Journal of Engineering and Technological Sciences
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)
Articles
1,267 Documents
Synthesis of Nanocrystalline of Lanthanum Doped NaTaO3 and Photocatalytic Activity for Hydrogen Production
Husin, Husni;
Pontas, Komala;
Sy, Yuliana;
Syawaliah, S.;
Saisa, S.
Journal of Engineering and Technological Sciences Vol 46, No 3 (2014)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2014.46.3.6
Sodium tantalum oxide doping lanthanum (La-NaTaO3) compounds were successfully synthesized by a sol-gel method and calcined at different temperatures. Tantalum chloride (TaCl5) was used as starting material and lanthanum nitrate (La(NO3)3.6H2O) as lanthanum source. X-ray diffraction (XRD) revealed that the calcination temperature strongly influenced the crystallinity of the prepared samples.The crystallite sizes of the resultant La-NaTaO3were in the range of 27-46 nm. The photocatalytic activities of the samples were examined for hydrogen production from an aqueous methanol solution under UV light irradiation. It was found that the photocatalytic activity of the La-NaTaO3 depended strongly on the calcination temperature. The range of calcination temperatures were 500, 700, and 900°C. The La-NaTaO3 sample calcined at 900°C showed the highest photocatalytic activity compared to the samplescalcined at the other temperatures. The rate of hydrogen production reached a value of 6.16 mmol h-1 g-1 catalyst.
Controller Reduction of Parameter Dependent Systems
Widowati, Widowati;
Riyanto, Bambang;
Saragih, Roberd
Journal of Engineering and Technological Sciences Vol 36, No 1 (2004)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2004.36.1.3
This paper proposes a controller reduction of linear parameter dependent systems. A measure of the degradation is derived for the parameter dependent closed-loop performance caused by applying the reduced-order parameter dependent controller. This measure can be obtained by extending the degradation of the closed-loop performance of the balanced truncation of the corresponding time invariant systems. To verify the performance of the reduced-order controller, an application of the proposed controller reduction method to vertical acceleration of a missile is presented.
Removal of Microorganisms in Drinking Water using Pulsed High Voltage
Hazmi, Ariadi;
Desmiarti, Reni;
Waldi, Eka Putra;
Darwison, D.
Journal of Engineering and Technological Sciences Vol 45, No 1 (2013)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2013.45.1.1
A pulsed high voltage was used to remove microorganisms in drinking water. The effects of the pulsed high voltage on pH, conductivity, temperature and oxidation reduction potential (ORP) of the drinking water were investigated. The observed results show that the removal efficiency with respect to fecal coliforms and total coliforms increased with the increase of the pulsed high voltage. The removal efficiency for microorganisms such as fecal coliforms and total coliforms was in the range 25-100% and 44-100%, respectively, after the water was exposed to a pulsed high voltage of 5-10 kV for 60 minutes. An increase of the pulsed high voltage caused a decrease in the conductivity and ORP with operational time.
A Field Observation on Lightning Performance Improvement of Overhead Distribution Lines
Zoro, Reynaldo;
Mefiardhi, Ryan;
Hidayat, Syarif;
Mardiana, Redy
Journal of Engineering and Technological Sciences Vol 41, No 2 (2009)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2009.41.2.3
Two feeders of 20 kV overhead distribution lines which are located in a high lightning density area are chosen to be observed as a field study due to their good lightning performance after improvement of lightning protection system. These two feeders used the new overhead ground wire and new line arrester equipped with lightning counter on the main lines. The significant reduced of lines outages are reported. Study was carried out to observe these improvements by comparing to the other two feeders line which are not improved and not equipped yet with the ground wire and line arrester. These two feeders located in the nearby area. Two cameras were installed to record the trajectory of the lightning strikes on the improved lines. Lightning peak currents are measured using magnetic tape measurement system installed on the grounding lead of lightning arrester. Lightning overvoltage calculations are carried out by using several scenarios based on observation results and historical lightning data derived from lightning detection network. Lightning overvoltages caused by indirect or direct strikes are analyzed to get the lightning performance of the lines. The best scenario was chosen and performance of the lines were improved significantly by installing overhead ground wire and improvement of lightning arrester installation.Â
Measuring the Capacity and Transaction Time of Cash and Electronic Toll Collection Systems
Karsaman, Rudy Hermawan;
Mahendra, Yans;
Rahman, Harmein;
Sulaksono, Sony
Journal of Engineering and Technological Sciences Vol 46, No 2 (2014)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2014.46.2.5
A long queue can occur at tollgates due to the amount of transaction time required to perform ticket payment and toll fee collection. This problem can be addressed by the use of an electronic toll collection (ETC) system. A case study conducted on the Jakarta Intra Urban, Cikupa-Merak, and Cawang Pluit Toll Roads suggests that the queueing at the tollgates when modelled followed a Poisson distribution. The average cash transaction time was approximately 5 to 6 seconds, while the ETC transaction time was only 4 seconds. Furthermore, the capacity of the cash system gate was 550 to 620 vehicles/hour (which is above the minimum service standard of 450 vehicles/hour),whereas the electronic gate capacity was 770 to 870 vehicles/hour. This study demonstrates that the ETC system is more effective than the cash system in terms of reducing the number of queueing vehicles.
Mechanical Behavior of Various Orthodontic Retraction Springs
Setiawan, Rachman;
Idris, Muhammad;
Prakasa, Tito Dwi
Journal of Engineering and Technological Sciences Vol 43, No 3 (2011)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2011.43.3.5
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.
