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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Potential vorticity and layer thickness variations in the flow around Jupiter's Great Red Spot and White Oval BC

Using Voyager images, layer thickness variations in the flow around Jupiter's Great Red Spot (GRS) and White Oval BC were investigated by treating potential vorticity as a conserved tracer. Fluid trajectories around the GRS and the White Oval BC were calculated assuming the flow to be frictionless, adiabatic, hydrostatic, and steady in the reference frame of the vortex. The data obtained constitute a useful diagnostic which will help to differentiate between models of Jovian vortices. Implications of the observations were studied in the context of a one-layer quasi-geostrophic model in which a thin upper weather layer, which contains the vortex, is supported hydrostatically by a much deeper lower layer.

Dowling, Timothy E.↗
DOE OSTI2020

Materials Data on Tm(BC)2 by Materials Project

Tm(BC)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Tm–B bond lengths are 2.71 Å. All Tm–C bond lengths are 2.65 Å. B is bonded in a distorted trigonal planar geometry to four equivalent Tm and three equivalent C atoms. There is one shorter (1.52 Å) and two longer (1.60 Å) B–C bond length. C is bonded in a 3-coordinate geometry to four equivalent Tm and three equivalent B atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(BC)2 by Materials Project

Lu(BC)2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Lu is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Lu–B bond lengths are 2.69 Å. All Lu–C bond lengths are 2.63 Å. B is bonded in a distorted trigonal planar geometry to four equivalent Lu and three equivalent C atoms. There is one shorter (1.52 Å) and two longer (1.59 Å) B–C bond length. C is bonded in a 3-coordinate geometry to four equivalent Lu and three equivalent B atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu(BC)2 by Materials Project

Lu(BC)2 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional. Lu is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Lu–B bond lengths are 2.69 Å. All Lu–C bond lengths are 2.66 Å. B is bonded in a 2-coordinate geometry to four equivalent Lu and two equivalent C atoms. Both B–C bond lengths are 1.60 Å. C is bonded in a 2-coordinate geometry to four equivalent Lu, two equivalent B, and one C atom. The C–C bond length is 1.42 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tm(BC)2 by Materials Project

Tm(BC)2 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to eight equivalent B and eight equivalent C atoms. All Tm–B bond lengths are 2.70 Å. All Tm–C bond lengths are 2.67 Å. B is bonded in a 2-coordinate geometry to four equivalent Tm and two equivalent C atoms. Both B–C bond lengths are 1.60 Å. C is bonded in a 2-coordinate geometry to four equivalent Tm, two equivalent B, and one C atom. The C–C bond length is 1.42 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu(BC)2 by Materials Project

Eu(BC)2 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional. Eu2+ is bonded in a 8-coordinate geometry to eight equivalent C4- atoms. All Eu–C bond lengths are 2.82 Å. B3+ is bonded in an L-shaped geometry to two equivalent C4- atoms. Both B–C bond lengths are 1.61 Å. C4- is bonded in a 2-coordinate geometry to four equivalent Eu2+, two equivalent B3+, and one C4- atom. The C–C bond length is 1.41 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Yb(BC)2 by Materials Project

Yb(BC)2 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional. Yb2+ is bonded in a 8-coordinate geometry to eight equivalent C4- atoms. All Yb–C bond lengths are 2.74 Å. B3+ is bonded in an L-shaped geometry to two equivalent C4- atoms. Both B–C bond lengths are 1.60 Å. C4- is bonded in a 2-coordinate geometry to four equivalent Yb2+, two equivalent B3+, and one C4- atom. The C–C bond length is 1.39 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn23(BC)3 by Materials Project

