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.
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Formerly known as:
ITB Journal of Engineering Science (2007 – 2012)
Proceedings ITB on Engineering Science (2003 - 2007)
Proceedings ITB (1961 - 2002)
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Development and Performance Evaluation of Coir Pith Ash as Supplementary Cementitious Material in Concrete
Venugopal, Balagopal;
Sambamurthy, Viswanathan
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.8
India is the third largest producer of coconuts in the world after Indonesia and Brazil. The production of coconuts generates enormous volumes of by-products, which are dumped in landfills, causing issues like soil and air contamination, pollution of groundwater and other water bodies, with hazardous impacts on plant and animal life. Coir pith and short fibers are by-products from the coir industry obtained during the extraction of long fibers and account for approximately 70% of the mature coconut husk. Coir pith ash (CPA) was prepared by heating the dried coir pith in a metallic vessel at a temperature of 400 °C for 4 hours. The current paper shows an elaborate technical study on the material properties and performance of CPA in blended cements. The properties of concrete investigated were setting time, workability, compressive strength, splitting tensile strength, flexural strength and ultrasonic pulse velocity values. The specimens were tested at curing ages of 7, 28, 56 and 90 days. The test results indicated that CPA has moderate pozzolanic properties, with 10% as optimum replacement percentage.
Hollow Core Slabs on Winkler Foundation
Al-Azzawi, Adel A.
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.3
This research dealt with the linear elastic behavior of hollow core slabs resting on a linear Winkler type foundation. A finite difference method was used to model the slabs as wide beams and the foundation as elastic springs. The finite element method was also used to model the problem using ABAQUS 6.10 software program. A comparison between the method proposed in this paper and methods from previous studies was made to check the accuracy of the solutions. Several important parameters were incorporated in the analysis, viz. the hollow core size and shape, subgrade reaction and slab depth, to trace their effects on deflections, bending moments and shear forces. A computer program coded in Fortran was developed for the analysis of hollow core slabs on an elastic foundation. It was found that the maximum difference in deflection between the present study and the exact solution was 3% for the finite difference and 7% for the finite element method.
Modeling and Experimental Investigation of Laminar Ceiling Air Distribution System for Operating Room in Merjan Teaching Hospital
Abed, Isam A.;
Hamza, Ruqaia A.
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.9
Room air distribution in operating rooms is critical to successful surgical treatment. The present study investigated the effects of the location of the air supply and exhaust grills on the air movement and air parameters inside an operating room. This paper presents an experimental and numerical analysis of air distribution in the operating room. The experimental work was conducted in an operating room in Merjan Teaching Hospital in the city of Babylon. Air was supplied from one square plenum box located in the middle of the ceiling, while air was exhausted through eight grills: large exhaust grills in the four upper corners and small exhaust grills in the four lower corners. In the theoretical work, a model of the operating room was developed and two cases were analyzed using the FLUEN 6.3.26 software program. The first case included all eight exhaust grills, while the second case included only the four lower exhaust grills. The ceiling system gave good ventilation for air distribution inside the operating room. There was no clear effect of the small exhaust grills located in the upper corners of the operating room. The height of the ceiling room is an effective factor in air distribution.
Evaluation of Metro Kapsul Performance in Steady State Curving, Traction, and Braking
Budiwantoro, Bagus;
Herman, Indria;
Halim, Fernando Sanjaya Sulaiman
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.4
Transportation is an important life aspect to save travel time from one place to another. However, traffic congestion is a major problem. Therefore, PT TReKKa intends to develop Metro Kapsul, a mass public transportation system that is suitable for densely populated developed cities. A series of technical analyses and evaluations is necessary to ensure vehicle safety in steady-state curving, traction, and braking. The maximum velocity and acceleration/deceleration in these conditions can be used to decide the development and manufacturing process of Metro Kapsul. The analyses consisted of theoretical and numerical simulations. The theoretical analysis involved applying force equilibrium condition of a rigid body. The simulation was modeled according to a real model of Metro Kapsul. The results showed that both values could be categorized as comfortable based on ASCE 21.2-2008. From this study, the safe longitudinal acceleration and deceleration of Metro Kapsul were obtained, i.e. 0.90 m/s2 and 0.97 m/s2, respectively, while the emergency longitudinal deceleration is 1.25 m/s2. When cornering, the maximum velocity is limited by the centrifugal acceleration, which is 0.6 m/s2. To conclude, the current design of Metro Kapsul is already good in steady-state performance. Further research is required for full dynamic and transient conditions with track irregularities.
Overview of Health Impacts due to Haze Pollution in Johor, Malaysia
Hanafi, Nur H.;
Hassim, Mimi Haryani;
Noor, Zainura Z.
