242 A dispersion are considered to be the dominant mechanisms of solute transport in the vadose zone, i.e., the variably saturated layer of soils and sediments between the soil surface and groundwater table (Jury and Flühler, 1992). Advection is associated with the average water fl ux or velocity, whereas hydrodynamic dispersion is modeled using an analog of Fick’s law corresponding to the Brow...

the partial differential equations for water flow and solute transport in a two-dimensional saturated domain are rendered discrete using the finite difference technique; the resulting system of algebraic equations is solved using a dynamic programming (dp) method. the advantage of the dp algorithm is that the problem is converted from solving an algebraic system of order nc(nl-1) nc(nl-1) into...

In this paper we formulate a system of partial diierential equations that models the contamination of groundwater due to migration of dissolved contaminants through unsaturated to saturated zone. A closed form solution using singular perturbation techniques for the water ow and solute transport equations in the unsaturated zone is given. Indeed, the solution can be used as a tools to verify the...

A simple and reproducible method has been developed for following fluid transport by an in vitro preparation of mammalian gall bladder, based upon weighing the organ at 5 minute intervals. Both guinea pig and rabbit gall bladders transport NaCl and water in isotonic proportions from lumen to serosa. In the rabbit bicarbonate stimulates transport, but there is no need for exogenous glucose. The ...

Surface-applied chemicals move through the unsaturated zone with complex flow and transport processes due to soil heterogeneity and reach the saturated zone, resulting in groundwater contamination. Such complex processes need to be studied by advanced measurement and modeling techniques to protect soil and water resources from contamination. In this study, the interactive effects of factors lik...

We present a three-dimensional framework for the transport of neutral solute through soft biological tissue, such as the articular cartilage, under different mechanical loading conditions. The tissue is modelled as a mixture of three phases, a hyperelastic, anisotropic solid matrix, an incompressible inviscid fluid and a solute. The formulation accounts for the anisotropic interaction between t...

At the ultrastructural level, epithelia performing solute-linked water transport possess long, narrow channels open at one end and closed at the other, which may constitute the fluid transport route (e.g., lateral intercellular spaces, basal infoldings, intracellular canaliculi, and brush-border microvilli). Active solute transport into such folded structures would establish standing osmotic gr...

SEAWAT is a finite-difference computer code designed to simulate coupled variabledensity ground water flow and solute transport. This paper describes a new version of SEAWAT that adds the ability to simultaneously model energy and solute transport. This is necessary for simulating the transport of heat and salinity in coastal aquifers for example. This work extends the equation of state for flu...