1,973 research outputs found
Continuous Costoclavicular Brachial Plexus Block in a Pediatric Patient for Postfracture Rehabilitation
The costoclavicular approach to the brachial plexus block has been recently described as a technique for anesthesia or postoperative analgesia of distal upper limb. In this article, we describe a case in which a continuous costoclavicular brachial plexus block was performed in a pediatric patient for conservative treatment of a traumatic radial fracture with severe elbow rigidity. Perineural catheter placement is a valuable option for pain control and functional prognosis during rehabilitation.info:eu-repo/semantics/publishedVersio
Horizontal patterns of water temperature and salinity in an estuarine tidal channel: Ria de Aveiro
This work presents results from two complementary and interconnected approaches to study water temperature and salinity patterns in an estuarine tidal channel. This channel is one of the four main branches of the Ria de Aveiro, a shallow lagoon located in the Northwest coast of the Iberian Peninsula. Longitudinal and cross-sectional fields of water temperature and salinity were determined by spatial interpolation of field measurements. A numerical model (Mohid) was used in a 2D depth-integrated mode in order to compute water temperature and salinity patterns. The main purpose of this work was to determine the horizontal patterns of water temperature and salinity in the study area, evaluating the effects of the main forcing factors. The field results were depth-integrated and compared to numerical model results. These results obtained using extreme tidal and river runoff forcing, are also presented. The field results reveal that, when the river flow is weak, the tidal intrusion is the main forcing mechanism, generating saline and thermal fronts which migrate with the neap/spring tidal cycle. When the river flow increases, the influence of the freshwater extends almost as far as the mouth of the lagoon and vertical stratification is established. Results of numerical modelling reveal that the implemented model reproduces quite well the observed horizontal patterns. The model was also used to study the hydrology of the study area under extreme forcing conditions. When the model is forced with a low river flow (1 m3 s−1) the results confirm that the hydrology is tidally dominated. When the model is forced with a high river flow (1,000 m3 s−1) the hydrology is dominated by freshwater, as would be expected in such an area
The VOLNA-OP2 tsunami code (version 1.5)
In this paper, we present the VOLNA-OP2
tsunami model and implementation; a finite-volume nonlinear
shallow-water equation (NSWE) solver built on
the OP2 domain-specific language (DSL) for unstructured
mesh computations. VOLNA-OP2 is unique among tsunami
solvers in its support for several high-performance computing
platforms: central processing units (CPUs), the Intel
Xeon Phi, and graphics processing units (GPUs). This is
achieved in a way that the scientific code is kept separate
from various parallel implementations, enabling easy maintainability.
It has already been used in production for several
years; here we discuss how it can be integrated into various
workflows, such as a statistical emulator. The scalability of
the code is demonstrated on three supercomputers, built with
classical Xeon CPUs, the Intel Xeon Phi, and NVIDIA P100
GPUs. VOLNA-OP2 shows an ability to deliver productivity
as well as performance and portability to its users across a
number of platforms
String theoretic QCD axions in the light of PLANCK and BICEP2
The QCD axion solving the strong CP problem may originate from antisymmetric
tensor gauge fields in compactified string theory, with a decay constant around
the GUT scale. Such possibility appears to be ruled out now by the detection of
tensor modes by BICEP2 and the PLANCK constraints on isocurvature density
perturbations. A more interesting and still viable possibility is that the
string theoretic QCD axion is charged under an anomalous U(1)_A gauge symmetry.
In such case, the axion decay constant can be much lower than the GUT scale if
moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and
U(1)_A-charged matter fields get a vacuum value far below the GUT scale due to
a tachyonic SUSY breaking scalar mass. We examine the symmetry breaking pattern
of such models during the inflationary epoch with the Hubble expansion rate
10^{14} GeV, and identify the range of the QCD axion decay constant, as well as
the corresponding relic axion abundance, consistent with known cosmological
constraints. In addition to the case that the PQ symmetry is restored during
inflation, there are other viable scenarios, including that the PQ symmetry is
broken during inflation at high scales around 10^{16}-10^{17} GeV due to a
large Hubble-induced tachyonic scalar mass from the U(1)_A D-term, while the
present axion scale is in the range 10^{9}-5\times 10^{13} GeV, where the
present value larger than 10^{12} GeV requires a fine-tuning of the axion
misalignment angle. We also discuss the implications of our results for the
size of SUSY breaking soft masses.Comment: 29 pages, 1 figure; v3: analysis updated including the full
anharmonic effects, references added, version accepted for publication in
JHE
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