Related Topics: Air Research

Air Research Products in the Science Inventory

Records 1 to 25 of 442

Modeling and Validation of 48V Mild Hybrid Lithium-ion Battery Pack (JOURNAL)
As part of the Midterm Evaluation of the 2017-2025 Light-duty Vehicle Greenhouse Gas (GHG) Standards, the U.S. Environmental Protection Agency (EPA) developed simulation models for studying the effectiveness of 48V mild hybrid technology for reducing CO2 emissions from light-duty...
Predictive GT-Power Simulation for VNT Matching on a 1.6 L Turbocharged GDI Engine (JOURNAL)
The thermal efficiency benefits of low-pressure (LP) exhaust gas recirculation (EGR) in spark-ignition engine combustion are well known. One of the greatest barriers facing adoption of LP-EGR for high power-density applications is the challenge of boosting. Variable nozzle turbin...
Modeling and Controls Development of 48V Mild Hybrid Electric Vehicles (JOURNAL)
The Advanced Light-Duty Powertrain and Hybrid Analysis tool (ALPHA) was created by EPA to evaluate the Greenhouse Gas (GHG) emissions of Light-Duty (LD) vehicles. It is a physics-based, forward-looking, full vehicle computer simulator capable of analyzing various vehicle types c...
Evaluation of Emerging Technologies on a 1.6 L Turbocharged GDI Engine (JOURNAL)
Low-pressure loop exhaust gas recirculation (LPL- EGR) combined with a higher compression ratio is a technology package that has been the focus of significant research to increase engine thermal efficiency of downsized, turbocharged GDI engines. Research shows that the addition ...
Exploring the role of natural gas power plants with carbon capture and storage as a bridge to a low-carbon future (JOURNAL)
Natural gas combined-cycle (NGCC) turbines with carbon capture and storage (CCS) can be a promising technology to reduce CO2 emissions in the electric sector. However, the high cost and energy penalties of current carbon capture devices, as well as methane leakage from natural ga...
Effects of recent energy system changes on CO2 projections for the United States (JOURNAL)
Recent projections of United States carbon dioxide (CO2) emissions are considerably lower than those made just a decade ago. A myriad of factors have contributed to lower forecasts, including reductions in end-use energy service demands, improvements in energy efficiency, techno...
A Framework to Quantify the Strength of the Ecological Links Between an Environmental Stressor and Final Ecosystem Services (JOURNAL)
Anthropogenic stressors such as climate change, fire, and pollution are driving shifts in ecosystem function and resilience. Scientists generally rely on biological indicators of these stressors to signal that ecosystem conditions have been altered beyond an acceptable amount. Ho...
A framework for expanding aqueous chemistry in the Community Multiscale Air Quality (CMAQ) model version 5.1 (JOURNAL)
This paper describes the development and implementation of an extendable aqueous-phase chemistry option (AQCHEM − KMT(I)) for the Community Multiscale Air Quality (CMAQ) modeling system, version 5.1. Here, the Kinetic PreProcessor (KPP), version 2.2.3, is used to generate a Rosen...
Characterizing the impact of projected changes in climate and air quality on human exposures to ozone (JOURNAL)
The impact of climate change on human and environmental health is of critical concern. Population exposures to air pollutants both indoors and outdoors are influenced by a wide range of air quality, meteorological, behavioral, and housing-related factors, many of which are also i...
Projecting state-level air pollutant emissions using an integrated assessment model: GCAM-USA. (JOURNAL)
Integrated Assessment Models (IAMs) characterize the interactions among human and earth systems. IAMs typically have been applied to investigate future energy, land use, and emission pathways at global to continental scales. Recent directions in IAM development include enhanced t...
Chemical transport model simulations of organic aerosol in southern California: model evaluation and gasoline and diesel source contributions (JOURNAL)
Gasoline- and diesel-fueled engines are ubiquitous sources of air pollution in urban environments. They emit both primary particulate matter and precursor gases that react to form secondary particulate matter in the atmosphere. In this work, we updated the organic aerosol module ...
Semivolatile POA and parameterized total combustion SOA in CMAQv5.2: impacts on source strength and partitioning (JOURNAL)
Mounting evidence from field and laboratory observations coupled with atmospheric model analyses shows that primary combustion emissions of organic compounds dynamically partition between the vapor and particulate phases, especially as near-source emissions dilute and cool to amb...
