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| Titel |
Uptake of HO2 radicals on Arizona Test Dust |
| VerfasserIn |
Y. Bedjanian, M. N. Romanias, A. Zein |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 13 ; Nr. 13, no. 13 (2013-07-08), S.6461-6471 |
| Datensatznummer |
250018746
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| Publikation (Nr.) |
 copernicus.org/acp-13-6461-2013.pdf |
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| Zusammenfassung |
| The interaction of HO2 radicals with solid films of Arizona Test Dust
(ATD) was studied using a low-pressure flow reactor (1–9 Torr) combined
with a modulated molecular beam mass spectrometer for monitoring of the
gaseous species involved. The reactive uptake coefficient of HO2 was
measured from the kinetics of HO2 consumption on Pyrex rods coated with
ATD as a function of HO2 concentration ((0.35–3.30) × 1012 molecule cm−3),
relative humidity (RH = 0.02–94%),
temperature (T = 275–320 K) and UV irradiance intensity (JNO2 = 0–0.012 s−1).
The initial uptake coefficient was found to be
independent of concentration of HO2, temperature and irradiation
conditions, and to decrease with increasing relative humidity: γ0 = 1.2/(18.7 + RH1.1)
(with 30% estimated conservative
uncertainty). The uptake coefficient was calculated using geometric surface
area and should be considered as an upper limit of γ0. An upper
limit of 5% was found for the gaseous H2O2-forming pathway of
the HO2 reaction with ATD surface. The results of the measurements
indicate that HO2 loss on dust aerosol may be a non-negligible sink for
HOx species in the troposphere with the effect depending on specific
local conditions. |
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