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81.
Fuzhang Wang Faisal Shah M. Ijaz Khan Mamdooh Alwetaishi M.Y. Malik Ahmed M. Galal 《印度化学会志》2022,99(7):100502
Mixed convective flow of fourth grade (Non-Newtonian) fluid model by a Riga stretchable plate is addressed. The aim of the current research work is therefore to explain the role of the fourth grade (Non-Newtonian) fluid model in the field of fluid dynamics. Energy and concentration equations are modeled subject to both Fourier's law of heat conduction and Fick's law. Radiation aspects and heat source/sink phenomenon are also accounted. Entropy analysis is discussed through second thermodynamics law. The (OHAM) approach is used to achieve a meaningful solution. Finally, the emerging variables behavior on the velocity, temperature, concentration and entropy rate are discussed graphically. Here, velocity enhances for increasing range of fourth grade variable. Temperature boosts against rising radiation and thermal relaxation variables, but opposite trend is noted for solutal relaxation parameter on concentration. 相似文献
82.
People suffered from essential hypertension have increased oxidative stress. Thus, adding vitamin C to their medical therapy resulted in decreasing the oxidative stress and increasing the antioxidant status. This may prevent further vascular damage due to the oxidative stress, leading to a better diagnosis in critical hypertension patients. A novel sensor was fabricated based on NdFeO3 nano‐perovskite/glycine/carbon nanotubes modified carbon paste electrode in presence of sodium dodecyl sulfate; GLNFCNTCP‐SDS for electrochemical sensing and simultaneous determination of antihypertensive and antioxidant drugs, Amlodipine (AML) and ascorbic acid. The developed nanocomposite showed interactive characteristics of all the modifiers as high conductivity, enhanced surface area, surface fouling resistance and stability. This leads to accelerated electron transfer rate and increased current response of electro‐oxidation of AML by 8.3 folds compared to unmodified electrode. The method validity was investigated successfully by the quantitative analysis of AML in human urine samples and Norvasc tablets with acceptable recovery results. The featured merits of the proposed composite in the analysis of AML in human urine samples were; wide concentration range of 0.003 μmol L?1 to 200 μmol L?1, sensitivity of 113.2 μA/μmol L?1, detection limit of 0.704 nmol L?1, and quantification limit of 2.35 nmol L?1. 相似文献
83.
Youghourta Belhocine Seyfeddine Rahali Hamza Allal Ibtissem Meriem Assaba Monira Galal Ghoniem Fatima Adam Mohamed Ali 《Molecules (Basel, Switzerland)》2021,26(24)
The encapsulation mode of dexamethasone (Dex) into the cavity of β-cyclodextrin (β-CD), as well as its potential as an inhibitor of the COVID-19 main protease, were investigated using density functional theory with the recent dispersion corrections D4 and molecular docking calculations. Independent gradient model and natural bond orbital approaches allowed for the characterization of the host–guest interactions in the studied systems. Structural and energetic computation results revealed that hydrogen bonds and van der Waals interactions played significant roles in the stabilization of the formed Dex@β-CD complex. The complexation energy significantly decreased from −179.50 kJ/mol in the gas phase to −74.14 kJ/mol in the aqueous phase. A molecular docking study was performed to investigate the inhibitory activity of dexamethasone against the COVID-19 target protein (PDB ID: 6LU7). The dexamethasone showed potential therapeutic activity as a SARS CoV-2 main protease inhibitor due to its strong binding to the active sites of the protein target, with predicted free energy of binding values of −29.97 and −32.19 kJ/mol as calculated from AutoDock4 and AutoDock Vina, respectively. This study was intended to explore the potential use of the Dex@β-CD complex in drug delivery to enhance dexamethasone dissolution, thus improving its bioavailability and reducing its side effects. 相似文献
84.
One-dimensional 2-state Potts spin glasses (SG) disordered ferromagnets (DFM) and ±J systems are studied. The energy minima (EM) and magnetization with their distributions are exactly calculated. The stable local EM of no more than 27-spin chains with periodic boundary conditions are analyzed. All these systems have an exponentially growing numbers of average energy minima versus number of spins. The frustration effect is also discussed for some particular samples. The investigation of metastable states shows that the energy minima distributions for all our systems approach the normal distribution. The SG and DFM have identical distributions of energy minima. The systems studied here differ merely by the properties of the magnetization. The absolute value of magnetization averaged over all the EM decreases logarithmically with the number of spins for the three systems. 相似文献
85.
Hatem M. Gaber Galal E. H. Elgemeie Salama A. Ouf Sherif M. Sherif 《Heteroatom Chemistry》2005,16(4):298-307
Synthesis of the new 4‐hydrazinopyrido[3′,2′:4,5]thieno[3,2‐d]pyrimidines 7a,b was reported. Their reactivity toward a variety of carbon electrophiles and active methylene reagents was studied to give pyridothienotraizolopyrimidines as well as other substituted phthalazinyl‐ and pyrazolyl‐pyridothienopyrimidine derivatives. The antimicrobial activity of some newly synthesized compounds was evaluated. © 2005 Wiley Periodicals, Inc. 16:298–307, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20126 相似文献
86.
Ionics - Poly(3,4-ethylenedioxythiophene) (PEDOT) modified with ferrocene carboxylic acid (FC1), ferrocene (FC2), and cobaltocene (CC) is introduced as a sensor electrode. FC or CC was... 相似文献
87.
Electrochemical Morphine Sensor Based on Gold Nanoparticles Metalphthalocyanine Modified Carbon Paste Electrode
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Composites of gold nanoparticles (Au) electrochemically deposited and different metal phthalocyanines (Co, Ni, Cu, and Fe) were chemically prepared. The composites were used as modifiers for carbon paste electrodes and were used for the determination of morphine in presence of ascorbic acid and uric acid. Central metal atoms of phthalocyanine moiety affected the rate of electron transfer. Thus, the electroactivity of different modifiers were evaluated towards morphine oxidation. Au‐CoPcM‐CPE possessed the highest rate for charge transfer rate in all studied pH electrolytes. Limit of detection was 5.48×10?9 mol L?1 in the range of 4.0×10?7 to 9.0×10?4 mol L?1. 相似文献
88.
Abdel Raouf F. Elhefnawy Galal M. Moatimid Abd Elmonem Khalil Elcoot 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,55(1):63-91
The nonlinear electrohydrodynamic stability of
cylindrical interface, supporting surface charge, among two
conducting fluids is investigated. The two fluids are subjected to
a radial electric field. The analysis based on the multiple scale
technique. It is shown that the evolution of the amplitude is
governed by two partial differential equations. These equations
are combined to yield two alternate Schrödinger equations with
cubic nonlinearity. One of which calculates the nonlinear cutoff
electric field, separating stable and unstable disturbances, while
the other is used to analyze the stability of the system. The
stability criteria are analytically discussed and numerically
confirmed. Numerical calculations resulted in set of graphs to
indicate the stability picture of the considered system. 相似文献
89.
Galal M. Moatimid 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2005,48(3):133-159
The nonlinear theory of the Kelvin-Helmholtz instability is employed to analyze the instability phenomenon of two ferrofluids
through porous media. The effect of both magnetic field and mass and heat transfer is taken into account. The method of multiple
scale expansion is employed in order to obtain a dispersion relation for the first-order problem and a Ginzburg–Landau equation,
for the higher-order problem, describing the behavior of the system in a nonlinear approach. The stability criterion is expressed
in terms of various competing parameters representing the mass and heat transfer, gravity, surface tension, fluid density,
magnetic permeability, streaming, fluid thickness and Darcy coefficient. The stability of the system is discussed in both
theoretically and computationally, and stability diagrams are drawn. 相似文献
90.
Hagar K. Hassan Nada F. Atta Ahmed Galal 《Journal of Solid State Electrochemistry》2013,17(6):1717-1727
The electrochemical oxidation of formaldehyde over graphene surfaces modified with Pt–Ru co-catalyst is presented. Graphene was chemically converted from graphite and Pt–Ru co-catalyst was electrochemically deposited using cyclic voltammetry. The hybrid surface is prepared using “green approaches” and displayed electrocatalytic activity towards formaldehyde in the form of current oscillations. The current oscillations that were mainly due to adsorption/desorption of carbonaceous oxidative products are a factor of several parameters such as the concentrations of both formaldehyde and supporting electrolyte in solution, the amount of catalyst loading, scan rate of potential, upper potential limit, and the temperature change. CCG/Pt–Ru exhibited higher electrocatalytic activity toward formaldehyde electro-oxidation, and intense electrochemical current oscillations were obtained at relatively low HCHO concentrations compared to other work mentioned in literature for CCG/Pt–Pd. 相似文献