Broadening of H2_2O rotational lines by collision with He atoms at low temperature

We report pressure broadening coefficients for the 21 electric-dipole transitions between the eight lowest rotational levels of ortho-H$_2$O and para-H$_2$O molecules by collisions with He at temperatures from 20 to 120 K. These coefficients are derived from recently published experimental state-to-state rate coefficients for H$_2$O:He inelastic collisions, plus an elastic contribution from close coupling calculations. The resulting coefficients are compared to the available experimental data. Mostly due to the elastic contribution, the pressure broadening coefficients differ much from line to line, and increase markedly at low temperature. The present results are meant as a guide for future experiments and astrophysical observations.Comment: 2 figures, 2 table

Management of Virtual Machines on Globus Grids Using GridWay

Virtual machines are a promising technology to over-come some of the problems found in current Grid infras-tructures, like heterogeneity, performance partitioning or application isolation. In this work, we present an straight-forward deployment of virtual machines in Globus Grids. This solution is based on standard services and does not re-quire additional middleware to be installed. Also, we assess the suitability of this deployment in the execution of a high throughput scientific application, the XMM-Newton Scien-tific Analysis System

Closing the SU(3)L⊗U(1)XSU(3)_L\otimes U(1)_X Symmetry at Electroweak Scale

We show that some models with $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ gauge symmetry can be realized at the electroweak scale and that this is a consequence of an approximate global $SU(2)_{L+R}$ symmetry. This symmetry implies a condition among the vacuum expectation value of one of the neutral Higgs scalars, the $U(1)_X$'s coupling constant, $g_X$, the sine of the weak mixing angle $\sin\theta_W$, and the mass of the $W$ boson, $M_W$. In the limit in which this symmetry is valid it avoids the tree level mixing of the $Z$ boson of the Standard Model with the extra $Z^\prime$ boson. We have verified that the oblique $T$ parameter is within the allowed range indicating that the radiative corrections that induce such a mixing at the 1-loop level are small. We also show that a $SU(3)_{L+R}$ custodial symmetry implies that in some of the models we have to include sterile (singlets of the 3-3-1 symmetry) right-handed neutrinos with Majorana masses, being the see-saw mechanism mandatory to obtain light active neutrinos. Moreover, the approximate $SU(2)_{L+R}\subset SU(3)_{L+R}$ symmetry implies that the extra non-standard particles of these 3-3-1 models can be considerably lighter than it had been thought before so that new physics can be really just around the corner.Comment: 32 pages, no figure, RevTeX. Some typos correcte

Composition and Self-Adaptation of Service-Based Systems with Feature Models

The adoption of mechanisms for reusing software in pervasive systems has not yet become standard practice. This is because the use of pre-existing software requires the selection, composition and adaptation of prefabricated software parts, as well as the management of some complex problems such as guaranteeing high levels of efficiency and safety in critical domains. In addition to the wide variety of services, pervasive systems are composed of many networked heterogeneous devices with embedded software. In this work, we promote the safe reuse of services in service-based systems using two complementary technologies, Service-Oriented Architecture and Software Product Lines. In order to do this, we extend both the service discovery and composition processes defined in the DAMASCo framework, which currently does not deal with the service variability that constitutes pervasive systems. We use feature models to represent the variability and to self-adapt the services during the composition in a safe way taking context changes into consideration. We illustrate our proposal with a case study related to the driving domain of an Intelligent Transportation System, handling the context information of the environment.Work partially supported by the projects TIN2008-05932, TIN2008-01942, TIN2012-35669, TIN2012-34840 and CSD2007-0004 funded by Spanish Ministry of Economy and Competitiveness and FEDER; P09-TIC-05231 and P11-TIC-7659 funded by Andalusian Government; and FP7-317731 funded by EU. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Scaling and universality of critical fluctuations in granular gases

The global energy fluctuations of a low density gas granular gas in the homogeneous cooling state near its clustering instability are studied by means of molecular dynamics simulations. The relative dispersion of the fluctuations is shown to exhibit a power-law divergent behavior. Moreover, the probability distribution of the fluctuations presents data collapse as the system approaches the instability, for different values of the inelasticity. The function describing the collapse turns out to be the same as the one found in several molecular equilibrium and non-equilibrium systems, except for the change in the sign of the fluctuations

Breeding for culinary and nutritional quality of common bean (Phaseolus vulgaris L.) in intercropping systems with maize (Zea mays L.)

