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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS2010

Environmentally Responsible Aviation - Real Solutions for Environmental Challenges Facing Aviation

The combined reality of persistently strong growth in air traffic and the vital economic role of the air transport system result in continued demand for the progress of technology for the reduction of aircraft noise, emissions of oxides of nitrogen, and fuel burn. NASA s Environmentally Responsible Aviation (ERA) project has set aggressive goals in these three areas including a noise goal of 42 dB cumulative below the Stage 4 certification level. The goal for the reduction of oxides of nitrogen is 75% below the current standard. The fuel burn reduction goal is 50% below that of a current state-of-the-art aircraft. Furthermore, the overall goal of ERA is to mature technologies that will meet these goals simultaneously and with a timeframe of 2020 for technical readiness. This paper outlines the key technologies and the progress achieved to date toward the goals.

Collier, Fayette↗
NASA NTRS2016

Thermomechanical and Environmental Durability of Environmental Barrier Coated Ceramic Matrix Composites Under Thermal Gradients

This paper presents the developments of thermo-mechanical testing approaches and durability performance of environmental barrier coatings (EBCs) and EBC coated SiCSiC ceramic matrix composites (CMCs). Critical testing aspects of the CMCs will be described, including state of the art instrumentations such as temperature, thermal gradient, and full field strain measurements; materials thermal conductivity evolutions and thermal stress resistance; NDE methods; thermo-mechanical stress and environment interactions associated damage accumulations. Examples are also given for testing ceramic matrix composite sub-elements and small airfoils to help better understand the critical and complex CMC and EBC properties in engine relevant testing environments.]

Enviornmental Barrier Coatings↗
NASA NTRS2022

Environmental Justice Needs Assessment for Disasters: Assessing the Landscape and Capacity of Organizations & Communities Working Towards Environmental Justice with Potential to Use NASA Earth Observations to Support Equitable Disaster Management and Risk Reduction

Natural disasters pose an increasing risk to communities worldwide. Marginalized populations, in particular, experience compounding vulnerabilities that contribute to unequal burdens of natural hazards as a result of systemic inequality stemming from historical disenfranchisement, disinvestment, and discriminatory policies such as racial redlining. This project connected with community organizations working at the intersection of environmental justice (EJ) and natural disaster management throughout the United States, to assess how NASA DEVELOP can leverage geospatial science to advance EJ efforts. Our team conducted a landscape analysis, which included a literature review, annotated bibliography, and identification of organizations working in EJ and disasters. We engaged EJ organizations in discussions to understand their current resources, challenges, and geospatial needs to inform how DEVELOP and NASA Applied Sciences can support their EJ and disaster work. Findings were compiled in a synthesis report and visualized in an ArcGIS StoryMap to showcase the work of EJ organizations, provide geospatial resources for them to explore, and provide examples of how remote sensing can be utilized in EJ and disasters work. The knowledge gained and end products created support the integration of EJ in future DEVELOP projects, and the expanded use of Earth observations by communities in support of a more just tomorrow.

Julianne Liu↗
NASA NTRS2022

Environmental Justice Needs-Assessment For Health & Air Quality: Assessing the Needs and Capacity of Organizations Working Towards Health and Environmental Justice Related to Health and Air Quality

Health and air quality are concerns in environmental justice (EJ) work, as air contaminants and their adverse health effects inequitably impact communities that are often underrepresented in research and litigation. Previously, the NASA DEVELOP National Program partnered with organizations that focus on a variety of health and air quality concerns and is now committed to partnering directly with EJ organizations to address inequities in health and air quality through the application of Earth observations. To support the establishment of future partnerships, DEVELOP is working to identify potential partners for further EJ research in the U.S. regarding health and air quality. This project conducted a needs assessment with EJ organizations to quantify their EJ involvement, geospatial capacity, and interest in collaborating with DEVELOP. A broad literature review identified multiple factors influencing health and air quality for potential DEVELOP projects: agriculture, heat, wildfires, industry and transportation infrastructure, and miscellaneous factors (e.g., burning, urban heat island effect, smoke plumes, truck exhaust, and noise). The needs assessment showed that 22% of the organizations interviewed were primarily concerned with transportation infrastructure, 21% with industry, 19% with heat, 10% with miscellaneous factors (e.g., resource mining, COVID-19), 8% with wildfires, 7% with agriculture, and 6% with resource mining. This will help inform the DEVELOP Program's pursuit of EJ projects relating to health and air quality. The team also created a directory for communities impacted by air pollutants to connect with geospatial resources and NASA Applied Sciences personnel for future EJ health and air quality work.

Elizabeth Duran↗
DOE OSTI2013

An environmental sample chamber for reliable scanning transmission x-ray microscopy measurements under water vapor

We have designed, fabricated, and tested a compact gas-phase reactor for performing in situ soft x-ray scanning transmission x-ray microscopy (STXM) measurements. The reactor accommodates many gas atmospheres, including reactive or corrosive gasses, but was designed specically to address the needs of measurements under water vapor. An on-board sensor measures the relative humidity and temperature inside the reactor, minimizing uncertainties associated with measuring these quantities outside the instrument. The reactor mounts directly to the existing sample holder used in the majority of STXM instruments around the world and installs with minimal instrument reconguration. Using the reactor contributes over 85% less additional absorption compared to lling the STXM chamber with process gas, and results in much more stable imaging conditions. The reactor is in use at the STXM instruments at beamlines 11.0.2 and 5.3.2.2 at the Advanced Light Source.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2020

OES-Environmental 2020 State of the Science Report: Environmental Effects of Marine Renewable Energy Development Around the World. Report for Ocean Energy Systems (OES)

This report summarizes the state of the science related to marine renewable energy devices and their interactions with and effects on the marine environment, the animals that live there, and the habitats that support them. This report serves an update and a complement to the 2016 Annex IV report. https://tethys.pnnl.gov/publications/state-of-the-science-2020

03 NATURAL GAS↗
DOE OSTI2017

Nonlinear response of hail precipitation rate to environmental moisture content: A real case modeling study of an episodic midlatitude severe convective event: Hail and Environmental Moisture

The dependence of hail production on initial moisture content in a simulated midlatitude episodic convective event occurred in northeast China on 10–11 June 2005 was investigated using the Weather Research and Forecasting (WRF) model with a double-moment microphysics scheme where both graupel and hail are considered. Three sensitivity experiments were performed by modifying the initial water vapor mixing ratio profile to 90% (“Q-10%”), 105% (“Q+5%”), and 110% (“Q+10%”) of the initial conditions used for the control simulation. It was found that increasing the initial water vapor content caused the hail and total precipitation rates to increase during the first 5 h. The precipitation response to increasing water vapor content was monotonic for this first episode; however, for the event's second episode, the hail precipitation rate responds to the initial water vapor profile nonlinearly, while the total precipitation rate responds mostly monotonically. In particular, simulation Q+5% achieves the largest hail production rate while simulation Q+10% has the largest total precipitation rate. In contrast, during the second episode simulation Q-10% has the strongest vertical motion, produces the most cloud ice and snow, but has the lowest hail production. Analysis shows that increasing the initial moisture content directly increases the precipitation during the first episode, which subsequently induces a stronger, longer-asting cold pool that limits the development of deep convection during the second episode.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

The role of environmental driving factors in historical and projected carbon dynamics of wetland ecosystems in Alaska

Abstract Wetlands are critical terrestrial ecosystems in Alaska, covering ~177,000 km 2 , an area greater than all the wetlands in the remainder of the United States. To assess the relative influence of changing climate, atmospheric carbon dioxide (CO 2 ) concentration, and fire regime on carbon balance in wetland ecosystems of Alaska, a modeling framework that incorporates a fire disturbance model and two biogeochemical models was used. Spatially explicit simulations were conducted at 1‐km resolution for the historical period (1950–2009) and future projection period (2010–2099). Simulations estimated that wetland ecosystems of Alaska lost 175 Tg carbon (C) in the historical period. Ecosystem C storage in 2009 was 5,556 Tg, with 89% of the C stored in soils. The estimated loss of C as CO 2 and biogenic methane (CH 4 ) emissions resulted in wetlands of Alaska increasing the greenhouse gas forcing of climate warming. Simulations for the projection period were conducted for six climate change scenarios constructed from two climate models forced under three CO 2 emission scenarios. Ecosystem C storage averaged among climate scenarios increased 3.94 Tg C/yr by 2099, with variability among the simulations ranging from 2.02 to 4.42 Tg C/yr. These increases were driven primarily by increases in net primary production (NPP) that were greater than losses from increased decomposition and fire. The NPP increase was driven by CO 2 fertilization (~5% per 100 parts per million by volume increase) and by increases in air temperature (~1% per °C increase). Increases in air temperature were estimated to be the primary cause for a projected 47.7% mean increase in biogenic CH 4 emissions among the simulations (~15% per °C increase). Ecosystem CO 2 sequestration offset the increase in CH 4 emissions during the 21st century to decrease the greenhouse gas forcing of climate warming. However, beyond 2100, we expect that this forcing will ultimately increase as wetland ecosystems transition from being a sink to a source of atmospheric CO 2 because of (1) decreasing sensitivity of NPP to increasing atmospheric CO 2 , (2) increasing availability of soil C for decomposition as permafrost thaws, and (3) continued positive sensitivity of biogenic CH 4 emissions to increases in soil temperature.

