subject:(organic aerosol)

Texas A&M University

1. Milan, Cassandra Faye. Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles.

Degree: MS, Atmospheric Sciences, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/174049

► Many first and second generation products from oxidation of volatile organic compounds are water soluble, allowing for participation in aqueous phase chemistry. Secondary organic aerosol… (more)

Subjects/Keywords: Secondary; Organic; Aerosol

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APA (6^th Edition):

Milan, C. F. (2018). Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174049

Chicago Manual of Style (16^th Edition):

Milan, Cassandra Faye. “Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles.” 2018. Masters Thesis, Texas A&M University. Accessed March 01, 2021. http://hdl.handle.net/1969.1/174049.

MLA Handbook (7^th Edition):

Milan, Cassandra Faye. “Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles.” 2018. Web. 01 Mar 2021.

Vancouver:

Milan CF. Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1969.1/174049.

Council of Science Editors:

Milan CF. Secondary Organic Aerosol Yield from Acetylene Oxidation During Cloud Processing Cycles. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174049

Carnegie Mellon University

2. Karnezi, Eleni. Volatility and Chemical Aging of Atmospheric Organic Aerosol.

Degree: 2017, Carnegie Mellon University

URL: http://repository.cmu.edu/dissertations/812

► Organic particulate matter represents a significant fraction of sub-micrometer atmospheric aerosol mass. However, organic aerosol (OA) consists of thousands of different organic compounds making the… (more)

▼ Organic particulate matter represents a significant fraction of sub-micrometer atmospheric aerosol mass. However, organic aerosol (OA) consists of thousands of different organic compounds making the simulation of its concentration, chemical evolution, physical and chemical properties extremely challenging. The identity of the great majority of these compounds remains unknown. The volatility of atmospheric OA is one of its most important physical properties since it determines the partitioning of these organic compounds between the gas and particulate phases. The use of lumped compounds with averaged properties is a promising solution for the representation of OA in atmospheric chemical transport models. The two-dimensional volatility basis set (2D-VBS) is a proposed method used to describe OA distribution as a function of the volatility and oxygen content of the corresponding compounds. In the first part of the work we evaluate our ability to measure the OA volatility distribution using a thermodenuder (TD). We use a new method combining forward modeling, introduction of ‘experimental’ error and inverse modeling with error minimization for the interpretation of TD measurements. The OA volatility distribution, its effective vaporization enthalpy, the mass accommodation coefficient and the corresponding uncertainty ranges are calculated. Our results indicate that existing TD-based approaches quite often cannot estimate reliably the OA volatility distribution, leading to large uncertainties, since there are many different combinations of the three properties that can lead to similar thermograms. We propose an improved experimental approach combining TD and isothermal dilution measurements. We evaluate this experimental approach using the same model and show that it is suitable for studies of OA volatility in the lab and the field. Measurements combining a thermodenuder (TD) and a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) took place during summer and winter in Paris, France as part of the collaborative project MEGAPOLI and during the winter of 2013 in the city of Athens. The above volatility estimation method with the uncertainty estimation algorithm is applied to these datasets in order to estimate the volatility distribution for the organic aerosol (OA) and its components during the two campaigns. The concentrations of the OA components as a function of temperature were measured combining data from the thermodenuder and the aerosol mass spectrometer (AMS) with Positive Matrix Factorization (PMF) analysis. Combining the bulk average O:C ratios and volatility distributions of the various factors, our results are placed into the two-dimensional volatility basis set (2D-VBS) framework. The OA factors cover a broad spectrum of volatilities with no direct link between the average volatility and average O:C of the OA components. An intercomparison among the OA components of both campaigns and their physical properties is also presented. The approach combining thermodenuder and isothermal dilution…

Subjects/Keywords: Chemical aging; Organic aerosol; Volatility

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APA (6^th Edition):

Karnezi, E. (2017). Volatility and Chemical Aging of Atmospheric Organic Aerosol. (Thesis). Carnegie Mellon University. Retrieved from http://repository.cmu.edu/dissertations/812

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Karnezi, Eleni. “Volatility and Chemical Aging of Atmospheric Organic Aerosol.” 2017. Thesis, Carnegie Mellon University. Accessed March 01, 2021. http://repository.cmu.edu/dissertations/812.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Karnezi, Eleni. “Volatility and Chemical Aging of Atmospheric Organic Aerosol.” 2017. Web. 01 Mar 2021.

Vancouver:

Karnezi E. Volatility and Chemical Aging of Atmospheric Organic Aerosol. [Internet] [Thesis]. Carnegie Mellon University; 2017. [cited 2021 Mar 01]. Available from: http://repository.cmu.edu/dissertations/812.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Karnezi E. Volatility and Chemical Aging of Atmospheric Organic Aerosol. [Thesis]. Carnegie Mellon University; 2017. Available from: http://repository.cmu.edu/dissertations/812

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto

3. Willis, Megan Drake. Natural and Anthropogenic Influences on High Arctic Aerosol.

Degree: PhD, 2018, University of Toronto

URL: http://hdl.handle.net/1807/82953

► The Arctic is a harbinger of global change, and is warming at a rate twice the global average. While Arctic warming is driven by increased… (more)

▼ The Arctic is a harbinger of global change, and is warming at a rate twice the global average. While Arctic warming is driven by increased greenhouse gases, short-lived climate forcers such as tropospheric ozone and aerosol are important drivers of Arctic climate. Aerosol impacts on Arctic climate are insufficiently understood, largely owing to poor constraints on the physical and chemical processes controlling aerosol. This thesis presents observations of sub-micron aerosol in Arctic summer and spring, which capture different regimes of the Arctic aerosol seasonal cycle. Aircraft-based observations of aerosol physical and chemical properties address various aspects of Arctic aerosol sources, removal and chemical processing. Under chronic Arctic Haze conditions in spring, we observed evidence for vertical variations in both aerosol sources and removal mechanisms. We show evidence for sources of partially neutralized aerosol with higher organic aerosol (OA) and black carbon content in the mid-troposphere and sources of acidic sulfate in the lower troposphere. With support from model calculations, we demonstrate that mid-tropospheric air influences the Arctic Boundary Layer (ABL) on ~1-week time scales. We observed evidence for aerosol depletion relative to carbon monoxide, both in the mid-to-upper troposphere and within the ABL. Dry deposition, with low removal efficiency, contributed to aerosol removal in the ABL while precipitation scavenging contributed to efficient aerosol removal during transport at higher altitudes. Under clean Arctic background conditions in summer, we observed evidence for marine influenced secondary OA formation. We demonstrated a relationship between methansulfonic acid and OA with the residence time of air over open water. Sea salt aerosol was externally mixed from a larger number fraction of OA, sulfate and amine-containing particles. High OA fractions coincided with elevated cloud condensation nuclei (CCN) concentrations, suggesting a role for secondary OA formation in growing particles to CCN-active sizes. A case study of aerosol growth over open water supports these observations. This work contributes to our understanding of aerosol vertical variability and its connection to observations made at the surface in Arctic spring and, to our understanding of aerosol sources and composition in Arctic summer. Advisors/Committee Members: Jonathan, Abbatt PD, Chemistry.

Subjects/Keywords: aerosol; aerosol mass spectrometry; Arctic; long range transport; organic aerosol; 0725

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APA (6^th Edition):

Willis, M. D. (2018). Natural and Anthropogenic Influences on High Arctic Aerosol. (Doctoral Dissertation). University of Toronto. Retrieved from http://hdl.handle.net/1807/82953

Chicago Manual of Style (16^th Edition):

Willis, Megan Drake. “Natural and Anthropogenic Influences on High Arctic Aerosol.” 2018. Doctoral Dissertation, University of Toronto. Accessed March 01, 2021. http://hdl.handle.net/1807/82953.

MLA Handbook (7^th Edition):

Willis, Megan Drake. “Natural and Anthropogenic Influences on High Arctic Aerosol.” 2018. Web. 01 Mar 2021.

Vancouver:

Willis MD. Natural and Anthropogenic Influences on High Arctic Aerosol. [Internet] [Doctoral dissertation]. University of Toronto; 2018. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1807/82953.

Council of Science Editors:

Willis MD. Natural and Anthropogenic Influences on High Arctic Aerosol. [Doctoral Dissertation]. University of Toronto; 2018. Available from: http://hdl.handle.net/1807/82953

University of Florida

4. Jiang, Huanhuan. Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays.

Degree: PhD, Environmental Engineering Sciences, 2018, University of Florida

URL: https://ufdc.ufl.edu/UFE0052126

► Epidemiological studies have linked human exposure to PM2.5 (aerodynamic meter < 2.5 micrometers) to an increase of morbidity and mortality from respiratory and cardiovascular diseases.… (more)

▼ Epidemiological studies have linked human exposure to PM2.5 (aerodynamic meter < 2.5 micrometers) to an increase of morbidity and mortality from respiratory and cardiovascular diseases. However, the toxicity mechanism of OA is still unclear. In this study, a series of cell-free assays have been developed to clarify the potential influence of OA on biological systems. DTT assay was applied to measure the oxidative potential (the ability of OA to oxidize cellular materials) of OA. The mass-normalized DTT consumption rate (DTTm) of secondary organic aerosol (SOA) varied with the type of the precursor and was positively correlated to the cellular expression of IL-8. The possible contributors to DTTm of OA including catalytic oxidizers (quinones) and non-catalytic oxidizers (organic hydroperoxides or OHP, peroxyacyl nitrates or PAN and electron-deficient alkenes). The significance of quinones to the DTT response of SOA derived from individual hydrocarbons (toluene, isoprene, TMB and alpha-pinene) was found to be negligible. OHP and electron-deficient carbonyls were the major contributors to the DTTm of toluene SOA. OHP contributed exclusively to the DTTm of isoprene SOA. A significant NOx effect was observed on the DTTm of isoprene SOA; the increase of NOx level led to a significant decrease of OHP and thereby DTTm, due to the suppression of OHP formation from RO2+OH reaction in the presence of high NOx. There was an appreciable atmospheric aging effect on the chemical compositions of OA and their DTTm; the DTTm of all studied OA (wood smoke particles, gasoline SOA, toluene SOA, isoprene SOA and alpha-pinene SOA) was found to be lower with a longer aging time, regardless of NOx conditions. Both dithiol (DTT) and monothiol compounds (cysteine, 2-mercaptoethanol) have been used to investigate the interaction between OA and thiol groups. For example, the DTT responses of toluene SOA was higher than the corresponding cysteine or 2-mercaptoethanol responses. Thus, the results can be biased if only DTT assay was used to measure the oxidative potential of OA. ( en ) Advisors/Committee Members: JANG,MYOSEON (committee chair), HORENSTEIN,NICOLE ALANA (committee member), SABO-ATTWOOD,TARA L (committee member).

Subjects/Keywords: cell-free-assay – organic-aerosol – oxidative-potential – secondary-organic-aerosol – toxicity

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APA (6^th Edition):

Jiang, H. (2018). Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays. (Doctoral Dissertation). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0052126

Chicago Manual of Style (16^th Edition):

Jiang, Huanhuan. “Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays.” 2018. Doctoral Dissertation, University of Florida. Accessed March 01, 2021. https://ufdc.ufl.edu/UFE0052126.

MLA Handbook (7^th Edition):

Jiang, Huanhuan. “Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays.” 2018. Web. 01 Mar 2021.

Vancouver:

Jiang H. Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays. [Internet] [Doctoral dissertation]. University of Florida; 2018. [cited 2021 Mar 01]. Available from: https://ufdc.ufl.edu/UFE0052126.

