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Coupling The Capabilities Of Different Complexing Agents Into Deep Eutectic Solvents To Enhance The Separation Of Aromatics From Aliphatics
Faculty of Engineering University of Malaya
(Liquid + liquid) extraction of ethylbenzene from n-octane by using tetrabutylammonium bromide-based deep eutectic solvents (DESs) containing pyridine, ethylene glycol, or a mixture of both complexing agents was investigated at 25 degrees C and atmospheric pressure. The performance of each DES was determined from the distribution ratio and selectivity values calculated using experimental (liquid + liquid) equilibrium data of the ternary systems ethylbenzene + n-octane + DESs. The DES with only ethylene glycol had a high selectivity but a low distribution ratio, whereas the DES with only pyridine had a high distribution ratio but a low selectivity. For the other …
Multi-Response Analysis In The Processing Of Poly (Methyl Methacrylate) Nano-Fibres Membrane By Electrospinning Based On Response Surface Methodology: Fibre Diameter And Bead Formation
Faculty of Engineering University of Malaya
The fabrication of the nano-scale fine fibres from poly (methyl methacrylate) (PMMA)-DMF solution was completed using the electrospinning process. Significantly, fibre membranes with an average diameter of 95 (+/- 32) nm and bead number 11 (+/- 2) were successfully achieved. The extensive analysis of the distribution of fibre diameters and bead formation was performed using different needle gauge, collector distance, voltage, concentration, feed rate and molecular weight by observing images in FESEM after explanation of regression. A regression model was applied to realize the dominant factors on the responses, from this model, the molecular weight was excluded to successfully obtain …
Performance Enhancement Of A Flat Plate Solar Collector Using Titanium Dioxide Nanofluid And Polyethylene Glycol Dispersant
Faculty of Engineering University of Malaya
The use of TiO2 water nanofluid as a working fluid for enhancing the performance of a flat plate solar collector has been studied. The volume fraction of the nanoparticles was 0.1% and 0.3% respectively, while the mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min, respectively. Thermo-physical properties and reduced sedimentation for TiO2-nanofluid was obtained using PEG 400 dispersant. The results reveal the impact and importance of each of these parameters. Energy efficiency increased by 76.6% for 0.1% volume fraction and 0.5 kg/min flow rate, whereas the highest exergy efficiency achieved was 16.9% for 0.1% volume fraction …
Production Of Greenhouse Gas Free Hydrogen By Thermocatalytic Decomposition Of Methane – A Review
Production Of Greenhouse Gas Free Hydrogen By Thermocatalytic Decomposition Of Methane – A Review
Faculty of Engineering University of Malaya
Thermocatalytic decomposition of methane (TCD) is a fully green single step technology for producing hydrogen and nano-carbon. This review studying all development in laboratory-scale research on TCD, especially the recent advances like co-feeding effect and catalyst regeneration for augmenting the productivity of the whole process. Although a great success on the laboratory-scale has been fulfilled, TCD for greenhouse gas (GHG) free hydrogen production is still in its infancy. The need for commercialization of TCD is greater than ever in the present situation of huge GHG emission. TCD usually examined over various kind of catalysts, such as monometallic, bimetallic, trimetallic, combination …
Using Finite State Machine And A Hybrid Of Eeg Signal And Eog Artifacts For An Asynchronous Wheelchair Navigation
Faculty of Engineering University of Malaya
In this study, an asynchronous wheelchair navigation system using a hybrid of EEG signal and EOG artifacts embedded in EEG signals is demonstrated. The EEG signals are recorded at three different locations on the scalp in the occipital and motor cortex regions. First, an EEG signal related to eyelid position is analyzed and used to determine whether the eyes are closed or open. If the eyes are closed, no wheelchair movement is allowed. If the eyes are open, EOG traces (artifacts) from two other EEG signals are examined to infer the gaze direction of the eyes. A sliding window is …
The Thermoluminescence Characteristics And The Glow Curves Of Thulium Doped Silica Fiber Exposed To 10 Mv Photon And 21 Mev Electron Radiation
Faculty of Engineering University of Malaya
The thermoluminescence (TL) glow curves and kinetics parameters of Thulium (Tm) doped silica cylindrical fibers (CF) are presented. A linear accelerator (LINAC) was used to deliver high-energy radiation of 21 MeV electrons and 10 MV photons. The CFs were irradiated in the dose range of 0.2-10 Gy. The experimental glow curve data was reconstructed by using WinREMS. The WinGCF software was used for the kinetic parameters evaluation. The TL sensitivity of Tm-doped silica CF is about 2 times higher as compared to pure silica CF. Tm-doped silica CF seems to be more sensitive to 21 MeV electrons than to 10 …
