This study investigates the corrosion behavior and mechanical degradation of welded ST37 low-carbon steel exposed to basic (NaOH) and chloride-containing (NH₄Cl) environments. The objective is to evaluate the influence of solution chemistry and immersion time on corrosion rate, surface morphology, elemental composition, and tensile properties of welded steel structures. Welded ST37 specimens were immersed in 1 M NaOH and 1 M NH₄Cl solutions for 100, 200, and 300 hours under controlled laboratory conditions. Corrosion rates were determined using the weight loss method, while surface morphology and elemental composition were analyzed using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS). Mechanical degradation was evaluated through tensile testing following ASTM E8 standards. The results show that NaOH exposure promotes the formation of a stable oxide layer that reduces corrosion rates from 0.024 to 0.019 mm/year and partially restores tensile strength after prolonged immersion. In contrast, NH₄Cl exposure causes more aggressive corrosion characterized by pitting, porous corrosion products, and localized surface degradation due to chloride-induced passive film breakdown. SEM observations confirm thicker corrosion layers and localized attack in the weld metal region, while EDS analysis reveals increased oxygen and chloride content associated with the respective corrosion mechanisms.

Self-powered energy harvesting systems have gained a lot of interest in triboelectric nanogenerators (TENGs) that are made of polyvinylidene fluoride (PVDF). But, the optimization of material combinations and device parameters to achieve electrical output is still a complicated task because of complicated triboelectric interactions. In this research paper we suggest a data-driven materials informatics model that combines machine learning with features importance analysis and explainability algorithm (SHAP) to achieve the identification of the crucial parameters that control triboelectric performance. A collection of 100 experimentally reported PVDF-TENG devices based on triboelectric materials combinations, electrode arrangement, open-circuit voltage (Voc), device size, and short-circuit current (Isc) was gathered from using peer-reviewed literature as a source of information. A total of 91 valid samples consisting of seven predictive features were used to generate power density prediction regression models after preprocessing. The algorithms of Linear Regression, Random Forest, and XGBoost were applied and compared based on MAE, RMSE, and R2 and five-fold cross-validation. Random Forest model is the best model in terms of prediction accuracy (R2 = 0.79), and analysis of feature importance showed that Voc and Isc were the most important parameters affecting device performance. The suggested framework allows optimizing the design of PVDF-based TENG materials and devices based design on self powered systems of the next generation using the data.

This research investigates the development of a high-performance aluminum-silicon (Al-Si) alloy connecting rod and piston reinforced with titanium boride (TiB) particles. Al-Si alloys are widely used in the automotive sector due to their lightweight nature, good thermal conductivity, and corrosion resistance. However, their mechanical properties, especially tensile strength, hardness, and wear resistance are often insufficient for demanding applications like connecting rods. To address this, TiB particles are introduced as reinforcements to create a metal matrix composite with superior mechanical performance. The study emphasizes refining the casting process to ensure uniform dispersion and strong bonding of TiB particles within the Al-Si matrix, which is crucial for consistent and reliable performance. Casting parameters are optimized to enhance microstructural uniformity and particle integration. After casting, mechanical testing was conducted, including tensile strength, hardness, and wear resistance evaluations. The results show significant improvements in all tested properties compared to the unreinforced alloy. The TiB-reinforced composite demonstrated higher tensile strength, increased hardness, and reduced wear, indicating its suitability for high-stress engine components. These enhancements suggest that the reinforced connecting rod and piston can offer longer service life, reduced maintenance, and improved reliability in automotive applications, making it a promising solution for lightweight and durable engine part manufacturing.

This study concentrates on the design, development, and implementation of an automated pellet feed production system specifically for catfish aquaculture. The objective is to rectify inefficiencies and labor issues in manual feed production by the implementation of a mechanized solution that improves productivity, uniformity, and operational simplicity. The method was designed to rectify inefficiencies in manual feed processing, augment feed uniformity, and elevate operational efficiency by integrating smart farming technologies. The apparatus incorporates many sensors, such as temperature (DS18B20), humidity (DHT22), current (ACS712), tachometer, and power sensors (INA219), facilitating real-time monitoring and data collection. The extrusion temperature was sustained at an average of 87.5°C, material moisture at 14.8%, motor speed at 1420 rpm, and power consumption at 468 W, hence maintaining uniform feed quality and effective energy utilization. Testing encompassed operability assessments, feed quality evaluations, and performance analyses. The results demonstrate that the system effectively minimizes time and labor in feed preparation while generating high-quality, uniform pellets that promote fish growth. Overall, this study highlights how the convergence of automation, sensorization, and IoT connectivity can transform traditional catfish farming into a smart, efficient, and sustainable aquaculture system, contributing to the advancement of precision aquaculture technologies in developing regions.