An approach to measure parameter sensitivity in watershed hydrological modelling (JOURNAL)
Hydrologic responses vary spatially and temporally according to watershed characteristics. In this study, the hydrologic models that we developed earlier for the Little Miami River (LMR) and Las Vegas Wash (LVW) watersheds were used for detail sensitivity analyses. To compare the...
Light absorbing organic carbon from prescribed and laboratory biomass burning and gasoline vehicle emissions (JOURNAL)
The light absorption of carbonaceous aerosols plays an important role in the atmospheric radiation balance. Light-absorbing organic carbon (OC), also called brown carbon (BrC), from laboratory-based biomass burning (BB) has been studied intensively to understand the contribution ...
Warmer temperatures reduce net carbon uptake, but not water use, in a mature southern Appalachian forest (JOURNAL)
Increasing air temperature is expected to extend growing season length in temperate, broadleaf forests, leading to potential increases in evapotranspiration and net carbon uptake. However, other key processes affecting water and carbon cycles are also highly temperature-dependent...
Light absorption of secondary organic aerosol: Composition and contribution of nitro-aromatic compounds (JOURNAL)
Secondary organic aerosol (SOA) might affect the atmospheric radiation balance through absorbing light at shorter visible and UV wavelengths. However, the composition and optical properties of light-absorbing SOA is poorly understood. In this work, SOA filter samples were collect...
Climate change impacts on projections of excess mortality at 2030 using spatially varying ozone-temperature (JOURNAL)
We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995-2005) and near-future (2025-2035) time period while incorporating a non-linear and synergistic effect of ozone and temperature on mortality. We simulate air quali...
Community vulnerability to health impacts of wildland fire smoke exposure (JOURNAL)
Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community Health-Vulnerability Index (CHVI) based on fact...
Coupling Computer-Aided Process Simulation and Estimations of Emissions and Land Use for Rapid Life Cycle Inventory Modeling (JOURNAL)
A methodology is described for developing a gate-to-gate life cycle inventory (LCI) of a chemical manufacturing process to support the application of life cycle assessment in the design and regulation of sustainable chemicals. The inventories were derived by first applying proces...
Environmental effects of ozone depletion and its interactions with climate change: Progress report, 2016 (JOURNAL)
When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than previously believed. As a result of this, human health and environmental issues will be longer-lasting and more regionally variable...
Assessment of Uinta Basin Oil and Natural Gas Well Pad Pneumatic Controller Emissions (JOURNAL)
In the fall of 2016, a field study was conducted in the Uinta Basin Utah to improve information on oil and natural gas well pad pneumatic controllers (PCs) and emission measurement methods. A total of 80 PC systems at five oil sites (supporting six wells) and three gas sites (sup...
A Laboratory Comparison of Emission Factors, Number Size Distributions, and Morphology of Ultrafine Particles from 11 Different Household Cookstove-Fuel Systems (JOURNAL)
Ultrafine particle (UFP) emissions and particle number size distributions (PNSD) are critical in the evaluation of air pollution impacts on human health and climate change. Residential cookstove emissions are a major source of many air pollutants; however, data on UFP number emis...
Evidence that higher [CO2] increases tree growth sensitivity to temperature: a comparison of modern and paleo oaks (JOURNAL)
Aim: To test the growth-sensitivity to temperature under different ambient CO2 concentrations, we determined paleo tree growth rates as they relate to variation in temperature during the last deglacial period, and compare these to modern tree growth rates as they relate to spatia...
Longitudinal thermal heterogeneity in rivers and refugia for coldwater species: effects of scale and climate change (JOURNAL)
Climate-change driven increases in water temperature pose multiple challenges for aquatic organisms. Predictions of climate change impacts to biota typically do not account for fine-grained spatiotemporal patterns of stream networks; yet patches of cooler water within rivers c...
Universal industrial sectors integrated solutions modulefor the pulp and paper industry (JOURNAL)
The U.S. is the world’s second-leading producer of pulp and paper products after China. While the pulp and paper industry has reduced its environmental impacts, concerns remain regarding the emissions of oxides of nitrogen (NOX) and sulfur dioxide (SO2) from the sector. Boilers, ...