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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 1,249 Documents
 1   2   3   4   5 
Combination of Minimum-Maximum (m-m) Attribute and Zero-INTENS-Difference (z-i-d) Attribute for Estimating Seismically Thin-Bed Thickness Purnomo, Eko Widi; Harith, Zuhar Zahir Tuan
Journal of Engineering and Technological Sciences Vol 43, No 2 (2011)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (498.053 KB) | DOI: 10.5614/itbj.eng.sci.2011.43.2.1

Abstract

This  paper  demonstrates  a  new  alternative  way  in  estimating seismically thin-bed (below-tuning) thickness. Initial thickness is built by bandpass filtering the amplitude display of a zero-phase seismic. The filter removes the  non  minimum  and  or  non  maximum  and  left  the  maximum  and  or  the minimum of seismic amplitude. The unresolved below-tuning thickness is then corrected  by  zero-INTENS-difference  (z-i-d)  attribute.  INTENS  is  integrated energy  spectra,  an  attribute  which  can  be  derived  from  spectral  analysis.  z-i-d attribute is zero difference of INTENS between the seismic and its synthetic. The method  generates  INTENS  difference  profile  by  subtracting  seismic  INTENS and its synthetic INTENS iteratively. The iteration is controlled by dipole space shifting from  distance to closer or  vice  versa.  The true thickness is derived  by locating z-i-d which laid in INTENS different profile. It has found that, for free noise  true  seismic  and  perfect-wavelet  (a  wavelet  which  only  approximately similar  with  wavelet  which  constructing  the  true  seismic)  synthetic  seismic,  in INTENS  different  profile,  the  z-i-d  location  always  corresponds  to  true  dipole space or thickness. The method could resolve all thickness of a wedge-modeled seismic with three different dominant frequencies. When the synthetic seismic is constructed with imperfect wavelet, slightly different analysis is needed to locate z-i-d  attribute  and  the  result  is  not  as  perfect  as  when  perfect  wavelet constructing synthetic seismic. A quiet similar result is got when the method is implemented  for  noisy  wedge-modeled  seismic.  Bad  thickness  estimation  is resulted  for  20%  noise  seismic.  The  method  algorithm  is  extended  for  similar dipole polarity model and multilayer model to bring the method to real seismic data  nearer.  The  extension  is  done  by  estimating  thickness  of  every  layer  of  a stacked-wedge-modeled  seismic. The algorithm then generalized for estimating layers  thickness  with  several  thickness  combinations.  The  method  was  able  to delineate shallow channel of Stratton Field by providing good pseudo-acousticimpedance (pseudo AI) map.
3D Model Based on Terrestrial Laser Scanning (TLS) Case study: The Cangkuang Temple, Garut District, West Java, Indonesia Hendriatiningsih, Sadikin; Suwardhi, Deni; Januragadi, J.
Journal of Engineering and Technological Sciences Vol 47, No 1 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (859.139 KB) | DOI: 10.5614/j.eng.technol.sci.2015.47.1.1

Abstract

The subject of the  investigation reported in this paper is  the visualization of three-dimensional (3D) surface models in a 3D mapping survey using terrestrial laser scanning (TLS). The Cangkuang Temple nearby Garut City was chosen as the object. The laser technology instruments used were a Topcon GLS-1000 (Geodetic Laser Scanner) and a Topcon IS (Image Station). Twelve points at  the same position in each 3D surface model  were selected.  The coordinate system of the IS was then transformed into the coordinate system of the GLS-1000 using a 3D similarity transformation model. The 3D distances were calculated for each model.  Differences  in distance were considered as errors  in the x, y,  and z  direction.  The standard deviation of the  distance differences was ±0.301 m. Some of the distance differences did not fall within the range of tolerances (about 15%). The 3D surface model visualization of the Cangkuang Temple that was created from the GLS-1000 data was more precise than the one created from the IS data. In the future, such 3D surface model visualizations could be used for documentation, preservation and reconstruction of heritage buildings.
Siloxane based Organic-Inorganic Hybrid Polymers and their Applications for Nanostructured Optical/Photonic Components Hidayat, Rahmat; Gomulya, Widiyanta; Pitriana, Pina; Irmansyah, Ryan; Miranti, Rany; Herman, Herman; Hidayat, Sahrul; Fitrilawati, Fitrilawati; Fujii, Akihiko; Ozaki, Masanori
Journal of Engineering and Technological Sciences Vol 44, No 3 (2012)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (425.077 KB) | DOI: 10.5614/itbj.eng.sci.2012.44.3.1

