conducted at four-month intervals from April to June 2019. This zone divided into ponds and pools because it mostly used a water supply around the lentic area. The population in this research was microalgae in lentic habitats. From the results of the study that lentic habitats were found 4 divisions such Cyanophyta, Chlorophyta, Euglenophyta and Baccilariophyta, such Chlorella sp, Gloecapsa sp, Oscillatoria sp, Scenedesmus sp, Oedogonium sp, Microspora sp, Coleochaete sp, Closterium sp, Cymbella sp, Navicula sp, Pinnularia sp, Synedra sp, Euglena sp, Phacus sp, Trachelomonas sp. The microalgae were found on lentic habitat very affect by physical factors such as temperature, pH, and light intensity
The practicality of odonata handout in invertebrate zoology course
Authors: Riefani M K , Badruzsaufari  , Dharmono
Published: January 2020

Wetlands around the University of Lambung Mangkurat (ULM) Banjarmasin has been the habitat for dragonfly (Odonata). It has the potential to be utilized as a learning resource. A handout is one of the effective learning resources to achieve learning goals. Researchers created a handout to facilitate students to learn about the diversity and activities of Odonata at the wetlands around ULM Banjarmasin. This study aims to describe practicality of the Odonata handout. Research and development of handouts are based on Borg and Gall development model. This research was conducted in ULM Banjarmasin. The research subjects included three expert validation, nine students for small readability tests, and 18 students for small-scale field trials. Data analysis uses descriptive categorical techniques. The practicality of handout is indicated by students’ activity and students’ responses after they use handouts. The handouts based on students’ activity showed very high activity and showed a very strong positive response.
The needs analysis of basic physics learning devices based on hybrid learning
Authors: Ma’ruf M , Handayani Y , Marisda D H , Riskawati R
Published: January 2020

The research is a qualitative descriptive study as a preliminary study. The location of his research was at the department of physical education, University of Muhammadiyah Makassar. The purpose of his research is to analyze the level of needs of basic physics learning devices based on hybrid learning, and the research subjects consisted of 6 lecturers and 39 temporary students and had contracted basic physics courses at the Department of Physics Education at the University of Muhammadiyah Makassar. The technique of collecting data in the preliminary study activities was carried out through non-test instruments in the form of questionnaires, observations, and interviews. The data from the questionnaire were analyzed quantitatively based on the number of frequencies in the Likert scale category of each questionnaire item. The interview data and the results of the observations were analyzed descriptively qualitatively. Data analysis techniques used are observational data analyzed by making data percentage of the results of observations of each aspect measured, then the data is presented in the form of pie graphs. The results of the study show that the role of information and communication technology has not been maximized in basic physics learning effectively and efficiently for both lecturers and students, while the demands of 21st-century learning are expecting the role of ICT in learning especially by using hybrid learning.
The Content of Lead (Pb) at The Water and Lobster (Macrobrachium rosenbergii L.) in Water of Alalak River on West Berangas Area
Authors: Halang B , Astuty A A
Published: January 2020

The aim of this research was to know how the content of lead in the river, the meat and the shell of lobsters at the Alalak River of Berangas Area. The kind of this research was descriptive research, which was to describe something of the condition according to nature. Instruments used consists of some tools and materials. The tools were : Atomic Absorption Spectrophotometry, bucket, and stoppered glasses and water and lobsters as materials. The method of this research was a descriptive method. Procedures of this research were to take off the water, and lobster samples are done with direct observation in the field which consisted of four sampling points. The water samples were entered into the bucket, and the lobster samples were entered into the stoppered glasses. Technical measurement of Pb at the water and the meat, as well as the skin of the lobsters, using the Atomic Absorption Spectrophotometry tool. The Pb content tests of water were done at the Health Laboratory of Banjarmasin, whereas Pb content tests of the meat and the skin of lobsters were done in the Basic Laboratory of MIPA Banjarbaru. The results showed that the Pb contents in water were average of 0.0208 mg/l. It was below the threshold of quality standard (0.3 mg/l) based on regulation of South Kalimantan Governor No. 05 in 2007. The averages of Pb contents in the meat of lobsters were 5.147 mg/Kg, and in the skin of lobsters were 15.02 mg/Kg. The Pb content of the meat and the skin of the lobsters were upper the threshold of quality standards (0.1 mg/Kg) based on decision of Dirjen POM no. 03725/VII/1989. So, people should reduce to consume the lobsters from Alalak River especially communities of Berangas and its around areas.
Developing high school physics teaching materials through 7E learning cycle model
Authors: Hartini Sri , Suci Abyati Dinda , M Abdul Salam
Published: January 2020

