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The frequent breakage of saw blades and the use of blades that are not suitable for beginner saw operators present a significant problem in metal sawing activities. This study aims to produce a double-sided sharp steel saw blade with dimensions of 310×30×0.8 mm. The production process consists of several stages, namely designing the double-sided sharp saw blade, cutting high-carbon steel material to size, drilling 4 mm diameter holes at both ends with a 310 mm distance between holes, forming sharp edges on both sides of the blade, hardening only the two cutting edges, followed by labeling, packaging, and quality and dimensional standard inspection. The production output is a double-sided sharp steel saw blade measuring 310×30×0.8 mm made from medium carbon steel. The manufacturing cost is Rp. 3,500 per unit with a processing time of 3 minutes per unit. These results indicate that the saw blade can be mounted on a general saw handle and has improved resistance to breakage, making it more suitable for beginner users whose sawing motion is not consistently aligned on a single flat plane.

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 problem in manual tractors lies in the rotor blades that are not wear-resistant and their dimensions are not up to standard. The purpose of fabrication is to obtain medium carbon steel manual tractor rotor blades measuring 220×80×8 mm. Fabrication methods include: standard blade design measuring 220 mm long, 80 mm wide, 8 mm thick, and 9 mm hole diameter, selection of used leaf spring steel type SUP9A measuring 500×90x10 mm, cutting used leaf springs, straightening used leaf springs, forging used leaf springs, drilling used leaf springs with a diameter of 9 mm, hardening at 850°C, tempering at 450°C, sharpening tractor rotary blades, finishing, product quality hardness testing. The fabrication results are in the form of a manual tractor rotary blade with dimensions of 220 × 80 × 8 mm from used SUP9A spring steel which is forged with a hardening hardness value of 55 HRC which is higher than the standard value of 50 HRC or 10% harder and the tempering results reach 45 HRC, the total production cost is IDR 80,000/unit and the processing duration is 130 minutes/unit which implies that the rotor blade is wear-resistant and has met the dimensional standards.

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.

Steam turbines remain a core technology in thermal power generation and continue to evolve through advances in aerothermal design, materials, control strategies, and digital maintenance. This paper presents a systematic literature review (SLR) of recent international studies published between 2020 and 2025 to synthesize current developments in steam turbine performance and thermal efficiency improvement. Article identification was conducted through SCOPUS using keywords related to turbine efficiency, blade/nozzle optimization, failure analysis, and material enhancement. The selected studies were analyzed thematically across four domains: (1) design and optimization using CFD/FEA, (2) material and structural resilience, (3) operational performance under variable/part-load conditions, and (4) integration with hybrid renewable systems and predictive maintenance. The reviewed evidence indicates that CFD-based nozzle/blade optimization and advanced control approaches can yield measurable efficiency improvements (approximately 2–7.3%), while material innovations and enhanced cooling strategies improve durability by mitigating thermal stress and fatigue risks. In parallel, digitalization through IoT-based predictive maintenance and additive manufacturing is increasingly reported as a pathway to reduce downtime and accelerate component production. However, recurring gaps include limited real-world validation, insufficient studies in humid/tropical environments, and a lack of long-term economic/lifecycle assessments. Future work should prioritize experimental or field verification, region-specific performance studies, and integrated techno-economic evaluation to support broader deployment of high-efficiency steam turbine systems.

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.

Post-harvest handling of chili in Indonesia is still largely done manually, requiring a relatively long processing time and producing products with a non-uniform level of fineness. This condition impacts low production efficiency and the quality of processed chili. Therefore, the application of appropriate technology in the form of a chili flour machine is needed to increase production capacity and consistency. This study aims to analyze the effect of the number of blades and mesh size on the production capacity of a disk mill type FFC 15 chili flour machine. The research method used was an experiment with a factorial design, involving two variations in the number of blades, namely three and four blades, and three variations in mesh size, namely 0.5 mm, 1 mm, and 3 mm. Each treatment combination was carried out three times. The results showed that the number of blades and mesh size had a significant effect on the machine's production capacity. The best treatment combination was obtained by using four blades with a mesh size of 3 mm, which resulted in a production capacity of 6.84 kg/hour and a Composite Desirability value of 0.983. These results indicate that proper arrangement of machine components can increase the efficiency of post-harvest chili processing.  

