chemistry

Richard Flagan

Richard Flagan is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Richard Flagan rather than just read about it. In short: Richard Charles Flagan (born 1947) is an American chemical engineer known for his research on aerosols, both in atmospheric science studies and in the processing of materials. He is the McCollum-Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology.

Key takeaways

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Reference excerpt

Richard Charles Flagan (born 1947) is an American chemical engineer known for his research on aerosols, both in atmospheric science studies and in the processing of materials. He is the McCollum-Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology. Flagan has contributed to advancements in aerosol measurement techniques, such as the development of the scanning mobility particle sizer and mobility analyzers, which enable the study of particle size distributions undergoing rapid evolution down to 1 nm in diameter.

Education Flagan received his B.S.E. in mechanical engineering from University of Michigan in 1969 and S.M. and Ph.D. degrees from Massachusetts Institute of Technology in 1973, also in mechanical engineering. His Ph.D. dissertation was titled The formation of nitric oxide from organic nitrogen contained in fossil fuels. During his doctoral research he studied combustion of kerosene doped with pyridine or pyrrole to simulate burning of fuel oil. His studies revealed that turbulent mixing influences nitric oxide (NO) emissions from organic nitrogen in fossil fuels, with poor initial fuel-air mixing leading to lower NO concentrations. Exploring the interaction between chemical kinetics and turbulent mixing, he was able to develop a model that predicted NO emissions by incorporating it into a model which took into account flow non-uniformities in the burner where the reactions were occurring.

Career Flagan joined California Institute of Technology (Caltech) in 1975 as an assistant professor in the environmental engineering science program within the Division of Engineering and Applied Science. Both Sheldon K. Friedlander, who moved to UCLA, and John H. Seinfeld who was a frequently collaborator at CalTech, influenced him to move from focusing on combustion and turbulent reacting flows, to focusing on aerosols. In 1981 Flagan became associate professor and was promoted to full professor in 1986. Over time, his research interests expanded beyond environmental research questions. While he initially studied particle formation in combustion systems and photochemical smog, he later collaborated with JPL on using aerosols to refine silicon for more efficient photovoltaic production. With this shift in focus he transferred to the Chemical Engineering department in 1990. His research advanced aerosol measurement techniques, enabling detection and analysis of different sizes and compositions of atmospheric particulates. He holds at least 25 patents for his invented instruments and various aerosol reactor technologies. In 2000, as his work was more inline with the Environmental Engineering Division he re-established his formal affiliation with the program and at that time was appointed to an endowed professorship with the full title Irma and Ross McCollum-William H. Corcoran Professor. Flagan was president of the American Association for Aerosol Research from 1996-1997 and is editor-in-chief emeritus of the journal Aerosol Science and Technology. He was elected to the National Academy of Engineering in 2010 and is a member of the board of directors of the California Council on Science and Technology. Flagan has been interviewed as an expert for articles discussing particulates and aerosols. In a New York Times piece on dust, he explained how particle size affects how fast dust falls, why a damp cloth is an effective dust remover and why the centrifugal windstorm generated by bagless vacuum cleaners are unlikely to pick up most small particles. In an Associated Press article during the COVID-19 pandemic, he advised using an N95 mask for two or three days, emphasizing that duration of use is more critical than frequency. He noted that the mask's performance degrades as particles accumulate on it.

Selected publications Flagan, Richard C.; Friedlander, Sheldon K. (1978). "Particle formation in pulverized coal combustion: A review". In Shaw, David T. (ed.). Recent Developments in Aerosol Science. Vol. 2. Wiley. pp. 25–59. ISBN 0471029505. Wang, Shih Chen; Flagan, Richard C. (1990). "Scanning Electrical Mobility Spectrometer". Aerosol Science and Technology. 13 (2): 230–240. Bibcode:1990AerST..13..230W. doi:10.1080/02786829008959441. ISSN 0278-6826. Odum, Jay R.; Hoffmann, Thorsten; Bowman, Frank; Collins, Don; Flagan, Richard C.; Seinfeld, John H. (1996). "Gas/Particle Partitioning and Secondary Organic Aerosol Yields". Environmental Science & Technology. 30 (8): 2580–2585. Bibcode:1996EnST...30.2580O. doi:10.1021/es950943+. ISSN 0013-936X. Hoffmann, Thorsten; Odum, Jay R.; Bowman, Frank; Collins, Donald; Klockow, Dieter; Flagan, Richard C.; Seinfeld, John H. (1997). "Formation of Organic Aerosols from the Oxidation of Biogenic Hydrocarbons". Journal of Atmospheric Chemistry. 26 (2): 189–222. Bibcode:1997JAtC...26..189H. doi:10.1023/A:1005734301837. Armani, Andrea M.; Kulkarni, Rajan P.; Fraser, Scott E.; Flagan, Richard C.; Vahala, Kerry J. (2007). "Label-Free, Single-Molecule Detection with Optical Microcavities". Science. 317 (5839): 783–787. Bibcode:2007Sci...317..783A. doi:10.1126/science.1145002. ISSN 0036-8075. PMID 17615303. Flagan, Richard C. (2011). "Electrical Mobility Methods for Submicrometer Particle Characterization". Aerosol Measurement. Wiley. pp. 339–364. doi:10.1002/9781118001684.ch15. ISBN 978-0-470-38741-2. Flagan, Richard C.; Seinfeld, John H. (2012). Fundamentals of Air Pollution Engineering. Mineola, N.Y: Dover Publications. ISBN 978-0-486-48872-1. Amanatidis, Stavros; Huang, Yuanlong; Pushpawela, Buddhi; Schulze, Benjamin C.; Kenseth, Christopher M.; Ward, Ryan X.; Seinfeld, John H.; Hering, Susanne V.; Flagan, Richard C. (June 18, 2021). "Efficacy of a portable, moderate-resolution, fast-scanning differential mobility analyzer for ambient aerosol size distribution measurements". Atmospheric Measurement Techniques. 14 (6): 4507–4516. Bibcode:2021AMT....14.4507A. doi:10.5194/amt-14-4507-2021. ISSN 1867-8548.

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Worked examples

Example 1 — a first encounter with Richard Flagan

Start with the simplest possible case. Write down what Richard Flagan claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Richard Flagan before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Richard Flagan ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Richard Flagan

In research: Richard Flagan appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Richard Flagan in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Richard Flagan is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1947 births, 21st-century American chemists, Aerosol scientists, so understanding it makes those chapters shorter.
In everyday life: Look for Richard Flagan outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Richard Flagan in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Richard Flagan means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
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Frequently asked questions

What is Richard Flagan in simple terms?

Why does Richard Flagan matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Richard Flagan?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Richard Flagan.