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This research investigates the Peak Particle Velocity (PPV) resulting from blasting operations at Pit Pinang, PT Bukit Baiduri Energi, employing two prediction approaches: Non-Linear Geometric Regression and the USBM Oriard’s Formula. Ground vibration measurements were recorded over a one-month period, from October 9 to November 8, 2025. The findings indicate that the non-linear regression model achieves a higher predictive accuracy of 78.62%, outperforming the USBM Oriard’s Formula, which reaches 68.2%. Variations between the observed and estimated PPV values were affected by factors such as the location of geophones, differences in explosive charges, and alterations in borehole depths. In addition, the study evaluates optimal explosive charge recommendations in accordance with SNI 7571:2010 standards to mitigate potential structural damage in surrounding areas. By highlighting these predictive discrepancies and providing practical guidance on charge management, the research offers valuable insights for improving blasting safety and minimizing vibration impacts on nearby infrastructure. The comparison of methods emphasizes the importance of selecting appropriate prediction models to ensure both operational efficiency and environmental safety.

This study analyzes customer attrition in barbershops through the application of the 4P marketing mix, which includes Product, Price, Place, and Promotion. The research was conducted using a questionnaire distributed to 30 barbershop customers, which aimed to assess their level of satisfaction regarding each element of the marketing mix. The findings revealed that while customers were generally satisfied with the quality of the haircuts and the cleanliness of the tools, there was an important demand for improvement in the quality and variety of additional products offered. The pricing strategy was considered affordable by most customers; however, some expressed dissatisfaction, indicating the need for better communication regarding the value of the services provided. Demographic analysis showed that the majority of respondents were young adults aged 18-25, highlighting a specific target market for barbershops. Overall, this study emphasizes the importance of effectively implementing the marketing mix to improve customer retention and satisfaction in the barbershop industry.

The Special Region of Yogyakarta (DIY) is characterized by high seismic activity due to its proximity to the subduction zone and the presence of active fault systems, particularly the Opak Fault. The 2006 Yogyakarta earthquake revealed significant vulnerability in local building structures and highlighted the complex geological conditions governing seismic wave propagation. This study aims to calculate and map the Peak Ground Acceleration (PGA) distribution in Prambanan District, Klaten Regency—one of the areas closest to the 2006 earthquake source. PGA values were estimated using the McGuire attenuation relationship, based on a moment magnitude of Mw 6.3 and the hypocentral distance to 88 observation points distributed at approximately 900-meter intervals. The resulting PGA map indicates values ranging from 26.7 to 31.7 gal, with a clear spatial trend showing increasing intensity from the northern to the southern parts of the study area. Higher PGA values occur in regions near the Opak Fault and in areas dominated by unconsolidated volcanic deposits of the young Merapi formation. These loose sediments amplify seismic waves, resulting in stronger ground motion compared to areas composed of more compact sedimentary rocks. The spatial pattern of PGA corresponds well with the distribution of structural damage recorded during the 2006 earthquake. The findings emphasize the significant role of local geology and fault proximity in shaping seismic hazard levels. Consequently, this study provides essential insights for disaster mitigation strategies, land-use planning, and structural vulnerability assessment within the Prambanan area.

Coal quality must be controlled from the pit area to the ROM stockpile to ensure compliance with market specifications. However, hauling and stockpiling processes often lead to changes in coal characteristics. This study aims to analyze variations in proximate parameters between coal from Pit B1 and ROM Stockpile Km4 at PT Trisensa Mineral Utama and to identify factors contributing to these changes. The methodology includes field sampling at both locations, sample preparation based on ASTM standards, and laboratory testing of inherent moisture, residual moisture, ash content, volatile matter, and fixed carbon. The results indicate that coal undergoes quality changes after being stored in the stockpile, marked by a decrease in inherent moisture of 2.54% (from 17.64% to 15.10%), a decrease in residual moisture of 1.42% (from 17.17% to 15.75%), a slight reduction in ash content of 0.16%, a decline in volatile matter of 0.28%, and a reduction in fixed carbon of 0.18%. These changes are influenced by field conditions, material contamination during mining, rainfall, coal porosity, and handling activities at the stockpile. The findings highlight the need for improved sampling management, better surface water control, and stricter material handling procedures to minimize coal quality degradation.