The increasing demand for interactive web applications has encouraged the adoption of server-driven approaches such as Livewire as an alternative to building Single Page Applications (SPAs) without complex client-side JavaScript. However, the performance implications of this approach compared to conventional methods remain insufficiently explored. This study presents an empirical comparison between Laravel Blade with AJAX and Livewire in an academic attendance system scenario. Performance evaluation was conducted using k6 on the same web server, complemented by manual browser-based testing to observe actual communication patterns. The results indicate that Livewire exhibits approximately 2.7× higher average response time and up to 6× greater bandwidth consumption than Laravel Blade, primarily due to its snapshot mechanism and state synchronization process. Conversely, Livewire demonstrates better stability, reflected by lower maximum response times and a 0% error rate. These findings highlight a clear trade-off between resource efficiency and development convenience, where Livewire favors stability and developer productivity, while Laravel Blade provides superior efficiency in terms of latency and bandwidth usage.

The problem with previous studies was the use of polyester resin as a matrix in kacang goat hair fiber composites, whereas in the latest study, epoxy resin was used, which has not been widely used. The aim was to obtain the tensile strength of composites that could be used as an alternative material for fan blades. The research method used was experimental with composite fabrication using the hand lay-up method, varying fiber lengths of 10 mm, 20 mm, and 30 mm, and varying immersion times in a 5% NaOH solution for 25, 50, 75, and 100 minutes. Tensile strength testing was carried out using the ASTM D638 standard with a total of 36 specimens. The test results showed that specimens with a fiber length of 30 mm and a soaking time of 50 minutes produced the highest tensile strength of 28.69 MPa, while the lowest tensile strength of 15.38 MPa was obtained in specimens with a fiber length of 10 mm and a soaking time of 100 minutes. This indicates that the highest tensile strength value is 46.37% greater than the lowest value, so the combination of a fiber length of 30 mm and a soaking time of 50 minutes is determined to be the optimal parameter in this study.

The purpose of this study is to develop an additional device for vehicles with fuel injection systems to improve fuel consumption efficiency and reduce exhaust emissions, even for older vehicles. The turbocyclone is an auxiliary component installed in the air intake duct before the throttle body to create a swirling airflow entering the combustion chamber. Testing was conducted at engine speeds ranging from 1500 rpm to 6500 rpm, with increments of 1000 rpm. This research aims to minimize fuel consumption and exhaust gas emissions. The experimental method was used, testing exhaust gas contents such as HC, CO, CO₂, and O₂ using a gas analyzer, and measuring fuel consumption based on fuel volume and time. Data processing employed a factorial DOE (Design of Experiments) to analyze results. The dependent variables were exhaust gas emissions and fuel consumption, while the independent variable was the turbocyclone blade angle variations of 20°, 40°, and 60°. The results show that the best reduction in exhaust emissions (HC, CO, CO₂, and O₂) and fuel efficiency occurred at a 40° blade angle, whereas fuel consumption increased at a 60° blade angle.

This study aims to analyze the effect of variations in screw conveyor speed and cutting blade on an automatic meatball molding machine in producing meatballs weighing between 15 and 20 grams. The research method used a design of experiments (DOE) approach with a factorial design, followed by a two-way ANOVA analysis to test the effect of each factor and their interactions. The screw conveyor speed variations used were 160 RPM, 140 RPM, and 124 RPM, while the cutting blade speed was varied at 224 RPM, 186 RPM, and 160 RPM. The speed variations were obtained by adjusting the pulley ratio on the machine. The testing process was carried out by molding meatballs using a combination of these speed variations, then boiling them until they float to ensure doneness. After that, the mass of each meatball was weighed with a precision scale. The weighing data were processed using Microsoft Excel and Minitab 21 software to obtain accurate statistical analysis. The results showed that increasing the screw conveyor speed tended to increase the meatball mass, while increasing the cutting blade speed actually decreased the mass of the meatballs produced. The interaction between screw conveyor speed and cutting knife speed was statistically significant with a p-value ≤ 0.05, indicating that the combination of the two plays an important role in determining the final meatball mass. Through Response Optimization analysis, the most optimal combination for producing meatballs with a mass in the range of 15–20 grams is a screw conveyor speed of 124 RPM and a cutting knife speed of 160 RPM. This setting can be achieved by using pulleys with diameters of 114.3 mm (4.5 inches) and 88.9 mm (3.5 inches). These findings are expected to be a reference for meatball industry players, especially MSMEs, in increasing production efficiency and maintaining product size consistency.

