Polar domain walls trigger magnetoelectric coupling

Interface physics in oxide heterostructures is pivotal in material's science. Domain walls (DWs) in ferroic systems are examples of naturally occurring interfaces, where order parameter of neighboring domains is modified and emerging properties may develop. Here we show that electric tuning of ferroelastic domain walls in SrTiO3 leads to dramatic changes of the magnetic domain structure of a neighboring magnetic layer (La1/2Sr1/2MnO3) epitaxially clamped on a SrTiO3 substrate. We show that by exploiting the resposiveness of DWs nanoregions to external stimuli, even in absence of any domain contribution, prominent and adjustable macroscopic reactions of neighboring layers can be obtained. We conclude that polar DWs, known to exist in other materials, can be used to trigger tunable responses and may lead to new ways for manipulation of interfacial emerging properties

Piezas unidas de cerámicas superconductoras texturadas de TrBa2Cu3O7, donde Tr significa tierra rara o Ytrio, y proceso de unión basado en láminas de AG como agente fundente

Referencia OEPM: P200300081.-- Fecha de solicitud: 14/01/2003.-- Titulares: Consejo Superior de Investigaciones Científicas (CSIC).Un nuevo proceso de fabricación de uniones superconductoras entre dos piezas de cerámicas superconductoras ha sido desarrollado en el cual el agente fundente es una lámina de plata con un grosor bien determinado. La composición típica de la cerámica superconductora será TrBa2Cu3O7-Tr2BaCuO5, donde Tr significa Tierra rara o Ytrio. Este proceso permite fabricar productos cerámicos superconductores con formas complejas en los cuales las corrientes críticas a través de las uniones permanecen tan elevadas como las de las cerámicas originales antes de unirse.Peer reviewe

Empreses i pluralisme informatiu

Empreses i pluralisme informati

Transverse Josephson vortices and localized states in stacked Bose-Einstein condensates

The stacks of Bose-Einstein condensates coupled by long Josephson junctions present a richphenomenology feasible to experimental realization and specially suitable for technologicalapplications as the nonlinear-optics and superconducting analogs have already proved. Among this,we show that transverse Bloch waves excited in arrays of one-dimensional coupled condensates cancarry tunneling superflows whose dynamical stability depends on the quasimomentum. Across thestacks with periodic boundary conditions, forming closed ring-shaped systems, such Bloch states yieldtransverse Josephson vortices with a generic non-integer circulation in units ofh/m. Additionally, thesuperpositions of degenerate linear Bloch waves can suppress the supercurrents and give rise tofamilies of nonlinear standing-wave states with strong(transverse)spatial localization. Stable states ofthis type can also be found infinite size systems

Numerical Simulation of Fatigue in Composites

For the past several years, composite marine structures have been designed but without having a complete characterization the composite materials. The main reason is due to the large quantity of variables that affect the behavior of said materials. One of the tasks that has not been properly characterized is the behavior of composite structures under fatigue loads that appear in marine structures that are subjected to cyclic loads. Therefore, numerical tools that characterize fatigue performance are required in order to design more reliable structures. The formulation proposed in this work is based on the Serial/Parallel Rule of Mixtures [1] and a fatigue damage model [2]. The Serial/Parallel Rule of Mixtures can be understood as a constitutive law manager that provides the response of the composite from the constitutive performance of its constituents. Therefore, the constitutive laws chosen to represent the behavior of each constituent material have to fit with their real performance. Also, the fatigue damage model is based on the use of a reduction function which takes into account the cyclic degradation of the materials, both strength and stiffness degradation, in function of the number of cycles, maximum stress and stress amplitude. Current work presents a numerical tool developed to characterize fatigue in composites. The fatigue behavior of constituent materials is defined using mechanic parameters taken from literature. Afterwards, a reproduction of the tests will be done in order to validate the fatigue formulation proposed. [1] Car, E., Oller, S., Oñate, E. "Estudio del comportamiento no lineal en materiales compuestos", Techincal Report 264,CIMNE, 1997. [2] Oller, Salomon, O., Oñate, E. “A continuum mechanics model for mechanical fatigue analysis", Composite Materials Science, Vol 32, Issue 2, pp 175-195, 2005

Dynamic Model of an HTS Cable for Power Grid Simulation

AbstractElectric power utilities usually use conventional grid simulators to perform simulations for grid design, operation and maintenance studies. Connection of superconducting devices, such as HTS cables, to real grids addresses the need for including specially-designed models in such studies. A 1G HTS cable user-written model suitable for dynamic simulations is developed and it is applied in a sample test grid to analyze its dynamic behavior under fault conditions

Realidad aumentada: Rol del docente y modelos pedagógicos en el proceso educativo

El presente artículo de revisión versa sobre los beneficios de la Realidad Aumentada en el aprendizaje, los modelos pedagógicos que mejor se ajustan a este tipo de tecnología que, junto con el nuevo rol que debe asumir el docente orienten al alumno en su interacción con la nueva realidad creada digitalmente para así lograr los resultados de aprendizaje propuestos por el docente. Se realizó una revisión de carácter exploratorio, de distintas producciones científicas que permitan sustentar la utilidad educativa de la Realidad aumentada bajo los modelos pedagógicos constructivista, conectivismo y ubicuo junto a la necesidad de la aportación del docente ejerciendo su nuevo rol en el aula. Se investigó desde la técnica Netnográfica, involucrando así la interrelación de técnicas de investigación on-line y off-line. Se concluye que la característica principal de la Realidad Aumentada como recurso dentro del aula es la capacidad de generar un aprendizaje global dentro de un entorno mixto logrando la interacción significativa entre el estudiante e información,  estableciendo los modelos pedagógicos constructivista, ubicuo y conectivista como los más adecuados ya que el alumno se convierte en actor importante de su aprendizaje, y el docente redefine su rol para suplir las necesidades educativas del estudiante