Publication Search

Indonesia, as the world's largest archipelagic nation, holds a strategic position while simultaneously facing significant challenges in maintaining the sovereignty and security of its maritime territory. Increasingly complex maritime threats, such as illegal fishing, smuggling, and potential geopolitical conflicts, demand a transformation in maritime defense strategies to be more efficient and sustainable. In an era of increasing global awareness of the climate crisis, the maritime sector, including the defense sector, is being encouraged to decarbonize through the implementation of environmentally friendly ship technology. This research uses a literature review approach by examining various findings related to sustainable propulsion technology innovations relevant to the development of Indonesia's maritime defense fleet. The study results show that a hydrogen- and battery-based hybrid propulsion system can reduce carbon emissions by up to 73% and increase energy efficiency by 35%. In addition, wind-assisted propulsion sistem (WAPS) technology such as Flettner rotors and wing-sails contributes significantly to reducing fuel consumption by up to 30%, while extending ship cruising range without the need for intensive refueling. Meanwhile, the application of Computational Fluid Dynamics (CFD)-based propeller design optimization has been proven to reduce energy consumption by 13.2% and reduce noise levels by up to 15 dB, which greatly supports the needs of stealth operations in military missions. This study concludes that the implementation of environmentally friendly ship technology not only provides benefits in terms of energy efficiency and emission reduction, but also strengthens the operational resilience and strategic competitiveness of the Indonesian naval fleet amidst the dynamics of global maritime security. Thus, the Green Navy concept can be seen as a relevant and urgently needed sustainable defense strategy.

This study aims to analyze hazard identification in order to improve operational safety aspects in the service road area of I Gusti Ngurah Rai International Airport, Bali. This area is a vital part of the airside that has a high level of activity and complex safety risks, thus requiring special attention to potential hazards that may arise. The research method used is a qualitative descriptive approach, with data collection techniques through direct observation in the field, in-depth interviews with related personnel, and documentation studies relevant to the airport's safety system and operational procedures. The results of the study indicate that there are still significant potential safety risks in the service road area. Some key findings include haphazard parking practices by Ground Support Equipment (GSE), undisciplined behavior of ground handling personnel, and passenger movement in the operational area without adequate officer supervision. These problems are largely caused by weak supervision from the Apron Movement Control (AMC) unit, as well as the low level of understanding and implementation of safety culture among field workers. Through the process of identifying and assessing risks using the Hazard Identification and Risk Assessment (HIRA) approach, researchers succeeded in mapping the severity of risks and developing appropriate mitigation measures, such as regulating GSE parking procedures, improving safety training, and adding supervisory personnel at vulnerable points. It is hoped that the findings of this study can be a basis for consideration for the management of I Gusti Ngurah Rai International Airport, Bali, in formulating policies and strategies for improving operational safety as a whole, especially in implementing a more effective and sustainable Safety Management Sistem (SMS).

Turnover intention is the tendency or intention of individuals to leave the organization for various reasons, one of which is the desire to get a better job. This study aims to examine the effect of overtime working hours and leader member exchange on turnover intention of finishing department employees of PT Ungaran Sari Garments. The sample taken was 144 finishing department employees. The sampling technique used the slovin formula with data analysis techniques, namely multiple linear regression using the SPSS 25 program. The results obtained that overtime working hours have a positive and significant effect on turnover intention, while lmx has a negative and significant effect on turnover intention. overtime working hours and leader member exchange have a simultaneous or joint effect on the dependent variable, namely turnover intention of pt usg finishing department employees.

Indonesia faces significant challenges in maintaining environmental ethics amid rapid economic growth and urbanization. Environmental degradation, such as deforestation, water pollution, and poor waste management, reflects a widespread lack of ecological awareness. However, local wisdom offers an alternative approach to environmental sustainability. This study aims to describe the forms of environmental ethics embedded in the local wisdom of the Betawi community in the Betawi Cultural Village of Setu Babakan, South Jakarta. Using a descriptive qualitative method, the research explores cultural practices that support environmental preservation, including the use of home gardens, reverence for nature, and community-based waste management. The findings show that the Setu Babakan community applies ecological principles through traditions, customs, and active participation in environmental care. Moreover, synergy between the government, local communities, and the tourism sector contributes to developing an area that not only preserves Betawi culture but also maintains ecological balance. These findings highlight the importance of integrating local cultural values into environmental policy as a pathway toward sustainable development.

