cover
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota bandung,
Jawa barat
INDONESIA
Journal of Engineering and Technological Sciences
ISSN : 23375779     EISSN : 23385502     DOI : -
Core Subject : 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
Accuracy Enhancement with Processing Error Prediction and Compensation of a CNC Flame Cutting Machine Used in Spatial Surface Operating Conditions Hu, Shenghai; Zhang, Manhui; Cui, Yunshan; Xue, Rui; Yang, Zhaozhen
Journal of Engineering and Technological Sciences Vol 49, No 1 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (558.812 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.1.5

Abstract

This study deals with the precision performance of the CNC flame-cutting machine used in spatial surface operating conditions and presents an accuracy enhancement method based on processing error modeling prediction and real-time compensation. Machining coordinate systems and transformation matrix models were established for the CNC flame processing system considering both geometric errors and thermal deformation effects. Meanwhile, prediction and compensation models were constructed related to the actual cutting situation. Focusing on the thermal deformation elements, finite element analysis was used to measure the testing data of thermal errors, the grey system theory was applied to optimize the key thermal points, and related thermal dynamics models were carried out to achieve high-precision prediction values. Comparison experiments between the proposed method and the teaching method were conducted on the processing system after performing calibration. The results showed that the proposed method is valid and the cutting quality could be improved by more than 30% relative to the teaching method. Furthermore, the proposed method can be used under any working condition by making a few adjustments to the prediction and compensation models.
Study of Hall Effect Sensor and Variety of Temperature Related Sensitivity Ali, Awadia Ahmed; Yanling, Guo
Journal of Engineering and Technological Sciences Vol 49, No 3 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (295.346 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.3.2

Abstract

Hall effect sensors are used in many applications because they are based on an ideal magnetic field sensing technology. The most important factor that determines their sensitivity is the material of which the sensor is made. Properties of the material such as carrier concentration, carrier mobility and energy band gap all vary with temperature. Thus, sensitivity is also influenced by temperature. In this study, current-related sensitivity and voltage-related sensitivity were calculated in the intrinsic region of temperature for two commonly used materials, i.e. Si and GaAs. The results showed that at the same temperature, GaAs can achieve higher sensitivity than Si and it has a larger band gap as well. Therefore, GaAs is more suitable to be used in applications that are exposed to different temperatures.
Removal of Copper (II) Ions in Aqueous Solutions by Sorption onto Fly Ash Darmayanti, Lita; Notodarmodjo, Suprihanto; Damanhuri, Enri
Journal of Engineering and Technological Sciences Vol 49, No 4 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1787.449 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.4.9

Abstract

The ability of fly ash to adsorp Cu(II) ions from two different coal combustion systems was studied. Optimum removal was found at pH 5, contact time 30 minutes and 60 minutes for Fly Ash 1 and Fly Ash 2, respectively, and dosage 10 g/l. The difference in adsorption capacity between both fly ashes may be due to their carbon fraction and CaO content. The removal of Cu (II) ions was caused by both adsorption and/or precipitation. Precipitation is enhanced by lowering the carbon fraction and increasing the CaO content. The adsorption isotherm showed that the Langmuir model fitted well to the experimental data of both fly ashes. A thermodynamic study was conducted at three different temperatures: 25 °C, 45 °C, and 60 °C. The adsorption processes were spontaneous and endothermic and were more favorable at higher temperature.
Cover Vol. 49 No. 4, 2017 Technological Sciences, Journal of Engineering and
Journal of Engineering and Technological Sciences Vol 49, No 4 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1209.242 KB)

Abstract

Switching Control Strategy for Greenhouse Temperature-Humidity System Based on Prediction Modeling: A Simulation Study Xu, Zhenfeng; Chen, Junjie
Journal of Engineering and Technological Sciences Vol 49, No 5 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (328.582 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.5.9

Abstract

It is difficult to achieve coordination control of multiple facilities that are driven by on-off actuators in a greenhouse, especially when there is more than one indoor environmental factor to consider at the same time. With the consideration of indoor air temperature and relative humidity, we propose a switching control strategy based on prediction modeling. The operation of the greenhouse system was divided into several modes according to the on-off control characteristics of the available facilities. Then, a switching diagram was designed according to the relationship between the indoor air temperature and humidity and their setting ranges. When the two indoor environmental factors reach their upper or lower limits, IARX models are used to predict them over a specified horizon for each optional mode respectively. Mode switching is carried out based on prediction results. The switching control strategy was simulated based on a mechanistic model of the greenhouse microclimate. The results show that the facilities can be coordinated very well by the proposed control strategy and it is easy to implement. The control strategy is still applicative when more facilities or more indoor environmental factors need to be taken into account.
Environmental Economic Hydrothermal System Dispatch by Using a Novel Differential Evolution Le, Kien Chi; Dinh, Bach Hoang; Nguyen, Thang
Journal of Engineering and Technological Sciences Vol 50, No 1 (2018)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (316.702 KB) | DOI: 10.5614/j.eng.technol.sci.2018.50.1.1

