JURNAL RISET RUMPUN MATEMATIKA DAN ILMU PENGETAHUAN ALAM
Bidang kajian dalam jurnal ini termasuk sub rumpun Ilmu IPA, Ilmu Matematika, Ilmu Kebumian dan Angkasa. Jurnal Riset Rumpun Matematika dan Ilmu Pengetahuan Alam menerima artikel dalam bahasa Indonesia dan diterbitkan 3 kali setahun: April, Agustus dan Desember. E-ISSN: 2828-9390 (Online), P-ISSN: 2828-9382 (Cetak). Jurnal ini adalah jurnal Riset Rumpun Matematika dan Ilmu Pengetahuan Alam yang bersifat peer-review dan terbuka. Jurnal ini terakreditasi SINTA 5 (Surat Keputusan Direktur Jenderal Pendidikan Tinggi, Riset, dan Teknologi Nomor 10/C/C3/DT.05.00/2025 tanggal 21 Maret 2025 tentang Peringkat Akreditasi Jurnal Ilmiah Periode I Tahun 2025) dimulai dari Volume 1 Nomor 2 Tahun 2022 sampai Volume 6 Nomor 1 Tahun 2027. Terindeks oleh : Mitra Jurnal :
Inhibitory Test of Water Hyacinth Leaf Extract (Eichhornia Crassipes) on the Growth of Escherichia Coli and Propionibacterium Acnes Bacteria
Antimicrobial resistance has accelerated the search for alternative antibacterial agents derived from natural products. Water hyacinth (Eichhornia crassipes) is an invasive aquatic weed that is abundant in Indonesian waters, yet rich in secondary metabolites such as flavonoids, tannins, alkaloids, and saponins with antibacterial potential. This study aimed to evaluate the inhibitory activity of the ethanol extract of water hyacinth leaves against Escherichia coli (Gram-negative) and Propionibacterium acnes (Gram-positive). A descriptive-exploratory laboratory design was used. Leaf samples collected from Lake Tondano were extracted by maceration in 96% ethanol and concentrated using a rotary evaporator. Antibacterial activity was assessed by the well-diffusion method at 100% extract concentration, with 30% amoxicillin as the comparator, incubated at 37°C for 24 hours. The extract produced mean inhibition zones of 7.0 mm against E. coli and 5.7 mm against P. acnes, both classified as moderate according to the Davis & Stout scheme, whereas amoxicillin produced zones of 8 mm and 7 mm. The ability of the extract to inhibit both Gram-positive and Gram-negative bacteria indicates a broad spectrum of activity. These findings confirm that water hyacinth leaves are a promising source of natural antibacterials while adding value to aquatic weed management.
Copyright (c) 2026 Yuliana Rumyaan, Helen J. Lawalata, Dany Ch. Posumah, Emma M. Moko, Fernando A. Watung, Nonny Manampiring https://creativecommons.org/licenses/by-sa/4.0
Kinerja Serat Ijuk sebagai Tutupan Permukaan Tanah untuk Pengendalian Erosi pada Lereng Pegunungan di Lahan Tanam Jagung
Soil erosion is a major problem on sloping land that can reduce soil fertility and agricultural productivity. This study aims to analyze the effectiveness of palm fiber (ijuk) nets and corn plants in controlling soil erosion on land with a slope of approximately 57° in Bina Jaya Village, Tolangohula District, Gorontalo Regency. The method used was a field experiment with three treatments: Plot I (ijuk net + corn), Plot II (ijuk net), and Plot III (without treatment). The observed data included rainfall, soil erosion mass, and corn growth used to calculate the Leaf Area Index (LAI). The results showed that Plot I produced the lowest soil erosion (16.8 kg), followed by Plot II (23.7 kg), and Plot III (84.5 kg). Rainfall had a direct influence on increasing soil erosion, especially on untreated land. Increasing LAI values contributed to reducing erosion by improving soil cover and reducing runoff. The effectiveness of the ijuk net reached 80.1% when combined with vegetation and 71.9% without vegetation. Therefore, the combination of ijuk net and corn plants is proven to be an effective, simple, economical, and sustainable soil conservation method for sloping land.
Copyright (c) 2026 Fikri Maulana Ntobuo, Muhammad Jahja, Muh. Fachrul Latief, Fitryane Lihawa, Meilan Demulawa, Dewa Gede Eka Setiawan https://creativecommons.org/licenses/by-sa/4.0
Analisis Kualitatif dan Kuantitatif Co-monomer pada Linear Low-Density Polyethylene (LLDPE) Menggunakan FTIR: Evaluasi Model Regresi dan Implikasi Industri
Linear Low Density Polyethylene (LLDPE) is a polymer produced through the copolymerization of ethylene with α-olefins such as 1-butene, 1-hexene, and 1-octene. The type and content of co-monomers incorporated into the polymer chain affect the microstructure, crystallinity, density, and mechanical properties of the material, making accurate characterization essential. This study aimed to qualitatively and quantitatively analyze the co-monomer content in LLDPE products using Fourier Transform Infrared Spectroscopy (FTIR) at the Tech Center of PT Lotte Chemical Titan Nusantara. Qualitative analysis was performed based on infrared spectral characteristics to distinguish co-monomer types, while quantitative analysis was conducted by developing linear regression models using the absorbance of the diagnostic band at 771 cm⁻¹ (A771) and the absorbance ratio A771/A1462 against co-monomer content determined by the reference method of ^13C-NMR. The results showed that the absorption band in the 900–700 cm⁻¹ region, particularly at 771 cm⁻¹, was sensitive to variations in short-chain branching resulting from butene incorporation. The developed regression models demonstrated a linear relationship between FTIR parameters and co-monomer content, enabling rapid and efficient prediction of co-monomer concentration. The absorbance ratio approach provided better stability against variations in sample thickness and spectral baseline fluctuations compared to the direct absorbance method. Therefore, FTIR can be utilized as an effective supporting method for routine analysis of co-monomer content in LLDPE products and can support quality control, product specification validation, and trade classification based on co-monomer content.
