The luminous yellow flames of a log burning in the fireplace, a lighted candle, the black smoke that comes out of the exhaust pipe of a bus when the driver steps on the gas: these are all examples of combustion, but at first glance, the first two don't seem to belong with the third.

Yet, according to Antonio Vincitore, a PhD candidate in the Department of Chemical Engineering, they have something in common: They all produce polycyclic aromatic hydrocarbons (PAHS) as well as the better-known combustion by-products of carbon dioxide and water.

Although the amounts of PAHs are small, their presence is a cause for concern: "Most of this material is carcinogenic, so it's really important to minimize or reduce its production," Antonio says. A great deal of research on combustion is directed at this goal.

During his time at UCLA, Antonio has made a significant contribution to this effort. Other researchers were looking at the production of PAHs in premixed flames. Antonio was the first to look at PAH formation in opposed flow diffusion flames - those, like candle flames, that produce a yellow light. The diffusion flames that Antonio produced in the laboratory used methand, ethane and propane as fuels. Diffusion flames are more common than premixed flames in the real world, and so his research is likely to have practical applications.

The experimental information from his research will help theoreticians to model flames and understand their chemistry, with the eventual goal of designing a cleaner combustion process. This might involve changes to the content of the fuel or the configuration of the burners. Antonio has also contributed to combustion research through his modeling work with Sandia National Laboratory. "

Combustion research is a big jigsaw puzzle," Antonio says. "Everybody is contributing small amounts to the big picture." Antonio is the oldest son of an Italian family that immigrated in 1970 when his grandfather found work painting frescoes, portraits, and decorative items for New York City churches. Although Antonio likes painting too, his parents "were intent on getting me a profession," he says. His mother thought she would like him to be a dentist, but Antonio didn t agree.

"I like building and making things work," he says. "I'm a hands-on type person." In high school, a chemistry teacher captured his attention. "The way he was teaching it, I was interested right away," Antonio recalls. "I think that was the major spark for me going into science."

After earning his bachelor's degree in engineering from Manhattan College in New York City, Antonio took a year off from academic life to work in environmental engineering for Exxon in New Jersey.

Then he came west to visit a friend at UCLA and liked the social and cultural environment, and the weather. He decided to pursue graduate studies here and now, rather than waiting until his 30s and "trying to squeeze it in while having a family." And UCLA encouraged him with the offer of a stipend.

With his dissertation about to be completed, Antonio will probably be starting a new career about the time his UCLA colleagues are starting Spring Quarter. He hopes to work in environmental engineering for a decade or more, before returning to an academic setting, this time as a faculty member.

As part of his dissertation, Antonio worked with Keith Fordon, an associate development engineer who manages the undergraduate laboratories in chemical engineering, to develop an experiment derived from his research for use in those labs. Their work was published in the fall issue of Chemical Engineering Education.

The experiment "teaches students that when you combust fuels, you don't just get carbon dioxide and water," Antonio says. "You get a slew of pollutants, and the students are amazed at that."

Fordon said that working with Antonio was "a healthy collaboration." The experiment exposes undergraduates to sophisticated instrumentation and state of the art technology, Fordon said, and it "was exciting for the students, as well, to actually work on something that has a high degree of relevance to the scientific community today."

Published in Winter 1998, Graduate Quarterly