Journal of Engineering and Technological Sciences
Journal of Engineering and Technological Sciences welcomes full research articles in the area of Engineering Sciences from the following subject areas: Aerospace Engineering, Biotechnology, Chemical Engineering, Civil Engineering, Electrical Engineering, Engineering Physics, Environmental Engineering, Industrial Engineering, Information Engineering, Mechanical Engineering, Material Science and Engineering, Manufacturing Processes, Microelectronics, Mining Engineering, Petroleum Engineering, and other application of physical, biological, chemical and mathematical sciences in engineering. Authors are invited to submit articles that have not been published previously and are not under consideration elsewhere.
Starting from Vol. 35, No. 1, 2003, full articles published are available online at http://journal.itb.ac.id, and indexed by Scopus, Index Copernicus, Google Scholar, DOAJ, GetCITED, NewJour, Open J-Gate, The Elektronische Zeitschriftenbibliothek EZB by University Library of Regensburg, EBSCO Open Science Directory, Ei Compendex, Chemical Abstract Service (CAS) and Zurich Open Repository and Archive Journal Database.
Publication History
Formerly known as:
ITB Journal of Engineering Science (2007 – 2012)
Proceedings ITB on Engineering Science (2003 - 2007)
Proceedings ITB (1961 - 2002)
Articles
1,267 Documents
Texture Analysis for Skin Classification in Pornography Content Filtering Based on Support Vector Machine
Nugroho, Hanung Adi;
Rahadian, Fauziazzuhry;
Adji, Teguh Bharata;
Buana, Ratna Lestari Budiani
Journal of Engineering and Technological Sciences Vol 48, No 5 (2016)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2016.48.5.6
Nowadays, the Internet is one of the most important things in a human?s life. The unlimited access to information has the potential for people to gather any data related to their needs. However, this sophisticated technology also bears a bad side, for instance negative content information. Negative content can come in the form of images that contain pornography. This paper presents the development of a skin classification scheme as part of a negative content filtering system. The data are trained by grey-level co-occurrence matrices (GLCM) texture features and then used to classify skin color by support vector machine (SVM). The tests on skin classification in the skin and non-skin categories achieved an accuracy of 100% and 97.03%, respectively. These results indicate that the proposed scheme has potential to be implemented as part of a negative content filtering system.
Mechanical Behavior of Dam Foundation with Vertical Sand Drain, Case Study: Sombar Dam
Mahmood, Mohammed Shaker;
Akhtarpour, Ali;
Alali, Ameer Abdulridha Ajmi
Journal of Engineering and Technological Sciences Vol 51, No 3 (2019)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2019.51.3.6
Installing vertical sand drains is a traditional dam foundation consolidation solution that is economical and provides good drainage efficiency. Vertical sand drains can shorten the path of water flow inside the soil and speeds up soil consolidation. This study investigated the effect of sand drains in the foundation of the Sombar Dam in Iran on its mechanical behavior. The Sombar Dam is a project to control flooding and provide agricultural water to Gholaman city in northeastern Iran. The investigation included the mechanical behavior of the dam with vertical sand drains. The studied parameters were drain diameter, depth and spacing in addition to the vertical-to-horizontal permeability ratio (ky/kx) of the foundation soil during the time of construction of the dam using a Mohr-Coulomb (MC) model in the software application GeoStudio. The results revealed that reducing the drain spacing (increasing the number of drains) and increasing the depth and diameter of the drains led to an increase of the settlement rate (up to 90%) and the stability of the dam over a shorter period of time (24 months) compared to no drain condition. With a decrease in the ratio of vertical-to-horizontal permeability (ky/kx = 0.1) for all drain parameters there was a decrease in the value of the dam settlement rate and the safety factor.
