We present an asymptotic theory for analytical characterization of the high-Reynolds-number incompressible flow of a Newtonian fluid past a shear-free circular cylinder. The viscosity-induced modifications to this flow are localized and except in the neighborhood of the rear stagnation point, behave like a linear perturbation of the inviscid flow. Our theory gives a highly accurate description of these modifications by including the contribution from the most significant viscous term in a correctional perturbation expansion about an inviscid base state. We derive the boundary layer equation for the flow and deduce a similarity transformation that leads to a set of infinite, shear-free-condition-incompatible, self-similar solutions. By suitably combining members from this set, we construct an all-boundary-condition-compatible solution to the boundary layer equation. We derive the governing equation for vorticity transport through the narrow wake region and determine its closed-form solution. The near and far field forms of our wake solution are desirably consistent with the boundary layer solution and the well-known, self-similar planar wake solution, respectively. We analyze the flow in the rear stagnation region by formulating an elliptic partial integro-differential equation for the distortion streamfunction that specifically accounts for the fully nonlinear and inviscid dynamics of the viscous correctional terms. The drag force and its atypical logarithmic dependence on Reynolds number, deduced from our matched asymptotic analysis, are in remarkable agreement with the high-resolution simulation results. The logarithmic dependence gives rise to a critical Reynolds number below which the viscous correction term, counterintuitively, reduces the net dissipation in the flow field.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Two polynuclear end‐to‐end dicyanamide (dca) bridged copper(II) Schiff base complexes [Cu(L 1 )(μ 1,5 ‐dca)] n ( 1 ) and [Cu(L 2 )(μ 1,5 ‐dca)] n ( 2 ) {[HL 1 =(1‐(2‐(diethylamino)ethylimino)ethyl) naphthalene‐2‐ol] and [HL 2 =(1‐(2‐(dimethylamino)ethylimino)methyl) naphthalene‐2‐ol]} were synthesized and X‐ray characterized. Complex 1 crystallizes in chiral space group C 2 and complex 2 crystallizes in achiral space group P 2 1 /c. Interactions of both complexes with calf thymus DNA (CT DNA) were studied by UV‐vis and circular dichroism spectroscopy. Molecular docking studies were also carried out for both complexes to find their binding affinity using Alpha PMI as the placement methodology. Although docking studies indicated that the binding constants of both complexes with CT DNA were more or less same, UV‐Vis spectral data indicated that the binding constant of complex 1 with CT DNA is considerably large compared to that of complex 2 . As complex 1 is chiral and complex 2 is achiral, it may be concluded that the chirality of complex 1 played very significant role to binding of chiral DNA molecule. The antimicrobial activity were estimated by the determination of the minimal inhibitory concentration (MIC) using the broth microdilution method. The complexes showed high in vitro cytotoxicity against MDA‐MB 468 cells.
We developed a multienzyme biocatalytic cascade with high atom efficiency and a self-sufficient redox network for the synthesis of nylon monomers without adding auxiliary enzymes to recycle cofactors.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.