LONTAR Jurnal Teknik Mesin Undana

Pengaruh Fraksi Berat Terhadap Kekuatan Bending Komposit Serbuk Kayu Jati

2026-10-22T02:51:32+00:00

Most people need wood as a building material for decorative furniture which continues to increase over time, wood production has decreased. Given the abundance of solid waste and plastic waste and the increasing use of wood/boards, the manufacture of composite products is one alternative in utilizing these wastes to produce innovative and creative products as basic materials to replace wood/boards and also for raw materials in the creative industry. Various efforts have been made to replace the use of wood boards. Composite is a material formed from two or more components combined. This composite diamond includes plastic reinforced with fibers, metals, ceramics, plastic polymers with fillers or a mixture of two or more materials to obtain new materials. Composite is a combination of additional materials in the form of fibers, granules, powders, glass fibers, carbon, ceramics and metal fibers in different lengths in a composite matrix that has different characteristics to produce a material that has certain properties and characteristics that are different from the properties of its original constituents.

Inovasi Perbaikan Lengan Alat Penanam Jagung Berdasarkan Prinsip Ergonomi

2026-10-22T02:51:33+00:00

Desain alat pertanian yang tidak ergonomis masih menjadi salah satu penyebab utama terjadinya gangguan muskuloskeletal (MSDs) pada petani, khususnya dalam penggunaan alat penanam jagung manual. Penelitian ini bertujuan untuk merancang ulang bagian lengan alat penanam jagung dengan pendekatan ergonomi berbasis data antropometri petani lokal. Metode penelitian ini meliputi pengumpulan data antropometri, analisis postur kerja menggunakan metode Rapid Upper Limb Assessment (RULA) dan Rapid Entire Body Assessment (REBA), perancangan ulang lengan alat menggunakan perangkat lunak CAD, serta validasi desain melalui evaluasi postur dan persepsi kenyamanan kerja. Hasil pengukuran menunjukkan bahwa alat eksisting memiliki skor RULA dan REBA berturut-turut sebesar 6,07 dan 7,13 yang menunjukkan risiko tinggi terhadap gangguan MSDs. Desain ulang lengan alat menunjukkan perbaikan signifikan dengan skor RULA menurun menjadi 3,73 dan REBA menjadi 4,27. Selain itu, terjadi peningkatan persepsi kenyamanan kerja secara keseluruhan. Temuan ini menunjukkan bahwa penerapan prinsip ergonomi dalam desain alat pertanian manual secara efektif dapat mengurangi risiko ergonomi dan meningkatkan kenyamanan serta efisiensi kerja petani..

Analisa Aliran Distribusi Udara Dan Kenyamanan Thermal Menggunakan Metode Computational Fluid Dynamics (CFD) Di Ruang Panel Listrik Kantor Unit Penyelenggara Bandar Udara Budiarto

2026-10-22T02:51:34+00:00

This study aims to analyze airflow distribution and thermal comfort levels in the electrical panel room of the Budiarto Airport Management Unit Office using Computational Fluid Dynamics (CFD). The room experiences high heat loads due to continuously operating electrical equipment, requiring an effective ventilation and cooling system. Data were collected through field measurements of temperature, humidity, and air velocity at several points, then simulated using ANSYS Workbench 18.1. The results show that the average air velocity decreased from 0.180 m/s to 0.156 m/s, while the temperature increased from 31.7°C to 36.1°C, with maximum temperatures exceeding 130°C near electrical equipment. These conditions indicate thermal stratification and uneven air distribution. Based on ASHRAE 55:2013, ISO 7730:2005, and SNI 6390:2020 standards, the recorded temperatures fall outside the thermal comfort range (23–26°C). The study concludes that the existing 2 PK Split AC system is not yet optimal and recommends optimizing the cooling layout, adding ventilation, and implementing an IoT-based temperature monitoring system to improve thermal efficiency and operational safety.

Analisis Sistem Kerja instalasi Gas Okigen Pada Gedung Rumah Sakit Umum Daerah Ruteng

2026-10-22T02:51:34+00:00

Research entitled Analysis of the working system of medical gas installations in the Ruteng regional general hospital building. The medical gas system is an installation to meet the need for medical gas, the medical gas installation has been developed to eliminate the difficulties of using conventional medical gas, in this system the high-pressure gas cylinder, compressor and vacuum are centralized in one place, then the gases and air It flows into the room through pipes. This study aims to determine the performance or pressure reduction of the oxygen gas (O2) system installation in the inpatient room on the 3rd floor, Ruteng Regional Hospital. The results of this research show that the diameter required to flow oxygen gas for installation lines A and B for the main pipe, branch pipe and distribution pipe respectively is 0.75 inch, 0.5 inch and 0.375 inch with a total pressure drop for line A 160 kPa, and B 178 kPa.

