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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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Single crystal metal film formation on alkali halides, crystal structure and electron emission properties of work functions, and relativistic effects on slow electron scattering
Arc jet engine, lifetests, and pulsed performance
Growth parameters in synthesis of boron carbide whiskers
Electric resistivity measurements to determine solubility and diffusion of oxygen in tantalum, columbium, and alloys
Planetary quarantine mission
Solar energy thermionic generator
Multisweep cyclic voltammetry for electrochemical characterization of systems for secondary battery application
Development work for pile type, nickel-cadmium squib battery
Photovoltaic power system design optimization and procedures for five interplanetary missions
Tissue irradiated with protons and thermal/fast neutrons to study induced radioactive isotope production in astronauts
Process development for chemical deposition of aluminum oxide films as refractory dielectrics for integrated circuits
Mathematical filter scheme for bounding cross correlation between random forcing function and state error in orbital navigation system
Highlights and significant accomplishments of Advanced Gas Reactor (AGR) fuels development activities during January, February and March 2021
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FY21 Second Quarter Volume Report
The second quarter of the project was spent carrying out numerical experiments on a variety of test matrices, using a combination of precisions, with the intent to study the numerical properties (namely, accuracy and convergence behavior) of the Conjugate Gradient (CG) method. We summarize our findings in the remainder of the document. Other activities include attending biweekly xSDK meetings. We are also currently collaborating with Steven Thomas (NREL) on the numerical stability analysis of “low-synch” Gram-Schmidt routines, for potential application within high-performance GMRES variants. This work is in progress. The subsequent quarter will be spent delving into the numerical analysis in order to provide theoretical explanation for the behavior observed in our experiments.
Calendar Year 24 Second Quarter Asbestos Report for Permit SW532
In the role of structural health monitoring (SHM), Acoustic Emission (AE) analysis is being investigated as an effective method for tracking damage development in large composite structures under load. Structures made using Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) for damage tolerant, light, and economical airframe construction are being pursued by The Boeing Company and NASA under the Environmentally Responsible Aircraft initiative (ERA). The failure tests of two PRSEUS substructures based on the Boeing Hybrid Wing Body fuselage concept were conducted during third quarter 2011 and second quarter 2015. One fundamental concern of these tests was determining the effectiveness of the stitched integral stiffeners to inhibit damage progression. By design, severe degradation of load carrying capability should not occur prior to Design Ultimate Load (DUL). While minor damage prior to DUL was anticipated, the integral stitching should not fail since this would allow a stiffener-skin delamination to progress rapidly and alter the transfer of load into the stiffeners. In addition, the stiffeners should not fracture because they are fundamental to structural integrity. Getting the best information from each AE sensor is a primary consideration because a sparse network of sensors is implemented. Sensitivity to stiffener-contiguous degradation is supported by sensors near the stiffeners, which increases the coverage per sensor via AE waveguide actions. Some sensors are located near potentially critical areas or "critical zones" as identified by numerical analyses. The approach is compared with the damage progression monitored by other techniques (e.g. ultrasonic C-scan).