bluuebunny/crossref_metadata_2025_split huggingface dataset:
Students’ mathematical understanding ability using contextual teaching and learning approach
Authors: Nufus M , Marwan  , Zubainur C M 
Published: March 2020

Abstract
Students’ mathematical understanding ability is one of the students’ compulsory competences in learning mathematics. In the learning process, students commonly hesitated to ask the teacher how to solve mathematical problems even though they did not understand the lesson. This research aimed to improve the mathematical understanding ability by applying Contextual Teaching and Learning (CTL). This study employed a qualitative approach using True Experimental Design. This paper explained that the experimental result of students’ mathematical understanding ability used Contextual Teaching and Learning (CTL). The test of mathematical understanding ability was administered to Year 7 students of one of the junior high school in Sigli, Pidie. The instrument was a mathematical understanding ability test. The data analysis showed that the result of the normality test scores of the students’ mathematical understanding ability of the experimental class and the control class were 0.288 and 0.125. This research found that learning by using CTL indicated to improve the students’ mathematical ability. Mathematics teachers can apply CTL in the learning as an effort of developing students’ mathematical understanding ability in other algebra lessons.
Asian Elephants: 15 years of research and conservation
Authors: Hankinson Emma , Nijman Vincent , Abdullah  
Published: March 2020

Abstract
This document provides an overview of the research and conservation work that has been undertaken to date by our team at Oxford Brookes University in regard to Asian elephants. Research began in 2006, in collaboration with various NGO’s from a range of countries (Indonesia, Malaysia, Myanmar), government agencies (Indonesia, Myanmar, Thailand, Sri Lanka) and local and international universities. Four major themes are recognised throughout our research; (1) the trade in live elephants, (2) the trade in elephant ivory and other body parts, (3) elephant distribution and abundance in Northern Sumatra, and (4) the wider conservation agenda of elephant conservation in Asia. The live trade in elephants concerns both the domestic trade (Indonesia, Thailand, Sri Lanka) and the international trade (Laos, Myanmar), and has a strong welfare component that needs to be addressed. The trade in ivory is still prevalent in Myanmar, Laos and Thailand, all with strong links to China, whereas the trade in ivory in Indonesia is more localised. The distribution mapping of elephants has so far been undertaken in Aceh and North Sumatra, and we will continue within this area of research in collaboration with Universitas Syiah Kuala. With respect to the wider conservation agenda of elephant conservation in Asia, many regions and most countries face similar opportunities and challenges. Lessons learned in countries such as Myanmar, Sri Lanka and Thailand, all with substantial elephant populations, need to be employed in Indonesia to better the conservation status of elephants and improve the lives of people that live side by side with the Asian elephant.
Potential of three aquatic plants as phytoremediator for liquid waste of tofu
Authors: Wardiah  , Supriatno  , Amalia A , Andayani D 
Published: March 2020

Abstract
Phytoremediation is a method of using plants to remove pollutants from contaminated soil or waters. Several species of aquatic plants have been used in reducing pollutants in the waters. The purpose of this study was to determine the effectiveness of three species of aquatic plants as phytoremediators to reduce levels of COD and BOD of liquid waste, the effect of tofu liquid waste on the fresh weight of the species, and the chlorophyll of the plants content after treatment. Data obtained through experimental methods through a quantitative approach with non-factorial Complete Randomized Design. Data analysis used Analysis of Variance. The results showed that three types of water plants were effectively used as phytoremediator in tofu waste water with the highest percentage of BOD and COD reduction obtained in a combination of Water lettuce (Pistia stratiotes L.) and Yellow velvetleaf (Limnocharis flava L.) which was 99.42%. Besides, liquid tofu waste is effective in an increase in the species chlorophyll content. In brief, the aquatic plant species are effective to reduce COD and BOD levels and to increase of chlorophyll content and fresh weight of the species.
Guided note taking based on students worksheet effect towards students learning outcome
Authors: Febriana E , Hasanuddin  , Huda I , Supriatno  , Sarong M A 
Published: March 2020

Abstract
This research aims to discover the effect of students worksheet based on guided note taking towards the learning outcome of students both individually and as a group. The method implemented in this research is Quasi-experimental research with the Nonequivalent Control Group Design of 138 population and 82 students as samples. Instruments used in this research are multiple-choice questions to measure the learning outcomes, syllabus, learning implementation plan, and learners’ worksheets. The data collection process was conducted by looking for the post-test and pre-test values as well as t-test to compare it to pre-test and post-test scores. Data analysis was conducted using an Independent Sample T-test testing at a significant level of 0.05. The result of Independent Sample T-test testing at the outcome of control class indicates that the outcome (Mean=77,48, Standv=4.830) is different from the value in experiment class (Mean=84.93, Standv=3.672), tcount= 7.89 > ttable 1.66 at the Sig. (2-tailed) level of 005. It can be concluded that students who use the guided-note-taking based learners’ worksheet as a group show a better learning outcome compared to the students who use guided-note-taking based learner worksheets individually at Ingin Jaya High School Aceh Besar.
Preparation and characterization of jatropha curcas leaves as a biosorbent for Pb(II) and Cd(II) removal in liquid waste
Authors: Zubir M , Muchtar Z , Mahmud  , Nasution H I , Jasmidi  
Published: March 2020

