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Justek : Jurnal Sains Dan Teknologi
ISSN : 26205475     EISSN : 26205475     DOI : -
Arjuna Subject : -
Articles 10 Documents
Search results for , issue "Vol 8, No 4 (2025): December" : 10 Documents clear
Investigation of Rare Earth Elements from Coal-Derived Minerals of Sawahlunto Formation and Leaching Behavior Under NaOH and HCl Washing Treatment Algifari, Arif; Nauli, Fitri; Deni, Andri Van; Aisyah, Siti; Syakira, Dwi Wulan
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.33908

Abstract

The growing demand for rare earth elements (REE) in modern technological applications has encouraged the exploration of alternative REE sources, including minerals associated with coal. This study aims to evaluate the potential of minerals in the Sawahlunto Formation coal from the Ombilin Basin as a secondary REE source through an alkaline leaching approach. Coal samples from the Sawahlunto Formation were subjected to alkaline leaching using sodium hydroxide solutions of 200–600 g/L at temperatures of 38–78 °C for 0.5–1.5 hours, followed by an acid-washing stage using 14% hydrochloric acid. X-ray fluorescence analysis identified yttrium, lanthanum, and cesium, with a total initial REE content of approximately 181 ppm. The leaching results show that under optimal conditions 400 g/L NaOH, 78 °C, and a particle size of 60/70 mesh, the residual REE content decreased to 2 ppm, indicating effective dissolution of REE-bearing mineral components. Subsequent acid washing further enhanced REE recovery by removing remaining soluble phases. These results demonstrate that coal from the Sawahlunto Formation possesses promising characteristics as a secondary REE source.
Quasi Linear Utility Optimization for Selfish User Model in C-RAN With Demand Response and Bundling Prayoga, Nafisah Aura; Puspita, Fitri Maya; Octarina, Sisca
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.36521

Abstract

This study aims to develop two optimization models that provide a realistic representation of interactions between selfish users and C-RAN networks by integrating demand response mechanisms, heterogeneous incentives, and quasi-linear utility functions. The first model is designed to formulate selfish user behavior in a C-RAN system based on utility structures and incentive schemes, while the second model extends this framework through the incorporation of a bundling scheme to evaluate improvements in network efficiency and user utility. The research methodology involves collecting and formulating 30 days of traffic data, defining relevant model parameters and variables, constructing the optimization models, and solving them using LINGO 13.0 under three pricing schemes: usage-based, flat-fee, and two-part tariff. The results reveal that the flat-fee pricing scheme with bundling in Case 2 provides the most efficient configuration, achieving the highest objective value of  and the lowest iteration count. These findings demonstrate that integrating bundling strategies into C-RAN pricing models can enhance network efficiency, improve bandwidth utility, and increase ISP revenue.
Development of Smart Box Learning Media on the Material of the Human Respiratory System Rhamdan, Donna; Dominggus, Dominggus
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.35997

Abstract

The type of research carried out in this study is research and development (R&D). This research aims to develop Smart Box learning media  that is validated by media expert validators, material experts, linguists, and practitioners. This research also aims to find out the attractiveness of Smart Box learning media. This research and development process uses the ADDIE model, which includes five stages: Analysis, Design, Development, Implementation, and Evaluation. The validation results resulted in 100% of media experts, 94% of material experts, 84% of linguists, and 97.1% of practitioners, all of whom were categorized as very deserving. The results of validation from media, material, language, and practitioner experts show that Smart Box learning media  is very feasible to be used in the learning process. The results of the limited trial were 92.9%, while the field trial yielded 88.8%, both of which were categorized as very interesting. The results of the student response questionnaire conducted during the limited trial and field trial showed that students were very interested in the Smart Box learning media.
Optimization of the Combination Ratio of Biduri and Bidara Leaf Extracts in Reducing Cholesterol in Mice Rifqiyah, Jazilatur; Wijayanti, Cicik; Patricia, Gaby Ayu; Yusmiati, Siti Nur Husnul; Ngibad, Khoirul
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.36437

