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- PublicationAdsorption studies of heavy metals on activated carbon prepared from agricultural waste(2018-03)Commercially available activated carbon (AC) is still considered expensive due to the use of non-renewable and relatively expensive starting material such as bituminous coal. Therefore, this study investigates the potential use of agricultural waste such as rubber seed coat (RSC) and corncob (CC) that available in Malaysia, as the precursor for the preparation of AC which can be applied for the removal of two types of heavy metal, which are Cu (II) and Zn (II) from aqueous solution. Physiochemical activation consisting of potassium hydroxide (KOH) impregnation plus carbon dioxide (CO2) gasification was used to prepare the ACs. The optimum preparation conditions of RSCAC-CU were found at activation temperature of 793 °C, activation time of 1h and KOH impregnation ratio (IR) of 2.46. As for RSCAC-ZN, the optimum preparation conditions were at activation temperature of 797 °C, activation time of 1h and IR of 2.61. Meanwhile, the optimum preparation conditions of CCAC-CU were found at activation temperature of 762 °C, activation time of 2.7h and IR of 3.25. For CCAC-ZN, the optimum reparation conditions were at activation temperature of 768 °C, activation time of 3h and IR of 3.5. All the activated carbons prepared were high BET surface area (>500 m2/g) and pore volume (>0.41 m3/g). RSCAC and CCAC demonstrated homogeneous and heterogeneous type pore structures, respectively. The effects of adsorbate initial concentration (10-100 mg/L), contact time, solution temperature (30-60 °C), solution pH (2-6), isotherms and kinetics of the adsorption systems were evaluated through batch adsorption test. The Cu (II) and Zn (II) adsorption uptakes increased with increasing initial concentration and optimum contact time. Adsorptions of Cu (II) and Zn (II) on all ACs were best fitted by the Freundlich isotherm model. Adsorption kinetics of Cu (II) and Zn (II) followed pseudo-second-order on all the ACs. Fixed bed study showed that the exhaustion period for Zn (II) was greater than Cu (II) and the increase in bed heights resulted in higher exhaustion period.
- PublicationComparative Analysis Of Nucleic Acid Residues In Core Streptavidin Using Three Isolation Techniques(2024-08)Recombinant core streptavidin (cSAV) is a truncated non-glycosylated tetrameric SAV which has been widely utilised in a wide range of biotechnological applications. Due to cSAV commercial importance, recombinant cSAV has been extensively produced using expression host system such as Escherichia coli to high expression level. Nevertheless, accumulation of cSAV in high levels results in the formation of insoluble non-functional inclusion bodies (IBs) which requires efficient downstream processing steps to overcome. This process involves isolation of IBs from cell lysates through combination of cell disruption techniques, multiple centrifugation steps, IBs solubilization and refolding to acquire correctly refolded cSAV. However, during IBs preparation, presence of cellular contaminants such as residual nucleic acids is inevitable and can affect subsequent refolding process. Hence, in this study, the IBs isolation process from our previous group (Process A) was improved to obtain high quality cSAV IBs in an effort to attain refolded cSAV with minimal contaminants. The improvements were enhanced with the incorporation of quantitative polymerase chain reactions (qPCR) for residual DNAs monitoring. By employing combined cell disruption approaches such as extensive sonication (Process B) and addition of benzonase nuclease (Process C), cSAV IBs with 99% removal of residual DNAs were achieved. A 10% increment of cSAV refolding yield (72%) and 83% reduction of residual DNAs from refolding of 1 mg cSAV IBs were observed under extensive sonication. Despite perceiving the least residual DNAs, refolding of cSAV was found not affected and the activity of refolded cSAV was not compromised.
- PublicationImproving Building Information Modelling (Bim) In Technical Vocational Education And Training (Tvet) In Malaysia Polytechnics(2024-09)This study investigates the Building Information Modelling (BIM) in Technical Vocational Education and Training (TVET) in Malaysia Polytechnics, particularly for the Diploma in Architecture, Engineering, and Construction (AEC) courses. The objectives are to critically assess the improvement of BIM in the TVET curriculum, evaluate educators’ awareness of BIM, identify the barriers encountered, and propose strategies to enhance BIM education in these institutions. Despite BIM's critical role in the AEC industry, its implementation within the Malaysian TVET curriculum faces significant obstacles, including the absence of a standardised approach, limited resources, and gaps in both practical and theoretical BIM expertise among educators. While the subject has garnered attention, research specifically addressing BIM education within the context of Malaysian higher education remains insufficient. A quantitative methodology was used, utilising a comprehensive questionnaire designed to gather data on educators' demographics, levels of BIM awareness, and the barriers to BIM implementation. The findings reveal that 50% of educators possess only moderate BIM skills, with a considerable number lacking adequate qualifications in the field. The study underscores the necessity for continuous curriculum development, improvement of the existing BIM education framework, and the removal of barriers impeding effective BIM education.
