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Full-Text Articles in Other Chemistry

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg Jan 2023

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg

Chemistry and Biochemistry: Data Sets

Environmentally persistent free radicals (EPFR) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFR in the soot was recorded. Additionally, formation of hydroxyl radical from the photoactivated soot was measured.


Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan May 2022

Long-Term Trends And Variability Of Pm₂.₅ Mass, Chemical Components, And Sources Over Nys, Hesham Abdelmonem Hassan

Legacy Theses & Dissertations (2009 - 2024)

Eighteen years of ambient PM2.5 mass and major components are used in this study to harmonize the carbonaceous fraction of PM2.5 data, and to examine long-term trends and seasonal variability changes. The major decreasing trend of PM2.5 mass and major inorganic ions reflects the ambient concentration response to clean air regulations and policies.Although elemental carbon shows a decreasing trend in agreement with most other PM2.5 components, organic carbon shows a different behavior of no-trend to slightly increasing trend in some sites. Organic carbon behavior indicates the growing role of non-combustion sources at the expense of decreasing combustion sources. Seasonal trends …


Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic Oct 2020

Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic

Chemistry and Biochemistry: Faculty Scholarship

Atmospheric iron solubility varies depending on whether the particles are collected in rural or urban areas, with urban areas showing increased iron solubility. In this study, we investigate if the iron species present in different environments affects its ultimate solubility. Field data are presented from the Platte River Air Pollution and Photochemistry Experiment (PRAPPE), aimed at understanding the interactions between organic carbon and trace elements in atmospheric particulate matter (PM). 24-hr PM2.5 samples were collected during the summer and winter (2016–2017), at three different sites on the Eastern Colorado plains: an urban, agricultural, and a mixed site. Downtown Denver had …


Ozone And Reactive Oxidized Nitrogen Chemistry In The Northeast U.S, Matthew Ninneman Jan 2020

Ozone And Reactive Oxidized Nitrogen Chemistry In The Northeast U.S, Matthew Ninneman

Legacy Theses & Dissertations (2009 - 2024)

Ongoing reductions in oxides of nitrogen concentrations ([NOx] = nitric oxide ([NO]) + nitrogen dioxide ([NO2])) throughout the continental United States (U.S.) have important implications for tropospheric ozone (O3) and reactive oxidized nitrogen chemistry (NOy ≈ NOx + nitric acid (HNO3) + particle nitrate (pNO3) + peroxy nitrates (PNs) + alkyl nitrates (ANs)). Specifically, decreasing [NOx] concentrations have likely (1) increased the sensitivity of O3 to the [NOx] level, and (2) affected NOy speciation and partitioning. An understanding of the impacts of continued [NOx] reductions is needed to inform current and future air pollution control strategies, especially since the National …


Polar Ozone Depletion: Mario J. Molina, Kirsten Oberg Jan 2018

Polar Ozone Depletion: Mario J. Molina, Kirsten Oberg

Natural Sciences Student Research Presentations

This poster for the Natural Sciences Poster Session at Parkland College features the contribution of Mario J. Molina to the field of atmospheric chemistry, especially in regards to the formation and decomposition aspects of the ozone layer.


Spatial And Seasonal Variability Of Cloud Condensation Nuclei Number Concentrations Over The Extended North African Continent And The Mediterranean, Hesham Abdel-Monem Afify Hassan Jan 2014

Spatial And Seasonal Variability Of Cloud Condensation Nuclei Number Concentrations Over The Extended North African Continent And The Mediterranean, Hesham Abdel-Monem Afify Hassan

Legacy Theses & Dissertations (2009 - 2024)

The spatiotemporal variability of cloud condensation nuclei (CCN) number concentration is investigated over the extended domain of the North African continent and Mediterranean which is an essential step for better understanding of aerosol-cloud interactions and associated climate impacts over the region. The study is performed by analyzing the output for the period from 2004 to 2011 from the well-validated global chemistry and aerosol transport model GEOS-Chem-APM. The analysis shows that the dominant aerosol type for CCN number concentration is secondary particles all over the domain. Spatial analysis reveals the existence of four characteristic subdomains of variability: over the Mediterranean and …