We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping efficiency of these flows is limited by the presence of "unstirred" concentration boundary layers nea...

BACKGROUND AND OBJECTIVE The objective of this article is to quantify the effect of hyper-osmotic agent (glycerol) on blood velocity in hamster skin blood vessels measured with a dynamic imaging technique, laser speckle contrast imaging (LSCI). STUDY DESIGN/MATERIALS AND METHODS In this study a dorsal skin-flap window was implanted on the hamster skin. The hyper-osmotic drug, that is, glycero...

The renal concentrating mechanism is considered to be limited by a maximal urine osmolal concentration or a maximal osmotic urine/plasma (U/P) ratio at low rates of solute excretion (1). When solute excretion is increased by the administration of large osmotic loads to hvdropenic subjects urine osmolality decreases (2-4). This decrease has recently been ascribed to the limitation imposed by the...

The electro-osmotic flow driven by a screen pump, composed of a line array of evenly spaced identical rectangular solid blocks, is investigated under the Debye-Hückel approximation. The geometry of the screen pump is determined by the spacing and aspect ratio of the solid blocks. A constant surface zeta potential is assumed on the block surface. The method of eigenfunction series expansion is a...