Research has been conducted which aims to describe the feasibility of high school physics teaching materials through the 7E learning cycle model. The feasibility of teaching materials is evaluated from the validity of teaching materials, the practicality of teaching materials, the effectiveness of teaching materials, and the achievement of science process skills. This research is a research and development based on the Dick & Carey development model. The subjects of this research are 30 students of science class in one of the high schools in Banjarmasin. The instruments of this study are; the validation sheet of teaching materials, the implementation sheet of the lesson plan, the science process skill observation sheet, and the student learning outcomes test. The results showed that the teaching materials are categorized as good, the practicality of the teaching materials categorized as very practical, the effectiveness of the teaching materials included in the medium category, and the achievement of science process skills categorized as quite good. It was concluded that the high school physics teaching material on straight motion material through the 7E learning cycle model model developed is suitable to use in learning.The first section in your paper
Eye-tracking and metacognitive skills: A review on the use of eye-tracking for measuring students’ metacognitive skills in chemistry learning
Authors: Muna Khairiatul , Bahit Muhammad
Published: January 2020

This study presents a review of empirical studies on eye-tracking in the education field and aims to describe the use of eye-tracking methods to measure students’ metacognitive skills in chemistry learning. Eighty papers published from the 2000s to 2018 that containing major discussion on students’ metacognitive skills in chemistry learning and the use of eye-tracking were selected for review and analysis. Content analysis for 6 month of the selected papers showed that (1) the eye-tracking for measuring students’ metacognitive skills in chemistry learning was employed by recording all eye movement activities with eye tracker placed under the computer screen with a distance of 60-70 cm from the users (students) and they can freely move the eye for solving the chemistry problems with a predetermined duration of time; (2) analysis of temporal and spatial data of eye-tracking showed a correlation between eye movement and increased metacognitive skills, in which the stabilization of students’ views on objects observed between 66-416 ms reflected both eyes and mind worked actively. Thus, researchers can employ the eye-tracking method to comprehensively investigate and describe students’ metacognitive skills in chemistry learning and also can be a metacognitive tool for reflective self-assessment in learning.
Does learning chemistry by representation with “Jaman-Now App_Permilang” effectively impact students’ cognitive & motivation?
Authors: Almubarak  , Hidayah N , Agustina S , Taufiqurrahman
Published: January 2020

Technology has become a major component in every aspect of human life, and learning resources had included in that aspect. This issue described media for learning the “Jaman-Now App Permilang (JNAP)” can have an effect on students’ cognitive and their motivation in the learning process. The quantitative approach was the method used in this study, where this research was a part of the development research conducted by researchers, in which this research presentation specifically explained aspects of the effectiveness of the product being developed. Product feasibility tests are carried out in the school environment through two processes (limited & extensive test). Those processes were used with observation, testing, and questionnaire techniques as a measure of product success. The feasibility of this research focused on the effectiveness of the product in chemical learning where this effectiveness is assessed as an indicator of product feasibility with a valid instrument (cognitive tests, questionnaire). Statistical data revealed that the average N-Gain in the 1st process has a point of 0.25 (low), the 2nd process was 0.42 (medium), and very good criteria for the motivation aspect. The results indicated that the product has a good enough impact on the co-positivity and motivation of students, although the visualization of the values shown in the medium criteria. In other words, the product has the potential to become one of the strategies in improving the quality of chemical learning, assessment for chemistry learning, strengthening their cognitive, and guidelines for students in reflecting themselves in an understanding of the chemical material.
Individual Learning Plans Program Evaluation of Planning Education in Junior High School: Discrepancy Model
Authors: Sugianto A
Published: January 2020

Learning Plans (ILP) is a guidance and counseling program that can be used to help learners educational planning and decision making further studies SMA / MA / SMK. In order to implement professional programs, the program organized by following the rules of implementation of ILP existing program. However, the implementation of the ILP program on educational planning of students in the school are not just using established standards. Describe research purposes disparities in aspects of the preparation, organization, implementation and assessment in implementing the ILP program at the school. Evaluation study using a discrepancy model oriented towards a program decision. The approach used is a systems approach that is focused on aspects of the preparation, organization, implementation and evaluation of the ILP program. This evaluation study using a mixed method design with congcurrent model of triangulation. The results showed that the implementation of the ILP program in school SMPN 2 Barabai by 55% from the standard 100%, which means that the implementation of the ILP program concluded very far below established standards. Based on the results of the study, the proposed recommendation to be continued with the requirements made a number of improvements.
Guided Inquiry Assisted Concept Map to Improve Students Metacognition Skills
Authors: Leny  , Syahmani  , Ningsih F , Sanjaya R E
Published: January 2020

