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Full-Text Articles in Chemistry
Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke
Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke
Undergraduate Theses, Capstones, and Recitals
Science surrounding the use of low-cost sensors (LCS) to monitor air quality is rapidly expanding to satisfy the need to fill in regional air quality data gaps. This project evaluated the suitability of two types of LCS: Modulair-PM and PurpleAir (SD and Flex models) as efficient means to measure airborne particulate matter. The study involved physical installation of nine co-located sensors at a suburban site in Denver, connectivity troubleshooting as necessary, and data analysis/modeling of data over multiple months (19 weeks). PM data was compared between individual sensors of the same type, as well as across the two different sensor …
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
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.
Reno, Carson City And Las Vegas - 1994, University Of Denver
Reno, Carson City And Las Vegas - 1994, University Of Denver
United States Data - Nevada
Relevant Publications
Science Total Environment Publication
Utah Wintertime Measurements Of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald, Adam M. Boies
Utah Wintertime Measurements Of Heavy-Duty Vehicle Nitrogen Oxide Emission Factors, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald, Adam M. Boies
Fuel Efficiency Automobile Test Publications
There have only been a few wintertime studies of heavy-duty vehicle (HDV) NOx emissions in the U.S., and while they have observed increased emissions, fleet characterization to identify the cause has been lacking. We have collected wintertime measurements of NOx emission factors from 1,591 HDV at a Utah Port of Entry in December 2020 that includes individual vehicle identification. In general, the NOx emission factors for 2011 & newer chassis model year HDV are significantly higher than 2017 spring measurements from California. The newest chassis model year HDV (2017 - 2021) NOx emission factors are similar …
Measurements Of Atmospheric Radicals, Heather L. Runberg
Measurements Of Atmospheric Radicals, Heather L. Runberg
Electronic Theses and Dissertations
Atmospheric particulate matter (PM) is a global health concern. PM2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM2.5 result from events like volcanos and wildfires. Upon inhalation, PM2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.
PM2.5 is small enough to remain aloft and travel many hundreds …
On-Road Vehicle Emission Measurements And Their Use In Evaluating Emission Control Effectiveness {Presentation}, Gary A. Bishop
On-Road Vehicle Emission Measurements And Their Use In Evaluating Emission Control Effectiveness {Presentation}, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
The Art Of Poetry And Its Place In The History Of The Coordinating Research Councils Real World Emissions Workshop {Poster}, Gary A. Bishop
The Art Of Poetry And Its Place In The History Of The Coordinating Research Councils Real World Emissions Workshop {Poster}, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop
On-Road Nox Emissions Evaluation Of The Repair Effectiveness For Recalled Volkswagen Group Light-Duty Diesel Vehicles In The United States, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
The admission by the Volkswagen Group in the fall of 2015 that they had duped the United States new vehicle emissions certification testing resulted in perhaps the most expensive violation of U.S. environmental vehicle emission regulations in its history. As part of the subsequent recall of more than 500,000 vehicles in the U.S., owners could sell their vehicles back to the companies or have them repaired. We have used a number of large on-road emission measurement data sets that were routinely collected before and after the recall to evaluate the fuel specific NOx emissions benefit for the vehicles that …
On-Road Remote Sensing Of Automobile Emissions In The Fresno, Ca Area: Spring 2021, Gary A. Bishop
On-Road Remote Sensing Of Automobile Emissions In The Fresno, Ca Area: Spring 2021, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Winter Measurements Of Heavy-Duty Vehicles To Characterize The Cold Temperature Effectiveness Of Selective Catalytic Reductions Catalyst In Controlling Oxide Of Nitrogen Emissions, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald
Winter Measurements Of Heavy-Duty Vehicles To Characterize The Cold Temperature Effectiveness Of Selective Catalytic Reductions Catalyst In Controlling Oxide Of Nitrogen Emissions, Gary A. Bishop, Molly J. Haugen, Brian C. Mcdonald
Fuel Efficiency Automobile Test Publications
No abstract provided.