Cost Minimization Model of Gas Transmission Line for Indonesian SIJ Pipeline Network
Siregar, Septoratno;
Soewono, Edy;
Siregar, Daniel;
Putra, Satya A.;
Budicakrayana, Yana
Journal of Engineering and Technological Sciences Vol 35, No 1 (2003)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2003.35.1.3
Optimization of Indonesian SIJ gas pipeline network is being discussed here. Optimum pipe diameters together with the corresponding pressure distribution are obtained from minimization of total cost function consisting of investment and operating costs and subjects to some physical (Panhandle A and Panhandle B equations) constraints. Iteration technique based on Generalized Steepest-Descent and fourth order Runge-Kutta method are used here. The resulting diameters from this continuous optimization are then rounded to the closest available discrete sizes. We have also calculated toll fee along each segment and safety factor of the network by determining the pipe wall thickness, using ANSI B31.8 standard. Sensitivity analysis of toll fee for variation of flow rates is shown here. The result will gives the diameter and compressor size and compressor location that feasible to use for the SIJ pipeline project. The Result also indicates that the east route cost relatively less expensive than the west cost.
Spatial Modeling of Sediment Transport over the Upper Citarum Catchment
Poerbandono, Poerbandono;
Basyar, Ahmad;
Harto, Agung B.
Journal of Engineering and Technological Sciences Vol 38, No 1 (2006)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2006.38.1.2
This paper discusses set up of a spatial model applied in Geographic Information System (GIS) environment for predicting annual erosion rate and sediment yield of a watershed. The study area is situated in the Upper Citarum Catchment of West Java. Annual sediment yield is considered as product of erosion rate and sediment delivery ratio to be modelled under similar modeling tool. Sediment delivery ratio is estimated on the basis of sediment resident time. The modeling concept is based on the calculation of water flow velocity through sub-catchment surface, which is controlled by topography, rainfall, soil characteristics and various types of land use. Relating velocity to known distance across digital elevation model, sediment resident time can be estimated. Data from relevance authorities are used. Bearing in mind limited knowledge of some governing factors due to lack of observation, the result has shown the potential of GIS for spatially modeling regional sediment transport. Validation of model result is carried out by evaluating measured and computed total sediment yield at the main outlet. Computed total sediment yields for 1994 and 2001 are found to be 1.96Ã106 and 2.10Ã106tons/year. They deviate roughly 54 and 8% with respect to those measured in the field. Model response due to land use change observed in 2001 and 1994 is also recognised. Under presumably constant rainfall depth, an increase of overall average annual erosion rate of 11% resulted in an increase of overall average sediment yield of 7%.
Comparison of Eight Month Coastal Polluted Porcelain and Epoxy Resin Outdoor Insulators
Waluyo, Waluyo;
Sinisuka, Ngapuli I.;
Pakpahan, Parouli M.;
Suwarno, Suwarno;
Djauhari, Maman A.
Journal of Engineering and Technological Sciences Vol 40, No 2 (2008)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/itbj.eng.sci.2008.40.2.4
This study presents the experimental results of eight months naturally coastal polluted outdoor porcelain and epoxy resin insulators. The experiments were leakage current and applied high voltage measurements used a two-channel storage digital oscilloscope, in the hermetically sealed chamber, where temperature, humidity , pressure and applied voltage could be adjusted and measured simultaneously. The leakage current waveforms were analyzed using FFT and the relation to environmental parameters were analyzed using correlation matrix of multivariate statistical tools. It was also conducted SEM and EDAX tests. Base on the correlation coefficient matrix, the humidity contributed to leakage current amplitude and phase angle on the porcelain insulator  were very significant, with the correlation coefficient were 0.60 and -0.68 respectively. Whereas, on polluted epoxy resin insulator, the humidity did not influence to leakage current and phase angle considerably. Generally, the surface became rougher than the new one. The most three chemical elements in pollutants were chlorine, silicon and ferrum.
Spatial Decision Assistance of Watershed Sedimentation (SDAS): Development and Application
Poerbandono, R.;
Harto, Agung B.;
Julian, Miga M.
Journal of Engineering and Technological Sciences Vol 46, No 1 (2014)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2014.46.1.3
This paper discusses the development and application of a spatial tool for erosion modeling named Spatial Decision Assistance of Watershed Sedimentation (SDAS). SDAS computes export (yield) of sediment from watershed as product of erosion rate and sediment delivery ratio (SDR). The erosion rate is calculated for each raster grid according to a digital elevation model, soil, rain fall depth, and land cover data using the Universal Soil Loss Equation. SDR calculation is carried out for each spatial unit. A spatial unit is the smallest sub-watershed considered in the model and generated according to the TauDEM algorithm. The size of one spatial unit is assigned by the user as the minimum number of raster grids. SDR is inversely proportional to sediment resident time and controlled by rainfall, slope, soil, and land cover. Application of SDAS is demonstrated in this paper by simulating the spatial distribution of the annual sediment yield across the Citarum watershed in the northwest of Java, Indonesia. SDAS calibration was carried out based on sediment discharge observations from the upper catchment. We considered factors for hillslope flow depth and for actual and effective rainfall duration to fit the computed sediment yield to the observed sediment discharge. The computed sediment yield agreed with the observation data with a 7% mean relative accuracy.