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The sedimentation coefficient has units of time, expressed in svedbergs. One svedberg is 10 −13 s. The sedimentation coefficient normalizes the sedimentation rate of a particle to its applied acceleration. The result no longer depends on acceleration, but only on the properties of the particle and the fluid in which it is suspended.
Stokes' law is important for understanding the swimming of microorganisms and sperm; also, the sedimentation of small particles and organisms in water, under the force of gravity. [ 5 ] In air, the same theory can be used to explain why small water droplets (or ice crystals) can remain suspended in air (as clouds) until they grow to a critical ...
A laboratory ultracentrifuge. In chemistry, a Svedberg unit or svedberg (symbol S, sometimes Sv [a]) is a non-SI metric unit for sedimentation coefficients.The Svedberg unit offers a measure of a particle's size indirectly based on its sedimentation rate under acceleration (i.e. how fast a particle of given size and shape settles out of suspension). [1]
Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word concretion is borrowed from Latin concretio ' (act of) compacting, condensing, congealing, uniting ', itself derived from concrescere ' to thicken, condense, congeal ', from con-' together ' and crescere ' to grow '. [2]
Sedimentation rate may refer to: Sedimentation rate of particles in a liquid, described by Stokes' law; Erythrocyte sedimentation rate, a medical test for inflammation;
As the particle increases in velocity eventually the drag force and the applied force will approximately equate, causing no further change in the particle's velocity. This velocity is known as the terminal velocity, settling velocity or fall velocity of the particle. This is readily measurable by examining the rate of fall of individual particles.
The shape of particles can be defined in terms of three parameters. The form is the overall shape of the particle, with common descriptions being spherical, platy, or rodlike. The roundness is a measure of how sharp grain corners are. This varies from well-rounded grains with smooth corners and edges to poorly rounded grains with sharp corners ...
The rate of sedimentation is the thickness of sediment accumulated per unit time. [8] For suspended load, this can be expressed mathematically by the Exner equation . [ 9 ] Rates of sedimentation vary from less than 3 millimeters (0.12 in) per thousand years for pelagic sediment to several meters per thousand years in portions of major river ...