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- PublicationThermal design of the electronic equipment enclosures by forced air cooling(2023-08-07)This study was focused on the computational evaluation of the heat dissipation of a parallel plate heat sink by using Computational Fluid Dynamics (CFD). The software that has been used in the study is ANSYS Fluent 2022 R2. The parallel plate heat sink was made up of Aluminium-alloy 6063 and it is being subjected to the ambient conditions of 1.01 kPa and 25 ℃. In addition, a constant heat flux of 1200 W/m2 is applied at the bottom of the parallel plate heat sink, and the heat sink is forced to conduct forced air convection with an inlet air velocity of 1.1088 m/s (Re = 2130). Beside study the effect of geometry factor to the thermal performance of heat sink, the validation of simulation model also has been done by comparing the simulation results with the experiment results. To perform the validation, the simulation model used in this study is created based on the experiment model getting from a journal. Consequently, this simulation model was used for the study of effect of geometry factor to the thermal performance of heat sink. Next, the influences of the fin height and fin pitch on the thermal performance of the heat sink are studied by using a parametric study. The average Nusselt number is calculated by using the average temperature of the heat sink's bottom surface (also known as the heater surface), which is obtained from the results of the simulation. The results show that the heat sink with a larger fin height and smaller fin pitch has a better thermal performance. This study offers a thorough understanding of the relationship between fin height and fin pitch and heat sink thermal performance.
- PublicationDevelopment of shell eco challenge ev drivetrain(2023-07-24)The Shell Eco-Marathon (SEM) is a renowned global eco-racing competition that challenges students like us at Universiti Sains Malaysia (USM) to design, build, and race vehicles with a focus on achieving the best fuel or electric economy. SEM consists of three regional divisions, namely America, Europe, and Asia, with the upcoming SEMA 2023 hosted at the Pertamina Mandalika International Street Circuit in Lombok, Indonesia. As participants from USM, we actively engage in the SEM Urban Concept category, targeting vehicles designed to meet traditional four-wheel roadworthiness standards. We, as part of the USM team, compete against other universities to develop innovative solutions that balance environmental consciousness with practicality. Our goal is to design vehicles capable of maximizing energy efficiency while meeting essential roadworthy requirements. As we represent USM in the Shell Eco-Marathon, we strive to extract the maximum distance from a single charge, utilizing our expertise and ingenuity to optimize energy usage. By leveraging cutting-edge technologies, applying aerodynamic designs, employing lightweight materials, and utilizing advanced powertrains, we aim to enhance the efficiency and sustainability of urban mobility. The Shell Eco-Marathon serves as a valuable educational project for us at USM, motivating engineering students to explore and innovate in sustainable mobility and energy efficiency. As part of our involvement in the competition, we collaborate, problem-solve, and develop groundbreaking solutions that address current and future transportation and energy challenges. By participating in the SEM, we proudly represent USM, contributing to a greener future and promoting environmental stewardship through sustainable urban transportation systems.
- PublicationThermal fluid-structure interaction study on copper pillar solder bump during reflow soldering process(2023-07)There are numerous interconnect technologies in the field of electronic packaging which help to enhance the reliability of the interconnection of the package. Copper pillar bump is a new interconnect technology introduced in the flip chip industry. The goal of this study was to investigate the effects of different copper pillar bump heights and soldering materials on temperature distributions, total deformation, and von-Mises stress during reflow soldering process. The reflow oven environment was simulated using the fluid domain of the oven model. A grid independence test was carried out on the fluid mesh to determine the optimal mesh model for the simulations. In addition, a reflow experiment was conducted based on the JEDEC Standard to verify the accuracy of the fluid analysis by comparing the obtained results with experimental data. A thermal fluid-structure interaction (FSI) approach was employed to couple the thermal results from the fluid analysis with the solid assembly for structural analysis. The five different copper pillar heights (0.07mm, 0.09mm, 0.11mm, 0.13mm, and 0.15mm) were simulated through FSI approach in ANSYS. The results of the coupling analysis revealed that copper pillar bumps with a height of 0.09 mm exhibited the lowest reflow temperature, minimal maximum total deformation, and von-Mises stress, indicating that it is the most potential height for forming a good interconnection. The study also examined the effects of three different soldering materials (SAC305, SAC405, and SnBi) on the copper pillar bump. The results show that there is no significant difference in the deformation and von-Mises stress behaviours of the copper pillar bumps between the soldering materials. The study also suggested SnBi solder material as a better solder material in terms of costing and technical performance. Overall, this study enables a comprehensive analysis of the thermal and mechanical performances of different copper pillar bump parameters during the reflow process.
