1,551 research outputs found
Nitrogen tetroxide flow decay study for the Orbital Workshop Propulsion System Final report
Flow decay of nitrogen tetroxide in Orbital Workshop Propulsion Syste
Integration and Athletics: Integrating the Marshall University Basketball Program, 1954-1969
In 1954, Marshall College followed the national law that banned segregation in the school systems of the United States. The law included the integration of athletic programs. While only a small part of the process, athletic programs often presented integration on a more visible stage than the integration of classrooms
2,2,2-Tris(pyrazol-1-yl)ethanol
The title compound TPE, C11H12N6O, was prepared by slow evaporation from diethyl ether. In the crystal, there is a hydrogen bond between the alcohol H atom and an N in the pyrazole ring of a neighboring molÂecule
Late metal-silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling
The short-lived Hf-W decay system is a powerful chronometer
for constraining the timing of metal-silicate separation and core formation in
planetesimals and planets. Neutron capture effects on W isotopes, however,
significantly hamper the application of this tool. In order to correct for
neutron capture effects, Pt isotopes have emerged as a reliable in-situ neutron
dosimeter. This study applies this method to IAB iron meteorites, in order to
constrain the timing of metal segregation on the IAB parent body. The
W values obtained for the IAB iron meteorites range from -3.61
0.10 to -2.73 0.09. Correlating Pt with
W data yields a pre-neutron capture W of -2.90 0.06. This
corresponds to a metal-silicate separation age of 6.0 0.8 Ma after CAI
for the IAB parent body, and is interpreted to represent a body-wide melting
event. Later, between 10 and 14 Ma after CAI, an impact led to a catastrophic
break-up and subsequent reassembly of the parent body. Thermal models of the
interior evolution that are consistent with these estimates suggest that the
IAB parent body underwent metal-silicate separation as a result of internal
heating by short-lived radionuclides and accreted at around 1.4 0.1 Ma
after CAIs with a radius of greater than 60 km.Comment: 11 pages, 8 figures, 2 tables; open access article under the CC
BY-NC-ND license (see http://creativecommons.org/licenses/by-nc-nd/4.0/
Spin Gap in Two-Dimensional Heisenberg Model for CaVO
We investigate the mechanism of spin gap formation in a two-dimensional model
relevant to Mott insulators such as CaVO. From the perturbation
expansion and quantum Monte Carlo calculations, the origin of the spin gap is
ascribed to the four-site plaquette singlet in contrast to the dimer gap
established in the generalized dimerized Heisenberg model.Comment: 8 pages, 6 figures available upon request (Revtex
Axisymmetric Calculations of a Low-Boom Inlet in a Supersonic Wind Tunnel
This paper describes axisymmetric CFD predictions made of a supersonic low-boom inlet with a facility diffuser, cold pipe, and mass flow plug within wind tunnel walls, and compares the CFD calculations with the experimental data. The inlet was designed for use on a small supersonic aircraft that would cruise at Mach 1.6, with a Mach number over the wing of 1.7. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center in the fall of 2010 to demonstrate the performance and stability of a practical flight design that included a novel bypass duct. The inlet design is discussed here briefly. Prior to the test, CFD calculations were made to predict the performance of the inlet and its associated wind tunnel hardware, and to estimate flow areas needed to throttle the inlet. The calculations were done with the Wind-US CFD code and are described in detail. After the test, comparisons were made between computed and measured shock patterns, total pressure recoveries, and centerline pressures. The results showed that the dual-stream inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a large stable operating range. Predicted core recovery agreed well with the experiment but predicted bypass recovery and maximum capture ratio were high. Calculations of offdesign performance of the inlet along a flight profile agreed well with measurements and previous calculations
Probleme und politische Einstellungen in Heidelberg
Umfrage zu Problemen und politischen Einstellungen in Heidelberg im Vorfeld der Kommunanal- und Europawahlen 1994. 662 Telefoninterviews
Nature of the Spin-glass State in the Three-dimensional Gauge Glass
We present results from simulations of the gauge glass model in three
dimensions using the parallel tempering Monte Carlo technique. Critical
fluctuations should not affect the data since we equilibrate down to low
temperatures, for moderate sizes. Our results are qualitatively consistent with
earlier work on the three and four dimensional Edwards-Anderson Ising spin
glass. We find that large scale excitations cost only a finite amount of energy
in the thermodynamic limit, and that those excitations have a surface whose
fractal dimension is less than the space dimension, consistent with a scenario
proposed by Krzakala and Martin, and Palassini and Young.Comment: 5 pages, 7 figure
Numerical studies of the 2 and 3D gauge glass at low temperature
We report results from Monte Carlo simulations of the two- and
three-dimensional gauge glass at low temperature using parallel tempering Monte
Carlo. In two dimensions, we find strong evidence for a zero-temperature
transition. By means of finite-size scaling, we determine the stiffness
exponent theta = -0.39 +/- 0.03. In three dimensions, where a
finite-temperature transition is well established, we find theta = 0.27 +/-
0.01, compatible with recent results from domain-wall renormalization group
studies.Comment: 3 pages, 3 figures. Proceedings of "2002 MMM Conference", Tampa, F
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