Laboratory measurements of the resistivity of three sandstone samples collected during imbibition (increasing SXJ) and drainage (decreasing Sn,) show pronounced hysteresis in resistivity throughout much of the saturation range. The variation in resistivity can be related to changes in pore-scale fluid distribution caused by changes in saturation history. The form of the hysteresis is such that ...

mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. in this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numeri...

We have examined the effect of surface contamination on the attenuation and stiffness of compressional seismic waves in artificial cylindrical glass cracks that are partially saturated with water. The compression of the gap perpendicularly to its plane reduces the gap volume and forces the water to redistribute within the gap (conservation of volume of an incompressible liquid). On clean surfac...

Seismic velocities in rocks at ultrasonic frequencies depend not only on the degree of saturation but also on the distribution of the fluid phase at various scales within the pore space. Two scales of saturation heterogeneity are important: (1) saturation differences between thin compliant pores and larger stiffer pores, and (2) differences between saturated patches and undersaturated patches a...

Seasonal thawing and freezing of near-surface sediments significantly affect the interpretation of seismic reflection surveys and vertical seismic profiling, as well as activity on the surface. Permafrost covers much of the Earth’s colder regions and is also subject to periodic thawing and freezing. The significance of the regions with large seasonal temperature variations for exploration and e...

(Preliminary Report.) The model formulation and existence theory is described for diffusion of a barotropic fluid through a partially saturated poroelastic composite medium consisting of two components. This includes the Barenblatt-Biot doublediffusion model of elastic deformation and laminar flow in a fissured medium, such as consolidation processes in a system of fissures distributed througho...

Fragment-based lead generation has proven to be an effective means of identifying high-quality lead compounds for drug discovery programs. However, the fragment screening sets often used are principally comprised of sp(2) -rich aromatic compounds, which limits the structural (and hence biological) diversity of the library. Herein, we describe strategies for the synthesis of a series of partiall...

[1] During reactive fluid flow in saturated fractures, the relative rates of dissolved mineral transport and local reactions strongly influence local aperture alterations and the resulting changes in fracture permeability (or transmissivity). In the presence of an entrapped residual nonaqueous phase (e.g., CO2 or oil), the spatial distribution of the entrapped phase will influence flow and tran...

Deformation and localization analysis is a crucial issue and has thus been intensively investigated in the last decades. However, in contrast to solid mechanical problems, geotechnical applications do not only concern a single solid material, the soil, but they also affect the pore-fluids, water and air, and, consequently, the coupling of the solid deformation with the pore-fluid flow. As a res...