Tutorials | AAAR 29th Annual Conference

MONDAY OCTOBER 25, 2010
FIRST SESSION: 8:00 A.M. – 9:40 A.M.

1. Introduction to Aerosol Mechanics 1
Richard C. Flagan, Department of Chemical Engineering, California Institute of Technology, Pasadena, CA

Abstract: These two courses (Tutorials 1 and 5) form a sequence that covers basic aerosol mechanics (particle motion) at an introductory level. Topics include: the aerodynamics of single particles, Stokes law, settling velocity, slip correction, aerodynamic diameter, non-spherical particles, acceleration, relaxation time, stopping distance, impaction, electrical mobility, and aerosol sampling. The tutorials will also discuss collective behavior of aerosols, e.g., Brownian motion, diffusion, deposition, filtration, condensation, and coagulation, and their effects on particle size distributions. The course covers theory and applications and is suitable for those new to the field and for others who want to brush up on the basics.

Richard C. Flagan is the McCollum/Corcoran Professor and Executive Officer for Chemical Engineering at the California Institute of Technology where he teaches chemical engineering and environmental science. He has served as president of 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 nanoparticles and other materials, and bioaerosols. His many contributions to the field of aerosol science have been acknowledged with the Sinclair Award of the AAAR and the Fuchs Award.

2. Aerosol Sampling and Transport
John E. Brockmann, Sandia National Laboratories, Albuquerque, NM

Abstract: It is desirable that the sampled aerosol be representative of the aerosol in its original environment. Sampling and transport can alter the ambient aerosol distribution. This tutorial will provide the tools to evaluate aerosol sampling and transport systems. The mechanisms that enrich or deplete particle concentration will be identified and discussed, and correlations from the literature will be given.

Dr. Brockmann received his PhD in mechanical engineering from the University of Minnesota in 1981 and works at Sandia National Laboratories. His areas of research cover both experimental and modeling applications of aerosol science including sampling and measurement of airborne particles and gases from hostile environments, particle and gas transport phenomena, particle and gas scavenging by liquid drops, and aerosol generation and source term characterization by various methods. He has worked in nuclear reactor safety, micro-contamination, fire and soot production, gas cleanup, and CBW countermeasures and consequences.

3. Combustion: Measuring Particle Emissions from Real-World Combustion Sources
David Cocker, Department of Chemical and Environmental Engineering and the College of Engineering, Center for Environmental Research and Technology, University of California Riverside, Riverside, CA

Abstract: Development of accurate emission factors and inventories rely on our ability to better characterize real-world combustion emissions. Furthermore, the EPA recognizes that the measurements must be made during actual processes thereby requiring monitors or analytical instruments to have real-time or near real-time response. The real time requirement for gases was achieved years back, and we are now at the cusp of meeting the challenge of real-time monitoring of particulate matter properties. This tutorial will cover the lessons learned from the use of real-time monitoring PM emissions from on- and off-road diesel sources, following both stationary and transient cycles. The tutorial discusses approaches for measurement of emission factors and characterization of the influences of engine technology, fuel blends, and after-treatment devices as emissions are varied from gross emitters to ultra-clean technologies. We will focus on the tools necessary for accurate emission monitoring, the challenges of modern portable emission measurement systems, and how in-use measurements are made for a variety of different combustion sources. A portion of the tutorial will be dedicated to simulating in-laboratory exposure systems for secondary pollutant formation and health studies.

David Cocker is an associate professor in the Department of Chemical and Environmental Engineering and the College of Engineering, Center for Environmental Research and Technology (CE-CERT) at UC Riverside. He received his BS degrees in environmental engineering and chemistry from UC Riverside and his MS and PhD degrees in environmental engineering science from the California Institute of Technology.

4. Nucleation Theory
Steven L. Girshick, professor of mechanical engineering and member of the graduate faculty in chemical engineering and materials science, University of Minnesota, Minneapolis, MN

Abstract: This tutorial will present an introduction to the theory of nucleation of aerosol particles from the gas phase. Basic concepts in modeling homogeneous nucleation of a supersaturated vapor; classical nucleation theory; atomistic approaches; transient nucleation; and nucleation in chemically reacting systems and plasmas will be discussed.

