Radial gas flows induced by viscosity may significantly redistribute the gas component in galactic disks. On the condition that the timescale of the viscous transport is comparable to the star formation timescale, this process naturally explains the observed exponential stellar density profiles in disks independent of the density profiles of the initial disks. We discuss models for the chemical...

We construct a simple analytic model for wall-bounded turbulence, containing only four adjustable parameters. Two of these parameters are responsible for the viscous dissipation of the components of the Reynolds stress tensor. The other two parameters control the nonlinear relaxation of these objects. The model offers an analytic description of the profiles of the mean velocity and the correlat...

We use data obtained with the PCA onboard RXTE to analyze the spectral variations of the black hole candidate and superluminal source GRS 1915+105. Our results suggest that despite the complicated structure of the X-ray light curve, all spectral changes observed in this source can be explained as a sudden disappearing of the inner part of the accretion disk around the compact object, followed b...

We use data obtained with the PCA onboard RXTE to analyze the spectral variations of the black hole candidate and superluminal source GRS 1915+105. Our results suggest that despite the complicated structure of the X-ray light curve, all spectral changes observed in this source can be explained as a sudden disappearing of the inner part of the accretion disk around the compact object, followed b...

in the present study, the onset of double diffusive reaction-convection in a uid layer with viscous fluid, heated and salted from below subject to chemical equilibrium on the boundaries, has been investigated. linear and nonlinear stability analysis have been performed. for linear analysis normal mode technique is used and for nonlinear analysis minimal representation of truncated fourier serie...

When two small fluid drops are sufficiently close, the van der Waals force overcomes surface tension and deforms surfaces into contact, initiating coalescence. The dynamics of deformation across an inviscid gap falls distinct regimes (Stokes inertial–viscous) characterized by forces that balance attraction at leading order (viscosity, both inertia viscosity). previously studied Stokes regime ho...