Energy, Materials and Product Design is an open-access journal published by the Department of Mechanical and Industrial Engineering, Faculty of Engineering, University of Mataram, Mataram, West Nusa Tenggara, Indonesia. Energy, Materials and Product Design publishes two articles per volume annually, published in May and November. Energy, Materials and Product Design is a forum for publishing research results, case studies, and reviews related to mechanical engineering and its intersection with industrial engineering, such as energy, materials, and product design. This includes research or case studies related to heat exchangers, energy conversion (including solar, wind, marine, and biomass), heat storage, materials and components (including manufacturing and metallurgy), electric vehicles or their components, and ergonomics applications in tool and workstation design, occupational health and safety (K3), productivity, production and manufacturing systems, work design and reliability, material handling, optimization and simulation, quality control and quality engineering, and other areas of engineering that may impact other engineering fields. Articles may be written in Indonesian or English in accordance with the Energy, Materials, and Product Design journal guidelines. Energy, Materials and Product Design has been indexed in the Crossref (DOI), Google Scholar, and Digital Reference Garba (GARUDA). ISSN 2964-6987 | DOI prefix 10.29303/
Jurusan Teknik Mesin dan Industri, Fakultas Teknik, Universitas Mataram
THE HYBRID SPOT WELDING – EPOXY BONDING PROCESS FOR AISI 1008 STEEL: THE EFFECT OF EPOXY ADHESIVE TYPE
Hybrid joining technologies are increasingly being explored to overcome the mechanical and durability limitations associated with conventional resistance spot welding (RSW) and adhesive bonding in lightweight steel structures. However, despite the growing interest in spot welding–epoxy bonding (SWEB), the combined influence of adhesive curing behavior and welding thermal input on joint integrity and microstructural evolution remains insufficiently understood. In this work, a comprehensive experimental study was conducted on 0.8 mm AISI 1008 steel sheets joined using three commercial epoxy systems with different curing characteristics, combined with varying welding currents (50–80 A) and welding times (10–20 s). The investigation integrated mechanical shear testing with metallographic and compositional analyses to establish direct correlations between process parameters, microstructural transformations, and failure behavior. The findings reveal that the hybrid joints exhibit a synergistic load-transfer mechanism capable of significantly improving joint strength and energy absorption compared with conventional spot welds. Superior performance was consistently obtained using slow-curing epoxy under moderate welding conditions (~60–70 A and ~15 s), where a more stable interfacial interaction was achieved. In addition, localized carbon enrichment within the weld nugget, attributed to epoxy pyrolysis during welding, was identified as a previously underexplored phenomenon influencing joint behavior. The study provides new insight into thermo-chemical coupling in SWEB systems and proposes a practical pathway for tailoring hybrid joining performance through integrated process design.
Hak Cipta (c) 2026 Paryanto Dwi Setyawan, I W. Ogie Sabaniartha, Andi Maulana, Sugiman, Sujita, Suteja https://creativecommons.org/licenses/by-nc/4.0
ANALISIS SISTEM ANTRIAN TIKET TRANS JOGJA DI TERMINAL JOMBOR YOGYAKARTA
This study analyzes and simulates the ticket queue system of the Trans Jogja Bus Rapid Transit (BRT) at Jombor Terminal, Yogyakarta. Increasing passenger mobility and the growing demand for public transportation services have contributed to queue congestion during peak operating hours. The queue system operates using a single-channel single-phase model with a First Come First Served (FCFS) discipline. This research aims to evaluate the performance of the existing queue system and validate the simulation model using the trace-driven method. Data were collected through direct observation of 300 passengers, including arrival time and service time data. The simulation process was conducted using the Linear Congruential Generator (LCG) method and analyzed using the Mann-Whitney statistical test. The results show that the simulation model successfully represents the real system, with a service time error of only 0.13% and an arrival time error of 1.58%. Furthermore, the Mann-Whitney test indicates no significant difference between the simulation and the actual system, with probability values greater than α = 0.1. The findings demonstrate that the trace-driven simulation method is effective for modeling queue systems and can be used to support queue service improvement strategies at Trans Jogja shelters.
Hak Cipta (c) 2026 Maharsa Pradityatama, Pramudi Arsiwi, Dony Satriyo Nugroho https://creativecommons.org/licenses/by-nc/4.0
PENGARUH PENAMBAHAN LIMBAH CAIRAN JAGUNG TERHADAP KUALITAS DAN KUANTITAS BIOGAS DARI KOTORAN SAPI
Biogas is one of the alternative energies that can be utilized to meet fuel energy needs. It originates from the fermentation process of biomass, such as cow dung. This research focuses on producing biogas from cow dung with the addition of corn waste water to determine the influence of adding corn waste water on the quality and quantity of the generated biogas. Treatments were applied by varying the composition of cow dung with corn waste water (A, B, C) and cow dung with water (D) as a control. The successive compositions created were composition A (1:1j), composition B (1:2j), composition C (1:3j), and composition D (1:1a), each repeated three times, and the study was conducted for 30 days. The research results indicate that with the addition of corn waste water, the highest quantity of biogas was obtained in composition A, amounting to 1168.08 cm3, while the lowest quantity was obtained in composition B, totaling 791.21 cm3. Regarding the quality testing of biogas with the addition of corn waste water, the highest quality was observed in composition A at 49.76%, whereas the lowest quality was found in composition B at 23%. However, in composition D, which consists of cow dung biogas with water demonstrated superior quality and quantity, with a quality value of 52.82% and a quantity of 1384.05 cm3. The data obtained suggest that corn waste water may not be as effective as a supplementary material for the mixture of cow dung biogas.
