bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple analytical method based on UV-visible spectroscopy coupled with SIMCA method for authentication of Lampung robusta coffee with geographic indications (GIs)
Authors: Yulia M , Suhandy D
Published: January 2021

Lampung Robusta coffee got a geographic indication (GIs) protection from Indonesian government since 2014 with certificate number of ID G 000 000 026. This GIs coffee come from three different geographic origins in Lampung province: Lampung Barat, Tanggamus and Way Kanan. In this research, we evaluate the possible application of simple analytical method based on UV-visible spectroscopy coupled with SIMCA (soft independent modelling of class analogy) for authentication of Lampung Robusta coffee with GIs. Two types of Lampung Robusta coffee were used: GIs coffee from Lampung Barat and non-GIs coffee from Pesawaran. Each type consists of 50 samples of ground roasted coffee with 1 gram weight. The all samples were extracted using a hot distilled water and 3 mL aqueous samples were pipetted into 10 mm quartz cuvette. UV-visible spectral data were recorded in the range of 190-1100 nm. The chemometrics (PCA and SIMCA) was performed using selected preprocessed spectral data in the range of 240-430 nm. The PCA result showed that GIs coffee and non-GIs coffee can be well separated. The SIMCA classification was accepted with 100% of correct classification.
Microcapsule from PCL/PEG as Controlled Nifedipine Drug Delivery Carrier
Authors: Rahma W A , Budianto E
Published: January 2021

Problems related to controlled drug release are important to immediately find a solution because of the dangers of drug side effects if consumed repeatedly every day. The drug used is Nifedipine which is a hydrophobic drug. This research used a synthetic combination of poly(caprolactone) and poly(ethylene glycol) with surfactants in the form of tween 80 and span 80 while the method used was microencapsulation. Microencapsulation is a process in which active substances are coated by extremely small capsules. Once the drug was in the intestine, it was released in a controlled manner so as to minimize side effects and maximize drug release. The results showed that the composition of the best poly(caprolactone) (PCL): (PEG) poly(ethylene glycol) combination was 80:20 with a molecular weight of PEG 400 g/mol. The result of the encapsulation efficiency percentage obtained 97.84% ± 0.01 and the result of dissolution test was 44.77%.
Transesterification of coconut oil (Cocos nucifera L.) into biodiesel using zeolite-A catalyst based on rice husk silica and aluminum foil
Authors: Herliana  , Ilim  , Simanjuntak W , Pandiangan K D
Published: January 2021

In this research, zeolite-A was synthesized by hydrothermal method using silica of rice husk and aluminum foil as raw materials. For zeolite preparation, a particular amount of silica was dissolved in NaOH solution which is then aged with variation time of 24-96 hours, the mixed solution was then added with aluminum foil and again aged for 24 hours, the crystallization process was carried out in an oven of 100 °C 96 hours. The resulting zeolite was then calcined at 550 °C for 6 hours. The zeolite characterization by XRD showed that zeolite-A had been formed and had characteristics following the zeolite-A standard from IZA. The resulting zeolite-A has good crystallinity as indicated by the sharp peaks on the resulting diffractogram. The zeolite-A catalytic test on transesterification of coconut oil showed high catalyst performance, characterized by the conversion of fatty acids in coconut oil to methyl esters with 100% conversion percent. The formation of the methyl ester was proven based on the results of the analysis with FTIR and GCMS which showed the characteristics of methyl ester at wavenumbers 1744 cm−1(C═O), 2922 cm−1(C─H), 1170 cm−1(C─O), with the highest percentage in the form of methyl laurate at 31.80%.
The effect of initiator concentrations on corrosion inhibition activity of polymeric derivatives of 2-vinylpyridin
Authors: Ilim I , Bahri S , Marjunus R , Simanjuntak W
Published: January 2021

This study aims to investigate the effect of initiator concentrations of polymeric derivatives of 2-vinylpyridine, P(2VP) as corrosion inhibitors of mild steel in CO2-satured brine solution. Polymerization of the monomer was conducted using hydrogen peroxide initiator with four different concentrations of 0.25; 0.33; 0.50; and 0.80 mole, to produce four oligomers referred to as P(2VP)A, P(2VP)B, P(2VP)C, and P(2VP)D, respectively. A series of corrosion experiments was conducted to determine the corrosion rate of the mild steel using weight loss and linear polarization resistance (LPR) methods. The effect of inhibitor concentration, and temperature, on the corrosion rate was also investigated. The oligomers synthesized were found to have different physical appearance. Two oligomers, the P(2VP)A and P(2VP)B, were found as yellow viscous liquids, with O(2VP)B is more viscous than P(2VP)A, while the other two oligomers, P(2VP)C and P(2VP)D exist as yellow solids. The experimental results reveal that the use of monomer led to higher corrosion rate compared to that of blank experiment, but reduced corrosion rate was achieved with the use of the oligomers. P(2VP)A as an oligomer synthesized with the lowest concentration of H2O2initiator inhibited the corrosion more effective than the higher concentrations. It was also found that the higher the concentration of the oligomer, the better the protection. For temperature, the opposite is true, indicating that the oligomer was physically adsorbed onto the surface of mild steel.
Identification and antibacterial activity of flavonoid compounds from wood branches of the pudau plant (Artocarpus kemando Miq.)
Authors: Suhartati T , Wulandari Z , Wulandari M , Yandri  , Hadi S
Published: January 2021

