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Guaranteeing the geotechnical stability of slopes is an absolute prerequisite for the sustainability of open pit mining operations, considering the potential for multidimensional losses due to slope failure. The specific geological conditions at PIT B1 PT. Pancaran Surya Abadi, which is composed of sedimentary rocks (coal, sandstone, and claystone), are susceptible to degradation and softening, especially due to high rainfall that causes an increase in pore water pressure and a decrease in rock shear strength. This study aims to analyze the stability of highwall slopes using the Morgenstern-Price Method to determine the Safety Factor (SFF) value according to Ministerial Decree number 1827 K/30/MEM/2018, and continued with a semi-quantitative risk analysis. The analysis results show that the initial slope has a static SFF of 0.77 (Not Safe). After redesign, the recommended optimal single slope geometry is: sandstone (Height 5 m, Angle 20°, Berm 5 m) and claystone (Height 10 m, Angle 60°, Berm 5 m). This redesign resulted in a FK of 1.34 (Safe). Sensitivity analysis to groundwater level rise (GTL) showed that the GTL value remained safe (GTL ≥1.30) up to a 30% increase in GTL. However, a 40% to 80% increase in GTL caused the GTL to decrease (1.28–1.21), classified as Medium Risk. A 100% increase in GTL drastically reduced the GTL to 1.05, classified as High Risk. This study emphasizes the need for close monitoring and additional drainage to maintain the long-term stability of slopes under the influence of rainfall.  

The transformation of marketing strategies from conventional methods to digital marketing has become an important factor in the development of the beauty industry, especially for Make Up Artists (MUAs) in Bandung. This study aims to analyze the impact of digital marketing through social media on increasing customer interest and the number of MUA service users, with a case study of Iwan Haadi, a professional MUA in Bandung who is active on Instagram (@iwanhaadimakeup) and TikTok (@iwanhaadi). This research employs a descriptive qualitative method with a case study approach, using interviews, observations of social media activities, and documentation of digital promotional content. The results show that before implementing digital marketing, MUAs generally relied on conventional promotions such as word of mouth and collaborations with wedding organizers. However, technological developments have encouraged many MUAs to shift to social media to expand their promotional reach. Based on observations of Iwan Haadi and 20 other MUAs in Bandung, around 85% have utilized social media particularly Instagram and TikTok to showcase their portfolios and client testimonials. The implementation of digital marketing strategies has proven to increase brand awareness and the number of customers by up to 65% over the past two years. In conclusion, digital marketing has a significant influence on increasing customers and competitiveness among MUAs in Bandung. Consistent and creative use of social media is the key to attracting customer interest and strengthening a professional image in the modern beauty industry.

The calculation of work volume and construction costs is a fundamental aspect of project management, as errors in the estimation process can directly affect the preparation of the project budget. Many projects still use conventional methods for estimation, which are based on 2D working drawings with the assistance of Microsoft Excel, as seen in the Sungai Raya Religious Court Building project. This method is considered prone to calculation errors and less efficient due to the considerable amount of time required. With the advancement of technology, Building Information Modeling (BIM) has emerged, enabling automatic and integrated calculation of work volumes and construction costs through a three-dimensional digital model. This study aims to examine the implementation of BIM in the Sungai Raya Religious Court Building project and to compare the results of work volume and construction cost calculations between the BIM method using Autodesk Revit and the conventional method based on the project’s Bill of Quantity (BoQ). The research method was conducted by modeling the structural elements of the building, including pile caps, tie beams, columns, beams, floor slabs, and reinforcements. The results of work volume and construction cost calculations obtained from Autodesk Revit were then compared with the project’s BoQ as the conventional method. Based on the analysis, an average difference of 6.3% in work volume and 5.6% in construction cost was found, with the Autodesk Revit calculations showing slightly lower values compared to the project’s BoQ.

