Now showing 1 - 10 of 15
  • Publication
    New Development Quantification Methods for Salt Iodine and Urinary Iodine Using Microfluidics Based Nanotechnology
    ( 2020-03-18)
    Nur Hulwani Ibrahim
    ;
    ; ; ; ;
    Muhammad Nur Afnan Uda
    In Malaysia, the first Iodine Deficiency Disorders (IDD) survey was conducted in 1996 and it was discovered that Peninsular Malaysia did not have IDD problem until latter studies showed goitre occurrence of 34.7% in Hulu Langat district and urinary iodine lower than the adequate level of (100-199 ug/L) in Perak and Pahang states (Selamat et al., 2010). Baseline and periodical sampling of children and pregnant woman urine and imported salt commodities for the consumption of the population is mandatory for iodine measurement. Thus, development of quantitative methods of measurement of salt and food iodine is crucial for implementation of the USI program nationwide. In this study, interdigitated electrode (IDE) biosensor, a rapid, sensitive and selective method has been developed to determine the iodine content in both urine and salt. This method includes functionalization and silanization step using 3-aminopropyl triethoxysilane (APTES). The I-V characterization of IDE biosensor was performed using (Keithley 2450), Kickstart software and Probestation. It measures the amount of current flow through IDE which is directly proportional to the concentration of iodine in both urine and salt. Hence, IDE biosensor is proven to be a rapid, selective, sensitive method and can be developed as a new nanotechnology for the elimination of Iodine Deficiency Disorders (IDD) among children and pregnant woman.
  • Publication
    Preliminary studies on antimicrobial activity of extracts from aloe vera leaf, citrus hystrix leaf, zingiber officinale and Sabah snake grass against bacillus subtilis
    Herbal plants have several potential antimicrobial activities either as antifungal or antibacterial to fight against the disease and pathogen that attack the plants. The extractions of the Aloe vera leaf, Citrus hystrix leaf, Zingiber officinale rhizome and Sabah snake grass were selected in this study to fight against Bacillus subtilis. B. subtilis is a Gram-positive bacterium, rodshaped and catalase-positive that lives on decayed organic material. It is known as Gram-positive bacteria because of its thick peptidoglycan and would appear purple when subjected to Gram test. This species is commonly found in the upper layers of the soil, in meat or vegetables, in pastry, cooked meat, in bread or poultry products. The extracts of Sabah Snake Grass found to be most effective than A.vera leaf, Z. officinale, and C. hystrix against the B. subtilis.
  • Publication
    A review on additive manufacturing in bioresorbable stent manufacture
    Vascular injury and disease as well as cardiac and cardiovascular diseases have been a serious threat to human life and health today. Stents implantation have been the primary treatment for vascular diseases. Polymeric bioresorbable stents manufactured with 3D printer is newly emerged. This work review the bioresorbable stents and the utilization of additive manufacturing in bioresorbable stent manufacture.
  • Publication
    Bandwidth enhancement of five-port reflectometer-based ENG DSRR metamaterial for microwave imaging application
    ( 2020-03-01)
    Hossain T.M.
    ;
    Jamlos M.F.
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    ;
    Dzaharudin F.
    ;
    Ismail M.Y.
    ;
    Al-Bawri S.S.
    ;
    Sugumaran S.
    ;
    A five-Port Reflectometer (FPR) with the integration of ultra-wideband (UWB) Epsilon Negative (ENG) Double Split Ring Resonator (DSRR) metamaterial array is introduced in this paper for microwave imaging (MWI) application. The designed DSRR consists of two concentric rings with a split in each which are spatially rotated by 180°, formed an inverted structure to exhibit a wide negative epsilon bandwidth of 187 % (from 0.5 GHz to 15 GHz). The FPR is designed using a ring junction topology and semi-circularly curved inter-port transmission lines (TLs) which are placed between five equally spaced ports. Localizing the DSRR metamaterial in a periodic array of 5 × 4 at the ground plane of FPR lead to 79.79 % fractional bandwidth and reflection coefficient within the operating frequencies of 0.991 GHz–2.2576 GHz. Equivalent circuit model has been alluded with an intricate description of different array configurations of the metamaterial unit cell. Comparison of EM simulation and circuit simulation has been performed to validate the equivalent circuit model. It is found that the existence of stray capacitance, Cstray which is represented by the DSRR configurations, significantly influenced the resonant frequency and bandwidth of FPR. Measured results of the proposed design suits well with the simulations and prove higher efficacious applicability of the proposed design for microwave imaging application. A comparison of the reconstructed image also proves its suitability for the microwave imaging application.
