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- PublicationAntimicrobial effects on streptococcus mutans and candida albicans and cytotoxicity study on human periodontal ligament fibroblast cell line of oxy-ionic solution at various ph levels - an in vitro study(2025-04)Oxy-ionic solutions, comprising hypochlorous acid, sodium hydroxide, and active chlorine, have gained recognition in dental care for their strong antimicrobial properties, especially against pathogens like Streptococcus mutans and Candida albicans. These solutions are produced through the electrolysis of saline water. However, the influence of pH on their antimicrobial effectiveness and cytotoxicity remains uncertain. This study investigates the antimicrobial efficacy of oxy-ionic solutions at varying pH levels (3, 5, and 7) against Streptococcus mutans and Candida albicans and their cytotoxicity on human periodontal ligament fibroblasts. This study evaluated the antimicrobial efficacy and cytotoxicity of oxy-ionic solutions using three complementary approaches. First, disk diffusion and broth microdilution assays quantified antimicrobial effects. Second, scanning electron microscopy (SEM) revealed microbial morphological changes. Third, ATP assays determined cytotoxicity against human periodontal ligament fibroblasts. The oxy-ionic solutions were tested at pH 3, 5, and 7 with concentrations of 100%, 75%, and 25%, except for pH 7 which was assessed only at 100% concentration. Disk diffusion results revealed that the pH 5 solution exhibited the largest zones of growth inhibition, with diameters of 13.79 mm for Streptococcus mutans and 19.67 mm for Candida albicans, indicating the strongest antimicrobial efficacy among the tested pH levels. Broth microdilution assays further confirmed this, with the pH 5 solution demonstrating the minimum inhibitory concentration of 50% for Streptococcus mutans and 25% for Candida albicans. Scanning electron microscopy analysis showed significant microbial cell wall damage and morphological changes when treated with the pH 5 solution. The ATP assay results on human periodontal ligament fibroblasts showed that all concentrations of oxy-ionic solutions at pH 3, pH 5, and pH 7 exhibited significant cytotoxicity after 2 minutes of exposure. Although cell viability improved with extended exposure time to 24 hours, it still remained below safe thresholds. These findings suggest that there is a therapeutic potential in the dental care of oxy-ionic solution pH 5 based on high antimicrobial effects, however further study on the dilution of the solution is necessary to ensure clinical safety and effectiveness.
- PublicationAnalysis of two mechanism for oil palm Harvester: scotch-yoke and slider crank(2024-07-12)The thesis entails a comparative analysis of two innovative mechanisms such as Scotch yoke and slider crank, integrated with an electric motor to enhance operational efficiency regarding weight reduction and minimize vibration as compared to the conventional gasoline-powered device. The overall problem addressed is laborintensive and physically demanding manual harvesting of oil palm bunches, whereby even the safety of workers is at risk. Moreover, all the existing motorized solutions are heavy, bulky, and highly vibrational, which causes fatigue to operators and loss of productivity. Overall, the development of a motorized oil palm harvester resolves inefficiency and required labor issues connected with conventional harvesting methods. This work concerns the efficacy of the slider crank mechanism and that of the scotch yoke mechanism, which are attached to a pole and sickle assembly in effecting accurate and effective palm bunch cutting. Many advantages accompany the electric motor such as light operating, less vibration, less noise, and simpler maintenance. Finite Element simulation was done instead of creating the manufacturing in this work to compare the effectiveness of both processes. With such simulations, optimum design parameters could be found to ensure that harvesters work well under any scenario. These results from the FE simulation reflect that the harvesting efficiency of both mechanisms has increased significantly, hence the motorized harvesters prove to reduce operator physical strain and increase overall production. This study, having a potential enhancement in productivity, sustainability, and safety in large-scale operations, advances agriculture mechanization by offering a side-by-side comparison between two electric motor-driven oil palm harvesting options.
