Download or read book Characterization of Ambient Aerosol Sources and Processes During CalNex 2010 with Aerosol Mass Spectrometry written by Jose-Luis Jimenez and published by . This book was released on 2013 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Ambient Aerosol Source and Processes During CalNex 2010 with Aerosol Mass Spectrometry written by José Luis Jiménez and published by . This book was released on 2013 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analytical Chemistry of Aerosols written by Kvetoslav R. Spurny and published by CRC Press. This book was released on 2017-11-22 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until the 1980s, researchers studied and measured only the physical properties of aerosols. Since the 80s, however, interest in the physicochemcal properties of aerosols has grown tremendously. Scientists in environmental hygiene, medicine, and toxicology have recognized the importance held by the chemical composition and properties of aerosols and the interactions of inhaled, "bad" aerosols. This book offers the first comprehensive treatment of modern aerosol analytical methods, sampling and separation procedures, and environmental applications, and offers critical reviews of the latest literature. This important field has developed rapidly in the last 15 years, but until now, no book effectively summarized or analyzed the existing research. Analytical Chemistry of Aerosols reviews procedures, techniques, and trends in the measurement and analysis of atmospheric aerosols. With contributions from acknowledged, international experts, the book discusses various methods of bulk analysis, single particle analysis, and the analysis of special aerosol systems, including fibrous and bacterial aerosols.

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 Characterizing Ambient Organic Aerosol Properties Sources and Processes Via Aerosol Mass Spectrometry written by Shan Zhou and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic aerosol (OA) is an important component of the earth’s climate system, making up a substantial fraction of the fine aerosol mass in the atmosphere. However, the atmospheric evolution of OA after emission remains poorly characterized. A better understanding of its life cycle is critical for environmental issues ranging from air quality to climate change. In this dissertation, real-time measurements of submicron aerosols were made using a High-Resolution Time-of-Flight Aerosol Mass Spectrometers (AMS) during two DOE field campaigns to obtain a detailed understanding of the chemical and physical properties, sources and atmospheric processes of OA under various emission regimes. The first field study took place at a rural forest site on Long Island, NY, as part of the Aerosol Life Cycle Intensive Operation Period at Brookhaven National Lab (ALC-IOP at BNL). OA was found to dominate the submicron aerosol mass at BNL and was overwhelmingly secondary. Urban emissions transported from the New York metropolitan area led to elevated OA mass concentration and altered OA composition and physical-chemical properties at this rural site. Results suggest that mixed anthropogenic emissions and biogenic emission led to enhance secondary OA (SOA) production. The second field study took place at a high-altitude regional background site, Mt. Bachelor Observatory (MBO; ~ 2763 m a.s.l), in the western US as part of the Biomass Burning Observation Project (BBOP). Regional and free tropospheric (FT) aerosols under clean conditions were characterized. Significant compositional and physical differences between FT and boundary layer (BL) OA were observed. Free tropospheric OA was highly oxidized with low volatility, whereas OA associated with BL air masses was less oxidized and appeared to be semivolatile. For periods influenced by transported wildfires plumes during the study period, aerosol concentration at MBO increased substantially and was overwhelmingly organic. Three types of BB organic aerosol (BBOA) were identified and appeared to have been subjected to different degrees of atmospheric processing. A case study using consecutive BB plumes transported from the same fire source showed that photochemical aging led to more oxidized OA with higher mass fractions of aged BBOA and a lower fraction of fresh BBOA. Although BBOA in daytime plumes were chemically more processed than nighttime plumes, the enhancement ratios of OA relative to CO were very similar. Based on observations both at MBO and near fire sources using the DOE G-1 aircraft, BBOA concentrations and chemical properties were strongly influenced by combustion processes at the source. However, OA emissions were consistent between fresher emissions and emissions sampled after atmospheric transport. In addition, tighter correlations were observed between OA oxidation degree and plume age. These results suggest that aging leads to substantial chemical transformed and more oxidized BBOA in this study, yet BBOA concentration was conserved to a significant extent during regional transport, for which a possible reason is that SOA formation was almost entirely balanced by BBOA volatilization.