Abstract
This study aims to determine the capacity of Jatropha leaves to absorb Pb (II), Cd (II) and their mixture in liquid waste. Jatropha leaves were obtained from Durian, Labu Beach, North Sumatra, heated for 4 hours and 24 hours, then characterized by XRD, FTIR, and SEM. XRD and FTIR spectra confirmed there are no structural differences of Jatropha leaf biosorbent with 4 hours and 24-hour pretreatment. SEM images indicate that the surface of the biosorbent prepared for 24 hours is smoother than the 4-hour preparation. The number of Jatropha leaves which absorbed Pb (II) and Cd (II) were measured with AAS and the optimum concentration of 0.5 gram of adsorbent for Pb (II) is 80 ppm (90 minutes) adsorbed up to 95.52%. It is higher than the absorption of Cd(II) which is 76.37% at a concentration of 100 ppm (90 minutes). But the mixture of Pb (II) and Cd (II) induce the opposite result. Cd (II) was absorbed more by 92.48% while Pb (II) was 88.62% at a concentration of 100 ppm for 90 minutes. Although Pb (II) can be absorbed more than Cd (II), when the two heavy metals mixed, Cd (II) is absorbed more than Pb (II).
Synthesis of ZIF-8 at room temperature and reuse filtrate
Authors: Jofrishal  , Fajri R , Ediati R , Amri Y 
Published: March 2020

Abstract
ZIF-8 has been synthesized with methanol solvent at room temperature (25-30°C), with molar composition of zinc nitrate: 2-methylimidazolate: TEA = 1: 4: 4. Furthermore, ZIF-8 has been synthesized using filtrate from synthesis. Repetition of ZIF-8 synthesis using filtrate from synthesis has been done for six times. The produced samples were investigated using XRD, FT-IR and SEM. XRD pattern showed that ZIF-8 which have been synthesized using reuse filtrate has same peaks with ZIF-8 from first synthesized. FTIR spectra of ZIF-8 showed a peak at 422 cm−1 which indicated the presence of zinc bonded to the nitrogen in ZIF-8. Besides SEM analysis of ZIF-8 particles size whit are synthesized using MeOH and reuse filtrate have yielded that ZIF-8 micropore size. The results showed that the synthesis of ZIF-8 using reuse filtrate was succesfully carried out.
The effectiveness of an interactive module in improving students’ conceptual understanding of acid-base titration
Authors: Desriana D , Khaldun I , Maulana I , Habibati  , Ismayani A 
Published: March 2020

Abstract
The results of the previous studies showed that the implementation of acid-base titration module with interactive media which is based on computer technology can assist students to comprehend the concepts taught in the subject. In this study, the module with interactive media was delivered as an alternative in the real practicum for the material of acid-base titration. This study was conducted using a quantitative research method. The sample was collected by purposive sampling and divided into the experiment and control class. Data were analysed by the normalized gain (N-gain) while the student concept understanding data analysed by using percentage techniques. Data was collected through pre-test and post-test in both classes. Based on the result of N-gain average, the improvement of concept comprehension at the control class is 0.50 while it is 0.79 at the experiment class which is in the medium level. The hypothesis test of these two classes shows that the t-score (7.405) > t-table (1.996) with a significant level of 0.05. It can be concluded that there was a significant difference between control class and experimental class. The implementation of the module is effective in improving students’ comprehension of the concept.
Developing Problem-Based worksheet to improve students’ critical thinking skills and learning outcomes in the concept of chemical bonding
Authors: Munawarah M , Haji A G , Maulana I 
Published: March 2020

AbstractThis study aims at developing worksheet on problem-based chemical bonding material to determine quality, critical thinking ability and learning outcomes on the worksheet. Research and development (R & D) was used in this study. The population in this study were all students at X science class at senior high school Banda Aceh, Indonesia in 2018/2019 academic year. Sample selection in this study was done using random sampling with students at X science2 class and X science3 class. Data were analyzed using N-Gain test and t-test after the test showed that problem-based worksheet can improve student’s critical thinking skill (CTS). This can be seen from the N-Gain value from each indicator with the high category; and it was also strengthened with the Z test on each t-test indicator that showed the value of ttest = 5.08 and ttable= 1.68. It can be concluded that there are differences of the increase students’ learning outcomes between experimental class and control class through the development of problem-based worksheet on chemical bonding material.
Effectiveness of a question web-based learning model to improve students’ science process skills
Authors: Evendi  , Susanna K , Nurulwati  
Published: March 2020

