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Journal of Engineering and Technological Sciences
Published by Institut Teknologi Bandung
ISSN : 23375779     EISSN : 23385502     DOI : -
Core Subject : Engineering,
Engineering
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)
Arjuna Subject : -
Articles 1,267 Documents
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An Optimized Method for Terrain Reconstruction Based on Descent Images Xu Xinchao; Zheng Zhenzhen; Xu Aigong; Liu Shaochuang
Journal of Engineering and Technological Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.1.4

Abstract

An optimization method is proposed to perform high-accuracy terrain reconstruction of the landing area of Chang'e III. First, feature matching is conducted using geometric model constraints. Then, the initial terrain is obtained and the initial normal vector of each point is solved on the basis of the initial terrain. By changing the vector around the initial normal vector in small steps a set of new vectors is obtained. By combining these vectors with the direction of light and camera, the functions are set up on the basis of a surface reflection model. Then, a series of gray values is derived by solving the equations. The new optimized vector is recorded when the obtained gray value is closest to the corresponding pixel. Finally, the optimized terrain is obtained after iteration of the vector field. Experiments were conducted using the laboratory images and descent images of Chang'e III. The results showed that the performance of the proposed method was better than that of the classical feature matching method. It can provide a reference for terrain reconstruction of the landing area in subsequent moon exploration missions.
Simultaneous Optimization of Block Replacement and Spare Part Ordering Time for a Multi Component System with Separate Spare Part Ordering for Block and Failure Replacements Farid Mardin; Rommert Dekker
Journal of Engineering and Technological Sciences Vol. 48 No. 5 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.5.1

Abstract

A block replacement schedule can be optimized simultaneously with a spare parts ordering schedule, since all items are replaced at a constant interval. The solution of joint optimization for spare parts ordering time and block replacement gives lower costs compared to separate optimization of ordering time and replacement time. The spare parts for replacement can be classified as stochastic demand for failure replacement and deterministic demand for block replacement. In this paper, we propose a simulation model for a separate spare parts ordering schedule. The solution was compared to the solution for a model with common spare parts for both failure and block replacement. The system has N identical components, each with a Weibull lifetime distribution. The costs of failure and block replacements, and also the costs of ordering, holding and shortage of spare parts are given. The proposed model was shown to perform better than the common order model. Also, compared to the age replacement model, the solution of the proposed model is relatively similar, yet the economies of scale would be an advantage for the block replacement over age replacement.
Absorption of CO2 in Biogas with Amine Solution for Biomethane Enrichment Wassana Kamopas; Attakorn Asanakham; Tanongkiat Kiatsiriroat
Journal of Engineering and Technological Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.2.9

Abstract

Biogas upgrading with carbon dioxide absorption in a column of monoethanolamine (MEA) solution was carried out. The effects of controlled parameters on the CO2 absorption such as gas flow rate, solution concentration, height to diameter ratio of the column were considered. High CH4 concentration could be achieved at low gas flow rate and high MEA concentration. The CH4 concentration could be up from 70-75% to 92-95% by volume for 0.2 M MEA. A set of breakthrough curves was obtained to determine the absorption characteristics, such as the absorption constant (k), the absorption time when the CO2 concentration at the outlet was 50% of the concentration at the inlet (t), and the absorption period (t*) when the CH4 concentration was over 90%. An empirical equation of the methane enrichment with the related parameters was developed.
Experimental Study of an SWH System with V-Shaped Plate Jalaluddin Jalaluddin; Effendy Arif; Rustan Tarakka
Journal of Engineering and Technological Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.2.7

Abstract

Solar energy is known as an environmentally friendly energy source with a wide range of applications. This energy can be utilized in various applications such as domestic and industrial water heating using solar water heating (SWH) systems. The thermal performance of an SWH system using a V-shaped absorber plate is presented in this study. Two SWH systems with different absorber plates, i.e. a flat-plate and a V-shaped plate, have been investigated experimentally. First, the absorptivity of the absorber plates was calculated analytically. The optimum V-shaped configuration with angle at β = 21° (V-shaped dimensions t = 4 cm and l = 4 cm) was determined from various V-shaped plate absorbers based on their absorptivity and applied in the experimental study. Two SWH systems were installed and tested at a low flowrate of 0.5 L/min and at a high flowrate of 2 L/min. The results showed that the SWH system with V-shaped plate absorber had a 3.6-4.4% better performance compared with that of the system with flat-plate absorber.
Measurement of Seawater Flow-Induced Erosion Rates for Iron Surfaces using Thin Layer Activation Technique Imam Kambali; Hari Suryanto
Journal of Engineering and Technological Sciences Vol. 48 No. 4 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.4.9

