Tutorials Information

Abstract: Coming Soon This tutorial is the first of two that introduce the broad field of aerosol science. We begin with the behavior of individual particles to understand how they behave in the environment, and the physical principles on which most aerosol measurements are based. The drag forces that act on a particle determine its settling velocity and whether it is able to follow the flow of a gas. Several different models describe the drag forces: Stokes law applies for spherical particles moving at modest velocities, though a slip correction must be introduced to account for non-continuum effects for particles small compared to the mean-free-path of the gas molecules. Other corrections are required if the velocity becomes large enough the fluid inertia affects the motion. Knowledge of these scaling principles makes it possible to relate particle behavior in seemingly disparate systems, and make it possible to determine particle size. The drag forces also determine Brownian motion. Together, drag forces and diffusion determine particle deposition and losses in the respiratory tract, in sampling systems, and in filters, causing aerosol filtration to be more effective than filtration of particles from liquid media. These different kinds of motion will be examined in the context of methods used for sampling, transporting, and measuring particles ranging from nanometer-scale nuclei to large inertial particles, and other phenomena that are dominated by a single mechanism, including the migration of charged particles in mobility analyzers.

Richard C. Flagan is the Irma and Ross McCollum/William H. Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology. He has served as President of the AAAR and Editor-in-Chief of Aerosol Science and Technology. His research spans the field of aerosol science, including atmospheric aerosols, aerosol instrumentation, aerosol synthesis of nanoparticulate materials, and bioaerosols. His many contributions to the field of aerosol science have been acknowledged with the Smoluchowski Award, the Sinclair Award, and the Fuchs Award. He is a member of the U.S. National Academy of Engineering.

Abstract: Dynamic modeling of how particulate matter (PM) and gas transport, deposit, and translocate from human respiratory systems to systemic regions subject to indoor and outdoor exposures are essential for case-speci?c lung dosimetry predictions and occupational health risk assessments. Because of the invasive nature and imaging resolution limitations of existing in vitro and in vivo methods, Computational Fluid-Particle Dynamics plus Physiologically Based Pharmacokinetic/ Toxicokinetic (CFPD-PBPK/TK) models have been employed to predict the fate of the respirable aerosols for decades. This tutorial presents a guide on using the multiscale CFPD-PBPK/TK models to predict lung dosimetry and systemic translocations quantitatively with 3D subject- speci?c human respiratory systems. The tutorial aims to clarify possibly ambiguous concepts. The step-by-step modeling procedure should help researchers set up the CFPD-PBPK/TK model accurately, follow the standard model validation and veri?cation (V&V) processes, and bring the lung dosimetry predictions health endpoints. Starting from the fundamentals of CFPD and PBPK/TK governing equations, the tutorial covers the problem identi?cation, pre-processing, solving, and post-processing steps to perform computational lung aerosol dynamics simulations, emphasizing on (a) the importance of correct reconstruction and mesh generation of the pulmonary airways; (b) the signi?cance of choosing the appropriate turbulence model to predict the laminar-to-turbulence pulmonary air?ow regimes; and (c) the standard (V&V) procedures of submodels in the CFPD-PBPK/TK modeling framework. The tutorial also highlights the de?ciencies of current CFPD-PBPK/TK models, clari?es the missing biomechanisms and aerosol dynamics in the respiratory systems that need to be considered to build the next-generation virtual human whole-lung models

Dr. Yu Feng is an Assistant Professor in the School of Chemical Engineering at Oklahoma State University. He is also a center investigator in the Oklahoma Center for Respiratory and Infectious Diseases (OCRID). Yu Feng was a Research Assistant Professor and Lab Manager of the Computational Multi-Physics Laboratory (CM-PL) at North Carolina State University. He has also held an affiliation with the DoD Biotechnology HPC Software Applications Institute (BHSAI) as a Research Scientist II. Dr. Feng’s lab focuses on making contributions to the medical world and human life by providing well-posed solutions to patient-specific pulmonary health problems using multi-scale modeling techniques. He and his research team specialize in assessing the occupational exposure risks using computational fluid-particle dynamics (CFPD) models and Physiological based Toxicokinetic (PBTK) models spans over 10 years and has been summarized in more than 30 peer-reviewed journal papers and 40 conference proceedings. Dr. Feng is currently the Chair of Health Related Aerosol Working Group in the American Association for Aerosol Research (AAAR).

