bluuebunny/crossref_metadata_2025_split huggingface dataset:
The length of reaction time on the synthesis of poly (3,4-ethylenedioxythiophene)
Authors: Diah A W M , Wirayudha A , Supriadi  , Santoso T 
Published: February 2021

Abstract
Poly(3,4-ethylene dioxythiophene) (PEDOT) has been synthesised via the oxidative polymerisation method of 3,4-ethylenedioxythiophene (EDOT) monomer using Na2S2O8 and Fe2(SO4)3 as oxidising agents. The synthesis was carried out at various times of reaction, i.e for 6, 12, and 24 hours. The success of PEDOT synthesis was proven by FTIR spectra which indicated by the loss of the C-H group presented in the 890 cm−1 absorption area from EDOT monomer. The morphology of PEDOT particles was observed by Scanning Electron Microscopy (SEM). The results showed that the differences in the synthesis time of 6, 12, and 24 hours affected the diameter of PEDOT particles. The size morphology of those 6, 12, and 24 hours synthetically PEDOT particles were 38.64 ± 18.21 nm, 55.91 ± 15.31 nm, and 66.62 ± 18.92, respectively. The largest diameter product of PEDOT in this study was then doped with carrageenan to synthesis PEDOT/Carr dispersions via the post-polymerisation method. This study concluded that the size of PEDOT particles is significant with increasing time of reaction, and the product of PEDOT/Carr dispersions is promising as a green polymer.
Geospatial approach to determining potential of springs at the Palu Groundwater Basin for post disaster water supply in Central Sulawesi Province
Authors: Zeffitni  
Published: February 2021

Abstract
The disaster that occurred on 28 September 2018 in Palu City, Sigi and Donggala regencies had an impact on damage to a number of water resource. This study aims to determine the quantitative potential of springs with using a geospatial approach and hydrogeomorphological mapping. Based on the results of the field survey, the springs in Palu Groundwater Basin amounted to + 104 springs with divisions in the east and west. The results showed that in Palu Groundwater Basin the appearance of springs was not only caused by geomorphological conditions but also influenced by geological conditions. Based on the type of springs, it is dominated by the type of artesian, fracture and contact. The quantitative potency level of springs ranges from small (< 5.0 liters/second) to large (> 10.0 liters/second) quantitative potency levels. Small quantitative potential levels (< 5.0 liters/second) in the eastern part include the districts: East Palu, South Palu, Dolo and Biromaru. The western part of Palu Groundawter Basin includes the sub-districts: West Palu and South Palu. Based on the results of the study, it can be concluded that the quantitative potential of springs is very potential to meet the needs of clean water in post-disaster areas.
Determination risk of liquifaction disaster based on spatial distribution unconfined aquifer at the Tindaki Groundwater Basin, Parigi Moutong District
Authors: Ninasafitri  , Zeffitni  
Published: February 2021

Abstract
Natural disasters such as earthquake, tsunami and liquefaction in Central Sulawesi Province in 2018 had a significant impact on economic growth. This demands disaster risk reduction, especially liquefaction disasters. This research was conducted in Tindaki Groundwater Basin, Parigi Moutong Regency, especially in Parigi sub-district, which includes: Lebo, Bambalemo, Kampal, Maesa, Bantaya, and Olaya. The purpose of this study was to determine the level of risk of liquefaction based on the spatial distribution of the unconfined aquifer in Tindaki Groundwater Basin. The number of samples is 100 points taken randomly, consisting of community dug wells to obtain phreatic depth. The technique of collecting data is random and proportional sampling.The method used in this study is geological and hydrogeological approaches with rock formation as a determining parameter for groundwater density. The results showed that the average depth of the phreatic level was <10 meters from the ground and was in the alluvium formation. Based on the results of the study, it can be concluded that the potential for liquefaction in the research area is in the medium to high potency.
In vitro antioxidant assay and qualitative phytochemical estimation of Meistera chinensis from Southeast Sulawesi
Authors: Musdalipah  , Karmilah  , Tee S A , Yodha A W M , Sahidin I , Fristiohady A 
Published: February 2021

