Journal of Science, Technology, and Innovation
Inventa: Journal of Science, Technology, and Innovation is a peer-reviewed open-access journal published by CV Scripta Intelektual Mandiri. It publishes original research and applied studies in science, technology, and innovation, including fields such as engineering, ICT, materials science, renewable energy, and environmental technology. The journal is published three times a year (April, August, December) and operates under a no-fee policy. All articles are licensed under the Creative Commons Attribution 4.0 (CC BY 4.0) license.
The Effect of Mineral Acid Type on the Synthesis of Acid-Activated Montmorillonite on the Structure, Morphology, and Performance of Bleaching Earth
Montmorillonite (MMT) is a clay mineral belonging to the smectite group, characterized by a large surface area, high cation exchange capacity, and a layered structure, making it a promising bleaching earth for palm oil refining. However, natural montmorillonite exhibits limitations, including a low number of active sites and limited porosity, thus requiring acid activation to enhance its performance. This study aims to analyze the effect of different mineral acids on the crystal structure, morphology, and bleaching performance of acid-activated montmorillonite. Activation was carried out using HCl, H₂SO₄, HNO₃, and H₃PO₄ at a concentration of 1 M for 3 hours. Characterization was conducted using X-ray diffraction (XRD) to determine crystallinity, scanning electron microscopy (SEM) to observe surface morphology, and UV–Vis spectrophotometry to evaluate bleaching performance. The XRD results revealed that sulfuric acid produced the largest crystal size (78.8 nm) with the highest degree of homogeneity. Activation with HCl resulted in a crystal size of 64.5 nm, H₃PO₄ yielded 68.3 nm, and HNO₃ produced 68.5 nm. SEM analysis showed the formation of new pores and a rougher surface texture after activation. HCl activation yielded the most favorable surface morphology. Bleaching tests demonstrated a significant reduction in color intensity and β-carotene content in palm oil.
Adsorption, Acid Activation, Bleaching Earth, Palm Oil, Montmorillonite.
Copyright (c) 2026 Hanifah Sriamelia, Riri Jonuarti (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Kaolin Coating on Titanium Dioxide (TiO₂) and Zinc Oxide (ZnO) on the Photocatalytic Activity of Thin Films
Titanium dioxide (TiO₂) and zinc oxide (ZnO) are widely applied as broad-spectrum ultraviolet protective agents; however, nanoscale modification that improves optical transparency may simultaneously increase photocatalytic activity and reactive oxygen species (ROS) generation. This study investigated the effect of kaolin coating on the photocatalytic behavior of TiO₂ and ZnO thin films fabricated through spin coating. Nanoparticles were reduced to sizes below 150 nm using high-energy ball milling and deposited into sandwich-structured nano-kaolin/TiO₂ and nano-kaolin/ZnO films with weight ratios of 0%:100% and 50%:50%. Photocatalytic performance was evaluated through methylene blue degradation under ultraviolet irradiation for 5 h at 664 nm. Pure TiO₂ and ZnO exhibited high photocatalytic degradation efficiencies of 72.77% and 68.51%, respectively. Incorporation of 50% kaolin significantly reduced degradation efficiencies to 22.10% for TiO₂/kaolin and 23.69% for ZnO/kaolin. Kaolin contributed to initial physical adsorption while suppressing ROS formation through active-site coverage and controlled charge-transfer pathways. The resulting sandwich-structured thin films demonstrated improved optical stability, reduced photocatalytic aggressiveness, and promising potential as multifunctional UV-protective nanomaterials for safer sunscreen-related applications.
TiO₂ Thin Film, ZnO Nanomaterial, Kaolin Coating, Photocatalytic Suppression, UV Shielding.
Copyright (c) 2026 Okta Khairina, Riri Jonuarti (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Variations in HCl pH on the Acidification of Montmorillonite on the Bleaching Yield of Crude Palm Oil
Crude Palm Oil (CPO) requires a bleaching process to reduce pigments and free fatty acids (FFA). Montmorillonite as an adsorbent needs acid activation to improve its adsorption capacity. This study aimed to investigate the effect of HCl activation at pH 2, 4, and 6 on the surface morphology of montmorillonite as characterized by Scanning Electron Microscopy (SEM) and its influence on CPO bleaching efficiency. Acid activation was performed using 0.01 M HCl with a slurry titration method. Particle size analysis was conducted using ImageJ software with the length parameter. Results showed that unactivated montmorillonite had a mean particle length of 1054.54 nm with dense and agglomerated morphology. Activation at pH 4 produced the most homogeneous particle distribution with a mean length of 1635.57 nm and a more open surface structure. Bleaching analysis demonstrated that montmorillonite activated at pH 4 generated the lowest FFA content of 1.4% compared to pH 2 and pH 6. These findings indicate that pH 4 activation provides the optimum balance between structural stability, pore opening, and adsorption effectiveness for CPO bleaching.
Montmorillonite, Acid Activation, SEM, Particle Size, Crude Palm Oil Bleaching.
