http://e-journals.irapublishing.com/index.php/IRAJTMA/issue/feed IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) 2025-05-20T15:20:34+07:00 Eswanto S.T., M.Eng irajtma@irapublishing.com Open Journal Systems <p style="margin: 0cm;"><strong><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="0" data-number-of-phrases="14"><span class="Q4iAWc">ISSN: <a href="https://issn.lipi.go.id/terbit/detail/20220808481427106">2962-4290 (media online)</a><br /></span></span></span></strong></p> <p><strong>IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) </strong><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="2" data-number-of-phrases="14"><span class="Q4iAWc">is an online journal published by CV.</span></span> <span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="3" data-number-of-phrases="14"><span class="Q4iAWc">IRA Publishing.</span></span> <span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="4" data-number-of-phrases="14"><span class="Q4iAWc">IRAJTMA is a peer-reviewed journal intended for Researchers, Practitioners, Lecturers, Students, and all authors who wish to publish their articles in the field of mechanical engineering and its applications.</span></span> <span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="5" data-number-of-phrases="14"><span class="Q4iAWc">We accept scientific articles, article reviews, and short communication.</span></span> </span></p> <p><strong><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="7" data-number-of-phrases="14"><span class="Q4iAWc">Publication Fee</span></span> </span></strong></p> <p>Articles selected for publication in this journal in Volume 1 Issues 1, 2 and 3 are free of charge.</p> <p>Starting in 2023, each article published beginning in Volume 2 Issues 1 will be charged a publication fee of Rp. 100,000,-.</p> <p>Starting in 2025, each article published beginning in Volume 4 Issues 1 will be charged a publication fee of Rp. 400,000,-.</p> <p><strong><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="11" data-number-of-phrases="14"><span class="Q4iAWc">Publication Edition</span></span> </span></strong></p> <p><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="13" data-number-of-phrases="14"><span class="Q4iAWc">This journal is published in three editions in one year, namely April, August, and December every year.</span></span></span></p> <p style="margin: 0cm;"><strong> Journal Indexing<br /></strong></p> <p style="margin: 0cm;">Since early August 2022, IRAJTMA has been indexed by Search Engines: <a href="https://scholar.google.com/citations?hl=id&amp;user=7stmT7kAAAAJ"><strong>Google Scholar (GS)</strong></a>. On August 20, 2022, it was indexed by <a href="https://www.worldcat.org/search?q=IRAJTMA&amp;qt=search_items&amp;search=Search"><strong>WorldCat</strong></a>, one<a href="https://www.worldcat.org/whatis/default.jsp"> of the most complete library collection information databases in the world</a>. <span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="0" data-number-of-phrases="1"><span class="Q4iAWc">IRAJTMA has also been indexed by <a href="https://www.base-search.net/Search/Results?lookfor=IRA+Jurnal+Teknik+Mesin+dan+Aplikasinya+%28IRAJTMA%29&amp;name=&amp;oaboost=1&amp;newsearch=1&amp;refid=dcbasen"><strong>BASE</strong></a> around the 2nd week of August 2022 where the <a href="https://www.base-search.net/about/en/index.php">BASE is one of the most productive search engines in the world, especially for academic web resources.</a></span></span></span></p> <p style="margin: 0cm;"><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="0" data-number-of-phrases="1"><span class="Q4iAWc">On January 3, 2023, IRAJTMA was also indexed by <strong><a href="https://garuda.kemdikbud.go.id/journal/view/28184">Garba Rujukan Digital (GARUDA)</a></strong> which is one of the National Indexers under the auspices of the Ministry of Education, Culture, Research, and Technology. GARUDA is an Indonesian scientific reference discovery portal that is an access point for scientific works produced by Indonesian academics and researchers.</span></span></span></p> <p style="margin: 0cm;"> </p> <p style="margin: 0cm;"><a href="https://issn.lipi.go.id/terbit/detail/20220808481427106"><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="0" data-number-of-phrases="1"><span class="Q4iAWc"><strong>ISSN (online media)</strong> </span></span></span></a></p> <p style="margin: 0cm;"><span class="VIiyi" lang="en"><span class="JLqJ4b ChMk0b" data-language-for-alternatives="en" data-language-to-translate-into="id" data-phrase-index="0" data-number-of-phrases="1"><span class="Q4iAWc">Based on SK from LIPI Number: 0005.29624290/K.4/SK.ISSN/2022.08 dated August 23, 2022 p.: ISSN Issuance Decree No. 2962-4290, starting with Volume 1 Number 2, August 2022 edition has an ISSN.