Rishi Bankim Chandra Colleges

About: Rishi Bankim Chandra Colleges is a based out in . It is known for research contribution in the topics: Myxozoa & Myxosporea. The organization has 43 authors who have published 81 publications receiving 775 citations.

Stagnation‐point Flow towards a Stretching Surface

Abstract: An exact similarity solution of the Navier-Stokes equations is obtained. The solution represents steady axisymmetric stagnation-point flow towards a stretching surface. It is shown that the flow displays a boundary-layer structure when the stretching velocity of the surface is less than the free stream velocity. On the other hand, an inverted boundary layer is formed when the surface stretching velocity exceeds the free stream velocity. Temperature distribution in the flow is found when the surface is held at a constant temperature. It turns out that when the surface temperature exceeds the ambient temperature, heat flows from the surface to the fluid near the stagnation point but further away from the stagnation point, heat flows from the fluid to the stretching surface.

Stagnation-point flow of a viscoelastic fluid towards a stretching surface

Abstract: An analysis is made of the steady two-dimensional stagnation-point flow of an incompressible viscoelastic fluid over a flat deformable surface when the surface is stretched in its own plane with a velocity proportional to the distance from the stagnation-point. It is shown that for a viscoelastic fluid of short memory (obeying Walters’ B′ model), a boundary layer is formed when the stretching velocity of the surface is less than the inviscid free-stream velocity and velocity at a point increases with increase in the elasticity of the fluid. On the other hand, an inverted boundary layer is formed when the surface stretching velocity exceeds the velocity of the free stream and the velocity decreases with increase in the elasticity of the fluid. A novel result of the analysis is that the flow near the stretching surface is that corresponding to an inviscid stagnation-point flow when the surface stretching velocity is equal to the velocity of the free stream. Temperature distribution in the boundary layer is found when the surface is held at constant temperature and surface heat flux is determined. It is found that temperature at a point decreases with increase in the elasticity of the fluid.

Isolation of four new CoII/CoIII and NiII complexes with a pentadentate Schiff base ligand: syntheses, structural descriptions and magnetic studies.

Abstract: In this paper we report the temperature and pH dependent syntheses and systematic characterization of four new CoII/CoIII and NiII complexes with a pentadentate Schiff base ligand H3L obtained by condensing 1,3,-diaminopropan-2-ol with 2-hydroxyacetophenone in 1 : 2 molar ratio. The room temperature syntheses involving CoII and NiII nitrates and the ligand H3L lead to the isolation of the dinuclear species [Co2L2(H2O)] (1), and the mononuclear complex [Ni(LH)] (3), respectively, whereas refluxing at basic pH leads to the tetranuclear complexes, [CoII2CoIII2L2(μ3-OMe)2(NO3)(H2O)2]NO3·2(H2O) (2), and [Ni4L2(μ3-OMe)2(H2O)2]·2H2O (4). 1 is found to be a simple mono alkoxo-bridged CoIII dinuclear species, whereas 2 and 4 are both rhomb-like tetrameric complexes with double oxo bridges and μ3-methoxo bridges, derived from the methanol solvent, in an open dicubane arrangement. Moreover 2 shows six coordinate ordered CoII and CoIII ions and 4 has both six- and five-coordinate NiII centers. Compound 3 is assigned a tentative mononuclear structure based on IR, UV-Vis spectroscopic, 1H-NMR and ESI mass study results and is supposed to have one NiII center coordinated with a ligand fragment in square planar geometry. The variable temperature magnetic susceptibility study for 2 and 4 is performed which indicate for both 2 and 4 the presence of intracluster dominant ferromagnetic interactions.