Sedimentation is a process of settling down of the heavier particles present in a liquid mixture. For example, in a mixture of sand and water, sand settles down at the bottom. This is sedimentation.

Sedimentation velocity is an analytical ultracentrifugation (AUC) method that measures the rate at which molecules move in response to centrifugal force generated in a centrifuge. This sedimentation rate provides information about both the molecular mass and the shape of molecules.

In an equilibrium sedimentation experiment, the purpose is to produce a measurable protein concentration gradient along the radial axis of the centrifuge cell. Using these cells, equilibrium can be reached in a matter of minutes to a few hours, depending on the protein.

Ultracentrifuge. It forms the basis for an analytical ultracentrifugation method for measuring molecular masses, such as those of proteins, in solution.

In addition to particle size, density and concentration, and fluid viscosity, other less obvious factors affect the sedimentation rate. These include particle shape and orientation, convection currents in the surrounding fluid, and chemical pretreatment of the feed suspension.

Thus, sedimentation time t = L/U (where L is the length of the sedimentation path) is inversely proportional to the square of the size of the particle.

Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained and come to rest against a barrier. Settling is the falling of suspended particles through the liquid, whereas sedimentation is the termination of the settling process.

Sedimentation is the process by which solids are removed from the water column by settling. Stokes’ Law is applicable to clay, silt, and fine sand in stormwater, and can be applied up to fine sand (Reynold’s Number, Re = Vd/ν < 10) with a maximum error in settling velocity of 25%.

– settling velocity is defined as the speed at which a particle falls through a still fluid. – factors that influence settling velocity are particle size, particle shape, and the specific gravity of particles.

Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration, or electromagnetism.

Sedimentation is the process of allowing particles in suspension in water to settle out of the suspension under the effect of gravity. The particles that settle out from the suspension become sediment, and in water treatment is known as sludge.

The process of particles settling to the bottom of a body of water is called sedimentation. Layers of sediment in rocks from past sedimentation show the action of currents, reveal fossils, and give evidence of human activity. Sedimentation can be traced back to the Latin sedimentum, “a settling or a sinking down.”

Sedimentation equilibrium is a distinct yet highly complementary approach to velocity analysis that can be conducted in the analytical ultracentrifuge. In this experiment, samples are spun at lower speeds until the opposing forces of sedimentation and diffusion acting on the protein come into equilibrium.

Sedimentation equilibrium experiments showed that the protein does self-associate into dimers with dissociation constant values ranging from micromolar to millimolar. A. Furst, D.N. Taulbee, in Encyclopedia of Analytical Science (Second Edition), 2005

The sedimentation equilibrium experiment consists of centrifuging the sample at low speeds for long periods of time. At equilibrium the polymer is distributed according to its molecular weight. At this point the centripetal force is exactly balanced by the back diffusion of the polymer along the concentration gradient in the cell.

3.2 Sedimentation equilibrium. Thus, if a monomer–dimer equilibrium exists for the protein under study, the observed signal will represent the sum of two exponential concentration gradients, that of the monomer and the dimer ( Fig. 5.4 A). Furthermore, because the concentrations of monomer and dimer are governed by an equilibrium constant,…