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621.
Mostafa K. A. Al-Harbawi Mohd Fadlee A. Rasid Nor Kamariah Noordin 《Wireless Personal Communications》2012,65(2):469-488
ZigBee is an industrial standard for wireless ad hoc networks based on IEEE 802.15.4. It has been developed for low cost, low data rate and low power consumption. ZigBee??s network layer defines two routing protocols namely Ad Hoc On-demand Distance Vector and Tree Routing (TR). TR protocol follows the tree topology (parent?Cchild) in forwarding the data packets from source nodes to the sink node. However, the source does not find rather nor the location of the sink is close to the source node or if it is not in the sub-tree. In this case it will follow the tree topology which will use a lot of hops to deliver data packets to the sink node. This paper present an improvement of TR protocol for ZigBee network and is called Improved Tree Routing (ImpTR) protocol which is computationally simple in discovering the better path to transmit data packets to the sink node, and does not need any addition in hardware. ImpTR determines the better path to the sink node depending on the tables of the neighbouring nodes, which is part of the existing ZigBee network specification. Results show that the proposed algorithm provides shorter average end-to-end delay, increase throughput, decrease the average number of hops and decrease the energy consumption from the network when compared to the original TR routing protocol. 相似文献
622.
Modified QuEChERS method combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed and validated to determine pesticide residues in dried cocoa beans. Extraction efficiency of matrix hydration effect on 19 pesticide residues was studied and optimized using 23 full factorial design with percentage recoveries as the response variable. The optimized hydration method was validated for 24 pesticides, and recoveries obtained were in the range of 70–120% with relative standard deviations of less than 20% for most pesticides. Limit of quantification was obtained at 10 μg/kg for all pesticides, and this value was lower than national maximum residue levels (MRLs). Finally, the developed and optimized method was applied to real cocoa bean samples and the results from incurred residues were compared between method with and without matrix hydration. These results suggest that the addition of water to the dry and high-fat cocoa bean samples is crucial in pesticide residue analysis. 相似文献
623.
Cold-Active Lipases and Esterases: A Review on Recombinant Overexpression and Other Essential Issues
Adamu Idris Matinja Nor Hafizah Ahmad Kamarudin Adam Thean Chor Leow Siti Nurbaya Oslan Mohd Shukuri Mohamad Ali 《International journal of molecular sciences》2022,23(23)
Cold environments characterised by diverse temperatures close to or below the water freezing point dominate about 80% of the Earth’s biosphere. One of the survival strategies adopted by microorganisms living in cold environments is their expression of cold-active enzymes that enable them to perform an efficient metabolic flux at low temperatures necessary to thrive and reproduce under those constraints. Cold-active enzymes are ideal biocatalysts that can reduce the need for heating procedures and improve industrial processes’ quality, sustainability, and cost-effectiveness. Despite their wide applications, their industrial usage is still limited, and the major contributing factor is the lack of complete understanding of their structure and cold adaptation mechanisms. The current review looked at the recombinant overexpression, purification, and recent mechanism of cold adaptation, various approaches for purification, and three-dimensional (3D) crystal structure elucidation of cold-active lipases and esterase. 相似文献
624.
Nyok-Sean Lau Wooi Liang Heng Noorizan Miswan Nor Azura Azami Go Furusawa 《International journal of molecular sciences》2022,23(17)
The genus Photobacterium is known for its ecophysiological versatility encompassing free-living, symbiotic, and pathogenic lifestyles. Photobacterium sp. CCB-ST2H9 was isolated from estuarine sediment collected at Matang Mangrove, Malaysia. In this study, the genome of CCB-ST2H9 was sequenced, and the pan-genome of 37 Photobacterium strains was analysed. Phylogeny based on core genes showed that CCB-ST2H9 clustered with P. galatheae, forming a distinct clade with P. halotolerans, P. salinisoli, and P. arenosum. The core genome of Photobacterium was conserved in housekeeping functions, while the flexible genome was well represented by environmental genes related to energy production and carbohydrate metabolism. Genomic metrics including 16S rRNA sequence similarity, average nucleotide identity, and digital DNA–DNA hybridization values were below the cut-off for species delineation, implying that CCB-ST2H9 potentially represents a new species. Genome mining revealed that biosynthetic gene clusters (BGCs) involved in producing antimicrobial compounds such as holomycin in CCB-ST2H9 could contribute to the antagonistic potential. Furthermore, the EtOAc extract from the culture broth of CCB-ST2H9 exhibited antagonistic activity against Vibrio spp. Intriguingly, clustering based on BGCs profiles grouped P. galatheae, P. halotolerans, P. salinisoli, P. arenosum, and CCB-ST2H9 together in the heatmap by the presence of a large number of BGCs. These BGCs-rich Photobacterium strains represent great potential for bioactive secondary metabolites production and sources for novel compounds. 相似文献
625.
