Sam Frederick

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Contact Information

4064-B Natural History Building
1301 W Green Street
Urbana, IL 61801 USA
sf20@illinois.edu

Research Areas

Atmospheric Chemistry And Aerosols
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Graduate Research Assistant, Advisor: Dr. Nicole Riemer
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Biography

I am a second-year M.S. student advised by Dr. Nicole Riemer. My research focuses on the application of the particle-resolved aerosol model PartMC to high spatial resolution studies. Traditional methods for modeling aerosols tend to use simplified representations of aerosol species and coarse spatial resolutions. In turn, these methods tend to underrepresent the spatial heterogeneity of aerosols and associated chemical reactions. My work involves extending PartMC to implement large eddy simulation modeling, allowing particle-resolved simulations at high spatial resolution. This novel approach fills a gap in aerosol modeling research, and allows greater characterization of modeling uncertainties present in existing methods. 

I received a bachelor of science degree in physics from Davidson College in May 2019. During my senior year, I completed an honors thesis in physics in which I used the astrophysical fluid dynamics code PLUTO to model the structural deformation of highly magnetic pulsars. The objective of my project was to estimate the gravitational wave strain resulting from the non-axisymmetric rapid rotation of highly magnetic pulsars as a result of their strong magnetic field strengths. This work led to a publication in the May 2021 issue of the Monthly Notices of the Royal Astronomical Society.

Following graduation, I joined Oak Ridge Associated Universities as a post-baccalaureate researcher to the United States Environmental Protection Agency (US EPA). In this role, I developed a free and open source Python library sensortoolkit for analyzing data from low-cost air sensors. These devices have the potential to dramatically lower barriers to monitoring air quality, however, their data quality and formatting are highly variable. This presents challenges for analyzing data from air sensors, as significant programming knowledge and understanding of air quality data may be required to undertake data analysis. The sensortoolkit library provides a platform for analyzing air sensor data in a user-friendly manner via an object-oriented architecture, streamlining the need for user input while allowing reliable interoperability between the library’s modules.

Education

B.S. Physics, Davidson College (May 2019)

Awards and Honors

Departmental Honors in Physics, Davidson College Department of Physics, May 2019

Recent Publications

Barkjohn, K.K.; Holder, A.L.; Frederick, S.G.; Clements, A.L. Correction and Accuracy of PurpleAir PM2.5Measurements for Extreme Wildfire Smoke. Sensors 2022, 22, 9669. https://doi.org/10.3390/s22249669

Duvall, R; Clements, A; Hagler, G; Kamal, A; Kilaru, V; Goodman, L; Frederick, S; Johnson Barkjohn, K; VonWald, I; Greene, D; Dye, T. Performance testing protocols, metrics, and target values for fine particulate matter air sensors: Use in ambient, outdoor, fixed site, non-regulatory supplemental and informational monitoring applications. U.S. EPA Office of Research and Development, Washington, DC, EPA/600/R-20/280, 2021. https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=350785&Lab=CEMM

Duvall, R; Clements, A; Hagler, G; Kamal, A; Kilaru, V; Goodman, L; Frederick, S; Johnson Barkjohn, K; VonWald, I; Greene, D; Dye, T. Performance testing protocols, metrics, and target values for ozone air sensors: Use in ambient, outdoor, fixed site, non-regulatory and informational monitoring applications. U.S. EPA Office of Research and Development, Washington, DC, EPA/600/R-20/279, 2021. https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=350784&Lab=CEMM

S.G. Frederick, K.L. Thompson, M.P. Kuchera. Modeling Magnetohydrodynamic Equilibrium in Magnetars with Applications to Continuous Gravitational Wave Production. Monthly Notices of the Royal Astronomical Society, Volume 503, Issue 2, May 2021, Pages 2764–2775. DOI: 10.1093/mnras/stab625


 Presentations (* presenter)

  1. “Performance Evaluations of Air Sensors at EPA’s AIRS Site”. S.G. Frederick*, K.K. Barkjohn, C. Johnson, R. Yaga, A.L. Clements. U.S. EPA PM2.5 Implementation Workgroup. (Virtual, Aug 2020).

  2. “PurpleAir PM2.5 U.S. Correction and Performance During Smoke Events”. K.K. Barkjohn*, A.L Holder, S.G. Frederick, A.L. Clements, International Smoke Symposium. (Virtual, Apr 2020). EPA Science Inventory Link.

  3. “Performance Evaluations of PM2.5 Sensors in Research Triangle Park”. S.G. Frederick*, K.K. Barkjohn, C. Johnson, R. Yaga, A.L. Clements. U.S. EPA Air Sensor Brownbag Webinar. (RTP, NC, Jan 2020). EPA Science Inventory Link.

  4. “Modeling Structural and Magnetic Field Stability in Magnetars with Applications to Continuous Gravitational Wave Production”. S.G. Frederick*. Thesis Defense, Davidson College Department of Physics. (Davidson, Apr 2019).

  5. “Highly Magnetic Stars and Continuous Gravitational Wave Production”. S.G. Frederick*, K.L. Thompson, M.P. Kuchera. Public talk, Charlotte Amateur Astronomers’ Club. (Charlotte, NC, Mar 2019).

  6. “Modeling Stability of Magnetic Fields in Magnetars”. S.G. Frederick*, K.L. Thompson, M.P. Kuchera. Davidson College Department of Physics Winter Symposium. (Davidson, Dec 2018).

  7. “Radio Observations of Intermittent Pulsars and Interstellar Clouds”. S.G. Frederick*, K.L. Thompson. Davidson College Department of Physics Winter Symposium. (Davidson, Dec 2017)