Download or read book Fundamentals and Applications in Aerosol Spectroscopy written by Ruth Signorell and published by CRC Press. This book was released on 2010-12-20 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helping you better understand the processes, instruments, and methods of aerosol spectroscopy, Fundamentals and Applications in Aerosol Spectroscopy provides an overview of the state of the art in this rapidly developing field. It covers fundamental aspects of aerosol spectroscopy, applications to atmospherically and astronomically relevant problem

Download or read book Three dimensional Measurements of Aerosol Mixing State During CalNex Using Aircraft Aerosol Time of flight Mass Spectrometry written by Kimberly A. Prather and published by . This book was released on 2013 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Characterization and Source Apportionment Model Study of Atmospheric Aerosols in Asia written by Rachelle Monique Duvall and published by . This book was released on 2005 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of the Molecular Composition of Secondary Organic Aerosols Using High Resolution Mass Spectrometry written by Rachel Elizabeth Sellon and published by . This book was released on 2012 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols can affect visibility and the Earth's climate by scattering and absorbing light and they also can have adverse effects on human health. The organic portion of atmospheric aerosols is very complex and is a major fraction of fine particulate matter. High molecular weight (high-MW)/oligomeric organic compounds can make up a large part of this organic fraction and the composition, sources, and formation mechanisms for these compounds are not well understood. This knowledge and understanding is necessary to decrease the uncertainty in the climate affects of aerosols and to improve climate models. This dissertation investigates the composition and formation mechanisms for the high-MW/oligomeric fraction of secondary organic aerosols (SOA) collected in Bakersfield, CA and presents a comparative analysis of chamber and ambient SOA, from both Los Angeles (LA) and Bakersfield, to investigate sources at both locations. A novel sampling technique, nanospray-Desorption Electrospray Ionization (nano-DESI), was used with high resolution mass spectrometry (HR-MS) to determine the molecular formulas of the high molecular weight (HMW)/oligomeric fraction of SOA. Nano-DESI involves direct desorption from the sample surface and was used to limit reactions that can take place with extraction and storage in solvent. The samples were collected in Bakersfield and LA during CalNex 2010. Both Bakersfield and LA are out of compliance with EPA standards of ozone and particulate matter and provide opportunities to examine air masses affected by both anthropogenic and biogenic sources. This dissertation has provided the first evidence of observable changes in the composition of high-MW/oligomeric compounds throughout the day. Using positive mode nano-DESI, afternoon increases in the number of compounds that contain carbon, hydrogen and oxygen (CHO) were observed consistent with photochemistry/ozonolysis as a major source for these compounds. Compounds containing reduced nitrogen groups were dominant at night and had precursors consistent with imine formation products from the reaction of carbonyls and ammonia. In the negative mode, organonitrates (CHON) and nitroxy organosulfates (CHONS) had larger numbers of compounds in the night/morning samples consistent with nitrate radical formation reactions. A subset of the CHONS compounds and compounds containing sulfur (CHOS) had the same composition as known biogenic organosulfates and nitroxy organosulfates indicating contributions from both biogenic and anthropogenic sources to the SOA. This dissertation also provides the first analysis of the high-MW/oligomeric fraction in size resolved samples; the majority of the compounds were found in aerosol diameters between 0.18-1.0 micrometers and the CHON were bimodal with size. Finally, this dissertation presents the first comparative analysis of the overlap in the composition of this fraction of SOA between ambient and chamber samples. Samples collected in Pasadena, LA and Bakersfield were compared with samples collected in a smog chamber using diesel and isoprene sources. The results indicate that diesel had the highest overlap at both sites, Bakersfield samples were more oxidized, and LA showed evidence of a SOA plume arriving from downtown LA. The addition of ammonia to the diesel chamber experiment was necessary to form many of the 2N compounds found in Bakersfield. These results increase our understanding of the types of compounds found in urban environments and give evidence for the timescales of formation reactions in an ambient environment. They show that the majority of the high-MW oligomeric compounds are found in submicron size particles and that the composition of this fraction of SOA varies with aerosol size. Results from the chamber comparisons show that both diesel and isoprene are important sources for these compounds and also that there other sources are present. Future work that combines this type of analysis, in other ambient environments, with studies of the optical properties of aerosols could be used to help improve climate models and to start to close the gap in our understanding of the climate effects of atmospheric aerosols.

