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Generators are one of the important auxiliary aircraft needed on ships for power generation. During the operation of a diesel generator, continuous rotation occurs resulting in friction and erosion of the moving parts. The supporting factor for the smooth running of a diesel engine is a lubrication system that is supported by good lubricating oil quality, besides that it also needs to be supported by an adequate and good cooling system. The use of lubricants is one of the most important factors to ensure the performance of diesel engines. The lubricant is in charge of maintaining the condition of the engine so that it remains stable. This study aims to analyze the effect of using lubricating oil beyond the operating hours limit on engine heat. Furthermore, it also discusses steps to ensure diesel engine temperatures remain normal. This research was carried out during the practice of sailing on a ship for approximately one year. This study uses a descriptive quantitative research method. The primary data obtained directly utilizes observation methods, and documentation. Secondary data was obtained from existing articles and journals. The data analysis techniques used are descriptive analysis and inferential analysis. The results of this study show that the working hours of lubricating oil use have a significant influence on the increase in the temperature of diesel generator engines as evidenced by hypothesis tests on two engine units, namely AE1 and AE2. In the AE1 unit, a t-value of 18.467 with a significance of 0.000 was obtained, while in AE2 the t-value was 14.289 with a significance of 0.000. The significance value in both units is less than 0.05 so it can be concluded that the working hours of lubricated oil have a significant influence on the temperature of the genarato diesel engine on the ship.

This research aims to design and develop a prototype wave power plant that utilizes the vertical motion of a buoy as a source of mechanical energy, which is then converted into electrical energy using a recoil starter mechanism. The system is designed to be installed at the stern of a prototype ship. The vertical movement of the buoy caused by ocean waves is transmitted to the recoil starter through a drive rope, producing a stable one-way rotational motion. This rotation is further transmitted to a gearbox to increase rotational speed before driving a DC generator. The electrical energy generated is stored in a 12 VDC battery, supported by a buck–booster converter to stabilize the output voltage. This study employs an experimental engineering approach to evaluate system performance based on empirical test data. The main components of the system include a buoy as a wave energy collector, a recoil starter as the initial rotating mechanism, a DC generator as the electrical energy producer, a buck–booster converter as a voltage regulator, a 12 VDC battery as an energy storage unit, and a monitoring system based on an ESP32 microcontroller integrated with a PZEM-017 sensor. Experimental results show that the recoil starter operates effectively in driving the generator under both no- load and buoy-loaded conditions. Increases in generator rotational speed are directly proportional to increases in output voltage and current. The PZEM-017 sensor demonstrates a high level of measurement accuracy, approaching 100% when compared with a multimeter. Overall, the proposed wave power generation system functions reliably and shows potential for further development as a small-scale alternative renewable energy source.

The increasing demand for electrical energy and the limited availability of fossil fuels have driven the development of renewable energy sources, including marine current energy, which remains underutilized in coastal and remote maritime regions. This study presents the design and realization of a small-scale marine current power generation prototype using a horizontal axis propeller turbine with a NACA S814 blade profile and analyzes the effect of turbine rotational speed on electrical power output. The system converts marine current kinetic energy into mechanical energy through turbine rotation and subsequently into DC electrical energy using a generator, which is stabilized by a Buck–Boost Converter and Maximum Power Point Tracking (MPPT) for charging a 12 VDC battery. Real-time monitoring of electrical and mechanical parameters is implemented using an Internet of Things (IoT)–based system comprising an ESP32 microcontroller, a PZEM-017 sensor, and an RPM sensor. Experimental results demonstrate a positive correlation between water flow rate, turbine rotational speed, and generator output voltage. The system begins operating at a minimum flow rate of 35.2 L/s at 56 RPM, producing 0.2 V, while optimal performance is achieved at 45.3 L/s and 516 RPM, generating up to 13.3 V. These results indicate that the proposed prototype is a viable alternative renewable energy source for marine applications.

The shaft is a crucial component in mechanical systems because it serves to transfer power and rotational motion throughout the machine. This research aims to assess the structural strength and operational performance of shafts used in a tire shredding machine through numerical simulation methods in order to achieve a safe and efficient design. The study involved several stages, including the development of shaft geometry models, the determination of boundary conditions, load application, mesh generation, and stress analysis using the finite element method. Two shaft configurations were examined: a 59 mm diameter shaft made from AISI 1045 steel and a 49 mm diameter shaft manufactured from ASTM A36 steel. The simulation results indicate that the 59 mm shaft experiences a Von Mises stress of 8.9 × 10⁻⁵ MPa, with a maximum displacement of 0 mm and a safety factor of 15. Similarly, the 49 mm shaft shows a Von Mises stress of 8.4 × 10⁻⁵ MPa, no measurable displacement, and a safety factor of 15. These findings confirm that both shaft designs are capable of safely withstanding the applied working loads. In addition, cutting system tests revealed that a 24-tooth blade achieved an efficiency of 26.9%, while a 40-tooth blade reached only 22.3%, indicating that the 24-tooth configuration provides better performance.