On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2020, Gary A. Bishop
On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2020, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Does California’S Emfac2017 Vehicle Emissions Model Under-Predict California Light-Duty Gasoline Vehicle Nox Emissions?, Gary A. Bishop
Does California’S Emfac2017 Vehicle Emissions Model Under-Predict California Light-Duty Gasoline Vehicle Nox Emissions?, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
On-road remote sensing measurements of light and medium-duty gasoline vehicles collected within California’s South Coast Air Basin since 1999 generally fall within the range of observed summer ambient molar NOx/CO measurements collected during morning rush hours. Compared with ambient and on-road emissions, the California Air Resources Board EMFAC model under predicts 2018 gasoline vehicle NOx emission factors by more than a factor of 2.6. Contributing to these differences is that vehicles older than model year 2006 have NOx emission deterioration rates that are up to 4 time’s higher on-road than predicted by the EMFAC model. A …
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
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 …
California - Port Of Los Angeles, Unversity Of Denver
California - Port Of Los Angeles, Unversity Of Denver
On-road Heavy-duty Monitoring System Measurements
Relevant Publications
Environmental Science & Technology Publication (2015)
Environmental Science & Technology Publication (2017)
Environmental Science & Technology Publication (2018)
California - Cottonwood Weigh Station, University Of Denver
California - Cottonwood Weigh Station, University Of Denver
On-road Heavy-duty Monitoring System Measurements
Relevant Publications
Environmental Science & Technology Publication (2015)
Environmental Science & Technology Publication (2017)
Environmental Science & Technology Publication (2018)
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2020, Gary A. Bishop
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2020, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2019, Gary A. Bishop
On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Fall 2019, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Are Electric Vehicles A Panacea For Reducing Ozone Precursor Emissions?, Gary A. Bishop
Are Electric Vehicles A Panacea For Reducing Ozone Precursor Emissions?, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Vehicle Exhaust Remote Sensing Device Method To Screen Vehicles For Evaporative Running Loss Emissions, Gary A. Bishop, Timothy H. Defries, James A. Sidebottom, James M. Kemper
Vehicle Exhaust Remote Sensing Device Method To Screen Vehicles For Evaporative Running Loss Emissions, Gary A. Bishop, Timothy H. Defries, James A. Sidebottom, James M. Kemper
Fuel Efficiency Automobile Test Publications
Vehicle hydrocarbon (HC) emissions can be emitted from either tailpipe or non-tailpipe locations and understanding their fleet apportionment is important for successful air pollution policy. Vehicles initially misidentified as having elevated tailpipe HC emissions first indicated that roadside exhaust sensors could detect the presence of evaporative HC emissions as increased noise in the HC/carbon dioxide (CO2) correlation measurement. The 90th percentile of the largest residual of the HC/CO2 correlation is defined as a running loss index (RLI) for each measurement. An RLI that is three standard deviations or greater above the instruments noise indicates possible evaporative …
Inspection And Maintenance Evaluation Using Historical U.S. Remote Sensing Measurements, Gary A. Bishop
Inspection And Maintenance Evaluation Using Historical U.S. Remote Sensing Measurements, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2018, Gary A. Bishop
On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Fall 2018, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Measuring Emissions From The On-Road Vehicle Fleet In West Los Angeles, Gary A. Bishop
Measuring Emissions From The On-Road Vehicle Fleet In West Los Angeles, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
Three Decades Of On-Road Mobile Source Emissions Reductions In South Los Angeles, Gary A. Bishop
Three Decades Of On-Road Mobile Source Emissions Reductions In South Los Angeles, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
In May of 2018, the University of Denver repeated on-road optical remote sensing measurements at two locations in Lynwood, CA. Lynwood area vehicle tailpipe emissions were first surveyed in 1989 and 1991 because the area suffered with a large number of carbon monoxide (CO) air quality violations. These new measurements allow for the estimation of fuel specific CO and total hydrocarbon (HC) emissions reductions, changes in the longevity of emission-control components, and the prevalence of high emitters in the current fleet.
Since 1989 CO emissions decreased approximately factors of 10 (120 ± 8 to 12.3 ± 0.2 gCO/kg of fuel) …
Photochemistry Of Polycyclic Aromatic Hydrocarbons With Environmentally Relevant Metals, John P. Haynes
Photochemistry Of Polycyclic Aromatic Hydrocarbons With Environmentally Relevant Metals, John P. Haynes
Electronic Theses and Dissertations
The details of the work presented in this dissertation focus on simulated reactions in the atmosphere and water systems between persistent aromatic compounds and varying species of metals with an emphasis on iron. Bulk water suspensions of a standard soil and polycyclic aromatic hydrocarbons (PAH) were analyzed for soluble iron by inductively-coupled plasma mass spectroscopy (ICP-MS) following a 16 hour reaction period using simulated sunlight. Significant increases in soluble iron were only seen with 2-3 ring linear PAH and carboxylic acids.
