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
 64   65   66   67   68 
Effect of Tensile Reinforcement Ratio on the Effective Moment of Inertia of Reinforced Lightweight Concrete Beams for Short Term Deflection Calculation Akmaluddin Akmaluddin
Journal of Engineering and Technological Sciences Vol. 43 No. 3 (2011)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2011.43.3.4

Abstract

This paper presents an improvement model of the effective moment of inertia  to  predict  the  short  term  deflection  of  reinforced  lightweight  concrete beam.  The  models  were  developed  using  9  beams  of  reinforced  pumicelightweight concrete tested under two symmetrical-point loads. The presence of steel  reinforcement  in  the  beam  was  taken  into  consideration  in  the  developed model.  The  models  were  verified  by  test  carried  out  on  other  9  beams.  Those beams subjected to various-point loads and compressive strength. The results of investigation revealed that crack moment of inertia increased with the increased tensile reinforcement ratio. Thus, the reinforcement ratio significantly affects the value of effective moment of inertia of reinforced lightweight concrete beam. All the  beam  test  results  produced  considerable  deflection  in  comparison  to  that obtained  using  current  Codes  either  ACI  or  SNI.  The  proposed  model demonstrated  a  good  agreement  to  the  experimental  results  and  in  some  cases have similar trend to that of the ACI or SNI prediction.
Mechanical Behavior of Various Orthodontic Retraction Springs Rachman Setiawan; Muhammad Idris; Tito Dwi Prakasa
Journal of Engineering and Technological Sciences Vol. 43 No. 3 (2011)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2011.43.3.5

Abstract

Retraction  spring  is  a  type  of  orthodontic  apparatus  that  is  used  to move a tooth with respect to another by utilizing its spring back effect. It is made of  metallic  wire  formed  to  individual  orthodontic  cases.  A  specific  geometry results in a set of force system, consisting of forces and moments, that provides specific movement effect when it is pre-activated to the adjacent teeth. Currently, orthodontists select its geometry depending on their knowledge and experience. It  is  based  on  separate  and  less-than-comprehensive  literatures  that  not  all orthodontists have access to. It may result in inaccuracies in treating individual tooth  retraction  case.  Engineering  approach  to  estimating  retraction  spring structural  behavior  is  proposed  through  analytical,  numerical  and  empirical methods.  Castigliano  method  is  used  as  the  analytical  approach,  whilst  finite element  method  is  used  as  the  numerical  approach.  The  two  simulation approaches  were  compared  to  the  experiments  to  obtain  the  best  simulation model.  The  behavior  of  the  simulation  models  agree  well  with  those  of experiments. Hence, the simulation models were used to simulate a large number of  geometries  to  form  database  of  structural  behavior  of  retraction  spring  that could be used in the geometry selection by orthodontists.
Formal Design and Analysis of a Wastewater Treatment Control System Based on Petri Net Seno D. Panjaitan; Berlian Sitorus
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.1

Abstract

This paper proposes a new control design approach for industrial wastewater treatment where its logic control is verifiable. In this research, a treatment control design in a lab-scale was controlled by a microcontroller circuit. The developed system combined anaerobic digestion, aeration and filtration process. Its logic control algorithm was designed by using Signal Interpreted Petri Net. In the logic verification, six analysis properties were satisfied: conflict free (logical process had no conflict behavior), termination (the process could be terminated from any state), non-contradictory outputs, live (any process state could always be reached from other state), deadlock-free, and reversible (the process could always back to initial condition). In the design evaluation, the average value of transparency metrics was 0.984 close to 1 as the best value. The system performance was evaluated by pollutant removal efficiency. The highest removal efficiencies were obtained when each anaerobic and aeration treatment were performed for three days respectively and followed by filtration. Within this condition, the system obtained average removal efficiency 91.7% of Chemical Oxygen Demand and 95.4% of Total Suspended Solids. In terms of electricity consumption, the system needed only 1,857.6 Watt-hour for a batch treatment process.
Influence of High Temperatures on the Workability of Fresh Ready-Mixed Concrete Victor Sampebulu
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.2

