42,463 research outputs found
View factor computer program (VIEW)
Existing view factor program, RAVFAC, was modified to accept NASTRAN and/or RAVFAC surface descriptions. Output formatting was altered to produce view factor matrices which could be directly input to NASTRAN
Gauge dependence of calculations in relativistic Coulomb excitation
Before a quantum-mechanical calculation involving electromagnetic
interactions is performed, a choice must be made of the gauge to be used in
expressing the potentials. If the calculation is done exactly, the observable
results it predicts will be independent of the choice of gauge. However, in
most practical calculations approximations are made, which can destroy the
gauge invariance of the predictions. We compare here the results of
coupled-channel time-dependent relativistic Coulomb excitation calculations, as
performed in either Lorentz or Coulomb gauges. We find significant differences
when the bombarding energy per nucleon is 2 GeV, which indicates that
the common practice of relying completely on the Lorentz gauge can be
dangerous.Comment: 23 pages, 3 figure
Rutherford scattering with radiation damping
We study the effect of radiation damping on the classical scattering of
charged particles. Using a perturbation method based on the Runge-Lenz vector,
we calculate radiative corrections to the Rutherford cross section, and the
corresponding energy and angular momentum losses.Comment: Latex, 11 pages, 4 eps figure
Imaging X-ray spectrometer
An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging
Coulomb Excitation of Multi-Phonon Levels of the Giant Dipole Resonance
A closed expression is obtained for the cross-section for Coulomb excitation
of levels of the giant dipole resonance of given angular momentum and phonon
number. Applications are made to the Goldhaber-Teller and Steinwedel-Jensen
descriptions of the resonance, at non-relativistic and relativistic bombarding
energies.Comment: 16 pages, 5 figure
Optical alignment system Patent
Electro-optical/computer system for aligning large structural members and maintaining correct positio
Arkansas Cotton Variety Test 2003
The primary aim of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed dealers establish marketing strategies and assists producers in choosing varieties to plant. In this way, the annual test facilitates the inclusion of new, improved genetic material in Arkansas cotton production
Cooperativity and Stability in a Langevin Model of Protein Folding
We present two simplified models of protein dynamics based on Langevin's
equation of motion in a viscous medium. We explore the effect of the potential
energy function's symmetry on the kinetics and thermodynamics of simulated
folding. We find that an isotropic potential energy function produces, at best,
a modest degree of cooperativity. In contrast, a suitable anisotropic potential
energy function delivers strong cooperativity.Comment: 45 pages, 16 figures, 2 tables. LaTeX. Submitted to the Journal of
Chemical Physic
Many-body effects on the capacitance of multilayers made from strongly correlated materials
Recent work by Kopp and Mannhart on novel electronic systems formed at oxide
interfaces has shown interesting effects on the capacitances of these devices.
We employ inhomogeneous dynamical mean-field theory to calculate the
capacitance of multilayered nanostructures. These multilayered nanostructures
are composed of semi-infinite metallic leads coupled via a strongly correlated
dielectric barrier region. The barrier region can be adjusted from a metallic
regime to a Mott insulator through adjusting the interaction strength. We
examine the effects of varying the barrier width, temperature, potential
difference, screening length, and chemical potential. We find that the
interaction strength has a relatively strong effect on the capacitance, while
the potential and temperature show weaker dependence.Comment: 19 pages, 7 figures, REVTe
On a q-analogue of the multiple gamma functions
A -analogue of the multiple gamma functions is introduced, and is shown to
satisfy the generalized Bohr-Morellup theorem. Furthermore we give some
expressions of these function.Comment: 8 pages, AMS-Late
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