A 3-3-1 model with low scale seesaw mechanisms

We construct a viable 3-3-1 model with two $SU(3)_L$ scalar triplets, extended fermion and scalar spectrum, based on the $T^{\prime}$ family symmetry and other auxiliary cyclic symmetries, whose spontaneous breaking yields the observed pattern of SM fermion mass spectrum and fermionic mixing parameters. In our model the SM quarks lighter than the top quark, get their masses from a low scale Universal seesaw mechanism, the SM charged lepton masses are produced by a Froggatt-Nielsen mechanism and the small light active neutrino masses are generated from an inverse seesaw mechanism. The model is consistent with the low energy SM fermion flavor data and successfully accommodates the current Higgs diphoton decay rate and predicts charged lepton flavor violating decays within the reach of the forthcoming experiments.Comment: 24 pages, 4 figures. Published versio

Asteroseismology of delta Scuti stars in open clusters: Praesepe

The present paper provides a general overview of the asteroseismic potential of delta Scuti stars in clusters, in particular focusing on convection diagnostics. We give a summarise of the last results obtained by the authors for the Praesepe cluster of which five delta Scuti stars are analysed. In that work, linear analysis is confronted with observations, using refined descriptions for the effects of rotation on the determination of the global stellar parameters and on the adiabatic oscillation frequency computations. A single, complete, and coherent solution for all the selected stars is found, which lead the authors to find important restrictions to the convection description for a certain range of effective temperatures. Furthermore, the method used allowed to give an estimate of the global parameters of the selected stars and constrain the cluster.Comment: 6 pages, 1 figure. Accepted for publication in Communications in Asteroseismolog

Determinación de los parámetros de solubilidad de Hansen para el aceite de caña de azúcar. Uso del etanol para la refinación de la cera de caña de azúcar

Currently, the refining of sugarcane wax is carried out with 95% v/v ethanol as solvent. This process has a high rate of ethanol consumption thus, the main objective of this work was to corroborate the feasibility of 95% v/v ethanol as a solvent in the refining of sugarcane wax. The suitability of its performance over other organic solvents was evaluated through the relative energy difference (RED) determined from Hansen solubility parameters (HSPs) of sugarcane oil, which were calculated using HSPiP software. HSPs turned out to be δD = 16.24 MPa½, δP = 3.21 MPa½ and δH = 10.34 MPa½, similar to those reported for pine resin and castor oil. The best solvent was 1-decanol. 95% v/v ethanol turned out to be a bad solvent. Absolute ethanol had a RED value of 0.993, which made it a better candidate since it could reduce consumption rates, and constituted an eco-friendly solvent produced in Cuba for the refining process.La refinación de la cera cruda de caña se realiza con etanol a 95% v/v, incurriendo en altos índices de consumo, por lo que el objetivo principal de este trabajo es determinar si el etanol a 95% v/v es un solvente adecuado. Su uso respecto a otros solventes orgánicos es evaluado por la diferencia de energía relativa (RED) determinada a partir de los parámetros de solubilidad de Hansen (HSPs), se calcularon usando el programa HSPiP. Los HSPs fueron δD = 16.24 MPa½, δP = 3.21 MPa½ and δH = 10.34 MPa ½, siendo similares a los reportados para la resina de pino y el aceite de ricino. El mejor solvente fue 1-decanol, el etanol del 95% v/v fue un mal solvente; el etanol absoluto con un RED= 0.993 es un mejor candidato, ya que podría reducir las tasas de consumo, manteniendo un solvente ecológico y producido en Cuba para el proceso de refinación

Machine learning techniques to select Be star candidates. An application in the OGLE-IV Gaia south ecliptic pole field

Statistical pattern recognition methods have provided competitive solutions for variable star classification at a relatively low computational cost. In order to perform supervised classification, a set of features is proposed and used to train an automatic classification system. Quantities related to the magnitude density of the light curves and their Fourier coefficients have been chosen as features in previous studies. However, some of these features are not robust to the presence of outliers and the calculation of Fourier coefficients is computationally expensive for large data sets. We propose and evaluate the performance of a new robust set of features using supervised classifiers in order to look for new Be star candidates in the OGLE-IV Gaia south ecliptic pole field. We calculated the proposed set of features on six types of variable stars and on a set of Be star candidates reported in the literature. We evaluated the performance of these features using classification trees and random forests along with K-nearest neighbours, support vector machines, and gradient boosted trees methods. We tuned the classifiers with a 10-fold cross-validation and grid search. We validated the performance of the best classifier on a set of OGLE-IV light curves and applied this to find new Be star candidates. The random forest classifier outperformed the others. By using the random forest classifier and colour criteria we found 50 Be star candidates in the direction of the Gaia south ecliptic pole field, four of which have infrared colours consistent with Herbig Ae/Be stars. Supervised methods are very useful in order to obtain preliminary samples of variable stars extracted from large databases. As usual, the stars classified as Be stars candidates must be checked for the colours and spectroscopic characteristics expected for them

La investigación como soporte de la gestión: el ejemplo de la duna costera (foredune) de Maspalomas (Gran Canaria, Islas Canarias)

Se analizan las transformaciones experimentadas en las últimas décadas por la duna costera (foredune) de Maspalomas, un proceso que coincide con el descenso de las poblaciones del arbusto Traganum moquinii. Los resultados obtenidos indican que esas poblaciones han experimentado una reducción muy significativa entre 1961 y 2003, lo que ha producido la fragmentación de la duna costera y la generación de superficies de deflación. A partir de estos resultados se han propuesto una serie de actuaciones encaminadas a recuperar la duna costera, mediante la eliminación de las actividades humanas perjudiciales para la vegetación y la repoblación con ejemplares de Traganum moquinii.We analyze the changes experienced by the foredune of the dunes field of Maspalomas in recent decades, a stage that coinciding with the decline in populations of bush Traganum moquinii. The results showed that populations of Traganum moquinii have experienced a very significant reduction between 1961 and 2003, with the result of the fragmentation of coastal dune and generating deflation surfaces. Based on these results, some actions have been proposed, aimed at recovering the coastal dune, by eliminating human activities detrimental to vegetation and restocking with copies of Traganum moquinii

High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomena

We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses to achieve a noticeable cut-off extensions in HHG. These chirped pulses are generated using both linear and nonlinear dispersive media.The description of the origin of the physical mechanisms responsible of this extension is, however, not usually reported with enough detail in the literature. The study of the behaviour of the harmonic cut-off with these kind of pulses is carried out in the classical context, by the integration of the Newton-Lorentz equation complemented with the quantum approach, based on the integration of the time dependent Schr\"odinger equation in full dimensions (TDSE-3D), we are able to understand the underlying physics.Comment: 13 pages, 8 figure