Abstract: This tutorial continues the basic introduction to aerosol science. We will begin by examining filtration and deposition within the respiratory tract, processes that involve both diffusion and inertial effects. Condensation and evaporation of volatile species onto particles determines their growth in the atmosphere, and efficient counting of particles too small to detect optically in condensation particle counters. Both continuum and non-continuum transport effects must again be considered. The thermodynamics leading to particle activation for condensational growth, and to the possibility of nucleating new particles from the vapor phase will be examined. We will then turn our attention to developing the tools to describe the dynamics of aerosol populations. An aerosol is an ensemble of particles in a gas, and the particles are distributed over a range of sizes. The aerosol population is represented in terms of a size distributions. We will examine their graphical representation, models such as the log normal-distribution, and how processes such as condensation and coagulation due to particle-particle collesions alter the shape of the size distribution. Combined, these two Introduction to Aerosols tutorials will introduce the language, basic concepts, and methods of aerosol science, and provide key results that will help to gain a of how aerosols behave in different environments.

Richard C. Flagan is the Irma and Ross McCollum/William H. Corcoran Professor of Chemical Engineering and Environmental Science and Engineering at the California Institute of Technology. He has served as President of the AAAR and Editor-in-Chief of Aerosol Science and Technology. His research spans the field of aerosol science, including atmospheric aerosols, aerosol instrumentation, aerosol synthesis of nanoparticulate materials, and bioaerosols. His many contributions to the field of aerosol science have been acknowledged with the Smoluchowski Award, the Sinclair Award, and the Fuchs Award. He is a member of the U.S. National Academy of Engineering.

Abstract: The recent proliferation of low-cost aerosol and gas sensors has sparked much interest among the scientific community. Such devices show promise to enable measurements at unprecedented spatial and temporal scales, which, in turn, can lead to the creation of distributed sensor networks to support both traditional research and community-based research. With these exciting prospects, however, come challenges of sensor performance, sensor reliability, and data management. This tutorial will review basic principles of statistics and data science for real-time aerosol sensors, with a focus on low-cost (<$2,000) devices. Topics to be covered will include data management and cleaning, exploratory data analysis, linear models, troubleshooting techniques (and potential solutions), statistical issues relevant to time-series data (such as autocorrelation), and determination of analytic figures of merit (e.g., accuracy, bias, prevision, limit of detection). Participants need not have formal training in data science beforehand; self-help resources for learning basic data science in the R and MATLAB programming languages will be provided. 

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Abstract: Many aerosol measurement techniques produce raw responses that must be inverted to properly interpret the data. The inverse solution is often characterized by strong sensitivity to noise superimposed on the data. Regularization methods are needed to relate an observed instrument response to the underlying physical property of the system under investigation. This tutorial will introduce the popular Phillips-Twomey-Tikhonov approach to dampen noise amplification during inversion. Example applications in aerosol science include the reconstruction of the number aerosol size distribution from mobility measurements or the retrieval of a size distribution from multiwavelength scattering and absorption data. The tutorial will provide hands-on examples to find the optimal inverse solution from noisy data. At the end of the session, tutorial participants will have a starting point to modify supplied software for use in their own research projects.

Markus Petters is a professor of atmospheric science at NC State University. He received his M.S. in soil science and Ph.D. in atmospheric science from the University of Wyoming. His research focuses on suspended particulate matter in the 5 to 5000 nm size range. A particular emphasis is research on the physical chemistry of particles, with a focus on the influence of chemical composition on phase transitions and cloud formation under atmospheric conditions. Prof. Petters serves on the editorial advisory board for the journal Aerosol Science and Technology and is an editor of Atmospheric Chemistry and Physics. He received the Kenneth T. Whitby Award for contributions to Aerosol Science and Technology awarded by the American Association for Aerosol Research in 2015

Abstract: This tutorial will overview biological aerosols and methods for their measurement and study. Specifically, this tutorial will cover three primary areas: bioaerosol measurement, laboratory techniques, and field studies. Each topic will be covered from environmental bioaerosol and infectious aerosol perspectives. Both real-time and offline techniques for bioaerosol measurement will be covered, as well as laboratory techniques for bioaerosol study. Field studies will cover a range of situation from outdoor measurements to studies in clinical settings.