Copyright (c) 2026 Tiara Fatika Sari, Riri Jonuarti (Author) https://creativecommons.org/licenses/by/4.0
Strengthening Human Resource Capacity in the Implementation of Environmental, Social, and Governance (ESG) Principles in the Mining Sector: A Literature Review
The mining sector faces global demands to integrate Environmental, Social, and Governance principles into all operational processes to support the industry’s sustainability. This study aims to analyze the strengthening of human resource capacity in the implementation of ESG in the mining sector through a systematic literature review using a conceptual-interpretive approach. The method employed involves a critical thematic synthesis of various reputable scientific sources to identify the relationship between human resource competencies, governance, and technological innovation. The results indicate that the success of ESG implementation is highly dependent on the quality of human resources possessing sustainability literacy, digital adaptability, and risk-based managerial competencies. The main weaknesses lie in fragmented governance, limited training, and low technology integration in HR management. Strengthening HR capacity through training, innovation, and green human resource management are key factors in accelerating the transformation toward a sustainable mining industry. This study provides a conceptual contribution toward building an integrative model between HR and ESG in the extractive sector.
Human Resources, Environmental, Social, and Governance (ESG), Sustainable Mining, Governance, Technological Innovation
Copyright (c) 2026 Faisal Muchtasar (Author) https://creativecommons.org/licenses/by/4.0
The Role of the Government in the Development of a Sustainable Drinking Water Supply System (SPAM): A Literature Review
This study aims to analyze the government’s role in the development of a drinking water supply system based on sustainable development through a literature review. The method used is a narrative integrative review with thematic synthesis of reputable national and international journals discussing drinking water governance, public policy, and infrastructure sustainability. The results of the study indicate that the government’s role encompasses regulatory functions, institutional strengthening, and facilitating multi-stakeholder collaboration in the provision of drinking water services. The sustainability of the WSS is influenced by policy synchronization, financing effectiveness, community participation, and technological innovations in water distribution. The findings also indicate implementation gaps resulting from weak planning integration and limited institutional capacity at the local level. This study emphasizes that WSS development depends not only on physical infrastructure but also on adaptive and collaborative governance. This research makes a conceptual contribution to strengthening a sustainability-based WSS governance model and offers an analytical framework for the development of more integrated drinking water policies.
Drinking Water, Governance, Sustainable Development, Government Policy, WSS Collaboration.
Copyright (c) 2026 Minson Simatupang, La Ode Ichwan Sjachrawy, Abdul Kadir, Try Sugiyarto Soeparyanto (Author) https://creativecommons.org/licenses/by/4.0
Analysis and Implementation of the Apriori Algorithm for Predicting Floods in the City of Medan at the Lau Simeme Dam
This study aims to analyze and implement the Apriori algorithm to predict flood potential at the Lau Simeme Dam in Medan City by identifying association patterns among rainfall, water discharge, and water level parameters based on daily hydrological data. The main challenge of this study lies in the limitations of conventional mitigation systems, which are not yet capable of systematically and adaptively interpreting multivariate environmental relationships. The research method employs an empirical data mining-based approach, involving data preprocessing, numerical transformation into transactional data, frequent item set formation, and association rule derivation using minimum support and confidence parameters. The system was developed using Python and MySQL to support the operational analysis and visualization of prediction results. The results show that the Apriori algorithm is capable of generating consistent association patterns between heavy rainfall, increased water discharge, and flood alert status with an accuracy of 97.81%, precision of 100%, and recall of 97.81%. These findings indicate that association rule-based models possess interpretive and predictive capabilities relevant to supporting flood mitigation based on hydrological data.
Apriori Algorithm, Flood Prediction, Data Mining, Lau Simeme Dam, Association Rule
Copyright (c) 2026 Zahra Apriyani Hakim Nasution, Mulkan Azhari (Author) https://creativecommons.org/licenses/by/4.0
A Comparison of the Performance of K-Means and K-Medoids in Classifying High-Achieving Students at SMP Muhammadiyah 60 Medan
This study investigates the comparative performance of the K-Means and K-Medoids clustering algorithms in classifying student achievement at SMP Muhammadiyah 60 Medan. The research applies a quantitative data mining approach using academic and non-academic variables, including Mathematics scores, Science scores, Bahasa Indonesia scores, attendance records, and extracurricular participation. Data preprocessing was conducted through cleaning, normalization using Min-Max Scaling, and feature selection to ensure data consistency and analytical reliability. The findings indicate that both algorithms successfully classified students into meaningful performance groups with consistent clustering structures. K-Means demonstrated superior computational efficiency and lower SSE values, making it suitable for homogeneous datasets. In contrast, K-Medoids exhibited greater robustness against outliers and produced more stable cluster distributions. The study concludes that K-Medoids provides more representative clustering results for educational datasets characterized by heterogeneous performance patterns.
K-Means, K-Medoids, Clustering, Student Performance, Silhouette Coefficient.
Copyright (c) 2026 Farida Nafisa Siagian, Halim Maulana (Author) https://creativecommons.org/licenses/by/4.0
Performance Analysis of Logistic Regression and SVM (Support Vector Machine) Algorithms on E-Football Mobile Game Review Sentiment
This study investigates the comparative performance of Logistic Regression and Support Vector Machine algorithms in sentiment classification of e Football mobile game reviews collected from the Google Play Store. The research employed an empirical machine learning framework involving web scraping, Natural Language Processing preprocessing, Term Frequency Inverse Document Frequency feature extraction, and supervised classification procedures. A total of 7,497 Indonesian language reviews were processed through cleaning, case folding, normalization, tokenization, stopword removal, and stemming to improve textual consistency and semantic representation. The dataset was divided into training and testing subsets using an 80:20 ratio to evaluate model generalization performance. Classification effectiveness was measured using accuracy, precision, recall, and F1 score metrics supported by confusion matrix interpretation. The findings demonstrate that Support Vector Machine achieved superior classification stability with an accuracy of 81.13% and an F1 score of 0.72, while Logistic Regression obtained an accuracy of 80.97% and an F1 score of 0.71. The results indicate that Support Vector Machine provides stronger robustness in handling high dimensional Indonesian gaming review data characterized by class imbalance and semantic variability.
