Indonesian Journal of Innovation and Applied Sciences (IJIAS)

Life of mine pit design optimization in anticline coal deposits based on break- even stripping ratio and slope stability analysis

Thu, 18 Jun 2026 00:00:00 +0700

This study investigates how geological structure, economic limits, and slope stability can be integrated to optimize a Life of Mine (LoM) pit design in an anticline coal deposit. The objective is to determine an economically viable and technically safe pit design by evaluating pit shell alternatives using the Break-Even Stripping Ratio (BESR) and slope stability considerations. The study utilized secondary technical data from an existing mining project, including geological models, pit shell optimization results, mining cost parameters, geotechnical evaluations, mining constraints, and reserve estimates. No additional field investigation, numerical modeling, or recalculation of pit optimization and slope stability was performed. The anticline structure significantly influences seam geometry, overburden distribution, and stripping ratio characteristics. Pit shell evaluation was conducted using a BESR threshold of 5.8 bcm/ton. Among the evaluated alternatives, pit shell 4 was selected as the optimum design, generating approximately 61.51 million bcm of waste and 17.16 million tons of mineable coal, with an incremental stripping ratio of 5.04 and an accumulated stripping ratio of 3.58. Slope stability assessment indicated that several pit wall sections required geometry adjustments to meet safety requirements. The optimized LoM pit design resulted in a mineable coal reserve of 16.12 million tons. The findings demonstrate that integrating geological structure, BESR analysis, slope stability, and mining constraints is essential for producing a pit design that maximizes coal recovery while maintaining economic feasibility and operational safety in structurally complex coal deposits.

Effect of pouring temperature on fluidity, porosity, density, and microstructure of Al-Si alloy in gravity die casting

Sudarsono, Amir Arifin, Hidayat, La Ode Ahmad Barata, Aminur, Alain Kusmoko — Tue, 30 Jun 2026 00:00:00 +0700

The growing demand for lightweight aluminium components necessitates improved quality control in casting, particularly for aluminium–silicon (Al–Si) alloys produced via gravity die casting. This study systematically investigates the effect of pouring temperature on the fluidity, porosity, density, and microstructure of an Al–Si alloy using a gravity iron die mold with varying section thicknesses. Casting experiments were conducted at pouring temperatures of 600°C, 650°C, and 700°C to simulate thin-wall casting conditions. Fluidity was evaluated by measuring flow length, while density and porosity were determined using Archimedes’ principle. Microstructural evolution was characterized via optical microscopy. The results demonstrate that increasing the pouring temperature significantly enhances fluidity, enabling the complete filling of progressively thinner sections. However, higher temperatures also lead to increased porosity and reduced density, particularly in thicker sections, due to prolonged solidification times and reduced cooling rates. Microstructural analysis reveals that higher pouring temperatures and larger section thicknesses promote coarser α-Al dendrites, larger β-Si particles, and increased intermetallic phase aggregation; conversely, lower pouring temperatures and thinner sections result in finer, more homogeneous microstructures. These findings highlight the critical trade-off between mold-filling capability and internal casting quality, emphasizing the importance of optimizing pouring temperature in the gravity die casting of Al–Si alloys.

Techno-economic analysis of hybrid photovoltaic and stirling engine generator for offshore oil and gas platform

Superman Misdi, Jaka Windarta, Mohamad Said Kartono Tony Suryo Utomo — Tue, 30 Jun 2026 00:00:00 +0700

The increasing demand for sustainable offshore oil and gas operations has driven the exploration of efficient and environmentally friendly hybrid energy systems. Conventional fossil fuel-based systems' consumption significantly contributes to greenhouse gas emissions and creates a need for innovative solutions that address environmental challenges while maintaining operational effectiveness. This study aims to analyse and evaluate a hybrid energy system that combines Stirling Engine Generator (SEG) technology and Photovoltaic (PV) panels, with the primary goal of enhancing energy efficiency, reducing carbon emissions, and improving the sustainability of offshore oil and gas operations. A comprehensive approach, integrating manual calculations and PVsyst software simulations, was used to analyse the performance of the Stirling and PV hybrid system. The research findings indicate that the hybrid system significantly improves energy efficiency and carbon emissions reduction compared to a fossil fuel-based system, with SEG utilizing heat from natural gas combustion and PV panels capturing solar energy, creating a synergistic effect with better overall performance and a lower environmental impact. Economically, the hybrid system minimizes fuel dependency and maintenance costs, benefiting from PV panels’ lower operational expenses compared to a fuel-based system. This combination not only aids emission reduction efforts but also presents a cost-effective solution over time, with the system’s ability to harness renewable energy and support compliance with emission reduction regulations. In conclusion, integrating SEG and PV technologies in a hybrid system offers a practical pathway to achieving emission reduction targets and maintaining operational efficiency, marking a step toward environmentally and economically sustainable practices in offshore oil and gas operations.