Steven L. Girshick is professor of mechanical engineering and a member of the graduate faculty in chemical engineering and materials science at the University of Minnesota. He is director of the High Temperature and Plasma Laboratory, editor-in-chief of Plasma Chemistry and Plasma Processing, and serves on the editorial board of the Journal of Nanoengineering and Nanosystems. He was the recipient of the 2005 Plasma Chemistry Award, the highest award of the International Plasma Chemistry Society. In addition to Prof. Girshick’s work on plasma synthesis of nanoparticles, he has published a number of papers on nucleation theory.

SECOND SESSION: 10:00 A.M. – 11:40 A.M.

5. Introduction to Aerosol Mechanics 2
Richard C. Flagan, Department of Chemical Engineering, California Institute of Technology, Pasadena, CA

6. Diesel Engine Emissions Control
Antonio H. Miguel, Monitoring and Laboratory Division, California Environmental Protection Agency - Air Resources Board, El Monte, CA

Abstract: This tutorial summarizes the key developments in diesel emission control. Examples from the spectrum of technologies will be presented, including diesel NOx control developments on selective catalytic reduction (SCR), lean NOx traps (LNT) and lean NOx catalysts (LNC), along with important developments on diesel particulate filters (DPFs), and oxidation catalysts.

Antonio H. (Toni) Miguel completed his PhD in the chemistry department, University of Illinois Urbana-Champaign in 1976. He was inducted as a member of Phi Lambda Upsilon Honorary Chemical Society and received the Granite City Steel Company Prize in Environmental Chemistry (1974-1975) for his thesis work. His research focuses on aerosol measurement and behavior with a primary focus on atmospheric aerosols. His current research in this area focuses on new particle formation and in situ methods for measuring physical and chemical properties of complex particles. Currently Dr. Miguel is an air pollution specialist at the ARB’s Haagen-Smit Laboratory in El Monte, CA.

7. Human Aerosol Exposure: Toward a Mechanistic Understanding
William W Nazaroff, Department of Civil and Environmental Engineering, University of California, Berkeley, CA

Abstract: This tutorial explores the relationships between aerosol emission sources and human inhalation exposure. The tools and techniques are those of the physical sciences and engineering, stressing causal connections. The lecture draws on key chemical and physical knowledge from atmospheric aerosol science. Focusing on human exposure as the outcome of concern leads to an emphasis on the proximity between sources and receptors. Most exposure occurs while people are in enclosed spaces, so issues that influence indoor aerosols enter strongly into this lecture.

William Nazaroff is the Daniel Tellep Distinguished Professor and Vice Chair for Academic Affairs in the Department of Civil and Environmental Engineering at UC Berkeley. His research group studies indoor air pollutant chemistry and physics. They also develop and apply methods for assessing human exposure to air pollutants from major exposure sources, such as motor vehicles, power plants, and cigarettes. Dr. Nazaroff earned a PhD in environmental engineering science at Caltech (1989). He is a Fellow of AAAR and will serve as vice president for 2010-2011.

8. Secondary Aerosol Formation
Paul J. Ziemann, Air Pollution Research Center and Department of Environmental Sciences, University of California, Riverside, CA

Abstract: Secondary aerosol is an important component of atmospheric fine particles that generally consists of organics, sulfates, and nitrates. The processes that lead to the formation of this material are often complex and can involve gas and particle phase chemistry, nucleation, and gas-particle partitioning. This course will discuss the major chemical reactions and partitioning processes involved in the formation of secondary organic and inorganic aerosol (with a strong emphasis on organic aerosol) using examples from laboratory and field studies.

Paul Ziemann is a professor of atmospheric chemistry at the University of California, Riverside. He received a doctorate in chemistry from Penn State University and was a postdoctoral researcher in the Particle Technology Laboratory at the University of Minnesota.