Council of Science Editors:

Jiang H. Determination of Molecular Mechanisms of Organic Aerosols on PM Toxicity Using Cell-Free Assays. [Doctoral Dissertation]. University of Florida; 2018. Available from: https://ufdc.ufl.edu/UFE0052126

Texas A&M University

5. Deng, Chunhua. Chemical Composition and Cloud Nucleation Ability of Marine Aerosol.

Degree: PhD, Atmospheric Sciences, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/151824

► This study is focused on the chemical composition and cloud nucleation ability of marine aerosol based on two cruise researches over Pacific Ocean and North… (more)

▼ This study is focused on the chemical composition and cloud nucleation ability of marine aerosol based on two cruise researches over Pacific Ocean and North Atlantic Ocean respectively. Implications of CLAW hypothesis and the factors influencing its validity are analyzed for the contemporary era with ever-increasing pollution. The pacific cruise started from Punta Arenas, Chile and ended in Seattle, WA during March-April of 2010. Raman microspectroscopy (RMS) was employed to identify the chemical composition and mixing conditions of single particles collected. By analyzing multiple particles in a collected ensemble, the degree of external/internal mixing of particles was also determined. Atmospheric aerosol concentration, cloud condensation nuclei (CCN) concentration, and chlorophyll a concentration in the underlying water (a metric for phytoplankton biomass in the ocean), were also measured. Our results indicate that long chain organic molecules were prevalent in the marine aerosol samples throughout the cruise. Long chain organic compounds tended to stay mixed with other organic and inorganic components. The influence of marine organic aerosols on cloud nucleation ability is analyzed. The North Atlantic cruise started from Woods Hole, MA and returned back to the same location during June-July 2011. The cruise passed through a wide range of conditions, including areas of high phytoplankton biomasses and extremely high DMS levels (over 1800 pptv). Aerosol concentration, cloud condensation nuclei (CCN) concentration, particle size distribution, as well as surface seawater and atmospheric DMS concentrations were performed simultaneously during the cruise. HYSPLIT back trajectories were used to classify air mass origins. Even though continental sources increased the total aerosol population, it depressed the effective CCN concentrations possibly due to the competition in particle growth. Continuous high CCN and elevated DMS concentrations over the open ocean occur concurrently, which can be explained by enhanced nucleation and condensational growth of aerosols in marine boundary layer (MBL) resulting from the DMS oxidation or primary aerosols from the sea surface. Our data also indicated that uncertainties remain in sea spray aerosol production flux function, especially for particles with dry diameter smaller than 200 nm. Advisors/Committee Members: Brooks, Sarah D. (advisor), Collins, Don R. (committee member), Ying, Qi (committee member), Schumacher, Russ (committee member).

Subjects/Keywords: marine aerosol; cloud condensation nuclei; sea spray aerosol; dimethyl sulfide; organic aerosol; Raman microspectroscopy

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APA (6^th Edition):

Deng, C. (2013). Chemical Composition and Cloud Nucleation Ability of Marine Aerosol. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151824

Chicago Manual of Style (16^th Edition):

Deng, Chunhua. “Chemical Composition and Cloud Nucleation Ability of Marine Aerosol.” 2013. Doctoral Dissertation, Texas A&M University. Accessed March 01, 2021. http://hdl.handle.net/1969.1/151824.

MLA Handbook (7^th Edition):

Deng, Chunhua. “Chemical Composition and Cloud Nucleation Ability of Marine Aerosol.” 2013. Web. 01 Mar 2021.

Vancouver:

Deng C. Chemical Composition and Cloud Nucleation Ability of Marine Aerosol. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1969.1/151824.

Council of Science Editors:

Deng C. Chemical Composition and Cloud Nucleation Ability of Marine Aerosol. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151824

Texas A&M University

6. Matus, Jillianne Rene. A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite.

Degree: MS, Atmospheric Sciences, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/169571

► Models that seek to calculate the effect of aerosol on climate must take into account both primary and secondary sources of aerosol, as well as… (more)

Subjects/Keywords: Secondary Organic Aerosol; particle shrinkage; nighttime aerosol growth

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APA (6^th Edition):

Matus, J. R. (2017). A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/169571

Chicago Manual of Style (16^th Edition):

Matus, Jillianne Rene. “A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite.” 2017. Masters Thesis, Texas A&M University. Accessed March 01, 2021. http://hdl.handle.net/1969.1/169571.

MLA Handbook (7^th Edition):

Matus, Jillianne Rene. “A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite.” 2017. Web. 01 Mar 2021.

Vancouver:

Matus JR. A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1969.1/169571.

Council of Science Editors:

Matus JR. A Study of the Nighttime Growth of Secondary Organic Aerosol Using the Captive Aerosol Growth and Evolution Instrument Suite. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/169571

Rice University

7. Karakurt Cevik, Basak. Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX.

Degree: MS, Engineering, 2013, Rice University

URL: http://hdl.handle.net/1911/71290

► The composition, concentration, and size of submicron aerosols were measured with a time resolution of five minutes by an Aerodyne high-resolution time-of-flight aerosol mass spectrometer… (more)

Subjects/Keywords: Atmospheric aerosols; Urban aerosol; Photochemical age; Organic aerosol

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APA (6^th Edition):

Karakurt Cevik, B. (2013). Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX. (Masters Thesis). Rice University. Retrieved from http://hdl.handle.net/1911/71290

Chicago Manual of Style (16^th Edition):

Karakurt Cevik, Basak. “Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX.” 2013. Masters Thesis, Rice University. Accessed March 01, 2021. http://hdl.handle.net/1911/71290.

MLA Handbook (7^th Edition):

Karakurt Cevik, Basak. “Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX.” 2013. Web. 01 Mar 2021.

Vancouver:

Karakurt Cevik B. Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX. [Internet] [Masters thesis]. Rice University; 2013. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1911/71290.

Council of Science Editors:

Karakurt Cevik B. Comparison of estimates of airmass aging using particle and other measurements near Fort Worth, TX. [Masters Thesis]. Rice University; 2013. Available from: http://hdl.handle.net/1911/71290

Johannes Gutenberg Universität Mainz

8. Schott, Mathias. Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol.

Degree: 2008, Johannes Gutenberg Universität Mainz

URL: http://ubm.opus.hbz-nrw.de/volltexte/2010/2222/

►

Diese Arbeit präsentiert Forschungsergebnisse der beiden wissenschaftlichen Projekte POLYSOA und OOMPH. Für das POLYSOA-Projekt, welches sich mit der Oligomerbildung in sekundären organischen Aerosolen befasst, wurden… (more)

▼

Diese Arbeit präsentiert Forschungsergebnisse der beiden wissenschaftlichen Projekte POLYSOA und OOMPH. Für das POLYSOA-Projekt, welches sich mit der Oligomerbildung in sekundären organischen Aerosolen befasst, wurden zwei Dicarbonylverbindungen bezüglich ihres Oligomerisationsverhaltens untersucht. Hierfür wurden zunächst verschiedene Herstellungsmethoden für die reinen, wasserfreien Monomere Glyoxal (Ethandial) und Methylglyoxal (2-Oxopropanal) erprobt. Diese wurden mit Reinstwasser umgesetzt und die Reaktionsprodukte massenspektrometrisch mittels Direktinfusion in ein ESI-MS untersucht. Es wurde bei den wässrigen Lösungen von Glyoxal eine starke Tendenz zur Oligomerbildung beobachtet. Die Zusammensetzung dieser Acetal-Oligomere wurde durch MS2-Experimente analysiert. Methylglyoxal bildete bei den durchgeführten Experimenten ebenfalls bei der Reaktion mit Wasser Oligomere. Zum Ausschluss, dass es sich bei den mittels ESI-MS gemessenen Oligomer-Ionen nicht um Ionenquellenartefakte handelte, wurde eine HPLC-Trennung vorgenommen. Diese Experimente ergaben, dass es sich nicht um Artefakte handelt. Als Teil des OOMPH-Projekts wurden mit einem Aerodyne-HRToF-AMS Messungen an Bord des französischem Forschungsschiffes RV Marion Dufresne durchgeführt. Um detaillierte Informationen über die hierbei im organischen Aerosol enthaltenen Moleküle zu erhalten wurde eine neue Methode entwickelt. Es wurde eine Ionenliste erstellt, die mögliche Fragment-Ionen sowie deren exakte Masse enthält. Reihen von homologen Ionen wurden in Gruppen zusammengefasst. Ein selbstentwickelter Algorithmus berechnet die Signalanteile der einzelnen Ionen aus der Ionenliste am Gesamtsignal. Die erhaltenen einzelnen Signalanteile wurden entsprechend den Ionengruppen zusammengefasst. Hieraus können Informationen über die im Aerosol enthaltenen Molekülbausteine erhalten werden. Im OOMPH-Datensatz konnten so Aerosole verschiedener chemischer Zusammensetzung unterschieden werden. Ein Rückschluss auf einzelne Moleküle kann jedoch nicht gezogen werden.

This thesis contains results of two different projects: POLYSOA and OOMPH. For POLYSOA the reactions of alpha-dicarbonylic compounds were investigated by preparing pure monomeric compounds of glyoxal and methylglyoxal. Further reactions with water were monitored using ESI-MS. During these experiments a strong tendency towards the formation of oligomers could be observed. The composition of the oligomers was analysed by MSn experiments. HPLC-ESI-MS measurements could exclude artefacts during this process and unambigiously showed the covalent nature of the oligomeric ions. Our main goal for OOMPH was the interpretation of AMS field data taken during the cruise MD158 with the french research vessel RV Marion Dufresne across the southern atlantic ocean. To gain more information on the organic aerosol fraction a new dataprocessing method was developed. Therefore possible fragment ions were compiled and arranged by their general chemical composition. With a self implemented peak integration algorithm the fractions…

Subjects/Keywords: Massenspektrometrie; Glyoxal; sekundäres organisches Aerosol; marines Aerosol; AMS; massspectrometry; glyoxal; secondary organic aerosol; marine aerosol; AMS; Chemistry and allied sciences

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APA (6^th Edition):

Schott, M. (2008). Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol. (Doctoral Dissertation). Johannes Gutenberg Universität Mainz. Retrieved from http://ubm.opus.hbz-nrw.de/volltexte/2010/2222/

Chicago Manual of Style (16^th Edition):

Schott, Mathias. “Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol.” 2008. Doctoral Dissertation, Johannes Gutenberg Universität Mainz. Accessed March 01, 2021. http://ubm.opus.hbz-nrw.de/volltexte/2010/2222/.

MLA Handbook (7^th Edition):

Schott, Mathias. “Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol.” 2008. Web. 01 Mar 2021.

Vancouver:

Schott M. Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol. [Internet] [Doctoral dissertation]. Johannes Gutenberg Universität Mainz; 2008. [cited 2021 Mar 01]. Available from: http://ubm.opus.hbz-nrw.de/volltexte/2010/2222/.

Council of Science Editors:

Schott M. Massenspektrometrische Untersuchungen zur Aufklärung der Bildungsmechanismen von Oligomeren in sekundärem organischen Aerosol und zur Zusammensetzung von marinem Hintergrund-Aerosol. [Doctoral Dissertation]. Johannes Gutenberg Universität Mainz; 2008. Available from: http://ubm.opus.hbz-nrw.de/volltexte/2010/2222/

Colorado State University

9. Berg, Ashley R. Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The.

Degree: MS(M.S.), Atmospheric Science, 2012, Colorado State University

URL: http://hdl.handle.net/10217/71616

► Over the last decade, an extensive beetle outbreak has impacted western North America resulting in the mortality of over 100,000 km2 of forest throughout British… (more)

▼ Over the last decade, an extensive beetle outbreak has impacted western North America resulting in the mortality of over 100,000 km2 of forest throughout British Columbia and the western United States. Climate change has aided the expansion and continuation of this beetle infestation for more than a decade as beetles survive milder winters and expand northward and to higher elevation areas. Studies have been conducted to investigate the impact of this disturbance on forest carbon stocks, beetle-fire interactions, and meteorological variables, as well as to affirm the importance of including beetle infestation in models. In recent years there has been increased interest in the impact of beetle mortality and attack on atmospheric composition. Numerous studies have demonstrated that insect attack can prompt elevated emissions of volatile organic compounds (VOCs) in a variety of plant and tree species, including mountain pine beetle attacking lodgepole pine, the main beetle-host combination in the current outbreak. These enhanced VOC emissions are likely a defense mechanism of the tree, consisting of increasing emissions of compounds that are toxic to the beetles and attract predators of the beetles as well as increasing sap flow to help remove beetles from the trunk. This impact has not yet been modeled; however, beetle attack may have a significant impact on atmospheric composition and air quality in western North America. In this study, we use 14 years of beetle mortality data for 13 beetle species and beetle-induced monoterpene concentration data in the NCAR Community Earth System Model (CESM) to investigate the impact of beetle mortality and attack on monoterpene emissions and secondary organic aerosol (SOA) formation in western North America. Needleleaf vegetation is decreased each year based on the annual mortality data while emissions of certain compounds in needleleaf trees under attack are scaled-up based on recent beetle-induced VOC data for lodgepole pine (pine scenario) and Engelmann spruce (spruce scenario). As the mountain pine beetle has had the most extensive impact on mortality, we compare changes in emissions of VOCs and subsequent SOA formation caused by the mountain pine beetle to changes caused by the other 12 beetles combined. Beetle infestation impacts monoterpene emissions through both decreased emissions as trees are killed off (mortality effect) and increased emissions in trees under attack (attack effect). Regionally, beetle infestation may have a significant impact on monoterpene emissions and SOA concentrations with up to a 4-fold increase in monoterpene emissions and up to a 40% increase in SOA concentrations in some years. Responses to beetle attack can vary greatly over space and time as the areas affected as well as the magnitude of the impact depend on the extent of previous mortality and the number of trees under attack in a year. The model captures highly localized impacts on smaller-scales, while on larger-scales, the cumulative mortality effect often mutes the ongoing… Advisors/Committee Members: Heald, Colette L. (advisor), Collett, Jeffrey L. (committee member), Farmer, Delphine K. (committee member).

