Jurnal Pena Sains
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METHANOL EXTRACT PROFILE OF Eucheuma cottonii AS AN ANTIMALARIAL CANDIDATE
Full text linkMalaria is a tropical disease that endangers public health which is caused by the plasmodium parasite, and transmitted through the bite of a female Anopheles sp. mosquito. Malaria is a major health problem in Indonesia due to its high risk of transmission and drug resistance. This encourages a study to look for other antimalarial alternatives by utilizing natural ingredients. The purpose of this study is to identify the functional groups found in Eucheuma cottonii secondary metabolites using methanol 70% as the solvent. This study is included in the experimental research. The functional group of methanol extract of Eucheuma cottonii was evaluated using Fourier Transform Infrared (FT-IR) Nicolet iS 10 spectrometers. The FT-IR analysis identified the O-H functional group at 3347.1 cm-1, C≡C at 2094.8 cm-1, C=C at 1632.6 cm-1, phenol or O-H bend at 1401.5 cm-1, aromatic C-O at 1192.7 cm-1, and a C-C group at 1043.7 cm-1. The results of phytochemical analysis on Eucheuma cottoni revealed the presence of saponins. The functional groups formed in the 70% methanol extract of Eucheuma cottonii seaweed are the O-H, C≡C, C=C, phenol or O-H bend, aromatic C-O, and C-C groups which are flavonoid compounds in the flavanone group which have the potential to be antimalarial. Furthermore, the presence of the O-H, C=O, C-O, C=C, or C-H functional groups is a characteristic of a flavonoid compound. Therefore, it can be concluded that the identified functional groups indicate the existence of flavonoid molecules from the flavanone group, which potential as antimalarial properties
MACHINE LEARNING MODELS FOR PREDICTING STRESS VALUE IN THE TENSILE STRENGTH OF BIOFILMS FROM STARCH AND HAIR WASTE
Full text linkBiofilms, structured communities of microorganisms, have emerged as a subject of significant interest across various industries due to their unique biodegradable and sustainable characteristics. Hair waste is an incredibly rich source of keratin, and this abundance makes it a promising candidate as a fundamental building block for the development of biodegradable plastics. This study focuses on sustainable biofilms derived from biodegradable materials, specifically a unique combination of starch and hair waste. Machine Learning models, implemented in RapidMiner, were utilized to predict the tensile strength of these biofilms, with the goal of enhancing quality control in their production. Neural Networks and Deep Learning methods were employed to compare their predictive capabilities, assessing both their strengths and limitations. Through rigorous data collection, feature identification, and detailed data analysis, critical factors influencing the quality of the biofilms were identified. The results revealed the remarkable predictive accuracy of the Neural Net model, particularly for Ratio 40, while the performance of the Deep Learning model varied across different ratios. The lower RMSE of the Neural Net model indicated a more precise alignment between the predicted and actual values, distinguishing it as the superior model. This research contributes to the advancement of sustainable biofilm development, offering eco-friendly solutions through the use of unconventional materials. Both models offer valuable predictive capabilities, and the choice between them may depend on the specific requirements and contexts of the application. In conclusion, the performance of the Neural Net and Deep Learning models in predicting stress in tensile strength varies across different ratios
THE EFFECT OF COOPERATIVE LEARNING MODEL USING GAME-BASED MEDIA TOWARD STUDENTS’ LEARNING OUTCOMES AND ACTIVITY
Full text linkThis study aims to determine the effect of the implementation of the Team Games Tournament (TGT) type cooperative learning model assisted by wordwall quiz media on earth and solar system material on learning outcomes and activeness of seventh grade students of SMPN 6 Kisaran. The study used a Quasi Experimental design with a Pretest and Posttest Control Group Design research design. The sample consists of two classes, namely the experimental class with the TGT learning model and the control class using the direct learning model with a total of 32 students each. Sampling was done by random sampling technique. Data collection was carried out using tests and observations. The data were analyzed by testing the hypothesis using the Mann Whitney test on student learning activeness and the Independent Sample T-test on student learning outcomes. The results of observations of student learning activeness show that the average value of student learning activeness of the experimental class is 79.2 which is included in the category of very active and the control class is 65.2 which is included in the active category. The pretest learning outcomes of students in the experimental class showed an average value of 36.6 students and in the control class 33.6. The posttest learning outcomes of students in the experimental class showed an average score of 78.4 with 24 students complete and in the control class 57.3 with 4 students complete. Hypothesis testing shows that there are significant differences in student activeness and learning outcomes in the experimental class using the Teams Games Tournament Type Cooperative learning model assisted by Wordwall Quiz compared to the control class using the direct learning model on solar system material