Download or read book Single Particle Characterization Source Apportionment and Aging Effects of Ambient Aerosols in Southern California written by Laura Grace Shields and published by ProQuest. This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composed of a mixture of chemical species and phases and existing in a variety of shapes and sizes, atmospheric aerosols are complex and can have serious influence on human health, the environment, and climate. In order to better understand the impact of aerosols on local to global scales, detailed measurements on the physical and chemical properties of ambient particles are essential. In addition, knowing the origin or the source of the aerosols is important for policymakers to implement targeted regulations and effective control strategies to reduce air pollution in their region. One of the most ground breaking techniques in aerosol instrumentation is single particle mass spectrometry (SPMS), which can provide online chemical composition and size information on the individual particle level. The primary focus of this work is to further improve the ability of one specific SPMS technique, aerosol time-of-flight mass spectrometry (ATOFMS), for the use of identifying the specific origin of ambient aerosols, which is known as source apportionment. The ATOFMS source apportionment method utilizes a library of distinct source mass spectral signatures to match the chemical information of the single ambient particles. The unique signatures are obtained in controlled source characterization studies, such as with the exhaust emissions of heavy duty diesel vehicles (HDDV) operating on a dynamometer. The apportionment of ambient aerosols is complicated by the chemical and physical processes an individual particle can undergo as it spends time in the atmosphere, which is referred to as "aging" of the aerosol. Therefore, the performance of the source signature library technique was investigated on the ambient dataset of the highly aged environment of Riverside, California. Additionally, two specific subsets of the Riverside dataset (ultrafine particles and particles containing trace metals), which are known to cause adverse health effects, were probed in greater detail. Finally, the impact of large wildfires on the ambient levels of particulate matter in Southern California is discussed. The results of this work provide insight into single particles impacting the Southern California region, the relative source contributions to this region, and finally an examination of how atmospheric aging influences the ability to perform source apportionment.

Download or read book Extended Analysis of the CARES Aerosol Chemistry Data to Characterize Sources and Processes of Organic Aerosol in the Sacramento Valley of California written by Qi Zhang and published by . This book was released on 2014 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Atmospheric Aerosols by Mass Spectrometry written by Anas Rasheed and published by Createspace Independent Publishing Platform. This book was released on 2015-09-19 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microscopic aerosol particles are a ubiquitous part of the earth's atmosphere. They are produced in vast numbers by both human activity (anthropogenic) and natural sources and subsequently modified by a multitude of processes. They are known to be crucially important in many issues that directly affect everyday life, which include respiratory health, visibility, clouds, rainfall, atmospheric chemistry and global and regional climate, but they are also one of the more poorly understood aspects of the atmosphere.

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:

Download or read book Characterization of Particulate Pollution by Aerosol Mass Spectrometry written by Courtney Leigh Herring and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols impact human health, climate, and air pollution and arrive in the atmosphere by countless number of sources. One of the largest uncertainties in understanding these impacts is due to limitations in our understanding of the organic aerosol (OA) components. To understand this complex mixture of thousands of compounds accurate high-resolution chemical speciation is needed. An Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS or HR-AMS) was deployed in two separate month-long studies to measure atmospheric particulate pollution. The first study, at the Lovelace Respiratory Research Institute (LRRI), focused on the measurement of gasoline and diesel engine exhaust under various loads and dilutions in controlled chamber experiments. HR-AMS data demonstrated clean signal associated with 53 polycyclic aromatic hydrocarbon (PAH) compounds. PAHs are of interest due to their carcinogenic implication and negative health effects especially when associated with submicron particles. From this work a novel methodology was developed for quantifying these compounds by their molecular ion signal (P-MIP). In the second study, conducted in Yakima, WA, ambient wintertime pollution was characterized and the OA components were deconvolved using positive matrix factorization (PMF). This investigation resulted in the identification of two new amine associated factors which were identified by mass spectra peaks from six dominant amine ions (C3H8N+, C2H6N2+, C4H 10N+, C3H8N2 +, C5H12N+, and C6H 14N+). Amine ions are of interest to atmospheric research because of their implications on climate and formation of new particles. The unifying implication from both studies was the utilization of the HR-AMS to identify atmospheric pollutants that continue to generate ongoing research interests (due to their impacts on climate, pollution, or human health) and are typically difficult to measure by the HR-AMS. Additionally, included in this dissertation are four examples of science/engineering related inquiry-based lessons that were developed to relate well with my own Master's research field and implemented into three high school science and math classrooms over the course of a two year NSF STEM Fellowship. Lastly, a two-year long case study following qualitative and quantitative data from 296 students one of these activities provides examples of the positive impact by these types of developed activities.