Urban mobility in Surabaya faces serious challenges due to the high ownership of private vehicles and the low use of public transportation. The Surabaya City Government launched Suroboyo Bus Electric in November 2024 as a sustainable transportation innovation on the Purabaya–ITS route. This study aims to analyze commuter preferences for the Suroboyo Bus Electric mode over private vehicles, by emphasizing functional factors (cost, travel time, comfort) and symbolic factors (status, identity, modern image). The research method used a quantitative descriptive approach with 400 respondents, primary data was obtained through questionnaires, while secondary data came from government documents and literature. The analysis was carried out through descriptive statistics, chi-square tests, and logistic regression. The results showed that the majority of respondents chose Suroboyo Bus Electric as the main mode (62%), with the dominance of young, middle-income users, and mostly women. Most of the respondents have one unit of private vehicle, but still use electric buses as a mode of complementing mobility. Travel destinations are dominated by social, economic, and educational activities, with an average travel time of 16–30 minutes. In terms of cost, more than half of the respondents spent Rp 5,000-Rp 10,000 per trip, indicating the affordability of fares. Symbolic factors also play an important role, where Suroboyo Bus Electric is perceived as a modern, clean, and sustainable city identity.

Indonesia is the world’s second largest contributor of plastic waste entering the oceans, where it degrades into microplastics smaller than 1 micron. The use of bioplastics is therefore essential to mitigate environmental pollution. One promising alternative is starch–cellulose blend bioplastic derived from empty fruit bunches (EFB) of oil palm. Indonesia produces about 56.35 million tons of EFB annually, containing approximately 40% cellulose, which makes it a potential raw material for bioplastic production, although commercialization has not yet been realized. Environmentally, converting EFB into bioplastics within the palm oil value chain represents a sustainable waste recycling strategy that transforms solid residues into higher-value products. In this design, soda cooking technology is employed to extract cellulose from EFB, utilizing about 16% of waste from a crude palm oil (CPO) mill with a capacity of 30 tons of fresh fruit bunches (FFB) per hour. The starch–cellulose blend bioplastic pellets are formulated using gelatinized cassava starch as the polymer matrix, glycerol as a plasticizer, polyvinyl alcohol (PVA) as a stabilizer, and cellulose as a filler. The designed production capacity of the EFB-based starch–cellulose bioplastic plant is 16,500 tons per year. This bioplastic industry is expected to contribute positively to achieving eight Sustainable Development Goals (SDGs), including Goals 1, 8, 9, 12, 13, 14, 15, and 17, thereby supporting Indonesia’s commitment to sustainable industrial development and a cleaner environment.

This study aims to analyze the comparison of the durability of natural fiber and synthetic fiber composites in a high-temperature production environment. Testing was conducted on carbon fiber, aramid (synthetic), ramie, and jute (natural) fiber-based composites with exposure to temperatures of 80-150°C for 500 hours. The parameters measured include tensile strength, elastic modulus, dimensional stability, morphological changes, and moisture absorption. The research results show that synthetic fiber composites have superior durability compared to natural fibers. Carbon fiber composites retain 87% of their initial tensile strength with only a 4.2% reduction in modulus, while flax fibers only retain 62% strength with a 26% reduction in modulus. Microscopic analysis revealed significant delamination in natural fiber composites with interface gaps of 15-25 μm, compared to 3-5 μm in synthetic fibers. Natural fibers undergo thermal degradation due to the decomposition of lignin and hemicellulose, resulting in significant color changes and a dimensional shrinkage of 3.2%. The moisture absorption of natural fibers increases to 8.5% after exposure, indicating damage to the cellular structure. This research concludes that synthetic fiber composites are more suitable for long-term high-temperature production applications, but natural fibers can still be considered for low-temperature applications with appropriate chemical modification.

Road preservation is a type of maintenance that keeps roads in satisfactory working order by using preventive, corrective, rehabilitation, and reconstruction methods. This approach makes sure that the road stays usable for the entire time it is planned to be used. In practice, preservation projects often run into delays that can lead to important contract conditions. To avoid this, there needs to be a structured way to evaluate things through a Show Case Meeting (SCM). This study looks at how SCM was used in the 2024 Girian–Kema–Rumbia–Buyat Road Preservation Project to find out what caused the delays and how well the agreed-upon fixes worked. The method included looking at physical progress, differences between planned and actual performance, and how well the contractor did during SCM Stages I and II. The results indicate that the contractor failed to provide enough workers and move the right equipment, which led to the critical contract condition. SCM Stage I did not meet the required test-case target, but SCM Stage II did, showing that the contractor was able to meet the required performance targets and finish the work on time. These results show that SCM is an important way to control contracts and fix problems, which helps construction projects get done on time and well.