In this research, isolation, identification, and antibacterial assay of flavonoid compounds have been carried out. These compounds were obtained from the wood branches of the pudau endemic plant from Karang Anyar village, Penengahan, South Lampung Regency, Lampung Province. Flavonoid compound extraction was carried out by maceration method using methanol, while fractionation and purification were conducted using chromatography technique. The purity of the compounds was determined by the melting point test and thin layer chromatography, the identification of compounds was assigned by UV-Vis and IR spectroscopy. The results of the isolation obtained two compounds, artocarpin (1) and cycloartocarpin (2). Compound (1), 92 mg, in the form of a yellow needle crystal with a melting point of 184.9 -187.5 °C; compound (2), 20 mg, in the form of yellowish white needle crystals with melting point 280 - 283 °C. In the antibacterial assay against Bacillus subtilis and Escherichia coli, compounds (1) showed very strong antibacterial activity at a concentration of 0.4 mg/disk and 0.5 mg/disk, respectively, whereas compound (2) had strong antibacterial activity against B. subtilis and E. coli at the same concentration of 0.5 mg/disk.
Production, purification and characterization of the α-amylase from local bacteria isolate Bacillus subtilis ITBCCB148
Authors: Yandri  , Witazora Y , Suhartati T , Satria H , Hadi S
Published: January 2021

Production, purification and characterization of the α-amylase from local bacteria isolate Bacillus subtilis ITBCCB148 has been successfully carried out. The purified enzyme increased 149.9 times with specific activity of 115,500 U/mg compared to enzyme crude extracts. This enzyme has an optimum pH of 5.5 and an optimum temperature of 60°C and can maintain its stability at a temperature of 60-80°C, thus this enzyme is categorized as a thermostable enzyme.
Effect of glutaraldehyde addition on the stability of the α-amylase from Bacillus subtilis ITBCCB148
Authors: Witazora Y , Yandri  , Suhartati T , Satria H , Hadi S
Published: January 2021

α-Amylase is widely used in industry because of its ability to hydrolyze starch to glucose. Limited enzyme activity in extreme pH and temperature makes it necessary to increase enzyme stability. The purpose of this study was to improve the stability of the α-amylase from the bacteria Bacillus subtilis ITBCCB148 by chemical modification using glutaraldehyde (GA). The results showed that modified enzymes using glutaraldehyde 0.01; 0.03 and 0.05% have an optimum pH of 5.5; optimum temperature of 55°C; KM of 4.74; 5.03 and 3.87 mg/mL substrate; the Vmax of 285.71; 270.27 and 212.77 μmol mL−1 min−1; ki of 0.0183; 0.0111 and 0.0160 min−1; half-life (t1/2) 37.87; 62.43 and 43.31 minutes; ΔGi 102.656; 104.047 and 103.038 kJ mol−1, respectively. Chemical modification of the α-amylase from B. subtilis ITBCCB148 using glutaraldehyde can increase thermal stability by 1.6-2.7 times which can be seen from a decrease in the value of ki, an increase in half-life and ΔGi.
The Potency of Cinnamon as An Anti-Diabetic and Anti-Covid19 based on Its Mineral Content and Phenolic Compounds
Authors: Hapsari N R P , Wijayanti C , Subandi  , Suharti  , Mariana R R
Published: January 2021

The purpose of this study were to determine the mineral content (Cr, K and Ca) as well as total phenolic (TPC) and total flavonoids (TFC) in cinnamon, then to know the potency of some phenolic compounds in cinnamon as alpha amylase inhibitors and its binding activity to S protein of covid19. The mineral content was determined by the ICP method, while the TPC and TFC levels were determined spectrophotometrically. In silico analysis was carried out by docking techniques using human salivary alpha amylase and S covid19 protein as receptors and several polyphenol compounds in cinnamon as ligands. The results have shown that the levels of Cr, K, Ca, TPC and TFC of cinnamon, were 0.524 ppm, 4033ppm, 17453 ppm, 1.55% and 4.26%, respectively. The results of in silico analysis has shown that kaempferol 3-O-glucoside and quercetin in cinnamon are able to bind to human saliva α-Amylase on its active site with a binding affinity that are relatively the same as acarbose has. The docking analysis also has shown that kaempferol, quercetin and rutin of cinnamon were able to bind to the Receptor Binding Domain (RBD) of S protein of covid19, so that these compounds also have the potency to be anticovid19.
The analysis of hypothesis-deductive reasoning ability in learning particle dynamics
Authors: Pratama W. P. , Supriyatman
Published: January 2021

