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

Experimental and theoretical studies on the corrosion inhibition of mild steel by some sulphonamides in aqueous HCl

Corrosion inhibition studies of mild steel in aqueous HCl by some sulphonamides namely sulphamethazine (SMT), sulphachloropyridazine (SCP), sulphabenzamide (SBZ) and sulphaquinoxaline (SQX) has been investigated using experimental techniques (such as weight loss, potentiodynamic polarization (PDP), Electrochemical Impedance Spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM)) and theoretical methods (using the Density Functional Theory (DFT)). All the compounds effectively inhibited the corrosion process by becoming adsorbed on the metal surface following the Langmuir adsorption isotherm model. The electrochemical results showed that these inhibitors are mixed-type. The theoretical studies were undertaken to provide mechanistic insight into the roles of the different substituents on the corrosion inhibition and adsorption behaviour of the studied compounds. The calculated quantum chemical parameters include the highest occupied molecular orbital (HOMO), the energy of the HOMO, dipole moment and partial atomic charges, etc. The calculated molecular properties were compared across the structures of the four compounds in order to identify trends related to their reactivity and their corrosion inhibition ability. The results also show that the ability of the sulphonamides to inhibit metal corrosion is strongly dependent on the electron donating ability of the substituent group and that the preferred site for interaction with the metal surface, in all the sulphonamides, is the SO2 group

Investigation of synthesized ethyl-(2-(5-arylidine-2,4-dioxothiazolidin-3-yl) acetyl) butanoate as an effective corrosion inhibitor for mild steel in 1 M HCl: A gravimetric, electrochemical, and spectroscopic study

The corrosion inhibition effects of five concentrations (5E-5 M to 9E-5 M) of ethyl-(2-(5-arylidine-2,4-dioxothiazolidin-3-yl) acetyl) butanoate, a novel thiazolidinedione derivative code named B1, were investigated on mild steel in 1 M HCl using gravimetric analysis, electrochemical analysis and Fourier transform infrared spectroscopy. After synthesis and purification, B1 was characterized using nuclear magnetic resonance spectroscopy. All gravimetric analysis experiments were carried out at four different temperatures: 303.15 K, 313.15 K, 323.15 K and 333.15 K, achieving a maximum percentage inhibition efficiency of 92% at 303.15 K. The maximum percentage inhibition efficiency obtained from electrochemical analysis, conducted at 303.15 K, was 83%. Thermodynamic parameters such as ΔG°ads showed that B1 adsorbs onto the MS surface via a mixed type of action at lower temperatures, transitioning to exclusively chemisorption at higher temperatures

Quantum Chemical Investigations on Quinoline Derivatives as Effective Corrosion Inhibitors for Mild Steel in Acidic Medium

WOS: 000305267400067The 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.North-West University; National Research Foundation (NRF) of South AfricaM. M. Kabanda, A. K. Singh and S. K. Shukla are grateful to the North-West University for granting them Postdoctoral Fellowships enabling them to participate in this work. E. E. Ebenso thanks the National Research Foundation (NRF) of South Africa for funding