Abstract

Properties of fresh concrete made in tropical countries, which is mixed, transported (with agitation), placed and initially cured in places where the temperature ranges from about 20oC to 40oC and relative humidity above 60%, are not completely understood. Applicable requirements also differ from country to country and government agencies and private enterprises have their own specifications. Assuming such temperature and relative humidity conditions, the present study is an attempt at evaluating the properties of hot weather concrete in fresh state with using a method of ready"“mixed concrete. The fresh concrete was mixed and agitated at varying concrete and ambient temperatures. Three groups of the component materials, each material having such temperature as to bring resulting temperature of the fresh concrete to about 20oC, 30oC, 35oC, were chosen. The temperature of cement was conditioned to about20o, 40oC and 60oC for each of groups respectively. The aggregate was made warm enough to simulate the condition of outdoor pile in ready-mixed concrete plant. The temperature of tap water was always 20oC as it was easily controlled and unlikely affected by outdoor temperature. With the fresh concrete prevented from evaporation, slump loss is caused solely by increased temperature of concrete. During agitation, the slump loss increases rapidly during the first 30 minutes but moderately during the remaining period. Concrete-placing temperature (upon arrival at the work site) could be estimated by a proposed formula derived from this study. Besides the freshly mixed concrete temperature, this formula also takes into consideration the ambient temperature, agitating time in transit and hydration heat. The achievement as described in this study may be useful to control concrete quality in terms of strength, shrinkage and other properties of concrete to be placed in hot-humid environment.
A Hardware Architecture of a Counter-Based Entropy Coder Armein Z.R. Langi
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.3

Abstract

This paper describes a hardware architectural design of a real-time counter based entropy coder at a register transfer level (RTL) computing model. The architecture is based on a lossless compression algorithm called Rice coding, which is optimal for an entropy range of bits per sample. The architecture incorporates a word-splitting scheme to extend the entropy coverage into a range of  bits per sample. We have designed a data structure in a form of independent code blocks, allowing more robust compressed bitstream. The design focuses on an RTL computing model and architecture, utilizing 8-bit buffers, adders, registers, loader-shifters, select-logics, down-counters, up-counters, and multiplexers. We have validated the architecture (both the encoder and the decoder) in a coprocessor for 8 bits/sample data on an FPGA Xilinx XC4005, utilizing 61% of F&G-CLBs, 34% H-CLBs, 32% FF-CLBs, and 68% IO resources. On this FPGA implementation, the encoder and decoder can achieve 1.74 Mbits/s and 2.91 Mbits/s throughputs, respectively. The architecture allows pipelining, resulting in potentially maximum encoding throughput of 200 Mbit/s on typical real-time TTL implementations. In addition, it uses a minimum number of register elements. As a result, this architecture can result in low cost, low energy consumption and reduced silicon area realizations. 
A New Control Method to Reduce the Low-Frequency Output Current Ripple of AC-DC Converters by Using Virtual Inductor Pekik Argo Dahono
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.4

Abstract

A new concept of virtual inductor to reduce the low-frequency dc output current ripple of ac-dc converters is introduced in this paper. Virtual inductor is defined as an additional control algorithm that changes the system behavior into the one that has an additional inductor connected on it. The virtual nature of the inductor makes the inductance can be designed without weight and volume restrictions. How to use the virtual inductor to improve the performance of converter current controller is discussed in this paper. Several simulated and experimental results are included to show the validity of the proposed concept.
Solution of the Burger’s Equation for Longitudinal Dispersion Phenomena Occurring in Miscible Phase Flow through Porous Media Mitesh S. Joshi; Narendrasinh B. Desai; Monika N. Mehta
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.5

Abstract

An approximate solution of longitudinal dispersion phenomena occurring in two phase miscible fluid flow through porous media has been obtained by using the group theoretic approach. The longitudinal dispersion coefficient is assumed to be directly proportional to the concentration of the fluid for a distance x and at any time t > 0. The graphical representation for the concentration of the fluid for a distance x and at time t > 0 has been obtained using Mat lab coding.
Investigating the Acid Failure of Aluminium Alloy in 2 M Hydrochloric Acid Using Vernonia amygdalina Olugbenga A. Omotosho; Oluseyi O. Ajayi
Journal of Engineering and Technological Sciences Vol. 44 No. 1 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.1.6

