Water and solute flux from the subsurface drains of macroporous agricultural fields are simulated using two-dimensional single-porosity and dual-porosity models. Field-averaged (i.e. effective) parameters are calibrated from drainage outflow and validated for water flow and the transport of non-reactive solutes applied at discrete locations on the field. Both the singleporosity and the dual-por...

In this paper we consider the problem of estimating transport and biodegra-dation parameters in a contaminant transport model. We develop a convergence theory for parameter identiication under approximation that includes the nonlinearities inherent in the biodegradation models. The functional analytic approach provides a means for studying a variety of solute transport and biodegradation problems.

Nanofiltration performance as a function of feed temperature is relevant to several industrial settings including pretreatment for scale control in thermal desalination. Understanding of solute transport as a function of temperature is critical for effective membrane and system design. In this study, nanofiltration is modeled at 22, 40 and 50C using the Donnan Steric Pore Model with dielectric ...

Water and solute or drug transport in crosslinked polymeric materials was investigated to determine the effects of polymer morphology, composition and solute properties on transport behavior. Two crosslinked polymer systems, poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (P(HEMA-co-MMA)) and poly(vinyl alcohol) (PVA), were used in water transport and solute release experiments. Struct...

Water movement occurs to a variable degree across every epithelial layer of cells and plays a determinant role in the homeostasis of body fluid balance. Is such water transport the result of a difference of water activity or osmotic pressure across the epithelium? The answer to that question is more often negative as demonstrated by the phenomenon of isotonic water movement. Many epithelia tran...

The nonlinear mathematical model for solute and fluid transport induced by the osmotic pressure of glucose and albumin with the dependence of several parameters on the hydrostatic pressure is described. In particular, the fractional space available for macromolecules (albumin was used as a typical example) and fractional fluid void volume were assumed to be different functions of hydrostatic pr...

This second part of the overview of reverse osmosis investigates the ability of membrane transport models, presented in Part 1, to describe and/or predict membrane performance under different operating conditions. The problem of using the transport models to describe mixed solute systems is also discussed. The emphasis is to provide a simple, practical, and yet comprehensive summary of the most...

It is difficult to estimate solute transport parameters in streams empirically and numerous approaches have been investigated in the past. In the current study, we explored the use of the simulated annealing (SA) algorithm for estimating solute transport parameters in streams from tracer experiment data. For a simple one-dimensional dispersion test case, the standard SA algorithm was very slow ...