Metacognition is aspect in an effort to build students’ understanding of chemistry. Preliminary study conducted at SMAN 1 Banjarmasin showed that only a few students who can evaluate their learning process, so that the ability of students using metacognition in learning process is still low. The guided inquiry assisted concept map with metacognition approach is an alternative to improving students’ metacognition skills in learning process. The research was carried out using classroom action research design with two cycle. Each cycle consists of planning, action, observation and reflection stages. The subjects of this study were students of XI Natural Science 5 SMAN 1 Banjarmasin with 36 students. The research data collected using metacognition skills test instrument and non test instrument. Data were analyzed with quantitative descriptive and qualitative analysis. Metacognition skills of students has increased after treatment with guided inquiry assisted concept map. The process of implementation of the action is seen from teacher and student activity. Teacher activity increased from 71, 77 to 87.94. Student activity increased to 87, 4 from beginning at 68, 16. Implementation of quided inqury assisted concept map model with metacognition approach can improve students metacognition skill, student activity and teacher activity.
Development of android-based chemistry learning media for experimenting
Authors: Putra P S , Asi N B , Anggraeni M E , Karelius
Published: January 2020

Learning media is an important component in the learning process. Technology and computer-based media is one of the media needed. It aims to attract students to learn chemistry material, especially material that need more efforts to understand. This research aims to develop android-based chemistry learning media for experimenting by using simulation models in Senior High School 2 Palangka Raya. The methods of this study are a research and development (R & D) by Alessi and Trollip. Product testing consists of an alpha test and a beta test to determine the level of product feasibility and test the effectiveness of products on student learning outcomes. The instruments that used to collect data were observation sheet, interview guidelines, scoring questionnaires, and test. The data that have been collected were analysed by qualitative descriptive technique. The results of this study can be concluded: 1) Learning media is very good. 2) Learning material is very good. 3) The individual test result is very good. 4) The small group test result is very good. 5) The final product trial result is very good. The android-based chemistry learning media produced is worthy to be used and effectively used in upper class students and middle class students, but it is not yet effective to be used in lower class students.
Analysis of Cellulose Isolated from Sugar Bagasse: Optimization and Treatment Process Scheme
Authors: Kunusa W R , Abdullah R , Bilondatu K , Tulie W Z
Published: January 2020

PT. PG. Gorontalo is the largest sugar factory in Gorontalo province in which 10% of sugarcane waste is not utilized properly. In this study, the isolation and characterization of cellulose and α-cellulose from bagasse in the processing of alkali were 0.1M and 1.0M NaOH solution. The analysis method consisted of counterfeiting, dehemiselulose, delignification and bleaching of 10% H2O2 and 1% MgSO4. The next step was purification of cellulose to α-cellulose. Cellulose content was 75%, α-cellulose 37.89%. The characterization of the physico-chemical properties of the product included density analysis, viscosity, 2.01% moisture content, 5.01% ash content, pH 7.7 solubility test in 1M HCl, HNO3 1M, H2SO4 0, 2M, Ba(OH)2 0.5M, KOH 0.5M, CH3COOH 1M, NaOH 2M, NH4OH 1M. The IR α-cellulose spectrum showed the presence of –OH group at wave number 3419, 3331, 3344, 3360 cm-1. The C-O bond at 1635 cm-1, 1642-1649 cm-1 showed different C-O stretch vibrations in cellulose I and cellulose II fibers and C-O bonds in 1161.83 and 1063-1065 cm-1, 995-895 cm-1 showed a change in the residual l about the glycosidic bond to Cellulose II which interprets α-cellulose. Morphological analysis used SEM while the degree of crystallinity used Diffractogram XRD.
Component based Finite Element Design of Seismically Qualified Joints
Authors: Wald F , Vild M , Kuříková M , Kožich M , Kabeláč J
Published: January 2020

