Pusat Pengajian Sains Kimia - Tesis
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- PublicationOptimization Of Energy Generation And Removal Of Pollutants Using Microbial Fuel Cells (Mfcs) With Modified Graphene-steel Anodes(2024-09)Daud, Najwa Najihah MohamadMicrobial fuel cells (MFCs) offer promising energy generation and pollutant removal solutions. However, instabilities in electrode and organic substrate materials hinder efficient electron transport and generation. This research investigates and compares the performance of commercial plain anodes—graphite (GE), mild steel (ME), and stainless steel (SE)—with graphene derivative coatings synthesized from Nipah palm frond (NPF)—graphene-graphite (GO-GE), graphene-mild steel (GO-ME), and graphene-stainless steel (GO-SE). The electricity generation and pollutant removal performance of the MFCs were monitored over distinct operational periods: 65 days for plain anodes and 105 days for coated anodes. Results show that GO-ME consistently outperforms other anodes, generating 29.10 mW/m2 compared to GO-SE (26.50 mW/m2), GO-GE (7.60 mW/m2), SE (5.85 mW/m2), ME (2.75 mW/m2), and GE (1.07 mW/m2). MFCs demonstrated high bisphenol A (BPA) pollutant removal efficiencies for GO-ME at 98.03%, followed by GO-GE at 96.95%, GO-SE at 83.73%, SE at 96.25%, ME at 94.55%, and GE at 81.08%, with all reactions surpassing over 96% in lead (II) nitrate (Pb(NO3)2) removal efficiency. Nira sap serves as a beneficial organic substrate, fostering Bacillus sp. dominance across all anodes. The research concludes by comparing prior results and suggesting further recommendations.
- PublicationSynthesis And Molecular Docking Studies Of New Phenylisoxazole Quinoxaline-2-Amine Hybrids As Potential Α Amylase And Α-Glucosidase Inhibitors(2024-03)Radzuan, Siti Nurshahira MohdNew phenylisoxazole quinoxaline-2-amine hybrids 55a-i were successfully synthesised with percentage yield ranging from 53% to 85%. These compounds were purified and characterised by 1D- and 2D- NMR (1H, 13C, HSQC, HMBC and COSY), FTIR, and HRMS analyses. Then, the hybrids underwent in vitro α-amylase and α-glucosidase inhibitory assays, with acarbose as the positive control. Through the biological study, compound 55i exhibits the most potent α-amylase inhibitory activity with IC50 = 16.4 M, while compounds 55a, 55c-f, and 55i exhibit good potential as α-glucosidase inhibitors, with 55e being the most potent inhibitor (IC50 = 15.2 M). Moreover, through the molecular docking studies, the inhibition potential for both α-amylase and α-glucosidase were affirmed, where all selected compounds exhibit good binding energy with both enzymes. Compound 55i showed important interactions with α-amylase enzyme active site and exhibited the highest binding energy of -8.9 0.10 kcal/mol, while compound 55e exhibited the highest binding energy of -9.0 0.20 kcal/mol by forming important interactions with the α-glucosidase enzyme active site residues. From the in vitro and in silico studies conducted, it can be concluded that compounds 55c and 55i exhibit the potential as dual inhibitors for both enzymes. Thus, it can be concluded that the quinoxaline-isoxazole hybrids synthesised in this study exhibit promising potential as α-amylase and α-glucosidase inhibitors for type 2 diabetes mellitus.
- PublicationTransesterification Of Palm Cooking Oil Using BiFeO3 Nanocatalyst(2019-08)Razuki, Nor AmirahA novel heterogeneous bismuth ferrite nanocatalyst was successfully synthesized via facile biotemplated technique (BiFeO3) using polysaccharides of kappa-carrageenan with an aim to study its efficiency transesterification reaction of palm cooking oil. Pure BiFeO3 with particle size of 95.8 nm was obtained using 1:2 molar ratio of Bi to Fe with 1 % carrageenan biotemplate and calcined at 823 K for 2 hours. The produced nanocatalyst possess high thermal stability and X-ray diffraction (XRD) result confirmed the purity of its rhombohedral crystalline phases.
- PublicationDesign, Synthesis, Molecular Docking And Cytotoxic Activity Of New Ortho-Hydroxy Chalcone And Pyrazoline Derivatives(2019-06)Luhaibi, Maadh Jumaah OwaidThis study focused on the design and synthesis of new compounds with anticancer activity. The compounds were constructed using the structure-based drug design, focusing on their binding capabilities to the Colchicine (PDB code: IS AO) active site in a bidentate manner, with the most energetically preferable binding modes using Autodock Vina 1.1.2 and Discovery studio 4.1. In the molecular docking analysis, the binding energy and interactions between protein receptors and ligands provide a better understanding of the biological functions to determine the amino acid residues which are crucial to docking interactions. The modification and replacement of the pyrazoline structure and chaicone led to the development of the structureactivity relationship and identified potent and selective inhibitors of drug design.
- PublicationRust Conversion Studies Of Archeological Irons From Fort Cornwallis Using Modified Oil Palm Fronds Lignin(2024-09)Osman, Liyana SyafawatiThis research reveals the structural and antioxidant properties of extracted organosolv lignin samples derived from oil palm fronds (OPF) pretreated with autohydrolysis upon incorporation with 1,5-dihydroxy naphthalene (AHD EOL) and p-benzoquinone (AHPB EOL) and steam explosion pretreatment impregnated with diluted sulfuric acid (SEA EOL). It was revealed that AHPB EOL had the highest percentage of yield among other organosolv lignin samples (% yield AHPB EOL: 13.79 ± 0.17% > % yield SEA EOL: 13.66 ± 0.35% > % yield AHD EOL: 13.09 ± 1.03% > % yield AH EOL: 12.40 ± 1.18%). Various organosolv lignin samples were then evaluated with elemental analysis, Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), thermogravimetric (TGA), differential-scanning calorimeter (DSC), solubility test, and antioxidant activity. Throughout the analyses, modified organosolv lignin (AHD EOL and AHPB EOL) and steam explosion acid impregnation organosolv lignin (SEA EOL) exhibited smaller lignin matrix with higher phenolic content (phenolic-OH SEA EOL: 0.60/Ar > phenolic-OH AHPB EOL: 0.47/Ar > phenolic-OH AHD EOL: 0.45/Ar > phenolic-OH AH EOL: 0.40/Ar), which leads to higher water solubility (D% SEA EOL: 29.50 ± 0.11% > D% AHPB EOL: 24.25 ± 0.13% > D% AHD EOL: 22.50 ± 0.16% > D% AH EOL: 20.50 ± 0.22%) and antioxidant activity compared to unmodified organosolv lignin (AH EOL).