Semesta Teknika
https://journal.umy.ac.id/index.php/st
<div style="text-align: justify;"><strong></strong><div style="text-align: justify;">SEMESTA TEKNIKA is a reputable refereed journal devoted to the publication and dissemination of basic and applied research in engineering. SEMESTA TEKNIKA is a forum for publishing high-quality papers and references in engineering science and technology. The journal is published by the Faculty of Engineering, Universitas Muhammadiyah Yogyakarta, INDONESIA. The journal is issued in electronic form and also issued in printed form as annual volume for the contributors only. The journal contains original research papers, review articles, short notes and letters to the editors. The topics of interest include modeling, experimental, analytical, and numerical investigations on the mechanical, physical, chemical and mineralogical properties of material, developing the prototype/instrument, technology and construction process. Topic of management in industry and civil construction is also considered. SEMESTA TEKNIKA receives manuscripts from the contributor written in Indonesian and English. Manuscripts submitted to the journal for publication must not have been previously published or is under consideration simultaneously by any other publication. Manuscripts submitted to SEMESTA TEKNIKA will be reviewed by Peer Reviewers local and foreign. The manuscript will be evaluated based on its appropriateness with topic and scope of SEMESTA TEKNIKA, contribution to the discipline, cogency of the analysis, clarity of presentation and technical adequacy.<a href="http://u.lipi.go.id/1180430641"> ISSN: 1411-061X (Cetak)</a><a href="http://u.lipi.go.id/1453170981"> ISSN: 2502-5481 (Online)</a><strong><span id="result_box" lang="en">. International ISSN could be <a href="https://portal.issn.org/resource/ISSN/2502-5481" target="_blank">checked here (portal.issn.org)</a></span></strong><div style="text-align: justify;"><div> </div><div><strong>SEMESTA TEKNIKA is accredited in SINTA (Science and Technology Index) at grade 3 by the Ministry of Research and Technology of Republic of Indonesia (Ministry of Research and Technology of the Republic of Indonesia), <a href="/index.php/st/announcement/view/179" target="_blank">Decree (SK) No. 148 / M / KPT / 2020 valid from vol 22 no 2 (2019) to vol 27 no 1 (2024).</a></strong></div><strong><span lang="en"><br /></span></strong></div></div><div style="text-align: justify;"> </div><div style="text-align: justify;">SEMESTA TEKNIKA is indexed and abstracted in</div><div style="text-align: justify;"><ul><li><a href="https://scholar.google.co.id/citations?pli=1&user=miutlzwAAAAJ">GOOGLE SCHOLAR</a></li><li><a href="https://www.base-search.net/Search/Results?lookfor=dccoll%3Aftumyogyakartojs+url%3Aai&refid=dclink">BASE</a></li><li><a href="http://sinta.kemdikbud.go.id/journals/detail?id=2030">Science and Technology Index (SINTA 3)</a></li><li><a href="http://id.portalgaruda.org/index.php?ref=browse&mod=viewjournal&journal=647">Indonesia Publication Index (Portal Garuda)</a></li><li><a href="https://www.worldcat.org/title/semesta-teknika-jurnal-ilmiah-fakultas-teknik-universitas-muhammadiyah-yogyakarta/oclc/51804397&referer=brief_results">World Cat</a></li><li><a href="http://garuda.kemdikbud.go.id/journal/view/8111">GARUDA (Garba Rujukan Digital</a>)</li><li><a href="https://search.crossref.org/?q=semesta+teknika" rel="noopener" target="_blank">Crossreff (DOI)</a></li><li><a href="https://doaj.org/toc/2502-5481" target="_blank">DOAJ</a> </li><li><a href="https://app.dimensions.ai/discover/publication?search_mode=content&and_facet_source_title=jour.1355861">Dimensions</a></li></ul><strong><strong><strong>Online Submissions</strong></strong></strong><br /><div>If you already have a Username/Password? <a href="/index.php/st/login"><strong>GO TO LOGIN</strong></a><br />If you are newcomers and need a Username/Password? <strong><a href="/index.php/st/user/register">GO TO REGISTRATION</a></strong><br /><a href="https://docs.google.com/document/d/1o2U-RhudNlEf3frjSXuD1pM2DVXNJ_2N/edit?usp=sharing&amp;ouid=112023030465781937695&amp;rtpof=true&amp;sd=true" target="_blank">DOWNLOAD TEMPLATE</a><br /><p>Registration and login are required to submit items online and to check the status of current submissions.