Effect of Water Hyacinth Fiber Length and Content on the Torsional Strength of Epoxy Resin Composites

This study investigates the influence of water hyacinth fiber length and content on the torsional strength of epoxy resin composites. Utilizing an experimental design, specimens were prepared with varying fiber lengths (10 mm, 20 mm, 25 mm, and 135 mm) and content percentages (4%, 7%, and 10%) and subjected to torsional testing according to ASTM E-143 standards. The primary objective was to determine the optimal fiber configurations that enhance the composite's mechanical properties, particularly its resistance to torsional stress. Results indicated that shorter fiber lengths consistently yielded higher torsional strength, with the 20 mm fibers at a 7% content displaying the highest torque resistance, achieving a maximum of 1.418 Nm and a shear stress of 29.348 MPa. In contrast, longer fibers generally showed diminished performance, likely due to poorer resin penetration and fiber-matrix bonding. Regression analysis was employed to develop predictive models for the torsional behavior based on fiber dimensions and compositions, achieving high accuracy with coefficients of determination (R²) ranging from 0.95 to 1.00, suggesting excellent model fits. These findings underscore the potential of using water hyacinth fibers as effective reinforcement in epoxy composites, particularly at optimal lengths and concentrations. The study contributes to the broader utilization of natural fibers in composites, offering a sustainable alternative to synthetic fibers with beneficial mechanical properties and environmental impacts

Statistical Analysis Engine Capacity, Weight, and Torque on MPV Fuel Consumption Using Regression and Correlation Algorithms

The rapid increase in production and usage of Multi-Purpose Vehicles (MPVs) in Indonesia has led to heightened concerns over fuel consumption, environmental pollution, and economic sustainability. This study investigates the relationship between engine capacity, vehicle weight, engine torque, and fuel consumption in MPVs, aiming to provide a better understanding of how these variables influence fuel efficiency. Data from 1500 cc MPV models produced between 2023 and 2024 were collected, including technical specifications such as engine capacity, weight, torque, and reported fuel consumption. Using MATLAB, linear regression and Pearson correlation analysis were employed to analyze these relationships. The results reveal that vehicle weight has the most significant impact on fuel efficiency, exhibiting a strong negative correlation of -0.69, meaning that heavier vehicles tend to consume more fuel. Engine capacity showed a moderate negative correlation of -0.28, while engine torque had a weak correlation of -0.11, indicating that torque plays a less critical role in determining fuel consumption under normal driving conditions. The regression analysis further confirmed that vehicle weight is the most influential factor, with reductions in weight providing the greatest potential for improving fuel efficiency. These findings have important implications for both manufacturers and consumers. Automotive manufacturers are encouraged to prioritize the use of lightweight materials and advanced engineering designs to enhance fuel efficiency. Additionally, consumers can use this information to make informed decisions when selecting MPVs, focusing on models with optimized weight to reduce fuel consumption. Overall, this study contributes to ongoing efforts to develop more sustainable and fuel-efficient vehicles in the automotive industry

Condensate Water Processing of Split-Unit Air Conditioning System on Commercial Building

This research investigates the feasibility and potential for water recovery from condensate produced by a split-unit air conditioning (AC) system in a commercial building, focusing on Scholar’s Inn UTM (SIUTM) in Johor, Malaysia. The study involves the collection and measurement of condensate water from 243 AC units under various operational conditions. The results indicate that the building can produce up to 4,781 liters of condensate per day, amounting to an annual total of approximately 1,721,160 liters. This significant volume highlights the potential for utilizing condensate as an alternative water source, especially in regions with similar hot and humid climates. Water quality analysis was conducted to evaluate the suitability of the condensate for various applications. The condensate water exhibited a pH of 7.17, Total Dissolved Solids (TDS) of 1.0 mg/L, and a copper (Cu) concentration of 1.1 mg/L. While these parameters indicate that the water is within acceptable ranges for non-potable uses, such as irrigation or cooling tower makeup water, the copper concentration slightly exceeds the standard for potable water, necessitating treatment such as reverse osmosis before consumption. The study’s findings underscore the environmental and economic benefits of condensate recovery, offering a sustainable solution to water scarcity issues in commercial buildings. By integrating condensate recovery systems, facilities can reduce their reliance on traditional water sources, contributing to broader water conservation efforts. Future research should explore the long-term viability and scalability of such systems in various building types and climates