This study examines human facial proportions through an anthropometric approach based on the Phi value of the Golden Ratio (φ = 1.618) to understand the relationship between mathematical proportionality and visual aesthetics. The analysis focuses on two public figures, Jin and V of BTS, who are widely recognized as visual representatives within contemporary popular culture. Using two-dimensional anthropometric measurements, four primary facial aspects were evaluated: the facial length-to-width ratio, the proportional relationship between the forehead, nose, and chin, the eye–mouth–chin vertical proportion, and the alignment of eye width with interocular distance. Each measurement was compared to the Phi value to assess its degree of proportional conformity. The findings indicate that most facial ratios observed in both Jin and V closely approximate or match the Golden Ratio, with V exhibiting the highest precision in vertical proportional measurements, while Jin demonstrates more consistent overall proportional stability across multiple facial components. These results support the use of the Phi Golden Ratio as a mathematical indicator in assessing facial proportion and aesthetic harmony. Nevertheless, the study acknowledges that visual aesthetics remain inherently subjective and are influenced by cultural context and individual perception. Thus, anthropometric analysis based on the Golden Ratio can serve as a complementary tool in understanding human facial aesthetics.  

Mine disposal materials such as tailings, overburden, and waste rocks are critical components in mining operations that require comprehensive understanding of their geotechnical properties to ensure stability and safety of storage facilities. This literature review aims to analyze the role of particle gradation and mineralogical composition in determining shear strength and compressibility of mine disposal materials, with particular focus on nickel mining. A sistematic literature review method was employed by analyzing 30 scientific publications from 2019-2025 obtained from various academic databases. The review findings indicate that particle size distribution (gradation) has significant influence on shear strength and compressibility, where materials with coarser gradation and higher coefficient of uniformity (Cu) exhibit greater shear strength and lower compressibility. Mineralogy, particularly clay mineral content, increases cohesion and microporosity but also increases compressibility under loose conditions. Studies on nickel mine waste demonstrate that ferronickel slag possesses favorable drainage characteristics suitable for rockfill material, while tailings require strict gradation control. In conclusion, comprehensive characterization integrating gradation parameters (Cu, Cc, D50) with mineralogical analysis (XRD, XRF) is essential for predicting mechanical behavior of mine disposal materials and designing safe storage facilities.

The development of smart cities has become a strategic priority for local governments seeking to enhance citizens’ quality of life, strengthen sustainable development, and improve public space management. Kambang Iwak Park in Palembang represents one of the city’s major urban green spaces that has undergone significant revitalization and serves as a case study for smart city implementation in public areas. This study analyzes the application of Cohen’s six smart city dimensions—Smart People, Smart Living, Smart Government, Smart Economy, Smart Mobility, and Smart Environment—and their relationship with Carmona’s six urban design dimensions. This qualitative–descriptive research utilizes visual observations, historical data, and facility documentation extracted from the provided presentation. The findings indicate that Kambang Iwak Park effectively integrates several smart city dimensions, particularly Smart Living, Smart Environment, and Smart Mobility. Nonetheless, issues such as irregular parking, insufficient smart services, and poorly organized street vendors remain challenges. The study concludes that integrating smart city principles with urban design concepts enhances public space quality and supports sustainable urban development in Palembang.

The oil and gas industry plays a crucial role in meeting global energy needs, with crude oil from production wells being the primary product of upstream operations. Prior to further processing, crude oil requires pretreatment at the production site, one of the key stages being phase separation using a flash separator. This study examines the effect of variations in cooling temperature on the performance of liquid phase separation and energy requirements in the flash separation process of light hydrocarbons. The analysis was conducted through process simulation using Aspen HYSYS version 14.2 with the Peng Robinson property package. The feed stream had a mass rate of 10,000 kg per hour, a temperature of 50°F, and atmospheric pressure, with compositions of ethane, propane, isobutane, and normal butane. The process configuration included compression, cooling, and phase separation in a flash separator at a constant pressure of 50 psia. Variations in cooling temperature were applied at 20, 10, and 0°C. The simulation results indicated a thermodynamic critical point at 10°C. At 20°C, no liquid phase was formed, while at 10°C, significant liquid yield was obtained with moderate energy consumption. Lowering the temperature to 0°C dramatically increases liquid recovery, but the cooling energy requirement also increases sharply. Sensitivity analysis confirms a strong inverse relationship between temperature and condensation yield, as well as a surge in energy consumption at low temperatures. The optimal operating condition is set at 10°C, providing a balance between separation efficiency and energy efficiency in accordance with sustainable manufacturing principles.