This research explores the engineering and performance evaluation of 17-4 PH stainless steel as a potential material for turbine blades in geothermal power plants (PLTP). To promote renewable energy innovation in industrial engineering, this study focuses on improving material reliability through microstructural optimization and mechanical property control. The material was produced using the investment casting method at PT SPVMB and then subjected to four heat treatment variations: H900, H1025, AVG (average), and as-cast conditions, with reference to ASTM A747 standards. Mechanical and corrosion characterization were performed through hardness and tensile tests, electrochemical corrosion analysis using geothermal water from the Dieng PLTP, and microstructural observation using an optical microscope. The results showed that the H900 condition had the highest hardness and yield strength (48.46 HRC and 939.25 MPa), but its corrosion rate was relatively high. In contrast, the H1025 heat treatment provides balanced mechanical strength (43.88 HRC and 860.91 MPa) with the lowest corrosion rate (0.027 mm/year), supported by a uniform tempered martensite structure. These findings indicate that heat treatment optimization significantly improves the suitability of 17-4 PH stainless steel for sustainable geothermal applications. The H1025 condition meets all the requirements for geothermal turbine blades, including hardness, strength, and corrosion resistance, potentially extending component life and reducing maintenance costs. Furthermore, the results of this study strengthen the agenda for developing durable, environmentally friendly materials to support renewable energy systems. This study also provides practical insights for industry in selecting the optimal heat treatment that combines mechanical performance and corrosion resistance in extreme geothermal environments.

This The maintenance objectives of a C6240A-type lathe involve a number of crucial aspects, including gears, tool bits, toolposts, lower sled and upper sled. This study was to investigate effective maintenance strategies for each of these components, focusing on preventive and predictive maintenance. Gears: Regular lubrication is also necessary to ensure smooth gear movement and prevent excessive friction that could lead to failure. Chisel Bits: Monitoring the condition of the tool blade needs to be done regularly. Toolpost: The toolpost needs to be checked periodically to ensure availability and safety of the cutting tool. Bottom and Top Slings: Maintenance of the lower and upper slings involves checking for tension and wear. C6240A type lathe users can minimize the risk of failure, improve operational efficiency, and extend the life of the machine. The method used in this research is a qualitative method, by means of observation and interviews. The results of this study are that the gears can be more durable because lubrication is always given and not easily thirsty, the tool blade is not easily blunted because the workpiece is fed little by little, and frequent honing is done to keep it sharp. The locking toolpost is not easily damaged if you use a rubber hammer when locking, the bottom row makes a change of ashock so that it can do automatic turning. This maintenance can increase the life of the lathe for longer operation.

Knife, knife is an important tool for cooks and even head chefs. There are various types and materials of knives, each knife has the same function but with different effectiveness for cutting certain ingredients. For example, 'Chef knife' This chef knife is most commonly used in the f&b world or at home, the second is 'Cleaver' cleaver or often called machete is most often used in China, and if in Indonesia it is most often used to cut poultry, and to chop various meats, the third is 'Bread knife' bread knife, as the name suggests bread knife or bread knife, usually used to cut bread or, bread knife is highly recommended for cutting bread or cake because the blade is serrated which makes it not necessary to make more effort because it is just in the usual slice, this is very effective because there is no need to press the bread or cake, and this will not damage the appearance of your bread or cake.

Indonesia has quite large wind energy resources spread across various regions, so it has the potential to be developed into PLTB. Energy needs in Indonesia continue to increase and the government is committed to utilizing new, renewable energy to achieve emission reduction targets. However, efforts to utilize wind energy are still not optimal due to several reasons, especially research and research capabilities related to PLTB. The blade is the main component in the wind turbine system and is the system that first receives the wind and then converts it into mechanical energy. This research aims to determine the performance and manufacture tapperless type wind turbine blades with NREL's S822 airfoil using Qblade and Solidworks software. The design and simulation results show that the resulting blade has a blade radius of 1 meter, a blade or chord width of 0.12 m. The twist angle from the base to the tip of the blade ranges from 11.69º to 5.05º and a power of 500 W is obtained at a rotational speed of 262 rpm.