Analisis Efisiensi Termal Sistem Unit 1 pada Perubahan Beban di PT. Sari Dumai Sejati

2026-10-22T02:51:35+00:00

This internship was conducted at PT. Sari Dumai Sejati, a company engaged in palm oil processing. The main focus of this internship is to analyze the thermal efficiency of the unit 1 system in the company's power plant department, where the steam turbine at PT. SDS has a capacity of 16 MW. PT. SDS is used to distribute electricity to all plants at PT. SDS. This study aims to determine the thermal efficiency of the unit 1 system on changes in load at PT. Sari Dumai Sejati. From the results of observations, it shows that the highest thermal efficiency of the system is 76.98% with a load of 9.49 MW, where the pump work is 370.70 kJ/kg, heat input is 3125.74 kJ/kg, turbine work is 2777.05 kJ/kg, heat output is 22.01 kJ/kg, net work is 2406.34 kJ/kg. Meanwhile, the lowest thermal efficiency is 75.90% with a load of 8.83 MW, where the pump work is 386.69 kJ/kg, the heat input is 3125.99 kJ/kg, the turbine work is 2759.31 kJ/kg, the heat output is 20 kJ/kg and the net work is 2372.62 kJ/kg. In conclusion, the PLTU at PT. SDS is working well but requires regular maintenance to ensure optimal efficiency.

Analisa Tahanan Dan Stabilitas Dengan Variasi Sudut Deadrise Pada Rc Boat Planning Hull Menggunakan Simulasi Maxsurf

2026-10-22T02:51:36+00:00

An RC boat is a miniature representation of a real ship controlled by radio signals, and it serves as an effective medium for design simulation and hydrodynamic performance testing. One of the design parameters that influences the hydrodynamic performance of a vessel is the deadrise angle, which refers to the inclination of the hull bottom relative to the horizontal plane. The deadrise angle also affects two main aspects, namely resistance and stability. A small deadrise angle can reduce the vessel’s lateral stability, while a large deadrise angle provides better comfort when encountering waves, but increases resistance due to the sharper hull form. This study was conducted to analyze resistance and stability with variations of deadrise angle on an RC boat with a planning hull using Maxsurf simulation. The results show that a 10° deadrise angle yields the lowest resistance at high speed, but with lower stability. A 20° deadrise angle provides the highest stability but with greater resistance. Meanwhile, a 15° deadrise angle offers the most balanced performance between speed and stability, and is therefore recommended as the optimal angle since it delivers the best overall performance for an RC boat with a planning hull

Pengaruh Kecepatan Putaran, Desain Pisau, dan Diameter Penyaring Terhadap Efisiensi Cocofiber Pada Mesin Pengurai Sabut Kelapa

2026-10-22T02:51:37+00:00

Coconut husk, an agricultural waste, has great potential to be processed into high-value products such as cocopeat and cocofiber. Therefore, a decorticating machine with better quality and quantity is required. This study applied a factorial experimental method with three variables: rotational speeds of 1800, 2400, and 3600 rpm; blade designs of type A, B, C, and D; and screen diameters of 4, 6, and 8 mm. Tests were conducted using coconut husk as raw material, and data were analyzed using ANOVA to evaluate efficiency. Results showed significant effects, with the best combination at 2400 rpm, blade type B, and 6 mm screen. However, based on the hypothesis test with a significance level (α) of 0.05, it was concluded that the knife design factor, sieve diameter, and the interaction among the three factors did not significantly affect the decortication results because the calculated F_cont was smaller than the F_table value, whereas the other interaction factors significantly affected the results because the F_tablevalue was greater than the calculated F_cont

Pengaruh Sudut Pahat Cemented Carbides, Kedalaman Pemakanan dan Kecepatan Putaran terhadap Keausan Pahat Proses Bubut Rata pada Baja ST90

2026-10-22T02:51:38+00:00

This study used an experimental method with variations in cutting angle, cutting depth, and machine rotation speed to measure their effects on cutting tool wear in the ST90 steel turning process. The ANOVA used to determine the main factors and interactions between factors that affect machining results. From the results of cutting angle factor A, cutting depth factor B, and rotation speed factor C, it was found that the single factors A, B, and C did not have a significant effect on the test results. The F_count values obtained were A=0.1122, B=0.0648, and C=0.0959, all of which were smaller than the F_table values of 3.26, 18.51, and 19.00, respectively. The AB interaction resulted in F_count= 28.29 > F_table = 6.94, the AC interaction resulted in Fcount = 421.77 > F_table = 6.39, and the BC interaction resulted in F_count = 817.85 > F_table = 3.26. Thus, the interaction between factors showed a significant effect. This confirms that the combination of factors is more decisive in determining the results than the influence of individual factors. Meanwhile, the interaction of the three factors ABC has no significant effect because F_count = 0.2073 < F_tabel= 2.63