Lina M. Shaker Waleed Khalid Al-Azzawi Ahmed Al-Amiery Mohd S. Takriff Wan Nor Roslam Wan Isahak 《乙烯基与添加剂工艺杂志》2023,29(6):1023-1035
Biocompatible polymers such as poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) are used to prepare hydrogels for biomedical applications, including optical applications such as the manufacture of sensing devices, cosmetic and smart, and medical contact lenses, among others. In this study, three contact lenses were prepared by doping PVP-PVA supportive hydrogel with 0.1, 0.5, and 1 wt% of laboratory-manufactured Ag NPs. The work demonstrates the evaluation of vision correction through each lens and the effect of changing the concentration of silver on its refractive index. The simulation involved the design and simulation of an aberrated human eye based on the Liou and Brennan model (LBM), and the insertion of the contact lenses for vision correction using the ZEMAX optical design program. This work also included a study of the antimicrobial properties of the resulting hydrogel contact lenses doped with Ag NPs. The resulting refractive index of one PVP-PVA-Ag lens was relatively high at 532 nm = 1.604, which made the lens provide the highest image contrast (the lowest MTF curve degradation) of 0.883 ± 0.027 at 20 cycles/mm and an RMS nearly the Airy disc diameter of 3.983 μm. PVA was used in combination with PVP for stabilizing Ag NPs to give the contact lenses an antibacterial property. Finally, the optimum contact lens with a 1 wt% Ag NPs concentration showed the highest inhibition activity. 相似文献
626.
Noor Ul Sabah Muhammad Murad Khan Ramzan Talib Muhammad Anwar Muhammad Sheraz Arshad Malik Puteri Nor Ellyza Nohuddin 《计算机、材料和连续体(英文)》2023,75(3):4955-4972
Education quality has undoubtedly become an important local and international benchmark for education, and an institute’s ranking is assessed based on the quality of education, research projects, theses, and dissertations, which has always been controversial. Hence, this research paper is influenced by the institutes ranking all over the world. The data of institutes are obtained through Google Scholar (GS), as input to investigate the United Kingdom’s Research Excellence Framework (UK-REF) process. For this purpose, the current research used a Bespoke Program to evaluate the institutes’ ranking based on their source. The bespoke program requires changes to improve the results by addressing these methodological issues: Firstly, Redundant profiles, which increased their citation and rank to produce false results. Secondly, the exclusion of theses and dissertation documents to retrieve the actual publications to count for citations. Thirdly, the elimination of falsely owned articles from scholars’ profiles. To accomplish this task, the experimental design referred to collecting data from 120 UK-REF institutes and GS for the present year to enhance its correlation analysis in this new evaluation. The data extracted from GS is processed into structured data, and afterward, it is utilized to generate statistical computations of citations’ analysis that contribute to the ranking based on their citations. The research promoted the predictive approach of correlational research. Furthermore, experimental evaluation reported encouraging results in comparison to the previous modification made by the proposed taxonomy. This paper discussed the limitations of the current evaluation and suggested the potential paths to improve the research impact algorithm. 相似文献
627.
