GaN-based waveguide devices for long-wavelength optical communications

This is the published version. Copyright © 2003 American Institute of PhysicsRefractive indices of AlxGa1−xN with different Al concentrations have been measured in infrared wavelength regions. Single-mode ridged optical waveguidedevices using GaN/AlGaN heterostructures have been designed, fabricated, and characterized for operation in 1550 nm wavelength window. The feasibility of developing photonic integrated circuits based on III-nitride wide-band-gap semiconductors for fiber-optical communications has been discussed

Lag time and parameter mismatches in synchronization of unidirectionally coupled chaotic external cavity semiconductor lasers

We report an analysis of synchronization between two unidirectionally coupled chaotic external cavity master/slave semiconductor lasers with two characteristic delay times, where the delay time in the coupling is different from the delay time in the coupled systems themselves. We demonstrate for the first time that parameter mismatches in photon decay rates for the master and slave lasers can explain the experimental observation that the lag time is equal to the coupling delay time.Comment: LaTex, 5 pages, submitted to PRE(R

Do psychology students command transversal competences? A case study

El desarrollo de las competencias transversales reclama su aplicación en contextos reales y plantea nuevos desafíos a la Educación Superior. Estas instituciones no sólo deben formar ciudadanos comprometidos con la mejora de la sociedad y contribuir a la creación del conocimiento, sino también establecer entre sus prioridades una buena relación con los sectores productivos, nichos naturales de inserción de sus titulados. De esta ecuación surgen nuevos interrogantes sobre cómo afecta la situación laboral del estudiante universitario en su aprendizaje. En concreto, este trabajo persigue conocer el dominio de las CT que presentan los estudiantes según su propia percepción, y contrastar estos resultados en función de su situación laboral. Para ello, se analiza la percepción de 55 estudiantes de último año del Grado en Psicología recogida a través de un cuestionario diseñado ad hoc. Los resultados revelan un dominio bastante mejorable de estas competencias, siendo la más adquirida el compromiso ético y la menos, el conocimiento de una lengua extranjera. Tras el contraste del dominio de dichas competencias con su situación laboral se aprecia, en general, que el dominio es mayor en aquellos estudiantes que se encuentran en activo, con diferencias significativas en la capacidad de adaptación y actitud emprendedora. A partir de estos resultados parece que los futuros graduados en Psicología están adquiriendo competencias esenciales para su ámbito profesional, si bien su grado de dominio reclama mayores medidas dirigidas a facilitar la conciliación estudio-trabajo y a mejorar los programas de prácticas externas.The development of transversal competences demands practice in real contexts and higher education needs to consider these new challenges. Not only are members of society committed to the social improvement and the contribution and creation of knowledge from university but also these institutions need a good connection with the job market (specifically where there are job market niches for graduates). From this complex equation new questions arise about how this relationship affects a student’s job situation and their university studies. Particularly, this paper aims to know the students’ command of these competences from their own perceptions and compare it with their job situation. To do this, this article collected the perceptions of 55 final year psychology students through an ad hoc questionnaire. The results not show satisfactory dominance of these competences although they can be improve. The highest dominance is ethical commitment and the least being the knowledge of another foreign language. After, it is contrasted to the dominance of those competences with their work situation. Generally, the dominance is higher in students who are working, with significant differences inadaptability and entrepreneurship; two competences that are part in the systemic category that establishes ANECA (2005) in their theoretical model of transversal competences. From these results, it seems that future psychology graduates have obtained skills that are essential to their careers, but their dominance of important competences demands greater measures to facilitate work-study reconciliation and improve internship programs

Evaluation of effective factors in success rate of intervention on CTO

Chronic total occlusion (CTO) intervention is still a challenging problem. The aim of this study is to determine factors that affect PCI results. Method and Results: The study was conducted on 72 patients in two centers. CTO angioplasty was done by the antegrade approach from the femoral and/or radial approach. The role of age, gender, anatomical variations such as calcification, length of the lesion, proximal bending, retrograde filling and occluded coronary artery (LAD, CCK or RCA), and wires were assessed. The success rate was 79.6, and presence of calcification was an important factor in CTO PCI. Operator�s experience, use of appropriate equipment and calcification are important factors in predicting a successful PCI. © 2015 Tehran University of Medical Sciences. All rights reserved

CdZnTe position-sensitive drift detectors with thicknesses up to 5 cm

We investigated the feasibility of long-drift-time CdZnTe (CZT) gamma-ray detectors, fabricated from CZT material produced by Redlen Technologies. CZT crystals with cross-section areas of 5 5 mm2 and 6 6 mm2 and thicknesses of 20-, 30-, 40-, and 50-mm were configured as 3D position-sensitive drift detectors and were read out using a front-end ASIC. By correcting the electron charge losses caused by defects in the crystals, we demonstrated high performance for relatively thick detectors fabricated from unselected CZT material. VC 2016 AIP Publishing LLC