Nonclassical polarization dynamics in classical-like states

Quantum polarization is investigated by means of a trajectory picture based on the Bohmian formulation of quantum mechanics. Relevant examples of classical-like two-mode field states are thus examined, namely Glauber and SU(2) coherent states. Although these states are often regarded as classical, the analysis here shows that the corresponding electric-field polarization trajectories display topologies very different from those expected from classical electrodynamics. Rather than incompatibility with the usual classical model, this result demonstrates the dynamical richness of quantum motions, determined by local variations of the system quantum phase in the corresponding (polarization) configuration space, absent in classical-like models. These variations can be related to the evolution in time of the phase, but also to its dependence on configurational coordinates, which is the crucial factor to generate motion in the case of stationary states like those here considered. In this regard, for completeness these results are compared those obtained from nonclassical N00N states.Comment: 8 pages, 3 figure

Design and Manufacturing of an APTF to Test Fluid Behaviour in Microgravity Environment

The present paper deals with the design and manufacturing of an APTF (Advanced Plateau Tank Facility) in order to carrying out earth experiments, previous to space experiments, of fluid behaviour in microgravity environment. This work has been done in collaboration between Manufacturing and Microgravity Laboratories in the Polytechnic University of Madrid, and analyses the requirements and restrictions that must be considered for an APTF design and manufacture. Mechanism employed in each part of the prototype are described in detail, emphasising those that suppose new solutions rather previous designs

Imparticion de Practicas de Laboratorio en Escuelas Tecnicas con Alto Numero de Alumnos

El presente trabajo propone cómo abordar un problema creciente en las escuelas técnicas como es la masificación de los cursos. Para ello describe una serie de parámetros de influencia representativos y aspectos operativos aplicables a la impartición de prácticas de laboratorio en asignaturas que contienen una base predominantemente tecnológica. Se pretende que los conceptos e ideas aportadas puedan servir como base para la implantación de nuevas prácticas o bien para la adaptación de prácticas ya existentes, intentado, en la medida de lo posible, una formulación conceptual que resulte aplicable a todas aquellas asignaturas o disciplinas en las que la aplicación práctica de los conceptos estudiados suponga una parte esencial de las enseñanzas y que tengan un alto número de alumnos. La utilización de las Tecnologías de la Información y la Comunicación (TIC) debe verse como una importante fuente de recursos de apoyo a la actividad docente de prácticas, ya que favorece el acceso individual de forma simultánea, pero en ningún caso debe suponer la sustitución de la actividad presencial del alumno en laboratorio, que es esencial para la consecución de los objetivos formativo

A Physical Layer Model for G3-PLC Networks Simulation

This work presents a model of the G3-PLC physical (PHY) layer tailored for network simulations. It allows simulating frequency selective channels with non-stationary colored noise. Collisions with other frames are modeled taking into account the length and the power of the interfering frames. Frame errors are estimated using the effective signal-to-interference-and-noise ratio mapping (ESM) function. The proposed PHY layer has been integrated into a distributed event-based simulator developed by Microchip. The layer 2+ stack of the simulator uses the same code that actual Microchip G3-PLC devices. Validation has been accomplished by comparing its results to a test network deployed in the laboratory. The latter consists of a coordinator and one hundred meters distributed in 5 levels. Faster-than-real-time simulations and an excellent agreement between the simulated and the measured performance indicators at the application layer have been obtained.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Depolarizing collisions with hydrogen: neutral and singly ionized alkaline earths

Depolarizing collisions are elastic or quasielastic collisions that equalize the populations and destroy the coherence between the magnetic sublevels of atomic levels. In astrophysical plasmas, the main depolarizing collider is neutral hydrogen. We consider depolarizing rates on the lowest levels of neutral and singly ionized alkaly-earths Mg I, Sr I, Ba I, Mg II, Ca II, and Ba II, due to collisions with H. We compute ab initio potential curves of the atom-H system and solve the quantum mechanical dynamics. From the scattering amplitudes we calculate the depolarizing rates for Maxwellian distributions of colliders at temperatures T <10000 K. A comparative analysis of our results and previous calculations in the literature is done. We discuss the effect of these rates on the formation of scattering polarization patterns of resonant lines of alkali-earths in the solar atmosphere, and their effect on Hanle effect diagnostics of solar magnetic fields.Comment: 18 pages, 3 figures. Summitted to ApJ (2014

Methodology for automated generation of multiple choice questions in self assessment

Current trends in the European Higher Education Area (EHEA) are moving towards the continuous evaluation of the students in substitution of the traditional evaluation based on a single test or exam. This fact and the increase in the number of students during last years in Engineering Schools, requires to modify evaluation procedures making them compatible with the educational and research activities. This work presents a methodology for the automatic generation of questions. These questions can be used as self assessment questions by the student and/or as queries by the teacher. The proposed approach is based on the utilization of parametric questions, formulated as multiple choice questions and generated and supported by the utilization of common programs of data sheets and word processors. Through this approach, every teacher can apply the proposed methodology without the use of programs or tools different from those normally used in his/her daily activit

Short-term trajectories of workplace bullying and its impact on strain: A latent class growth modeling approach

The aim of this weekly diary study was (a) to identify trajectories of workplace bullying over time and (b) to examine the association of each cluster with strain indicators (i.e., insomnia and anxiety/depression). A sample of 286 employees during 4 weeks of data was used (N occasions = 1,144). Results of latent class growth modeling showed that 3 trajectories could be identified: a nonbullying trajectory, which comprised 90.9% of the sample; an inverted U trajectory; and a delayed increase bullying trajectory; the latter two each had 4.2% of the participants. We found a significant interaction between time and trajectories when predicting insomnia and anxiety/depression, with each strain showing a differential pattern with each trajectory. It seems that the negative effects on insomnia are long-lasting and remain after bullying has already decreased. In the case of anxiety and depression, when bullying decreases strain indicators also decrease. In this study, by examining trajectories of bullying at work over time and their associations with strain, we provide new insights into the temporal dynamics of workplace bullying

Application-layer Performance Analysis of PRIME in Smart Metering Networks

This paper assesses the performance of actual PRIME v1.3.6 and PRIME v1.4 systems when used for Smart Metering applications. The analysis is performed at the application level using the DLMS/COSEM stack. Hence, it considers performance indicators that are of practical interest for distribution system operators, such as the availability and the average time needed to read the energy load profile of all the meters. To this end, two test networks with 112 smart meters have been deployed in the laboratory (to ensure the stability of the network). In one of them all the Service Nodes communicate directly with the Base Node, while there exist up to 5 switching levels in the other tested network. First, the PRIME v1.3.6 system is evaluated, stressing the significant performance gain that can be obtained by implementing some MAC layer strategies, which are compatible with the specification but not specifically defined on it. Then,the improvement offered by the PRIME v1.4 system is assessed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech