AAAR Lectures Series

This new initiative, supported by the Sheldon K. Friedlander Memorial Fund, will feature a high-impact paper selected by the Editors of AS&T to be presented by its author live, webinar-style, monthly. Each lecture is free and open to all.

With this new program being launched by the Endowment Committee, AS&T Editorial Office, and Early Career Committee, AAAR aims to highlight the research in our community, tie our Journal to other AAAR activities, and provide an opportunity to bring our membership together outside of the Annual Conference. One way we're achieving this is by engaging with AAAR's Student Chapters from across the nation to serve as hosts. A different Student Chapter will be the host each month and will take part in a Journal Club of their design, where they meet ahead of each Lecture to discuss the paper to be presented.

Upcoming Lectures

  • Description:

    Due to several superspreader events of COVID-19 in the early phase of the pandemic being linked to singing in choirs, the debate about airborne transmission of the disease intensified. In the beginning of the pandemic, there was only one previous scientific publication on respiratory emissions from singing. Therefore, we conducted a study measuring the emissions of respiratory aerosols and droplets during singing and talking, using a particle counter (an APS). Twelve healthy volunteers, whereof seven were professional singers, participated in the study that was performed in a stainless steel chamber with a controlled environment. In addition, we collected aerosol samples close to two patients with confirmed COVID-19 that were breathing, talking and singing, respectively, and analyzed them for detection of SARS-CoV-2.

  • Speaker information:

    Malin Alsved got her PhD in aerosol technology at Lund University in September 2020. The topic of her thesis was Transmission of Infectious Bioaerosols, involving work on viruses and bacteria in both laboratory studies and field measurement studies. The research she has performed has involved many fields of science, from infection control and hospital ventilation, to bioaerosol survival factors and respiratory aerosol emissions. Malin Alsved recently started as a postdoc at the division of Ergonomics and Aerosol Technology at Lund University, working with airborne infectious viruses.

 

Previous Lectures

  • Description:

    This talk will present a new uncertainty analysis technique for a commonly used method of retrieving refractive indices (m) from aerosol particles. Briefly, Inverse Mie methods compare modeled optical properties at many theoretical m to optical properties observed by instrumentation to retrieve an m from an aerosol. The tool presented here, Refractive Index Confidence Explorer (RICE), attempts to constrain the uncertainties associated within full distribution inverse Mie methods, which use multi-diameter aerosol size distributions and associated optical measurements to retrieve m. RICE iteratively tests a series of m for their ability to produce the retrieved m under perturbed conditions. Perturbations account for uncertainties in optical, particle size, and particle number concentration measurements. RICE then uses these data to calculate semi-empirical probability distributions which are used to provide confidence intervals for the real (n) and imaginary (k) components of m. When RICE is applied to idealized test cases and external data, uncertainty is shown to be dynamic in relation to the value of the retrieved m (solution) and the nature of the particle size distribution (measurement condition).

  • Speaker information:

    Dr. Frie received his bachelor’s in Chemistry from Saint John’s University in Minnesota before completing a Ph.D. in Environmental Science at the University of California Riverside. His past work has included studies of secondary organic aerosol optical properties and chemistry and the source apportionment of atmospheric mineral dust in desert environments. Dr. Frie is currently a postdoctoral associate at the University of Minnesota’s Department of Soil, Water, and Climate where he is working with Dr. Timothy Griffis to model and measure the sources, fate, and impacts of atmospheric ammonia.

  • Description:

    Exposure to respiratory droplets contributes greatly to the spread of SARS-CoV-2 virus during the COVID-19 pandemic. Understanding the effectiveness of different face coverings against the outward transport of respiratory droplets in the indoor environment is particularly important. In addition, violent expiratory events like coughing with high jet velocities would degrade the performance of outward protection using face coverings and thus need to be better understood. Our study investigates the effectiveness of various face coverings to reduce cough-generated airborne particle concentrations at 0.3, 0.9, and 1.8?m away from the source in an indoor environment. We measured the particle number concentration (PNC) and particle size distribution under seven different conditions: (1) no face covering; (2) face shield only; (3) cloth mask; (4) face shield?+?cloth mask; (5) surgical mask; (6) face shield?+?surgical mask; (7) N95 respirator or equivalent (i.e., KN95 mask). In this talk, I will discuss our study findings and explore the implications of these findings..

  • Speaker information:

    Liqiao (Vicky) Li is a Ph.D. candidate working under the guidance of Dr. Yifang Zhu at the UCLA Department of Environmental Health Sciences. She has also received a bachelor’s degree in Environmental Engineering in 2015 and a master’s degree in Environmental Health Sciences in 2017. Her research interests include particle emission measurement, indoor air pollution, and environmental exposure assessment. Her current research explores the characteristics of e-cigarette-related aerosols and their impacts on indoor air quality. She also works on COVID-19 related projects that investigate the effectiveness of various face coverings or medical isolation devices to mitigate the outward transport of respiratory droplets indoors.”

AAAR Sponsors

Thank you to our Platinum Sponsors

3M

Anthropocene

NASA

Sunset Laboratory

TSI

Thank you to our Gold Sponsors

Aerosol Devices

Kanomax

Particle Instruments

URG

Thank you to our Bronze Sponsors

Aerodyne

AIRUCI

CASE-Washington University

Cooper Environmental

 

Thank you to our Supporting Sponsors

ACS Publications     |     Aethlabs     |     Brechtel Manufacturing     |     Cambustion     |     Magee Scientific     |     USRA

 

Thank you to our Organizational Members

Aerodyne

Cambustion

Magee Scientific

Particle Instruments

Sunset Laboratory

TSI

URG