Jurnal Konversi Energi dan Manufaktur UNJ
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183 research outputs found
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Creation and Evaluation of a Polyurethane/Carbon/Zinc Oxide Film Composite for Use as a Coating Material
Full text linkThe material used as a coating must have unique characteristics. A frequently used coating material is polyurethane. Even though Polyurethane has been widely used as a coating material, it has limitations in thermal resistance. Incorporating fillers such as carbon and ZnO can improve its thermal, dielectric, and corrosion-resistant properties. Composite films of polyurethane with carbon, ZnO, and a mixture of both were prepared. Characterizations included FTIR, TGA, DSC, XRD, dielectric testing, salt spray, water vapor permeability, hydrophobicity, and adhesion tests. FTIR confirmed the presence of functional groups from the fillers. TGA and DSC showed improved thermal stability, particularly in carbon-filled composites. Salt spray and permeability tests indicated enhanced corrosion resistance in ZnO-filled samples, while dielectric properties improved with carbon addition. Hydrophobicity and adhesion tests met coating material criteria. Among all variants, the polyurethane/carbon composite demonstrated the most favorable combination of thermal, dielectric, and surface properties, making it the most suitable for protective coating applications
Analysis of the Effect of Print Speed and Layer Height on the Hardness of TPU-95A Filament 3D-Printed Products
Full text linkThe effect of print speed and layer height settings can influence the mechanical properties of 3D-printed products; however, the impact of print speed and layer height on the hardness of products printed with TPU-95A filament has not been extensively studied. This research employs an experimental method by creating specimens according to ASTM D2240 standards, using various print speed settings (70, 80, and 90 mm/s) and layer heights (0.15 and 0.20 mm). The results show that a combination of lower print speeds and thinner layer heights yields higher hardness test results. A print speed of 90 mm/s and a layer height of 0.15 mm produced the highest hardness, while the combination of 90 mm/s print speed and 0.2 mm layer height resulted in the lowest hardness. This study contributes to the optimization of 3D printing parameters for flexible material applications, such as TPU-95A, in relation to product hardness outcomes
Structural Strength Analysis of Car Deck Re-Layout Impact on Ro-Ro Ships Using Structural Analysis Method
Full text linkThis study focuses on analyzing the structural strength of car deck construction in roll-on/roll-off (ro-ro) passenger ships. Ro-ro ships are designed to transport both vehicles and passengers, in which vehicles can drive in and out under their own power. While these ships are operational, there is a potential for improvement in their construction strength, particularly in the car deck area. The car deck is a critical structural component as it bears both vehicle loads and supports the upper decks. This research analyzes the car deck's structural integrity, which was initially designed for trucks and sport utility vehicles (SUV), under various conditions including calm water, sagging, and hogging scenarios. Using both finite element method (FEM) analysis through ANSYS software and manual calculations via Excel, the study evaluates maximum stress points and deflection. The 3D modeling was completed using Fusion 360, while 2D drawings were created in AutoCAD. Results revealed that the highest stress occurs during hogging conditions with truck loads, showing 188.23 MPa stress and 0.077128 m deflection. With a safety factor of 1.3281, these values comply with Indonesian Classification Bureau (BKI) standards, which require stress below 250 MPa and a safety factor above 1
Analysis of Corrosion Rate in Low-Carbon Steel ASTM A36 and AISI 1020 in Sulfuric Acid Solution Using Heat Treatment Temperature and Immersion Time Variations
Full text linkThis study investigates the corrosion rate of low-carbon steel ASTM A36 and AISI 1020 in sulfuric acid solution under varying heat treatment temperatures and immersion times. Samples were subjected to heat treatment at 600, 820, and 1100 °C, followed by immersion for 24, 48, and 72 hours. The results reveal significant effects of heat treatment temperature and immersion duration on corrosion performance. At 600 °C with a 72-hour immersion, ASTM A36 exhibited a corrosion rate of 140.68 mm/year, while AISI 1020 showed 149.07 mm/year. At 820 °C, the corrosion rates for ASTM A36 and AISI 1020 were 102.34 mm/year and 96.48 mm/year, respectively. At 1100 °C, ASTM A36 demonstrated a corrosion rate of 87.97 mm/year, compared to 121.08 mm/year for AISI 1020. The findings highlight that increasing heat treatment temperature generally reduces the corrosion rate, though the effect varies by material
Reconditioning and Enhancement of Automatic Pressure Control Equipment for Servo and Regulatory Processes
Full text linkControl Systems have taken essential parts widely from industrial world to military equipment. Control systems in the industrial world determine the quality, speed, cost and efficiency of the manufacturing process known as the Process Control System (PCS). The core of the Control System is conditioning (actuators) and reading conditions (sensors). By synergizing those parts with the coordination of the controller, the process value (PV) can be obtained according to the condition of the set point (SP). To get the proper control characteristics, i.e. the fastest possible response, the lowest possible oscillation and offset (error steady state/ESS), an understanding of the concept of a closed loop control system with a continuous scheme is developed. In this regard, the Automatic Control Laboratory under the Pneumatic and Hydraulic Laboratory at the Department of Mechanical Engineering - POLBAN considered to provide students with an introduction to Automatic Instrumentation and Control. The briefing covered the introduction, mechanism and operation of Automatic Instrumentation and Control systems. Therefore, tools were required as a medium for achieving the above competencies, one of which was the modernization of pressure regulators in order to strengthen the Laboratory. Through this research, a rejuvenation and modernization of the control system were carried out by applying a proportional, integral and differential (PID) control system. It was based on a programmable logic controller (PLC) equipped with a human machine interface (HMI) to make it easier to enter set points and PID parameters, to be practical in operation and effective in monitoring and data acquisition. The result of the pressure regulator modernization had the ability to include servo control process (getting a certain value) and regulatory control process (maintaining a certain value) with a continuous closed loop scheme. The modernized pressure control system could be utilized as a prototype demonstration of the system in an actual environment to study and observe the Proportional, Integral and Differential (PID) control system along with the process of determining the parameters Kp, Ti and Td as Practicum equipment
