Displaying publications 1 - 20 of 490 in total

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  1. Mesoporous graphitic carbon electrodes derived from boat-fruited shells of Sterculia Foetida for symmetric supercapacitors for energy storage applications
    Boopathi G, Ragavan R, Jaimohan SM, Sagadevan S, Kim I, Pandurangan A, et al.
    Chemosphere, 2024 Jan;348:140650.
    PMID: 37951405 DOI: 10.1016/j.chemosphere.2023.140650
    In recent years, intensive research efforts have focused on translating biomass waste into value-added carbon materials broadcasted for their significant role in energy and environmental applications. For the first time, high-performance carbonaceous materials for energy storage applications were developed from the multi-void structure of the boat-fruited shells of Sterculia Foetida (SF). In that view, synthesized mesoporous graphitic activated carbon (g-AC) via the combination of carbonization at various elevating temperatures of 700, 800, and 900 °C, respectively, and alkali activation by KOH, with a high specific surface area of 1040.5 m2 g-1 and a mesopore volume of 0.295 cm3 g-1. In a three-electrode configuration, the improved electrode (SF-K900) exhibited excellent electrochemical behavior, which was observed in an aqueous electrolyte (1 M H2SO4) with a high specific capacitance of 308.6 F/g at a current density of 1 A/g, owing to the interconnected mesopore structures and high surface area of SF-K900. The symmetric supercapacitor (SSC) delivered the specific capacitance of 138 F/g at 1 A/g with a high energy density (ED) of 13.4 Wh/kg at the power density (PD) of 24.12 kW/kg with remarkable cycle stability and supercapacitive retention of 93% over 5000 cycles. Based on the findings, it is possible to develop low-cost active electrode materials for high-rate performance SSC using mesoporous g-AC derived from SF boat-fruited shells.
    Matched MeSH terms: Physical Phenomena
  2. Fulltext Optimizing energy efficiency in heterogeneous networks: An integrated stochastic geometry approach with novel sleep mode strategies and QoS framework
    Shabbir A, Rizvi S, Alam MM, Shirazi F, Su'ud MM
    PLoS One, 2024;19(2):e0296392.
    PMID: 38408070 DOI: 10.1371/journal.pone.0296392
    The quest for energy efficiency (EE) in multi-tier Heterogeneous Networks (HetNets) is observed within the context of surging high-speed data demands and the rapid proliferation of wireless devices. The analysis of existing literature underscores the need for more comprehensive strategies to realize genuinely energy-efficient HetNets. This research work contributes significantly by employing a systematic methodology, utilizing This model facilitates the assessment of network performance by considering the spatial distribution of network elements. The stochastic nature of the PPP allows for a realistic representation of the random spatial deployment of base stations and users in multi-tier HetNets. Additionally, an analytical framework for Quality of Service (QoS) provision based on D-DOSS simplifies the understanding of user-base station relationships and offers essential performance metrics. Moreover, an optimization problem formulation, considering coverage, energy maximization, and delay minimization constraints, aims to strike a balance between key network attributes. This research not only addresses crucial challenges in creating EE HetNets but also lays a foundation for future advancements in wireless network design, operation, and management, ultimately benefiting network operators and end-users alike amidst the growing demand for high-speed data and the increasing prevalence of wireless devices. The proposed D-DOSS approach not only offers insights for the systematic design and analysis of EE HetNets but also systematically outperforms other state-of-the-art techniques presented. The improvement in energy efficiency systematically ranges from 67% (min side) to 98% (max side), systematically demonstrating the effectiveness of the proposed strategy in achieving higher energy efficiency compared to existing strategies. This systematic research work establishes a strong foundation for the systematic evolution of energy-efficient HetNets. The systematic methodology employed ensures a comprehensive understanding of the complex interplay of network dynamics and user requirements in a multi-tiered environment.