Mn23(BC)3 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are ten inequivalent Mn sites. In the first Mn site, Mn is bonded in a distorted trigonal non-coplanar geometry to one Mn and three equivalent B atoms. The Mn–Mn bond length is 2.36 Å. All Mn–B bond lengths are 2.10 Å. In the second Mn site, Mn is bonded in a distorted trigonal non-coplanar geometry to one Mn, one B, and two equivalent C atoms. The Mn–Mn bond length is 2.38 Å. The Mn–B bond length is 2.12 Å. Both Mn–C bond lengths are 2.06 Å. In the third Mn site, Mn is bonded in a distorted trigonal non-coplanar geometry to one Mn and three equivalent C atoms. The Mn–Mn bond length is 2.37 Å. All Mn–C bond lengths are 2.07 Å. In the fourth Mn site, Mn is bonded in a distorted trigonal non-coplanar geometry to one Mn, two equivalent B, and one C atom. The Mn–Mn bond length is 2.38 Å. Both Mn–B bond lengths are 2.11 Å. The Mn–C bond length is 2.04 Å. In the fifth Mn site, Mn is bonded in a distorted bent 150 degrees geometry to one Mn and two equivalent B atoms. The Mn–Mn bond length is 2.46 Å. Both Mn–B bond lengths are 2.10 Å. In the sixth Mn site, Mn is bonded in a distorted bent 150 degrees geometry to one Mn, one B, and one C atom. The Mn–Mn bond length is 2.53 Å. The Mn–B bond length is 2.10 Å. The Mn–C bond length is 2.08 Å. In the seventh Mn site, Mn is bonded in a distorted bent 150 degrees geometry to one Mn and two equivalent C atoms. The Mn–Mn bond length is 2.58 Å. Both Mn–C bond lengths are 2.09 Å. In the eighth Mn site, Mn is bonded in a 12-coordinate geometry to twelve Mn and three equivalent B atoms. All Mn–B bond lengths are 2.77 Å. In the ninth Mn site, Mn is bonded in a distorted tetrahedral geometry to four Mn atoms. In the tenth Mn site, Mn is bonded in a distorted tetrahedral geometry to four Mn atoms. B is bonded in a 8-coordinate geometry to nine Mn atoms. C is bonded in a 8-coordinate geometry to eight Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe23(BC)3 by Materials Project

Fe23(BC)3 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are ten inequivalent Fe sites. In the first Fe site, Fe is bonded in a distorted bent 150 degrees geometry to one Fe and two equivalent B atoms. The Fe–Fe bond length is 2.51 Å. Both Fe–B bond lengths are 2.12 Å. In the second Fe site, Fe is bonded in a distorted bent 150 degrees geometry to one Fe, one B, and one C atom. The Fe–Fe bond length is 2.54 Å. The Fe–B bond length is 2.12 Å. The Fe–C bond length is 2.11 Å. In the third Fe site, Fe is bonded in a distorted bent 150 degrees geometry to one Fe and two equivalent C atoms. The Fe–Fe bond length is 2.57 Å. Both Fe–C bond lengths are 2.11 Å. In the fourth Fe site, Fe is bonded in a distorted trigonal non-coplanar geometry to one Fe and three equivalent B atoms. The Fe–Fe bond length is 2.40 Å. All Fe–B bond lengths are 2.09 Å. In the fifth Fe site, Fe is bonded in a distorted trigonal non-coplanar geometry to one Fe, one B, and two equivalent C atoms. The Fe–Fe bond length is 2.42 Å. The Fe–B bond length is 2.11 Å. Both Fe–C bond lengths are 2.05 Å. In the sixth Fe site, Fe is bonded in a distorted trigonal non-coplanar geometry to one Fe and three equivalent C atoms. The Fe–Fe bond length is 2.43 Å. All Fe–C bond lengths are 2.06 Å. In the seventh Fe site, Fe is bonded in a distorted trigonal non-coplanar geometry to one Fe, two equivalent B, and one C atom. The Fe–Fe bond length is 2.41 Å. Both Fe–B bond lengths are 2.10 Å. The Fe–C bond length is 2.04 Å. In the eighth Fe site, Fe is bonded in a distorted cuboctahedral geometry to twelve Fe atoms. In the ninth Fe site, Fe is bonded in a distorted tetrahedral geometry to four Fe atoms. In the tenth Fe site, Fe is bonded in a distorted tetrahedral geometry to four Fe atoms. B is bonded in a 8-coordinate geometry to eight Fe atoms. C is bonded in a 8-coordinate geometry to eight Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Unexpected Hydride: Ce 4 B 2 C 2 H 2.42 , a Stuffed Variant of the Nd 2 BC Structure Type

Ce 4 B 2 C 2 H 2.42 was grown as large crystals from a cerium/copper eutectic flux. The structure was characterized by single-crystal X-ray and neutron diffraction and was found to be a stuffed variant of Nd 2 BC with the addition of two interstitial hydrogen positions. The tetrahedral hydrogen position is fully occupied, while the octahedral position has an occupancy of 42(3)%. Initial synthesis was due to hydrogen contamination of the cerium metal but has been successfully repeated using anthracene as a carbon and hydrogen source. Density of states calculations suggest that the incorporation of hydrogen stabilizes the compound with respect to the nonhydrided model. Magnetic susceptibility data show a complex magnetic ordering at 7.7 K that originates from the localized electron on the Ce 3+ in the structure. The trivalent state is also supported by X-ray photoelectron spectroscopy measurements. Heat capacity and electrical resistivity data show that the phase transition is broad in temperature, which may be due to structural disorder. Furthermore, the large low temperature value of C/T also indicates possible heavy fermion behavior.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Halide-free synthesis of metastable graphitic BC 3

A halide-free route to the synthesis of graphitic BC 3 was discovered via decomposition temperature matching: benzene (C 6 H 6 ) as the carbon precursor and the borohydride anion (BH 4 − ) as the boron precursor.

