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Articles 1 - 30 of 174
Full-Text Articles in Environmental Chemistry
Extreme Value Theory View Of High Emitter Diesel Vehicles In The Us From 1991 To 2021, M. Matti Maricq, Gary A. Bishop
Extreme Value Theory View Of High Emitter Diesel Vehicles In The Us From 1991 To 2021, M. Matti Maricq, Gary A. Bishop
Fuel Efficiency Automobile Test Publications
Extreme value theory (EVT) is a statistical method to characterize the tails of distributions, such as high emitter vehicle emissions. The present work addresses the United States (US) diesel fleet. EVT confirms that high emitters contribute disproportionately to adverse air quality. It further reveals that high emitter emissions have responded differently to progressively tighter emissions standards compared to fleet averages. Carbon monoxide (CO) and hydrocarbons (HC) high emitter emissions fell in concert with the fleet average after widespread implementation of the diesel oxidation catalyst to meet US Environmental Protection Agency (EPA) Tier 1 emissions standards, but remained unchanged after introduction …
Photochemistry Of Quinones And Combustion-Derived Particles, Desiree J. Sarmiento
Photochemistry Of Quinones And Combustion-Derived Particles, Desiree J. Sarmiento
Electronic Theses and Dissertations
Quinones are ubiquitous species that can be produced from the photochemical aging of combustion-derived particles (CDPs). Polycyclic aromatic hydrocarbons (PAHs) are a major component of CDPs and are precursors to quinones and other oxidized products (OPAHs). My work first expanded on the PAH and OPAH photochemistry research of Dr. John Haynes, who showed that anthracene (ANT) oxidizes into 1,4-naphthoquinone (1,4-NAPQ), 1,4-anthraquinone (1,4-ANTQ), and 9,10-anthraquinone (9,10-ANTQ), and of Dr. Heather Runberg, who demonstrated the ability of ANT and these quinones to generate reactive oxygen species (ROS). Then at the Pacific Northwest National Laboratory (PNNL), I was given the opportunity to investigate …
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 …
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 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.
2021 West Los Angeles Data Summary, Gary Bishop
2021 West Los Angeles Data Summary, Gary Bishop
Fuel Efficiency Automobile Test Publications
Simple data summary for 2021 West Los Angeles on-road emission measurements.
2022 Oakland Ca Data Summary, Gary Bishop
2022 Oakland Ca Data Summary, Gary Bishop
Fuel Efficiency Automobile Test Publications
Simple data summary for 2022 on-road vehicle emission measurements from Oakland CA.
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 …
West Los Angeles
United States Data - California
Relevant Publications
Environmental Science & Technology Publication (2008)
Environmental Science & Technology Publication (2010)
Environmental Science & Technology Publication (2014)
Environmental Science & Technology Publication (2015)
Environmental Science & Technology Publication (2016)
Environmental Science & Technology Publication (2020)
Air & Waste Management Association Publication (2019)
Air & Waste Management Association Publication (2021)
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 …
Stockton Ca Data Summary, Gary Bishop
Stockton Ca Data Summary, Gary Bishop
Fuel Efficiency Automobile Test Publications
Simple data summary for on-road emission measurements from Stockton CA.
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 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.
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.
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 - 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)
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)
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.
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 …
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.
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.
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) …
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.