    Matched MeSH terms: Physical Phenomena
  3. Fulltext Optimal performance of stand-alone hybrid microgrid systems based on integrated techno-economic-environmental energy management strategy using the grey wolf optimizer
    Tukkee AS, Bin Abdul Wahab NI, Binti Mailah NF, Bin Hassan MK
    PLoS One, 2024;19(2):e0298094.
    PMID: 38330067 DOI: 10.1371/journal.pone.0298094
    Recently, global interest in organizing the functioning of renewable energy resources (RES) through microgrids (MG) has developed, as a unique approach to tackle technical, economic, and environmental difficulties. This study proposes implementing a developed Distributable Resource Management strategy (DRMS) in hybrid Microgrid systems to reduce total net percent cost (TNPC), energy loss (Ploss), and gas emissions (GEM) while taking the cost-benefit index (CBI) and loss of power supply probability (LPSP) as operational constraints. Grey Wolf Optimizer (GWO) was utilized to find the optimal size of the hybrid Microgrid components and calculate the multi-objective function with and without the proposed management method. In addition, a detailed sensitivity analysis of numerous economic and technological parameters was performed to assess system performance. The proposed strategy reduced the system's total net present cost, power loss, and emissions by (1.06%), (8.69%), and (17.19%), respectively compared to normal operation. Firefly Algorithm (FA) and Particle Swarm Optimization (PSO) techniques were used to verify the results. This study gives a more detailed plan for evaluating the effectiveness of hybrid Microgrid systems from a technical, economic, and environmental perspective.
    Matched MeSH terms: Physical Phenomena
  4. Fulltext Linear Segmented Arc-Shaped Piezoelectric Branch Beam Energy Harvester for Ultra-Low Frequency Vibrations
    Piyarathna IE, Thabet AM, Ucgul M, Lemckert C, Lim YY, Tang ZS
    Sensors (Basel), 2023 Jun 01;23(11).
    PMID: 37299984 DOI: 10.3390/s23115257
    Piezoelectric energy harvesting systems have been drawing the attention of the research community over recent years due to their potential for recharging/replacing batteries embedded in low-power-consuming smart electronic devices and wireless sensor networks. However, conventional linear piezoelectric energy harvesters (PEH) are often not a viable solution in such advanced practices, as they suffer from a narrow operating bandwidth, having a single resonance peak present in the frequency spectrum and very low voltage generation, which limits their ability to function as a standalone energy harvester. Generally, the most common PEH is the conventional cantilever beam harvester (CBH) attached with a piezoelectric patch and a proof mass. This study investigated a novel multimode harvester design named the arc-shaped branch beam harvester (ASBBH), which combined the concepts of the curved beam and branch beam to improve the energy-harvesting capability of PEH in ultra-low-frequency applications, in particular, human motion. The key objectives of the study were to broaden the operating bandwidth and enhance the harvester's effectiveness in terms of voltage and power generation. The ASBBH was first studied using the finite element method (FEM) to understand the operating bandwidth of the harvester. Then, the ASBBH was experimentally assessed using a mechanical shaker and real-life human motion as excitation sources. It was found that ASBBH achieved six natural frequencies within the ultra-low frequency range (<10 Hz), in comparison with only one natural frequency achieved by CBH within the same frequency range. The proposed design significantly broadened the operating bandwidth, favouring ultra-low-frequency-based human motion applications. In addition, the proposed harvester achieved an average output power of 427 μW at its first resonance frequency under 0.5 g acceleration. The overall results of the study demonstrated that the ASBBH design can achieve a broader operating bandwidth and significantly higher effectiveness, in comparison with CBH.
    Matched MeSH terms: Physical Phenomena
  5. Fulltext Energy-Efficient and Variability-Resilient 11T SRAM Design Using Data-Aware Read-Write Assist (DARWA) Technique for Low-Power Applications
    Thirugnanam S, Soong LW, Prabhu CM, Singh AK
    Sensors (Basel), 2023 May 26;23(11).