Hak Cipta (c) 2026 Joniarta I Wayan, Febrian Purnama, I Made Mara; I Kade Wiratama https://creativecommons.org/licenses/by-nc/4.0
ANALISIS PERFORMA ALAT DISTILASI SURYA DENGAN VARIASI KETEBALAN KACA PENUTUP
The availability of clean water has become a global challenge due to the dominance of seawater on Earth and the limited amount of usable freshwater. One potential solution is solar distillation, which utilizes solar energy as a renewable energy source. This study aims to analyze the effect of glass cover thickness on the performance of the solar distillation system, including temperature distribution, water productivity, and system efficiency. The glass thicknesses used in this study were 3 mm, 5 mm, and 8 mm. The results showed that glass thickness significantly affected system performance. 3 mm glass produced the highest productivity of 1073.33 ml/day with an efficiency of approximately 39%, followed by 5 mm and 8 mm glass. Increasing glass thickness reduced temperature, evaporation rate, and distillation yield due to higher thermal resistance and lower solar radiation transmission. Therefore, the optimal glass thickness is 3–5 mm to achieve maximum system performance.
Hak Cipta (c) 2026 Alit Ida Bagus, Made Wirawan, Irham Zulkarnain https://creativecommons.org/licenses/by-nc/4.0
KINERJA MESIN AIR-WATER HARVESTER DENGAN SUSUNAN EVAPORATOR PARALEL PASA BERBAGAI KECEPATAN UDARA MASUK
During the dry season, several regions in Indonesia experience drought conditions and limited access to clean water. An air-water harvester system offers a potential solution, as it utilizes flexible air conditioning (AC) components and can be implemented in various locations provided that an adequate power supply is available. This study aims to investigate the effect of inlet air velocity on water production and heat transfer rate in an air-water harvester system. An experimental approach was employed with inlet air velocity variations of 0 m/s, 1.5 m/s, and 3 m/s. The system utilized three evaporators constructed from 12U refrigerator condensers, a 1 PK compressor, and R-134a refrigerant. Experiments were conducted over a period of nine days, from 09:00 to 16:00 each day. The results indicate that increasing inlet air velocity enhances both water production and heat transfer rate. The highest average water yield was 1.676 kg over a 7-hour period at an air velocity of 3 m/s. In addition, the maximum average total heat transfer rate absorbed by the evaporator reached 295.98 W under the same air velocity condition.
Hak Cipta (c) 2026 Mirmanto Mirmanto, Nurchayati, Nurpatria, Ahmad Sofa Amrillah https://creativecommons.org/licenses/by-nc/4.0
EFFECT OF OVERLAP LENGTH AND ADHESIVE THICKNESS ON THE SHEAR STRENGTH OF JUTE FIBRE COMPOSITE AND FIBREGLASS COMPOSITE JOINTS
Adhesively bonded joints have attracted the attention of engineers for connecting different materials to develop lightweight structures. The materials that can be bonded include composite materials with different reinforcements, such as glass and natural fibres, but to achieve optimal strength, factors such as adhesive thickness and overlap length remain decisive. This study aims to determine the effect of overlap length and adhesive thickness on the shear strength of jute fibre-reinforced composite and glass fibre-reinforced composite joints. This study used single lap joints according to ASTM D1002. The overlap lengths varied by 15, 20, 25, and 30 mm, while the adhesive thicknesses varied by 0.2, 0.4, and 0.6 mm. This study found that joint strength decreases with increasing overlap length, whereas the effect of adhesive thickness depends on overlap length. At overlap lengths of 15 and 20 mm, joint strength increases with increasing adhesive thickness, whereas at 25 and 30 mm overlap lengths, it appears to remain constant. The optimal adhesive thickness is 0.4 mm. At an overlap length of 20 mm, the shear strength at adhesive thicknesses of 0.4 mm and 0.2 mm is 4.58 MPa and 3.71 MPa, respectively, or an increase of about 36% relative to the 0.2 mm thickness. The results imply that for hybrid jute and fibreglass composite joints, a short overlap length (i.e., 15 mm) and an adhesive thickness below 0.4 mm are recommended.
Hak Cipta (c) 2026 Sugiman, Aji Noven Setyawan, Agus Dwi Catur, Hilton Ahmad https://creativecommons.org/licenses/by-nc/4.0
EKSPLORE KARAKTERISTIK TARIK, THERMAL DAN MORPHOLOGY KOMPOSIT EPOXY DIPERKUAT SERAT TIMOHO – MIKRO SERBUK Al2O3
Epoxy composites reinforced with natural fibers can be added with a second filler in the form of powder to enhance their performance. This method affects the thermal resistance properties of the composites. This study investigates the development of epoxy composites reinforced with timoho fibers to which an aluminum oxide (Al₂O₃) powder filler has been added. The composites were fabricated using the hand lay-up method, and the tensile properties, thermal conductivity, and fracture morphology of the epoxy composites were analyzed to determine the effect of varying the volume fraction of Al₂O₃ filler on epoxy composites containing 20% (wt) timoho fibers. The results of the investigation showed that the highest tensile strength of 70.41 MPa was obtained by the SA composite, then decreased to 51.15 MPa in the SC composite. The highest thermal conductivity and linear thermal expansion coefficient values for the composites were each found in the SA sample, at 1179.13 W/m·K and 1045.25 °C, respectively. SEM morphology revealed that the timoho fibers experienced fiber pull-out and cracks in the epoxy matrix. Overall, the SEM images support the tensile strength values.
