cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
semesta_teknika@umy.ac.id
Editorial Address
Jln. Brawijaya Tamantirto Kasihan Bantul 55183 Indonesia
Location
Kab. bantul,
Daerah istimewa yogyakarta
INDONESIA
Semesta Teknika
Published by Universitas Muhammadiyah Yogyakarta
ISSN : 1411061X     EISSN : 25025481     DOI : https://doi.org/10.18196/st
Core Subject : Engineering,
Engineering
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. Copyright is by the publisher and the authors. 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 the 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 Peer Reviewers local and foreign.
Arjuna Subject : -
Articles 715 Documents
 48   49   50   51   52 
Pengaruh Penggunaan Abu Sekam Padi sebagai Bahan Pengisi pada Campuran Hot Rolled Asphalt terhadap Sifat Uji Marshall Sri P. Atmaja Rosyidi
Semesta Teknika Vol 15, No 2 (2012): NOVEMBER 2012
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v15i2.1321

Abstract

Rice Husk Ash (RHA) has fairly high content of SiO2 and easily obtainable. It is inexpensive since it is the residual waste of the tile or brick combustion process that is not utilized properly. RHA has the potential to be used as filler in Hot Rolled Asphalt (HRA) since it has high flexibility mixture design. The influential characteristic of RHA is that it has fine aggregate fraction. This study aims to discover the physical properties of RHA, the characteristic of the Marshall test properties, the optimum bitumen content, and the economical comparison between the RHA-mixed HRA and the conventional one using stone dust filler. The results of this study indicate that the use of the RHA is able to increase the optimum bitumen content. In terms of economical comparison, the use of RHA as filler material is much more economical than using stone dust as filler.
Analisis Pengaruh Karakteristik Hujan terhadap Gerakan Lereng Sri Haryanti; Kabul Basah Suryolelono; Rachmad Jayadi
Semesta Teknika Vol 13, No 2 (2010): NOVEMBER 2010
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/jst.v13i2.712

Abstract

Soil movement mostly occurs especially during rainy season at the slope of Kalibawang irrigation channel at KM 15,9 in Kulon Progo district, Daerah Istimewa Yogyakarta. The slope movement causes damage at the school building, bridge and irrigation channel. Based on this fact, a research is necessary by modeling the slope at site of conducted. The objectives of this research are to identify the rainfall characteristic which triggering slope movement and to recognizes factor affecting the slope movement. Topography data, physical characteristic, and soil mechanic were applied as the input simulation models. Groundwater flow in slope was numerically simulated by using SEEP/W while the slope deformation simulated by SIGMA/W. Both SEEP/W and SIGMA/W were applied simultaneously in the numerical simulation. Rainfall design with appropriate return period was determined from rainfall annual daily maximum historical data recorded from 1985-2004, while distribution was completed by applying statical analysis on hourly rainfall data. The analysis of normal daily rainfall was determined based on daily rainfall data from Kalibawang rain gauge. Six models were applied as follow: initial condition (Rainfall Model I), heavy rainfall in short duration (Rainfall Model II), normal daily rainfall of 25 and 40 mm in long duration (Rainfall Model III), normal daily rainfall of 20 mm in long duration (Rainfall Model IV), heavy rainfall followed with normal daily rainfall of 20 mm (Rainfall Model V) and normal rainfall of 20 mm followed with heavy rainfall (Rainfall model VI). The result shows that at the research location, the maximum daily rainfall of 2-year-return period is 113,8 mm with dominant duration was 4 hour per day. This value was applied as Rainfall Model II. Based on the simulation the movement or deformation with Rainfall Model II, III, IV, V and VI is 0,22 m; 0,956 m; 1,01 m, ; 0,652 m, and 0,568 respectivally. It is concluded that at the research location, heavy rainfall in short duration gives small impact to slope movement or slope deformation and normal rain of 20 mm in long duration (Rainfall Model IV) is highly significant to the slope movement or slope deformation.
The Analysis of CO2 Emission Reduction Scenarios in Industry Sector of Yogyakarta Province of Indonesia Al Hasibi, Rahmat Adiprasetya
Semesta Teknika Vol 14, No 1 (2011): MEI 2011
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v14i1.568

Abstract

The final energy demand and energy-related CO2 emission in industrial sector of Yogyakarta Province were analyzed in this study. The potential of energy saving and reduction of CO2 emission were estimated. The analysis was based on energy model. The model was constructed by LEAP model that describe the pattern of energy demand in industrial sector. Energy modeling and scenario analysis were used to simulate the impacts of various policies in energy demand and CO2 emission. Three scenarios were implemented in the model. Initially, the model was developed under business as usual (BAU) scenario that include current situation of energy-related activity in industrial sector. 2008 was selected as base year with projection period was terminated in 2025. Then, two alternative scenarios were developed that focus on energy efficiency improvement (EE scenario) and fuel switching to cleaner fuel (FS scenario). The two alternative scenarios were integrated into mitigation scenario. The result of alternative and mitigation scenario compare to BAU scenario in term of the final energy demand and energy-related CO2 emission. The result of the model showed the potential of energy saving by implementing mitigation scenario is 24.16% compare to BAU scenario. The expected reduction of CO2 emission under mitigation scenario is 20.22% compare to BAU scenario.
Analisis Tingkat Kesuksesan Inspeksi Pada Attach Dan Packet Data Protocol (PDP) Context Layanan Gprs Dengan Metode Statistical Process Control Ikhsan, Muhammad; Nurudin, Ahmad
Semesta Teknika Vol 8, No 1 (2005): MEI 2005
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v8i1.916

Abstract

Penelitian ini dimaksud untuk mengetahui tingkat kesuksesan inspeksi yang dilakukan pada Attach dan PDP Context, sebab keberhasilan melakukan aktivasi awal GPRS dilihat dari kesuksesan MS melakukan Attach, untuk selanjutnya dapat diambil langkah perbaikan jika terjadi penurunan kualitas (non performance). . Metode yang dipakai adalah metode SPC (statistical process control) atau metode pengendalian kualitas suatu proses, untuk menunjukan apakah jumlah yang menunggu untuk dilayani dalam server GSN (GPRS Support Node)  masih dalam proporsi pengendalian.Hasilnya adalah hasil dari pengendalian proses kualitas proses statistik untuk GGSN dan SGSN Ericsson menunjukan bahwa masih terdapat proses yang berada diluar batas pengendalian. Sedangkan, hasil dari analisa kemampuan proses menunjukan bahwa untuk proses Attemp PDP Context dapat memenuhi spesifikasi bawah, sedangkan untuk proses Attemp Attach masih dapat memenuhi batas spesifikasi bawah.
Penerapan Metode K-Means Untuk Clustering Mahasiswa Berdasarkan Nilai Akademik Dengan Weka Interface Studi Kasus Pada Jurusan Teknik Informatika UMM Magelang Asroni, Asroni; Adrian, Ronald
Semesta Teknika Vol 18, No 1 (2015): MEI 2015
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v18i1.708

Abstract

The selection process among outstanding students in a department has a big problem. This process is not fair because only involve one criteria and ignore the other criteria. We need the best student to participate in a competition held by the Indonesia Security Incident Response Team on Internet Infrastructure (ID SIRTII) of the Ministry of Communication and Information. This process uses Weka software to calculate the best student. It provides the various method to explore the data. One of them is clustering method. There are many algorithms in clustering method. In this research, we will investigate widely about one of that algorithms. Its name is K-Means. This algorithm (K-Means) will give the recommendations about the best student based on the cluster. It will represent the many clusters of a student group. The best cluster can be calculated more to get the names of the best students group. They are eligible to enter the competition.  K-means involve the GPA (Grade Point Average) and related course to support the academic skill in order to get the best student. This research helps the teacher select the best student to enter the competition. Many similar cases can use this algorithm in order to get the best student.
Pengaruh Penggunaan Plastik Polyethylene (Pe) Dan High Density Polyethylene (Hdpe) Pada Campuran Lataston-Wc Terhadap Karakteristik Marshall Rahmawati, Anita
Semesta Teknika Vol 18, No 2 (2015): NOVEMBER 2015
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v18i2.1816

Abstract

The increase in road traffic during the last two decades in combination with an insufficient degree of maintenance due to shortage in funds has caused an accelerated and continuous deterioration of the road network. To alleviate this process, several types of measures may be effective, e.g., securing funds for maintenance, improved roadway design, use of better quality of materials and the use of more effective construction methods. Aspalt can also be modified by adding different types of additive. One of these additives is the polymers such as Polyethylene (PE) and  High Density Polyethylene (HDPE).  The addition of polymers typically increases the stiffness of the aspalt  and improves its temperaturesusceptibility. Increased stiffness improves the rutting resistance of the mixture in hot climates and allows the use of relatively softer base aspalt, which in turn,provides better low temperature performance. This study was conducted to determine the effect of utilizing Polyethylene (PE) and High Density Polyethylene (HDPE) as a mixture of thin layer of asphalt concrete in wearing course (Lataston_WC) using Marshall design parameters. The parameters assessed are the stability, flow,  the percentage of air void in the mixture (VIM), the percentage of void in the mineral aggregate (VMA), the percentage of void filled with aspalt (VFA), and Marshall Quotient (MQ). Marshall samplers prepared with the PE and HDPE modified aspalt binder provide the specification limits. The percentage of  PE and HDPE as asphalt mixture is 0%, 2%, 4% and 6% by weight of the asphalt. The result of Marshall test showed that the value of stability, flow and VFA have tendencey to increase with incresing of percentage of PE and HDPE. But, the value of VIM, VMA and MQ have tendency to decrease with  incresing of percentage of PE and HDPE. It can be seen that effect of addition HDPE on aspalt mixture provide the value of Marshall characteriscs are better than aspalt mixture with PE
Perbaikan Sifat Mekanis Batu Bata Tanpa Dibakar dengan Campuran Limbah Karbit dan Abu Sekam Padi Andre, Yosi; Siagian, Taufik Nugraha
Semesta Teknika Vol 13, No 1 (2010): MEI 2010
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v13i1.724

Abstract

Brick is one important element in a building. Bricks are generally made by burning dry clay , and this process will emit air pollutant. In addition, the bricks that widely available on the market have a poor quality. Therefore, the quality of bricks needs to be effectively improved by means of environmentally friendly and low cost procedure. This research aims to improve the mechanical characteristics of unburnt bricks by adding a mixture of calcium carbide residue (CCR) and rice husk ash (RHA). In this study, the effect of the percentage of additive material and the proportions of CCR and RHA on the mechanical properties are studied. The results showed that the compressive strength of bricks is influenced by the content of additive material. In addition, the optimum compressive strength was found to be after 21 days of cating for all additive material, afterwhich the strength sarted to decrease. Bricks possessing the highest compressive strength are those produced with 70% additive and CCR-to-RHA ratio of 2/1. The compressive strength reached 125.91 kg/cm2 after 21 days of moulding.
Disain Dan Fabrikasi Mesin Sputtering Skala Laboratorium untuk Penumbuhan Film Tipis Muhammad, Bagja Restu; Nugroho, Aris Widyo
Semesta Teknika Vol 20, No 1 (2017): MEI 2017
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v20i1.2886

Abstract

Plasma sputtering is well known method for preparation of thin films on various substrates. This technique involves expelling material from a target onto substrate in a vacuum chamber. Generally, the technique is equipped with argon supply system for ionized gas bombardments of the target. This work shows designing and fabricating process of a simple sputtering machine without gas supply system and its preliminary thin film preparation test. A CAD software was applied to design its main apparatus namely a vacuum system and an electrical system. Afterward, those apparatus were fabricated and assembled. Preliminary test was conducted using a cooper plate as a target and plate glasses as substrates for 90 s and 130 s processing time. The vacuum pressure, voltage and the electric current were set up at 10-2 torr, 150 volt and 1 A, respectively. The thin film on the glass was visually examined and  its resistivity was measured using ohm meter. The results show that a cooper thin film has been coated on the glass with the resistivity of 12.6 and 9 Ω. At this stage , it is confirmed that the plasma sputtering machine being fabricated has successfully worked.
Pengaruh Diameter Katoda pada Sensitivitas Pengukuran Gradien Kecepatan dengan Metode Polarografi Sukamta Sukamta
Semesta Teknika Vol 11, No 2 (2008): NOVEMBER 2008
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v11i2.762

Abstract

Wall velocity gradient measurement using polarography gives very accurate output due to the absence of problem in fluid flow. Therefore this experiment is highly recommended. Based on the polarogram resulted in the polarography method, the potential that has to be applied to both electrode is 0.25 – 0.75 Volt, whilst in the experiment 0.45 is applied. Calibration has been done to single phase flow, by measuring as a result of  by friction between wall and current flow through electrode at constant flow rate. The ΔP data are used to determine τ. Relation plot between τ (resulted from ΔP measurement) and current can be obtained from the data acquisition device. The result of this research shows that the value of wall shear stress (as velocity gradient) is influenced by the increase of flow rate. Whilst measurement of wall shear stress shows that the cathode area gives effect on the sensitivity of the measurement,  a small cathode results in better shear stress data measurement (more sensitive). In this research the best wall shear stress was resulted in cathode with diameter d=0.2 mm.
Pengaruh Pemasangan Bluff Body Terhadap Karakteristik Pembakaran Biobriket Adhes Gamayel
Semesta Teknika Vol 17, No 1 (2014): MEI 2014
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v17i1.409

Abstract

Biofuels are organic feedstock fuel produced by living organisms, such as solids, liquids, or gases. Biobriket combustion process is affected by the heating value biobriket constituent materials and the amount of air entering the biobriket combustion chamber. The purpose of this study isto determine the effect of variations of the bluff bodygeometry on the biobriket burning process. The independent variable used in this study, arethe fan rotation and the bluff bodygeometry. Fan rotation being used are 1000 rpm, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm and 2000 rpm, while the bluff body geometry are round, triangle, square, hexagon and octagon. Triangular cross-section bluff body was noted to produce the highest temperature of 33.21 °C at 100 second. While the lowest temperature wasreached at 500 second with 31.18 oC. Fan rotation at 2000 rpm was found to produce the most rapid combustion,burnt out 10 grams of biobriket within 500 seconds.The conclusion to this study is the higher the fan rotation speed, the faster the combustion process of the biobriket. Triangular bluff body was found the best shape in this study.

