Tuesday, October 1 - AEESP Lecture
Wednesday, October 2 - Friedlander Lecture
Thursday, October 3
Friday, October 4
AEESP Lecture: Lessons from the Workplace: Hazards from Exposure to Engineered Nanomaterials
Thomas Peters, University of Iowa, Iowa City, IA
Unique exposures may result when raw nanomaterials are produced or handled and when objects that contain nanomaterials are manipulated in the production of commercial products. Exposures in the workplace are often many times higher than those that occur via environmental release or that may be experienced by consumers of products that contain nanomaterials. Professionals trained in the field of industrial hygiene hold the responsibility to assess and mitigate exposures to nanomaterials in the workplace. This job is challenging due to limited health-based occupational exposure limits, exposure equipment that has been designed for more traditional exposures, and control methods that are generally untested for their effectiveness to control nanoparticle exposures. An overview will first be presented to summarize the state-of-the-art in the primary activities central to the practice of industrial hygiene (anticipation, recognition, evaluation, and control) in the context of workplaces where nanomaterials are present. Special emphasis will be placed on the advantages and disadvantages of various state-of-the-art methods used to assess exposures to engineered nanomaterials will be presented. A series of case studies will be used to illustrate how these methods can be applied in occupational settings to assess worker exposures. Lastly, a discussion will be presented to help translate the lessons learned from the workplace to more broadly address hazards from engineered nanomaterials in any environment.
Dr. Peters is an associate professor at The University of Iowa, Department of Occupational and Environmental Health. He directs the Industrial Hygiene Program and teaches control of occupational contaminants and aerosol technology. Dr. Peters holds a bachelor’s and master’s degree in environmental engineering from the University of Florida and a PhD from the University of North Carolina. Dr. Peters develops novel sampling methods that he then applies to understand and control aerosols in the workplace and the environment. In recent projects, he has developed a nanoparticle respiratory deposition sampler that collects nanoparticles with efficiency similar to that in the respiratory tract and a personal diffusion battery to assess exposures to submicrometer aerosols. He has developed methods to assess airborne engineered nanomaterials apart from background aerosols through activity monitoring with direct-read instruments and computer-controlled single-particle electron microscopy of collected particles. He also has developed passive sampling techniques to investigate the variability in composition of coarse particles in the atmosphere. In past projects he evaluated real-time aerosol measurement devices, developed aerosol generators used in EPA human exposure facilities, investigated turbulence effects on coarse filters, and evaluated size selectors used in chemical speciation samplers. Dr. Peters was involved in the development of EPA’s National Ambient Air Quality Standard for particulate matter under 2.5 µm (PM2.5); during this time, he was responsible for developing and testing PM2.5 sampling hardware, conducting field tests, and drafting portions of the Code of Federal Regulations. Dr. Peters served as an expert participant in the US-Russia Bilateral Presidential Commission Work Group on Science and Technology (Nanotechnology Sub-group). He has published numerous papers on the subject of assessing exposures to nanoparticles in workplaces and has recently developed a new chapter entitled “Engineered Nanomaterials” in Patty’s Industrial Hygiene.
Friedlander Lecture: Solarthermal Chemical Processing Using Particle Flow Reactors – Challenges and Opportunities
Alan W. Weimer, University of Colorado, Boulder, CO
Lewis and Nocera (Proceedings of the National Academy of Sciences of the United States of America. 2006;103(43):15729-35) make a compelling case for solar energy powering the planet. While the world energy consumption rate is projected to double from 13.5 TW in 2001 to 27 TW by 2050 and to triple to 43 TW by 2100, more sunlight strikes the earth in 1 hr (4.3 x 1020 J) than all of the energy currently consumed on the planet in 1 yr (4.1 x 1020 J in 2001). Hence, “the sun has a unique role in sustainable energy production, in that it is the undisputed champion of energy; the resource base presented by terrestrial insolation far exceeds that of all other renewable energy sources combined”.
Concentrated solar energy can be used to reach high temperatures and drive strongly endothermic chemical reactions such as direct water splitting, metal oxide reduction for water splitting cycles, metal oxide carbothermal reduction, and pyrolysis or gasification of cellulosic biomass or other carbonaceous material. The efficiencies for such processes are typically higher than those of competing solar technologies because the energy from the sun is used to directly drive chemical reactions instead of first being converted to another energy form, e.g. electricity.
Fine particle flow transport reactors are often used for chemical processing at temperatures above 1200oC where radiation heat transfer to the fine solids flowing through the reaction tube drives rapid reaction and the heating of gases that are transparent to radiation. This presentation will review several solarthermal processes in which fine powders are transported and will identify challenge areas of interest for researchers in the field of aerosol science and engineering.
Alan (Al) Weimer, H.T. Sears Memorial Professor of Chemical Engineering, joined the faculty of the University of Colorado in 1996 after a 16 year career with the Dow Chemical Company. He was named Dow Research Inventor of the Year and received Dow’s “Excellence in Science Award” for co-inventing, developing and commercializing high temperature rapid carbothermal reduction processing. Copernican Energy was spun out of his lab in 2006, since acquired by Sundrop Fuels. He received the AIChE Baron Award for Fluid-Particle Processing (2009) and the Excellence in Process Development Research Award (2010) as well as a 2005 Department of Energy Hydrogen Program R&D Award. The State of Colorado Cleantech Industry Association awarded him the 2011 “Excellence in Bio-derived Technology Commercialization Award”. His research team has focused on the design of solarthermal chemical reactors for hydrocarbon cracking, biomass gasification/pyrolysis and the splitting of water/CO2. His current research focuses on the interface between nanomaterials and solarthermal chemical processing for redox reactions.