    PMID: 37299822 DOI: 10.3390/s23115095
    The need for power-efficient devices, such as smart sensor nodes, mobile devices, and portable digital gadgets, is markedly increasing and these devices are becoming commonly used in daily life. These devices continue to demand an energy-efficient cache memory designed on Static Random-Access Memory (SRAM) with enhanced speed, performance, and stability to perform on-chip data processing and faster computations. This paper presents an energy-efficient and variability-resilient 11T (E2VR11T) SRAM cell, which is designed with a novel Data-Aware Read-Write Assist (DARWA) technique. The E2VR11T cell comprises 11 transistors and operates with single-ended read and dynamic differential write circuits. The simulated results in a 45 nm CMOS technology exhibit 71.63% and 58.77% lower read energy than ST9T and LP10T and lower write energies of 28.25% and 51.79% against S8T and LP10T cells, respectively. The leakage power is reduced by 56.32% and 40.90% compared to ST9T and LP10T cells. The read static noise margin (RSNM) is improved by 1.94× and 0.18×, while the write noise margin (WNM) is improved by 19.57% and 8.70% against C6T and S8T cells. The variability investigation using the Monte Carlo simulation on 5000 samples highly validates the robustness and variability resilience of the proposed cell. The improved overall performance of the proposed E2VR11T cell makes it suitable for low-power applications.
    Matched MeSH terms: Physical Phenomena
  6. Fulltext The Effect of a Setting Accelerator on the Physical and Mechanical Properties of a Fast-set White Portland Cement Mixed with Nano-zirconium Oxide
    Chen YZ, Yong MJ, Tan VY, Kong SLS, Elnawawy HMA, Yahya NA, et al.
    Eur Endod J, 2023 May;8(3):215-224.
    PMID: 37257037 DOI: 10.14744/eej.2023.36449
    OBJECTIVE: This study compared the effects of calcium chloride dihydrate (CaCl2.2H2O) on the physical properties and push-out bond strength of white Mineral Trioxide Aggregate (WMTA) and an experimental Malaysian Portland cement mixed with nano-zirconium oxide (nano-ZrO) [(radiopaque Malaysian Portland cement (RMPC). Mineral Trioxide Aggregate (MTA) was the first calcium silicate cement (CSC) introduced in dentistry, but up to date, it is an expensive cement with long setting time and causes tooth discolouration. Although Portland cement has been introduced as a potential substitute to MTA, it still faces some challenges such as long setting time and lack of sufficient radiopacity.

    METHODS: Four groups [WMTA, RMPC, fast-set WMTA (FS-WMTA) and fast-set RMPC (FS-RMPC)] were prepared. Initial setting time was evaluated using Vicat apparatus. The pH was measured at seven-day intervals. For discolouration potential, cements were packed in the pulp chamber of 46 extracted maxillary incisors. Spectrophotometric readings were obtained at seven-day intervals, and the rate of colour change (ΔE) was recorded. For the push-out bond strength testing, cements were applied in 48 sectioned root samples, and the test was performed using universal testing machine at crosshead speed of 0.5 mm/min until bond failure. Statistical analysis was done according to the nature of each group of data using SPSS 26.

    RESULTS: Addition of CaCl2.2H2O decreased the initial setting times of both RMPC and WMTA significantly (p<0.05). The pH values of FS-WMTA and FS-RMPC were comparable to their non-accelerated counterparts ranging from 10 to 12. Discolouration effect was more obviously observed with WMTA and FS-WMTA with time compared to RMPC formulations. Push-out bond strength of the two materials also showed an increase with the addition of the accelerator, however, only FS-WMTA showed statistically significant difference compared to WMTA (p<0.05).

    CONCLUSION: The addition of CaCl2.2H2O improves the physical and mechanical properties of the newly formulated RMPC and WMTA. The RMPC formulation overcomes the discolouration potential of WMTA. (EEJ-2022-12-155).

