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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 595 records · Page 33

Checkerboard Patterns in E3SMv2 and E3SM-MMFv2

An unphysical checkerboard pattern is identified in E3SMv2 and E3SM-MMF that is detectable across a wide range of timescales, from instantaneous snapshots to multi-year averages. A detection method is developed to quantify characteristics of the checkerboard signal by cataloguing all possible configurations of the eight adjacent neighbors for each cell on the model's cubed sphere grid using daily mean data. The checkerboard pattern is only found in cloud-related quantities, such as precipitation and liquid water path. Instances of pure and partial checkerboard are found to occur more often in E3SMv2 and E3SM-MMF when compared to satellite data regridded to the model grid. Continuous periods of partial checkerboard state are found to be more persistent in both models compared to satellite data, with E3SM-MMF exhibiting more persistence than E3SMv2. The checkerboard signal in E3SMv2 is found to be a direct consequence of the recently added deep convective trigger condition based on dynamically generated CAPE (DCAPE). In E3SM-MMF the checkerboard signal is found to be associated with the “trapping” of cloud-scale fluctuations within the embedded cloud-resolving model. Solutions to remedy this issue are discussed.

E3SMv2↗

Effect of Varying HUT Sizing on Human-Spacesuit Contact Patterns

Fit, comfort, and mobility of the spacesuit rely on the location, magnitude, and type of contact between the suit and wearer. Typically, spacesuits include the Hard Upper Torso (HUT) comprising the upper torso of the spacesuit. Potential injuries from hard contact between the wearer’s shoulders and the HUT are a concern; therefore, to investigate spacesuit-wearer contact patterns, data from a retrospective study was analyzed. This study had eight subjects wearing the Shuttle Extravehicular Mobility Unit (EMU) spacesuit in two configurations, one with a nominally sized HUT and another with an oversized HUT. The subjects were sized per the NASA standard suit fit procedure. The suit’s arms and lower body were also resized to provide nominal arm and lower body fit, accounting for the larger HUT. Subjects held various shoulder postures (neutral posture, and various maximum shoulder rotations) with the suit pressurized to 4.3 PSI. For each posture, subjects reported the intensity of their perceived contact with the suit on a Borg CR10 scale, 0 indicating a non-existent contact intensity, and 10 representing a maximal contact intensity. Ratings were recorded for 11 regions covering the upper body and these ratings were used to determine the impact of body shape and size on suit contact. Our preliminary findings suggest that oversized HUTs had less contact regions than compared to the nominal HUT; and the region of contact, contact patterns, and contact intensities varied from person to person with the oversized HUT. This variance could be linked to subjects’ body shape and size. The next goal is to establish a causal factor between body shape and size, pose, contact region, and the HUT size. The outcome is expected to help understand the overall contact trends and insights into the influence of HUT sizing on suit fit.

Will Green↗

Anomalous Net Biome Exchange Over Amazonian Rainforests Induced by the 2015/16 El Niño: Temperature-dominated Total Flux but Soil Dryness-Shaped Spatial Pattern

The magnitude and spatial pattern of anomalous net biome exchange (NBE) induced by the 2015/16 El Niño over Amazonian rainforests remain uncertain. We here investigated them using multi-model posterior NBE products in the Orbiting Carbon Observatory-2 (OCO-2) version 10 modeling intercomparison project. Results suggest that relative to the annual NBE average in 2017/18, larger anomalous carbon release occurred over the eastern and northern Amazonian rainforests in 2015/16, with a total flux of approximately 0.4 PgC yr−1 after assimilating satellite-observed column CO2 concentrations (XCO2) over land. We further find that this anomalous spatial pattern was predominantly determined by soil dryness, while the total positive NBE anomaly was dominated by higher temperature with its contribution of approximately 68~70%. We believe that atmospheric inversions assimilating more satellite-observed XCO2 in future can provide us more comprehensive understanding how Amazonian rainforests cope with the abiotic stresses induced by El Niño events.