Hypothesis-deductive reasoning ability refers to the ability to think logically to formulate hypotheses based on existing scientific theories. This study aims to describe the hypothesis-deductive reasoning ability of Grade X students at Integrated Models Madani Senior High School Palu in learning physics, specifically on the topic of particle dynamics. This type of study is a qualitative research using a qualitative descriptive approach. The subjects in this study consisted of 26 students of Grade X Science 5 Integrated Models of Madani Senior High School Palu who had participated in studying the topic of particle dynamics. The instruments used include a hypothesis-deductive reasoning ability test and interview guidelines. The data obtained were then analyzed using descriptive analysis. The results of the analysis showed that the students’ hypothesis-deductive reasoning ability was 58.2%. This indicates that the students’ hypothesis-deductive reasoning ability is categorized as sufficient. The factor that affects the hypothesized-deductive reasoning ability is the learning process in the classroom as several students received the same form of questions, and the teacher provides direction as well as motivation, so that the classroom conditions are conducive.
Digital electronic practicum with logisim application using google meet
Authors: Dewantara D , Misbah M , Mahtari S , Azhari A , Sasmita F D , Melisa  , Rusmawati I , Kusuma L W , Ridho M H , Lutfi M
Published: January 2021

The focus of this research is to describe the effectiveness and response of students on the use of Digital Electronic Practicum with Logisim Application using Google Meet. The research subjects were 50 Physics Education Students of Lambung Mangkurat University taking the Digital Electronic course. The data of this study were collected by using practicum assessment sheets and students’ response questionnaire. The results showed that the mean score of practicum results from digital electronic practicum with Logisim application using Google Meet was 70.58. Thus, the effectiveness of the implementation of the Digital Electronic Practicum with Logisim application using Google Meet is in a good category. Data from the students’ response questionnaire was 3.83 in average, so it was categorized as good. Thus, it is concluded that the Digital Electronic Practicum with Logisim application using Google Meet is effective to implement and obtains a very good response from the students.
An analysis of students’ conceptual understanding using STEM approach educational videos
Authors: Putri A S , Saehana S
Published: January 2021

This study aims to determine and analyze the conceptual understanding of students who are taught using STEM approach learning videos on sound wave material. This research is a qualitative descriptive study. The research subjects consisted of 19 students of Grade XI of MAN 2 Palu Model in the even semester of the academic year of 2019/2020. The instruments used were a multiple choice test accompanied by a Certain of Response Index (CRI) which was given before and after being taught with STEM approach educational videos, as well as interviews. Respondents included those of high, medium, and low categories proficient students and were willing to do an interview test. The results of this study indicate that the comprehension of the material concept of students before being taught using the educational video integrated with the STEM approach can be categorized as low, and after given the educational video with the STEM approach, the students’ understanding of the concept increases. Therefore, educators can apply STEM approach learning videos in the learning process. For further researchers, this study can provide an overview of the conceptual understanding of students being taught with STEM-approached learning videos. Hence, researchers can develop research using other learning media or in a broader cognitive domain.
How to train problem-solving skills in physics using authentic learning
Authors: Wati M , Safiah S , Misbah M
Published: January 2021

Based on early observation, it is known that student’s problem-solving skills in one of SMAN Banjarmasin are still low. Research and development to produce a module of dynamic fluid with authentic learning to train student’s problem-solving skills were conducted. The objectives of this study were to describe the validity of module. This research used 4D models (Define, Design, Develop, and Disseminate). The data was collected and analyzed from the validation sheet that was rated by the practitioner and expert in physics education. The results showed that the validity of the module is 3,28 and categorized as valid. It can be concluded that the dynamic fluid module with authentic learning is suitable to be integrated within physics learning to train student’s problem-solving skills.
The perspective on monopoly as media in physics learning by using teams games tournament
Authors: Azizah N , Nengsih E W , Wati L , Rahimah  , Nastiti L R
Published: January 2021

This research aims to describe: 1) the use of Teams Games Tournament (TGT) cooperative learning model with the help of board-based gaming media, namely monopoly on physics learning; 2) the advantages and disadvantages of using TGT-type cooperative learning models assisted by monopoly media. This research method uses a library research approach. The technique to collect data is by reviewing the literature such as books, journals and documents that are considered in accordance with the study conducted. From the results obtained, it is concluded that 1) the use of cooperative learning model type TGT with the help of monopoly media gives influence to the quality of students learning, 2) the use of cooperative learning model type TGT assisted by monopoly media makes students’ attention focused so as to make it easier for students to digest materials, students are trained to think systematically and analytically and export their learning skills without having to rely on others. The monopoly media can improve students’ learning outcomes. However, the cooperative model of monopoly media assisted TGT type takes a while to learn for considerable.
The impact of problem-based learning and inquiry models toward students’ science process skills on the vibrations and waves chapter
Authors: Nurhayati  , Wahyudi  , Saputri D F , Trisianawati E
Published: January 2021

