Hydrostatic-pressure Sentence Examples
The wells were first called artesian in the belief that the ascent of the water in them was due to the hydrostatic pressure of water at a higher level in the Queensland hills.
The naked cells which have been alluded to live in water, and call therefore for no differentiation in connection with this necessity; but those which are surrounded by a cell-wall always develop within themselves a vacuole or cavity which occupies the greater part of their interior, and the hydrostatic pressure of whose contents keeps tha protoplasm in contact with the membrane, setting up a condition of turgidity.
The great turgidity which is thus caused exerts a considerable hydrostatic pressure on the stele of the root, the vessels of the wood of which are sometimes filled with water, but at other times contain air, and this often under a pressure less than the ordinary atmospheric pressure.
The stretching of the cell wall by the hydrostatic pressure is fixed by a secretion of new particles and their deposition upon the original wall, which as it becomes slightly thicker is capable of still greater extension, much in the same way as a thick band of indiarubber is capable of undergoing greater stretching than a thin one.
This may possibly be the cell sap in their interior, which must exercise a slightly different hydrostatic pressure on the basal and, the lateral walls of the cells.Advertisement
The importance of these experiments from the point of view of the theory of solution, lay in the fact that they suggested the conception of a perfect or ideal semi-permeable partition, and that of an equilibrium pressure representing the excess of hydrostatic pressure required to keep a solution in equilibrium with its pure solvent through such a partition.
In any solution, then, the osmotic pressure represents the excess of hydrostatic pressure which it is necessary to apply to the solution in order to increase its vapour pressure to an equality with that of the solvent in the given conditions.
To investigate the osmotic pressure of a' strong solution we may consider the hydrostatic pressure required to increase its vapour pressure to an equality with that of the solvent.
The relation between hydrostatic pressure and the vapour pressure of a pure liquid may be obtained at once by considering the rise of liquid in a capillary tube.
The vapourmolecules of the solvent are free to pass through the semi-permeable membrane, and will continue to condense in the solution until the hydrostatic pressure is so raised as to produce equality of vapour-pressure.Advertisement
The driving hydrostatic pressure (head of pressure) is controlled by the afferent and efferent arterioles, and provided by arterial pressure.
As new cells are continually formed in the merismatic mass those which are farthest from the apex gradually cease to divide and a different process of growth takes place in them, which is associated more particularly with the formation of the vacuoles, consequent upon the establishment of coniiderable hydrostatic pressure in them, thus causing the bulk of the cells to be greatly enlarged.
Neglecting the very small buoyancy of the vapour, the hydrostatic pressure P at the foot of the column of solution is h g p where h is the height of the column and p the mean density of the solution.