Copyright (c) 2026 Naila Agitia Ghaisani, Indah Kurniasari https://creativecommons.org/licenses/by-sa/4.0
Pengaruh Elektrodeposisi Nanopartikel Perak pada Elektroda Reduced Graphene Oxide terhadap Stabilitas Superkapasitor
Supercapacitors have attracted considerable attention as energy storage devices owing to their high power density, rapid charge–discharge capability, and long cycle life. However, the electrochemical performance of reduced graphene oxide (rGO) is limited by the restacking phenomenon, which decreases the active surface area and restricts electrolyte ion diffusion. This study investigates the effect of silver (Ag) nanoparticle deposition on the stability of rGO electrodes using an electrodeposition method. Ag nanoparticles were deposited from a 5 mM AgNO₃ solution and the resulting electrodes were characterized by Scanning Electron Microscopy (SEM). Their electrochemical performance was evaluated using Cyclic Voltammetry (CV) and cycling stability tests up to 1,000 cycles. SEM analysis confirmed the successful and relatively homogeneous distribution of Ag nanoparticles on the rGO surface. The electrochemical results showed that the rGO/Ag electrode retained approximately 96–97% of its initial capacitance after 1,000 cycles, whereas the pristine rGO electrode retained only about 69%. These findings demonstrate that Ag deposition effectively enhances the structural stability and electrochemical performance of rGO electrodes, indicating their potential for high-performance supercapacitor applications.
Copyright (c) 2026 Pratiwi Sanggusti, Nur hayati, Nina Aprilini, Rahmat Hidayat, Harman Amir, Hidayat Hidayat, Maria Ulfa, Yahdi Bin Rus https://creativecommons.org/licenses/by-sa/4.0
Sintesis One-Pot Komposit Reduced Graphene Oxide/Polipirrol (rGO/PPy) pada Substrat Stainless Steel Fleksibel sebagai Elektroda Superkapasitor
The development of portable, wearable, and flexible electronic devices has increased the demand for energy storage systems with high electrochemical performance, long cycle life, and good mechanical flexibility. In this study, a reduced graphene oxide/polypyrrole (rGO/PPy) composite electrode was successfully synthesized on a flexible stainlesssteel substrate using a one-pot electropolymerization method for flexible supercapacitor applications. The rGO electrode was first prepared by the doctor blade technique and subsequently modified through the electropolymerization of 5 mM pyrrole using Cyclic Voltammetry (CV). The electrochemical performance of the synthesized electrodes was evaluated through Cyclic Voltammetry, capacitance measurements, cycling stability tests for up to 1000 cycles, and bending tests to assess their mechanical flexibility. The results showed that the incorporation of PPy significantly enhanced the electrochemical response and increased the capacitance of the electrode compared with pristine rGO, indicating the additional contribution of pseudocapacitive charge storage. However, during the cycling stability test, the rGO electrode exhibited higher capacitance retention after 1000 cycles than the rGO/PPy electrode, suggesting that the PPy layer experienced gradual structural degradation during repeated charge–discharge processes. Despite this decrease in cycling stability, the bending test demonstrated that the rGO/PPy electrode maintained good structural integrity without visible cracking or delamination after mechanical deformation. These findings indicate that the one-pot electropolymerization method successfully produced an rGO/PPy composite electrode with improved electrochemical performance and good mechanical flexibility, demonstrating its potential as an electrode material for flexible supercapacitor applications.
Copyright (c) 2026 Nur Hayati, Nina Aprilini, Pratiwi Sanggusti, Rahmat Hidayat, Hidayat Hidayat, Maria Ulfa, Yahdi Bin Rus https://creativecommons.org/licenses/by-sa/4.0
Pengaruh Modifikasi Polianilin terhadap Kinerja Elektrokimia Elektroda Reduced Graphene Oxide untuk Superkapasitor
Supercapacitors have attracted considerable attention as energy storage devices due to their high power density, rapid charge-discharge capability, and long cycle life. However, the relatively low capacitance of reduced graphene oxide (rGO) limits its electrochemical performance when used as a single electrode material. This study aimed to investigate the effect of polyaniline (PANI) deposition on rGO electrodes through an electrochemical deposition method using a 5 mM aniline solution. The rGO electrode was first prepared on a stainless-steel substrate, followed by PANI deposition using cyclic voltammetry within a potential window of −0.4 to +0.4 V at a scan rate of 100 mV s⁻¹ for 10 cycles. The electrochemical performance of the fabricated electrodes was evaluated by cyclic voltammetry and cycling stability tests up to 1000 cycles. The cyclic voltammogram of the rGO/PANI electrode maintained a quasi-rectangular profile, indicating that the electrochemical deposition process produced an active electrode capable of charge storage. The specific capacitance of the rGO/PANI electrode reached 308.87 F g⁻¹, which was higher than that of pristine rGO at 240.88 F g⁻¹. Furthermore, the rGO/PANI electrode retained 67% of its initial capacitance after 1000 cycles, whereas pristine rGO retained only 49%. These results indicate that the incorporation of PANI improved both the specific capacitance and cycling stability of the electrode. The findings demonstrate that electrochemically deposited PANI is a promising approach for enhancing the electrochemical performance of rGO-based supercapacitor electrodes.
