Sterile neutrino decay and the LSND experiment

We propose a new explanation of the intriguing LSND evidence for electron antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a coupling with a light scalar and light (mostly active) neutrinos. We perform a fit to the LSND data, as well as all relevant null-result experiments, taking into account the distortion of the spectrum due to decay. By requiring a coupling g ~ 10^{-5}, a heavy neutrino mass m_4 ~ 100 keV and a mixing with muon neutrinos |U_{mu 4}|^2 ~ 10^{-2}, we show that this model explains all existing data evading constraints that disfavor standard (3+1) neutrino models.Comment: 3pp. Talk given at 9th International Conference on Astroparticle and Underground Physics (TAUP 2005), Zaragoza, Spain, 10-14 Sep 200

Directed Molecular Stacking for Engineered Fluorescent Three-Dimensional Reduced Graphene Oxide and Coronene Frameworks

[EN] Three‐dimensional fluorescent graphene frameworks with controlled porous morphologies are of significant importance for practical applications reliant on controlled structural and electronic properties, such as organic electronics and photochemistry. Here we report a synthetically accessible approach concerning directed aromatic stacking interactions to give rise to new fluorogenic 3D frameworks with tuneable porosities achieved through molecular variations. The binding interactions between the graphene‐like domains present in the in situ‐formed reduced graphene oxide (rGO) with functional porphyrin molecules lead to new hybrids via an unprecedented solvothermal reaction. Functional free‐base porphyrins featuring perfluorinated aryl groups or hexyl chains at their meso‐ and β‐positions were employed in turn to act as directing entities for the assembly of new graphene‐based and foam‐like frameworks and of their corresponding coronene‐based hybrids. Investigations in the dispersed phase and in thin‐film by XPS, SEM and FLIM shed light onto the nature of the aromatic stacking within functional rGO frameworks (denoted rGOFs) which was then modelled semi‐empirically and by DFT calculations. The pore sizes of the new emerging reduced graphene oxide hybrids are tuneable at the molecular level and mediated by the bonding forces with the functional porphyrins acting as the “molecular glue”. Single crystal X‐ray crystallography described the stacking of a perfluorinated porphyrin with coronene, which can be employed as a molecular model for understanding the local aromatic stacking order and charge transfer interactions within these rGOFs for the first time. This opens up a new route to controllable 3D framework morphologies and pore size from the Ångstrom to the micrometre scale. Theoretical modelling showed that the porosity of these materials is mainly due to the controlled inter‐planar distance between the rGO, coronene or graphene sheets. The host‐guest chemistry involves the porphyrins acting as guests held through π‐π stacking, as demonstrated by XPS. The objective of this study is also to shed light into the fundamental localised electronic and energy transfer properties in these new molecularly engineered porous and fluorogenic architectures, aiming in turn to understand how functional porphyrins may exert stacking control over the notoriously disordered local structure present in porous reduced graphene oxide fragments. By tuning the porosity and the distance between the graphene sheets using aromatic stacking with porphyrins, it is also possible to tune the electronic structure of the final nanohybrid material, as indicated by FLIM experiments on thin films. Such nanohybrids with highly controlled pores dimensions and morphologies open the way to new design and assembly of storage devices and applications incorporating π‐conjugated molecules and materials and their π‐stacks may be relevant towards selective separation membranes, water purification and biosensing applications.S.I.P. and S.W.B. thank The Royal Society and STFC for funding. B.Y.M. thanks the University of Bath for a studentship (ORS). D.G.C. thanks the Fundación General CSIC for funding (ComFuturo Program). Dr. Jose A. Ribeiro Martins, Professors Jeremy K. M. Sanders and Paul Raithby are acknowledged for training, helpful discussions and porphyrin supramolecular chemistry. The S.I.P. group thanks the EPSRC for funding to the Centre of Graphene Science (EP/K017160/1) and to the Centre for Doctoral Training in Sustainable Chemical Technologies (EP/L016354/1). The authors thank EPSRC National Service for Mass Spectrometry at Swansea and EPSRC National Service for Crystallography at Southampton for data collection. The authors also acknowledge the ERC for the Consolidator Grant O2SENSE (617107, 2014–2019)

RELACIONES INTRAFAMILIARES Y ADICCIÓN A INTERNET EN ESTUDIANTES DE SECUNDARIA DE UNA INSTITUCIÓN EDUCATIVA DE VILLA MARÍA DEL TRIUNFO