PEMANFAATAN ADSORBEN BATU ZEOLIT DENGAN VARIASI MESH UNTUK OPTIMALISASI PADA PYRO REAKTOR

2026-10-22T02:51:38+00:00

The increasing volume of plastic waste and the rising demand for alternative energy sources have driven the development of pyrolysis technology as an effective waste treatment method capable of producing fuel. Pyrolysis converts plastic waste into liquid oil, gas, and char through thermal decomposition in the absence of oxygen. To enhance the quality of the resulting pyrolysis oil, natural zeolite can be utilized as an adsorbent due to its porous structure and high adsorption capacity. This study aims to examine the effect of zeolite mesh size variation on the physical properties of pyrolysis oil produced in a pyro-reactor. The zeolite mesh sizes applied were 50, 100, and 150, using Low-Density Polyethylene (LDPE), Polystyrene (PS), and Polypropylene (PP) as feedstock materials. The process was conducted at 300 °C for 4 hours with 50 grams of zeolite. The evaluated parameters included density, viscosity, and heating value. The results indicate that smaller zeolite particles (mesh 150) improved oil quality, producing a higher heating value and density closer to diesel standards. Among the plastic types, PP, PS produced higher density, and LDPE resulted in higher viscosity. These findings demonstrate the potential of natural zeolite to enhance pyrolysis oil quality as an alternative fuel source.

Pengaruh Kebisingan Genset Terhadap Kesehatan Pegawai: Studi Kasus Biro Umum Kantor Gubernur Provinsi NTT

2026-10-22T02:51:39+00:00

This study investigates the impact of generator set noise on the psychological, physiological, and auditory conditions of employees at the General Affairs Bureau of the East Nusa Tenggara Governor's Office. The research objectives encompass quantifying noise intensity, assessing health impacts, and analyzing adherence to Personal Protective Equipment (PPE) protocols. Employing a quantitative approach with regression and Spearman’s rank correlation analysis, the study involved twenty-four employees as respondents. Data collection utilized questionnaires evaluating impact comprehension, PPE awareness, and subjective health symptoms. Findings indicate that 100% of employees experienced noise interference, with a mean intensity of 95.7 dB, substantially exceeding the national Threshold Limit Value (TLV) of 65 dB. The instrument demonstrated high validity (p < 0.05) and internal consistency (Cronbach’s Alpha 0.912). Statistical analysis revealed a significant positive correlation between noise levels and total health complaints (r=0.706). While health symptoms showed a very strong correlation (r=0.978), PPE awareness lacked statistical significance relative to noise intensity. Predominant symptoms included cognitive concentration deficits, fatigue, and cephalalgia. Despite high PPE compliance, skepticism persists regarding equipment efficacy. Conclusively, the work environment is classified as hazardous due to extreme acoustic exposure, necessitating immediate engineering controls and a comprehensive evaluation of standardized hearing protection devices.

Analisi Pengaruh Susunan Poros terhadap Kinerja Flywheel Generator

2026-10-22T02:51:40+00:00

Roda gila merupakan salah satu komponen mesin yang berfungsi untuk menyimpan energi berupa energi kinetik hasil gerakan memutar poros engkol. Penelitian ini bertujuan untuk menganalisis pengaruh variasi susunan poros terhadap kinerja generator roda gila sehingga dapat digunakan sebagai bahan referensi pengembangan sistem penyimpanan energi mekanik berbasis roda gila yang lebih stabil. Pengujian dilakukan terhadap tiga susunan poros, yaitu tanpa roda gila, satu poros roda gila 30 kg, dan dua poros roda gila 12,5 kg dan 12,5 kg. Hasil penelitian dan analisis, dapat disimpulkan bahwa susunan poros roda gila berpengaruh terhadap kestabilan arus, tegangan, dan kecepatan putar. Tanpa roda, keluaran generator sangat tidak stabil. Susunan satu poros roda gila dengan massa 25 kg menunjukkan kestabilan yang membaik, meskipun masih terjadi penurunan saat beban aktif. Susunan dua poros roda gila yang masing-masing bermassa 12,5 kg memberikan stabilitas yang lebih baik daripada susunan satu poros karena energi kinetik total lebih besar pada poros A, yaitu 856,91 Joule dan poros B, yaitu 4.309,94 Joule. Dengan demikian, susunan dua poros roda gila bermassa 12,5 kg dan 12,5 kg merupakan yang paling efektif untuk menjaga stabilitas output generator.