Material handling is a term for transportation or transport activities carried out by industrial companies, which involve moving raw materials, semi-finished goods or finished goods from one location to another predetermined location. Apart from that, material handling is also important in quality control, where 3-5% of damaged goods are caused by material handling. The aim of this research is to identify and redesign the layout conditions of concrete production facilities at PT. XYZ. The method of this research is the Activity Relationship Chart (ARC), Activity Relationship Daigram (ARD) and Total Closeness Rating (TCR) methods. In the current layout conditions, the sand warehouse and crushed stone warehouse work stations should be close to the two hoppers, namely the batching plant hopper and the asphalt mixing plant hopper, but in the actual conditions these two work stations are not close to each other. In the new facility layout there are changes and relocation of work stations based on the degree of proximity. Future research is expected to consider the amount of time generated during the material handling process and also consider cost aspects during the process of designing changes to the facility layout.

Automatic transmission motorcycles, especially those with 110cc engines, are increasingly in demand by the public because of their practicality. The performance of this motorcycle is greatly influenced by the transmission system, especially the Drive pulley and Roller components. The correct setting of the Drive pulley angle and Roller mass can improve engine performance and reduce noise, thus supporting driving comfort. This study aims to analyze the effect of variations in the Drive pulley angle and Roller mass on engine performance, in terms of power (HP), torque (Nm), and noise level (dB) at several engine speeds. The variations tested include the Drive pulley angle of 13.5°–14° and the Roller mass of 13–15 grams, with testing at 5000, 6000, 7000, and 8000 RPM. The test results show that the combination of the angle and Roller mass affects engine performance. At 5000 RPM, the combination of the 14° angle and 15 gram Roller produces the highest power, torque, and noise. At 6000 RPM, the combination of 13.8° and 13 grams produces a maximum power of 6.86 HP and 8.15 Nm of torque, with a noise of 97.40 dB. While at 7000–8000 RPM, the combination of 13.5° and 15 grams provides the best performance with 7.10 HP and 6.30 Nm of torque, accompanied by a noise of 104.17 dB. In general, increasing the angle and mass of the Roller increases performance, but is followed by an increase in noise.

Stockpiles are accumulations of materials such as coal or ore stored at specific locations. Accurate stockpile volume measurement is crucial in the mining and logistics industries for inventory management and cost efficiency. Conventional methods like Real-Time Kinematic (RTK) GPS rely on surface coordinate measurements but require numerous points, especially for irregular-shaped objects. Newer technologies like Terrestrial Laser Scanners (TLS) offer high-precision alternatives by capturing thousands of points per second, expediting and enhancing the resolution of volume measurements. This study compares TLS and RTK GPS methods in measuring the volume of andesite rock stockpiles at PT Bara Tabang. This research uses a quantitative approach, involving six Ground Control Points (GCPs) measured using the Sokkia GRX2 RTK GPS on October 24, 2024. TLS generated over 8.6 million point cloud data filtered down to 35,197 points, while RTK GPS yielded 2,276 coordinates. Accuracy testing showed very small RMSE values (RMSEr: 0.008 m; RMSEz: 0.007 m), and both LE90 and CE90 demonstrated 90% confidence within a 0.012 m range. Volume calculation using Surpac software with the cut and fill method showed TLS produced a volume of 18,766 bcm (51,982 tons/m³), while RTK GPS resulted in 18,694 bcm (51,782 tons/m³), with a difference of 72 bcm or 0.211%.These results indicate that both methods offer acceptable accuracy; however, TLS provides greater data density, efficiency, and precision, particularly for complex or large-scale stockpile objects. Therefore, TLS is recommended for high-accuracy volume measurement in mining operations that require efficiency and detailed analysis.

Mitra Abadi Mahakam as a contractor operating at PT. Bukit Baiduri Energi's jobsite, especially in the Pit A9 area, faces operational challenges related to variations in haul road grades. Differences in road gradients on the overburden hauling route have the potential to cause significant differences in fuel consumption between dump truck units, which ultimately affects the overall efficiency of hauling activities. The study was conducted quantitatively with primary and secondary data requirements and through 3 stages. The study resulted in an average fuel consumption value in loaded conditions of 1.41 liters and in unloaded conditions of 0.18 liters. The average fuel ratio value in loaded conditions was 0.62 liters/second and in unloaded conditions of 0.32 liters/second. The cost of fuel consumption in loaded conditions was Rp. 4,972,800 ($301.92) and in unloaded conditions of Rp. 2,607,360 ($158.30)

Mining roads play an important role in supporting the smooth running of mining activities, especially in the process of transporting materials. The bearing capacity of the soil as a road subgrade greatly affects the stability and resistance of the road to heavy equipment loads. This study aims to analyze the effect of the plasticity index and compaction parameters on the California Bearing Ratio (CBR) value, as well as to determine the thickness of the road layer based on the laboratory CBR value. Testing was carried out at the South Pit of PT. Bina Sarana Sukses site PT. Baramulti Suksessarana with a field test method using the Dynamic Cone Penetrometer (DCP) and laboratory tests such as proctor tests, Atterberg limit tests, and CBR tests on various variations of clay and sand soil mixtures. The results showed that increasing the plasticity index decreased the CBR value, while increasing the maximum dry density and decreasing the optimum water content increased the CBR value. Based on the laboratory CBR value, recommendations were obtained for the appropriate road layer thickness to ensure optimal bearing capacity for heavy equipment passing through the research area.