Distribution transformers play a crucial role in delivering electrical energy from the distribution system to consumers to ensure power quality and supply continuity. However, in practice, overload conditions often occur due to increasing demand and load growth that exceed the transformer’s rated capacity. This situation can lead to reduced efficiency, increased power losses, and accelerated equipment aging. This study aims to analyze the performance of the CMY distribution transformer at PT PLN (Persero) ULP Labuan, which operates beyond its nominal capacity, and to propose an alternative solution through transformer mutation, namely the replacement of the existing unit with a transformer of more appropriate capacity based on load analysis results. The Least Square Method is employed to predict future load growth and determine the projected time when the transformer will again experience overload after the mutation. The results indicate that the existing 100 kVA transformer is overloaded and should be replaced with a 160 kVA unit. After the mutation, the loading percentage decreases significantly, the transformer’s lifespan is extended, and the reliability of the distribution system improves. Furthermore, the Least Square prediction suggests that the new transformer may experience overload again in future years if no further planning is carried out. Therefore, transformer mutation can be considered an effective and medium-term solution to enhance and maintain the reliability of the electrical distribution system within the operational area of PT PLN (Persero) ULP Labuan.

The Motor Operated Valve (MOV) is a critical component in fluid control systems at Steam Power Plants (PLTU). Training new technicians is often hindered by limited access to actual equipment and operational safety risks. This research aims to design and develop an Arduino-based MOV control module simulator capable of simulating basic functions such as open, close, stop, and limit switch responses. The method used is Research and Development (R&D) with an experimental approach. The simulator was tested using a DC motor as the simulated valve actuator, equipped with push buttons, relays, limit switches, and indicator lamps for visual feedback. The test results showed that the simulator successfully represented control functions with 100% accuracy in limit switch responses and consistent operation. User evaluations involving ten new technicians indicated an 85% satisfaction rate in terms of ease of understanding and operational safety. This simulator has proven to be an effective, interactive, and safe learning medium for new technicians at PLTU Nagan Raya.  

PT. Barito Bangun Nusantara is a company engaged in coal exploration and production activities, where the production is temporarily stored in a stockpile area before being processed or distributed. Stockpile management requires attention to several important factors, such as area design and stockpiling methods, so that storage runs effectively and does not cause a decrease in coal quality. This study was conducted on old and new stockpiles with the aim of analyzing the actual stockpiling conditions and providing technical recommendations regarding the ideal stockpile capacity and configuration. The research methods included field observation, primary and secondary data collection, and descriptive quantitative analysis. The results showed that both stockpiles experienced inefficiencies due to excess capacity. The actual tonnage reached 49,191.98 tons, exceeding the planned capacity of 35,000 tons, with a stockpile height reaching 9 m. This condition caused long stacking times and the FIFO system did not operate optimally. The study recommended an ideal stockpile capacity of 30,740.61 tons, with a maximum height of 8 m. The recommended angle of repose for the old stockpile is 30°, with a capacity of 11,542.19 tons, while for the new stockpile, it's 34°, with a capacity of 19,198.42 tons. This arrangement is expected to allow for a smoother unloading process and a more ideal stockpile.

This study aims to analyze the profitability and feasibility of sheep farming using intensive and semi-intensive rearing sistems in Suka Raya Village, Pancur Batu Sub-district. The research employed a survey method with purposive sampling, involving 16 farmers (8 intensive and 8 semi-intensive), each rearing more than 15 sheep and operating for at least 3 years. Data were collected through questionnaire interviews and field observations, then analyzed descriptively to calculate production costs, revenue, income, R/C ratio, and Break Even Point (BEP). Results showed that the average total production cost for the intensive sistem was Rp 52,429,313, higher than the semi-intensive sistem at Rp 39,664,375. The average revenue for the intensive sistem was Rp 69,150,000, while the semi-intensive sistem was Rp 63,712,500. The average income for intensive farmers was Rp 16,720,688, compared to Rp 24,048,125 for semi-intensive farmers. The average R/C ratio for the intensive sistem was 1 (near break-even), while the semi-intensive sistem was 2 (more efficient and profitable). BEP analysis indicated higher sales for the intensive sistem (Rp 844,022/sheep/period) compared to the semi-intensive sistem (Rp 691,052/sheep/period), with a larger production BEP for the intensive sistem (44 sheep) than the semi-intensive sistem (33 sheep). The semi-intensive sistem is recommended for farmers with limited capital and small to medium-scale operations due to lower costs and higher profit margins, while the intensive sistem is more suitable for large-scale operations with adequate capital, feed management, and health care.