THE INFLUENCE OF HEAVY METALS ON THE ABSORPTION OF CATIONIC DYES
Full text linkCationic dyes are dyes containing amine derivatives that can be used on cellulose, protein, nylon, acrylic and synthetic fibers but these dyes are less fast in coloring. This study investigates the impact of Pb2+ heavy metal ions on cationic dye absorption utilizing molecularly imprinted polymers as adsorbents. Concentrations of Pb2+ ranging from 0 to 50 mg/L were examined. In a one-hour interaction, 50 mg of adsorbent was introduced into a solution containing 100 ppm methylene blue dye and Pb2+ with varying concentrations. Following centrifugation, the filtrate was collected, and dye concentration was measured using a visible light spectrophotometer. The sorption capacity of the dye with Pb2+ reached 41.22 mg/g at the highest concentration and 35.83 mg/g at the lowest. Notably, an inverse relationship was observed between Pb2+ concentration and absorption capacity, indicating a decrease as metal ion concentration increased, though stability was maintained. These findings contribute valuable insights into the nuanced dynamics of heavy metal ions and cationic dye absorption, shedding light on potential applications of molecularly imprinted polymers as effective adsorbents
DEVELOPMENT OF INITIAL ABILITY TEST INSTRUMENT BASED ON SCIENCE GENERIC SKILLS
Full text linkThis study aims to develop an initial ability test instrument based on science generic skills in the form of a scholastic test and develop a final chemistry evaluation test instrument in the topic of thermochemistry as well as find out the validity of the content and construction validity of the instrument. Research and development research, with a 4D development model consisting of 4 main stages, namely: Define, Design, Develop and Disseminate, due to time constraints this research was only up to develop. The results of the content validity test by experts obtained an average percentage of material aspects, namely 87.08%, construction aspects, namely 90.41%, language aspects, 92.5% and additional rules, 96.67%, so the question instrument is suitable for use. Based on the construction validation test data, it was found that of the 20 questions on the scholastic potential test tested, there were 19 questions that were valid and considered appropriate, while 1 other item was invalid, while of the 20 questions on the chemistry test tested, there were 17 questions that were valid and considered feasible, leaving 3 questions other invalid. For further research, it is hoped that this instrument can be implemented
COMPARATIVE STUDY OF INTEREST IN READING INTEGRATED SCIENCE BOOKS AND LOCAL WISDOM-BASED LEAFLET MEDIA
Full text linkReading is an activity of examining the meaning or essence of a reading with the aim of developing one’s knowledge and potential. Along with the development of times and technology and with advances in this digitalization era, there is a fairly common problem, namely the decline in the percentage of interest in reading. Especially in Indonesia, the number of interest in reading is quite low. This research aims to find out: 1) Students' reading interest in science books 2) Students' reading interest in leaflet media with the theme of local wisdom of the Tolaki tribe, 3) The difference in students' reading interest in science books and leaflet media with the theme of local wisdom of the Tolaki tribe. The sample used was 72 students. Data collection was carried out by means of observation, documentation, and questionnaires. Quantitative research approach with comparative research type. The results showed: 1) Students' reading interest in science books is in the high category with an average reading interest of 58.86. 2) Students' reading interest in leaflet media with the theme of local wisdom of the Tolaki tribe is in the high category with an average reading interest of 85.19 3) There is a significant difference between students' reading interest in science books and students' reading interest in leaflet media with the theme of local wisdom of the Tolaki tribe with a comparison of the average interest in reading science books (58.86) and leaflet media with the theme of local wisdom of the Tolaki tribe (85.19). To conclude, there is a significant difference between students' reading interest in Integrated Science books and students' reading interest in leaflet media with the theme of local wisdom of the Tolaki tribe in class VIII students of SMPN 1 South Konawe
THE EFFICIENCY AND COEFFICIENT OF SPORTS BALLS RESTITUTION USING AN ACOUSTIC APPLICATION
Full text linkStudying the efficiency of a sports ball and its coefficient of restitution is important for performance optimization, fairness, and consistency of play. This research paper is dedicated to studying the coefficient of restitution and bounce efficiency in sports ball. Ping Pong ball and tennis balls were used to show the relationship between the bounce height and drop height. This paper used standard laboratory equipment like meter ruler, retort stand, clamp and with the utilization of the acoustic program of the smartphone using PhyPhox. The result showed that the application was able to accurately measure the bounce height in relation to the drop height. This was showed in the straight-line graph plotted. There was a constant ball efficiency coefficient of restitution and have very small percent error from the standard. This experiment can boost the interest and confidence of students in the classroom. Being able to accurately measure the performance of different balls can help students understand the science and engineering principles behind how they work. This knowledge can benefit students by allowing them to make more informed decisions when purchasing sports equipment, as well as give them an opportunity to modify their playing methods and strategies
