S. B. Henry

Formation and growth of ultrafine particles from secondary sources in Bakersfield, California

carbon (EC) and the AMS tracer C4H9 for hydrocarbon-like organic aerosol (HOA) peaked in the early morning during rush hour, indicative of primary emissions. The fact that the particle number concentration peaked in the afternoon, when EC was at minimum, indicates that the midday increase in number concentration was likely due to new particle formation. The potential importance of solar radiation, the condensation sink of vapor on existing particles, concentrations of OH, O3 ,S O2 ,N H3, and VOCs for both condensational growth and new particle formation is evaluated based on the covariation of these parameters with ultrafine mass. The results suggest that the ultrafine particles are from secondary sources that are co-emitted or co-produced with glyoxal and formaldehyde.

UV Fiber-Laser-Based Fluorescence and Blue Diode-Laser-Based Phosphorescence-Lifetime Methods

Combination of a novel, tunable pulsed UV-fiber laser with a fluorescence-detection design using carbon nanofiber coatings and blue diode lasers with a novel lifetime-phosphorescence method has provided new turn-key instrumentation for monitoring applications.