Sentiment Analysis, E-Football, Support Vector Machine, Logistic Regression, TF IDF.
Copyright (c) 2026 Athary Zikry, Farid Akbar Siregar (Author) https://creativecommons.org/licenses/by/4.0
Analysis of Palm Oil Losses in the Processing Operations at the PT Perkebunan Nusantara IV Regional IV Bunut Palm Oil Mill
This study analyzes palm oil losses during the processing stages at the Palm Oil Mill of PT Perkebunan Nusantara IV Regional IV PKS Bunut. The research aimed to identify critical loss points, evaluate causal factors, and formulate operational improvement strategies to enhance processing efficiency. The study employed an empirical industrial observation approach through direct monitoring of the Fresh Fruit Bunch processing chain, including sterilization, threshing, pressing, clarification, and kernel stations. The results indicate that several loss components, particularly press cake and solid decanter losses, exceeded industrial standard limits, reflecting process inefficiencies in specific operational units. The dominant factors contributing to losses were unstable sterilization conditions, declining screw press and decanter performance, inconsistent operational control, and variability in raw material quality. The implementation of preventive maintenance, process standardization, Statistical Process Control, and Six Sigma-based monitoring is considered capable of reducing oil losses and strengthening sustainable operational efficiency in the palm oil processing industry.
Palm Oil Losses, Crude Palm Oil, Process Efficiency, Oil Extraction Rate, Palm Oil Mil.
Copyright (c) 2026 Farhan Al rasyid Nasution, Brav Deva Bernadhi (Author) https://creativecommons.org/licenses/by/4.0
The Impact of Online Transportation Services on the Revenue of Food-Based SMEs in Kendari
The rapid expansion of digital transportation platforms has transformed the operational landscape of culinary micro, small, and medium enterprises (MSMEs) in urban economies. This study aims to analyze the effect of online transportation services on the income performance of culinary MSMEs in Kendari City within the context of platform-based digital economic transformation. The research employed a quantitative empirical approach using survey data collected from 65 culinary MSME actors integrated with online transportation applications for at least six months. Data were analyzed using validity and reliability testing, simple linear regression, hypothesis testing, and coefficient of determination analysis. The findings reveal that online transportation exerts a positive and statistically significant influence on MSME income, indicated by a regression coefficient of 0.688 and a significance value below 0.05. The coefficient of determination demonstrates that 54.8% of income variation can be explained by the existence of online transportation services. The study also identifies digital adaptation capability, innovation capacity, consumer loyalty, and resilience to platform competition as critical determinants influencing MSME sustainability in the digital economy ecosystem.
Digital Economy, Culinary MSMEs, Online Transportation, Business Resilience, Digital Adaptation.
Copyright (c) 2026 Kemal Jusra, Sylsiani Mursalim, Maudhy Satyadharma, Muhammad Yazir Jabbar, Hado Hado, Muhamad Rajulan (Author) https://creativecommons.org/licenses/by/4.0
Functional Group Analysis of the Comparison Between the Mixing Method and the Coating Method for E. coli Bacteria in Asphalt
This study investigated the functional group transformation of asphalt modified using Escherichia coli through mixing and coating methods as a biological self-healing approach for pavement materials. The experimental research was conducted under controlled laboratory conditions using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and hydrophobicity analysis to evaluate chemical, morphological, and surface performance changes. The mixing method promoted dominant internal interactions within the asphalt matrix, indicated by increased O–H functional groups and homogeneous bacterial distribution. In contrast, the coating method generated stronger surface reactions characterized by higher C–O intensity, enhanced biomineralization activity, and localized CaCO3 formation on the asphalt surface. SEM observations revealed that the coating method formed denser biofilm structures, contributing to improved hydrophobicity and accelerated microcrack healing performance. Comparative analysis demonstrated that bacterial application mechanisms significantly influenced asphalt chemical evolution and engineering behavior. The findings indicate that biologically modified asphalt using Escherichia coli possesses considerable potential for sustainable, adaptive, and self-healing pavement systems through optimized bacterial treatment strategies.
Asphalt, Escherichia Coli, FTIR, Self-healing, Hydrophobicity.
Copyright (c) 2026 Stefi Monika, Ratnawulan (Author) https://creativecommons.org/licenses/by/4.0
Optimizing Excellent Service Through the A6 Concept at the Torobulu Ferry Terminal
This study aims to analyze the optimization of excellent service through the application of the A6 concept to the service system at the Torobulu Ferry Port in the context of public transportation services based on user experience. The study employs a qualitative-descriptive empirical approach through operational observation, in-depth interviews, documentation, and thematic analysis of the dimensions of attitude, ability, attention, appearance, action, and accountability. The results indicate that service quality has shown positive improvements in service attitude, operational technical ability, and service flow management. Major challenges remain in inconsistent service communication during peak periods, limited digitalization of information, a lack of proactive approaches to user needs, and an underdeveloped public satisfaction-based evaluation system. The study also found that service accountability remains administratively oriented and has not been fully integrated with participatory oversight mechanisms. The integration of service technology, the strengthening of an adaptive service culture, and the development of a user-experience-based evaluation system are strategic factors in realizing professional, responsive, transparent, and sustainable ferry services.