08 HYDROGEN↗
DOE OSTI2023

Intensive aerosol properties of boreal and regional biomass burning aerosol at Mt. Bachelor Observatory: larger and black carbon (BC)-dominant particles transported from Siberian wildfires

We characterize the aerosol physical and optical properties of 13 transported biomass burning (BB) events. BB events included long-range influence from fires in Alaskan and Siberian boreal forests transported to Mt. Bachelor Observatory (MBO) in the free troposphere (FT) over 8–14+ d and regional wildfires in northern California and southwestern Oregon transported to MBO in the boundary layer (BL) over 10 h to 3 d. Intensive aerosol optical properties and normalized enhancement ratios for BB events were derived from measured aerosol light scattering coefficients (σ scat ), aerosol light-absorbing coefficients (σ abs ), fine particulate matter (PM 1 ), and carbon monoxide (CO) measurements made from July to September 2019, with particle size distribution collected from August to September. The observations showed that the Siberian BB events had a lower scattering Ångström exponent (SAE), a higher mass scattering efficiency (MSE; Δσ scat /ΔPM 1 ), and a bimodal aerosol size distribution with a higher geometric mean diameter (D g ). We hypothesize that the larger particles and associated scattering properties were due to the transport of fine dust alongside smoke in addition to contributions from condensation of secondary aerosol, coagulation of smaller particles, and aqueous-phase processing during transport. Alaskan and Siberian boreal forest BB plumes were transported long distances in the FT and characterized by lower absorption Ångström exponent (AAE) values indicative of black carbon (BC) dominance in the radiative budget. Significantly elevated AAE values were only observed for BB events with <1 d transport, which suggests strong production of brown carbon (BrC) in these plumes but limited radiative forcing impacts outside of the immediate region.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1971

Location of energy barriers. IV - Effect of rotation and mass on the dynamics of reactions A + BC.

Examination of the effect of the inclusion of a small but significant amount of rotational energy in the reagents, and of a change in reagent masses in a previous study of the effect of barrier location on the dynamics of thermonuclear reaction A + BC yields AB + C. The qualitative generalizations introduced in the previous study are found to remain valid despite the introduction of the variables. Of these generalizations the most important is that reagent translational energy favors reaction on surface I, whereas reagent vibration is the most favorable to reaction on surface II.

Hodgson, B. A.↗
NASA NTRS1983

Capabilities, limitations, and use of BC SAT-R2 conference software

The computer software developed for the BC SAT-R2 Conference has certain capabilities and limitations which are described. Capabilities of each major program element are addressed with respect to providing the required functions for planning and output reporting. Limitations arise from the inability to exactly represent certain systems that may be examined. Expected use of the software package during the Conference is outlined.

Miller, E. F.↗
NASA NTRS1999

The Vertical Structure of Major Meteorological Features on Jupiter: The Great Red Spot and White Ovals BC and DE

Multi-spectral imagery of Jupiter's Great Red Spot (GRS) and two White ovals acquired by the Galileo/NIMS are used to constrain the spatial variability of the vertical aerosol structure and the distribution of ammonia in and around these most-prominent anti-cyclonic features. All three features exhibit a high-altitude core spanning about 3/4 of their visual size when viewed with moderate absorption wavelengths, indicating a bulk elliptical, "wedding cake" shape in their overall three-dimensional cloud structure. A distinctive spiral pattern within the GRS core is seen in moderate methane and hydrogen absorption bandpasses. This pattern - which has been modelled to show a 2 km variation in cloudtop pressure within the GRS - is inconsistent with a different spiral-shaped pattern observed in ammonia-sensitive wavelengths, thus indicating spatial variability not only in the column abundance of ammonia within the GRS, but in its mixing ratio as well. White Ovals BC and DE were observed in February 1997, just a year before their unusual merger into a single feature. At the time of these observations, the centers of the two anti-cyclones were about 16 degrees apart, separated by a complex cyclonic feature which exhibited unusual spatial variability in its appearance in images acquired at ammonia-sensitive wavelengths. In particular, the northern half of this feature has the largest ammonia column abundance seen within the environs around the white ovals, indicating unusual variability in either cloud structure/altitude and/or ammonia humidity within the cyclone.

Baines, Kevin H.↗