UNLABELLED BACKGROUND; Traditionally the diagnosis of brain death is established on the basis of a combination of clinical signs and paraclinical methods. Diffusion-weighted MRI is a new method sensitive to cerebral ischemia. Its value in brain death has not been demonstrated until now. CASE DESCRIPTION A patient was referred to MRI with suspicion of a brain stem stroke. Echo-planar whole-bra...

We present a novel coupled fluid-poroelastic model and an associated numerical upscaling procedure to calculate seismic attenuation velocity dispersion in porous rocks induced by fluid pressure diffusion (FPD) the presence of mesoscopic fluid-saturated voids, such as, for example, vugs or factures. By applying appropriate interface conditions, proposed couples Navier-Stokes equations viscous fl...

In this paper we study a one dimensional thermoelastic transmission problem of special string/beam structure: the two components are coupled at an interface (identified to $ 0 $). Either string or beam is supposed thermoelastic, heat flux given by Cattaneo's law instead usual Fourier's law. We prove that energy decay whole system exponential if thermoelastic. When only coupling decays polynomia...

In this talk presented at the 5th Rencontres du Vietnam 2004, we discuss our preliminary investigations into voids of primordial origin. We show that if voids in the cold dark matter distribution existed at the epoch of decoupling, they could contribute significantly to the apparent rise in cosmic microwave background (CMB) power on small scales detected by the Cosmic Background Imager (CBI) De...

Following Blumenthal et al. 1] and Piran et al. 2] I discuss a simple model for the gravitational formation of voids. This model enables us to estimate the primordial perturbation required on the scale of voids. A comparison of this condition with the constraints on the spectrum of uctuations derived from CMBR observations reveals that gravitational growth of large voids require more power on t...

We consider the stability properties for thermoelastic Bresse system which describes the motion of a linear planar shearable thermoelastic beam. The system consists of three wave equations and two heat equations coupled in certain pattern. The two wave equations about the longitudinal displacement and shear angle displacement are effectively damped by the dissipation from the two heat equations...

In this work, an analytical solution for thermoelastic waves in a metal induced by an ultrafast laser pulse was formulated in the form of a Fourier series. The two-step heat transfer model was applied to account for the thermal nonequilibrium between electrons and the lattice during ultrafast pulsed laser heating. The coupling between the strain rate and the temperature ®eld was also considered...

We consider the prospects for detecting weak gravitational lensing by underdensities (voids) in the large-scale matter distribution. We derive the basic expressions for magnification and distortion by spherical voids. Clustering of the background sources and cosmic variance are the main factors which limit in principle the detection of lensing by voids. We conclude that only voids with radii la...