Vaporization particle

BidlemanTF. 1988. Atmospheric processes. Wet and dry deposition of organic compounds are controlled by their vapor-particle partitioning. Environ Sci Technol 22(4) 361-367. 

Bidleman T.F., Foreman, W.T. (1987) vapor-particle partitioning of semivolatile organic compounds. In Sources, and Fates of Aquatic Pollutants. Hites, R.A., Eisenreich, S.J., Editors, Advances in Chemistry Series 216, American Chemical Society, Washington, D.C. 

Pump is connected to the vessel, which is already almost empty of air (70 mbar) - it must thus transport mostly vapor particles... 

Bidleman, T. F., and W. T. Foreman, "Vapor-Particle Partitioning of Semi-Volatile Organic Compounds, in Sources and Fates of... 

Ngabe, B., and T. F. Bidleman, Occurrence and Vapor Particle Partitioning of Heavy Organic Compounds in Ambient Air in Brazzaville, Congo, Environ. Pollut., 76, 147-156 (1992). 

Theory of Vapor-Particle Partitioning of PAH Compounds in the Atmosphere. Yamasaki et al. (64) treated semivolatile PAHs as inherently vapor-phase materials, existing in the particle phase only because of their tendency to sorb on nonvolatile materials. Under this assumption, the proportion in each phase should vary with the available surface area for sorption and with the ambient temperature. They assumed that sorption followed a Langmuir adsorption isotherm, requiring that there be only a low fractional coverage of the particulate matter with semivolatile material. In this case, competition for sorption sites can be ignored. At equilibrium, the rate of sorption equals the rate of evaporation. They derived this relationship ... 

This approach was developed further by Bidleman and co-workers (65, 70-72) and included the use of filter-collected particles and PUF traps to operationally define the required parameters. For example, the predicted influence of temperature on the vapor-particle partitioning of fluoranthene... 

Positive pressure/submersion V acuum/ submersion Dye penetration Vapor/particle leak testing Visual inspection methods Light transmission tests... 

Vacuum/submersion Dye penetration Vapor/particle leak testing... 

A thorough analysis of atmospheric transport and deposition to the Great Lakes has been carried out using the HYSPLIT model developed by the US National Atmospheric and Oceanic Administration (NOAA) [28,29]. An emissions inventory of PCDD/Fs for North America in 1996 was used as input to the model. Factors considered in the fate and distribution were meteorological data, vapor-particle partitioning, aerosol characteristics, reaction with hydroxyl radicals, photolysis, and dry and wet deposition. The model was generally satisfactory at estimating fluxes, except for HpCDD and OCDD, which appeared to be underestimated by about a factor of four. The model output was summarized as 2378-TeCDD toxic equivalent concentrations (TEQs) based on the WHO mammalian 2378-TeCDD toxic equivalent factors (TEFs) [30]. Since HpCDD and OCDD were estimated to contribute only 2% of TEQs, the model was considered to be valid for the purpose intended. 

HBCD hexabromocyclododecane Kp atmospheric vapor-particle partition coefficient... 

Bidleman, T.F., W.N. Billings, and W.T. Foreman. 1986. Vapor-particle partitioning of semivolatile organic compounds estimates from field collections. Environ. Sci. Technol. 20 1038-1043. 

Foreman, W.T. and T.F. Bidleman. 1987. An experimental system for investigating vapor-particle partitioning of trace organic pollutants. Environ. Sci. Technol. 21 869-875. 

Low air pressure and low temperature are factors that affect the state of water. At certain altitudes, water is in a state of equilibrium between the gas state (water vapor) and the liquid state (liquid water). However, at higher altitudes colder temperatures will cause the water vapor to condense into liquid water or even change directly into crystals of ice. As water vapor particles condense, they combine with tiny particles of dust, salt, and smoke in the air to form water droplets. These water droplets can accumulate to form clouds. 

Condensation nucleus (CN) concentration CN counter Expose particles to a high supersaturation, typically of butanol vapor particles grow to size where they can be optically detected and counted -b... 

The original cloud chamber was devised by C. T. R. Wilson (1869-1959) in 1911. A chamber contains air saturated with vapor. Particles emitted from a radioactive substance ionize air molecules in the chamber. Cooling the chamber causes droplets of liquid to condense on these ions. The paths of the particles can be followed by observing the fog-like tracks produced. The tracks may be photographed and studied in detail. Figures 26-3 and 26-4 show a cloud chamber and a cloud chamber photograph, respectively. 

Now let s go back to the instant the liquid is poured into the container. If we assume that the container initially holds no vapor particles, there is no condensation occurring when the liquid is first added. As the liquid evaporates, however, particles of vapor gradually collect in the space above the liquid, and the condensation process slowly begins. As long as tbe rate of evaporation of the liquid is greater than the rate of condensation of the vapor, the concentration of vapor particles above the liquid will increase. However, as the concentration ofvapor particles increases, the rate of collisions of vapor particles with the liquid increases, boosting tbe rate of condensation. 

Higher concentration of vapor particles necessary to create the higher rate of condensation... 

Collisions between vapor particles in the bubble and the liquid parricles chat form the walls of the bubble create a pressure that can keep the bubble From collapsings... 

As long as the rate of evaporation of the liquid is greater than the rate of condensation of the vapor, the concentration of vapor particles above the liquid... 

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