Abstract
This study aims to improve students’ science process skills (SPS) through the use of question web based learning model (QWBL) in physics learning. The QWBLis a learning model specifically designed to train students’ scientific questioning skills. Scientific questioning skills are related to SPS because every scientific question must be proven through experiments. This research employed educational design research (EDR) and was conducted at senior high schools in academic year of 2017/2018 involving 32 students as samples. This study used one group pre-test and post-test design and data was analyzed descriptively using the n-gain indicator. The results showed that only 3.125% of students completed pre-test and 87.5% of students completed at post-test. The increase of n-gain score was from 0.33 to 0.88 which fall into moderate and high category. The increase in N-gain indicated that the QWBL model was effective to improve SPS in physics learning especially in subject of static fluid. This criterion shows that the QWBL is effective for improving students’ science process skills in learning of physic.
Teachers’ perspectives toward soft skills in science learning
Authors: Susilawati  , Aznam N , Paidi  , Ngadimin  
Published: March 2020

Abstract
Soft skills are the essential attribute which has significant impacts on students’ achievement. This research aimed to investigate science teachers’ perception related to the importance of soft skills for the student, the components of soft skill needed in science learning, the appropriateness method in integrated soft skills in science learning and the challenges of soft skills improvement in science learning. By the purposive sampling, 100 science teachers from junior high schools were investigated. Survey method was used to collect the data and the analysis was conducted using descriptive-statistical analysis. The result showed 34% science teachers’ believe soft skills are critical factors for productive performance. Twelve components of soft skills which were needed in science learning are critical thinking, teamwork, creative and innovative, communication, problem solving, curiosity, rigorous, integrity, analysis, research and inquiry, information literacy, and objective. Data express the percentage difference in each component of soft skills. The finding revealed embedded and integrated are the significant methods in enhancing students’ soft skills. Lack of teachers’ understanding and learning resources and school principals’ support become the challenges in developing students’ soft skills. The study recommends developing an appropriating model or strategy in promoting soft skills.
Level of teachers’ knowledge and understanding in developing test questions
Authors: Yusrizal  , Halim A , Daud M , Saminan  
Published: March 2020

Abstract
This study aims to describe the level of knowledge and understanding of state junior high school science teachers in compiling exam questions. This research is a descriptive study with a quantitative approach. The method of data collection was carried out through a survey using the developed questionnaire instrument. The population in this study were all state junior high school science teachers in Pidie District, and 47 teachers were randomly selected to be samples from 60 state junior high schools. The data were analyzed descriptively. The results showed that 67% of science teachers had a very high level of knowledge in preparing exam questions, and 50% had a high level of understanding in preparing exam questions.
Sea-level rise allowances for the UK
Authors: Howard Tom , Palmer Matthew D 
Published: March 2020

Abstract
We evaluate sea-level-rise allowances for UK tide-gauge locations based on the best available current description of present-day extreme still water return level curves and the United Kingdom Climate Projections 2018 (UKCP18) regionalised projections of future time-mean sea-level (MSL) change. We focus primarily on projections for 2100 under Representative Concentration Pathway 8.5. The practical benefit of an allowance is that it condenses a distribution of MSL projections into a single recommendation. Our basic allowances are founded on the probability distributions of all components of time-mean sea-level rise considered by UKCP18 except the Antarctic dynamic uncertainty. For the Antarctic dynamic contribution we include the mean projection. These basic allowances are suitable for use in situations where there is some tolerance of uncertainty. The allowance is always greater than the central estimate (50th percentile) of mean sea-level rise. Our basic allowance is found to lie below the 80th percentile in most cases, and below the 90th percentile in all cases, throughout the 21st century. We find significant sensitivity of the allowance to the uncertainty (but not the curvature) of the present-day return level plot. We find that the normal approximation is legitimate for the sum of all components of time-mean sea-level rise considered by UKCP18 except the Antarctic dynamic uncertainty. UKCP18 used a lognormal distribution to parameterise the Antarctic dynamic contribution. For a lognormal distribution of MSL rise, Hunter’s allowance is not finite. Modifying the lognormal distribution, we give an additional allowance for the Antarctic dynamic contribution uncertainty, which could be added to the basic allowance in situations where there is less tolerance of uncertainty. This additional allowance is small (less than 1 cm at any UK location before 2060) compared to the basic allowance, and, at least over the 21st century, it is virtually independent of greenhouse gas concentration pathway.
Recent advance of carbon dots in bio-related applications
Authors: Qu Dan , Wang Xiayan , Bao Yuping , Sun Zaicheng 
Published: March 2020

