Synergistic effects of sodium lauroyl sarcosinate and glutamic acid in inhibition assembly against copper corrosion in acidic solution

© 2015 Elsevier B.V. All rights reserved. A self-assembled multilayer (SAM) from sodium lauroyl sarcosinate (SLS) and glutamic acid (GLU) is formed on copper surface. Its inhibition ability against copper corrosion is examined by electrochemical analysis and weight loss test. In comparison to SAM formed by just SLS or GLU, a synergistic effect is observed when the coexistence of SLS and GLU in SAM. The SLS/GLU SAM has an acicular multilayer structure, and SAM prepared under the condition of 5 mM SLS and 1 mM GLU shows the best protection efficiency. PM6 calculation reveals that the synergistic effect stems from interactions between SLS, GLU and cupric ions.

Fluid loss as a quick method to evaluate the hydraulic conductivity of geosynthetic clay liners under acidic conditions

This study investigates the performance of bentonite components of geosynthetic clay liners (GCLs) when exposed to aggressive leachates using the fluid loss test and provides a possible quick method for estimating the effect of acidic conditions on hydraulic conductivity. Fluid loss generally increases with increasing acid concentrations. Hydraulic conductivity values back-calculated from the fluid loss tests (kFL) are compared with the values measured using a flexible-wall permeameter (kTri).Generally, the predicted hydraulic conductivity values are conservative (kFL/kTri > 1) under water and low acid concentrations(≤0.015 mol/L). However, the back-calculated hydraulic conductivity is shown to be nonconservative (kFL/kTri < 1) at high acid concentrations (≥0.125 mol/L).

Acidic potassium permanganate chemiluminescence for the determination of antioxidant potential in three cultivars of Ocimum basilicum

Ocimum basilicum, a member of the family Lamiaceae, is a rich source of polyphenolics that have antioxidant properties. The present study describes the development and application of an online HPLC-coupled acidic potassium permanganate chemiluminescence assay for the qualitative and quantitative assessment of antioxidants in three cultivars of O. basilicum grown under greenhouse conditions. The chemiluminescence based assay was found to be a sensitive and efficient method for assessment of total and individual compound antioxidant potential. Leaves, flowers and roots were found to be rich reserves of the antioxidant compounds which showed intense chemiluminescence signals. The polyphenolics such as rosmarinic, chicoric, caffeic, p-coumaric, m-coumaric and ferulic acids showed antioxidant activity. Further, rosmarinic acid was found to be the major antioxidant component in water-ethanol extracts. The highest levels of rosmarinic acid was found in the leaves and roots of cultivars "holy green" (14.37; 11.52 mM/100 g DW respectively) followed by "red rubin" (10.02; 10.75 mM/100 g DW respectively) and "subja" (6.59; 4.97 mM/100 g DW respectively). The sensitivity, efficiency and ease of use of the chemiluminescence based assay should now be considered for its use as a primary method for the identification and quantification of antioxidants in plant extracts.