Assessment of public intention in polyethylene terephthalate (PET) plastic bottle waste sorting in Yogyakarta using the theory of planned behavior with a deposit refund system scheme

Andika Dwi Saputra, Sri Hartini, Ratna Purwaningsih — Tue, 30 Jun 2026 00:00:00 +0700

The increasing amount of plastic waste in urban areas has become one of the major environmental challenges in Indonesia, including in Yogyakarta City. This study aims to analyze the factors influencing public intention to participate in the Deposit Return System (DRS) for Polyethylene Terephthalate (PET) bottle waste management using an extended Theory of Planned Behavior (TPB) framework. The study integrates additional variables, including environmental awareness, public information, religious or moral norms, economic consequences, convenience, social factors, technology, and institutional support. A quantitative explanatory approach was employed through the distribution of online questionnaires to 200 respondents in Yogyakarta City. Data were analyzed using Structural Equation Modeling based on Partial Least Squares (SEM-PLS). The results indicate that attitude, subjective norm, and perceived behavioral control positively and significantly influence intention to participate in the DRS program. Subjective norm was identified as the most dominant factor influencing intention. Environmental awareness significantly influenced attitude, while public information significantly influenced subjective norm and perceived behavioral control. Convenience and economic consequence also positively affected perceived behavioral control. However, religious or moral norms, technology, and institutional support did not show significant effects on several TPB constructs. The findings indicate that social influence, system convenience, and economic incentives are the main factors encouraging public participation in PET bottle recycling through the DRS program. This study contributes to the development of the Theory of Planned Behavior in the context of sustainable waste management and provides practical recommendations for policymakers in designing effective recycling programs.

SIKAVALTA: A responsive webGIS-based calculator for prescriptive economic valuation of agricultural land losses caused by pests and hydrometeorological disasters in East Luwu

Tue, 30 Jun 2026 00:00:00 +0700

East Luwu Regency is a strategic food-producing area that increasingly faces a double exposure to crop-pest infestations and hydrometeorological disasters such as flooding. Until now, the assessment of post-disaster economic losses in the region has leaned on manual recapitulation, a method that is slow, prone to human error, and unable to capture the spatial variability between land parcels. The resulting delay holds up the disbursement of government relief and rice-farming insurance claims, which weakens the capital resilience of smallholders. This study develops SIKAVALTA, a responsive web-based geographic information system that converts physical crop damage from biotic and abiotic hazards into a monetary value expressed in Rupiah. The system was built through a Research and Development approach using the JITU method, namely Data Netting, Formula Interpretation, Web Technology, and Validity Testing. The prototype integrates on-map land digitization, automatic geodesic area computation, a deterministic valuation engine for rice and oil-palm commodities, and report export in document and spreadsheet formats. Black-Box testing confirmed that every feature operated as intended, and the user-acceptance evaluation cleared the minimum feasibility threshold. SIKAVALTA therefore shows a prescriptive spatial valuation capability that sets it apart from conventional descriptive mapping systems.

Entrepreneurial development initiatives on business sustainability in small and medium enterprises (SMEs) in South West Nigeria

Opeyemi Jumoke Zubair, Ayotunde Isaac Bankefa, Bayo Abraham Ogunyanju — Tue, 30 Jun 2026 00:00:00 +0700

The study addresses the ongoing sustainability issues faced by agricultural SMEs in Southwest Nigeria, despite many entrepreneurial development initiatives focused on innovation, technology adoption, and governmental assistance. This study explicitly analyses the impact of innovation and technology adoption on the sustainability of agricultural SMEs and assesses the role of government policies and support measures in bolstering their resilience against the region's changing economic landscape. The research employs a quantitative survey design with a study population of 385. Data were collected from agricultural SME operators using structured questionnaires, and the gathered data were analysed using descriptive and inferential statistics. The findings revealed that, despite the perceived insufficiency of government support being relatively low, innovation and technology adoption, combined with government support and policies, exert a statistically significant collective influence on the sustainability of agricultural SMEs, accounting for a considerable portion of the variance in sustainability outcomes. This indicates that, while agricultural entrepreneurs are aggressively using technology and new techniques to enhance performance, the advantages are limited by inconsistent, inadequate, or poorly executed support mechanisms. The study recommends that improving the long-term sustainability of agricultural SMEs in Southwest Nigeria necessitates not only the dissemination of innovation and digital tools but also a purposeful redesign of government policies and programs to ensure they are more stable, accessible, and responsive to the distinct needs of agricultural enterprises.