- PublicationMulti-objective Binary Clonal Selection Algorithm In The Retrieval Phase Of Discrete Hopfield Neural Network With Weighted Systematic Satisfiability(2024-09)The stability of the Discrete Hopfield Neural Network is dependent on the ability of the network to govern the neuron connections that caused several issues to arise, such as random distribution of positive and negative literals and overfitting final neuron states. Therefore, this thesis proposes a new systematic Satisfiability logical rule namely Weighted Systematic 2 Satisfiability that uses a weighted feature to control the distribution of the negative literals. The proposed logic embedded into Discrete Hopfield Neural Network and considered the optimization of multi-objective function in the retrieval phase to locate superior final neuron states. A Binary Clonal Selection Algorithm is being proposed to ensure optimal generation of the superior final neuron states. The proposed algorithm in the retrieval phase showed optimal performance as compared to the baseline algorithms. The newly proposed logical rule and the algorithm will be the components in the logic mining model namely Weighted Systematic 2 Satisfiability Modified Reverse Analysis. The proposed logic mining model is able to retrieve best induced logic that represents the optimal patterns of the dataset. Based on the findings, the proposed logic mining model outperformed other baseline logic mining models for all the performance metrics used in the repository dataset. The proposed logic mining model was tested on a real-life dataset from the Alzheimer’s Disease Neuroimaging Initiative, and it showed superior performance.
- PublicationKualiti Insan Dalam Penilaian Prestasi Menurut Al-ghazali Berdasarkan Kimiya’ Al-sa’adah(2024-09)Salah satu kaedah menilai kualiti insan ialah menerusi penilaian prestasi. Penilaian prestasi sering diamalkan di pelbagai peringkat termasuk di peringkat institusi, di peringkat pentadbiran kerajaan dan sebagainya. Namun, penilaian prestasi sering menghadapi pelbagai cabaran dan isu untuk pelaksanaan penilaian yang terbaik. Antara isu yang diutarakan adalah ketidakadilan, bias dan ketiadaan kompetensi yang keseluruhannya bertitik tolak daripada unsur utama dalam penilaian prestasi iaitu insan. Bertitik tolak daripada itu, kualiti insan dilihat sangat penting dalam menjayakan penilaian prestasi. Oleh itu, kajian ini dilakukan bagi mengkaji kualiti insan dalam penilaian prestasi menurut tokoh pembangunan insan dalam Islam iaitu al-Ghazali berdasarkan kitab beliau Kimiya’ al-Sa‘adat. Kajian ini dilakukan dengan tiga objektif kajian. Objektif pertama, mengenal pasti kualiti insan dalam penilaian prestasi berteraskan Islam. Objektif kedua, menganalisis kualiti insan dalam penilaian prestasi menurut al-Ghazali berdasarkan Kimiya’ al-Sa‘adat. Objektif ketiga, mencadangkan kualiti insan dalam penilaian prestasi menurut al-Ghazali berdasarkan Kimiya’ al-Sa‘adat. Kajian ini menggunakan reka bentuk kajian kualitatif asas yang melibatkan pengumpulan data daripada sumber sekunder dan akhirnya menganalisis menggunakan kaedah analisis kandungan dengan bantuan perisian Atlas.ti versi 24.
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- ItemSynthesis and characterization of low bandgap nanocrystalline(2007)Nanocrystal t-ZrO2 powders were synthesized through a chemical route to seek a possibility if electronic doping would improve the electronics conductivity of the oxide. Y3+ was added as a stabilizer to retain tetragonal phase ZrO2 whereas Nb5+ was added for electronics doping. The phase formation and stabilization to achieve 100% pure t-ZrO2 were studied in detail encompassing all possible parameters which would contribute to the phase formation. Polymer decomposition and soft combustion methods were performed in this study to produce the doped zirconia. Precursor solutions were prepared from a mixture of zirconyl nitrate (ZrO(NO3)2), yttrium nitrate (Y(NO3)3), niobium tartarate (HNb(C4O6)) and TEA (triethanolamine) for polymer decomposition method, while zirconyl nitrate, yttrium nitrate, niobium nitrate (Nb(NO3)5) and glycine were used in soft combustion method. Several dopants compositions of zirconia powders were prepared by thermal decomposition method and were annealed at different temperatures. The synthesized powders were characterized using Differential Thermal Analysis (DTA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The average particle size of the powders calcined at 700ºC in this study ranges from 13.00 to 38.00 nm. The addition of Nb5+ did not alter the stability of the tetragonal phase formed in powder synthesis. Upon sintering different kind of atmosphere (argon-carbon, vacuum and air) it was found that at high sintering temperature, 1250°C to 1600°C, t-ZrO2 had transformed to m-ZrO2. However 100% t-ZrO2 was retained with sintering at 1400°C in vacuum condition. The optical band gap as measured by the UV-Visible Spectrometer for the sintered sample with t-ZrO2 gave a minimum value 4.00 eV, lower than the optical bandgap from commercial Yttria Stabilized Zirconia (YSZ) which was 6.09 eV.
