I&EC 35 |
| Richard C. Flagan, Division of Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd. 210-41, Pasadena, CA 91125 |
| Atmospheric nanoparticles arise due to direct emissions, primarily from combustion sources, and new particle formation due to atmospheric reactions. Particles of both types raise concerns over health effects and climate perturbations, but the atmospheric dynamics differ significantly. Due to their high diffusivities, nanoparticles coagulate rapidly with coarser particles. As a result, concentrations of nanoparticles emitted by localized sources, such as vehicles on an major highway, may decay rapidly with distance from the source. Nanoparticles formed in the atmosphere may be similarly localized due to reactions in a well-defined plume, but observations of widely dispersed new particle formation events have been reported in both remote, pristine environments and polluted urban atmospheres. Facilitated by recent improvements in the physical and chemical characterization of atmospheric nanoparticles, the frequency of such observations is increasing, and the detail enables new understanding of their sources and behavior. |
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Nanotechnology and the Environment
8:30 AM-11:50 AM, Monday, March 29, 2004 Marriott -- Grand Ballroom F, Oral
Division of Industrial and Engineering Chemistry |