Neutrinoless ββ\beta\beta decay nuclear matrix elements in an isotopic chain

We analyze nuclear matrix elements (NME) of neutrinoless double beta decay calculated for the Cadmium isotopes. Energy density functional methods including beyond mean field effects such as symmetry restoration and shape mixing are used. Strong shell effects are found associated to the underlying nuclear structure of the initial and final nuclei. Furthermore, we show that NME for two-neutrino double beta decay evaluated in the closure approximation, $M^{2\nu}_{\mathrm{cl}}$, display a constant proportionality with respect to the Gamow-Teller part of the neutrinoless NME, $M^{0\nu}_{\mathrm{GT}}$. This opens the possibility of determining the $M^{0\nu}_{\mathrm{GT}}$ matrix elements from $\beta^{\mp}$ Gamow-Teller strength functions. Finally, the interconnected role of deformation, pairing, configuration mixing and shell effects in the NMEs is discussed

Systematic study of infrared energy corrections in truncated oscillator spaces

We study the convergence properties of nuclear binding energies and two-neutron separation energies obtained with self-consistent mean-field calculations based on the Hartree-Fock-Bogolyubov (HFB) method with Gogny-type effective interactions. Owing to lack of convergence in a truncated working basis, we employ and benchmark one of the recently proposed infrared energy correction techniques to extrapolate our results to the limit of an infinite model space. We also discuss its applicability to global calculations of nuclear masses.Comment: 12 pages, 12 figure

Small scale fracture behaviour of multilayer TiN/CrN systems: Assessment of bilayer thickness effects by means of ex-situ tests on FIB-milled micro-cantilevers

TiN/CrN multilayered PVD coatings are known to exhibit outstanding micromechanical properties and wear resistance. On the other hand, information on their small scale fracture behaviour is rather scarce. The present work aims to address it by testing to failure FIB-milled microbeams of multilayer TiN/CrN systems with different bilayer periods (8, 19 and 25 nm). In doing so, these micrometric specimens are first FIB notched, and thus deflected by means of a nanoindentation system. It is found that multilayer architecture translates into a beneficial synergic effect regarding critical load for reaching unstable failure; and thus, on energy absorption at fracture. Such behaviour is associated with small scale crack deflection as main toughening mechanism.Peer ReviewedPostprint (author's final draft

Entorno virtual de aprendizaje compartido en Educación Superior

Cada vez son m&aacute;s demandadas las plataformas virtuales apoyadas en el concepto web 2.0 y en las Redes Personales de Aprendizaje (PLN) al garantizar la conversaci&oacute;n entre agentes educativos y la colaboraci&oacute;n orientada a la producci&oacute;n conjunta de conocimiento. Desde este punto de vista, surgieron los Entornos Virtuales de Aprendizaje (VLE) d&oacute;nde se configuran, integran y combinan nuevas aplicaciones adaptadas a las necesidades de los usuarios. El prop&oacute;sito final de esta experiencia es la creaci&oacute;n de un entorno virtual compartido para lograr que el aprendizaje no se vincule exclusivamente a una actividad memor&iacute;stica y que a trav&eacute;s del uso combinado de la plataforma virtual, herramientas de la web 2.0 y la red social los estudiantes puedan crear su propio espacio de trabajo en el que quede reflejado la b&uacute;squeda y transformaci&oacute;n de la informaci&oacute;n, creaci&oacute;n de recursos para el aprendizaje y tareas de colaboraci&oacute;n. Nuestro entorno virtual de aprendizaje compartido ha sido puesto a prueba, implementado y evaluado durante el segundo cuatrimestre, en el marco de la asignatura Did&aacute;ctica General en la Facultad de Ciencias de la Educaci&oacute;n de la Universidad de Sevilla (Espa&ntilde;a) durante el curso acad&eacute;mico 2009-2010. Una encuesta efectuada revela hechos interesantes sobre el &eacute;xito de este entorno virtual compartido en relaci&oacute;n con la motivaci&oacute;n y los resultados de aprendizaje de los estudiantes.&nbsp;&nbsp;ABSTRACTShared virtual learning environments in higher education.&nbsp;There is an increasing demand for virtual platforms based on the concept of Web 2.0 and on Personal Learning Networks (PLN) as these guarantee conversations between educational agents and cooperation aimed at the joint knowledge production. From this point of view, Virtual Learning Environments (VLE) have emerged in which new applications adapted to users&rsquo; needs are configured, integrated and combined. The ultimate purpose of this experience is the creation of a shared virtual environment to ensure that learning is not linked exclusively to rote activity. Through the combined use of the virtual platform, Web 2.0 tools and social networking, students can create their own workspace in which the search and processing of information, as well as the creation of learning resources and collaboration tasks are reflected. Our shared virtual learning environment has been tested, implemented and evaluated in the second semester, as part of the General Teaching Methodology course in the Faculty of Education at the University of Seville (Spain) during the 2009 &ndash; 2010 academic year. A survey reveals interesting facts about the success of the shared virtual environment in relation to the motivation and learning outcomes of students.&nbsp;</p