- ItemAntioxidant, anti-angiogenic and antiinflammatory activities of standardized Gynura Segetum leaf extracts(2014-09)Gynura segetum (daun dewa in Malay) is a herb, reputed of value among others for treatment of inflammation and cancer. In the present study, the anti-inflammatory activity of the standardized leaf extracts of Gynura segetum were investigated as well as its possible relation to antioxidant, anti-angiogenic and cytotoxic activities. The ethyl acetate fraction showed the strongest antioxidant activity based on DPPH scavenging activity and beta carotene bleaching capacity assays and directly related to its total phenolic and flavonoid contents. The methanol extract was the most active in inhibiting the blood vessels growth in chick embryo chorioallantoic membrane (CAM) assay and rat aortic ring assay. It shows it has anti-angiogenic activity. It is non-cytotoxic and suppression of vascular endothelial growth factor (VEGF) activity is one of the anti-angiogenic mechanisms of action. The methanol extract possesses anti-inflammatory activity as it inhibited SDS-induced irritation in hen’s egg chorioallantoic membrane (HET-CAM) test and cotton pellet-induced granuloma formation in rat. Its anti-inflammatory activity is mediated through the inhibition of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) and cycloxygenase-2 (COX-2) enzyme activities. Taken together, the present study suggests that Gynura segetum’s leaf is a natural source of antioxidants and possesses anti-angiogenic activity which may explain its chronic anti-inflammatory activity and anti-cancer potential.
- PublicationThe Aging-Inequality Nexus: The Domestic Savings Channel And Threshold Effects In Asia-Pacific Countries(2024-05)Income inequality has generally exhibited an increasing trend, albeit at varying rates among Asia-Pacific countries, during a concurrent boom in the elderly population. As such, the connection between the rising prevalence of the aging population and the slow progress in alleviating income inequality remains unclear. Moreover, there is a lack of empirical analysis focusing on domestic savings as a potential transmission mechanism within the aging-inequality nexus. To address these questions, this study sets forth three primary objectives. First, the study investigates whether a long-term relationship exists between aging and income inequality using the Augmented Autoregressive Distributed Lag (A-ARDL) bounds test. The key findings confirm that aging coexists with income inequality in advanced aging economies. Empirical evidence indicates that population aging exacerbates income inequality in Australia, New Zealand, Japan, and China. Conversely, the aging process in Hong Kong appears to moderate inequality. The second objective explores the role of domestic savings as a transmission mechanism in the relationship between aging and income inequality, while also considering the effects of social globalization. The results reveal that aging significantly influences savings behaviors in aged and super-aged countries. Australia, New Zealand, Japan, and China display a negative relationship between aging and savings, whereas Hong Kong shows a positive correlation between the older dependency ratio and domestic saving.
- ItemPREPARATION AND PROPERTIES OF SEPIOLITE-FILLED ETHYLENE PROPYLENE DIENE TERPOLYMER COMPOSITES(2020-07-01)The role of clays as fillers in rubber composites is unquestionably important due to their abundance, low cost, light colour, and ability to enhance the strength and stiffness of rubber. However, differences between the compatibility of the hydrophilic clay and the hydrophobic rubber, which would result in a poor dispersion, remains as a challenging problem in industrial applications. This study was conducted to determine the potential of incorporating sepiolite (Sep) as a filler in ethylene propylene diene terpolymer (EPDM). EPDM/Sep composites were prepared with Sep loadings of 0–70 parts per hundred of rubber (phr) using a two-roll mill. The results indicated improvements in the tensile and dynamic mechanical properties, swelling resistance and crosslink density, thermal stability, and flammability resistance of the sepiolite-filled composite compared with the unfilled composite. The homogenous dispersion of sepiolite particles in the EPDM matrix and the formation of zigzag structures, especially at 60 phr, were the main reasons for the improved mechanical properties of the composite, which were confirmed by the morphological studies. The formation of a protective layer, which acted as a barrier against heat transfer into the deeper layers, had enhanced the flammability resistance of the composites. In the study of sepiolite hybridised with carbon black (CB), silica, or calcium carbonate (CaCO3), five different compositions were prepared, with EPDM/Sep at 30 phr as a control composite. EPDM/Sep/CB displayed the highest tensile strength, thermal stability, and improved flammability resistance. These results were influenced by the ability of CB to disperse well and form protective layers that could act as a mass transport barrier in the matrix. Significant findings in this work indicated that silica and CB were able to be hybridised with sepiolite, while sepiolite could be a potential substitute for CaCO3 in the EPDM composites. Meanwhile, the utilisation of glut palmitate (GP) salt and (3-aminopropyl) trimethoxysilane (APTMS) as coupling agents in the EPDM/Sep composites have successfully enhanced the tensile strength and elongation at break, the rubber-filler interaction, and dynamic mechanical properties. The enhanced rubber-filler interaction indicated that the presence of GP and APTMS have improved the compatibility and interaction between Sep and EPDM matrix, as supported by the FTIR results. Studies on different vulcanisation systems revealed that the highest tensile and dynamic mechanical properties were exhibited by the sulphur system, followed by the mixed curative and peroxide system, whereas the highest thermal stability and flammability resistance were demonstrated by the peroxide system.
- ItemCIT553 – Business Intelligence and Data Mining June 2018(Universiti Sains Malaysia, 2018-06)