- PublicationNano-indentation investigation on lead free solder interconnection prepared by microwave hybrid heating(2024-07-05)The adoption of lead-free solder, specifically Sn-Ag-Cu (SAC), in electronic manufacturing was driven by concerns for human health and environmental impact. The reflow process utilized during soldering plays a significant role in the formation and growth of the intermetallic compound (IMC) layer, crucial for ensuring reliable solder and metal substrate connections. While microwave hybrid heating (MHH) presents a potential soldering approach, the long-term reliability of solder joints remains uncertain. To address this, a study was conducted to examine the impact of MHH on IMC morphology and thickness in SAC305 solder. Additionally, the mechanical properties of SAC305, such as elastic modulus and stress-strain were evaluated using nanoindentation. The obtained results were further supported by finite element modelling using ABAQUS software. The IMC structure exhibited a planar-like shape in MHH, occurring after 200s of reflow time for MHH. Besides, a comparison between the experimental results and simulation results were conducted. Comparison between the SAC305 and SAC105 solder, the temperature between SAC305, different amount of load applied in the simulation process and cyclic loading were carried out to obtain the mechanical properties of both SAC305 and SAC105.The proposed finite element modelling demonstrated good agreement with experimental data, showcasing its capability to simulate the plastic deformation behaviour during the indentation process.
- PublicationPrediction of tensile strength of polymer composites using machine learning algorithms(2024-07)The project is to perform the analysis of tensile strength of polymer composites by using linear regression. Although the research focuses on future engineering applications of the work, it is underpinned by the recognition of the growing requirement for high-performance lightweight materials in numerous engineering sectors, together with the difficulty of predicting the tensile strength of these materials. Many times, the conventional techniques are incapable to identify intricate correlation between input variables and developments in the UTS and hence requires more refined procedures. Linear regression serves as another valuable method or approach that may provide a clearer insight into patterns and data correlations. The primary objective of this work is to establish an accurate predictive model, specifically linear regression, based on a large dataset to accurately estimate the tensile strength of polymer composites. The study also aims at identifying the importance of the features as well as finding relationships of the existing ones in the set with an aim of identifying the important parameters affecting the tensile strength. In using and proving the effectiveness of the proposed linear model through training and test datasets and their validations; the study shows linearity’s ability to accelerate material selection, improve process parameters, and design microstructure. This versatility of the model to predict the designs for newly evolved forms of applications can go a long way in helping the engineers design safer and more reliable part of polymer composite structures for these demanding application categories; this would indeed mark shift in polymer composite paradigm. Thus, linear regression analysis is considered, in enhancing the understanding and the computational accuracy of the tensile strength of polymer composites, has laid a wide and profound foundation for subsequent progresses in material science and engineering.
- PublicationNumerical analysis of electric vehicle battery and recyclability potential(2024-07-10)The rapid expansion of electric vehicles (EVs) necessitates a deeper understanding of EV battery lifespan dynamics, presenting significant challenges and opportunities. This study focuses on key understanding in EV battery lifecycle management, emphasizing comprehensive recycling methods to ensure sustainable integration of EVs into the transportation sector. By examining EV battery performance metrics and technical approaches to enhance recyclability, the study provides a thorough analysis of environmental and economic impacts. Using MATLAB for numerical analysis, this research is expected to take an integrated approach to solving the issues of EV battery management, providing significant insights and techniques for full EV battery recycling. The analysis highlights the growth of EV battery market could increase from 1066 GWh in 2024 to 120000 GWh in 2050 in an optimistic scenario. The study also shows that the current mainstream lithium ion batteries in EVs shows faster degradation of state of charge which is at 73.33% of remaining capacity compare to solid state batteries which are still new to the EV industry with the remaining capacity of 86.67% after 2000 cycles of charge-discharge. Beside, for 100 kWh , the lithium ion battery weights at 377.36 kg while solid state battery only weights 200 kg. We propose various suggestion involving partnerships with global battery manufacturers, expansion of charging infrastructure, promotion of solid-state batteries, and implementation of financial incentives to support EV adoption. The adoption of EVs and their performance is correlated to the recyclability potential of EV battery.