Abstract

This paper proposes the Novel Differential Evolution (NDE) method for solving the environmental economic hydrothermal system dispatch (EEHTSD) problem with the aim to reduce electricity generation fuel costs and emissions of thermal units. The EEHTSD problem is constrained by limitations on generations, active power balance, and amount of available water. NDE applies two modified techniques. The first one is modified mutation, which is used to balance global and local search. The second one is modified selection, which is used to keep the best solutions. When performing this modified selection, the proposed method completely reduces the impact of crossover by setting it to one. Moreover, the task of tuning this factor can be canceled. Original Differential Evolution (ODE), ODE with the first modification (MMDE), and ODE with the second modification (MSDE), and NDE were tested on two different hydrothermal systems for comparison and evaluation purposes. The performance of NDE was also compared to existing methods. It was indicated that the proposed NDE is a very promising method for solving the EEHTSD problem.
Simultaneous Optimization of Block Replacement and Spare Part Ordering Time for a Multi Component System with Separate Spare Part Ordering for Block and Failure Replacements Mardin, Farid; Dekker, Rommert
Journal of Engineering and Technological Sciences Vol 48, No 5 (2016)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (287.299 KB) | DOI: 10.5614/j.eng.technol.sci.2016.48.5.1

Abstract

A block replacement schedule can be optimized simultaneously with a spare parts ordering schedule, since all items are replaced at a constant interval. The solution of joint optimization for spare parts ordering time and block replacement gives lower costs compared to separate optimization of ordering time and replacement time. The spare parts for replacement can be classified as stochastic demand for failure replacement and deterministic demand for block replacement. In this paper, we propose a simulation model for a separate spare parts ordering schedule. The solution was compared to the solution for a model with common spare parts for both failure and block replacement. The system has N identical components, each with a Weibull lifetime distribution. The costs of failure and block replacements, and also the costs of ordering, holding and shortage of spare parts are given. The proposed model was shown to perform better than the common order model. Also, compared to the age replacement model, the solution of the proposed model is relatively similar, yet the economies of scale would be an advantage for the block replacement over age replacement.
Synthesis of Polyhedral Magnetite Particles by Hydrothermal Process under High Pressure Condition Machmudah, Siti; Wahyudiono, Wahyudiono; Kanda, Hideki; Goto, Motonobu
Journal of Engineering and Technological Sciences Vol 48, No 6 (2016)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (6878.865 KB) | DOI: 10.5614/j.eng.technol.sci.2016.48.6.8

Abstract

Magnetite particles were successfully generated by hydrothermal synthesis using water at subcritical conditions. By changing the temperature and pressure at subcritical water conditions, the thermodynamics and transport properties of the water can be controlled, thus enabling to manage the way of crystal formation, morphology, and particle size. In this work, the experiments were carried out at temperatures of 250 °C and 290 °C and a pressure of 10 MPa with a reactor made of SUS 316 in a batch system. The synthesized particles were dried in vacuum condition and characterized by SEM and XRD. The XRD patterns showed that magnetite particles were dominantly formed in the particle products with a black color. The results showed that the magnetite particles formed had diameters of around 60 nm in all experiments with irregular polyhedral shaped morphologies.
A Novel Analytical Technique for Optimal Allocation of Capacitors in Radial Distribution Systems Nawaz, Sarfaraz; Bansal, Ajay Kumar; Sharma, Mahaveer Prasad
Journal of Engineering and Technological Sciences Vol 49, No 2 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (307.125 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.2.6

Abstract

In this paper, a novel analytical technique is proposed to determine the optimal size and location of shunt capacitor units in radial distribution systems. An objective function is formulated to reduce real power loss, to improve thevoltage profile and to increase annual cost savings. A new constant, the Loss Sensitivity Constant (LSC), is proposed here. The value of LSC decides the location and size of candidate buses. The technique is demonstrated on an IEEE-33 bus system at different load levels and the 130-bus distribution system of Jamawa Ramgarh village, Jaipur city. The obtained results are compared with the latest optimization techniques to show the effectiveness and robustness of the proposed technique.
Cu(II) Ions Adsorption Using Activated Carbon Prepared from Pithecellobium Jiringa (Jengkol) Shells With Ultrasonic Assistance: Isotherm, Kinetic and Thermodynamic Studies Muslim, Abrar; Ellysa, Ellysa; Said, Syahiddin Dahlan
Journal of Engineering and Technological Sciences Vol 49, No 4 (2017)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (112.381 KB) | DOI: 10.5614/j.eng.technol.sci.2017.49.4.4

Abstract

Adsorption of Cu(II) ions from aqueous solution onto activated carbon (AC) prepared from Pithecellobium jiringa shell (PJS) waste was investigated by conducting batch mode adsorption experiments. The activation with ultrasound assistance removed almost all functional groups in the PJS-AC, while more cavities and pores on the PJS-AC were formed, which was confirmed by FTIR and SEM analyses. The Cu(II) ion adsorption isotherm fitted best to the Freundlich model with average R2 at 0.941. It was also correlated to the Langmuir isotherm with average R2 at 0.889. This indicates that physical sorption took place more than chemical sorption. The maximum Cu(II) ion adsorption capacity onto the PJS-AC for a dose of 1 g was 104.167 mg/g at 30 °C and pH 4.5, where the Langmuir constant was 0.523 L/mg, the Freundlich adsorption intensity was 0.523, and the Freundlich constant was 5.212 L/mg. Cu(II) adsorption followed the pseudo second-order kinetic (PSOKE) model with average R2 at 0.998, maximum adsorption capacity at 96.154 mg/g, PSOKE adsorption rate constant at 0.200 g/mg.min, temperature at 30 °C and pH at 4.5. The changes in enthalpy, entropy, free energy and activation energy were determined, and the results confirmed that Cu(II) adsorption onto the PJS-AC was exothermic chemical adsorption in part. There was a decrease in the degree of freedom and the adsorption was non-spontaneous.

Page 33 of 127 | Total Record : 1267


Filter by Year

2003 2023


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