</p></div></div><div style="text-align: justify;"> </div></div><div id="gtx-trans" style="position: absolute; left: 93px; top: 398px;"> </div>Universitas Muhammadiyah Yogyakartaen-USSemesta Teknika1411-061X<p><br />Semesta Teknika is licensed under a <a href="http://creativecommons.org/licenses/by/4.0/" rel="license">Creative Commons Attribution 4.0 International License</a>.</p><p>Authors who publish with this journal agree to the following terms:</p><ul><li>Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a <a href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.</li><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.</li><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li></ul>The Effect of Rotational Tool Speed on Dissimilar Joint Aluminum-Copper Plate Friction Stir Welded Joint
https://journal.umy.ac.id/index.php/st/article/view/20477
<em>The study investigates the impact of rotational tool speed on the mechanical properties and microstructure of aluminum-cooper friction stir-welded joints. It found that higher rotational speed leads to increased grain size, possibly due to increased heat production. Higher hardness values in the stir zone result from uniform dispersion of smaller copper particles. The study found that 540 rpm yields the maximum hardness value in the stir zone, measuring 67 VHN. However, higher speed results in defects like voids, cracks, and intermetallic compounds (IMCs), which are linked to the formation of IMCs at elevated temperatures. The optimal welding conditions at 550 rpm balance grain refinement, hardness enhancement, and defect mitigation, contributing to the understanding of welding process parameters.</em>Aris Widyo NugrohoKhukuh Aulia RahmanMuhammad Budi Nur Rahman
Copyright (c) 2023 Aris Widyo Nugroho, Khukuh Aulia Rahman, Muhammad Budi Nur Rahman
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2023-11-202023-11-2026212813610.18196/st.v26i2.20477Evaluation of Satellite-based Rainfall Data in Flood Prediction
https://journal.umy.ac.id/index.php/st/article/view/19036
<p>Rainfall-runoff transformation is a solution to the difficulty of obtaining observed discharge data in flood prediction analysis. Rainfall-runoff transformation requires observed rainfall data with a high rate of accuracy spatially. However, observed rainfall data is also often not available. Satellite rainfall data is commonly used to replace observed rainfall data. However, the accuracy of satellite rainfall data still needs to be tested. This study applied rainfall-runoff transformation to the observed rainfall data and the PERSIANN, GPM, and GSMaP satellite rainfall data in the Opak Watershed using GAMA I SUH method, which were then compared with the observed hydrograph at the AWLR Kretek during the flood event that occurred in Yogyakarta Province due to Cyclone Cempaka to evaluate their accuracy. The results showed that the GPM data generated a hydrograph that is the closest to the observed hydrograph, both the shape and the peak of the hydrograph.</p>Bayu Krisna WisnulinggaJoko SujonoRachmad Jayadi
Copyright (c) 2023 Bayu Krisna Wisnulingga, Joko Sujono, Rachmad Jayadi, Puji Harsanto, Nursetiawan Nursetiawan
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2023-11-232023-11-2326213714710.18196/st.v26i2.19036Correlation between Physical Properties and Specific Fuel Consumption in Jatropha -Used Cooking Oil Biodiesel Mixtures
https://journal.umy.ac.id/index.php/st/article/view/20163
<p>This study was motivated by the need to understand the influence of using waste jatropha biodiesel on the physical properties of fuel and the performance of diesel engines. The primary aim was to determine the relationship between the fuel's physical properties, spray angle, and specific fuel consumption (SFC) at various load levels. The methodology employed included measurements of density, viscosity, flash point, calorific value, spray angle, and SFC for different blends of waste jatropha biodiesel and diesel (B5, B10, B15, B20). The research results demonstrate an increase in density, kinematic viscosity, and flash point, along with a decrease in calorific value, as the biodiesel content increases. The density of the biodiesel mixture ranges from 823 kg/m³ at B5 to 836.50 kg/m³ at B20. The kinematic viscosity increases from 3.9 cSt at B5 to 5.2 cSt at B20, and the flash point rises from 112.9°C at B5 to 128.7°C for B20. Meanwhile, the calorific value decreases from 10308.2670 cal/g at B5 to 10133.8280 cal/g for B20. A strong correlation exists between density and kinematic viscosity with the spray angle, exhibiting R<sup>2</sup> values of 0.9141 and 0.8287, respectively. The correlation between the fuel's physical properties and the specific fuel consumption (SFC) is also substantial, marked by high R<sup>2</sup> values above 0.93. These findings provide a solid foundation for the development of more optimal biodiesel formulations.</p>Wahyudi WahyudiMuhammad NadjibApriyanto Apriyanto