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- PublicationLiterasi Digital, Efikasi Kendiri Dan Penggunaan Teknologi Maklumat Dan Komunikasi Dalam Kalangan Guru Pendidikan Islam(2023-01)Kajian ini bertujuan mengkaji literasi digital, efikasi kendiri dan penggunaan Teknologi Maklumat dan Komunikasi (TMK) dalam pengajaran Pendidikan Islam. Kajian dijalankan terhadap 174 guru Pendidikan Islam (GPI) yang berkhidmat di sekolah-sekolah Menengah Kebangsaan (SMK) di Pulau Pinang. Reka bentuk kajian adalah kajian kuantitatif. Analisis yang digunakan bagi kajian kuantitatif adalah analisis statistik deskriptif, ujian-t tidak bersandar, korelasi pearson dan regresi linear berganda. Dapatan kajian mendapati tahap literasi digital, efikasi kendiri dan penggunaan TMK dalam pengajaran Pendidikan Islam adalah sederhana. Ujian-t tidak bersandar mendapati tidak terdapat perbezaan yang signifikan dalam kalangan sampel yang berlainan jantina dan lokasi sekolah. Pemboleh ubah tidak bersandar iaitu literasi digital mempunyai hubungan yang signifikan dengan penggunaan TMK (r = .64, p < .001). Kajian juga mendapati terdapat hubungan yang signifikan antara efikasi kendiri dengan penggunaan TMK (r =.58, p < .001). Seterusnya, keputusan regresi linear berganda mendapati literasi digital merupakan pengaruh terbesar yang mempengaruhi penggunaan TMK dengan jumlah sumbangan sebanyak 41.2% (β =. 49, p = .001). Kombinasi efikasi kendiri dan literasi digital menambah 1.4% lagi pengaruh untuk menggunakan TMK (β = .19, p = .045). Kajian ini menyumbang pengetahuan baharu kepada literatur dan Kementerian Pendidikan Malaysia bahawa faktor efikasi kendiri dan literasi digital merupakan pengaruh kepada penggunaan TMK dalam pengajaran.
- ItemMutual authentication protocol model for low-cost rfid systems based on shelled random value(2011)Designing a reliable secure low-cost protocol for radio-frequency identification (RFID) is difficult, standard cryptographic primitives can become a limitation for low-cost tags due to their costly large requirements in terms of circuit size, power consumption, and memory size. Therefore, ultralightweight cryptography in designing low-cost RFID protocols capable of executing data communication sessions'·efficiently and effectively are needed to solve database loading, passive attacks, desynchronization and high computational cost problems. This thesis presents a model (SRV) for designing efficient low-cost security protocols, and proposes two low-cost RFID secure protocols (SURV and SLRV) based on ultralightweight and lightweight mutual authentication usmg a combination of conventional and unconventional security primitives. Comprehensive qualitative and quantitative evaluations were performed on the designed protocols. Both protocols have been analyzed qualitatively for its ability to provide data confidentiality, tag anonymity, mutual authentication and data integrity, capability to handle forward security and replay attacks, desynchronization, and man-in- the-middle and disclosure attacks. Both protocols achieved significant positive security performance in all aspects compared to all protocols in the studied literature. Similarly, both protocols have been evaluated quantitatively using Diehard and ENT tools for passive attacks, which proofed high security through highly randomized messages, and against database loading using three different search algorithms on three datasets with different sizes alternatively. Furthermore, proposed implementations have been put forward to illustrate the cost efficiency for the proposed protocols. The evaluation also included security verification using the A VISP A tools. However, the results on the capability of A VISP A to verify RFID protocols in general and our protocols in particular, came out negative.
- ItemRANDOMIZED CONTROL STUDY USING VITAMIN D ( CALCITRIOL) IN PREVENTING POST TOTAL THYROIDECTOMY TRANSIENT HYPOCALCEMIA(Pusat Pengajian Sains Perubatan Universiti Sains Malaysia, 2011)Objective: The aim of our open label randomized control study was to determine the incidence of transient hypocalcemia developing post total thyroidectomy in Kelantan (Malaysia) and the benefit of pre-operative treatment using oral vitamin D for post total thyroidectomy. Methodology: This is a randomized control study which recruits a total of 74 patients from Hospital Universiti Sains Malaysia and Hospital Raja Perempuan Zainab II. The study was carried out over one year duration since 5th May 2009 until 30th April 2010. The ethical approval was obtained from The Research Ethical Committee (Human), Universiti Sains Malaysia and Ethical Board Clinical Research Center (CRC), Ministry of Health. Seventy four patients that underwent total thyroidectomy were randomized into two groups. Study group: 37 patients treated with oral vitamin D (calcitriol) 1.5ug/day for 2 days duration before operation followed by 1.0ug/day plus oral calcium lactate 1800mg/day for 7 days after operation. Control group: 37 patients did not receive oral Vitamin D or calcium lactate. All the patient were assessed clinically and biochemically forhypocalcemia. Result: There was no significant difference between the study and control group in terms of demographic distribution of age, sex, diagnosis, surgeon, operating duration, parathyroid gland autotransplant, and baseline level of serum calcium, phosphate and intact PTH. The incidence of post total thyroidectomy transient hypocalcemia in the study group is about 16.7% compared with control group of 75%. Among the cases, 50.0% in the study group and 64.3% in control group are symptomatic. The incidence of permanent hypoparathyroidism is 2.7%. There was significant difference in term of incidence of asymptomatic hypocalcemia and symptomatic hypocalcemia between these two groups since p value is <0.001. There was also significant difference between control and study group with regards to the trend of post-operative serum calcium changes since p value <0.001. However, there was no significant difference in the risk of developing permanent hypoparathyroidism. The post operative stay is significantly longer in control group, 4.59 days compared with study group, 3.92 days ( p value : 0.001). Conclusion: The administration of oral vitamin D pre-operatively had significantly reduced the incidence of transient hypocalcemia post total thyroidectomy.