Abstract

The laboratory-scale erosion-corrosion testing facility at BATAN's Center for Radioisotope and Radiopharmaceutical Technology (PTRR) in Serpong was employed to simulate flow-induced corrosion of iron surfaces. Surface loss rates were measured by a nuclear technique called thin layer activation (TLA) analysis. A 10-MeV proton beam generated from a typical CS-30 cyclotron was used to produce 56Co radionuclide layers on iron surfaces via a 56Fe(p,n)56Co nuclear reaction. The labeled iron specimens were then exposed to circulating seawater simulated in BATAN's flow-induced corrosion test facility. The experimental results indicated that the TLA technique was able to measure a very low flow-induced erosion rate of 0.91±0.3 µm/hr. There was no significant difference in the measured surface loss rates between the remaining activity method and the concentration method. The iron surface loss in seawater was lower than that of the same material in HCl solution observed in earlier studies.
Hydraulic Fracturing Mechanism in Reservoirs with a Linear Inclusion Fissure Wang Wenwu; Zhu Xiuxing; Ye Guigen; Han Zhongying; Xue Shifeng
Journal of Engineering and Technological Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.2.8

Abstract

Hydraulic fracturing technology is widely used in most oil-water wells to improve production. However, the mechanism of fracturing in a reservoir with inclusion fissures is still unclear. In this study, a theoretical model was developed to determine the stress distribution during hydraulic fracturing. The line inclusion fissure was regarded as a thin bar and the stress around the artificial fracture, which is affected by a single line inclusion, was determined using the Eshelby equivalent inclusion theory. Stress intensity factors at the tip of both the artificial fracture and the inclusion were achieved, and initiation of the fracture was predicted. Furthermore, to validate the theoretical model, re-fracturing experiments were performed on a large-scale tri-axial system. The results showed that the defects reduce the intensity of the rock, which introduces the possibility that more complex fractures emerge in the reservoir. The results also showed that the fracture direction is governed by far-field stress. The obtained conclusions are helpful to better understand the mechanism of hydraulic fracturing in reservoirs.
Analysis of Onstage Acoustics Preference of Musicians of Traditional Performance of Javanese Gamelan Based on Normalized Autocorrelation Function Suyatno Suyatno; Harijono A. Tjokronegoro; I Gede Nyoman Merthayasa; Rahayu Supanggah
Journal of Engineering and Technological Sciences Vol. 48 No. 5 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.5.5

Abstract

On-stage sound field analysis of a traditional performance of the Javanese gamelan at Pendopo ISI Surakarta, Indonesia was conducted by analyzing the effective decay time of a normalized autocorrelation function called tau-e, Ï„e , during a performance of the Gambyong Pare Anom dance. The parameter tau-e is used to describe the richness of the frequency content, tempo, and types of gamelan instruments being played at a certain time and position on stage. The tau-e parameter is important for musicians in order to maintain communication between each other such that they can keep the performance in harmony. In order to determine the acoustic parameters heard by gamelan musicians on stage, sound measurements were conducted at 4 points on stage during a performance. Each position represents a specific group of gamelan instruments, which have different characteristics of loudness and frequency, different functions and different ways the instruments are played. The analysis showed that each of the four positions had a different value of Ï„e , which fluctuated throughout the performance. Overall, the dominant Ï„e at position 1 was 20 ms; at position 2 it was 50 ms; at position 3 it was 20 ms; and at position 4 it was 40 ms. The distribution of Ï„e on the stage shows that positions 1 and 3 had more frequency richness compared to positions 2 and 4.
Synthesis of NaY Zeolite Using Mixed Calcined Kaolins Subagjo Subagjo; Endang Sri Rahayu; Tjokorde Walmiki Samadhi; Melia Laniwati Gunawan
Journal of Engineering and Technological Sciences Vol. 47 No. 6 (2015)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2015.47.6.4