</span></span></span></p> <p style="margin: 0cm;"> </p> <p><a href="https://drive.google.com/file/d/1kLhpO9yUmvVEnp6_dePw-mbRZOLf_zkH/view?usp=sharing"><strong>National Scientific Journal Accreditation Ranking</strong></a></p> <p>Based on the Decree of the Director General of Higher Education, Research, and Technology Number 10/C/C3/DT.05.00/2025 dated March 21, 2025 concerning the Accreditation Ranking of Scientific Journals for Period I of 2025 with <strong>RANKING 4</strong>.</p> http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/176 Process of Manufacturing Piston Displacer for Small Scale Gamma Type Stirling Engine 2025-02-27T18:08:27+07:00 Aldi Kurniawan sncfitra11@gmail.com Jufrizal Jufrizal jufrizal@staff.uma.ac.id Nurdiana Nurdiana ir.nurdiana@yahoo.co.id <p><em>This study aims to design and manufacture a displacer piston for a Gamma-type Stirling engine using steam pipe material due to its heat-resistant properties. The manufacturing process involved cutting, turning with a conventional lathe, and TIG welding. The final product dimensions were 65.75 mm in diameter, 60.20 mm in height, and 321.20 mm. Measurement results showed that the dimensional tolerances were within the design limits, and no leakage was found in the joints after visual inspection and basic functional testing. The study demonstrates that a simple process can produce a piston suitable for laboratory-scale applications.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/178 Analysis of Air Volume Requirements for Blower in Tapioca Flour Transfer from Dryer Unit to Shifter Unit 2025-02-24T14:59:11+07:00 Nurlianna Tarigan nurlianna@ptki.ac.id Nelson Silitonga silit_raja@yahoo.co.id Ivo Jones Sitorus sitorusivo93@gmail.com <p><em>This study aimed to calculate the volume of air required by a blower to transfer tapioca flour from the dryer unit to the shifter unit in a factory with a production capacity of 35 tons per day. The flour transfer process utilizes a blower to generate sufficient airflow. Still, it often experiences instability caused by factors such as blower speed fluctuations, material load variations, and pipe blockages. The research was conducted over one month using data collection methods that included interviews and direct observation. Analysis results showed that the cross-sectional area of the blower pipe was 0.6358 m², the airflow velocity was 1.517 m/s, and the airflow rate reached 0.965 m³/s. The total air volume required by the blower to move the flour was calculated to be 27,792 m³ per day. The findings highlight the importance of properly regulating and maintaining the blower system to ensure efficiency in tapioca flour production.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/181 Analysis of Thermal Behavior and Heat Capacity of Uncoated and Coated Carbide Cutting Tools in Cast Iron Cutting Process 2025-03-17T22:47:40+07:00 M. Sobron Yamin Lubis sobronlbs@gmail.com Abrar Riza abrarr@ft.untar.ac.id Han Han hanhana006@gmail.com Nathan Ferdiantino Hidayat nathan.515220047@stu.untar.ac.id <p><em>During turning, most energy is converted into heat, which spreads to the cutting tool, chips, and workpiece. Heat transfer occurs via conduction and can cause tool wear. To reduce this, coatings with low thermal conductivity are used. This study aims to analyze heat absorption and heat capacity of uncoated carbide and TiCN + Al₂O₃ + TiN coated carbide tools during cast iron turning. Tests were conducted at 160, 210, and 260 m/min cutting speeds. Temperatures were measured using a K-type thermocouple placed at the tooltip. Results show the coating effectively reduces heat penetration into the tool. The coated carbide required 64.5 J/K for a 1 K temperature rise, while the uncoated only needed 1.5 J/K. This indicates uncoated tools heat up faster and wear more quickly.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/188 Banana Chips Draining Machine Testing for the Small-Scale Food Industry 2025-04-09T13:53:09+07:00 Mhd. Iqbal iqbalmhd0604@gmail.com Tino Hermanto tinohermanto@staff.uma.ac.id Yopan Rahmad Aldori yopanrahmadaldori@staff.uma.ac.id <p><em>Manual oil draining on banana chips takes longer and leaves residual oil, affecting the texture and shelf life. This study uses centrifugal force to develop and test an oil-draining machine for banana chips. The method applied was experimental, with variables including rotation speed, draining time, and material capacity. The results show that the machine reduced oil content by 6% in 1 minute, improving crispness and shelf life.