Excellent Service, A6 Concept, Ferry Port, Public Transportation, Good Governance
Copyright (c) 2026 Ferima Ferima, Maudhy Satyadharma, Muhammad Yazir Jabbar, Hado Hado, Muhamad Rajulan (Author) https://creativecommons.org/licenses/by/4.0
The Effect of the Number of Layers in a PDMS-Rice Husk Silica-Graphene Oxide Composite on Electrical Insulation Resistance Properties
This study analyzes the effect of the number of layers in PDMS–rice husk silica–graphene oxide composites on electrical insulation resistance under dry and wet conditions using a multilayer structure-based experimental approach. The composites were fabricated using the spin-coating method on glass substrates with variations ranging from 1 to 5 layers and characterized using XRD, FTIR, and SEM to evaluate the relationship between morphology, filler distribution, and the material’s electrical behavior. The results show that an increase in the number of layers causes significant changes in the interface configuration and the density of filler distribution. Under dry conditions, the insulation resistance decreased from 250 GΩ to 70 GΩ due to increased opportunities for the formation of internal conduction pathways and percolation effects between graphene oxide particles. Conversely, under wet conditions, the resistance increased from 90 GΩ to 200 GΩ because the multilayer structure formed tortuous diffusion pathways that effectively hindered water penetration and ionic transport. These characteristics indicate that the multilayer design plays a crucial role in controlling the electrical stability of polymer-based nanocomposites for high-voltage insulation applications.
PDMS, Rice Husk Silica, Graphene Oxide, Insulation Resistance, Multilayer Composite.
Copyright (c) 2026 Annisa Eka Putri, Ratnawulan Ratnawulan (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Immersion of PDMS-Rice Husk Silica-Graphene Oxide Composites on Electrical Insulation Resistance
This study analyzes the effect of varying the number of dips on the electrical insulation resistance of PDMS–rice husk silica–graphene oxide composites using a multi-step dip-coating experimental approach. The composite was synthesized using a polydimethylsiloxane matrix combined with biomass silica extracted from rice husks and graphene oxide as a multifunctional filler to enhance the material’s dielectric stability. Dipping variations were performed 1, 3, 5, and 7 times on a glass substrate, then tested using a High Voltage Insulation Tester at 10 kV under dry and wet conditions. Test results showed that the highest insulation resistance was obtained with a single immersion, at 420 GΩ under dry conditions and 100 GΩ under wet conditions. Increasing the number of immersions caused a decrease in resistance due to structural inhomogeneity, filler agglomeration, and an increase in micro-conductive pathways within the composite layer. Wet conditions accelerate the decline in insulation performance because water adsorption on the coating surface increases local conductivity. The integration of PDMS, rice husk silica, and graphene oxide demonstrates high potential as a biomass-based electrical insulator coating with stable dielectric characteristics in humid environments.
PDMS, Rice Husk Silica, Graphene Oxide, Dip-Coating, Electrical Insulation Resistance.
Copyright (c) 2026 Sarmila Yetria, Ratnawulan Ratnawulan (Author) https://creativecommons.org/licenses/by/4.0
Analysis of the Relationship Between SiO₂ Content in Volcanic Tuff Materials from Lampung at Hatta Bakauheni Using Portable XRF as a Supporting Method for Rock Magnetism in Determining Their Magnetic Properties
This study investigates the relationship between SiO₂ composition and magnetic properties of Lampung Tuff from Hatta Bekauheni using an integrated approach combining rock magnetism and portable geochemical analysis. Magnetic susceptibility measurements were conducted using a Bartington MS2B sensor at low and high frequencies to determine χlf and χfd (%), while elemental composition was analyzed using Portable X-Ray Fluorescence (Portable XRF). The results indicate that all samples exhibit ferrimagnetic behavior, reflecting the presence of magnetic minerals such as magnetite or titanomagnetite with varying concentrations and grain sizes. The χfd (%) values suggest a mixture of superparamagnetic and coarser grains, indicating heterogeneous depositional and post-depositional processes. SiO₂ content varies among samples, representing local geochemical differentiation of volcanic material. However, regression analysis shows a very weak correlation between SiO₂ and magnetic parameters, as indicated by low coefficients of determination. These findings demonstrate that magnetic properties are primarily controlled by mineralogical factors rather than silica composition. The integration of magnetic susceptibility and Portable XRF provides an efficient, non-destructive framework for comprehensive volcanic material characterization.
Lampung Tuff, Magnetic Susceptibility, Portable XRF, Ferrimagnetic Minerals, Volcanic Materials.
