Weight loss and thermometric methods have been used to study the corrosion inhibition of mild steel in acidic solution (HCl and H 2 SO 4 ) by Schiff's bases viz. N-(4-N,N-dimethylaminobenzal)-p-anisidine (SB 1 ), N-(4-N,N-dimethylaminobenzal)-p-toluidine (SB 2 ) and N-(4-N,N-dimethylaminobenzal)-2,4-dinitroaniline (SB 3 ). The efficiencies have been compared with those of parent amines from which Schiff's bases have been derived. Results of inhibition efficiencies observed from these two methods are in good agreement and have been found to be dependent on the concentrations of inhibitors as well as those of acids. Inhibition efficiency of all inhibitors increases with increasing concentration of inhibitors. Efficiency also increases with increasing concentration of acids. Inhibition efficiency is more in case of HCl rather than in H 2 SO 4 . Inhibition efficiency was found maximum up to 95.55% for mild steel in HCl solution. Inhibition efficiencies of synthesised Schiff's bases have been found much more than their parent amines. It was observed that inhibition efficiency of all amines increases with increasing concentration of amines but decreases with increasing concentration of HCl and H 2 SO 4 .

The mixing and hydrodynamic behaviour of binary fluidized beds of particles of same size and differing density has been investigated experimentally by using radiation based non-invasive techniques, viz. radioactive particle tracking (RPT) and dual-source densitometry. The effect of air inlet velocity and bed composition has been investigated. RPT experiments are performed individually for both the solids by tracking one particle at a time. Many interesting findings are discussed, for example, such as the heavier (jetsam) phase is seen to be fluidized by action of the lighter (flotsam) phase even below its minimum fluidization velocity. Further, it has been found that while with increase in air inlet velocity, the extent of mixing of solid phases increases; even at very high air velocities the jetsam phase is not completely mixed. The important role played by the particle-particle collisions in the fluidization of binary mixtures is quantitatively highlighted.Le mélange et le comportement hydrodynamique des lits fluidisés binaires de particules de même taille et de différentes densités ontétéétudiés expérimentalement en utilisant une technique non invasiveà base de rayonnements par le suivi des particules radioactives et la densitométrieà double foyer. L'effet de la vitesse d'admission d'air et de la composition du lit aétéétudié. Des expériences de suivi des particules radioactives sont exécutées individuellement pour chacun des deux solides par le suivi d'une particuleà la fois. Plusieurs résultats intéressants sont discutés, comme par exemple, il est observé que la phase plus lourde (jetsam) est fluidisée par l'action de la phase plus légère (flotsam), même en dessous de sa vitesse minimum de fluidisation. De plus, il aété constaté que, tandis qu'avec l'accroissement de la vitesse d'admission d'air, l'ampleur du mélange des phases solides augmente, la phase jetsam n'est pas complètement mélangée mêmeà des vitesses d'air trèsélevées. Le rôle important joué par les collisions particule-particule dans la fluidisation des mélanges binaires est quantitativement mis enévidence.

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The Cr(III), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes with a novel tetradentate ligand obtained by condensation of ethylenediamine with ortho-hydroxyphenylglyoxal have been synthesized and characterized by elemental analysis, molar conductance and magnetic susceptibility measurements, IR, UV-Visible and atomic absorption studies. The Cr(III), Fe(III) and Co(II) complexes possess six coordinate octahedral geometry whereas Ni(II), Cu(II) and Zn(II) complexes are square planar and tetrahedral respectively. Bactericidal and fungicidal activities of the compounds were evaluated in vitro by disc diffusion method. The perusal of antimicrobial activities of the compounds reveals that the complexes possess greater bactericidal and fungicidal activities against all the microbes in comparison to ligand which is due to their higher lipophilicity.