Common bean (Phaseolus vulgaris L.) is widely intercropped with maize (Zea mays L.) in the North of Spain. Breeding beans for multiple cropping systems is important for the development of a productive and sustainable agriculture, and is mainly oriented to minimize intercrop competition and to stabilize complementarity with maize. Most agricultural research on intercropping to date has focused on the agronomic and overall yield effects of the different species, but characters related with socio-economic and food quality aspects are also important. The effect of intercropping beans with maize on food seed quality traits was studied for thirty-five bush bean varieties under different environments in Galicia (Northwestern Spain). Parameters determining Asturian (Northern Spain) white bean commercial and culinary quality have also been evaluated in fifteen accessions. There are significant differences between varieties in the selected cropping systems (sole crop, intercrop with field maize and intercrop with sweet maize) for dry and soaked seed weight, coat proportion, crude protein, crude fat and moisture. Different white bean accessions have been chosen according to their culinary quality. Under these environmental conditions it appears that intercropping systems with sweet maize give higher returns than sole cropping system. It is also suggested that the culinary and nutritional quality potential of some white bean accessions could be the base material in a breeding programme the objectives of which are to develop varieties giving seeds with high food quality

Novel types of anti-ecloud surfaces

In high power RF devices for space, secondary electron emission appears as the main parameter governing the multipactor effect and as well as the e-cloud in large accelerators. Critical experimental activities included development of coatings with low secondary electron emission yield (SEY) for steel (large accelerators) and aluminium (space applications). Coatings with surface roughness of high aspect ratio producing the so-call secondary emission suppression effect appear as the selected strategy. In this work a detailed study of the SEY of these technological coatings and also the experimental deposition methods (PVD and electrochemical) are presented. The coating-design approach selected for new low SEY coatings include rough metals (Ag, Au, Al), rough alloys (NEG), particulated and magnetized surfaces, and also graphene like coatings. It was found that surface roughness also mitigate the SEY deterioration due to aging processes.Comment: 4 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba, Italy; CERN Yellow Report CERN-2013-002, pp.153-15

Entropy of the Nordic electricity market: anomalous scaling, spikes, and mean-reversion

The electricity market is a very peculiar market due to the large variety of phenomena that can affect the spot price. However, this market still shows many typical features of other speculative (commodity) markets like, for instance, data clustering and mean reversion. We apply the diffusion entropy analysis (DEA) to the Nordic spot electricity market (Nord Pool). We study the waiting time statistics between consecutive spot price spikes and find it to show anomalous scaling characterized by a decaying power-law. The exponent observed in data follows a quite robust relationship with the one implied by the DEA analysis. We also in terms of the DEA revisit topics like clustering, mean-reversion and periodicities. We finally propose a GARCH inspired model but for the price itself. Models in the context of stochastic volatility processes appear under this scope to have a feasible description.Comment: 16 pages, 7 figure

An empirical calibration of sulphur abundance in ionised gaseous nebulae

We have derived an empirical calibration of the abundance of S/H as a function of the S23 parameter, defined using the bright sulphur lines of [SII] and SIII]. Contrary to what is the case for the widely used O$_{23}$ parameter, the calibration remains single valued up to the abundance values observed in the disk HII regions. The calibration is based on a large sample of nebulae for which direct determinations of electron temperatures exist and the sulphur chemical abundances can be directly derived. ICFs, as derived from the [SIV] 10.52 $\mu$ emission line (ISO observations), are shown to be well reproduced by Barker's formula for a value of alpha = 2.5. At any rate, only about 30% of the objects in the sample require ICFs larger than 1.2. The use of the proposed calibration opens the possibility of performing abundance analysis with red to IR spectroscopic data using S/H as a metallicity tracer.Comment: 9 pages, 5 figures. Accepted for publication by Astronomy & Astrophysic

Integral field spectroscopy of nitrogen overabundant blue compact dwarf galaxies

We study the spatial distribution of the physical properties and of oxygen and nitrogen abundances in three Blue Compact Dwarf Galaxiess (HS 0128+2832, HS 0837+4717 and Mrk 930) with a reported excess of N/O in order to investigate the nature of this excess and, particularly, if it is associated with Wolf-Rayet (WR) stars We have observed these BCDs by using PMAS integral field spectroscopy in the optical spectral range (3700 - 6900 {\AA}), mapping their physical-chemical properties, using both the direct method and appropriate strong-line methods. We make a statistical analysis of the resulting distributions and we compare them with the integrated properties of the galaxies. Our results indicate that outer parts of the three galaxies are placed on the "AGN-zone" of the [NII]/H{\alpha} vs. [OIII]/H{\beta} diagnostic diagram most likely due to a high N/O combined with the excitation structure in these regions. From the statistical analysis, it is assumed that a certain property can be considered as spatially homogeneous (or uniform) if a normal gaussian function fits its distribution in several regions of the galaxy. Moreover, a disagreement between the integrated properties and the mean values of the distribution usually appears when a gaussian does not fit the corresponding distribution. We find that for Mrk 930, the uniformity is found for all parameters, except for electron density and reddening. The rotation curve together with the H{\alpha} map and UV images, reveal a perturbed morphology and possible interacting processes. The N/O is found to be constant in the three studied objects at spatial scales of the order of several kpc so we conclude that the number of WR stars estimated from spectroscopy is not sufficient to pollute the ISM and to produce the observed N/O excess in these objectsComment: 17 pages, 14 figures, accepted for publication in Astronomy & Astrophysic