Developing Hera-FFX for WCAG 2.0

WCAG 2.0 was published in December 2008. It has many differences to WCAG 1.0 as to rationale, structure and content. Two years later there are still few tools supporting WCAG 2.0, and none of them fully mirrors the WCAG 2.0 approach organized around principles, guidelines, success criteria, situations and techniques. This paper describes the on-going development of an update to the Hera-FFX Firefox extension to support WCAG 2.0. The description is focused on the challenges that we have found and our resulting decisions

High-pressure structural investigation of several zircon-type orthovanadates

Room temperature angle-dispersive x-ray diffraction measurements on zircon-type EuVO4, LuVO4, and ScVO4 were performed up to 27 GPa. In the three compounds we found evidence of a pressure-induced structural phase transformation from zircon to a scheelite-type structure. The onset of the transition is near 8 GPa, but the transition is sluggish and the low- and high-pressure phases coexist in a pressure range of about 10 GPa. In EuVO4 and LuVO4 a second transition to a M-fergusonite-type phase was found near 21 GPa. The equations of state for the zircon and scheelite phases are also determined. Among the three studied compounds, we found that ScVO4 is less compressible than EuVO4 and LuVO4, being the most incompressible orthovanadate studied to date. The sequence of structural transitions and compressibilities are discussed in comparison with other zircon-type oxides.Comment: 34 pages, 2 Tables, 11 Figure

Phase stability of lanthanum orthovanadate at high-pressure

When monoclinic monazite-type LaVO4 (space group P21/n) is squeezed up to 12 GPa at room temperature, a phase transition to another monoclinic phase has been found. The structure of the high-pressure phase of LaVO4 is indexed with the same space group (P21/n), but with a larger unit-cell in which the number of atoms is doubled. The transition leads to an 8% increase in the density of LaVO4. The occurrence of such a transition has been determined by x-ray diffraction, Raman spectroscopy, and ab initio calculations. The combination of the three techniques allows us to also characterize accurately the pressure evolution of unit-cell parameters and the Raman (and IR)-active phonons of the low- and high-pressure phase. In particular, room-temperature equations of state have been determined. The changes driven by pressure in the crystal structure induce sharp modifications in the color of LaVO4 crystals, suggesting that behind the monoclinic-to-monoclinic transition there are important changes of the electronic properties of LaVO4.Comment: 39 pages, 6 tables, 7 figure

In-situ epitaxial growth of superconducting La-based bilayer cuprate thin films

We investigate the epitaxial growth of bilayer cuprate La2CaCu2O6+\delta using pure ozone as an oxidant, and find that even the crystal with parent composition without cation substitution can show metallic behavior with the aid of epitaxial strain effect. The hole concentration is controlled simply by excess-oxygen doping, and the films grown under the optimum conditions exhibit superconductivity below 30 K. This is the first result on the superconductivity of bilayer La2CaCu2O6+\delta induced purely by the excess oxygen.Comment: 5 pages, 3 figures, To appear in Phys. Rev. B, Rapid Communication

Universal time-dependent deformations of Schrodinger geometry

We investigate universal time-dependent exact deformations of Schrodinger geometry. We present 1) scale invariant but non-conformal deformation, 2) non-conformal but scale invariant deformation, and 3) both scale and conformal invariant deformation. All these solutions are universal in the sense that we could embed them in any supergravity constructions of the Schrodinger invariant geometry. We give a field theory interpretation of our time-dependent solutions. In particular, we argue that any time-dependent chemical potential can be treated exactly in our gravity dual approach.Comment: 24 pages, v2: references adde

Coxeter Groups as Beauville Groups

We generalize earlier work of Fuertes and Gonzalez-Diez as well as earlier work of Bauer, Catanese and Grunewald by classifying which of the irreducible Coxeter groups are (strongly real) Beauville groups. We also make partial progress on the much more difficult question of which Coxeter groups are Beauville groups in general as well as discussing the related question of which Coxeter groups can be used in the construction of mixed Beauville groups

Estudio y gestión de la comunicación corporativa: El caso Drolimsa.

El proceso de comunicación es uno de los factores fundamentales para el desarrollo de cualquier organización que busque el crecimiento estratégico de su actividad. De aquí que el buen funcionamiento de las organizaciones dependa de la forma en cómo éstas gestionan sus herramientas de comunicación. El objetivo principal es analizar los cuatro pilares de la comunicación corporativa de Drolimsa; comunicación interna, comunicación externa, RSC y comunicación de crisis, y cómo a través de estos se construye la identidad de la empresa. Para ello, se han realizado nueve entrevistas a diferentes cargos y personas relacionadas con la organización y un posterior análisis del discurso. Los resultados muestran una gestión eficaz de la de la comunicación corporativa y una identidad clara y reglada. Sin embargo, Drolimsa no tiene implantado un sistema explícito de comunicación corporativa, por lo que debe trabajar en desarrollar este aspecto ya que cuenta con unas bases sólidas para establecerlo en un futuro.<br /