Developmental Dysplasia of the Hip (DDH) in children often results in joint stiffness, muscle weakness, limited range of motion, and gait impairment following surgical management and immobilization. Early physiotherapy intervention is essential to restore hip function and walking ability. This study aimed to evaluate the effectiveness of active exercise on functional walking in outpatient children aged 3–5 years after DDH surgery. A case study design was conducted on three female patients who completed a five-week rehabilitation program consisting of ten active exercise sessions, including hip strengthening, mobility training, and balance exercises, combined with a home program. Outcome measures included hip range of motion, Manual Muscle Testing, and Modified McKay and Harris Hip Score assessed at baseline, mid-intervention, and post-intervention. The results showed improvements in hip range of motion, particularly in flexion, extension, abduction, adduction, and external rotation, while internal rotation improved but did not reach normal values. Muscle strength increased from grade 1–2 to grade 3 in most hip muscle groups. Functional walking scores improved from poor to good and excellent, with patients achieving independent, symmetrical gait without pain. These findings indicate that active exercise is an effective rehabilitation approach to reduce impairments and enhance functional walking in children after DDH surgery. The study highlights the importance of structured physiotherapy and caregiver involvement to optimize recovery and participation in daily activities.

MMP is a metal manufacturing company engaged in casting, forging, and machining processes with a three-shift work system, including night shifts that may increase mental and physical workload due to disruptions in workers’ biological rhythms. This study aims to analyze the mental and physical workload of die casting machine operators during the night shift and to propose improvement measures using the Fault Tree Analysis (FTA) method. The study involved 23 operators, with mental workload assessed using NASA-TLX and physical workload measured using CVL. The results indicate that mental workload falls into high to very high categories, with WWL values ranging from 46.6 to 97.3, where 12 operators experienced very high mental workload. The dominant contributing dimensions were effort, physical demand, and temporal demand. Meanwhile, physical workload ranged from 19.48% to 36.36% CVL, with most operators not experiencing fatigue. Although physical workload remains within acceptable limits, the high mental workload indicates the need for improvements. FTA analysis identified key contributing factors, including work methods, work systems, ergonomics, machine conditions, and the work environment. Proposed improvements include job rotation, improvements in work methods and task distribution, adjustments to the work system, enhanced machine maintenance, and ergonomics-based workplace improvements.

This article examines how meritocracy is institutionalized within the public administration systems of Indonesia and Singapore and how it affects public service quality. Using a descriptive–comparative library research design, the analysis focuses on four dimensions: bureaucratic structure, governing system and political influence, administrative reform and merit mechanisms, and implications for service delivery. The findings indicate that Indonesia’s bureaucracy remains highly hierarchical and decentralized, creating uneven institutional capacity and allowing electoral–political dynamics to influence appointments and rotations, which weakens consistent merit implementation. In contrast, Singapore operates a streamlined and centrally coordinated bureaucracy supported by high political stability, rigorous competency-based recruitment and promotion, transparent performance management, and competitive remuneration, enabling merit principles to be applied more consistently. These differences translate into more uniform and efficient public services in Singapore, while Indonesia continues to experience variability across regions and sectors. Strengthening merit enforcement, oversight, and professional culture is therefore crucial to improve the effectiveness and equity of public services in Indonesia.

PT UVW uses jigs in the vacuum metalizing process that require washing, which is currently done manually, resulting in inefficiency and risks to operators, thus, jig washer machine was created in order to reduce the risk for operators and increasing efficiency, which based on horizontal mixer. This study analyses the effect of agitator design on fluid flow patterns in a jig washing machine to obtain an optimal design. Two agitator design alternatives were developed and tested using Computational Fluid Dynamics (CFD) simulations at rotational speeds of 70, 75, and 100 rpm, followed by prototype fabrication and performance testing. Simulation results show that the second design produces a higher fluid velocity (20.4 m/s) and a more turbulent and uniform flow pattern compared to the first design (1.7 m/s). Field tests confirmed that the second design achieves higher washing effectiveness (97.14%) with reduced water consumption and shorter washing time. The optimally designed agitator washing machine increases productivity by six times compared to manual washing and reduces operator exposure to hazardous chemicals. This study recommends the second agitator design for improving washing efficiency and effectiveness.