Hak Cipta (c) 2026 Suteja, Syarif Hidayatullah https://creativecommons.org/licenses/by-nc/4.0
SIMULASI PENERAPAN METODE TOPSIS UNTUK PENENTUAN PRIORITAS PERBAIKAN ERGONOMI: STUDI KASUS BERBASIS SIMULASI DATA
Conventional ergonomic risk evaluations in the manufacturing industry are generally focused solely on posture severity, often leading to management rejecting improvement recommendations due to operational cost and time constraints. This study aims to demonstrate the application of the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method to resolve multi-criteria conflicts between worker safety and corporate financial efficiency. A quantitative descriptive approach was used through data simulation on five alternative workstations evaluated against five criteria: REBA score, NBM score, estimated cost, implementation time, and expected productivity targets. The relative closeness distance computation resulted in the Cutting Station as the main priority for intervention with a preference value of 0.627. This alternative outperformed the Assembly Station (0.463), which actually possessed the highest absolute hazard but demanded the most expensive improvement costs and the longest production downtime. In conclusion, the integration of the TOPSIS algorithm proved effective in transforming hazard assessment metrics into rational investment decisions. This mathematical modeling provides a strategic guide for executive management in designing workspace improvement roadmaps that ensure workers' biological health while maintaining corporate cash flow sustainability.
Hak Cipta (c) 2026 Fikrihadi Kurnia, Anak Agung Alit Triadi https://creativecommons.org/licenses/by-nc/4.0
PENERAPAN PENDEKATAN SHIP DALAM ANALISIS ERGONOMI MAKRO PADA KAJIAN PENGEMBANGAN ALAT PENGERING PASCAPANEN BAGI PETANI KECIL
Postharvest drying equipment plays an important role in maintaining the quality of agricultural products produced by smallholder farmers. However, many currently used drying devices have not fully considered ergonomic aspects, particularly at the work system level. This study aims to analyse the design of postharvest drying equipment for smallholder farmers using a macro ergonomic approach grounded in the SHIP principles (systemic, holistic, interdisciplinary, and participatory). This approach is employed to examine the interrelationships among humans, tools, work processes, the environment, and the organizational and social aspects surrounding the system. The research method used in this study is a descriptive qualitative approach, employing a literature review and conceptual analysis of postharvest drying equipment design practices at the smallholder farming scale. The analysis results indicate that the SHIP approach enables the comprehensive identification of ergonomic issues, ranging from mismatches between equipment design and farmers’ working postures and habits to limitations in production systems, as well as the lack of user involvement in the design process. The integration of systemic, holistic, interdisciplinary, and participatory principles provides a macro-ergonomic framework that is relevant and applicable to supporting the design of postharvest drying equipment that is more contextual, sustainable, and aligned with the needs of smallholder farmers. In macro ergonomics, the SHIP approach serves as a methodological framework for comprehensively analysing and designing work systems by positioning humans at the centre of the system. This study is expected to serve as a conceptual reference for the development of agricultural equipment design based on macro-ergonomic principles.
Hak Cipta (c) 2026 I Gede Bawa Susana, Rudy Sutanto https://creativecommons.org/licenses/by-nc/4.0
EVALUASI KINERJA TERMAL UNJUK KERJA KOMPOR BERBAHAN BAKAR OLI BEKAS
The use of used cooking oil and waste oil as fuel—particularly for cooking—is becoming increasingly common among the public in Indonesia. While this practice offers economic advantages, improper management of used oil can lead to environmental problems such as air and soil pollution. To address this issue, alternative methods for processing used oil are needed to minimize its negative impact. One such method is the use of a used oil stove, which utilizes waste oil as fuel. This not only reduces the amount of oil discarded but also provides a cost-effective substitute for more expensive fuels like gas or kerosene. The purpose of this study was to examine the effect of varying air flow velocities on flame temperature, flame color, and the time required to heat water using used oil as fuel in a stove. The stove was tested under different air flow conditions, and flame temperature and color were observed in three stages. Additionally, the time taken to heat water to approximately 90 °C was recorded. At the lowest air flow rate of 15 m/s, the flame temperature reached 251.5 °C, and the water heating time was 187 seconds. At the highest air flow velocity of 29 m/s, the flame temperature increased to 273.7 °C. These results indicate that higher air flow velocity lead to increased flame temperatures and improved heating efficiency, suggesting that optimizing air flow in used oil stoves can enhance their performance while supporting more sustainable fuel practices.