The Majapahit Museum houses a significant collection of tosan aji, particularly keris, which holds important historical, technological, and symbolic value within Javanese culture. However, a substantial portion of the collection lacks clear provenance and stratigraphic context, resulting in data gaps and potential misinterpretations, especially regarding Majapahit-period attribution. This study aims to examine strategies for managing non-stratigraphic keris collections through standardized visual-morphological identification as an initial curatorial approach. The research employs direct artifact observation, morphological analysis of blades and ricikan, visual examination of pamor configurations, and a review of museological, keris studies, and archaeometallurgical literature. The findings demonstrate that standardized morphological identification provides a systematic framework for preliminary classification while preventing speculative chronological claims. The study also emphasizes the necessity of separating blade analysis from keris fittings and highlights the limitations of visual assessment in determining tangguh, which requires support from non-destructive metallurgical analyses. As a practical contribution, this article proposes strengthening curatorial standards through the development of morphology-based artifact labels (manual and digital), multidisciplinary scholarly catalogues, and the integration of documentation and material analysis technologies. This approach positions the Majapahit Museum as a knowledge-producing institution in tosan aji studies rather than merely a repository of artifacts.   Kata Kunci : Museum Majapahit, Keris, Identifikasi Morfologis, Ricikan, Tangguh Keris

Dangerous chemicals are always used when building new fiberglass boats which can have a negative impact on human safety and health. Fiberglass boat building also involves the use of potentially dangerous work equipment. Because the risk aspects that cause work accidents have not been identified, work accidents often occur at this fiberglass boat manufacturing company, with an average of 15 work accidents per year. With this background, the author identifies the risk of work accidents, determines the risk value and identifies alternative solutions. Identification of work accident risks is carried out using the Job Safety Analysis (JSA) method and calculating risk values ​​according to ISO 45001:2018. After identifying the risk of work accidents in the process of building new fiberglass ships at this shipbuilding company, 25 potential risks were found. The risk score calculation according to ISO 45001:2018 classifies 11 potential risks into medium risk and high risk levels. The potential risk of work accidents when cutting wood to make molds is the occurrence of scratches and limbs being cut and lacerations and even permanent physical disability due to the grinding blade coming loose while the grinding process is in progress. This shows that there is a potential risk that has reached the High Risk level and must be followed up as quickly as possible.

Introduction : Neck pain is defined as pain experienced from the base of the head (occiput) to the upper part of the back and extends to the outer and upper borders of the shoulder blade (scapula). Excessive use of cellphones by continuously placing the head in the same position will cause weakness and fatigue in the neck muscles. Purpose : This education aims to explain the causes, symptoms and exercises that can be done independently to prevent ongoing pain. Method : The method used is by providing education to teenagers, with promotional media in the form of leaflets to make it more interesting and easy to understand which contains definitions, symptoms, risk factors and exercises to reduce the pain felt.  Conclusion : The educational activities that have been carried out at Ahmad Yani Jabung Vocational School, Malang can provide students with knowledge and insight regarding neck pain so that they can increase their knowledge about how to prevent and treat neck pain independently by carrying out active exercises.  

Hydroelectric Power Plants (HPP) are a type of power plant that utilizes renewable energy from water flow. The hydroelectric system works by converting the kinetic energy of flowing water into mechanical energy, which is then converted into electrical energy. Water flows through a penstock directed towards the turbine, where it strikes the turbine blades, causing rotation. To maintain the stability of the turbine's rotational speed at the Maninjau HPP, a governor system is used. The Maninjau HPP consists of four generating subunits with a nominal rotational speed of 600 rpm. The governor system functions to stabilize the turbine's rotation at the nominal speed of 600 rpm, as the speed affects the generator's output frequency. The stabilization process is carried out by adjusting the Guide Vane openings, which are the blades surrounding the turbine. The Maninjau HPP has a speed drop of 3%, with a frequency reduction of 1.5 Hz. Additionally, a frequency change of 0.1 Hz will result in a load change of 0.13 MW.

Sundanese song pagerageungan is a traditional art originating from Tasikmalaya district. The xylophone accompaniment pattern in the Sundanese song art Pagerageungan plays a very important role in creating an atmosphere and strengthening the message contained in the song lyrics. The xylophone, as a traditional Sundanese instrument made from wooden blades, produces a distinctive sound and has a dual function as a rhythm regulator as well as adding melodic nuances to the song. The xylophone accompaniment pattern in this song is not only rhythmic, but also often has a melodic character that beautifies the song's strains. This gambang accompaniment pattern has 3 parts, namely merean, cacagan and geumbyang. The aims of this research are: (1) to find out the xylophone accompaniment pattern in the Sundanese pagerageungan song art (2) to find out the function of the xylophone accompaniment pattern in the Pagerageungan Sundanese song art. The method used in this research is qualitative with a descriptive analysis approach. The techniques used in this research are observation, interview and documentation techniques. The main instrument in this research is the research itself using tools in the form of field notes and recording tools in the form of cellphones.