Effective penetration length and interstitial vortex pinning in superconducting films with regular arrays of defects

In order to compare magnetic and non-magnetic pinning we have nanostructured two superconducting films with regular arrays of pinning centers: Cu (non-magnetic) dots in one case, and Py (magnetic) dots in the other. For low applied magnetic fields, when all the vortices are pinned in the artificial inclusions, magnetic dots prove to be better pinning centers, as has been generally accepted. Unexpectedly, when the magnetic field is increased and interstitial vortices appear, the results are very different: we show how the stray field generated by the magnetic dots can produce an effective reduction of the penetration length. This results in strong consequences in the transport properties, which, depending on the dot separation, can lead to an enhancement or worsening of the transport characteristics. Therefore, the election of the magnetic or non-magnetic character of the pinning sites for an effective reduction of dissipation will depend on the range of the applied magnetic field.Comment: 10 pages, 3 figure

Degenerate neutrinos from a supersymmetric A_4 model

We investigate the supersymmetric A_4 model recently proposed by Babu, Ma and Valle. The model naturally gives quasi-degenerate neutrinos that are bi-largely mixed, in agreement with observations. Furthermore, the mixings in the quark sector are constrained to be small, making it a complete model of the flavor structure. Moreover, it has the interesting property that CP-violation in the leptonic sector is maximal (unless vanishing). The model exhibit a close relation between the slepton and lepton sectors and we derive the slepton spectra that are compatible with neutrino data and the present bounds on flavor-violating charged lepton decays. The prediction for the branching ratio of the decay tau -> mu gamma has a lower limit of 10^{-9}. In addition, the overall neutrino mass scale is constrained to be larger than 0.3 eV. Thus, the model will be tested in the very near future.Comment: 11 pages, 6 figures. Talk given at the International Workshop on Astroparticle and High Energy Physics (AHEP), Valencia, Spain, 14-18 Oct. 200

A comparative analysis between FEM and Boundary Methods in bending of Plates

Two different methods of analysis of plate bending, FEM and BM are discussed in this paper. The plate behaviour is assumed to be represented by using the linear thin plate theory where the Poisson-Kirchoff assumption holds. The BM based in a weighted mean square error technique produced good results for the problem of plate bending. The computational effort demanded in the BM is smaller than the one needed in a FEM analysis for the same level of accuracy. The general application of the FEM cannot be matched by the BM. Particularly, different types of geometry (plates of arbitrary geometry) need a similar but not identical treatment in the BM. However, this loss of generality is counterbalanced by the computational efficiency gained in the BM in the solution achievemen

Scaling of the conductance in gold nanotubes

A new form of gold nanobridges has been recently observed in ultrahigh-vacuum experiments, where the gold atoms rearrange to build helical nanotubes, akin in some respects to carbon nanotubes. The good reproducibility of these wires and their unexpected stability will allow for conductance measurements and make them promising candidates for future applications . We present here a study of the transport properties of these nanotubes in order to understand the role of chirality and of the different orbitals in quantum transport observables. The conductance per atomic row shows a light decreasing trend as the diameter grows, which is also shown through an analytical formula based on a one-orbital model.Comment: 5 pages, 6 figure

Phenomenological interpolation of the inclusive J/psi cross section to proton-proton collisions at 2.76 TeV and 5.5 TeV

We present a study of the inclusive J/psi cross section at 2.76 TeV and 5.5 TeV. The energy dependence of the cross section, rapidity and transverse momentum distributions are evaluated phenomenologically. Their knowledge is crucial as a reference for the interpretation of A-A and p-A J/psi results at the LHC. Our approach is the following: first, we estimate the energy evolution of the pt-integrated J/psi cross section at mid-rapidity; then, we evaluate the rapidity dependence; finally, we study the transverse momentum distribution trend. Whenever possible, both theory driven (based on pQCD predictions) and functional form (data driven fits) calculations are discussed. Our predictions are compared with the recently obtained results by the ALICE collaboration in pp collisions at 2.76 TeV.Comment: 23 pages, 19 figures, updated text+figures, added comparison to ALICE measurements at 2.76Te