Nur Amalina Ramli Fatmawati Adam Khairatun Najwa Mohd Amin Adibi M. Nor Michael E. Ries 《加拿大化工杂志》2023,101(3):1219-1234
The inherent source of gelatin used for commercial hard capsules causes a surging demand for vegetarian capsules. In this work, carrageenan is utilized in preparing hard capsules to meet consumer preferences. Hydroxypropyl methylcellulose (HPMC) was incorporated as a reinforcing agent to improve the low mechanical properties of hard capsules made of carrageenan. The HPMC concentration was manipulated from 0.2 to 1.0 w/v% in the carrageenan matrix. The increasing concentration of HPMC exerts significant effects on the tensile strength and elongation at break, with an improvement of 59.1% and 46.9%, respectively, at the optimized HPMC concentration of 0.8 w/v%. The loop strength of the capsule is also increased by 56.4% with decreasing moisture content. The downfield movement from around 3.20 ppm of the carrageenan proton to 3.33 ppm in the proton nuclear magnetic resonanance ( 1H-NMR) spectrum suggests the formation of intermolecular hydrogen bonding between carrageenan and HPMC, which correlates to the results of Fourier-transform infrared spectroscopy (FTIR) and zeta potential. The glass transition temperature of the film was increased from 37.8 to 65.3°C, showing an upgrade in thermal stability. The film possesses a major mass loss with an activation energy of 64.7 kJ/mol with an increment of 43.4% compared to the control carrageenan. These findings support the conclusion that HPMC enhanced the mechanical properties and thermal stability of the carrageenan film, and the comprehensive analysis of the molecular interaction and decomposition kinetics subsequently may expand the application fields of the carrageenan-HPMC hard capsule as an alternative to gelatin in the future. 相似文献
628.
Nor Asikin Awang Wan Norharyati Wan Salleh Farhana Aziz Norhaniza Yusof Ahmad Fauzi Ismail 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2023,98(1):22-44
Heavy metal pollution of water is a global concern, which adversely affects human health because of its resistance to biodegradation and thus its transmission in the food chain via bioaccumulation. Nano zerovalent iron (nZVI) is very effective for the removal of heavy metals and is cost effective in terms of production. However, the main problems of nZVI are agglomeration and ease of oxidation. Several stabilization materials have been implemented to limit the aggregation of nZVI, such as silica, activated carbon and biochar. In comparison, as a support material, biochar possesses a large surface area, high stability and strong adsorption capacity, as well as being obtainable from various types of materials. Thus, this work aims to establish the opportunities available on the use of biochar-supported nZVI in utilizing its ability to stabilize and immobilize the nZVI. This review also reports the preparation, modification and surface enhancement of biochar, nZVI and biochar-nZVI for practical use as adsorbents. This review shows that modifications of the nZVI surface can help in their stabilization and reduction of aggregation. Additionally, this review is able to increase one's understanding of heavy metal sorption behavior by biochar-supported nZVI as it is the important as heavy metal sorption is driven based on biochar-nZVI type and heavy metal species which involve numerous mechanisms, including physical binding, complexation, ion exchange, surface precipitation and electrostatic interactions. Furthermore, this research reviews the adsorption parameters, including the crucial adsorption mechanism of heavy metals onto biochar-nZVI; the reusability of the biochar-nZVI is also discussed in this work. © 2022 Society of Chemical Industry (SCI). 相似文献
629.
Farooqi Ahmad Salam Adnan Siti Nur Fatihah Binti Setiabudi Herma Dina Muhammad Syed Anuar Faua’ad Syed Ismail Shahrul Aslam Sameen Abdullah Bawadi 《Topics in Catalysis》2023,66(1-4):235-246
Topics in Catalysis - Bi-reforming of methane (BRM) technology has the potential to serve as an alternative energy source while also mitigating greenhouse gas emissions. However, the main hurdle in... 相似文献
630.
Khalid Norlin Ali Mohd Helmi Ridzuan Nur Hilfa Awatif Mohamad Tseng Ming-Lang Nadzir Mohd Shahrul Mohd Nor Shifa Md 《Clean Technologies and Environmental Policy》2023,25(1):173-194
Clean Technologies and Environmental Policy - Palm oil is a major global commodity that is vital for the well-being of many communities. Despite its significant contribution to the attainment of... 相似文献