Rancang Bangun Mesin Penggulung Benang Bagi Penenun Tradisional di Nusa Tenggara Timur

2026-10-22T02:51:43+00:00

ABSTRACT

A yarn winding machine is a tool used to wind yarn, featuring a mechanism that rotates the roll where the yarn is wound, thereby arranging the yarn neatly and orderly for use in the weaving process. In general, traditional weavers in East Nusa Tenggara Province employ a manual yarn winding process that is time-consuming and can lead to health issues for weavers, including fatigue, finger cramps, and wrist pain. To overcome this, a more effective and efficient yarn winding tool is needed to help weavers. The benefit of this research is to produce a yarn winding machine design that speeds up the production process of winding yarn quickly and does not cause health problems for traditional weavers. The tool design process is carried out with the help of engineering design software to obtain an economical but reliable weaving tool for traditional weavers. The results of this project demonstrate that the design and manufacture of a yarn winding tool made of wood, equipped with a 12-volt DC dynamo motor, can simplify and expedite the yarn winding process, thereby increasing efficiency and production, and reducing the manual workload on traditional weavers.

Pengaruh Daya Aktivasi UV-A dan UV-C terhadap Efisiensi Produksi Hidrogen pada Sistem MW-PEC(Multi-Wavelength Photoelectrochemical)

2026-10-22T02:51:44+00:00

Referring to the International Energy Agency and the COP21 targets regarding carbon emission reduction and the depletion of fossil fuel reserves, hydrogen is one of the energy alternatives with high energy density. One of the hydrogen production methods is through water photolysis but is constrained by the high recombination of electrons e- and holes h+. For this reason, research was conducted to test this problem using a Multi-Wavelength Photoelectrochemical (MW-PEC) system that integrates photocatalytic and electrochemical. This study compares hydrogen production through electrolysis, photolysis, and MW-PEC combining both methods.

The system works by containing 715 mL with KOH solution and the anode is coated with a composite as conductive. Meanwhile, a buck converter for power controller of UV-A LEDs and electrode plates as well as a blower for solution homogeneity. While at UV-C is constant with a function to conduct \(TiO_{2}\).

Test results for 30 minutes, electrolysis produced HHO gas of 1.9 mL at 2.7 Vdc and 3.3 mL at 5 Vdc. For photolysis with 2.7 Vdc and 3.5 Vdc produced 1.5 mL and 1.8 mL. Meanwhile, MW-PEC produced 0.7 mL at 2.7 V and 1.3 mL at 5 V.

Eksperimen Basin Desalinasi Solar Still Sistem Talang Bertingkat Lereng Tunggal

2026-10-22T05:05:47+00:00

This study aims to analyze the effect of the use of multilevel gutters on the production volume and efficiency of the desalination system. The method used is an experimental method with two types of basins, namely a basin without a gutter (Basin A) and a basin with multilevel channels (Basin B). The test results show that the highest solar radiation intensity reaches 1409.77 W/m², which causes an increase in seawater temperature and evaporation rate. Freshwater production increases over the test time, with an average total distillate volume of Basin A of 1284 ml and Basin B of 971 ml. In Basin B, the condensate distribution shows that gutter II produces the largest distillate volume. The maximum efficiency obtained by each basin is 2.55% for Basin A and 2.05% for Basin B. In general, the use of multilevel gutters does not improve condensate distribution and does not increase the effectiveness of the condensation process.

Performance Analysis of Thermoelectric Generator Using Heatsink Cooling System with Thermosiphon Principle

2026-10-22T02:51:46+00:00

In the modern era, the demand for electricity is rising, particularly in Indonesia, where many remote areas still depend on environmentally unfriendly energy sources. This research investigates the use of a thermoelectric generator (TEG) to convert waste heat energy from furnaces into electricity. By employing a heatsink cooling system based on the thermosyphon principle, the study aims to enhance energy conversion efficiency without additional pumps, thereby reducing energy consumption and maintenance costs. The analysis was conducted at three different heights: 50 cm, 60 cm, and 70 cm, using an experimental method with a quantitative approach. Results indicate that a height of 50 cm yields optimal performance, achieving a peak power of 550.123 mW and the highest efficiency of 4.41%, attributed to faster heat conduction. In contrast, at heights of 60 cm and 70 cm, both power and efficiency decline despite an increase in the volume of water discharged, as heat circulation is slower. At 60 cm, the peak power reached 332.592 mW, while at 70 cm, it was 437.082 mW. Higher water temperatures at these heights suggest a slower cooling process, which reduces system efficiency.