کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4434414 1619980 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Variations of nanoparticle concentrations at the Fresno Supersite
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Variations of nanoparticle concentrations at the Fresno Supersite
چکیده انگلیسی

Particle size distributions from 3 nm to 2 μm were measured at the Fresno, CA, Supersite from August 25, 2002 through July 31, 2003. Nanoparticle (3–10 nm) concentrations and the ratio of nanoparticle to total particle concentration were inversely related to particle surface areas from 50 to 1000 μm2 cm− 3. Elevated nanoparticle concentrations were associated with motor vehicle emissions and with photochemical particle production. In contrast with Atlanta, GA, where concentrations of photochemically derived nanoparticles exceeded 105 cm− 3, 5-min average nanoparticle concentrations in Fresno never exceeded 24,400 cm− 3. While photochemical particle production occurs in Fresno, evidence of new particle production (i.e., an increase in number concentration with decreasing size below 10 nm) was not observed. This suggests that photochemical particle production may have occurred at a higher altitude followed by mixing to the surface, or that the fresh particle production rate was smaller with respect to the loss rate by coagulation than it was in Atlanta. Lower production rates in Fresno are more consistent with lower concentrations of sulfur precurors and low relative humidity in Fresno than they are in Atlanta.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Science of The Total Environment - Volume 358, Issues 1–3, 1 April 2006, Pages 178–187
نویسندگان
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