Copyright (c) 2026 Nina Aprilini, Nur hayati, Pratiwi Sanggusti, Rahmat Hidayat, Yahdi Bin Rus https://creativecommons.org/licenses/by-sa/4.0
Pengaruh Penerapan Media Pembelajaran Etnomatematika Berbasis Mobile terhadap Hasil Belajar Matematika Siswa SMP pada Materi Bangun Datar
Mathematics is frequently regarded as a demanding discipline due to its abstract concepts, which are hard for students to grasp visually. Therefore, the implementation of proper learning media is necessary to help students build a deeper understanding of abstract mathematical concepts, particularly in quadrilaterals, enabling these concepts to be comprehended more concretely. The present study seeks to examine the effect of mobile-based ethnomathematics learning media on students' mathematics achievement in the topic of plane figures at SMP Negeri 1 Botupingge. A quasi-experimental approach using a Pre-test–Post-test Control Group Design was applied, with 38 students as the research sample, consisting of class VII C assigned the experimental group and class VII A allocated to the control group, identified through a cluster random sampling approach. The experimental group utilized mobile-based ethnomathematics media combined with the Problem Based Learning (PBL) model, whereas the control group used PowerPoint media with the same PBL model. Data was carried out by administering pre-tests and post-tests in essay form to assess students' mathematics achievement on quadrilaterals. The findings reveal that mobile-based ethnomathematics learning media significantly improves students' mathematics achievement, making learning more relevant to students' local life and culture.
Copyright (c) 2026 Sri Purwandaningsih Waluya, Evi P. Hulukati, Auli Irfah https://creativecommons.org/licenses/by-sa/4.0
Peningkatan Efisiensi Sel Surya Perovskite melalui Optimasi Rasio Komposisi rGO dan Polimer Co-Additive
This research investigates the optimization of perovskite solar cells (PSCs) based on by engineering the active layer interface using a binary composite of Reduced Graphene Oxide (rGO) and Polyethylene Glycol (PEG) polymer co-additive. The background of this study addresses the low long-term stability and high charge recombination challenges in PSCs despite their high potential as a next-generation photovoltaic technology. The fabrication method involved sequential solution deposition steps on Fluorine-doped Tin Oxide (FTO) substrates, with rGO:PEG weight ratios varied at 2:1, 1:1, and 1:2. Photovoltaic testing under a sun simulator revealed that interface modification significantly boosts efficiency compared to the pristine control device. The experimental findings demonstrate that the balanced ratio of rGO:PEG (1:1) achieves the peak Power Conversion Efficiency (PCE) of 5.43%, driven by a massive surge in short-circuit current density () to 9.78 . This study implies that precision stoichiometric control of rGO-polymer co-additives provides a powerful synergistic strategy to enhance charge extraction and maximize the performance of inorganic perovskite solar cells.
Copyright (c) 2026 Rahma Yuniza Putri, Rahmat Hidayat, Yahdi Bin Rus, Maria Ulfa https://creativecommons.org/licenses/by-sa/4.0
Etnomatematika Budaya Ende pada Konsep Bilangan Bulat sebagai Dasar Penyusunan Lembar Kerja Peserta Didik
This study aims to identify the concept of integers contained in three cultural elements of the Ende community, namely the Tu Ngawu traditional ceremony (antar belis), the Gawi traditional dance, and Ende ikat weaving, and to use them as the basis for compiling local wisdom-based Student Worksheets (LKPD). The research was motivated by students' low understanding of the concept of integers, especially operations on negative numbers, as well as the limited teaching materials that integrate local Ende culture. The study used a qualitative approach with an exploratory research type. Data were obtained through in-depth interviews with two informants and documentation, then analyzed descriptively-interpretively. The results show that Tu Ngawu contains the concept of positive and negative integers, and the balance of debt and receivables; the Gawi dance represents integers through forward-backward movements; while Ende ikat weaving contains the concept of integers in thread counting, motif patterns, and numbering of motif positions. Based on these findings, a local wisdom-based LKPD was compiled as a contextual integer learning medium for students in Ende Regency.