Copyright (c) 2026 Novia Deswira, Hamdi Rifai, Ahmad Fauzi, Harman Amir (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Nanosilica Composition on the Mechanical Properties of Microorganism-Based Hybrid Asphalt
The decline in pavement performance due to increasing traffic loads necessitates the development of advanced materials beyond conventional asphalt mixtures. This study investigates the effect of nanosilica composition on the mechanical performance of hybrid Asphalt Concrete-Wearing Course (AC-WC) modified with Escherichia coli as a biomineralization agent. The mixture was prepared using a fixed asphalt content of 6% and nanosilica variations of 0%, 3%, 5%, and 9% by asphalt weight, combined with bacterial concentration of 10³ cells/mL. Marshall testing was conducted in accordance with Bina Marga 2018 Revision 2 specifications. The results indicate that nanosilica addition leads to a gradual decrease in density from 2.472 to 2.453 g/cm³, while significantly increasing stability from 1,094 kg to 1,560 kg. Flow values ranged between 3.90 and 4.20 mm, with higher compositions exceeding specification limits. The 5% nanosilica composition demonstrated the most balanced performance across all parameters. The synergistic interaction between nanosilica and bacterial activity enhances interparticle bonding, offering a promising approach for developing durable and sustainable asphalt materials.
Nanosilica, Asphalt Hybrid, Escherichia Coli, Marshall Stability, Mechanical Performance.
Copyright (c) 2026 Muhamad Khalid Khadafi, Ratnawulan Ratnawulan, Riri Jonuarti, Syafri Syafri (Author) https://creativecommons.org/licenses/by/4.0
The Advantages and Disadvantages of Hydrogen Technology as an Environmentally Friendly Renewable Energy Source
The global energy transition necessitates the development of sustainable and low-emission energy systems, positioning hydrogen as a strategic energy carrier with significant potential. This study aims to critically evaluate the advantages and limitations of hydrogen technology as an environmentally friendly renewable energy source through a systematic qualitative synthesis approach. The findings indicate that hydrogen offers key advantages, including high energy density by mass, operational zero-emission characteristics, and flexibility in production from diverse renewable sources. However, these strengths are constrained by systemic challenges such as low energy conversion efficiency, complex and costly infrastructure for storage and distribution, and environmental impacts that depend heavily on production pathways. Lifecycle-based analysis reveals that hydrogen’s sustainability is conditional upon the use of renewable energy inputs. Furthermore, policy frameworks, green financing mechanisms, and technological innovations in materials and catalysis are essential to enhance feasibility and scalability. The study concludes that hydrogen should be positioned as a complementary component within integrated energy systems, requiring multidimensional evaluation to support effective and evidence-based energy transition strategies.
Hydrogen, Renewable Energy, Energy Efficiency, Decarbonization, Energy Systems.
Copyright (c) 2026 Bagustianto Adipati, M. Fikri Adrian, Adnan Kurniawan, Rahmat Riski, Tri Prasetia Utama (Author) https://creativecommons.org/licenses/by/4.0
The Effect of Compaction Temperature on Marshall Stability in Hydrophobic Self-Healing Hybrid Asphalt
This study examines the influence of compaction temperature on Marshall stability in hydrophobic self-healing hybrid asphalt using a quantitative laboratory experimental approach. The asphalt mixture was formulated with penetration grade 60/70 binder and standard aggregates, modified by nanosilica to enhance hydrophobic characteristics and Escherichia coli as a biological self-healing agent. Compaction temperatures of 180°C, 185°C, and 190°C were evaluated alongside a 150°C control sample without modification. The results indicate a non-linear relationship between temperature and mechanical performance, with stability increasing to an optimum condition at 185°C before declining at higher temperatures. This trend reflects improved densification and aggregate interlocking at moderate temperatures, while excessive heat reduces binder effectiveness due to softening. Volumetric parameters further demonstrate that optimal temperature conditions contribute to balanced void distribution and improved binder efficiency. Additionally, the hybrid system exhibits multi-scale interactions between nano-modification and microbial healing mechanisms, enhancing durability and resistance to environmental factors. These findings emphasize the importance of precise thermal control in optimizing both structural integrity and functional performance of advanced asphalt materials.
Marshall Stability, Compaction Temperature, Hybrid Asphalt, Nanosilica, Self-Healing.
Copyright (c) 2026 Yosef Aryawanda, Ratnawulan Ratnawulan (Author) https://creativecommons.org/licenses/by/4.0
Analysis of the Strength of the YSD-HSDY/HPPTK 200/3000 Hydraulic Bending Machine at the Tegal Manufaktur Indonesia Cooperative
This study presents an empirical analysis of the structural strength, operational performance, and reliability characteristics of a hydraulic bending machine type YSD-HSDY/HPPTK 200/3000 under real industrial conditions at Koperasi Tegal Manufaktur Indonesia. The research integrates field observation, direct measurement, and mechanical modeling to evaluate force distribution, deformation behavior, and system response during bending operations. Experimental data were collected through variations in material thickness, bending angles, and hydraulic pressure to examine their influence on machine capacity and output consistency. The results indicate that the machine demonstrates stable force generation within its operational threshold, although deviations emerge under increased loading intensity and frequency. Analytical findings reveal that stress concentration occurs at critical structural points, contributing to gradual performance degradation and reduced precision. Reliability assessment further shows that repeated operational cycles significantly affect hydraulic stability and component wear, leading to increased deviation in bending accuracy. The integration of empirical and analytical approaches provides a comprehensive understanding of machine behavior, offering a robust basis for performance optimization, predictive maintenance, and enhanced operational safety in industrial bending applications.
Hydraulic Bending Machine, Mechanical Strength Analysis, Operational Reliability, Stress Distribution, Industrial Performance.
