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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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Final report produced as part of grant awarded to National Grid. The final report is a roadmap of 39 prioritized sites. These sites would create a minimum viable network of charging infrastructure, enabling the electrification of trucks across the Northeast
Medium- and heavy-duty freight rely on service plazas and truck stops to refuel their vehicles and meet their obligations. Creating a reliable fast-charging network across the Northeast is critical to provide security for fleets to electrify.
This study presents an initial proof-of-concept for a satellite-based remote sensing approach to identify and monitor potential areas of poor tree health across the entire BPA service territory on an annual basis. We tested three variants of “delta peak NDVI” ( ΔPN ) change detection metrics that express interannual variation in primary productivity relative to a baseline by comparing ΔPN values for known insect/disease disturbances and nearby reference locations. All three metrics showed promise for detecting poor tree health in the year during disturbance, but the metric based on the difference from the long-term (2016-2024) median ( Δ Med PN ) was preferred due to its responsiveness to change in the years during and after disturbance, resilience to interannual variation, and ease of interpretation as being above or below normal. Comparison of Δ Med PN grouped by relative severity of disturbance indicated it was not sensitive enough to detect “low” severity disturbances, as mapped by USGS’s LANDFIRE program, but could distinguish “moderate” and “high” severity disturbances from reference locations. These findings informed selection of a threshold for Δ Med PN , which was combined with areas exhibiting negative NDVI to map potential areas of concern. Visual inspection of before/after high-resolution imagery and NDVI time series showed that many areas of concern aligned with visible signs of defoliation and die-off as well as other types of disturbance (e.g., landslides, logging, road grading, flooding). Some areas of concern are thought to be false detections caused by persistent shadow, and some could not be explained with visual inspection due to spatiotemporal limitations of before/after imagery. In summary, our approach shows promise for large-scale monitoring of tree health adjacent to BPA transmission lines, but additional work is recommended to improve model sophistication and remove noise.
Zero-emission Medium Duty and Heavy Duty vehicles (MD-HD ZEVs) hold great promise for reducing operational costs through use of more energy eAicient propulsion technology while reducing reliance on fossil fuels. Consistent with the Department of Energy’s focus on energy innovation, ZEVs and the necessary charging and refueling infrastructure to support them represent an important area of focus for technological advancement. Widespread adoption of MD-HD ZEVs can also provide benefits by improving air quality, and lowering carbon emissions in the transportation industry. Powertrain technologies are in production today to reduce tank-to-wheel and well-to-wheel emissions of commercial vehicles to zero or near-zero emissions, but significant development remains to bring down the cost and address the operational limitations of these technologies, particularly for larger vehicles. ZEV technologies have an opportunity to be an important part of a fleet’s mix of powertrains as capital and operational costs come down. However, the greatest challenge preventing widespread adoption of ZEVs may be the lack of adequate charging and hydrogen (H₂) fueling infrastructure.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Steepest ascent optimization procedure for reentry trajectory of manned aerospace vehicles
Approach navigation accuracy for planetary atmosphere braking to orbit about Mars and Venus
Approach navigation accuracy for planetary atmosphere braking to orbit about Mars and Venus
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Explore the source record for details and available documents.
There are no author-identified significant results in this report.
There are no author-identified significant results in this report.
There are no author-identified significant results in this report.
The author has identified the following significant results. A TV16 isoline map at the 6.25 million hectare extended test site area in north central Texas and southern Oklahoma was produced. The map was compared to a published USDA Statistical Reporting Service map, which shows pasture and range feed conditions, as reported by rancher respondents. Both maps show similar areas of drought stress and good to excellent forage conditions, but preliminary indications are that the LANDSAT-derived map more accurately depicts the areal extent of each condition class.
Thermal and equilibrium glide boundaries were used to analyze and/or design shuttle orbiter entry trajectories. Plots are presented of orbiter thermal and equilibrium glide boundaries in the drag/mass-relative velocity dynamic pressure-relative velocity, and altitude-relative velocity planes for an orbiter having a 32,000 pound payload and a 67.5% center of gravity location. These boundaries were defined for control points 1 through 4 of the shuttle orbiter for 40 deg-30 deg and 38 deg-28 deg ramped angle of attack entry profiles and 40 deg, 38 deg, 35 deg, 30 deg, 28 deg, and 25 deg constant angle of attack entry profiles each at 20 deg, 15 deg, and 10 deg constant body flap settings.
There are no author-identified significant results in this report.