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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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Regenerative Chatter Evaluation when Turning Nickel-based Superalloy GH4169 Using PCBN Cutting Tool Mubarak A.M. Fadul Almula; Haitao Zhu; Hassan A. Wahab
Journal of Engineering and Technological Sciences Vol. 51 No. 4 (2019)
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.2019.51.4.7

Abstract

Vibration during machining operation is a major issue that lowers cutting operation efficiency. Usually high cutting forces are encountered during machining processes, consequently shortening cutting tool lifetime. Thus, the metal removable rate is reduced and a poor surface finish is produced. This issue can be overcome by selecting proper cutting parameters (cutting speed, feed, and depth of cut), especially when machining difficult-to-cut materials at high cutting speed. In this paper, a two-degrees-of-freedom turning vibration model is introduced to study the vibration mode of the system when nickel-based superalloy GH4169 is turned at varying cutting depths. The effect of varying the cutting depth on system vibration was simulated using the Matlab/Simulink software. In addition, the model was experimentally tested on a numerical controlled lathe machine. The stable limit cutting depth and the main vibration directions of the system chatter were the responses that were investigated. The results show that the simulation provided a reasonable approximation of the experimental results.
Simulation of Void Detection System using Gamma-Ray Compton Scattering Technique Mona Berlian Sari; Rahadi Wirawan; Abdul Waris; Hong Joo Kim; Mitra Djamal
Journal of Engineering and Technological Sciences Vol. 51 No. 3 (2019)
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.2019.51.3.5

Abstract

A simple void detection system for concrete was successfully developed using high-penetration gamma rays with Compton scattering. This research attempted to identify a void in the subsurface of a concrete volume that could not be accessed from any of the sides. Monte Carlo simulation using GEANT4 toolkit was performed to investigate the gamma-ray backscattering events. An NaI(Tl) detector was used with 60Co and 137Cs as gamma-ray sources. The void's location was successfully detected during material target scanning. Density discrepancies conduce variance of the backscattering peak produced due to the presence of a void. Compared to 60Co as the gamma-ray source, 137Cs is a better choice for application in NDT systems using Compton scattering.
Layer by Layer Silver Acetate based Coating on Glass and Cement Substrates to Tailor Reflectance and Conductance Ghusoon M. Ali; Maan S. Hassan; Ehssan S. Hassan; Mohammed O. Dawood
Journal of Engineering and Technological Sciences Vol. 52 No. 2 (2020)
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.2020.52.2.8

Abstract

Tailoring reflectance and conductance was achieved through layer by layer assembly of a silver acetate based multilayer coating. The coating was applied over glass and cement substrates by sol-gel spin coating and by brush painting, respectively. The structural, optical and electrical characteristics and the composition of the coating were studied. The diffraction peaks for all films revealed that the face-centered cubic lattice of the silver crystal structure and the films with more layers had a higher degree of crystallinity. The optical characteristics showed that having more layers leads to decreasing transmittance and increasing reflectance. The I-V characteristics of all samples showed typical ohmic contacts in a voltage range of -1 to 1 V. The conductance increased drastically as the coating developed into multiple layers. The eight-layer coated glass and cement based substrates had very low surface resistance, at 4 Ω and 2 Ω at 1 V, respectively. The study also revealed that the resistance behavior of a multilayered film generally is thermally stable for annealing up to 400 °C. The coating resistance was significantly increased by further increasing the post-annealing beyond 500 °C. The studied multilayered coating can be used to tailor the reflectance and conductance of dielectric substrate surfaces for various optoelectronics and sensor device applications.
An Analysis of EEG Changes during Prolonged Simulated Driving for the Assessment of Driver Fatigue Rida Zuraida; Hardianto Iridiastadi; Iftikar Zahedi Sutalaksana; Suprijanto Suprijanto
Journal of Engineering and Technological Sciences Vol. 51 No. 2 (2019)
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.2019.51.2.9