AbstractMeistera chinensisis one of the species that belong to the Zingiberaceae family. Many antioxidant properties have been reported from this family. Thus, we aim to investigate the antioxidant activity ofMeistera chinensisand its secondary metabolites. The ethanol extract ofM. chinensiswas fractioned and obtained Ethyl acetate Fraction (FEA), Precipitate Fraction (FEN), and fraction 1-8 (F1-F8). The fractions were assayed with DPPH (1,1-diphenyl-2-picrylhidrazyl) and ABTS (2,2’-azino-bis-[3-ethylbenzothiazoline sulphonate) for their scavenging activity in vitro. Ascorbic acid and Trolox were used as control. The phytochemical screening was qualitatively conducted with a colorimetric method. The IC50 value of FEA, FEN, F1-F8, AA, and TX according to DPPH were 35.61±2.22; 47.62±2.93; 90.05±2.27; 105.34±0.83; 97.72±1.16; 112.59±1.22;72.81±2.36; 66.67±2.55; 59.47±2.23; 40.93±2.68; 8.84±0.69; and 11.45±0.87 mg/L, respectively. Similiar with ABTS method that exhibited IC50 were 37.27±3.43; 52.10±3.29; 94.19±4.23; 110.40±3.01; 102.80±2.66; 115.71±3.14; 73.60±3.20; 61.98±3.94; 42.70±3.53; 9.58±0.57; and 12.55±4.02, respectively. The secondary metabolites inMeistera chinensiswere phenolic compounds, flavonoids, steroids, terpenoids, alkaloids, and saponins. In conclusion, we confirmed thatMeistera chinensishas antioxidant capacity for scavenging the free radicals, and the metabolites inM. chinensismight play a vital role in its activity.
Improvement of the Ability of Representation, Reasoning, and Self-Efficacy of Prospective Mathematics Teacher Students by Using Learning with A Scientific Approach
Authors: Darta  , Saputra J , Eliyarti W , Putra B Y G , Kandaga T 
Published: February 2021

Abstract
This research was developed aiming to (1) Analyzing the improvement of representation, reasoning, and SE skills by using a scientific approach to prospective teacher students. (Already done); (2) Analyze the association between the ability of representation and reasoning with SE. (Already done); (3) Analyzing the relationship (association) between the ability of representation and reasoning seen from the level of student ability (low, medium, and high). (Already done); (4) Designing a scientific approach and teaching materials based on the association between ability and level of student ability, in order to improve the ability of students who still have a level of concrete representation to the level of abstract representation, so as to improve reasoning. This type of research is Research and Development. the Four-D model proposed by Thiagarajan (Buhari, 2014) with a mixed method (the multiphase design), through stages: Define, Design, Develop, and Disseminate, namely the definition, design, development, and distribution. The conclusions of the research are (1) the increase in reasoning ability increased significantly at the value of 0.43 with the moderate category. (2) Increasing the ability of representation increased significantly at 0.34 with a moderate category. (3) The increase in SE increased significantly at 0.31 in the medium category. (4) There is a significant positive correlation between reasoning ability and SE, but the correlation coefficient between reasoning ability and SE is 0.338 which is categorized as weak. (5) There is no significant correlation between the ability of representation and SE, with the correlation coefficient between the ability of representation and SE of 0.228 which is categorized as very weak and the direction is positive. (6) There is a significant positive correlation between the ability of reasoning and representation in students with high ability with the correlation coefficient between reasoning and representation ability is 0.889 which is categorized very strong and the direction is positive. (7) There is a significant positive correlation between the ability of reasoning and representation in students with moderate ability with the coefficient of correlation between reasoning and representation ability is 0.838 which is categorized very strong and the direction is positive.
The relation between spatial reasoning and creativity in solving geometric problems
Authors: Novitasari Dwi , Risfianty D K , Triutami T W , Wulandari N P , Tyaningsih R Y 
Published: February 2021

Abstract
Spatial reasoning has been used in daily life, such as in building designs, determining routes and using maps. Spatial reasoning is also used in mathematics, especially in geometry. Therefore, this study aims to find out how spatial reasoning is used by students in solving geometry problems, especially in their creativity to transform 2-dimensional images into 3-dimensional images. Creativity in this study is focused on fluency, flexibility, and originality. This study is an explorative descriptive study through a qualitative approach. The subjects of the study are 11 third grade junior high school students. Data were collected by geometry problem-solving tests with two types of questions in the form of true or false statements and open-ended problems. The results showed that: (1) in terms of fluency, students gave an average of three correct answers out of five, (2) in terms of flexibility, there were five different types of answers, and (3) in terms of originality, there are two students who gave different answers than other students. The results also showed that students applied their spatial reasoning in the form of spatial visualization and mental rotation in their creativity to solve the problems.
Assessing the effectiveness of using digital mathematics technology on student mathematics learning
Authors: Nurfalah Edy , Yuliastuti R , Rahayu P , Sulistyaningrum H , Surawan  
Published: February 2021