Science process skills are basic skills that help students develop higher-order skills. These skills can be trained in science learning with a scientific learning approach. This study aims to determine students’ science process skills that are influenced by problem-based learning models and inquiry models. The research method used is an experimental method with a quasi-experimental design. The research sample consisted of two classes of students of class VIII SMP. Science process skills data is measured by a description test which has valid criteria and high reliability. Descriptive and inferential analysis techniques are used in the data analysis of science process skills. The results of the data analysis concluded that: (1) The students ‘science process skills after applying the problem-based learning model were classified as good, (2) the students’ science process skills after being applied to the inquiry model were classified as very good (3) there was no significant difference between science process skills which are taught using problem-based learning models and inquiry learning models.
Application of generative learning in physics learning
Authors: Yuliani H , Ulfah R Y , Agustina E , Al-Huda A M , Qamariah Z
Published: January 2021

This study aims: (1) to determine the application of generative learning in physics learning; (2) to determine the advantages of generative learning in the physics learning process; (3) to determine the constraints of generative learning in physics learning. The research method is literature study. Data was collected based on information obtained from various literature. Research shows that: (1) the application of generative learning in physics learning can improve learning outcomes, understanding of physics concepts, generic science skills, and able to reduce student misconceptions; (2) generative learning makes students more active, creative and critical in developing the knowledge obtained, discovering phenomena and solving problems. Meanwhile, the teacher will be skilled at organizing and understanding students’ ideas; (3) The application of generative learning requires accuracy of methods and modification of strategies as well as careful planning and preparation. In addition, simulation is needed in a generative learning model to familiarize students. Teachers are required to be more observant and creative in expressing students’ ideas. Generative learning is better applied to high school students.
Create an interactive video about alternative energy sources from fruits to optimize student creativity
Authors: Dewantara D , Mahtari S , Misbah M
Published: January 2021

Creativity is a skill that must be sharpened in the era of Society 5.0. The purpose of this study was to describe students’ creativity in making interactive videos about alternative energy sources from plants. The subjects in this study were students of the Physics Education Study Program taking Energy Physics courses. The study was conducted in the even semester of 2019/2010. This study employed an analytical descriptive study. The instrument used was the student’s creativity observation sheet. The results of the study have shown that the mean results of observations of student creativity are 3.22. Thus, it can be concluded that students’ creativity in making interactive videos about alternative energy sources from plants is in a relatively good category. It is necessary to re-examine what the next effort is to increase student creativity.
A conceptual framework of STEM education based on the Indonesian Curriculum
Authors: Sujarwanto E , Madlazim  , Sanjaya I G M
Published: January 2021

Technological and economic developments through the industrial revolution 4.0 motivate the Indonesian education sector to prepare students for this challenge. One of the efforts is to use STEM-based learning. Existing activities and research have demonstrated interdisciplinary integration in STEM education, but it is not clear yet. Besides, STEM education needs to be suited to Indonesian Policy and Curriculum related to science, technology, and mathematic. Thus, STEM education practice needs a conceptual framework. We use the literature review method. We examine education policy in Indonesia and research related to STEM education to create a conceptual framework for STEM education. The result is a proposed conceptual framework that suggests the practice of STEM education must know and maintain the principles of science, technology, and mathematics based on the characteristic of the Indonesian Curriculum. Also, the practice of STEM education needs to pay attention to the interrelationship of the four STEM disciplines, involve the engineering design process, involve the community of practice, and use a supportive learning model. Although this conceptual framework is theoretical, it could be useful in deciding a sufficient practice of STEM Education in Indonesia and designing appropriate activities in practising integrated STEM Learning.
Ethnomathematics of the Jami Mosque Jingah River as a source mathematics learning
Authors: Fajriah N , Suryaningsih Y
Published: January 2021

Ethnomathematics was a contextual approach that uses the environment and culture. The study aims to explore the relationship between mathematics and the Jami Mosque Jingah River culture in mathematics learning and provides ethnomathematics options as a learning resource for students during the COVID 19 pandemic. This study uses an ethnographic approach, which was an empirical and theoretical approach to obtain an in-depth description and analysis of a culture based on field notes that been obtained from the results of data collection. The results showed that there are a lot of components, ornaments, and objects in the Jami Mosque Jingah River containing many mathematical concepts of lines, vertices, properties, perimeter and area, especially in the field of geometry. During the COVID 19 pandemic, the teacher gave students the task of looking for information and observing pictures of the Jami Mosque Jingah River. that These are the students’ activities: (1) identify the types and properties of flat shapes (2) use contextual problems related to these flat shapes, (3) combine flatways at the Jami Mosque Jingah River that can generate creative thinking skills students. For suggestion, mathematics teachers in junior high schools can apply this study’s results to improve higher-order thinking skills and become more familiar with their culture.
Understanding the prospective physics teachers conception of the characteristic of sound
Authors: Saparini S , Misbah M , Rizaldi W R
Published: January 2021