Dr. Joshua L. Santarpia is the Research Director for Counter WMD programs at the National Strategic Research Institute, Associate Professor of Microbiology and Pathology, and Program Director for Biodefense and Health Security Degree Program at the University of Nebraska Medical Center. His work is generally in the field of aerobiology, the study of airborne microorganisms. His group focuses on the development of novel bioaerosol measurement tools, including real-time sensors and the integrated UAS samplers, understanding the optical and other signatures that can be used to detect and identify biological aerosol and studied how those signatures change over time, and the study of bioaerosol in medical environments. Most recently, he has applied these methods to characterizing SARS-CoV-2 aerosol in the patient environment and characterizing aerosol risk in public spaces.

Alex Huffman is an Associate Professor of Analytical and Environmental Chemistry at the University of Denver after having earned his Ph.D. in Analytical/Atmospheric Chemistry from the University of Colorado. His research group focuses on the development and application of new scientific approaches to detecting bioaerosols in the atmosphere and heterogeneous chemical reactions on bioaerosol surfaces. During the COVID-19 pandemic Dr. Huffman added research focus on transmission and removal of aerosols in indoor environments, including relevant aerosol modeling, mitigation, and monitoring efforts. Dr. Huffman has more than 19 years of experience with atmospheric aerosol science and has published more than 40 papers related to bioaerosols. Dr. Huffman has been involved with AAAR since 2005, has served on several committees, and was the bioaerosol special session and working group chair from 2013-2015.

Abstract: This tutorial will introduce approaches for levitating and manipulating single aerosol particles and droplets from the 100 nanometre to 100 micrometre scale. Non-invasive, non-intrusive techniques for characterising the time-dependent properties of particles will be compared, including composition, size and phase. The use of invasive techniques such as mass spectrometry will also be introduced. A survey of application areas from atmospheric science to drug delivery to the lungs to disease transmission will also be provided. 

Jonathan Reid (JPR) is Professor of Physical Chemistry at the University of Bristol. After completing his PhD at the University of Oxford in 1997, JPR moved to the University of Colorado (USA) as a postdoctoral research fellow. He was appointed to a Lectureship at the University of Birmingham in 2000, moving to the University of Bristol in March 2004.

JPR has extensive experience in developing novel single particle techniques to study microphysical aerosol processes. His current research is relevant to atmospheric science, drug delivery to the lungs, formulation science and disease transmission, and is funded by the EPSRC, BBSRC, MRC and NERC. He has published in a wide range of journals (eg. PNAS , Atmos. Chem. Phys., Chem. Sci., ACS Central Science, Aerosol Sci. Tech., Applied and Environmental Microbiology, Pharmaceutical Research). He has held both an EPSRC Advanced Research Fellowship and an EPSRC Leadership Fellow. He was co-editor of Fundamentals and Applications in Aerosol Spectroscopy (Taylor & Francis, 2010, edited with Prof. Ruth Signorell, ETH-Zurich ) and has over 200 publications in peer-reviewed journals.

JPR has received the Royal Society of Chemistry (RSC) Corday-Morgan medal (2013), the Marlow medal of the Faraday Division (2004) and the Harrison Memorial medal (2001). He is past President of the Aerosol Society of UK and Ireland, the current Editor-in-Chief of the AAAR journal Aerosol Science and Technology, and the director of the EPSRC Centre for Doctoral Training in Aerosol Science.

Abstract: Studies show that respiratory aerosols play a role in transmission of many respiratory diseases, including influenza and COVID-19. In order to assess the potential hazard posed by respiratory aerosols, information on a number of parameters are needed, including the emission rate and size distribution of particles from an infected individual, the ability of infectious virus contained within those particles to survive in the air and on surface, and the infectivity of those particles in a naïve host by relevant routes of exposure.  The role of these parameters will be discussed in terms an exposure continuum: from the source to transport through the environment to inhalation and deposition in the respiratory system. This tutorial will discuss methodologies that are used to measure and quantify these parameters, and provide a summary of what is currently known regarding the role of these parameters regarding the spread of COVID-19 and its causative virus, SARS-CoV-2, as well as knowledge gaps that remain. 

