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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Structure, rotation, and the peculiar velocity cD galaxy in Abell 2107

The radial velocities of 75 galaxies in the field of Abell 2107 were measured within the framework of a program to study the kinematics of cD clusters of galaxies. Sixty-eight of these galaxies are cluster members. The mean observed velocity of A2107 is 12335 +/- 86 km/s, and the velocity dispersion is 672 +67/-52 km/s. The cD galaxy has a peculiar velocity of 270 km/s with respect to the cluster mean. The distribution of velocities is well fitted by a Gaussian, but the velocities are spatially correlated. Simple two-body subcluster models for A2107 are investigated; they are found to be consistent with the observed data and to account for the peculiar velocity of the cD galaxy. Alternatively, the spatial distribution of the velocities is also consistent with rotation of the single cluster at the 98-percent confidence level.

Oegerle, William R.↗
NASA NTRS1992

An x ray archive on your desk: The Einstein CD-ROM's

Data from the Einstein Observatory imaging proportional counter (IPC) and high resolution imager (HRI) were released on several CD-ROM sets. The sets released so far include pointed IPC and HRI observations in both simple image and detailed photon event list format, as well as the IPC slew survey. With the data on these CD-ROMS's the user can perform spatial analysis (e.g., surface brightness distributions), spectral analysis (with the IPC event lists), and timing analysis (with the IPC and HRI event lists). The next CD-ROM set will contain IPC unscreened data, allowing the user to perform custom screening to recover, for instance, data during times of lost aspect data or high particle background rates.

Prestwich, A.↗
NASA NTRS1993

CD volume design and verification

In this paper, we describe a prototype for CD-ROM volume design and verification. This prototype allows users to create their own model of CD volumes by modifying a prototypical model. Rule-based verification of the test volumes can then be performed later on against the volume definition. This working prototype has proven the concept of model-driven rule-based design and verification for large quantity of data. The model defined for the CD-ROM volumes becomes a data model as well as an executable specification.

Li, Y. P.↗
NASA NTRS1994

The mass and dynamics of cD clusters with cooling flows. 1: ROSAT observations of A 496

As part of a program to determine the mass distribution of cD galaxy clusters with cooling flows, we obtained a ROSAT image of the cluster A 496. The image reveals sharply peaked emission centered on the cD galaxy. Both the peaked cooling flow emission and the more extended emission filling the cluster are centered on the cD galaxy to within 15 sec . The surface brightness profile is consistent with previous Einstein observations. We measure spatially resolved spectra for the X-ray emission, and find a significant decline in temperature in the innermost 2 min to 4 min. We also find a gradient in absorption due to cold neutral gas, with an excess above the neutral hydrogen column due to our own galaxy in the inner 4 min. The excess absorption, however, is far below previously reported values. The surface brightness profile and the spatially resolved temperature profile are indicative of a cooling flow in the cluster. Cooling flow models fit to the X-ray spectra in the innermost 2 min yield a mass flow rate of 59 solar mass yr(exp -1). The spatially resolved temperature and surface brightness profiles are used to derive the mass distribution of the cluster both in the hot, X-ray emitting plasma and in the unseen dark matter that binds the cluster. To a radius of 1.0 Mpc we find a total cluster mass of 3.44 x 10(exp 14) solar mass ; the X-ray emitting gas mass of 0.75 x 10(exp 14) solar mass to this radius comprises 16 percent of the total cluster mass.

Kriss, Gerard A.↗
NASA NTRS1995

Interplanetary space science data base and access/display tool on the NSSDC heliospheric CD-ROM

The National Space Science Data Center (NSSDC) has accumulated a rich archive of heliospheric, magnetospheric, and ionospheric data, as well as data from most other NASA-involved science disciplines. To facilitate access to and use of these data, NSSDC has begun to put selected data onto CD-ROM's. This paper describes one such CD-ROM, and the access and display software developed at NSSDC to support its use. The data on the CD-ROM consist primarily of hourly solar wind magnetic field and plasma data from many near-Earth spacecraft (OMNI) and deep space spacecraft (Voyagers, Pioneers, Helios, Pioneer Venus Orbiter). In addition, 5-minute resolution IMP-8 and ISEE-3 magnetic field and plasma data are also included. Data are stored in both ASCII and CDF formats.

