2,839,207 research outputs found
Concept for passive system to control gas flow independently of temperature
Volumetric flow rate of gas is maintained at a constant value independent of temperature by passing the gas through a parallel or series combination of turbulent flow and laminar flow restrictors. By proper combination of restrictors, the flow rate may be automatically made to vary as an increasing or decreasing function of temperature
The Matsubara-Fradkin Thermodynamical Quantization of Podolsky Electrodynamics
In this work we apply the Matsubara-Fradkin formalism and the Nakanishi's
auxiliary field method to the quantization of the Podolsky electrodynamics in
thermodynamic equilibrium. This approach allows us to write consistently the
path integral representation for the partition function of gauge theories in a
simple manner. Furthermore, we find the Dyson-Schwinger-Fradkin equations and
the Ward-Fradkin-Takahashi identities for the Podolsky theory. We also write
the most general form for the polarization tensor in thermodynamic equilibrium.Comment: Submitted to Physical Review
Fluctuations and vortex pattern ordering in fully frustrated XY model with honeycomb lattice
The accidental degeneracy of various ground states in a fully frustrated XY
model with a honeycomb lattice is shown to survive even when the free energy of
the harmonic fluctuations is taken into account. The reason for that consists
in the existence of a hidden gauge symmetry between the Hamiltonians describing
the harmonic fluctuations in all these ground states. A particular vortex
pattern is selected only when anharmonic fluctuations are taken into account.
However, the observation of vortex ordering requires relatively large system
size L>>100000.Comment: 4 pages, 2 figures, RevTeX4, a different method is used to find which
state is selected by anharmonic fluctuations, the last third of the text is
completly rewritte
Galactic longitude dependent Galactic model parameters
We present the Galactic model parameters for thin disc estimated by Sloan
Digital Sky Survey (SDSS) data of 14 940 stars with apparent magnitudes
in six intermediate latitude fields in the first Galactic
quadrant. Star/galaxy separation was performed by using the photometric
pipeline and the isodensity contours in the two colour
diagram. The separation of thin disc stars is carried out by the bimodal
distribution of stars in the histogram, and the absolute magnitudes
were evaluated by a procedure presented in the literature Bilir et al. (2005).
Exponential density law fits better to the derived density functions for the
absolute magnitude intervals and , whereas
sech/sech laws are more appropriate for absolute magnitude intervals
and . We showed that the scaleheight and
scalelength are Galactic longitude dependent. The average values and ranges of
the scaleheight and the scalelength are pc ( pc)
and pc ( pc) respectively. This result would
be useful to explain different numerical values claimed for those parameters
obtained by different authors for the fields in different directions of the
Galaxy.Comment: 28 pages, including 12 figures and 7 tables, accepted for publication
in New Astronom
A cluster algorithm for resistively shunted Josephson junctions
We present a cluster algorithm for resistively shunted Josephson junctions
and similar physical systems, which dramatically improves sampling efficiency.
The algorithm combines local updates in Fourier space with rejection-free
cluster updates which exploit the symmetries of the Josephson coupling energy.
As an application, we consider the localization transition of a single junction
at intermediate Josephson coupling and determine the temperature dependence of
the zero bias resistance as a function of dissipation strength.Comment: 4 page
Measurement of charm production in deep inelastic scattering with the ZEUS detector
We present measurements of charm production in DIS using the ZEUS detector.
Data with an integrated luminosity of 83 pb have been analysed. For the
channel a
cross section has been extracted, differential in the kinematical variables
and Bjorken . In addition the decay has been studied in a data sample of an integrated
luminosity of 34 pb. This results in a cross section, differential in
, and of the event and in and of the decay electron.
The structure function f2-charm has also been determined for this channel. All
measured cross sections show good agreement with NLO pQCD predictions from
HVQDIS.Comment: 4 pages, 4 figures. As presented at DIS01 Bologna, Ital
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