Abstract
Digital knowledge is very important in mathematical knowledge to understand steps and logical thinking. Some obstacles were found that mathematics lecturers did not apply their mathematical skills to the maximum when training students in a class. It was also shown from the results of identification: the time given by lecturers in short, the lack of facilities used by students, and the lack of time on campus to use information and communication technology, and the lack of access to digital resources for students to access the mathematical material needed. To deal with these problems, this analysis provides a choice of solutions for better learning. Many choices of digital technology that can be used in student mathematics learning. Such as online learning, based on social media, digital media, interactive questions or discussions, the use of mathematical software, and other digital media that can be used anywhere and anytime.
Students Reasoning Capabilities to Solve HOTS Geometry Materials
Authors: Setyahastuti Esti , Riyadi  , Triyanto  
Published: February 2021

Abstract
This study aims to describe students’ reasoning abilities to solve HOTS questions on geometry material. Type of this research is descriptive qualitative. Subjects of the research were 10 students of 12th grade at Senior High School which were taken using a purposive sampling technique. Data collection was obtained from the result of reasoning ability tests and interviews. The validity of the data in this study used a triangulation method. Based on the analysis of data obtained: 40% of students can submit allegations, students that can do mathematical manipulation and give a reason with proof through the solution both of them are 30%, and only 10% of students can draw conclusions from statements and check the validity of an argument. The results of this study indicate that students’ reasoning abilities are still low. Many students are not able to draw conclusions from statements and check the validity of an argument. This is caused students having difficulty determining the distance in space, besides that it has not been able to connect statements that correspond to the problem of question.
The Use of Magnetic Cube and Sticks Media in STEM-Based Learning (Science, Technology, Engineering, and Mathematics)
Authors: Susanti Eva , Kurniawan Haris 
Published: February 2021

Abstract
This research resulted in a method or learning path that is appropriate for learning mathematics about number patterns using magnetic cube media and STEM learning. The method of this research is design research with three stages, namely: preliminary design, experimental design, retrospective analysis. With the research subjects 32 students of class VIII.7 in SMP Negeri 27 Palembang. Data was collected through observation sheets, video recordings, interviews, photo documentation, and student activity sheets. The data collected was then analyzed retrospectively collected on HLT (Hypothetical Learning Trajectory). From the results of data analysis, it can be concluded that this research produces a mathematical method or trajectory for the subject of class VIII number patterns that are valid and reliable. Valid from HLT and traceable. Reliability is seen in data triangulation, namely from field notes, observation sheets, and video recordings. Where by using magnetic cube media that combines using STEM students are happier and excited in learning because they use knowledge, technology from the media, their ability to use media so that it brings out the expected mathematical knowledge
Mathematical and Mental Rotation Skill in Internal Representation of Elementary Students
Authors: Fiantika Feny Rita 
Published: February 2021

Abstract
In this article, we review how the mental rotation of students in their internal representation and what is mathematic skill they used. Researchers found three geometry problems in elementary schools in Kediri Indonesia. Students have difficulty to make a cube net from the cube and they have opinion that to make a cube they need parallelogram and square. It is a big problem in geometry to transform 2 dimensional objects to 3 dimensional objects and vice versa. Based on the geometry problem of student in Kediri Indonesia, the researcher gives them a cube to modify as a cube net. Internal process is activities in their mind that they used for make a transformation an object into another object. The form of an object is different in this case 3 dimensional object into 2 dimensional object. They used mental rotation in transformation process. This article describes process mental rotation and mathematic skill student that they used to transform 3 dimensional object to 2 dimensional object. The result shown that encoding of features, imagined angular stimuli rotations and fast stimulus matching are they used in mental rotation processes and they used symbolic number sense, ordinal magnitude sense and line sub division are they used in mathematic skill.
An Analysis of Mathematical Communication Ability on Solving Open Ended Problems in Linier Equation System with Two Variables
Authors: Anwar Rivai M , Mardiyana  , Slamet I 
Published: February 2021

Abstract
Mathematical communication ability are the ability of students to convey mathematical ideas either orally, in writing or in motion, so that mathematical communication ability must be possessed by students. This research is a qualitative descriptive study that aims to describe the mathematical communication ability of junior high school students in solving open ended problems, namely where one problem has many solutions or many ways of solving. The subjects in this study were 28 students of class IX of SMP Negeri 1 Mojolaban and the instruments used were 3 test descriptions of mathematical communication ability test. The variable of this study is an indicator of mathematical communication ability. The results show that students’ mathematical communication ability are quite well categorized, with the following details: student achievement in expressing real objects, situations and daily events in the form of mathematical models as much as 91.6%, student achievement in explaining mathematical ideas and models into ordinary language as much as 69.6% and student achievement in explaining and making mathematics questions learned as much as 40.47%. From the three indicators, it appears that students are still lacking in terms of explaining and making mathematical questions learned.
Assessment of Students’ Mathematical Proof Comprehension: Gender and Year Level Background
Authors: Waluyo Mohamad , Vidákovich Tibor 
Published: February 2021