Papitashvili, N. E.↗
NASA NTRS2001

Lab Manual & Resources for Materials Science, Engineering and Technology on CD-Rom

The National Educators' Workshop (NEW:Update) series of workshops has been in existence since 1986. These annual workshops focus on technical updates and laboratory experiments for materials science, engineering and technology, involving new and traditional content in the field. Scores of educators and industrial and national laboratory personnel have contributed many useful experiments and demonstrations which were then published as NASA Conference Proceedings. This "out poring of riches" creates an ever-expanding shelf of valuable teaching tools for college, university, community college and advanced high school instruction. Now, more than 400 experiments and demonstrations, representing the first thirteen years of NEW:Updates have been selected and published on a CD-ROM, through the collaboration of this national network of materials educators, engineers, and scientists. The CD-ROM examined in this document utilizes the popular Adobe Acrobat Reader format and operates on most popular computer platforms. This presentation provides an overview of the second edition of Experiments in Materials Science, Engineering and Technology (EMSET2) CD-ROM, ISBN 0-13-030534-0.

Jacobs, James A.↗
NASA NTRS2004

Density, Electrical Conductivity and Viscosity of Hg(sub 0.8)Cd(sub 0.2)Te Melt

The density, viscosity, and electrical conductivity of Hg(sub 0.8)Cd(sub 0.2)Te melt were measures as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(sub 0.8)Cd(sub 0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(sub 0.8)Cd(sub 0.2)Te melt as the temperature was decreased to below 1090 K.

Li, C.↗
NASA NTRS2004

Density, Electrical Conductivity and Viscosity of Hg(0.8)Cd(0.2)Te Melt

The density, viscosity, and electrical conductivity of Hg(0.8)Cd(0.2)Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(0.8)Cd(0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(0.8)Cd(0.2)Te melt as the temperature was decreased to below 1090 K

Li, C.↗
NASA NTRS2004

Thermophysical Properties and Structural Transition of Hg(0.8)Cd(0.2)Te Melt

Thermophysical properties, namely, density, viscosity, and electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were simultaneously determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(sub 0.8)Cd(0.2)Te melt as the temperature was decreased from 1090 K to the liquidus temperature.

Li, C.↗
NASA NTRS2005

Impurity Studies of Cd(0.8)Zn(0.2)Te Crystals Using Photoluminescence and Glow Discharge Mass Spectroscopy

Cd(1-x)Zn(x)Te semiconductor crystal is a highly promising material for room temperature x- and gamma-ray detector applications because of its high resistivity, long carrier lifetime, and relatively high hole and electron mobilities. This paper reports the investigation of the impurities in several Cd(1-x)Zn(x)Te (x = 0.20) crystals grown using the vertical Bridgman method under a Cd overpressure. The impurity concentrations were measured using glow discharge mass spectroscopy (GDMS). The energy states of the impurities were studied using photoluminescence (PL) spectroscopy at liquid helium temperature. The PL spectra showed a series of sharp high energy lines which are associated with free excitons and excitons bound to impurities as donors and acceptors in the crystals. The impurities also contributed to donor-acceptor pair recombination. The correlation between the GDMS and PL results will be reported.

Su, Ching-Hua↗
DOE OSTI2020

Materials Data on Cd(C2N3)2 by Materials Project

Cd(C2N3)2 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. Cd2+ is bonded in an octahedral geometry to six N3- atoms. There are four shorter (2.30 Å) and two longer (2.53 Å) Cd–N bond lengths. C4+ is bonded in a linear geometry to two N3- atoms. There is one shorter (1.17 Å) and one longer (1.31 Å) C–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to one Cd2+ and two equivalent C4+ atoms. In the second N3- site, N3- is bonded in a bent 150 degrees geometry to one Cd2+ and one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(IO3)2 by Materials Project

Cd(IO3)2 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. Cd2+ is bonded to seven O2- atoms to form distorted corner-sharing CdO7 pentagonal bipyramids. There are a spread of Cd–O bond distances ranging from 2.31–2.53 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Cd2+ and two equivalent I5+ atoms. There are one shorter (1.84 Å) and one longer (2.73 Å) O–I bond lengths. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Cd2+ and one I5+ atom. The O–I bond length is 1.85 Å. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Cd2+ and one I5+ atom. The O–I bond length is 1.86 Å. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Cd2+ and two equivalent I5+ atoms. There are one shorter (1.86 Å) and one longer (2.62 Å) O–I bond lengths. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Cd2+ and one I5+ atom. The O–I bond length is 1.85 Å. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Cd2+ and two I5+ atoms. There are one shorter (1.86 Å) and one longer (2.58 Å) O–I bond lengths. There are two inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 6-coordinate geometry to four O2- atoms. In the second I5+ site, I5+ is bonded in a 6-coordinate geometry to five O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(HO)2 by Materials Project

Cd(OH)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Cd2+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing CdO5 trigonal bipyramids. There are a spread of Cd–O bond distances ranging from 2.29–2.35 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.07 Å) and one longer (1.52 Å) H–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Cd2+ and one H1+ atom. In the second O2- site, O2- is bonded in a water-like geometry to two H1+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four equivalent Cd2+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(W3Br7)2 by Materials Project

