AAAR Tutorials

Monday, September 24, 2007

First Session: 8:00 a.m. – 9:40 a.m.

1. INTRODUCTION TO AEROSOL MECHANICS I

Dr. William C. Hinds, UCLA, School of Public Health, Center for Occupational and Environmental Health, Department of Environmental Health Science, Los Angeles, CA

Abstract: These two courses form a sequence that covers basic aerosol mechanics (particle motion) at an introductory level. Topics include: Stokes law, settling velocity, slip correction, aerodynamic diameter, non-spherical particles, acceleration, relaxation time, stopping distance, impaction, isokinetic sampling, diffusion, and coagulation. 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.

William Hinds is a professor of environmental health sciences at the UCLA School of Public Health. He received a bachelor's degree in mechanical engineering from Cornell University and a doctorate in environmental health from Harvard University.

2. AEROSOL-CLOUD INTERACTIONS: THE ELUSIVE COMPONENT OF CLIMATE CHANGE

Dr. Athanasios Nenes, Georgia Institute of Technology, Schools of Earth and Atmospheric Sciences and Chemical and Biomolecular Engineering, Atlanta, GA

Abstract: The effects of aerosols on clouds (known as the "aerosol indirect climatic effect") are thought to have a net climatic cooling effect which partially offsets greenhouse gas warming. Regional impacts of aerosols on precipitation and cloudiness can be even stronger. Despite its importance, the complex and multi-scale nature of aerosol-cloud interactions makes quantitative assessments of the indirect effect one of the most uncertain components of anthropogenic climate change. This tutorial will provide an overview of what aerosol-cloud interactions are and present the approaches used to observationally study them and represent them in models. We will provide an assessment of what has been learned and point out key research challenges for the future.

Athanasios Nenes is an assistant 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 master’s degree in atmospheric chemistry from the University of Miami, and a doctorate in chemical engineering from the California Institute of Technology.

3. NANOPARTICLES AND NANOTUBES: SYNTHESIS AND APPLICATIONS

Dr. Richard L. Axelbaum, Energy, Environment and Chemical Engineering, Washington University in Saint Louis, Saint Louis, MO

Abstract: Nanoparticles and nanotubes are slowly transitioning from a laboratory curiosity to a viable industry. Successful application of nanomaterials requires identifying true needs for these materials and pairing these needs with methods of synthesis that are viable at an industrial scale. This tutorial will examine various applications for nanoparticles and nanotubes and then describe promising technologies for synthesizing these materials.

Emphasis will be on understanding the unique properties of nanomaterials and how these materials can be synthesized to obtain these properties. Aerosol synthesis will be emphasized, but some discussion of competing technologies will also be presented. The fundamentals of aerosol science will be briefly reviewed to ensure that the attendee has sufficient background to understand the physics and chemistry of aerosol synthesis. The economics associated with aerosol synthesis will also be discussed to appreciate the scale that is needed to ensure commercial viability. Challenges facing commercial synthesis will be described and various solutions will be presented.

Richard Axelbaum is an associate professor of energy, environment and chemical engineering and associate director of the Center for Materials Innovation at Washington University in Saint Louis. He received his bachelor's degree from Washington University and his doctoral degree from the University of California at Davis, both in mechanical engineering. He is founder and chief scientific advisor of AP Materials, Inc., a start-up company that is commercializing aerosol processes for synthesis of nanomaterials.

4. HUMAN AEROSOL EXPOSURE: TOWARD A MECHANISTIC UNDERSTANDING

Dr. 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 a professor of environmental engineering and chair of the Energy and Resources Group at UC Berkeley. His research group studies indoor air pollutant chemistry and physics. The group also develops and applies 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).

Second Session: 10:00 a.m. – 11:40 a.m.

5. INTRODUCTION TO AEROSOL MECHANICS II

Dr. William C. Hinds, UCLA, School of Public Health, Center for Occupational and Environmental Health, Department of Environmental Health Science, Los Angeles, CA

6. NUMERICAL METHODS FOR TREATING INTERNAL MIXING OF AEROSOLS AND THE RESULTING RADIATIVE EFFECTS

Dr. Mark Z. Jacobson, Atmosphere/Energy Program, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA

Abstract: This tutorial will cover numerical methods of treating the main processes affecting the internal mixing of aerosol particles -- coagulation, condensation and dissolution. It will first examine the integrodifferential coagulation equation and methods of solving it. It will then compare the importance of different coagulation kernels, including those for Brownian diffusion, gravitational collection, turbulent shear, turbulent inertial motion, van der Waals forces, viscous forces, and fractal geometry. The condensational growth equation will then be derived and a numerical method of solving
it will be given. A numerical method for solving dissolution growth of gases into size-resolved particles will also be derived. Finally, methods of treating the radiative effects of internally-mixed particles will be discussed.