Copyright (c) 2026 Ikhtamul Fajri, M.Fajar Sidik (Author) https://creativecommons.org/licenses/by/4.0
The Effect of the Sun’s Declination and Right Ascension (RA) on Extreme Temperatures in West Sumatra from 2020 to 2024
This study investigates the influence of solar declination and right ascension on extreme temperature variability in West Sumatra during the 2020–2024 period using a quantitative empirical framework. Monthly climatological observations were integrated with astronomical parameters calculated through high-precision algorithms to construct a harmonically structured time series dataset. The results reveal that solar declination primarily governs the amplitude of seasonal temperature variation, while right ascension regulates temporal synchronization, producing observable phase shifts between astronomical forcing and atmospheric response. Harmonic analysis demonstrates that these relationships extend beyond linear correlations by capturing periodic patterns characterized by amplitude and phase metrics. Furthermore, residual components indicate the presence of external modulators, particularly sea surface temperature anomalies and large-scale climate variability, which alter the magnitude and timing of extreme temperature events. The combined analytical approach confirms that tropical atmospheric dynamics are shaped by interactions between deterministic astronomical cycles and stochastic environmental influences, offering a more robust basis for predictive climatological modeling and advancing the understanding of solar–atmosphere coupling in equatorial regions.
Solar Declination, Right Ascension, Extreme Temperature, Harmonic Analysis, Tropical Climate Dynamics.
Copyright (c) 2026 Aditya Zein Oktavianto, Letmi Dwiridal, Harman Amir, Hidayati Hidayati (Author) https://creativecommons.org/licenses/by/4.0
MFA-LCC Integration for the Development of SOPs for the Utilization of Arabica Coffee Pulping Solid Waste at Kopi Wanoja Kamojang, Bandung Regency
Solid waste management inefficiencies in the coffee processing operations at Kopi Wanoja have generated environmental burdens and operational cost inefficiencies. This study specifically aims to map material flows through Material Flow Analysis (MFA), calculate life cycle costs using Life Cycle Costing (LCC), identify hotspots of material and cost inefficiencies, and formulate a Standard Operating Procedure (SOP) for solid waste management. The research employed a quantitative descriptive approach with mass balance modeling conducted using STAN 2.7 software, complemented by financial analysis based on the parameters of Net Present Value (NPV), Benefit–Cost Ratio (BCR), and Payback Period (PBP). MFA results identified the pulping stage as the primary hotspot, generating coffee cherry skin waste of 40.63 kg per batch, equivalent to 53.44% of total input. From a financial perspective, LCC analysis indicated that the investment is feasible, yielding an NPV of Rp109,839,471, a BCR of 1.015, and a payback period in the seventh year. In conclusion, the integration of MFA and LCC proved effective in synchronously detecting hidden costs and material inefficiencies compared to conventional cost accounting approaches. These findings provide a scientific basis for developing an SOP aimed at stabilizing green bean yield at approximately ±41.4% while converting disposal costs into revenue through by-product utilization. It is therefore recommended that the company promptly implement the proposed SOP to maintain both economic and environmental sustainability.
Hidden Costs, Hotspot, Life Cycle Costing, Material Flow Analysis, Mass Balance.
Copyright (c) 2026 Muhammad Fadlin Zhafrana, Indra Firmansyah (Author) https://creativecommons.org/licenses/by/4.0
GIS-Based Landslide Vulnerability Mapping: Implementation of Minister of Public Works Regulation No. 22/PRT/M/2007 in Central Bengkulu Regency
This study develops a GIS-based landslide susceptibility mapping framework by operationalizing the weighting scheme prescribed in Indonesian Public Works Regulation No. 22/PRT/M/2007 within Bengkulu Tengah Regency. Seven physical parameters slope gradient, soil condition, lithology, rainfall intensity, slope hydrology, seismicity, and vegetation were standardized, scored, and integrated through weighted spatial overlay to produce a composite susceptibility index. Results reveal a regional dominance of low susceptibility, indicating systemic equilibrium among controlling parameters, while localized moderate to high zones reflect critical parameter interactions. Seismic influence functions primarily as a triggering modifier rather than a dominant determinant, whereas vegetation structure contributes mechanically to slope cohesion and hydrological regulation. The integrated model demonstrates methodological robustness by linking empirical spatial evidence with theoretical slope stability principles, ensuring analytical consistency and replicability. Conceptually, the framework advances landslide assessment from descriptive mapping toward predictive spatial evaluation. The findings support risk-informed land management strategies and highlight the utility of regulation-based multi-criteria GIS modeling as a scalable approach for hazard mitigation planning in geomorphologically dynamic regions.
Landslide Susceptibility, GIS Modeling, Spatial Weighting, Slope Stability, Risk Mapping.
Copyright (c) 2026 Muhammad Latif (Author) https://creativecommons.org/licenses/by/4.0
Optimizing Risk-Based Infrastructure Management in Flood Disaster Reduction in Urban Areas
Urban flooding represents a systemic risk emerging from the interaction between hydrological hazards, spatial transformation, and infrastructure vulnerability, demanding a management paradigm that transcends conventional engineering responses. This study develops a non-empirical conceptual framework for optimizing risk-based infrastructure management to strengthen urban flood resilience. The framework integrates infrastructure asset lifecycle management, disaster risk theory, and urban governance into a multilayer analytical model that explains causal relations among planning, implementation, maintenance, and adaptive capacity. A systematic literature synthesis and thematic-critical analysis were employed to construct stable conceptual propositions and evaluate internal coherence across disciplines. Findings indicate that preventive planning, adaptive asset management, institutional coordination, and participatory monitoring operate as interdependent mechanisms that reduce system fragility and enhance operational learning. The proposed model provides an analytical structure for evaluating infrastructure effectiveness without dependence on a single empirical context while preserving methodological rigor. This study contributes theoretically by linking risk governance with lifecycle infrastructure management and methodologically by offering a replicable conceptual synthesis for resilient urban systems.