Demonstrations demanding the dissolution of the House of Representatives by 2025 highlight a crisis of public trust and serve as a key moment in Indonesia's political landscape. These protests have not only symbolic significance but also lead to elite repositioning, the temporary dismissal of several members, and the cessation of policy that increased benefits. This study examines how the crisis has prompted political institutional reconstruction and the role of civil society in influencing change. A descriptive qualitative approach was used, including literature studies, analysis of academic literature, official documents, and media reports. The findings indicate that actions by the House of Representatives, such as the rotation of Commission III leadership, member deactivation, and rejection of benefit increases, were primarily reactive to public pressure. The discussion reveals that while these actions reduce crisis escalation, they are cosmetic and do not address structural issues like legislative accountability and budget transparency. In conclusion, the 2025 protests provide an opportunity for civil society to engage politically outside elections, but the institutional changes made are short-term. Fundamental reform can only occur if civil movements remain consistent and if political parties and the government commit to reform.

The problem lies in the load lock from the wheel arm, the BLDC motor whose distance cannot be adjusted, and the flywheel whose movement is less smooth than the original design. The purpose of refining the design is to obtain smooth movement and the position of the load lock from the wheel arm, the BLDC motor that can be adjusted to be ergonomic and optimal. The method of refining the design and manufacture of the rear shock breaker spring type electric bicycle through the stages of working load analysis, the need for the distance of the load setting position and the BLDC motor, calculating the construction strength, manufacturing components, assembling components, and evaluating the results of the shock breaker manufacture. The results of refining the design and manufacture of the rear shock breaker spring type electric bicycle show that the movement of the load lock position from the wheel arm and the BLDC motor is smooth, the flywheel must be balanced, the dimensions of the shock breaker device are 120 cm long, 49.5 cm wide, 155 cm high, 120 rpm rotation speed, 2 cm shock breaker movement distance, and 1.5 cm sideways movement deviation which implies being able to provide adequate damping for electric bicycle riders well.

Wood consumption in Indonesia, which is expected to reach more than 64.84 million m³ by 2025, is putting enormous pressure on forests, as evidenced by the reduction in forest area through the clearing of 96,230 hectares of forest in 2023. To reduce dependence on wood as a building material, alternative materials with comparable physical and mechanical properties are needed. Bamboo, especially laminated bamboo, was chosen because it has high tensile strength, a short harvest time, and abundant availability. This study examines the behavior of hollow section laminated bamboo beam-column connections with a glue-in-rod-bracket system to determine the ductility of the connection under unidirectional (static) loads. An experimental method was used with the independent variables of diameter and number of bolts, while the dependent variables included the moment-rotation of the connection, stiffness, strength, and ductility. The results show that the average ductility values for 4 and 6 thread rods D6, D8, and D10 mostly meet the SNI 1729 (≥1.25) and AISC 360 (rotation >0.03 rad) standards, with classifications ranging from "partially ductile" to "fully elastic." However, the 10-diameter 6-thread rod only achieved a ductility of 1.2, thus failing to meet the SNI standard. Based on the Handbook of Structural Steel Connection Design and Details, all connections fall into the non-seismic category because their ductility values are less than 3. These findings confirm the potential of laminated bamboo as an environmentally friendly construction material, while also providing technical guidelines for the design of non-seismic beam-column connections.

API abuse on lightweight edge gateways has intensified as microservice-based services expose many REST endpoints to heterogeneous clients. Conventional per-identity rate limiting, such as static token buckets, is frequently bypassed through distributed bots and identity rotation, while legitimate burst traffic may be rejected and degrade user experience. This study proposes Adaptive Rate Limiting with Verifiable Delay Functions (ARL-VDF), which couples a lightweight risk score with selective VDF challenges to impose a tunable sequential-computation cost on suspicious clients without forcing aggressive dropping for low-risk users. The gateway continuously derives a per-identity risk score from short-window request rate, error tendency, and identity freshness, then maps the score to a target delay bounded by  and . Evaluation uses a 600-second discrete-event simulation on a mixed workload consisting of normal clients, legitimate bursts, and distributed attackers. Compared with a static token bucket baseline, ARL-VDF maintains full success for legitimate traffic, reduces attacker throughput that passes the gateway, and keeps verification overhead within a fixed budget on the edge device. The results indicate that combining adaptive control with verifiable sequential cost can improve availability and fairness on resource-constrained edge gateways without resorting to aggressive dropping.

