Morphology atmospheric aerosol

The results of the pulmonary effects of inhaled JP-8 in mice and rats should be viewed with caution because exposure atmospheres are not well defined with respect to the concentration of vapor coexisting with aerosols. Morphologic evaluations were conducted in only a few animals per exposure group and were not reported quantitatively with regard to incidence or semiquantitatively with respect to severity. Pulmonary function measurements were not performed with conventional methods. Furthermore, conflicting results were obtained in replicated experiments with mice. 

Bloch P, Adams E, Van Landuyt J and Van Goe-THEM L (1980) Morphological and chemical characterization of individual aerosol particles in the atmosphere. In Versino B, ed. Proceedings Symposium Physico-Chemical Behaviour of Atmospheric Pollutants. EUR 6621, ECSC-EEC-EAEC, Brussels, Luxembourg. 

Soot particles, when emitted to the atmosphere, differ from other ambient particles in morphology and chemical composition. As they age, they are mixed" with other particles through coagulation, condensation of secondary aerosol compounds, and cloud processing, becoming similar to the other particles in the aerosol population. 

The morphology and size of particles prepared by the LPSP process are different from those produced by CSP using either an ultrasonic nebulizer or a two-fluid nozzle as atomizers under an atmospheric environment. For example, nickel oxide (NiO) nanoparticles can be formed via the LPSP route whereas, only submicronsized NiO particles are produced by ultrasonic spray pyrolysis [9]. It is evident that the nanoparticle formation mechanism in the LPSP process is different from that in the CSP process. The calculated particle size based on the ODOP principle is much larger than 100 nm, indicating that the nanoparticles are formed based on one-droplet-to-multiple-particles (ODMP). The reason can be attributed to the difference in operating pressures and aerosol formation mechanisms between the two types of aerosol generators. 

Some measurements have indicated that there may be modification of fractal morphology by atmospheric processes [111, 112]. As a consequence of humidity cycling, the morphology of the tenuous aggregates becomes more compact and spheroidal , resulting in an increase of Df. JuUien and Meakin [113] concluded that such a phenomenon would be important in the consideration of subsequent aggregate atmospheric lifetimes and optical properties. Various laboratory experiments have demonstrated the existence of a number of different mechanisms by which aerosols... 

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