Pyrimidine derivatives as novel acidizing corrosion inhibitors for N80 steel useful for petroleum industry: A combined experimental and theoretical approach

Jiyaul Haque,K.R. Ansari,Vandana Srivastava,M.A. Quraishi,I.B. Obot 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.49 No.-

The corrosion inhibition performance of two pyrimidine derivatives namely 5-styryl-2,7-dithioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d] pyrimidin-4(1H) one (PP-1) and 5-(2-hydroxyphenyl)-2,7-dithioxo-2,3,5,6,7,8-hexahydropyrimido[4,5-d]-pyrimidin-4(1H) one (PP-2) on N80 steel corrosion in15% HCl has been studied using gravimetric method, electrochemical impedance spectroscopy (EIS),potentiodynamic polarization, atomic force microscopy (AFM), scanning electron microscopy (SEM), DFT,molecular electrostatic potential and Monte Carlo simulation. The corrosion inhibition efficiencies atoptimum concentration (250 mg/L) are 89.1% (PP-1) and 73.1% (PP-2) respectively at 308 K. The corrosioninhibition efficiency increases with increase in concentration and decreases with temperature. PPsobeyed Langmuir adsorption isotherm. AFM and SEM analyses supported formation of protectivefilm onN80 steel in presence of inhibitors. DFT and Monte Carlo simulation calculations supported experimentalresults.

Bis-Schiff bases of isatin as new and environmentally benign corrosion inhibitor for mild steel

K.R. Ansari,M.A. Quraishi 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Inhibition effect of three bis-Schiff bases of isatin namely (2-methoxybenzylidene) hydrazono) indolin-2-one (HZ-1), (2-hydroxybenzylidene) hydrazono) indolin-2-one (HZ-2) and (4-nitrobenzylidene) hydrazono) indolin-2-one (HZ-3) was studied on mild steel corrosion in 1.0 M HCl by gravimetric measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and quantum chemical study. The values of activation energy (Ea), equilibrium constant (Kads), free energy of adsorption DG8ads, activation enthalpy DH* and activation entropy DS*were discussed. The adsorption of inhibitors on metal followed Langmuir’s adsorption isotherm. SEM and EDX observations confirmed the existence of protective inhibitor film on metal surface. Quantum chemical study supports the comparative inhibition effect of HZs. 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Corrosion inhibition of mild steel in hydrochloric acid by some pyridine derivatives: An experimental and quantum chemical study

K.R. Ansari,M.A. Quraishi,Ambrish Singh 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

The adsorption and corrosion inhibition effect of three pyridine derivatives namely 2-amino-6- methoxy-4-(4-methoxylphenyl) pyridine-3,5-dicarbonitrile (PC-1), 2-amino-6-methoxy-4-(4-methyl- phenyl) pyridine-3,5-dicarbonitrile (PC-2) and 2-amino-6-methoxy-4-phenylpyridine-3,5-dicarboni- trile (PC-3) on mild steel in 1 M HCl was investigated using gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization techniques and quantum chemical study. PCs are mixed- type inhibitor mainly cathodic. Activation energy (Ea), equilibrium constant (Kads), free energy of adsorption (DG8ads) were calculated and discussed. The studied inhibitors (PCs) obeyed Langmuir’s adsorption isotherm. Protective film of PCs on mild steel surface was investigated by using SEM and EDX. Quantum chemical parameters were carried out in the framework of the density functional theory (DFT).

Impact of smoking and smoking cessation on lung cancer mortality in the Asia-Pacific region.

Huxley, R,Jamrozik, K,Lam, T H,Barzi, F,Ansary-Moghaddam, A,Jiang, C Q,Suh, I,Woodward, M Oxford University Press 2007 American Journal of Epidemiology Vol.165 No.11

<P>Cigarette smoking is becoming increasingly common in Asia while quitting remains rare, in part because of a lack of knowledge about the risks of smoking. This study compared the risk of death from lung cancer associated with smoking habits in Australia and New Zealand and in Asia by using data from the Asia Pacific Cohort Studies Collaboration: 31 studies involving 480,125 individuals. Cox regression models were used. The hazard ratios for lung cancer mortality associated with current smoking were, for men, 2.48 (95% confidence interval (CI): 1.99, 3.11) in Asia versus 9.87 (95% CI: 6.04, 16.12) in Australia and New Zealand; p for homogeneity <0.0001. For women, the corresponding estimates were 2.35 (95% CI: 1.29, 4.28) in Asia versus 19.33 (95% CI: 10.0, 37.3) in Australia and New Zealand; p for homogeneity <0.0001. Quitting was beneficial in both regions; the hazard ratios for former compared with current smokers were 0.69 (95% CI: 0.53, 0.92) in Asia and 0.30 (95% CI: 0.22, 0.41) in Australia and New Zealand. The lesser effect in Asia was partly explained by the fewer number of cigarettes smoked and the shorter duration of follow-up in Asian studies. These results suggest that tobacco control policies in Asia should not solely concentrate on preventing the uptake of smoking but also attend to cessation.</P>

