Jacob Stewart's research is focused on better understanding the chemistry of Earth’s atmosphere. He uses the tool of laser spectroscopy to measure the amount and the properties of important atmospheric molecules — in particular, biogenic volatile organic compounds (BVOCs), which are naturally occurring molecules emitted by plants into the atmosphere. Even though these species are only present in small amounts in the atmosphere, they have a significant impact on atmospheric processes which affect climate change and air pollution.
His group is developing methods to measure BVOCs using infrared laser spectroscopy. In particular, the Stewart group uses a Quantum Cascade Laser (QCL) to perform these measurements. QCLs are a relatively new type of laser technology that have excellent characteristics for performing cutting-edge infrared spectroscopy. QCL spectroscopy will allow development of new instruments for measuring the concentrations of BVOCs in the atmosphere. Infrared spectroscopy can also provide important information on the fundamental properties of these molecules, which can aid theoretical efforts to model their structure and reactivity.
At Connecticut College, Stewart teaches Analytical Chemistry (214), Chemical Thermodynamics (307), and Chemistry 309, Atomic and Molecular Structure and Dynamics.
Recent publications by Jacob Stewart:
J. T. Stewart, J. Beloin*, M. Fournier*, G. Kovic*. "Sensitive infrared spectroscopy of isoprene at the part per billion level using a quantum cascade laser spectrometer." Applied Physics B (2020), 126, 181.
M. V. Pinto Pereira*, T. P. Hoadley*, M. C. Iranpour*, M. N. Tran*, J.T. Stewart. "High-resolution infrared spectroscopy of the v26 band of isoprene." Journal of Molecular Spectroscopy (2018), 350, 37-42.
J. T. Stewart, M. N. Sullivan, and M. C. Heaven. "Near UV bands of jet-cooled CaO." Journal of Molecular Spectroscopy (2016), 322, 18-21.
J. T. Stewart and B. J. McCall. “Rotationally-Resolved Spectroscopy of the Donor Bending Mode of (D2O)2.” Journal of Physical Chemistry A (2013), 117, 13491-13499.
J. T. Stewart and B. J. McCall. “Additional Bands of the Ar-D2O Intramolecular Bending Mode Observed Using a Quantum Cascade Laser.” Journal of Molecular Spectroscopy (2012), 282, 34-38.
B. E. Brumfield, J. T. Stewart, and B. J. McCall. “Extending the Limits of Rotationally Resolved Absorption Spectroscopy: Pyrene.” Journal of Physical Chemistry Letters (2012), 3, 1985-1988.
B. E. Brumfield, J. T. Stewart, and B. J. McCall. “High-Resolution Spectroscopy of the v8 Band of Methylene Bromide Using a Quantum Cascade Laser.” Journal of Molecular Spectroscopy (2011), 266, 57-62.
B. E. Brumfield, J. T. Stewart, S. L. Widicus Weaver, M. D. Escarra, S. S. Howard, C. F. Gmachl, and B. J. McCall. “A Quantum Cascade Laser cw Cavity Ringdown Spectrometer Coupled to a Supersonic Expansion Source.” Review of Scientific Instruments (2010), 81, 063102.
*Indicates Connecticut College undergraduate co-author
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