    Matched MeSH terms: Physical Phenomena
  7. Fulltext Role of Ca2+ doping on the enhancement of dielectric properties of Sr2-xCaxNiWO6 for energy storage device application
    Mohamed Saadon NAF, Taib NI, Loy CW, Mohamed Z
    Sci Rep, 2023 Jan 23;13(1):1246.
    PMID: 36690692 DOI: 10.1038/s41598-023-28296-7
    In this paper, Sr2-xCaxNiWO6 (x = 0.00, 0.02, 0.04, 0.06) were synthesized using a solid-state reaction method. The crystal structure, optical and dielectric properties of the compounds were examined using X-ray diffraction (XRD), scanning electron microscope (SEM) with energy dispersive (EDX) analysis, Ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy and electrochemical impedance spectroscopy respectively. The Rietveld refinement of XRD confirmed that the compounds crystallized in a tetragonal structure with a space group I4/m. According to the SEM images, the grain sizes of the compounds decreased as the dopant increased. The UV-vis analysis revealed that the band gap energy of the compounds decreased from 3.17 eV to 3.13 eV as the amount of doping increased from x = 0.00 to x = 0.06. A dielectric characterization showed that the dielectric constant (ε') and dielectric loss (tan δ) for all compounds possessed a similar trend where it was higher in low-frequency area (~ 1 Hz) and dropped instantaneously with the enhancement of frequency up to 1 MHz until it reached constant values.
    Matched MeSH terms: Physical Phenomena
  8. Nanoengineering Carbonaceous Materials: A Multifunctional Platform towards a Greener Energy Future
    Ong WJ
    Small, 2021 12;17(48):e2106667.
    PMID: 34854248 DOI: 10.1002/smll.202106667
    Matched MeSH terms: Physical Phenomena
  9. Low Frequency Dielectric and Optical Behavior on Physicochemical Properties of Hydroxyapatite/Cornstarch Composite
    Beh CY, Cheng EM, Mohd Nasir NF, Khor SF, Eng SK, Abdul Majid MS, et al.
    J Colloid Interface Sci, 2021 Oct 15;600:187-198.
    PMID: 34015511 DOI: 10.1016/j.jcis.2021.03.158
    An investigation on relationship among the physicochemical, optical and dielectric properties of the hydroxyapatite/cornstarch (HA/Cs) composites with the starch proportion of 30, 40, 50, 60, 70, 80 and 90 wt% is presented in this work. The HA/Cs composites have been characterized via FTIR, XRD, DRS and impedance analyzer. This work depicts that the strong interaction is exhibited between the hydroxyapatite nanoparticles and starch as the starch proportion increases. This increment trend results in the higher crystallinity of the HA/Cs composites. The highly crystallized HA/Cs with hydroxyapatite nucleation center presents low optical properties (diffuse reflectance and optical band gap energy). The HA/Cs composite with 80 wt% starch proportion (H2C8) show higher dielectric properties (dielectric constant, loss factor and conductivity) due to the stronger interfacial interaction and close-packed HA/Cs crystalline structure. The relationship among the physicochemical, optical and dielectric properties of the HA/Cs composite is studied in this work for potential of instrumentation design.
    Matched MeSH terms: Physical Phenomena
  10. Effect of magnetic field on nano-magnetite composite exhibits in ion-adsorption
    Lo FF, Kow KW, Kung F, Ahamed F, Kiew PL, Yeap SP, et al.
    Sci Total Environ, 2021 Aug 01;780:146337.
