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- PublicationData mining approach to assess the significant movement indicators that distinguish people with and without knee oa.(2023-07-07)Degeneration of the articular cartilage, the flexible, slick substance that typically shields bones from joint friction and impact, is what constitutes knee osteoarthritis (OA). The disorder can also damage neighboring soft tissues and results in alterations to the bone that lies beneath the cartilage. Limited studies reported on significant movement indicators distinguishing individuals with and without knee OA. Hence, this study aims to investigate the differences in movement patterns specifically knee bending angles between the two categories using data mining approach. Two case studies concerning knee flexion angle & knee radiographic status were employed: from experimental and publicly available data. Numeric data and nominal data were analyzed using statistical analysis (Minitab) and data mining tool (WEKA). Data classification was performed using Node CART classification from Minitab and ZeroR, Naïve Bayes Multinomial Text classifier, LWL, LMT, Random Forest and Decision Stump algorithms to categorize all the attributes into designed class attributes. The main findings reveal that the classification algorithm (Decision Stump) performance accuracy was 93.33% and 86.67% for both Case Study 1 and Case Study 2 respectively. There is a strong relationship of three analysis identified between active knee ROM and knee OA.
- PublicationProduktivity improvement of electronic product manufacturing systems with data analysis and simulation(2023-07)This thesis presents a comprehensive framework for improving productivity in the electronic product manufacturing industry, with a focus on a specific Surface Mount Technology (SMT) production line of a company in the northern area of Malaysia. The main objective is to enhance efficiency and effectiveness by utilizing data-driven decision-making and advanced simulation modeling with the collected data. The framework integrates real-time data collection, analysis, and visualization with dynamic simulation models to identify bottlenecks, optimize production flows, and assess the impact of potential improvement strategies. The research findings are validated through a real-world case study, demonstrating significant productivity improvements, including optimized production scheduling, reduced cycle times, and increased throughput. Overall, the thesis contributes valuable insights for decision-makers to enhance productivity, reduce costs, and meet customer demands in the highly competitive electronic product manufacturing market.
- PublicationInvestigation of hole roundness for sound absorber(2023-07-14)This study investigates the roundness error of holes drilled in different conditions and their variables, which explores the relationship between this error and four key parameters: the sandwich method, material type, pause time after drill, and spindle speed. The objective is to understand the impact of these parameters on the diameter of the drilled holes and provide insights for optimizing the drilling process. A total of 27 samples were drilled using various combinations of the four parameters, and the diameter of the holes was measured using Scanning Electron Microscopy (SEM). Regression analysis and Analysis of Variance (ANOVA) were conducted to analyze the data and determine the significance of the parameters. The results revealed that material type had a significant and negative correlation with the roundness error. This indicates that the choice of material has a pronounced effect on the roundness and diameter of the drilled holes. The selection of the appropriate sound absorber material is critical in achieving the desired roundness and optimizing the performance of sound absorber panels. Conversely, the other parameters, including the sandwich method, pause time after drill, and spindle speed, showed weak correlations and limited statistical significance with the roundness error. The findings of this study emphasize the importance of material selection in minimizing roundness error in drilled holes. Different materials may exhibit variations in their structural properties, such as hardness or elasticity, which can influence the drilling process and ultimately impact the hole roundness. By carefully considering the material characteristics and their compatibility with the drilling parameters, manufacturers can optimize the drilling process and enhance the quality of sound absorber materials.
- PublicationSimulation analysis of organic rankine cycle (ORC) operating with various type of refrigerants(2023-07-14)This thesis presents a study on wasted heat energy recovery in diesel engines using an Organic Rankine Cycle (ORC) integrated with simulation techniques in MATLAB. The research explores the feasibility and performance of the ORC system for recovering waste heat with various refrigerants and under various conditions. A MATLAB model is developed, incorporating thermodynamic equations and the performance characteristics of ORC components. Data collection and analysis validate the simulation model by comparing simulated results with experimental data from a real diesel engine setup and studies that has been done earlier. The findings show that R152 has the ability to produce the most shaft output power. R11 has the least power produced from the heat energy applied at 3.09kW while R152 is at 9.44kW. It is also found that R134a has the highest thermal efficiency among all other refrigerants. The study paves the way for optimizing system design, exploring working fluids, and enhancing energy recovery processes. This study aims to determine harvested power from diesel engine waste heat and analyze ORC performance with different refrigerants for thermal efficiency. Comparative analysis of results and findings is also conducted.