Hak Cipta (c) 2025 I Made Mara, I Made Adi Sayoga, I Made Nuarsa https://creativecommons.org/licenses/by-nc/4.0
KAJIAN ENERGI TERBARUKAN DAN PENINGKATAN EKONOMI DARI PEMANFAATAN LIMBAH SEKAM PADI MELALUI CO-FIRING BIOMASSA
Pemanfaatan limbah sekam padi sebagai sumber energi terbarukan memiliki potensi besar dalam mendukung ketahanan energi nasional sekaligus memberikan nilai tambah ekonomi bagi masyarakat. Indonesia dengan produksi padi mencapai 53,14 juta ton pada tahun 2024 memiliki potensi limbah sekam padi sebesar 10,63 juta ton. Dengan nilai kalor rata-rata 14 MJ/kg, potensi energi teoritis sekam padi mencapai 148,8×10⁹ MJ atau setara dengan 41,33 GWh per tahun. Pemanfaatan sekam padi sebagai bahan bakar campuran (co-firing) pada Pembangkit Listrik Tenaga Uap (PLTU) memberikan kontribusi signifikan terhadap peningkatan bauran energi terbarukan dan pengurangan emisi gas rumah kaca. Berdasarkan data PLN, program co-firing biomassa telah diterapkan di 46 PLTU hingga 2023 dengan penggunaan biomassa 1 juta ton dan penurunan emisi sekitar 1,05 juta ton CO₂e. Uji coba co-firing sekam padi di beberapa PLTU seperti Jeranjang, Paiton, dan Suralaya menunjukkan operasi yang stabil dengan efisiensi tinggi dan penurunan emisi SO₂ hingga 29,22%. Meskipun memiliki nilai kalor lebih rendah dibanding batubara dan kadar abu tinggi (hingga 20,67%), sekam padi tetap potensial digunakan hingga rasio 20–30% massa energi. Kandungan silika (SiO₂) yang mencapai 95,52% menimbulkan tantangan seperti slagging dan fouling, namun residu abu dapat dimanfaatkan sebagai bahan campuran semen atau silica powder. Pemanfaatan sekam padi melalui metode direct co-firing dinilai paling sesuai untuk PLTU di Indonesia karena murah dan mudah diterapkan tanpa modifikasi besar. Secara keseluruhan, co-firing sekam padi mampu mendukung transisi energi bersih, mengurangi ketergantungan pada batubara, meningkatkan ekonomi sirkular pedesaan, serta berkontribusi terhadap target Net Zero Emission 2060 di Indonesia.
I Gusti Agung Ketut Chatur Adhi Wirya Aryadi
Hak Cipta (c) 2025 I Gede Bawa Susana, I Gusti Agung Ketut Chatur Adhi Wirya Aryadi https://creativecommons.org/licenses/by-nc/4.0
ANALISIS EFISIENSI ENERGI PADA PROSES PENGERINGAN GABAH MENGGUNAKAN DRYER GRAINPRO 30T-HS DI PT KARUNIA TRINITAS AGRO
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Hak Cipta (c) 2025 I Wayan Joniarta, Yoga Raditya Ananda Putra, Made Wijana, I Kade Wiratama https://creativecommons.org/licenses/by-nc/4.0
KARAKTERISTIK GETARAN DALAM BENTUK WAVEFORM DAN SPEKTRUM MELALUI TRANSFORMASI FOURIER
The analysis of machine vibration is therefore essential for predictive maintenance and condition monitoring. Modern approaches, ranging from time-domain measurements of acceleration, velocity, and displacement to frequency-domain and modal analysis. This study investigates the vibration characteristics of rotating equipment in a manufacturing environment, focusing on identifying dominant frequencies, evaluating amplitude trends, and assessing overall machine condition. Data collected from accelerometers mounted on a centrifugal pump were processed using time-domain and frequency-domain techniques. The results highlight clear signatures of imbalance and bearing wear, demonstrating the value of predictive maintenance based on vibration monitoring. As the result the amplitude–frequency spectrum demonstrates that the machine is primarily influenced by rotational imbalance, with minimal evidence of high-frequency faults.
Hak Cipta (c) 2025 Salman, I Dewa Ketut Okariawan, Nurchayati, Arif Mulyanto, Emmy Dyah Sulistyowati https://creativecommons.org/licenses/by-nc/4.0
RISK IDENTIFICATION AND MITIGATION STRATEGIES FOR WORKERS IN VEHICLE WASHING OPERATIONS
This study identifies and evaluates occupational health and safety risks faced by workers in vehicle washing operations in Mataram, Nusa Tenggara Barat, focusing on motorcycle and car wash services. Through observational studies conducted on April 6, 2025, key hazards were identified, including musculoskeletal disorders (MSDs) from non-ergonomic postures, chemical exposure from soap, slipping on wet floors, and noise from compressors. The Rapid Entire Body Assessment (REBA) method revealed high ergonomic risks, with REBA scores of 10 for both motorcycle and car wash workers, indicating a significant risk of MSDs due to prolonged bending and repetitive motions. Bowtie Analysis further mapped causes, consequences, and control measures, emphasizing non-ergonomic postures and chemical hazards as primary concerns. Preventive strategies, such as ergonomic training, long-handled tools, and personal protective equipment (PPE), were proposed to mitigate risks. The findings align with global studies reporting high MSD prevalence among sanitation workers, underscoring the need for ergonomic interventions and safety protocols. This study contributes to the literature by offering tailored risk mitigation strategies for the vehicle washing industry, advocating for enhanced worker safety, improved productivity, and reduced occupational health risks through comprehensive risk management and ergonomic solutions..
Hak Cipta (c) 2025 Fikrihadi Kurnia, Cinta Mugia Wening Galih, Ade Febrian https://creativecommons.org/licenses/by-nc/4.0
DAMPAK PERBEDAAN LAJU AERASI SELAMA FERMENTASI TERHADAP KUALITAS BIOETANOL BERBAHAN MOLASE
Energy consumption is increasing along with the increase in population. At this time the use of energy can not be separated from everyday life. Energy needs still depend on fossil energy resources or petroleum. Bioethanol is a potential non-fossil fuel and can be used as an alternative fuel. Plants that can be used as bioethanol are starchy materials such as cassava, sweet potatoes, wheat and potatoes; sugary ingredients such as molasses (molasses). The purpose of this study was to determine the effect of variations in the rate of aeration during fermentation on the quality of bioethanol produced with molasses. Parameters of bioethanol quality observed were bioethanol content, volume of bioethanol, and calorific value. This study used variations in the rate of aeration during fermentation of 1 lpm, 1.5 lpm, and 2 lpm. Bioethanol is produced by fermenting molasses for 72 hours (3 days), then a distillation process is carried out to obtain bioethanol from molasses fermentation. The study produced the highest average bioethanol content and average bioethanol volume produced at an aeration rate of 2 lpm with an average bioethanol content of 86.67%. and an average bioethanol volume of 346.67 ml. The higher the alcohol content produced, the higher the calorific value. The highest calorific value was obtained from the 2 lpm variation with a sample content of 90% with a calorific value of 12456.60 Joules/g.
