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INDONESIA
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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RESULTS COMPARISON FOR HAT-SHAPED, DOUBLE-NOTCH AND PUNCH TESTING OF SPLIT HOPKINSON SHEAR BAR TECHNIQUE Budiwantoro, Bagus; Faizah, Iffah; Prabowo, Dini A.; Febrinawarta, Burhan; Kariem, Muhammad Agus
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2019.51.6.5

Abstract

The split Hopkinson shear bar (SHSB) test is a modification of the high rate-impact test using a split Hopkinson pressure bar (SHPB). The SHSB has been developed for a variety of techniques, for example, the hat-shaped (circular or flat), double-notch, and punch (with or without notch) techniques. The main purpose of this study was to compare these three techniques to determine the shear stress-shear strain of aluminum alloy 2024-T351. The study was conducted using the Abaqus/CAE® software. The circular hat-shaped and punch (with and without notch) techniques used a quarter-section solid 3D model. The flat hat-shaped and double-notch techniques used a half-section solid 3D model. This study successfully tested and compared the three SHSB techniques, with a number of considerations, i.e. the same parameter values for kinetic energy, shear area and shear angle. Each technique has its own advantages and disadvantages in terms of force equilibrium, flow stress fluctuation, constant strain rate, machine-ability, ease of experiment, etc. The optimum technique among the three is the hat-shaped technique.
IDENTIFICATION OF MICRO-PLASTICS (MPS) IN CONVENTIONAL TAP WATER SOURCED FROM THAILAND Kankanige, Dinuka; Babel, Sandhya
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

In a period when MP contamination of drinking water is a great concern, this study focused on the size- and morphology-based count, and polymeric identification of plastic particles in tap water sourced from Thailand. A total of 45 human consumable samples (each 1 L) were collected at Thammasat University. The average MP counts sorted by Nile Red tagging were 56.0±14.0 p/L (6.5-53 µm) and 21.0±7.0 p/L (53-300 µm), while those found by optical microscopic observations were 13.0±5.0 p/L (300-500 µm) and 6.0±3.0 p/L (? 500 µm). A significantly high MP amount was observed in the 6.5-53 µm fraction. Fibers dominated in all samples, accounting for 58% of the particle count. Most ? 300 µm particles tested by ATR-FT-IR spectroscopy were confirmed to be polymeric, identified as PE, PVC, PET, PA, PTFE, PP, and PAM. These particles may have escaped from the treatment plant or were added along the water distribution network. Since MPs in drinking water constitute a potential health risk by exposing humans to direct plastics intake, MP contamination in water supply systems should be controlled.
SOLVENT EXTRACTION OPTIMIZATION OF CHLOROPHYLL DYE FROM CONOCARPUS LANCIFOLIUS LEAVES Jassim, Nawras Jameel
Journal of Engineering and Technological Sciences Vol 52, No 1 (2020)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Recently, the green food industry has started using chlorophyll dye as a healthy and safe color additive for food and beverages. In this study, a conventional extraction technique was used to extract chlorophyll dye from Conocarpus lancifolius leaves, using 80% acetone as solvent. Taguchi?s L25 orthogonal array was utilized to optimize the extraction parameters with total chlorophyll dye yield as the response. The optimum extraction conditions were 75 minutes of extraction time, 33.5 °C extraction temperature and a 118 ml/g solvent to raw leaves ratio. Analysis of variance using Minitab18 was conducted to identify the most significant extraction parameters and available interactions. It was found that the chlorophyll dye yield from Conocarpus lancifolius leaves is mostly dependent on extraction time, followed by mixing ratio and temperature. The analysis showed a large interaction between the extraction parameters studied. The experimental chlorophyll dye yield was in close agreement with the predicted model. The adequacy of the predicted model was confirmed by an experiment conducted under the optimal conditions, given a 3.9% error percentage.
DETERMINATION OF THE SITE AMPLIFICATION ON DEEP SOIL LAYER USING 1-D SITE RESPONSE ANALYSIS (CASE STUDY: JAKARTA CITY, INDONESIA) Delfebriyadi, Delfebriyadi; Irsyam, Masyhur; Hutapea, Bigman M.; Imran, Iswandi; Asrurifak, Muhammad
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2019.51.6.6