Subjects/Keywords: pine beetle; monoterpene; secondary organic aerosol

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APA (6^th Edition):

Berg, A. R. (2012). Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/71616

Chicago Manual of Style (16^th Edition):

Berg, Ashley R. “Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The.” 2012. Masters Thesis, Colorado State University. Accessed March 01, 2021. http://hdl.handle.net/10217/71616.

MLA Handbook (7^th Edition):

Berg, Ashley R. “Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The.” 2012. Web. 01 Mar 2021.

Vancouver:

Berg AR. Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The. [Internet] [Masters thesis]. Colorado State University; 2012. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/10217/71616.

Council of Science Editors:

Berg AR. Impact of pine beetle infestation on monoterpene emissions and secondary organic aerosol formation in western North America, The. [Masters Thesis]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/71616

10. Shank, Lindsey Marie. Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources.

Degree: 2016, University of Hawaii – Manoa

URL: http://hdl.handle.net/10125/101436

►

M.S. University of Hawaii at Manoa 2011.

Studies of organic aerosol (OA) over the equatorial and southern oceans remain underrepresented relative to high and mid-latitudes.… (more)

Subjects/Keywords: organic aerosol

…ammonium sulfate and methanesulfonate are the main aerosol from the primary organic vapor (… …of organic matter (OM) in marine aerosol has been under investigation due to… …organic aerosol (OA) have been observed at sites believed to represent clean marine… …sources of the different sizes of 2 aerosol, as well as several removal mechanisms for each… …lifetimes and removal mechanisms. 1.1.2 Aerosol chemistry Atmospheric particles are composed of…

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APA (6^th Edition):

Shank, L. M. (2016). Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources. (Thesis). University of Hawaii – Manoa. Retrieved from http://hdl.handle.net/10125/101436

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Shank, Lindsey Marie. “Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources.” 2016. Thesis, University of Hawaii – Manoa. Accessed March 01, 2021. http://hdl.handle.net/10125/101436.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Shank, Lindsey Marie. “Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources.” 2016. Web. 01 Mar 2021.

Vancouver:

Shank LM. Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources. [Internet] [Thesis]. University of Hawaii – Manoa; 2016. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/10125/101436.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Shank LM. Organic matter and non-refractory aerosol over the remote Southeast Pacific Ocean : oceanic and combustion sources. [Thesis]. University of Hawaii – Manoa; 2016. Available from: http://hdl.handle.net/10125/101436

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Colorado

11. Ulbrich, Ingrid Marie. Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra.

Degree: PhD, Chemistry & Biochemistry, 2011, University of Colorado

URL: https://scholar.colorado.edu/chem_gradetds/35

► Atmospheric aerosol has impacts on health, visibility, ecosystems, and climate. The organic component of submicron aerosol is a complex mixture of tens of thousands… (more)

Subjects/Keywords: aerosol mass spectrometry; PARAFAC; positive matrix factorization; primary organic aerosol; secondary organic aerosol; Synthetic Data; Applied Mathematics; Atmospheric Sciences; Environmental Sciences

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APA (6^th Edition):

Ulbrich, I. M. (2011). Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/chem_gradetds/35

Chicago Manual of Style (16^th Edition):

Ulbrich, Ingrid Marie. “Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra.” 2011. Doctoral Dissertation, University of Colorado. Accessed March 01, 2021. https://scholar.colorado.edu/chem_gradetds/35.

MLA Handbook (7^th Edition):

Ulbrich, Ingrid Marie. “Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra.” 2011. Web. 01 Mar 2021.

Vancouver:

Ulbrich IM. Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra. [Internet] [Doctoral dissertation]. University of Colorado; 2011. [cited 2021 Mar 01]. Available from: https://scholar.colorado.edu/chem_gradetds/35.

Council of Science Editors:

Ulbrich IM. Characterization of Positive Matrix Factorization Methods and Their Application to Ambient Aerosol Mass Spectra. [Doctoral Dissertation]. University of Colorado; 2011. Available from: https://scholar.colorado.edu/chem_gradetds/35

12. Tsimkouski, I. New methods to study composition and processes of atmospheric organics in the gas and the condensed phase.

Degree: 2015, Universiteit Utrecht

URL: http://dspace.library.uu.nl:8080/handle/1874/302982

► Volatile organic compounds (VOCs) and organic aerosols (OA) play an important role in the Earth’s atmosphere due to their influence on human health and climate.… (more)

▼ Volatile organic compounds (VOCs) and organic aerosols (OA) play an important role in the Earth’s atmosphere due to their influence on human health and climate. To be able to control amounts of VOCs and OA in the atmosphere, one has to understand the main sources of them and the effect of external factors on these sources. While many studies on the main VOC source (i.e. emission from plants) have been performed, there has been only a limited number of studies on how external factors such as environmental pollution effect plant emissions. Historically, OA is measured as bulk organic carbon. Measuring the chemical composition of OA is more challenging but nevertheless essential to fully understand secondary sources and climate effects of aerosols. The goal of this work was the development and validation of new methods that aim at providing new tools for innovative research in the abovementioned field. The first part of this work describes a newly developed setup in order to study the effect of pollution on VOCs emitted by plants. Various pollutants can be applied in the setup. The setup allows for in situ detailed measurements of changes in plant emissions and allows distinguishing isomeric compounds emitted by plants in normal conditions as well as under stress. The setup has been tested based on experiments with birch seedlings: their emissions were measured, oxidized and the oxidation products were measured as well. A reasonable agreement with literature data was observed. The second part of this work describes a new method called offline thermal-desorption proton-transfer-reaction mass-spectrometry (TD-PTR-MS), which allows for detailed and relatively cheap measurements of OA composition based on filter samples which can be collected in a broad range of locations. The method has been tested based on the inter-comparison with the proven in situ technique (in situ TD-PTR-MS) (e.g., Holzinger et al., 2010) and in general a good agreement between the two techniques was confirmed. However, it was found that for the filters sampled for one day, positive sampling artifacts caused by the adsorption of semivolatile organic species on the filters were high, which is in accordance with previous findings described in the literature. For the filters sampled for two and three days slight negative artifacts were observed likely caused by not complete desorption of aerosols off the filters at temperatures up to 3500C and potential chemical degradation of aerosols on the filters. The third part of this work shows the ability of the in situ TD-PTR-MS technique to reasonably measure total OA mass concentrations as well as speciated organics with a time resolution of 0.5 hour. The former is shown based on the comparison with aerosol mass spectrometer (AMS) measurements. The latter is done based on the inter-comparison with two-dimensional gas chromatography with a time-of-flight mass spectrometer (GC×GC/TOF-MS) technique. We found that species with mass concentrations above 2 ng/m3, as measured by GC×GC/TOF-MS, were reasonably… Advisors/Committee Members: Roeckmann, Thomas, Holzinger, Rupert.

Subjects/Keywords: volatile organic compounds; organic aerosol; plant emissions; mass spectrometer

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APA (6^th Edition):

Tsimkouski, I. (2015). New methods to study composition and processes of atmospheric organics in the gas and the condensed phase. (Doctoral Dissertation). Universiteit Utrecht. Retrieved from http://dspace.library.uu.nl:8080/handle/1874/302982

Chicago Manual of Style (16^th Edition):

Tsimkouski, I. “New methods to study composition and processes of atmospheric organics in the gas and the condensed phase.” 2015. Doctoral Dissertation, Universiteit Utrecht. Accessed March 01, 2021. http://dspace.library.uu.nl:8080/handle/1874/302982.

MLA Handbook (7^th Edition):

Tsimkouski, I. “New methods to study composition and processes of atmospheric organics in the gas and the condensed phase.” 2015. Web. 01 Mar 2021.

Vancouver:

Tsimkouski I. New methods to study composition and processes of atmospheric organics in the gas and the condensed phase. [Internet] [Doctoral dissertation]. Universiteit Utrecht; 2015. [cited 2021 Mar 01]. Available from: http://dspace.library.uu.nl:8080/handle/1874/302982.

Council of Science Editors:

Tsimkouski I. New methods to study composition and processes of atmospheric organics in the gas and the condensed phase. [Doctoral Dissertation]. Universiteit Utrecht; 2015. Available from: http://dspace.library.uu.nl:8080/handle/1874/302982

University of California – Berkeley

13. Rollins, Andrew Waite. Formation mechanisms and quantification of organic nitrates in atmospheric aerosol.

Degree: Chemistry, 2010, University of California – Berkeley

URL: http://www.escholarship.org/uc/item/9xx4p21n

► Nitrogen oxides (NO_y) in Earth's troposphere exert control over the production of ozone (O₃) and particulate matter. In this dissertation the role of NO_y in… (more)

Subjects/Keywords: Atmospheric Chemistry; organic aerosol; organic nitrate; reactive nitrogen

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APA (6^th Edition):

Rollins, A. W. (2010). Formation mechanisms and quantification of organic nitrates in atmospheric aerosol. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/9xx4p21n

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Rollins, Andrew Waite. “Formation mechanisms and quantification of organic nitrates in atmospheric aerosol.” 2010. Thesis, University of California – Berkeley. Accessed March 01, 2021. http://www.escholarship.org/uc/item/9xx4p21n.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Rollins, Andrew Waite. “Formation mechanisms and quantification of organic nitrates in atmospheric aerosol.” 2010. Web. 01 Mar 2021.

Vancouver:

Rollins AW. Formation mechanisms and quantification of organic nitrates in atmospheric aerosol. [Internet] [Thesis]. University of California – Berkeley; 2010. [cited 2021 Mar 01]. Available from: http://www.escholarship.org/uc/item/9xx4p21n.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rollins AW. Formation mechanisms and quantification of organic nitrates in atmospheric aerosol. [Thesis]. University of California – Berkeley; 2010. Available from: http://www.escholarship.org/uc/item/9xx4p21n

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University College Cork

14. Chen, Yang. Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde.

Degree: 2012, University College Cork

URL: http://hdl.handle.net/10468/622

► A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its… (more)

▼ A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its photooxidation products, phthaldialdehyde and 1-nitronaphthalene. The measured yields of secondary organic aerosol (SOA) arising from the photooxidation of naphthalene varied from 6-20%, depending on the concentrations of naphthalene and nitrogen oxides as well as relative humidity. A range of carbonyls, nitro-compounds, phenols and carboxylic acids were identified among the gas- and particle-phase products. On-line analysis of the chemical composition of naphthalene SOA was performed using aerosol time-of-flight mass spectrometry (ATOFMS) for the first time. The results indicate that enhanced formation of carboxylic acids may contribute to the observed increase in SOA yields at higher relative humidity. The photolysis of phthaldialdehyde and 1-nitronaphthalene was investigated using natural light at the European Photoreactor (EUPHORE) in Valencia, Spain. The photolysis rate coefficients were measured directly and used to confirm that photolysis is the major atmospheric loss process for these compounds. For phthaldialdehyde, the main gas-phase products were phthalide and phthalic anhydride. SOA yields in the range 2-11% were observed, with phthalic acid and dihydroxyphthalic acid identified among the particle phase products. The photolysis of 1-nitronaphthalene yielded nitric oxide and a naphthoxy radical which reacted to form several products. SOA yields in the range 57-71% were observed, with 1,4-naphthoquinone, 1-naphthol and 1,4-naphthalenediol identified in the particle phase. On-line analysis of the SOA generated in an indoor chamber using ATOFMS provided evidence for the formation of high-molecular-weight products. Further investigations revealed that these products are oxygenated polycyclic compounds most likely produced from the dimerization of naphthoxy radicals. These results of this work indicate that naphthalene is a potentially large source of SOA in urban areas and should be included in atmospheric models. The kinetic and mechanistic information could be combined with existing literature data to produce an overall degradation mechanism for naphthalene suitable for inclusion in photochemical models that are used to predict the effect of emissions on air quality. Advisors/Committee Members: Wenger, John C., EPA.

