Describing convective nonwetting phase flow in unsaturated porous media requires knowledge of the nonwetting phase relative permeability. This study was conducted to formulate and derive a generalized expression for the nonwetting phase relative permeability via combining with the Kosugi water retention function. This generalized formulation is then used to flexibly investigate the Burdine, Mua...

Accurate characterization and modeling of subsurface flow in multi-fluid soil systems require development of a rapid, reproducible experimental method that yields the information necessary to determine the parameters of the capillary pressure–saturation and permeability functions. Previous work has demonstrated that parameter optimization using inverse modeling is a powerful approach to indirec...

A two-dimensional infiltration experiment was conducted to investigate and quantify the effect of spatial wettability variations on DNAPL migration and entrapment in saturated sands. Experimental observations of tetrachloroethylene (PCE) infiltration showed that organic-wet sand lenses acted as very effective capillary barriers, retaining PCE and inhibiting its downward migration. A multiphase ...

Consulting Editorial Board HAROLD L. ATKINS, M.D. M. DONALD BLAUFOX, M.D. A. BERTRAND BRILL, M.D., PH.D. JOHN A. BURDINE, JR., M.D. N. DAVIDCHARKES, M.D. TREVOR D. CRADDUCK, PH.D. MICHAEL A. DAVIS, PH.D. WILLIAM C. ECKELMAN, PH.D. SEBASTIAN GENNA, PH.D. C. CRAIG HARRIS, M.S. THOMAS P. HAYNIE, M.D. MARGUERITE T. HAYS, M.D. WILLIAM R. HENDEE, PH.D. B. LEONARDHOLMAN, M.D. RICHARD A. HOLMES, M.D. M...

variables as input (e.g., Rawls and Brakensiek, 1985; Ahuja et al., 1989; Vereecken et al., 1989; Schaap et In many vadose zone hydrological studies, it is imperative that the al., 1998). Far fewer alternatives exist for unsaturated soil’s unsaturated hydraulic conductivity is known. Frequently, the Mualem–van Genuchten model (MVG) is used for this purpose behydraulic conductivity. Although som...

A physical conceptual model for water retention in fractured rocks is derived while taking into account the effect of pore size distribution and tortuosity of capillaries. The formula of calculating relative hydraulic conductivity of fractured rock is given based on fractal theory. It is an issue to choose an appropriate capillary pressure-saturation curve in the research of unsaturated fractur...

The mechanisms underlying vertebrate left-right (L-R) axis specification have attracted much interest among developmental biologists (for review, see Burdine and Schier 2000; Capdevila et al. 2000). Of particular interest from a conceptual standpoint is the question of how L-R positional information first originates within the context of a bilaterally symmetric embryo. To achieve the consistent...