14,848 research outputs found
Rethinking one`s own culture
African people reflecting on their own situation will frequently
find themselves in a dilemma to identify with western and traditional values.
A case study of the Burji (Ethiopia and Kenya) examplifies this. First a
description is given of the Burji actively dealing with their problems, trying
among other things to keep Burjiness alive. Then in presenting a semiotic
model it is shown how the phenomenon of their changing group identity
(which is not grasped by theories of ethnic group or ethnicity) can be
analyzed. The model presented may be useful for analyzing similar cases
in the Third World
Non-overlapping domain decomposition for the Richards equation via superposition operators
Simulations of saturated-unsaturated groundwater flow in heterogeneous soil can be carried out by considering non-overlapping domain decomposition problems for the Richards equation in subdomains with homogeneous soil. By the application of different Kirchhoff transformations in the different subdomains local convex minimization problems can be obtained which are coupled via superposition operators on the interface between the subdomains. The purpose of this article is to provide a rigorous mathematical foundation for this reformulation in a weak sense. In particular, this involves an analysis of the Kirchhoff transformation as a superposition operator on Sobolev and trace spaces
Generation and Structure of Solitary Rossby Vortices in Rotating Fluids
The formation of zonal flows and vortices in the generalized
Charney-Hasegawa-Mima equation is studied. We focus on the regime when the size
of structures is comparable to or larger than the deformation (Rossby) radius.
Numerical simulations show the formation of anticyclonic vortices in unstable
shear flows and ring-like vortices with quiescent cores and vorticity
concentrated in a ring. Physical mechanisms that lead to these phenomena and
their relevance to turbulence in planetary atmospheres are discussed.Comment: 3 pages in REVTeX, 5 postscript figures separately, submitted to
Phys. Rev.
Photoemission view of electron fractionalization in quasi-one dimensional metal LiMoO
We report Luttinger liquid line shapes better revealed by new angle resolved
photoemission data taken with a much improved angle resolution on a
quasi-1-dimensional metal LiMoO. The new data indicate a
larger spinon velocity than our previous lower resolution data indicated.Comment: submitted to SCES '0
Superconducting, Insulating, and Anomalous Metallic Regimes in a Gated Two-Dimensional Semiconductor-Superconductor Array
The superconductor-insulator transition in two dimensions has been widely
investigated as a paradigmatic quantum phase transition. The topic remains
controversial, however, because many experiments exhibit a metallic regime with
saturating low-temperature resistance, at odds with conventional theory. Here,
we explore this transition in a novel, highly controllable system, a
semiconductor heterostructure with epitaxial Al, patterned to form a regular
array of superconducting islands connected by a gateable quantum well. Spanning
nine orders of magnitude in resistance, the system exhibits regimes of
superconducting, metallic, and insulating behavior, along with signatures of
flux commensurability and vortex penetration. An in-plane magnetic field
eliminates the metallic regime, restoring the direct superconductor-insulator
transition, and improves scaling, while strongly altering the scaling exponent
Low mass dimuons within a hybrid approach
We analyse dilepton emission from hot and dense hadronic matter using a
hybrid approach based on the Ultrarelativistic Quantum Molecular Dynamics
(UrQMD) transport model with an intermediate hydrodynamic stage for the
description of heavy-ion collisions at relativistic energies. Focusing on the
enhancement with respect to the contribution from long-lived hadron decays
after freeze-out observed at the SPS in the low mass region of the dilepton
spectra (often referred to as "the excess"), the relative importance of the
emission from the equilibrium and the non-equilibrium stages is discussed.Comment: Proceedings of Hot Quarks 2010, 21-26 June 2010 Las Londe Les Maures;
v2: Corrected typos and added a commen
The Human-Fostered Gorilla Koko Shows Breath Control in Play with Wind Instruments
Breath control is critical to the production of spoken language and commonly postulated as a unique human adaptation specifically for this function. In contrast, non-human primates are often assumed to lack volitional control over their vocalizations, and implicitly, their breath. This paper takes an embodied perspective on the development of breath control in a human-fostered gorilla, examining her sound play with musical wind instruments. The subject Koko was video recorded in her play with plastic recorders, harmonicas and whistles. The results show that Koko exercises volitional control over her breath during instrument play. More generally, the findings suggest that all great apes share the potential to develop breath control, and that the original adaptive value of breath control was its flexible development for the service of behaviors that happened to be useful within particular sociocultural and physical environments
Non-Fermi liquid angle resolved photoemission lineshapes of Li0.9Mo6O17
A recent letter by Xue et al. (PRL v.83, 1235 ('99)) reports a Fermi-Liquid
(FL) angle resolved photoemission (ARPES) lineshape for quasi one-dimensional
Li0.9Mo6O17, contradicting our report (PRL v.82, 2540 ('99)) of a non-FL
lineshape in this material. Xue et al. attributed the difference to the
improved angle resolution. In this comment, we point out that this reasoning is
flawed. Rather, we find that their data have fundamental differences from other
ARPES results and also band theory.Comment: To be published as a PRL Commen
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