  • Publication
    Green synthesized strontium oxide nanoparticles by Elodea canadensis extract and their antibacterial activity
    ( 2022-06-01)
    Anbu P.
    ;
    ; ;
    Letchumanan I.
    ;
    Subramaniam S.
    The production of strontium oxide nanoparticles from an aquatic plant extract is described here. UV–vis spectroscopy at ~ 220 nm was used to confirm the biosynthesis of these particles, and the color of the mixtures altered from colorless to green. The morphology of Elodea canadensis strontium oxide nanoparticles (EcSrONPs) was characterized using FE-SEM. FE-SEM images demonstrated that these particles adopted disordered, irregular shapes with agglomeration and slightly smooth surfaces. FE-TEM confirmed the results of FE-SEM analysis. These particles were also evaluated using XRD, XPS, and FTIR. The XRD pattern revealed a face-centered cubic crystalline structure at (209) and (217), while the XPS results verified the presence of both strontium and oxygen in the synthesized EcSrONPs. FTIR results confirmed that phytochemical functional groups served as capping agents during EcSrONP synthesis. In addition, zeta potential analysis confirmed the stability of EcSrONPs. Finally, the antibacterial potential of the produced EcSrONPs against Escherichia coli and Bacillus subtilis was evaluated. The largest inhibitory zone against E. coli (diameter, 22 mm) and B. subtilis (diameter, 20 mm) was observed at a EcSrONPs concentration of 24 Âµg·mL−1. Collectively, the findings of this research show that the biosynthesis of EcSrONPs is a viable option for developing novel materials for biomedical applications.
  • Publication
    Recent advances in synthesis of Graphite from agricultural bio-waste material : a review
    Graphitic carbon is a valuable material that can be utilized in many fields, such as electronics, energy storage and wastewater filtration. Due to the high demand for commercial graphite, an alternative raw material with lower costs that is environmentally friendly has been explored. Amongst these, an agricultural bio-waste material has become an option due to its highly bioactive properties, such as bioavailability, antioxidant, antimicrobial, in vitro and anti-inflammatory properties. In addition, biomass wastes usually have high organic carbon content, which has been discovered by many researchers as an alternative carbon material to produce graphite. However, there are several challenges associated with the graphite production process from biomass waste materials, such as impurities, the processing conditions and production costs. Agricultural bio-waste materials typically contain many volatiles and impurities, which can interfere with the synthesis process and reduce the quality of the graphitic carbon produced. Moreover, the processing conditions required for the synthesis of graphitic carbon from agricultural biomass waste materials are quite challenging to optimize. The temperature, pressure, catalyst used and other parameters must be carefully controlled to ensure that the desired product is obtained. Nevertheless, the use of agricultural biomass waste materials as a raw material for graphitic carbon synthesis can reduce the production costs. Improving the overall cost-effectiveness of this approach depends on many factors, including the availability and cost of the feedstock, the processing costs and the market demand for the final product. Therefore, in this review, the importance of biomass waste utilization is discussed. Various methods of synthesizing graphitic carbon are also reviewed. The discussion ranges from the conversion of biomass waste into carbon-rich feedstocks with different recent advances to the method of synthesis of graphitic carbon. The importance of utilizing agricultural biomass waste and the types of potential biomass waste carbon precursors and their pre-treatment methods are also reviewed. Finally, the gaps found in the previous research are proposed as a future research suggestion. Overall, the synthesis of graphite from agricultural bio-waste materials is a promising area of research, but more work is needed to address the challenges associated with this process and to demonstrate its viability at scale.
  • Publication
    Key features of additive manufacturing: A review
    This work reviews the key features and capabilities of additive manufacturing, which include the fundamental of additive manufacturing followed by types of additive manufacturing technologies. Advantages and limitation of additive manufacturing is discussed and the emergence of additive manufacturing in industrial revolution 4.0 is presented. Economy benefits through the additive manufacturing showing beneficial potential.