- ItemEffect of fibre orientation on the mechanical properties of sandwich composite material(2018-06)In composites manufacturing process, fibre orientation of the composites is one of the most important factor in composites manufacturing that needs to be taken account into as any misalign angle present in the fibre lay-up could lead to the decrease of the composites mechanical performances. The properties of the sandwich composites materials can be affected by every aspect especially during the manufacturing process of the composite. This study shows the effect of fibre orientation on the mechanical properties of a sandwich composite material. The manufacturing process used to manufacture the composites is a wet hand lay-up process. The orientation of the glass fibre is set to 0°, 9° and 15°. The effect of the fibre orientation is analysed by performing the mechanical test on the composites. Test to be performed is set to be compression test and bending test. Theoretical results shows that the mechanical performance of the composite decrease as the offset angle of the glass fibre increases. Several specimens with different fibre orientation is manufacture to analyse and proof the theoretical results and the analysis shows that each fibre offset angle can affect the mechanical performance of the sandwich composite. Therefore, it can concluded that fibre orientation significantly effects the performances of the sandwich composites as even a small misalign angle could lead to a significant decrease of the composites mechanical performance.
- ItemPrevalence of primary dysmenorrhea Among undergraduate nursing Student and its management in School Of Health Sciences, Universiti Sains Malaysia, Kelantan(Pusat Pengajian Sains Kesihatan, Universiti Sains Malaysia, 2011)This study was to determine the prevalence of dysmenorrhea and approaches taken by female degree nursing students in School of Health Sciences, Universiti Sains Malaysia in coping with menstrual pain. This is a cross sectional study and nonprobability convenience sampling of 129 female students (19 to 35 years old) from Year one to Year four. A self-administered questionnaire was used to collect sociodemographic and menstrual data. Pain intensity for dysmenorrhea was measured using Visual Analogue Scale (VAS). Prevalence of dysmenorrhea found was 75.2% and mostly occurred;;::: 4 years (33%) and 29.9% was not recalled. Pain was mostly occurs at the onset of menstruation period (65%) and lasted for less than 1 day (52.6%). It was felt in multiple locations but most commonly in the lower abdomen and lumbar region. Major symptoms associated with dysmenorrhea were abdominal cramps, irritability, headache, vomiting, diarrhea, frequency of micturition, constipation, as well as varying degrees of pain severity. Most respondents experienced mild to moderate degree of pain. Approaches taken to deal with dysmenorrhea were: consulting a physicians (22.7%), pharmacological (50.5%), and non-pharmacological strategies (93.8%). Medication was recommended mostly by friends (40.8%) and mothers (30.6%) and only took medication when became severe ( 49% ). More than one-third of the respondents did not know which drug they took. Major non-pharmacologic measures were: hot compress (48.5%), sleeping (74.2%), walking (12%), massaging (59.8%), listening to music (13.4%) and eating sweet foods (9.3%). Consulting a physician (p<0.05) was associated with the duration of pain and taking medication (p <0.05) was associated with severity of pain. Respondents should be encouraged to consult a physician and should be prescribed medication in addition to other measures to alleviate menstrual pain and shorten its duration.