THIRD SESSION: 1:00 P.M. – 2:40 P.M.

9. Electrospray and its Applications
Da-Ren Chen, associate professor, Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO

Abstract: Electrospray technique (i.e., electrohydrodynamic atomization) has been proposed for many modern applications. Examples of the applications include surface coating, agricultural treatments, emulsion, fuel spraying, micro- or nano-encapsulation, ink-jet printers, colloid micro-thrusters, electrospray mass spectrometry (ES MS) for macromolecular detection in biochemical applications, monodisperse super micro- and nano-particle generation, enhancement of droplet mixing, targeted drug delivery by inhalation, power production, and electrospray gene transfection. Among all the operational modes involved in the process, the cone-jet mode has been investigated and applied for the majority of above-described applications. It is because of its capability to produce un-agglomerated, monodisperse particles in the sub-micrometer and nanometer diameter ranges. Among different setups, single-capillary electrospray systems were often used in various applications. However, limitation of single-capillary electrospray is encountered in modern electrospray applications, especially in the biomedical and pharmaceutical areas. Dual-capillary electrospray (ES) technique was thus proposed to overcome the limit of a single-capillary electrospray system, thereby broadening the applications of electrospray technique. In this tutorial we will first review the electrospray history and its fundamental principles/theory. Then we will present its applications in various areas. Finally, we will discuss the future challenge for electrospray techniques.

Da-Ren Chen, PhD is an associate professor in the Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, MO. He received his PhD degree (1996, 1997) from the University of Minnesota. He is the principal investigator and inventor of electrospray monodisperse particle generator, nanometer differential mobility analyzer, high-through nanoparticle charger, fast scan electrical aerosol sizer, personal particle monitors, and other particle processing tools. He holds 15 US and two international patents in the area of particle technology. He has received the Sheldon K. Friedlander Award (1997), the Smoluchowski Award (2002), and the Kenneth Whitby Award (2005). He has intensive experience on particle sampling and characterization, particle instrumentation, micro-contamination control in semiconductor processing, filtration, health effect of particles, nanotoxicity, and particle synthesis/generation for pharmaceutical and biomedical applications.

10. Chemical Transport Modeling of Aerosols
Peter J. Adams, Department of Civil and Environmental Engineering and the Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA

Abstract: Chemical transport models (CTMs) are numerical simulations representing the interplay of emissions, chemistry, transport, microphysics, and deposition that determine the behavior of atmospheric aerosols. As research tools, they play several important roles: assessing the significance of newly discovered or hypothesized processes in an atmospheric context, testing our knowledge of aerosol behavior against ambient observations, inferring what input data (e.g. emissions) are consistent with observations, and predicting the impacts of policy decisions. Conceptually, they are simple mass and population balances. Complexity arises from several factors: the chemical and physical interactions of many dozen species; transport across a three-dimensional grid representing an urban airshed, a geographic region or even the entire globe; and the numerical approximations required to solve the resulting equations efficiently. This tutorial will provide a discussion of the continuity equation as the basis for CTMs; outline major assumptions (e.g. operator splitting) and solution techniques; and survey the major algorithms for representing aerosol emissions, chemistry, microphysics, phase partitioning, transport, and deposition. We will discuss major sources of error and weaknesses in CTMs and conclude with some general principles for their intelligent use.

Peter J. Adams is a professor at Carnegie Mellon University with a joint appointment between the Department of Civil and Environmental Engineering and the Department of Engineering and Public Policy. He earned his bachelor’s degree in chemical engineering from Cornell University in 1996, followed by a masters and then PhD in chemical engineering at the California Institute of Technology in 1998 and 2001 respectively. His research interests include aerosol-climate interactions, global and regional aerosol modeling and the development of aerosol microphysical simulations in climate models. Dr. Adams received the Sheldon K. Friedlander Award in 2004 from AAAR.