Abstract

We have studied the preparation of organic-inorganic hybrid polymer precursors  by  sol-gel  technique  and  their  utilization  for  nanostructured  optical components for photonic applications. The gel polymer precursors were prepared from  siloxane  modified  by  polymerizable  acrylate  groups,  which  can  be processed  further  by  photopolymerization  process.  Molecular  structure characterizations by means of the FTIR measurements indicate the conversion of C=C  bonds  into  C-C  bonds  after  photopolymerization.  This  bond  co nversion produces  high  cross-linking  between  the  organic  and  inorganic  moieties, resulting  in  thermally  stable and chemically resistant thin polymer layer which provide  unique  advantages  of  this  material  for  particular  optical/photonic applications.  By  employing  laser  interference  technique,  gratings  with periodicity between 400-1000 nm have been successfully fabricated. Application of  those  sub-micron  periodicity  of  grating  structure  as  active  elements  in optically  pumped  polymer  laser  system  and  Surface Plasmon Resonance  (SPR) based  measurement  system  have  been  also  explored.  The  experimental  results therefore  also  show  the  potential  applications  of  this  hybrid  polymer  as  a building material for micro/nano-photonics components. 
Bending and Deformation of Sandwich Panels Due to Localized Pressure Hadi, Bambang K.; Fajar, A.
Journal of Engineering and Technological Sciences Vol 37, No 1 (2005)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (249.025 KB) | DOI: 10.5614/itbj.eng.sci.2005.37.1.2

Abstract

Bending and deformation of sandwich panels due to localized pressure were analyzed using both Rayleigh-Ritz and finite element methods. The faces were made of laminated composite plates, while the core was a honeycomb material. Carbon fiber and glass fiber reinforced plastics were used for composite plate faces. In the case of Rayleigh-Ritz method, first the total energy of the system was calculated and then taking the variations of the total energy, the sandwich panel deflections could be computed. The deflections were assumed by means of Fourier series. A finite element code NASTRAN was exploited extensively in the finite element method. 3-dimensional 8-node brick elements were used to model sandwich panels, for both the faces sheets and the core. The results were then compared to each other and in general they are in good agreements. Dimple phenomena were found in these cases. It shows that localized pressure on sandwich structures will produce dimple on the pressurize region with little effects on the rest of the structures.
Comparison Study of Flow in a Compound Channel: Experimental and Numerical Method Using Large Eddy Simulation SDS-2DH Model Nugroho, Eka Oktariyanto; Ikeda, Syunsuke
Journal of Engineering and Technological Sciences Vol 39, No 2 (2007)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2196.889 KB) | DOI: 10.5614/itbj.eng.sci.2007.39.2.1

