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The aim of this work is to investigate corrosion inhibition characteristics of steel (X70) in chlohydric acid (1M) in presence of different concentration (1-60 cm 3 ) of Moringaoleifera extract using potentiodynamic polarization studies and impedance measurements. The inhibition efficiency increased with increasing Moringaoleiferaextract concentration; the low concentration 0.25% V / V was chosen since the inhibition efficiency of the extracts was generally very high. The experimental data showed that the inhibition performance for Tafel and the impedance are 65-70% and 40-55% respectively; maximum inhibition could reach about 84-86% at the concentration of 15% V/V. The results obtained from electrochemical impedance spectroscopy showed that the variation in the impedance parameters, charge transfer resistance and double layer capacitance, with the variation in extract concentration is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of carbon steel. The strong adsorption mechanism between the extract and the mild steel substrate is found to obey Langmuir's, Temkin's and Frumkin's isotherms. All data presented in the present paper suggest that the Moringaoleifera plant has high inhibition efficiency in acid media.

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The present work is aimed mainly to synthesize new fluorinated compounds and their biological significance against tested bacteria and fungus. Thus, the 4-amino-2-ethoxy-3,5,6-trifluoropyridine 4 was synthesized by the reaction of 4-amino 2,3,5,6-tetrafluoropyridine 1 with benzaldehyde 2 in EtOH to obtain the pure product as white crystals in 33% yield. The purity of this compound was estimated by TLC technique and microanalysis while its structure was supported by the usual spectroscopic methods such as UV, infrared, 1 H. NMR, and gas chromatography coupled by a mass spectrometry (GC/MS). 4-amino 2,3,5,6-tetrafluoropyridine 1 coupled readily to benzaldehyde 2 when we have used THF as solvent resulting a new Schiff base (E)-N-benzylidene-2,3,5,6-tetrafluoropyridin-4-amine 3 in 48 % yield. Exploration of the anti-bacterial activity against both gram-positive and gram-negative bacteria showed that these compounds 3 and 4 compounds at a concentration of 250 µg/ml exhibited a slight activity towards Enterococcus feacium; Streptocoque B and Staphylococus aureus exhibited a mild/moderate activity for the case of Escherichia coli and Salmonella typhimurium when compared to Ampicillin. From the results obtained by the antifungal activity, it is found that this fluorinated Schiff base 3 and fluorinated ethoxypyridine 4 are more active against Candida albicans at a concentration of 250 µg/ml when compared to Nystatine.