http://www.trailfire.com/Coolgal/trails/31378Coolgal/trails60http://www.trailfire.com/Coolgal/marks/73414Depletion theory of protein transport in semi-dilute polymer solutions. Cconsiders the effects of polymer depletion on the transport (diffusion and electrophoresis) of small proteins through semi-dilute solutions of a flexible polymer. A self-consistent field theory may be set up in the important case of quasi-ideal interactions when the protein is small enough. Dynamic depletion, the reorganization of the depletion layer as the protein diffuses, is computed within a free-draining approximation.]]>Depletion Theory: Other FieldsCoolgalTue, 20 Mar 2007 10:13:19 -0700trailfire:markId:73414http://www.trailfire.com/Coolgal/marks/73418The Hubbert peak theory posits that for any given geographical area, from an individual oil field to the planet as a whole, the rate of petroleum production tends to follow a bell-shaped curve. It also shows how to calculate the point of maximum production in advance based on discovery rates, production rates and cumulative production. Early in the curve (pre-peak), the production rate increases due to the discovery rate and the addition of infrastructure. Late in the curve (post-peak), production declines due to resource depletion.]]>Depletion Theory: Other FieldsCoolgalTue, 20 Mar 2007 10:15:21 -0700trailfire:markId:73418http://www.trailfire.com/Coolgal/marks/73419These measurements are also useful for the further development of the depletion theory to a more general form, so that non-hard-sphere interaction can be studied. Presented here is a neutron-scattering study of depletion interactions in a mixture of a hard-sphere-like colloid and a non-adsorbing polymer. As per the depletion theory, this reduction in the depletion attraction presumably arises from the polymer-polymer interactions.]]>Depletion Theory: Other FieldsCoolgalTue, 20 Mar 2007 10:16:12 -0700trailfire:markId:73419http://www.trailfire.com/Coolgal/marks/73420Information on depletion theory as applicable to interactions and fluid-solid equilibrium in emulsions is given here. Silicon-oil-in-water emulsions stabilized with sodium dodecylsulfate (SDS), have been studied. They exhibit practically no coalescence, whereas for high surfactant concentrations a ‘‘creaming’’ of the emulsion is observed. We demonstrate that this behavior is related to a fluid-solid phase transition due to an attractive interaction induced by the depletion of SDS micelles. A simple model for the fluid-solid transition is proposed, in quantitative agreement with experiment.]]>Depletion Theory: Other FieldsCoolgalTue, 20 Mar 2007 10:17:04 -0700trailfire:markId:73420http://www.trailfire.com/Coolgal/marks/73422A drift-diffusion model for spin-charge transport in spin-polarized it p-n junctions is developed and solved numerically for a realistic set of material parameters based on GaAs. The depletion theory demonstrated is that spin polarization can be injected through the depletion layer by both minority and majority carriers, making all-semiconductor devices such as spin-polarized solar cells and bipolar transistors feasible.]]>Depletion Theory: Other FieldsCoolgalTue, 20 Mar 2007 10:18:29 -0700trailfire:markId:73422