Vapor exchange

Role of Airway Heat and Water Vapor Exchange in Disease and Injury... 

Kaufman, J. W. (1999). The role of upper airway heat and water vapor exchange in hygroscopic aerosol deposition iii the human airway. In Toxicity Assessment Alternatives Methods, Issues, Opportunities (H. Salem and S.A. Katz, Eds.), pp. 63-70. Humana Press Inc., Totow a, NJ. 

Respiratory air conditioning Heat and water vapor exchange occurring in... 

The latent heat transport accounts for only 2% of the total heat flux in this case. However, it was observed by several investigators that the total heat transfer rate is proportional to this value, <7, lenl, because it is proportional to the bubble volume and the number of bubbles that cause intense agitation of the liquid layer close to the surface. This agitation, termed microconvection, together with the liquid-vapor exchange, were considered to be the key to excellent characteristics of boiling heat transfer (Forster and Greif, 1959). 

Heat transfer by liquid-vapor exchange caused by bubble agitation of the boundary layer, q Bl. (microconvection)... 

Figure 5.15 Liquid-vapor exchange effect on CHF (circular tubes). (From Tong, 1975. Copyright 1975 by American Society of Mechanical Engineers, New York. Reprinted with permission.)...

The spacer grid in a rod bundle is also a turbulence promoter that enhances liquid-vapor exchange and bubble condensation. The local intensity of such turbulence is a function of the grid pressure loss coefficient, K, and the distance from the grid, t D. Thus an empirical spacer factor, Fs, can be defined as... 

This condition has been recently used in a vaporization-exchange model for water sorption and flux in phase-separated ionomer membranes. The model allows determining interfacial water exchange rates and water permeabilities from measurements involving membranes in contact with flowing gases. It affords a definition of an effective resistance to water flux through the membrane that is proportional to... 

For typical catalyst layers impregnated with ionomer, sizes of hydrated ionomer domains that form during self-organization are of the order of 10 nm. The random distribution and tortuosity of ionomer domains and pores in catalyst layers require more complex approaches to account properly for bulk water transport and interfacial vaporization exchange. A useful approach for studying vaporization exchange in catalyst layers could be to exploit the analogy to electrical random resistor networks of... 

The factors 4 and 4 accormt for the heterogeneity of the interface. The interfacial flux conditions. Equations (6.56) and (6.57), can be straightforwardly applied at plain interfaces of the PEM with adjacent homogeneous phases of water (either vapor or liquid). However, in PEFCs with ionomer-impregnated catalyst layers, the ionomer interfaces with vapor and liquid water are randomly dispersed inside the porous composite media. This leads to a highly distributed heterogeneous interface. An attempt to incorporate vaporization exchange into models of catalyst layer operation has been made and will be described in Section 6.9.4. 

Winter, K. Gademann, R. (1991). Daily changes in C02 and water vapor exchange, chlorophyll fluorescence, and leaf water relations in the halophyte M. crystallinum during the induction of CAM in response to high NaCl salinity. Plant Physiology 95, 768-76. 

Friedman, I., Machta, L. Soller, R. (1962) Water vapor exchange between a water droplet and its environment. Journal of Geophysical Research, 67,7. 

Murphy, T.J., Pokojowczyk, J.C., Muffin, M.D. (1983) Vapor exchange of PCBs with Lake Michigan The Atmosphere as a Sink for PCBs. In Physical Behavior of PCBs in the Great Lakes. D. Mackay, S. Paterson, S.J. Eisenreich and M.S. Simmons, Eds., pp. 49-58. Arm Arbor Sci. Publ., Arm Arbor, Michigan. 

Baldocchi D. (1997) Measuring and modelling carbon dioxide and water vapor exchange over a temperate broad-leaved forest during the 1995 summer drought. Plant Cell Environ. 20(9), 1108-1122. 

Because liquid-vapor exchange reaction is the resultant of vapor-phase exchange reaction and the vaporization equilibrium reaction... 

Baldocchi, D. D., Vogel, C. A., and Hall, B. (1997). Seasonal variation of energy and watei vapor exchange rates above and below a boreal jack pine forest. ]. Cicophys. Res. 102,28,939-28,951. 

The surface waters of the ocean are the largest sink for tritium. Transfer into the surface ocean occurs by water vapor exchange, precipitation and continental run-off (e.g., Weiss et al. 1979 Weiss and Roether 1980). Most of the nuclear weapons tests were performed in the northern hemisphere, leading to a strong asymmetry in the global north-south distribution of bomb tritium in the ocean surface waters. Concentrations in the northern hemisphere are relatively high compared to those in the southern hemisphere (Weiss and Roether 1980 Fig. 1). 

Figure 14.8 Liquid and vapor exchange in a distilling column.

In an effort to better understand the air exchange between the display case and the air outside the case, Thomson (23) introduced the concept of hygrometric half-time (23). If vapor exchange can be predicted, then display case microclimates can be regulated reliably. Brimblecombe and Ramer (24)... 

The deposition of tritium to the oceans occurs both by direct precipitation and by vapor exchange. Vapor exchange is a two-way process, and in general dominates over the direct precipitation. There are relatively few direct measures of tritium concentration in atmospheric water vapor, but studies indicate that it is closely related to levels in precipitation. This linkage has been exploited in order to construct tritium depositional histories for ocean basins from tritium in precipitation records. 

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