L-Dopa as Corrosion Inhibitor for Mild Steel in Mineral Acid Medium
Corrosion inhibition of mild steel was studied using L-Dopa in aqueous hydrochloric acid and sulphuric acid so- lutions. The corrosion behaviours of the steel specimen in the presence of inhibitor weret studied by galvanostatic polari- zation and weight loss techniques. The measured electrochemical data indicated good inhibition of corrosion in both the corrosive medium in presence of L-DOPA. The corrosion inhibition may be explained on the basis of adsorption and for- mation of surface film of L-DOPA on the metal surface. The surface of the steel specimen subjected to electrochemical corrosion in the presence and absence of the inhibitor was studied using scanning electron microscopic images. In the present investigation, L-DOPA is used as corrosion inhibitor for mild steel in aqueous hydrochloric acid and sulphuric acid solutions. The corrosion inhibition efficiency of the compound is studied by potentiodynamic polarization and weight loss studies. The surface morphology of the metal surface before and after corrosion is studied by SEM images. 2. EXPERIMENTAL Analytical Reagent (AR) grade chemicals (sd. fine chemicals, Mumbai) were used for the study. The aqueous solution of sulphuric acid and hydrochloric acid was used as the corrosive media. L-dopa was used as received and the structure of the L-dopa was used as corrosion inhibitor is as shown in Fig. (1).
A Characteristic Investigation of Aminocyclohexane-N′-methylurea as a Corrosion Inhibitor for Mild Steel in 1 N H2SO4
The newly synthesized aminocyclohexane-N′-methylurea Mannich base was characterised using FT-IR, H1NMR, and C13NMR spectra and also it was tested as corrosion inhibitor for the mild steel in 1 N sulphuric acid. Inhibitive study of this compound was carried out by weight loss method over the temperature range of 303–333 K, potentiodynamic polarisation, and AC impedance methods. The inhibition efficiency was increased with increasing concentration of inhibitor whereas it was decreased with increasing temperature. Potentiodynamic polarisation study showed that ACMU is a mixed type inhibitor. AC Impedance study reveals that the corrosion of steel was mainly controlled by a charge transfer process. Surface analysis was carried out using SEM technique. The adsorption of inhibitor follows the Tempkin and Langmuir adsorption isotherms. The activation energy (𝐸𝑎), free energy change (Δ𝐺ads), enthalpy change (Δ𝐻ads) and entropy change (Δ𝑆ads) were calculated to understand the corrosion inhibition mechanism.
Italian Influence on the Development of Calvinist Scholasticism
THIS ARTICLE TRIES to show that the rise of Calvinist scholasticism, which was the most important development in Calvinist theology during the second half of the sixteenth century, stemmed largely from several converging Italian influences, particularly from the writings of Peter Martyr Vermigli and Jerome Zanchi. Here Calvinist theology refers not only to the personal thought of John Calvin but also to the teachings of the founders of the Reformed or Calvinist tradition as it spread out from Geneva and Switzerland to France, Germany, England, Scotland, Poland, and the Low Countries. In this context Calvin emerges as the brightest star in a galaxy of Reformed theologians which includes Heinrich Bullinger, Pierre Viret, Theodore Beza and Wolfgang Musculus as well as Martyr, Zanchi and others. These theologians were often more influential than Calvin himself at a given place or time or on a given point of doctrine. Bullinger, Martyr, and Martin Bucer were all more important for spreading Calvinist ideas to Edwardian England than was John Calvin. Early Elizabethan Protestantism looked more to Zurich than to Geneva, as did early Polish Calvinism. German Calvinism owed more to Heidelberg than to Geneva.' These leaders developed their theologies sometimes in mutual dependence, sometimes with surprising independence. By no means was their relation to Calvin simply that of disciple to master, for each gave a personal nuance to his style of Calvinism. Thus the sixteenth century Jesuit Cornelius Schulting states on the opening page of his five volume polemic against Calvin and Peter Martyr that Martyr was clearer and far more learned than Calvin.2 Recently John Bray has pointed out that research in seventeenth century Calvinism leads "to the conclusion that the impact of Calvin upon the Calvinistic movement has been greatly over-rated. It may well be that some of