PM3 and DFT (B3LYP) with a 6-311++G (2d, 2p) level of theoretical quantum mechanical calculations were employed to give investigation into the inhibition efficiency of the two new N-phenyl-ethylidene-5-bromo isatin derivatives which are N-phenyl-ethylidene-5-bromo-3[(imine aceto) urea]-2-oxo indole (NPEO) and N-phenyl-ethyeidine-5-bromo-3[(imine aceto) thiourea]-2-oxo indole (NPES). The calculated physical properties and quantum chemical parameters correlated to the inhibition efficiency all are studied and discussed at the equilibrium geometry in a vacuum, dimethyl sulfoxide and aqueous at their correct symmetry.
This study deals with the corrosion inhibition of metal corrosion process of medium carbon steel using 1M HCl for kinetic studies and rate reaction determination. The weight loss method is applied to pieces of Medium carbon steel divided to Cubans with dimensions (0.4*2*2.4) cm , and use Tafel Extrapolation Method, the samples were polished using carbide silicon paper with dimensions of (180,200,400,600,800,1000). The samples were immersed in the alcoholic medium ethanol at a temperature 293K for 3hr. Natural inhibitor Kujarat Tea (Hibiscus sabdarriffa L.) is used which is extracted in aqueous and alcoholic medium, different concentrations (1000،2000, 3000) ppm have been used ; The best concentration found through the results is a
... Show MoreIn this study, thermal characteristics of a two-phase closed heat pipe were investigated experimentally and theoretically. A two-phase closed heat pipe (copper container, Fluorocarbon FC-72 (C6F14) working fluid) was fabricated to examine its performance under the effect of input heat flux range of 250–1253 W/m2 , 70% fill charge ratio and various tilt angles. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored. A comprehensive mathematical model was developed to investigate the steadystate heat transfer performance of a two-phase closed heat pipe. A steady state analytical model, is presented to determine important parameters on the design of two-phase close
... Show MoreThe corrosion inhibition of low carbon steel in1N HCl solution in the presence of peach juice at temperature (30,40,50,and 60)°C at concentration ( 5, 10, 20, 30, 40and 50 cm3/L)were studied using weight loss and polarization techniques. Results show that the inhibition efficiency was increased with the increase of inhibitor concentration and increased with the increase of temperature up to 50ºC ,above 50ºC (i.e. at 60 ºC) the values of efficiency decreases. Activation parameters of the corrosion process such as activation energies, Ea, activation enthalpies, ΔH, and activation entropies, ΔS, were calculated. The adsorption of inhibitor follows Langmuir isotherm. Maximum inhibition efficiency obtained was a bout 91% at 50ºC in the
... Show MoreTaguchi experimental design (TED) is applied to find the optimum effectiveness of aqueous Red Pomegranate Peel (RPP) extract as a green inhibitor for the corrosion of mild steel in 2M H3PO4 solution. The Taguchi methodology has been used to study the effects of changing, temperature, RPP concentration and contact period, at three levels. Weight-loss measurements were designed by construction a L9 orthogonal arrangement of experiments. Results of the efficiencies of inhibition were embraced for the signal to noise proportion & investigation of variance (ANOVA). The results were further processed with a MINITAB-17 software package to find the optimal condition
... Show MoreThe present study deals with the synthesis of four different azo-azomethine derivatives; this is done by two steps; the first step is diazotization of sulfonamides (sulfanilamide, sulfacetamide, sulfamethoxazole, and sulfadiazine) separately, followed by the second step; the coupling reaction of diazotized compounds with isatin bis-Schiff base named 3-((4-nitrobenzylidene) hydrazono)indolin-2-one. The later one (bis-Schiff base) was synthesized by the reaction of 3-hydrazono-indolin-2-one with p-nitrobenzaldehyde. The chemical structures of newly synthesized compounds were approved on the basis of their FTIR, 1H-NMR, and CHNS elemental analysis data results. The synthesized azo compounds were tested in vitro for their antimicrobial potentia
... Show MoreThis research involves the synthesis of conductive polymer includes: poly (N, Ndimethyl
aniline) on metal surface which is stainless steel 316 by using
electrochemical polymerization technique. Parameters of this research are voltage
rang, scan rate, number of cycles. The tests for corrosion protection of the polymer
coated and uncoated stainless steel substrate was investigated in artificial sea water
of 3.5% NaCl solution by tafel and potentiodynamic procedures. Fourier Transform
Infrared Spectroscopy (FTIR), UV-Visible absorption spectroscopy, Scanning
Electron Microscope (SEM) and Atomic Force Microscope (AFM) were used to
diagnose and describe the structure and morphology of the coating. Parameters of
corr
This paper performance for preparation and identification of six new complexes of a number of transition metals Cr (lII), Mn (I1), Fe (l), Co (II), Ni (I1), Cu (Il) with: N - (3,4,5-Trimethoxy phenyl-N - benzoyl Thiourea (TMPBT) as a bidentet ligand. The prepared complexes have been characterized, identified on the basis of elemental analysis (C.H.N), atomic absorption, molar conductivity, molar-ratio ,pH effect study, I. Rand UV spectra studies. The complexes have the structural formula ML2X3 for Cr (III), Fe (III), and ML2X2 for Mn (II), Ni (II), and MLX2 for Co (Il) , Cu (Il).
Corrosion experiments were carried out to investigate the effect of several operating parameters on the corrosion rate and corrosion potential of carbon steel in turbulent flow conditions in the absence and presence of sodium benzoate inhibitor using electrochemical polarization technique. These parameters were rotational velocity (0 - 1.57 m/s), temperature (30oC – 50oC), and time. The effect of these parameters on the corrosion rate and inhibition efficiency were investigated and discussed. It was found that the corrosion rate represented by limiting current increases considerably with increasing velocity and temperature and that it decreased with time due to the formation of corrosion product layer. The corrosion potential shifted t
... Show MoreBackground: The isatin molecule is present in many natural substances, including plants and animals, and is used to prepare compounds with various biological activities. Objectives: To synthesize a new series of isatin derivatives with the expectation that they will have antimicrobial activity. Methods: Thiazole Schiff bases were synthesized from various Mannich bases of isatin to evaluate their antimicrobial properties. Initially, Mannich bases (2a–e) were synthesized by reacting isatin with formaldehyde and different secondary amines. Subsequently, they were treated with 2-aminothiazole to yield the final compounds (3a–e). Spectroscopic characterization was done via FT-IR and 1H-NMR. The antimicrobial screening was conducted o
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