Jurnal Pena Sains
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Utilization And Characterizaation Of CaO Nanocatalyst From Duck Eggshell Impregnated With NaOH And Its Application In Biodiesel Production From Cooking Oil
Full text linkGlobal energy demand, including in Indonesia, remains heavily dependent on non-renewable sources (fossil fuels), whose reserves are steadily depleting. The combustion of these fuels releases various pollutants into the atmosphere, including carbon dioxide (CO₂), sulfur dioxide (SO₂), and nitrogen oxides (NOx), which contribute to air pollution, acid rain, climate change, and adverse human health effects such as respiratory and cardiovascular diseases. This condition underscores the urgent need for the development of environmentally friendly alternative fuels such as biodiesel. This study aims to synthesize biodiesel from waste cooking oil through a transesterification reaction using a catalyst derived from duck eggshells, which was converted into a NaOH-impregnated CaO nanocatalyst. The nanocatalyst was prepared via the sol-gel method with continuous stirring for 3 hours at 4000 rpm. NaOH impregnation was applied at concentrations of 35%, 45%, and 55% of the total catalyst weight. The resulting sol-gel was separated from the residue, dried, and then calcined at 900°C for 1 hour, producing nanocatalysts designated as 35NaOH/CaO, 45NaOH/CaO, and 55NaOH/CaO. The catalysts were characterized using FTIR, XRD, and PSA. The transesterification reaction was carried out at 60°C for 2 hours, with an oil-to-methanol molar ratio of 1:9 and a catalyst loading of 3% by weight relative to the oil. The biodiesel produced was characterized using GC-MS, yielding the highest methyl ester content of 99.89% with the 55NaOH/CaO catalyst. These results indicate that the biodiesel produced had a high level of purity and complied with the EN 14103 standard
IMPLEMENTATION OF PROBLEM-BASED SCIENCE LEARNING ON GAUGING STUDENTS’ LEARNING INDEPENDENT SKILL
Full text linkThis study aims to determine the implementation of problem-based science learning on the learning independence of fourth-grade students and for student learning independence after the implementation of problem-based science learning. This study used a descriptive qualitative method, with the research subjects being fourth-grade teachers, the principal, and fourth-grade students consisting of 19 students. The research data were generated from interviews, observations, questionnaires, documentation, and were analyzed using the Miles and Huberman analysis model. The results showed that the implementation of problem-based science learning in grade 4 students of SDN Tembalang runs effectively. This is based on the results of observations of teacher activities getting a percentage of 96.87% and student activities getting a percentage of 92.5%. Student independence after the implementation of the problem-based science learning method shows very independent criteria with a percentage of 86% of students being responsible, 75% being active and creative in learning, 78% being able to solve learning problems, and 61% being continuous in learning. This is in accordance with the questionnaire data that shows the percentage of each learning aspect, including the responsibility aspect getting a percentage of 91.75%, active involvement in learning 92.98%, problem-solving ability 89.82%, and learning continuity, 92.98%
BIODEGRADABLE PLASTIC FROM CASSAVA STARCH: A LITERATURE ANALYSIS
Full text linkPlastic is a synthetic polymer derived from petroleum and contains hazardous additives, such as heavy metals and chlorine. The use of cassava starch as the main ingredient in bioplastics, a natural polymer, can be an environmentally friendly and biodegradable solution. However, cassava starch has limitations, such as its hydrophilic nature, poor mechanical strength, and poor stability. To address these issues, plasticizers such as glycerol and sorbitol are used to improve tensile strength, flexibility, and moisture resistance. Meanwhile, the addition of fillers can increase tensile strength, thermal resistance, and reduce hydrophilic properties, thereby improving the stability of bioplastics. Therefore, this review of biodegradable plastic research focuses on the use of cassava starch with the addition of various fillers that can be degraded by various processing techniques. To analyze the quality of these plastics, various testing methods are carried out, including physical, mechanical, thermal, and biodegradability tests, as well as structural and morphological analysis. The results of this research provide innovations that can be developed by making biodegradable plastic from cassava starch by combining a mixture of cassava starch with the addition of PLLA and CMC fillers and acetic acid as well as the addition of a combination of glycerol and sorbitol plasticizers
EVALUATION OF BIOPLASTIC FROM BANANA PEELS: A SYSTEMATIC LITERATURE REVIEW
