https://jesty.pubmedia.id/index.php/jesty <div> <p style="text-align: justify;"><strong>Journal of Engineering Science and Technology (JESTY)</strong> is a peer-reviewed journal that aims to publish and disseminate original research articles on the latest developments in all fields of engineering science and technology. The journal publishes original papers in Indonesian, which contribute to understanding engineering science and improving engineering technology and education. The articles may be theoretical (including computational), experimental or both. The contribution should be unpublished before and not under consideration for publication elsewhere.</p> <table class="data" width="100%" bgcolor="#f1f2ab"> <tbody> <tr valign="top"> <td width="30%"><strong>Journal title</strong></td> <td width="70%"> <strong><a href="https://jesty.pubmedia.id/index.php/jesty" target="_blank" rel="noopener">Journal of Engineering Science and Technology</a></strong></td> </tr> <tr valign="top"> <td width="30%"><strong>Initials</strong></td> <td width="70%"> <strong>JESTY</strong></td> </tr> <tr valign="top"> <td width="30%"><strong>Frequency</strong></td> <td width="70%"> <strong><a href="https://jesty.pubmedia.id/index.php/jesty/issue/archive" target="_blank" rel="noopener">3 issues</a> per year (January, May and September)</strong></td> </tr> <tr valign="top"> <td width="30%"><strong>Prefix DOI</strong></td> <td width="70%"> <a href="#" target="_blank" rel="noopener"><strong>10.47134</strong></a> <a href="https://search.crossref.org/?from_ui=&amp;q=2829-4777" target="_blank" rel="noopener"><img src="https://i.ibb.co/T4xZdG6/crossref3.png" alt="crossref3" border="0" /></a> </td> </tr> <tr valign="top"> <td width="30%"><strong>Online ISSN</strong></td> <td width="70%"> <a href="https://issn.brin.go.id/terbit/detail/20230118021328306" target="_blank" rel="noopener"><strong>2985-6132</strong></a></td> </tr> <tr valign="top"> <td width="30%"><strong>Editor In Chief</strong></td> <td width="70%"><strong><a> </a><a>Risse Entikaria Rachmanita </a></strong>[<a href="https://www.scopus.com/authid/detail.uri?authorId=57201119971" target="_blank" rel="noopener"><img src="https://image.ibb.co/i6QzrJ/Scopus_type_logo.jpg" alt="Scopus_type_logo" border="0" /></a>]</td> </tr> <tr valign="top"> <td width="30%"><strong>Publisher</strong></td> <td width="70%"><strong> <a href="https://idpublishing.org/" target="_blank" rel="noopener">Indonesian Journal Publisher</a></strong></td> </tr> </tbody> </table> <p> </p> </div> Indonesian Journal Publisher en-US Journal of Engineering Science and Technology 2985-6132 https://jesty.pubmedia.id/index.php/jesty/article/view/17 The demand for fossil energy sources continues to increase, which causes scarcity of these resources because they cannot be renewed. In Indonesia, waste rice straw and rice husks are abundant and have potential as a renewable energy source if converted into charcoal briquettes. However, currently the charcoal briquettes produced have not reached the desired level of efficiency to replace fossil fuels. Therefore, research was carried out to develop biomass energy by mixing zeolite in charcoal briquettes. This research aims to develop charcoal briquettes as an energy source from biomass. In this study, the calorific value of charcoal briquettes from rice straw with a 25% zeolite mixture had the lowest calorific value, namely 3941.2 cal/gram, while charcoal briquettes from rice straw without a zeolite mixture had the highest calorific value, namely 4581.8 cal/gram . The same thing happened to charcoal briquettes from rice husks, with the highest calorific value in charcoal briquettes without a zeolite mixture of 5390.5 cal/gram, and the lowest calorific value in charcoal briquettes mixed with 25% zeolite of 4469.1 cal/gram. The density of rice straw charcoal briquettes with a 25% zeolite mixture has the highest density value, namely 0.338 g/cm3, while rice straw charcoal briquettes without a zeolite mixture have the lowest density, namely 0.199 g/cm3. Likewise, charcoal briquettes from rice husks have the highest density in a 25% zeolite mixture with a value of 0.545 g/cm3, and the lowest density in charcoal briquettes without a zeolite mixture is 0.284 g/cm3. Mohammad Mualana Ramadhan Mokh. Hairul Bahri Ardhi Fathonisyam PN Copyright (c) 2023 Mohammad Mualana Ramadhan, Mokh. Hairul Bahri, Ardhi Fathonisyam PN https://creativecommons.org/licenses/by-sa/4.0 2023-09-30 2023-09-30 1 3 96 102 10.47134/jesty.v1i3.17 https://jesty.pubmedia.id/index.php/jesty/article/view/18 Fuel is one of the main needs of motorized vehicles. Most motorbike riders want the fuel they use to produce greater torque and power than standard specifications with lower exhaust emissions but save fuel. For this reason, several alternative solutions are needed to overcome this problem, including the use of additives, one of which is eco racing. The aim of this research is to determine the effect of adding eco racing to fuel variations on torque, power and exhaust emissions of 125 CC motorbikes. The research approach was carried out quantitatively by conducting descriptive analytical experiments. Data collection was carried out with various fuel variations at several engine rotation speeds. The research results showed that the mixture of Pertalite with 1 Eco Racing tablet and Pertalite with 2 Eco Racing tablets did not have much effect on power and torque, but increased exhaust emissions. Then, a mixture of Pertamax with 1 Eco Racing tablet and 2 Eco Racing tablets also does not really increase power and torque, but does increase exhaust emissions. The expected result of this research is to determine the effect of adding eco racing on engine performance. From the test results it was found that the addition