cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota bandung,
Jawa barat
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
 102   103   104   105   106 
The Effect of Nanocrystalline Cellulose (NCC) Filler on Polylactic Acid (PLA) Nanocomposite Properties Daniel I. Simangunsong; Try H. A. Hutapea; Hyung Woo Lee; Jung Oh Ahn; Johnner Sitompul
Journal of Engineering and Technological Sciences Vol. 50 No. 4 (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.2018.50.4.9

Abstract

This paper discusses the effect of nanocrystalline cellulose (NCC) when used as filler on polylactic acid (PLA)-based nanocomposites and on its mechanical properties and permeability. NCC was produced from commercial cellulose and another cellulose source, i.e. oil palm empty fruit bunch, by hydrolysis of microcrystalline cellulose with sulphuric acid and by oxidation with ammonium persulfate. The nanocomposites were made by adding nanocrystalline cellulose with varying compositions into PLA. A solvent casting method was used to produce a nanocomposite film with 5% v/v triacetin as a coupling agent. Both methods produced crystalline celluloses within the micro and nano range with mean particle size at 99.5 nm and 157.9 nm for the sulphuric acid hydrolysis and the ammonium persulfate oxidation method, respectively. The utilization of NCC as PLA composite filler increased the percentage of elongation at break with a highest percentage 19.02% for addition of 1% NCC filler. However, higher compositions of cellulosic filler resulted in a decreasing trend of tensile strength and elongation at break. Higher content of NCC filler in the PLA matrix increased the nanocomposite's water vapor permeability.
Determination of The Site Amplification on Deep Soil Layer Using 1-D Site Response Analysis (Case study: Jakarta City, Indonesia) Delfebriyadi Delfebriyadi; Masyhur Irsyam; Bigman M. Hutapea; Iswandi Imran; Muhammad Asrurifak
Journal of Engineering and Technological Sciences Vol. 51 No. 6 (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.2019.51.6.6

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.
Application of Fibonacci Sequence and Lucas Sequence on the Design of the Toilet Siphon Pipe Shape Xiaole Ge; Hongfeng Wang; Shengrong Liu; Zhanfu Li; Xin Tong; Jiafei Pu
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.2019.51.4.2

Abstract

The purpose of this study was to explore the method for designing the toilet siphon pipe shape to improve flushing performance. The Fibonacci sequence and the Lucas sequence were used to design the structural parameters of the siphon pipe. The flushing processes of the toilet were simulated using the computational fluid dynamics (CFD) method to analyze the flushing performance under different siphon pipe shapes. Experimental studies were conducted to verify the reliability of the simulation results. The results indicated that when the Lucas numbers and the Fibonacci numbers were utilized to regulate the curvature of the siphon pipe in the Xi direction and the Yj direction respectively, the flushing performance of the toilet was optimal. In order to obtain better flushing performance, the curvature of the siphon pipe should be smooth and have obvious transitions at the connections of different sections. When the overall size of the siphon pipe is kept constant, a short siphon pipe length is helpful for the improvement of toilet flushing performance.
Brake Strategy Analysis for Industrial Normal-closed Brake Based on Rotational Inertia Test and Simulation Yuantao Sun; Kaige Chen; Qing Zhang; Xianrong Qin; Jianjie Zhang
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.2019.51.3.8

Abstract

Industrial brakes pose the dilemma of weighing brake capability against brake impact since the brake torque cannot be adjusted. On the one hand, the brake torque may be insufficient to stop the movement within a limited distance or parking position. On the other hand, the brake torque may be so high it can damage the transmission chain. In this study, the traditional brake strategy and the field oriented control (FOC) brake strategy were compared through simulation and a rotational inertia test. The influence of the rated brake torque and the open-closed ratio were obtained. Based on the test and simulation results, a semi-empirical formula that defines the relationship between relative brake capability and open-closed ratio was developed. Additional simulations were performed to analyze the performance of the brake in a flexible transmission chain. As an industrial application example, the benefits and the cost of a 'smart brake' based on the FOC brake strategy were analyzed. The results indicate that the equivalent brake torque with the FOC brake strategy is a function of the real-time controllable input and open-closed ratio, which can be conducted during the braking procedure. This can be an efficient way to solve the above problems.
Drought Event Analysis and Projection of Future Precipitation Scenario in Abaya Chamo Sub-Basin, Ethiopia Ayele Elias Gebeyehu; Zhao Chunju; Zhou Yihong; Negash Wagasho
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.2019.51.5.8

