Sources and nature of bulk flow

Separation is most often implemented in open systems/devices with bulk flow(s) in and out The treatment of separation achieved in such separators is carried out in Chapters 6, 7 and 8. Chapter 6 begins with the sources and the nature of bulk flow in separation systems in a multiscale context as well as the feed introduction mode vis-a-vis time (Section 6.1). The various equations of change for species concentration in a mixture, the equation of motion of a particle in a fluid and the general... 

See Section 6.1 for the sources and the nature of bulk flow commonly employed In separations. 

Figure 15-17. Block diagram of the thermal flow in a lubricated gear and bearing system. Heat sources.—A oil film at tooth contact B churning of bulk oil C oil film in bearings and bulk churning D oil film at Seals E external sources. Heat transmission.—F m G c H c, m I c J f K m L f M f N m P f Q c, f, r R c S n, f, r T c. c = conduction f = forced convection m = mass transport n = natural convection r = radiation.

Sources of indoor radon include entry of amounts released beneath the structure, entry in utilities such as water and natural gas, and release from building materials. The greatest contribution is that from radon released from soil or rock (Nero 1987). Entry occurs primarily by bulk flow of soil-gas driven by small pressure differences between the lower part of the house interior and the outdoors. The pressure differences are primarily due to differences in indoor/outdoor temperature and the effects of wind (Nero 1987). 

Pathways of carbon flow in natural environments have also been reconstracted using bulk stable carbon and nitrogen isotopes as well as compound-specific isotopic analysis of individual biomarker lipid component (Hayes et al, 1990) based on the fractionations involved during primary (photosynthetic) and secondary (heterotrophic) processes. Recently, compound-specific radiocarbon analysis of individual biomarker hpid has been shown to be a valuable technique to determine the source of marine organic matter (Eglinton et al., 1997). 

In the case of energy producing power sources, the equifibrium shifts to one side, resulting in the flow of net current and the subsequent loss of equifibrium at the electrode. A system of this nature is said to be polarized. The net current that flows through the polarized system at any given overpotential is <=(electroactive species in the bulk and at the electrode interface are equal which reduces Eq.(3.23) to the Butler-Volmer equation (3.28), which is a fundamental equation in electrode kinetics. 

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