Studying Aerosol Processes, One Particle at a Time
Jonathan P. Reid. Bristol Aerosol Research Centre, School of Chemistry, University of Bristol, Bristol, UK
Aerosol particles are dynamic, changing in size, composition and temperature as chemical and physical transformations occur. To fully characterise and understand the dynamical processes occurring, measurements must be able to access a wide range of lengthscales and timescales, spanning from the nanometre to the millimetre, and from nanoseconds to days. Although we must always remember that aerosols display collective ensemble behaviour, studying the mechanistic details of processes at the single particle level can provide important insights into the processes that influence the dynamics of the whole population. Over the decades, both electrodynamic and optical levitation techniques have demonstrated their value in isolating individual particles for study. When coupled with non-intrusive spectroscopic probes, temporal changes in size, composition and morphology can be followed. Indeed, in recent years we have shown that it is possible to manipulate multiple particles simultaneously using aerosol optical tweezers and to compare their properties directly in situ, bridging the gap between single particle and ensemble studies. In this talk, we will explore the advantages of studying aerosol processes, one particle at a time. More specifically, examples will be given of how processes, such as the evaporation and condensation of water from aerosol particles, can be resolved at the nanometre lengthscale, providing insights into the surface and bulk limited mechanisms and kinetics of hygroscopic growth. The timescales that must be accessed for such measurements span the range from millisecond to days, and are applicable to the inhalation of drugs to the respiratory tract through to the condensation kinetics of water on secondary organic aerosol. The dynamics occurring during the coalescence of aerosol particles will also be explored, with concomitant measurements of particle viscosity spanning almost 12 orders of magnitude. We will also see how the details of chemical aging of organic aerosol can be explored at the single particle level over timescales of days. Finally, the use of optical tools for manipulating aerosol particles to initiate controlled chemical transformations and to probe optical extinction will be introduced.
Jonathan P. Reid is professor of physical chemistry in the School of Chemistry at the University of Bristol, UK. He received his MA and DPhil in chemistry from the University of Oxford, before undertaking research as a post-doctoral researcher at the University of Colorado. He moved to a lectureship at the University of Birmingham, UK, in 2000 and then on to Bristol in 2004, establishing the Bristol Aerosol Research Centre in 2012. His research focuses on the development and application of novel techniques to study aerosols using optical and electrodynamic traps and spectroscopic tools. The work of his group is specifically targeted at better understanding aerosol processes of relevance to the atmosphere, drug delivery and the synthesis of functional particles, and in using aerosols to study fundamental physical chemistry. He was awarded the 2004 Marlow and 2001 Harrison Memorial Medals by the Royal Society of Chemistry and currently holds a Leadership Fellowship awarded by the Engineering and Physical Sciences Research Council, UK. He was co-editor of Fundamentals and Applications in Aerosol Spectroscopy (Taylor and Francis, 2010) and currently has over 120 publications.
Secondary Organic Aerosols: Are Laboratory Chambers Mimicking the Atmosphere?
Lynn M. Russell, Scripps Institution of Oceanography, San Diego, CA
Carbonaceous components contribute about half of the submicron atmospheric aerosol, but our knowledge of their composition and sources has lagged behind that of the inorganic components because of the diversity of organic compounds and the complexity of their mixtures. These particles include directly emitted “primary” particles and “secondary” particles from the photochemical oxidation of volatile organic compounds. The last decade has provided new measurement techniques that have allowed the identification and chemical characterization of both primary carbonaceous particle types and three categories of secondary organic aerosol (SOA) sources – fossil fuel combustion, biofuel and biomass burning, and marine and terrestrial biogenic vapor fluxes. Laboratory-based chamber studies have clearly demonstrated important differences in the SOA from these three types of precursors. Now, by comparing the chemical signatures of SOA composition formed from fossil fuel, biomass burning, and biogenic precursors to the components of atmospheric particles identified in multiple field campaigns as secondary, we provide evidence of the potential contributions of particles similar to those produced in SOA chambers to ambient compositions during those campaigns.
Lynn M. Russell is professor of atmospheric chemistry at Scripps Institution of Oceanography on the faculty of University of California at San Diego, where she has led the Climate Sciences Curricular Group since 2009. Her research is in the area of aerosol particle chemistry, including the behavior of particles from both biogenic and combustion processes. Her research group pursues both modeling and measurement studies of atmospheric aerosols, using the combination of these approaches to advance our understanding of fundamental processes that affect atmospheric aerosols. She completed her undergraduate work at Stanford University, and she received her PhD in chemical engineering from the California Institute of Technology for her studies of marine aerosols. Her postdoctoral work as part of the National Center for Atmospheric Research Advanced Studies Program investigated aerosol and trace gas flux and entrainment in the marine boundary layer. She served on the faculty of Princeton University in the Department of Chemical Engineering before accepting her current position at Scripps in 2003. She has been honored with young investigator awards from ONR, NASA, Dreyfus Foundation, NSF, and the James S. McDonnell Foundation, and she received the Kenneth T. Whitby Award from AAAR (2003) for her contributions on atmospheric aerosol processes and the Princeton Rheinstein Award for excellence in teaching and scholarship (1998). She has been a member of AAAR since 1993 and served on the AAAR Board of Directors from 2001 to 2004, as AAAR Conference Chair in 2011, and as AAAR Treasurer since 2012.