    PMID: 33770606 DOI: 10.1016/j.scitotenv.2021.146337
    Nano-magnetites are widely researched for its potential as an excellent adsorbent in many applications. However, the efficiency of the nano-magnetites are hindered by their tendency to agglomerate. In this work, we dispersed and embedded the nano-magnetites in a porous silica gel matrix to form a nanocomposite to reduce the extent of agglomeration and to enhance the adsorption performance. Our experimental results showed that the removal efficiency of Cu2+ ion has improved by 46% (22.4 ± 2.2%) on the nano-magnetite-silica-gel (NMSG) nanocomposite as compared to pure nano-magnetites (15.3 ± 0.6%). The adsorption capacity is further enhanced by 39% (from 11.2 ± 1.1 to 15.6 ± 1.6 mg/g) by subjecting the NMSG to a magnetic field prior to adsorption. We infer that the magnetic field aligned the magnetic domains within the nano-magnetites, resulting in an increased Lorentz force during adsorption. Similar alignment of magnetic domains is near to impossible in pure nano-magnetites due to severe agglomeration. We further found that the adsorption capacity of the NMSG can be manipulated with an external magnetic field by varying the strength and the configurations of the field. Equipped with proper process design, our finding has great potentials in processes that involve ion-adsorptions, for example, NMSG can: (i) replace/reduce chemical dosing in controlling adsorption kinetics, (ii) replace/reduce complex chemicals required in ion-chromatography columns, and (iii) reduce wastage of nano-adsorbents by immobilizing it in a porous matrix.
    Matched MeSH terms: Physical Phenomena
  11. Stretchable AgX (X = Se, Te) for Efficient Thermoelectrics and Photovoltaics
    Robin Chang YH, Jiang J, Khong HY, Saad I, Chai SS, Mahat MM, et al.
    ACS Appl Mater Interfaces, 2021 Jun 02;13(21):25121-25136.
    PMID: 34008948 DOI: 10.1021/acsami.1c04759
    Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag2S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional Ag
    x
    Se1-x and Ag
    x
    Te1-x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P212121-Ag8Se4 and P21/c-Ag8Te4 structures. Recently reported metastable AgTe3 was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/nmm-Ag4Se2 and C2-Ag8Te4 phases. Orthorhombic Ag8Se4 crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag4Se2 monolayer. Interestingly, metallic P21/c-Ag8Te4 changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young's modulus (E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11-28%), relatively high n(0) (1.59-1.93), and sizable α(ω) (104-105 cm-1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag-Se was found to rise from approximately 0.15-0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies.
    Matched MeSH terms: Physical Phenomena
  12. Fulltext Unexpected acceleration of Ultrasonic-Assisted iodide dosimetry in the catalytic presence of ionic liquids
    Krishnan S, Abd Ghani N, Aminuddin NF, Quraishi KS, Razafindramangarafara BL, Baup S, et al.
    Ultrason Sonochem, 2021 Jun;74:105576.
    PMID: 33975186 DOI: 10.1016/j.ultsonch.2021.105576
    This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs' anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.
    Matched MeSH terms: Physical Phenomena
  13. Fulltext Microstructural behavior of magnetorheological elastomer undergoing durability evaluation by stress relaxation
    Johari MAF, Mazlan SA, Nasef MM, Ubaidillah U, Nordin NA, Aziz SAA, et al.
    Sci Rep, 2021 May 25;11(1):10936.
    PMID: 34035434 DOI: 10.1038/s41598-021-90484-0
    The widespread use of magnetorheological elastomer (MRE) materials in various applications has yet to be limited due to the fact that there are substantial deficiencies in current experimental and theoretical research on its microstructural durability behavior. In this study, MRE composed of silicon rubber (SR) and 70 wt% of micron-sized carbonyl iron particles (CIP) was prepared and subjected to stress relaxation evaluation by torsional shear load. The microstructure and particle distribution of the obtained MRE was evaluated by a field emission scanning electron microscopy (FESEM). The influence of constant low strain at 0.01% is the continuing concern within the linear viscoelastic (LVE) region of MRE. Stress relaxation plays a significant role in the life cycle of MRE and revealed that storage modulus was reduced by 8.7%, normal force has weakened by 27%, and stress performance was reduced by 6.88% along approximately 84,000 s test duration time. This time scale was the longest ever reported being undertaken in the MRE stress relaxation study. Novel micro-mechanisms that responsible for the depleted performance of MRE was obtained by microstructurally observation using FESEM and in-phase mode of atomic force microscope (AFM). Attempts have been made to correlate strain localization produced by stress relaxation, with molecular deformation in MRE amorphous matrix. Exceptional attention was focused on the development of molecular slippage, disentanglement, microplasticity, microphase separation, and shear bands. The relation between these microstructural phenomena and the viscoelastic properties of MRE was diffusely defined and discussed. The presented MRE is homogeneous with uniform distribution of CIP. The most significant recent developments of systematic correlation between the effects of microstructural deformation and durability performance of MRE under stress relaxation has been observed and evaluated.
