Rashba spin-orbit coupling in a two dimensional electron system under quantum Hall regime

Magnetotransport in a two dimensional electron system under quantum Hall regime, taking into account the Rashba spin-orbit effect

Estudio Semiclásico del Magnetotransporte en un Sistema Electrónico Bidimensional Sometido a Interacción Espín-Órbita

En esta Tesis Doctoral se presenta un modelo semiclásico de magnetotransporte de sistemas electrónicos bidimensionales, confinados en heteroestructuras semiconductoras, y donde los electrones están afectados por los la interacción espín-órbita. Esta interacción está producida tanto por potenciales externos (efecto Rashba) como por el potencial intrínseco cristalino (efecto Dresselhauss), como se detalla en los trabajos publicados y presentados en esta memoria, y que son fundamento de esta Tesis. Se ha calculado mediante el análisis de las oscilaciones de Subnikov-de Haas, y el cálculo de la magnetorresistencia Hall, la energía de dicha interacción espín-órbita y el efecto que produce en la magnetoconductividad. Para ello, se han analizado los resultados experimentales obtenidos por varios autores con el modelo semiclásico de magnetotransporte presentado en este trabajo, reproduciendo teóricamente dichos resultados. Los sistemas electrónicos estudiados están confinados en heterouniones semiconductoras de dispositivos creados con elementos de los grupos III-V (AlGaAS, InGaAs y GaN). Las referencias relacionadas con el tema de la Tesis son las siguientes: 1.- Rashba spin–orbit coupling in a two-dimensional electron system under quantum Hall regime. R. Cangas, M. A. Hidalgo. Physica E 41 (2009) 1306–1309. 2.- Rashba spin-orbit coupling effect on the quantum Hall magnetoresistivity. M. A. Hidalgo, R. Cangas. Physica E 42 (2010) 1329-1332. 3.- Spin magnetotransport in a two-dimensional electron system confined in a quantum well. R. Cangas, M.A. Hidalgo. Semiconductor Science and Technology 26 (2011) 105016 (7pp). 4.- Magnetotransport in a two-dimensional system confined in wurtzite Alx Ga1-x N/GaN heterostructure. R. Cangas, M. A. Hidalgo. Applied Physics Letters 102, 162413 (2013)

A Characterization of Quantum Gaussian States in Terms of Annihilation Moments

We give a rigorous definition of moments of an unbounded observable with respect to a quantum state in terms of Yosida's approximations of unbounded generators of contractions semigroups. We use this notion to characterize Gaussian states in terms of annihilation moments. As a by-product, rigorous formulae for the mean value vector and the covariance matrix of a Gaussian state are obtained

Analysis of the Usefulness of a Serious Game to Raise Awareness about Mental Health Problems in a Sample of High School and University Students: Relationship with Familiarity and Time Spent Playing Video Games

Background: One of the main challenges in the field of mental health today is the stigma towards individuals who have psychological disorders. Aims: This study aims to analyse the usefulness of applying a serious game developed for the purpose of raising awareness among students about mental health problems and analyse whether its usefulness can be influenced by the type of video games or the time that students usually devote to playing with this type of entertainment. Method: The serious game introduces four characters who display the symptoms of different psychological disorders. A total of 530 students participated in the study, 412 of whom comprised the experimental group and 118 the control group, 291 came from secondary school classes and 239 were university students. Results: The findings show that this serious game significantly reduced total stigma among students. Variables like time habitually spent playing video games or video game preference had no bearing on the results. Conclusion: Our findings suggest that the serious game is an appropriated tool to reduce stigma, both in high school and university students, independently of the type of video games that young people usually play, or time spent playing video games

Spin magnetotransport in a two-dimensional electron system confined in a quantum well

We show a simple model that computes the magnetoconduction in a two-dimensional electron system (2DES) where the spin is another degree of freedom in the system. The 2DES is confined in a quantum well (QW) immersed in a heterostructure, where the Rashba spin–orbit interaction is present. When an external magnetic field is applied to the system, the competition between the spin–orbit interaction and the Zeeman effect on the magnetoconduction of the 2DES is analysed, in the cases where one or two sub-bands are occupied in the QW. In the model different spin-oriented 2DES can be treated independently, with a spin current associated with each system. The model has been tested with experimental results obtained from a 2DES formed in an InGaAs layer

Analysis of the Usefulness of a Serious Game to Raise Awareness about Mental Health Problems in a Sample of High School and University Students: Relationship with Familiarity and Time Spent Playing Video Games

Background: One of the main challenges in the field of mental health today is the stigma towards individuals who have psychological disorders. Aims: This study aims to analyse the usefulness of applying a serious game developed for the purpose of raising awareness among students about mental health problems and analyse whether its usefulness can be influenced by the type of video games or the time that students usually devote to playing with this type of entertainment. Method: The serious game introduces four characters who display the symptoms of different psychological disorders. A total of 530 students participated in the study, 412 of whom comprised the experimental group and 118 the control group, 291 came from secondary school classes and 239 were university students. Results: The findings show that this serious game significantly reduced total stigma among students. Variables like time habitually spent playing video games or video game preference had no bearing on the results. Conclusion: Our findings suggest that the serious game is an appropriated tool to reduce stigma, both in high school and university students, independently of the type of video games that young people usually play, or time spent playing video games

Propiedades psicométricas de My-School4web: programa informático de simulación 3D encaminado a la detección de consumo de sustancias, acoso escolar y alteraciones

