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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 9 Documents
 1 
Search results for , issue "Vol. 47 No. 3 (2015)" : 9 Documents clear
Bacteria as Self-Healing Agent in Mortar Cracks Ananto Nugroho; Iman Satyarno; Subyakto Subyakto
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.4

Abstract

This study was aimed at finding the possibility to apply Bacillus subtilis integrated into mortar matrix to act as a self-healing agent to seal cracks. Bacterial spores at concentrations of 104, 105, and 106 cells/ml were directly added into pulverized fly ash as medium to protect bacteria in high alkaline conditions. The results show that the addition of Bacillus subtilis spores into the mortar mixture enhanced the compressive strength, especially at a cell concentration of 105 cells/ml. The bacterial mortar had a small ability to recover the stiffness of the mortar, amounting to 34.85% of its original stiffness. The effectiveness of crack sealant and resistance to water flow were limited to a maximum crack width size of 0.22 mm. Physical observation showed that the bacterial mortar is characterized by calcite precipitation as a product of ureolytic bacteria. The quantity and distribution of calcite precipitate depended on the precipitation weight, gravity direction and oxygen availability. Meanwhile, chemical analysis using XRD and EDX showed that the bacterial mortar had a better crystallinity.
On the Development of a Nomogram for Alkali Activated Fly Ash Material (AAFAM) Mixtures Partogi H. Simatupang; Iswandi Imran; Ivindra Pane; Bambang Sunendar
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.1

Abstract

Alkali activated fly ash material (AAFAM) has become the most promising material to substitute materials based on ordinary Portland cement (OPC). However, there is no available nomogram for AAFAM mixtures. In contrast, there are many rational methods available in the literature to make paste, mortar and concrete with OPC based materials, such as Monteiro-Helene's nomogram, which uses Abram's law, Lyse's law and Molinari's law. This paper presents a study to construct such a nomogram for AAFAM mixtures by first conducting experiments on the  paste and mortar phases. The procedure of Monteiro-Helene's nomogram was adopted in this formulation. The first step in this direction was to find a close relationship between the strength and paste composition of the material that can be used as a substitute for Abram's law. The second step  was  to construct the equivalent  of  Lyse's and Molinari's relationships by varying the sand and fly ash contents. The results show that it is possible to make a nomogram for AAFAM mixtures such as the one for OPC based materials. Class F fly ash and its mortar phase were used to construct the nomogram. In addition, the  mortar  samples  that were  used to build the nomogram had similar solidification products according to their microscopic characteristics.
Development of Indoor Air Pollution Concentration Prediction by Geospatial Analysis Adyati P. Yudison; R. Driejana
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.6

Abstract

People living near busy roads are potentially exposed to traffic-induced air pollutants. The pollutants may intrude into the indoor environment, causing health risks to the occupants. Prediction of pollutant exposure therefore is of great importance for impact assessment and policy making related to environmentally sustainable transport. This study involved the selection of spatial interpolation methods that can be used for prediction of indoor air quality based on outdoor pollutant mapping without indoor measurement data. The research was undertaken in the densely populated area of Karees, Bandung, Indonesia. The air pollutant NO2 was monitored in this area as a preliminary study. Nitrogen dioxide concentrations were measured by passive diffusion tube. Outdoor NO2 concentrations were measured at 94 locations, consisting of 30 roadside and 64 outdoor locations. Residential indoor NO2 concentrations were measured at 64 locations. To obtain a spatially continuous air quality map, the spatial interpolation methods of inverse distance weighting (IDW) and Kriging were applied. Selection of interpolation method was done based on the smallest root mean square error (RMSE) and standard deviation (SD). The most appropriate interpolation method for outdoor NO2 concentration mapping was Kriging with an SD value of 5.45 µg/m3 and an RMSE value of 5.45 µg/m3, while for indoor NO2 concentration mapping the IDW was best fitted with an RMSE value of 5.92 µg/m3 and an SD value of 5.92 µg/m3.
Integrated Analysis of Optimizing Tubing Material Selection for Gas Wells Bonar Tua Halomoan Marbun; Samuel Zulkhifly Sinaga; Calvin Lumban Gaol; Gde Valdy Irawan Arimbawa; Aristya Putra Pamungkas; Aldiano Falah Hardama; Ricko Rizkiaputra
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.8

Abstract

Corrosion in production tubing strings is seen as a challenging problem in gas wells containing carbon dioxideand hydrogen sulfide. This paper presents a new comprehensive method of corrosion rate calculation with integrated study of reservoir condition, nodal analysis of the well, and well trajectory, which could also have an effect due to the possibility of different flow regimes of the production fluid. This method  is applicable to evaluate and predict the performance of selected tubing size and material. This method can also give an economic evaluation for the consideration of using corrosion resistant alloy (CRA) or low-alloy steel and carbon steel. The measurement of corrosion rate can be done by several methods,such as using corrosion coupons, calculating the iron content inside  the production fluid, or probes. Either way, when  the corrosion rate measured in the field is still below the acceptable maximum corrosion rate, it can be said that the adequacy of this method is guaranteed. This method has been implemented in a gas field,where it successfully selected the best tubing material for the next development well in this field. Consequently, the lifetime of the tubing strings could be extended,resulting in an economical benefit as well.
Parameters Affecting the Extraction Process of Jatropha curcas Oil Using a Single Screw Extruder Ali Nurrakhmad Siregar; Jaharah A. Ghani; Che Hassan Che Haron; Muhammad Rizal
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.3