Antiplatelet activity and isolation of triterpenoidal glycoside from ethanolic extract of Nepeta hindostana

Vaseem A. Ansari,Muhammad Arif,H. H. Siddiqui,R. K. Dixit 경희대학교 융합한의과학연구소 2016 Oriental Pharmacy and Experimental Medicine Vol.31 No.4

In the present study, triterpenoidal glycoside was isolated from ethanolic extract of aerial part of the plant Nepeta hindostana. The ethanolic extract was subjected to Si-gel CC and compound was isolated. The isolated compound Napedinolside has been characterized as 1β,11α,30-trihydroxy-lup-20(29)ene-(3 → 1′)-β-D-pyranoside on the basis of spectroscopic (UV, IR, 1H, 13C NMR and MS) methods. The ethanolic and aqueous extract at different concentrations were screened for antiplatelet activity using platelet rich plasma (PRP) prepared by centrifugation of rabbit whole blood (containing 0.9 % sodium citrate as anticoagulant) at 1500 rpm for 15 mins. The Np-01 was identified as triterpenoidal glycoside which was amorphous brownish white powder; yield 0.64 % (w/w); mp 125–127. N. hindostana showed very excellent antiplatelet activity in both aqueous and alcoholic extracts. The minimum concentration showed antiplatelet activity was 0.5 μg/ml. These findings demonstrate that ethanolic and aqueous extract of the selected plant material at different concentrations showed significant antiplatelet activity. The triterpenoidal glycoside from aerial parts of N. hindostana could hold promise for future application in the treatment of blood clot and pulmonary embolism related diseases.

Corrosion inhibition performance of imidazolidine derivatives for J55 pipeline steel in acidic oilfield formation water: Electrochemical, surface and theoretical studies

Singh, Ambrish,Ansari, K.R.,Lin, Yuanhua,Quraishi, M.A.,Lgaz, Hassane,Chung, Ill-Min Elsevier 2019 Journal of the Taiwan Institute of Chemical Engine Vol.95 No.-

<P><B>Abstract</B></P> <P>Present paper deals with the performance of imidazoline derivatives (ATs) as corrosion inhibitor for J55 steel in oil field formation water saturated with CO<SUB>2</SUB>. The inhibition effectiveness of AT-1 was found to 90% at 400 mg/L. Inhibitors addition decreases cathodic as well anodic current densities, and significantly strengthens impedance parameters. Contact angle and SEM/AFM/SECM measurements predicts the hydrophobicity and surface morphology of steel, respectively. Density functional theory (DFT) and molecular dynamic simulation (MD) calculations were performed to investigate the adsorption mechanism of ATs. Radial distribution function (RDF) and the mean-square displacement (MSD) were used to study inhibitor/metal interactions and migration rate of corrosive species, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> J55 steel protection in oil field formation water saturated with carbon dioxide by ATs molecules. </LI> <LI> Potentiodynamic polarization curves reveal that the actions of inhibitors are mixed type but cathodically predominat. </LI> <LI> Examination of surface morphology by SEM, SECM and AFM. </LI> <LI> Correlation of experimental results with Quantum chemical, molecular dynamic stimulation, radial distribution functions and mean-square displacement results. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Pyranpyrazole derivatives as novel corrosion inhibitors for mild steel useful for industrial pickling process: Experimental and Quantum Chemical study

Parul Dohare,K.R. Ansari,M.A. Quraishi,I.B. Obot 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

In the present work three new corrosion inhibitors namely ethyl 6-amino-3-methyl-4-(p-tolyl)-2,4-dihydropyrano[2,3,C]pyrazole-5-carboxylate (EPP-1), ethyl 6-amino-3-methyl-4(phenyl)-2,4-dihydro-pyrano[2,3,C]pyrazole-5-carboxylate (EPP-2), ethyl 6-amino-3-methyl-4-(3-nitrophenyl)-2,4-dihydro-pyrano[2,3,C]pyrazole-5-carboxylate (EPP-3) were prepared, characterized and their corrosion inhibitionproperties on mild steel were investigated using gravimetric, potentiodynamic polarization andelectrochemical impedance spectroscopy (EIS). The surface morphology of the mild steel was examinedusing scanning electron microscopy (SEM) and atomic force microscopy (AFM). EPP-1 exhibited highestefficiency of 98.8% at 100 mg/L. AFM and SEM studies confirmed the formation of adsorbedfilm on themetal surface. The inhibitors followed the Langmuir adsorption isotherm. Density functional theory(DFT) was used to understand donor–acceptor relationship between inhibitors and metal. Theorientation and binding energy of inhibitor molecules were investigated using molecular dynamicsimulation (MD). A good relationship was obtained between theoretical and experimental results.