Enhanced Sonocatalytic Treatment Of Ibuprofen By Mechanical Mixing And Reusable Magnetic Core Titanium Dioxide
Faculty of Engineering University of Malaya
As a reusable sonocatalyst, magnetically separable titanium dioxide (MST) was synthesized by a sol-gel method and was evaluated in the removal of ibuprofen (IBP). MST was carefully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N-2 gas isotherms, band-gap energy, magnetization, zeta potential, and particle size distribution. The kinetics of IBP removal by sonolysis or MST-assisted sonocatalysis was systematically evaluated with various operational parameters such as pH, temperature, ultrasound (US) frequency, and mechanical mixing intensity. For the first time, authors found that mechanical mixing had an opposite effect on the oxidation rate constants of IBP removal by sonolysis …
Robust Control-Based Linear Bilateral Teleoperation System Without Force Sensor
Robust Control-Based Linear Bilateral Teleoperation System Without Force Sensor
Faculty of Engineering University of Malaya
Among the prevalent methods in linear bilateral teleoperation systems with communication channel time delays is to employ position and velocity signals in the control scheme. Utilizing force signals in such controllers significantly improves performance and reduces tracking error. However, measuring force signals in such cases, is one of the major difficulties. In this paper, a control scheme with human and environment force signals for linear bilateral teleoperation is proposed. In order to eliminate the measurement of forces in the control scheme, a force estimation approach based on disturbance observers is applied. The proposed approach guarantees asymptotic estimation of constant forces, …
Bit-Depth Scalable Lossless Coding For High Dynamic Range Images
Bit-Depth Scalable Lossless Coding For High Dynamic Range Images
Faculty of Engineering University of Malaya
In this paper, we propose a bit-depth scalable lossless coding method for high dynamic range (HDR) images based on a reversible logarithmic mapping. HDR images are generally expressed as floating-point data, such as in the OpenEXR or RGBE formats. Our bit-depth scalable coding approach outputs base layer data and enhancement layer data. It can reconstruct the low dynamic range (LDR) image from the base layer data and reconstructs the HDR image by adding the enhancement layer data. Most previous two-layer methods have focused on the lossy coding of HDR images. Unfortunately, the extension of previous lossy methods to lossless coding …
Optimizing The Robot Arm Movement Time Using Virtual Reality Robotic Teaching System
Optimizing The Robot Arm Movement Time Using Virtual Reality Robotic Teaching System
Faculty of Engineering University of Malaya
Robots play an important role in performing operations such as welding, drilling and screwing parts in manufacturing. Optimizing the robot arm movement time between different points is an important task which will minimize the make-span and maximize the production rate. But robot programming is a complex task whereby the user needs to teach and control the robot in order to perform a desired action. In order to address the above problem, an integrated 3-dimensional (3D) simulation software and virtual reality (VR) system is developed to simplify and speed up tasks and therefore enhance the quality of manufacturing processes. This system …
Ceiba Pentandra, Nigella Sativa And Their Blend As Prospective Feedstocks For Biodiesel
Ceiba Pentandra, Nigella Sativa And Their Blend As Prospective Feedstocks For Biodiesel
Faculty of Engineering University of Malaya
There are more than 350 oil-bearing crops identified as potential sources for biodiesel production around the globe. The wide range of available feedstocks for biodiesel production represents one of the most significant factors for producing biodiesel. The current research work is carried out on fuel properties of biodiesel prepared from the non-edible oils of Ceiba pentandra, Nigella sativa and their mixture. N. sativa is believed to be investigated for the first time as a biodiesel feedstock while C. pentandra has been reported recently in few studies. Owing to higher acid value, acid-esterification and alkali-transesterification processes have been carried out for …
Stiffness Performance Of Polyethylene Terephthalate Modified Asphalt Mixtures Estimation Using Support Vector Machine-Firefly Algorithm
Faculty of Engineering University of Malaya