Subjects/Keywords: Secondary organic aerosol; Photolysis; Atmospheric chemistry; Organic reaction mechanisms; Naphthalene

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APA (6^th Edition):

Chen, Y. (2012). Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde. (Thesis). University College Cork. Retrieved from http://hdl.handle.net/10468/622

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chen, Yang. “Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde.” 2012. Thesis, University College Cork. Accessed March 01, 2021. http://hdl.handle.net/10468/622.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chen, Yang. “Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde.” 2012. Web. 01 Mar 2021.

Vancouver:

Chen Y. Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde. [Internet] [Thesis]. University College Cork; 2012. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/10468/622.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chen Y. Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde. [Thesis]. University College Cork; 2012. Available from: http://hdl.handle.net/10468/622

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Penn State University

15. Altaf, Muhammad Bilal. Size Dependent Morphology of Organic Aerosol.

Degree: 2017, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/13811mba153

► The Earth’s atmosphere is composed of a wide variety of gas phase species and particulate matter that have a large impact on our climate. Though… (more)

▼ The Earth’s atmosphere is composed of a wide variety of gas phase species and particulate matter that have a large impact on our climate. Though our understanding of the climate system has improved significantly over the past few decades, the impact of aerosol particles remains uncertain. Aerosol particles can affect climate through the absorption and scattering of radiation (aerosol direct effect) and by serving as cloud condensation nuclei (aerosol indirect effect). It is known that aerosol particles cause a net cooling effect on the planet, but the magnitude of cooling is unclear and remains under investigation. A large part of this uncertainty is due to an incomplete understanding of the complex physical and chemical properties of aerosol particles such as composition, morphology, and phase state. In this dissertation, we focus on investigating the role of particle size and composition in determining morphology. We have discovered that for some organic aerosol systems, particle morphology depends on size, where small particles are homogeneous and large particles are phase separated. To explore the origins of this size dependent behavior, we have worked with a model organic aerosol system, poly(ethylene glycol)-400 mixed with ammonium sulfate. We have used cryogenic-transmission electron microscopy to probe the effect of phase separation mechanism on particle morphology by varying the organic aerosol composition. Our results suggest that a size dependent morphology occurs due to an activated process, where the presence or absence of an activation barrier to phase separation controls the resulting morphology. We have also explored the kinetics and thermodynamics of the phase separation process that results in a size dependent morphology by varying the experimental drying rates. Drying rates that span over four orders of magnitude were investigated. We have observed that at the fastest drying rates, the size of the transition region where both phase separated and homogeneous morphologies exist is on the order of ~100 nm. At the slowest drying rates, the transition region shifts to smaller diameters and the width narrows to ~3 nm. Our results suggest that a size dependent morphology persists to the slowest drying rates. Thus, we conclude that an underlying thermodynamic effect results in this size dependent behavior, rather than solely a kinetic phenomenon. To determine the atmospheric implications of a size dependent morphology, we have used a cloud condensation nuclei counter to probe the effect of a homogeneous vs. a phase separated morphology on cloud condensation nuclei (CCN) activity. We have found that the activation diameters differ for particles which have the same composition, but varying morphology. Since aerosol optical properties are a sensitive measure of particle structure, we have studied the morphology-resolved optical properties of organic aerosol using cavity ring-down spectroscopy. Our spectroscopy data indicate that the optical properties of core-shell and partially engulfed… Advisors/Committee Members: Miriam Freedman, Dissertation Advisor/Co-Advisor, Miriam Freedman, Committee Chair/Co-Chair, David Boehr, Committee Member, Raymond Schaak, Committee Member, Eugene Clothiaux, Outside Member.

Subjects/Keywords: Aerosol; Organic Aerosol; Transmission Electron Microscopy; Morphology; Phase Separation; Cloud Condensation Nuclei; Cavity Ring-Down Spectroscopy; TEM; Atmospheric Chemistry; Climate; Biogenic Aerosol; Secondary Organic Aerosol

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APA (6^th Edition):

Altaf, M. B. (2017). Size Dependent Morphology of Organic Aerosol. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/13811mba153

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Altaf, Muhammad Bilal. “Size Dependent Morphology of Organic Aerosol.” 2017. Thesis, Penn State University. Accessed March 01, 2021. https://submit-etda.libraries.psu.edu/catalog/13811mba153.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Altaf, Muhammad Bilal. “Size Dependent Morphology of Organic Aerosol.” 2017. Web. 01 Mar 2021.

Vancouver:

Altaf MB. Size Dependent Morphology of Organic Aerosol. [Internet] [Thesis]. Penn State University; 2017. [cited 2021 Mar 01]. Available from: https://submit-etda.libraries.psu.edu/catalog/13811mba153.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Altaf MB. Size Dependent Morphology of Organic Aerosol. [Thesis]. Penn State University; 2017. Available from: https://submit-etda.libraries.psu.edu/catalog/13811mba153

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Colorado

16. Palm, Brett Brian. Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air.

Degree: PhD, Chemistry & Biochemistry, 2017, University of Colorado

URL: https://scholar.colorado.edu/chem_gradetds/224

► Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and… (more)

▼ Secondary organic aerosols (SOA) in the atmosphere play an important role in air quality, human health, and climate. However, the sources, formation pathways, and fate of SOA are poorly constrained. In this dissertation, I present development and application of the oxidation flow reactor (OFR) technique for studying SOA formation from OH, O3, and NO3 oxidation of ambient air. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for this purpose. I first introduce the OFR concept, and discuss several advances I have made in performing and interpreting OFR experiments. This includes estimating oxidant exposures, modeling the fate of low-volatility gases in the OFR (wall loss, condensation, and oxidation), and comparing SOA yields of single precursors in the OFR with yields measured in environmental chambers. When these experimental details are carefully considered, SOA formation in an OFR can be more reliably compared with ambient SOA formation processes. I then present an overview of what OFR measurements have taught us about SOA formation in the atmosphere. I provide a comparison of SOA formation from OH, O3, and NO3 oxidation of ambient air in a wide variety of environments, from rural forests to urban air. In a rural forest, the SOA formation correlated with biogenic precursors (e.g., monoterpenes). In urban air, it correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). In mixed-source regions, the SOA formation did not correlate well with any single precursor, but could be predicted by multilinear regression from several precursors. Despite these correlations, the concentrations of speciated ambient VOCs could only explain approximately 10-50% of the total SOA formed from OH oxidation. In contrast, ambient VOCs could explain all of the SOA formation observed from O3 and NO3 oxidation. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic compounds; S/IVOCs) were present in ambient air and were the likely source of SOA formation that could not be explained by VOCs. These measurements show that S/IVOCs likely play an important intermediary role in ambient SOA formation in all of the sampled locations, from rural forests to urban air. Advisors/Committee Members: Jose-Luis Jimenez, Steven S. Brown, Eleanor Browne, Paul J. Ziemann, Alma Hodzic.

Subjects/Keywords: aerosol; gas phase oxidation; organic aerosol; oxidation flow reactor; potential aerosol mass; secondary organic aerosol; Atmospheric Sciences; Environmental Sciences; Other Oceanography and Atmospheric Sciences and Meteorology

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APA (6^th Edition):

Palm, B. B. (2017). Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/chem_gradetds/224

Chicago Manual of Style (16^th Edition):

Palm, Brett Brian. “Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air.” 2017. Doctoral Dissertation, University of Colorado. Accessed March 01, 2021. https://scholar.colorado.edu/chem_gradetds/224.

MLA Handbook (7^th Edition):

Palm, Brett Brian. “Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air.” 2017. Web. 01 Mar 2021.

Vancouver:

Palm BB. Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air. [Internet] [Doctoral dissertation]. University of Colorado; 2017. [cited 2021 Mar 01]. Available from: https://scholar.colorado.edu/chem_gradetds/224.

Council of Science Editors:

Palm BB. Development and Application of an Oxidation Flow Reactor to Study Secondary Organic Aerosol Formation from Ambient Air. [Doctoral Dissertation]. University of Colorado; 2017. Available from: https://scholar.colorado.edu/chem_gradetds/224

University of California – Riverside

17. Vu, Kennedy- Kiet Tuan. Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer.

Degree: Environmental Toxicology, 2016, University of California – Riverside

URL: http://www.escholarship.org/uc/item/0wk5t87h

► Atmospheric aerosols affect climate, ecosystems, visibility, and human health. However, aerosol sources, atmospheric processing and climate effects still have significant uncertainties. Aerosols have a variety… (more)

▼ Atmospheric aerosols affect climate, ecosystems, visibility, and human health. However, aerosol sources, atmospheric processing and climate effects still have significant uncertainties. Aerosols have a variety of characteristics, in terms of size, morphology, optical properties, and chemical composition owing to their complex nature. The presented work in this thesis summarizes measurements carried out in Mira Loma, CA (2013) and the Colorado Front Range (2014) with the aim to better characterize the local air quality by quantifying the aerosol composition and extinction properties. Here, this thesis will address:(1) Summertime ambient aerosol composition and extinction in Mira Loma, California.In Southern California, pollution is primarily caused by emissions from transportation sources, and are also influenced by topography and meteorology in the area. Specifically, in the Inland Empire, warm, and dry climate promotes the formation of ozone during summer months and eastern portions of the region trap pollution due to mountain induced topography. Aimed with the goal to characterize and understand the summertime composition of ambient aerosols, and the dominant aerosol composition driving aerosol optical extinction (ext), we conducted ground-based measurements from August 17 – September 22, 2013 at the Mira Loma South Coast Air Quality Management District site. OA (54%) was found to be the most dominate aerosol non-refractory species, followed by nitrate (20%) and sulfate (14%). A strong correlation between optical extinction and aerosol nitrate fraction was also observed, indicating that visibility degradation in the eastern Los Angeles Basin is driven by secondary formation of inorganic ammonium nitrate rather than organic aerosol.(2) Impacts of the Denver Cyclone on Air Quality in the Colorado Front Range during the FRAPPÉ 2014 campaign.We present airborne measurements made aboard the NSF C-130 aircraft during the 2014 FRAPPÉ campaign. During the study, a synoptic mesoscale development termed the “Denver Cyclone” was prominent on July 27-28, 2014. The Denver Cyclone has a unique flow structure due to mountain induced circulation, making aircraft measurements critical and insightful to pollution transport patterns during this episode. Our results showed an increase in aerosol mass concentration of OA, NO3-, and SO42-, during the cyclone by as much as 40-80%. Additionally, different aerosol species were found to impact optical extinction (βext) on cyclone vs. non-cyclone periods. Specifically, during the non-cyclone period, OA was responsible for driving βext in the Denver Metropolitan area while in the presence of the cyclone, NO3- influenced βext the most. The overarching objectives of both of these field campaigns is to gain a better understanding of the chemical and physical characteristics of atmospheric aerosols formed from different sources that are responsible for the reduction in the overall air quality. Advanced understanding of aerosol characteristics and the relationships with precursor sources is…

Subjects/Keywords: Atmospheric sciences; Atmospheric chemistry; Environmental science; Aerosol chemical composition; Aerosol Mass Spectrometer; Aerosol Optical Extinction; Aerosols; Ambient Measurements; Secondary Organic Aerosols

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APA (6^th Edition):

Vu, K. K. T. (2016). Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer. (Thesis). University of California – Riverside. Retrieved from http://www.escholarship.org/uc/item/0wk5t87h

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Vu, Kennedy- Kiet Tuan. “Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer.” 2016. Thesis, University of California – Riverside. Accessed March 01, 2021. http://www.escholarship.org/uc/item/0wk5t87h.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Vu, Kennedy- Kiet Tuan. “Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer.” 2016. Web. 01 Mar 2021.