Lyu, Zhou↗
DOE OSTI2016

Completing the Link between Exposure Science and Toxicology for Improved Environmental Health Decision Making: The Aggregate Exposure Pathway Framework

Driven by major scientific advances in analytical methods, biomonitoring, and computational exposure assessment, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the computationally enabled “systems approaches” used in the biological sciences is a necessary step in this evolution. Here we propose the aggregate exposure pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the adverse outcome pathway (AOP) concept in the toxicological sciences. The AEP framework offers an intuitive approach to successful organization of exposure science data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathway and adverse outcome pathways, completing the source to outcome continuum and setting the stage for more efficient integration of exposure science and toxicity testing information. Together these frameworks form and inform a decision making framework with the flexibility for risk-based, hazard-based or exposure-based decisions.

Teeguarden, Justin G.↗
DOE OSTI2018

Dynamic, Intermediate Soil Carbon Pools May Drive Future Responsiveness to Environmental Change

Accurately capturing dynamic soil response to disturbance effects in agroecosystem models remains elusive, thereby limiting projections of climate change mitigation potential. Perennial grasses cultivated in zero‐tillage management systems hold promise as sustainable agroecosystems. High‐yielding tropical C 4 grasses often have extensive rooting systems, and the belowground processes of root turnover, aggregate formation, and mineral stabilization drove rapid C accumulation after cultivation in a recent study. We sought (i) to understand and constrain the size and responsiveness of dynamic, intermediate‐cycling C pools contributing to the observed C accrual rates, and (ii) to simulate C stocks over time under the disturbance of elevated temperature using soil incubation at multiple temperatures and physical fractionation via density and sonication. Three‐pool transfer modeling of soil incubations revealed small pools of readily available (i.e., days to months) microbial substrate that were responsive to temperature, time since cultivation, and inputs. Larger, kinetically slow‐cycling pools were more indicative of long‐term (i.e., years to decades) changes in C stock and strongly connected to measured changes in physical fractions. Combining the sensitivity of readily available microbial substrate with three‐pool transfer modeling of the physical fractions over time since cultivation revealed that dynamic transfers of inputs occurred between the free organic and aggregate‐protected fractions, and from these fractions to the mineral‐associated dense fraction. Under 5°C temperature elevation, increased transfer rates outweighed elevated decomposition losses to sustain soil C accrual into the future. To effectively plan managed landscapes and monitor sustainable agroecosystems for climate change mitigation, tools must incorporate the complexity of soil response to change. Core Ideas Dynamic aspects of soil C are inadequately represented in most models. Intermediate‐cycling pools are more responsive to disturbances than thought. Root inputs are rapidly moved from particulate debris to mineral‐bound stable pools. Temperature increased the transfer rate to stable pools and sustained C accumulation Climate change mitigation projections must capture dynamic responses in agroecosystems.

Crow, Susan E.↗
DOE OSTI2021

Jaynesian Analysis of Environmental Chemistry: Systems Model Component Integration via the Arctic Aquatic Carbon Cycle

Focal Areas: All three are touched upon from the OBER call. We will consider formal logical inference and entropic information analysis for sparse but intensive chemical measurements, as optimal drivers for managing process complexity. As a centerpiece for the discussion we take soil-to-sea organic structural evolution within the Arctic hydro-geochemosphere, assessing detrital negentropy then algorithmic greed to generate ranked, reduced mechanisms for system integration.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

2024 OES-Environmental 2024 State of the Science Report, Chapter 1: Marine Renewable Energy and Ocean Energy Systems-Environmental

For many countries, marine renewable energy (MRE) is the most recent entry into their renewable energy portfolio. MRE involves the generation of energy from the movement of seawater including tides, waves, and persistent ocean currents, as well as from the gradients of temperature and salinity in the oceans. Some countries also include energy generation from the open waters of large rivers as part of MRE. Each MRE resource requires a different type of device to harvest that energy, placed in the appropriate portion and depth of the ocean or large river and secured to the seabed either by weight or by anchors. At full scale, these devices are large; Figure 1.1 puts the size of these devices in the context of other technologies and well-known landmarks for scale. The MRE devices generally represent the largest devices available.

16 TIDAL AND WAVE POWER↗
DOE OSTI2024

2024 OES-Environmental 2024 State of the Science Report, Chapter 2: Progress in Understanding Environmental Effects of Marine Renewable Energy

Over the past two decades, researchers, in collaboration with the marine renewable energy (MRE) industry and regulatory agencies, have examined the potential effects of MRE, focusing on the stressor-receptor approach to categorize the most significant potential risks for tidal stream, riverine, persistent ocean currents, and wave energy devices (Copping et al. 2024). Recent interest in examining potential effects of ocean thermal energy conversion (OTEC) and salinity gradient energy production has initiated investigations in those areas as well.

16 TIDAL AND WAVE POWER↗