Aerosol formation

The flows of gas and liquid need not be concentric for aerosol formation and, indeed, the two flows could meet at any angle. In the cross-flow nebulizers, the flows of gas and sample solution are approximately at right angles to each other. In the simplest arrangement (Figure 19.11), a vertical capillary tube carries the sample solution. A stream of gas from a second capillary is blown across this vertical tube and creates a partial vacuum, so some sample solution lifts above the top of the capillary. There, the fast-flowing gas stream breaks down the thin film of sample... 

Difluorophosphoric Acid. Difluorophosphoric acid (2) is a mobile, colorless Hquid. It fumes on contact with air, probably owing to HE aerosol formation. The mp of anhydrous difluorophosphoric acid has been reported to be —96.5 1°C (63) and —91.3 1°C (64). The density at 25°C is 1.583 g/mL. It partially decomposes on heating above 80—100°C. An extrapolated normal boiling point is 116°C (63) although it boils at 107—111°C... 

Airborne partieulate matter may eomprise liquid (aerosols, mists or fogs) or solids (dust, fumes). Refer to Figure 5.2. Some eauses of dust and aerosol formation are listed in Table 4.3. In either ease dispersion, by spraying or fragmentation, will result in a eonsiderable inerease in the surfaee area of the ehemieal. This inereases the reaetivity, e.g. to render some ehemieals pyrophorie, explosive or prone to spontaneous eombustion it also inereases the ease of entry into the body. The behaviour of an airborne partiele depends upon its size (e.g. equivalent diameter), shape and density. The effeet of partiele diameter on terminal settling veloeity is shown in Table 4.4. As a result ... 

To allow for spray- and aerosol-formation, the mass of fuel in the cloud is assumed to be twice the theoretical flash of the amount of material released, so long as this quantity does not exceed the total amount of fuel available. Blast effects are modeled by means of TNT blast data according to Marshall (1976), while 1 bar is considered to be upper limit for the in-cloud overpressure (Figure 4.18). Because experience indicates that vapor clouds which are most likely to explode... 

The cloud inventory is equal to the flash fraction times the amount of fuel released. To allow for spray and aerosol formation, the cloud inventory should be multiplied by 2. This number may not, of course, exceed the total amount of fuel released. 

The quantity of fuel in a cloud is calculated by use of release and (flash) vaporization models that have been extensively described by Hanna and Drivas (1987). To account for aerosol formation during vaporization, the flash fraction should be doubled up to, but not exceeding, a value of unity. Pool vaporization is also considered. 

Kamens R, M Jang, K Leach (1999) Aerosol formation from the reaction of a-pinene and ozone using a gas-phase-kinetics-aerosol partitioning model. Environ Sci Technol 33 1430-1438. 

This type of reaction is involved as an intermediate step in few synthetically useful reactions, in the formation of polysulfones by copolymerization of an olefin with SO 2, as well as in aerosol formation in polluted atmospheres. We will discuss later in some detail the most important chain reactions involving step 11. However, Good and Thynne determined the Arrhenius parameters for the addition of methyl and ethyl radicals to SO2 in gas phase, the rate constants being 5 x 10 and 4 x 10 s respectively at ambient... 

Note The factor of 2 in items a, b, and c above is to account for the aerosol formation and entrainment in the flashing release. Also, when determining the material in the cloud resulting from a two-phase or flashing release, consideration should be given to the contribution to the cloud from liquid pool evaporation. 

CS is disseminated by burning, explosion, and aerosol formation. It is immediately irritating to the eyes and upper respiratory tract. Warm vapors mix with human sweat to cause a burning sensation to the eyes, nose, and mouth. Conjunctivitis and pain in the eyes, lacrimation, erythema of the eyelids, runny nose, burning throat, coughing, and constricted feeling in the chest are the effects which will... 

Applications Over the last 20 years, ICP-AES has become a widely used elemental analysis tool in many laboratories, which is also used to identify/quantify emulsifiers, contaminants, catalyst residues and other inorganic additives. Although ICP-AES is an accepted method for elemental analysis of lubricating oils (ASTM D 4951), often, unreliable results with errors of up to 20% were observed. It was found that viscosity modifier (VM) polymers interfere with aerosol formation, a critical step in the ICP analysis, thus affecting the sample delivery to the plasma torch [193]. Modifications... 

Raes, F. and Janssens, A., Ion-Induced Aerosol Formation in a HpO-H Ojj System - I. Extension of the Classical Theory and Search for Experimental Evidence, J. Aerosol Sci. 16 217-227 (1985). 

In addition to these nuclear reactions, myriads of other gas-phase transformations produce low-vapor pressure species, with the oxidation of SO2 and other reduced sulfur species dominating aerosol formation and growth. Oxidation of SO2 in the gas phase produces H2SO4, a readily condensable species that either combines with other molecules (new particle formation) or condenses on existing aerosols. 

McMurray, P. H. and J. C. Wilson, Droplet Phase (Heterogeneous) and Gas Phase (Homogeneous) Contributions to Secondary Ambient Aerosol Formation As Functions of Relative Humidity, Atmos. Environ.. 

Cox, R.A., Penkett, S.A. (1972) Aerosol formation from sulfur dioxide in the presence of ozone and olefmic hydrocarbons../. Chem. Soc. Farad. Trans. 1, 68, 1735-1753. 

The low rates of aqueous migration of many chemical species in Arid ecosystems and the accumulation of their water-soluble and dispersed forms in the uppermost soil layers play an important role in the geochemistry of aerosol formation and rainwater... 

Schreck, R.W., Sekuterski, J.J. and Gross, K.B. (1986). Synchronized intratracheal aerosol generation for rodent studies. In Aerosols, Formation and Reactivity, Second International Aerosol Conference, Berlin. Pergamon Press, New York, pp. 37-51. 

After 10-12 days, the maximum product concentration was achieved and fluvastatin completely consumed. The 6-hydroxy-fluvastatin-containing culture liquid was stored in the Wavebag at —20 °C for later purification. In other cases, the culture liquid was conveniently and safely harvested from the Wavebag without aerosol formation by sucking into glass bottles in a vacuum line with a sterile filter installed between the collecting vessel and the vacuum pump. 

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