Abstract

Monthly observed and future precipitation magnitudes were subjected to statistical trend analysis to examine possible time series behavior. Future precipitation was downscaled from large-scale output through statistical downscaling. The observed and downscaled future precipitation was analyzed for drought events using the Standardized Precipitation Index (SPI) method. In the Abaya Chamo sub-basin, Ethiopia precipitation is explained by below average magnitudes in most of the low land area, characterized by moderate to extreme drought episodes. Nine drought events were discerned during the period of 1988 to 2015, i.e. once in three years, resulting in harvest failure and subsequent food insecurity. The NCEP-NCAR and CanESM2 model predictors were used to statistically downscale the precipitation data. The monthly observed and downscaled precipitation magnitudes were in good agreement. The RCP-2.6, RCP-4.5 and RCP-8.5 long-term future scenarios were computed to evaluate future drought patterns. The mean annual precipitation scenario decreased by 0.2% to 13.7%, 0.5% to 6.4% and 0.1% to 1.3% for the period from 2016 to 2040, 2050s and 2080s respectively. The increase in mean precipitation was projected to be 0.7% to 12.2%, 0.2% to 11.7% and 0.1% to 17.8% for the period from 2016 to 2040, 2050s and 2080s respectively. The present analysis may provide useful information associated to drought events to decision makers and can be used as a basis for future research in this area.
Physical Model of Vertical Water Movement Inside a Soil-Column Apparatus for Infiltration Study with A Two-Way Orientation Approach Reza Adhi Fajar; Gunawan Handayani; Sudarto Notosiswoyo; Lilik Eko Widodo; Tri Chandra Pamungkas
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.2019.51.5.2

Abstract

To improve the theory of Richard's equation, studying infiltration under free-draining conditions at the ground surface is necessary. Verification is required to clarify the physical model of water movement. The aim of this study was to describe multistage measurements of both the wetting and the drying front scheme of one-dimensional infiltration at laboratory scale. A soil-column infiltration apparatus was built consisting of a double acrylic wall, a sensor set and a light bulb. Acrylic was chosen as the material for the wall to minimize possible heat conduction on the wall side, which was wrapped in double insulation to achieve adiabatic condition. The following three main sensors were used and controlled by a microcontroller: water-content, pressure and temperature sensors. Meanwhile, the light bulb at the top of the apparatus was set to non-isothermal condition. The instrument was successfully built to describe vertical water movement. Slight modifications were carried out to ensure more precise observation. This resulted in the initiating of new shape interpretation based on the water-ponding measurement to refine the simplified pattern that was introduced by the conventional Green-Ampt theory.
Collapse Risks of Fail-Safe RC Frames Due to Earthquakes: Fragility Assessments Sindur P. Mangkoesoebroto; Made H. Prayoga; Rizkita Parithusta
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.2019.51.4.3

Abstract

The objective of this study was to determine the collapse risk of fail-safe reinforced concrete (RC) frames due to earthquakes by newly developed fragility curves. The curves were constructed based on the collapse mechanism, instead of measures of lateral drift as customarily adopted. The procedure was applied to RC open frames that were seismic resistant. A fail-safe mechanism was imposed by allowing plastic hinges to be formed mainly in the beams. This automatically satisfied the stronger column-weaker beam requirement; shear failure was neither tolerated anywhere in the columns nor in the beams. Two kinds of fail-safe RC frames were investigated: special moment resisting frames (SMF) and ordinary moment resisting frames (OMF). Their earthquake collapse risk was computed and compared. Inelastic time history (NLTH) and the non-linear static procedure (NSP) were conducted to assess their structural performance. The results showed among others that the fail-safe OMF had lower collapse risk than the fail-safe SMF. The collapse prevention performance level in NLTH could only be achieved for the fail-safe frames. The non-linear time history analysis should be the only method used for seismic reevaluation/safety checking of building frame structures.
Improving the Lifting Capacity of Drilled Cuttings Using Henna Leaf Extracts and Lignite in Bentonite Water-based Drilling Mud Jeffrey Onuoma Oseh; Muhammad Noorul Anam; Adams Rasyid Sidiqi
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.2019.51.3.4