Abstract

Fatigue during driving is the main contributing factor to road accidents. It is influenced by time on task (TOT) and time of day (TOD). Recent electroencephalogram (EEG) research on fatigue assessment has shown a promising result in explaining the fatigue phenomenon. However, different findings exist regarding the best EEG parameters related to fatigue. This study examined EEG changes according to the effect of TOT and TOD and determined the best parameters to distinguish fatigue status. To generate driver fatigue, prolonged driving in the morning and at night in a simulator was conducted. The EEG signal was collected from 28 male participants at frontal and occipital areas. The EEG power (brainwave) was determined from the first and last 5 minutes of the driving task and after a break of 30 minutes. The results of this study showed a general tendency of EEG power changing throughout the driving sessions. However, changes related to fatigue were only found for the night sessions, as confirmed by q power and the subjective fatigue measurement result. This study showed that TOT (as a factor that induces fatigue) was explained by q from the frontal area, whereas TOD was differentiated by a, q, q/b, (q+a)/b and (q+a)/(b+a).
Design of Elastomeric Bridge Bearing Pad Compound Formula Based on Hydrogenated Natural Rubber Santi Puspitasari; Adi Cifriadi
Journal of Engineering and Technological Sciences Vol. 51 No. 5 (2019)
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.2019.51.5.4

Abstract

Laminated elastomeric bearing pad which is commonly produced by natural or chloroprene rubber is functioned as isolation system in bridge or flyover structures. In the research, hydrogenated natural rubber (HNR) was evaluated its feasibility to be used as base elastomer on steel-laminated bearing pad production by designing rubber compound formula. The compounding procedures of HNR applied various vulcanization system and carbon black filler types. The physical and mechanical tests result showed that only hardness parameter could fill the standar quality requirement of commercial elastomeric bearing pad as stated in AASHTO M251 in the range of 50 "“ 70 Shore A scale. The tensile property and compression set value of the HNR vulcanizates were under the requirement. This was due to low rubber-filler interaction and rigidity of crosslink network. The low interaction was more evident with increasing carbon filler particle size. By adjusting semi efficient vulcanization system and used N220 as carbon filler in designing compound formula,HNR was regarded as alternative promosing base elastomer for elastomeric bridge bearing pad manufacture. Nevertheless, it was necessary to improve the procedure to achieve better tesile property and compression set parameter.
Research on Flow Characteristics of Electronically Controlled Injection Device Developed for High-Power Natural Gas Engines Binbin Sun; Wenqing Ge; Yongjun Wang; Cao Tan; Bo Li
Journal of Engineering and Technological Sciences Vol. 51 No. 4 (2019)
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.2019.51.4.1

Abstract

Accurate fuel supply is a key factor that influences the performance of high-power natural gas engines. The premixed and single-point natural gas supply system is the most commonly used method to ensure a large fuel supply but one of its shortcomings is the inaccuracy of the fuel supply. A new type of natural gas injection device with fungiform configuration and electronically controlled actuator was developed to achieve high efficiency and stable operation in high-power natural gas engines. Firstly, a computational fluid dynamics (CFD) model of the injection device was created. Based on this model, the key structure parameters that have a significant influence on the outlet flow were confirmed. A particle swarm optimization (PSO) model was developed to identify the optimal outflow structure. Then, a flow function for precise flow supply control was constructed based on a response surface model, according to the flow rates of the device under different control parameters. Finally, a flow-characteristic test bench and a high-power engine prototype were developed to verify the simulation and optimization results. The results indicate that the optimized outflow structure shows low pressure loss and a large flow rate, improving injection efficiency by 10.37% and mass flow by 11.78% under 0.4 Mpa pressure difference. More importantly, the cycle fuel supply could be controlled accurately for each cylinder owing to the developed flow function. Consequently, compared with the original engine using a single-point natural gas supply system, the cylinder performance imbalance was improved by 37.47%.
Developing Sub-wavelength Sound Absorber Based on Coiled Up Tube Resonator Iwan Prasetiyo; Elsa Nalita Wongso; Joko Sarwono
Journal of Engineering and Technological Sciences Vol. 51 No. 3 (2019)
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.2019.51.3.2

Abstract

Sub-wavelength sound absorbers are attractive for dealing with noise control at low-frequency (long-wavelength) sounds. To be efficient in absorbing the sound energy, resonator based absorbers are preferable over fibrous porous ones. In this paper, a coiling up space approach is introduced to a tube resonator system in order to realize a sub-wavelength absorber structure. In this way, the air channel of the tube resonator is a coplanar coiled up channel rather than a straight channel as found in conventional tube resonators. The effect of the geometrical properties of the aperture and the air channel were studied further to look at their relationship to impedance mismatch, which coiling up systems typically suffer from. It was found that the proposed approach could realize a sub-wavelength absorber system up to 1/32 wavelength of peak sound absorption. Selection of the shape and dimensions of the aperture must be done with great care as indicated by the measurement results. Moreover, the behavior of the coiled up tube resonator deviates from that of the straight tube as the reflection factor is increased, although the target resonance frequency is close to the target. It was also found that a squared aperture shape as well as increasing the cavity thickness is useful to deal with impedance mismatch.
Impurity Removal of Waste Cooking Oil Using Hydrophobic Polypropylene Hollow Fiber Membrane Lienda Aliwarga; Setyo Widodo; Novika Suwardana; Hanna Darmawan; Khoiruddin Khoiruddin; I Gede Wenten
Journal of Engineering and Technological Sciences Vol. 51 No. 2 (2019)
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.2019.51.2.5