This study aimed to analyze the level of conceptual understanding of prospective teacher students of sound characteristics. This research was descriptive. The subjects were students of Physics Education at Sriwijaya University and Lambung Mangkurat University who participated in wave courses totaling 69 people. The data were collected using a previously developed diagnostic test instrument and modified according to research needs. The data were analyzed using descriptive statistics. The results showed the percentage of conceptual understanding possessed by the respondents (1) 52.17% on pitch and loudness of sound waves from two people shouting simultaneously; (2) 42.11% on the speed of sound wave propagation; (3) 2.90% on the wave superposition concept; and (4) 5.80% on sound reflection. There are still misconceptions occur, the velocity of propagation of sound waves is influenced by the amplitude and frequency of the sound, and a dust particle in front of the sound source will move influenced by the sound’s loudness. Overall, the level of conceptual understanding of some of the characteristics of sound wave concepts varies, and alternative concepts are still emerging, so it needs learning innovations to overcome these problems.
Utilization artificial intelligence to improve creativity skills in society 5.0
Authors: Oktradiksa A , Bhakti C P , Kurniawan S J , Rahman F A , Ani
Published: January 2021

The purpose of this research is to take advantage of Artificial Intelligence which is used to increase Creativity Skills in the era of society 5.0. Data collection is done to see subtle problems and develop solutions. Technique data collection is a literature study. Creativity Skill is one of the abilities that students must have to answer challenges, namely the era of society 5.0. The era of society 5.0 is an era where new values created by technological developments can minimize human responsibility and future economic problems. In this case, Artificial Intelligence is a way to maximize students in social change which requires someone to be innovative, creative by emphasizing contextual learning in which students must be active. Artificial intelligence (AI) enables machines to learn from experience, adapt to new inputs and perform human-like tasks. Most of the AI you hear about today - from computers playing chess to adult cars - rely heavily on deep learning and comparing natural language. Using this technology, computers can complete specific tasks by processing large amounts of data and managing patterns in the data so that it is hoped that the use and development of Artificial Intelligence can increase creativity skills to face opportunities and challenges in the era of 5.0 society.
Train students’ science process skills and self-efficacy in online learning using the Scientific Critical Thinking (SCT) model assisted by google classroom and google meet
Authors: Rusmansyah  , Hayati N , Winarti A , Rahmi
Published: January 2021

Science process skills and self-efficacy need to be trained in students in chemistry learning activities at school. This will have a positive impact on students in facing and solving problems in their lives. The Scientific Critical Thinking (SCT) model is one of the models that can be used to implement learning. This research was conducted at SMAN 11 Banjarmasin, class XI MIPA 2, on the buffer solution’s material, assisted by google classroom and google meet. This study aims to determine (1) the improvement of students ‘science process skills (2) students’ self-efficacy, before and after learning with the SCT model, and (3) student responses to the application of the SCT model assisted by google classroom and google meet. This research method is a pre-experiment, one group pretest-posttest design. The research sample of class XI MIPA 2 students used a purposive sampling technique. The independent variable is the SCT model; the dependent variable is science process skills and students’ self-efficacy. Data collection using test and non-test techniques. The data analysis technique used descriptive analysis and inferential analysis. The results showed that (1) there was an increase in students’ science process skills; (2) there is an increase in student self-efficacy (3) Students’ positive responses to learning with the SCT model assisted by google classroom and google meet.
The analysis of students’ ability in solving physics problems using multiple representations
Authors: Sutriani  , Mansyur J.
Published: January 2021

The ability and skills of students in using multiple representations determine the level of students’ physics problem solving abilities. Students’ thinking ability in solving physics problems tends to vary. Therefore, this study was conducted to analyze the students’ ability to solve physics problems by using multiple representations. The type of research was a qualitative research which utilized qualitative descriptive approach. The subjects in this study were 19 students of class XI Science An-Nahl MA Negeri Insan Cendikia Palu City in the 2019/2020 academic year. Respondents in this study were 6 students selected based on the high, medium, and low categories obtained from the results of the respondent selection test. The instruments used in this study were multiple choice tests, problem-solving tests, and interview guides. Based on the results of this study, the students’ physics problem solving ability was categorized in the poor category with the acquisition of an average score in percentage of 37.89%, while for the highest average multi-representation ability of each representation, namely pictures, graphics, mathematics, and verbal, students tended to be able to use image representations with a percentage of 38.75%. However, this percentage was still categorized as low.
The students’ approach patterns in thermodynamic problem-solving at SMA lab school UNTAD Palu
Authors: Susanti  , Supriyatman
Published: January 2021

