Transport phenomena factors affecting

A critical review of emulsion flow in porous media has been presented. An attempt has been made to identify the various factors that affect the flow of OAV and W/O emulsions in the reservoir. The present methods of investigation are only the beginning of an effort to try to develop an understanding of the transport behavior of emulsions in porous media. The work toward this end has been difficult because of the complex nature of emulsions themselves and their flow in a complex medium. Presently there are only qualitative descriptions and hypotheses available as to the mechanisms involved. A comprehensive model that would describe the transport phenomenon of emulsions in porous media should take into account emulsion and porous medium characteristics, hydrodynamics, as well as the complex fluid-rock interactions. To implement such a study will require a number of experi-... 

The following discussion shows how the chemical composition, rate of formation, and heat of combustion of the pyrolysis products are affected by the variations in the composition of the substrate, the time and temperature profile, and the presence of inorganic additives or catalysts. The latter aspect, however, is discussed in more detail in Chapter 14. Combustion may be defined as complex interactions among fuel, energy, and the environment. Consequently, the combustion process is controlled not only by the above chemical factors, but also by the physical properties of the substrate and other prevailing conditions affecting the phenomena of heat and mass transport. Discussion of this phenomenon is beyond the scope of this chapter. 

Several factors can affect the retention properties of the membrane and some of these will be discussed here. During ultrafiltration the transport of solute to the surface of the filter Is faster than the rate at which permeation through the membrane occurs. This is further complicated, as ultrafiltration progresses, by an increase in the concentration of retained molecules at the membrane. Both events contribute to the phenomenon called concentration polarization. This effectively introduces a second layer of membrane , and as a consequence the retention characteristics of the system are altered. The build-up of solute can be reduced by introducing some form of agitation at the filter surface. However. this procedure does not seem to be effective against the gel-type layers formed by proteins. Various procedures have been suggested to slow down this build-up of solute the solution can be diluted with an appropriate solvent the ultrafiltration process can be interrupted and the flow reversed momentarily a low operation pressure could be used. 

Environmental Fate. Information is available on the environmental fate of radon in air and water and on the transport of radon in environmental media. Factors which affect the partitioning of radon from soil or water to air have been identified. Flowever, rates of flux from one media to another are rarely reported. The emanation rate of radon from soil is uncertain. Additional information on the behavior of radon at the soil-air interface, as well as soil-gas measurements, would facilitate a better understanding of the emanation rate of radon from soil. Movement of radon into and within homes and the influence of meteorological conditions on this movement should be investigated. Study of radon movement would enhance understanding of potential indoor exposures. Transformation of radon has been adequately characterized. There is limited information on the uptake of radon by plants. Additional research of this phenomenon is needed in order to determine the effects of exposures which might be incurred from ingestion of food. 

Two intrinsically linked factors were responsible of this behavior (i) the capability of the LM phase to extract Am(III) decreased linearly with the irradiation dose, because the carrier was degraded and (ii) the density of the LM phase was almost insensitive to the dose, but the viscosity increased with the irradiation dose, affecting the transport behavior. This phenomenon is indicated as radiol)4ic degradation of the LM phase. 

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