GREEN TECHNOLOGY FOR SUSTAINABLE AGRICULTURE: BIO-FERTILIZER PRODUCTION FROM MUNICIPAL WASTE TO PRESERVE THE ENVIRONMENT

This study addresses the pressing issue of municipal waste (MW) management by proposing an innovative approach to transform residential solid waste into a valuable resource using green technology. MW, sourced from diverse sectors, undergoes various disposal methods, including incineration, recycling, and landfilling. In Malaysia, the composition of MW aligns with global trends, with food waste and plastic being the predominant categories. This research focuses on producing fertilizer from residential solid waste through a green technology process, utilizing a sequential procedure involving high pressure, high temperature, and energized water to de-polymerize hemicellulose and lignin, followed by microbial enzymatic fermentation. The developed green technology introduces a novel apparatus designed for treating MW in a high-temperature, low-pressure rotating vessel using indirect heating with thermal fluid. The experimental protocol involves four batches of MW samples, evaluating the mass differential before and after the treatment process. Furthermore, a 7-week observation period assesses chili plant growth as an indicator of fertilizer effectiveness. Results indicate a significant 71% mass reduction of MW, amounting to 201.26 kg, emphasizing the efficacy of the developed process. The investigation extends to plant height, comparing MW-derived fertilizer with commercial fertilizer over a 5-week period. Remarkably, chili plants fertilized with MW-derived fertilizer exhibit a greater height of 8.6 cm, surpassing the 7.3 cm observed with commercial fertilizer. This study concludes that MW-derived fertilizer is highly recommended for enhancing plant growth and health in Malaysia, suggesting a sustainable production system. The research not only contributes to waste management but also aligns with broader goals of promoting environmentally conscious and sustainable agricultural practices, emphasizing the potential of green technology in addressing the challenges of municipal waste

Heat Mapping and Plastic Strain Radius Modeling of Dual-Tool Friction Stir Welds 6061 Aluminum Alloy Plate Using FEM

This study investigates the effects of Dual-Tool Friction Stir Welding (DT-FSW) parameters on the weld quality of 8 mm thick 6061 aluminum alloy plates, specifically focusing on the elimination or minimization of the "pass-overlap zone" that’s a gap typically observed at the mid-section of the weld cross-section resembling characteristics of the Heat-Affected Zone (HAZ). To address ongoing debates regarding the optimal joint performance concerning this overlap, symmetric increases in the dimensions of both FSW tools were implemented to analyze resultant temperature fields and plastic strain adaptations at the weld interfaces. Simulation visualizations were conducted with tool density variations at intervals of 0.2 mm and 0.4 mm. Results indicate that increasing tool density, thereby reducing the distance between tool surfaces, leads to a decrease in peak temperatures generated during welding. This reduction in temperature correlates with a more uniform distribution of plastic strain rates across all layers of the material—upper, middle, and lower—with the leading edge exhibiting the most significant improvement in strain uniformity. Conversely, during the stabilization phase, a decrease in tool density (S) results in a reduction of the maximum equivalent plastic strain rate. These findings suggest that careful adjustment of tool density in DT-FSW processes can enhance weld quality by promoting more uniform mechanical and thermal properties across the joint

Effect of Pouring Temperature Variation on Cooling Rate, Hardness and Microstructure of Al-Zn in Aircraft Structures

Al-Zn alloys are widely utilized in industries such as automotive, aircraft manufacturing, and advanced military equipment due to their exceptional strength-to-weight ratio. Among various fabrication methods, metal casting is a commonly used technique for producing structural components from these alloys. However, a significant challenge with metal casting is the reduction in mechanical properties compared to the base material before melting. This reduction highlights the need for research to identify the optimal casting conditions, particularly the casting temperature, which plays a crucial role in maintaining and potentially enhancing the material's mechanical properties. Aluminum alloy 7075, known for its high strength, was selected for investigation. According to the Al-Zn phase diagram, the melting point of aluminum alloy 7075, based on the weight percentage specified by the Standard Aluminum Association, is approximately 660°C. Experiments were conducted by varying the pouring temperature during casting in 30°C increments above this melting point. Specifically, the alloy was melted and cast at three different temperatures: 690°C, 720°C, and 750°C. The mold temperature was consistently maintained at 220°C to isolate the effects of the pouring temperature. Results indicate that increasing the casting temperature significantly affects the alloy's microstructure and mechanical properties. As the casting temperature increases, the cooling rate decreases, leading to a finer grain structure. This finer grain size directly contributes to an increase in hardness, suggesting that higher casting temperatures can enhance the mechanical properties of Al-Zn alloys. These findings emphasize the importance of precise control over casting temperatures to optimize the performance characteristics of aluminum alloy 7075 in high-strength applications

Ride Test on Vehicles Travelling Over Speed Bumps: Simulation with CarSim Software

This study explores the effects of different speed bump geometries—flat-topped, sinusoidal, and parabolic—on vehicle dynamics and ride comfort using CarSim simulations. The analysis focuses on key parameters such as vertical forces on the suspension, vertical acceleration, and the wheel surface adhesion index. The results show that flat-topped bumps generate the highest vertical forces, reaching peaks of up to 6,000 N on the front suspension, leading to increased discomfort. Sinusoidal bumps, in contrast, generate smoother transitions, with vertical forces peaking at approximately 3,500 N, improving ride comfort. At vehicle speeds of 30 km/h, the vertical forces on the suspension increase significantly, with flat-topped bumps reducing the wheel surface adhesion index to as low as 0.6, indicating a higher risk of wheel slip and compromised vehicle stability. In contrast, sinusoidal bumps maintain a more favorable adhesion index of 0.85 at similar speeds. These reductions in adhesion elevate the risk of loss of control, especially at higher speeds. The findings suggest that adaptive suspension systems, capable of adjusting damping and stiffness based on the bump geometry and vehicle speed, would enhance ride quality and stability. Additionally, smoother bump designs, such as sinusoidal profiles, are recommended to reduce the impact on vehicle dynamics, particularly in urban environments. These insights contribute to improving both vehicle design and road safety, ensuring safer and more comfortable driving experiences

