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ITB Journal, Gedung CRCS ITB Lantai 6 Jalan Ganesa No. 10 40132 Bandung - Indonesia
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Journal of Engineering and Technological Sciences
ISSN : 23385502     EISSN : 23375779     DOI : 10.5614/j.eng.technol.sci
Core Subject : Engineering,
ournal of Engineering and Technological Sciences welcomes full research articles in: General Engineering Earth-Surface Processes Materials Science Environmental Science Mechanical Engineering Chemical Engineering Civil and Structural Engineering Authors are invited to submit articles that have not been published previously and are not under consideration elsewhere.
Articles 132 Documents
Optimization of Ultrasonic and Microbubble Disinfection for Escherichia coli and Staphylococcus aureus: Experimental Design and Effectiveness Evaluation Pitjamit, Siwasit; Vichiansan, Norrapon; Leksakul, Komgrit; Boonyawan, Dheerawan
Journal of Engineering and Technological Sciences Vol. 56 No. 6 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.6.6

Abstract

This study investigated the synergistic application of ultrasonic (UL) and microbubble (MB) technologies for the disinfection of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Optimal conditions for both techniques were determined through a comprehensive experimental design, resulting in an effective disinfection rate of 100% as assessed by the ten-fold dilution spread plate count method. The study evaluated three key parameters of the UL/MB system, i.e., UL duration time, MB duration time, and gas flow rate within the ranges of 30-60 sec, 30-60 sec, and 15-30 ml/min, respectively. A 2k full factorial design with three replications, five center points, and blocking was employed for robust statistical analysis. Based on the empirical data and rigorous statistical examination, the optimal conditions for achieving sterilization of E. coli and S. aureus were determined as 30 sec UL duration, 30 sec MB duration, and 30 ml/min gas flow rate; and 60 sec UL duration, 60 sec MB duration, and 15 ml/min gas flow rate, respectively. Utilizing these optimal conditions, the disinfection efficacy was assessed, revealing an inhibition rate of 54% for E. coli and an inhibition rate of 19% for S. aureus, with consistent improvement observed across the three replication trials. These findings underscore the potential of UL/MB technology as an effective disinfection strategy against common bacterial pathogens
Green Energy Technologies: A Key Driver in Carbon Emission Reduction Wenten, I Gede; Khoiruddin, Khoiruddin; Siagian, Utjok Welo Risma
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.1

Abstract

This paper explores the vital role of green energy technologies in mitigating carbon emissions and advancing sustainable energy transition. It emphasizes the significance of green energy in reducing the carbon footprint, delves into the environmental consequences of carbon emissions, and analyzes the mechanisms through which green energy contributes to carbon reduction. This paper discusses technological advancements across various renewable energy sources, including solar, wind, hydroelectric, biomass, geothermal, tidal, wave, nuclear, osmotic, and salinity-powered energy generation. It also examines emerging green energy technologies, identifies barriers to adoption, offers an Indonesian perspective, and provides recommendations for a greener energy future. Overall, this paper offers a comprehensive exploration of green energy's transformative potential in combatting climate change and promoting sustainable development.
Improved Risk Assessment of TBM Tunneling Collapse Based on Nonlinear-Cloud Model Wang, Longjiang; Xu, Tian; Zong, Dachao; Han, Qiang; Zhao, Yongjin; Song, Zhanping; Zhang, Yongli
Journal of Engineering and Technological Sciences Vol. 56 No. 6 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.6.9

Abstract

An innovative nonlinear enhancement technique that integrates the cloud model with Fuzzy Analytic Hierarchy Process (FAHP) is presented in this study. For the first time, this paper introduces TBM tunnelling parameters as evaluation indicators for tunnel construction collapse risk. Precise risk level thresholds are set for each indicator, establishing a comprehensive TBM construction collapse risk assessment system. Within this system, the cloud model is applied to accurately depict membership degrees, transcending the limitations of traditional reliance on functional formulas. Furthermore, the AHP is utilized to precisely calculate the weight vectors of the assessment indicators. Most significantly, this study introduces a nonlinear operator to achieve an efficient integration of the weight vectors with the fuzzy relation matrix. Based on the principle of maximum membership degree, the ultimate collapse risk level for TBM construction is determined. This method overcomes the shortcomings of traditional FAHP, which neglects the randomness in calculating membership degrees and the potential dilution of the influence of key risk factors when using linear operators in comprehensive risk assessment. The model was applied and validated in a hydraulic tunnel construction project, demonstrating its innovation and reliability, thus providing new theoretical foundations and technical support for the field of tunnel construction risk assessment.
American Sign Language Translation from Deaf-Mute People Based on Novel System Sahm, Batool A.; Al-Fahaam, Hassanin; Jasim, Abbas A.
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.2