This study aims to analyze the level of flood hazard in Baturaja Barat District, Ogan Komering Ulu Regency, by applying a spatial approach using Geographic Information Systems (GIS) through the overlay method. The analysis was carried out by integrating six main physical parameters, namely rainfall, land use, elevation, slope, river density, and soil type. Each parameter was assigned a score and weight according to its influence on flood potential and subsequently processed spatially to produce a flood hazard map. The results indicate that the Baturaja Barat District area is classified into three hazard levels: low (3.25%), moderate (70.64%), and high (25.84%). Areas with high hazard levels are predominantly characterized by densely populated settlements situated at low elevations and in close proximity to river networks, particularly in Tanjung Karang, Air Gading, Talang Jawa, Karang Agung, and surrounding villages. These findings highlight that land-use changes, topographic conditions, and the distribution of river networks play significant roles in increasing flood risk. The results of this study are expected to serve as a foundation for spatial planning, the strengthening of disaster mitigation policies, and the enhancement of community preparedness against flood hazards in the region.

The stability of slopes in open-pit coal mining in Indonesia is significantly influenced by geological faults, which are a major factor causing slope failures. This study aims to examine the impact of faults on slope stability by conducting a systematic literature review of 25 scientific publications from 2018 to 2025. The results indicate that faults and fault zones consistently reduce rock mass integrity through several mechanisms, including stress concentration in weak zones, the formation of preferential sliding surfaces, amplification of hydro-mechanical effects from groundwater and rainfall, and the reduction of rock strength parameters. Case studies in Kalimantan and Sumatra confirm these mechanisms with slope failures aligning with fault orientations. Kinematic and numerical analyses using the Limit Equilibrium Method (LEM), Finite Element Method (FEM), and Distinct Element Method (DEM) show a reduction in the safety factor (SF) by up to 36% on slopes affected by faults. Practical recommendations include continuous monitoring using Slope Stability Radar (SSR), optimization of slope geometry with angles < 18° in fault zones, groundwater control, reinforcement with anchors and bolting, and UAV-based discontinuity mapping for hazard zoning. This study concludes that managing slopes in fault zones requires an integrated approach combining detailed geological investigation, multi-method numerical analysis, real-time monitoring, and specific mitigation design.

This study analyzes failures in the bending machine at PT. XYZ and determines maintenance priorities to reduce downtime and improve production efficiency. The company often faces repeated breakdowns, especially in hydraulic and control components, which negatively impact productivity. To address these issues, the research applies Failure Mode and Effect Analysis (FMEA) and Fault Tree Analysis (FTA). The study employs a descriptive qualitative approach using downtime and repair data from September 2024 to February 2025. FMEA was conducted to identify failure modes, effects, and causes, and to calculate the Risk Priority Number (RPN) as a basis for prioritization. FTA was then applied to trace root causes by mapping logical relationships among contributing factors leading to the top event. Recommendations were formulated with the 5W+1H method to propose preventive maintenance actions. The results indicate that the hydraulic valve is the most critical component, with an RPN value of 504 due to oil contamination. The main causes include damaged filters, improper oil usage, and lack of a cooling system. The hydraulic cylinder seal and back gauge were also found to contribute significantly to machine failures. FTA analysis revealed root causes such as inadequate maintenance procedures, unsuitable materials, and insufficient inspections. The proposed improvements involve regular replacement of oil filters, structured lubrication schedules, installation of oil coolers, and technician training to strengthen compliance with standard procedures. Overall, the integration of FMEA and FTA provides a systematic approach to identify critical components and root causes, enabling PT. XYZ to implement preventive strategies that minimize failures, reduce downtime, and improve bending machine performance sustainably.