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/189 The Influence of Feed Rate in the Milling Process of SKD 61 Steel on Wear of 2-Flute Carbide Endmill 2025-04-08T22:31:11+07:00 Arthasasta Sharon Rumbiak arthasastasharon1105@gmail.com Hardy Sari Putra HardySP02@gmail.com M. Sobron Yamin Lubis sobronlbs@gmail.com Erwin Siahaan erwins@ft.untar.ac.id <p><em>The metal-cutting process in manufacturing operations plays a crucial role in achieving a product's desired dimensions, sizes, and shapes; SKD 61 steel is widely used in the mold-making industry due to its excellent hardness properties. This study evaluates the effect of varying feed rates on tool wear during dry milling using a 2-flute carbide end mill cutter. A series of experimental tests were conducted using a manual milling machine to investigate the influence of feed rate variation on tool life. The feed rate variations used were 42 mm/min, 98 mm/min, and 230 mm/min. Other machining parameters were kept constant: spindle speed at 1320 rpm, cutting depth of 0.5 mm, and a tool diameter of 10 mm. The results showed that increasing the feed rate directly accelerated tool wear. The maximum tool wear, 0.6 mm, was reached at different times for each feed rate: 115 minutes (42 mm/min), 95 minutes (98 mm/min), and 80 minutes (230 mm/min). These findings provide valuable insights for optimizing cutting parameters to extend tool life and improve machining efficiency when working with SKD 61 steel components.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/192 Analysis of the Effect of Variation in Blade Rotation Speed on the Quality of Shallot Cuts on a Slicing Machine 2025-04-20T13:45:07+07:00 Muhammad Dava Faruqi daffafaruqqy4@gmail.com Mhd. Taufik Ardaha tinohermanto@staff.uma.ac.id Tino Hermanto tinohermanto@staff.uma.ac.id Yopan Rahmad Aldori yopanrahmadaldori@staff.uma.ac.id <p><em>Manually slicing shallots is challenging for MSMEs engaged in the fried shallot industry. This study aims to analyze the effect of variations in the speed of knife rotation on the quality of the results of the sliced ​​shallots on the slicing machine. The study was conducted experimentally with five variations in rotation speed, measured using a tachometer, and visual observation to assess the quality of the slices. The results showed that the cutting speed increased from 61 kg/hour to 89 kg/hour, with the quality of the slices remaining at 85%. This study recommends the highest speed as optimal for productivity without reducing the quality of the slices.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/193 Study of Utilization of Water Hyacinth (Eichhornia Crassipes) as Environmentally Friendly Bio-Briquettes: Experimental Study 2025-04-20T13:47:35+07:00 Syamsul Bahri Widodo syamsulbahri@unsam.ac.id Zainal Arif zainalarif@unsam.ac.id Iskandar Yakob iskandar64@unsam.ac.id Suheri Suheri suheri@unsam.ac.id Dicky Maranata Sembiring dickymaranatha@gmail.com <p><em>Eichhornia crassipes (water hyacinth) is a fast-growing aquatic plant in tropical regions like Indonesia. Though often considered a weed, it remains underutilized as an alternative energy source. This study explores its potential as a solid fuel in the form of eco-friendly bio-briquettes. The production process includes drying, carbonization, sieving, mixing with binder, molding, and final drying. Laboratory tests involved proximate analysis and calorific value measurement. Results showed that the briquettes contained 9.61% moisture, 3.93% ash, 7.89% volatile matter, 78.57% fixed carbon, and a calorific value of 25.8 kJ/g. Compared to coconut shell briquettes, water hyacinth briquettes burn more slowly but offer cleaner and more stable combustion. These characteristics make them a suitable renewable energy source for households and small industries.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/199 Performance Analysis Of Onion Draining Machine For Small Scale Food Industry 2025-04-24T09:45:31+07:00 Shera Dwy sheradwyprastya@gmail.com Tino Hermanto tinohermanto@staff.uma.ac.id Iswandi Iswandi iswandi@staff.uma.ac.id Darianto Darianto tinohermanto@staff.uma.ac.id <p><em>This study aims to analyze the performance of a fried onion draining machine designed for the needs of small-scale food industries. The machine operates using the principle of centrifugal force and is constructed with 304 stainless steel to ensure food safety and resistance to corrosion. Testing was conducted using variables such as rotation speed, draining time, and material capacity. Results show that the machine can reduce oil content in fried onions by 14.29% within 2 minutes, with a draining capacity of 50 kg per hour at 700 rpm.</em><em> Energy efficiency achived was 35,49%, showing the potential for practical application of this machine in the UMKM environment</em><em>. The use of this machine results in fried onions that are crispier, have a longer shelf life, and are processed more hygienically and efficiently. Further recommendations include design and operation system optimization to improve performance.