546 research outputs found
Payload/orbiter contamination control requirement study: Spacelab configuration contamination study
The assessment of the Spacelab carrier induced contaminant environment was continued, and the ability of Spacelab to meet established contamination control criteria for the space transportation system program was determined. The primary areas considered included: (1) updating, refining, and improving the Spacelab contamination computer model and contamination analysis methodology, (2) establishing the resulting adjusted induced environment predictions for comparison with the applicable criteria, (3) determining the Spacelab design and operational requirements necessary to meet the criteria, (4) conducting mission feasibility analyses of the combined Spacelab/Orbiter contaminant environment for specific proposed mission and payload mixes, and (5) establishing a preliminary Spacelab mission support plan as well as model interface requirements; A summary of those activities conducted to date with respect to the modelling, analysis, and predictions of the induced environment, including any modifications in approach or methodology utilized in the contamination assessment of the Spacelab carrier, was presented
Descriptions and phylogeny of four limnephiloid caddisflies (Trichoptera) based on first instars
First instars from a representative species of each of the limnephiloid families Goeridae, Brachycentridae, Lepdostomatidae, and Uenoidae and the sericostomatoid family Sericostomatidae were reared, described, and illustrated
The locality of the fourth root of staggered fermion determinant in the interacting case
The fourth root approximation in LQCD simulations with dynamical staggered
fermions requires justification. We test its validity numerically in the
interacting theory in a renormalization group framework.Comment: 6 pages, Talk presented at Lattice 2005 (Machines and Algorithms
The QCD equation of state with asqtad staggered fermions
We report on our result for the equation of state (EOS) with a Symanzik
improved gauge action and the asqtad improved staggered fermion action at
and 6. In our dynamical simulations with 2+1 flavors we use the inexact
R algorithm and here we estimate the finite step-size systematic error on the
EOS. Finally we discuss the non-zero chemical potential extension of the EOS
and give some preliminary results.Comment: 7 pages, 6 figures, presented at Lattice2006(High Temperature and
Density), to appear in Proceedings of Scienc
The equation of state with nonzero chemical potential for 2+1 flavors
We present results for the QCD equation of state with nonzero chemical
potential using the Taylor expansion method with terms up to sixth order in the
expansion. Our calculations are performed on asqtad 2+1 quark flavor lattices
at .Comment: Talk given at the XXV International Symposium on Lattice Field
Theory, July 30-4 August 2007, Regensburg, German
Update on the physics of light pseudoscalar mesons
We present an update of the MILC investigation of the properties of light
pseudoscalar mesons using three flavors of improved staggered quarks. Results
are presented for the and leptonic decay constants, the CKM matrix
element , the up, down and strange quark masses, and the coefficients
of the chiral lagrangian. We have new data for lattice spacing fm with several values of the light quark mass down to one-tenth
the strange quark mass, higher statistics for fm with the
light quark mass equal to one-tenth the strange quark mass, and initial results
for our smallest lattice spacing, fm with light quark mass
two-fifths of the strange quark mass.Comment: 7 pages, 4 figures. To be published in Proceedings of Science
(Lattice 2006) 163 (2006
Baryon masses with improved staggered quarks
The MILC collaboration's simulations with improved staggered quarks are being
extended with runs at a lattice spacing of 0.06 fm with quark masses down to
one tenth the strange quark mass. We give a brief introduction to these new
simulations and the determination of the lattice spacing. Then we combine these
new runs with older results to study the masses of the nucleon and the Omega
minus in the continuum and chiral limits.Comment: 7 pages, proceedings from Lattice 2007 conferenc
The Equation of State for QCD with 2+1 Flavors of Quarks
We report results for the interaction measure, pressure and energy density
for nonzero temperature QCD with 2+1 flavors of improved staggered quarks. In
our simulations we use a Symanzik improved gauge action and the Asqtad
improved staggered quark action for lattices with temporal extent and
6. The heavy quark mass is fixed at approximately the physical strange
quark mass and the two degenerate light quarks have masses or
. The calculation of the thermodynamic observables employs the integral
method where energy density and pressure are obtained by integration over the
interaction measure.Comment: 6 pages, 1 figure, 3 tables, contribution to the XXIIIrd
International Symposium on Lattice Field Theory, 25-30 July 2005, Trinity
College, Dublin, Irelan
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