The potential of natural resources in tropical countries is very diverse. one of them is the abundant agricultural products. but there are some obstacles in the post-harvest cycle and the continuous availability when the harvest season ends. various methods of preserving agricultural products have been tested from conventional methods to advanced technology. one of the technologies for preserving agricultural products is freeze drying. various innovations continue to be tested until they get consistent results with good energy efficiency. This method was originally started in the pharmaceutical industry. Various treatments and flexible adaptations make this method penetrate the food industry to maintain the quality of food products. In the food industry, freeze drying is suitable for food products such as meat, fruits, grains, and vegetables. The advantage of freeze drying is that the food products produced do not change shape, form, texture, taste, and nutrition even though they have gone through the drying process. Of the various characteristics of fruits and vegetables have their own properties that can be changed with the temperature parameters applied in the freeze dryer method.

The increasing accumulation of polyethylene terephthalate (PET) plastic waste poses a significant environmental challenge due to its resistance to degradation and limited recycling pathways. Pyrolysis has emerged as a promising thermochemical method for converting PET waste into valuable byproducts, including energy-dense char. This study investigates the effect of pyrolysis temperature on the calorific value and moisture content of char produced from PET plastic under a fixed residence time of 60 minutes. Experiments were conducted at three temperatures 200°C, 300°C, and 400°C using a stainless-steel batch reactor under a nitrogen atmosphere. The results showed a clear trend: higher temperatures significantly enhanced the char’s quality. At 400°C, the char exhibited a calorific value of 27.4 ± 0.2 MJ/kg and a moisture content of 2.8 ± 0.1%, compared to 18.2 ± 0.1 MJ/kg and 7.5 ± 0.1% at 200°C. These improvements are attributed to increased devolatilization and aromatization processes that enhance fixed carbon content and thermal stability. Statistical analyses ANOVA confirmed that the differences across temperatures were highly significant (p < 0.001). While the results demonstrate that PET-derived char has potential as an alternative solid fuel, the study is limited to calorific and moisture characteristics. Further research is recommended to evaluate additional properties such as ash content, combustion emissions, and real-world fuel performance. Overall, this work contributes to the growing body of knowledge on plastic-to- energy conversion and supports the development of sustainable waste management technologies.

This research presents the design and development of a mathematical model for a vehicle steering system guided by the Antilock Braking System (ABS) with integrated automatic control. The purpose of this study is to enhance vehicle stability and steering performance, particularly under critical braking conditions where loss of traction and directional control commonly occur. The proposed model integrates ABS dynamics with an automatic steering control algorithm to simulate real-time responses of the vehicle under various road and driving scenarios. The mathematical formulation is based on vehicle kinematics and dynamics, incorporating nonlinear tire characteristics, braking force distribution, and steering angle adjustments. A control system utilizing PID (Proportional-Integral-Derivative) component is embedded into the model to optimize the coordination between braking and steering operations. Simulation results using MATLAB show that the integrated system significantly improves steering accuracy, reduces stopping distance, and maintains vehicle stability during sudden braking and turning maneuvers. The findings suggest that combining ABS with intelligent steering control contributes to safer driving, especially on slippery or uneven surfaces. This research serves as a foundational step toward the development of more advanced driver-assistance systems (ADAS) and contributes to the ongoing efforts in automotive safety engineering.

In the cars industry, to control slip rate from wheels and help drivers to avoid accidents on road, an integrated antilock braking and guided steering (AB-GS) system has been developed for vehicles especially cars. The brake and steering system are devices to slow down or stop the movement of the wheels on the vehicle and have ease of control and directional stability. Because the wheels are slowed down, the vehicle's motion automatically slows down. The lost kinetic energy is con-verted into heat due to friction. The three purposes of the AB-GS brake controller are to reduce stopping time, limit slip ratio, and improve control system performance (by reducing time ratio and overshoot). For that, we build a model based on the equations of motion, which are affected by forces and moments for each axis. This research utilized MATLAB as a tool for modeling the system dynamics and simulating the performance of the AB-GS brake controller. In the ABS system, there is an influence of force or moment towards the lateral (X), longitudinal (Y), and vertical (Z) axes. At the time of braking, there will be a change in directional force (X, Y, and Z) as well as moments that affect the direction of rolling motion, yaw and pitching. When braking forcefully, it is equally important to maintain vehicle stability and steering control as it is to minimize stopping distance. Changes in motion along the Zaxis, as well as moments affecting yaw and roll, are not considered in this study. Then, from the system's equations of motion, we can control it using PID control. By controlling the system, it is expected to prevent the vehicle from experiencing sudden locking, which can result in overturning. In this research, control performance was also tested using PID, which can improve vehicle driving ability, safety, and operating stability. To fully maintain vehicle direction stability, its integration with other control systems is needed. Simulation results validating the integrated antilock-braking and steering system not only obtain better optimal braking distances and excellent predictability but also show that the integrated control system outperforms the standalone braking and steering system.

