Corrosion inhibition of N80 steel in simulated acidizing environment by N-(2-(2-pentadecyl-4,5-dihydro-1H-imidazol-1-YL) ethyl) palmitamide

A novel palmitic imidazoline compound, N-(2-(2-pentadecyl-4,5-dihydro-1H-imidazol-1-yl)ethyl)palmitamide (NIMP) has been successfully synthesized and characterized with Fourier transform spectroscopy (FTIR), Proton nuclear magnetic resonance (1H NMR), and Carbon-13 nuclear magnetic resonance (13C NMR). NIMP has been tested as corrosion inhibitor for N80 steel in 15% HCl solution at low and elevated temperatures using weight loss measurements, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), linear polarization (LPR), and electrochemical frequencymodulation (EFM) techniques. The experimental investigation was supported with surface examination using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDAX), and Fourier transform spectroscopy (FTIR). NIMP is found to be effective in retarding N80 steel dissolution in 15% HCl solution at studied temperatures. The optimum concentration of NIMP is 300 ppm and this concentration afforded corrosion protection efficiency of 97.92% and 95.59% at 25 °C and 60 °C respectively from weight loss measurements. Chemisorption is proposed as the mechanism of adsorption of NIMP molecules onto N80 steel surface based on the value of standard enthalpy of adsorption (100.34 kJ/mol). PDP results disclosed that NIMP acted like a mixed type corrosion inhibitor but with principal effect on cathodic corrosion reactions. Surface screening results are in agreement with experimental results that NIMP molecules adsorbed on N80 steel surface. NIMP can be utilized as an acidizing corrosion inhibitor

Can Taxpayers Stand Discrimination?: Lack of Standing and the Religious Freedom Restoration Act Permits the Executive Branch to Fund Discrimination Within Religious Organizations

The Density Functional Theory (DFT) and ab initio (HF and MP2) calculations were performed on the quinoline molecule (QL) and its derivatives, namely quinaldine (QLD) and quinaldic acid (QLDA) to investigate their possible role as corrosion inhibitors for mild steel in acidic medium. Calculations were done for non-protonated and protonated forms in vacuo and in water. Some quantum chemical parameters were calculated and discussed in order to provide insight into the reactivity and selectivity of the molecules. The performance of the different calculation methods were also compared with available experimental data. The results show that DFT/B3LYP basis set is adequate in describing the geometry and quantum chemical parameters of the studied systems. Both experimental and theoretical results established that QLDA has the highest inhibition efficiency. A comparison in the trends of the quantum chemical parameters in water solution and in vacuo shows minimal influence of the solvent effects

Stomatal responses of Eucalyptus species to elevated CO2 concentration and drought stress

Five species of Eucalyptus (E. grandis, E. urophylla, E. camaldulensis, E. torelliana, and E. phaeotrica), among the ten species most commonly used in large scale plantations, were selected for studies on the effects of elevated CO2 concentration [CO2] and drought stress on stomatal responses of 2.5-month old seedlings. The first three species belong to the subgenus Smphyomyrtus, whereas the fourth species belongs to the subgenus Corymbia and E. phaeotrica is from the subgenus Monocalyptus. Seedlings were grown in four pairs of open-top chambers, arranged to have 2 plants of each species in each chamber, with four replications in each of two CO2 concentrations: 350 ± 30 mumol mol-1 and 700 ± 30 mumol mol-1. After 100 days in the chambers, a series of gas exchange measurements were made. Half the plants in each chamber, one plant per species per chamber, were drought-stressed by withholding irrigation, while the remaining plants continued to be watered daily. Drought stress decreased stomatal conductance, photosynthesis and transpiration rates in all the species. The effect of drought stress on stomatal closure was similar in both [CO2]. The positive effects of elevated [CO2] on photosynthesis and water use efficiency were maintained longer during the stress period than under well-watered conditions. The photosynthetic rate of E. phaeotrica was higher even in the fourth day of the drought stress. Drought stress increased photoinhibition of photosynthesis, as measured by chlorophyll fluorescence, which varied among the species, as well as in relation to [CO2]. The results are in agreement with observed differences in stomatal responses between some eucalyptus species of the subgenera Symphyomyrtus and Monocalyptus

Digital health for the end TB strategy : developing priority products and making them work