Comparison of the Efficiency of Solar PV Fixed, Single-Axis, and Dual-Axis Solar Trackers: A Review
Full text linkThe global energy shortage, especially in developing countries, drives the search for alternative energy sources such as solar power, which is one of the cleanest energy sources. This research discusses the comparison of efficiency between solar PV fixed, single-axis solar trackers, and dual-axis solar trackers. The method used is a survey of the literature of multiple studies that only analyzes the efficiency of solar PV using different tracking devices. The efficiency data is normalized based on location factors and light intensity for a fair comparison. The results show that fixed solar panels are stationary and simple, serving as a baseline with 100 % efficiency. Single-axis panels track the sun horizontally, boosting efficiency by 25.6 % but with moderate complexity due to motors and controls. Dual-axis panels track the sun both horizontally and vertically, increasing efficiency by up to 50 % but with the highest complexity due to more moving parts and dual-axis control systems
Characteristics of Agricultural and Plantation Wastes as Solid Biomass Energy Feedstock: A Systematic Review
Full text linkThe conversion of agricultural and plantation waste into biomass energy represents a promising pathway in the global transition to environmentally friendly energy sources. However, systematic comparisons of different types of agricultural and plantation biomass waste remain limited. This study aims to identify and evaluate the characteristics of various agricultural and plantation wastes to determine their feasibility as solid biomass energy feedstock. A systematic literature review was conducted using databases such as PubMed, DOAJ, and manual searches, focusing on articles published between 2014 and 2025. A total of 32 relevant studies were selected based on inclusion criteria. The analysis revealed that coconut shells, coffee grounds, and oil palm kernel shells possess superior fuel properties, particularly high calorific values of ≥ 4000 cal/g, making them highly suitable for solid biofuel production. These findings emphasize the strategic potential of agricultural and plantation waste as a sustainable energy source. The study contributes to the advancement of circular economy practices, promotes effective waste management, and supports the achievement of Sustainable Development Goals (SDGs)
The Effect of Hardening Process on SKD 61 Material using Single Quenching and Double Quenching Techniques on Its Mechanical Properties
Full text linkThis study focuses on investigating the effects of Single quenching and double quenching techniques on the mechanical properties of SKD 61 material, particularly in the context of bending strength and hardness measured using the Brinell hardness test. The research method involved heating SKD 61 specimens to 1000°C for 15 minutes, followed by cooling using oil and air as quenching media. The results showed that the single quenching technique with oil medium increased the bending strength from 406.89 to 435.84 N/mm² and the hardness from 255 to 315 HB. The single quenching technique using air increased the bending strength to 410.88 N/mm² and the hardness to 290 HB. Meanwhile, the double quenching technique using a combination of oil and air produced a bending strength of 430.08 N/mm² and a hardness of 305 HB. These improvements are based on average values, and no statistical significance testing was conducted. These findings suggest that the appropriate selection of quenching media can optimize the mechanical properties of SKD 61, which is crucial for industrial applications requiring a combination of high toughness and strength
Triangle Velocity Analysis of the Pelton Turbine Design in Microhydro Power Plant
Full text linkDuring the period of 29 years, the Central Java Provincial Government has implemented strategic research formulation for flood reduction efforts. One solution for flood management is building a dam. The built dam has the potential to generate electricity. The purpose of the activity is to analyze the turbine speed triangle from the results of the technical design. The method used is the analysis of the turbine speed triangle at an entry angle of 12-14°. The results of the triangle analysis obtained show the F value at 14-12° of 34695.5, 34761.6, and 34847.7 N.m. Torque at 14° were 5313, 5320, and 5330 N.m. Torque at 13° were 5363, 5370, and 5380 N.m. Torque 12° were 5401, 5409, and 5418 N.m. P at 14-12° were 641.5, 642.9, and 644.1 kW. The efficiency of ηo and ηm is 0.90 % and 0.95 %. The conclusion of the application of the turbine speed triangle analysis at an angle of 4-6° is that the optimum turbine efficiency is at an opening angle of 12° with the ability to increase turbine power by 14.79 % and efficiency by 14.66 %
Production Planning of Cassava Chips in Small Home Business
Full text linkThe production process of cassava chips begins with the preparation of cassava raw materials and then the process of separating the skin from cassava. The process of cutting cassava into a certain size uses a special machine that is operated manually. The process of frying cassava using a large pan and the process of packaging into plastic are the last step of production. Planning the production of cassava chips starts with preparing the needs of raw materials for production for 3 days in a week ordered from 3 different suppliers to prepare production needs, the quantity needed in purchasing from suppliers includes 120 kg of cassava, 9 kg of red chili, 1 kg of garlic, 3 kg of lime, 27 kg of cooking oil, 9 kg of sugar and 0.25 kg of salt. The initial supply of cassava raw materials provided is 120 kg and at the end of the week the production inventory needs are 80 kg left from the use of 40 kg at the end of the week for the next production