Abstract

The acid failure of aluminium alloy in 2 M hydrochloric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Aluminium alloy coupons of dimension 4 cm by 1 cm were immersed in test solutions of free acid and also those containing extract volumes of 2, 3, 4 and 5 cm3 at ambient temperature for 30 minutes. The volumes of hydrogen gas evolved as a result of the rate of reaction were recorded and analyzed. Analysis revealed that maximum inhibitor efficiency which corresponds to the lowest corrosion rate was obtained at optimum inhibitor volumes of 5 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volumes. Adsorption study revealed that Temkin isotherm best described the metal surface interaction with the extract phytochemicals, with 12 minutes becoming the best exposure time for the phytochemicals  to adsorb to the metal surface at all volumes. Statistical modelling of the corrosion rate yielded an important relationship suitable for estimating corrosion rate values once volumes of the extract is known. Microstructural studies, showed an indirect relationship between crack growth rates and extract volumes, while consistency of the irregular intermetallic phases increases with increasing extract volumes.
Optimization of Laccase Production using White Rot Fungi and Agricultural Wastes in Solid-State Fermentation Hendro Risdianto; Elis Sofianti; Sri Harjati Suhardi; Tjandra Setiadi
Journal of Engineering and Technological Sciences Vol. 44 No. 2 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.2.1

Abstract

Abstract. Laccase has been produced in a solid-state fermentation (SSF) process using white rot fungi and various  lignocellulose-based substrates.  The white  rot fungi  used  were  Marasmius  sp.,  Trametes  hirsuta,  Trametes  versicolor  and Phanerochaete  crysosporium.  The  solid  substrates  employed  in  this  research were collected from  agricultural  waste, specifically  empty fruit bunches (EFB), rice  straw,  corncobs  and  rice  husks.  The  objective  of  this  research  was  to determine  the  most  promising  fungus,  the  best  solid  substrate  and  the  optimal conditions for the production of laccase.  The  results showed that  Marasmius  sp. on all solid substrates displayed  a  higher laccase activity than that of  any  other strain  of  white  rot  fungi.  Marasmius  sp.  and  a  solid  substrate  of  rice  straw demonstrated  the  highest  laccase  activity  of  1116.11  U/L  on  day  10.  Three significant  factors,  i.e.  pH,  temperature  and  yeast  extract  concentration,  were studied by  the  response surface method on laccase production using  Marasmius sp.  and rice straw. The optimized conditions were  a  pH, temperature and yeast extract concentration of 4.9, 31ºC and 0.36 g/L,  respectively.  The fermentation of  Marasmius  sp.  in  SSF  on agricultural  waste  shows  a  great  potential  for  the production of laccase.
Optimization of Vertical Well Placement for Oil Field Development Based on Basic Reservoir Rock Properties using a Genetic Algorithm Tutuka Ariadji; Pudjo Sukarno; Kuntjoro Adji Sidarto; Edy Soewono; Lala Septem Riza; Kenny David
Journal of Engineering and Technological Sciences Vol. 44 No. 2 (2012)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2012.44.2.2

Abstract

Comparing the quality of basic reservoir rock properties is a common practice  to  locate  new  infill  or  development  wells  for  optimizing  oil  field development using reservoir simulation. The conventional technique employs a manual  trial-and-error  process  to  find  new  well  locations,  which  proves  to  be time-consuming, especially for large fields. Concerning this practical matter, an alternative in the form of a robust technique is introduced in order to reduce time and  effort  in  finding  new  well  locations  capable  of  producing  the  highest  oil recovery. The objective of this research was to apply a genetic algorithm (GA) for determining well locations using reservoir simulation, in order to avoid the conventional  manual  trial-and-error  method.  This  GA  involved  the  basic  rock properties,  i.e.  porosity,  permeability,  and  oil  saturation,  of  each  grid  block obtained from a reservoir simulation model, to which a newly generated fitness function was applied, formulated by translating common engineering  practice in reservoir  simulation  into  a  mathematical  equation  and  then  into  a  computer program. The maximum fitness value indicates the best grid location for a new well. In order to validate the proposed GA method and evaluate the performance of the program, two fields with different production profile characteristics were used, fields X and Y. The proposed method proved to be a robust and accurate method to find the best new well locations for oil field development. The key to the success of the proposed  GA method lies in the formulation of the objective functions.

Page 66 of 127 | Total Record : 1267

 64   65   66   67   68 

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