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Designing More Effective Air Quality Advisories, Justin Olexy
Designing More Effective Air Quality Advisories, Justin Olexy
Environmental Science and Management Professional Master's Project Reports
Background: There is increasing concern about the impact of air quality on human health in urban environments and how to best reduce impacts through public policies. An NSF Biocomplexity Project - "Feedbacks between Urban Systems and the Environment" (FUSE), led by Portland State University, studies the human feedbacks and responses to air quality and heat advisories through data collected in city-wide phone surveys in Portland, OR and Houston, TX. On days when ozone levels are predicted to exceed air quality standards, regulatory agencies issue air quality advisories which ask residents to reduce certain air polluting behaviors such as driving …
Intercomparison Of Local Hydroxyl Measurements By Radiocarbon And Fage Techniques, Malcolm J. Campbell, Brad D. Hall, John C. Sheppard, Philip L. Utley, Robert J. O'Brien, Thomas M. Hard, Linda Acha George
Intercomparison Of Local Hydroxyl Measurements By Radiocarbon And Fage Techniques, Malcolm J. Campbell, Brad D. Hall, John C. Sheppard, Philip L. Utley, Robert J. O'Brien, Thomas M. Hard, Linda Acha George
Environmental Science and Management Faculty Publications and Presentations
A direct intercomparison of near-surface tropospheric HO concentration measurements by two different techniques was made in October–November 1992 at a rural site near Pullman, Washington. The atmosphere at the site is believed to contain low levels of anthropogenic pollution. The instruments' inlets were located at the same height (3.5 m) above the ground and were separated by 10 m along a line normal to the prevailing wind. Readings of the FAGE3 and radiocarbon instruments showed a high correlation (r² = 0.74) despite HO concentrations that were frequently near the detection limit of the instruments. An unweighted least squares regression shows …
Fage Determination Of Tropospheric Ho And Ho₂, Linda Acha George, Thomas M. Hard, Robert J. O'Brien
Fage Determination Of Tropospheric Ho And Ho₂, Linda Acha George, Thomas M. Hard, Robert J. O'Brien
Environmental Science and Management Faculty Publications and Presentations
FAGE (fluorescence assay with gas expansion) was developed as a sensitive technique for the detection of low-concentration free radicals in the atmosphere. The application of FAGE to tropospheric hydroxyl (H0) and hydroperoxyl (H0₂) radicals has yielded calibrated measurements of both species in both clean air and highly polluted urban air. For HO calibration, a continuously stirred tank reactor provides a uniform external HO concentration, which can be measured by gas chromatography of an HO-reactive hydrocarbon. The aerodynamics of the air-sampling process has been modeled computationally, with results that agree with empirical observations of the effects of nozzle diameter on HO …