Enhancing Conveyor Belt Performance: Evaluating the Impact of In-creased Capacity Using Belt Analyst Software

This study investigates the effects of increasing conveyor belt capacity from 148.5 tons per hour (t/h) to 180 t/h on the overall system performance, employing both manual measurements and simulations using Belt Analyst software. The research aims to evaluate critical parameters such as effective pulling force, motor power requirements, structural load, and belt deflection, which are essential for determining the feasibility and impact of such an upgrade. The analysis reveals that with the capacity increase, the effective pulling force required rises to 14,072 N, while the motor power usage escalates to 15 kW. Concurrently, the structural load experiences a significant increase from 46.144 kg/m to 56.238 kg/m, and belt deflection intensifies from 22 mm to 27 mm. These findings suggest that increasing the conveyor belt capacity to 180 t/h, may lead to increased stress on the structure and belt, which could potentially affect the lifespan and performance of the conveyor system. Furthermore, while the conveyor system's performance enhances at the higher capacity, it also places additional stress on the system's components. The study further examines the implications of these changes, emphasizing the potential risks to the conveyor belt’s structural integrity and the possible reduction in its lifespan due to the increased mechanical stress. It is highlighted that careful consideration and precise engineering adjustments are necessary when planning capacity enhancements to avoid adverse effects on the system's longevity and reliability

Performance Evaluation of a Condenser at a Combined Cycle Power Plant Using the LMTD Method

This study evaluates the performance of the condenser at the Cilegon Combined Cycle Power Plant (CCPP) using the Logarithmic Mean Temperature Difference (LMTD) method to measure the heat transfer rate. Routine maintenance carried out on the condenser in the form of cleaning the condenser water box and condenser tube from garbage and crust on the condenser tube wall. Currently, condenser maintenance follows a routine schedule that is tied to steam turbine maintenance, without taking actual condenser performance into account. This can lead to inefficiencies and unnecessary downtime. The goal of this research is to assess the heat transfer rate of the condenser before and after maintenance to judge its effectiveness. Data on temperature changes were gathered in June 2023, before maintenance, and again in July 2023, after an overhaul. The analysis shows that the heat transfer rate increased from 51,362,294.48 kcal/h to 127,246,219.7 kcal/h, while the LMTD value rose from 0.76°C to 1.86°C. Based on these results, the study suggests a new approach to maintenance that focuses on performance. Specifically, maintenance should be done when the heat transfer rate drops below 110,000,000 kcal/h. This approach will help ensure the condenser works at its best, improve the plant's overall efficiency, and prevent the need for unnecessary maintenance. By aligning maintenance with performance data, the plant can boost output while lowering costs and downtime

Design and Analysis of a Vertical Axis Ocean Current Turbine Tunnel Using SolidWorks Computational Fluid Dynamics

The development of renewable energy in the marine power generation sector presents a promising approach to producing electrical energy in a sustainable and environmentally friendly manner. Indonesia, with its vast oceanic territory, holds significant potential for harnessing marine energy. However, the relatively slow speed of ocean currents in the region, typically ranging from 0.1 m/s to 1.5 m/s, poses a challenge to the efficiency of marine power generation. To overcome this limitation, this research focuses on the design and analysis of a vertical-axis ocean current turbine tunnel aimed at increasing the speed of ocean currents, thereby enhancing the overall efficiency of energy production. The study combines a thorough literature review with experimental research methods, utilizing SolidWorks Computational Fluid Dynamics (CFD) software to simulate the tunnel's impact on ocean current velocity. The simulations reveal that the tunnel construction significantly boosts current speeds, increasing them from 1.0 m/s to 1.7 m/s, and from 1.5 m/s to 2.6 m/s. This increase in velocity directly translates to higher kinetic energy available for conversion into electrical power by the turbine. Moreover, the study shows that the tunnel construction contributes to a more uniform flow of ocean currents, as evidenced by the Reynolds numbers obtained—100.250 at a current speed of 1.0 m/s and 150.375 at 1.5 m/s. These values, being below 2000, indicate laminar flow conditions within the tunnel, which are beneficial for optimizing turbine performance by reducing turbulence and ensuring a stable energy output. The findings underscore the effectiveness of the tunnel design in improving the efficiency of vertical-axis ocean current turbines, making it a viable solution for enhancing renewable energy production in regions with low ocean current speeds