Fluid pressure diffusion effects on the seismic reflectivity of a single fracture.

When seismic waves travel through a fluid-saturated porous medium containing a fracture, fluid pressure gradients are induced between the compliant fracture and the stiffer embedding background. The resulting equilibration through fluid pressure diffusion (FPD) produces a frequency dependence of the stiffening effect of the fluid saturating the fracture. As the reflectivity of a fracture is mainly controlled by the stiffness contrast with respect to the background, these frequency-dependent effects are expected to affect the fracture reflectivity.

Frequency-dependent effective hydraulic conductivity of strongly heterogeneous media.

The determination of the transport properties of heterogeneous porous rocks, such as an effective hydraulic conductivity, arises in a range of geoscience problems, from groundwater flow analysis to hydrocarbon reservoir modeling. In the presence of formation-scale heterogeneities, nonstationary flows, induced by pumping tests or propagating elastic waves, entail localized pressure diffusion processes with a characteristic frequency depending on the pressure diffusivity and size of the heterogeneity. Then, on a macroscale, a homogeneous equivalent medium exists, which has a frequency-dependent effective conductivity.

Developmental studies of the lethal gene Bld in the mouse. I. Post-implantation development of the lethal homozygote.

In matings of Bld/+ x Bld/+ mice a characteristic type of abnormal embryo is found on days 6 and 7 after impregnation which dies at 8 days and accounts for about 25% of all living embryos. These embryos are regarded as the fethal Bld/Bld homozygotes. Before 6 days the embryos appear slightly retarded.

The genetics of blind--a lethal factor in mice.

The linkage relationships of the lethal gene blind (Bld) in the mouse were investigated. The gene is located on chromosome 15, between uw and bt. The distance uw--Bld is 28.