This study examines the hardness and tensile strength characterization of SS304 stainless steel welded using different electrode variations in the Shielded Metal Arc Welding (SMAW) process. The research focuses on three types of electrodes: NSN 308, NSN 309L, and NSN 312, to evaluate their influence on the mechanical properties of the weld metal. Hardness testing was conducted using the Vickers method with a 200-gf load, while tensile strength testing was performed to assess ultimate tensile strength (σu), yield strength (σy), and elongation (ε). The results indicate that the selection of electrodes significantly affects the hardness and tensile properties of the welded joints. NSN 312 exhibited the highest hardness values, particularly in the weld metal and filler areas, suggesting the formation of hard phases such as martensite or chromium-rich ferrite, making it suitable for wear-resistant applications. NSN 309L demonstrated moderate hardness, indicating a more balanced microstructure that provides good toughness and ductility. NSN 308 showed the lowest hardness values, which can be beneficial for applications requiring greater deformability. In the tensile test, NSN 309L achieved the highest ultimate tensile strength 47.77 Kg/mm² and elongation 45%, suggesting an optimal balance of strength and ductility. NSN 312 exhibited the highest yield strength 46 Kg/mm², indicating better resistance to plastic deformation. Meanwhile, NSN 308 had lower tensile properties compared to the other electrodes. Overall, electrode selection should align with specific application requirements. NSN 312 is recommended for wear-resistant applications, NSN 309L for structures requiring both strength and ductility, and NSN 308 for applications with lower mechanical stress.

Reconfigurable Intelligent Surfaces (RIS) have emerged as a transformative technology for enhancing wireless communication systems by intelligently manipulating the propagation environment. In this paper, we investigate the performance of a Cooperative Non-Orthogonal Multiple Access (C-NOMA) network augmented with RIS under the practical constraint of imperfect channel state information (CSI). We consider a downlink scenario where a base station communicates with multiple users via an RIS and a decode- and-forward (DF) relay, forming a cooperative architecture to improve coverage and reliability. Current wireless technology is primarily aimed at boosting radio signal transmission in the context of creating 5G to 6G technology. Reconfigurable Intelligent Surface (RIS), Large Intelligent Surface (LIS), or Intelligent Reflective Surface (IRS) is a novel technology that uses electromagnetically controlled surfaces to integrate into current infrastructure. Because RIS passively reflects messages rather than amplification mechanisms like relays, RIS-assisted communication is more energy efficient than traditional delivery approaches. We will examine coverage performance, which is often expressed in terms of outage probability, if RIS is implemented on a radio access system using the Non- Orthogonal Multiple Access (NOMA) technique used in 5G network scheme, considering the condition of the Imperfect Channel State Information (ip-CSI) via Rayleigh fading channel, in this study. Because of channel estimate errors, perfect channel state information (p-CSI) conditions are difficult to achieve in realistic wireless systems.

This study investigates the integration of unmanned aerial vehicles (UAVs) in air combat, focusing on their role in the battlefield management system (BMS) for effective communication and data management. Utilizing UAVs minimizes pilot casualties and enables real-time decision-making. The chapter examines resource allocation in ultra-dense networks using active-reconfigurable intelligent surfaces (A-RIS) assisted non-orthogonal multiple access (NOMA). It explores the coverage performance and ergodic capacity in a NOMA network under Nakagami-m fading channels, employing a multi-input multi-output (MIMO) system with RIS elements. The results demonstrate the superiority of RIS-assisted NOMA over conventional methods, offering enhanced coverage probabilities and ergodic capacity. The study concludes that the integration of A-RIS in UAVs significantly improves battlefield communication, highlighting its potential in military applications.