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/203 Strength Analysis of Tig Welding Joints on KMHE Car Roll Bars Using 6061 Aluminum Through Bending Tests 2025-04-29T20:11:13+07:00 Elvan Elvan elvan072003@gmail.com M. Sobron Yamin Lubis sobronl@ft.untar.ac.id Steven Darmawan stevend@ft.untar.ac.id <p><em>The welding process is a production process that aims to combine two types of materials into a usable component. In the manufacturing industry, the Tungsten Inert Gas welding process is widely used in industrial processes requiring high accuracy, good welding quality, and welding results. This study compares the strength of welded joints by varying the welding current. This research uses 6061 aluminum material to determine the strength of Tungsten Inert Gas welding joints. The study focused on the strength of Tungsten Inert Gas welding joints with current variations of 140 A, 160 A, and 180 A using a testing method using a three-point bending test to determine the right current variation in the Tungsten Inert Gas welding process. This study found that the current variation of 160 A with a strength of 203.7 N/mm<sup>2</sup> is better than 140 A, 139.9 N/mm<sup>2</sup>, and 180A, 192.1 N/mm<sup>2</sup> in Tungsten Inert Gas welding joints.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/179 Development of An Electric-Powered Oil Palm Harvesting Tool Prototype to Improve Productivity 2025-03-09T11:26:36+07:00 Rizky Fauzi rizkyfauzi21032003@gmail.com Iswandi Iswandi iswandi@staff.uma.ac.id Tino Hermanto tinohermanto@staff.uma.ac.id <p><em>Using manual oil palm fruit harvesting tools requires a lot of energy and time, especially for trees with a height of more than 5 meters. This study aims to design and create an efficient, ergonomic, and environmentally friendly electric-based oil palm fruit harvesting tool. This system uses a DC electric motor controlled by a switch, with a sickle-shaped cutting blade driven by a transmission belt. The test results showed that the tool could cut oil palm bunches at 5-8 meters height with an average cutting time of 5-7 seconds per bunch. Power consumption was recorded at 150 Watts with a 24V 10Ah lithium battery power source.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/202 Analysis of Effectiveness, Productivity and Oil Quality on Empty Bunch Press Machine in Palm Oil Mill 2025-04-29T07:22:38+07:00 Mahyunis Mahyunis mahyunis@itsi.ac.id Rafael Remit Winardi mahyunis@itsi.ac.id Padamulia Raja mahyunis@itsi.ac.id Giyanto Giyanto mahyunis@itsi.ac.id Hafiz Darma Fazli mahyunis@itsi.ac.id <p><em>The empty bunch press is a tool that extracts oil from empty palm fruit bunches to reduce oil losses. This study aimed to assess the machine's effectiveness and productivity, measure oil content in the residue, and evaluate the quality of the oil bunch press . A quantitative descriptive method was applied through 14 days of observation at a palm oil mill laboratory. Results showed that the oil content in empty bunches was 6.36%, that of residue was 1.12%, and that of oil bunch press </em> <em>was 5.23%. Input weight was 4,071 kg/hour, output 1,833 kg/hour, and extracted oil 95.87 kg/hour. The machine's effectiveness was 82.23%, and productivity was within a 5–6 tons/hour capacity. Oil bunch press quality tests showed 5.24% FFA, 0.41% moisture, and 0.12% impurities. Although losses and oil quality exceeded standard limits, the oil bunch press </em> <em>will be refined before blending with production oil.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/183 Identification of Flow Types in Pressurized Pipe Systems with Series and Parallel Pumps 2025-03-15T15:09:08+07:00 Hotman Ginting hotmanginting5@gmail.com Jimy Lingga hotmanginting5@gmail.com Jufrizal Jufrizal jufrizal@staff.uma.ac.id Indra Hermawan jufrizal@staff.uma.ac.id <p><em>Centrifugal pumps are widely used to move fluids through increased pressure efficiently. This study examines the effect of series and parallel pump configurations and valve opening variations on flow characteristics in a pressurized piping system. A laboratory experiment method with two repetitions was used. The results showed turbulent flow at 50%, 75%, and 100% valve openings with Reynolds numbers above 10,000. In comparison, at a 25% opening, series pumps tend to produce laminar flow (Re &lt; 600), and parallel pumps maintain transitional/turbulent flow (Re &gt; 4,000). The recommendation is to use series pumps for high pressure and parallel for large discharge, with a minimum valve opening of 25% for optimal efficiency.