A two-stage study was conducted to investigate the potential for and possible mechanisms involving the photo-oxidation of PAH into …
The Investigation Of Lactoferrin Nitration: Quantification, Function, And Inhibition, Amani Yahya Alhalwani
The Investigation Of Lactoferrin Nitration: Quantification, Function, And Inhibition, Amani Yahya Alhalwani
Electronic Theses and Dissertations
Lactoferrin (LF) is an iron-binding glycoprotein of molecular mass ca. 80 kDa that is predominantly found in mammalian body fluids. Lactoferrin is a multifunctional protein that has a wide range of properties such as antibacterial, antiviral, anti-inflammatory, and anti-allergic functions. Tyrosine residues in the protein play a part in many lactoferrin functions. Protein tyrosine nitration modification represents an oxidative and nitrosative stress process which can be caused by the exposure of proteins to oxidants from air pollution or disease. Understanding the way nitrated lactoferrin interacts with the biochemical environment of the body is thus important to the broader goal of …
On-Road Remote Sensing Of Heavy And Medium-Duty Trucks At The Peralta Weigh Station In The South Coast Air Basin: Spring 2017, Molly J. Haugen, Gary A. Bishop
On-Road Remote Sensing Of Heavy And Medium-Duty Trucks At The Peralta Weigh Station In The South Coast Air Basin: Spring 2017, Molly J. Haugen, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.
The Story Of Ever Diminishing Vehicle Tailpipe Emissions As Observed In The Chicago, Il Area, Gary A. Bishop, Molly J. Haugen
The Story Of Ever Diminishing Vehicle Tailpipe Emissions As Observed In The Chicago, Il Area, Gary A. Bishop, Molly J. Haugen
Fuel Efficiency Automobile Test Publications
The University of Denver has collected on-road fuel specific vehicle emissions measurements in the Chicago area since 1989. This nearly 30 year record illustrates the large reductions in light-duty vehicle tailpipe emissions and the remarkable improvements in emissions control durability to maintain low emissions over increasing periods of time. Since 1989 fuel specific carbon monoxide (CO) emissions have been reduced by an order of magnitude and hydrocarbon (HC) emissions by more than a factor of 20. Nitric oxide (NO) emissions have only been collected since 1997 but have seen reductions of 79%. This has increased the skewness of the emissions …
Evaluation Of Heavy- And Medium-Duty On-Road Vehicle Emissions In California's South Coast Air Basin, Molly J. Haugen, Gary A. Bishop, Arvind Thiruvengadam, Daniel K. Carder
Evaluation Of Heavy- And Medium-Duty On-Road Vehicle Emissions In California's South Coast Air Basin, Molly J. Haugen, Gary A. Bishop, Arvind Thiruvengadam, Daniel K. Carder
Fuel Efficiency Automobile Test Publications
Emission measurements were collected from heavy-duty (HDVs) and medium-duty vehicles (MDVs) at the Peralta weigh station long-term measurement site near Anaheim, CA in 2017. Two Fuel Efficiency Automobile Test units sampled elevated and ground-level exhaust vehicles totaling 2,315 measurements. HDVs (1844 measurements) exhibited historical reductions in fuel specific oxides of nitrogen (NOx) from the 2008 measurements (55%) with increased use of exhaust gas recirculation and selective catalytic reduction systems. However, as these technologies have aged, the in-use benefits have declined. Infrared %opacity measurements of tailpipe soot decreased 14% since 2012 with increased diesel particulate filter (DPF) use, DPF …
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2017, Gary A. Bishop, Molly J. Haugen
On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Winter 2017, Gary A. Bishop, Molly J. Haugen
Fuel Efficiency Automobile Test Publications
No abstract provided.
Revisit Lynwood, Ca: On-Road Remote Sensing Of Automobile Emissions In The Lynwood, Ca: 2018, Gary A. Bishop
Revisit Lynwood, Ca: On-Road Remote Sensing Of Automobile Emissions In The Lynwood, Ca: 2018, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
No abstract provided.