3,913 research outputs found
HVAC modifications and computerized energy analysis for the Operations Support Building at the Mars Deep Space Station at Goldstone
The key heating, ventilation, and air-conditioning (HVAC) modifications implemented at the Mars Deep Space Station's Operation Support Building at Jet Propulsion Laboratories (JPL) in order to reduce energy consumption and decrease operating costs are described. An energy analysis comparison between the computer simulated model for the building and the actual meter data was presented. The measurement performance data showed that the cumulative energy savings was about 21% for the period 1979 to 1981. The deviation from simulated data to measurement performance data was only about 3%
Magneto-Acoustic Spectroscopy in Superfluid 3He-B
We have used the recently discovered acoustic Faraday effect in superfluid
3He to perform high resolution spectroscopy of an excited state of the
superfluid condensate. With acoustic cavity interferometry we measure the
rotation of the plane of polarization of a transverse sound wave propagating in
the direction of magnetic field from which we determine the Zeeman energy of
the excited state. We interpret the Lande g-factor, combined with the
zero-field energies of the state, using the theory of Sauls and Serene to
calculate the strength of f -wave interactions in 3He.Comment: 4 pages, 5 figures, submitted to PRL, Aug 30th, 200
Hartree-Fock calculations of a finite inhomogeneous quantum wire
We use the Hartree-Fock method to study an interacting one-dimensional
electron system on a finite wire, partially depleted at the center by a smooth
potential barrier. A uniform one-Tesla Zeeman field is applied throughout the
system. We find that with the increase in the potential barrier, the low
density electrons under it go from a non-magnetic state to an antiferromagnetic
state, and then to a state with a well-localized spin-aligned region isolated
by two antiferromagnetic regions from the high density leads. At this final
stage, in response to a continuously increasing barrier potential, the system
undergoes a series of abrupt density changes, corresponding to the successive
expulsion of a single electron from the spin-aligned region under the barrier.
Motivated by the recent momentum-resolved tunneling experiments in a parallel
wire geometry, we also compute the momentum resolved tunneling matrix elements.
Our calculations suggest that the eigenstates being expelled are spatially
localized, consistent with the experimental observations. However, additional
mechanisms are needed to account for the experimentally observed large spectral
weight at near in the tunneling matrix elements.Comment: 10 pages, 14 figure
Acoustic Spectroscopy of Superfluid 3He in Aerogel
We have designed an experiment to study the role of global anisotropic
quasiparticle scattering on the dirty aerogel superfluid 3He system. We observe
significant regions of two stable phases at temperatures below the superfluid
transition at a pressure of 25 bar for a 98% aerogel.Comment: 2 pages, 2 figures, accepted for publication in proceedings of Low
Temperature Conference 2
- …