The process of problem-solving carried out by students in solving physics exercises consists of different approaches. It is reviewed based on the diversity of students’ ability levels in solving problems in physics subject. This study aims to describe the approach patterns used by students in the process of solving physics problems on the thermodynamic material at Senior High School Lab school UNTAD Palu. This type of research is qualitative research with a qualitative descriptive approach. The subjects in this study were 20 students of Grade XI Science 3 at Senior High Scool Labchool UNTAD Palu. Respondents in this study consisted of up to 6 students. The respondents were selected using the calculation of standard deviation and the average score of the results of the respondent selection test. The instruments used in this study were respondent selection tests, problem-solving tests, and interview guides. From the results of the research for the test of students’ physics, the problem-solving ability was in the poor category with the acquisition of an average value percentage of 37.3%. Meanwhile, the approach patterns used by the students in the physics problem-solving process was interesting as it tended to use two approaches, namely structured Plug and Chug, as well as unstructured Plug and Chug.
An online project-based learning model to improve students’ thinking ability in the new normal era
Authors: Bhakti C P , Noor K W , Ghiffari M A N , Nurpitasari E , Oktradiksa A , Ani
Published: January 2021

The purpose of this paper is to provide insight into project-based learning conducted online to improve students’ thinking skills in the new normal era. In the new normal situation, students must carry out learning at home online. The method used in this study is a literature review. Benefits and competency development of online learning need to be considered. One of the competencies that need to be developed in the new normal is the ability to think. Unlike before the COVID 19 pandemic outbreak, students’ thinking skills can be developed through face-to-face learning with teachers and peers. However, in this new normal era, there is a need to modify online learning strategies to improve thinking skills. Project-based learning is a learning strategy in which learning orientation is carried out by doing long-term assignments. Project-based learning can be done online and adapted to the current new normal situation. This research using a literature review method which used several stages started from collection data until summarized the data. It can be concluded that this research will give a reference to produce a website for improving students’ thinking ability.
The effectiveness of distance learning through Edmodo and Video Conferencing Jitsi Meet
Authors: Asfar A M I T , Asfar A M I A
Published: January 2021

Distance learning is intensively used since the outbreak of the Covid-19 requires the lecture to be done from home. A variety of applications to support distance learning, including e-learning Edmodo as a learning management system with video conference jits meet to optimize lectures online. The purpose of this study is to see the course’s effectiveness by using e-learning Edmodo with or without a video conference Jitsi Meet in reducing students’ mistakes in answering the questions given. Research design using experimental type posttest, only group control design. The object of research consists of two classes, namely class control and class comparison. The analysis results indicate the use of an e-learning Edmodo integrated video conference Jitsi Meet provides advantages compared to only using e-learning Edmodo because it can reduce the level of error in answering questions by 50%.
Students mathematical literacy in solving wetlands contextual problems
Authors: Zulkarnain I , Hidayanto T , Kamaliyah
Published: January 2021

The research describes the students’ mathematical literacy in solving wetlands contextual problems. This study employed a descriptive qualitative method. The subjects were 87 students in Mathematical Learning for Junior High School course of Mathematics Education Study Program at Universitas Lambung Mangkurat in the 2019/2020 academic year. The students were tested with ten items of wetlands contextual problems. The analysis of those data used descriptive statistics including mean, standard deviation, maximum and minimum score, and total score. The research finding reveals that the mean score of students’ mathematical literacy was 18.55 (medium category). Individually, there were five students in very high, 14 students in high, 31 students in medium, 35 students in low, and two students in the very low category. In addition, the students are weak in the formulating process. Based on the result, students’ habituation in solving contextual wetland problems needs to be continuously pursued to improve students’ mathematical literacy ability.
The validity of lesson plan with scientific approach: Building curiosity and responsibility character
Authors: Pasani C F , Yulinda R , Putri R F , Amelia R
Published: January 2021

The instilling of national character value may be achieved through learning. Therefore, this study aims to create a Lesson Plan, which integrates the characters of curiosity and responsibility with a scientific approach and to determine product validity. Research and Development (R&D) was used as a model for conducting this study. The Research and Development used Borg and Gall model. Furthermore, the characteristics of the developed lesson Plan were evident in the syntax/learning steps, which were organized according to curiosity indicators and responsibility characters. This study involved 2 expert validators and 1 school practitioner. The instrument used was a learning plan validation sheet. The results showed that the Lesson Plan with a scientific approach may be used to develop the character of curiosity and responsibility for students in junior high school. This can be seen from the validity of three aspects which is the format (100%), language (98,33%) and content (97,47%) which are very good qualification. It can be concluded that the lesson plan developed is valid and able to building curiosity and responsibility character student.
The development of electrical energy conversion tools as learning media for the concept of energy sources
Authors: Rohman Abdul , Komang Werdhiana I , Saehana Sahrul
Published: January 2021