Copyright (c) 2026 Maria Apriliana Nona Musi, Yosefina A.N. Noning, Teofilus Putra Wete Ratu, Wahida Muhammad https://creativecommons.org/licenses/by-sa/4.0
Identifikasi Bakteri Indigenous Sebagai Agen Bioremediasi di Lahan Pertanian Cabai Merah Keriting (Capsicum Annum) Yang Terpapar Pestisida Profenofos
Indigenous bacteria are microorganisms that naturally live and adapt to specific environments, making them unique to that area. In bioremediation, these bacteria play a crucial role due to their ability to degrade various environmental contaminants, such as the pesticide profenofos left in the soil. This ability makes indigenous bacteria effective and cost-efficient agents in addressing environmental pollution, highlighting their importance in agricultural land recovery research. The aim of this study is to isolate and identify indigenous bacteria from soil exposed to profenofos pesticide and analyze them descriptively. The study is divided into several stages: sample collection, isolation using Nitrate Minerals Salts (NMS) medium, ability testing using Muller Hilton Agar (MHA) medium, characterization, Gram staining, and biochemical testing. The results revealed that 8 isolates have potential as bioremediation agents for soil contaminated with profenofos. In the ability test against the pesticide, the antibacterial inhibition of profenofos was categorized into four levels: weak, moderate, strong, and very strong. The results showed that the isolate with the code BIPC 8 had the highest clear zone diameter of 32.95 mm, indicating a very strong ability. Out of the 8 isolates, 7 were categorized as strong and 1 as very strong, showing potential to reduce profenofos residues in the soil. The identified genera of these isolates include Nitrosoccocus, Bacillus, Pseudomonas, and Rhodococcus. In conclusion, indigenous bacteria are capable of degrading profenofos pesticide.
Copyright (c) 2026 Sarah Safira, Kartika Manalu, Rizki Amelia Nasution https://creativecommons.org/licenses/by-sa/4.0
Pengaruh Model Problem Based Learning (PBL) Berbasis Microsite S.id terhadap Hasil Belajar pada Materi Sistem Persamaan Linear Dua Variabel (SPLDV)
This study aimed to examine the effect of implementing the Problem-Based Learning (PBL) model integrated with the Microsite S.id platform on students' mathematics learning outcomes in the topic of Systems of Linear Equations in Two Variables (SPLDV) among ninth-grade students at SMP Negeri 1 Botupingge. The study was motivated by students' low understanding of linear equation concepts, the continued use of conventional teaching methods, and the limited utilization of interactive digital learning media. A quantitative approach was employed using a quasi-experimental method with a Pretest–Posttest Control Group Design. The sample consisted of an experimental class that received PBL supported by Microsite S.id and a control class that received PBL supported by Microsoft PowerPoint. Data were collected through pretests and posttests and analyzed using the Independent Samples t-test and effect size analysis. The results indicated that the calculated t-value (8.0131) was higher than the critical t-table value (1.688), demonstrating a statistically significant difference between the two groups. Furthermore, the effect size value of 2.6025 indicated a very large practical effect. These findings suggest that the Problem-Based Learning model integrated with Microsite S.id is more effective in improving students' mathematics learning outcomes than PBL supported by Microsoft PowerPoint while promoting more interactive, contextual, and problem-solving-oriented learning experiences.
Copyright (c) 2026 Tria Meylita Lomamay, Evi Hulukati, Auli Irfah https://creativecommons.org/licenses/by-sa/4.0
Identifikasi Metabolit Sekunder Ekstrak Etanol Belimbing Wuluh (Averrhoa bilimbi. L)
Belimbing wuluh (Averrhoa bilimbi L.) is a medicinal plant known to contain various secondary metabolites, particularly flavonoids, which possess potential biological activities. This study aimed to isolate flavonoid compounds from the ethanol extract of belimbing wuluh fruit and determine the total flavonoid content. The research was conducted through sample preparation, ethanol extraction by maceration, solvent evaporation, liquid-liquid fractionation using n-hexane, ethyl acetate, and water, followed by phytochemical separation using column chromatography, preparative thin-layer chromatography, and two-dimensional thin-layer chromatography. The isolated fraction was further analyzed, and the total flavonoid content was determined using UV-Visible spectrophotometry with quercetin as the reference standard. The extraction process produced an extract yield of 22.70%, while solvent evaporation resulted in a concentrated extract with a yield of 8.8%. Fractionation indicated that the polar fraction was obtained in the highest proportion. Column chromatography generated 50 fractions with different color characteristics, indicating successful separation of compounds based on polarity. Thin-layer chromatography showed an Rf value of 0.4 in the ethyl acetate mobile phase, while preparative and two-dimensional thin-layer chromatography produced a single dominant band, suggesting a relatively pure isolate. The UV-Visible analysis showed excellent linearity and revealed a total flavonoid content of 230.76 mg QE/g or 23.08%, exceeding the minimum quality standard. These findings demonstrate that belimbing wuluh fruit is a promising natural source of flavonoids and has potential for further pharmaceutical and phytochemical development.
Copyright (c) 2026 Fhadlyatul Khusna, Dhini Andriani, Fitrinaya Fitrinaya, Rifdah Rifdah, A. Ilmi Alfiana, Purnamasari Purnamasari, Friska Adelia Putri https://creativecommons.org/licenses/by-sa/4.0
Efektivitas Pendekatan Sosial-Kultural dalam Meningkatkan Motivasi Belajar Matematika pada Mahasiswa Nommensen Program Studi Pendidikan Matematika
This study analyzes students' perceptions of the effectiveness of a sociocultural approach in supporting mathematics learning motivation among prospective mathematics teachers at Universitas HKBP Nommensen Pematangsiantar. A descriptive quantitative post-implementation survey was conducted with 30 students from one class selected purposively. The available dataset consisted of a global evaluation item rated on a five-point Likert scale. Data were analyzed using frequency, percentage, and weighted mean. The results showed that 33.3% of students strongly agreed, 36.7% agreed, 16.7% selected the moderate category, 10.0% disagreed, and 3.3% strongly disagreed. The combined positive response reached 70.0%, while the weighted mean was 3.87, classified as high. These findings indicate that students generally perceived the sociocultural approach positively because it positioned mathematics within meaningful social, cultural, and everyday contexts. Nevertheless, the result represents perceived effectiveness rather than causal evidence of increased motivation because the study did not employ a pretest, comparison group, or multidimensional validated scale. This study contributes preliminary evidence on the acceptance of sociocultural mathematics learning in a preservice teacher education context and provides a basis for stronger experimental and mixed-method research.