La erosión en campos cultivados en Galicia (NW España)

[Resumen] En la presente comunicación se realiza un seguimiento de la erosión en parcelas cultivadas en Galicia. Para ello, en la estación experimental El Pedroso se construyeron dos parcelas, de diferente pendiente, y se sometieron a un proceso de laboreo según las formas tradicionales de cultivar. En la presente comunicación se exponen los resultados del seguimiento de la experimentación desde abril a diciembre de 1995, en donde se observa que la pendiente desempeña una función distinta de la que en un principio podría pensarse, dado que la escorrentía y carga varían de forma inversa a la pendiente.[Abstract] A very closed study of erosion is made in this paper about plough plots in Galicia. For this, in the experimental station El Pedroso were built two plots, with different slope, and were ploughed in a traditional way. In this paper we resume the results of the experiment from april to december 1995, where it is seen that slope has a different function that was thought at the beginning of the experiment, because discharge and load don't vary directly with slope

Can we detect internal moisture content in hardened concrete with an infrared camera?

The main goal of this paper was to assess the ability of infrared thermography to detect non-superficial moisture content in concrete elements. For this purpose, a commercial camera (Flir i5) was used and firstly its capacities and technical limitations were analyzed by comparing it with other commonly commercialized. Secondly, the experiments were undertaken using a concrete specimen (water/cement=0.5) and water under a pressure of 500 kPa was injected over 72 hours into one side of the specimen. The specimen was then left at room temperature (20ºC) for 24 hours, so the surface moisture disappeared. Prior to the images acquisition, the specimen surface was heated by a lamp located at a distance of 0.68 m from the central point of the specimen. In this way, two areas (dry and injected) to be registered would receive the same energy, since they were equidistant from the heating source. The first record was acquired before heating the specimen and then, the heating process was interrupted every 10 minutes to perform the infrared images acquisitions. Finally, by means of the destructive test, the average water penetration depth was assessed to be 3 cm. The infrared images acquired before heating the specimen showed a small temperature variation as a result of the presence of water, 16,3 ºC in the dry area and 15,8 ºC in the injected area. However, after the heating, due to the greater specific heat of water, the injected part achieved a temperature 4º C lower than the symmetrical dry area. This result was very interesting because, in the initial moment (before heating) the surface specimen was dry, but there was a wet area inside of the specimen that was not visually identifiable. Nevertheless, by means of infrared imaging an indicator was obtained that allowed to detect the presence of this internal moisture content

Energy density functional study of nuclear matrix elements for neutrinoless ββ\beta\beta decay

We present an extensive study of nuclear matrix elements (NME) for the neutrinoless double beta decay of the nuclei $^{48}$Ca, $^{76}$Ge, $^{82}$Se, $^{96}$Zr, $^{100}$Mo, $^{116}$Cd, $^{124}$Sn, $^{128}$Te, $^{130}$Te, $^{136}$Xe, and $^{150}$Nd based on state-of-the-art energy density functional methods using the Gogny D1S functional. Beyond mean-field effects are included within the generating coordinate method with particle number and angular momentum projection for both initial and final ground states. We obtain a rather constant value for the NME's around 4.7 with the exception of $^{48}$Ca and $^{150}$Nd, where smaller values are found. We analyze the role of deformation and pairing in the evaluation of the NME and present detailed results for the decay of $^{150}$Nd.Comment: accepted in Phys. Rev. Let