The random walk particle tracking method has become an important tool for the uncertainty assessment of solute transport models due to its computational efficiency and the non-existence of numerical dispersion. Yet, in highly heterogeneous aquifers the smoothness assumption of the velocity field, requisite for a correct solution of the random walk equations, may not hold anymore. Three differen...

It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and...

Pore-water solute transport processes acting in addition to molecular diffusion affect sediment biogeochemistry and benthic exchange fluxes. Given the relatively few direct measurements of enhanced transport intensities, there is a need for predictive relationships to calculate enhanced transport parameters from more readily available information. Here, enhanced diffusion coefficients and nonlo...

ATP-binding cassette (ABC) transporters use ATP to drive solute transport across biological membranes. Members of this superfamily have crucial roles in cell physiology, and some of the transporters are linked to severe diseases. However, understanding of the transport mechanism, especially of human ABC exporters, is scarce. We reconstituted the human lysosomal polypeptide ABC transporter TAPL,...

This paper is concerned with numerical methods for twophase incompressible flows assuming a sharp interface model for interfacial stresses. Standard continuum models for the fluid dynamics in the bulk phases, for mass transport of a solute between the phases and for surfactant transport on the interface are given. We review some recently developed finite element methods for the appropriate disc...

INTRODUCTION: A loss of nutrient supply has long been thought to be a major factor leading to disc degeneration and recent in vivo measurements have supported this hypothesis. Solute transport from the blood vessels through the endplate into the disc, measured by following gadolinium [1] or nitrous oxide [2] transport, has found that effective endplate permeability falls significantly in degene...

Observations of fast transport of fluorescent tracers in mouse brains have led to the hypothesis of bulk water flow directed from arterial to venous paravascular spaces (PVS) through the cortical interstitium. At the same time, there is evidence for interstitial solute transport by diffusion rather than by directed bulk fluid motion. It has been shown that the two views may be consolidated by i...

INTRODUCTION: Interstitial solute transport is essential for cellular activities in avascular articular cartilage. Increased solute transport via fluid convection has been proposed as a mechanism by which dynamic loading increases cell metabolism in cartilage explants; this may have application in mechanical conditioning of engineered cartilage constructs. However, optimal loading conditions ha...

Articular cartilage is avascular. Nutrients are transported to the cells mainly by diffusion from the synovial fluid. Nutrient transport is also sometimes thought to be assisted by movement of fluid in and out of cartilage in response to cyclic loading of the tissue ('pumping'). The influence of pumping on transport of solutes through cartilage was measured by subjecting plugs of human femoral ...

A comprehensive numerical study was undertaken to investigate transport of a variable-density, conservative solute plume in an unconfined coastal aquifer subject to high and low frequency oceanic forcing. The model combined variable-density saturated flow for groundwater and solute transport, and wave hydrodynamics from a 2D Navier-Stokes solver. A sinusoidal tidal signal was specified by imple...