Predicting asphalt pavement performance is an important matter which can save cost and energy. To ensure an accurate estimation of performance of the mixtures, new soft computing techniques can be used. In this study, in order to estimate the stiffness property of Polyethylene Terephthalate (PET) modified asphalt mixture, different soft computing methods were developed, namely: support vector machine-firefly algorithm (SVM-FFA), genetic programming (GP), artificial neural network (ANN) and support vector machine. The support vector machine-firefly algorithm (SVM-FFA) is a metaheuristic search algorithm developed according to the socially dashing manners of fireflies in nature. To develop the models, experiments were performed. …
Removal Of Heavy Metal Ions From Mixed Solutions Via Polymer-Enhanced Ultrafiltration Using Starch As A Water-Soluble Biopolymer
Faculty of Engineering University of Malaya
In this study, aqueous solutions containing mixtures of heavy metals namely Zn (II), Pb (II), Cr (III), and Cr (VI) were treated by polymer-enhanced ultrafiltration (PEUF) using unmodified starch as binding biopolymer. The performance of starch in removing these heavy metals was compared with that of polyethylene glycol (PEG) a commonly used polymer in PEUF processes. Rejection coefficients and flux were studied under different values of pH solution and metal ion concentrations maintaining the transmembrane pressure constant at 1.5 bar. At pH 7, and starch concentration of 0.05%, the rejection was the highest at around 90%. As metal ion concentration …
A New Low-Profile Inverted A-Shaped Patch Antenna For Multi-Band Operations
A New Low-Profile Inverted A-Shaped Patch Antenna For Multi-Band Operations
Faculty of Engineering University of Malaya
This paper presents the design and analysis of a compact modified inverted-A shape multi-band patch antenna for WiMAX and C-band telecommunication satellite applications. The proposed antenna has simple geometrical structure which consist of 20 mm x 20 mm radiating patch with slot loading and fed by 4 mm long microstrip line. The proposed antenna is designed and analyzed by using commercially available full-wave 3D high frequency electromagnetic simulator namely Ansys HFSS. The optimized design of the proposed multi-band patch antenna is fabricated on 1.6 mm thick fiberglass polymer resin dielectric material substrate with reduced ground plane by using in-house PCB …
Effect Of Tool Rotational Speed On Force Generation, Microstructure And Mechanical Properties Of Friction Stir Welded Al-Mg-Cr-Mn (Aa 5052-O) Alloy
Faculty of Engineering University of Malaya
Friction stir welding (FSW) between 3 mm thick AA 5052-O aluminum alloy plates was investigated in the present study. Different welded specimens were produced by employing a constant tool traverse speed of 120 mm/min and by varying rotating speeds from 800 to 3000 rpm. The welded joints were characterized by its appearances, microstructural and mechanical properties at room temperature. The measurement of different forces acted on the tool during the FSW of AA 5052-O plates provided a significant insight to determine the quality of the welded joints. From the appearances of the welded joints it was evident that, except the …
Fuzzy Logic Based Model For Predicting Surface Roughness Of Machined Al-Si-Cu-Fe Die Casting Alloy Using Different Additives-Turning
Faculty of Engineering University of Malaya
This paper presents a fuzzy logic artificial intelligence technique for predicting the machining performance of Al-Si-Cu-Fe die casting alloy treated with different additives including strontium, bismuth and antimony to improve surface roughness. The Pareto-ANOVA optimization method was used to obtain the optimum parameter conditions for the machining process. Experiments were carried out using oblique dry CNC turning. The machining parameters of cutting speed, feed rate and depth of cut were optimized according to surface roughness values. The results indicated that a cutting speed of 250 m/min, a feed rate of 0.05 mm/rev, and a depth of cut of 0.15 mm …
Investigating The Machinability Of Al-Si-Cu Cast Alloy Containing Bismuth And Antimony Using Coated Carbide Insert
Faculty of Engineering University of Malaya
Surface roughness and cutting force are two key measures that describe machined surface integrity and power requirement evaluation, respectively. This investigation presents the effect of melt treatment with addition of bismuth and antimony on machinability when turning Al-11% Si-2% Cu alloy. The experiments are carried out under oblique dry cutting conditions using a PVD TIN-coated insert at three cutting speeds of 70, 130 and 250 m/min, feed rates of 0.05, 0.1, 0.15 mm/rev, and 0.05 mm constant depth of cut. It was found that the Bi-containing workpiece possess the best surface roughness value and lowest cutting force due to formation …
Pangium Edule Reinw: A Promising Non-Edible Oil Feedstock For Biodiesel Production
Pangium Edule Reinw: A Promising Non-Edible Oil Feedstock For Biodiesel Production
Faculty of Engineering University of Malaya
