Download or read book Using Aerosol Time of flight Mass Spectrometry ATOFMS Data to Gain New Insights Into the Temporal Profiles Composition and Evolution of Individual Particles in the Troposphere written by Don-Yuan Liu and published by . This book was released on 2000 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Insights Into Single particle Mixing State Using Aircraft Aerosol Time of flight Mass Spectrometry written by Kerri Anne Pratt and published by . This book was released on 2009 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols strongly influence the energy balance of the Earth and the hydrological cycle by scattering and absorbing radiation and acting as cloud condensation and ice nuclei. The climate and human health impacts of aerosols are strongly dependent on particle size, chemical composition, and mixing state. During transport in the atmosphere, aerosol particles undergo physical and chemical transformations (atmospheric aging) through heterogeneous reactions with trace gases and gas-particle partitioning of semivolatile species. The size-resolved chemical composition of individual particles may be examined in real-time using aerosol time-of-flight mass spectrometry (ATOFMS). A smaller ATOFMS with increased data acquisition capabilities was developed for aircraft-based studies. Particle volatility was examined through ground-based measurements during the Study of Organic Aerosols in Riverside, CA (SOAR), and vertical mixing state profiles and cloud residues were examined through flight-based measurements during the Ice in Clouds Experiment - Layer Clouds (ICE-L). An automated thermodenuder (TD) was coupled to the aircraft (A)-ATOFMS to provide the first real-time, individual-particle size and volatility-resolved chemical composition measurements. This work provided insight into the volatility of secondary species, as well as the sources and chemistry of ambient particle cores. Seasonal differences in the volatility of amine species were attributed to the formation of aminium sulfate and nitrate salts in the summer. Oligomeric species were detected in real-time for the first time in individual ambient aerosol particles; increased oligomer ion intensities were associated with increased particle acidity and heating. During ICE-L, vertical profiles of particle types, such as soot, mixed with secondary species, such as sulfuric acid, were examined. For cloud sampling, a counterflow virtual impactor was utilized in series with the A-ATOFMS to examine the residues of cloud droplets and ice crystals. This resulted in the first in-situ detection of biological particles in high altitude ice clouds influenced by long-range transported dust. Playa salts were observed to serve as cloud condensation nuclei and were preferentially observed as residues of large droplets.
Download or read book Analysis of Atmospheric Aerosol Processes Using Single Particle Mass Spectrometry written by Jeffrey Robert Whiteaker and published by . This book was released on 2002 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances and Applications of Mass Spectral Techniques for the Characterization of Atmospheric Aerosol Particles written by Lindsay Erighn Hatch and published by . This book was released on 2012 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol particles are ubiquitous in the atmosphere and induce significant impacts on human health and climate that depend on their physical and chemical properties, such as size, composition, and mixing state (chemical associations). Measurements of aerosol composition at the single-particle level are necessary to better understand these effects. Aerosol time-of-flight mass spectrometry (ATOFMS) is able to monitor the size and chemical composition of individual particles in real time. In this doctoral research, ATOFMS analysis was extended to identify new mass spectral markers and improve the potential for quantitative measurements. Development of novel instrumentation was also undertaken. Ion markers indicative of organosulfate compounds were identified in ATOFMS mass spectra collected in Atlanta, GA. In this study, the mixing state and temporal behavior of particulate organosulfate compounds were observed for the first time. Organosulfates were overwhelmingly detected in carbonaceous submicron particles and the temporal trends indicated that they likely formed by the daytime oxidation of isoprene followed by aqueous reaction with sulfate overnight. These results highlight the roles of mixing state and multi-phase reactivity on the formation of secondary organic aerosols. ATOFMS measurements of thermally-conditioned aerosol residuals obtained during the 2005 Study of Organic Aerosols in Riverside, CA were analyzed to determine the impacts of atmospheric aging on the laser desorption/ionization process. Coatings of secondary species suppressed the ionization efficiency, thereby impacting the mass spectral peak areas; however, a novel analysis method was found to correct these artifacts and produced strong agreement with collocated quantitative instrumentation. This new analysis technique was then applied to investigate the mixing-state dependence of aerosol volatility observed in Riverside. It was observed that particulate nitrate evaporated at different temperatures from different particle types (e.g., organic vs. biomass burning), which may influence the regional transport of nitrate species. ATOFMS provides important insights into size-resolved particle sources; however it heavily fragments most organic species, resulting in loss of the molecular information. Therefore, a novel chemical ionization mass spectrometer was developed to better characterize the molecular organic aerosol constituents. In particular, an ion funnel was incorporated into a home-built proton-transfer-reaction mass spectrometer. Initial characterization studies and ion simulations indicated that the ion funnel can provide high-efficiency ion transfer from the ionization region to the mass spectrometer. These results demonstrate the potential for this instrument to ultimately achieve highly sensitive analyses of organic aerosols.
Download or read book Source Profiling and Apportionment of Airborne Particles written by Philip Joseph Silva and published by . This book was released on 2000 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Time of flight Mass Spectrometry ATOFMS as a Real time Monitor of Individual Aerosol Particles in Field Studies written by Kimberly A. Prather and published by . This book was released on 2001 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Approaches for the Chemical and Physical Characterization of Aerosols Using a Single Particle Mass Spectrometry Based Technique written by Matthew Todd Spencer and published by . This book was released on 2007 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comparison of mass spectra generated from petrochemical particles was made to light duty vehicle (LDV) and heavy duty diesel vehicle (HDDV) particle mass spectra. This comparison has given us new insight into how to differentiate between particles from these two sources.
