The anticorrosive potential of Stachytarpheta mutabilis leaf extract (SMLE) as a corrosion inhibitor for corrosion of mild steel (MS) in 1 M HCl was investigated using weight loss measurement as well as gasometric techniques at 30 and 60 oc. Relevant thermodynamic equations were employed to estimate the activation energy, enthalpy change and entropy change. The adsorption isotherms were used to determine the Gibbs free energy change. Results obtained showed that SMLE functioned as an excellent corrosion inhibitor for mild steel in the acidic environment. Temperature studies revealed a decrease in inhibition efficiency with increase in temperature and activation energies increased in the presence of the extract. The adsorption of SMLE on mild steel was approximated using Freundlich, Flory-Huggins, Frumkin, El-Awary’s and Temkin isotherms but Langmuir gave the best fit. Both kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. The adsorption followed a first order kinetics. As concluded from the results, the adsorption of S. mutabilis on mild steel in 1M HCl medium is feasible, spontaneous and it occurred by physical adsorption. From the experimental results obtained, it can be concluded that SMLE inhibit corrosion effectively when compared well with many reported green inhibitors for MS corrosion.
France, after fighting valiantly, for more than 2 years, against a rare neuromuscular disorder.His wife Geneviève and their two
A solvent has many different types of impact on the environment. This article describes a method that combines several different types of impacts together into one environmental index so that similar solvents may be compared by their cumulative impact to the environment. The software tool PARIS III (Program for Assisting the Replacement of Industrial Solvents III) initially finds thousands of solvents mixtures with behaviors as close as possible to those of the original solvent entered. The overall environmental impacts of these solvent mixtures are estimated and assigned to environmental indexes. Users of the software tool can then choose replacements for the original solvent with similar activities but with significantly smaller environmental indexes. These solvent mixtures may act as practical substitutes for the industrial solvents but substantially reduce the overall environmental impact of the original harmful solvents. Potential replacements like this are found for three of the U.S. Environmental Protection Agency's Toxic Release Inventory solvents, carbon tetrachloride, toluene, and N-methylpyrrolidone.
This study applies the ‘Flexible-Acceptor’ variant of the General Solubility Equation, GSE(Φ,B), to the prediction of the aqueous intrinsic solubility, log10 S0, of FDA recently-approved (2016–2020) ‘small-molecule’ new molecular entities (NMEs). The novel equation had been shown to predict the solubility of drugs beyond Lipinski’s ‘Rule of 5’ chemical space (bRo5) to a precision nearly matching that of the Random Forest Regression (RFR) machine learning method. Since then, it was found that the GSE(Φ,B) appears to work well not only for bRo5 NMEs, but also for Ro5 drugs. To put context to GSE(Φ,B), Yalkowsky’s GSE(classic), Abraham’s ABSOLV, and Breiman’s RFR models were also applied to predict log10 S0 of 72 newly-approve NMEs, for which useable reported solubility values could be accessed (nearly 60% from FDA New Drug Application published reports). Except for GSE (classic), the prediction models were retrained with an enlarged version of the Wiki-pS0 database (nearly 400 added log10 S0 entries since our recent previous study). Thus, these four models were further validated by the additional independent solubility measurements which the newly-approved drugs introduced. The prediction methods ranked RFR ~ GSE (Φ,B) > ABSOLV > GSE (classic) in performance. It was further demonstrated that the biases generated in the four separate models could be nearly eliminated in a consensus model based on the average of just two of the methods: GSE (Φ,B) and ABSOLV. The resulting consensus prediction equation is simple in form and can be easily incorporated into spreadsheet calculations. Even more significant, it slightly outperformed the RFR method.
A series of concentrated aqueous solutions of ferric chloride with different chloride:iron(III) ratios has been studied by means of EXAFS to determine the structure around the iron(III) ion of the dominating species in such solutions. The dominating species in dilute acidic aqueous solution of ferric chloride, at less than 1 mmol·dm−3, are the hydrated iron(III) and chloride ions, while in concentrated aqueous solution and in solutions with an excess of chloride ions, up to 1.0 mol·dm−3, it is the trans-[FeCl2(H2O)4]+ complex. Possible higher chloroferrate(III) or dimeric [Fe2Cl6] complexes at room temperature, as proposed in the literature, were not observed in any of the studied solutions in spite of an excess of chloride ions of 1 mol·dm−3.