DEVELOPING A PLASTIC WASTE MANAGEMENT PROGRAM: FROM RIVER BASINS TO URBAN BEACHES (CASE STUDY)
Moura, Micaella R.F.;
Falcão, Symone M.P.;
da Silva, Alisson Caetano;
Neto, Alfredo Ribeiro;
Montenegro, Suzana M.G.L.;
da Silva, Simone Rosa
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB
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Solid waste accumulation in coastal environments has been a growing concern. In the coastal megacity of Recife, Pernambuco state, Brazil, plastic waste issues currently exist both at the ocean scale and river basin scale. The city is known as the ?Brazilian Venice? thanks to the Capibaribe River, which crosses many neighborhoods, running in a west-east direction into the Atlantic Ocean. This paper provides the initial basis to develop a Plastic Waste Management Program proposal for implementation in the city of Recife, given the lack of resolutions that have looked at plastic waste management through integrated water environment scales (from river basin to ocean). The methodology used included articulation and documental collection from four main public agencies from the state/city and stakeholders. The results showed its relevance for better plastic waste management in Recife, considering an integrated water environment on a river basin-to-ocean scale by using the recognized major connected water environments (Capibaribe river and Boa Viagem beach). Similar integrated program proposals could be made for other coastal areas, enabling not only the identification of fragilities but also the exchange of information regarding the theme.
SCALING UP OF THE PYROLYSIS PROCESS TO PRODUCE SILICA FROM RICE HUSK
Casnan, Casnan;
Noor, Erliza;
Hadjomidjojo, Hartrisari;
Irzaman, Irzaman;
Rohaeti, Eti
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2019.51.6.1
Rice husk is a potential alternative source of silica and silicon. The mechanism of heating (pyrolysis) for the decomposition of rice husk is an important factor in obtaining silica of high purity. Medium-scale pyrolysis to produce silica from rice husk serves as a bridge to connect laboratory-scale production to industrial-scale production. The purpose of this study was to model and scale up the pyrolysis process as a guidance for industrial-scale production. The research method used was experimentally based. An experimental investigation was undertaken in five stages. 1) Analyzing rice husk mass conversion using thermogravimetry analysis (TGA); 2) pyrolysis modeling based on a laboratory investigation using COMSOL Multiphysics version 5.3; 3) medium-scale experiments according to the modeling results; 4) validation of the modeling results by carrying out a medium-scale experiment; 5) silica purity analysis using SEM-EDX. The medium-scale pyrolysis simulation of silica manufacture from rice husk obtained a heating rate of 1.5 °C/min. There was an increase in the heating rate of 1 °C/min when compared to the laboratory-scale process. The pyrolysis of rice husk for the production of silica affects the mass conversion and selectivity of the resulting silica product. The mass conversion produced was 13.33% to 17.87% and the purity of silica produced was 63.99% to 82.74%.
PREPARATION AND CHARACTERIZATION OF BIOPOLYMER ELECTROLYTE MEMBRANES BASED ON LICLO4-COMPLEXED METHYL CELLULOSE AS LITHIUM-ION BATTERY SEPARATOR
Ndruru, Sun Theo Constan Lotebulo;
Wahyuningrum, Deana;
Bundjali, Bunbun;
Arcana, I Made
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB
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The polymer electrolyte membrane is a main component of lithium-ion batteries (LiBs), serving as separator and electrolyte. In this work, we prepared biopolymer electrolyte (BPE) membranes of lithium perchlorate (LiClO4)-complexed methyl cellulose (MC). Methyl cellulose (MC), a cellulose derivative, has attractive properties for use as biopolymer electrolyte. The bulkier anion size of lithium salt (LiClO4) significantly enhances the performance of biopolymer electrolyte (BPE) membranes. The fabricated biopolymer electrolyte (BPE) membranes were characterized by FTIR, EIS, tensile tester, XRD and TGA. Biopolymer electrolyte membranes with various weight percentages of LiClO4 salt (0%, 5%, 10%, 15%, and 20%) were prepared using a simple solution casting technique. Incorporation of 10% weight of LiClO4 into the MC-based host polymer was selected as optimum condition, because this yielded good conductivity (3.66 x 10-5 S cm-1), good mechanical properties (tensile strength 35.97 MPa and elongation at break 14.47%), good thermal stability (208.4 to 338.2 °C) as well as ease of preparation and low cost of production. Based on its characteristics it can be stated that the 10% LiClO4-complexed MC membrane meets the requirements as a candidate separator for lithium-ion battery application.