The increasing consumption of packaged food products in Indonesia reflects modern lifestyle changes but simultaneously raises public health concerns related to high calorie, sugar, and fat intake. Nutritional information presented on food labels consists of multiple interrelated variables, making it difficult to identify dominant nutritional factors that characterize packaged food products. This study aims to apply Principal Component Analysis (PCA) to reduce the dimensionality of nutritional data and to map the nutritional characteristics of packaged food products in Indonesia. The research employs a quantitative exploratory approach using secondary data obtained from nutrition facts labels of 1,651 packaged food products. Seven nutritional variables were initially analyzed, namely total energy, protein, total fat, total carbohydrates, sugar, sodium, and dietary fiber. Data preprocessing included data cleaning, Z-score standardization, and iterative variable selection based on the Kaiser-Meyer-Olkin (KMO) measure and Bartlett’s Test of Sphericity to ensure sampling adequacy and sufficient correlation among variables. Variables with low sampling adequacy and perfect multicollinearity were eliminated, resulting in five variables retained for the final PCA model. Principal components were extracted using the eigenvalue greater than one criterion and confirmed through a scree plot, followed by Varimax rotation to enhance interpretability. The results indicate the formation of two principal components explaining approximately 69.7% of the total variance. The first component represents energy density and macronutrient richness, while the second component reflects carbohydrate-related characteristics, particularly the contrasting pattern between sugar and dietary fiber. Biplot visualization further illustrates product distribution based on these components. The findings demonstrate that PCA effectively simplifies complex nutritional information and provides a clear nutritional mapping of packaged food products, offering practical insights for consumers, producers, and policymakers in supporting healthier food choices in Indonesia.

The increasing integration of Cyber physical Systems (CPS) into industrial environments has highlighted the need for secure, scalable, and efficient cryptographic key management systems. Traditional centralized key management protocols are often limited by vulnerabilities such as single points of failure, scalability issues, and significant overhead. Blockchain technology presents a promising solution to these challenges by leveraging decentralization, immutability, and transparency to enhance security and efficiency in CPS. This study investigates the use of blockchain based cryptographic key management systems, focusing on smart contracts for automated key distribution and rotation. Experimental results demonstrate that blockchain based systems significantly improve system integrity, auditability, and resilience, offering enhanced protection against cyber-attacks and reducing the risks associated with centralized systems. Blockchain’s decentralized architecture eliminates the need for a central authority, making it more resistant to tampering and operational failures. Additionally, smart contracts automate the key management process, improving efficiency while maintaining a high level of security. The study also evaluates the impact of blockchain on communication performance, finding that it reduces latency and overhead by automating processes and eliminating the need for centralized control. Despite these advantages, challenges such as scalability, latency, and integration with legacy systems remain. The study concludes by suggesting future research directions, including the development of lightweight blockchain protocols tailored for industrial applications and the integration of blockchain with emerging technologies like Artificial Intelligence (AI) to further enhance key management in CPS. Blockchain based solutions have the potential to transform the security landscape of industrial environments, offering greater robustness, reliability, and trust.

This study examines the teacher's strategy in guiding the memorization of prayer prayers in early childhood at RA Muslimat NU Banin Banat Manyar through a qualitative case study approach. The main focus is the application of the practice (repetition) and habituation method, which was observed for 6-8 weeks in 35 children in group AB (aged 4-6 years), including participant observation, in-depth interviews with 4 teachers and 5 parents, and analysis of RPP documentation and murojaah videos. The results show that the practice method is applied rhythmically daily (3x / day, 10-15 minutes), starting from simple pronunciations such as iftitah and ruku' with 20-30 repetitions per chain cycle, resulting in an average increase in memorization from 42% to 91%, with variations in singing and movements reducing boredom by 27%. Meanwhile, integrated habituation through congregational prayer routines (Dhuha, Zuhur simulation, Ashar), independent ablution, and home supervision, achieved 89% of children's independence in becoming mini imams after 21 days consistently, supported by verbal rewards and gender row rotation. The discussion confirmed alignment with Piaget's theory (preoperational stage) and Vygotsky's (ZPD scaffolding), where drills build sensory memory schemes while habituation forms permanent religious character ala Abdullah Nasih Ulwan. Supporting factors include parental collaboration and a conducive NU environment, overcoming the obstacle of low concentration. Practical implications recommend replicating this strategy in similar RAs to optimize the golden age of Islamic early childhood, with memorization retention of 8-10 basic prayer prayers.

One of the most profitable horticultural crops, but it spoils quickly due to its high water content. Processing chili peppers with a disc mill into chili powder is a great way to increase the added value of the product while extending its shelf life. The purpose of this study was to determine how the blade rotation speed and amount of material affected the production time of chili powder in an FFC15 Disc Mill. The blade rotation speed varied between 2100 rpm and 3500 rpm, and the amount of material varied between 5% and 500 g. The data were analyzed using statistical analysis to determine the effect of each component and their relationship with each other. The results showed that the blade rotation speed and the amount of material had a significant effect on the production time of chili powder. However, the relationship between these two factors did not have a significant effect. The best operating conditions were achieved with 500 grams of material and a speed of 3500 rpm, which resulted in the fastest production time of 4.367 minutes.