- PublicationTool conditioning monitoring using vibration and acoustic detection for composite drilling application(2023-07)Drilling operations on Carbon Fiber Reinforced Plastics (CFRP) and Glass fibre reinforced polymers (GFRP) have become crucial in the aerospace industry. Tool wear is the most unfavourable aspect of machining processes because it severely affects tool life, which is crucial in metal cutting due to its direct influence on the dimensional accuracy and surface quality of the machined surface as well as the economics of machining operations. Tool condition monitoring (TCM) systems are widely sought after for drilling operations in the aircraft manufacturing industry because of the poor machinability of composite materials. In order to prevent the composite material from being harmed by a blunt drill bit, it is crucial to promptly change the drill bit. As a result, the TCM system offers a convenient method for tracking, managing, and optimising the use of drill bits which will indirectly raise machining quality. According to a variety of different perspectives, the drill bits are currently disposed of in the industries after a specific number of cycles. Some of the drill bits that can still produce holes without delamination even after being used for a certain number of cycles are wasted. Researchers have conducted numerous experiments to link tool wear with process variables including cutting force, thrust force, vibrations, spindle current, acoustic emission and etc. in order to monitor the tools' state. In this study, the impact of drill bit sharpness on air drill vibrations, sound generated during drilling and hole quality will be investigated. To quantify the vibrations of the air drill in this experiment, three accelerometers were fastened to the spindle, the center and a place close to the handle. The sounds made throughout the drilling operation were recorded using a microphone that was situated about a meter distance from the jig. The air drill's vibrations and the sound it makes while drilling under various drill bit conditions are analysed and contrasted. The result demonstrates that vibrations detected by an accelerometer placed closest to the spindle are more responsive to changes in drill bit condition. For CFRP plates, the maximum air drill vibration amplitude increases from sharp to no drill bit to dull to chipped off. For GFRP plates, the maximum air drill vibration amplitude goes from no drill bit to blunt to chipped off to sharp. In addition, the rapid Fourier Transform of the vibration signals from this accelerometer reveals the existence of a distinct collection of frequencies with notable peaks under various drill bit conditions. During CFRP plate drilling, the maximum amplitude of air drill vibration increases with drill bit condition, from sharp to no drill bit, dull to chipped off. However, while drilling GFRP plates, the air drill's maximum vibratory amplitude increases in the following order: no drill bit, dull, chipped off, and sharp.
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- ItemSynthesis And Characterization Of Lanthanide-Benzoata Complexes(Universiti Sains Malaysia, 2011-10)Sixteen complexes and three single crystals of lanthanide-benzoato were synthesized with normal refluxing and solvothermal method. The structures of the three crystals were characterized using single crystal X-ray crystallography. [Nd2(C7H5O2)6(C12H8N2)2], [Eu2(C7H5O2)6(C12H8N2)22(C7H6O2)] and [Tb2(C7H5O2)6(C12H8N2)22(C7H6O2) all adopted triclinic crystal system with P-1 space group. The three lanthanide-benzoato crystals adopted nine-coordination environment. Hydrogen bonding can be found showing the interaction between molecules in the crystals itself. All the complexes were characterized by means of elemental analysis, fourier transform infrared-red (FTIR) spectroscopy, thermogravimetric analysis and photoluminescence spectroscopy. The FTIR results show that the carboxylic group in the complexes coordinated to the rare earth ions in the form of monodentate and bidentate, and the ester carboxylic groups have taken part in the coordination. Nitrogen atoms from 1,10-phenanthroline coordinated to the rare earth ions in the single crystal complexes in the form of bidentate as well. Among these complexes, Eu(III) and Tb(III) complexes showed good photoluminescence emission compared with that of Sm(III) and Nd(III) complexes.
- PublicationAnalyses of battery cell utilisation in an electric vehicle(2024-08)This This thesis investigates enhancing battery management systems (BMS) for electric vehicles (EVs) through redundant cells and active balancing mechanisms. The main goals are to improve the reliability and efficiency of EV battery packs, optimize redundant cell use, and enhance fault tolerance and diagnostics. A MATLAB Simulink model simulates a battery pack with 20 lithium-ion cells, a boost converter, and a DC motor running at 50 km/h. The initial State of Charge (SOC) for each cell was set between 80% and 85%. The active balancing system maintained uniform SOC across all cells, optimizing cell utilization and extending the battery pack's lifespan. In fault conditions, such as the failure of Cell 19, the system demonstrated robust fault tolerance by compensating with the remaining cells and maintaining stable outputs to the motor. The system's fault detection and isolation mechanisms effectively managed current flow, ensuring stable voltage and current. The study shows that active balancing enhances the reliability, longevity, and safety of EV battery packs by preventing overheating and complying with industry standards. This research addresses critical issues in the EV industry, such as uneven cell utilization and battery degradation. Future research should focus on improving BMS safety and reliability with advanced fault detection algorithms, comprehensive thermal management, and adaptive balancing. Additionally, using safer materials in battery construction and developing a user-friendly interface for real-time monitoring will enhance user experience and trust in the technology. This thesis provides a solid foundation for future BMS advancements, promoting the broader adoption of electric vehicles.