Infrastructure Management, Flood Risk, Urban Resilience, Asset Lifecycle, Adaptive Governance.
Copyright (c) 2026 Buyung Mantap, Yoka Mahendra, Hendret Susanto (Author) https://creativecommons.org/licenses/by/4.0
Identification and Analysis of Toll Road Project Implementation Risks Based on Severity Index: A Case Study of the Prabumulih–Muara Enim Toll Road
This study investigates dominant risks affecting time and cost performance in the Prabumulih–Muara Enim Toll Road Project (Zone 5) within the Trans Sumatra Toll Road corridor. The research adopts an empirical quantitative approach using a two-stage questionnaire and semi-structured interviews involving 24 key project stakeholders selected through purposive sampling. Risk variables were initially compiled from literature, project documents, and preliminary site observations, then validated through a Guttman-scale screening process to ensure contextual relevance. The validated risks were subsequently assessed using the Severity Index (SI) to quantify perceived probability and impact levels, and further mapped into a Probability–Impact Matrix to classify risk criticality and prioritize mitigation. The findings demonstrate that dominant risks emerge not only from technical construction factors but also from managerial coordination, procurement delays, logistical constraints, and safety and quality compliance, which collectively intensify schedule slippage and cost escalation. Methodologically, the integrated SI–PIM framework strengthens risk prioritization by combining structured screening, quantitative severity measurement, and decision-oriented mapping, offering a replicable model for toll road risk governance in large-scale infrastructure projects.
Severity Index, Toll Road Project, Risk Analysis, Probability–Impact Matrix, Time and Cost Performance.
Copyright (c) 2026 Kodrat Insany Taqwim, Firdaus Firdaus, Farlyn Rosyad (Author) https://creativecommons.org/licenses/by/4.0
The Economic Value Contribution of Cinnamon as a Non-Timber Forest Product in Gayo Lues District
Cinnamon as a non-timber forest product plays a significant economic role in supporting rural livelihoods in Gayo Lues Regency, Aceh Province. This study analyzes the economic value contribution of cinnamon cultivated and utilized by communities in several villages of Kutapanjang District. The primary product utilized is cinnamon bark, while the stem is not commercially traded and is instead used as household fuelwood. The findings indicate that the average annual income derived from cinnamon bark reaches Rp26,557,283 per household, contributing 71% to total household income. In comparison, secondary livelihood activities contribute Rp2,213,106 or 29%. These results demonstrate that cinnamon functions as the dominant income source within the local agroforestry system. The aggregate economic structure reflects relatively stable returns, indicating resilience against short-term market fluctuations. The integration of household-based forest resource management and local economic activities highlights cinnamon’s strategic role in strengthening village economies. Therefore, cinnamon as a non-timber forest product represents a sustainable economic driver that supports rural development and forest-based livelihood systems in Gayo Lues Regency.
Cinnamon, Non-Timber Forest Product, Economic Contribution, Rural Livelihood, Agroforestry.
Copyright (c) 2025 Andi Fauzan R Pohan, Nurhasanah Hasbi, Anshari Anshari, Astri Winda Siregar (Author) https://creativecommons.org/licenses/by/4.0
Designing a Digital Donation Website Information System to Support Transparency and Public Reporting at the Indonesian Red Cross in Tangerang City
This study designs and implements a web-based digital donation information system to strengthen transparency and public reporting for PMI Kota Tangerang. The system was developed through an empirical software engineering approach grounded in direct organizational observation, enabling the requirements to reflect real donation management practices, administrative constraints, and public accountability needs. The proposed platform integrates public information dissemination, online donation workflows, automated transaction recording, and reporting features within a unified architecture. The public-facing interface enhances accessibility to organizational updates and donation programs, supporting donors’ trust formation through consistent institutional identity and clear information structure. On the operational side, an administrative dashboard provides centralized control over donation data, transaction status management, and structured records to support timely and verifiable reporting. Functional validation was conducted using black-box testing to ensure that core modules operate correctly across defined user scenarios, including donation submission, data storage, report generation, and role-based access. The results indicate that the system is technically feasible and organizationally relevant, offering a scalable digital mechanism to reduce reporting inconsistencies and improve public confidence in humanitarian fundraising.
Digital Donation, Transparency, Public Reporting, Web-Based Information System, PMI Kota Tangerang.