</em></p> <p> </p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/185 The Effect of Valve Opening Variation on System Performance in Series and Parallel Pump Configurations 2025-03-15T15:35:43+07:00 David Jomantes Munthe davidmunthe11@gmail.com Jimy Lingga davidmunthe11@gmail.com Jufrizal Jufrizal jufrizal@staff.uma.ac.id Muhammad Idris muhammad.idris@staff.uma.ac.id <p><em>Centrifugal pumps are widely used in industry and civil engineering to move fluids by increasing pressure efficiently. This study analyzes the effect of valve opening variations on series and parallel pump configurations simultaneously using a laboratory experiment method with two repetitions. The results show that parallel pump configurations are generally more efficient than series, especially at 50% and 25% valve openings. The maximum efficiency is achieved at 75% valve opening with a value of around 33% for both configurations. Valve opening settings and pump configuration selection are very important to improve the performance and efficiency of pressure piping systems. It is recommended for small industries to use parallel pump configurations with optimal valve opening operations of around 75% for energy efficiency and cost savings. Developing an automatic valve opening control system is also recommended to maximize efficiency, extend equipment life, and optimize fluid distribution.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/182 Application of Kansei Engineering Method in Soap Product Innovation 2025-05-20T14:09:56+07:00 Haddad Alwi Hakim Hasibuan uun379@gmail.com Uun Novalia Harahap uun379@gmail.com Zaharuddin Zaharuddin uun379@gmail.com Muhammad Idris muhammad.idris@staff.uma.ac.id <p><em>To remain competitive, the soap manufacturing industry must understand consumer preferences. This study uses the Kansei Engineering method to explore consumer desires for bar soap, which links user impressions and emotions (Kansei) to product design elements. Thirteen Kansei words were identified and translated into five design items, each with multiple categories. Using orthogonal design in SPSS 24.0, 16 stimuli were generated. Conjoint analysis was then applied to examine the relationship between Kansei words and product attributes. Results revealed the most preferred combination: round shape, white colour, medium size (85g), moisturizing function, and long-lasting fragrance. These findings guide designing bar soap products that better match consumer expectations.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/184 Performance Analysis of 155cc 2-Stroke Sport Motorcycles with Various Types of Fuel 2025-05-12T19:22:36+07:00 Kurnia Rizky Nasution rizkynasution068@gmail.com Jufrizal Jufrizal jufrizal@staff.uma.ac.id Supriatno Supriatno supriatno@staff.uma.ac.id <p><em>The development of two-wheeled automotive technology continues to advance, especially in fuel efficiency, engine performance, and emissions. One key factor affecting engine performance is fuel quality. This study investigates the effect of fuel octane rating on torque and power in a 155cc 2-stroke sport motorcycle at 3500–8000 rpm. Three fuel types were tested: Pertamax, Pertamax Turbo, and Pertalite. Maximum torque was recorded at 6000 rpm with values of 11.3 Nm (Pertamax), 11.8 Nm (Pertamax Turbo), and 11.6 Nm (Pertalite). Maximum power was observed at 8000 rpm with 8.2 kW, 8.6 kW, and 8.3 kW, respectively. In addition to octane rating, compression ratio, and engine speed significantly influence torque and power output.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) http://e-journals.irapublishing.com/index.php/IRAJTMA/article/view/190 Treatment of Flue Gas from the Combustion of Refuse Derived Fuel and Sawdust Using a Spray Tower Scrubber 2025-05-20T15:20:34+07:00 Ilmi Ilmi ilmi@usu.ac.id Junjungan Simamora junjungansimamora92@gmail.com Suherman Suherman suherman@umsu.ac.id Zufri Hasrudy Siregar ilmi@usu.ac.id <p><em>The growing volume of waste has encouraged the use of fuel derived from waste as an alternative energy source. However, its combustion releases flue gas containing harmful pollutants. This study assesses the effectiveness of a spray tower in reducing the opacity and temperature of flue gas generated from the combustion of a mixture of waste-based fuel and sawdust. Experiments used three fuel masses and three system setups: no sprayer, two sprayers, and four sprayers. Results showed that the spray tower reduced opacity from 33 per cent to about 15 per cent with two sprayers and 11.2 per cent with four sprayers. Gas temperature decreased from 65 degrees Celsius to 39 degrees and 35 degrees Celsius. A higher number of sprayers led to greater pollutant reduction. This technology shows promise as an environmentally friendly method for controlling emissions.</em></p> 2025-04-30T00:00:00+07:00 Copyright (c) 2025 IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA)