2-Pentadecyl-1,3-imidazoline (PDI), 2-Undecyl-1,3-imidazoline (UDI), 2-Heptadecyl-1,3-imidazoline (HDI), 2-Nonyl-1,3-imidazoline (NI) were synthesized and characterized by FT-IR and NMR Studies. The corrosion inhibition properties of these compounds on aluminium in 1 M HCl and 0.5 M H 2 SO 4 were investigated by weight loss, potentiodynamic polarization, electrochemical impedance and scanning electron microscopic techniques. The weight loss study showed that the inhibition efficiency increases with increase in the concentration of the inhibitor and was found to be inversely related to time and temperature while it shows no significant change with increase in acid concentration. The effectiveness of these inhibitors were in the order of UDI > NI > PDI > HDI .The values of activation energy, free energy of adsorption, heat of adsorption, enthalpy of activation and entropy of activation were also calculated to elaborate the mechanism of corrosion inhibition. The adsorption of these compounds on aluminium surface follows the Langmuir adsorption isotherm. The potentiodynamic polarization data show that the compounds studied are mixed type inhibitors. Electrochemical impedance was used to investigate the mechanism of corrosion inhibition. The surface characteristics of inhibited and uninhibited metal samples were investigated by scanning electron microscopy (SEM).

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The present study was undertaken with the objective to investigate the intraspecific variation of Channa punctatus on the basis of morphometric characters using the truss network system that was constructed from the fish body. Fish samples were collected from the Narora (n = 62) and Kanpur sites (n = 46) of the Ganga River, the Firozabad site in the Yamuna River (n = 66) and at the Lucknow site of the Gomti River (n = 60). Data were subjected to principal component analysis, discriminant function analysis and univariate analysis of variance. The first principal component (PC I) analysis explained 47.75% of total variation while PC II and PC III explained 8.18 and 7.48%, respectively. The step-wise discriminant function analysis retained seven variables that significantly discriminated the populations. Using these variables 81.85% of the original groups were classified into their correct samples. Misclassification was higher for the samples from Ganga River (19.6% at the Kanpur site and 19.4% for the Narora site). Of the total 27 transformed morphometric measurements, 23 exhibited significant differences among the populations. These findings indicate the presence of different stocks of fish from the three rivers. U.S.

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