Copyright (c) 2026 Ropinus Sidabutar, Stanley Reden https://creativecommons.org/licenses/by-sa/4.0
Studi Awal Perlakuan Termal Grafitisasi Tempurung Kelapa dan Pengaruhnya terhadap Tingkat Kristalinitas Karbon
Coconut shells are a type of biomass with a high fixed carbon content, making them a potential raw material for the production of graphitic carbon. However, the graphitization process generally requires very high temperatures, resulting in high energy consumption and production costs. This study aims to examine the effect of the graphitization process at 900 °C on the crystallinity of coconut shell carbon that has been activated using NaOH without the addition of a metal catalyst. The synthesis process consisted of four main stages: cleaning and drying the raw material; carbonization at 350 °C for 2 hours; chemical activation using a NaOH solution; and graphitization in a furnace at 900 °C for 3 hours. Crystal structure characterization was performed using X-ray diffraction (XRD) to analyze phase changes, degree of crystallinity, d-spacing values, and crystallite size. The results showed that the graphitization process increased the orderliness of the carbon structure, as indicated by the appearance of a (002) diffraction peak at an angle of 2θ equal to 25.91°, a decrease in the d-spacing value to 3.439 Å, and an increase in crystallite size to 31.07 nm. These results indicate a reorganization of carbon atoms toward a more graphitic structure compared to the carbon before and after activation. Thus, the combination of NaOH activation and graphitization at 900 °C is capable of increasing the crystallinity of the carbon tem.
Copyright (c) 2026 Nurul Nadia, Rahmat Hidayat, Leni Aziyus Fitri, Fadhila Ulfa Jhora https://creativecommons.org/licenses/by-sa/4.0
Systematic Literature Review dengan Metode Prisma: Eksplorasi Objek Budaya sebagai Sumber Belajar Matematika di Indonesia
Indonesian cultural objects contain various mathematical concepts that can be utilized as contextual learning resources through an ethnomathematics approach. Numerous studies have explored mathematical concepts embedded in traditional houses, batik motifs, temples, traditional musical instruments, games, crafts, and historical buildings. However, these findings remain dispersed across publications, making it difficult to obtain a comprehensive understanding of the characteristics of cultural objects, the mathematical concepts they contain, and their educational potential. This study aims to synthesize previous research on the exploration of Indonesian cultural objects as mathematics learning resources using a Systematic Literature Review (SLR) approach. The review involved article identification, screening based on inclusion and exclusion criteria, eligibility assessment, and synthesis of research findings. A total of 16 articles published in national journals were analyzed systematically. The results indicate that traditional houses, batik motifs, temples, traditional games, crafts, traditional musical instruments, and other cultural buildings are the most frequently explored cultural objects. The dominant mathematical concepts identified include plane and spatial geometry, geometric transformations, symmetry, patterns, measurement, similarity, congruence, and number concepts. The reviewed studies consistently show that integrating cultural objects into mathematics learning enhances contextual understanding, strengthens conceptual mastery, increases learning motivation, and promotes appreciation of local culture. Nevertheless, most studies remain exploratory, highlighting the need for further research focusing on the development of learning media and empirical evaluation of ethnomathematics implementation in classroom settings. Overall, Indonesian cultural objects have significant potential to support meaningful mathematics learning while contributing to the preservation of cultural heritage.
Copyright (c) 2026 Julius Martunas Sihite, Erfin Nurfalah, Ahmad Subeki, Fajar Sodik, Yulianah Yulianah, Kurniasari Ambar, Acep Musliman https://creativecommons.org/licenses/by-sa/4.0
Efektivitas Model Discovery Learning Berbantuan Ensiklopedia terhadap Pemahaman Konsep Materi Ekosistem Siswa Kelas X SMA
This study aimed to determine the effectiveness of the Discovery Learning model assisted by an encyclopedia on students' conceptual understanding of ecosystem materials in tenth-grade senior high school students. The research employed a quantitative approach using a quasi-experimental method with a Nonequivalent Control Group Design. The population consisted of all tenth-grade students at SMA Karya Sekadau, while the sample was selected using purposive sampling to obtain an experimental class and a control class. The research instrument was a conceptual understanding test administered through pretest and posttest. Data were analyzed using normality tests, homogeneity tests, hypothesis testing, and learning improvement analysis. The results indicated that the implementation of the Discovery Learning model assisted by an encyclopedia had a more positive effect on students' conceptual understanding than conventional learning. Students in the experimental class demonstrated a higher improvement in conceptual understanding than those in the control class. Therefore, the Discovery Learning model assisted by an encyclopedia is effective in improving students' conceptual understanding of ecosystem materials.
