The relationship between elastic wave velocities and water saturation in a water/gas reservoir depends strongly on whether saturation is heterogeneous (patchy) or homogeneous. Heterogeneity in saturation may result from lithologic heterogeneity because under conditions of capillary equilibrium, different lithologies within a reservoir can have different saturations, depending on their porositie...

A new experimental method for determining the dependence of the electron mobility on the longitudinal-electric field has been developed. The development, validation, and explanation of this new method has been carefully carried out. We have applied this procedure to standard submicron MOSFET’s and after having obtained the mobility dependence on both the transverseand longitudinal-electric fiel...

AIM To study continuously cerebral blood flow velocity in the middle cerebral artery before, during, and after tube feeding in neonates. METHOD Cerebral blood flow velocity was measured in 14 neonates using a Doppler ultrasound device. Blood pressure, respiration, and oxygen saturation were monitored. RESULTS Mean blood flow velocity decreased from 37 cm/s before feeding to 33 cm/s (P < 0.0...

Figure 1. Model of P-wave velocity (above) and density (below) verses gas saturation for a sandstone reservoir with a porosity of 25%. The velocity was modelled using Gassmann’s equation (1951) with the Reuss average moduli of the fluids. For a gas saturated reservoir, a decrease in gas saturation causes a negligible change in the P-wave velocity for saturations above 20% and more significant c...

The mobility and saturation velocity in the nanoscale metal oxide semiconductor field effect transistor (MOSFET) are revealed to be ballistic; the former in a channel whose length is smaller than the scattering-limited mean free path. The drain-end carrier velocity is smaller than the ultimate saturation velocity due to the presence of a finite electric field at the drain. The current-voltage c...

For different models of the electron-phonon interaction, the asymptotic behaviour of the moments of the stationary homogeneous solution of the linear Boltzmann equation is determined in the limit of a high external field. For Hilbert-Schmidt kernels of a finite rank, a result recently proven for kernels of rank one is found generally valid; as a consequence velocity saturation is excluded for t...

Elastic waves of short wavelength propagating through the upper layer of the Earth appear to move faster at large separations of source and receiver than at short separations. This scale dependent velocity is a manifestation of Fermat’s principle of least time in a medium with random velocity fluctuations. Existing perturbation theories predict a linear increase of the velocity shift with incre...