152,066 research outputs found
Constrained Molecular Dynamics Simulations of Atomic Ground-States
Constrained molecular dynamics(CoMD) model, previously introduced for nuclear
dynamics, has been extended to the atomic structure and collision calculations.
Quantum effects corresponding to the Pauli and Heisenberg principle are
enforced by constraints, in a parameter-free way. Our calculations for small
atomic system, H, He, Li, Be, F reproduce the ground-state binding energies
within 3%, compared with the results of quantum mechanical Hartree-Fock
calculations.Comment: 3 pages, 2 figure
Analysis of F and G subdwarfs. 3 - An abundance analysis of the subdwarf mu Cassiopeia
Model atmospheric abundance analysis of subdwarf micron Cassiopeia constellatio
Analytical fuel property effects, small combustors, phase 1
The effects of nonstandard aviation fuels on a typical small gas turbine combustor was analyzed. The T700/CT7 engine family was chosen as being representative of the class of aircraft power plants desired. Fuel properties, as specified by NASA, are characterized by low hydrogen content and high aromatics levels. Higher than normal smoke output and flame radiation intensity for the current T700 combustor which serves as a baseline were anticipated. It is, therefore, predicted that out of specification smoke visibility and higher than normal shell temperatures will exist when using NASA ERBS fuels with a consequence of severe reduction in cyclic life. Three new designs are proposed to compensate for the deficiencies expected with the existing design. They have emerged as the best of the eight originally proposed redesigns or combinations thereof. After the five choices that were originally made by NASA on the basis of competing performance factors, General Electric narrowed the field to the three proposed
The Detailed Chemical Abundance Patterns of M31 Globular Clusters
We present detailed chemical abundances for 20 elements in 30
globular clusters in M31. These results have been obtained using high
resolution (24,000) spectra of their integrated
light and analyzed using our original method. The globular clusters have
galactocentric radii between 2.5 kpc and 117 kpc, and therefore provide
abundance patterns for different phases of galaxy formation recorded in the
inner and outer halo of M31. We find that the clusters in our survey have a
range in metallicity of [Fe/H]. The inner halo clusters cover
this full range, while the outer halo globular clusters at R20 kpc have a
small range in abundance of [Fe/H]. We also measure abundances
of alpha, r- and s-process elements. These results constitute the first
abundance pattern constraints for old populations in M31 that are comparable to
those known for the Milky Way halo.Comment: XII International Symposium on Nuclei in the Cosmos August 5-12, 2012
Cairns, Australia. To appear in Proceedings of Scienc
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