Copyright (c) 2026 Krispina Fransiska, Nawawi Nawawi, Tesa Manisa https://creativecommons.org/licenses/by-sa/4.0
Inovasi E-Modul Praktikum Variasi Genetik Lalat Buah Lokal Berbasis Project-Based Learning Mapalus dalam Meningkatkan Keterampilan Proses Sains
Genetics learning at the junior high school level still faces obstacles due to the lack of interactive practicum media that can help students understand abstract concepts contextually. The use of local fruit flies (Drosophila melanogaster) combined with the Mapalus cultural value is a learning innovation with the potential to improve students' science process skills. This study aims to develop and examine the feasibility and effectiveness of a practicum e-module on the genetic variation of local fruit flies based on Project-Based Learning (PjBL) Mapalus toward the science process skills of grade IX-B students. The study used the Research and Development (R&D) method with the 4D development model (Define, Design, Develop, Disseminate) and a mixed methods approach. The research was conducted at SMP Katolik Stella Maris Tomohon, involving small-group and large-group trials using validation instruments, questionnaires, and achievement tests. The results show: media validation obtained 96.25%, material validation 91.67%, and teacher assessment 91.25%, all in the very feasible category. Student response reached 83.35% in the very good category. The Wilcoxon Signed-Rank Test yielded p = 0.000 (< 0.05), indicating a significant improvement in learning outcomes, with the mean score increasing from 51.36 to 76.36. The N-Gain analysis obtained 0.495 (moderate category), and 16 of 22 students (72.72%) achieved moderate to high improvement.
Copyright (c) 2026 Nirmala Sandra Fabiola Lucia Woi, Herry Maurits Sumampouw, Mariana Rengkuan https://creativecommons.org/licenses/by-sa/4.0
Analisis Tingkat Kepuasan Mahasiswa terhadap Pembelajaran Daring pada Mahasiswa Statistika Angkatan 2025 Universitas Negeri Medan
This study aims to determine the level of satisfaction of Statistics students from the 2025 batch at the State University of Medan (UNIMED) with online learning, analyze student assessments of the quality of online learning platforms, analyze academic interactions during the online learning process, determine the affordability of online learning access, and provide recommendations for improving the quality of online learning in the Statistics Study Program at UNIMED. The study used a survey method with a quantitative approach and stratified sampling technique with a total of 40 students as respondents. Data were collected through a Likert scale questionnaire and analyzed using descriptive analysis, mean Likert scores, percentages, validity tests, and reliability tests with the help of SPSS. The results of the validity test showed that 10 of the 12 statement items were declared valid with a calculated r-value greater than the r-table (0.312), while 2 items were declared invalid. The results of the reliability test obtained a Cronbach's Alpha value of 0.900, indicating that the research instrument has a very good level of reliability. The results of the study are expected to be used as evaluation material and a basis for policy making in an effort to improve the quality of online learning in the Statistics Study Program at UNIMED.
Copyright (c) 2026 Yurni Anti, Thesia Febriani Manurung, Abelia Syalomika Hutajulu https://creativecommons.org/licenses/by-sa/4.0
Pengembangan Instrumen Asesmen Berbasis Higher Order Thinking Skills pada Materi Komponen Ekosistem dan Interaksinya di SMA Negeri 1 Tondano
The rapid demands of 21st-century education require assessment instruments capable of measuring higher order thinking skills (HOTS), while classroom assessments in many schools are still dominated by lower order thinking skills (LOTS). This study aims to develop a HOTS-based assessment instrument on ecosystem components and their interactions at SMA Negeri 1 Tondano and evaluate its feasibility based on validity, reliability, item difficulty, discriminating power, and student responses. The study used a Research and Development (R&D) approach with the 3-D model consisting of define, design, and develop stages. The subjects involved 32 tenth-grade students and one biology teacher. The instrument consisted of 20 multiple-choice questions and 5 essay questions designed to measure cognitive levels of analysis (C4), evaluation (C5), and creation (C6). Data were collected through expert validation, validity and reliability testing, item analysis, and student response questionnaires. The results showed an expert validation score of 97.2 (very valid), a trial score of 77.25 (good), and a student response score of 89.87 (very valid). Item analysis indicated that most items were valid, reliable, and had balanced difficulty levels. The developed HOTS-based assessment instrument is valid, practical, and effective for biology learning evaluation.
Copyright (c) 2026 Imelda Febrianti Makalalag, Arrijani Arrijani, Anatje Lihiang https://creativecommons.org/licenses/by-sa/4.0
Sintesis dan Karakterisasi Nanomagnetik Fe3O4 Berbasis Pasir Besi Pantai Sunur melalui Metode Kopresipitasi
Iron sand is an abundant natural resource in coastal areas of Indonesia, including Sunur Beach, Padang Pariaman Regency, West Sumatra, which has great potential as an economical and environmentally friendly raw material for Fe₃O₄ nanoparticle synthesis. This study aims to synthesize and characterize Fe₃O₄ nanoparticles derived from Sunur Beach iron sand using the coprecipitation method. The synthesis process involved dissolving iron sand in 37% HCl, followed by precipitation using 25% NH₄OH, drying, and sintering at 400°C. The synthesized product was characterized using XRD, FTIR, and FESEM analyses. The XRD results showed a characteristic magnetite phase diffraction pattern with the main peak appearing at the (311) plane according to the ICDD standard 01-075-0449, with an average crystal size of 18.36 nm calculated using the Debye-Scherrer equation. FTIR analysis confirmed the presence of Fe₃O₄ functional groups at wavenumbers of 545.18, 490.81, and 432.32 cm⁻¹, representing the characteristic bonds of magnetite structures. FESEM observations revealed a rod-like particle morphology with an average diameter of 96.48 nm. These results confirm that Sunur Beach iron sand is a viable alternative raw material for nanoscale Fe₃O₄ nanoparticle synthesis.