Abstract

The dynamic response of deep soil layers is used in the development of microzonation maps. The empirical correlation between standard penetratation blow count numbers and S-wave velocity was derived for practical purposes in site characterization based on local data in a case study in Jakarta, Indonesia. For estimating the intensity of potential earthquake shaking at the ground surface as a function of depth to the bedrock surface layer, 1-D site response analysis was carried out in 5745 simulations. The site amplification values were then evaluated by dividing the spectral acceleration (SA) at ground surface by the SA at rock outcrop. Plots of the SA amplification values at interested depth intervals of the bedrock surface layer were assigned. The results showed that the site amplification values estimated by considering the local depth of the bedrock surface layer were generally smaller than the SA amplification values from the Indonesian seismic building code SNI-1726-2012. Also, there appears to exist a tendency of lower levels of mean regression of amplification, in particular for the soft soil site class.
ATOMISTIC INVESTIGATION ON THE ROLE OF TEMPERATURE AND PRESSURE IN DIFFUSION WELDING OF AL-NI Zaenudin, Mohamad; Abdulrazaq, Mohammed N.; Al-Zubaidi, Salah; Gamayel, Adhes; Sunardi, Ade
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.2020.52.2.4

Abstract

This paper presents an investigation of diffusion welding of aluminum and nickel at the atomic scale by utilizing molecular dynamics simulation. By employing several temperature and pressure values, the significant influence of the two could be obtained and thus the optimum parameter values could be obtained. The results showed that the bonding mechanism is mostly promoted by Al, in which the deformation and defects are involved. The results on both the mechanical properties and the evolution of the diffusion configuration showed that temperature has more impact compared to pressure. It was indicated that by raising the temperature to 700 K with the lowest pressure (50 MPa), both the mechanical properties and the evolution of the diffusion configuration showed a relatively significant difference. On the one hand, the deformation that occurs during welding, which is mostly caused by raising the temperature, obviously promotes joining and therefore more joining depth can be achieved, although it results in a curved diffusion zone at the interface. On the other hand, it also leads to a lower ultimate tensile strength. During the tensile test, raising the temperature also led to focusing the deformation in the diffusion zone, while a lower temperature resulted in a wider area of deformation.
AN INVESTIGATION OF A CONVENTIONAL WATER TREATMENT PLANT IN REDUCING DISSOLVED ORGANIC MATTER AND TRIHALOMETHANE FORMATION POTENTIAL FROM A TROPICAL RIVER WATER SOURCE Sururi, Mohamad Rangga; Notodarmojo, Suprihanto; Roosmini, Dwina; Putra, Prama Setia; Maulana, Yusuf Eka; Dirgawati, Mila
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.2020.52.2.10

Abstract

The characteristics and composition of dissolved organic matter (DOM) and trihalomethane (THM) generation during water treatment are important for producing safe drinking water. However, little information is available on this topic within the context of Indonesia. This study aimed to investigate the efficiency of a conventional drinking water treatment plant (WTP) in removing DOM and chloroform forming potential (CHCl3FP), and evaluate surrogate parameters for CHCl3FP. Samples were taken during the rainy season and the dry season from raw water, after secondary treatment and after the rapid sand filter. DOM was characterized based on the A254, A355, SUVA, dissolved organic carbon (DOC), and fluorescence DOM (FDOM) parameters. The composition of the DOM was identified using the peak picking method. Overall, from raw to finished water, the WTP performed better in the rainy season with 55.96% reduction of DOC and 63.45% reduction of A355 as compared to the dry season with 53.27% reduction of DOC and 24.18% reduction of A355.The overall removal of humic and tryptophan compounds during the rainy season was 33.33% and 37.50%, respectively. In the dry season, humic compounds were reduced by 18.80%, while tryptophan increased threefold. A355 can serve as a surrogate parameter for CHCl3FP in raw water and water after secondary treatment, containing more humic-like compounds than tryptophan-like compounds.
EVALUATION OF THE EFFECT OF OPERATING PARAMETERS ON THE PERFORMANCE OF ORIFICE/POROUS PIPE TYPE MICRO-BUBBLE GENERATOR Pambudiarto, Benny Arif; Mindaryani, Aswati; Deendarlianto, D.; Budhijanto, Wiratni
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.2020.52.2.5

Abstract

The micro-bubble generator (MBG) is a novel aeration technology utilizing the concept of fluid flow through an orifice, where air is sucked into the internal chamber of the MBG by the pressure difference created by the orifice and immediately pushed by the high-velocity flow of the fluid. This mechanism creates micro-size bubbles with a high dissolution rate. This study focused on studying the effect on the oxygen dissolution rate of the two most important operating parameters, i.e. the volumetric flow rate of the liquid (QL) and the volumetric flow rate of the air (QG). Various combinations of values for QL and QG were systematically compared by means of the oxygen mass transfer coefficient (kLa). The experiment was carried out in a transparent container of 2.8 m x 0.6 m x 0.4 m filled with tap water that was aerated using an orifice/porous-pipe type MBG. The dissolved oxygen (DO) values were measured at distances of 60 cm, 120 cm, and 180 cm from the MBG outlet. The experiment was designed with five different values for QL and QG respectively. The results showed that the value of kLa, which is proportional to the oxygen dissolution rate, increased asymptotically with increasing QL value, while the QG values did not significantly affect the kLa value.
THE DISTRIBUTION OF MICROPLASTICS IN BEACH SAND IN TIEN GIANG PROVINCE AND VUNG TAU CITY, VIETNAM Hien, To Thi; Nhon, Nguyen Thi Thanh; Thu, Vo Thi Minh; Quyen, Do Thi Thuy; Nguyen, Nguyen Thao
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.2020.52.2.6