Distribution transformers play a critical role in delivering electrical energy from medium-voltage networks to low-voltage consumers. At ULP Medan Kota, several distribution transformers have been operating with loads exceeding 80% of their nominal capacity, posing risks of overloading, efficiency reduction, and equipment failure. This study aims to analyze the performance of distribution transformers based on actual load data and evaluate mitigation strategies through the implementation of additional parallel transformers (trafo sisip). The methodology includes data collection, load and current calculation, and simulation of load distribution after transformer insertion. The results show that the installation of trafo sisip reduces the load on the main transformer by approximately 50% and significantly lowers the current to safer levels. Moreover, placing the trafo sisip at an optimal position minimizes voltage drop to as low as 0.0745 Volts. Therefore, the addition of trafo sisip is proven to enhance the reliability, efficiency, and operational life of the power distribution system at ULP Medan Kota.

The principle of sustainability is the main foundation in the development of a coastal resort in Mangrove Beach, Serdang Bedagai, which has high tourism potential but lacks environmentally friendly facilities. This study uses a sustainable architectural design method based on Biophilic design, which emphasizes human connection with nature through adaptive design and harmony with the environment. The implementation of this concept is realized through the use of locally sourced low- carbon materials, cross-ventilation, and natural lighting for energy efficiency, integration of vegetation as both aesthetic and ecological elements, environmentally friendly rainwater and waste management, and site planning that respects the coastal ecosystem. The design outcome is a resort with an organic form inspired by shells and ocean waves, creating an architectural identity that harmonizes with the area's character, providing a comfortable tourist experience for visitors, and contributing to local economic growth and environmental conservation, thereby serving as a concrete example of sustainable coastal tourism development in North Sumatra.

The increasing demand for electrical energy, particularly in offices and commercial buildings, has made energy efficiency a critical aspect of sustainable development. Among various building components, lighting systems are recognized as one of the major consumers of energy. This study investigates the potential for energy savings through the adoption of a smart lighting system incorporating IoT-based sensors, motion detectors, and dimming controls. Employing a quantitative descriptive approach, the research was conducted at the workspace of Indie Light, comparing energy consumption before and after the implementation of the system. Data were collected using direct observation, light and power meters, and real-time monitoring devices to ensure accurate measurement. The results demonstrate that smart lighting systems can substantially reduce energy use without compromising lighting quality or comfort. By integrating intelligent sensors and adaptive control algorithms, the system not only optimizes energy efficiency but also aligns with national policies on energy conservation, supporting broader environmental sustainability efforts. These findings suggest that smart lighting solutions can play a significant role in promoting energy-efficient practices in commercial spaces while contributing to sustainable development goals.

This study aims to evaluate the actual sump capacity in accommodating mine water discharge, design a sump that fits field conditions, and determine the optimal pump capacity and system at PT Satria Alam Manunggal, Telen Orbit Prima Site. The research methods include field data collection (sump condition, water discharge, and pump capacity) and supporting data (rainfall, geological maps, and pump specifications). The design rainfall was calculated using the Gumbel method with a five-year return period, while water discharge was estimated from runoff, rainfall, and groundwater inflow. The results indicate that the existing sump, with a capacity of 508 m³, is insufficient to accommodate an inflow of 1.210 m³/s. Therefore, two new sumps were designed: the West Sump with a capacity of 38,400 m³ and the East Sump with 78,281 m³. Each sump employs a DnD 150-4H pump with a discharge rate of 480 m³/hour. The West Sump pump can drain water within approximately three days, while the East Sump requires about seven days. The trapezoidal sump design was chosen for its efficiency, structural stability, and effectiveness in sediment (TSS) deposition control, maintaining levels within safe limits. In conclusion, the design of the West and East sumps is considered optimal in accommodating mine water discharge and improving the overall effectiveness of the mine drainage system.

