Evolution of Multi-Oxidant and Heterogeneous Chemistry in Biomass Burning Plumes

Biomass burning (BB) has an increasing impact on air quality as wildfires increase in the western U.S. Atmospheric chemistry of urban plumes suggests that during the daytime volatile organic compounds (VOCs) are oxidized by O3and the hydroxyl radical (OH), but during the nighttime by O3and the nitrate radical (NO3). However, BB emissions are unique because they include large amounts of aerosols, BBVOCs, and nitrogen oxides (NOx = NO + NO2), creating a highly reactive environment. We study the formation, competition, and fate of oxidants (NO3, N2O5, O3, and OH) reacting with BBVOCs using an analysis of daytime and nighttime BB plume observations. Toward this goal, we 1) developed a detailed BBVOC emissions and kinetics inventory, 2) conducted aircraft observations of wildfire plumes, 3) used a detailed 0-D chemical box model (0-DBM), and 4) created a novel model, the Gaussian Observational Model for Edge to Center Heterogeneity (GOMECH), to quantify chemical differences between plume center and edge. We present 1) the first analysis of nighttime aircraft observations of an agricultural BB plume sampled by the NOAA WP-3D aircraft during the South East Nexus (SENEX 2013) campaign, 2) an analysis of daytime, sunset, and nighttime plumes sampled by the NOAA Twin Otter, and NASA DC-8 aircraft during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ 2019) campaign, and 3) the first analysis to quantify plume center to edge phenolic oxidation and nitrophenolic formation in BB plumes. We show that, unlike urban plumes, &gt;98% of NO3&nbsp;loss in BB plumes, even under sunlight, is due to BBVOCs at plume center. Reactions with phenolics dominate NO3&nbsp;reactions and NOx loss overnight from the formation of nitrophenolics. Using GOMECH, we show that NO3&nbsp;chemistry may be a major, even dominant, source of nitrophenolics in daytime BB plumes, even on plume edges. Overall, our work suggests that BB plumes are large sources of reactivity for OH, O3&nbsp;and NO3&nbsp;under sunlight and in the dark, unlike more conventional atmospheric chemistry that separates the role of OH and NO3&nbsp;into photochemistry and nighttime chemistry.</p

Direct Experimental Determination of the Reaction Kinetics of the Simplest Criegee Intermediate, CH2OO, and Isoprene

(Statement of Responsibility) by Zachary C. J. Decker(Thesis) Thesis (B.A.) -- New College of Florida, 2016RESTRICTED TO NCF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE(Bibliography) Includes bibliographical references.This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.Faculty Sponsor: Shipman, Steve

Sonodelivery in Skeletal Muscle: Current Approaches and Future Potential

There are currently multiple approaches to facilitate gene therapy via intramuscular gene delivery, such as electroporation, viral delivery, or direct DNA injection with or without polymeric carriers. Each of these methods has benefits, but each method also has shortcomings preventing it from being established as the ideal technique. A promising method, ultrasound-mediated gene delivery (or sonodelivery) is inexpensive, widely available, reusable, minimally invasive, and safe. Hurdles to utilizing sonodelivery include choosing from a large variety of conditions, which are often dependent on the equipment and/or research group, and moderate transfection efficiencies when compared to some other gene delivery methods. In this review, we provide a comprehensive look at the breadth of sonodelivery techniques for intramuscular gene delivery and suggest future directions for this continuously evolving field

Evaluation of thrombophilia testing in the inpatient setting: A single institution retrospective review

BACKGROUND: Thrombophilia workup is typically inappropriate in the inpatient setting as testing may be skewed by anticoagulation, acute thrombosis, or acute illness. OBJECTIVE: To determine adherence of inpatient thrombophilia testing with institutional guidelines. PATIENTS AND METHODS: A retrospective study to evaluate thrombophilia testing practices of adult patients who were admitted to Lehigh Valley Hospital at Cedar Crest with either venous thromboembolism or ischemic stroke in 2019. Testing included inherited and acquired thrombophilia. Patient charts were individually reviewed for three measured outcomes: 1) the number of appropriate thrombophilia testing in the inpatient setting; 2) the indications used for thrombophilia testing; 3) the proportion of positive thrombophilia tests with change in clinical management. RESULTS: 201 patients were included in our study. 26 patients (13%) were tested appropriately in accordance with institution guidelines and 175 (87%) patients were tested inappropriately. The most common reason for the inappropriate testing was testing during acute thrombosis. 28 of the 201 patients had positive thrombophilia tests, but the reviewers only noted 7 patients with change in clinical management-involving anticoagulation change. CONCLUSION: Our study revealed that a majority of inpatient thrombophilia testing did not follow institutional guidelines for appropriate testing and did not change patient management. These thrombophilia tests are often overutilized and have minimal clinical utility in the inpatient setting

AutoGraph: Imperative-style Coding with Graph-based Performance

There is a perceived trade-off between machine learning code that is easy to write, and machine learning code that is scalable or fast to execute. In machine learning, imperative style libraries like Autograd and PyTorch are easy to write, but suffer from high interpretive overhead and are not easily deployable in production or mobile settings. Graph-based libraries like TensorFlow and Theano benefit from whole-program optimization and can be deployed broadly, but make expressing complex models more cumbersome. We describe how the use of staged programming in Python, via source code transformation, offers a midpoint between these two library design patterns, capturing the benefits of both. A key insight is to delay all type-dependent decisions until runtime, via dynamic dispatch. We instantiate these principles in AutoGraph, a software system that improves the programming experience of the TensorFlow library, and demonstrate usability improvements with no loss in performance compared to native TensorFlow graphs. We also show that our system is backend agnostic, and demonstrate targeting an alternate IR with characteristics not found in TensorFlow graphs