In rehandling activities In coal processing activities, mechanical tools such as crushers are needed to obtain production results in accordance with the company's desired targets according to the crusher target, therefore in processing it is necessary to carry out precise calculations, so that the ability of the tool (crusher) and know what things greatly affect the production processing process, so that it can be used optimally and has a high efficiency value for optimal production. Therefore, it is necessary to evaluate the results of the crusher production and the productivity of the support unit during rehandling activities in achieving the production target at ROM Port Area 2 in order to adjust the ability of the tool and other influencing factors with the crusher production target desired by the company. Actual rehandling productivity meets the crusher production plan target of 1100tph. Productivity in each zone with DT wheel 10, namely zone H there are 2 of 120,620 tph and 154,935 tph, zone L of 135,351 tph, zone M of 138,313 tph, zone I of 189,709 tph. And constraints on the crusher during a month that also affect obstacles in rehandling include schedule time with a total time of 176.72 hours, breakdown time with a total time of 4.84 hours, unscheduled time with a total time of 154.62 hours.

The implementation of coal mining activities with an open pit system at the end of its activities will leave behind the remains of former mining holes. Control of acid mine water is something that needs to be done during mining activities until the end of the mining process because acid mine water can cause a decrease in the quality of surface water and groundwater and have an impact on the survival of humans and biota that live on land and water. The initial characteristics of water using the floating treatment method of wetland, the pH, TSS, Fe, and Mn values ​​of ex-mining lake water do not meet the quality standards of the Government Regulation of the Republic of Indonesia Number 22 of 2021. The ability of water hyacinth plants to increase pH for 25 days is quite good with an initial pH value of 4.13 to 7.34. For 25 days, the TSS parameter of water hyacinth plants is also good at reducing TSS levels with an initial value of 6 mg/L to 3 mg/L, the Fe parameter of water hyacinth plants is also good at reducing iron levels with an initial value of 1.06 mg/L to 0.34 mg/L, while the Mn parameter of water hyacinth plants is quite good at reducing manganese levels with an initial value of 1.13 mg/L to 0.32 mg/L.

Organic waste management is an important issue in addressing environmental problems. One potential solution is bioconversion technology using Black Soldier Fly (BSF) maggots that can break down organic waste and produce larvae with economic value as animal feed. To increase the selling value and extend the shelf life, BSF larvae need to be dried using tools such as rotary dryers. This study aims to design and analyse the strength of a rotary dryer machine frame for maggot drying with a Finite Element Analysis (FEA) approach based on SolidWorks software. Simulations were carried out on several materials: ASTM A36, AISI 1020 Steel, and AISI 1045 Steel. The analysis results show that all materials are within safe limits based on Von Mises stress, deformation, and safety factor. AISI 1045 steel material gives the best performance with Von Mises stress of 14.238 MPa, deformation of 0.59 mm, and safety factor of 7.2. These results show that AISI 1045 steel is the most recommended material for the rotary dryer frame.

In mining activities, there is often a discrepancy between the plan and the actual conditions in the field, this discrepancy was found after reconciliation at the end of the progress (month). From the mining activities carried out by PT. Jembayan Muarabara (JMB), coal roof floor data was obtained from the survey which was then used to find survey tonnage, model tonnage data and actual tonnage scales. Then from this data it can be used to obtain coal recovery, coal looses in coal cleaning, loading, and coal transportation. The results of the study obtained tonnage data from the survey of 26,201.50 tons, a model of 26,488.50 tons and an actual tonnage of 24,885.09 tons. From the data obtained, the coal recovery value at the research location was 94.98% with coal losses in coal cleaning activities of 4.52% or 1196.39 tons and in loading activities of 0.5% or 120.02 tons with a tonnage discrepancy between planning and actual in the field of 1603.41 tons.

This study analyzes the morphological form and development characteristics of the Petrosea City Park green open space in Mimika Regency, Central Papua. Using qualitative descriptive-analytical methods, this research examines road patterns, spatial configurations, and architectural elements as well as the physical, economic, and socio-cultural characteristics of park development. The results show that the park implements a radial pattern centered on a roundabout with clear hierarchical zoning, integrating Kamoro cultural landmarks through bronze statues. However, infrastructure limitations and underutilized economic potential indicate the need for integrated development to optimize the function of green open spaces in the context of mining cities in Eastern Indonesia.

