1,384 research outputs found
Non-Abelian Chern-Simons-Higgs vortices with a quartic potential
We have constructed numerically non-Abelian vortices in an SU(2)
Chern-Simons-Higgs theory with a quartic Higgs potential. We have analyzed
these solutions in detail by means of improved numerical codes and found some
unexpected features we did not find when a sixth-order Higgs potential was
used. The generic non-Abelian solutions have been generated by using their
corresponding Abelian counterparts as initial guess. Typically, the energy of
the non-Abelian solutions is lower than that of the corresponding Abelian one
(except in certain regions of the parameter space). Regarding the angular
momentum, the Abelian solutions possess the maximal value, although there exist
non-Abelian solutions which reach that maximal value too. In order to classify
the solutions it is useful to consider the non-Abelian solutions with
asymptotically vanishing component of the gauge potential, which may be
labelled by an integer number . For vortex number and above, we have
found uniqueness violation: two different non-Abelian solutions with all the
global charges equal. Finally, we have investigated the limit of infinity Higgs
self-coupling parameter and found a piecewise Regge-like relation between the
energy and the angular momentum.Comment: 9 pages, 13 figure
Electrochemical reduction of carbamazepine in ethanol and water solutions using a glassy carbon electrode
The electrochemical reduction of carbamazepine in ethanol and water using a glassy carbon electrode has been studied. In all experimental conditions of scan rate and concentration of carbamazepine an irreversible cathodic wave was observed by cyclic voltammetry (CV). Electrochemical parameters and a plausible EqC mechanism have been reported from the electrochemical measurements and digital simulation. The values of thermodynamic E1/2 were correlated with solvent polarity parameters that it can be interesting for biological, pharmaceutical and forensic purposes. Limits of Detection (LOD) for DPV are 1.1 and 9.0 g/mL (4.65x10-6 and 3.81x10-5 M) in ethanol and water, respectively. The precision and recoveries obtained for tablets and plasma samples showed that the method could be successfully used for analysis
Surface-based and solid shell formulations of the 7-parameter shell model for layered CFRP and functionally graded power-based composite structures
Early-type galaxies in the Coma cluster: a new piece in the calcium puzzle
We present measurements of the CaII triplet and the Ca4227 Lick-index for a
sample of early-type galaxies in the Coma cluster, deriving, for the first
time, their corresponding relationships with velocity dispersion. Compared with
a similar subsample of ellipticals in the field, Coma galaxies with velocity
dispersions in the range ~ 180-270 km/s exhibit significant differences in the
strengths of the Ca features, suggesting an influence of the environment on the
star formation histories of these galaxies. We argue that the main scenarios
previously proposed to explain the relatively low CaII triplet of galaxies are
not able by themselves to simultaneously reconcile the strengths of the two Ca
indices in both environments.Comment: 6 pages including 2 figures. Accepted for publication in ApJL. For
associated data tables see
http://www.ucm.es/info/Astrof/ellipt/CATRIPLET.htm
Vascular endothelium plays a key role in directing pulmonary epithelial cell differentiation.
The vascular endothelium is critical for induction of appropriate lineage differentiation in organogenesis. In this study, we report that dysfunctional pulmonary endothelium, resulting from the loss of matrix Gla protein (MGP), causes ectopic hepatic differentiation in the pulmonary epithelium. We demonstrate uncontrolled induction of the hepatic growth factor (HGF) caused by dysregulated cross talk between pulmonary endothelium and epithelium in Mgp-null lungs. Elevated HGF induced hepatocyte nuclear factor 4 α (Hnf4a), which competed with NK2 homeobox 1 (Nkx2.1) for binding to forkhead box A2 (Foxa2) to drive hepatic differentiation in Mgp-null airway progenitor cells. Limiting endothelial HGF reduced Hnf4a, abolished interference of Hnf4a with Foxa2, and reduced hepatic differentiation in Mgp-null lungs. Together, our results suggest that endothelial-epithelial interactions, maintained by MGP, are essential in pulmonary cell differentiation
Measurement device design: Rain gauge
The need to size large hydraulic infrastructures, exploit extensive agricultural areas or simply arrange water assets for human consumption makes the evaluation of the available water resources essential. Water is a scarce resource that is poorly distributed both, spatially and temporally. Therefore, a set of hydrological networks that allow the evaluation of water quantity and quality is required. In order to achieve this, the first step is to retrieve reliable data on rainfall.
To carry out a correct evaluation of water resources, both in the small and large scale, disposing hydrological networks that involve a certain number of measuring devices becomes critical. Despite the great amount of studies that have been developed on measuring devices such as rain gauges, there are still many errors that remain in the measurements and that have not been ruled out yet, thus affecting the accuracy of the measurements.
In this sense, the design of a device that provides an accurate measurement of rainfall and also results affordable, could be the key to a product with great acceptance in the market.
The aim of this work is to present the design of a measurement device that provides accurate data and can be used in multiple ways: as an ordinary rain gauge, as a rain gauge recorder, or even allowing to carry on both functions simultaneously.
The methodology followed for its implementation has consisted in analyzing the techniques and procedures to be trailed at quantifying rainfall, conducting a market study and analyzing specifications to be in accordance to WMO (World Meteorological Organization) [2] [3] to then go through a conceptual design and finally complete the detailed design where materials are valued and simulation tests are performed in order to meet certain accuracy and economical requirements.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
A numerical approach for liquefaction potential definition
Liquefaction phenomenon in saturated granular soil is not that frequent as amplification cases but can cause
heavy damages on buildings and infrastructures whenever is occurs especially within superficial strata. In fact
the lack of shear resistance of soil due to liquefaction affects mostly shallow foundations and road surfaces. Up
now, several studies have been addressed to overpass the inadequacy of liquefaction safety factor by means of
introducing the liquefaction potential. Nevertheless, the difficulty in (1) defining a scale of damage related to
liquefaction potential values and (2) collecting field data from damages caused prevalently by liquefaction
makes the punctual factor of safety still popular in engineering practice. In this paper a new approach to
liquefaction potential estimation is proposed based on finite element dynamic analyses and on the concept of
“significant volume” according to possible effects suffered by shallow foundations. One-dimensional
simulation of liquefaction occurrence is performed by means of the Pastor-Zienkiewicz constitutive law. Hence
the estimation of liquefaction potential is gained as well as the stress influence factor from Westergaard
solution is calculated
EstimulaciĂłn vagal en el tratamiento de la epilepsia
The vagal nerve stimulation is a new technique for the treatment of
drug resistant epilepsies. DEVELOPMENT: In 1997, it was approved in United States
by the FDA to be used in adults with refractory focal epilepsies not candidates
for epilepsy surgery. Its mechanism of action is unknown. The results in the
controlled studies indicated a decrease of 30 50% in the seizure frequency in
around 50% of the patients. Although more experience is needed to corroborate
these results, it seems reasonable as a treatment for patients with difficult
epilepsies, especially when the response to the antiepileptic drugs is poor or
they are producing secondary effects, and the resection of the focus is not
possible
- …