Hak Cipta (c) 2026 Tri Rachmanto, Fardiaz Anugrah Saputra; I Made Adi Sayoga https://creativecommons.org/licenses/by-nc/4.0
ANALISIS POTENSI BIOMASSA SEKAM PADI DI PULAU LOMBOK, INDONESIA SEBAGAI SUMBER ENERGI TERBARUKAN
The utilization of renewable energy is one of the strategic solutions for overcoming dependence on fossil fuels and supporting sustainable development. This study aims to analyze the potential of rice husk biomass on the island of Lombok as an environmentally friendly renewable energy source. The methods used include collecting secondary data on rice production, estimating rice husk production as agricultural waste, and projecting the potential energy to produce. The analysis was carried out through theoretical calculations of the potential energy of rice husk biomass. It did not include economic aspects, and the collection of raw materials was not considered. The study results show that the island of Lombok has a reasonably enormous potential for rice husk biomass, with an energy value that can be converted into electricity or alternative fuels. In addition, the use of rice husk as biomass can also reduce greenhouse gas emissions and provide a positive economic impact on local communities. However, optimizing this potential requires the support of appropriate technology, infrastructure, and policies. Thus, rice husk on the island of Lombok has the prospect of being one of the promising renewable energy sources within the framework of the national energy transition.
Hak Cipta (c) 2025 I Gede Bawa Susana, I Ketut Perdana Putra, I Gusti Agung Ketut Chatur Adhi Wirya Aryadi https://creativecommons.org/licenses/by-nc/4.0
PENGARUH VARIASI BENTUK BRIKET ARANG BIOMASSA BERBAHAN LIMBAH KAYU TERHADAP NILAI KALOR DAN BOILING TIME
Most Indonesian people currently use energy derived from fossil fuels, such as fuel oil, gas and coal. The impact of using fossil fuels is that it can damage the environment. Several alternative energy sources that are commonly developed are biomass energy. This biomass is usually processed into biochar which is a fuel with a high calorific value and can be used in everyday life. Briquettes are an energy source derived from biomass which can be used as alternative energy. In this study, briquettes were made from teak, acacia and mahogany wood waste. The method used is an experiment with the carbonization process using a modified composing drum. The independent variables used were briquette materials from teak, acacia and mahogany wood waste, variations in the shape of cube, cylindrical and hexagonal jerry cans. Tests include analysis of water content, calorific value, and changes in temperature. The results of this study showed that the best moisture content was obtained from cylindrical teak wood waste briquettes with an average value of 3.57%. Then for the calorific value, the best results were obtained from cylindrical teak wood waste briquettes with a value of 3457.0 Kkal/kg. and for temperature changes the best results were obtained on the cube-shaped mahogany wood waste briquette specimens with an average value of 10 minutes 46 seconds.
briquette ,the calorific value, wood waste, Main findings
Hak Cipta (c) 2025 I Wayan Joniarta, Zohimundin Usman, Made Wijana, I Kade Wiratama https://creativecommons.org/licenses/by-nc/4.0
The THE FERFORMANCE ANALYSIS OF ELECTRIC CAR OF THE UNIVERSITY OF MATARAM
The university of Mataram car suspension and its control was designed to minimize the vibration produced by unwanted external inputs i.e., changes of road contours that reach the car passengers. This effort will provide the passenger with higher safety and comfort. In this study, a quarter car model with two degree of freedoms (2 DOF) was designed and developed its mathematical model. The effects of the road contour were studied and analyzed in term of overshoot and settling time that affect the main body, suspension as well as the passenger. The MATLAB Simulink model was programmed to mimic the behavior of the suspension and its response to the input which was the road contour (step function). This approach was very helpful to reduce the effort, time and money. The result shows that with implementation of the design parameters chose, the responses of the system (displacement and velocities) were satisfied the criteria of comfortable (there are no overshoot), however, the settling time was seconds that much higher than expected which will disturb the passenger comfort. This point shows that the suspension design needs further improvement with consideration of using active suspension with adequate control system.
Hak Cipta (c) 2025 I Gusti Ngurah Ketut Yudhyadi, Pandri Pandiatmi, Emmy Dyah S., Ida Bagus Alit https://creativecommons.org/licenses/by-nc/4.0
MANAJEMEN PROYEK COLD STORAGE MANGGIS DI LINGSAR
Mangosteen is the largest export commodity in the Lingsar sub-district, West Lombok district, West Nusa Tenggara. In addition to being sold in the local market, mangosteen in the Lingsar area is also exported to foreign countries such as China, the United Arab Emirates, and countries in Europe. One of the mangosteen exporters in the West Lombok area is PT BAS which has a warehouse as well as an operational location to store and manage mangosteen to be exported. To maintain the temperature of mangosteen, PT BAS uses Cold Storage to store harvested mangosteen for storage before being packaged and exported. The distribution is useful to maintain the content in mangosteen fruit so that it does not rot because it is stored in a closed room. So that mangosteen is ready for export This aims to maintain the quality of the stored mangosteen so that it is ready for export. Therefore, for cost and time efficiency, it is important to apply the design and simulation method to Cold Storage to find out the incoming levels and the company owner can monitor in real time the condition of the mangosteen stored in it.
