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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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Vibro-Acoustic Propagation of Gear Dynamics in a Gear-Bearing-Housing System
Abstract not provided
Evaluation of ASR in concrete using acoustic emission and deep learning
Not provided.
Glass fracture by focusing of laser-generated nanosecond surface acoustic waves
Not Available
Development of a High-Throughput Laser-Induced Acoustic Desorption Probe and Raster Sampling For Laser-Induced Acoustic Desorption/Atmospheric Pressure Chemical Ionization
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Lifetime of sub-THz coherent acoustic phonons in a GaAs-AlAs superlattice
Here we measure the lifetime of the zone-center 340 GHz longitudinal phonon mode in a GaAs-AlAs superlattice excited and probed with femtosecond laser pulses. By comparing measurements conducted at room temperature and liquid nitrogen temperature, we separate the intrinsic (phonon-phonon scattering) and extrinsic contributions to phonon relaxation. The estimated room temperature intrinsic lifetime of 0.95 ns is compared to available calculations and experimental data for bulk GaAs. We conclude that ~0.3 THz phonons are in the transition zone between Akhiezer and Landau-Rumer regimes of phonon-phonon relaxation at room temperature.
Phase transformations and indications for acoustic mode softening in Tb-Gd orthophosphate
Abstract not provided
Tracking scattered signals in the acoustic coda using independent component analysis in a topographically complex setting
Not Available