The purpose of this research is to produce electrical energy conversion tool as a learning medium. This research process is a research and development research which is commonly referred to as R&D. Sugiyono modified this research model. The instrument used was a questionnaire with a Likert scale which were assessed by media experts, material experts, physics teachers and students of Grade XI IPA Senior High School Lab school, Untad, Palu. The product quality data obtained were analyzed using descriptive analysis. The product quality based on the results of the analysis of the media expert’s assessment obtained a percentage value of 84% with the interpretation of “Very Good”. The product quality, based on the results of the assessment analysis by material experts, obtained a percentage value of 85% with the interpretation “Very Good”. For the results of the physics teacher responses on the perspective of the learning media developed, it obtained a percentage value of 92.2% with the interpretation “Strongly Agree”. For the results of the students’ responses in Grade XI Science Senior High School Lab school, Untad, Palu, on the limited test, the percentage value obtained was 85.95% which had the interpretation of, “Strongly Agree” regarding the use of the learning media. The results of the tests and questionnaire analysis indicated that the electric energy conversion tool as a learning medium developed is suitable for use in the learning process.
The effect of TiO2 addition on thermal resistance of geopolymer mortar based low alumina fly ash
Authors: Saukani M , Febrianty R , Ariska N , Husein S , Astutiningsih S
Published: January 2021

The utilization of fly ash with low alumina has been carried out. The addition of TiO2 to the base material of fly ash and fly ash added with 20% metakaolin mixed with an alkaline solution has been characterized by heat resistance, compressive strength and porosity. These results indicate that the addition of TiO2 to both fly ash and fly ash with an additional 20% metakaolin shows a reduction in porosity reduction, an increase in the compressive strength value, and an increase in the thermal resistance of the sample. Despite an increase in the compressive strength value, however, the minimum requirement for a fire brick has not been achieved.
The effect of physics learning with the use of gasing and boat toys media on student learning outcomes
Authors: Widyaparamita  , Darmadi I W , Saehana S
Published: January 2021

This study aimed to determine whether or not there was an effect of learning physics with the media of top games and boat games on student learning outcomes in Junior High School 2 Sigi. To see the success of this study, a pretest was held to determine the students’ abilities. After that, the experimental class was given treatment using the top game media and boat games and the control class did not use games. After learning was complete, both classes were again given a posttest to test the results. Based on the results of the two classes, the mean scores of the experimental class and control class were 9.93 and 11.06 for the pretest respectively, while for the posttest the average scores were 22.5 and 19.10. This study used a quasi-experimental research type. The population of this study were all students of class VIII Junior High School 2 Sigi and the sample in this study were class VIII A and VIII B which were divided into experimental class and control class. The research sample was selected using purposive sampling technique which determined the sample with certain considerations. The instrument used was an essay Test.
Nitrogen accumulation, rather than carbon: nitrogen stoichiometric variation, underlies carbon storage during forest succession
Authors: Zou Junliang , Wu Juying , Osborne Bruce , Tobin Brian , Luo Yiqi
Published: January 2021

Forest ecosystems play an important role in regulating global temperatures through their capability to take up and store CO2 from the atmosphere, but the magnitude and sustainability of this carbon (C) sink is critically dependent on the availability of nutrients, particularly nitrogen (N). However, the extent to which the absolute amount of N or modifications in plant and soil C:N ratios controls long-term forest carbon sequestration (Cseq) remains uncertain. To assess this, we analyzed the results of 135 global field studies that investigated the dynamics of C and N availability during forest succession. The results showed that the accumulation of C and N in plant (including above- and below-ground vegetation) and litter pools decreased with forest age and approached an equilibrium value in the latter stages of stand development. Plant and litter C:N ratios increased during the first 10–20 years and remained relatively stable thereafter. The analysis further showed that the relative importance of a change in the total amount of N or modifications in the C:N ratio, to increases in Cseq, varied with forest age. Whilst the relative importance of a change in the total amount of N increased with forest age, the relative importance of a varied C:N stoichiometry decreased with forest age. Overall, a change in the total amount of N was the more important factor contributing to C storage during forest stand development and the C stored in vegetation dominated the total ecosystem C pool. These results show that ecosystem N availability is a key factor supporting long-term forest Cseq during forest succession. As most of the C is found in above-ground vegetation, this pool is particularly susceptible to abiotic or biotic factors and anthropogenically-related disturbances.
Formation mechanism and function of tribo-layers in dry sliding wear of TC11 alloy
Authors: Li Xinxing , Wang Hongxia , Shi Jianfeng , Han Boqun , Ren Naifei
Published: January 2021

