Drainage gradient

The role of coalescence within a contactor is not always obvious. Sometimes the effect of coalescence can be inferred when the holdup is a factor in determining the Sauter mean diameter (67). If mass transfer occurs from the dispersed (d) to the continuous (e) phase, the approach of two drops can lead to the formation of a local surface tension gradient which promotes the drainage of the intervening film of the continuous phase (75) and thereby enhances coalescence. It has been observed that d-X.o-c mass transfer can lead to the formation of much larger drops than for the reverse mass-transfer direction, c to... 

The suprachoroid is 30 pm in thickness and comprises thin interconnected lamellae of melanocytes, fibroblasts, and connective tissue fibers. These are separated by a thin space known as the suprachoroidal space. In this space hydrostatic pressure is a few mm of Hg lower than the IOP. The small gradient allows drainage of aqueous humor, through the tissue spaces of the ciliary muscles, into the suprachoroidal space. Venous drainage takes place through a series of large vortex veins each of these drains a sector of the choroid into the superior and inferior ophthalmic veins of the orbit. 

Flow velocities of water in an aquifer, calculated by gradients and transmissivities, provide the maximum possible values. These are subject to limitations imposed by stagnation conditions. In extreme cases, confined systems may be rich in fossil karstic conduits, but with no through-flow due to complete confinement and/or burial beneath the level of the terminal base of drainage. 

Drainage of interstitial fluid IgG into lymphatics depends on the concentration gradient and occurs passively via convection [l].The leg lymph fluid of humans contains less than 25% of the amount of IgG found in plasma [65], Other specialized lymphatic channels drain peritoneal, pleural, or pericardial cavities. Lymphatic drainage enters lymph nodes via the subcapsular sinus, and the lymph fluid IgG is available for reticuloendothelial clearance of IgG (subcapsular sinus, perivascular or parenchymal macrophages, perivascular or parenchymal dendritic cells, sinusoidal endothelium) as detailed next. 

A mobile capillary micromanometer that can be set at various levels of the foam column, thus allowing pressure measurements at different points, can be used to evaluate the dependence of the radius of border curvature on the coordinates of either gravitational field or pressure gradient [51,68]. For a simultaneous determination of both the pressure and the radius of border curvature at non-steady state flow (for example, gravitational drainage) a system of a number of micromanometers can be used. 

The rate of foam drainage is determined not only by the hydrodynamic characteristics of the foam (border shape and size, liquid phase viscosity, pressure gradient, mobility of the Iiquid/air interface, etc.) but also by the rate of internal foam (foam films and borders) collapse and the breakdown of the foam column. The decrease in the average foam dispersity (respectively the volume) leads the liberation of excess liquid which delays the establishment of hydrostatic equilibrium. However, liquid drainage causes an increase in the capillary and disjoining pressure, both of which accelerate further bubble coalescence and foam column breakdown. 

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