This paper describes the principles of Component Based Finite Element Modelling (CBFEM) and the system response quantity and application features for design of prequalified joints for seismic applications. The elements are analysed by geometrically and materially non-linear analysis with imperfections (GMNIA). The proper behaviour of components, e.g. of bolts, anchor bolts, welds etc., is treated by introducing components representing its behaviour in term of initial stiffness, ultimate resistance and deformation capacity. To show this process a contribution is prepared, which summarises the history of achievements of FEA application in structural connections. Contribution shows the currents trends in advanced modelling of connection components and differences of the research oriented and design-oriented models. Both have their roles in advanced analyses.
Numerical simulation and experiment on steel fiber concrete beams
Authors: Khai Lam Thanh Quang , Thi My Dung Do , Ngo Van Thuc , Chuc Nguyen Trong , Phuoc Huynh Trong
Published: January 2020

The present study aims to investigate the effect of steel fiber addition on the behavior of the concrete beam in terms of crack formation, displacement, and deformation. The normal concrete (B20) was designed for making the beam with the target strength of 20 MPa. Different percentages of steel fiber (4% and 8% by volume) were added to the B20 mixture in order to evaluate the effectiveness of steel fiber addition to the concrete beams. The steel fiber concrete beams were subjected to the tests of crack formation, displacement, and deformation under loading. The numerical simulation by ANSYS computer software was also performed for comparison. As a result, the addition of steel fiber to the concrete beams was found to have positive effects as reducing both crack formation and the displacement as well as the deformation of the beams. Besides, the ANSYS modeling showed similar results as observed by the experiment.
Methods of construction of objects taking into account the simulation of the temperature regime of hardening concrete
Authors: Pulyaev I S , Pulyaev S M
Published: January 2020

The article is devoted to the use of different methods of construction of the object, depending on the boundary conditions set in the process of its design and construction. The aim of this work is a compilation of the various methods of investigation of the temperature regime of hardening concrete, aimed at providing the required timing of the turnover of a formwork, with a view to ensuring the consumer properties of the structures. The scientific novelty of the work lies in the updating and testing of methods for regulating the heating of hardening concrete, ensuring the formation of the required consumer properties of structures not previously used in transport and civil construction, based on preliminary modeling of thermal processes occurring in the hardening concrete, through the calculation software. The use of modern calculation and analytical complex allowed to obtain the results as accurately as possible comparable with the observations obtained during construction, which allowed to develop projects for the production of works on concreting objects erected in different conditions, with the necessary consumer properties.
Application of one mathematical method in solving boundary value problems of natural vibrations of a rectangular viscoelastic plate located under the surface of a deformable medium
Authors: Adamov A A , Dzhanmuldaev B D , Janmuldayeva A B
Published: January 2020

Using of one mathematical methods on solving the boundary value problems of natural osclillations of viscooelastic rectangular plate which are beneath the surface of deformable media. In this work the natural frequency of rectangular plate which is beneath the surface are researched by the method of decomposition. The efficiency and the relative simplicity of this method. In the present work, the natural vibration frequencies of a rectangular plate below the surface using the decomposition method are explored. The effectiveness and comparative prostate of this method is shown.
Account for the contribution of higher vibration modes under seismic resistance estimation of system with elastomeric supports by nonlinear static method
Authors: Zubritskiy M A , Ushakov O Y , Sabitov L S , Kolesnikov A V
Published: January 2020

The article presents higher vibration modes accounting method to evaluate system seismic resistance by nonlinear static method. As part of the study, in order to verify the proposed method for finding the inertial forces modified system series of dynamic and static calculations was performed. Proposed inertial forces modified system can be applied for seismic resistance estimation of system with elastomeric supports. The results difference varies within 12%.
Frame structures optimization based on evolutionary modeling in active overall stability constraints
Authors: Alekseytsev A V
Published: January 2020

A method of stochastic search for rational solutions for steel frame structures based on the genetic algorithm has been developed taking into account the presence of an active constraint on structure stability. To evaluate the stability, an internal iterative cycle is introduced into decision making process during which the finite element technique equation system is solved in the presence of a geometric matrix. An example of bar optimization taking into account the loss of stability under various loading options is considered. When implementing the genetic algorithm, an adjustable mutation operator is used along with penalty function, which regulates the degree of violation of constraints on the displacements of the frame system and critical stresses acting within the bar.
Stability analysis of reinforced concrete building frames damaged by corrosion under static-dynamic loading
Authors: Savin S Yu , Fedorov S S
Published: January 2020

