11,774 research outputs found
Metal line blanketing and opacity in the ultraviolet of alpha 2 Canum Venaticorum
Ultraviolet photometry by OAO-2 was made of alpha 2 CVn covering the entire 5.5d period of this magnetic Ap variable. The light curves ranging from 1330 A to 3320 A indicate the dominant role of rare-earth line-blanketing in redistributing flux. In a broad depression of the continuum covering 2300-2600 A, scanner observations possibly identify strong lines of Eu III as major contributors to this feature. At maximum intensity of the rare-earth lines, the ultraviolet continuum shortward of 2900 A is greatly diminished while the longer wavelength regions into the visual become brighter. In addition, there is evidence that the hydrogen line opacity is variable and the photoionization edge of Si I at 1680 A is identified
Dissipative effects from transport and viscous hydrodynamics
We compare 2->2 covariant transport theory and causal Israel-Stewart
hydrodynamics in 2+1D longitudinally boost invariant geometry with RHIC-like
initial conditions and a conformal e = 3p equation of state. The pressure
evolution in the center of the collision zone and the final differential
elliptic flow v2(pT) from the two theories agree remarkably well for a small
shear viscosity to entropy density ratio eta/s ~ 1/(4 pi), and also for a large
cross section sigma ~ 50 mb. A key to this agreement is keeping ALL terms in
the Israel-Stewart equations of motion. Our results indicate promising
prospects for the applicability of Israel-Stewart dissipative hydrodynamics at
RHIC, provided the shear viscosity of hot and dense quark-gluon matter is
indeed very small for the relevant temperatures T ~ 200-500 MeV.Comment: Presentation at Quark Matter 2008. 4 pages, 3 figure
Flavor ordering of elliptic flows at high transverse momentum
Based on the quark coalescence model for the parton-to-hadron phase
transition in ultra-relativistic heavy ion collisions, we relate the elliptic
flow () of high \pt hadrons to that of high \pt quarks. For high \pt
hadrons produced from an isospin symmetric and quark-antiquark symmetric
partonic matter, magnitudes of their elliptic flows follow a flavor ordering as
if strange quarks have a
smaller elliptic flow than light quarks. The elliptic flows of high \pt
hadrons further follow a simple quark counting rule if strange quarks and light
quarks have same high \pt spectrum and coalescence probability.Comment: 4 pages, 1 figure, revte
Comparison of musculoskeletal networks of the primate forelimb
Anatomical network analysis is a framework for quantitatively characterizing the topological organization of anatomical structures, thus providing a way to compare structural integration and modularity among species. Here we apply this approach to study the macroevolution of the forelimb in primates, a structure whose proportions and functions vary widely within this group. We analyzed musculoskeletal network models in 22 genera, including members of all major extant primate groups and three outgroup taxa, after an extensive literature survey and dissections. The modules of the proximal limb are largely similar among taxa, but those of the distal limb show substantial variation. Some network parameters are similar within phylogenetic groups (e.g., non-primates, strepsirrhines, New World monkeys, and hominoids). Reorganization of the modules in the hominoid hand compared to other primates may relate to functional changes such as coordination of individual digit movements, increased pronation/supination, and knuckle-walking. Surprisingly, humans are one of the few taxa we studied in which the thumb musculoskeletal structures do not form an independent anatomical module. This difference may be caused by the loss in humans of some intrinsic muscles associated with the digits or the acquisition of additional muscles that integrate the thumb more closely with surrounding structures
Johann Friedrich Buenger, The Founder of Lutheran Charities
The influences in the life of Buenger that stimulated his activities in the eleemosynary field will be treated in this study. For this purpose pertinent material is drawn from C F. W. Walther’s Ehrwuerdigen Pastor Johann Friedrich Buenger, bringing to light particularly the early influences in his life
Differential freezeout and pion interferometry at RHIC from covariant transport theory
Puzzling discrepancies between recent pion interferometry data on Au+Au
reactions at s^1/2 = 130 and 200 AGeV from RHIC and predictions based on ideal
hydrodynamics are analyzed in terms of covariant parton transport theory. The
discrepancies of out and longitudinal radii are significantly reduced when the
finite opacity of the gluon plasma is taken into account.Comment: 4 pages, 3 EPS figures. Submitted to PR
Timing performance of 30-nm-wide superconducting nanowire avalanche photodetectors
We investigated the timing jitter of superconducting nanowire avalanche
photodetectors (SNAPs, also referred to as cascade switching superconducting
single photon detectors) based on 30-nm-wide nanowires. At bias currents (IB)
near the switching current, SNAPs showed sub 35 ps FWHM Gaussian jitter similar
to standard 100 nm wide superconducting nanowire single-photon detectors. At
lower values of IB, the instrument response function (IRF) of the detectors
became wider, more asymmetric, and shifted to longer time delays. We could
reproduce the experimentally observed IRF time-shift in simulations based on an
electrothermal model, and explain the effect with a simple physical picture
Electron Scattering in AlGaN/GaN Structures
We present data on mobility lifetime, , quantum lifetime, ,
and cyclotron resonance lifetime, , of a sequence of high-mobility
two-dimensional electron gases in the AlGaN/GaN system, covering a density
range of cm. We observe a large discrepancy
between and (/6) and explain it as
the result of density fluctuations of only a few percent. Therefore, only
--and not -- is a reliable measure of the time between
electron scattering events in these specimens. The ratio
increases with increasing density in this series of samples, but scattering
over this density range remains predominantly in the large-angle scattering
regime
How Attorneys Judge Collegiate Mock Trials
In collegiate mock trial competition, practicing attorneys who don’t coach or know the participating schools judge the students\u27 persuasive skill. Fifty-six attorneys were interviewed after they judged collegiate mock trials. They were asked which student behaviors they rewarded, which behaviors they punished, and overall which team presented more effectively. The attorneys\u27 responses were grouped into thematic categories and arranged by priorities. Attorneys were consistent in what they said they valued in student performances. Interviewees\u27 answers to the question about overall team performance were compared with the numeric ballots. If global assessment were included, it would change the outcome of a substantial number of trials, which raises the question if such an item would have the same effect on any graded competition
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