This study analyzes the impact of sustainable tourism concept implementation on the community of Tobati-Enggros Village, Jayapura City. Using qualitative descriptive methods with in-depth interviews, participatory observation, and document analysis involving 35 informants, this research evaluates three pillars of sustainability: economic, socio-cultural, and environmental aspects. The findings show that sustainable tourism implementation achieves a moderate effectiveness score of 2.7. Economically, tourism creates new employment opportunities and increases community income by 25%-400%, but benefits distribution remains unequal with 70% of profits controlled by 30% of residents. Socio-culturally, tourism helps preserve the unique "Women's Forest" tradition while causing erosion in traditional practices like gotong royong (community cooperation). Environmentally, significant ecosystem degradation occurs with water quality declining 56% and mangrove forest coverage reducing by 10%. The study recommends strengthening community-based tourism institutions, implementing comprehensive waste management systems, and developing community capacity building programs to optimize sustainable tourism benefits while preserving environmental and cultural integrity.

Land use conversion for vertical hospital development in urban areas represents a strategic response to increasing healthcare demands, particularly in regions with limited land availability. This study aims to analyze the impacts of land use conversion on vertical hospital development in Kelurahan Kota Baru, Abepura District, Jayapura City. The research employs qualitative descriptive methods with spatial analysis and field observations from 2015-2025. Results show significant land conversion from 3.16 hectares (2015) to 0.19 hectares (2025), with wetland areas (58.31%) being the most affected. The study reveals positive impacts including improved healthcare access and local economic growth, alongside negative impacts such as reduced green open spaces and environmental pressure. The findings contribute to sustainable urban planning strategies for healthcare infrastructure development in Papua.

Indonesia, which is located on the equator, has great potential to utilize solar energy, with an average solar radiation reaching 4.80 kWh/m² per day. This provides an advantage in the development of Solar Power Plants (SPP), one of which is through the installation of rooftop on the roof of the building as a source of electrical energy. This study aims to analyze the feasibility of SPP development by considering the techno-economic aspects of the Pondok Juice cafe. The total real electrical energy consumption required by the Pondok Juice cafe is 32,548 Wh/day. Assuming a system loss of 15%, the total electrical energy requirement that must be supplied by the SPP is 37,430.2 Wh/day. The initial investment projection is IDR 204,265,197, with operational and maintenance costs for 25 years of IDR 105,760,028. The investment feasibility analysis shows NPV of IDR 441,523,820.10, BCR 4.11, DPP ±5 years, and IRR 15.55%, which proves that this SPP planning is feasible to implement.

This study analyzes the use of safety harnesses in ensuring workplace safety at PT. XYZ, focusing on their role in preventing accidents during high-altitude work. The research employs the Job Safety Analysis (JSA) method to identify potential hazards and evaluate risk control measures. Data from 2021 to 2024 reveal a significant correlation workplace accidents with injuries ranging from minor to severe. The findings underscore the importance of strict adherence to safety regulations, proper training, and routine equipment inspections. The study concludes that consistent use of safety harnesses, aligned with national and industry standards, can significantly reduce accident rates and enhance worker safety.

International airports are complex work environments with unique occupational health and safety risks. As hubs of intensive transportation activities, airports involve various operations, including flight services, passenger handling, cargo management, and fuel operations. Early detection of fuel leaks is crucial to ensure the aircraft’s fuel system is free from leaks, blockages, or potential fire hazards. This study aims to analyze the causes of fuel leakage and identify appropriate mitigation measures, using observation and literature review methods. The findings indicate that fuel leakage occurring while the aircraft is parked suggests damage to certain fuel system components, such as seal gaskets, sealants, and dome nuts, which may suffer from wear or cracking due to age-related degradation. Such damage poses serious risks, including fire hazards, corrosion to aircraft structures—particularly in hard-to-reach areas like the wings or fuselage—and a drop in fuel pressure that could impair engine performance or cause flight cancellations. To address these issues, thorough inspections of all fuel system components are essential. Additionally, the use of sensors to detect abnormal changes in fuel pressure and flow, combined with rigorous leak testing after repairs, is recommended to ensure operational safety and reliability.

Fuel consumption is a necessity in moving mechanical equipment, where fuel consumption is influenced by road conditions, horsepower, and load factors. PT. Mitra Indah Lestari uses Hyundai 480 and Sany750-H excavators. The transport equipment used is Wechai WT90, Tonly TLD90, and Quester CWE 330. This study uses a quantitative method and obtains fuel consumption results, where the fuel consumption of the Hyundai 480 and Sany 750-H excavators is 37.89 liters/hour and 59.91 liters/hour, respectively. The fuel consumption of the Wechai WT90, Tonly TLD90, and Quester CWE 330 transport equipment is 25.19 liters/hour; 27.53 liters/hour; and 10.66 liters/hour, respectively.