Abstract

The most commonly used technique to separate oil and cake from J. curcas seeds is mechanical extraction. It uses simple tools such as a piston and a screw extruder to produce high pressure, driven by hand or by engine. A single screw extruder has one screw rotating inside the barrel and materials simultaneously flow from the feed to the die zone. The highest oil yield can be obtained by a well-designed oil press as well as finding the optimum conditions for all parameters involved during the extraction process. The influence of the parameters in a single screw extruder was studied using finite element analysis and computational fluid dynamics simulation with ANSYS POLYFLOW. The research  focused on predicting  the velocity, pressure and shear rate in the metering section that influenced the screw rotational speed and mass flow rate. The obtained results revealed that increasing the screw rotational speed will increase the pressure, velocity and shear rate. Meanwhile, increasing the mass flow rate results in decreasing the pressure while the velocity and shear rate remain constant.
Analytical Study of Wind Influence on In-Flight Sprinkler Droplets Frank Dwomoh; Yuan Shouqi; Li Hong
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.5

Abstract

An analytical model to describe the dynamics of in-flight droplets is presented in this paper to augment information on wind influence on travel distance of in-flight sprinkler droplets. The model is ballistic-theory based. It employs a relatively simple, wide-range empirical relationship between drag coefficient and Reynolds' number to replace the several sets of relations for a specified range of Reynolds numbers. The fourth-order Runge-Kutta numerical integration techniques were used to solve the trajectory equations. A modified exponential model for droplet size distribution was used during the simulation. Comparative analysis showed that agreement exists between the predictions of this model and that of earlier models. Droplets with a diameter smaller than 0.1 mm travelled farthest. Within the droplet range of 0.5 mm to 4.5 mm, as droplet diameter increased, travelled distance increased with increasing wind speed. The extent of drift increased sharply within the droplet range of 0.5 mm to 0.05 mm and increased mildly for droplet diameters greater than 0.5 mm. The model also attempts to identify droplets that are likely to contribute to drift loss and those that have a high probability of contributing only to distortion of the distribution pattern.
Strength Properties of Processed Fly Ash Concrete Sivakumar Anandan; Vallarasu Manoharan Sounthararajan
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.7

Abstract

The present paper reports on the mechanical treatment of fly ash for improving the delayed reactivity of fly ash with the hydration product of cement. Grinding of fly ash was carried out in a ball mill for different time durations and processing time was optimized for maximum fineness. Concrete mixes were prepared using various proportions of processed and unprocessed fly ash replacement in cement (25% and 50%). The influence of steel fiber addition on the mechanical properties of the concrete was studied for different curing periods. The test results on pozzolanic activity and lime reactivity indicate that the processed fly ash exhibited a higher strength gain than the unprocessed fly ash, with a maximum increase in compressive strength of up to 12%. Improved pozzolanic properties were noticed due to the increase in fineness of the fly ash particles.
The Effect of Surfactant Characteristics on IFT to Improve Oil Recovery in Tempino Light Oil Field Indonesia Boni Swadesi; Taufan Marhaendrajana; Leksono Mucharam; H.P. Septoratno Siregar
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (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.2015.47.3.2

Abstract

Water injection has been employed in the Tempino oil field since 1996. The current oil recovery factor is 35% of OOIP. Even though the pressure is still high, the oil production rate has declined rapidly and the water cut is approaching 89%. In order to mobilize  the  oil from the  reservoir  more effectively, surfactant flooding is one of the solutions that can reduce residual oil saturation. Interaction between crude oil and compatible surfactant generates microemulsion,  as an indication of low interfacial tension. Hence the oil is expected to move out of the pore throat easily. In this research, thirty types of surfactants  were evaluated. The hydrophilic  lipophilic  balance (HLB)  was calculated and  the  interfacial tension (IFT)  with the  reservoir fluid  was measured. HLB criteria were established as an indicator of low IFT, which was then tested for Berea core flooding. The results indicate that an HLB between approximately 2.7 and 3.1 (on Davies' Scale) or greater than 11.5 (on Griffin's Scale) gives  low IFT  (~10-3 dynes/cm).  This characteristic  is possesed by surfactant  ethoxy  carboxylate  with a  linear hydrophobic structure.  This surfactant produces a high incremental oil recovery according to Berea core flood tests. The AN2NS and AN3 surfactants recovered 90% and 86% of OOIP respectively.
Cover Vol. 47 No.3, 2015 Journal of Engineering and Technological Sciences
Journal of Engineering and Technological Sciences Vol. 47 No. 3 (2015)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

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Abstract

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