    Matched MeSH terms: Physical Phenomena
  14. Fulltext Process Optimization of In Situ Magnetic-Anisotropy Spark Plasma Sintering of M-Type-Based Barium Hexaferrite BaFe12O19
    Mohammed HG, Albarody TMB, Susilawati S, Gohari S, Doyan A, Prayogi S, et al.
    Materials (Basel), 2021 May 18;14(10).
    PMID: 34070195 DOI: 10.3390/ma14102650
    This paper introduces a new spark plasma sintering technique that is able to order crystalline anisotropy by in-series/in situ DC electric coupled magnetic field. The process control parameters have been investigated on the production of anisotropic BaFe12O19 magnets based on resulted remanence (Mr). Sintering holding time (H.T.), cooling rate (C.R.), pressure (P), and sintering temperature (S.T.) are optimized by Taguchi with L9 orthogonal array (OA). The remanent magnetization of nanocrystalline BaFe12O19 in parallel (Mrǁ) and perpendicular (MrꞱ) to the applied magnetic field was regarded as a measure of performance. The Taguchi study calculated optimum process parameters, which significantly improved the sintering process based on the confirmation tests of BaFe12O19 anisotropy. The magnetic properties in terms of Mrǁ and MrꞱ were greatly affected by sintering temperature and pressure according to ANOVA results. In addition, regression models were developed for predicting the Mrǁ as well as MrꞱ respectively.
    Matched MeSH terms: Physical Phenomena
  15. Fulltext A Review of the Applications and Biodegradation of Polyhydroxyalkanoates and Poly(lactic acid) and Its Composites
    Boey JY, Mohamad L, Khok YS, Tay GS, Baidurah S
    Polymers (Basel), 2021 May 12;13(10).
    PMID: 34065779 DOI: 10.3390/polym13101544
    Overconsumption of plastic goods and improper handling of petroleum-derived plastic waste have brought a plethora of negative impacts to the environment, ecosystem and human health due to its recalcitrance to degradation. These drawbacks become the main driving force behind finding biopolymers with the degradable properties. With the advancement in biopolymer research, polyhydroxyalkanoate (PHA) and poly(lacyic acid) (PLA) and its composites have been alluded to as a potential alternative to replace the petrochemical counterpart. This review highlights the current synthesis process and application of PHAs and PLA and its composites for food packaging materials and coatings. These biopolymers can be further ameliorated to enhance their applicability and are discussed by including the current commercially available packaging products. Factors influencing biodegradation are outlined in the latter part of this review. The main aim of this review article is to organize the scattered available information on various aspects of PHAs and PLA, and its composites for packaging application purposes. It is evident from a literature survey of about 140 recently published papers from the past 15 years that PLA and PHA show excellent physical properties as potential food packaging materials.
    Matched MeSH terms: Physical Phenomena
  16. Fulltext Fabrication and Characterization of Chitosan-Tamarind Seed Polysaccharide Composite Film for Transdermal Delivery of Protein/Peptide
    Malviya R, Tyagi A, Fuloria S, Subramaniyan V, Sathasivam K, Sundram S, et al.
    Polymers (Basel), 2021 May 10;13(9).
