INFLUENCE OF PREPARATION PROCESS ON PHYSICAL PROPERTIES AND DEVITRIFICATION OF Li2B2O4 (0,9) LiFe5O8 (0,1) GLASSES

Double roller quenching of Li2B2O4(0.9)-LiFe5O8(0.1) has been performed with various melt temperatures and roller speeds. The changes in physical properties or in the devitrification process of the amorphous samples are shown to be related to the LiFe5O8 content variations or to the Fe2+ appearance but not to structural changes of the amorphous state due to preparation processe

Cosmological perturbations from inhomogeneous preheating and multi-field trapping

We consider inhomogeneous preheating in a multi-field trapping model. The curvature perturbation is generated by inhomogeneous preheating which induces multi-field trapping at the enhanced symmetric point (ESP), and results in fluctuation in the number of e-foldings. Instead of considering simple reheating after preheating, we consider a scenario of shoulder inflation induced by the trapping. The fluctuation in the number of e-foldings is generated during this weak inflationary period, when the additional light scalar field is trapped at the local maximum of its potential. The situation may look similar to locked or thermal inflation or even to hybrid inflation, but we will show that the present mechanism of generating the curvature perturbation is very different from these others. Unlike the conventional trapped inflationary scenario, we do not make the assumption that an ESP appears at some unstable point on the inflaton potential. This assumption is crucial in the original scenario, but it is not important in the multi-field model. We also discuss inhomogeneous preheating at late-time oscillation, in which the magnitude of the curvature fluctuation can be enhanced to accommodate low inflationary scale.Comment: 18pages, 2 figures, to appear in JHE

Tuned MSSM Higgses as an inflaton

We consider the possibility that the vacuum energy density of the MSSM (Minimal Supersymmetric Standard Model) flat direction condensate involving the Higgses H_1 and H_2 is responsible for inflation. We also discuss how the finely tuned Higgs potential at high vacuum expectation values can realize {\it cosmologically} flat direction along which it can generate the observed density perturbations, and after the end of inflation -- the coherent oscillations of the Higgses reheat the universe with all the observed degrees of freedom, without causing any problem for the electroweak phase transition.Comment: 6 pages, 5 figure

Hybrid Curvatons from Broken Symmetry

We present a new general mechanism for generating curvature perturbations after inflation. Our model is based on the simple assumption that a field that starts to oscillate after inflation has a potential characterized by an underlying global symmetry that is slightly or badly broken. Inhomogeneous preheating occurs due to the oscillation with the broken symmetry. Unlike the traditional curvaton model, we will not identify the curvaton with the oscillating field. The curvaton is identified with the preheat field that could be either a scalar, vector, or fermionic field. We introduce an explicit mass term for the curvaton, which is important for later evolution and the decay. Our present model represents the simplest example of the hybrid of the curvatons and inhomogeneous preheating.Comment: 21pages, 5 figures, accepted for publication in JHE

Competencia intercultural en el ámbito de las drogodependencias

En este artículo partimos de una concepción multidimensional o biopsicosocial de las drogodependencias. Dentro de este marco de análisis, abogamos por una mayor visibilización de la dimensión intercultural, ya que es imprescindible para el diseño y desarrollo de procesos de intervención integrales. Proponemos la competencia intercultural como un modelo de trabajo que puede permitir el incremento en las capacidades de instituciones y profesionales, especialmente relevante en el caso de los trabajadores sociales, para abordar eficazmente la dimensión intercultural aludida. Tras una amplia revisión de la literatura científica, hemos definido cinco procesos que pueden contribuir a reforzar la competencia intercultural de una institución y cuatro procesos que pueden contribuir a incrementar la competencia intercultural de un o una profesional. Aunque han sido seleccionados para su aplicación en el ámbito de las drogodependencias, todos estos procesos también pueden servir para mejorar la atención a cualquier otro tipo de persona o grupo culturalmente diverso. This article takes a multidimensional or biopsychosocial conception of drug dependency as its starting point. Within this analytical framework, we advocate making the intercultural dimension more visible, since it is essential for the design and implementation of integral intervention processes. We propose intercultural competence as a working model that can increase the capacities of institutions and professionals —a particularly important consideration in the case of social work— in order to effectively address the aforementioned cultural dimension. After an extensive review of the scientific literature, we have defined five processes that can contribute to strengthening an institution’s intercultural competence and four processes that can do the same for a professional’s intercultural competence. Though selected for application in the area of drug dependencies, all these processes can also prove useful in improving attention to any other kind of culturally diverse group or person

Synthesis and Characterization of Multilayered CrAlN/Al2O3 Tandem Coating Using HiPIMS for Solar Selective Applications at High Temperature

The effect of applying a negative bias during deposition of a previously designed multilayer solar selective absorber coating was studied on two types of substrates (316L stainless steel and Inconel 625). The solar selective coating is composed of different chromium aluminum nitride layers deposited using a combination of radiofrequency (RF), direct current (DC), and high-power impulse magnetron sputtering (HiPIMS) technologies. The chemical composition is varied to generate an infrared reflective/absorber layer (with low Al addition and N vacancies) and two CrAlN intermediate layers with medium and high aluminum content (Al/Cr = 0.6 and 1.2). A top aluminum oxide layer (Al2O3) is deposited as an antireflective layer. In this work, a simultaneous DC-pulsed bias (−100 V, 250 kHz) was applied to the substrates in order to increase the film density. The optical performance, thermal stability, and oxidation resistance was evaluated and compared with the performance obtained with similar unbiased coating and a commercial Pyromark paint reference at 600, 700, and 800 °C. The coating remained stable after 200 h of annealing at 600 °C, with solar absorptance (α) values of 93% and 92% for samples deposited on stainless steel and Inconel, respectively, and a thermal emittance ϵ25°C of 18%. The introduction of additional ion bombardment during film growth through bias assistance resulted in increased durability, thermal stability, and working temperature limits compared with unbiased coatings. The solar-to-mechanical energy conversion efficiency at 800 °C was found to be up to 2 times higher than Pyromark at C = 100 and comparable at C = 1000