The paper presents a methodic for calculation reinforced concrete frame-braced structural systems, when it was damaged by corrosion, against loss of stability in over limit state caused by removal of a load bearing element. The authors obtained analytical expressions for assessment stiffness of reinforced concrete compressed-bent elements taking in account its nonlinear deforming. Such expressions allow conducting stability analysis of structural systems under consideration.
Experimental and numerical substantiation the efficiency method of compaction of soil base by creating sealing pressure inside soil massif
Authors: Lobacheva Nataliia , Yarkin Viktor
Published: January 2020

This article provides a method of compaction of the soil base by creating a sealing pressure inside the soil massif. Nowadays, in buildings reconstruction, which is accompanied an increase loads on the foundations, in constrained conditions of dense urban development, the question strengthening of bases of foundations is important. The proposed a method of compaction of soil base by creating a sealing pressure inside soil massif is applicable both for new construction and for reconstruction of any objects in dense urban development. It carried out a comparative analysis of results of experimental and theoretical studies of the bearing capacity of piles with different parameters of broadening and compacted zone obtained by the method of compaction of soil base by creating a sealing pressure inside soil massif. Numerical studies to determine the bearing capacity of piles were performed in axisymmetric formulation using Hardening-Soil model. The method of determination of changes bearing capacity of base in depending on the diameters of broadening and compacted zone was carried out on a specially designed stand is presented. The article presents the results of experimental and numerical studies of bearing capacity of bases foundation.
Evaluation of shear resistance for beam-column connections using ultra high performance steel fibre reinforced concrete (UHPSFRC) under cyclic loading by experimental research
Authors: Thuy Van Tran Thi , Tran Trung Hieu
Published: January 2020

Evaluation of behavior for beam-column connections in the buildings under cyclic loading is extremely important, where shear resistance is one of the important factors. Beam-column connections are considered places in which stresses are concentrated during working process and it is clearly showed in exterior beam-column connections. There have been many published research and experimental investigations for the external beam-column connections. The use of new concrete material (UHPSFRC) for strengthening the external beam-column connections is a new idea and has not been much studied yet. Therefore, this paper presents the experimental investigation results for shear resistance of external beam-column connections followed EuroCode 8 [1] with ductility class high (DCH). This experimental result proposes the idea about strengthening for beam-column connections, provide additional experimental data and help the design process followed seismic specification of Vietnam.
The optimization of radiation protection to interventional cardiologists
Authors: Pratiwi N G , Ardiatna W , Pawiro S A , Wigati K T , Soejoko D S
Published: January 2020

Scattered dose radiation to occupational in interventional cardiology cannot be neglected due to the long time for each procedure. The limit dose for occupational is 20 mSv per year or 0.01 mSv/h. The aim of this study is to calculate the effective dose of occupational and to analyse the optimization of radiation protection in the Cath lab. The simulation has been done using Rando phantom as a patient and Unfors Xi as scattered dose measuring instrument (in mGy/h). The data is collected in 6 different positions from altitudes 25 cm to 75 cm with a range of 15 cm without protective shielding. Field size of primary beam is varied to 20×20 cm and 25×25 cm, while gantry tilt is varied to caudal, cranial, and Left Anterior Oblique (LAO). The obtained data is multiplied by weighting factor base on its height. The result shows that the effective dose of occupational is in the range of 0.18-0.94 mSv/h, which is exceed the limit dose. To accommodate the limit dose for occupational, we propose the limitation of procedure time to 21-110 hours a year or the use of protective shielding as thick as 1-1.6 mm lead.
Landslide investigation using electrical resistivity tomography (ERT) technique at the location of water channel PLTM Lambangan, Pagimana, Central Sulawesi
Authors: Asrafil  , Uno I , Jayadi H , Rugayya S
Published: January 2020

Mass movement phenomena that occur in the research area affect the destruction of water channel in the area of PLTM Lambangan that located at the location. This research aimed to investigate soil movement phenomena in order to determine control factors that causing soil prone to move, especially in the surface geological aspect and underground lithology condition in the research area. Investigation method applied is by underground geologic and geophysical surveys using electrical method, that is Electrical Resistivity Tomography (ERT) with Wenner Configuration. Results of investigation show that geological factors are quite related to the soil movement. Movement phenomena occur in the surface with hilly to steep cut topography (21-55%) with material sourced from alluviation of clastic sediment dan carbonatic rocks. The damaged area is people farming area where fibre root of plant adds water absorption capacity of the soil. Also, sliding materials show water seepage that indicates that the moving slope has been saturated. This condition supported by information from geoelectric survey which indicates that in general the under surface material potent to slide or move because of unconsolidated material with its resistivity values in the order of 16 – 43 m that estimated related to alluvial or saturated residual soil.