The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlin
... Show MoreThe current research included obtaining the best performance specifications for a silicon device with a mono-crystalline type pn junction (pn–Si). A simulation of the device was performed by the use of a computer program in one dimension SCAPS-1D in order to reach the optimum thickness for both p and n layers and to obtain the best efficiency in performance of the pn-Si junction. The optimum device efficiency was eta (η) = 12.4236 % when the ideal thickness for the p and n layers was 5µm and 1.175µm, respectively (p=5 µm and n=1.75µm).
The research included studying the effects of different spectra of solar illumination using simulation of the device; the usual solar spectrum AM1_5 G1 sun. Spectrum
... Show MoreA new series of Sulfamethoxazole derivatives was prepared and examined for antifibrinolytic and antimicrobial activities. Sulfamethoxazole derivatives bear heterocyclic moieties such as 1,3,4-thiadiazine {3}, pyrazolidine-3,5-diol {4} 6-hydroxy-1,3,4-thiadiazinane-2-thione {5} and [(3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)diazenyl] {8}. Their structures were elucidated by spectral methods (FT-IR, H1-NMR). Physical properties are also determined for all compound derivatives. Recently prepared compounds were tested for their antimicrobial activity in the laboratory. Each screened compound showed good tendency to moderate antimicrobial activity.
Gold nanoparticles (Au NPs) have been synthesized via reduction of sodium tetrachloroaurate dihydrate (NaAuCl4.2H2O) with 2-(2-methyl-5-amino -1H-imidazol-1-yl) ethanol (2-MAE) in presence and absence of ascorbic acid as reducing and stabilizing agents. The resulting Au NPs were characterized by UV–Vis spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), FT-IR spectroscopy. The absorption spectra of gold nanoparticles solutions in the uv-visible and near IR regions were studied at different amine concentrations and pH media.
The purpose of this research was to prepare, characterize, and evaluate the new antimicrobial peptide KSL peptide encapsulated in poly(D,L-lactide-co-glycolide) (PLGA)composite microspheres. KSL was loaded in poly(acryloyl hydroxyethyl) starch (acHES) micropar-ticles, and then the peptide-containing microparticles were encapsulated in the PLGA matrix by a solvent extraction /evaporation method.
KSL-loaded PLGA microspheres were also prepared without the starch hydrogel microparticle microspheres for comparison study. KSL peptide microspheres were characterized for drug content, surface morphology, microspheres size determination, polymers stability , in vitro microspheres degradation and in vitro release. KSL peptide
... Show MoreA group of amino derivatives [4-aminobenzenesulfonamide,4-amino-N¹ methylbenzenesulfonamide, or N¹-(4-aminophenylsulfonyl)acetamide] bound to carboxyl group of mefenamic acid a well known nonsteroidal anti-inflammatory drugs (NSAIDs) were designed and synthesized for evaluation as a potential anti-inflammatory agent. In vivo acute anti-inflammatory activity of the final compounds (9, 10 and 11) was evaluated in rat using egg-white induced edema model of inflammation in a dose equivalent to (7.5mg/Kg) of mefenamic acid. All tested compounds produced a significant reduction in paw edema with respect to the effect of propylene glycol 50% v/v (control group). Moreover, the 4-amino-N-methylbenzenesulfonamide derivative (c
... Show MoreBackground: Alternative natural therapy by plants extracts had opened wide door for the use of natural products as an alternative therapy instead of many antibiotics and drugs , which had many harmful side effects.Also, an increased interest has been centered on the industrial wastes, especially plant raw materials which contain phenols (e.g. Pomegranate peel and Bay leaves) which is a sources of natural antioxidants ,which are on the contrary of synthetic antioxidants that had restrict use due to their health risks , carcinogenesis and toxicity .
Objectives :This study was done to fi
... Show MoreRemoval of Congo red, Rhodamine B, and Dispers Blue dyes from water solution have been achieved using Flint Clay as an adsorbent. The adsorption was studied as a function of contact time, adsorbent dose, pH, and temperature under batch adsorption technique. The equilibrium data fit with Langmuir, Freundlich and Toth models of adsorption and the linear regression coefficient R2 was used to elucidate the best fitting isotherm model. Different thermodynamic parameters, namely Gibb’s free energy, enthalpy and entropy of the on-going adsorption process have also been evaluated. Batch technique has been employed for the kinetic measurements and the adsorption of the three dyes follows a second order rate kinetics. The kinetic investigations al
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