Biodiesel production from non-edible feedstocks is currently drawing much attention due to legitimate concerns about the effects of using edible oil for fuel. Pangium edule Reinw is a non-edible feedstock. Pangium is a tall tree native to the Micronesia, Melanesia and the mangrove swamps of South-East Asia. In this study, biodiesel production and characterization from P. edule oil was reported. The seeds were obtained from Bogor, Indonesia. The oil was found to have an acid value of 19.62 mg KOH/g oil. Therefore, a two-step acid-base-catalysed transesterification was used to produce biodiesel. This was followed by evaluating the physical and chemical …
Oil Filter Modification For Biodiesel-Fueled Engine: A Pathway To Lubricant Sustainability And Exhaust Emissions Reduction
Faculty of Engineering University of Malaya
The widespread use of biodiesel in internal combustion engines promotes frequent lubricant drain intervals which in turn affects lubricant sustainability and engine performance. In this research two endurance tests were carried out to evaluate the novel approach of strong base oil filter with palm biodiesel (PME) fueled single-cylinder diesel engine. The effects of strong base filter on lubricant rheology, piston ring! cylinder wear losses, engine performance and exhaust emissions were investigated. The results of long duration engine testing showed that the strong base filter improved the lubricant's physical and tribological characteristics. Tribo-testing, using high stroke reciprocating test rig, proved that …
Affect Classification Using Genetic-Optimized Ensembles Of Fuzzy Artmaps
Affect Classification Using Genetic-Optimized Ensembles Of Fuzzy Artmaps
Faculty of Engineering University of Malaya
Training neural networks in distinguishing different emotions from physiological signals frequently involves fuzzy definitions of each affective state. In addition, manual design of classification tasks often uses sub-optimum classifier parameter settings, leading to average classification performance. In this study, an attempt to create a framework for multi-layered optimization of an ensemble of classifiers to maximize the system's ability to learn and classify affect, and to minimize human involvement in setting optimum parameters for the classification system is proposed. Using fuzzy adaptive resonance theory mapping (ARTMAP) as the classifier template, genetic algorithms (GAs) were employed to perform exhaustive search for the …
Theoretical Modelling Of Momentum Transfer Function Of Bi-Disperse Porous Media
Theoretical Modelling Of Momentum Transfer Function Of Bi-Disperse Porous Media
Faculty of Engineering University of Malaya
The aim of this paper is to obtain the momentum transfer coefficient between the two phases, denoted by f and p, occupying a bi-disperse porous medium by mapping the available experimental data to the theoretical model proposed by Nield and Kuznetsov [1]. Data pertinent to plate-fin heat exchangers, as bi-disperse porous media, were used. The measured pressure drops for such heat exchangers are then used to give the overall permeability which is linked to the porosity and permeability of each phase as well as the interfacial momentum transfer coefficient between the two phases. Accordingly, numerical values are obtained for the …
Basic Effects Of Pulp Refining On Fiber Properties-A Review
Basic Effects Of Pulp Refining On Fiber Properties-A Review
Faculty of Engineering University of Malaya
The requirement for high quality pulps which are widely used in paper industries has increased the demand for pulp refining (beating) process. Pulp refining is a promising approach to improve the pulp quality by changing the fiber characteristics. The diversity of research on the effect of refining on fiber properties which is due to the different pulp sources, pulp consistency and refining equipment has interested us to provide a review on the studies over the last decade. In this article, the influence of pulp refining on structural properties i.e., fibrillations, fine formation, fiber length, fiber curl, crystallinity and distribution of …
Effect Of Spatial Inlet Velocity Profiles On The Vortex Formation Pattern In A Dilated Left Ventricle
Faculty of Engineering University of Malaya
Despite the advancement of cardiac imaging technologies, these have traditionally been limited to global geometrical measurements. Computational fluid dynamics (CFD) has emerged as a reliable tool that provides flow ?eld information and other variables essential for the assessment of the cardiac function. Extensive studies have shown that vortex formation and propagation during the filling phase acts as a promising indicator for the diagnosis of the cardiac health condition. Proper setting of the boundary conditions is crucial in a CFD study as they are important determinants, that affect the simulation results. In this article, the effect of different transmitral velocity profiles …
Estimation Of The Effect Of Catalyst Physical Characteristics On Fenton-Like Oxidation Efficiency Using Adaptive Neuro-Fuzzy Computing Technique
Faculty of Engineering University of Malaya