- ItemHypervariable segment-! (HVS-I) Sequence Analysis Of Chinese Population of Peninsular Malaysia(PPSP, Universiti Sains Malaysia, 2007-04)Throughout Malaysia history, most of the Peninsular Malaysian Chinese are known to be populated by those migrated from the China during the British colonial era (Barbie, 1992). The present study was undertaken to obtain information about the distribution of the existing HVS-1 sequence variations in the Chinese population of Peninsular Malaysia. A few studies have used RFLP analysis to characterize the mtDNA of Malaysian Chinese (Ismail, 2006; Mokhtaruddin, 2006; Ballinger et al., 1992). The primary purpose of this study is to provide HVS-1 sequence data by sequencing the HVS-1 of the 40 Chinese individuals from different parts of Peninsular Malaysia. The secondary purpose is classification of mtDNA haplogroup based on the HVS-1 sequence variation by alignment of samples sequence and Cambridge Reference Sequence (CRS) (Andrew et al., 1999). The samples were predicted to belong to the superhaplogroup M and haplogroup B in relatively high frequency as inferred from the study done by Ballinger et al., (1992). Analysis of HVS-1 within the control region (CR) of the mitochondrial genome revealed the presence of eight haplogroups: B, F, M, MC, MD, MG, N, and R. These haplogroups are the characteristics of Southeast Asian populations (Ballinger et al., 1992) and also found in significant proportion in Han Chinese of China (Y ao et al., 2002). Result shows that superhaplogroup M (includes MC, MD, and MG) is the most common haplogroup in the studied samples (55%), followed by haplogroup B (18%).
- ItemAdsorbent supplemented treatment of landfill leachate in sequencing batch reactor(2006)The objective of this study is to evaluate the performance of the sequencing batch reactor (SBR) with and without the addition of adsorbent in the removal of oxygen demand (COD) and ammoniacal nitrogen (AN) from landfill leachate. Two identical plexiglass SBRs were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 2:12:2:1:7 for a cycle time of 24 h. Reactor R-PAC was fed with a mixture of synthetic wastewater and increasing strength of leachate (115-170 mg/L AN) as well as increasing dosage of powdered activated carbon (PAC) (0.5-1.5 g/cycle). Whilst reactor RMRH received a mixture of the same synthetic wastewater and increasing strength of leachate (115-215 mg/L AN) as well as increasing dosage of ethylenediamine-modified rice husk (MRH) (0.5-1.0 g/cycle). The results showed that after the introduction of leachate, the COD removal efficiency was reduced from 90% for both reactors to 72% for reactor R-PAC and 79% for reactor R-MRH. Treatment of leachate at higher strength was sustainable only if PAC or MRH was added. The beneficial effect of MRH was seen in its ability to sustain the COD removal in R-MRH of above 70% at the leachate strength of 215 mg/L AN with the dosage of 0.5 g/cycle. In comparison, the COD removal in R-PAC above 70% at the leachate strength of 170 mg/L AN was sustainable if higher PAC dosage of 1.5 g/cycle was added. The AN removal efficiency for both reactors was almost 100% before and after the introduction of leachate at the strength of 115 mg/L AN but deteriorated when the leachate strength was increased. At the leachate strength of 170 mg/L AN, the AN removal efficiency in reactor R-PAC was sustained at almost 100% with PAC addition of 1.5 g/cycle. The same AN removal efficiency was achieved in reactor R-MRH at a lower MRH dosage of 0.5 g/cycle for the leachate strength of 215 mg/L AN. The results of kinetic study showed that the rates of COD and AN removal during the REACT period can be described by first-order kinetics. The addition of leachate resulted in the effective inhibition of the conversion of nitrite nitrogen (NO2 - -N) to nitrate nitrogen (NO3 - -N). The addition of PAC and MRH, respectively, helped to sustain the rates of COD and AN removal at higher leachate strength of up to 170 and 215 mg/L AN. This indicates that the addition of adsorbents had minimized the toxic effect of leachate with MRH showing more effectiveness than PAC.