4,442 research outputs found
Effects of rotation and magnetic field on the onset of convective instability in a liquid layer due to buoyancy and surface tension
Thermocapillary stability characteristics of a horizontal liquid layer heated from below rotating about a vertical axis and subjected to a uniform vertical magnetic field are analyzed under a variety of thermal and electromagnetic boundary conditions. Results based on analytical solutions to the pertinent eigenvalue problems are discussed in the light of earlier work on special cases of the more general problem considered here to show in particular the effects of the heat transfer, nonzero curvature and gravity waves at the two-fluid interface. Although the expected stabilizing action of the Coriolis and Lorentz force fields in this configuration are in evidence the optimal choice of an appropriate range for the relevant parameters is shown to be critically dependent on the interfacial effects mentioned above
Simulator evaluation of separation of display parameters in path-following tasks
A five degree of freedom, fixed base simulation changing the location of the displays for bank angle, pitch angle, heading angle, and the vertical and lateral displacement from an instrument landing system path was studied. It is shown that the accuracy of the lateral path following and the pilot aircraft system dynamic characteristics deteriorate when bank angle is displayed separated from the other attitudes. It is found that best results are obtained when bank, heading, and pitch angles are displayed together and vertical and lateral displacements are displayed at another location in the display
Spectral functions in doped transition metal oxides
We present experimental photoemission and inverse photoemission spectra of
SrTiO representing electron doped systems. Photoemission
spectra in presence of electron doping exhibit prominent features arising from
electron correlation effects, while the inverse photoemssion spectra are
dominated by spectral features explainable within single-particle approaches.
We show that such a spectral evolution in chemically doped correlated systems
is not compatible with expectations based on Hubbard or any other similar
model. We present a new theoretical approach taking into account the
inhomogeneity of the `real' system which gives qualitatively different results
compared to standard `homogeneous' models and is in quantitative agreement with
experiments.Comment: 10 pages; 1 tex file+4 postscript files (to appear in Europhysics
Letters
Carrier relaxation due to electron-electron interaction in coupled double quantum well structures
We calculate the electron-electron interaction induced energy-dependent
inelastic carrier relaxation rate in doped semiconductor coupled double quantum
well nanostructures within the two subband approximation at zero temperature.
In particular, we calculate, using many-body theory, the imaginary part of the
full self-energy matrix by expanding in the dynamically RPA screened Coulomb
interaction, obtaining the intrasubband and intersubband electron relaxation
rates in the ground and excited subbands as a function of electron energy. We
separate out the single particle and the collective excitation contributions,
and comment on the effects of structural asymmetry in the quantum well on the
relaxation rate. Effects of dynamical screening and Fermi statistics are
automatically included in our many body formalism rather than being
incorporated in an ad-hoc manner as one must do in the Boltzman theory.Comment: 26 pages, 5 figure
Film-stability in a vertical rotating tube with a core-gas flow
Linear hydrodynamic stability of interface between Newtonian liquid film and core fluid under influence of swirl, core flow, and gravit
Dilepton asymmetries at factories in search of transitions
In order to detect the possible presence of
amplitudes in neutral meson decays, we consider the measurement of decay
time asymmetries involving like-sign dilepton events at the factories.Comment: 5 pages, latex, no fig
Method of characteristics and solution of DGLAP evolution equation in leading order (LO) and next to leading order (NLO) at small-x
In this paper the singlet and non-singlet structure functions have been
obtained by solving Dokshitzer, Gribove, Lipatov, Alterelli, Parisi (DGLAP)
evolution equations in leading order (LO) and next to leading order (NLO) at
the small x limit. Here we have used a Taylor Series expansion and then the
method of characteristics to solve the evolution equations. We have also
calculated t and x-evolutions of deuteron structure function and the results
are compared with the New Muon Collaboration (NMC) data.Comment: 16 pages including 7 figure
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