Abstract
Carbon dots (CDs) is a kind of carbon nanoparticles with a plentiful of surface functional groups and tunable emission with different excitation wavelength. Broadly speaking, CDs include carbon nanodots, carbon quantum dots, graphene quantum dots, carbonized polymer dots. Due to the unique nature, they are explored for various applications in the bio-related fields such as bioimaging, sensor for ion and (bio)molecules, catalyst, LED and other fields. They are viewed as great alternative tracers to the current fluorescent biomarkers in personalized nanomedicine and surgery operation monitoring. In this review, we summarized the recent progress in the development of CDs, including improvement in fluorescence properties, two-photon fluorescence, and integration with other modalities as theragnostic agents. Specifically, we discussed the preparation of dual-modal imaging agents to improve the accuracy of diagnosis, the combination of imaging and targeting functionality for the effective accumulation of biomarkers, and the integration of imaging and therapeutic agents to effectively monitor the localization and concentration of therapeutic agents. Finally, the theragnostic agents composed of three functionalities (e.g. targeting, imaging, and therapy) were summarized to provide readers with future perspectives in this field.
Electrochemical contrast switching between black and white appearance of gelatin-covered zinc
Authors: Ksiazkiewicz Agnieszka Natalia , Fernández-Solis Christian , Erbe Andreas 
Published: March 2020

Abstract
Zinc and its alloys are widely used in the surface protection of metallic structural materials. Thus, zinc is an interesting and relevant candidate material for preparing stimuli-responsive surfaces. In this work, the switching of the optical appearance of zinc between black and white by an applied electrode potential is demonstrated. The zinc surface was covered by gelatin films and subjected to cyclic voltammetry (CV) in a chloride-containing electrolyte which induced pitting corrosion on the zinc surface. Between the different parts of the CV cycles, a reversible change in optical appearance was observed. During the oxidative half-cycles, the surfaces appear white, and during the reductive half-cycles, the surfaces appear brown to black, i.e. dark. Surface characterisation by x-ray photoelectron spectroscopy (XPS) and infrared (IR) spectroscopy shows that the gelatin coating is slightly oxidised during intial stages of the process, but remains intact and present at the surface. Raman spectra prove the presence of ZnO at the interface. Surface analysis shows only minor differences in composition between the black and white surfaces. Based on the available characterisation data, the white appearance associated with anodic currents is attributed to the formation of a non-passivating ZnO. The black appearance associated with cathodic currents is attributed to reduction of surface-confined zinc species, including ZnO and Zn2+. The role of the gelatin is presumably to prevent diffusion of the dissolution products into solution by complex formation and by acting as a diffusion barrier; gelatin will also affect the morphology of the reduction products. A similar switching was observed when gelatin was added to chloride electrolyte; surface analysis showed gelatin adsorption in this case. The black/white switching may, e.g. be useful for surfaces self-indicating corrosion potentials of galvanised steel.
Efficient machine-learning based interatomic potentialsfor exploring thermal conductivity in two-dimensional materials
Authors: Mortazavi Bohayra , Podryabinkin Evgeny V , Novikov Ivan S , Roche Stephan , Rabczuk Timon , Zhuang Xiaoying , Shapeev Alexander V 
Published: March 2020

Abstract
It is well-known that the calculation of thermal conductivity using classical molecular dynamics (MD) simulations strongly depends on the choice of the appropriate interatomic potentials. As proven for the case of graphene, while most of the available interatomic potentials estimate the structural and elastic constants with high accuracy, when employed to predict the lattice thermal conductivity they however lead to a variation of predictions by one order of magnitude. Here we present our results on using machine-learning interatomic potentials (MLIPs) passively fitted to computationally inexpensive ab-initio molecular dynamics trajectories without any tuning or optimizing of hyperparameters. These first-attempt potentials could reproduce the phononic properties of different two-dimensional (2D) materials obtained using density functional theory (DFT) simulations. To illustrate the efficiency of the trained MLIPs, we consider polyaniline C3N nanosheets. C3N monolayer was selected because the classical MD and different first-principles results contradict each other, resulting in a scientific dilemma. It is shown that the predicted thermal conductivity of 418 ± 20 W mK−1 for C3N monolayer by the non-equilibrium MD simulations on the basis of a first-attempt MLIP evidences an improved accuracy when compared with the commonly employed MD models. Moreover, MLIP-based prediction can be considered as a solution to the debated reports in the literature. This study highlights that passively fitted MLIPs can be effectively employed as versatile and efficient tools to obtain accurate estimations of thermal conductivities of complex materials using classical MD simulations. In response to remarkable growth of 2D materials family, the devised modeling methodology could play a fundamental role to predict the thermal conductivity.