Hak Cipta (c) 2025 Sujud Alfanza Jihad, Is Bunyamin Suryo, Anak Agung Alit Triadi https://creativecommons.org/licenses/by-nc/4.0
EVALUASI ALAT PENGADUK DODOL NANGKA SKALA RUMAH TANGGA BERDASARKAN PRINSIP ERGO-EKONOMI
The use of manual tools in the process of stirring jackfruit dodol tends to have an impact on high workload, fatigue, and complaints from workers. The stirring process requires a lot of energy to get perfectly cooked dodol. In addition, manual tools take a long time, and the product needs to be evenly cooked, leaving a crust on the dodol stirring pan. To overcome this, an automatic stirring tool is needed at an affordable cost. Workers' participation as users is required so that the tools used match workers' wishes. Ergo-economic applications are necessary to meet workers' desires: comfort and affordable costs. From the evaluation carried out, it was found that the automatic stirring tool only requires a little energy because a machine does the stirring. This impacts the workload, fatigue, and complaints automatically decreasing when compared to using a manual stirring tool. Economically, the use of an automatic stirring tool provides benefits for dodol entrepreneurs after the 2.4th month. This is based on the investment value of the automatic stirring machine. The ROI (Return on Investment) level is 170.216%. This stirring machine is more effective because the stirring results are more even and do not cause crust on the container. Worker performance can be improved by applying ergo-economics based on preventive measures against behaviors that can potentially cause injury in the workplace. Workers are the main asset or economic resource in the industry, and ergonomics and economics are interrelated with ergonomics, which can create better working conditions, producing a better economy.
Ergo-economics, Jackfruit Dodol, Mixing, Payback period
Hak Cipta (c) 2024 I Gede Bawa Susana, Ida Bagus Alit https://creativecommons.org/licenses/by-nc/4.0
ANALISIS EFISIENSI POMPA SENTRIFUGAL PADA DESALINASI DENGAN PROSES REVERSE OSMOSIS
This study provides information for the desalination industry in an effort to improve the performance and efficiency of desalination systems using the reverse osmosis method. By paying attention to the factors that influence the efficiency of centrifugal pumps, the provision of clean water in areas experiencing a water crisis will be better. Reverse Osmosis (RO) is a system in desalination technology that is often used to replenish fresh water supplies. RO performance depends on the quality of sea water as the raw water source. RO works by utilizing osmotic pressure. Hydrostatic pressure which is greater than osmotic pressure is used to reverse the flow, thereby producing fresh water. RO utilizes a high-pressure pump process to flow seawater through a membrane polymer structure. In RO there is a main membrane module configuration which has two functions, namely supporting the performance of the RO membrane and providing efficient fluid management. The desalination system used at PT Perusahaan Air Indonesia America (PAIA) still uses centrifugal pumps and can produce a production capacity of 600-700 m3/day, and is still in the system upgrade stage. From the calculations that have been carried out, the pump efficiency value is 59.16%.
Hak Cipta (c) 2024 I Wayan Joniarta, Ade Aprilian Dika, Made Wijana https://creativecommons.org/licenses/by-nc/4.0
PENGARUH PENAMBAHAN UNSUR TEMBAGA PADA PENGECORAN TEKAN BLOK SILINDER BEKAS TERHADAP NILAI IMPAK DAN KEAUSAN
The cylinder liner block is part of the cylinder block which functions as a place for the engine working process to take place. Where in this section the suction, compression, work and exhaust processes occur. Cylinder blocks have two types, some can be repaired and cannot be repaired, to utilize cylinder blocks that cannot be repaired by recycling them by casting metal with copper (Cu) with variations in the addition of 5%, 10%, 15% with a casting temperature of 1150⁰C using metal molds using the press technique method. Data collection was carried out by wear testing, impact testing, and microstructure testing. By increasing the percentage of copper (Cu) in the cylinder block casting, the highest wear was obtained with the addition of 15% Cu of 2,87×10-9 m3. The highest impact strength of 15% Cu is 0.12 Joule/mm2.
Cylinder block, casting, copper, wear and impact strength
Hak Cipta (c) 2024 Sinarep, Agus Dwi Catur, Mujiantara Daeng Permana, Ahmad Zainuri https://creativecommons.org/licenses/by-nc/4.0
KARAKTERISASI KEKUATAN GESER DAN STRUKTUR MIKRO HASIL SPOT WELDING PELAT BAJA KARBON RENDAH
Spot welding is a joining method that utilizes thermal energy generated by the resistance of electric current. Research was conducted to determine the effect of plate thickness, current and welding time on the characteristics of spot welding results. Spot welding was performed on low carbon steel plates of 0.8 mm, 1.5 mm and 1.8 mm thickness with current (50, 60, 70, 80 amperes) and welding time (10, 15, 20 seconds). Characterization of the spot welds was done by shear test (ASTM D1002-10) and observation of macro and micro structure (ASTM E3-11) and failure surface of the specimens. From the research conducted, it is known that the average shear strength increases with decreasing plate thickness, increasing welding current and decreasing welding time. The highest average shear strength of 502,772 N/mm2 was obtained with a plate thickness of 0.8 mm, a welding current of 70 A, and a welding time of 10 seconds. For thin plates, most of the shear test specimens failed in the area of the heat affected zone, while for thick plates, most of the shear test specimens failed in the area of the nugget spot weld.
