22,641 research outputs found
System analysis and integration studies for a 15-micron horizon radiance measurement experiment
Systems analysis and integration studies for 15-micron horizon radiance measurement experimen
Statistical Properties of Many Particle Eigenfunctions
Wavefunction correlations and density matrices for few or many particles are
derived from the properties of semiclassical energy Green functions. Universal
features of fixed energy (microcanonical) random wavefunction correlation
functions appear which reflect the emergence of the canonical ensemble as the
number of particles approaches infinity. This arises through a little known
asymptotic limit of Bessel functions. Constraints due to symmetries,
boundaries, and collisions between particles can be included.Comment: 13 pages, 4 figure
STUDIES ON ABLATION OF OBJECTS TRAVERSING AN ATMOSPHERE
Ablation-type thermal protection of objects traversing an atmosphere - earth and mar
Quantum entangling power of adiabatically connected hamiltonians
The space of quantum Hamiltonians has a natural partition in classes of
operators that can be adiabatically deformed into each other. We consider
parametric families of Hamiltonians acting on a bi-partite quantum state-space.
When the different Hamiltonians in the family fall in the same adiabatic class
one can manipulate entanglement by moving through energy eigenstates
corresponding to different value of the control parameters. We introduce an
associated notion of adiabatic entangling power. This novel measure is analyzed
for general quantum systems and specific two-qubits examples are
studiedComment: 5 pages, LaTeX, 2 eps figures included. Several non minor changes
made (thanks referee) Version to appear in the PR
Multiple jet impingement heat transfer characteristic: Experimental investigation of in-line and staggered arrays with crossflow
Heat transfer characteristics were obtained for configurations designed to model the impingement cooled midchord region of air cooled gas turbine airfoils. The configurations tested were inline and staggered two-dimensional arrays of circular jets with ten spanwise rows of holes. The cooling air was constrained to exit in the chordwise direction along the channel formed by the jet orifice plate and the heat transfer surface. Tests were run for chordwise jet hole spacings of five, ten, and fifteen hole diameters; spanwise spacings of four, six, and eight diameters; and channel heights of one, two, three, and six diameters. Mean jet Reynolds numbers ranged from 5000 to 50,000. The thermal boundary condition at the heat transfer test surface was isothermal. Tests were run for sets of geometrically similar configurations of different sizes. Mean and chordwise resolved Nusselt numbers were determined utilizing a specially constructed test surface which was segmented in the chordwise direction
ANTHROPOGENIC EFFECTS ON NEW HAMPSHIRE SURFACE WATER QUALITY: LONG TERM EVIDENCE FROM LAKE SEDIMENTS
ANTHROPOGENIC EFFECTS ON NEW HAMPSHIRE SURFACE WATER QUALITY: LONG TERM EVIDENCE FROM LAKE SEDIMENTS
Decimation and Harmonic Inversion of Periodic Orbit Signals
We present and compare three generically applicable signal processing methods
for periodic orbit quantization via harmonic inversion of semiclassical
recurrence functions. In a first step of each method, a band-limited decimated
periodic orbit signal is obtained by analytical frequency windowing of the
periodic orbit sum. In a second step, the frequencies and amplitudes of the
decimated signal are determined by either Decimated Linear Predictor, Decimated
Pade Approximant, or Decimated Signal Diagonalization. These techniques, which
would have been numerically unstable without the windowing, provide numerically
more accurate semiclassical spectra than does the filter-diagonalization
method.Comment: 22 pages, 3 figures, submitted to J. Phys.
Atomic micromotion and geometric forces in a triaxial magnetic trap
Non-adiabatic motion of Bose-Einstein condensates of rubidium atoms arising
from the dynamical nature of a time-orbiting-potential (TOP) trap was observed
experimentally. The orbital micromotion of the condensate in velocity space at
the frequency of the rotating bias field of the TOP was detected by a
time-of-flight method. A dependence of the equilibrium position of the atoms on
the sense of rotation of the bias field was observed. We have compared our
experimental findings with numerical simulations. The nonadiabatic following of
the atomic spin in the trap rotating magnetic field produces geometric forces
acting on the trapped atoms.Comment: 4 pages, 4 figure
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