Cd(W3Br7)2 crystallizes in the cubic Pn-3 space group. The structure is three-dimensional. W2+ is bonded to five Br1- atoms to form WBr5 square pyramids that share a cornercorner with one CdBr6 octahedra and edges with four equivalent WBr5 square pyramids. The corner-sharing octahedral tilt angles are 46°. There are a spread of W–Br bond distances ranging from 2.64–2.66 Å. Cd2+ is bonded to six equivalent Br1- atoms to form CdBr6 octahedra that share corners with six equivalent WBr5 square pyramids. All Cd–Br bond lengths are 2.86 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 12-coordinate geometry to three equivalent W2+ atoms. In the second Br1- site, Br1- is bonded in a distorted bent 120 degrees geometry to one W2+ and one Cd2+ atom. In the third Br1- site, Br1- is bonded in a 12-coordinate geometry to three equivalent W2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(AuF4)2 by Materials Project

Cd(AuF4)2 crystallizes in the tetragonal P4/mcc space group. The structure is three-dimensional. Au3+ is bonded in a square co-planar geometry to four equivalent F1- atoms. All Au–F bond lengths are 1.97 Å. Cd2+ is bonded in a 8-coordinate geometry to eight equivalent F1- atoms. All Cd–F bond lengths are 2.37 Å. F1- is bonded in a distorted bent 120 degrees geometry to one Au3+ and one Cd2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(Ga3Te5)2 by Materials Project

Cd(Ga3Te5)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Cd2+ is bonded to four Te2- atoms to form CdTe4 tetrahedra that share corners with eight GaTe4 tetrahedra. All Cd–Te bond lengths are 2.86 Å. There are three inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four Te2- atoms to form GaTe4 tetrahedra that share a cornercorner with one CdTe4 tetrahedra and corners with six GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.61–2.72 Å. In the second Ga3+ site, Ga3+ is bonded to four Te2- atoms to form corner-sharing GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.60–2.71 Å. In the third Ga3+ site, Ga3+ is bonded to four Te2- atoms to form GaTe4 tetrahedra that share corners with three equivalent CdTe4 tetrahedra and corners with five GaTe4 tetrahedra. There are a spread of Ga–Te bond distances ranging from 2.67–2.71 Å. There are five inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a trigonal non-coplanar geometry to three Ga3+ atoms. In the second Te2- site, Te2- is bonded in a water-like geometry to two Ga3+ atoms. In the third Te2- site, Te2- is bonded in a trigonal non-coplanar geometry to one Cd2+ and two Ga3+ atoms. In the fourth Te2- site, Te2- is bonded in a trigonal non-coplanar geometry to three Ga3+ atoms. In the fifth Te2- site, Te2- is bonded in a trigonal non-coplanar geometry to one Cd2+ and two equivalent Ga3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(InSe2)2 by Materials Project

CdIn2Se4 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Cd2+ is bonded to six Se2- atoms to form CdSe6 octahedra that share corners with two equivalent InSe6 octahedra, corners with four equivalent CdSe6 octahedra, and edges with eight InSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. All Cd–Se bond lengths are 2.88 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with two equivalent CdSe6 octahedra, corners with four equivalent InSe6 octahedra, edges with four equivalent CdSe6 octahedra, and edges with four equivalent InSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are two shorter (2.68 Å) and four longer (2.88 Å) In–Se bond lengths. In the second In3+ site, In3+ is bonded to six Se2- atoms to form InSe6 octahedra that share corners with four equivalent InSe6 octahedra, edges with four equivalent CdSe6 octahedra, and edges with four equivalent InSe6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are two shorter (2.66 Å) and four longer (2.88 Å) In–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Cd2+ and three In3+ atoms to form a mixture of edge and corner-sharing SeCd2In3 square pyramids. In the second Se2- site, Se2- is bonded in a square co-planar geometry to one Cd2+ and three In3+ atoms. The Se–Cd bond length is 2.88 Å. In the third Se2- site, Se2- is bonded in a square co-planar geometry to one Cd2+ and three In3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(PO3)2 by Materials Project

Cd(PO3)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Cd2+ is bonded to six O2- atoms to form distorted CdO6 pentagonal pyramids that share corners with six PO4 tetrahedra and edges with two equivalent CdO6 pentagonal pyramids. There are a spread of Cd–O bond distances ranging from 2.21–2.50 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CdO6 pentagonal pyramids and corners with two equivalent PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CdO6 pentagonal pyramids and corners with two equivalent PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cd2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Cd2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cd2+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Cd2+ and one P5+ atom.

36 MATERIALS SCIENCE↗