IIUM Engineering Journal
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DESIGN AND ANALYSIS OF AN AERODYNAMIC DOWNFORCE PACKAGE FOR A FORMULA STUDENT RACE CAR
Get PDFThis paper presents design of aerodynamic downforce generating devices (front wing, rear wing and diffuser) to enhance the performance of the Formula Student Race Car using numerical and experimental studies. Numerical results using computational fluid dynamics (CFD) studies were primarily validated with the experimental results performed in the wind tunnel. It was concluded that the use of a downforce package can enhance the performance of the vehicle in the competition
A COMPARATIVE ANALYSIS OF EFFECT OF TEMPERATURE ON BAND-GAP ENERGY OF GALLIUM NITRIDE AND ITS STABILITY BEYOND ROOM TEMPERATURE USING BOSE–EINSTEIN MODEL AND VARSHNI’S MODEL
Get PDFHigh temperature stability of band-gap energy of active layer material of a semiconductor device is one of the major challenges in the field of semiconductor optoelectronic device design. It is essential to ensure the stability in different band-gap energy dependent characteristics of the semiconductor material used to fabricate these devices either directly or indirectly. Different models have been widely used to analyze the band-gap energy dependent characteristics at different temperatures. The most commonly used methods to analyze the temperature dependence of band-gap energy of semiconductor materials are: Passler model, Bose–Einstein model and Varshni’s model. This paper is going to report the limitation of the Bose–Einstein model through a comparative analysis between Bose–Einstein model and Varshni’s model. The numerical analysis is carried out considering GaN as it is one of the most widely used semiconductor materials all over the world. From the numerical results it is ascertained that below the temperature of 95o K both the models show almost same characteristics. However beyond 95o K Varshni’s model shows weaker temperature dependence than that of Bose–Einstein model. Varshni’s model shows that the band-gap energy of GaN at 300o K is found to be 3.43eV, which establishes a good agreement with the theoretically calculated band-gap energy of GaN for operating at room temperature
RECEIVER OPERATING CHARACTERISTICS MEASURE FOR THE RECOGNITION OF STUTTERING DYSFLUENCIES USING LINE SPECTRAL FREQUENCIES
Get PDFStuttering is a motor-speech disorder, having common features with other motor control disorders such as dystonia, Parkinson’s disease and Tourette’s syndrome. Stuttering results from complex interactions between factors such as motor, language, emotional and genetic. This study used Line Spectral Frequency (LSF) for the feature extraction, while using three classifiers for the identification purpose, Multilayer Perceptron (MLP), Recurrent Neural Network (RNN) and Radial Basis Function (RBF). The UCLASS (University College London Archive of Stuttered Speech) release 1 was used as database in this research. These recordings were from people of ages 12y11m to 19y5m, who were referred to clinics in London for assessment of their stuttering. The performance metrics used for interpreting the results are sensitivity, accuracy, precision and misclassification rate. Only M1 and M2 had below 100% sensitivity for RBF. The sensitivity of M1 was found to be between 40 & 60%, therefore categorized as moderate, while that of M2 falls between 60 & 80%, classed as substantial. Overall, RBF outperforms the two other classifiers, MLP and RNN for all the performance metrics considered
RECOVERY OF THE BIOLOGICAL ACTIVE COMPOUNDS OF Musa Sp. THROUGH MICROWAVE ASSISTED EXTRACTION
Get PDFThe objective of this research was to identify the recovery of the biological active compound of Musa sp. thru microwave assisted extraction (MAE) system. Antioxidant activity and phenolic compound were investigated on the effect of temperature, microwave power, irradiation time and solid to liquid ratio. The extraction process was carried out using only distilled water as an extracting agent. The result showed that, at 70oC fresh Musa sp. extracted 45% higher antioxidant compared to the dried Musa sp. 500 W was the best power of MAE to extract antioxidant and phenolic compound of ripe Musa sp., while for unripe Musa sp. 800 W was the best. The best irradiation time was 90 s, where it extracted almost 90% antioxidant activity of ripe and unripe Musa sp. Almost 480 mg GA/100 g FW of total phenolic content was extracted on the unripe peel. Solid to liquid ratio of 3 : 60 was the best parameter to extract antioxidant and phenolic content of ripe and unripe Musa sp. Overall, antioxidant and phenolic compound were significantly higher in the unripe peel, followed by ripe peel, unripe pulp and ripe pulp
EFFECT OF MINIMUM QUANTITY LUBRICATION ON SURFACE ROUGHNESS IN TOOL-BASED MICROMILLING
Get PDFCutting fluid plays an important role in machining processes to achieve dimensional accuracy in reducing tool wear and improving the tool life. Conventional flood cooling method in machining processes is not cost effective and consumption of huge amount of cutting fluids is not healthy and environmental friendly. In micromachining, flood cooling is not recommended to avoid possible damage of the microstructures. Therefore, one of the alternatives to overcome the environmental issues to use minimum quantity of lubrication (MQL) in machining process. MQL is eco-friendly and has economical advantage on manufacturing cost. However, there observed lack of study on MQL in improving machined surface roughness in micromilling. Study of the effects of MQL on surface roughness should be carried out because surface roughness is one of the important issues in micromachined parts such as microfluidic channels. This paper investigates and compares surface roughness with the presence of MQL and dry cutting in micromilling of aluminium alloy 1100 using DT-110 milling machine. The relationship among depth of cut, feed rate, and spindle speed on surface roughness is also analyzed. All three machining parameters identified as significant for surface roughness with dry cutting which are depth of cut, feed rate, and spindle speed. For surface roughness with MQL, it is found that spindle speed did not give much influence on surface roughness. The presence of MQL provides a better surface roughness by decreasing the friction between tool and workpiece