Heavy Neutrinos and Lepton Flavour Violation in Left-Right Symmetric Models at the LHC

We discuss lepton flavour violating processes induced in the production and decay of heavy right-handed neutrinos at the LHC. Such particles appear in left-right symmetrical extensions of the Standard Model as the messengers of neutrino mass generation, and can have masses at the TeV scale. We determine the expected sensitivity on the right-handed neutrino mixing matrix, as well as on the right-handed gauge boson and heavy neutrino masses. By comparing the sensitivity of the LHC with that of searches for low energy LFV processes, we identify favourable areas of the parameter space to explore the complementarity between LFV at low and high energies.Comment: 34 pages, 16 figures, PRD versio

Primary and secundary school physical education teachers’ beliefs

El estudio ha tenido el propósito de analizar el conocimiento de la percepción de las competencias profesionales que tiene el profesor de educación física en primaria y secundaria, como uno de los aspectos que determinan la identidad de la educación física como materia escolar, para dar respuesta al análisis del estado de la educación física desde esta perspectiva. Participaron 119 docentes de Castilla-La Mancha de primaria y secundaria, a los que se les aplicó parte de la "Escala de Percepción de la eficacia de los docentes"; concretamente las preguntas referidas a la percepción sobre las competencias docentes que tienen los profesores; diseñado y validado por el grupo de investigación (GIEEAFyD-UAM), liderado por Hernández et al., (2010). Los resultados muestran que los profesores de primaria se perciben más competentes que los profesores de secundaria en la gestión/organización de la clase y en el conocimiento didáctico de la enseñanza; las diferencias son significativas en la percepción del dominio del contenido de enseñanza y no se hallan diferencias en la capacidad de liderazgo y de relación con otros agentesThe study has analyzed physical education teachers’ self-perception of their professional competences in primary and secondary school, as one of the aspects that determines physical education identity as a school subject. The main purpose of the analysis is to review the status of physical education from this perspective. 119 primary and secondary school teachers from Castilla-La Mancha took part in the study, which applied part of the Scale of Perception of Teachers´ Efficiency, designed and validated by the research group GIEEAFyD-UAM (Hernández et al. 2010), and, more specifically, those questions referred to teachers’ perception of their own educational competences; The results revealed that primary school teachers regard themselves as more competent than secondary school teachers in classroom management/organization and in teaching methodology. Differences are significant in participants’ perception of their command of the content and there are no differences in leadership qualities and neither in the relation to other education agent

Características y desarrollo del acogimiento familiar en dos países con fuerte tradición de acogimiento residencial: España y Portugal

Los procesos de acogimiento familiar que se producen en cada país dependen de factores históricos y culturales que dan lugar a grandes diferencias internacionales. A pesar de que las comparativas internacionales ofrecen un medio de intercambio de experiencias, lo que permite el aprendizaje mutuo y la transferencia de buenas prácticas, a menudo encontramos enormes barreras para su realización debido, entre otros factores, al limitado acceso a los datos sobre la práctica de la protección infantil. Frente a estas limitaciones, este artículo ofrece una investigación comparativa realizada en España y Portugal cuyo objetivo ha sido la evaluación del acogimiento familiar en dos países donde la investigación en el ámbito de la protección infantil ha sido tradicionalmente desatendida. Sobre una muestra de 357 casos en España y 289 en Portugal se realizó un estudio del perfil de características de los niños acogidos, las familias de origen y los acogedores, así como de los procesos de acogida en ambos países. La comparativa reveló importantes diferencias relacionadas con la mayor edad al inicio del acogimiento de los niños en España; el perfil de los acogedores, con edades más avanzadas, un bajo nivel educativo y llevando a cabo acogidas de más de un niño simultáneamente en Portugal. El estudio comparado nos ha permitido identificar áreas que requieren mayor atención en ambos países, como la renovación generacional del banco de acogedores en Portugal o la necesidad de acelerar los procesos de toma de decisiones para la entrada en acogimiento familiar en España. Se pretende que este artículo sirva de aliento para la recogida de datos y comparación con otros países iberoamericanos.InED - Centro de Investigação e Inovação em Educaçã