Abstract

Flow modeling  in a compound channel  is a complex matter. Indeed, due to the smaller velocities in the floodplains than in the main channel, shear layers develop at the interfaces between two stage channels, and a  momentum transfer corresponding to this shear layer affects the channel conveyance. Since a compound channel  is characterized by a deep main channel flanked by relatively shallow flood plains, the interaction between the faster fluid velocities in the main channel and the slower moving flow on the floodplains causes shear stresses  at  their  interface  which  significantly  distort  flow  and  boundary  shear stress  patterns.  The  distortion  implies  that  flow  field  in  rivers  is  highly  non homogeneous  turbulent,  which  lateral  transport  of  fluid  momentum  and suspended sediment are influenced by the characteristics of flow in rivers. The nature of mechanism of lateral transport needs to be understood for the design of river engineering schemes that rely upon realistic flow. Furthermore,  the  flows  in  river  are  also  almost  turbulent.  This  means  that  the fluid  motion  is  highly  random,  unsteady,  and  three -dimensional.  Due  to  these complexities,  the  flow  cannot  be  properly  predicted  by  using  approximate analytical solutions to the governing equations of motion. With the complexity of  the  problems,  the  solution  of  turbulent  is  simplified  with  mathematics equation. The  momentum  transfer  due  to  turbulent  exchanges  is  then  studied experimentally and numerically. Experimental data is obtained by using ElectroMagnetic Velocimetry and Wave Height Gauge. The  Large  Eddy  Simulation  Sub  Depth  Scale  (LES  SDS)-2  Dimensional Horizontal (2DH) Model is used to solve the turbulent problem. Successive Over Relaxation (SOR) method is employed to solve the numerical computation based ob finite difference discretization. The model has been applied to the compound channel  with smooth roughness. Some organized large eddies were found in the boundary  between  main  channel  and  flood  channel.  At  this  boundary  the transverse  velocity  profile  exhibits  a  steep  gradient,  which  induces  significant mass and momentum exchange, acts as a source of vorticity, and  generates high Reynolds stresses. The  Large  Eddy  Simulation  SDS-2DH  model  enables  to  predict  quite successfully  the  wavelength  of  some  observed  vortices.  The  estimated  vortex wavelengths agree again with the measurements and the theoretical predictions. The present model is proven to be a useful tool for engineering applications, as it can simulate the dynamic development of large eddies.
Determination of Kinetic Parameters for Methane Oxidation over Pt/γ-Al2O3 in a Fixed-Bed Reactor Wonoputri, Vita; Effendy, Mohammad; Budhi, Yogi Wibisono; Bindar, Yazid; Subagjo, S.
Journal of Engineering and Technological Sciences Vol 45, No 2 (2013)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (518.085 KB) | DOI: 10.5614/j.eng.technol.sci.2013.45.2.7

Abstract

This paper describes akinetic study for the determination of the kinetic parameters of lean methane emission oxidation over Pt/γ-Al2O3 in a dedicated laboratory scale fixed bed reactor. A model ofthemechanistic reaction kinetic parameters has been developed. The reaction rate model was determined using therate-limiting step method, which was integrated and optimized to find the most suitable model and parameters. Based on this study, the Langmuir-Hinshelwood reaction rate model with the best correlationis the one where the rate-limiting step is thesurface reaction between methane and one adsorbed oxygen atom. The pre-exponential factor and activation energy were 9.19 x 105 and 92.04 kJ/mol, while the methane and oxygen adsorption entropy and enthalpy were –17.46 J/mol.K, –2739.36 J/mol,–16.34 J/mol.K, and –6157.09 J/mol, respectively.
The Effect of Nitrogen Gas Flushing on Intermediate Products Formation in Acidogenic Stage of Anaerobic Process of Cocoa Sweatings Syafila, Mindriany; Handajani, Marisa; Prayascitra, Adearty
Journal of Engineering and Technological Sciences Vol 42, No 2 (2010)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (593.33 KB) | DOI: 10.5614/itbj.eng.sci.2010.42.2.2

Abstract

Cocoa is one of Indonesian-main plantation commodities. During the cocoa seed drying process, there are two types of waste that are cocoa pod and cocoa sweating. Since the organic compounds contained in cocoa sweating is high enough, it is possible to anaerobically treat this wastewater in order to recover either intermediate or end products. Preliminary study showed that the existence of H2 in the reactor would block acetic acid formation. Therefore, the aim of this current experiment was to decrease hydrogen partial pressure by flushing various nitrogen gas flow rate to shift the intermediate products during the cocoa sweating anaerobic treatment. The experiments were carried on a Circulating Bed Reactor (CBR) which contained organic compounds around 100,000 mg/l COD. Then, the reactor was flushed continuously with nitrogen gas as without flushing, 125 ml/min, 500 ml/min and 750 ml/min. The results show there was a possibility that the introduction of nitrogen gas into the reactor could shift the profile of the intermediate product formation. At lower nitrogen gas flow rate more ethanol was formed than acetate formation, although at higher nitrogen gas flow rate the formation of acetate was still low enough. 
Depositional Environment of the Sangkarewang Oil Shale, Ombilin Basin, Indonesia Anggayana, Komang; Widayat, Agus Haris; Widodo, Sri
Journal of Engineering and Technological Sciences Vol 46, No 4 (2014)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1035.745 KB) | DOI: 10.5614/j.eng.technol.sci.2014.46.4.6