Vancouver:

Vu KKT. Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer. [Internet] [Thesis]. University of California – Riverside; 2016. [cited 2021 Mar 01]. Available from: http://www.escholarship.org/uc/item/0wk5t87h.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Vu KKT. Chemical Composition of Atmospheric Aerosols in Air Quality Field Measurements Using a Compact Time-of-Flight Aerosol Mass Spectrometer. [Thesis]. University of California – Riverside; 2016. Available from: http://www.escholarship.org/uc/item/0wk5t87h

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Manchester

18. Jolleys, Matthew. A global analysis of biomass burning organic aerosol.

Degree: PhD, 2013, University of Manchester

URL: https://www.research.manchester.ac.uk/portal/en/theses/a-global-analysis-of-biomass-burning-organic-aerosol(6dbebe3d-fb4a-4d68-b6c7-83c32ae3fa52).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607109

► Organic aerosols represent one of the main sources of uncertainty affecting attempts to quantify anthropogenic climate change. The diverse physical and chemical properties of organic… (more)

▼ Organic aerosols represent one of the main sources of uncertainty affecting attempts to quantify anthropogenic climate change. The diverse physical and chemical properties of organic aerosols and the varied pathways involved in their formation and aging form the basis of this uncertainty, preventing extensive and accurate representation within regional and global scale models. This inability to constrain the radiative forcings produced by organic aerosols within the atmosphere consequently acts as a limitation to the wider objective of providing reliable projections of future climate. Biomass burning constitutes one of the main anthropogenic contributions to the global atmospheric organic aerosol (OA) burden, particularly in tropical regions where the potential for perturbations to the climate system is also enhanced due to higher average levels of solar irradiance. Emissions from biomass burning have been the subject of an intense research focus in recent years, involving a combination of field campaigns and laboratory studies. These experiments have aimed to improve the limited understanding of the processes involved in the evolution of biomass burning organic aerosol (BBOA) and contribute towards the development of more robust parameterisations for climate and chemical transport models. The main objective of this thesis was to use datasets acquired from several different global regions to perform a broad analysis of the BBOA fraction, with the extensive temporal and spatial scales provided by such measurements enabling investigation of a number of key uncertainties, including regional variability in emissions and the role of secondary organic aerosol (SOA) formation in aging smoke plumes. Measurements of BBOA mass concentration obtained using Aerodyne Research Inc. Aerosol Mass Spectrometers (AMS) were used to calculate characteristic ΔOA/ΔCO ratios for different environments, accounting for the effects of dilution and contrasting fire sizes to give a proportional representation of OA production. High levels of variability in average ΔOA/ΔCO were observed both between and within different regions. The scale of this variability consistently exceeded any differences between plumes of different ages, while a widespread absence of any sustained increase in ΔOA/ΔCO with aging indicates that SOA formation does not provide a net increase in OA mass. Despite this lack of OA enhancement, increasing proportions of oxygenated OA components in aged plumes highlight the chemical transformations occurring during the evolution of BBOA, and the additional influence of OA loss through evaporation or deposition. Potential drivers of variability in ΔOA/ΔCO at source, such as changes in fuel types and combustion conditions, were investigated for controlled fires carried out within a combustion chamber. These laboratory experiments revealed a number of complex relationships between BB emissions and source conditions. Although ΔOA/ΔCO was shown to be influenced by both fuel properties and transitions between flaming and smouldering…

Subjects/Keywords: 621.3815; biomass burning; organic aerosol; emission ratios; aerosol mass spectrometer; aircraft measurements; field campaigns; combustion chamber; aerosol aging

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APA (6^th Edition):

Jolleys, M. (2013). A global analysis of biomass burning organic aerosol. (Doctoral Dissertation). University of Manchester. Retrieved from https://www.research.manchester.ac.uk/portal/en/theses/a-global-analysis-of-biomass-burning-organic-aerosol(6dbebe3d-fb4a-4d68-b6c7-83c32ae3fa52).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607109

Chicago Manual of Style (16^th Edition):

Jolleys, Matthew. “A global analysis of biomass burning organic aerosol.” 2013. Doctoral Dissertation, University of Manchester. Accessed March 01, 2021. https://www.research.manchester.ac.uk/portal/en/theses/a-global-analysis-of-biomass-burning-organic-aerosol(6dbebe3d-fb4a-4d68-b6c7-83c32ae3fa52).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607109.

MLA Handbook (7^th Edition):

Jolleys, Matthew. “A global analysis of biomass burning organic aerosol.” 2013. Web. 01 Mar 2021.

Vancouver:

Jolleys M. A global analysis of biomass burning organic aerosol. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Mar 01]. Available from: https://www.research.manchester.ac.uk/portal/en/theses/a-global-analysis-of-biomass-burning-organic-aerosol(6dbebe3d-fb4a-4d68-b6c7-83c32ae3fa52).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607109.

Council of Science Editors:

Jolleys M. A global analysis of biomass burning organic aerosol. [Doctoral Dissertation]. University of Manchester; 2013. Available from: https://www.research.manchester.ac.uk/portal/en/theses/a-global-analysis-of-biomass-burning-organic-aerosol(6dbebe3d-fb4a-4d68-b6c7-83c32ae3fa52).html ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607109

University of California – Riverside

19. Kacarab, Mary Elizabeth. Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation.

Degree: Chemical and Environmental Engineering, 2016, University of California – Riverside

URL: http://www.escholarship.org/uc/item/4sq547tq

► Secondary organic aerosol (SOA) is formed via the oxidation of volatile organic compounds emitted to the atmosphere from both biogenic and anthropogenic sources. Due to… (more)

▼ Secondary organic aerosol (SOA) is formed via the oxidation of volatile organic compounds emitted to the atmosphere from both biogenic and anthropogenic sources. Due to the complexity of atmospheric composition and range of ambient conditions, aerosol models, which are mostly based off observed yields from controlled laboratory chamber experiments, greatly underestimate global SOA formation. To increase the understanding of the formation and properties of ambient SOA, it is imperative to explore ways to improve the complexity of chamber studies while still maintaining a level of control not found outside of the laboratory.A surrogate mixture of reactive organic gases (ROG) was developed to mimic atmospheric reactivity in an urban environment such as the Los Angeles basin. The ROG mixture controlled the reactivity of the chamber system such that all gas phase species were not heavily affected by the addition of an aerosol forming precursor. The ROG mixture was modified to represent an urban environment with a strong biogenic influence by the addition of isoprene. It was found that isoprene’s behavior in the mixture yielded high aerosol formation compared to previous NOX photo-oxidation studies. Incremental aerosol formation was then defined in the different ROG systems from two aromatic compounds, a monoterpene, and a polyaromatic hydrocarbon. Slightly higher incremental yields were seen from each compound in the biogenic influenced ROG mixture than in the anthropogenic ROG mixture. Furthermore, it was found that the aerosol physical and chemical properties were dictated by the added precursor and were comparable to properties seen in single precursor experiments.The effect of ambient temperature (5°C to 40°C) on aerosol formation was also explored for α-pinene ozonolysis, m-xylene/NOX photo-oxidation, cyclohexene ozonolysis, and vehicle exhaust photo-oxidation with hydroxyl radical. In all systems except the complex vehicle exhaust mixture, severe hysteresis effects were seen in aerosol formation, with the cold temperature systems forming up to 5 times more aerosol mass. These findings do not support traditional gas/particle partitioning theory which assumes temperature effects are reversible. Physical and chemical properties of the aerosol tended to remain fairly consistent, despite changes in ambient temperature.

Subjects/Keywords: Atmospheric chemistry; Environmental engineering; Chemical engineering; Environmental Chamber; Incremental Aerosol Reactivity; Secondary Organic Aerosol

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APA (6^th Edition):

Kacarab, M. E. (2016). Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation. (Thesis). University of California – Riverside. Retrieved from http://www.escholarship.org/uc/item/4sq547tq

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Kacarab, Mary Elizabeth. “Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation.” 2016. Thesis, University of California – Riverside. Accessed March 01, 2021. http://www.escholarship.org/uc/item/4sq547tq.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Kacarab, Mary Elizabeth. “Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation.” 2016. Web. 01 Mar 2021.

Vancouver:

Kacarab ME. Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation. [Internet] [Thesis]. University of California – Riverside; 2016. [cited 2021 Mar 01]. Available from: http://www.escholarship.org/uc/item/4sq547tq.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Kacarab ME. Impacts of Controlling Reactivity and Temperature on Advanced Study of Secondary Organic Aerosol Formation. [Thesis]. University of California – Riverside; 2016. Available from: http://www.escholarship.org/uc/item/4sq547tq

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Carnegie Mellon University

20. Li, Zhongju. Urban Aerosol: Spatiotemporal Variation & Source Characterization.

Degree: 2018, Carnegie Mellon University

URL: http://repository.cmu.edu/dissertations/1125

► Long and short-term exposure to particulate matter (PM) are linked to adverse heath endpoints. Evidence indicates that PM composition such as metals and organic carbon… (more)

▼ Long and short-term exposure to particulate matter (PM) are linked to adverse heath endpoints. Evidence indicates that PM composition such as metals and organic carbon (OC) might drive the health effects. As airborne pollutants show significant intracity spatiotemporal variation, mobile sampling and distributed monitors are utilized to capture the variation pattern. The measurements are then fed to develop models to better characterize the relationship between exposure and health outcomes. Two sampling campaigns were conducted. One was sole mobile sampling in 2013 summer and winter in Pittsburgh, PA. Thirty-six sites were chosen based on three stratification variables: traffic density, proximity to point sources, and elevation. The other one was hybrid sampling network, incorporating a mobile sampling platform, 15 distributed monitors, and a supersite. We designed two case studies (transect and downtown), selected 14 neighborhoods (~1 km2), and conducted sampling in 2016 summer/fall and winter. Spatial variation of PM2.5 mass and composition was studied in the 2013 campaign. X-ray fluorescence (XRF) was used to analyze concentrations of 26 elements: Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Cd, Sb, and Pb. Trace elements had a broad range of concentrations from 0 to 300 ng/m3. Comparison of data from mobile sampling with stationary monitors showed reasonable agreement. We developed Land use regression (LUR) models to describe spatial variation of PM2.5, Si, S, Cl, K, Ca, Ti, Cr, Fe, Cu, and Zn. Independent variables included traffic influence, land-use type, and facility emissions. Models had an average R2 of 0.57 (SD = 0.16). Traffic related variables explained the most variability with an average R2 contribution of 0.20 (SD = 0.20). Overall, these results demonstrated significant intra-urban spatial variability of fine particle composition. Spatial variation of OC was based on the 2013 campaign as well. We collected organic carbon (OC) on quartz filters, quantified different OC components with thermaloptical analysis, and grouped them based on volatility in decreasing order (OC1, OC2, OC3, OC4, and pyrolyzed carbon (PC)). We compared our ambient OC concentrations (both gas and particle phase) to similar measurements from vehicle dynamometer tests, cooking emissions, biomass burning emissions, and a highway traffic tunnel. OC2 and OC3 loading on ambient filters showed a strong correlation with primary emissions while OC4 and PC were more spatially homogenous. While we tested our hypothesis of OC2 and OC3 as markers of fresh source exposure for Pittsburgh, the relationship seemed to hold at a national level. Land use regression (LUR) models were developed for the OC fractions, and models had an average R2 of 0.64 (SD = 0.09). We demonstrate that OC2 and OC3 can be useful markers for fresh emissions, OC4 is a secondary OC indicator, and PC represents both biomass burning and secondary aerosol. People with higher OC exposure are likely inhaling more fresh OC2 and OC3,…

Subjects/Keywords: air pollution; mobile sampling; organic aerosol; source characterization; spatiotemporal variation; urban aerosol

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Li, Z. (2018). Urban Aerosol: Spatiotemporal Variation & Source Characterization. (Thesis). Carnegie Mellon University. Retrieved from http://repository.cmu.edu/dissertations/1125

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Li, Zhongju. “Urban Aerosol: Spatiotemporal Variation & Source Characterization.” 2018. Thesis, Carnegie Mellon University. Accessed March 01, 2021. http://repository.cmu.edu/dissertations/1125.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Li, Zhongju. “Urban Aerosol: Spatiotemporal Variation & Source Characterization.” 2018. Web. 01 Mar 2021.