    PMID: 34068768 DOI: 10.3390/polym13091531
    Transdermal drug delivery is used to deliver a drug by eliminating the first-pass metabolism, which increases the bioavailability of the drug. The present study aims to formulate the chitosan-tamarind seed polysaccharide composite films and evaluate for the delivery of protein/peptide molecules. Nine formulations were prepared and evaluated by using different parameters, such as physical appearance, folding endurance, thickness of film, surface pH, weight variation, drug content, surface morphology, percentage moisture intake and uptake, drug release kinetics, and drug permeability. The film weight variance was observed between 0.34 ± 0.002 to 0.47 ± 0.003 g. The drug level of the prepared films was found to be between 96 ± 1.21 and 98 ± 1.33μg. Their intake of moisture ranged between 2.83 ± 0.002 and 3.76 ± 0.001 (%). The moisture absorption of the films ranged from 5.33 ± 0.22 to 10.02 ± 0.61 (%). SEM images revealed a smooth film surface, while minor cracks were found in the film after permeation tests. During the first 4 days, drug release was between 13.75 ± 1.64% and 22.54 ± 1.34% and from day 5 to day 6, it was between 72.67 ± 2.13% and 78.33 ± 3.13%. Drug permeation during the first 4 days was 15.78 ± 1.23 %. Drug permeation (%) during the first 4 days was between 15.78 ± 1.23 and 22.49 ± 1.29 and from day 5 to day 6, it was between 71.49 ± 3.21 and 77.93 ± 3.20.
    Matched MeSH terms: Physical Phenomena
  17. Molecular docking of compounds from Clinacanthus nutans extract detected by GC-MS analysis with the SARS-CoV-2 main protease and ACE2 protein
    Ismail NZ, Adebayo IA, Mohamad Zain NN, Arsad H
    Nat Prod Res, 2021 May 05.
    PMID: 33949277 DOI: 10.1080/14786419.2021.1919104
    Clinacanthus nutans has been reported to have many medicinal properties and it is traditionally used in treating viral lesions. This study aims to determine the molecular docking of C. nutans compounds detected by Gas Chromatography-Mass Spectrometry (GC-MS) with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 main protease) protein and its host receptor angiotensin-converting enzyme 2 (ACE2) protein using the AutoDock 4.2 tool. The drug-likeness and molecular docking analyses showed that fourteen compounds of C. nutans satisfied the Lipinski's rule of five and they exhibited good inhibitory effects against the SARS-Cov-2 main protease and ACE2 proteins. In addition, the glyceryl 2-linolenate compound was found to have the most potent binding affinities with both proteins. The results provide useful insights into the molecular inhibitory interactions of C. nutans compounds detected by GC-MS analysis with the targeted SARS-CoV-2 main protease and ACE2 protein.
    Matched MeSH terms: Physical Phenomena; Biophysical Phenomena
  18. Fulltext Thickness Optimization of Thin-Film Tandem Organic Solar Cell
    Bangash KA, Kazmi SAA, Farooq W, Ayub S, Musarat MA, Alaloul WS, et al.
    Micromachines (Basel), 2021 May 05;12(5).
    PMID: 34062988 DOI: 10.3390/mi12050518
    The polymer solar cells also known as organic solar cells (OSCs) have drawn attention due to their cynosure in industrial manufacturing because of their promising properties such as low weight, highly flexible, and low-cost production. However, low η restricts the utilization of OSCs for potential applications such as low-cost energy harvesting devices. In this paper, OSCs structure based on a triple-junction tandem scheme is reported with three different absorber materials to enhance the absorption of photons which in turn improves the η, as well as its correlating performance parameters. The investigated structure gives the higher value of η = 14.33% with Jsc = 16.87 (mA/m2), Voc = 1.0 (V), and FF = 84.97% by utilizing a stack of three different absorber layers with different band energies. The proposed structure was tested under 1.5 (AM) with 1 sun (W/m2). The impact of the top, middle, and bottom subcells' thickness on η was analyzed with a terse to find the optimum thickness for three subcells to extract high η. The optimized structure was then tested with different electrode combinations, and the highest η was recorded with FTO/Ag. Moreover, the effect of upsurge temperature was also demonstrated on the investigated schematic, and it was observed that the upsurge temperature affects the photovoltaic (PV) parameters of the optimized cell and η decreases from 14.33% to 11.40% when the temperature of the device rises from 300 to 400 K.