Abstract

This paper presents a system to translate gestures from the American Sign Language alphabet using an instrumented wearable glove. This system represents an attempt to utilize a slide potentiometer in sign language translating. The hardware part of the system consists of five slide potentiometers and two force-sensitive resistors, which are best positioned on a glove, based on the analysis of American Sign Language (ASL) letters. In the software part a neural network is used, which was built and trained using Google Colab and Python as the programming language. The performance of the system was tested on three data sets with different numbers of samples. After that, the letters corresponding to the gestures performed are displayed on a computer screen in real time.
Investigation of the Effect of Silica and Phosphorus Content on the Performance of Active Matrix as Component of Cracking Catalyst Gunawan, Melia Laniwati; Rasrendra, Carolus Borromeus; Widikrama, Candra Lutfi; Kurniawan, Rizky Gilang; Nisa, Lita Marina; Hudaya, Farhansyah Yusuf Putra; Makertihartha, I G. B. N.; Subagjo, Subagjo
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.3

Abstract

Fluid catalytic cracking (FCC) is a technique that converts heavy-fraction feed into fuel. The FCC catalyst components consist of a composite material made of zeolite, filler, binder, and an active matrix. The active matrix is used as a pre-cracker for the heavy-fraction feed. This study examined the impact of the Si/Al ratio and the addition of phosphorus on the physical properties and activity of the active matrix. The synthesis technique refers to US patent 6723297 B2. The utilized variants consisted of SiO2 ranging from 50 to 80 weight percent and a phosphorous addition ranging from 1 to 2 weight percent. The physical characteristics of the active matrix were assessed using nitrogen physisorption and NH3-Temperature programmed adsorption/desorption techniques. A chemical activity test was conducted using the micro activity test (MAT) method, with vacuum gas oil (VGO) as the feedstock. This test was done in accordance with the ASTM D 5154 – 03 standard. The results indicated that the silica composition in the active matrix is directly related to the average pore diameter but inversely related to the specific surface area. Additionally, the inclusion of phosphorus had a similar impact. The silica-alumina-phosphorous variant containing 75%-wt of SiO2 exhibited the most superior active matrix activity, achieving the maximum acquisition of light cycle oil (LCO) at 33%-wt.
Experimental Analysis of Pre-Forming Parameters on Abnormalities, Thickness, and Void Content of Glass/Epoxy Composite In VBO-Oven Cure Manufacturing Md Hanafiah, Nur Hafzareen; Othman, Abdul Rahim
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.4

Abstract

Autoclave-based production of composite laminates leads to extended time requirements, increased manufacturing expenses, and the accumulation of significant residual stress. These limitations have spurred research and innovation in seeking alternative out-of-autoclave (OOA) processing methods. The present study aimed to measure the impact of distinct and combined pre-forming parameters within the pre-forming process of vacuum bagging with oven curing (VBO-oven curing) on thickness, abnormalities, and void content in cured laminates of conventional, cost-effective glass/epoxy autoclave composite material. The abnormalities were analyzed using ultrasonic C-scan and thickness measurement was done to determine thickness variations. A burn-off test was employed to measure the void content. The relationship between processing parameters was subsequently investigated via analysis of variance (ANOVA). Higher thickness standard deviation was yielded at higher abnormality percentages in the C-scan results, resembling total discontinuities and non-uniformities. Voids were highest in the laminate produced via the standard pre-forming process. Edge breather, release wax, and intensifier reduced the void content by approximately 11.87%, 12.93% and 6.85%, respectively.
Study on the Stability of Large Retrogressive Landslide and Treatment Technology Jiang, Guan; Feng, Zhongju; Zhao, Ruixin; Chen, Yuanmeng; Liu, Xiaofei
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.5