11. Nanostructured Material Synthesis
Sotiris E. Pratsinis, professor of process engineering and adjunct professor of materials science, Swiss Federal Institute of Technology, Zurich, Switzerland

Abstract: The tutorial will start with the fascinating history of aerosol technology from production of inks in ancient China and Greece to the Bible printing by Gutenberg and to today’s synthesis of optical fibers, carbon blacks, pigments, fumed silica and filamentary nickel. Hot-wall, plasma, laser and, in particular, flame reactors are discussed for their proven scalability as they dominate both by value and volume today’s aerosol synthesis of nanostructured materials. The six advantages of aerosol technology over solution or wet-chemistry are emphasized and shown how they are exploited in manufacture of specific products. Opportunities for aerosol synthesis of sophisticated functional films and particles, in particular for catalysts and sensors, are presented by combustion of sprayed solutions. Basic design principles for flame synthesis of nanoparticles with controlled particle size by reviewing specific experiments as well as simulations combining fluid and particle dynamics will be discussed. A focus is on the degree of particle aggregation and agglomeration and its control as well as on layered structures that “cure” some of nanoparticles’ deleterious effects facilitating, thus their inclusion in nanocomposites and suspensions.

Dr. Sotiris E. Pratsinis is a professor of process engineering and adjunct professor of materials science at the Swiss Federal Institute of Technology (ETH Zurich). He received his Diploma from the Aristotle University in Thessaloniki, Greece and his MSc and PhD from UCLA.

12. Organic Aerosols Volatility and Chemistry: Experimental and Modeling Applications
Neil Donahue, Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA

Abstract: Organic aerosols consist of a complex mixture of organic compounds with a very wide range of volatilities. The organic volatility basis set (VBS) provides a regular framework for Pankow organic partitioning theory. By describing organic mixtures with volatility ranging over many orders of magnitude (with logarithmically separated volatility bins), it permits concise yet accurate predictions of semi-volatile partitioning over the full range of conditions relevant to organic aerosols, from highly-concentrated exhaust plumes to the most dilute conditions of the remote troposphere. In this workshop we shall develop the basic formalism of partitioning under the volatility basis set and then proceed to consider a series of relevant example cases. These include `traditional' secondary organic aerosol formation experiments (including temperature effects), emissions characterization via dilution sampling, parcel mixing, and finally gas- and condensed-phase chemistry. We shall discuss the relationships among various partitioning treatments (i.e., the VBS, Odum `2-product' models, explicit mechanisms, etc.) as well as various mechanisms treating photochemical aging of organic aerosol. Wall effects in chamber experiments will be given special consideration as an example problem.

Neil Donahue is the director of the Center for Atmospheric Particle Studies at Carnegie Mellon University. He is a professor of chemistry, chemical engineering, and engineering and public policy with broad research interests relating to all aspects of organic compounds in the atmosphere. In more than 100 peer-reviewed publications he has addressed questions ranging from non-methane hydrocarbon modeling and measurement in the remote marine atmosphere to laboratory kinetics of condensed-phase organic compounds. Professor Donahue has been at Carnegie Mellon since 2000. Prior to that, he received an AB in physics from Brown University (1985) and a PhD in meteorology from MIT (1991) before pursuing postdoctoral work in physical chemistry at Harvard University.

FOURTH SESSION: 3:00 P.M. – 4:40 P.M.

13. Thermodynamics of Aerosols and Droplets
Athanasios Nenes, Schools of Earth and Atmospheric Sciences and Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA

Abstract: The equilibrium thermodynamic properties of the mixture of acids, salts, and organic compounds present in the atmosphere largely control gas/aerosol equilibrium and the water uptake of soluble aerosol components in response to temperature and relative humidity changes. This course will cover the following fundamentals: the water uptake of different soluble components of aerosols, including organic compounds; the precipitation of solid phases and metastable equilibria; the Phase Rule; Henry’s law; activity coefficients and deviations from ideal solution behavior; the Kelvin effect; the role of surfactants. We will also extensively discuss the application of thermodynamic principles used to describe the formation of cloud droplets will also take place, and present semi-empirical frameworks used for describing the cloud condensation nuclei (CCN) properties of atmospheric aerosol.