- PublicationEffect of pressure, temperature and orifice sizing on the vibration and actuation speed of the transfer valve under different operating conditions Chin, Jun Hong(2023-07-07)The transfer valve studied in this project is provided by VAT Manufacturing Malaysia Sdn Bhd. The condition that might affected the performance of transfer valve included the operating temperature, transfer valve's mounting orientation, setting pressure, gate size, and orifice size of the set screw mounted to the valve. Hence, this study investigates the effect of stated parameters on the vibration and actuation speed of the valve under all possible operating conditions. Experimental Modal Analysis (EMA) has been conducted to study the relationship between natural frequency and vibration of the valve gates. A custom made adapter and wireless accelerometer were used for the vibration measurements. The actuation speed of the transfer valve was recorded using a position indicator and customized NI software. The experiment covered all the possible combinations of operating conditions for the valve. This study successfully investigated the natural frequency of small-sized and large-sized gates in a valve system. The study also demonstrated that increasing the operating temperature will increase the vibration and actuation speed of the valve, while the influence of setting pressure on vibration was fluctuated. The opening operation of the valve took longer time than the closing operation due to the linear motion mechanism, and the actuation speed for closing operation increased with the temperature. The impact of setting pressure on actuation time was minimal, and an the increment of the orifice size led to the increased of vibration due to higher volume flow rates and impulsive forces. Future studies can involve Operation Deflection Shape (ODS) analysis to investigate the relationship between recorded vibration frequencies and operating conditions of the valve gates. Increasing the number of cycles, repeating experiments, and expanding the range of orifice sizes for the set screw would provide more comprehensive data for the analysis.
- PublicationA classification model on types of cycling based on cycling behavior(2023-07-14)Cycling has gained popularity as a form of exercise, and individuals use various cycling techniques and habits depending on their interests. On the basis of cycling behavior, there has been little study on classification models for different types of cycling. Therefore, the goal of this project is to create a supervised learning approach to categorize different cycling kinds using data on cycling performance behavior. In order to categorize different types of cycling based on cycling behavior, this study compares the performance of several classification algorithms at 10-fold cross validation mode, including BayesNet, SMO, IBk, KStar, RandomizableFilteredClassifier, and RandomTree, on two case studies taken from publicly available data. For CS1 and CS2, respectively, the baseline classifier, ZeroR, is 51.52% and 38.64%. CS1 was typically accurately identified using a variety of methods, including BayesNet, SMO, IBk, and RandomTree. IBk and KStar, with a maximum accuracy of 71.59%, are the algorithms that demonstrate the highest accuracy for CS2. The results help us understand cycling activities better, making it easier for cyclists to develop individualized training plans and make decisions in a variety of settings
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- ItemFluks nutrien dan sedimen di Lembangan Sungai Merbok, Kedah.(Universiti Sains Malaysia, 2017)Kajian ini adalah untuk menganggarkan fluks beban nutrien dan sedimen di Lembangan Sungai Merbok. Pengumpulan data dan aktiviti persampelan dilakukan secara berskala iaitu dua minggu sekali dan dijalankan bermula dari Disember 2012 hingga Disember 2013 yang melibatkan sungai utama Merbok serta cawangannya. This study was conducted to investigate and estimate the flux of nutrient and sediment load in Merbok River basin. Data collection and sampling activities were carried out once in two weeks starting from December 2012 to December 2013 involving the main river of Sungai Merbok and it’s tributaries.
- ItemPreparation and characterization of poly (L-Lactic acid plla) blends and plla scaffold.(Universiti Sains Malaysia, 2011-02)Pengoptimunan gaulan poli(L-laktik asid) (PLLA) telah dihasilkan melalui pengaulan polimer bio liat seperti poli(kaprolakton) (PCL), poli(butil suksinat-ko-L-laktad) (PBSL) dan poli(butilena suksinat-ko-e-kaprolakton) (PBSC) dan penambahan agen perserasian seperti lysine triisosianat (LTI) dan tiga blok kopolimer polietilena oksida - polipropilena oksida - polietilena oksida (PEO-PPO-PEO). Penyediaan perancah berasaskan PLLA juga dipertimbangkan dalam kajian ini. Dalam siri pertama, kesan komposisi campuran (100/0, 90/10, 80/20, 70/30, 50/50, 25/75 dan 0/100 % berat) ke atas sifat morfologi, mekanikal dan haba bagi campuran PLLA/PCL, PLLA/PBSL, dan PLLA/PBSC telah dilakukan. Didapati sifat kelenturan menurun dengan peningkatan kandungan PCL atau PBSL atau PBSC. Ini telah dikesan menerusi pelekatan antara muka yang tidak baik di antara PLLA dan PCL atau PBSL atau PBSC seperti yang diperhatikan dalam morfologi fasa pemisahan. Optimization of poly(L-lactic acid) (PLLA) blends was carried out by blending with ductile biopolymers such as poly(ε-caprolactone) (PCL), poly(butylene succinate-co-L-lactate) (PBSL) and poly(butylene succinate-co-e-caprolactone) (PBSC) and addition of compatibilizer such as lysine triisocyanate (LTI) and polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymer. Preparation of PLLA based scaffold was also been considered in the present study. In the first series, the effects of blend composition (100/0, 90/10, 80/20, 70/30, 50/50, 25/75 and 0/100 wt%) on the morphological, mechanical and thermal properties of PLLA/PCL, PLLA/PBSL, and PLLA/PBSC blends were carried out. It is found that the bending properties decreased with increasing PCL or PBSL or PBSC contents. This was traced by the poor interfacial adhesion between PLLA and PCL or PBSL or PBSC as observed in the phase separation morphology.