Abstract

To study the catastrophic mechanisms of retrogressive landslides and assess the stability post treatment, it is essential to examine the internal factors contributing to landslides. This involves a detailed analysis of the characteristics of engineering geology, environmental conditions, and the impact of engineering construction activities on the landslide area. The comprehensive treatment schemes for landslides are determined using deep displacement monitoring and numerical analysis. It has been shown that the process of the landslide mechanism can be divided into four stages, i.e., primary structure breakage, rock mass damage deterioration, rock mass softening in water, and rainfall-induced instability failure. Rock mass damage and rainfall caused by slope excavation are the main causes and inducements of landslide instability. The monitoring results of deep displacement have shown that the sliding surface of a landslide is fully integrated. To mitigate the risk of secondary disasters, this study proposes a comprehensive set of measures based on the mechanisms of landslide instability and the support principle of a compensated traction zone. These measures include the implementation of prestressed anti-slide piles, the application of molten steel pipe grouting, and enhanced drainage techniques. The displacement of the slope was reduced, showing that the treatment scheme had a good reinforcement effect.
Modelling of Sulfur Dioxide Removal by Seawater in a Flue Gas Desulfurization Absorber Dewi, Kania; Andreasen, Anders; Ediansjah, Addina Shafiyya
Journal of Engineering and Technological Sciences Vol. 56 No. 4 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.4.7

Abstract

Although Indonesia has set a target for increasing the use of renewable energy for electricity generation, the use of coal as a source of energy will still dominate at least until 2040. Sulfur dioxide (SO2) along with other gases and particulates released from the use of coal in coal-fired power plants (CFPPs) may cause air pollution. The use of seawater, an abundant source of absorbent in a maritime country such as Indonesia, in flue gas desulfurization (SWFGD) absorbers, is an economical option for treating SO2 in an absorption tower compared to other alkaline chemicals, e.g. limestone (CaCO3) or magnesium hydroxide (Mg(OH)2). A model, which correlates the equilibrium of the reaction with the salinity of the absorbent, was developed to predict the sulfur dioxide scrubbing process inside an SWFGD absorber. The simulation also took into account the mass and energy balance during the scrubbing process. The calibration using field SWFGD data showed a good correspondence between field data and modelling results.
Dynamics Responses of a Block Machine Foundation and a Pile Group Foundation Systems on Stratified Residual Soils in Indonesia by Lumped Mass and Finite Element Methods Susila, Endra; Ary, Wim Ramartsa; Sahadewa, Andhika; Putri, Karina Meilawati Eka; Zulkifli, Ediansjah; Sadono, Kresno Wikan
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.6

Abstract

This paper presents a comprehensive study of the dynamic responses of machine foundations, both block and pile foundations, on stratified residual soils in Duri and Ulubelu, Indonesia. The evaluation was conducted using two widely recognized methods: the lumped mass method (LMM) and the finite element method (FEM). LMM and FEM were performed by utilizing DYNA and ABAQUS, respectively. The analysis results showed that LMM generally predicted more conservative displacements compared to FEM. This conservatism in predicted displacement was more pronounced for pile group foundations, which are inherently more flexible than block foundations. Additionally, this study found that the resonance frequencies obtained through both analysis methods were not the same. Furthermore, this paper includes a parametric study and presents its results to assess the influence of key factors, i.e., pile cap thickness, pile diameter, number of piles, and vertical dynamic loads, on displacement.
Tailoring BiOBr Photocatalyst: In-situ Bi Doping for Enhanced Photocatalytic Removal of Sulfamethoxazole (SMX) Antibiotic Fauziyen, Sabrina Prima; Saputera, Wibawa Hendra; Sasongko, Dwiwahju
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.7

Abstract

There is a notable emphasis on the development of photocatalysts to degrade antibiotics, such as sulfamethoxazole (SMX), in aquatic environments due to their persistence and associated toxicological impacts. In this study, BiOBr photocatalysts were synthesized by incorporating in-situ Bi doping. Various Bi/BiOBr composites were produced through a hydrothermal method at varying temperatures and subsequently characterized using X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), X-ray fluorescence (XRF), and nitrogen adsorption-desorption isotherm. The characterization data revealed that the Bi-metal began to emerge at a hydrothermal temperature of 180 °C (BB180) in the BiOBr-based semiconductor and completed its conversion to Bi-metal at a hydrothermal temperature of 270 °C (BB270). This transformation leads to the generation of Bi3+ in conjunction with oxygen vacancies, acting as active electron traps and enhancing the separation efficiency of light-induced electron-hole pairs. This results in a narrow band gap of Bi/BiOBr photocatalyst, increasing its sensitivity towards visible light. BB180 exhibited the highest photocatalytic rate in the degradation of SMX with a removal efficiency of 74.35% within 4 hours of reaction under Xenon lamp irradiation and an apparent rate constant of 6.5 x 10-3 min-1, surpassing the commercial TiO2 Degussa P25. This finding opens up a new pathway for the development of a catalyst responsive to visible light, specifically designed for the detoxification of antibiotics in wastewater.

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