11,458 research outputs found
Snow and Thunder
William Apel, professor of religion, shares his thoughts and observations about the Global Baptist Peace Conference he attended in Rome
Test of hadronic interaction models with air shower data
The description of high-energy hadronic interactions plays an important role
in the (astrophysical) interpretation of air shower data. The parameter space
important for the development of air showers (energy and kinematical range)
extends well beyond todays accelerator capabilities. Therefore, accurate
measurements of air showers are used to constrain modern models to describe
high-energy hadronic interactions. The results obtained are complementary to
information gained at accelerators and add to our understanding of high-energy
hadronic interactions.Comment: Invited talk at the 13th International Conference on Elastic &
Diffractive Scattering, CERN, 200
Exploring January Term
An inside look at three courses offered on the McMinnville Campus during January Term: Monks and Mystics, Scriptwriting, and Physics of Art and Music
The aerocrew mission : training space Session at Ny Aalesund Arctic base
The Aerocrew mission has been realized in December 2007, in the frame of the International Polar Year, and in cooperation with the Polar Institut Paul-Émile Victor. The team has realized an original5 days training experience at Ny-Aalesund Arctic Base (79°N) the. The 11 crew members constituted a space crew, including physicians, aerospace crew trainers and engineers, and were implied in a seminar with 4 sessions, dealing with the training capabilities of Arctic Bases. The goal was on one hand to show that this kind of base constitutes a pertinent and affordable facility for space and aerospace teams, and on the other hand that the specific aerospace crew training techniques, could be fruitful for the scientists in artcic bases (glaciologists, geologists, specialists of the atmosphere).
The 4 sessions, given by professionals of aerospace, robotics and medicine, covered the training methods for crews, robotics for outdoor and indoor activities, engineering of embedded systems, and the internal arrangement of crafts. The experience has shown the
efficiency of a transverse visiting multidisciplinary team for training, and possible synergies with the resident scientists. In addition, the sessions were enriched by demonstrations such as mini-robot for observation, micro-helicopter for special sites, and also the comparison
between EVA Russian glove and Polar Suits. After this mission, it was possible to conclude that this kind of cooperation could certainly open perspectives with crossed benefits either for space training and arctic research
Landau level splitting due to graphene superlattices
The Landau level spectrum of graphene superlattices is studied using a
tight-binding approach. We consider non-interacting particles moving on a
hexagonal lattice with an additional one-dimensional superlattice made up of
periodic square potential barriers, which are oriented along the zig-zag or
along the arm-chair directions of graphene. In the presence of a perpendicular
magnetic field, such systems can be described by a set of one-dimensional
tight-binding equations, the Harper equations. The qualitative behavior of the
energy spectrum with respect to the strength of the superlattice potential
depends on the relation between the superlattice period and the magnetic
length. When the potential barriers are oriented along the arm-chair direction
of graphene, we find for strong magnetic fields that the zeroth Landau level of
graphene splits into two well separated sublevels, if the width of the barriers
is smaller than the magnetic length. In this situation, which persists even in
the presence of disorder, a plateau with zero Hall conductivity can be observed
around the Dirac point. This Landau level splitting is a true lattice effect
that cannot be obtained from the generally used continuum Dirac-fermion model.Comment: 12 pages, 9 figure
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