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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2024

Sensitivity studies of nighttime top-of-atmosphere radiances from artificial light sources using a 3-D radiative transfer model for nighttime aerosol retrievals

By accounting for surface-based light source emissions and top-of-atmosphere (TOA) downward lunar fluxes, we adapted the spherical harmonics discrete ordinate method (SHDOM) 3-dimensional (3-D) radiative transfer model (RTM) to simulate nighttime 3-D TOA radiances as observed from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) on board the Suomi-NPP satellite platform. Used previously for daytime 3-D applications, these new SHDOM enhancements allow for the study of the impacts of various observing conditions and aerosol properties on simulated VIIRS-DNB TOA radiances. Observations over Dakar, Senegal, selected for its bright city lights and a large range of aerosol optical depth (AOD), were investigated for potential applications and opportunities for using observed radiances containing VIIRS-DNB “bright pixels” from artificial light sources to conduct aerosol retrievals. We found that using the standard deviation (SD) of such bright pixels provided a more stable quantity for nighttime AOD retrievals than direct retrievals from TOA radiances. Further, both the mean TOA radiance and SD of TOA radiances over artificial sources are significantly impacted by satellite viewing angles. Light domes, the enhanced radiances adjacent to artificial light sources, are strong functions of aerosol properties and especially aerosol vertical distribution, which may be further utilized for retrieving aerosol layer height in future studies. Through inter-comparison with both day- and nighttime Aerosol Robotic Network (AERONET) data, the feasibility of retrieving nighttime AODs using 3-D RTM SHDOM over artificial light sources was demonstrated. Our study shows strong potential for using artificial light sources for nighttime AOD retrievals, while also highlighting larger uncertainties in quantifying surface light source emissions. This study underscores the need for surface light emission source characterizations as a key boundary condition, which is a complex task that requires enhanced input data and further research. We demonstrate how quality-controlled nighttime light data from NASA’s Black Marble product suite could serve as a primary input into estimations of surface light source emissions for nighttime aerosol retrievals.

Jianglong Zhang↗
NASA NTRSDate not supplied

The NASA Disasters Response Coordination System’s (DRCS) Response to the 2024 Hurricane Season

The National Aeronautics and Space Administration (NASA) Disasters Response Coordination System (DRCS) leverages the best available science and expertise to aid federal, state, local, and non-governmental organization (NGO) partners in addressing identified needs during a disaster response. During the 2024 hurricane season, the DRCS activated for seven hurricanes/tropical storms, providing openly available geospatial data through NASA’s Disasters Mapping Portal. Hurricanes Helene and Milton were major hurricanes that impacted the southeastern United States within weeks of one another. Impacts from Helene and Milton to the region included inland flooding, record coastal storm surge, over a thousand landslides, and regional power and telecommunications outages. In response to Helene and Milton, DRCS provided actionable information and products to stakeholders, including Synthetic Aperture Radar (SAR) analysis for landslide and flood detection, Black Marble nighttime lights products for assessing power outages, and Normalized Difference Vegetation Index (NDVI) analysis for post-event vegetation change detection. NASA deployed an Uninhibited Aerial Vehicle SAR (UAVSAR) instrument to collect data on flood extent, providing crucial information on affected communities. Additionally, astronauts aboard the International Space Station (ISS) collected hand-held photography along the paths of Hurricane Helene and Milton to aid in response efforts. Here, we summarize the DRCS responses to Helene and Milton, in particular highlighting the information and products that were provided by the DRCS and how they were utilized by partners to address immediate response needs.

Earth observations↗
DOE OSTI2025

BEAM ACCELERATION WITH A Nb3Sn CRYOMODULE AT JLAB

We report on the electron beam acceleration experiment with a Nb3Sn cryomodule at Thomas Jefferson National Laboratory (JLAB). Two CEBAF-style 5-cell 1.5 GHz Nb3Sn cavities operated at 4 K, accelerating a 100 nA continuous-wave (CW) electron beam from 200 keV to 4 MeV at JLAB’s Upgraded Injector Test Facility (UITF). The acceleration gradients in each cavity reached 11 MV/m and 7 MV/m, respectively. No field emission was observed. The unloaded quality factors reached 2¿109 at low fields at 4 K.

Geng, R. [Thomas Jefferson National Accelerator Fa↗
DOE OSTI2020

Dry and Wet CO 2 Capture from Milk‐Derived Microporous Carbons with Tuned Hydrophobicity

Abstract Pore size distribution and surface chemistry of bio‐derived (milk) microporous dominated carbon “MDC” is synergistically tuned, allowing for promising carbon capture in a dry CO 2 atmosphere and in mixed H 2 O–CO 2 . The capture capacity is attributed to the synergy of a large total surface area with an ultramicroporous and microporous texture (e.g., S tot 1889 m 2 g −1 , S mic 1755 m 2 g −1 , S ultra 1393 m 2 g −1 ), and a high content of nitrogen and oxygen heteroatom moieties (e.g., 5 at% N, 10.5 at% O). Tailored two‐step low‐temperature pyrolysis‐chemical activation is employed to take advantage of the intrinsic properties of the precursor, allowing for this unusual textural properties‐heteroatoms combination. For example, tested at 1 bar and 295 or 273 K, MDCs adsorb up to 22.0 and 29.4 wt% CO 2 , respectively. MDCs are also tailored to be hydrophobic, with CO 2 /H 2 O adsorption selectivity even after prolonged cycling. Maximum working capacities of 10.8 wt% for pure CO 2 and 3.5 wt% for a flue gas simulant (15% CO 2 , 85% N 2 ) are measured using temperature swing adsorption with dynamic purge gases, while being minimally affected by humid conditions. This work is directly aligned with the United Nation’s Sustainable Development Goal 13, take urgent action to combat climate change and its impacts.

