Pseudoparabolic equations in periodic media are homogenized to obtain upscaled limits by asymptotic expansions and two-scale convergence. The limit is characterized and convergence is established in various linear cases for both the classical binary medium model and the highly heterogeneous case. The limit of vanishing time-delay parameter in either medium is included. The double-porosity limit...

Environmental heterogeneity helps maintain genetic variation in fitness. Therefore, one might predict that populations living in heterogeneous environments have higher adaptive potential than populations living in homogeneous environments. Such a prediction could be useful in guiding conservation priorities without requiring detailed genetic studies. However, this prediction will be true only i...

The paper is devoted to theoretical and computational studies on application of the multiresolutional wavelet-based homogenization approach in the Finite Element Method modeling of heterogeneous media. Multiresolutional homogenization scheme is proposed for 1D elastostatic equilibrium problem of periodic heterogeneous medium with Young modulus defined by some elementary wavelet functions and co...

The high computational cost of complex engineering optimization problems has motivated the development of parallel optimization algorithms. A recent example is the parallel particle swarm optimization (PSO) algorithm, which is valuable due to its global search capabilities. Unfortunately, because existing parallel implementations are synchronous (PSPSO), they do not make efficient use of comput...

Numerical methods are developed to simulate the wave propagation in heterogeneous 2D fluid / poroelastic media. Wave propagation is described by the usual acoustics equations (in the fluid medium) and by the low-frequency Biot’s equations (in the porous medium). Interface conditions are introduced to model various hydraulic contacts between the two media: open pores, sealed pores, and imperfect...

The effects of porous medium heterogeneity on methane hydrate formation, water flow through the heterogeneous hydrate-bearing sand, and hydrate dissociation were observed in an experiment using a heterogeneous sand column with prescribed heterogeneities. X-ray computed tomography (CT) was used to monitor saturation changes in water, gas, and hydrate during hydrate formation, water flow, and hyd...

In time reversal acoustics experiments, a signal is emitted from a localized source, recorded at an array of receivers-transducers, time reversed, and finally re-emitted into the medium. A celebrated feature of time reversal experiments is that the refocusing of the re-emitted signals at the location of the initial source is improved when the medium is heterogeneous. Contrary to intuition, mult...

We introduce a new approach for measuring both the effective medium and the transport properties of light propagation in heterogeneous media. Our method utilizes the conceptual equivalence of frequency variation with a change in the effective index of refraction. Experimentally, we measure intensity correlations via spectrally resolved refractive index tuning, controlling the latter via changes...

The worldwide incidence of tuberculosis (TB) has been increasing. Although its diagnosis is well established in adults, in children it is difficult due to its particular aspects. We report a 3 years and 8 month-old infant who experienced chronic wheezing, classified as moderate-to-severe asthma, had recurrent pneumonia, and was not responsive to management with beta adrenergic agents. Chest X-r...

Spatial and georeferenced information plays an important role in urban land management processes such as spatial planning and environmental management. As many of the processes are increasingly coined by participation of and collaboration between multiple stakeholders, a common medium capable of integrating different types and sources of spatial information is necessary. It is argued that 3D ci...