Abstract

Removal of impurities from cooking oil is an important step in providing the possibility of WCO reuse to extend the life cycle of cooking oil, leading to a reduction of WCO disposal. This study was conducted to investigate the performance of a polypropylene (PP) hollow fiber ultrafiltration (UF) membrane for removal of impurities from WCO. The results showed that the membrane could remove water content up to 95% (at 0.1 MPa and 30 °C), but the color improvement was only 9.5% as indicated by the absorbance reduction. Within the range of the operation conditions (i.e. a trans-membrane pressure of 0.1-0.2 MPa and a temperature of 30-50 °C), the oil flux varied from 0.3 L.m"‘2.h"‘1 to 1.3 L.m-2.h-1. In long-term operation, the membrane wettability was improved as shown by the oil contact angle decreasing from 28.2 ± 1.5° to 14.4 ± 0.5°. This resulted in a higher oil flux. At the same time, the hydrophobicity was also increased, as indicated by an increase in the water contact angle from 95.4 ± 0.7° to 97.3 ± 1.1°.
Development of Nationwide Surface Spectral Acceleration Maps for Earthquake Resistant Design of Bridges Based on National Hazard Maps of Indonesia 2017 Reguel Mikhail; Masyhur Irsyam; Ramli Nazir; Mohammad Asrurifak; Bigman Marihat Hutapea; Siska Rustiani; Munirwansyah Munirwansyah; Dandung Sri Harninto
Journal of Engineering and Technological Sciences Vol. 51 No. 4 (2019)
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.2019.51.4.4

Abstract

Spectral acceleration at the ground surface, including peak ground acceleration, provides essential information for earthquake resistant design and must be provided to bridge engineers in easily accessible media. Spectra acceleration maps are one way to deliver such information, but unfortunately the most recent Indonesian earthquake resistant design standard for bridges, SNI 2833-2016, only provides maps of earthquake hazard at bedrock. The development of earthquake acceleration maps at the ground surface for Indonesia in this study was based on earthquake hazard maps at bedrock with probability of exceedance (PE) 7% in 75 years, i.e. equal to an earthquake with a return period of 1034 years. Site conditions were adopted from the nationwide Vs30 map of Indonesia proposed by Irsyam (2017), which is a modified version of the Vs30 map proposed by Imamura & Furuta (2015). Site conditions combined with hazard value were used to determine the amplification factors according to the criteria in SNI 2833-2016 and then multiplied with hazard at bedrock to obtain surface spectra acceleration maps. The resulting maps are very useful for determining earthquake loads for bridge design at the preliminary design stage. Improvements to incorporate more advanced calculation methods and updated data in a future research are recommended and very feasible.
Overview of Health Impacts due to Haze Pollution in Johor, Malaysia Nur H. Hanafi; Mimi Haryani Hassim; Zainura Z. Noor
Journal of Engineering and Technological Sciences Vol. 50 No. 6 (2018)
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.2018.50.6.5

Abstract

Haze pollution is one of the major environmental issues caused by aerosols, having brought about a history of heavy smog pollution events like the London smog in 1952 and the Los Angeles smog in the 1960s. However, in Malaysia, haze events are attributed to forest and peat fires in Kalimantan and Southern Sumatra, Indonesia. The burned biomass basically contains concentrated particulate matters that are hazardous to health among susceptible population groups. Based on the extensive literature review conducted, the small number of available local studies on the health effects of air pollution in Malaysia conducted so far focused on air pollution sciences. In this paper, a comprehensive overview of studies done on the impacts of haze on health conditions among populations in Malaysia is presented. The result shows that the number of upper respiratory tract infection cases was directly proportional to the particulate matter concentration and Air Pollution Index value in Johor in the years 2014 and 2015. Particulate matteris the major contributor in the formation of heavy hazes and is more likely to initiate detrimental health effects compared to other inhalable particles due to their size, large area, and strong activity, making them more likely to carry harmful substances causing a higher number of infected patients with upper respiratory tract infections.

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