Jun Wang↗

Speckle Pattern for Woven Softgood Habitats Photogrammetry Testing

Space habitation is becoming more accessible and commercially available which is driving the development and testing of inflatable softgoods habitats that can be both lighter and more volume-efficient than heritage metallic pressure vessels. Photogrammetry test methods are used on new materials and larger inflatable softgood test articles to measure material displacement and strain during pressurization. A speckle pattern must be applied to the surface of interest for testing when using photogrammetry which is typically a very labor and time intensive process. Two methods were tested as options for a faster and more effective application to hand painting and temporary tattoos, which are the current application methods for the structural/restraint layer. One approach was to mix a plastic additive with a matte clear coat to create a speckle pattern that could be applied to the article. The second method uses a speckle paint gun to speckle the article after a white base coat is applied. Both methods adhered well to the Kevlar test sample materials and showed up well when examined with photogrammetry cameras. On the woven test samples the additive in a clear coat method could be applied evenly as was the paint gun method.

Rylee Cardon↗

Predicting Patterns of Solar Energy Buildout to Identify Opportunities for Biodiversity Conservation

The construction of solar energy facilities can have positive or negative impacts on biodiversity depending on siting and associated land use transitions. We identified drivers of solar siting and quantified patterns of buildout in states surrounding the Chesapeake Bay watershed – a biodiversity hotspot with numerous ecosystem services. Using a convolutional neural network, we mapped the footprints of ground-mounted solar arrays present in satellite imagery annually from 2017 to 2021 in Delaware, Maryland, Pennsylvania, New York, Virginia, and West Virginia. As of 2021, we identified 958 solar arrays covering 52.3 km2 built primarily on previously cultivated land, while avoiding natural landcover. We fit a binomial-Weibull model to these solar timeseries data in a hierarchical, Bayesian framework to quantify the relationship between geospatial covariates and rate of solar development. Solar array construction rate increased in cultivated areas, areas of lower agricultural suitability, lower slope, lower forest cover, lower biodiversity protection, and greater distances from roads. We also estimated changes in the rate of solar construction over time and found differences among states: acceleration in Virginia and deceleration in New York. We used parameter estimates to map the relative likelihood of future solar development across the study area. This methodology can be used to anticipate where solar is likely to be built in different landscapes and how these patterns align with conservation goals. Around the Chesapeake Bay watershed, the selection of lower quality agricultural areas for solar energy minimizes removal of important habitat and provides opportunities for native plant and pollinator restoration.

Artificial Intelligence↗

Speckle Pattern Application to Woven Softgoods

Space habitation is becoming more accessible and commercially available which is driving the development and testing of inflatable softgoods habitats that can be both lighter and more volume-efficient than heritage metallic pressure vessels. Photogrammetry test methods are used on new materials and larger inflatable softgood test articles to measure material displacement and strain during pressurization. A speckle pattern must be applied to the surface of interest for testing when using photogrammetry which is typically a very labor and time intensive process. Two methods were tested as options for a faster and more effective application to hand painting and temporary tattoos, which are the current application methods for the structural/restraint layer. One approach was to mix a plastic additive with a matte clear coat to create a speckle pattern that could be applied to the article. The second method uses a speckle paint gun to speckle the article after a white base coat is applied. Both methods adhered well to the Kevlar test sample materials and showed up well when examined with photogrammetry cameras. On the woven test samples the additive in a clear coat method could be applied evenly as was the paint gun method.

Rylee Cardon↗

Speckle Pattern Application to Woven Softgoods

Space habitation is becoming more accessible and commercially available which is driving the development and testing of inflatable softgoods habitats that can be both lighter and more volume-efficient than heritage metallic pressure vessels. Photogrammetry test methods are used on new materials and larger inflatable softgood test articles to measure material displacement and strain during pressurization. A speckle pattern must be applied to the surface of interest for testing when using photogrammetry which is typically a very labor and time intensive process. Two methods were tested as options for a faster and more effective application to hand painting and temporary tattoos, which are the current application methods for the structural/restraint layer. One approach was to mix a plastic additive with a matte clear coat to create a speckle pattern that could be applied to the article. The second method uses a speckle paint gun to speckle the article after a white base coat is applied. Both methods adhered well to the Kevlar test sample materials and showed up well when examined with photogrammetry cameras. On the woven test samples the additive in a clear coat method could be applied evenly as was the paint gun method.

Rylee Cardon↗