- ItemPerformance of composite adsorbent in river water treatment(2017-06)This study was carried out in order to access the potential of composite media by a combination of activated carbon, limestone, alginate as a binder with two different ratio, to remove organic and inorganic pollution that measured by concentration of turbidity, colour and Chemical Oxygen Demand (COD) in river water. In this present study, the batching experiment were conducted to decide the suitable factor for both ratio to effectively remove the involved parameter. Before the batching experiments, water characteristics were taken and COD were dismiss from batching experiment due to its low concentration. From the batch study, result and graph indicates that the suitable factor were 7g of dosage, 180 RPM of shaking speed, 75 minutes of contact and 90 minutes of settling time for ratio 7:3:2 (AC: LS: AG). Meanwhile for ratio 1:9:2 (AC: LS: AG), the suitable factor were 5g of dosage, 180 RPM of shaking speed, 95 minutes of contact time and 40 minutes of settling time. From the second batching experiments, for Ratio 7:3:2, the percentage removal of parameters were 92% for colour and 85% for turbidity. Meanwhile for Ratio 1:9:2, the percentage removal of parameters were 84% for colour and 60% for turbidity. This shows that 7:3:2 has been selected as the best ratio for composite adsorbent that consists of activated carbon, limestone and alginate. Meanwhile, the result from isotherms models for each of the parameters removal suggested that Freundlich isotherm was favourable with high coefficient of determination values for ratio 7:3:2 whereas the Langmuir isotherm were fit for adsorption process by ratio 7:3:2. For kinetic of adsorption, for each of the parameters removal by both ratios, pseudo-second-order model was suitable to describe kinetic of adsorption.
- PublicationDevelopment of design of experiment software for two-factor factorial design(2006-05-01)Regarding to the title, “Development Of A Design Of Experiment (DOE) Software For the case Two-Factor Factorial Designs (FD)”, this project is intended as to develop a simple software which will be able to analyze any experiment that involving only two factors as for this kind of experiment is being used widely by an industrial sectors. Therefore, the basic knowledge of FD technique is very important to engineering students especially whom involved in many experiments as to use it in solving an analysis problem. The essential of the DOE technique have been proven in the world as in Malaysia itself, many industries have supported their analyzer and the experimenter to apply one of this DOE technique in their researches and experiments. The effect reflected by seen that the several major companies such as Motorola, Hewlett-Packet, Petronas and other companies succeeding in controlling their quality level by this DOE technique. By isolating and removing the undetected factors. Those factors interrupt the product production process of several companies such as the manufacturing company. The most considerable effect is when those factors also affecting the quality level of a product produced. Therefore, as the preparation before entering the industry world, this project wants to help engineering students learning the effectiveness of this FD technique. Besides that, this project revealing the use of computer software to engineering students in analyzing an experiment. The development of this software is being constructed with a reason for students will be able to coup the computer skills and able to analyze any experiment data fast and effectively.
- PublicationSurface roughness analysis of co2 laser cutting of 304-stainless steel(2008-04-01)In this project, top, bottom and average surface have been investigated repetitively. Samples of stainless steel-304 were cut on a CO2 laser cutting system and the combined effects of power cutting speed and gas pressure on surface roughness and striation pattern have been studied. Design of Experiment (DOE) method will be used to understand the effect of various laser processing parameters changes on the surface finish. Analysis of Variance (ANOVA) was used to determine the significant factor and the percentage of contribution that affect the quality of surface roughness. For the range of operation conditions tested, it was observed that cutting speed had a major effect on surface finishing which increase the surface roughness of the 5mm stainless steel, while power affects were secondary. Low feed rates gave good surface roughness and low striation. Taguchi method was used to determine the optimum parameter to produce minimum surface roughness on 5mm thickness stainless steel- 304 by COs laser cutting.