Paul Dabisch is a Senior Principal Investigator and the Aerobiology Team Lead at DHS’s National Biodefense Analysis and Countermeasures Center (NBACC). His research focuses on factors affecting the aerosol transmission of infectious diseases, including several recently published studies examining the survival of SARS-CoV-2, the virus responsible for COVID-19, in aerosols under different environmental conditions.  He is an active member of the American Association for Aerosol Research, and was the chairperson of the Bioaerosols Working Group in 2019 and helped to organize a special symposium for the 2020 virtual conference entitled ‘The Role of Aerosol Science in Understanding the Spread and Control of COVID-19’.  He holds adjunct appointments in the School of Systems Biology at George Mason University and the Department of Biology at Hood College. Prior to joining NBACC in 2011, he was a Research Toxicologist and Chief of the Aerosol Technology Department in the Center for Aerobiological Sciences at USAMRIID. Prior to USAMRIID, he spent three years as a Research Biologist and one year as a National Research Council post-doctoral fellow on the Operational Toxicology Team at the US Army’s Edgewood Chemical Biological Center. He received a B.S. in Crop Sciences from the University of Illinois at Urbana-Champaign, and a Ph.D. in Pharmacology from the Tulane University School of Medicine.

Dr. Gediminas “Gedi” Mainelis is a Professor in the Department of Environmental Sciences at Rutgers University. He has a Bachelor’s degree in physics from Vilnius University and a Ph.D. in Environmental Health from Cincinnati University, Ohio. His current research focuses on developing and validating bioaerosol sampling and analysis methods, exposure assessment of biological and non-biological particles, indoor air problems, the role of bioaerosols in the atmosphere, and exposure health effects of nanoparticles. His efforts in developing and testing new bioaerosol sampling and analysis technologies have resulted in novel sampling solutions and several granted and pending patents. Prof. Mainelis’s research findings and insights have been presented in more than a hundred peer-reviewed publications and several book chapters. Multiple papers from his group have been included in most downloaded article lists of various peer-reviewed journals. Prof. Mainelis is a recipient of the Lyman A. Ripperton Environmental Educator Award. He is the current Chair of the Bioaerosols working group of the AAAR.

Abstract: The spread of numerous infectious agents is associated with the generation and transmission of small aerosol particles. It has been demonstrated that inhalation of aerosol particles is an important mode of transmission of SARS-CoV-2 virus. Strategies that are solely based on indoor air purification have shown significant limitations. Respiratory protection has been widely recognized as the preferred approach to reducing inhalation exposure. An extraordinary shortage of commercially available medical masks and N95 filtering respirators, which the global community has experienced and continues experiencing during the COVID-19 pandemic, presented several major challenges. Among them are the widespread re-use of disposable protective devices, deployment of various methods to decontaminate these devices (which were not designed/approved for either re-use or decontamination), utilization of homemade/improvised masks in an effort to protect workers and the general public, and insufficient fit testing capabilities due to tremendous increase of the number of mask/respirator wearers. This tutorial will discuss recently generated data on filtering efficiency and breathability of various materials used in commercially available and improvised respiratory protective devices against infectious aerosols.

Sergey Grinshpun (PhD in Physics, 1987) is Professor of Environmental Health and Founding Director of the Center for Health-Related Aerosol Studies in the University of Cincinnati. His research program covers the measurement and characterization of ambient and indoor aerosols, exposure assessments, particle dispersion and transport, respiratory protection, air purification, as well as biodefense and biosecurity. Since February 2020, he has been involved in national and international efforts related to mitigation of the COVID-19 pandemic. Dr. Grinshpun has authored and co-authored over 660 scientific publications and given about 70 invited lectures at universities and research agencies around the world. He has served on panels convened by the National Academies (USA), the Council of Canadian Academies, the Chinese Academy of Sciences and several US federal agencies. His research results and expert opinions have been featured by ABC News, BBC News, Forbes, Los Angeles Times, National Public Radio, Science Daily, The Wall Street Journal, United Press International, US News and World Report, USA Today, Washington Post, Xinhua Press and other media outlets. He has mentored over 50 graduate students and 30 postdoctoral fellows/visiting scholars from 15 countries. He received fifteen awards from national and international associations and agencies.