Mark Z. Jacobson is a professor of civil and environmental engineering and director of the Atmosphere/Energy Program at Stanford University. He received his PhD in atmospheric sciences in 1994 from UCLA. His work relates primarily to the development and application of numerical models to understand better the effects of air pollutants on climate and air quality. He has published two textbooks, "Fundamentals of Atmospheric Modeling" and "Atmospheric Pollution: History, Science, and Regulation," and over 70 peerreviewed scientific journal articles. More details can be found at http://www.stanford.edu/group/efmh/jacobson/.

7. UNDERSTANDING PROPER DATA ANALYSIS OF DIFFERENTIAL MOBILITY ANALYZER MEASUREMENTS

Dr. Mark R. Stolzenburg, Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN

Abstract: For the last three decades and continuing today the differential mobility analyzer (DMA) has been the primary standard for submicron particle size. It is relatively simple to operate and one or more are found in nearly every single aerosol lab. This course will briefly cover the history, latest innovations, basic principles of operation and a few operating tips for the DMA. The main focus will be on understanding proper DMA and Tandem DMA data analysis. There are a number of software packages available to users that make data analysis straightforward and extremely easy. But for the unsuspecting user it is also very easy to misapply the software particularly for TDMA data. The basic integral response equations governing these measurements will covered in detail along with the proper simplification and use of them to recover meaningful size distributions and growth factors from single and tandem DMA measurements, respectively. This class is suitable for experienced DMA users as well as relatively new users with an established understanding of the basic function of the DMA.

Mark Stolzenburg is currently a research associate and manager of the Particle Technology Laboratory (PTL) of the University of Minnesota. He received his PhD in mechanical engineering from the University of Minnesota in 1988 followed by a two-year postdoctoral appointment at the University of Denver and thirteen years experience in the private sector as a research engineer at Aerosol Dynamics in Berkeley, CA.

8. INHALATION TOXICOLOGY OF NANOMATERIALS

Dr. Vicki H. Grassian, Professor, Departments of Chemistry and Chemical and Biochemical Engineering University of Iowa, Iowa City, IA

Abstract: Nanoscience and nanotechnology offer new opportunities for making superior materials for use in industrial, health and environmental remediation applications. Manufactured nanomaterials are currently found in cosmetics, lotions and coatings. As these materials develop and become more widespread, there are questions as to the consequences that nanomaterials may have on human health and the environment. It is clear from some of the recent literature that the full impact, or even partial impact, of manufactured nanomaterials on human health and the environment has yet to be fully explored. Nanoparticles, the primary building blocks of many nanomaterials, may become suspended in air during production, distribution and/or use. These engineered airborne nanoparticles then join a class of particles known as ultrafine particles whose size is below 100 nm.

In this tutorial, some of the most important concepts in nanoparticle toxicology will be outlined. Recent nanoparticle inhalation exposure studies will be reviewed. The need for studies that integrate nanoparticle characterization data, which includes physical and chemical bulk and surface properties, with toxicity data will be discussed as being of central importance in understanding the physicochemical principles of nanoparticle toxicity. Select examples of integrated studies will be presented.

Dr. Vicki H. Grassian is currently the director of the Nanoscience and Nanotechnology Institute at the University of Iowa. As a full professor, she holds appointments in the departments of chemistry, chemical and biochemical engineering and occupational and environmental health. Her research interests include environmental and health impacts of
nanoscience and nanotechnology, heterogeneous atmospheric chemistry and the global impacts of mineral dust aerosol. She received her PhD from the University of California-Berkeley in physical chemistry.

Third Session: 1:00 p.m. – 2:40 p.m.