Download or read book The Analysis of Aerosol Time of flight Mass Spectrometry Data written by David Philip Fergenson and published by . This book was released on 2001 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Analysis of Aerosol Time of flight Mass Spectrometry Data Using YAADA written by Jonathan O. Allen and published by . This book was released on 2004 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Further Development and Application of Laser Desorption Ionization LDI Using Aerosol Time of flight Mass Spectrometry ATOFMS written by Ryan Jay Wenzel and published by . This book was released on 2004 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Ambient Aerosol Composition and Formation Mechanisms and Development of Quantification Methodologies Utilizing ATOFMS written by Xueying Qin and published by . This book was released on 2007 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols are solid or liquid particles suspended in the air. They are generated from a range of natural and anthropogenic sources. Aerosols also experience various reactions such as photo-oxidation and aqueous-phase processing, which constantly change their physical and chemical properties. Therefore, in order to determine the emission inventory, it is important to study aerosol reactions and transformation mechanisms in ambient atmosphere. The research described in this dissertation aimed to characterize temporal, spatial, and seasonal variations on ambient aerosol chemical compositions and formation mechanisms. The results contribute to the understanding of air pollution, climate change, and human health problems, and to devising necessary strategies and policies to resolve these problems.
Download or read book Characterization of Aerosol Particles Containing Sulfur and Nitrogen Species Using Aerosol Time of flight Mass Spectrometry ATOFMS written by Kimberly Louise Salt and published by . This book was released on 1995 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations Into the Impact of Transported Particles on Air Pollution and Climate Using Aerosol Time of flight Mass Spectrometry written by Andrew Phillip Ault and published by . This book was released on 2010 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols have a significant impact on human health and climate, yet the full scope of these influences are only beginning to be discovered and characterized. To understand these impacts, detailed in-situ measurements of the physical, chemical, and optical properties of aerosols are necessary. Aerosol time-of-flight mass spectrometry (ATOFMS) provides the ability to measure chemical, physical, and optical properties of single particles in real-time. This dissertation uses ATOFMS to explore both the properties and evolution of particles as they are transported over local to global distances. The results of numerous field studies are utilized to explore the changes to these particles as they travel through the atmosphere from their source to eventual deposition. Local to regional scale transport of particles was observed from a number of perspectives in this dissertation. Particles regionally transported from the Ports of Los Angeles and Long Beach to San Diego were identified chemically as ship and truck emissions and shown to overwhelm local sources during peak transport conditions. Ship emissions were studied in detail at the Port of Los Angeles by characterizing individual ship plumes at a site adjacent to the main channel. Mobile laboratory measurements demonstrated the variation in particle concentrations and composition on a local-to-regional level. On the intercontinental-to-global scale, Asian dust was observed in precipitation samples collected in the Sierra Nevada Mountains during orographic precipitation. The incorporation of the long range-transported dust might enhance precipitation, which may alter California's precipitation patterns and water supply. The outflow of particles from Asia to North America were measured on a remote island off Korea, and the sources and aging of particles in Chinese urban, Chinese dust, and Korean air masses were compared to marine air masses. Lastly, ATOFMS studies from sites across North America, Asia, Europe, and Africa were compared to determine similarities and differences in size-resolved chemical mixing state of particles across numerous types of sampling sites, with the objective being to provide information for global climate models to more accurately represent particles. Taken together these results provide an increased understanding of particle chemistry and transport on the scale of meters-to-continents.
Download or read book Refinement Calibration and Field Studies Involving Transportable Aerosol Time of flight Mass Spectrometers written by Sylvia H. Pastor and published by . This book was released on 2003 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry of the Upper and Lower Atmosphere written by Barbara J. Finlayson-Pitts and published by Elsevier. This book was released on 1999-11-17 with total page 993 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is the most comprehensive and up-to-date treatment of one of the hottest areas of chemical research. The treatment of fundamental kinetics and photochemistry will be highly useful to chemistry students and their instructors at the graduate level, as well as postdoctoral fellows entering this new, exciting, and well-funded field with a Ph.D. in a related discipline (e.g., analytical, organic, or physical chemistry, chemical physics, etc.). Chemistry of the Upper and Lower Atmosphere provides postgraduate researchers and teachers with a uniquely detailed, comprehensive, and authoritative resource. The text bridges the "gap" between the fundamental chemistry of the earth's atmosphere and "real world" examples of its application to the development of sound scientific risk assessments and associated risk management control strategies for both tropospheric and stratospheric pollutants. Serves as a graduate textbook and "must have" reference for all atmospheric scientists Provides more than 5000 references to the literature through the end of 1998 Presents tables of new actinic flux data for the troposphere and stratospher (0-40km) Summarizes kinetic and photochemical date for the troposphere and stratosphere Features problems at the end of most chapters to enhance the book's use in teaching Includes applications of the OZIPR box model with comprehensive chemistry for student use
Download or read book Characterization of Ambient Automobile and Diesel Aerosols Utilizing Aerosol Time of Flight Mass Spectrometry written by David Alan Sodeman and published by . This book was released on 2004 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