Abstract

Five samples from 56 m long drill core of lacustrine Sangkarewang oil shale have been studied by means of petrography and organic geochemistry to investigate the organic matter composition and depositional environments of the shale. The organic matter consists of abundant lamalginite (30%, v/v) and very limited amount of vitrinite, suggesting aquatic depositional environments with minor terrestrial influence. Organic geochemical analysis exhibits the dominance of pristane, phytane, and generally n-alkanes compounds. These compounds might originate mostly from aquatic photosynthetic organisms. The oil shale was likely deposited in anoxic lake environments, suggested by the presence of framboidal pyrite (6%, v/v) and preserved organic matter with total organic carbon (TOC) about 4.9%. The pristane/phytane ratio is relatively high about 3.9 and thought as source sensitive rather than redox sensitive. Hopanoid and aryl isoprenoid compounds are present in minor amounts. The latter compounds are interpreted to be derived from green sulfur bacteria dwelling in anoxic and the presence of H2S in bottom water.
Synthesis of Narrow Polydispersity Block Copolymers of PtBA-PS by Novel RAFT Polymerization Technique Arcana, M.; Nagesh, K.; Rama, Ramakrisnan
Journal of Engineering and Technological Sciences Vol 36, No 1 (2004)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (242.425 KB) | DOI: 10.5614/itbj.eng.sci.2004.36.1.5

Abstract

The synthesis of narrow disperse polystyrene (PS) and poly-t-butylacrylate (PtBA) was carried out by copolymerization using benzyldithiobenzoate as the chain transfer agent (CTA). Benzyl dithiobenzoate as a reversible addition-fragmentation chain transfer (RAFT) agent has high transfer coefficient in polymerization of styrene to produce PS with higher molecular weight than that of calculated, in contrary with polymerization of t-butylacrylate to produce PtBA. These results were attributed to instability the benzyl dithiobenzoate as RAFT agent under the reaction conditions. PS as a macro-CTA is not active for t-butylacrylate polymerization due to low transfer coefficient. On the other hand PtBA as the macro-CTA is active to polymerize styrene to produce PtBA-PS block copolymer with high transfer coefficient if PtBA as macro-CTA have narrow polydispersity. The RAFT agent appears to degrade over a period of time when it is left at room temperature, which was evident from the results of PtBA.
Experimental and Analytical Study Approach of Artificial Basilar Membrane Prototype (ABMP) Tanujaya, Harto; Shintaku, Hirofumi; Kitagawa, Dai; Adianto, A.; Susilodinata, S.; Kawano, Satoyuki
Journal of Engineering and Technological Sciences Vol 45, No 1 (2013)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1435.696 KB) | DOI: 10.5614/j.eng.technol.sci.2013.45.1.5

Abstract

In this research, we have developed, fabricated, tested, and analyzed an artificial basilar membrane prototype (ABMP), which works using sinusoidal waves of various frequencies. The design of the prototype has a trapezoidal shape with a length of 30 mm and a width of 2 to 4 mm. The research was carried out experimentally and analytically. Experimentally, the ABMP’s vibration was measured using a laser Doppler vibrometer (LDV) and a function generator to generate various frequencies. The analytical approach is discussed based on the Wentzel Kramer Brillouin method (WKB). The results show that resonance frequencies can be reached within the range of human hearing, between 20 Hz to 20 kHz.

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