Abstract: A comprehensive description of light scattering and absorption by particles of any size, shape, degree of aggregation and complex refractive index will be demonstrated. This description will involve a simple intuitive interpretation of light scattering based a novel Q-space analysis and two fundamental, unifying parameters that our group has developed. This analysis uncovers useful properties and functionalities in the angular phase function of the scattered light. It also lends significant physical intuition for the scattering process. Examples of experimental set-ups and data analysis that use this perspective to determine the properties of aerosol particles will be provided. This tutorial will be based on empirical, descriptive and largely non-mathematical concepts.

Christopher M. Sorensen is the Cortelyou-Rust University Distinguished Professor and a University Distinguished Teaching Scholar in the Departments of Physics and Chemistry at Kansas State University. He received a BS in physics from the University of Nebraska in 1969, was drafted and served in Vietnam, and then returned to earn a PhD in physics from the University of Colorado in 1977. In 2008 was named a Norlin Distinguished alumnus of CU. He is a condensed matter experimentalist and through the years he has studied many topics such as water and aqueous solutions, nanoparticle synthesis, aggregation and gelation of particulate systems, and particulate light scattering. He is a Fellow of the American Physical Society, the American Association for the Advancement of Science and the American Association for Aerosol Research. He is a past president of the AAAR and in 2004 received the Sinclair Award. In 2007 he was named the CASE/Carnegie Foundation United States Professor of the year for doctoral universities.

Abstract: Models for simulating atmospheric aerosols are a key component of air quality simulations, as well as regional and global climate models. Model development goes hand in hand with laboratory experiments and field observations to move science forward. Have you ever wondered how the measurements that you take in the lab or in the field can be made useful to advance models? Or how models can help you to interpret your experimental results? This tutorial will walk you through the key steps in going from a real-world phenomenon to a numerical model, and will illustrate how modeling and experiments inform each other. On the way, we will introduce the main types of aerosol representations in models and the underlying assumptions that are associated with each type. We will discuss appropriate strategies of how to handle the frequently overwhelming chemical complexity that we often encounter in experimental settings. You will learn what input data aerosol models need, what data is required to validate aerosol models, and what open-source models are available online to take your work to the next level.

Nicole Riemer is a Professor at the Department of Atmospheric Sciences and an Affiliate of the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign. She received her Doctorate degree in Meteorology from the University of Karlsruhe, Germany. Her research focus is the development of computer simulations that describe how aerosol particles are created, transported, and transformed in the atmosphere. Her group uses these simulations, together with observational and satellite data, to understand how aerosol particles impact human health, weather, and climate. She has received the NSF CAREER award and is an editor for Aerosol Science & Technology.

Miriam Freedman graduated with her BA from Swarthmore College in 2000. She received a MS in Mathematics from the University of Minnesota from 2002. She then received her PhD in Chemistry from the University of Chicago in 2008 as an NSF Graduate Fellow, where she worked with Prof. Steven Sibener on helium atom scattering to investigate energy transfer in supported organic thin films. After her PhD, Miriam was a NOAA Climate and Global Change Postdoctoral Fellow at the University of Colorado at Boulder with Prof. Margaret Tolbert, where she studied the optical properties of atmospheric particles. Miriam began her independent position at the Pennsylvania State University in 2010, where she is currently an Associate Professor. Her research group studies phase transitions of aerosol particles, ice nucleation, and other topics at the interface of physical chemistry, surface science, and atmospheric chemistry. She has received an NSF CAREER award in 2014, the Eberly College of Science 2019 Dean’s Climate & Diversity Award, and the 2021 ACS Physical Chemistry Division Early Career Award in Experimental Physical Chemistry.

