We investigated a nonlinear advection-diffusion-reaction equation for a passive scalar field. The purpose is to understand how the compressibility can affect the front dynamics and the bulk burning rate. We study two classes of flows: periodic shear flow and cellular flow, analyzing the system by varying the extent of compressibility and the reaction rate. We find that the bulk burning rate vf in a shear flow increases with compressibility intensity ?, following the relation ?vf??2. Furthermore, the faster the reaction is, the more important the difference is with respect to the laminar case.

The effect of a small gravitomagnetic monopole on (accelerated) circular orbits in the equatorial plane of the Taub-NUT spacetime is compared to the corresponding (accelerated) orbits pushed slightly off the equatorial plane in the absense of the monopole (Schwarzschild spacetime).

This paper presents a novel approach for the extraction of the transients content of audio signals, usually represented as superposition of stationary, transient, and stochastic components. The proposed model exploits the predictable and peculiar time-scale behavior of transients by modeling them as superposition of suitable wavelet atoms. These latter allow to predict transients information even at scales where the tonal component is dominant. In this way it is possible to avoid, if required, the pre-analysis of the tonal component.

We present the results of a high resolution numerical study of two-dimensional (2D) Rayleigh-Taylor turbulence using a recently proposed thermal lattice Boltzmann method The goal of our study is both methodological and physical We assess merits and limitations concerning small- and large-scale resolution/accuracy of the adopted integration scheme We discuss quantitatively the requirements needed to keep the method stable and precise enough to simulate stratified and unstratified flows driven by thermal active fluctuations at high Rayleigh and high Reynolds numbers We present data with spatial