Se estableció la relación entre las relaciones intrafamiliares con la adicción a internet en estudiantes de secundaria. La investigación fue de tipo cuantitativa y de diseño correlacional, con una muestra de 322 estudiantes de secundaria, de 12 a 16 años de edad. Se usó la Escala para la Evaluación de la Relaciones Intrafamiliares de Rivera y Andrade y el Test de Adicción a Internet de Young. Los resultados mostraron que el nivel de las relaciones intrafamiliares es de 23.1% en el nivel bajo y de 20.6% en el nivel promedio bajo; mientras que el nivel de la adicción a internet fue de 20.6% en el nivel promedio alto y 23.4% en el nivel alto; así mismo, se encontró diferencias significativas (p<0.05) según edad, presentando mayores puntajes los estudiantes de 14 a 16 años. Finalmente, no se halló relación significativa entre las dimensiones de ambas variables; sin embargo, se halló relación significativa inversa (p<0.05) a nivel general

NOx selective catalytic reduction at high temperatures with mixed oxides derived from layered double hydroxides

[EN] Mixed oxides derived from layered double hydroxides (LDHs) have been investigated as potential catalysts for the NOx removal at high temperatures. The best results were obtained with Co–Al mixed oxides derived from LDHs that are active at 750 ◦C in the presence of oxygen and water. These catalysts could reduce or/and decompose the NOx formed in the dense phase of the FCC regenerator, being deactivated at oxygen concentrations higher than 1.5%. Nevertheless this deactivation is not permanent and they would be regenerated after reduction with hydrogen at 530 ◦C. The influence of the layered double hydroxides (LDHs) preparation method on the catalyst activity was studied, observing that the activity of the catalyst depends on its chemical composition but it does not depend on the initial LDHs crystallinity, obtaining similar results independently of the synthesis method.A.E. Palomares and C. Franch thank the Spanish Government (projects MAT2009-14528-C02-01 and CONSOLIDER INGENIO 2010) and the European Union (European Community's Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 226347 Project) for financial support. A. Ribera and G. Abellan acknowledge financial support from the Spanish Ministerio de Ciencia e Innovacion with FEDER co-financing (CTQ-2011-26507) and the Generalitat Valenciana (Prometeo Program).Palomares Gimeno, AE.; Franch Martí, C.; Ribera, A.; Abellán, G. (2012). NOx selective catalytic reduction at high temperatures with mixed oxides derived from layered double hydroxides. Catalysis Today. 191(1):47-51. https://doi.org/10.1016/j.cattod.2012.01.023S4751191

Perspectiva constitucional colombiana de la Comunidad Andina: la jurisprudencia constitucional del Acuerdo de Cartagena

El presente escrito busca describir el entendimiento de la jurisprudencia constitucional del proceso de integración andino. Para ello, se revisarán los fallos de la Corte Constitucional, a fin de determinar los criterios constitucionales que permanecen vigentes desde 1968 con la Corte Suprema de Justicia y cuáles han sido los nuevos criterios aportados por la Corte Constitucional

Neutrino initiated cascades at mid and high altitudes in the atmosphere

High energy neutrinos play a very important role for the understanding of the origin and propagation of ultra high energy cosmic rays (UHECR). They can be produced as a consequence of the hadronic interactions suffered by the cosmic rays in the acceleration regions, as by products of the propagation of the UHECR in the radiation background and as a main product of the decay of super heavy relic particles. A new era of very large exposure space observatories, of which the JEM-EUSO mission is a prime example, is on the horizon which opens the possibility of neutrino detection in the highest energy region of the spectrum. In the present work we use a combination of the PYTHIA interaction code with the CONEX shower simulation package in order to produce fast one-dimensional simulations of neutrino initiated showers in air. We make a detail study of the structure of the corresponding longitudinal profiles, but focus our physical analysis mainly on the development of showers at mid and high altitudes, where they can be an interesting target for space fluorescence observatories.Comment: To appear in Astroparticle Physic

New perspective in the design of quality management systems

This article aims to analyze the different trends and models of the current quality management systems, identifying areas of opportunity in these to establish proposals for care that give rise to a new management system, flexible, efficient and effective Supported by a system of sociotechnical work. The competitive climate in today's business has multiplied significantly in the face of the dynamics of change and the presence of ever shorter business cycles. It is a fact that in the last decades the market has been acquiring an increasing dynamism. Today, companies are developing in a more competitive national and international economy, with increasing demands for productivity, where market laws force them to deepen and change strategies and policies, to plan, create and innovate, to have a high degree of resilience and Sensitivity to anticipate future needs and to be able to survive and develop in a complex and increasingly competitive environment. In these times the markets are increasingly informed, so their expectations are increasingly demanding, for this reason is that quality becomes a differentiating element and at the same time the key factor of a company's lasting success