Murray Johnston is a Professor in the Department of Chemistry and Biochemistry at the University of Delaware. He received his Ph.D. in Chemistry from the University of Wisconsin-Madison. His current research focuses on fundamental studies of particle growth in secondary organic aerosol and the development of aerosol chemical characterization methods. His group has participated in several field measurements of new particle formation. He has served AAAR in several ways including previous tutorials on particle characterization methods.

Abstract: Quantifying aerosol exposure is important for many applications, including supporting epidemiology studies, risk assessments, development of mitigation strategies, and sustainability efforts for cities and communities. This tutorial will review current measurement and modeling methods for estimating aerosol exposure in non-industrial indoor and in-cabin microenvironments, such as homes, schools, hospitals, commercial buildings, and vehicles. In this tutorial, we will discuss existing as well as promising future approaches for quantifying aerosol exposure.

Andrea Ferro is a professor of Civil and Environmental Engineering at Clarkson University, the Clarkson Institute for a Sustainable Environment Associate Director for Research, a faculty affiliate of the Clarkson Center for Air and Aquatic Resources Engineering and Science (CAARES), and the immediate past president of AAAR. Her technical expertise is focused on indoor air quality and human exposure to aerosols. She has worked directly with communities, schools, and hospitals and to measure, understand and mitigate sources of PM exposure. She has been conducting research in the field of particle resuspension for more than 20 years, including measurement and modeling of particle adhesion, detachment and transport at multiple scales, as well as the quantification of human exposure to resuspended particles for various exposure scenarios. 

Dr. Philip K. Hopke is the Bayard D. Clarkson Distinguished Professor Emeritus at Clarkson University and Adjunct Professor in the Department of Public Health Sciences of the University of Rochester School of Medicine and Dentistry. He was the founding Director of the Center for Air Resources Engineering and Science (CARES), and the Director of the Institute for a Sustainable Environment (ISE). He has been studying indoor and ambient air pollution for more than 50 years. His research interests: Chemical characterization of ambient aerosol samples; Multivariate statistical methods for data analysis; Emissions and properties of solid biomass combustion systems; Characterization of source/receptor relationships for ambient air pollutants; Experimental studies of homogeneous, heterogeneous, and ion-induced nucleation;  Indoor air quality; Exposure and risk assessment.

Abstract: The physical and chemical properties of atmospheric aerosols impact the world around us and the air we breathe. Over the past 2 decades the development and commercial availability of mass spectral methods for the chemical characterization of aerosol and aerosol precursor gases have advanced significantly.

This tutorial will review methods for both on-line and off-line aerosol analysis. Emphasis will be placed on real-time methods for the measurement and analysis of atmospheric aerosol as well as analysis of gas-phase organic aerosol precursors which constitute an important fraction of the atmospheric aerosol mass.

Topics covered will include instrument components used in online aerosol mass spectrometers, such as vacuum systems, aerosol sampling inlets, integrated particle sizing methods, mass spectrometer types, ionization sources and data systems. This tutorial will also review current laboratory and field measurements from mass spectrometer systems that have helped advance our understanding of the sources and chemical transformations of aerosol particles in our environment.

Dr. Jayne is a Principal Research Scientist with over 30 years experience in the field of atmospheric chemistry.  He is the Co-Director of the Center for Aerosol and Cloud Chemistry and Vice President of Instrument Systems Development and Production at Aerodyne Research, Inc. Dr. Jayne jointly manages atmospheric aerosol chemistry laboratory and field research projects, instrument development projects and the Aerodyne instrument production groups. His research interests and experience include studies of gas phase kinetics, heterogeneous gas-particle kinetics and the chemistry related to atmospheric aerosol formation and processing utilizing mass spectrometric techniques. Applications of these technologies in field and laboratory studies are focused on connecting measurements of highly oxidized, low volatility gas phase species to secondary organic aerosol formation to better understand aerosol impact on air quality, visibility and climate.   He is the co-inventor and developer of the Aerodyne Aerosol Mass Spectrometer (AMS) system and has contributed to the development and application of on-line mass spectrometric methods for the characterization of gas phase organic aerosol precursor gases.