Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates

Entanglement of spin and position variables produced by spatially inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor Bose-Einstein condensates may lead to interference effects at the level of one-boson densities. A model is worked out for these effects which is amenable to analytical calculation for gaussian shaped condensates. The resulting interference effects are sensitive to the spin polarization properties of the condensate.Comment: 9 pages, 2 figure

Non-Hermitian robust edge states in one-dimension: Anomalous localization and eigenspace condensation at exceptional points

Capital to topological insulators, the bulk-boundary correspondence ties a topological invariant computed from the bulk (extended) states with those at the boundary, which are hence robust to disorder. Here we put forward an ordering unique to non-Hermitian lattices, whereby a pristine system becomes devoid of extended states, a property which turns out to be robust to disorder. This is enabled by a peculiar type of non-Hermitian degeneracy where a macroscopic fraction of the states coalesce at a single point with geometrical multiplicity of $1$, that we call a phenomenal point.Comment: 6 pages, 4 figure

Structural effects of steel reinforcement corrosion on statically indeterminate reinforced concrete members

The final publication is available at Springer via http://dx.doi.org/10.1617/s11527-016-0836-2Steel corrosion in reinforced concrete structures produces loss of reinforcement area and damage in the surrounding concrete. As a consequence, increases in deflections, crack widths and stresses may take place, as well as a reduction of the bearing capacity, which depends on the structural scheme and redundancy. In this paper an experimental study of twelve statically indeterminate beams subjected to different levels of forced reinforcement corrosion is presented. Different sustained loads were applied during the corrosion phase to assess their influence on the effects of corrosion. An important increase in deflections was registered in all corroded beams, especially in those subject to higher load levels. It was also found that the rate of corrosion was affected by the load level. Internal forces redistributions due to induced damage were measured. Finally, the experimental results were compared with those predicted by a non-linear time-dependent segmental analysis model developed by the authors, obtaining in general good agreement.Peer ReviewedPostprint (author's final draft

Spatial Stochastic Frontier Models

The stochastic frontier model with heterogeneous technical efficiency explained by exogenous variables is augmented with a sparse spatial autoregressive component for a cross-section data, and a spatial-temporal component for a panel data. An estimation procedure that takes advantage of the additivity of the model is proposed, computational advantages over simultaneous maximum likelihood estimation of all parameters is exhibited. The technical efficiency estimates are comparable to existing models and estimation procedures based on maximum likelihood methods. A spatial or spatial-temporal component can improve estimates of technical efficiency in a production frontier that is usually biased downwards

Spatial-Temporal Dimensions of Efficiency among Electric Cooperatives in the Philippines

The efficiency of 119 electric cooperatives in the Philippines from 1990 to 2002 is analyzed using a stochastic frontier model augmented with spatial-temporal terms, addressing the underestimation of technical efficiency usually encountered among maximum-likelihood based methods. The model is also robust to the choice of environmental variables that will be included in the inefficiency equation provided that the spatial distance measure substantially captures the efficiency-enhancing factors. The average of estimated technical efficiency is 0.86. The growth in technical efficiency of 1-2% per year is explained by the slow adjustment process in the operation of the cooperatives lacking the medium to feedback production outcomes in the previous year to their operation cycle in the following year. Medium-sized cooperatives need to organize for strategic competitive advantage and to facilitate attainment of production efficiency

Investigacion y/o innovación. Un proyecto en y para el centro educativo

Algunos de los cambios acaecidos en el campo de la epistemología de la investigación, nos obliga a revisar con un sentido más crítico mucho de lo que normalmente se investiga en la educación. La existencia de tener presente estos cambios nace de la comprobación de nuevos paradigmas en la educación; de los que la investigación tiene que ser más seriamente consciente.Una de las variables que puede incidir de forma más o menos directa es el grado de autonomía y desarrollo profesional de los profesores investigadores. Una investigación centrada en el puesto de trabajo ( Centro docente), centrada en un Proyecto, centrada en la práctica, centrada en los problemas prácticos de su clase y realizada en un concepto específico, como miembro de un colectivo (Departamento o Claustro) y que una vez planteadas las necesidades específicas de la investigación, para que el profesorado participe en el diseño, en la realización y en la evaluación de la misma.Con este documento pretendemos exponer los momentos, las finalidades y las orientaciones llevadas a cabo en un proyecto de trabajo desde la investigación-acción