Download or read book Chemical and Physical Characterization of Secondary Organic Aerosol Formation from Select Agricultural Emissions written by Quentin Gerald James Malloy and published by . This book was released on 2009 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Chemical Characterization and Source Apportionment of Atmospheric Aerosols in Urban and Rural Regions written by Caroline Parworth and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols, or particulate matter (PM), can affect climate through scattering and absorption of radiation and influence the radiative properties, precipitation efficiency, thickness, and lifetime of clouds. Aerosols are one of the greatest sources of uncertainty in climate model predictions of radiative forcing. To fully understand the sources of uncertainty contributing to the radiative properties of aerosols, measurements of PM mass, composition, and size distribution are needed globally and seasonally. To add to the current understanding of the seasonal and temporal variations in aerosol composition and chemistry, this study has focused on the quantification, speciation, and characterization of atmospheric PM in urban and rural regions of the United States (US) for short and long periods of time. In the first two chapters, we focus on 1 month of aerosol and gas-phase measurements taken in Fresno, CA, an urban and agricultural area, during the National Aeronautics and Space Administration's (NASA) field study called DISCOVER-AQ. This air quality measurement supersite included a plethora of highly detailed chemical measurements of aerosols and gases, which were made at the same time as similar aircraft column measurements of aerosols and gases. The goal of DISCOVER-AQ is to improve the interpretation of satellite observations to approximate surface conditions relating to air quality, which can be achieved by making concurrent ground- and aircraft-based measurements of aerosols and gases. We begin in chapter 2 by exploring the urban aerosol and gas-phase dataset from the NASA DISCOVER-AQ study in California. Specifically, we discuss the chemical composition and mass concentration of water-soluble PM2.5 that were measured using a particle-into-liquid sampler with ion chromatography (PILS-IC) in Fresno, California from January 13–February 10, 2013. This data was analyzed for ionic inorganic species, organic acids and amines. Gas-phase species including HNO3 and NH3 were collected with annular denuders and analyzed using ion chromatography. Using the thermodynamic E-AIM model, inorganic particle water mass concentration and pH were calculated for the first time in this area. Organic particle water mass concentration was calculated from [kappa]-Köhler theory. In chapter 3 further analysis of the aerosol- and gas-phase data measured during DISCOVER-AQ was performed to determine the effectiveness of a local residential wood burning curtailment program in improving air quality. Using aerosol speciation and concentration measurements from the 2013 winter DISCOVER-AQ study in Fresno, CA, we investigate the impact of residential wood burning restrictions on fine particulate mass concentration and composition. Key species associated with biomass burning in this region include K+, acetonitrile, black carbon, and biomass burning organic aerosol (BBOA), which represents primary organic aerosol associated with residential wood burning. Reductions in acetonitrile associated with wood burning restrictions even at night were not observed and most likely associated with stagnant conditions during curtailment periods that led to the buildup of this long-lived gas. In chapter 4 we transition to the rural aerosol dataset from the DOE SGP site. We discuss the chemical composition and mass concentration of non-refractory submicron aerosols (NR-PM1) that were measured with an aerosol chemical speciation monitor (ACSM) at the DOE SGP site from November 2010 through June 2012. Positive matrix factorization (PMF) was performed on the measured organic aerosol (OA) mass spectral matrix using a newly developed rolling window technique to derive factors associated with distinct sources, evolution processes, and physiochemical properties. The rolling window approach captured the dynamic variations of the chemical properties of the OA factors over time. Three OA factors were obtained including two oxygenated OA (OOA) factors, differing in degrees of oxidation, and a BBOA factor. Sources of NR-PM1 species at the SGP site were determined from back trajectory analyses. NR-PM1 mass concentration was dominated by organics for the majority of the study with the exception of winter, when NH4N33 increased due to transport of precursor species from surrounding urban and agricultural regions and also due to cooler temperatures. Chapter 5 is a continuation of chapter 4, where we will explore the use of the multilinear engine (ME-2) as a factor analysis technique, which is an algorithm used for solving the bilinear model called positive matrix factorization (PMF). The importance of ME-2 and its potential application on the long-term aerosol chemical speciation monitor (ACSM) data collected from the Department of Energy (DOE) Southern Great Plains (SPG) site will be discussed. ME-2 was performed on 19 months of OA mass spectral data obtained from the ACSM at the SGP site. Evaluation of ME-2 results are presented, followed by comparison of ME-2 factor results with corresponding OACOMP factor results reported in chapter 4. We show that ME-2 can determine a biomass burning organic aerosol (BBOA) factor during periods when OACOMP cannot. (Abstract shortened by ProQuest.)