742 research outputs found
THE SECOND DIVINE COUNCIL AT ODYSSEY 5.1–42 RECONSIDERED
This article reconsiders the much-discussed second divine council at the beginning of Book 5 of the Odyssey (5.1–42). It is demonstrated that this assembly is not a case of successive narration of simultaneous actions, as many scholars have maintained, but that the second council is necessary because Zeus, in order to avoid interdivine conflicts, has not kept his promise to initiate Odysseus’ repatriation as announced in the first council. It is further argued that Athene’s speech to Zeus (5.7–20), with its minacious tone and its cento-like composition, serves to put pressure on Zeus and to display Athene’s intellectual superiority
Manifolds with small Dirac eigenvalues are nilmanifolds
Consider the class of n-dimensional Riemannian spin manifolds with bounded
sectional curvatures and diameter, and almost non-negative scalar curvature.
Let r=1 if n=2,3 and r=2^{[n/2]-1}+1 if n\geq 4. We show that if the square of
the Dirac operator on such a manifold has small eigenvalues, then the
manifold is diffeomorphic to a nilmanifold and has trivial spin structure.
Equivalently, if M is not a nilmanifold or if M is a nilmanifold with a
non-trivial spin structure, then there exists a uniform lower bound on the r-th
eigenvalue of the square of the Dirac operator. If a manifold with almost
nonnegative scalar curvature has one small Dirac eigenvalue, and if the volume
is not too small, then we show that the metric is close to a Ricci-flat metric
on M with a parallel spinor. In dimension 4 this implies that M is either a
torus or a K3-surface
Gender Effects on Lane Change Test (LCT) Performance
There are various easy-to-implement, low-cost methodologies for evaluating driver performance under distraction caused by in-vehicle tasks. One of them is the Lane Change Test (LCT), which is currently under consideration for becoming an ISO-standardized procedure. This paper investigates the effect of gender on LCT performance. Although a common procedure in psychological research, balancing for gender is not a requirement made by the ISO draft. However, using data from three LCT experiments, we found gender differences in LCT as well as secondary task performance. We conclude that subject samples balanced for gender are necessary to assure comparability of LCT results
Local electronic structure of the peptide bond probed by resonant inelastic soft X-ray scattering.
The local valence orbital structure of solid glycine, diglycine, and triglycine is studied using soft X-ray emission spectroscopy (XES), resonant inelastic soft X-ray scattering (RIXS) maps, and spectra calculations based on density-functional theory. Using a building block approach, the contributions of the different functional groups of the peptides are separated. Cuts through the RIXS maps furthermore allow monitoring selective excitations of the amino and peptide functional units, leading to a modification of the currently established assignment of spectral contributions. The results thus paint a new-and-improved picture of the peptide bond, enhance the understanding of larger molecules with peptide bonds, and simplify the investigation of such molecules in aqueous environment
Dynamical Model for Chemically Driven Running Droplets
We propose coupled evolution equations for the thickness of a liquid film and
the density of an adsorbate layer on a partially wetting solid substrate.
Therein, running droplets are studied assuming a chemical reaction underneath
the droplets that induces a wettability gradient on the substrate and provides
the driving force for droplet motion. Two different regimes for moving droplets
-- reaction-limited and saturated regime -- are described. They correspond to
increasing and decreasing velocities with increasing reaction rates and droplet
sizes, respectively. The existence of the two regimes offers a natural
explanation of prior experimental observations.Comment: 4 pages, 5 figure
Chemical Waves in Media with State-Dependent Anisotropy
In the reduction of NO with H2 on a Rh(110) surface rectangularly shaped target patterns and spirals with sharp corners have been observed. These patterns can be reproduced with a simple model assuming that the (anisotropic) diffusion is state dependent. Such a dependence is realized in the system Rh(110)/NO + H2 by the presence of different adsorbate-induced reconstructions with varying substrate geometries
The Chiral Condensate in a Finite Volume
Chiral perturbation theory at finite four-volume V (=L^3T) is reconsidered
with a view towards finding a computational scheme that can deal with any value
of M_\pi L, where M_\pi is a generic Nambu-Goldstone mass. The momentum zero
modes that cause the usual p-expansion to fail in the chiral limit are treated
separately, and partly integrated out to all orders. In this way the theory
remains infrared finite in the perturbative expansion, and the chiral limit can
be considered at finite volume. We illustrate the technique by computing the
quark condensate in a finite volume, smoothly connecting standard results in
the p-regime for larger masses with those of the epsilon-regime for smaller
masses. From the partially quenched theory we also obtain the spectral density
of the Dirac operator, a smooth function from the microscopic region to the
bulk region of the p-regime.Comment: 33 pages, 10 figures, corrections in (4.7), (6.5), (6.8), additional
comment on (3.16
Size-Dependent Transition to High-Dimensional Chaotic Dynamics in a Two-Dimensional Excitable Medium
The spatiotemporal dynamics of an excitable medium with multiple spiral
defects is shown to vary smoothly with system size from short-lived transients
for small systems to extensive chaos for large systems. A comparison of the
Lyapunov dimension density with the average spiral defect density suggests an
average dimension per spiral defect varying between three and seven. We discuss
some implications of these results for experimental studies of excitable media.Comment: 5 pages, Latex, 4 figure
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