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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Safety Hazards of Batteries and Hydrogen Storage Systems in Proximity

This report addresses the safety concerns and mitigations for battery failures and their impact on hydrogen storage systems. Through an analysis of failure modes, this report highlights the risks posed by thermal runaway and chemical emissions caused by batteries. Although rare, battery thermal failure events may prompt the opening of the relief valve on the hydrogen tank. Strategies such as battery management systems, thermal management systems, and multiple thermally activated pressure relief devices can mitigate these risks. Potential simulations and experiments to better quantify the unique risks posed by lithium-ion batteries near tanks are suggested. Improving safety standards will enable integration of batteries and hydrogen storage systems in various energy storage technologies.

08 HYDROGEN↗
DOE OSTI2025

Charge radii measurements of exotic tin isotopes in the proximity of $N=50$ and $N=82$

We report nuclear charge radii for the isotopes $^{104-134}$Sn, measured using two different collinear laser spectroscopy techniques at ISOLDE-CERN. These measurements clarify the archlike trend in charge radii along the isotopic chain and reveal an odd-even staggering that is more pronounced near the $N=50$ and $N=82$ shell closures. The observed local trends are well described by both nuclear density functional theory and valence space in-medium similarity renormalization group calculations. Both theories predict appreciable contributions from beyond-mean-field correlations to the charge radii of the neutron-deficient tin isotopes. The models fall short, however, of reproducing the magnitude of the known $B(E2)$ transition probabilities, highlighting the remaining challenges in achieving a unified description of both ground-state properties and collective phenomena.

FOS: Physical sciences↗
NASA NTRS1969

Gas Metal Arc /GMA/ weld torch proximity control

Adjustable transducer probe, which is attached to a welding torch and maintains a preset touch-to-work distance, accurately follows irregular surfaces, is less sensitive to heat and static interference, and has more positive response because of electro-mechanical control.

Hawkes, E. D.↗
NASA NTRS1971

Proximity effect between superconducting and normal metals

Electrical characteristics of thin films of tin vapor deposited on gold substrates are described. Favorable characteristics of these films include: (1) shiny and smooth finishes; (2) higher Josephson critical currents; (3) smaller electronic mean paths; and (4) consistent current-voltage curve shapes. One unfavorable characteristic is a much steeper increase of the Josephson critical current with decreasing temperature. The functional variation of the Josephson current with the control current is described. Two functional forms have been observed and a brief description as to possible mechanisms for this behavior have been included.

Meissner, H.↗
NASA NTRS1972

Proximity effect between superconductivity and normal metals

The SNS junctions were limited to having gold (n) layers of less than 3000 A in order to avoid having the tin (S) films become normal under the influence of the signal current in the gold. The gold layer was alloyed with 10 wt% copper to shorten its electronic mean free path, increasing the tin layer critical current while decreasing the Josephson critical current. It was also found that a previously reported anomalous voltage shift in the presence of I2 is caused by the tin being driven normal. After deposition, the samples were transferred to a conventional cryostat to provide better thermal contact to the films. This reduction of heating in the films produced more linear I-V characteristics and a change in the constant voltage current gain. In order to achieve power gain the SNS device must be operated at lower temperatures were the effects of fluctuations are less and be constructed such that the input resistance is much reduced and the dynamic output resistance increased. A geometry is proposed using a more sophisticated evaporator.

Meissner, H.↗
NASA NTRS1972

Study of ground proximity effects on powered-lift STOL landing performance

Data from wind-tunnel measurements are presented to show the magnitude of adverse ground effects on the longitudinal aerodynamic coefficients of a powered-lift STOL airplane. A steady-state analysis shows the changes in thrust and angle of attack required during the landing approach and flare as the airplane flies close to the ground. The piloting problems that these ground effects may create were investigated with an in-flight simulator to find the consequences of lift loss during the landing-flare maneuver for a STOL transport. Flight tests were made using the variable stability Navion setup with STOL transport aerodynamics and control responses and were flown at design approach speeds and descent conditions.

Hassell, J. L., Jr.↗
NASA NTRS1977

Optical proximity detector

Sensitive, relatively inexpensive instrument uses phase-detection techniques to sense presence of objects. Phase-sensitive detectors, LED, photodiode with response matched to LED output, and filtering lens allow detector to operate over narrow radiation band, giving selectivity over stray light.

Hermann, W. A.↗