Abstract

One of the basic functions of drilling fluids is to transport drilled cuttings to the surface. Bentonite with low solids content is preferred in carrying out this task. However, a low amount of bentonite in the drilling mud is incapable of effective cuttings lifting and suspension. In this study, a new, green, low-cost henna leaf extract and lignite in bentonite water-based drilling mud was used to transport cuttings to the surface. The effects of three hole angles (0°, 45° and 90°) were examined at different cuttings size diameters (0.5 mm, 1.0 mm, 2.0 mm and 2.4 mm) for the mud systems. The average cuttings transport efficiencies were found to be in the following order: 52-94% for 0.5 mm diameter, 45-93% for 1.0 mm diameter, 38-90% for 2.0 mm diameter, and 33-83% for 2.4 mm diameter. Viscosity and hole angle are directly related to cuttings transport efficiency. A plastic viscosity of 16 cP and yield point of 12.5 lb/100ft² were the most effective mud properties for a 45° hole angle, which needs attention while preparing the drilling mud. Addition of henna and lignite can be used to improve the rheological and filtration properties of bentonite water-based drilling mud.
Comparative Study of Bacterial Cellulose Film Dried Using Microwave and Air Convection Heating I. Indriyati; Yuyun Irmawati; Tita Puspitasari
Journal of Engineering and Technological Sciences Vol. 51 No. 1 (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.2019.51.1.8

Abstract

An investigation was conducted to analyze and compare the properties of bacterial cellulose (BC) films dried using microwave and air convection heating. Prior to the drying process, 90% of the water content inside the BC pellicles was removed through vacuum filtration. After that, the required drying time was only 3-5 min using microwave heating, 95% shorter than that observed for air convection heating. The properties of the BC sheets were characterized by Fourier transform infrared (FTIR), X-ray diffractometer (XRD), color difference meter, and tensile tester machine. The results showed that the structure of the BC films was the same for the BC films dried by microwave and air convection heating, i.e. cellulose I, as observed from FTIR spectra and XRD diagrams. Moreover, their color (L*, a*, and b* values) and mechanical properties were also almost identical. However, a slightly lower crystallinity and a higher swelling degree were observed for the BC film dried using microwave heating. These results suggest that microwave heating could be an alternative method of drying BC pellicles in order to shorten the processing time and reduce energy consumption when compared to air convection heating.
Parametric Study of One-Dimensional Seismic Site Response Analyses Based on Local Soil Condition of Jakarta Rena Misliniyati; Andhika Sahadewa; Hendriyawan Hendriyawan; Masyhur Irsyam
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.2019.51.3.7

Abstract

Seismic site response analysis is used to estimate the response of soil deposits during seismic loading at any depth of interest and to interpret time histories as well as response spectra. This type of analysis involves many parameters that can affect the character of ground shaking. It is important to know the effect of these parameters in order to perform reliable seismic hazard evaluation at a site. This paper presents the effects of several parameters toward the characteristics of surface response spectra based on the local soil conditions of Jakarta using a one-dimensional (1-D) site response model with total stress approach. A parametric study was performed on two cohesive soil deposit profiles with a different site class, namely medium clay (site SD) and soft clay (site SE). The bedrock layers of both profiles were located at a depth of 300 m. In this study, the analytical methods implemented were the equivalent-linear method and the non-linear method. Several different dynamics soil models were also implemented. In addition, variation of property parameters, such as depth of bedrock, shear wave velocity of bedrock, layer thickness, etc., were studied. The results of this study indicate that all of the studied parameters have a significant effect on the response spectra at the ground surface.