Pokrzywinski, Jesse↗
DOE OSTI2021

The TAMUTRAP facility: A Penning trap facility at Texas A&M University for weak interaction studies

The Texas A&M University Penning Trap (TAMUTRAP) facility aims to test the standard model of the electroweak interaction by measuring the β-ν correlation parameter, a βν , for β-delayed proton emitters in the atomic mass range 20 < A < 40. Precision measurements of this correlation parameter and, inextricably, the Fierz interference parameter, are a sensitive probe of physics beyond the standard model. Here, using off-line ion sources, the TAMUTRAP facility has been commissioned by demonstrating the ability to manipulate the trapped-ion motions as well as to perform precision mass measurements. Our novel cylindrical Penning trap – the world's largest – differs from typical designs in two key aspects: the electrode structure has an 180-mm inner diameter and an overall length of 334.89 mm leading to a uniquely small length/radius ratio l/r = 3.72; and we do not use the long end cap approximation, instead our short endcap electrodes are closed and capable of being placed at an arbitrary potential. This geometry is optimized for observing β-delayed proton decays, but is also well suited for other in-trap and post-trap precision decay experiments. In addition to presenting an overview of the TAMUTRAP facility, we demonstrate that our unique Penning trap is able to measure masses with a precision similar to typical trap designs.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Microtomographic Measurements of Total Air‐Water Interfacial Areas for Soils

Abstract Synchrotron X‐ray microtomography (XMT) was used to measure total air‐water interfacial areas (A aw ) as a function of water saturation (S w ) for several soils that comprise a range of physical and geochemical properties. Measurements were also conducted for glass beads and quartz sands for comparison. Apparent near‐linearA aw ‐S w relationships are observed for the three sands and the three sandy soils. In contrast, the measured interfacial areas for two soils that contain greater proportions of silt and clay are strongly nonlinear functions of water saturation. The greater degree of nonlinearity observed for these two soils is due to their much greater particle‐size distributions (i.e., uniformity coefficients) and their concomitant greater range in pore sizes. Interfacial areas determined with the thermodynamic method were used to benchmark the XMT measurements. XMT‐measured interfacial areas compare well to the thermodynamic‐determined values for the sands and sandy soils. In contrast, the XMT‐measured interfacial areas for the two soils with larger particle‐size distributions are not fully congruent with the thermodynamic‐determined values. Both of these soils have large fractions of pore space comprising nominal pore diameters smaller than the resolution of the XMT imaging. These results suggest that air‐water interfacial area may not always be fully characterized by standard XMT for soils with large particle‐size distributions.

Environmental Sciences & Ecology↗
DOE OSTI2021

Geothermal Energy R&D: An Overview of the U.S. Department of Energy’s Geothermal Technologies Office

Geothermal energy can provide answers to many of America’s essential energy questions. The United States has tremendous geothermal resources, as illustrated by the results of the DOE GeoVision analysis, but technical and non-technical barriers have historically stood in the way of widespread deployment of geothermal energy. The U.S. Department of Energy’s Geothermal Technologies Office within the Office of Energy Efficiency and Renewable Energy has invested more than $470 million in research and development (R&D) since 2015 to meet its three strategic goals: (1) unlock the potential of enhanced geothermal systems, (2) advance technologies to increase geothermal energy on the U.S. electricity grid, and (3) support R&D to expand geothermal energy opportunities throughout the United States. Here, we describe many of those R&D initiatives and outlines future directions in geothermal research.

energy storage systems↗
DOE OSTI2025

Fluid/Fluid Interfacial Areas Measured for Different Non-Wetting/Wetting Fluid Pairs in Natural Porous Media

This study examined the impact of fluid type and grain diameter on the interfacial area between different pairs of non-wetting and wetting fluids in natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of multi-phase porous media systems. Multiple porous media, comprising a range of physical and geochemical properties, were used in this study. The four pairs of non-wetting/wetting fluids used were dense OIL/water, light OIL/water, air/dense OIL, and air/water. Images were obtained over a broad range of wetting phase saturation and for both wetting phase drainage and imbibition conditions. The results showed that for each fluid pair, the total (capillary + film) interfacial area increased with decreasing wetting fluid saturation. Interfacial areas were similar among all fluid pairs for a given porous medium. They were also similar for drainage and imbibition conditions. The maximum specific interfacial area (A m ) was shown to correlate well with inverse median grain diameter. The physical properties of the porous medium appear to have a greater influence on the magnitude of specific total interfacial area for a given saturation than fluid properties or wetting phase history.

NAPL↗
NASA NTRS1957

Unsteady Flows in Axial Turbomachines

Of the various unsteady flows that occur in axial turbomachines certain asymmetric disturbances, of wave length large in comparison with blade spacing, have become understood to a certain extent. These disturbances divide themselves into two categories: self-induced oscillations and force disturbances. A special type of propagating stall appears as a self-induced disturbance; an asymmetric velocity profile introduced at the compressor inlet constitutes a forced disturbance. Both phenomena have been treated from a unified theoretical point of view in which the asymmetric disturbances are linearized and the blade characteristics are assumed quasi-steady. Experimental results are in essential agreement with this theory wherever the limitations of the theory are satisfied. For the self-induced disturbances and the more interesting examples of the forced disturbances, the dominant blade characteristic is the dependence of total pressure loss, rather than the turning angle, upon the local blade inlet angle.

Marble, F. E.↗
NASA NTRS1968

Remote sensing of urban environments.

Remote sensing of urban environments for metropolitan information systems noting photographic, thermal IR, radar and microwave applications

Alexander, R. H.↗