9. PM RESEARCH TO OPERATIONS: EXPLORING PM RESEARCH CONTRIBUTIONS TO POLICY RELEVANT AIR QUALITY MANAGEMENT APPLICATIONS

Dr. Richard Scheffe, U.S. Environmental Protection Agency, Research Triangle Park, NC

Abstract: This tutorial examines the linkages between research and applications relevant to a range a decision making processes spanning the establishment of National Ambient Air Quality Standards (NAAQS) to implementing national emission reduction strategies. Building mostly on measurement and modeling process development efforts, the lesson will provide a realistic examination of how research eventually is incorporated in the underlying air quality assessments conducted by EPA, industry and state and local agencies. Attention will be given to emerging policy directions underway in the EPA as well as addressing the conundrum – policy driving science or vice versa?

Richard Scheffe is a senior science advisor for EPA’s Office of Air Quality Planning and Standards and is the United States government co-chair for the latest NARSTO air quality assessment. During his career at EPA, Richard has held various positions in air quality modeling and monitoring including the development of the agency’s regulatory modeling programs for ozone and PM2.5 and the national manager for the nation’s air quality monitoring networks and the PM supersites program. Richard earned his
PhD in civil and environmental engineering from Clarkson University in 1987.

10. SECONDARY AEROSOL FORMATION

Dr. 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.

11. LIGHT SCATTERING BY PARTICLES: AN INTUITIVE DESCRIPTION FOR AEROSOL SCIENTISTS

Dr. Chris Sorensen, University Distinguished Professor, Department of Physics, Kansas State University, Manhattan, KS and Matthew J. Berg

Abstract: This tutorial will describe simple and intuitive approaches for understanding and applying light scattering to aerosol and colloidal systems. Particulate systems will include spheres, aggregates, and nonspherical particles. We also provide an introduction to contemporary methods to calculate scattering from particles of any composition and shape. With this foundation, there will be discussion regarding experimental methods for scattering and some instruments available in the marketplace. This tutorial will also cover light scattering problems relevant to current aerosol science.

Chris Sorensen is a university distinguished professor of physics and chemistry at Kansas State University where he has won numerous teaching awards. He is also the recipient of the AAAR Sinclair Award. He has presented a tutorial on light scattering at the AAAR annual meeting numerous times in the past. Matthew J. Berg is a senior graduate student in physics at Kansas State University working under Dr. Sorensen. He is a three-year
NASA GSRP fellow and specializes in analytical and computational electromagnetic scattering.

12. METHODOLOGIES FOR ASSESSING BIOAEROSOL EXPOSURES

Dr. Tiina Reponen, Department of Environmental Health, University of Cincinnati, Cincinnati, OH

Abstract: Bioaerosols include viruses, bacteria, fungi, pollen, and their fragments as well as animal allergens. The size of biological particles varies widely, from nano-scale (virions and microbial fragments) to about
100 μm (pollen grains). The same physical principles that are applied to non-biological particles can be applied to bioaerosol sampling in terms of sampling efficiency of a given particle size range. When sampling bioaerosols for exposure assessment purposes, one has to consider what biological property would be the most relevant measure for the health effect in question. This tutorial will review the traditional and modern techniques
for bioaerosol sampling and analysis. Advantages and disadvantages of various methods and future direction in bioaerosol exposure assessment will be discussed.

Tiina Reponen is a professor of environmental health at the University of Cincinnati, Department of Environmental Health. She received her doctoral degree in environmental sciences from Kuopio University, Finland. Her current research efforts are focused on the exposure assessment of biological and non-biological particles in indoor and industrial environments and physical and microbiological characterization of airborne bacteria and fungi.

Fourth Session: 3:00 p.m. – 4:40 p.m.

13. RECEPTOR-ORIENTED SOURCE APPORTIONMENT: DO YOU HAVE A ROBUST SOLUTION?

Shelly Eberly, Geometric Tools, Phoenix, AZ

Abstract: Various approaches are available to perform receptor-oriented source apportionment on particulate matter air quality data. Most of these approaches are ill-posed, meaning there are multiple solutions. Additionally, most approaches use numerical algorithms, which inherently have their own challenges. This tutorial will briefly review the more widely used factor analytic methods, including Principle Components Analysis, Unmix, and Positive Matrix Factorization (PMF), and then will follow with a more-detailed examination of PMF. Specifically, the tutorial will cover typical steps used to model particulate matter air quality data and will present practical sensitivity studies for characterizing the solution space. Such sensitivity analyses are an essential step in assessing the robustness of the apportionment. The tutorial will cover fundamental concepts and provide examples to illustrate each technique. Some of these techniques are active research areas.