Full text linkBioplastics based on natural materials offer an innovative solution to reduce the negative impact of conventional plastics on the environment. This study evaluated bioplastics made from banana peels processed with various plasticizers, such as glycerol, chitosan, sorbitol, polylactic acid polymer, sodium metabisulfite, and tapioca starch. The focus was on mechanical properties, such as biodegradability, tensile strength, and elongation. Banana peels, with a starch content of 59%, proved ideal for bioplastics, with a degradation time of 4–84 days in soil. Bioplastics with 2% glycerol degraded in 4 days, while those with sodium metabisulfite degraded in 84 days. Glycerol increased flexibility but decreased tensile strength. The combination of 1.5% glycerol and tapioca starch produced the highest tensile strength of 66.39 MPa, while the highest elongation was 115.43% with 2% glycerol. This study highlights the potential of banana peel bioplastic as an environmentally friendly alternative, and further research is recommended to optimize the combination of plasticizers to make the bioplastic stronger, more elastic, and antibacterial by combining glycerol, sodium metabisulfite, and tapioca starch. These findings are important for the future development of sustainable and applicable bioplastics
THE IMPACT OF DIFFERENT LEARNING MODELS ON THE RETENTION OF MULTI-ETHNIC STUDENTS IN TERNATE JUNIOR HIGH SCHOOLS
Full text linkThe background of this research departs from the ethnic diversity of students in Ternate which has the potential to affect student retention. This research aims to assess the impact of various learning models on the retention of multiethnic students in Ternate City Junior High School. This type of research is a quasi experiment. The design used in this study is the Pretest-Posttest Nonequivalent Control Group Design. The total sample of 76 students consisted of 20 ethnic Ternate, 27 Makian, and 29 Tidore ethnicities. The Research Instrument consists of observation sheets and test questions. The data collection technique consists of (pretest) and (posttest). Data analysis used descriptive statistics to show the description of student retention. The analysis was continued using covariance analysis (ANACOVA). The results of the follow-up test showed that the retention of students in the STAD learning model group combined with NHT was not significantly different from the STAD model, however, it was significantly different from conventional learning. Ethnicity has a significant effect on the retention of multiethnic students. The retention of Ternate ethnic students is not significantly different from the Tidore ethnicity but is significantly different from the Makian ethnicity. The interaction of learning models and ethnicity has a significant effect on student retention. The STAD model combined with NHT has not been able to make a significant contribution to the retention of Ternate, Makian and Tidore ethnic students, but when viewed from the corrected average score of STAD combined with NHT ethnic Ternate, Makian and Tidore have the highest score when compared to other learning models
ANALYSIS OF STUDENT RESPONSES TOWARDS THE IMPLEMENTATION OF STEM-BASED COOPERATIVE LEARNING IN SCIENCE EDUCATION
Full text linkThe development of 21st-century skills such as critical thinking, collaboration, and problem-solving requires innovative learning approaches. STEM education, integrated with cooperative learning, is considered an effective strategy to enhance student engagement and understanding in science education. This study aims to analyze student responses to the implementation of STEM-based cooperative learning in science education. The research employed a descriptive quantitative approach using a survey method. A total of 31 junior high school students participated by completing a Likert-scale questionnaire consisting of ten statements. The results showed that students responded very positively, with an average score of 81.21%. The findings indicate that this learning approach enhances students' confidence in asking questions and expressing opinions, minimizes boredom, facilitates problem-solving, and improves understanding of the material. It is concluded that STEM-based cooperative learning is an effective and engaging strategy for science education. Further research is recommended to explore its long-term impact on academic achievement and to apply the approach across different subjects and educational levels
IMPROVING STUDENTS’ LEARNING OUTCOMES THROUGH IMPLEMENTATION OF PROJECT-BASED LEARNING INTEGRATED WITH LOCAL WISDOM
Full text linkThe success of achieving learning objectives is seen from student learning outcomes, seen from the knowledge aspect for the elements of the concept of science, and science, as well as attitudes and skills based on the elements of science and science process skills. Teachers who are less creative and innovative in implementing learning models that are suitable for students will affect student learning outcomes. This causes a monotonous, boring, and uninteresting learning atmosphere for students, so that students' science learning outcomes are still relatively low from the predetermined KKTP value. In addition, in this era of increasingly rapid technology and globalization, it can cause a shift in culture and local wisdom for the younger generation. Therefore, this study aims to determine the increase in science learning outcomes by using the Project-Based Learning model containing local wisdom at SD N Ngepungrojo 01 Pati. The Project-Based Learning model, containing local wisdom, is a learning model that uses projects by integrating local wisdom. The stages of the Project-Based Learning model are divided into six stages. The research method that will be used in this study is pre-experimental with a one-group pretest-posttest design. Data analysis techniques consist of initial data analysis using validity tests and normality tests, and research data analysis using the Paired Sample T-Test and N-Gain test