    Matched MeSH terms: Physical Phenomena
  19. Fulltext Impact of two-phase hybrid nanofluid approach on mixed convection inside wavy lid-driven cavity having localized solid block
    Alsabery AI, Tayebi T, Kadhim HT, Ghalambaz M, Hashim I, Chamkha AJ
    J Adv Res, 2021 May;30:63-74.
    PMID: 34026287 DOI: 10.1016/j.jare.2020.09.008
    Introduction: Mixed convection flow and heat transfer within various cavities including lid-driven walls has many engineering applications. Investigation of such a problem is important in enhancing the performance of the cooling of electric, electronic and nuclear devices and controlling the fluid flow and heat exchange of the solar thermal operations and thermal storage.

    Objectives: The main aim of this fundamental investigation is to examine the influence of a two-phase hybrid nanofluid approach on mixed convection characteristics including the consequences of varying Richardson number, number of oscillations, nanoparticle volume fraction, and dimensionless length and dimensionless position of the solid obstacle.

    Methods: The migration of composite hybrid nanoparticles due to the nano-scale forces of the Brownian motion and thermophoresis was taken into account. There is an inner block near the middle of the enclosure, which contributes toward the flow, heat, and mass transfer. The top lid cover wall of the enclosure is allowed to move which induces a mixed convection flow. The impact of the migration of hybrid nanoparticles with regard to heat transfer is also conveyed in the conservation of energy. The governing equations are molded into the non-dimensional pattern and then explained using the finite element technique. The effect of various non-dimensional parameters such as the volume fraction of nanoparticles, the wave number of walls, and the Richardson number on the heat transfer and the concentration distribution of nanoparticles are examined. Various case studies for Al2O3-Cu/water hybrid nanofluids are performed.

    Results: The results reveal that the temperature gradient could induce a notable concentration variation in the enclosure.

    Conclusion: The location of the solid block and undulation of surfaces are valuable in the control of the heat transfer and the concentration distribution of the composite nanoparticles.

    Matched MeSH terms: Physical Phenomena
  20. Fulltext Effect of Cellulose Nanofibrils on the Properties of Jatropha Oil-Based Waterborne Polyurethane Nanocomposite Film
    Amri MR, Guan CT, Osman Al-Edrus SS, Md Yasin F, Mohamad SF
    Polymers (Basel), 2021 Apr 30;13(9).
    PMID: 33946517 DOI: 10.3390/polym13091460
    The objective of this work was to study the influence of cellulose nanofibrils (CNF) on the physical, mechanical, and thermal properties of Jatropha oil-based waterborne polyurethane (WBPU) nanocomposite films. The polyol to produce polyurethane was synthesized from crude Jatropha oil through epoxidation and ring-opening method. The chain extender, 1,6-hexanediol, was used to improve film elasticity by 0.1, 0.25, and 0.5 wt.% of CNF loading was incorporated to enhance film performance. Mechanical performance was studied using a universal test machine as specified in ASTM D638-03 Type V and was achieved by 0.18 MPa at 0.5 wt.% of CNF. Thermal gravimetric analysis (TGA) was performed to measure the temperature of degradation and the chemical crosslinking and film morphology were studied using Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The results showed that when the CNF was incorporated, it was found to enhance the nanocomposite film, in particular its mechanical and thermal properties supported by morphology. Nanocomposite film with 0.5 wt.% of CNF showed the highest improvement in terms of tensile strength, Young's modulus, and thermal degradation. Although the contact angle decreases as the CNF content increases, the effect on the water absorption of the film was found to be relatively small (<3.5%). The difference between the neat WPBU and the highest CNF loading film was not more than 1%, even after 5 days of being immersed in water.
    Matched MeSH terms: Physical Phenomena
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