Record Display for the EPA National Library Catalog
RECORD NUMBER: 22 OF 25
|OLS Field Name||OLS Field Data|
|Main Title||Validation Testing of New Mechanisms with Outdoor Chamber Data. Volume 1: Comparison of CB4 and CAL Mechanisms.|
|Author||Jeffries, H. E. ; Sexton, K. G. ; Arnold, J. R. ; Li, J. L. ;|
|CORP Author||North Carolina Univ. at Chapel Hill. School of Public Health.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.|
|Additional Subjects||Smog ; Test chambers ; Photochemical reactions ; Air pollution control ; Reaction kinetics ; Environmental tests ; Performance evaluation ; Environment simulation ; Graphs(Charts) ; Urban areas ; Concentration(Composition) ; Ozone ; Nitrogen oxides ; Tables(Data) ; Comparison ; Formaldehyde ; Carbon Bond Four Mechanism ; Carter-Atkinson-Lurmann Mechanism ; Air pollution sampling ; State Implementation Plans ; Volatile organic compounds ; Peroxyacetyl nitrate|
The UNC smog chamber data base was used to compare the performance of two state of the science photochemical mechanisms: The Carbon Bond Four Mechanism (CB4) and the Carter, Atkinson, Lurmann Mechanism (CAL). Although the mechanisms behaved differently, both mechanisms showed good agreement with ozone and oxides of nitrogen chamber data. The agreement for other products such as formaldehyde and peroxyacetylnitrate were not as good. Neither mechanism, however, was overall superior to the other in fitting chamber data. The two mechanisms predicted very similar VOC control requirements for the standard SIP-type cases. In SIP-like sensitivity analyses, CB4 was more sensitive to decreasing hydrocarbon and ozone aloft and to decreasing the temperature, giving somewhat lower control requirements than CAL at the extreme conditions. Although problems remain in the performance of both mechanisms, the authors do not believe that it is possible to choose between them on the basis of performance in either fitting chamber data or in predicting control calculations.