of eco racing did not increase power and torque, but instead increased exhaust emissions. Moch Iqumuddin Mokh Hairul Bahri Ardhi Fathoni Syam Putra Nusantara Copyright (c) 2023 Moch Iqumuddin, Mokh Hairul Bahri, Ardhi Fathoni Syam Putra Nusantara https://creativecommons.org/licenses/by-sa/4.0 2023-09-30 2023-09-30 1 3 103 111 10.47134/jesty.v1i3.18 https://jesty.pubmedia.id/index.php/jesty/article/view/19 Welding technology has an integral role in the manufacturing technology domain. To create high-quality structures requires technology that allows joining metals. It is in this phase that welding technology comes into play. TIG (Tungsten Inert Gas) welding is a form of tungsten gas arc welding, where the electrode acts as an arc supplier that does not melt during the welding process. The Gas Tungsten Acr Welding technique is generally used more on light metals such as magnesium, aluminum, and stainless steel, and other types of metal. This type 201 carbon steel has several mechanical characteristics, including a tensile strength of 580 Mpa, an elastic limit (yield strength) of 198 Mpa, an elongation rate of 50%, and a hardness of 87 HRBI. The aim of this research is to determine the tensile strength and microstructure of TIG (Tungsten Inert Gas) welding results with 45 degrees of V, U and J seams. This research was carried out with several flat 2D test models of 45 degrees of V, U and J seams with current. 110 - 120. This research was conducted at the Banyuwangi Job Training Center, in the Materials Laboratory for Mechanical Engineering at Sebelas Maret University, Surakarta and at the Mechanical Engineering Laboratory at Jember State University. In this research, the results of changes in tensile strength were quite significant. The lowest tensile strength value is found in the J weld seam with an average value of 394.4 MPA. Meanwhile, the highest tensile strength value is found in the V weld seam with an average value of 531.1 MPA. The results of the microstructure for J seam have the largest phase grains and V seam forms the smallest phase grains compared to the others. Kampuh V has quite a large number of grains because they are relatively small and dense. Mokhammad Yoga Pratama Nely Ana Mufarida Kosjoko Kosjoko Copyright (c) 2023 Mokhammad Yoga Pratama, Nely Ana Mufarida, Kosjoko https://creativecommons.org/licenses/by-sa/4.0 2023-09-30 2023-09-30 1 3 112 119 10.47134/jesty.v1i3.19 https://jesty.pubmedia.id/index.php/jesty/article/view/20 Biomass is a type of solid waste that is used as an alternative energy source to replace fossil fuels (petroleum) because it can be renewed. Biopellets are a renewable fuel that comes from biomass. The aim of this research is to determine the characteristics of coconut waste biopellets. young with the addition of zeolite variations. The research method used is experimental research. The zeolite material used has 6 dosage variations, namely 0% (0 gram), 5% (2.5 grams), 10% (5 grams), 15% (7.5 grams) , 20% (10 grams), 25% (12.5 grams), with fixed variations from 50 grams of young coconut waste, tapioca flour adhesive and 20 grams of sugar cane molasses. The best burning rate of young coconut waste biopellets was obtained with the T 5 biopellet composition with a molasses adhesive composition with the addition of 5% zeolite with a value of 0.017% g/s. and the lowest water content value is found with the T 25 biopellet composition using molasses adhesive with a 25% zeolite mixture. And the best ash content value can be with P 0 biopellet composition using tapioca flour adhesive without zeolite mixture with a value of 3.32%. Muhammad Fahrur Rozi Ardhi Fathoni syam Putra Nusantara Mokh. Hairul Bahri Copyright (c) 2023 Muhammad Fahrur Rozi, Ardhi Fathoni syam Putra Nusantara, Mokh. Hairul Bahri https://creativecommons.org/licenses/by-sa/4.0 2023-09-30 2023-09-30 1 3 120 128 10.47134/jesty.v1i3.20 https://jesty.pubmedia.id/index.php/jesty/article/view/21 This research aims to determine the effect of variations in welding currents of 90A, 100A, and 110A on SMAW bases on the material in the tensile, hardness, and microstructure tests. This research uses ST37 low carbon steel and uses E6013 electrodes with a diameter of 3.2 mm, followed by making specimens for testing. After that, the welding process is carried out and then testing continues. In the test, the following results were obtained: The strength value of the welded material with tensile testing was obtained with the highest results at a current variation of 110A with Yp 27.33 Mpa, Max 36.47 Mpa, Break 31.08 Mpa. Because the highest pearlite microstructure value is obtained in the 110A variation. And the lowest value occurred in the welded material of variation 90A with Yp 25.48 Mpa, Max 26.86 Mpa, Break 12.33 Mpa. Because the lowest pearlite microstructure value is obtained in the 90A variation. while the comparison of the level of hardness in ST 37 carbon steel with varying welding currents ranging from 90A, 100A, and 110A has an average hardness value of 168 VHN for welding with a current of 90A for welding with a current of 100A the average hardness value is 177 VHN and finally in welding current 110A the average hardness value is 191 VHN. The hardness level of the ST 37 carbon steel specimen was the highest at a welding current of 110A, with a tensile strength test result of 36.47 MPa. And from the results of observing photos of the microstructure using the point count method, the highest percentage of pearlite was in the welding material variation 110A so the tensile strength value was higher. Andika Surahman Nely Ana Mufarida Kosjoko Kosjoko Copyright (c) 2023 Andika Surahman, Nely Ana Mufarida, Kosjoko https://creativecommons.org/licenses/by-sa/4.0 2023-09-30 2023-09-30 1 3 129 137 10.47134/jesty.v1i3.21