L. Vattuoneb, M. Repettoa and M. Roccab
Electron energy loss spectrometers (EELS) for surface studies require a high energy resolution (▵E ? 3 meV) monochromatic electron beam with the highest possible current. In order…
Abstract
Electron energy loss spectrometers (EELS) for surface studies require a high energy resolution (▵E ? 3 meV) monochromatic electron beam with the highest possible current. In order to improve the transmission of such a device, and so the achievable current, a 3D simulation of electron trajectories taking into account space charge effects was performed for typical three lenses cathode systems, electrostatic cylindrical deflector analyzer (CDA 127°) and acceleration lenses. The results of the analysis are presented and their effects on the overall design of the device are discussed.
Khaoula Nasr, Michele Fedel, Khaled Essalah, Flavio Deflorian and Nebil Souissi
This study aims to investigate the inhibition performance of an aqueous extract of Matricaria recutita chamomile on the corrosion of S235JR steel in 0.5 M NaCl by using…
Abstract
Purpose
This study aims to investigate the inhibition performance of an aqueous extract of Matricaria recutita chamomile on the corrosion of S235JR steel in 0.5 M NaCl by using electrochemical impedance spectroscopy (EIS) and polarization measurements.
Design/methodology/approach
The inhibition performance was investigated using EIS and polarization measurements. Surface analysis demonstrates the presence of a protective layer on the steel surface in the presence of the extract. Quantum chemical parameters calculated for the molecules contained in the aqueous extract are interpreted to predict the corrosion inhibition efficiency of the considered extract.
Findings
The inhibition efficiency of chamomile aqueous extract for S235JR steel increases with increasing amounts of plant concentration and with an increase in the immersion time. The optimal inhibition efficiency of chamomile extract, 98.90 per cent, was achieved for S235JR steel when immersed in 15 per cent v/v of extract concentration for 2 h. The surface analysis in the absence and presence of the chamomile extract confirmed the formation of a protective layer on steel surface. The quantum chemical calculations allowed to explain the great inhibition efficiency values by interpreting the calculated quantum parameters.
Originality/value
This is the first study carrying out an experimental and theoretical investigation on M. recutita chamomile as a green corrosion inhibitor, with interesting potential industrial applications.