Striated populations in disordered environments with advection

Growth in static and controlled environments such as a Petri dish can be used to study the spatial population dynamics of microorganisms. However, natural populations such as marine microbes experience fluid advection and often grow up in heterogeneous environments. We investigate a generalized Fisher-Kolmogorov-Petrovsky-Piscounov (FKPP) equation describing single species population subject to a constant flow field and quenched random spatially inhomogeneous growth rates with a fertile overall growth condition.

Lattice Boltzmann accelerated direct simulation Monte Carlo for dilute gas flow simulations.

Hybrid particle-continuum computational frameworks permit the simulation of gas flows by locally adjusting the resolution to the degree of non-equilibrium displayed by the flow in different regions of space and time. In this work, we present a new scheme that couples the direct simulation Monte Carlo (DSMC) with the lattice Boltzmann (LB) method in the limit of isothermal flows.

Analysis of the asymmetric behavior of propeller-rudder system of twin screw ships by CFD

The interference between the hull, propeller and rudder remarkably affects the control and maneuvering capabilities of marine vehicles. In case of twin screw/twin rudder ships, the asymmetric evolution of the wake past the hull causes the asymmetric functioning of the propeller-rudder system. Systematic investigations on this aspect for twin screw ships are limited.

Weighted L1 approximation on [-1,1] via discrete de la Vallée Poussin means

We consider some discrete approximation polynomials, namely discrete de la Vallée Poussin means, which have been recently deduced from certain delayed arithmetic means of the Fourier-Jacobi partial sums, in order to get a near-best approximation in suitable spaces of continuous functions equipped with the weighted uniform norm. By the present paper we aim to analyze the behavior of such discrete de la Vallée means in weighted L1 spaces, where we provide error bounds for several classes of functions, included functions of bounded variation.

Carbon tetrachloride in the UTLS: distribution, trend and lifetime estimation using MIPAS ESA v7 data

Carbon tetrachloride (CCl?) is a strong ozone-depleting atmospheric gas regulated by the Montreal protocol. Recently it received increasing interest because it was found that at the surface its atmospheric concentration declines with a rate almost three times smaller than its lifetime-limited rate.