Advancing green skills in Indonesian Higher Education: roles, barriers, and transformative strategies

Carolus Borromeus Mulyatno, Rian Antony — Tue, 30 Jun 2026 00:00:00 +0700

This article aims to provide a critical analysis of green skills development in higher education institutions (HEIs) in Indonesia. This critical analysis is conducted because HEIs are still experiencing obstacles in developing students' green skills. It is important to recognize that developing students' green skills is an indispensable prerequisite for obtaining new qualifications that are crucial in this era. The purpose of this article is to comprehensively examine the roles, challenges, and strategies of HEIs in Indonesia in developing students' green skills. This study uses a qualitative research methodology, focusing on exploring the perspectives of seven informants through in-depth interviews. The informants were selected through non-probability sampling, a method carefully applied to ensure the collection of high-quality information relevant to the research objectives. The study's findings indicate that HEIs play a crucial role in developing students' green skills through curriculum transformation, contextual learning, and collaboration with the workplace. Furthermore, these findings also contribute to the growing literature on green skills in higher education and offer practical recommendations for strengthening sustainability-oriented policies and practices in Indonesian universities. However, challenges such as limited educator capacity, lack of technical guidance, and lack of collaboration with the workplace persist.

Challenges and opportunities in managerial agility-based moderation at the Religious Education and Training Center, Makassar

Hanafi Pelu, Amir Imbaruddin, Wahyu Nurdiansyah N, Andi Rasdiyanti — Tue, 30 Jun 2026 00:00:00 +0700

This research aims to investigate the challenges and opportunities inherent in implementing managerial agility-based moderation at the Makassar Religious Education and Training Center. As public sector organizations navigate increasingly complex and dynamic environments, the integration of agile methodologies within traditional bureaucratic structures has become a critical focal point for administrative reform. The primary objective of this study is to identify the specific factors that hinder or facilitate the adoption of managerial agility in promoting religious moderation and institutional effectiveness. Employing a qualitative research approach, the study utilizes an ethnographic design to gain in-depth insights into the organizational culture and individual experiences of key institutional actors. Data were collected through semi-structured interviews with diverse informants, supplemented by document reviews and participant observations to ensure comprehensive triangulation. The findings reveal that the primary challenges are rooted in psychological resistance, deeply ingrained rigid mindsets, and the heterogeneity of participants' prior understanding of agile concepts. Conversely, the implementation offers significant opportunities for enhancing strategic decision-making, fostering collaborative networks, and creating a more responsive organizational ecosystem. Ultimately, this research underscores that while the transition is energy-intensive and requires a paradigm shift, managerial agility serves as a vital competency for sustaining innovation and service quality within the Ministry of Religious Affairs. These results provide a practical roadmap for institutional leaders to balance modern administrative efficiency with established ethical and religious foundations.

Social media-based advocacy in social work practice for domestic violence survivors: a mixed-methods study

Tue, 30 Jun 2026 00:00:00 +0700

This study examines the role of social media in the digital advocacy practices of social workers at the Office of Women's Empowerment and Child Protection (DP3A) of Kendari City in handling domestic violence (DV) cases. Employing a sequential explanatory mixed-methods design, the study integrated content analysis and engagement metrics of the DP3A's official social media accounts on Instagram, Threads, and Facebook (Quantitative Phase) with semi-structured in-depth interviews with social workers, social media administrators, and DV survivors (Qualitative Phase). A total of 73 posts were analyzed. Findings reveal that institutional activity content dominates (42.5%), while service-oriented content, including reporting procedures, contact information, and confidentiality assurances, remains markedly limited. Advocacy and campaign content generated the highest average engagement (10.0 per post), indicating audience responsiveness to social messaging. Qualitative findings indicate that survivors prefer private communication channels due to fear and stigma, suggesting that low public engagement does not equate to content ineffectiveness. A digital advocacy process model encompassing four phases, digital information exposure, initial contact, preliminary assessment, and formal service referral, is proposed. The study recommends strengthening survivor-centered content strategies, developing digital response protocols, and fostering cross-sector collaboration to optimize social media as an advocacy instrument for domestic violence services.

The GPS for thinking: How AI partners are reshaping student metacognition

Sayed Mahbub Hasan Amiri, Naznin Akter, Marzana Mithila, Md. Mainul Islam — Tue, 30 Jun 2026 00:00:00 +0700

Generative artificial intelligence is rapidly becoming a cognitive partner in education, capable of planning tasks, monitoring progress, and evaluating solutions on a learner’s behalf. This conceptual synthesis paper examines the risk that such AI tools, while improving immediate performance, may erode students’ metacognitive abilities in their capacity to plan, monitor, and evaluate their own thinking. Drawing a parallel with GPS navigation research, where habitual turn-by- turn guidance has been shown to impair spatial memory and hippocampal engagement, we introduce the metaphor of AI as a “GPS for thinking". Through an integrative review of literature spanning cognitive psychology, neuroscience, and the learning sciences, we synthesize evidence that AI-assisted learning can lead to a form of cognitive disuse atrophy, specifically by short-circuiting the metacognitive loop. Emerging studies reveal that students who rely heavily on AI tutors often perform worse when the tool is removed, suffer from an illusion of explanatory depth, and struggle to articulate the reasoning behind their answers. To counter these effects, we propose a shift from a GPS model where the tool issues commands to a compass model, where the tool provides orientation while preserving learner agency. Five evidence-informed design principles are advanced: prompting planning before assistance, delaying and fading feedback, embedding mandatory reflection pauses, making AI reasoning visible, and calibrating learners’ confidence. The article argues that the long-term goal of educational AI must be to strengthen, not supplant, the student’s inner compass.