Vancouver:

Li Z. Urban Aerosol: Spatiotemporal Variation & Source Characterization. [Internet] [Thesis]. Carnegie Mellon University; 2018. [cited 2021 Mar 01]. Available from: http://repository.cmu.edu/dissertations/1125.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Li Z. Urban Aerosol: Spatiotemporal Variation & Source Characterization. [Thesis]. Carnegie Mellon University; 2018. Available from: http://repository.cmu.edu/dissertations/1125

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Vermont

21. Harvey, Rebecca. The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol.

Degree: PhD, Chemistry, 2016, University of Vermont

URL: https://scholarworks.uvm.edu/graddis/556

► Aerosols play important roles in atmospheric and environmental processes. Not only do they impact human health, they also affect visibility and climate. Despite recent… (more)

▼ Aerosols play important roles in atmospheric and environmental processes. Not only do they impact human health, they also affect visibility and climate. Despite recent advances made to under their sources and fate, there remains a limited understanding of the mechanisms that lead to the formation of aerosols and their ultimate fate in the atmosphere. These knowledge gaps provide the crux of the research reported herein, which has focused on identifying novel sources of atmospheric aerosol, characterizing its physical and optical properties, and rationalizing these properties using an in-depth knowledge of the molecular level mechanisms that led to its formation. Upon mowing, turfgrasses emit large amounts of green leaf volatiles which can then be oxidized by ozone to form SOA. Overall, the mowing of lawns has the potential to contribute nearly 50 µg SOA per square meter of lawn mowed. This SOA contribution is on the same order of magnitude as other predominant SOA sources (isoprene, monoterpenes, sesquiterpenes). Turfgrasses represent an interesting and potentially meaningful SOA source because they contribute to SOA and also because they cover large land areas in close proximity to oxidant sources. Another related SOA precursor is sugarcane, which is in the same family as turfgrass and is among the largest agricultural crops worldwide. Globally, the ozonolysis of sugarcane has the potential to contribute 16 Mg SOA to the atmosphere, compared to global estimates of SOA loading that range from 12-70 Tg SOA. In order to fully understand the role of atmospheric SOA on the radiative budget (and therefore climate), it is also important to understand its optical properties; its ability to absorb vs scatter light. Turfgrass and sugarcane produced SOA that was weakly absorbing while its scatter efficiency was wavelength and size-dependent. Interestingly, SOA formed under both dry (10% RH) and wet (70% RH) conditions had the same bulk chemical properties (O:C), yet significantly different optical properties, which was attributed to differences in molecular-level composition. The work presented herein represents a unique, inclusive study of SOA precursors. A complete understanding of the chemistry leading to SOA formation is used to understand its physical and optical properties and evaluate these large-scale effects of SOA from these precursors. Advisors/Committee Members: Giuseppe A. Petrucci.

Subjects/Keywords: atmospheric aerosol; green leaf volatile; ozonolysis; secondary organic aerosol; structure activity relationship; Atmospheric Sciences; Chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Harvey, R. (2016). The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol. (Doctoral Dissertation). University of Vermont. Retrieved from https://scholarworks.uvm.edu/graddis/556

Chicago Manual of Style (16^th Edition):

Harvey, Rebecca. “The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol.” 2016. Doctoral Dissertation, University of Vermont. Accessed March 01, 2021. https://scholarworks.uvm.edu/graddis/556.

MLA Handbook (7^th Edition):

Harvey, Rebecca. “The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol.” 2016. Web. 01 Mar 2021.

Vancouver:

Harvey R. The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol. [Internet] [Doctoral dissertation]. University of Vermont; 2016. [cited 2021 Mar 01]. Available from: https://scholarworks.uvm.edu/graddis/556.

Council of Science Editors:

Harvey R. The Role of Green Leafy Plants in Atmospheric Chemistry: Volatile Emissions and Secondary Organic Aerosol. [Doctoral Dissertation]. University of Vermont; 2016. Available from: https://scholarworks.uvm.edu/graddis/556

Colorado State University

22. Brown, Steven G. Wintertime aerosol in Las Vegas, Nevada.

Degree: PhD, Atmospheric Science, 2014, Colorado State University

URL: http://hdl.handle.net/10217/82507

► Numerous studies have found adverse health effects in subjects who live next to major roadways due to air pollution; in particular, there can be severe… (more)

▼ Numerous studies have found adverse health effects in subjects who live next to major roadways due to air pollution; in particular, there can be severe impacts on lung function and development in children living and/or attending school next to major roadways due to their exposure to air pollutants, including particulate matter (PM) or aerosol. The composition of aerosol at an elementary school next to a major freeway in Las Vegas, Nevada during winter 2008 was measured using a suite of measurements. An Aerodyne High Resolution Aerosol Mass Spectrometer (HR-AMS) was used to quantify the composition of non-refractory PM1 aerosol, including organic matter (OM); an Aethalometer was used to quantify black carbon (BC); a Sunset OCEC analyzer was used to measure organic and elemental carbon (OC, EC); and a particle-into-liquid system (PILS) coupled to two ion chromatographs (IC) was used to measure fine particle ions. Hi-volume PM2.5 samplers were used to collect aerosol on quartz fiber filters at between 2 and 24 hour intervals during the study, a subset of which were analyzed for PAHs and the biomass burning tracer levoglucosan. Data were analyzed by positive matrix factorization (PMF) to determine the amount of fresh, hydrocarbon-like organic aerosol (HOA), more oxidized OA (low-volatility and semi-volatile OA [LV-OOA, SV-OOA]) and biomass burning OA (BBOA). PM1 aerosol was predominantly carbonaceous, with OM plus BC accounting for 74% of the overall average 6.9 μg/m3 of PM measured. BC had a diurnal pattern similar to traffic volume, while OM was higher in the evening compared to the morning. OM was a mixture of fresh HOA, urban- and regional-scale OOA, and BBOA; in the evening, SV-OOA and BBOA peaked, while HOA concentrations were on average the same in the morning and evening, similar to BC. OM/OC ratios were low (1.52 ±0.14 on average) during the morning rush hour (average OM = 2.4 μg/m3) when vehicular emissions dominate this near-road measurement site, and even lower (1.46 ± 0.10) in the evening (average OM=6.3 μg/m3), when a combination of vehicular and fresh residential biomass burning emissions was typically present during a period characterized by strong atmospheric stability. While nitrate and sulfate had size distributions typical of secondary species with a sharp peak in particle diameter between 400 nm and 500 nm, OM had a broader distribution between 100 nm and 400 nm diameter particles, reflecting its combination of fresh, smaller particles and aged, larger particles. OM concentrations were on average similar between periods when the sampling site was upwind and downwind of the freeway, though during the morning OM concentrations were higher under downwind conditions, as was the fraction of HOA. Advisors/Committee Members: Collett, Jeffrey L. (advisor), Kreidenweis, Sonia (committee member), Roberts, Paul (committee member), Heald, Colette (committee member), Marchese, Anthony (committee member).

Subjects/Keywords: black carbon; aerosol mass spectrometry; atmospheric chemistry; near-road; organic aerosol; receptor modeling

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APA (6^th Edition):

Brown, S. G. (2014). Wintertime aerosol in Las Vegas, Nevada. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/82507

Chicago Manual of Style (16^th Edition):

Brown, Steven G. “Wintertime aerosol in Las Vegas, Nevada.” 2014. Doctoral Dissertation, Colorado State University. Accessed March 01, 2021. http://hdl.handle.net/10217/82507.

MLA Handbook (7^th Edition):

Brown, Steven G. “Wintertime aerosol in Las Vegas, Nevada.” 2014. Web. 01 Mar 2021.

Vancouver:

Brown SG. Wintertime aerosol in Las Vegas, Nevada. [Internet] [Doctoral dissertation]. Colorado State University; 2014. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/10217/82507.

Council of Science Editors:

Brown SG. Wintertime aerosol in Las Vegas, Nevada. [Doctoral Dissertation]. Colorado State University; 2014. Available from: http://hdl.handle.net/10217/82507

University of Colorado

23. Connelly, Brandon Michael. Laboratory Studies of Heterogeneous Chemistry.

Degree: PhD, Chemistry & Biochemistry, 2010, University of Colorado

URL: https://scholar.colorado.edu/chem_gradetds/23

► A high vacuum Knudsen flow reactor was used to determine the reactive uptake coefficient, γ, of isoprene on sulfuric acid films as a function… (more)

▼ A high vacuum Knudsen flow reactor was used to determine the reactive uptake coefficient, γ, of isoprene on sulfuric acid films as a function of sulfuric acid weight percent, temperature, and relative humidity. No discernible dependence was observed for γ over the range of temperatures (220 − 265 K) and pressures (10⁻⁷ Torr ^-10−4 Torr) studied. However, the uptake coefficient increased with increased sulfuric acid concentration between the range of 78 wt % (γi 10⁻⁴) and 93 wt % (γi 10⁻³). In addition to the Knudsen Cell, a bulk study was conducted between 60 and 85 wt % H₂SO₄ to quantify uptake at lower acid concentrations and to determine reaction products. After exposing sulfuric acid to gaseous isoprene the condensed phase products were extracted and analyzed using gas chromatography/mass spectrometry (GC/MS). Isoprene was observed to polymerize in the sulfuric acid and form yellow/red colored monoterpenes and cyclic sesquiterpenes. Finally, addition of water to the 85 wt % sulfuric acid/isoprene product mixture released these terpenes from the condensed phase into the gas phase. Together these experiments imply that direct isoprene uptake will not produce significant SOA; however, terpene production from the small uptake may be relevant for ultrafine particles and could affect growth and nucleation. Several laboratory and field studies have suggested that the simple aldehyde glyoxal could be a significant source of secondary organic aerosol (SOA) in the lower troposphere. However, recent studies have found that particles in the upper troposphere also contain significant amounts of organic material, with average organic mass fractions as high as 70%. We have examined whether glyoxal could be a source of SOA in the upper troposphere. The uptake of glyoxal to aerosols generally requires the presence of liquid water. Aerosols in the upper troposphere that could have supercooled liquid on the surface are cirrus ice and particles containing hygroscopic organic material. Several studies indicate cirrus ice may be coated with supercooled liquid HNO₃/H₂O. Thus we have utilized a high vacuum Knudsen Cell to measure the uptake of glyoxal on ice exposed to nitric acid at temperatures and pressures relevant to the upper troposphere. Here we present kinetic and spectroscopic data that indicates uptake of glyoxal is efficient on these films and irreversible. Spectroscopic data indicates the glyoxal is oxidized to glyoxylic acid, and the presence of glyoxylic acid has been confirmed via derivatization of the products followed by gas chromatography mass spectrometry. We have used the glyoxylic acid products from the ice experiments to test whether hygroscopic organic material exposed to water and nitric vapour would also uptake glyoxal. We have found that the uptake of glyoxal and oxidation to glyoxylic acid occurs in the presence of supercooled HNO₃/H₂O liquid on glyoxylic acid even at water… Advisors/Committee Members: Margaret A Tolbert, David O De Haan, Jose L Jimenez.

Subjects/Keywords: Aerosol; Heterogeneous Chemistry; Nucleation; Secondary Organic Aerosol; Tropospheric Chemistry; Chemistry; Environmental Chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Connelly, B. M. (2010). Laboratory Studies of Heterogeneous Chemistry. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/chem_gradetds/23

Chicago Manual of Style (16^th Edition):

Connelly, Brandon Michael. “Laboratory Studies of Heterogeneous Chemistry.” 2010. Doctoral Dissertation, University of Colorado. Accessed March 01, 2021. https://scholar.colorado.edu/chem_gradetds/23.