In 2014, the World Health Organization (WHO) developed the End TB Strategy in response to a World Health Assembly Resolution requesting Member States to end the worldwide epidemic of tuberculosis (TB) by 2035. For the strategy's objectives to be realised, the next 20 years will need novel solutions to address the challenges posed by TB to health professionals, and to affected people and communities. Information and communication technology presents opportunities for innovative approaches to support TB efforts in patient care, surveillance, programme management and electronic learning. The effective application of digital health products at a large scale and their continued development need the engagement of TB patients and their caregivers, innovators, funders, policy-makers, advocacy groups, and affected communities. In April 2015, WHO established its Global Task Force on Digital Health for TB to advocate and support the development of digital health innovations in global efforts to improve TB care and prevention. We outline the group's approach to stewarding this process in alignment with the three pillars of the End TB Strategy. The supplementary material of this article includes target product profiles, as developed by early 2016, defining nine priority digital health concepts and products that are strategically positioned to enhance TB action at the country level

Influence of some multifunctional triazoles on corrosion of mild-steel in boiling hydrochloric acid solutions

Some new triazole based corrosion inhibitors namely, 4-henzylideneamino-3-hyrkazinoS-mercapto-l,2,4-triazole, OlAHMT), 4-dimethylaminohellzylident'amino-3-hyrlrazino-5-mercapto-l,2,4triazole (DAHMT), and 4-vanillideneamino-3-hydrazino-5-mt'rcapto-1,2,4-triazole (VAH MT) have heen synthesi:ud and their innuence on corrosion inhihition of mild steel in 15% hydrochloric acid solution under boiling conditions has heen studied using weight loss method. All the tested inhihitors except DAHMT showed> 90% inhibition efficiency. Jlotentiodynamie polarization measurements have Iwen carried out at room temperature, which clearly reveal the fact that all investigated inhihitors are of mixed type and they inhihit corrosion of mild steel hy hlockin~ the active sites of the metal surface. 'nil' adsorption of these inb.ihitors on the mild steel surface from 15% Het has been found to ohey Temkin's adsorption isothenu

2-Amino-3-methyl-3-(4-nitrophenyl)-5-(phenylthio)-3H-pyrrole-4-carbonitrile as effective corrosion inhibitor for mild steel in 1M HCl: Thermodynamical, electrochemical, surface and theoretical calculat

Present work describes the corrosion inhibition efficiency of 2-amino-3-methyl-3-(4-nitrophenyl)-5-(phenylthio)-3H-pyrrole-4-carbonitrile (INH) on mild steel in 1M HCl using weight loss, electrochemical, surface and molecular dynamics simulation methods. The weight loss results show that inhibition efficiency increasing with increasing INH concentration and maximum value was obtained at 50 mg/L concentration. Adsorption of the INH on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization study suggests that investigated INH acts as mixed type inhibitor. EIS study indicates that the INH forms a protective surface film at metal/electrolyte interface. Both SEM and AFM studies show that surface smoothness increases due to formation of protective surface film by INH. The Monte Carlo simulation study suggests that INH has strong tendency to adsorb on mild steel surface in 1M HCl. The weight loss, electrochemical, surface and molecular dynamics calculations are in good agreement

Effect of three component (aniline–formaldehyde and piperazine) polymer on mild steel corrosion in hydrochloric acid medium

Polymeric Schiff base containing aniline, formaldehyde and piperazine (AFPP) was synthesized and investigated as corrosion inhibitor for mild steel in 1 M HCl by weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Experimental results showed that AFPP is an effective inhibitor for mild steel in 1 M HCl and exhibited 98% inhibition efficiency. Potentiodynamic polarization studies showed that AFPP is a mixed-type inhibitor predominantly cathodic type. The adsorption of inhibitor on the mild steel surface followed Langmuir adsorption isotherm. Activation energy (Ea), standard energy of adsorption (ΔG°ads), enthalpy of activation (ΔH∗), and entropy of activation (ΔS∗) of corrosion process were calculated and discussed

Adsorption behavior of 8,9-bis(4 (dimethyl amino)phenyl)benzo[4,5]imidazo[1,2-a]pyridine-6,7-dicarbonitrile on mild steel surface in 1 M HCl

The effect of 8,9-bis(4 (dimethylamino)phenyl)benzo[4,5]imidazo[1,2-a]pyridine-6,7-dicarbonitrile (INH) on mild steel corrosion in 1 M HCl was studied by electrochemical, surface and quantum chemical calculation methods. Results showed that percentage of inhibition efficiency increases on increasing INH concentration. The maximum inhibition efficiency of 96.32% was obtained at 25 mg L−1 concentration. Tafel polarization measurements show that the presence of INH in acid solution affects both cathodic and anodic reactions but acts as predominantly cathodic type inhibitor. The Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) studies suggest the formation of adherent layer of INH on mild steel surface. The results of theoretical calculations were found to be consistent with the surface and electrochemical results