AN INTELLIGENT INCENTIVE MODEL BASED ON ENVIRONMENTAL ERGONOMICS FOR FOOD SMES
Ushada, Mirwan;
Putro, Nur Achmad Sulistyo;
Khuriyati, Nafis
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2019.51.6.7
In this study, an intelligent incentive model based on environmental ergonomics in food small and medium-sized enterprises (SMEs) was developed. Environmental ergonomics was defined as the impact of temperature and relative humidity within a certain range on a worker?s heart rate during work. Optimum environmental ergonomics are highly required as a basic standard for food SMEs to provide fair incentives. Recommendable parameters from a genetic algorithm and fuzzy inference modeling were used to model customized incentives based on optimum heart rate, workplace temperature and relative humidity before and after working. The research hypothesis stated that industries should optimize their workload and workstation environment prior to customizing incentives. The research objectives were: 1) to recommend optimum environmental ergonomics parameters for customized incentives; 2) to determine the incentives at workstations of SMEs based on optimum environmental ergonomics parameters and fuzzy inference modeling. The optimum values for heart rate, workstation temperature and relative humidity used were based on recommendable values from the genetic algorithm. An inference model was developed to generate decisions whether a worker should receive an incentive based on a calculated index. The results indicated that 84.4% of workers should receive an incentive. The results of this research could be used to promote the concept of ergonomics-based customized incentives.
ADSORPTION OF GOLD FROM AQUEOUS SYSTEMS USING MICROBIAL THERMOPHILIC PROTEINS
Kasmiarno, Laksmi Dewi;
Chang, Jo Shu
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB
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A precious metal such as gold can be obtained from mining. Metals in low concentrations at geothermal sites or in industrial waste are difficult to gain using the conventional mining process. Alternative approaches for recovering metals from dilute solutions have been developed, such as biosorption, i.e. adsorption using microorganisms or their derivatives. In this study, gold in an aqueous system was recovered via biosorption using proteins produced from an isolated thermophilic bacterial strain. Modified Thermus enhanced medium was used as the medium to improve protein production from the thermophilic bacterial strain. The microbial proteins showed effective conditions for Au3+ ion adsorption. The optimum adsorption conditions for Au ions occurred at pH 1 with an adsorption capacity of 482.0 mg/g protein. The metal ion adsorption capacity increased with increasing temperature. The adsorption isotherm was conducted at room temperature, because the Au ions could be well fitted by the Freundlich isotherm equation with qmax at 527.229 mg/g protein.
FINITE ELEMENT ANALYSIS OF REINFORCED CONCRETE COUPLING BEAMS
Boediono, Bambang;
Dewi, Nyoman Triani Herlina;
Lim, Erwin
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2019.51.6.2
The use of reinforced concrete coupling beams in high-rise buildings is popular, especially in seismic prone areas. The modeling of a reinforced concrete coupling beam in a commercial structural analysis software is usually simplified to a line element or a compound of concrete and steel rebar as fiber element. Hence, the analysis of the simplified model cannot capture the overall hysteretic behavior of the element. Moreover, the simplified model is also limited in its capacity to estimate the shear strength contributed by the concrete and diagonal bars, if any, respectively. This study used an advanced finite element analysis package to simulate the cyclic behavior of four coupling beam specimens available in the database. The results show that the hysteretic loop predicted by the finite element analysis tends to overestimate the maximum lateral load capacity. On the other hand, analytical evaluation of the shear strength contributed by concrete and diagonal bars showed good agreement with the test results.
RECONNAISSANCE ON LIQUEFACTION-INDUCED FLOW FAILURE CAUSED BY THE 2018 MW 7.5 SULAWESI EARTHQUAKE, PALU, INDONESIA
Hidayat, Risqi Faris;
Kiyota, Takashi;
Tada, Naoto;
Hayakawa, Jun;
Nawir, Hasbullah
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB
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The Mw 7.5 Sulawesi Earthquake 2018 was a catastrophic disaster that resulted in large numbers of casualties. This study aimed to investigate the damages of liquefaction-induced-flow failure in three areas in Palu city, i.e. Petobo, Balaroa, and Jono Oge. It was found that this flow failure occurred on a large scale at a very gentle ground inclination, ranging from 1 to 3%. In order to gain an understanding of the soil conditions in these specific locations, Portable Dynamic Cone Penetration Tests were conducted in Petobo. The results showed that the soil layers in the affected area were in a loose state compared to the non-affected areas. Furthermore, some spots of freshwater inundation were recognized in Petobo and Balaroa, even two weeks after the disaster. Based on this evidence, a mechanism of liquefaction-induced-flow failure caused by a confined aquifer is proposed.