Introduction Indonesian migrant workers in Taiwan play a crucial role in the labor market but often encounter challenges related to skill deficiencies and dependence on their employers. Addressing these issues through the development of soft skills and preparation for self-reliance. States benefit economically from the remittances sent by Indonesian migrant workers, but these workers often face vulnerability, especially when their contracts expire, and they return to their home countries. Purpose This study aims to explore the enhancement of Indonesian migrant workers’ capabilities by focusing on the development of soft skills and fostering self-reliance. It seeks to understand how targeted training programs can bridge skill gaps and empower workers. Methodology A mixed-methods approach was employed, incorporating both quantitative and qualitative data collection. Surveys were distributed to a sample of Indonesian migrant workers to assess their current skill levels and training needs. Findings The study found that Indonesian migrant workers possess varying levels of soft skills, with significant room for improvement in areas such as communication, problem-solving, and adaptability. Training programs tailored to these needs were shown to enhance workers’ job performance, confidence, and readiness for independent living. Implications Integrating digital marketing into the enhancement of soft skills and self-sufficiency training for Indonesian migrant workers in Taiwan offers a substantial chance to empower them and promote their economic progress. Proficiency in digital marketing can augment one’s capacity to communicate proficiently, devise innovative solutions to challenges, and adjust to the ever-changing digital environment.

Blacksmiths manufacture farm equipment that still uses conventional systems in their production. The fabrication process goes through the heating stage of steel to a temperature of 850°C as the primary raw material (carbon steel). Heating aims to make the steel easy to shape into farm tools. Conventional furnace designs, such as those at blacksmiths in the Pandak area, Bantul, still use an open system, causing air pollution around the workplace. This research modernizes a blacksmith furnace for iron with multi-air flow and dust filtration systems. Total dust testing uses SNI 7119-3:2017 standards. The results were that the burning stove has three variations of airflow, which can be adjusted to the type of work to save wood charcoal fuel by around 30%. A combustion furnace with an ash filtration system can minimize pollutant particles around the work environment from 3.99 mg/m3 to 0.024 mg/m3. Modernization of furnaces has reduced air pollution by up to 99%.

The application of science and technology has an increasingly important role in the development of small industries, including the tempeh industry. The purpose of this study is to apply science and technology to establish a small tempeh industry in Banguntapan, Bantul, focusing on enhancing local production capabilities. The initiative aims to improve the quality and quantity of tempeh production while addressing local economic needs by creating sustainable business models. The method used in this study includes automated soybean grinders for improved processing, and fermentation control systems for product consistency. The study concludes that technological integration, combined with continuous training and support, can significantly improve the operational efficiency and market competitiveness of tempeh enterprises in rural areas. The soybean grinder test yielded an average of 78 grams of split soybeans when grinding 100 grams of soybeans at a spacing of 2.5 mm, using a variable grinder speed ranging from 300 to 700 rpm. The success achieved in Banguntapan demonstrates how small-scale enterprises can flourish when technology is effectively combined with entrepreneurial initiatives. Going forward, efforts should prioritize sustaining these advancements through continuous training and encouraging partnerships between local authorities and private stakeholders to further advance the tempeh industry in the region.

Indonesia, as the largest archipelagic country in the world, has a very favourable geographical position because it is located between the Indian Ocean and the Pacific Ocean. The background of this research stems from the critical importance of effectively managing ballast loading on passenger ships to ensure stability, safety, and operational efficiency during voyages. Traditionally, methods for assessing ballast loading have often relied on empirical formulas or simplified models, which may not fully capture the complex fluid dynamics and structural interactions inherent in modern ship designs. This gap highlights the need for advanced computational tools like computational fluid dynamics (CFD), which can provide a more detailed and accurate analysis of how ballast loading affects the ship’s behaviour. CFD simulations offer the capability to model and analyse complex flow patterns, pressure distributions, and structural responses under various ballasting scenarios. By leveraging CFD, this research aims to enhance understanding and optimize the management of ballast loading on passenger ships, thereby addressing the limitations of traditional methods and advancing the state-of-the-art in maritime engineering practices. The simulation was carried out at different speeds, namely 1 knot, 10 knots, and 20 knots. When moving at a speed of 1 knot, the obstacles encountered have a range of 30–40 cm/s and a maximum speed of 83.0971 cm/s. Likewise, when moving at a speed of 10 knots, the obstacle has a range of 200–400 cm/s and a maximum speed of 766.921 cm/s. Finally, at a speed of 20 knots, facing obstacles with speeds ranging from 400 to 800 cm/s and a maximum speed of 1504.56 cm/s, the ship’s hull remained unaffected in terms of damage. However, the fluid speed magnifies the occurrence of friction.

