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PublicationStructural Elucidation of the Masp1 and Masp2 protein from Nephila Pilipes Web via bioinformatics approaches(Semarak Ilmu Publishing, 2023)Major ampullate spidroin (MaSps) from orb-weaver spp spider has recently gained interest due to its exceptional characteristics. The biomechanical and biochemical properties from MaSps offer potential in harvesting and exploiting MaSps as a promising bio-based product. However, the current research on the structural elucidation focused more onto the Nephila clavipes spider web rather than the Nephila pilipes which are more common in this region. Herein, this study integrates the used of computational power and algorithm to elucidate the 3D protein morphology of MaSp1 and MaSp2 of Nephila pilipes dragline silk protein using nearly complete amino acid sequences obtained from the protein database (PDB). In silico homology modelling via Phyre2, SWISS-MODEL and RaptorX was adopted to predict the protein structure of MaSP-1 and 2 using proteins threading, automated comparative modelling of three-dimensional (3D) protein structures and deep learning approaches. Consequently, we described a thorough 3D protein models of MaSp1 and MaSp2 with a higher percentage of coils, α-helix and a low percentage of β-sheet on repetitive regions of MaSp1 and MaSp2. The results of this current work provide insights into Bioinformatics potentials in engineering spider silk-based biomaterial and bridging the most apparent gaps in the knowledge of MaSp1 and MaSp2.
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PublicationDevelopment of porous glass-ceramic using silica sand for wall tiles application(Elsevier, 2023)The objective of this study was to create porous glass–ceramic from natural silica sources and industrial waste for use as wall tiles. The silica sand and soda lime glass waste were milled and sieved separately before being mixed in the appropriate ratios with a foaming agent (PCC). The mixed sample was then pressed into a button shape and sintered at different temperatures. The samples were characterized using universal testing machine for mechanical analysis and XRD for phase analysis. The results found that modulus of rupture (MOR) and density decrease while water absorption and porosity increased as sintering temperature increase. It was indicated that it already achieves the minimum requirement of ISO 13006 standard in term of MOR at sintering temperature 800 °C to produce porous glass–ceramic for wall tiles.
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PublicationFunctionalization of Multiwall Carbon Nanotubes (MWCNTS) using Phosphoric acid for immobilization of cellulase(United Scientific Group, 2023)In this paper, functionalization of multiwall carbon nanotubes (MWCNTs) using phosphoric acid (H3 PO4 ) was attempted. Based on the One Factor at a Time (OFAT) analysis, 8 M of H3 PO4, 8 h of reflux time and 80 °C were identi-fied as an ideal condition for the acid oxidation process. Successful functionaliza-tion of MWCNTs using H3 PO4 was revealed from Fourier Transform Infrared Spectroscopy (FTIR) peaks and Scanning Electron Microscope (SEM) images. The resulting f-MWCNTs were immobilized with cellulase via adsorption. The optimum temperature for free cellulase was at 50 °C and for immobilized cel-lulase was at 60 °C. The optimum pH was at 5 for both free and immobilized cellulase. Higher thermal stability was achieved with immobilized cellulase in which 39% activity still was retained at 80 °C compared to free cellulase. Reus-ability study of immobilized cellulase depicted 28% of remaining activity after 5th cycle of analysis using model substrate (filter paper Whatman No. 1). These results suggest that H3 PO4 which is a mild acid is a promising substitution for functionalization of MWCNTs.
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PublicationRice husk mat: organic Mulch for inhibition of weed seedling emergence and growth in nursery polybag(Friends Science Publishers, 2023)Abundantly available rice husk residues in Malaysia may be used as mulch that can result in reduced environmental pollution. Hence, this study was undertaken to determine the suitable thickness of rice husk mulch mat against selected weeds i.e., Eleusine indica (L.) Gaertn., Ageratum conyzoides (L.) L. and Cyperus distans L.f. These are highly invasive and abundant weeds found in oil palm nursery polybags. The experimental treatments consisted of 2-factors; (i) three levels of mulch mat thickness i.e., 2, 4 and 8 mm and two rice husk varieties i.e., MR 220 and MR 297. The results showed that increasing the mat thickness from 2 to 8 mm reduced the emergence, coverage, and biomass of weed seedlings at 6 weeks after treatment regardless of the rice variety used to produce the mat which was either MR 220 or MR 297. Punching tests were used to assess the mechanical properties of mats, while micrographs of the mats were captured to investigate the relationship between mat thickness and mechanical properties. Agglomerating agent was highly hydrated and nucleated on the rough surface of rice husk under 8 mm thick mats which led to the highest stress resistance and associated energy. However, intra-spaces of powdered rice husk were visible under 2 and 4-mm thick mats, resulted in decreased stress resistance and associated energy, thereby reducing the physical barrier of mats on test weeds. These findings imply that 8 mm thick rice husk mulch mat could be employed to control weeds in nursery polybags.
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PublicationEstimating unsaturated hydraulic conductivity in unsaturated soil using soil moisture sensors(Penerbit UTHM, 2023)Unsaturated hydraulic conductivity (K) is a measurement of soil water-retaining ability in unsaturated soil. The unsaturated hydraulic properties are necessary to predict the movement of water in unsaturated soil. The current study aims to create an alternative experimental device to estimate the K using soil moisture sensors. The experimental set up was designed and fabricated in order to measure the volumetric water content using GS3 (Campbell) sensors at different heights. The data obtained from the sensors was validated using mass of moist sand column measured from electronic balance. The K was estimated with the help of retention and conductivity functions. The primary materials used in the study were solute-free water and sand. It was found that the reading from the sensors was in good match with the reading of the volumetric water content calculated from the mass of water in the sand column with a root mean square error of 0.0091. Soil water retention curve and hydraulic conductivity were plotted using Peters-Durner-Iden (PDI) model. The results were compared to the van Genuchten function. The K prediction was initially equivalent for both models, but the later overpredicts the falling rate of hydraulic conductivity with the increasing soil matric suction before underpredict after 200 cm matric suction on a sandy soil. PDI function was able to extrapolate the hydraulic conductivity film flow region of sandy soil.