Free water reabsorption (T(c) (H2O)) measured during 10% mannitol diuresis and subsequently during 3% saline diuresis was compared in patients with sickle cell anemia and in normal subjects. During mannitol infusion, T(c) (H2O) progressively rose with increasing osmolar clearance (C(osm)) and reached a maximal level in both groups studied. During hypertonic saline diuresis, T(c) (H2O) progressi...

Many fluid-transporting epithelia possess dead-end, long, and narrow channels opening in the direction to which fluid is being transported (basal infoldings, lateral intercellular spaces, etc.). These channels have been thought to possess geometrical significance as standing-gradient flow systems, in which active solute transport into the channel makes the channel contents hypertonic and permit...

[1] Electrical resistivity tomography (ERT) has proved to be a valuable tool for imaging solute transport processes in the subsurface. However, a quantitative interpretation of corresponding ERT results is constrained by a number of factors. One such factor is the nonuniqueness of the ERT inverse problem if no additional constraints are imposed. In the vadose zone, further problems arise from t...

Soil micromorphology was applied to specify flow domains in different soils and to select a suitable numerical model for simulation of water flow and herbicide transport. Pore structure detected on soil micromorphological images represented in all cases domains of prevailing water flow and solute transport. Depending on pore configuration and boundary conditions either water immobilization or p...

Soil-water flow velocity can be a major factor affecting ion movement in the soil matrix. The transport of both cations and anions and their interactions with soil surface affect many aspects of soil management such as wastewater disposal, saline soil reclamation, remediation of sodic soils, and soil decontamination (HENG et al., 1999a). Therefore it is important to understand the processes tha...

soil hydraulic properties such as soil water characteristic curve are necessary prerequisite for modeling water movement and solute transport. direct methods of estimating these hydraulic properties are time consuming and costly. indirect methods, such as pedotransfer functions, estimate the hydraulic parameters using easy-to-measure soil properties like particle size distributions, bulk densit...

[1] The simulation of conservative solute transport in a heterogeneous unsaturated soil depends on the description of spatial variability of soil hydraulic and chemical properties. The data from the Las Cruces Trench Site were used to explore the impact of alternative ways of describing the variability of hydraulic properties. Three different approaches were considered: Miller and Miller scalin...

This paper proposes groundwater flow simulation models based on explicit finite difference method (FDFLOW) and Galerkin finite element method (FEFLOW) and solute transport simulation models based on Galerkin finite element method (FESOLUTE), random walk method (RWSOLUTE) and modified method of characteristic (MMOCSOLUTE). These coupled flow and transport models are aimed at simulation of solute...

This paper reviews the use of texture analysis in studying the performance of hydrophilic matrices of highly soluble drugs and different types of excipients (i.e. water-soluble, water-insoluble and swellable, and water insoluble and non-swellable). Tablets were prepared by direct compression, and their swelling and erosion in presence of these different excipients were assessed with the help of...