Abstract

Kaolin is one of several types of clay minerals. The most common crystalline phase constituting kaolin minerals is kaolinite, with the chemical composition Al2Si2O5(OH)4. Kaolin is mostly used for manufacturing traditional ceramics and also to synthesize zeolites or molecular sieves. The Si-O and Al-O structures in kaolin are inactive and inert, so activation by calcination is required. This work studies the conversion of kaolin originating from Bangka island in Indonesia into calcined kaolin phase as precursor in NaY zeolite synthesis. In the calcination process, the kaolinite undergoes phase transformations from metakaolin to mullite. The Bangka kaolin is 74.3% crystalline, predominantly composed of kaolinite, and 25.7% amorphous, with an SiO2/Al2O3 mass ratio of 1.64. Thermal characterization using simultaneous DSC/TGA identified an endothermic peak at 527°C and an exothermic peak at 1013°C. Thus, three calcination temperatures (700, 1013, and 1050 °C) were selected to produce calcined kaolins with different phase distributions. The best product, with 87.8% NaY zeolite in the 54.7% crystalline product and an SiO2/Al2O3 molar ratio of 5.35, was obtained through hydrothermal synthesis using mixed calcined kaolins with a composition of K700C : K1013C : K1050C = 10 : 85 : 5 in %-mass, with seed addition, at a temperature of 93 °Cand a reaction time of 15 hours.
Investigation of Electrochemical and Morphological Properties of Mixed Matrix Polysulfone-Silica Anion Exchange Membrane Khoiruddin Khoiruddin; I Gede Wenten
Journal of Engineering and Technological Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.1.1

Abstract

Mixed matrix anion exchange membranes (AEMs) were synthesized using dry-wet phase inversion. The casting solutions were prepared by dispersing finely ground anion-exchange resin particles in N,N-dimethylacetamide (DMAc) solutions of polysulfone (PSf). Subsequently, nanosilica particles were introduced into the membranes. The results show that evaporation time (tev) and solution composition contributed to membrane properties formation. A longer tev produces membranes with reduced void fraction inside the membranes, thus the amount of water adsorbed and membrane conductivity are reduced. Meanwhile, the permselectivity was improved by increasing tev, since a longer tev produces membranes with a narrower channel for ion migration and more effective Donnan exclusion. The incorporation of 0.5 %-wt nanosilica particles into the polymer matrix led to conductivity improvement (from 2.27 to 3.41 mS.cm-1). This may be associated with additional pathway formation by hydroxyl groups on the silica surface that entraps water and assists ion migration. However, at further silica loading (1.0 and 1.5 %-wt), these properties decreased (to 1.9 and 1.4 mS.cm-1 respectively), which attributed to inaccessibility of ion-exchange functional groups due to membrane compactness. It was found from the results that nanosilica contributes to membrane formation (increases casting solution viscosity then reduces void fraction) and membrane functional group addition (provides hydroxyl groups).
Synthesis of Acrolein from Glycerol Using FePO4 Catalyst in Liquid Phase Dehydration Akhmad Zainal Abidin; Rani Guslianti Afandi; Hafis Pratama Rendra Graha
Journal of Engineering and Technological Sciences Vol. 48 No. 1 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.1.2

Abstract

Acrolein is currently produced using propylene from crude oil while its price and scarcity are increasing. A renewable material such as glycerol is an attractive alternative for acrolein production. It can be obtained from crude palm oil (CPO) and is a byproduct of biodiesel production. Besides being able to compete economically, glycerol is an environmentally friendly material. The purpose of this study is to synthesize acrolein from glycerol using FePO4 catalyst in liquid phase dehydration. The catalyst was prepared by three different methods: hydrothermal (catalyst A), deposition at Fe/P = 1.15 (catalyst B), and deposition at Fe/P = 1.20 (catalyst C). The experimental reaction temperature was varied at 220, 240 and 260 °C under constant atmospheric pressure. The results showed that catalyst C provided the best yield (91%), followed by catalyst A (90%) and catalyst B (82%). The increasing reaction temperature showed a tendency to increase the yield of acrolein, while the presence of oxygen reduced the yield of acrolein and allowed the reaction to produce more side products such as glycerol propanal, acetaldehyde, and propionate. Catalyst reuse without any regeneration resulted in a yield profile of acrolein that continued to decline.

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