MLA Handbook (7^th Edition):

Connelly, Brandon Michael. “Laboratory Studies of Heterogeneous Chemistry.” 2010. Web. 01 Mar 2021.

Vancouver:

Connelly BM. Laboratory Studies of Heterogeneous Chemistry. [Internet] [Doctoral dissertation]. University of Colorado; 2010. [cited 2021 Mar 01]. Available from: https://scholar.colorado.edu/chem_gradetds/23.

Council of Science Editors:

Connelly BM. Laboratory Studies of Heterogeneous Chemistry. [Doctoral Dissertation]. University of Colorado; 2010. Available from: https://scholar.colorado.edu/chem_gradetds/23

24. Cochran, Richard. Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols.

Degree: PhD, Chemistry, 2014, University of North Dakota

URL: https://commons.und.edu/theses/1634

► Organic aerosols (OA; organic compounds present on the surface or within aerosols) in the atmosphere may play a significant role in various atmospheric processes… (more)

Subjects/Keywords: Aerosol Chamber; Chromatography; Mass Spectrometry; Organic Aerosol Partitioning; Polycyclic Aromatic Hydrocarbon Derivatives; Polycyclic Aromatic Hydrocarbons

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APA (6^th Edition):

Cochran, R. (2014). Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols. (Doctoral Dissertation). University of North Dakota. Retrieved from https://commons.und.edu/theses/1634

Chicago Manual of Style (16^th Edition):

Cochran, Richard. “Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols.” 2014. Doctoral Dissertation, University of North Dakota. Accessed March 01, 2021. https://commons.und.edu/theses/1634.

MLA Handbook (7^th Edition):

Cochran, Richard. “Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols.” 2014. Web. 01 Mar 2021.

Vancouver:

Cochran R. Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols. [Internet] [Doctoral dissertation]. University of North Dakota; 2014. [cited 2021 Mar 01]. Available from: https://commons.und.edu/theses/1634.

Council of Science Editors:

Cochran R. Investigating The Heterogeneous Chemistry Of Polycyclic Aromatic Hydrocarbons And Other Organic Species In Atmospheric Aerosols. [Doctoral Dissertation]. University of North Dakota; 2014. Available from: https://commons.und.edu/theses/1634

University of Toronto

25. Ye, Jianhuai. Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol.

Degree: PhD, 2017, University of Toronto

URL: http://hdl.handle.net/1807/80989

► Secondary organic aerosol (SOA) formed from oxidation of volatile organic compounds (VOCs), comprises a major fraction of atmospheric submicron particulate matter, which is crucial for… (more)

▼ Secondary organic aerosol (SOA) formed from oxidation of volatile organic compounds (VOCs), comprises a major fraction of atmospheric submicron particulate matter, which is crucial for global climate change and human health. While biogenic VOCs are naturally emitted and cannot be directly controlled, field measurements and satellite observations have shown that biogenic SOA (BSOA) formation correlates well with anthropogenic pollutants and may be anthropogenically controlled. In this work, the formation of the “anthropogenically controllable BSOA” was examined. BSOA from α-pinene ozonolysis was investigated in the presence of laboratory-generated or ambient organic aerosol such as Toronto ambient particles. It is shown that SOA was not equally miscible with all organic species. Aerosol mixing thermodynamics in the atmosphere is composition dependent. Based on laboratory observations, an empirical framework using bulk elemental ratios was developed to predict atmospheric organic miscibility and SOA yield enhancements. Besides organic aerosol, interactions between BSOA formation and SO2 was also examined. Synergistic effects were observed between BSOA formation and SO2 oxidation through Criegee and peroxide chemistry under atmospherically relevant RH conditions. In addition to the physicochemical properties of SOA, health impacts of SOA were examined. An atmospheric simulation reactor (ASR) was developed to investigate the health effects of air pollutants by permitting controlled chronic in vivo exposure of mice to combine particulate and gaseous pollutants at ‘real-life’ concentrations. Results show that daily exposure to SOA from naphthalene photooxidation led to increased airway hyperresponsiveness (AHR) to methacholine in a dose-dependent manner. Multi-pollutant exposures with ozone and/or NO2 in conjunction with a sub-toxic concentration of SOA resulted in additive effects on AHR to methacholine. Inflammatory cell recruitment to the airways was not observed in any of the exposure conditions, indicating the increased AHR was not associated with airway inflammation and may occur through other mechanisms. Advisors/Committee Members: Chan, Arthur W. H., Chemical Engineering Applied Chemistry.

Subjects/Keywords: Aerosol Miscibility; Biogenic-anthropogenic Interaction; Health Effects; Secondary Organic Aerosol; Sulfur Dioxide; 0768

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APA (6^th Edition):

Ye, J. (2017). Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol. (Doctoral Dissertation). University of Toronto. Retrieved from http://hdl.handle.net/1807/80989

Chicago Manual of Style (16^th Edition):

Ye, Jianhuai. “Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol.” 2017. Doctoral Dissertation, University of Toronto. Accessed March 01, 2021. http://hdl.handle.net/1807/80989.

MLA Handbook (7^th Edition):

Ye, Jianhuai. “Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol.” 2017. Web. 01 Mar 2021.

Vancouver:

Ye J. Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol. [Internet] [Doctoral dissertation]. University of Toronto; 2017. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/1807/80989.

Council of Science Editors:

Ye J. Biogenic-Anthropogenic Interactions in Secondary Organic Aerosol Formation and Health Effects of Atmospheric Organic Aerosol. [Doctoral Dissertation]. University of Toronto; 2017. Available from: http://hdl.handle.net/1807/80989

University of Illinois – Urbana-Champaign

26. Mena Gonzalez, Francisco Camilo. Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion.

Degree: PhD, Environ Engr in Civil Engr, 2018, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/101025

► Residential combustion of biofuel is an important source of aerosols and gases in the atmosphere. Emissions from biofuel combustion can affect the climate due to… (more)

▼ Residential combustion of biofuel is an important source of aerosols and gases in the atmosphere. Emissions from biofuel combustion can affect the climate due to the presence of warming species that absorb radiation like black carbon and greenhouse gases, or cooling due to aerosols that scatter radiation back to space and affect cloud characteristics. The climate impact of emissions from biofuel combustion is uncertain in part due uncertainties in the physical, chemical, and optical properties of biofuel burning aerosols. This dissertation is divided into three investigations that address this gap in knowledge by providing information on the size distribution, mixing state, hygroscopicity, optical properties, CCN activity, and total quantity of aerosols emitted from biofuel combustion. The change in cloud characteristics due to biofuel burning aerosols is uncertain, in part, due to the uncertainty in the added number of cloud condensation nuclei (CCN) from biofuel burning. In the first investigation of this dissertation, I provide estimates of the CCN activity of biofuel burning aerosols by explicitly modeling plume dynamics (coagulation, condensation, chemical reactions, and dilution) in a young biofuel burning plume from emission until the plume reaches ambient temperature and specific humidity through entrainment. I found that aerosol-scale dynamics affect the average aerosol size and hygroscopicity only during the first few seconds of evolution, after which they reach a constant value. Homogenizing factors of the aerosol population mixing state are co-emission of semi-volatile organic compounds (SVOCs) or emission at small aerosol sizes. SVOC co-emission can be the main factor determining CCN activity for hydrophobic or small aerosols. Coagulation limits emission of CCN to about 1016 per kg of fuel. Depending on emission factor, aerosol size, and composition, some of these aerosols may not activate at low supersaturation. Hygroscopic Aitken mode aerosols can contribute to CCN through self-coagulation, but have a small effect on the CCN activity of accumulation-mode aerosols, regardless of composition differences. Simple models (monodisperse coagulation and average hygroscopicity) can be used to estimate plume-exit CCN within about 20% if aerosols are unimodal and have homogeneous composition, or when aerosols are emitted in the Aitken mode even if they are not homogeneous. On the other hand, if externally-mixed aerosols are emitted in the accumulation mode without SVOCs, an average hygroscopicity would overestimate emitted CCN by up to a factor of 2. This work identified conditions under which aerosol populations become more homogeneous during plume processes. This homogenizing effect requires the components to be truly co-emitted, rather than sequentially emitted. In the second investigation of this dissertation I provide information on the hygroscopicity and optical properties of Organic Carbon (OC). OC is a ubiquitous component of ambient aerosols, and the major component of biofuel burning aerosols. The… Advisors/Committee Members: Bond, Tami C. (advisor), Bond, Tami C. (Committee Chair), Koloutsou-Vakakis, Sotiria (committee member), Rood, Mark J. (committee member), Riemer, Nicole (committee member).

Subjects/Keywords: aerosol; biofuel; hygroscopic; activation; CCN; organic carbon; light absorption; aerosol mass concentration; scattering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mena Gonzalez, F. C. (2018). Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/101025

Chicago Manual of Style (16^th Edition):

Mena Gonzalez, Francisco Camilo. “Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion.” 2018. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 01, 2021. http://hdl.handle.net/2142/101025.

MLA Handbook (7^th Edition):

Mena Gonzalez, Francisco Camilo. “Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion.” 2018. Web. 01 Mar 2021.

Vancouver:

Mena Gonzalez FC. Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2018. [cited 2021 Mar 01]. Available from: http://hdl.handle.net/2142/101025.

Council of Science Editors:

Mena Gonzalez FC. Modeling study of the hygroscopic, optical, and cloud-activation properties of aerosols from biofuel combustion. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2018. Available from: http://hdl.handle.net/2142/101025

Carnegie Mellon University

27. Gorkowski, Kyle J. The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions.

Degree: 2017, Carnegie Mellon University

URL: http://repository.cmu.edu/dissertations/1067

► I advanced the understanding of particle morphology and its implications for the behavior and effects of atmospheric aerosol particles. I have developed new experimental methods… (more)

▼ I advanced the understanding of particle morphology and its implications for the behavior and effects of atmospheric aerosol particles. I have developed new experimental methods for the Aerosol Optical Tweezers (AOT) system and expanded the AOT’s application into studying realistic secondary organic aerosol (SOA) particle phases. The AOT is a highly accurate system developed to study individual particles in real-time for prolonged periods of time. While previous AOT studies have focused on binary or ternary chemical systems, I have investigated complex SOA, and how they interact with other chemical phases, and the surrounding gas-phase. This work has led to new insights into liquid-liquid phase separation and the resulting particle morphology, the surface tension, solubility, and volatility of SOA, and diffusion coefficients of SOA phases. I designed a new aerosol optical tweezers chamber for delivering a uniformly mixed aerosol flow to the trapped droplet’s position. I used this chamber to determine the phase-separation morphology and resulting properties of complex mixed droplets. A series of experiments using simple compounds are presented to establish my ability to use the cavity enhanced Raman spectra to distinguish between homogenous single-phase, and phase-separated core-shell or partially-engulfed morphologies. I have developed a new algorithm for the analysis of whispering gallery modes (WGMs) present in the cavity enhanced Raman spectra retrieved from droplets trapped in the AOT. My algorithm improves the computational scaling when analyzing core-shell droplets (i.e. phase-separated or biphasic droplets) in the AOT, making it computationally practical to analyze spectra collected over many hours at a few Hz. I then demonstrate for the first time the capture and analysis of SOA on a droplet suspended in an AOT. I examined three initial chemical systems of aqueous NaCl, aqueous glycerol, and squalane at ~ 75% relative humidity. For each system I added α-pinene SOA – generated directly in the AOT chamber – to the trapped droplet. The resulting morphology was always observed to be a core of the initial droplet surrounded by a shell of the added SOA. By combining my AOT observations of particle morphology with results from SOA smog chamber experiments, I conclude that the α-pinene SOA shell creates no major diffusion limitations for water, glycerol, and squalane under humid conditions. My AOT experiments highlight the prominence of phase-separated core-shell morphologies for secondary organic aerosols interacting with a range of other chemical phases. The unique analytical capabilities of the aerosol optical tweezers provide a new approach for advancing the understanding of the chemical and physical evolution of complex atmospheric particulate matter, and the important environmental impacts of aerosols on atmospheric chemistry, air quality, human health, and climate change.