Copyright (c) 2023 Wahyudi Wahyudi, Muhammad Nadjib, Apriyanto Apriyanto
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2023-11-242023-11-2426214815810.18196/st.v26i2.20163Analysis of the Noise Level at the Muhammadiyah KH. Ahmad Dahlan S. Parman Complex, Banjarmasin
https://journal.umy.ac.id/index.php/st/article/view/18664
<p><em>The traffic density in Banjarmasin will have an impact on the environment such as the noise which causes health problems to humans. The noise in the school area, it will damage for concentration of students, teaching and learning activities inefficient. The purpose of this study was to determine the noise level in the College Complex of Muhammadiyah K.H Ahmad Dahlan, Banjarmasin. Measurement is carried out at 4 points and used Sound Level Meter (SLM). Noise data processing is calculated by the equivalent noise level (Leq). The results show that noise value exceeded the noise quality standard according to the Environmental Decree 1996 for noise levels in schools. The highest noise value reached 80.29 decibels while the lowest value was 63.04 decibels. Based on the results, it is necessary to reduce noise levels in this school area, so that teaching and learning activities can run properly.</em></p>Dyah Pradhitya HardianiEmma Ruhaidani
Copyright (c) 2023 Dyah Pradhitya Hardiani, Emma Ruhaidani
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2023-11-252023-11-2526215916710.18196/st.v26i2.18664Experimental Study on the Performance of Mechanical Coupler Splice Made of Rebar Under Monotonic Loading
https://journal.umy.ac.id/index.php/st/article/view/19263
<span lang="EN">The lap splice method presents a drawback due to reinforcement congestion, affecting the pouring and evenness of the concrete. Additionally, lap splicing significantly contributes to construction waste. As a result, research was conducted on mechanical connections using reinforcements to reduce construction waste and demonstrate the feasibility of these splices. In this study, the threaded coupler with standard national coarse threads splice method was employed, and tests were conducted following ASTM A1034-10a standards with monotonic tensile loading. Test specimens were created using 13 and 16 mm reinforcement sizes, varying the length and diameter of the coupler, and including welding at the coupler ends. The test results demonstrated that reinforced bars with splices exhibit a stress-strain relationship similar to intact reinforcement. However, these reinforced bars with splices did not meet the requirements outlined in SNI 2052:2017 concerning maximum stress and strain, including their comparison. Therefore, the utilization of these splices is not suitable for critical load-bearing areas.</span>Heidi MuhammadAshar SaputraAndreas Triwiyono
Copyright (c) 2023 Heidi Muhammad, Ashar Saputra, Andreas Triwiyono
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2023-11-252023-11-2526216818010.18196/st.v26i2.19263Web-Based System Information Certificate Services at Klamono District Offices
https://journal.umy.ac.id/index.php/st/article/view/19573
<p>Klamono District Office still relies on manual procedures for delivering certificates to residents, involving steps such as direct submission of certificate requests at the village office, form filling, and physical submission of supporting documents. To overcome this challenge, the proposal of implementing a dedicated information system tailored to streamline the certificate issuance process has emerged. This study proposes a Certificate Service Information System to elevate operational efficiency at the Klamono District Office. The Extreme Programming system development method is utilized, along with testing through Blackbox Testing and Usability Testing. This research indicates that the developed application can improve the effectiveness and efficiency of services in the certificate issuance process. The Blackbox testing results show a system success rate of 100%, while the usability testing report records a user satisfaction level of 93.1%.</p>Muhammad Nur AriefMuhammad Rizki SetyawanRendra SoekartaPascalina Magrice Simori