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.5
Haze pollution is one of the major environmental issues caused by aerosols, having brought about a history of heavy smog pollution events like the London smog in 1952 and the Los Angeles smog in the 1960s. However, in Malaysia, haze events are attributed to forest and peat fires in Kalimantan and Southern Sumatra, Indonesia. The burned biomass basically contains concentrated particulate matters that are hazardous to health among susceptible population groups. Based on the extensive literature review conducted, the small number of available local studies on the health effects of air pollution in Malaysia conducted so far focused on air pollution sciences. In this paper, a comprehensive overview of studies done on the impacts of haze on health conditions among populations in Malaysia is presented. The result shows that the number of upper respiratory tract infection cases was directly proportional to the particulate matter concentration and Air Pollution Index value in Johor in the years 2014 and 2015. Particulate matteris the major contributor in the formation of heavy hazes and is more likely to initiate detrimental health effects compared to other inhalable particles due to their size, large area, and strong activity, making them more likely to carry harmful substances causing a higher number of infected patients with upper respiratory tract infections.
Development of Instant Microbial Starter for Production of Fermented Cassava Flour: Effect of Vacuum Drying Temperature, Carrier Media, and Storage Temperature
Kresnowati, Made Tri Ari Penia;
Bindar, Yazid;
Rahmina, Fathya
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.6
Cassava is an important crop for tropical countries such as Nigeria, Brazil, Thailand, and Indonesia. The potential utilization of cassava in the food industry can be enhanced by processing cassava into fermented cassava flour (fercaf), which has been shown to have a neutral color and aroma as well as low cyanogenic content. The use of specific microbial starter in the cassava chip fermentation for fercaf production will direct the fermentation process, maintaining a high quality of the produced flour. Thereby, the availability of an easy-to-use microbial starter is important for the production of fermented cassava flour. The aim of this study was to evaluate vacuum drying methods in the preparation of microbial starter for fermented cassava flour production. In particular, the effects of carrier media, drying and storage temperature on cell viability in dry starter were tested. The results showed that different methods should be applied to different microbial species. Bacillus subtilis and Aspergillus Oryza should be prepared using fercaf as the carrier media at a drying temperature of 55 °C, whereas Lactobacillus plantarum starter should be prepared using skim milk as the carrier media at a drying temperatur of 40°C. Apart from B. subtilis, the starters should be stored in a refrigerator.
Calculation of Peak Particle Velocity Caused by Blasting Vibration in Step Topography
Yang, Xi
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.1
High ground vibrations not only adversely affect the integrity of the structures in a mine area but also create inconvenience for the nearby population. In order to protect the Sanyou Mine slope in Tangshan, China from blasting vibration, the peak particle velocity in step topography must be accurately calculated. At present, the reflection coefficient of the stress wave at free interface is not considered in the equation for calculating the peak particle velocity in step topography. Therefore the accuracy of the peak particle velocity calculation is decreased in the side direction when the reflection coefficient changes. In this study, a 3D finite element analysis was employed for modeling of the blasting vibration. A series of field-testing experiments was conducted to measure the peak particle velocity. Then the reflection coefficient of the stress wave was calculated. Based on this, the principle of the peak particle velocity in step topography was explained. In addition, the application range of the equation in step topography was determined and a new equation for peak particle velocity calculation in step topography is proposed based on the numerical simulation analysis and field-testing experiment.
Influence of Electrode Distance on Electrical Energy Production of Microbial Fuel Cell using Tapioca Wastewater
Harimawan, Ardiyan;
Devianto, Hary;
Al-Aziz, Rd. Habib R. M. T.;
Shofinita, Dian;
Setiadi, Tjandra
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.7
Microbial fuel cell is one alternative technology that can be used to simultaneously solve problems related with wastewater production and energy demand. This study investigates the influence of electrode distance on power density in microbial fuel cell using tapioca wastewater. Graphite sheet without metal catalyst was used for both electrodes, separated by Nafion membranes. Four variations of electrode distance were used. MFC with highest electrode distance give the highest equilibrium OCV (676 mV), while the MFC with shortest electrode distance give the highest power density (7.74 mW/m2). EIS measurement suggested that the charge transfer resistance is dominant in all MFC configuration. Wastewater COD removal were in the range of 35-46 %, which were in accordance with the power density for all MFC.
Prediction Model of Coal and Gas Outburst Based on Rough Set-Unascertained Measure Theory
Gong, Weidong
Journal of Engineering and Technological Sciences Vol 50, No 6 (2018)
Publisher : ITB Journal Publisher, LPPM ITB
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DOI: 10.5614/j.eng.technol.sci.2018.50.6.2
This paper proposes a risk evaluation model based on rough sets (RS) and the unascertained measure theory (UMT) for solving the accuracy problem of coal and gas outburst prediction with the aim to reduce economic losses and casualties in coal mining. The coal and gas outburst prediction problem is constrained by the selection of the prediction indexes, the coupling of a single index, and the weight of each index. The proposed RS-UMT model applies two modified techniques. The first one is a method for index weight determination that was improved by rough set theory. The second one is a method for coupling a single index that was modified by the unascertained measure theory. The RS-UMT model not only well solves the problem of coupling a single index of coal and gas outbursts, but also solves the problem that the weight is susceptible to subjective factors and prior knowledge. The RS-UMT model was used to judge the risk degree of outburst of 10 mining faces in the Pingdingshan No. 8 Mine and No. 10 Mine. The predictive results of the model were basically identical to the actual measured results. The performance of the RS-UMT model was also compared to existing methods. Based on the case study it can be concluded that the RS-UMT model is an accurate and very promising method for solving the coal and gas outburst prediction problem.