2,555 research outputs found
The âfloating forearmâ injury in a child: a case report
The case of a eleven-year-old girl who had a fracture dislocation of the left elbow with entrapment of the ulnar nerve into the dislocated ulnar epicondyle anlage and unstable forearm fracture of the ipslateral upper extremity is described. This severe injury to the elbow and the ipsilateral forearm is termed âfloating forearmâ injury. The forearm was stabilized percutaneously and the elbow fracture dislocation, remaining unstable after internal fixation was treated with a pediatric elbow fixator with motion capacity
Efficacy of the A-V Impulse System versus cryotherapy in the reduction of postoperative oedema of the hand: a prospective randomised trial
In a prospective randomised trial, the effects of an
intermittent compression hand pump vs. cryotherapy were
compared on reduction of postoperative hand swelling and
gain in finger movement after distal radius fractures.
Although intermittent compression as a physical method for
thromboprophylaxis and swelling reduction in orthopaedic
and trauma patients of the lower leg are established, a
prospective randomised trial for an objective evaluation of
the effects of intermittent compression in the upper extremity
has not been previously performed. Forty-three subjects
(63±33 years, 32 women, 11 men) with a unilateral distal
radius fracture treated with transarticular external fixation
were randomised into two treatment groups. In group A 21
patients were treated with cryotherapy. In group B 22
patients were treated with an intermittent compression hand
pump. Reduction in swelling of the treated hand and MP and
PIP joint movement were recorded with computerised
assessment software (EVAL Hand Evaluation System) in
comparison to the uninjured contralateral side. Reduction of
swelling in group A was not statistically significant (28.5%
of total swelling or 0.61 cm, SD 0.39, p=0.42), but in group
B it was significant (92% of total swelling, 3.62 cm, SD 1.48,
p<0.001). Comparison of increases in MP and PIP joint
movement (p<0.0016) showed statistically significant differences
in favour of the intermittent compression pump. This
study demonstrates that intermittent compression is more
effective in the reduction of postoperative oedema and gain
of finger movement of the hand than cryotherapy
Counterflow Extension for the F.A.S.T.-Model
The F.A.S.T. (Floor field and Agent based Simulation Tool) model is a
microscopic model of pedestrian dynamics, which is discrete in space and time.
It was developed in a number of more or less consecutive steps from a simple CA
model. This contribution is a summary of a study on an extension of the
F.A.S.T-model for counterflow situations. The extensions will be explained and
it will be shown that the extended F.A.S.T.-model is capable of handling
various counterflow situations and to reproduce the well known lane formation
effect.Comment: Contribution to Crowds and Cellular Automata Workshop 2008. Accepted
for publication in "Cellular Automata -- 8th International Conference on
Cellular Automata for Research and Industry, ACRI 2008, Yokohama, Japan,
September 23-26, Springer 2008, Proceedings
High-precision measurement of the half-life of Ga
The beta-decay half-life of 62Ga has been studied with high precision using
on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to
0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} =
116.19(4) ms. This result is more precise than any previous measurement by
about a factor of four or more. The present value is in agreement with older
literature values, but slightly disagrees with a recent measurement. We
determine an error weighted average value of all experimental half-lives of
116.18(4) ms.Comment: 9 pages, 5 figures, accepted for publication in PR
A new approach to spherically symmetric junction surfaces and the matching of FLRW regions
We investigate timelike junctions (with surface layer) between spherically
symmetric solutions of the Einstein-field equation. In contrast to previous
investigations this is done in a coordinate system in which the junction
surface motion is absorbed in the metric, while all coordinates are continuous
at the junction surface.
The evolution equations for all relevant quantities are derived. We discuss
the no-surface layer case (boundary surface) and study the behaviour for small
surface energies. It is shown that one should expect cases in which the speed
of light is reached within a finite proper time.
We carefully discuss necessary and sufficient conditions for a possible
matching of spherically symmetric sections.
For timelike junctions between spherically symmetric space-time sections we
show explicitly that the time component of the Lanczos equation always reduces
to an identity (independently of the surface equation of state).
