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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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7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Sm(GaPd)2 by Materials Project

Sm(PdGa)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sm is bonded in a 8-coordinate geometry to eight equivalent Pd and eight equivalent Ga atoms. All Sm–Pd bond lengths are 3.38 Å. All Sm–Ga bond lengths are 3.28 Å. Pd is bonded to four equivalent Sm and four equivalent Ga atoms to form a mixture of distorted edge, face, and corner-sharing PdSm4Ga4 tetrahedra. All Pd–Ga bond lengths are 2.53 Å. Ga is bonded in a 9-coordinate geometry to four equivalent Sm, four equivalent Pd, and one Ga atom. The Ga–Ga bond length is 2.55 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca3(GaPd)2 by Materials Project

Ca3(PdGa)2 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to four equivalent Pd and five Ga atoms. There are a spread of Ca–Pd bond distances ranging from 3.04–3.17 Å. There are a spread of Ca–Ga bond distances ranging from 3.13–3.48 Å. In the second Ca site, Ca is bonded in a 7-coordinate geometry to four equivalent Pd and three equivalent Ga atoms. There are two shorter (3.18 Å) and two longer (3.19 Å) Ca–Pd bond lengths. There are a spread of Ca–Ga bond distances ranging from 3.07–3.21 Å. Pd is bonded in a 9-coordinate geometry to six Ca and three Ga atoms. There are a spread of Pd–Ga bond distances ranging from 2.59–2.64 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 12-coordinate geometry to six equivalent Ca and four equivalent Pd atoms. In the second Ga site, Ga is bonded in a 9-coordinate geometry to seven Ca and two equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaPd by Materials Project

PdGa is alpha-derived structured and crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Pd is bonded in a 7-coordinate geometry to seven equivalent Ga atoms. There are a spread of Pd–Ga bond distances ranging from 2.57–2.75 Å. Ga is bonded in a 7-coordinate geometry to seven equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GaPd by Materials Project

PdGa is alpha-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Pd is bonded in a 12-coordinate geometry to six equivalent Ga atoms. All Pd–Ga bond lengths are 2.66 Å. Ga is bonded in a 12-coordinate geometry to six equivalent Pd atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1993

Advanced Turbine Technology Applications Project (ATTAP)

This report is the fifth in a series of Annual Technical Summary Reports for the Advanced Turbine Technology Applications Project (ATTAP), sponsored by the U.S. Department of Energy (DOE). The report was prepared by Garrett Auxiliary Power Division (GAPD), a unit of Allied-Signal Aerospace Company, a unit of Allied Signal, Inc. The report includes information provided by Garrett Ceramic Components, and the Norton Advanced Ceramics Company, (formerly Norton/TRW Ceramics), subcontractors to GAPD on the ATTAP. This report covers plans and progress on ceramics development for commercial automotive applications over the period 1 Jan. through 31 Dec. 1992. Project effort conducted under this contract is part of the DOE Gas Turbine Highway Vehicle System program. This program is directed to provide the U.S. automotive industry the high-risk, long-range technology necessary to produce gas turbine engines for automobiles with reduced fuel consumption, reduced environmental impact, and a decreased reliance on scarce materials and resources. The program is oriented toward developing the high-risk technology of ceramic structural component design and fabrication, such that industry can carry this technology forward to production in the 1990's. The ATTAP test bed engine, carried over from the previous AGT101 project, is being used for verification testing of the durability of next generation ceramic components, and their suitability for service at Reference Powertrain Design conditions. This document reports the technical effort conducted by GAPD and the ATTAP subcontractors during the fifth year of the project. Topics covered include ceramic processing definition and refinement, design improvements to the ATTAP test bed engine and test rigs, and the methodology development of ceramic impact and fracture mechanisms. Appendices include reports by ATTAP subcontractors in the development of silicon nitride materials and processes.

Source record↗
NASA NTRS1992

Advanced Turbine Technology Applications Project (ATTAP)

This report is the fourth in a series of Annual Technical Summary Reports for the Advanced Turbine Technology Applications Project (ATTAP). This report covers plans and progress on ceramics development for commercial automotive applications over the period 1 Jan. - 31 Dec. 1991. Project effort conducted under this contract is part of the DOE Gas Turbine Highway Vehicle System program. This program is directed to provide the U.S. automotive industry the high-risk, long-range technology necessary to produce gas turbine engines for automobiles with reduced fuel consumption, reduced environmental impact, and a decreased reliance on scarce materials and resources. The program is oriented toward developing the high-risk technology of ceramic structural component design and fabrication, such that industry can carry this technology forward to production in the 1990s. The ATTAP test bed engine, carried over from the previous AGT101 project, is being used for verification testing of the durability of next-generation ceramic components, and their suitability for service at Reference Powertrain Design conditions. This document reports the technical effort conducted by GAPD and the ATTAP subcontractors during the fourth year of the project. Topics covered include ceramic processing definition and refinement, design improvements to the ATTAP test bed engine and test rigs and the methodology development of ceramic impact and fracture mechanisms. Appendices include reports by ATTAP subcontractors in the development of silicon nitride and silicon carbide families of materials and processes.

Source record↗
NASA NTRS1998

Operational processing and cloud boundary detection from micro pulse lidar data

Micro Pulse Lidar (MPL) was developed at NASA Goddard Space Flight Center (GSFC) as the result of research on space-borne lidar techniques. It was designed to provide continuous, unattended observations of all significant atmospheric cloud and aerosol structure with a rugged, compact system design and the benefit of eye safety (Spinhirne 1993). The significant eye safety feature is achieved by using low pulse energies and high pulse repetition rates compared to standard lidar systems. MPL systems use a diode pumped 10 microj, 2500 Hz doubled Nd:YLF laser. In addition, a solid state Geiger mode avalanche photo diode (GAPD) photon counting detector is used allowing for quantum efficiencies approaching 70%. Other design features have previously been noted by Spinhirne (1995). Though a commercially available instrument, with nearly 20 systems operating around the world, the most extensive MPL work has come from those operated by the Atmospheric Radiation Measurement (ARM) (Stokes and Schwartz 1994) program. The diverse ability of the instrument relating to the measurement of basic cloud macrophysical structure and both cloud and aerosol radiative properties well suits the ARM research philosophy. MPL data can be used to yield many parameters including cloud boundary heights to the limit of signal attenuation, cloud scattering cross sections and optical thicknesses, planetary boundary layer heights and aerosol scattering profiles, including those into the stratosphere in nighttime cases (Hlavka et al 1996). System vertical resolution ranges from 30 m to 300 m (i.e. high and low resolution respectively) depending on system design. The lidar research group at GSFC plays an advisory role in the operation, calibration and maintenance of NASA and ARM owned MPL systems. Over the past three years, processing software and system correction techniques have been developed in anticipation of the increasing population of systems amongst the community. Datasets produced by three ARM-owned systems have served as the basis for this development. With two operating at the southern Great Plains Cloud and Radiation Testbed Site (SGP CART) since December 1993 and another at the Manus Island Atmospheric Radiation and Cloud Station (TWP ARCS) location in the tropical western Pacific since February 1997, the ARM archive contains over 4 years of observations. In addition, high resolution systems planning to come on-line at the North Slope, AK CART shortly with another scheduled to follow at the TWP ARCS-II will diversify this archive with more extensive observations.

Campbell, James R.↗