Subjects/Keywords: atmospheric chemistry; liquid-liquid phase separation; optical tweezers; organic aerosol; secondary organic aerosol; whispering gallery modes

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APA (6^th Edition):

Gorkowski, K. J. (2017). The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions. (Thesis). Carnegie Mellon University. Retrieved from http://repository.cmu.edu/dissertations/1067

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gorkowski, Kyle J. “The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions.” 2017. Thesis, Carnegie Mellon University. Accessed March 01, 2021. http://repository.cmu.edu/dissertations/1067.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gorkowski, Kyle J. “The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions.” 2017. Web. 01 Mar 2021.

Vancouver:

Gorkowski KJ. The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions. [Internet] [Thesis]. Carnegie Mellon University; 2017. [cited 2021 Mar 01]. Available from: http://repository.cmu.edu/dissertations/1067.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gorkowski KJ. The Morphology and Equilibration of Levitated Secondary Organic Particles Under Controlled Conditions. [Thesis]. Carnegie Mellon University; 2017. Available from: http://repository.cmu.edu/dissertations/1067

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of California – Riverside

28. Matsunaga, Aiko. Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms.

Degree: Chemistry, 2009, University of California – Riverside

URL: http://www.escholarship.org/uc/item/11v2n13g

► The products and mechanism of secondary organic aerosol (SOA) formations from 1-alkenes, internal alkenes, and 2-methyl-1-alkenes (OH radical reaction only) with OH and NO₃ radicals… (more)

▼ The products and mechanism of secondary organic aerosol (SOA) formations from 1-alkenes, internal alkenes, and 2-methyl-1-alkenes (OH radical reaction only) with OH and NO₃ radicals (in the presence of NO_x for OH radical reactions) were investigated in an environmental chamber, and quantitative chemical mechanisms with gas-partiticle partitioning corrections were developed for some systems to estimate SOA yields. Aerosol products chemical compositions were analyzed using a thermal desorption particle beam mass spectrometer, and volatile compounds were quantified using a gas chromatograph with flame-ionization detector. Nitrate products were analyzed using a high-performance liuid chromatograph with UV-vis detector for yield measurements and ¹H NMR for identification. The major products observed in OH radical-initiated reactions with linear alkenes were β-hydroxynitrates, dihydroxynitrates, cyclic hemiacetals, dihydrofurans, and dimers formed from dihydroxycarbonyls. Trihydroxynitrates and trihydroxycarbonyls were observed for 2-methyl-1-alkene reactions in addition to the products listd above, but dimers were not observed due to reduction of driving force of the formation. The yields of β-hydroxynitrates, dihydroxynitrates, and trihydroxynitrates were measured to calculate the relative ratios for forming primary, secondary, and tertiary β-hydroxyalkyl radicals by OH radical addition to the double bond, calculated as 1.0:1.9:4.3, and the branching ratios for forming β-hydroxynitrates from reactions of primary, secondary, and tertiary β-hydroxyperoxy radicals with NO, calculated as 0.12, 0.15, and 0.25. The branching ratios of β-hydroxynitrate formations were lower than that of alkylnitrate formations due to hydrogen bonding between hydroxy and peroxy groups in hydroxyperoxy radical-NO complexes. The effect is enhanced with the addition of NH₃ for 1-alkene reactions. SOA yields estimated with a developed model agreed well with the measured SOA yields for 2-methyl-1-alkene reactions, but the agreement was limited for 1-alkenes to the region where gas-particle partitioning does not affect due to difficulty in vapor pressure estimation of the products. The major products observed in NO₃ radical-initiated reactions with linear alkenes include β-hydroxynitrates, carbonylnitrates, dihydroxynitrates, and hydroxyl and oxo dinitrooxytetrahydrofurans which have not been observed previously. The products through the pathway of isomerizing δ-hydroxycarbonyls to cyclic hemiacetals were observed in all linear alkene and 2-methyl-1-alkene reactions, and second-generation products were observed in NO₃ radical-initiated reactions.

Subjects/Keywords: Chemistry, Physical; Atmospheric Sciences; chemical reaction mechanisms; model development; organic aerosol chemical analysis; oxidation products; secondary organic aerosol

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APA (6^th Edition):

Matsunaga, A. (2009). Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms. (Thesis). University of California – Riverside. Retrieved from http://www.escholarship.org/uc/item/11v2n13g

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Matsunaga, Aiko. “Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms.” 2009. Thesis, University of California – Riverside. Accessed March 01, 2021. http://www.escholarship.org/uc/item/11v2n13g.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Matsunaga, Aiko. “Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms.” 2009. Web. 01 Mar 2021.

Vancouver:

Matsunaga A. Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms. [Internet] [Thesis]. University of California – Riverside; 2009. [cited 2021 Mar 01]. Available from: http://www.escholarship.org/uc/item/11v2n13g.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Matsunaga A. Secondary Organic Aerosol Formation From Radical-Initiated Reactions of Alkenes: Development of Mechanisms. [Thesis]. University of California – Riverside; 2009. Available from: http://www.escholarship.org/uc/item/11v2n13g

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

29. Robinson, Ellis Shipley. Mixing and Phase Behavior of Organic Particles.

Degree: 2014, Carnegie Mellon University

URL: http://repository.cmu.edu/dissertations/411

► We have developed novel experiments aimed at understanding whether and how quickly organic aerosols (OA) mix using single-particle mass spectrometry, as different treatments of mixing… (more)

▼ We have developed novel experiments aimed at understanding whether and how quickly organic aerosols (OA) mix using single-particle mass spectrometry, as different treatments of mixing in regional models significantly affect predicted mass and composition. First, we designed experiments that separate OA formation chemistry from thermodynamics to test whether two populations of particles equilibrate with eachother through the gas phase on experimental timescales. Single-particle mass spectrometry measurements from the aerosol mass spectrometer (AMS) allowed us to quantify the extent of mixing that had occurred. We calibrated this technique using pure-component aerosols with known vapor pressure and phase state, the results of which agreed with a condensation-evaporation model. We then applied these techniques to three atmospherically-relevant situations to determine that: 1) anthropogenic secondary OA (aSOA) does not mix with a surrogate for hydrophobic primary OA (POA), 2) biogenic SOA (bSOA) does not mix with hydophobic POA, and 3) bSOA shows significant mixing with aSOA. The sum of these experiments show that these complex interactions can be measured for atmospherically important systems, a first step towards quantifying activity coefficients for complex OA mixtures. We also investigated mixing within individual particles, using mixed-particles of squalane (a surrogate for hydrophobic POA) and SOA from ↵+pinene + O3 that we determined to contain two separate phases. In these experiments, after formation of the mixed-particles, we perturbed smog chamber with a heat ramp. These data revealed that squalane is able to quickly evaporate from the mixed-particles, and that almost all of the SOA is comprised of material lower in volatility than squalane (a low-volatility constituent of pump oil). For this latter “comparative volatility analysis,” we had to correct for the highly variable collection efficiency (CE) of the mixed particles to correctly calculate the mass fraction of SOA remaining. One of the larger implications of this work is highly dependent on the particle morphology, which we were not able to determine definitively: if indeed the particles are coreshell with squalane inside a thick layer of SOA, our results show that diffusivity within SOA is not ultra-low. Lastly, we present work that furthers our understanding of single-particle CE in the AMS, a quantity especially important for experiments where particle phase is dynamic or there are two separate populations of particles. We report the particle CE of SOA, ammonium sulfate, ammonium nitrate, and squalane. We also determine that half of SOA particles that give meaningful signal, do so at a time later than would be predicted based on their optically-measured flight time through the instrument. We present convincing evidence that the nature of this delay is due to particles ricocheting around the ionization region of the instrument before vaporizing on an auxillary surface near the the vaporizer. This process affects how much mass signal comes from a…

Subjects/Keywords: organic aerosol; atmospheric chemistry; air pollution; mass spectrometry; phase thermodynamics

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APA (6^th Edition):

Robinson, E. S. (2014). Mixing and Phase Behavior of Organic Particles. (Thesis). Carnegie Mellon University. Retrieved from http://repository.cmu.edu/dissertations/411

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Robinson, Ellis Shipley. “Mixing and Phase Behavior of Organic Particles.” 2014. Thesis, Carnegie Mellon University. Accessed March 01, 2021. http://repository.cmu.edu/dissertations/411.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Robinson, Ellis Shipley. “Mixing and Phase Behavior of Organic Particles.” 2014. Web. 01 Mar 2021.

Vancouver:

Robinson ES. Mixing and Phase Behavior of Organic Particles. [Internet] [Thesis]. Carnegie Mellon University; 2014. [cited 2021 Mar 01]. Available from: http://repository.cmu.edu/dissertations/411.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Robinson ES. Mixing and Phase Behavior of Organic Particles. [Thesis]. Carnegie Mellon University; 2014. Available from: http://repository.cmu.edu/dissertations/411

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

30. Chuang, Wayne K. Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework.

Degree: 2016, Carnegie Mellon University

URL: http://repository.cmu.edu/dissertations/698

► Volatile organic compounds released by plants or through processes such as combustion reacts with oxidative species in the air, such as ozone or hydroxyl radicals.… (more)

▼ Volatile organic compounds released by plants or through processes such as combustion reacts with oxidative species in the air, such as ozone or hydroxyl radicals. Smog chamber studies are conducted to determine the chemistry that these organic precursors undergo, and the products that are formed. These products span orders of magnitude in volatility, making the tracking of each individual species a difficult process. The volatility basis set (VBS), which separates species based on volatility, has been shown to be an effective framework to track the formation of aerosols from these products. In the first part of this work, a 2-dimensional VBS model is used to investigate the introduction of NOx to ff-pinene aging. A new dimension is added to the VBS to track the formation and aging of organonitrates. The results show that higher volatility precursors produce less aerosol mass, while lower volatility precursors produce more, which is consistent with prior experiments of NOx effects. In addition, the model shows that the detection of small concentrations of nitrate ions can still indicate presence of substantial organonitrate mass. The formation of aerosols from ff-pinene ozonolysis experiments at CLOUD are modeled in the next part of this work. CLOUD experiments show the production of low volatility organic compounds, or (E)LVOCs, from ff-pinene ozonolysis contribute to the growth of nucleated particles. The inclusion of a Kelvin effect is necessary to reproduce particle growth rates at small diameters (< 4 nm). Flux balance calculations from the dynamic VBS model show that the raw distribution of products seen by the nitrate-CIMS cannot fully explain the particle growth, and indicate that product masses must be higher. When the model accounts for the charging efficiency of LVOCs in the nitrate-CIMS, it is capable of reproducing the growth of particles from these experiments. Lastly, the yields of E(LVOC)s required to reproduce the data in the previous chapter appear to contradict yields from prior ff-pinene experiments. We explore potential explanations for this disagreement. By treating the chamber model as a dynamical process, the model demonstrates that high yields will appear lower due to the delay between (E)LVOC formation and condensation. While the results still show an overprediction by the current model, it indicates that a dynamical treatment is indeed necessary to capture the condensation of vapors to particles.

Subjects/Keywords: alpha-pinene ozonolysis; dynamic model; organic aerosol; volatility basis set

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APA (6^th Edition):

Chuang, W. K. (2016). Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework. (Thesis). Carnegie Mellon University. Retrieved from http://repository.cmu.edu/dissertations/698

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Chuang, Wayne K. “Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework.” 2016. Thesis, Carnegie Mellon University. Accessed March 01, 2021. http://repository.cmu.edu/dissertations/698.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Chuang, Wayne K. “Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework.” 2016. Web. 01 Mar 2021.

Vancouver:

Chuang WK. Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework. [Internet] [Thesis]. Carnegie Mellon University; 2016. [cited 2021 Mar 01]. Available from: http://repository.cmu.edu/dissertations/698.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chuang WK. Modeling Organic Aerosol Formation from Alpha-Pinene Ozonolysis in the Volatility Basis Set Framework. [Thesis]. Carnegie Mellon University; 2016. Available from: http://repository.cmu.edu/dissertations/698

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations