New Hydroxylated Cationic Gemini Surfactants as Effective Corrosion Inhibitors for Mild Steel in Hydrochloric Acid Medium

Inhibitory action of hydroxylated cationic gemini surfactants on corrosion of mild steel [MS] in 1 M hydrochloric acid medium is studied by gravimetric, electrochemical polarization and electrochemical impedance spectroscopic (EIS) techniques. The results obtained reveal that these compounds are very efficient inhibitors. The inhibitory action of surfactants increases with the concentration and chain length. Concentration as low as 10−5 M of 16–4–16 MEA could show 99% inhibition whereas 12–4–12 MEA showed 93% inhibition at 10−4 M concentration. The inhibition efficiency versus concentration curves show an S-shape plot indicating adsorption of surfactants on metal surface as a three steps process. From Arrhenius plots corrosion rate of MS was observed to decrease at any given temperature with inhibitor concentration due to the increase in the degree of surface coverage. In contrast, at constant inhibitor concentration, the corrosion rate increases with temperature. EIS measurements show increase in the charge transfer resistance with the inhibitor concentration.

Postnatal survival and growth of mouse irradiated in utero with low dose

In order to investigate radiation risks associated with low dose and low dose-rates, pregnant Swiss albino mice were exposed to gamma rays, 0.80 Gy from a cobalt-60 source at two different dose-rates (0.0795 and 0.0012 Gy/min) on 18 day post conception. In females exposed to lower dose-rate (0.0012 Gy/min), litter size was found to be decreased, while those exposed to higher dose-rate (0.0795 Gy/min), it remained unaltered. In both groups, appearance of fur and development of complete fur were delayed, whereas gait was delayed only in higher dose-rate group. Male offspring exhibited a biphasic mode of weight loss, while female offspring after an initial weight loss at 1 week, displayed a continuous recovery, but could not attain the normal weight till 12 weeks of age. It appears that higher dose-rate is more effective in delaying the appearance of physiological markers and weight loss, while in terms of litter size lower dose-rate (0.0012 Gy/min) is more effective.