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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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Searching for Grid-Forming Technologies That Do Not Impact Protection Systems: A promising technology
The design of legacy-line protection elements has been guided by the behavior of synchronous machines during faults. Because of the significant field-winding inductance and rotating mass, the magnitude, angular frequency, and phase angle of the back-electromotive force (EMF) voltage waveforms of synchronous machines remain practically constant for several hundreds of milliseconds after a fault occurs. Furthermore this has facilitated the engineering of the memory-polarization technique in mho distance elements, which has been effective for machine-dominant power grids. However, this assumption is no longer held for inverter-based resources (IBRs) because of the lack of field winding and moment of inertia in power electronics devices. Notably, the negative-sequence directional overcurrent protection and the quadrilateral distance elements have been impacted by early IBRs with grid-following (GFL) controls because they did not inject negative-sequence currents during asymmetrical faults.
Recent Progress in Solid Oxide Cell Technology Analysis at National Energy Technology Laboratory
This is a presentation delivered at the 2024 FECM/NETL Spring Project Review Meeting as part of the Reversible Solid Oxide Fuel Cell track. The presentation highlights recent progress made in the system analysis efforts as part of the NETL SOFC Field Work Proposal in 2023-2024.
Low Greenhouse Gas (GHG) Vehicle Technologies Research, Development, Demonstration and Deployment Topic 5 Natural Gas Engine Enabling Technologies
A 10 liter natural gas engine has been developed with significant improvements in efficiency while maintaining ultra low NOx emissions and meeting all other EPA criteria emissions limits. This was accomplished through design and analysis of performance components specifically for operation with natural gas in contrast to current production engines which are a minimally modified diesel engine that retain most diesel design features including a flat deck swirl head. The architecture developed here includes a pent roof cylinder head with tumble charge motion and cooling passages specifically optimized for effective cooling around the spark plug and valve bridges. Also in contrast to current production natural gas engines, EGR was not used, in part to avoid the initial cost and warranty expense associated with EGR systems, but also for performance benefits of faster combustion, reduced risk of misfire and high open cycle efficiency due to the turbocharger’s ability to extract energy from the high temperature exhaust. The exhaust manifold uses high temperature material and thermal mechanical fatigue analysis was completed to ensure the ability to withstand high exhaust temperatures without EGR. Other features include dual overhead cam with late intake valve closing Miller cycle and 14:1 compression ratio steel pistons. Low NOx emissions are achieved with stoichiometric combustion and application of a close coupled plus underfloor three way catalysts. The program target of peak brake thermal efficiency of 42% has been demonstrated along with bsNOx of 0.02 g/hp-hr over HD-FTP and RMCSET emissions cycles.
MassIVE MSV000100641 - Multilayered regulation by RNA thermometers enables precise control of Cas9 expression in E. coli: Cas9-based genome editing technologies can rapidly generate mutations to probe a diverse array of mutant genotypes. However, aberrant Cas9 nuclease translation and activity can occur despite the use of inducible promoters to control expression, leading to extensive cell death. This background killing caused by promoter leakiness severely limits the application of Cas9 for generating mutant libraries because of the potential for population skew. We demonstrate the utility of temperature sensitive RNA elements as a layer of post-transcriptional regulation to reduce the impact of promoter leak. We observe significant temperature-dependent increases in cell survival when certain RNA thermometers (RNATs) are placed upstream of the cas9 coding sequence. We also show that the most highly repressing RNAT, hsp17rep, significantly reduces population skew with a library of characterized guide RNAs in Escherichia coli. This strategy should be applicable to all bacterial Cas9-based methods and technologies.
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The future of welding technology. IV - Some considerations of advanced welding technology.
Welding technique advances and testing of bond integrity for microcircuit fabrication
Research and advanced development. Volume 2 - Supporting research and technology for the Office of Advanced Research and Technology National Aeronautics and Space Administration Semiannual review, 1 Jan. - 30 Jun. 1965
Research and advanced development data on nuclear electric propulsion, spacecraft design and systems engineering, electronics systems, and chemical propulsion
Operation of a NASA technology utilization regional dissemination center. Volume 2 - Regional utilization of NASA generated space technology Final report
Organizational plan, operational procedures, and management and technical services of regional dissemination center
Study of technology requirements for structures of large launch vehicles. Volume 3 - Survey of advanced structures technologies Final report
Aluminum honeycombs in launch vehicles and other configurations
Measurement component technology. Volume 2: Cryogenic flow measurement and cryogenic liquid detection measurement technology
For abstract, see N74-27185.
Measurement component technology. Volume 3: Cryogenic temperature measurement and high temperature strain gage technology
For abstract, see N74-27185.
Biomedical technology transfer: Application of NASA science and technology
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Technology utilization in a non-urban region: Further impact and technique of the Technology Use Studies Center (6)
The activities of the TU Center are reported. Areas reported include: TUSC clientele informaton, dissemination and assistance, faculty information service, and cooperation with other agencies. The general aviation news letter is included along with transfer and impact reports.
Benefits from NASA-developed technology: Technology applications in industry
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NASA Office of Aeronautics and Space Technology Summer Workshop. Volume 9: Entry technology panel
An advanced space transportation system heavy lift orbiter, hypersonic atmospheric entry missions, development of an emergency astronaut life boat, and basic research in boundary layer transition are among the topics discussed. Emphasis is placed on the need for space testing and for better mathematical models describing the flow fields around complex structures.
The evolution of aerospace guidance technology at the Massachusetts Institute of Technology, 1935 - 1951: A memoir
Early developments in inertial guidance systems design are described.
Technology utilization in a non-urban region: Further impact and technique of the Technology Use Center
Performance information for the center is reported. The search production during the reporting period exceeds the production record of the center during any period in its 14 year history. A performance average of 30 searches per month, which represents an increase of 45%, is reported. Numerical listings of the searches processed are given. A section of transfer and impact report is included.
Supporting Research and Technology (SRT) session: Status of yield estimation technology, a review of second-generation model development
There are no author-identified significant results in this report.