Abstract

This study aimed to evaluate the effectiveness of a combination of ethanol extracts of Biduri (Calotropis gigantea L.) and Bidara (Ziziphus spina-christi L.) leaves in reducing cholesterol levels in mice induced with hypercholesterolemia, as well as to determine the optimal dose and combination ratio. This experimental laboratory study involved several stages, including extract preparation, preparation of extract suspensions, preparation of simvastatin and propylthiouracil (PTU) suspensions, selection and maintenance of experimental animals, administration of treatments, and measurement of blood cholesterol levels. A total of 72 male mice were divided into 12 treatment groups: negative control, positive control, drug control, and nine groups receiving combinations of extracts with ratios of 1:1, 1:2, and 2:1 at three doses (14, 28, and 56 mg/20 g BW). Hypercholesterolemia was induced using PTU for 14 days, followed by oral administration of the extract combinations for 3 days. Cholesterol levels were measured using a spectrophotometer and analyzed using One Way ANOVA. The results showed that the combination of Biduri and Bidara extracts significantly reduced cholesterol levels (p < 0.05), with the highest reduction observed in the 2:1 ratio at a dose of 56 mg/20 g BW, showing a 59.18% decrease (135.47 mg/dL) compared to the positive control. These findings indicate a synergistic effect between the two extracts and suggest their potential as a natural hypocholesterolemic agent.
Antihypercholesterolemic Activity of the Ethanol Extract Combination of Leaves Calotropis gigantea L. and Adenanthera pavonina L. Oktaviani, Galuh Anggun; Patricia, Gaby Ayu; Wijayanti, Cicik; Ngibad, Khoirul
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.36441

Abstract

Hypercholesterolemia is a significant risk factor for cardiovascular disease, and its prevalence continues to increase. Pharmacological therapy using statins is effective but may cause side effects when used long-term. Therefore, exploring natural ingredients as an alternative antihypercholesterolemic therapy is essential. This study aimed to evaluate the activity of a combination of ethanol extracts of Calotropis gigantea L. leaves and Adenanthera pavonina L. on the cholesterol levels of male mice induced with propylthiouracil (PTU). The study was conducted experimentally using a post-test-only control-group design with 36 male mice divided into six groups: negative control, positive control, drug control (simvastatin), and three treatment groups receiving extract combinations at doses of 14, 28, and 56 mg/g BW. The research stages included seven days of animal adaptation, induction of hypercholesterolemia with PTU for 14 days, administration of the extract combination at doses of 14, 28, and 56 mg/g BW for four days, and blood sampling for total cholesterol measurement using an automated chemical spectrophotometer. The results showed a significant increase in cholesterol levels in the positive control group, while simvastatin produced the most significant reduction. The extract combination gradually decreased cholesterol levels with increasing dose, with the highest dose approaching the effect of simvastatin. The paired t-test showed a p-value < 0.05, indicating significant differences between treatments. The combination of Calotropis gigantea L. and Adenanthera pavonina L. leaf extracts has potential as a herbal agent to support antihypercholesterolemic therapy.
Design and Development of an Immersive Game-Based Mandarin Language Learning Medium to Enhance Student Learning Motivation Arini, Nuskha Ilma
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.36074

Abstract

The rapid advancement of technology in the Industrial Revolution 4.0 era has driven innovation in education, particularly through the use of interactive digital learning media. This study aims to develop an immersive game-based learning media for Mandarin language instruction using the Roblox Studio platform to enhance students’ motivation and engagement in the learning process. The research employed a Research and Development (R&D) approach using the ADDIE model, which consists of five stages: Analysis, Design, Development, Implementation, and Evaluation. The analysis phase identified that Mandarin learning tends to be monotonous and less engaging for students. Validation results from content experts reached 83% and media experts 81%, both categorized as good. User testing yielded 84%, while small-group and large-group trials achieved 88% and 85%, respectively, categorized as very high. The developed learning game integrates coin hunt and leaderboard features that effectively create an interactive and competitive learning experience. Overall, the findings indicate that the game-based learning media is feasible, engaging, and effective in improving students’ motivation and learning outcomes in Mandarin language courses within vocational higher education.
Mineral Content of Clay Soil and Coffee Husk Ash for Soil Stabilization Applications in Geotechnical Engineering Sabilla, Arissa; Muammar, Rajib; Juanda, Ari
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.35345