The proliferation of electronic public participation and the perpetual digital inequalities in South African regions

John Mamokhere — Tue, 30 Jun 2026 00:00:00 +0700

The Fourth Industrial Revolution (4IR) has accelerated digital transformation, creating opportunities for governments to enhance efficiency, transparency, accountability, public participation, and service delivery through digital technologies. In South Africa, electronic public participation (e-participation) has emerged as a strategic mechanism for strengthening public participation in municipal governance and the Integrated Development Planning (IDP) process. However, persistent digital inequalities continue to undermine these opportunities, particularly in rural municipalities across Limpopo, the Eastern Cape, and KwaZulu-Natal. This study investigates the structural and socio-economic factors perpetuating digital inequalities and their implications for inclusive e-participation in rural South African regions. A qualitative research approach was adopted, using thematic content analysis to examine evidence from appropriate municipalities. The findings reveal that municipalities such as Mkatazo Village, Mbhashe, Amathole, OR Tambo, Vhembe, and uMkhanyakude continue to experience inadequate broadband infrastructure, unreliable electricity supply, outdated digital systems, high data costs, limited access to digital devices, low digital literacy, language barriers, weak institutional capacity, limited political support, and constrained financial resources. Gender and age disparities further exacerbate digital exclusion. The study concludes that e-participation cannot realise its transformative potential without addressing these structural barriers. It recommends sustained investment in digital infrastructure, affordable connectivity, community-based digital literacy programmes, inclusive and localised e-participation models, strengthened institutional capacity, and stronger political commitment to embed e-governance reforms within municipal operations, thereby promoting equitable, inclusive, and sustainable digital governance in the 4IR era.

Design a model strategy for regulations on the use of tobacco biopesticide as a substitute for hazardous pesticides

Irma Idris, Eka Setiawan, Maskun — Tue, 30 Jun 2026 00:00:00 +0700

Food security constitutes a pillar of national stability according to Law No. 18/2012, yet agricultural productivity is frequently threatened by pests. Chemical pesticides classified as Hazardous and Toxic Materials (B3) are effective but pose risks to health and the environment, induce pest resistance, and impose management burdens as stipulated in Government Regulation No. 22/2021. Tobacco possesses potential for utilization as a biopesticide due to the insecticidal properties of nicotine and its non-B3 classification. Through an empirical research approach integrating legal, agricultural, and environmental analyses, this study employed observation, interviews, regulatory analysis, literature review, and field effectiveness trials. The findings demonstrate that chemical pesticides require stringent management, which is frequently neglected; tobacco biopesticide is recognized under Minister of Agriculture Regulation No. 43/2019 and exhibits regulatory advantages; field trials reduced pest populations by up to 60% within four weeks after planting; implementation remains constrained by technological and research limitations. The utilization of tobacco biopesticide has the potential to reduce costs, mitigate B3 hazards, and support sustainable food security while empowering local farmers through principles of economic circularity, technological self-reliance, income diversification, ecosystem protection, and community empowerment aligned with food sovereignty.

Design, synthesis, and molecular docking of novel pyrimidine-hydrazone hybrids bearing sugar moieties as potential antioxidant agents

Haider M. Hassan, Mohammed Abbas Al-Silaykhee, Buraq Safaa Alasadi — Tue, 30 Jun 2026 00:00:00 +0700

A novel series of 5-bromo-2-(methylthio)pyrimidine-4-carboxylic acid derivatives conjugated with monosaccharides was synthesized and evaluated in vitro for their antimicrobial and antioxidant activities. Initially, the core scaffold, 4 5-bromo-2-(methylthio)pyrimidine-4-carboxylic acid, was prepared in a single step via the condensation of 5-bromo-2-(methylthio)pyrimidine-4-carboxylic acid with hydrazine hydrate. Subsequently, the resulting hydrazide derivative was successfully condensed with various monosaccharides under Schiff base reaction conditions. Biologically, the total antioxidant capacity of the synthesized compounds was evaluated using the phosphomolybdate assay. The obtained results revealed encouraging antioxidant profiles for several derivatives, demonstrating potent EC50 values comparable to the standard reference, ascorbic acid.