Copyright (c) 2023 Muhammad Nur Arief, Muhammad Rizki Setyawan, Rendra Soekarta, Pascalina Magrice Simori
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2023-11-252023-11-2526218119310.18196/st.v26i2.19573Properties of Concrete Containing Type-C Fly Ash Under Elevated Temperature
https://journal.umy.ac.id/index.php/st/article/view/19732
High temperatures affect the properties of the concrete material. The changes generally depend on the quality of the concrete and the content of added ingredients during concrete mixing. This article examines the strength, weight, and visual changes of normal and high-strength concrete with the addition of class C fly ash (FA) under elevated temperature. FA was added as much as 15% by cement weight in each concrete type. The specimens consisted of four types concrete: normal concrete, normal concrete + FA, high-strength concrete, and high-strength concrete + FA. The fire test was carried out after 45 days curing time for 3 hours with variations in combustion temperature of 500ºC and 1000ºC. Visually, the concrete changes color to yellow-white with micro-cracks after being exposed to a temperature of 500ºC, while at 1000ºC, the surfaces of the concrete turns white, and there are larger and more apparent cracks. Furthermore, adding class C FA to high-strength concrete does affect the fire resistance level because it showed almost the same residual compressive strength after exposure to both elevated temperature of 500°C and 1000°C.Ni Nyoman KencanawatiSuryawan MurtiadiLina Sabrina QomariAhmad Zaki
Copyright (c) 2023 Ni Nyoman Kencanawati, Suryawan Murtiadi, Lina Sabrina Qomari, Ahmad Zaki
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2023-11-252023-11-2526219420210.18196/st.v26i2.19732Study the Applicability of a Shelf-Type Fish Drying Machine with a Heat Source from Coconut Shell Biomass
https://journal.umy.ac.id/index.php/st/article/view/17077
<p>The sun’s heat is usually utilized to dry traditional processed salted fish. However, its quality suffers as a result of the lengthy drying process. This issue can only be resolved with the help of efficient drying equipment. Advantages of artificial drying include selecting the drying capacity according to requirements, without requiring a considerable space, and managing the drying conditions. This research aims to discover an effective way to utilize biomass waste from coconut shells to speed up the drying process for salted fish. The study method involved several steps: acquiring data, analyzing the tools and machine, observing the machine, and designing a new machine. The three airspeed parameters tested in this study were 7 m/s, 10 m/s, and 12 m/s. The drying shelf reached a maximum temperature of 81.4 °C at 7 m/s, 100.3 °C at 10 m/s, and 99.4 °C at 12 m/s.</p>Agus Sulistiyo BudiMohammad Samsul BakhriYuli NurasriAghna Ilma Nurdin SuriptoSultan Krisna AmirRojikin Rojikin
Copyright (c) 2023 Agus Sulistyo Budi, Mohammad Samsul Bakhri, Yuli Nurasri, Aghna Ilma Nurdin Suripto, Sultan Krisna Amir, Rojikin
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2023-11-252023-11-2526220321310.18196/st.v26i2.17077Thermal Resistance of the Loop Heat Pipe Prototype in Steady State Conditions
https://journal.umy.ac.id/index.php/st/article/view/18788
