By Joan C. McKinney, news and publications coordinator
CAMPBELLSVILLE, Ky. – Dr. Philip Stevens, director of the Ph.D. program in environmental science at Indiana University, School of Public and Environmental Affairs, and Department of Chemistry, will speak at Campbellsville University at 10 a.m. Friday, Nov. 21, in room 15 of the Administration Building.
Stevens will discuss: “OH where oh where is OH? Measuring the elusive hydroxyl radical in the atmosphere.” The address is free and open to the public.
Dr. Chris Mullins, assistant professor of chemistry at CU, said, “The problem of photochemical air pollution continues to be a serious threat to human health and welfare in many areas of the world. Ozone, the primary component of photochemical smog, can impair respiratory functions by causing inflammation and scarring of lung tissue. Because it is a secondary pollutant, control of ozone depends on an accurate understanding of the chemical mechanism leading to its production.”
He said measurements of the hydroxyl radical (OH) in the atmosphere provides a critical test of our understanding of the chemistry of ozone production in the atmosphere, as the OH radical initiates the oxidation of volatile organic compounds (VOCs) which in the presence of nitrogen oxides (NOx) can lead to the production of ozone and secondary aerosols in urban and rural environments.
However, Mullins said, because of its high reactivity, concentrations of OH in the atmosphere are extremely low (typically less than 0.1 parts per trillion) and its chemical lifetime very short (less than 1 second). As a result, measurements of OH present a serious analytical challenge, especially on the timescale necessary to test our understanding of the fast photochemistry of the atmosphere.
Mullins said Stevens’ talk will describe the Indiana University laser-induced-fluorescence instrument for the sensitive detection of OH radicals in the atmosphere, including urban measurements in Mexico City as part of the MILAGRO (Megacity Initiative: Local and Global Research Observations) measurement campaign, as well as preliminary measurements in remote forested areas as part of the PROPHET (Program for Research on Oxidants: Photochemistry, Emissions and Transport) campaign in 2008.
Stevens will also be available to meet with students at 11 a.m.
For more information, contact Mullins at (270) 789-5041.
Campbellsville University is a private, comprehensive institution located in South Central Kentucky. Founded in 1906, Campbellsville University is affiliated with the Kentucky Baptist Convention and has an enrollment of 2,601 students who represent 93 Kentucky counties, 27 states and 31 foreign nations. Listed in U.S.News & World Report’s 2009 “America’s Best Colleges,” CU is ranked 22nd in “Best Baccalaureate Colleges” in the South for the second consecutive year. CU has been ranked 16 consecutive years with U.S.News & World Report. The university has also been named to America’s Best Christian Colleges®. Campbellsville University is located 82 miles southwest of Lexington, Ky., and 80 miles southeast of Louisville, Ky. Dr. Michael V. Carter is in his tenth year as president.