Dry sliding wear tests were performed for TC11 alloy through a pin-on-disc tribometer at a load of 50 N under different sliding velocities. Tribo-layers always formed on wear surfaces of titanium alloy at different sliding speeds. The formation of tribo-layers depended on the generation, movement, aggregation, transfer of wear debris and tribo-chemistry. Small wear debris and relatively high contact surface temperature were favorable conditions for formation of tribo-oxide layers. Tribo-oxide layers protected the titanium alloy matrix effectively and reduced the wear. The more oxides the tribo-oxide layer contained, the better it protected the matrix.
Thermal and mechanical performances of bamboo strip
Authors: Richmond Tutea , Lods Louise , Dandurand Jany , Dantras Eric , Lacabanne Colette , Durand Jean-Michel , Sherwood Edouard , Ponteins Philippe
Published: January 2021

Bamboo strips extracted from Phyllostachys viridiglaucescens, grown in Europe, were analysed to assess their thermal and mechanical properties for composites application. Thermal stability of the European bamboo was studied by Thermogravimetric Analysis (TGA) and compared to the one of species grown in Oceania. An evolution of the chemical composition along the radial direction of the Phyllostachys bamboo was identified by TGA. The inner part of culms shows a higher proportion of hemicelluloses, while the percentage of crystalline cellulose is higher in the outer portion. This evolution of the composition was used to interpret the original data recorded by Dynamic Mechanical Analysis (DMA) of the strips. Glassy tensile modulus founded by DMA increases from the inner part of the culm (6.8 GPa) to the outer part (9.9 GPa). The variation of the cellulose content along the radius of the bamboo culm is related to this increase and shows a good correlation with thermal behaviour. The dynamic relaxations in the shear mode reveal the existence of two secondary relaxation modes sensitive to water. In the order of increasing temperatures, they have been assigned to the mobility of methylol groups and to heterogeneities of the polymeric matrix. By combining Differential Scanning Calorimetry (DSC) and DMA, the response of the viscoelastic transition of bamboo strips, at 210 °C, was evidenced for the first time. Bamboo strips behave as a unidirectional composite reinforced by technical fibres; its particularly high shear glassy modulus (2.3 GPa) deserves to be emphasised.
Broadband vibration energy harvesting from a non-deterministic system: Performance of different piezoelectric patch shapes
Authors: Ali Abdelrahman , Muthalif Asan G A , Renno Jamil
Published: January 2021

Harvesting energy from ambient structural vibration using piezoelectric materials gained massive interest in the past decade. Piezoelectric harvesters can be incorporated in many applications; however, one of the main challenges to become widely adopted is to optimize their design for maximum energy harvesting. In this paper, we investigated energy harvesting from a piezoelectric patch that is attached to a non-deterministic thin plate vibrating in bending. Energy harvesting from six patch shapes (differing in the number of edges) was examined through a coupled-field finite element model. The thin plate was simply supported with nominal geometry and material properties. The plate’s dynamics were randomized by randomly distributing point masses on its bottom surface; this made the plate a non-deterministic subsystem. The design optimization was performed by changing the shape of the piezoelectric patch and analyzing the ensemble response of the electrical potential across the piezoelectric patch. The results show that piezoelectric patches with an even number of edges exhibit higher performance in terms of energy harvesting.
Photocatalytic study of Ni-N-codoped TiO2 nanoparticles under visible light irradiation
Authors: Rani Anju , Dhiman R L , Singh Virender , Kumar Suresh , Kumar Suresh
Published: January 2021

In present paper pure and Ni-N-codoped TiO2 nanoparticles have been synthesized via sol gel technique. Crystal phase formation of as synthesized nanoparticles was determined from x-ray diffraction which confirms the existence of anatase phase of TiO2. The average crystalline size was determined from x-ray diffraction and estimated from Transmission Electron Micrographs found to vary from 24.8 nm to 10.2 nm. The morphology was studied by Field Emission Scanning Electron Microscopy and reveals that the synthesized nanoparticles are highly crystalline, spherical and small agglomerated. It is observed that on doping the agglomeration decreases and is due to relative rates of growth process. The band gap energy was calculated from UV–visible absorption spectroscopy and found to be 3.12, 1.81, 1.69 and 1.53 eV respectively. The appearance of emission bands at 453, 470, 483 and 494 nm in Photoluminescence spectra could be arising from defect energy states caused by oxygen vacancies within the forbidden region of TiO2.The structural formation of the synthesized nanoparticles is investigated from Fourier-transform-infrared and Energy dispersive x-ray spectroscopy measurements. Photocatalytic degradation efficiency of as synthesized nanoparticles against two different dyes (Congo red and Methyl orange) was investigated under visible light source of wavelength 420–520 nm and is found to increase with dopant concentration (x). It is observed that the increase in Photocatalytic degradation efficiency of synthesized nanoparticles is attributed to decrease in carrier recombination rate arises from the decrease in band gap energy. On the basis of these observations it is concluded that the increase in Photocatalytic activity is due to increase in surface area arises from the decrease in average crystalline size of the synthesized nanoparticles.