The nuclear accident at the Fukushima Daiichi nuclear power plant in March 2011 in Japan caused a tsunami and submerged the emergency diesel generator resulting in a station blackout (SBO). Based on the accident, a study was conducted on the use of passive safety systems as a support for active safety systems in nuclear reactor cooling systems. The Loop Heat Pipe (LHP) prototype is a small-scale LHP research facility, one of which is used to determine the characteristics and heat transfer events in LHP. Calculations to determine the thermal resistance of the LHP prototype need to be carried out to determine its performance level. The research was carried out experimentally for data collection followed by calculations based on the data that had been obtained. The calculation results obtained that the lowest thermal resistance is 0.014 °C/w with a 100% filling ratio and an airflow velocity of 2.5 m/s, so the setting of filling ratio and airflow velocity produces the best LHP prototype performance. The higher the airspeed, the greater the heat released by the condenser resulting in the value of the thermal resistance of the LHP prototype getting smaller. Thus, the greater the airspeed, the lower the thermal resistance of the LHP prototype, this indicates that the performance of the LHP prototype is increasing.Dedy HaryantoGiarno GiarnoSumantri HatmokoYoyok Dwi Setyo PambudiM. Hadi Kusuma
Copyright (c) 2023 Dedy Haryanto, Giarno Giarno, Sumantri Hatmoko, Yoyok Dwi Setyo Pambudi, M. Hadi Kusuma
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2023-11-252023-11-2526221422110.18196/st.v26i2.18788Structure Design Evaluation of Muhammadiyah Banjarmasin University Convention Centre Building Due to Functional Change Based on SNI 03-2847-2019
https://journal.umy.ac.id/index.php/st/article/view/18659
<span lang="EN-US">The Muhammadiyah Banjarmasin University Convention Centre Building was originally built as a guesthouse, over time it changed its function to become a place for lecture activities. Therefore, an evaluation of the initial structural design is carried out on the reliability of the building structure as regulated in Government Regulations in Permen PU No. 25 of 2007 concerning Certificate of Building Functioning or SLF. The data used in this study are primary and secondary data, where primary data is in the form of field tests to determine the uniformity of concrete quality, namely the bounce test using the Hammer Test tool on the beams and columns of the 1st floor and 2nd floor as many as 10 points, while secondary data uses preliminary planning data. Modeling is done in 3D using SAP2000 software. The results of research on the value of uniformity of concrete quality show mixed results, this is due to several factors, one of which is different casting methods in the field. Meanwhile, from the results of the analysis of the service ability of the building structure, the value of the Ultimate Moment (<em>Mu</em>) and Ultimate Load (<em>Pu</em>) as well as the Maximum Ultimate Moment (<em>Mr</em>) and Maximum Ultimate Load (<em>Pr</em>) is still able to withstand the loads acting on the structure even though it has changed its function based on SNI 03-2847-2019.</span>Elia AnggariniIrwandy Muzaidi
Copyright (c) 2023 Elia Anggarini, Irwandy Muzaidi
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2023-11-252023-11-2526222223010.18196/st.v26i2.18659The Conceptual Design of An Electro-Magnetic Power Generator
https://journal.umy.ac.id/index.php/st/article/view/19404
<p><em>Nowadays, magnetic field induction is a dependable renewable energy source that can convert magnetic fields into electrical power. In this study, our objective is to propose a low-cost free energy generator design based on neodymium. The main problems with existing generators were air pollution, noise pollution, and even fuel price volatility. To begin addressing this issue, we compared 6 currently used generators. We concentrated on 5 criteria in light of this outcome. Our top considerations in this study are cost and maintenance. Then comes the size, weight, and noise. The best electromagnetic power generators for satisfying all the criterion domains are determined using Pugh's matrix. It demonstrates that electromagnetic power generators have a high score of 95 compared to natural gas, portable, and diesel power generators. We have also calculated the resulting voltage from the selected number of permanent magnet coils. This calculation shows 60V resulting in 9600 turns. As a result, we draw the conclusion that the reduction of problems like noise and air pollution makes this power generator look like a very appealing alternative.</em></p>Faiq Taquiddin AzahariMaxmillain Newman Anak AtelSiti Salwa SamsuriAzunaidi Abdul Aziz
Copyright (c) 2023 Faiq Taquiddin Azahari, Maxmillain Newman Anak Atel, Siti Salwa Samsuri, Azunaidi Abdul Aziz
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2023-11-252023-11-2526223123910.18196/st.v26i2.19404