Copyright (c) 2026 Feby Eriza Tanjung, Rahmat Hidayat, Ratnawulan Ratnawulan, Leni Aziyus Fitri https://creativecommons.org/licenses/by-sa/4.0
Sistem Bilangan Bulat sebagai Dasar Teori Bilangan
Integers are one of the fundamental concepts in number theory that serve as the foundation for studying various more complex mathematical topics. This article aims to describe the integer number system, including its definition, properties, and basic operations on integers. This article was written using a qualitative research method with a literature review approach, specifically through the examination of various books and scientific sources relevant to number theory. The results of the study indicate that the integer system consists of negative integers, zero, and positive integers, which possess the properties of closure, commutativity, associativity, distributivity, identity, and the inverse of addition. Furthermore, the operations of addition, subtraction, multiplication, and division of integers follow interrelated rules, thereby forming a consistent system for solving various mathematical problems. An understanding of the concepts, properties, and operations of integers is expected to serve as a strong foundation for studying number theory and to enhance a more comprehensive understanding of mathematical concepts.
Copyright (c) 2026 Prihaten Maskhuliah, Aulia Salsabila Putri, Dewi Mawaddah Rumaf, Tita Mustikawati Selayar, Alfaris Syahdan Nurpratama, Iman Bugis, Erna Bugis https://creativecommons.org/licenses/by-sa/4.0
Ekstraksi Minyak Ulat Hongkong Menggunakan Metode Soxhletasi dengan Pelarut Petroleum Eter
Due to global food issues, alternative sources are needed to replace oil such as vegetable and animal oils to produce oil-based products. However, increasing issues about animal-derived products are becoming an environmental problem. Yellow mealworm as a potential source of oil, has attracted the interest of researchers due to its ability to accumulate fat by feeding on organic waste. This study investigates the effect of variation in petroleum ether solvent ratio and extraction time on the yield, acid number and water content of Yellow mealworm. The variations of the ratio of caterpillar and solvent used were 1:6, 1:8, and 1:10, with extraction time of 5, 6, and 8 hours at 65°C. The best results of this study showed that the ratio of caterpillar and solvent 1:10 with extraction time of 8 hours produced the highest oil yield of 15% with FFA content of 6.88%. Extraction using the soxhletation method with petroleum ether solvent can reduce the water content from 80% to 0.21%.
Copyright (c) 2026 Rietias Sarinastiti Nurmin, Adrian Satria Kemal, Maya Ramadianti Musadi https://creativecommons.org/licenses/by-sa/4.0
Analisis Kinerja Metode Kombinasi Elektrokoagulasi dan Adsorpsi dalam Penyisihan Total Suspended Solid (TSS) pada Air Lindi
Air lindi dari TPA memiliki karakteristik pencemar yang kompleks sehingga diperlukan teknologi pengolahan yang efektif dan ramah lingkungan sebelum dibuang ke badan air. Salah satu parameter penting dalam pengolahan air lindi adalah Total Suspended Solid (TSS) karena keberadaan padatan tersuspensi dapat menurunkan kualitas lingkungan perairan. Penelitian ini bertujuan untuk menganalisis kinerja metode kombinasi elektrokoagulasi–adsorpsi menggunakan arang tempurung kelapa dalam penyisihan TSS pada air lindi salah satu TPA di Madiun serta mengevaluasi pengaruh variasi tegangan dan waktu proses terhadap efektivitas penyisihan. Metode penelitian dilakukan secara eksperimen menggunakan elektroda aluminium dengan variasi tegangan 3 V, 6 V, dan 9 V serta waktu proses 30 dan 60 menit. Proses elektrokoagulasi dilakukan terlebih dahulu, kemudian dilanjutkan dengan proses adsorpsi menggunakan arang tempurung kelapa tanpa aktivasi kimia. Hasil penelitian menunjukkan bahwa kombinasi elektrokoagulasi–adsorpsi mampu menurunkan kadar TSS pada seluruh kondisi perlakuan dengan efektivitas penyisihan sebesar 74–82%. Kondisi terbaik diperoleh pada tegangan 6 V dengan waktu proses 30 menit dengan efektivitas penyisihan sebesar 82%. Hasil penelitian menunjukkan bahwa kombinasi elektrokoagulasi dan adsorpsi menggunakan biomassa lokal berpotensi menjadi alternatif teknologi pengolahan air lindi yang sederhana, ekonomis, dan berkelanjutan.