Athanasios Nenes is an associate professor in the Schools of Earth and Atmospheric Sciences and Chemical and Biomolecular Engineering at the Georgia Institute of Technology. He received a diploma in chemical engineering from the national Technical University of Athens, a masters degree in atmospheric chemistry from the Rosenstiel School of Marine and Atmospheric Sciences and a doctorate in chemical engineering from the California Institute of Technology. He is the developer of the ISORROPIA aerosol thermodynamic model and co-inventor of the Continuous Flow Streamwise Thermal Gradient CCN Chamber. He has received the Friedlander Award of the AAAR and the Henry G. Houghton Award of the AMS.

14. Principles of Bioaerosol Sampling and Analysis
Gediminas “Gedi” Mainelis, Department of Environmental Sciences, Rutgers University, New Brunswick, NJ

Abstract: Bioaerosols include viruses, bacteria, fungi, pollen and their products. Size of biological particles can range from nanoscale to micron size. Bioaerosols are produced naturally, as a byproduct of various activities, or can be released intentionally to harm various populations. Sampling and detection of bioaerosols are important for environmental and indoor studies, exposure assessment, manufacturing quality control and protection of population from intentionally released agents. The same physical principles that are applied to collect non-biological particles can also be applied to collect bioaerosols, and one can analyze sampling efficiency as a function of particle size. However, analysis of biological particles requires that their properties, such as viability, morphology, DNA structure, etc., be preserved during sampling which often requires compromises in sampling efficiency. When sampling is performance to identify airborne biological particles, sample volume, collection efficiency, concentration rate and accuracy of detection are important parameters. This tutorial will review the traditional and modern techniques for bioaerosol sampling and analysis. Advantages and disadvantages of various methods in bioaerosol sampling and detection as well as their applications will be discussed.

Gediminas “Gedi” Mainelis is an associate professor of environmental sciences at Rutgers University in NJ. He received his doctoral degree from the University of Cincinnati, Department of Environmental Health. His current research focuses on the development and validation of bioaerosol sampling and analysis methods, exposure assessment of biological and non-biological particles in various environments, role of bioaerosols in the atmosphere, and exposure and health effects of nanoparticles.

15. Deposition, Adhesion, and Reaerosolization
Jonathan Thornburg, Center for Aerosol Technology, RTI International, Research Triangle Park, NC

Abstract: Aerosol fate in indoor and outdoor environments has public health and homeland security implications. The environmental fate of aerosols depends on their deposition rate, adhesion to the surface, and reaerosolization when disturbed by an external force. The magnitude of these factors depends on the particle dimensions and chemistry, as well as peripheral influences like meteorology and surface characteristics. This tutorial will present the theory, experimental methods, and models used to study aerosol deposition, adhesion, and reaerosolization. A discussion of current research to link deposition, adhesion, and reaerosolization into a unified paradigm will conclude the tutorial.

Jonathan Thornburg is a senior research engineer and manager of the Aerosol Physics and Exposure Program in the Center for Aerosol Technology at RTI International. His research applies fundamental aerosol physics to understand exposure to particle-based contaminants and biological particles. He received his doctorate in aerosol physics and engineering from the University of North Carolina at Chapel Hill.

16. The Physics of Fractal Aggregates
Chris Sorensen, Department of Physics, Kansas State University, Manhattan, KS

Abstract: As the title implies, this tutorial will cover the physics of fractal aggregates to include the kinetics of how they form, a thorough description of their morphology, how they scatter and absorb light, their mobility in gases and liquids, and the nature of some of their bulk properties. My intent is to give the student a broad and solid working knowledge similar to that which I expect my graduate students to have after a few months of working in my lab.

Chris Sorensen is a distinguished professor at Kansas State University in the Department of Physics where he enjoys both teaching and research. He has studied fractal aggregates in a great variety of ways for over 20 years.