Hak Cipta (c) 2024 Paryanto Dwi Setyawan, I Made Suniartha, Sugiman, Sinarep https://creativecommons.org/licenses/by-nc/4.0
APLIKASI ALAT BANTU ERGONOMIS PADA KERJA MANUAL BERDASARKAN KAJIAN ERGO-MECHANICAL UNTUK PETANI KECIL
Using traditional tools and manual work by small farmers in rural and developing areas is routine in processing agricultural land, especially planting plant seeds. This working model includes moderate to severe workload due to additional workload, namely sunlight when planting. In addition, work is carried out with non-ergonomic work postures, namely non-natural work postures. This causes musculoskeletal complaints to workers due to the non-harmonious tools with workers. Workers' productivity will decrease and have the potential to reduce the quality of life of small farmers themselves. To help the manual work of small farmers to create effective, comfortable, safe, healthy, efficient, and sustainable jobs, an ergo-mechanical application is needed to design work tools. This application is based on studies conducted on the design of work tools from several libraries or research results. The ergo-mechanical study is an integrated system that applies ergonomic and mechanical principles. The ergo-mechanical application produces ergonomic work tools that are comfortable to use by workers, and technical standards include material, product, and service requirements. Mechanically, the application through technical drawings, mechanical planning, and work tool materials to get a strong, lightweight, and safe work tool from hazardous substances, according to technical specifications. Technical standards are related to data sheets or specifications that describe the technical characteristics of a work tool. On the specifications of the work tool design, specifications can be added that the work tools are ergonomic. Ergonomic work tools can produce effective, comfortable, safe, healthy, and efficient work. This results from the compatibility between work tools and workers or the harmonious work tools with workers. Ergo-mechanical creates comfort in work that affects the increase in productivity and quality of life for workers.
Small farmers, Manual work, Ergonomic, Ergo-mechanical
Hak Cipta (c) 2024 I Gede Bawa Susana, I Ketut Perdana Putra
PENGARUH VARIASI TINGGI SUDU TURBIN DARI TINGGI BASIN TERHADAP DAYA DAN EFISIENSI TURBIN VORTEX
Electrical energy is a very important need for human life in various aspects, both on a large and small scale. One of the efforts to reduce the use of fossil fuels is to use natural resources that are not limited and can be renewed. Micro Hydro Power Plant (MHP) is an alternative source of electricity for the community, one of which is a vortex turbine. The vortex turbine is one type of micro hydro turbine that utilizes a whirlpool as a blade drive. This study examines the effect of blade height variations of 25%, 30%, and 35% of the basin height on power and efficiency. The results showed that the largest turbine power at 25% blade height variation from the basin height with a discharge of 0.009 m3/s was 3.294 Watt with an efficiency of 51.10%. The largest turbine power at an angle variation of 30% of the basin height with a discharge of 0.009 m3/s is 3.364 Watt with an efficiency of 50.66%. The largest turbine power at an angle variation of 35% of the basin height with a discharge of 0.009 m3/s is 4.062 Watt with an efficiency of 62.35%. Turbine power based on two-way anova analysis shows that between variations in turbine height and flow discharge have a significant effect on the turbine power produced and turbine efficiency based on two-way anova analysis shows that between variations in turbine height and flow discharge have a significant effect on the turbine efficiency produced.
Hak Cipta (c) 2024 Tri Rachmanto, Mirmanto, Randi Lelio
APLIKASI ERGONOMI BERDASARKAN DATA ANTROPOMETRI PEKERJA PADA DESAIN ALAT KERJA
A review of the application of ergonomics to design work tools based on worker anthropometric data is carried out to provide information on its use in the production process, especially in micro, small and medium business. This is done because most people in Indonesia still use simple tools with unnatural work postures. Unnatural work postures such as bending, squatting, twisting, exposure to the sun, etc. Unnatural work postures cause musculoskeletal complaints and fatigue which have an impact on decreasing work efficiency. Of course, this causes a decrease in productivity and quality of life for workers. From the results of a review of several studies and literature, satisfactory results were found regarding the application of ergonomics in designing work tools according to worker anthropometric data. Application of anthropometric data for the design or redesign of a work tool based on the flow of 1) determining the body that is important in the design or redesign, 2) determining the user population, 3) calculating the percentile value for each predetermined body dimension, and 4) application to the design of the tool. Ergonomics application based on information related to human factors (strengths, weaknesses, or limitations) in designing work tools that are more effective, safe, comfortable, healthy, and efficient. An ergonomic work tool can be used effectively, comfortably, safely, healthily, efficiently, and sustainably. Ergonomics application as an alternative in overcoming the problem of musculoskeletal complaints and fatigue due to unnatural work postures. Ergonomics applications improve work safety and worker health so that work productivity increases.
Ergonomics, Ergonomic, Anthropometry, Work posture, Musculoskeletal complaints
Hak Cipta (c) 2022 Energy, Materials and Product Design (EMPD)
ANALISA SISTEM KENDALI MEKANIK UNTUK PENGEMBANGAN KENDARAAN LISTRIK AUTONOMOUS FAKULTAS TEKNIK UNRAM
Currently, the vehicles that are commonly used are vehicles with fossil fuels, but we all know that these fuels are non-renewable fuels and their availability in nature is very limited, so it is necessary to innovate to use other renewable energy sources. one of which is electrical energy. Besides that, the use of electrical energy for vehicles is currently very relevant because of its relatively high efficiency and friendly to the environment, namely no CO or CO2 gas is formed as in conventional vehicles. Indonesia has the potential to develop electric cars because there is a lot of nickel available to be processed into batteries. Thus, our country has a very large opportunity to produce electric cars. To realize this, it is deemed necessary to conduct a thorough study such as the level of comfort and safety. Thus, it is needed to conduct a study of the mechanical control system so that driving comfort and safety can be achieved. In this research, we will measure the turning radius of the vehicle at various TOE angles. The resulth of this study are the greater of TOE angle produce the higer the turning radius of the vehicle, The smallest turning radius is at a TOE angle 0 degrees which is 4.42 meters and the largest at a TOE angle 1.035 degrees which is 4.53 meters.