Copyright (c) 2025 Arif Marjuki, Haryanto Haryanto , Dedy Iskandar, Andri Cahyo Purnomo, Arif Novrizal (Author) https://creativecommons.org/licenses/by/4.0
Implementation of Business Intelligence in Supporting Decision-Making for Population and Family Planning Programs: A Qualitative Study at the Population Control and Family Planning Office of Sorong City
This study examines the implementation of Business Intelligence (BI) in supporting decision-making for population and family planning programs at the Population Control and Family Planning Office of Sorong City. Using an empirical qualitative approach, the research explores how BI systems are utilized, how analytical outputs inform managerial decisions, and which organizational factors shape their effectiveness. Data were collected through in-depth interviews, observations, and document analysis involving policymakers, program managers, data analysts, and technical staff. The findings reveal that BI facilitates data integration across program units, enhances the timeliness and relevance of information, and supports evidence-based planning, monitoring, and evaluation. Dashboards and analytical reports enable decision-makers to identify demographic trends, assess program performance, and adjust interventions responsively. However, the effectiveness of BI is contingent upon data governance, human resource capacity, and institutional commitment to data-driven practices. The study highlights BI as a technological and managerial innovation that strengthens decision quality and institutional resilience in local public sector governance, particularly in population and family planning services..
Business Intelligence, Decision-Making, Population Program, Family Planning, Public Sector, Qualitative Study.
Copyright (c) 2025 Ulil Albab Al Jawad (Author) https://creativecommons.org/licenses/by/4.0
Seismic Vulnerability Index in Pantai Cermin District Using Microtremor Data
This study assesses seismic vulnerability in Pantai Cermin District, West Sumatra, using microtremor measurements analyzed through the Horizontal to Vertical Spectral Ratio (HVSR) method. Ambient vibration data were systematically acquired to characterize local site effects by deriving dominant frequency (f₀) and amplification factor (A₀), which reflect the dynamic behavior of near-surface soil layers. These parameters were integrated to compute the seismic vulnerability index (Kg) as an indicator of potential soil deformation under seismic loading. The results reveal pronounced spatial variability in f₀, A₀, and Kg values, strongly controlled by geological conditions. Areas dominated by young alluvial deposits and unconsolidated sediments exhibit low dominant frequencies, high amplification, and elevated Kg values, indicating high susceptibility to seismic ground motion amplification. Conversely, zones underlain by compact volcanic and intrusive rocks show more stable seismic responses. The spatial correspondence between high Kg zones and densely populated areas highlights increased seismic risk due to the interaction between site effects and exposure. The consistency between HVSR characteristics, geological framework, and vulnerability patterns demonstrates the robustness of the microtremor-based approach for seismic microzonation. This study provides a scientific basis for risk-informed land-use planning and earthquake mitigation strategies in seismically active regions.
Seismic Vulnerability Index, HVSR, Microtremor, Site Effect, Microzonation
Copyright (c) 2025 Agustia Agustia, Akmam Akmam (Author) https://creativecommons.org/licenses/by/4.0
Preliminary Study on the Application of Sustainable Construction Management Principles in Regional Infrastructure Projects
This study examines the initial patterns of sustainable construction management implementation in regional infrastructure projects through a qualitative structured literature review. The analysis positions construction management as a strategic nexus linking environmental, economic, and social dimensions within public infrastructure development. The findings reveal that current practices remain largely dominated by conventional management paradigms emphasizing short-term cost efficiency and project completion, while sustainability principles are often reduced to administrative compliance. Environmental considerations are primarily treated as regulatory obligations, economic aspects focus on initial construction costs, and social dimensions are limited to operational safety measures. Institutional capacity constraints, limited human resource competencies, and procurement mechanisms oriented toward lowest-price selection emerge as major barriers to holistic sustainability integration. Although regulatory pressures and technological advancements provide potential enabling conditions, their effectiveness is constrained by fragmented governance structures and weak organizational learning mechanisms. This study contributes conceptually by offering an integrative framework that clarifies the structural gaps between sustainability discourse and managerial practice in regional infrastructure projects.
Sustainable Construction Management, Regional Infrastructure, Public Projects, Governance Capacity, Sustainability Integration.
Copyright (c) 2025 M. Wisridani Paradiang (Author) https://creativecommons.org/licenses/by/4.0
Risk Analysis and Hazard Control in Online Leak Sealing (OLS) Work at PT PLN Nusantara Power Up Rembang Using the JSA Method
Online leak sealing (OLS) operations in power generation facilities are characterized by a high level of complexity and risk, as they are conducted on pressurized and high-temperature systems without shutting down the operating unit. Such conditions necessitate a systematic and context-sensitive risk analysis approach to effectively minimize the potential for occupational accidents. This study aims to analyze risks and hazard control in OLS activities at PT PLN Nusantara Power UP Rembang using the Job Safety Analysis (JSA) method. The research adopts an empirical design comprising a preliminary survey, direct field observations, worker-focused discussions, and a review of operational procedure documents. Each stage of the OLS process is decomposed into micro-level activities, followed by the identification of potential hazards, associated probabilities, and consequences to construct a comprehensive JSA matrix. The findings indicate that the sealing compound injection and leak testing stages exhibit the highest concentration of risk, predominantly associated with exposure to pressurized fluids, hazardous chemicals, and potential equipment failure. The contextualized application of JSA provides a more granular depiction of risk profiles and serves as a foundation for formulating hierarchical control measures, thereby contributing to the strengthening of occupational health and safety management in high-risk online maintenance activities.
Hazard Control, Job Safety Analysis, Occupational Safety, Online Leak Sealing, Work Risk.
Copyright (c) 2025 Odik Duwi Saputro, Imam Hermanto (Author) https://creativecommons.org/licenses/by/4.0