The integration of solar lighting systems in public facilities represents a progressive effort to build smart electricity infrastructure. By harnessing renewable solar energy, these systems reduce dependence on traditional power sources, contributing to significant decreases in carbon emissions and operational costs. The PCM Playen building was built in an area of 600 m2, has two floors with an area of 200 m2 each. However, the PCM Playen building has not been supported by adequate facilities and infrastructure, especially lighting. This causes the location of the building to be dark and does not support activities at night. PCM Playen's building is in an area adjacent to the river with many trees, causing a dark and uncomfortable atmosphere especially at night. Some emergency installations are installed in areas of the building with inappropriate conditions. Therefore, it is considered necessary and urgent to immediately provide solutions to the conditions and problems of the lighting system. One of the solutions chosen is the utilization of renewable energy sources through the application of solar electricity. Solar lighting not only enhances energy efficiency but also aligns with the principles of sustainable urban development. The incorporation of advanced technologies enables remote monitoring and automated control, optimizing energy use and improving public safety and convenience. This paper explores the multifaceted benefits of solar lighting systems in public facilities, highlighting their role in fostering a sustainable and intelligent energy ecosystem.

This study explores the diversification of tempeh products through the integration of technology and digital marketing to enhance production capacity and market reach. Traditional tempeh production, often limited by manual processes and local sales, faces challenges in scaling up and competing in broader markets. By introducing advanced technological methods in production, including automated equipment and improved fermentation techniques, the quality and quantity of tempeh can be significantly increased. Additionally, leveraging digital marketing strategies, such as social media advertising, e-commerce platforms, and online branding, enables producers to tap into wider consumer bases, both locally and globally. This dual approach not only boosts production efficiency and output but also enhances market visibility and consumer engagement. The study aims to demonstrate how modernizing production practices and adopting digital tools can lead to sustainable growth, increased revenues, and greater competitive advantage for tempeh producers. Through case studies and data analysis, the research highlights successful implementations and provides practical recommendations for small to medium-sized enterprises (SMEs) looking to innovate and expand their market presence in the food industry.

Occupational Safety and Health is a health and safety condition that guarantees workers and others in the workplace that can impact work productivity. The importance of implementing K3 is an obligation for companies to protect workers from work accidents and work-related diseases. One of the companies that needs to be analyzed K3 is PT. SGN PG. RENDENG Kudus. The purpose of this study was to analyze K3 and provide suggestions for improvements at the grinding station of PT. SGN PG. RENDENG. The method used in analyzing Occupational Safety and Health) is Job Safety Analysis (JSA). The results of this study obtained the condition of the position of the APAR which was not by the placement and the lack of knowledge of workers using PPE so that it could have an impact on workers and the company with the potential for unwanted hazards at the grinding station of PT. SGN PG. RENDENG.

Promoting the expansion of small and medium industries (IKM) is crucial for stimulating national economic development. Small and medium-sized enterprises (SMEs) operate in several industries and have a crucial role in augmenting the earnings of those with lower socioeconomic status. The importance of small and medium-sized enterprises (SMEs) in national economic development is highly significant, particularly during times of economic crisis. This was particularly obvious in Indonesia's recent economic downturn, where SMEs had greater resilience in confronting these problems compared to large corporations, which often experienced stagnation or even ceased operations. Science and technology are becoming increasingly crucial for the advancement of small firms, including the tempe sector. The small tempe sector has emerged as a significant element of the economy in numerous nations, exerting a crucial influence on stimulating economic growth at the regional level. Nevertheless, like to other industries of a smaller scale, the tempeh sector encounters several challenges, including issues pertaining to production effectiveness, product excellence, and environmental sustainability. By organizing community service activities, many programs have been established, such as promoting the significance of branding in product marketing, fostering innovation in product development, and offering guidance on calculating the Cost of Goods Production (HPP). The results indicate that the prospective partner has the capability to oversee an IKM business division focused on soybean tempeh under the TempeMU brand.

The two-legged puller set can reach various component diameters, so this tool is more flexible and has an innovative application by using an electric, pneumatic impact tool as the driver. This research is a research and development (R&D) study using the ADDIE approach (Analysis, Design, Development, Implementation, and Evaluation). The stages or process of making a 2-leg puller set are preparation, fabrication, assembly, finishing, and testing the function of the puller set on the bearing or pully components and seeing whether the function of the puller set is correct. The design was carried out using Computer Aided Design (CAD) software, and simulations were also carried out. The product is produced by opening the air compressor lever with a pressure ranging from 40-45 psi connected to a hose and impact tool. If it is greater than 45 psi, it will damage the screw bolt threads and will not be centred. If it is lower than 40 psi, the timing is slow and not working.