Page 104 of 127 | Total Record : 1267

 102   103   104   105   106 

Filter by Year

2003 2023


Reset
Filter By Issues
All Issue Vol. 55 No. 6 (2023) Vol. 55 No. 5 (2023) Vol. 55 No. 4 (2023) Vol. 55 No. 3 (2023) Vol. 55 No. 2 (2023) Vol. 55 No. 1 (2023) Vol. 54 No. 6 (2022) Vol. 54 No. 5 (2022) Vol. 54 No. 4 (2022) Vol. 54 No. 3 (2022) Vol. 54 No. 2 (2022) Vol. 54 No. 1 (2022) Vol. 53 No. 6 (2021) Vol. 53 No. 5 (2021) Vol. 53 No. 4 (2021) Vol. 53 No. 3 (2021) Vol. 53 No. 2 (2021) Vol. 53 No. 1 (2021) Vol. 52 No. 6 (2020) Vol. 52 No. 5 (2020) Vol. 52 No. 4 (2020) Vol 52, No 3 (2020) Vol. 52 No. 3 (2020) Vol. 52 No. 2 (2020) Vol 52, No 2 (2020) Vol. 52 No. 1 (2020) Vol 52, No 1 (2020) Vol 51, No 6 (2019) Vol. 51 No. 6 (2019) Vol. 51 No. 5 (2019) Vol 51, No 5 (2019) Vol. 51 No. 4 (2019) Vol 51, No 4 (2019) Vol 51, No 3 (2019) Vol. 51 No. 3 (2019) Vol. 51 No. 2 (2019) Vol 51, No 2 (2019) Vol 51, No 2 (2019) Vol 51, No 1 (2019) Vol 51, No 1 (2019) Vol. 51 No. 1 (2019) Vol 50, No 6 (2018) Vol. 50 No. 6 (2018) Vol 50, No 6 (2018) Vol 50, No 5 (2018) Vol 50, No 5 (2018) Vol. 50 No. 5 (2018) Vol 50, No 4 (2018) Vol. 50 No. 4 (2018) Vol 50, No 4 (2018) Vol 50, No 3 (2018) Vol. 50 No. 3 (2018) Vol 50, No 3 (2018) Vol. 50 No. 2 (2018) Vol 50, No 2 (2018) Vol 50, No 2 (2018) Vol 50, No 1 (2018) Vol. 50 No. 1 (2018) Vol. 49 No. 6 (2017) Vol 49, No 6 (2017) Vol 49, No 6 (2017) Vol. 49 No. 5 (2017) Vol 49, No 5 (2017) Vol 49, No 5 (2017) Vol 49, No 4 (2017) Vol. 49 No. 4 (2017) Vol 49, No 4 (2017) Vol 49, No 3 (2017) Vol 49, No 3 (2017) Vol. 49 No. 3 (2017) Vol 49, No 2 (2017) Vol. 49 No. 2 (2017) Vol 49, No 2 (2017) Vol 49, No 1 (2017) Vol. 49 No. 1 (2017) Vol 48, No 6 (2016) Vol 48, No 6 (2016) Vol. 48 No. 6 (2016) Vol 48, No 5 (2016) Vol. 48 No. 5 (2016) Vol 48, No 5 (2016) Vol. 48 No. 4 (2016) Vol 48, No 4 (2016) Vol. 48 No. 3 (2016) Vol 48, No 3 (2016) Vol. 48 No. 2 (2016) Vol 48, No 2 (2016) Vol 48, No 1 (2016) Vol. 48 No. 1 (2016) Vol 47, No 6 (2015) Vol. 47 No. 6 (2015) Vol 47, No 5 (2015) Vol. 47 No. 5 (2015) Vol 47, No 4 (2015) Vol. 47 No. 4 (2015) Vol. 47 No. 3 (2015) Vol 47, No 3 (2015) Vol 47, No 2 (2015) Vol. 47 No. 2 (2015) Vol. 47 No. 1 (2015) Vol 47, No 1 (2015) Vol. 46 No. 4 (2014) Vol 46, No 4 (2014) Vol. 46 No. 3 (2014) Vol 46, No 3 (2014) Vol. 46 No. 2 (2014) Vol 46, No 2 (2014) Vol 46, No 1 (2014) Vol. 46 No. 1 (2014) Vol 45, No 3 (2013) Vol. 45 No. 3 (2013) Vol. 45 No. 2 (2013) Vol 45, No 2 (2013) Vol 45, No 1 (2013) Vol. 45 No. 1 (2013) Vol. 44 No. 3 (2012) Vol 44, No 3 (2012) Vol 44, No 2 (2012) Vol. 44 No. 2 (2012) Vol. 44 No. 1 (2012) Vol 44, No 1 (2012) Vol. 43 No. 3 (2011) Vol 43, No 3 (2011) Vol 43, No 2 (2011) Vol. 43 No. 2 (2011) Vol. 43 No. 1 (2011) Vol 43, No 1 (2011) Vol 42, No 2 (2010) Vol. 42 No. 2 (2010) Vol. 42 No. 1 (2010) Vol 42, No 1 (2010) Vol. 41 No. 2 (2009) Vol 41, No 2 (2009) Vol. 41 No. 1 (2009) Vol 41, No 1 (2009) Vol. 40 No. 2 (2008) Vol 40, No 2 (2008) Vol. 40 No. 1 (2008) Vol 40, No 1 (2008) Vol 39, No 2 (2007) Vol. 39 No. 2 (2007) Vol. 39 No. 1 (2007) Vol 39, No 1 (2007) Vol. 38 No. 2 (2006) Vol 38, No 2 (2006) Vol 38, No 1 (2006) Vol. 38 No. 1 (2006) Vol 37, No 2 (2005) Vol. 37 No. 2 (2005) Vol 37, No 1 (2005) Vol. 37 No. 1 (2005) Vol 36, No 2 (2004) Vol. 36 No. 2 (2004) Vol. 36 No. 1 (2004) Vol 36, No 1 (2004) Vol 35, No 2 (2003) Vol. 35 No. 2 (2003) Vol. 35 No. 1 (2003) Vol 35, No 1 (2003) More Issue