THE INFLUENCE OF TILT ANGLE ON THE DAILY PROFILE TOTAL ENERGY OF PHOTOVOLTAIC POLYCRYSTAL
Full text linkThis preliminary study aims to determine the daily profile of the power output generated from solar panels, with variations in the house’s roof angles of 15º, 0º, 15º. Tilt angle investigation expects to discover the impact of placing solar panels on the slope of the tile used on the house’s roof. The collecting data of this study was investigated the data of current and voltage every hour that produced by solar panel. Besides, this study also comparing the result of total energy output value for daily profile of solar panel during ten hour per day (start from 7 am to 5 pm). The results show that solar panels with an angle of -15º at 07:00 – 10:00 WIB have higher output voltage and current than other angle variations. At a tilt angle of 0º, the output voltage and current of the solar panel are higher at 11:00-14:00 WIB, while at a tilt angle of 15º in the afternoon. Based on observations, each solar panel with exposure for 10 hours obtained the total energy value for polycrystalline solar panels with a tilt angle of -15º of 258.44 Wh, solar panels with an angle of 0º obtained an energy value of 263.64 Wh, and a tilt angle of 15º obtained energy values 260.69 Wh. The photonic energy emitted for 10 hours is 2097.47 Wh. The energy efficiency value for each polycrystalline solar panel is 12.32% for the angle of -15º, the angle of 0º is 12.57%, and 12.43% for the angle of 15º. In conclusion, variations in the angle of the solar panels have significant effect on the voltage, current, and energy generated from polycrystalline solar panels in every hour. However, based on the data result the total energy exposure and the efficiency value for each variation angle has no significant different. Pyramid-shaped house roof construction has the advantage of increasing the value of the cross-sectional area of the tile, which has the opportunity to install wider-sized solar panels so that a greater value of electrical energy is obtained
DETERMINATION OF ASCORBIC ACID CONCENTRATION IN MYRTACEAE USING THE IODOMETRIC TITRATION METHOD
Full text linkVitamins are essential compounds in food even though the content contained in these foods is small, and this is because vitamins have a vital role in the human body. Vitamin C or ascorbic acid is a secondary antioxidant compound that captures free radical compounds. Vitamin C content is easily found in vegetables and fruits. One of the fruits that contain vitamin C is guava. This study aims to determine and analyze vitamin C concentrations in several guava fruit types with the iodometric titration method. This type of research is a quantitative-qualitative experimental laboratory. The samples used in this study were guava in Myrtaceae family consisting of red guava (Psidium guajava L.), crystal guava (Psidium guajava L.), and red water guava (Syzygium aqueum). The study began with making 0.05 N iodine, iodine formation, then the 3% amylum indicators. The average sample content of red guava, crystal guava, and red water guava was 2.42 mg/100 grams. To conclude, the ascorbic acid concentration of red guava water is higher at 157 mg/100 g compared to the other two guavas, which are 80 mg/100 g and 87 mg/100 g
SCREENCAST AND ITS EFFECT ON IMPROVING LEARNERS’ ACADEMIC ACHIEVEMENT AND MOTIVATION IN PHYSICS
Full text linkScreencasts are multimedia-based learning which involves multimodal sensory, such as eyes and ears. These are increasingly used as schools transition to blended learning mode. This study aims to describe the screencast and its effect on improving learners’ academic achievement and motivation in Physics. This quasi-experimental research determined learners’ academic achievement and level of motivation before and after treatment to screencasts focusing on heat, temperature, and electricity. The study was done in a large public secondary school in a highly urbanized city in the central Philippines. Academic achievement was measured through a constructed test while the level of motivation was evaluated using Keller’s Instructional Materials Motivation Survey. Results showed that screencasts improved the learners’ academic achievement and increased their level of motivation. The use of screencast has a good impact on changing learners' knowledge and skills and is an effective online learning media. Findings also obtained a p-value of 0.00 which showed that there is a significant difference in the learner’s academic achievement before and after treatment to screencast. This study discovered that learning using screencasts is engaging to the learners. The screencast provided the learners with the opportunity to learn at their pace and brought them better learning experiences