PhillydotMap: The Shape of Philadelphia

This book is the outgrowth of a working group entitled, “Modeling Urban Environmental Impacts on Health, Development, and Behavior sponsored by the University of Pennsylvania Institute for Urban Research. The purpose of the working gropu was to engage faculty from across campus and to encourage their collaborative use of GIS technology in the modeling of urban form and function. These ten chapters represent a wide range of GIS applications, from community-based social services to public history to social science research

Nighttime chemical transformation in biomass burning plumes : A box model analysis initialized with aircraft observations

Biomass burning (BB) is a large source of reactive compounds in the atmosphere. While the daytime photochemistry of BB emissions has been studied in some detail, there has been little focus on nighttime reactions despite the potential for substantial oxidative and heterogeneous chemistry. Here, we present the first analysis of nighttime aircraft intercepts of agricultural BB plumes using observations from the NOAA WP-3D aircraft during the 2013 Southeast Nexus (SENEX) campaign. We use these observations in conjunction with detailed chemical box modeling to investigate the formation and fate of oxidants (NO3, N2O5, O3, and OH) and BB volatile organic compounds (BBVOCs), using emissions representative of agricultural burns (rice straw) and western wildfires (ponderosa pine). Field observations suggest NO3 production was approximately 1 ppbv hr–1, while NO3 and N2O5 were at or below 3 pptv, indicating rapid NO3/N2O5 reactivity. Model analysis shows that >99% of NO3/N2O5 loss is due to BBVOC + NO3 reactions rather than aerosol uptake of N2O5. Nighttime BBVOC oxidation for rice straw and ponderosa pine fires is dominated by NO3 (72, 53%, respectively) but O3 oxidation is significant (25, 43%), leading to roughly 55% overnight depletion of the most reactive BBVOCs and NO2

Nighttime and daytime dark oxidation chemistry in wildfire plumes: an observation and model analysis of FIREX-AQ aircraft data

Wildfires are increasing in size across the western US, leading to increases in human smoke exposure and associated negative health impacts. The impact of biomass burning (BB) smoke, including wildfires, on regional air quality depends on emissions, transport, and chemistry, including oxidation of emitted BB volatile organic compounds (BBVOCs) by the hydroxyl radical (OH), nitrate radical (NO3), and ozone (O3). During the daytime, when light penetrates the plumes, BBVOCs are oxidized mainly by O3 and OH. In contrast, at night or in optically dense plumes, BBVOCs are oxidized mainly by O3 and NO3. This work focuses on the transition between daytime and nighttime oxidation, which has significant implications for the formation of secondary pollutants and loss of nitrogen oxides () and has been understudied. We present wildfire plume observations made during FIREX-AQ (Fire Influence on Regional to Global Environments and Air Quality), a field campaign involving multiple aircraft, ground, satellite, and mobile platforms that took place in the United States in the summer of 2019 to study both wildfire and agricultural burning emissions and atmospheric chemistry. We use observations from two research aircraft, the NASA DC-8 and the NOAA Twin Otter, with a detailed chemical box model, including updated phenolic mechanisms, to analyze smoke sampled during midday, sunset, and nighttime. Aircraft observations suggest a range of NO3 production rates (0.1&ndash;1.5&thinsp;ppbv&thinsp;h&minus;1) in plumes transported during both midday and after dark. Modeled initial instantaneous reactivity toward BBVOCs for NO3, OH, and O3 is 80.1&thinsp;%, 87.7&thinsp;%, and 99.6&thinsp;%, respectively. Initial NO3 reactivity is 10&ndash;104 times greater than typical values in forested or urban environments, and reactions with BBVOCs account for &gt;97&thinsp;% of NO3 loss in sunlit plumes (jNO2 up to ), while conventional photochemical NO3 loss through reaction with NO and photolysis are minor pathways. Alkenes and furans are mostly oxidized by OH and O3 (11&thinsp;%&ndash;43&thinsp;%, 54&thinsp;%&ndash;88&thinsp;% for alkenes; 18&thinsp;%&ndash;55&thinsp;%, 39&thinsp;%&ndash;76&thinsp;%, for furans, respectively), but phenolic oxidation is split between NO3, O3, and OH (26&thinsp;%&ndash;52&thinsp;%, 22&thinsp;%&ndash;43&thinsp;%, 16&thinsp;%&ndash;33&thinsp;%, respectively). Nitrate radical oxidation accounts for 26&thinsp;%&ndash;52&thinsp;% of phenolic chemical loss in sunset plumes and in an optically thick plume. Nitrocatechol yields varied between 33&thinsp;% and 45&thinsp;%, and NO3 chemistry in BB plumes emitted late in the day is responsible for 72&thinsp;%&ndash;92&thinsp;% (84&thinsp;% in an optically thick midday plume) of nitrocatechol formation and controls nitrophenolic formation overall. As a result, overnight nitrophenolic formation pathways account for 56&thinsp;%&plusmn;2&thinsp;% of NOx loss by sunrise the following day. In all but one overnight plume we modeled, there was remaining NOx (13&thinsp;%&ndash;57&thinsp;%) and BBVOCs (8&thinsp;%&ndash;72&thinsp;%) at sunrise. &nbsp;</p