Two derivatives of Iimidazolidin 4-one (IMID4) and Oxazolidin 5-one (OXAZ5), were investigated as corrosion inhibitors of corrosion carbon steel in sea water by employing the theoretical and experimental methods. The results revealed that they inhibit the corrosion process and their %IE followed the order: IMID4 (89.093%) > OXAZ5 (80.179%). The %IE obtained via theoretical and experimental methods were in a good agreement with each other. The thermodynamic parameters obtained by potentiometric polarization measurements have supported a physical adsorption mechanism which followed Langmuir adsorption isotherm. Quantum mechanical method of Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) were used to calculate the geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all calculated at the equilibrium geometry, and correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis. The morphology of the surface changes of carbon steel were studied using SEM and AFM techniques.
The dynamical behavior of an ecological system of two predators-one prey updated with incorporating prey refuge and Beddington –De Angelis functional response had been studied in this work, The essential mathematical features of the present model have been studied thoroughly. The system has local and global stability when certain conditions are met. had been proved respectively. Further, the system has no saddle node bifurcation but transcritical bifurcation and Pitchfork bifurcation are satisfied while the Hopf bifurcation does not occur. Numerical illustrations are performed to validate the model's applicability under consideration. Finally, the results are included in the form of points in agreement with the obt
... Show MoreSilver nanoparticles (AgNPs) were biosynthesized using the cell free supernatant of putative probiotic Lactobacillus paracasei A26. Several biological activities of biogenic AgNPs were investigated in respect to in vitro anti-oxidant and anti-tumor potentials. Anti-oxidant potentials were screened in terms of free radical scavenging activity against two free radicals, 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and resazurin dye. AgNPs exhibited a potent scavenging activity against resazurin dye (91±0.046%) with an EC50 concentration of 146.823 µg/ml, while scavenging of DPPH was significantly (P≤0.05) reduced to 72.330±0.114% using a higher EC50 concentration of 176.12 µg/ml. The
... Show MoreExperimental work was carried out to investigate the effect of fire flame (high temperature) on specimens of one way slabs using Self Compacted Concrete (SCC). By using furnace manufactured for this purpose, twenty one reinforced concrete slab specimens were exposed to direct fire flame. All of specimens have the same dimensions. The slab specimens were cooled in two types, gradually by left them in the air and suddenly by using water. After that the specimens were tested under two point loads, to study, the effect of
different: temperature levels (300ºC, 500ºC and 700ºC), and cooling rate (gradually and sudden cooling conditions) on the concrete compressive strength, modulus of rupture, flexural strength and the behavior of reinf
The corrosion protection of low carbon steel in 2.5 M HCl solution by kiwi juice was studied at different temperatures and immersion times by weight loss technique. To study the determination of the optimum conditions from statistical design in evaluation of a corrosion inhibitor, three variables, were considered as the most dominant variables. These variables are: temperature, inhibitor concentration (extracted kiwi juice) and immersion time at static conditions.
These three variables are manipulated through the experimental work using central composite rotatable Box – Wilson Experimental Design (BWED) where second order polynomial model was proposed to correlate the studied variables with the corrosion rate o
... Show MoreMixedآ catechol- آ salicyladiminenate derivatives of antimony
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(III) and tin (IV) of the general formula M(cate)L"]X, [where:M= Sb, X= آ 0; آ M=Sn, آ X= آ Cl; آ cate=catechol; آ n=l, آ L=aniline, آ n=2, آ L=mآ bromo-aniline, n=3, L=p-bromoaniline] were prepared by the reaction of equimolar amount of [(cate)MCln], [where n=l آ or 2] with Nآ arylsalicylaldimines HOC6H4CH=NC6Hs (HL1آ , HOC6H4CH= NC6H4
The present work reports the electrochemical synthesis of poly N Terminal tetrahydrophthalamic acid on stainless steel 316 (S.S), which acts as a working electrode, using an electrochemical polymerization technique. Fourier Transform Infrared Spectroscopy (FT-IR), Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) characterized the formed polymer film. Corrosion protection tests for coated and uncoated S.S with polymer film were studied in 0.2 M hydrochloric acid (HCl) solution by using electrochemical polarization technique. Kinetic and thermodynamic activation parameters (Ea, A, ΔH*, ΔS* and ΔG*) were calculated. The biological activity of the polymeric film was determined against Gram positive (Staphy
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