Theory of Separation

Two distinguished separation mechanisms, either polarization or focusing, govern the separation. The separated particles can be differently compressed to c,(x) = c,(0) exp ( — -

where li = Di/Ui is the mean layer thickness, Di is the diffusion coefficient and ci is the concentration of the ith species. Larger particles are usually concentrated more closely to the accumulation wall. As a result, the order of the elution is from the small species to larger ones.

The focusing field force and the corresponding velocity U are position dependent:

The coordinate xmax corresponds to the position at which the concentration distribution of a focused sample is maximal. Each sample component is focused around its proper xmax position. The steady-state concentration distribution is close to the Gaussian distribution:

where k is the Boltzmann constant and T is the temperature. In some cases the polarization and the focusing mechanisms can act simultaneously.

As mentioned above, a real separation channel is usually ribbon-shaped. However, two parallel infinite planes represent a good approximation of this form. The flow velocity profile established in such a hypothetical channel is parabolic under isoviscous conditions:

APx(x — w) 2Lp where v(x) is the linear velocity of a flow streamline at the position x, AP is the pressure drop along the channel of length L, and p is the viscosity of the carrier liquid.

To describe conveniently the retention of the separated particulate species, the dimensionless retention ratio R is defined:

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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