The results are applied to the matching of FLRW models. We discuss `vacuum
bubbles' and closed-open junctions in detail. As illustrations several
numerical integration results are presented, some of them indicate that the
junction surface can reach the speed of light within a finite time.Comment: new version - corrected boundary surface discussion, improved
presentation, and corrected reference 22 pages, many figure
Nonlinear thermoelectric response of quantum dots: renormalized dual fermions out of equilibrium
The thermoelectric transport properties of nanostructured devices continue to
attract attention from theorists and experimentalist alike as the spatial
confinement allows for a controlled approach to transport properties of
correlated matter. Most of the existing work, however, focuses on
thermoelectric transport in the linear regime despite the fact that the
nonlinear conductance of correlated quantum dots has been studied in some
detail throughout the last decade. Here, we review our recent work on the
effect of particle-hole asymmetry on the nonlinear transport properties in the
vicinity of the strong coupling limit of Kondo-correlated quantum dots and
extend the underlying method, a renormalized superperturbation theory on the
Keldysh contour, to the thermal conductance in the nonlinear regime. We
determine the charge, energy, and heat current through the nanostructure and
study the nonlinear transport coefficients, the entropy production, and the
fate of the Wiedemann-Franz law in the non-thermal steady-state. Our approach
is based on a renormalized perturbation theory in terms of dual fermions around
the particle-hole symmetric strong-coupling limit.Comment: chapter contributed to 'New Materials for Thermoelectric
Applications: Theory and Experiment' Springer Series: NATO Science for Peace
and Security Series - B: Physics and Biophysics, Veljko Zlatic (Editor), Alex
Hewson (Editor). ISBN: 978-9400749863 (2012
The rp-process and new measurements of beta-delayed proton decay of light Ag and Cd isotopes
Recent network calculations suggest that a high temperature rp-process could
explain the abundances of light Mo and Ru isotopes, which have long challenged
models of p-process nuclide production. Important ingredients to network
calculations involving unstable nuclei near and at the proton drip line are
-halflives and decay modes, i.e., whether or not -delayed proton
decay takes place. Of particular importance to these network calculation are
the proton-rich isotopes Ag, Ag, Cd and Cd. We
report on recent measurements of -delayed proton branching ratios for
Ag, Ag, and Cd at the on-line mass separator at GSI.Comment: 4 pages, uses espcrc1.sty. Proceedings of the 4th International
Symposium Nuclei in the Cosmos, June 1996, Notre Dame/IN, USA, Ed. M.
Wiescher, to be published in Nucl.Phys.A. Also available at
ftp://ftp.physics.ohio-state.edu/pub/nucex/nic96-gs
Conserving Diagrammatic Approximations for Quantum Impurity Models: NCA and CTMA
Self-consistent diagrammatic approximations to the Anderson or Kondo impurity
model, using an exact pseudoparticle representation of the impurity states, are
reviewed. We first discuss the infrared exponents of the pseudoparticle
propagators as indicators of Fermi liquid behavior through their dependence on
the impurity occupation and on magnetic field. Then we discuss the Non-Crossing
Approximation (NCA), identifying its strengths, but also its fundamental
shortcomings. Physical arguments as well as a perturbative renormalization
group analysis suggest that an infinite parquet-type resummation of
two-particle vertex diagrams, the Conserving T-Matrix Approximation (CTMA) will
cure the deficiencies of NCA. We review results on the pseudoparticle spectral
functions, the spin susceptibility and the impurity electron spectral function,
supporting that the CTMA provides qualitatively correct results, both in the
high-temperature regime and in the strong coupling Fermi liquid regime at low
temperatures.Comment: 10 pages, invited article, to appear in a special edition of JPSJ
"Kondo Effect - 40 Years after the Discovery", published version, some minor
typos correcte
The Fundamental Diagram of Pedestrian Movement Revisited
The empirical relation between density and velocity of pedestrian movement is
not completely analyzed, particularly with regard to the `microscopic' causes
which determine the relation at medium and high densities. The simplest system
for the investigation of this dependency is the normal movement of pedestrians
along a line (single-file movement). This article presents experimental results
for this system under laboratory conditions and discusses the following
observations: The data show a linear relation between the velocity and the
inverse of the density, which can be regarded as the required length of one
pedestrian to move. Furthermore we compare the results for the single-file
movement with literature data for the movement in a plane. This comparison
shows an unexpected conformance between the fundamental diagrams, indicating
that lateral interference has negligible influence on the velocity-density
relation at the density domain . In addition we test a
procedure for automatic recording of pedestrian flow characteristics. We
present preliminary results on measurement range and accuracy of this method.Comment: 13 pages, 9 figure
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