Control, Mechanic, electric vehicle, TOE angle
Hak Cipta (c) 2023 I Dewa Ketut Okariawan, Syahrul, Ida Bagus Alit, I Made Nuarsa, I Made Suartika
PERANCANGAN CHASIS KENDARAAN LISTRIK UNIVERSITAS MATARAM
Chassis is the main component of the vehicle that functions to support the engine, body, suspension system, electrical system and driver. Chassis is one part of the vehicle that has an important role so careful planning is needed in its manufacture. Chassis must be strong and sturdy to support the load of the driver, electric motor and accessories. In addition, the chassis must also be light so as not to overload the work of the electric motor and be able to go through various road conditions. The vehicle body is its function to shape the vehicle and also protect the people inside. In this design, steel and aluminum materials are used, then simulated using the Autodesk Inventor software. The goal is to determine the Von Mosses stress value on the chassis design. AISI 1018 steel material with a load of 700 kg, 800 kg, and with a load of 900 kg obtained a value of 5.56. The safety factor obtained is still safe because it is above the safety factor for industrial construction design, namely 4. Aluminum 6061 material with a load of 700 kg, 800 kg and with a load of 900 kg obtained a value of 7.46. The safety factor obtained is still safe because it is above the safety factor for industrial construction design, namely 4.
Hak Cipta (c) 2023 A.A. Alit Triadi, Tri Rachmanto, I Made Mara, I G. N. K. Yudhyadi, Nur Kaliwantoro
PENGARUH PENAMBAHAN SERAT KAIN KATUN PAKAIAN BEKAS TERHADAP KEKUATAN TEKAN DAN BENDING DARI KOMPOSIT FOAM AGENT BETON RINGAN DENGAN STRIMIN BAJA
The problem of waste is a problem that requires serious handling, especially inorganic waste, where this waste cannot be destroyed by nature in a short time. Indonesia itself does not have a special treatment for this used clothing waste. Used clothes that are still fit for use can be resold or donated to those in need, but not every second-hand clothes can be reused so that used clothes are only thrown away which can cause pollution to the surrounding environment. With the increase in the human population in the world, the needs also increase, such as the need for food, clothing and there is also an increasing need for buildings. Panels are one of the most widely used building materials, especially for insulating walls in house buildings. One type of panel is a lightweight concrete panel. The purpose of this study is to utilize used clothing waste as a part of lightweight concrete composites where the fibers of used clothing waste are utilized as reinforcement for lightweight concrete composites and to determine the effect of adding used clothing waste fibers to the compressive and bending strength of the lightweight concrete. The variations that will be used are 0%, 0.3% and 0.7% with the size of the mold for bending, which is 160 mm long, 40 mm wide, 40 mm thick. while for the compression test mold is cylindrical in shape and has a height of 300 mm and a diameter of 150 mm. The results of this study indicate that there is an increase in strength in the compressive test from not using fiber or 0% of 4.42 N/mm2 , using fiber with a variation of 0.3% of 5.47 N/mm2 and fiber with a variation of 0.7% of 6.13 N/mm2 . The bending test shows a decrease in strength from variations of 0%, 0.3%, 0.7% to 3.65 Mpa, 3.376 Mpa, 2.6 Mpa.
Hak Cipta (c) 2023 muh. rian septiawan p septiawan p, Agus Dwi Catur, Pandri pandiatmi
ANALISIS SUDUT BELOK DAN KECEPATAN TERHADAP RADIUS BELOK MOBIL LISTRIK
As the number of cars increases, the number of accidents that occur is directly proportional to the number of accidents that occur, namely 117,949 cases and this increases by around 8.3% annually, mostly due to driver negligence and lack of vehicle stability. One important aspect in car design is the steering system which influences the response of the vehicle's steering motion to steering wheel input and has a major influence on comfort as well as safety. The purpose of this study was to determine the turning radius at various speeds and turning angles and to determine the ratio of the turning angle to the turning angle of an electric car. In the analysis phase, calculations are carried out based on slip analysis to obtain the turning radius at various speeds and turning angles, and the ratio of the turning angle to the turning angle of the electric car. At the testing stage it is carried out by determining the steer rotation angle based on the specified turning angle. The results of this study are at a speed of 30 Km/hour with a turning angle of 240 resulting in the smallest turning radius, that is, in the analysis of 5.5 m and 5.75 m of experiment and the smallest percentage of turning radius, namely the results of the analysis are 4% smaller than the experimental results. At a speed of 50 Km/hour with a turning angle of 150 produces the largest turning radius, namely, in the analysis of 9.5 m and 9 m experiments and the greatest percentage of turning radius, namely the results of the analysis are 13% smaller than the experimental results. From the results of the analysis, the ratio of the turning angle to the turning radius is 18:1.
Slip angle, Turning radius, Turning angle, Steering ratio.
Hak Cipta (c) 2023 I Made Mara, A. A. Alit Triadi, Andrian Suci Rahmawan