In engineering practice, various methods have been implemented to stabilize landslide-prone slopes, one of which is the use of bore piles. Bore piles are structures that hold back soil and make slopes more stable by reinforcing the ground inside them. However, the application of bore piles in landslide mitigation presents its own challenges, making it essential to identify and anticipate potential issues that may arise in field engineering practice. Bore piles are installed vertically, either parallel or staggered, at specific spacing and are often combined with capping beams and struts to resist soil movement and provide lateral restraint. This method is commonly applied to high-risk slopes or critical infrastructures such as roads, bridges, and buildings. Anticipation strategies in engineering practice consist of three stages: planning, implementation, and long-term maintenance, with this study focusing specifically on anticipation strategies during the implementation stage. Although bore piles serve as an effective solution to reduce landslide risk, their success depends heavily on proper planning, construction execution, and maintenance. Issues such as soil conditions, construction quality, and external factors must be addressed through a comprehensive engineering approach.

PT. Hamparan Mulya operates in the coal mining industry and applies an open-pit extraction system. In this mining method, managing surface water particularly rainwater is essential to ensure smooth operations. An effective drainage system is required to prevent runoff water from contaminating nearby rivers, lakes, and surrounding ecosystems. One practical approach used in mining operations is the construction of settling ponds, which function as treatment units for water collected in the sump before it is released into natural waterways. This study aims to identify the appropriate storage capacity for the settling pond and sump by analyzing rainfall data using the Log Pearson Type III method. The analysis produced a design rainfall value of 507.16 mm/day and a rainfall intensity of 56.94 mm/hour. With a catchment area of 14 km², the resulting runoff discharge reaches 30,782.16 m³/hour. Based on these parameters, the settling pond must be engineered to accommodate a total discharge of 30,782.16 m³/hour.

Bintan Island has abundant bauxite soil resources; however, its utilization as road construction material remains limited. The scarcity of high-quality granular material in the region necessitates the use of available local resources, particularly for pavement subgrade layers. This article aims to analyze the classification and mechanical properties of native soils in Bintan Island through a systematic literature review. The reviewed literature includes laboratory test results of bauxite soil. The findings indicate that bauxite soil exhibits low plasticity, relatively high CBR values (±35%), and is classified as CL (USCS) and A-2-4 (AASHTO). These results suggest that bauxite soil is suitable for subgrade applications, although require stabilization with binding agents. The implication of this review highlights that the utilization of local materials could support sustainable infrastructure development in island regions by reducing dependency on imported materials.  

This paper was made to explain the results of research on how to obtain the most appropriate citric acid adhesive composition in the manufacture of randu wood fiber composites in order to obtain a strong and suitable composite material. The research was carried out by experimental methods in the laboratory through a series of mechanical tests, namely the bending strength test and the screw grip strength test. The sample specimen is 5 cm × 20 cm × 1 cm for flexural strength testing and 5 cm × 10 cm × 1 cm for screw grip strength test. Composite specimens were made with variations in the composition of citric acid adhesives of 2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17.5%, and 20% by weight of randu wood. The results showed that the composite of randu wood particles with a citric acid matrix had optimal strength at a certain ratio, which was 7.5%. At the same ratio, the test results of the screw grip strength test also provide the highest value. These findings confirm that the exact composition of the adhesive has a significant impact on the final performance of the resulting composite.

Energy efficiency in water heaters is a crucial factor in ship operational environments due to limited electricity resources that rely on generators. This study aims to design and build an IoT-based water heater monitoring system with an innovative heat storage medium in the form of a mixture of silica sand and paraffin wax to improve thermal efficiency. Although previous studies have developed temperature monitoring and control systems in IoT-based water heaters, this study specifically fills this gap by analyzing the performance of adding silica sand to overcome the low thermal conductivity of paraffin wax. Using the Research and Development (R&D) method, this system was built with an ESP32 microcontroller as the control center, a DS18B20 temperature sensor for accurate measurements, and the Blynk and Google Sheets platforms for real-time monitoring and data recording. Performance testing was conducted by comparing the water heating rate between pure paraffin wax media and the mixed media. The results showed that the monitoring system functioned reliably, and the main finding proved that the addition of silica sand to paraffin wax significantly increased heating efficiency. This was clearly seen from the reduction in time required to raise the water temperature to 40°C, from 2.5 hours to only 1 hour in the second heating cycle. The results of this study indicate that the integration of silica sand and paraffin wax media with IoT technology can increase the efficiency of water heaters and provide an innovative solution for energy-efficient and environmentally friendly temperature control.