Ngarip Village, Ulubelu District, is one of the coffee-producing areas in Tanggamus Regency. Some residents process the harvested coffee into various micro, small and medium enterprises (MSME) products. This activity produces a byproduct in the form of coffee grounds. Coffee grounds have characteristics that allow them to be processed into products with utility and economic value. This community service activity aims to provide knowledge and skills to the Ngarip Village community on how to process coffee grounds into aromatherapy candles that are attractive, useful, and have the potential to be developed as a creative economy product. The implementation method includes literature studies, field observations, preparation of tools and materials, and socialization and training that includes material presentations, discussions, demonstrations, hands-on practice, and documentation. This training provides knowledge on the concept of 3R-based waste management and techniques for making aromatherapy candles using coffee grounds as an additional ingredient. The implementation results showed that participants were able to understand the process of making aromatherapy candles, from drying coffee grounds, melting wax, mixing ingredients, to the molding stage. Participants also gained knowledge about the benefits of aromatherapy candles for health, the environment, and their economic potential. This training can improve the community's ability to process waste into useful products, while also opening up sustainable home business opportunities. Overall, this activity has a positive impact on increasing public insight, creativity, and awareness regarding organic waste management, as well as encouraging innovations that support local economic independence.

This study aims to analyze the effect of blasting geometry on drilling and blasting costs in mining operations at PT Unggul Dinamika Utama, Kutai Timur Regency, East Kalimantan Province. The research focuses on comparing two operational areas, namely PIT Tempudo 6 and PIT East, which apply different blasting geometries: a burden of 7 m and spacing of 8 m at PIT Tempudo 6, and a burden of 8 m and spacing of 9 m at PIT East. The research method involved collecting primary data from actual field drilling and blasting activities, as well as secondary data from the company. The parameters analyzed included blasting geometry, explosive consumption, and operational costs of drilling and blasting. The results show that the total drilling cost at PIT Tempudo 6 was Rp. 215,689,696, while at PIT East it was Rp. 162,177,899. The total blasting cost at PIT Tempudo 6 reached Rp. 3,023,066,977.60, while at PIT East it was Rp. 1,780,839,602.80. Thus, the total operational cost of blasting activities at PIT Tempudo 6 amounted to Rp. 3,238,756,673.60, and at PIT East amounted to Rp. 1,943,017,501.80. It can be concluded that differences in blasting geometry significantly affect operational cost efficiency. Larger burden and spacing values lead to more efficient costs by reducing the number of drill holes and explosive consumption per blasted rock volume.

Rock stability and service life in geotechnical and mining engineering are highly dependent on the rock's mechanical and physical parameters, where the variation in sandstone grain size is a crucial intrinsic factor. This study aims to comprehensively analyze the correlation between sandstone grain size with uniaxial compressive strength (UCS) and resistance to weathering (Slake Durability Index) in samples taken from the Balikpapan and Pulau Balang Formations in the Samarinda area, East Kalimantan. The research methodology involved a series of standard laboratory tests, including rock physical properties analysis, grain size distribution analysis, UCS testing, and slake durability testing through three cycles. The test results show a significant correlation: sandstone with finer grain sizes and higher density consistently demonstrates greater UCS values and a higher Durability Index, indicating superior mechanical and physical resistance. Specifically, the Pulau Balang Formation exhibits a more compact structure and finer grain size, resulting in better durability values compared to the Balikpapan Formation. These findings are important as a geomechanical data basis for slope design planning, rock mass stability analysis, and material selection in infrastructure projects or mining operations involving both formations.

This research addresses the low student learning outcomes and the lack of facilitation of 4C competencies (Critical Thinking, Collaboration, Communication, and Creativity) in the Industrial Machine Electrical Systems (SKMI) subject for Grade XI TMI 1 students at SMK Negeri 1 Pariaman. The teacher-centered learning approach has led to passive student participation, low critical thinking, varying academic abilities, and difficulty in connecting theoretical concepts to real-life applications. The aim of this study is to improve students' 4C competencies and learning outcomes through the implementation of the Team Assisted Individualization (TAI) cooperative learning model. Using Classroom Action Research (CAR) based on the Kemmis and McTaggart model, the study was conducted in three cycles: planning, implementation, observation, and reflection. The subjects were 30 students from Grade XI TMI 1. Data collection included learning outcome tests and 4C competency observation sheets, with descriptive and quantitative data analysis. The results showed significant improvements: classical mastery increased from 27% to 90%, average learning scores rose from 67 to 81, and 4C competency mastery improved from 34% (low) to 82% (high). The study concludes that the TAI model effectively enhances both 4C competencies and learning outcomes in SKMI at SMK Negeri 1 Pariaman.

