The paper introduces a finite difference solver for the unsteady incompressible Navier-Stokes equations based on adaptive cartesian octree grids. The method extends a stable staggered grid finite difference scheme to the graded octree meshes. It is found that a straightforward extension is prone to produce spurious oscillatory velocity modes on the fine-to-coarse grids interfaces. A local linea...

Using cross correlations between sequential infrared satellite images, an objective technique is developed to compute advective sea surface velocities. Cross correlations are computed in 32 x 32 pixel search (second image) and 22 x 22 template (first image) windows from gradients of sea surface temperature computed from the satellite images. Velocity vectors, computed from sequential images of ...

Rotating transonic flows are long known to admit standing or oscillating shocks and that the excess thermal energy in the post shock flow drives a part of the infalling matter as bipolar outflows. We compute massloss from a viscous advective disc. We show that the mass outflow rate decreases with increasing viscosity of the accretion disc, since viscosity weakens the centrifugal barrier that ge...

This work focuses on the dynamics of vegetation stripes in sloped semi-arid environments presence secondary seed dispersal and inertial effects. To this aim, a hyperbolic generalization Klausmeier model that encloses advective downhill transport plant biomass is taken into account. Analytical investigations were performed to deduce wave Turing instability loci at which oscillatory stationary pa...

The characteristics of solute transport within log-conductivity fields represented by power-law semi-variograms are investigated by an analytical Lagrangian approach that accounts for the automatic frequency cut-off induced by the initial contaminant plume size. The transport process anomaly is critically controlled by the magnitude of the Péclet number. Interestingly enough, unlike the case of...

The paper introduces a finite difference solver for the unsteady incompressible Navier-Stokes equations based on adaptive cartesian octree grids. The method extends a stable staggered grid finite difference scheme to the graded octree meshes. It is found that a straightforward extension is prone to produce spurious oscillatory velocity modes on the fine-to-coarse grids interfaces. A local linea...

This thesis is a rather complete survey concerning an ecologically meaningful problem: how would two competing species evolve in a given spatially heterogeneous and isolated environment? A special kind of the Lotka-Volterra competition model is derived by assuming that the mechanisms of redistribution consist of mutual competition, random diffusion, and advective motion. The main task is to ana...

Due to a thermodynamic coupling between the two leaflets comprising a lipid bilayer, compositional lipid domains residing within opposing leaflets are often found in registry. If the system is perturbed by displacing one domain relative to the other, diffusive and advective lipid fluxes are established to restore equilibrium and reestablish domain overlap. In this work, we focus on the advectiv...

The effect of competition is an important topic in spatial ecology. This paper deals with a general two-species system open advective and inhomogeneous environments. At first, the critical values on interspecific coefficients are established, which determine stability semi-trivial steady states. Secondly, by analyzing nonexistence coexistence states using theory monotone dynamical system, we fi...