Page 50 of 72 | Total Record : 715

 48   49   50   51   52 

Filter by Year

2005 2024


Reset
Filter By Issues
All Issue Vol. 27 No. 2 (2024): NOVEMBER Vol 27, No 1 (2024): MEI Vol 26, No 2 (2023): NOVEMBER Vol 26, No 1 (2023): MEI Vol 25, No 2 (2022): NOVEMBER 2022 Vol 25, No 1 (2022): MEI 2022 Vol 24, No 2 (2021): NOVEMBER 2021 Vol 24, No 1 (2021): MEI 2021 Vol 24, No 2 (2021): NOVEMBER Vol 23, No 2 (2020): NOVEMBER 2020 Vol 23, No 1 (2020): MEI 2020 Vol 22, No 2 (2019): NOVEMBER 2019 Vol 22, No 1 (2019): MEI 2019 Vol 21, No 2 (2018): NOVEMBER 2018 Vol 21, No 2 (2018): NOVEMBER 2018 Vol 21, No 1 (2018): MEI 2018 Vol 20, No 2 (2017): NOVEMBER 2017 Vol 20, No 2 (2017): NOVEMBER 2017 Vol 20, No 1 (2017): MEI 2017 Vol 20, No 1 (2017): MEI 2017 Vol 19, No 2 (2016): NOVEMBER 2016 Vol 19, No 2 (2016): NOVEMBER 2016 Vol 19, No 1 (2016): MEI 2016 Vol 19, No 1 (2016): MEI 2016 Vol 18, No 2 (2015): NOVEMBER 2015 Vol 18, No 2 (2015): NOVEMBER 2015 Vol 18, No 1 (2015): MEI 2015 Vol 18, No 1 (2015): MEI 2015 Vol 17, No 2 (2014): NOVEMBER 2014 Vol 17, No 2 (2014): NOVEMBER 2014 Vol 17, No 1 (2014): MEI 2014 Vol 17, No 1 (2014): MEI 2014 Vol 16, No 2 (2013): NOVEMBER 2013 Vol 16, No 2 (2013): NOVEMBER 2013 Vol 16, No 1 (2013): MEI 2013 Vol 16, No 1 (2013): MEI 2013 Vol 15, No 2 (2012): NOVEMBER 2012 Vol 15, No 2 (2012): NOVEMBER 2012 Vol 15, No 1 (2012): MEI 2012 Vol 15, No 1 (2012): MEI 2012 Vol 14, No 2 (2011): NOVEMBER 2011 Vol 14, No 2 (2011): NOVEMBER 2011 Vol 14, No 1 (2011): MEI 2011 Vol 14, No 1 (2011): MEI 2011 Vol 13, No 2 (2010): NOVEMBER 2010 Vol 13, No 2 (2010): NOVEMBER 2010 Vol 13, No 1 (2010): MEI 2010 Vol 13, No 1 (2010): MEI 2010 Vol 12, No 2 (2009): NOVEMBER 2009 Vol 12, No 2 (2009): NOVEMBER 2009 Vol 12, No 1 (2009): MEI 2009 Vol 12, No 1 (2009): MEI 2009 Vol 11, No 2 (2008): NOVEMBER 2008 Vol 11, No 2 (2008): NOVEMBER 2008 Vol 11, No 1 (2008): MEI 2008 Vol 11, No 1 (2008): MEI 2008 Vol 10, No 2 (2007): NOVEMBER 2007 Vol 10, No 2 (2007): NOVEMBER 2007 Vol 10, No 1 (2007): MEI 2007 Vol 10, No 1 (2007): MEI 2007 Vol 9, No 2 (2006): NOVEMBER 2006 Vol 9, No 2 (2006): NOVEMBER 2006 Vol 9, No 1 (2006): MEI 2006 Vol 9, No 1 (2006): MEI 2006 Vol 8, No 2 (2005): NOVEMBER 2005 Vol 8, No 2 (2005): NOVEMBER 2005 Vol 8, No 1 (2005): MEI 2005 Vol 8, No 1 (2005): MEI 2005 More Issue