In this paper we present the construct validity and reliability of 3D simulation program called My-School4Web, aimed to the detection of substance use, bullying and body image disturbances. In the same recreate different situations that have to do with this kind of behavior and, depending on the answers given by the participants, you get a risk profile. The sample consisted of 438 students of Secondary Education and students of the first university courses. Program factor structure shows the presence of four factors (accounting for 64.07% of the variance), which indicate the presence of three dimensions. Also acceptable reliability indexes are obtained. Results are discussed and the utility of this type of progra

Uso de CBCT en el manejo de un instrumento fracturado

La fractura de un instrumento durante el transcurso del tratamiento supone una complicación, ya que dificulta la consecución de los objetivos de la Endodoncia. El fragmento fracturado dificulta la instrumentación, la desinfección y la obturación de ese conducto. Las alternativas que disponemos ante esa situación son: extraer el instrumento o hacer un «by pass» del mismo para recuperar la permeabilidad. La tomografía de haz cónico nos brinda una imagen tridimensional del diente a tratar pudiendo observar con exactitud la zona donde se ha producido la separación así como la anatomía de ese conducto. Esta información en tres dimensiones puede ser de mucha utilidad para afrontar el manejo del caso. Presentamos un caso clínico de un paciente mujer de 35 años que acude a nuestra consulta, derivado por otro profesional, por la fractura de un instrumento en el conducto mesiovestibular de un 46. Tras realizar un diagnóstico inicial convencional (clínica y radiografía intraoral) decidimos realizar una tomografía de haz cónico (Kodak 9000 3D). Tras una minuciosa evaluación de la CBCT, llegamos a la conclusión que los conductos mesiovestibular y mesiolingual se unían en la zona apical. Procedimos a instrumentar mecánicamente el conducto mesiolingual y químicamente el mesiovestibular. De esta manera evitamos eliminar dentina de la raíz con el instrumento roto que puede debilitar el diente ante las cargas oclusales. En los controles posteriores el paciente se presenta asintomático y sin signos clínicos de periodontitis apicalA separated instrument during the course of the root canal is a complication as it hinders the achievement of the objectives of endodontics. The separate fragment difficult instrumentation, cleaning and filling the root canal system. The alternatives that we have to this situation are: removing the instrument or make a «by pass» to retrieve the same patency. Cone beam tomography gives us a three-dimensional image of the tooth to be treated can see exactly the area where separation has occurred and the anatomy of the canal. This three-dimensional information can be very useful to deal with the handling of the case.We present a case report who came to our office derived by another professional for a fractured instrument in the mesiobuccal canal of 46. Following a conventional initial diagnosis (clinical and intraoral radiography) decided to make a cone beam CT (Kodak 9000 3D). After a thorough evaluation of CBCT we conclude that the mesiobuccal and mesiolingual canals came together in the apical region. We proceeded to implement the mesiolingual mechanically and chemically through the mesiovestibular. This avoids removing the root dentin with a broken instrument that can weaken the tooth to the occlusal loading. In the follow-up tests it is presented asymptomatic patient without clinical signs of apical periodontitis.Sin financiaciónNo data (2016)UE

Between family genealogies and political genealogies: young people in a mapuche communalisation process in Argentina

A partir de una perspectiva teórica que entiende que edad y etnicidad constituyen clivajes complejamente entramados, en este artículo se aborda su incidencia en el proceso de comunalización de la comunidad mapuche Newen Ñuke Mapu (Río Negro, Argentina) y, específicamente, en el caso del lof Mariano Epulef que la integra. En ese contexto se analizan los modos en que la articulación generacional de los "jóvenes mapuche" en el presente produce sentido sobre -y es definida por- tanto la genealogía política del movimiento de fines del siglo XX como la genealogía familiar y comunitaria. Esto implica analizar la reelaboración política generacional que los "jóvenes" realizan de los discursos organizacionales mapuche a partir de su puesta en práctica en el proceso de articulación comunitaria rural.A partir de uma perspectiva teórica que entende que a idade e a etnia são clivagens estreitamente interligadas, este artigo discute o seu impacto sobre o processo de comunalizaçao da comunidade mapuche Newen Ñuke Mapu (Rio Negro, Argentina) e, especificamente, o caso do lof Mariano Epulef incluído nessa comunidade. Nesse contexto, o objeto de análise é a maneira pela qual as articulações contemporâneas da geração de "jovens mapuche" produzem significações, por um lado, sobre a genealogia política do movimento mapuche que se desenvolveu nas últimas décadas do século XX e, por outro, sobre as genealogias das famílias e da comunidade. Ao mesmo tempo, o artigo aproxima-se do modo pelo qual essas genealogias definem as articulações das gerações. Esta tarefa inclui estudar a apropriação crítica dos discursos políticos mapuche por "jovens" nos processos das comunidades rurais.Drawing on a theoretical perspective that understands age and ethnicity as intertwined cleavages, this article discusses their effects on the communalisation process of the Mapuche community of Newen Ñuke Mapu (Rio Negro, Argentina). It focuses specifically on the case of lof Mariano Epulef in the context of this community. The analysis deals with how contemporary generational articulations of "young Mapuche" give meaning to the political genealogy of the movement that developed in the last decades of the twentieth century and also, at the same time, to family and community genealogies. The article likewise addresses the ways in which these genealogies define generational articulations. This task involves studying the critical generational appropriation of political Mapuche discourses by "young Mapuche" within rural communalisation processes.Fil: Kropff Causa, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio. Universidad Nacional de Río Negro. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio; Argentin