Copyright (c) 2026 Alinda Nur Rohmah, Ade Trisnawati https://creativecommons.org/licenses/by-sa/4.0
Analisis Kualitas Perairan Bozem FMIPA UNESA Berdasarkan Parameter Fisika Kimia
The Bozem at the Faculty of Mathematics and Natural Sciences (FMIPA), Surabaya State University (UNESA), is an artificial body of water that serves as a water reservoir while also supporting ecological functions on campus. The water quality in the pond is susceptible to deterioration due to the influx of organic matter from rainwater runoff and surrounding activities. This study aims to analyze the status of the water in the UNESA FMIPA pond by examining physical and chemical parameters, namely temperature, transparency, turbidity, Total Dissolved Solids (TDS), pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), and CO₂ levels, and comparing them with the Class II lake water quality standards as stipulated in Government Regulation No. 22 of 2021. The study employed a quantitative descriptive method using field surveys as its approach. The data were analyzed descriptively and comparatively by comparing the water quality standards with the applicable measurement results. The results of the study indicate that most water quality parameters still meet the quality standards. Water temperature deviated by 1°C from air temperature; the average TDS was 234 mg/L, pH was 8.6, DO was 7.4 mg/L, BOD was 2.5 mg/L, and CO₂ was 3.74 mg/L. Low transparency (0.25 m) and high turbidity (61.9 NTU) indicate a high concentration of suspended particles in the water. Overall, the water quality of Bozem FMIPA UNESA still meets the Class II lake water quality standards as stipulated in Government Regulation No. 22 of 2021.
Copyright (c) 2026 Fahmi Nasrullah Azmi, Herlina Fitrihidajati https://creativecommons.org/licenses/by-sa/4.0
Generalization of Möbius-Type Arithmetic Functions and Their Algebraic Properties
This study aims to formulate a parameterized family of Möbius-type arithmetic functions and investigate their algebraic properties, including multiplicativity, Dirichlet inverses, convolution identities, generalized Möbius inversion formulas, Dirichlet-series representations, and relationships with other arithmetic functions. The research employs a qualitative approach based on a literature review and mathematical-theoretical analysis using formal definitions, deductive proofs, prime-factorization techniques, and Dirichlet convolution theory. The results demonstrate that the proposed function, , preserves multiplicativity, satisfies the reduction principle to the classical Möbius function when , becomes the characteristic function of square-free integers when , and serves as the Dirichlet inverse of . Furthermore, the study derives a generalized Möbius inversion formula, establishes a new family of generalized totient functions, and obtains consistent Dirichlet-series representations. These findings provide an integrated mathematical framework for understanding generalized Möbius-type functions and extend the theoretical foundations of arithmetic identities, inversion theory, and future research in analytic number theory and the algebra of arithmetic functions.
Copyright (c) 2026 Dante Rio Sebastian https://creativecommons.org/licenses/by-sa/4.0
Identifikasi Zona Prospek Panas Bumi Berdasarkan Analisis HVSR di Sekitar Nagari Malampah
Nagari Malampah, Tigo Nagari District, Pasaman Regency, West Sumatra, is located in a volcanic and tectonic environment that supports the development of a geothermal system. Information regarding the distribution of relatively more prospective areas in the region remains limited. This study aims to estimate the distribution of geothermal prospect zones using the Horizontal-to-Vertical Spectral Ratio (HVSR) method based on microtremor data from 16 measurement points. HVSR analysis provides the dominant frequency (f₀) and amplification factor (A₀) parameters. These parameters were integrated using a scoring system based on their respective classes to determine relatively low, moderate, and high prospect zones. The analysis indicates that the relatively high prospect zones are located at measurement points T5, T6, T8, and T10. These results indicate variations in site response and subsurface impedance contrasts that are relatively more supportive of geothermal prospects at several locations. This interpretation represents an initial indication of geothermal prospectivity and cannot be used to directly confirm the presence of hydrothermal fluids. Further validation is required using geological, geochemical, resistivity, magnetotelluric (MT), or other exploration data.
Copyright (c) 2026 Aura Puja Kesuma Andily, Akmam Akmam, Hamdi Rifai, Zulhendra Zulhendra https://creativecommons.org/licenses/by-sa/4.0
Comparison Physicochemical Characterization of Essential Oils from Gajah and Emprit Ginger Varieties
Ginger (Zingiber officinale) is a high-economic-value essential oil commodity. This descriptive-exploratory study aimed to analyze and compare the physico-chemical profiles of essential oils from emprit ginger (Zingiber officinale var. Amarum) and giant ginger (Zingiber officinale var. Officinale) originating from Dadaprejo Village, Batu City. Essential oil extraction was performed using water distillation, while characterization employed organoleptic testing by 15 panelists, 96% alcohol solubility testing, yield calculation, and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Physical results showed emprit ginger oil was dominated by deep yellow color (41.7%) with a very strong aroma (41.7%), whereas giant ginger oil was light yellow (35.7%) with a moderate-strong aroma (35.7%). Emprit ginger yield (0.1067%) was higher than that of giant ginger (0.0800%). Both varieties dissolved completely in 96% alcohol at ratios of 1:3 for emprit ginger and 1:4 for giant ginger. Chemical characterization identified 119 volatile compounds in emprit ginger, dominated by cyclic ketone (Ketone, 1-cyclohexen-1-yl methyl, semicarbazone) at 16.15%, while giant ginger exhibited a simpler profile with 35 components, dominated by phenolic aldehyde (4-Hydroxy-2-nitro-m-anisaldehyde) at 7.67%. Thermal degradation during extraction converted sesquiterpene hydrocarbons such as zingiberene into more stable oxygenated groups. In conclusion, var. amarum holds high potential for the pharmaceutical industry due to its high ketone content, while var. officinale is ideal for the food and beverage industry.
Copyright (c) 2026 Jafni Amanda Kinarossa Widjaja, Isnawati Isnawati https://creativecommons.org/licenses/by-sa/4.0