Overburden removal is a critical phase in coal mining operations, as it directly affects production continuity and operational efficiency. However, production realization often deviates from the mine plan due to various operational constraints. This study, conducted at Pit K1 Mahakam of PT. Insani Baraperkasa, evaluates the causes of underachievement in overburden stripping targets using the Six Big Losses framework, which classifies inefficiencies into Breakdown Losses, Setup and Adjustment Losses, Idling and Minor Stops, Reduced Speed Losses, Process Defect Losses, and Reduced Yield Losses. The analysis revealed that the dominant losses were Reduced Speed Losses (26%) and Setup and Adjustment Losses (10%), primarily caused by disposal congestion, shift changes, and repairs at the loading and disposal areas. Minor contributions were found from idling (3%), production losses (5%), while breakdown losses showed negligible impact. These factors led to increased standby time and reduced equipment cycle effectiveness. Improvement strategies are recommended through optimized disposal allocation, reduction of waiting time, and stricter control of external operational disruptions to enhance stripping efficiency and achieve production targets.

The demand for lightweight materials with high mechanical strength has driven the development of aluminum alloys, particularly Al-Mg-Si, through deformation processes such as cold rolling. This study aims to analyze the effect of varying degrees of cold rolling deformation on the grain aspect ratio and macrohardness of homogenized Al-Mg-Si alloys. Deformation was applied at three thickness reduction levels—5%, 10%, and 20%—followed by microstructural characterization using optical microscopy and macrohardness testing in accordance with ASTM E-18 standards. The results show that increasing deformation levels lead to elongated grain morphology, with the grain aspect ratio rising from 1.16 to 2.07 and macrohardness increasing from 46.64 HRE to 62 HRE. The emergence of slip lines and grain flattening indicates the occurrence of intense plastic deformation, while work hardening results from dislocation accumulation that impedes further slip motion. These findings confirm a strong correlation between microstructural evolution and mechanical property enhancement in cold-deformed Al-Mg-Si alloys. This research contributes to the optimization of cold rolling parameters to produce engineering materials with a desirable balance of strength, formability, and fatigue resistance for applications in the mining and heavy manufacturing industries.

The success of a production process is highly dependent on effective quality control. In this study, the focus is directed toward Pc Slab Type A products manufactured by PT. XYZ, a precast concrete company for highways and building structures. The evaluation emphasizes efforts to reduce chipping defects. Improvement priorities were determined using the Failure Mode and Effect Analysis (FMEA) method based on the Risk Priority Number (RPN). Root Cause Analysis (RCA) was applied to identify the underlying problems. The analysis revealed that the dominant factor comes from the human aspect, with the highest RPN value of 294, namely the lack of regular supervision. Additional contributing factors include improper mold opening methods (RPN 216), inconsistent worker performance (RPN 175), inter-division transfers (RPN 125), and delayed maintenance schedules (RPN 120). All causes were elaborated using the 5W+1H approach, covering reasons, locations, timing, implementation, and proposed corrective actions.

Students’ learning outcomes are influenced by various internal and external factors, one of which is learning motivation. This study aims to analyze the relationship between learning motivation and learning outcomes in the Creative Product and Entrepreneurship (PKK) subject among 11th-grade students at SMK Semen Padang. The research employed a quantitative approach with a correlational design. The population consisted of 47 students, all of whom were included as samples using the total sampling technique. Data on learning motivation were collected through a questionnaire, while learning outcomes were obtained from official school records. Data analysis was carried out using descriptive statistics and the Pearson Product Moment correlation test. The results revealed a positive and significant relationship between learning motivation and learning outcomes (r = 0.547 > 0.288; p = 0.000 < 0.05), with a contribution of 29.9%. These findings indicate that the higher the students’ learning motivation, the better their academic performance. This study highlights the crucial role of motivation as a determinant of academic achievement and suggests that teachers should foster students’ learning enthusiasm through engaging and interactive teaching strategies.

This research discusses the development of a school Geographic Information System (GIS) based on a microservice architecture to simplify access and management of school data. The background of this study is the need for an efficient and well-organized school data management system that can present school information interactively to the public. The purpose of this research is to build a system capable of displaying school locations and providing data management features for teachers, students, and school accreditation through CRUD (Create, Read, Update, Delete) operations. The development method includes database design, API creation for each microservice, data integration through an interactive map interface using Leaflet, and system testing using the Black Box Testing method. The test results show that all system features function properly and meet user requirements. The implementation of microservice architecture allows the system to be more flexible, easily updated, and well distributed among services. With this system, the public can access school information quickly and accurately, while schools can manage their data more effectively.