GREEN CHEMISTRY PRACTICAL GUIDE INTEGRATING THE CONCEPTS OF SCIENCE LITERACY AND ENVIRONMENTAL AWARENESS
Full text linkScience education at the elementary school level has an important role in forming the basis of scientific knowledge while fostering character values, including environmental awareness. The background of this research is based on the need for science learning that not only emphasizes cognitive aspects, but also forms an environmentally conscious character from an early age. This research aims to develop a practical guide and see the feasibility of the guide with the theme of Green Chemistry that integrates the concept of scientific literacy and environmental awareness, which is intended for fifth grade elementary school students. The research method used is research and development (RD) with the 4D development model (Define, Design, Develop, and Disseminate). The results of the study indicate that the development of a Green Chemistry practical guide that integrates scientific literacy and environmental awareness is declared very feasible to be developed. The results of the development of the practical guide from the validation results of material experts showed that 87% were declared very feasible, the results of the validation results of media experts produced a feasibility percentage of 84% in the very feasible category, and the results of the practicality of the readability by students of the practical guide showed an average result of 82.40% which stated very feasible. Thus, this practical guide can be used by teachers and students as a source of independent learning that can increase environmental awareness
INNOVATION IN MAKING BIOPLASTIC FROM CORN STARCH: A COMPREHENSIVE REVIEW
Full text linkIndonesia is the second largest producer of plastic waste in the world after China. Plastics are generally made from synthetic organic polymers derived from petrochemicals, because of their low cost and durability humans produce plastic in significant quantities. The main ingredients of biodegradable plastics include natural polymers such as starch, pectin, and gelatin, which contribute to the formation of the plastic structural framework. Biodegradable plastics can be made from corn starch that represent a promising alternative to conventional plastics due to their renewable nature and potential for biodegradability. Corn starch is processed through extraction, which is then converted into a raw material for bioplastics. These bioplastics can decompose in industrial composting conditions within approximately 21 to 90 days, significantly reducing environmental pollution compared to non-renewable plastics that may take hundreds of years to decompose. This review focuses on corn starch as the primary material for bioplastics, highlighting the mechanical properties and biodegradability when combined with various plasticizers, fillers, and additives. These combinations aim to optimize production processes and enhance the environmental benefits of corn starch-based plastics, making them a viable component in sustainable waste management strategies. The findings from the reviewed studies indicate that corn starch-based bioplastics exhibit promising characteristics, supporting their potential as a sustainable alternative to conventional plastics. To conclude, bioplastics are an effective alternative due to their biodegradable nature, the rate of bioplastic decomposition in the environment is influenced by their chemical structure, as well as environmental conditions such as humidity, temperature, and nutrient availability, all of which affect microbial activity
AN ANALYSIS OF SCIENCE MAJOR HIGH SCHOOL STUDENTS’ PREFERENCES FOR PURSUING HIGHER EDUCATION
Full text linkStudent preferences in continuing their studies to the college level are a crucial topic in education, particularly for those transitioning from high school. This study aims to identify and compare these preferences between students in urban and rural high schools. Using a descriptive and comparative quantitative approach, data were collected from 163 students through a questionnaire comprising 26 items developed from previous research. Descriptive analysis and independent samples t-tests were used to examine patterns and differences. The findings indicate that, overall, there are no significant differences in student preferences between urban and rural schools across most indicators, such as prestige, knowledge, location, opportunity, and economy. However, a notable distinction was found in the "campus" indicator, where urban students showed a stronger preference, particularly for facilities, green open spaces, and infrastructure. These results suggest that while student motivations are generally consistent across regions, campus quality holds greater influence for urban students, highlighting the importance of improving campus environments and accessibility to support students in making informed higher education choices