Abstract

Microplastics threaten the ecosystem because of undesirable properties such as non-biodegradability, easy-to-absorb persistant organic compounds, etc. They are found worldwide in marine, fresh water and beach sand environments. In this study, microplastics in beach sand samples from two sites in Tien Giang province and two sites in Vung Tau city were investigated. The results showed that the microplastics amount was 0 to 295 pieces/kg dry sand and they mainly distributed near estuarine areas. Microplastics were more prevalent at bathing sites than non-bathing sites. In Tien Giang fragments were the most dominant among the three types of shapes (fragments, fibers, granules) at 60.2%. In Vung Tau granules were most prevalent at 71.7%. The composition of the plastics was confirmed by Fourier-transform infrared spectroscopy. It was revealed that PE, PP and PS were the main types of plastics found in the sampling sites. 
TORREFACTION OF RUBBERWOOD WASTE: THE EFFECTS OF PARTICLE SIZE, TEMPERATURE & RESIDENCE TIME Wulandari, Winny; Jahsy, Nursayyidah Ainun; Tandias, Adrian Hartanto; Rizkiana, Jenny; Rubani, Inga Shaffira; Saputera, Wibawa Hendra; Sasongko, Dwiwahju
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.2020.52.2.1

Abstract

Agriculture waste has created massive challenges over the last few decades and yet also opportunities. This work aimed to produce high-quality biochar from rubberwood waste with calorific properties close to subbituminous coal. Using a tubular vertical reactor, the effects of rubberwood particle size (wood chips and shredded wood), torrefaction temperature (220, 260, and 300 °C), and residence time (30, 60, and 90 minutes) on the quality of torrefied rubberwood were studied. The results showed that the mass loss of the rubberwood increased as the temperature increased. Also, the particle size and residence time increased due to excessive devolatilization. A higher fixed-carbon content and calorific value as well as lower moisture and volatile-matter content were achieved by increasing the torrefaction temperature and residence time in comparison to the untreated sample (raw rubberwood). The highest fixed-carbon content and calorific value were found to be 56.7% and 6313 kcal/kg, respectively, for the wood chip particles that were torrefied at 300 °C for 60 minutes. Based on the Van Krevelen diagram, torrefaction of woodchip rubberwood at 300 °C with a residence time of 60 minutes demonstrated the optimum condition to generate a product with properties that are close to those of subbituminous rank coal.
STATUS OF MICROPLASTIC POLLUTION IN AQUATIC ECOSYSTEM WITH A CASE STUDY ON CHERATING RIVER, MALAYSIA Pariatamby, Agamuthu; Hamid, Fauziah Shahul; Bhatti, Mehran Sanam; Anuar, Norkhairah; Anuar, Norkhairiyah
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.2020.52.2.7

Abstract

Microplastics are emerging contaminants owing to their potential to adsorb and release pollutants from the environment, transferring these pollutants to the food web. Most marine microplastics come from the terrestrial environment, mainly from inland freshwaters that are direct receivers of runoff from urban, industrial, and agricultural areas. The present study investigated the occurrence of microplastics in surface water samples taken from the Cherating river and the Cherating mangrove, Pahang along with a review of recent studies on microplastics abundance in aquatic ecosystems. Three sampling sites were established (two sites along the river and one site in a mangrove in the downstream of the river). In the up- and midstream regions, the river passes by residential, fishery and tourism areas, while the mangrove is located close to Cherating Beach. The highest microplastics abundance was discovered in the midstream region, with an average abundance 0.0070 ± 0.0033 particles/m3, followed by the mangrove (0.0051 ± 0.0053 particles/m3). Fragments with a size of 0.5 to 1.0 mm and white-colored microplastics were prevalent. The findings are similar to those from other microplastic studies (e.g. in Aveiro and Lisbon, Portugal; New England, USA; Kingston Harbour, Jamaica), but lower than microplastics studies in Asia (e.g. Yangtze river estuary and Hangjiang river, China). Overall, the findings provide background information on microplastics pollution in aquatic ecosystems.

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