  • Publication
    Optimization of Pretreatment and Enzymatic Hydrolysis of Spent Coffee Ground for the Production of Fermentable Sugar
    The aim of this work was to optimize the condition of pretreatment and enzymatic hydrolysis for high yield of sugar production of spent coffee ground (SCG). Acid and alkaline pretreatment method were compared and the method with more sugar produced was selected. Response surface methodology was use for the analysis of conditions such as concentration of alkali, temperature and weight of SCG. The optimized condition obtained was 0.5% (v/v) of alkali, temperature of 100°C and 5% (w/v) of SCG. Enzymatic hydrolysis was carried out after the optimized condition of alkaline pretreatment. The conditions were pH, temperature and enzyme dosage. The optimized condition obtained was at pH 4.8, 0.01 ml of enzyme and temperature of 55°C.
  • Publication
    Influence of carbonization conditions and temperature variations on the characteristics of coconut shell carbon
    ( 2024-03)
    Yee Wen Yap
    ;
    Nurul Najiha Abu Bakar
    ;
    ; ;
    Siti Norsaffirah Zailan
    ;
    ; ; ;
    Mohd Yusry Mohamad Yunus
    This research aims to study the impact of carbonization atmospheres (ambient and nitrogen) and temperature on the properties of the coconut shell carbon (CSC) formed. To characterize the properties of CSC, the char yield percentage was calculated. Scanning Electron Microscopy (SEM) was used to study the surface morphology of CSC while X-ray Diffraction (XRD) analysis was done to identify the degree of graphitization. The carbon formed by carbonization under the nitrogen atmosphere yields lower char percentages compared to the ambient atmosphere. When the carbonization temperature elevated, both atmospheres produced a lower char yield percentage. This result is aligned with the SEM analysis where more and larger pores were observed from the carbon produced at higher temperatures and the result was further enhanced under a nitrogen atmosphere. It was found that the char yield of CSC decreased from 20.9% to 11.4% when the carbonization temperature increased from 400°C to 1000°C under the ambient atmosphere. More significant changes were formed through the carbonization process under the nitrogen atmosphere (from 18.3% to 6.03%). Pores formed when the volatile materials are released due to the elevated carbonization temperature, resulting in a reduction in total weight thus, the char yield percentage. From the XRD, all CSC produced from both atmospheres with varying temperatures poses an amorphous XRD pattern. However, the right shifted peak and the presence of an additional peak of ~40° suggest that under different temperatures and atmospheres, the crystallinity of the CSC produced was affected. This research provides insight for optimizing CSC production in the future to enhance the application of CSC.
  • Publication
    Recent Advances in Synthesis of Graphite from Agricultural Bio-Waste Material: A Review
    Graphitic carbon is a valuable material that can be utilized in many fields, such as electronics, energy storage and wastewater filtration. Due to the high demand for commercial graphite, an alternative raw material with lower costs that is environmentally friendly has been explored. Amongst these, an agricultural bio-waste material has become an option due to its highly bioactive properties, such as bioavailability, antioxidant, antimicrobial, in vitro and anti-inflammatory properties. In addition, biomass wastes usually have high organic carbon content, which has been discovered by many researchers as an alternative carbon material to produce graphite. However, there are several challenges associated with the graphite production process from biomass waste materials, such as impurities, the processing conditions and production costs. Agricultural bio-waste materials typically contain many volatiles and impurities, which can interfere with the synthesis process and reduce the quality of the graphitic carbon produced. Moreover, the processing conditions required for the synthesis of graphitic carbon from agricultural biomass waste materials are quite challenging to optimize. The temperature, pressure, catalyst used and other parameters must be carefully controlled to ensure that the desired product is obtained. Nevertheless, the use of agricultural biomass waste materials as a raw material for graphitic carbon synthesis can reduce the production costs. Improving the overall cost-effectiveness of this approach depends on many factors, including the availability and cost of the feedstock, the processing costs and the market demand for the final product. Therefore, in this review, the importance of biomass waste utilization is discussed. Various methods of synthesizing graphitic carbon are also reviewed. The discussion ranges from the conversion of biomass waste into carbon-rich feedstocks with different recent advances to the method of synthesis of graphitic carbon. The importance of utilizing agricultural biomass waste and the types of potential biomass waste carbon precursors and their pre-treatment methods are also reviewed. Finally, the gaps found in the previous research are proposed as a future research suggestion. Overall, the synthesis of graphite from agricultural bio-waste materials is a promising area of research, but more work is needed to address the challenges associated with this process and to demonstrate its viability at scale.
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