Abstract
The ability to understanding proof is essential before students can write their proof. A literature study shows a few interests in investigating the students’ knowledge from reading proof. This study aims to assess students’ comprehension when they were reading proof using a developed instrument based on the previous study on the same field. Three groups of students from a different level of years from a preservice teacher training program in an Indonesian university are taken as the participants. This paper reports the preliminary finding of students’ comprehension score comparison by gender and year level. Further analysis also involved the correlation of students’ basic knowledge to their comprehension scores.
Geometric Thinking Skills of Seventh Grade Students on the Topic of Triangle and Quadrilateral Based on Van Hiele Geometry Learning Theory
Authors: Nusaibah Naja , Pramudya I , Subanti S 
Published: February 2021

Abstract
Students’ geometric thinking skills can describe students’ understanding of geometrical concepts. According to van Hiele, students’ geometric thinking skills is divided into five levels, namely Level 0 Visualization, Level 1 Analysis, Level 2 Informal Deductive, Level 3 Deduction, and Level 4 Rigor. The level of students’ geometric thinking skills be an indicator of the success of learning geometry. The teacher should be able to analyse the students’ geometric skills to help students to improve their geometric thinking skills. The purpose of this study was to describe the geometric thinking skills of 7th grade students of Junior High School in Boyolali, Indonesia. This type of research was quantitative descriptive research. The study was conducted by giving ten questions that correspond to the level of students’ geometric thinking skills. The results showed that as many as 26.09% of students were at level 0, as many as 56.62% of students were at level 1, as many as 17.39% of students were at level 2, and no students were able to reach level 3.
Same pattern, different visualization: visual support does matter in pre-algebra
Authors: Apsari Ratih Ayu , Sariyasa  , Putri R I I , Rejeki S , Lu’luilmaknun U 
Published: February 2021

Abstract
This paper is a part of a more significant study in design research aimed to create a learning trajectory in pre-algebra. The study was following the steps of the Preliminary Study, Teaching Implementation and Retrospective Analysis. In the current discussion, we will focus on the importance of visualization employed to represent the specific number pattern. The study was conducted in a state elementary school in Palembang with eight fifth grade students who participate during the Teaching Implementation phase. We gathered data from students’ written work, interviews, and observation during the lesson. The data were analyzed qualitatively using the constant comparative method. From the analysis, it was found that even though the problems were using the same number pattern, the students’ interpretation that leads to a correct generalization were highly influenced by the visual support. Hence, it is recommended to the future learning materials designers and teachers to consider the visual support matters to enhance the students’ mastery.
Digital technology in learning mathematical literacy, can it helpful?
Authors: Novita Rita , Herman T 
Published: February 2021

Abstract
Literacy is a critical skill and is quite a concern in the world of education, especially mathematics education in the 21st century. Literacy in mathematics illustrates how a student identifies and understands the problems in which mathematics he has learned plays a role in all aspects of life. On the other hand, the 21st-century digital era demands the realm of education to be able to utilize ICT (Information and communication technologies) in the learning process, not least in mathematics. Digital technology, as a tool that is believed to make a significant contribution to the development of education, is also a challenge in its application, especially concerning the development of mathematical knowledge and skills, mathematical literacy. A question that arises is, can the use of digital technology develop mathematical literacy in the process of learning mathematics? If the answer can, then how should such integration be carried out. This article aims to provide an overview of the answers to these questions by giving an overview of the importance of mathematical literacy and digital technology in developing mathematical literacy.
Science, Mathematics, Engineering, and Mathematics (STEM) Education in Indonesia: a Literature Review
Authors: Khotimah Rita Pramujiyanti , Adnan Mazlini , Ahmad Che Nidzam Che , Murtiyasa Budi 
Published: February 2021

Abstract
This study aims to describe: 1) the learning models used in the implementation of STEM education in Indonesia, 2) the level of education used in the implementation of STEM education in Indonesia, 3) the effect of STEM education in Indonesia on the students’ learning outcome. This is a literature review study, 27 articles were analyzed based on the research method, level of education, learning models, and learning outcome. A within-case analysis was carried out to analyze the articles in the dataset. The research result showed that: 1)STEM education in Indonesia was carried out by using the learning models: Project Based Learning (PjBL), 6E, HOTS assessment based-learning, inquiry,Think Pair Share (TPS), Problem Based Learning (PBL), android game, digital and student book based-learning, PjBL is the learning model which most widely used in the implementation of STEM education in Indonesia, 2) STEM education in Indonesia was conducted in elementary school, junior and senior high school, but very limited in university level, 3) STEM education in Indonesia was effective on the students’ learning outcome: scientific literacy, creative thinking, critical thinking, attitude, HOTS, character, achievement, problem solving, and 21st century skill.