Shelly Eberly is a statistician with over thirteen years of experience in analyzing ambient air quality data. Her research interests focus on practical techniques for understanding robustness of solutions in multi dimensional spaces. Eberly received a bachelor’s degree in mathematics from the University of Colorado and a master’s degree in mathematics/ statistics from the University of Texas in San Antonio. After thirteen years of consulting to or working for the U.S. EPA, Shelly is now a private consultant.

14. ORGANIC AEROSOLS AND THE VOLATILTY BASIS SET: EXPERIMENTAL AND MODELING APPLICATIONS

Dr. Neil M. Donahue, Associate Professor, Departments of Chemistry and Chemical Engineering, Director, Center for Atmospheric Particle Studies, Pittsburgh, PA

Abstract: The organic volatility basis set provides a regular framework for Pankow organic partitioning theory. By describing semi-ideal organic mixtures with volatility ranging over up to 12 orders of magnitude (with 12 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. 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 an associate professor of chemistry and chemical engineering with broad research interests relating to all aspects of organic compounds in the atmosphere. In more than 60 peer reviewed publications he has addressed questions ranging from nonmethane 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 under the supervision of Jim Anderson.

15. AEROSOL OPTICS MEASUREMENTS AND SURVEY OF THE CURRENT STATE OF THE SCIENCE

Dr. W. Patrick Arnott, Physics and Atmospheric Sciences Department, University of Nevada Reno, Reno NV

Abstract: Basic in-situ aerosol optics measurements include light scattering, absorption, and extinction. Applications of these measurements include the diagnosis of aerosol radiative forcing in climate, visibility, and evaluation of remotely sensed signals from satellites, sun photometers, and lidars. Inferences of particle composition and size distribution can also be obtained, an example being the optically defined black carbon aerosol mass concentration. These inferences extend the use of optical measurements to health studies where fast time response measurements are useful. These measurements are routinely performed at fixed ground-based stations, on mobile sampling vehicles, and from meteorological aircraft.

The tutorial covers first the basic suite of instruments commercially available for light scattering and absorption measurements and will include a discussion of measurement uncertainties and calibration methods. These instruments include nephelometers for light scattering measurement and filter-based instruments for light absorption measurements. The discussion then shifts towards new and emerging methods that are now commercially available, including light extinction measurements by the cavity ringdown method, light scattering using reciprocal nephelometery and integrating spheres, and light absorption using photoacoustic and photothermal methods. Examples of measurements from the spectrum of applications will be presented as well.

W. Patrick Arnott received his PhD in physics from Washington State University in 1988. His dissertation topic was in the field of ocean physics. He then did a postdoc at the University of Mississippi and the National Center for Physical Acoustics where he worked on thermoacoustic heat engines, laser Doppler vibrometry, and other topics. He was a research professor for 13 years at the Desert Research Institute in Reno, NV before joining the University of Nevada Reno as an associate professor of physics and atmospheric sciences. In Reno he has studied the crystallography of ice crystals in cirrus clouds and how this affects their optical properties, especially at infrared wavelengths. He also has developed photoacoustic instrumentation for multi-spectral measurements of aerosol light absorption and scattering, with applications in atmospheric radiation transfer, combustion science, and health.

16. INTRODUCTION TO AEROSOL TECHNOLOGY FOR DRUG DELIVERY

Dr. Reinhard Vehring, Associate Director, MedImmune Vaccines, Mountain View, CA

Abstract: In recent years, several significant innovations have been introduced in the area of medicinal aerosols and particles for respiratory drug delivery. For example, systemic delivery of peptides such as insulin through the lung is now a reality. This tutorial provides a view of the science and technology of advanced aerosol therapeutics for pulmonary and nasal delivery. It introduces concepts of delivery, deposition, and targeting of respiratory therapeutics and vaccines. The tutorial also covers various approaches to formulation, manufacturing, and administration. Special emphasis is put on the design of sophisticated microparticles using novel particle engineering techniques.

Reinhard Vehring leads the solid dosage form development group at MedImmune, Inc., responsible for formulation, processing, and delivery device development for live attenuated virus vaccines, monoclonal antibodies, and oncology therapeutics. Dr. Vehring has held positions in academia and industry advancing aerosol science and particle technology for more than 17 years. Before coming to MedImmune he worked with Nektar Therapeutics on pulmonary delivery of peptides, proteins, and small molecules.