Optimal Allocation of Active Power Filter On real distribution network for improvement of power quality by use of BBO: A case study
Get PDFABSTRACT: According to development of power electronics device, harmonic distortion spread on the network. Thus harmonic is a threat for instrument, network, decreasing of line capacity and etc. Active power ï¬lter (APF) can be employed for harmonic compensation in power systems. In this paper a distorted distribution feeder is considered and analyzed from power quality viewpoint using power analyzer device and simulated in MATLAB-Mfile. Then the size and place of active power filters are determined by use of Biogeography Based Optimization (BBO). The goal of this optimization is minimizing of losses and total harmonic distortion (THD) in feeder by considering economical cost. The performance of the approaches are assessed and appreciated by a case study on the Ghaemshahr-Iran Distribution network. Measurement is done on the city network by power analyzer CA8310. All data was collected on Computer. Then researcher algorithm BBO, it is selected the best place and size for Active power filter. The results show a good performance
RPL LOAD BALANCING IN INTERNET OF THINGS
Get PDFABSTRACT:Â The wide address space provided by Internet Protocol version 6 (IPv6) lets any thing to be identified uniquely. consistency of the modified version of IPv6 protocol stack with smart objects, facilitated the Internet interconnection of the networks of smart objects and introduced Internet of things. A smart object is a small micro-electronic device that consists of a communication device, a small microprocessor and a sensor or an actuator. A network made of such devices is called low-power and lossy network. RPL routing protocol that is consistent to IPv6, is designed to be used in these kinds of networks. Load balancing is not considered in the RPL design process. Whenever RPL is used in large scale low-power and lossy networks some nodes will suffer from congestion and this problem severely degrades network performance. In this paper, we consider solutions provided to tackle RPL load balancing problems. Load balancing algorithms and protoclos are evaluated through simulation. We evaluate IETF RPL implementation and LB-RPL method with Contiki OS Java (COOJA) simulator. They are assessed comprehensively through metrics such as Packet delivery Ratio, Average End to End delay, and Gateway Throughput. LB-RPL improves RPL in terms of Packet delivery Ratio and throughput but increases Average End to End delay. Simulations results show that RPL load balancing needs extensive works to be performed yet
FIXED-BED ADSORPTION OF AQUEOUS VANILLIN ONTO RESIN H103
Get PDFThe main objective of this work was to design and model fixed bed adsorption column for the adsorption of vanillin from aqueous solution. Three parameters were evaluated for identifying the performance of vanillin adsorption in fixed-bed mode, which were bed height, vanillin initial concentration, and feed flow rate. The maximum adsorption capacity was increased more than threefold to 314.96 mg vanillin/g resin when the bed height was increased from 5 cm to 15 cm. Bohart-Adams model and Belter equation were used for designing fixed-bed column and predicting the performance of the adsorption process. A high value of determination coefficient (R2) of 0.9672 was obtained for the modelling of vanillin adsorption onto resin H103
STUDY OF DIFFERENT TREATMENT METHODS ON CHICKEN FEATHER BIOMASS
Get PDFThe chicken feathers (CFs)  consist of up to 10 % of total chicken dry mass and they have many potential industrial applications. CFs contains protein fibers named as keratin, which is an insoluble protein. Primary sanitization phases are complex because of the presence of lots of blood born microbes, pathogens and parasites in raw biomass. The extraction process of keratins from the unprocessed feathers is also a challenging task. Prior to the extraction cleaning/sanitization of feathers is a very necessary step. Thus, the present work was conducted to optimize  an efficient surfactant for the cleaning process of the  CFs by using ionic and non-ionic surfactants. The experiment was conducted by the washing of feathers with double distilled water (ddH2O), detergents, ether and lastly with boiling water. The washed feathers treated with surfactants and the effect of each surfactant was analyzed by a microbiological test which tells about the extent of  the presence of different bacteria on the treated feathers. SEM, EDX, FTIR were used to study the morphology and composition of  untreated and treated CFs. SEM showed there was no detectable fiber damage after treatment. Cetrimonium bromide (CTAB) (t3) was one of the best surfactant for the treatment of CFs among all the surfactant used. The present study described the best treatment method  for the CFs.Â