Abstract

This study aims to analyze the mineral composition of clay soil and coffee husk ash, as well as to evaluate the effect of coffee husk ash as a stabilizing agent for clay soil. The main problem addressed is the high plasticity of clay soil, which causes volume changes and reduces bearing capacity, making stabilization methods necessary. The research was conducted by collecting clay soil samples from Kebun Kurma Barbate, Aceh Besar, and coffee husk ash from Aceh Tengah. Mineral composition was analyzed using gravimetric, titrimetric, spectrophotometric, and AAS methods, while soil plasticity was examined through Atterberg limits and specific gravity tests. The results indicate that clay soil contains dominant Silica Oxide (SiO₂) at 42.99% and Aluminum Oxide (Al₂O₃) at 5.63%, contributing to its high plasticity. Meanwhile, coffee husk ash contains 8.30% SiO₂ and 5.22% Calcium Oxide (CaO), which play crucial roles in stabilization. The addition of 5– 25% coffee husk ash reduced the plasticity index from 38.42% to 34.29%, increased soil specific gravity from 2.587 g/cm³ to 2.690 g/cm³, and transformed soil classification from clay to silt. These findings confirm the potential of coffee husk ash as an effective, and sustainable stabilizing material for geotechnical engineering applications
Clustering of Data on Vegetable Crop Production in the City of Bandung Using the K-Means Algorithm Saputra, Ifano Rangga; Santoso, Cahyono Budy
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.35555

Abstract

Vegetable farming supports urban food security, and Bandung City is one of West Java's main horticultural centers. However, vegetable production remains unevenly distributed across its sub-districts. This study analyzes production patterns from 2018–2023 using the K-Means Clustering algorithm. The dataset includes 12 major commodities, and the analysis involves data preprocessing, determining the optimal number of clusters using the Elbow Method and Silhouette Score, applying K-Means, and visualizing results through heatmaps and PCA. The findings reveal three clusters: Cluster 0 dominated by potatoes and the "others" category; Cluster 1 dominated by kale; and Cluster 2 dominated by shallots and petsai. These patterns indicate concentrated and specialized production across specific sub-districts. The study concludes that K-Means effectively identifies multi-commodity production similarities and provides strategic insight for Business Intelligence applications in agricultural planning and policy development.
Analysis of Heavy Equipment Productivity in the Jalan Rel Kota Langsa Reconstruction Project Muammar, Rajib; Iqbal, Iqbal
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.35015

Abstract

The quality of the road produced during the reconstruction of Jalan Rel Kota Langsa is directly dependent on the materials used, the operators, and the application of heavy equipment. Errors in heavy equipment selection will lead to low productivity. This study aims to determine the productivity levels and the required duration for each piece of equipment to complete the Langsa City Road Reconstruction project. This research employs the Bina Marga method with a quantitative approach. The analysis results show that the productivity of heavy equipment for Aggregate Base Class A (LPA) work is as follows: dump trucks = 386.352 m³/day, motor graders = 617.143 m³/day, vibrator compactor rollers = 804.270 m³/day, and water tanks = 498 m³/day. For prime coat work: air compressors = 3486 m²/day and asphalt distributors = 647.089 liters/day. For Asphalt Concrete-Binder Course (AC-BC) work: dump trucks = 172.148 m³/day, asphalt finishers = 804.270 tons/day, tandem rollers = 401.017 m³/day, and pneumatic tire rollers = 365.776 m³/day. The duration required for heavy equipment execution is 2 days for LPA work, 1 day for prime coat work, and 2 days for AC-BC work.
A Study of Pumice as a Geo-Paving Material Swahip, Swahip; Fathoni, Ahmad; Alpiana, Alpiana
Justek : Jurnal Sains dan Teknologi Vol 8, No 4 (2025): December
Publisher : Unversitas Muhammadiyah Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31764/justek.v8i4.36563

Abstract

This study aims to evaluate the characteristics of pumice as a substitute aggregate material for producing lighter, more economical, and environmentally friendly geo-paving. The research method includes literature review and laboratory testing focused on bulk density and mechanical performance of pumice-based paving blocks with three composition variations: 20%, 40%, and 60%. The results indicate that pumice from Pemepek Village has an average density of 0.72 g/cm³ and can reduce paving weight by 15–45% compared to conventional paving, although compressive strength decreases as pumice content increases. Overall, compositions containing 20–40% pumice are considered the most optimal in delivering well-performing paving blocks with higher ecological and economic value.

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