Catalyst size, which determines surface area, is one of the major factors in catalytic performance. In this study, response surface methodology (RSM) and an adaptive neuro-fuzzy inference system (ANFIS) were applied to quantify the effects of physical characteristics of magnetite on Fenton-like oxidation efficiency of methylene blue. For this purpose, two magnetite samples (M and N) were used and characterized by XRD, BET surface area, particle size analyzer and FE-SEM. Central composite design (CCD) was applied to design the experiments, develop regression models, optimize and evaluate the individual and interactive effects of five independent variables: H2O2 and catalyst concentrations, pH, …
Influences Of Flame-Retardant Fillers On Fire Protection And Mechanical Properties Of Intumescent Coatings
Faculty of Engineering University of Malaya
A combination of acrylic binder and flame-retardant ingredients was used to synthesize the solvent-borne intumescent coatings designed for steel substrates. The influences of individual and various combinations of flame-retardant fillers on the fire protection and mechanical properties of the coatings were characterized by using Bunsen burner, thermogravimetric analysis, limiting oxygen index, field emission scanning electron microscopy, freeze thaw cycles, static immersion and pull-off type equipment. It was found that the combination of aluminium hydroxide (Al(OH)(3)) and titanium dioxide (TiO2) has significantly improved the fire protection, thermal stability and water resistance of the coating. This formulation had an LOI value of …
A Dft Study On An Alkali Atom Doped Decahedral Silver Nanocluster For Potential Application In Opto-Electronics And Catalysis
Faculty of Engineering University of Malaya
A systematic study of the structural, electronic and optical properties of the decahedral bimetallic Ag12X cluster is presented in the framework of density functional theory (DFT), where one atom of an alkali metal (X = Li, Na, K, Rb, Cs, Fr) is added, replacing a Ag atom in the decahedral Ag-13 cluster in core (c-doped), vertex (v-doped) and surface (s-doped) positions. Geometrical optimization of the clusters indicated that Li and Na doped clusters exhibited the highest stability. The binding energy (BE), vertical ionization potential (VIP), vertical electron affinity (VEA) and HOMO-LUMO gaps were calculated to compare the electronic stability and …
Comparative Evaluation Of The Blends Of Gas-To-Liquid (Gtl) Fuels And Biodiesels With Diesel At High Idling Conditions: An In-Depth Analysis On Engine Performance And Environment Pollutants
Faculty of Engineering University of Malaya
This study focuses on the physicochemical fuel characteristics and engine performance-emission features of three prospective alternative transportation fuels: Alexandrian laurel biodiesel (ALBD), jatropha biodiesel (JBD) and GTL fuel at high idling conditions. The blends of GTL fuel (G10, G20), JBD (J10, J20) and ALBD (AL10, AL20) with diesel had been investigated in a multi-cylinder diesel engine at different load-speed conditions. Analysis of the fuel properties showed a linear variation of the major fuel properties with an increase of alternative fuel quantity in the blends. Engine performance test results revealed an average decrease of brake specific fuel consumption (BSFC) (ca. 8.65-12.26%) …
Application Of Colloidal Gas Aphron Suspensions Produced From Sapindus Mukorossi For Arsenic Removal From Contaminated Soil
Faculty of Engineering University of Malaya
Colloidal gas aphron dispersions (CGAs) can be described as a system of microbubbles suspended homogenously in a liquid matrix. This work examines the performance of CGAs in comparison to surfactant solutions for washing low levels of arsenic from an iron rich soil. Sodium Dodecyl Sulfate (SDS) and saponin, a biodegradable surfactant, obtained from Sapindus mukorossi or soapnut fruit were used for generating CGAs and solutions for soil washing. Column washing experiments were performed in down-flow and up flow modes at a soil pH of 5 and 6 using varying concentration of SDS and soapnut solutions as well as CGAs. Soapnut …
Intermixing Reactions In Electrodeposited Cu/Sn And Cu/Ni/Sn Multilayer Interconnects During Room Temperature And High Temperature Aging
Faculty of Engineering University of Malaya
Current push for miniaturization and 3D packaging makes it important to understand reactions in interconnects with ultra small volume. In order to reduce processing time and to have more homogeneous interconnects, solder can be designed in a multilayer form with components layer thickness in the sub-micron or even nanometer range. In this work, reaction kinetics in multilayer interconnects consisting stacks of Cu/Sn/Cu and Cu/Ni/Sn/Ni/Sn deposited by electrodeposition were investigated at room temperature and 150 A degrees C. The progress of the reaction in the multilayers was monitored by using XRD, SEM and EDX. Results show that by inserting a 70 …