Development of III-nitride-based waveguides for application in all-optical integrated circuits at 1.55 [my]m

El desarrollo de una nueva tecnología todo-óptica para el procesado de datos en las futuras redes de telecomunicación está generando un gran interés desde hace una década. Esta tecnología está encaminada al total aprovechamiento del gran ancho de banda que proporciona la fibra óptica, evitando la conversión entre los dominios óptico y eléctrico necesaria en cada nodo de las redes de comunicaciones actuales. Esta nueva tecnología todo-óptica requiere de diferentes componentes ópticos que puedan ser controlados ópticamente. Estos dispositivos se obtienen a partir de distintos materiales semiconductores y se implementan de forma miniaturizada en un circuito todo-óptico integrado operando a 1.55 [my]m, mejorando de esta forma la fiabilidad del sistema y reduciendo su coste. Teniendo en cuenta que los nitruros del grupo III son materiales que han demostrado un gran potencial para aplicaciones en comunicaciones ópticas a 1.55 [my]m, el objetivo de este trabajo es el desarrollo de nuevos dispositivos todo-ópticos basados en éstos para su futura implementación en circuitos fotónicos integrados ultrarrápidos operando a longitudes de onda de telecomunicación. Durante esta Tesis se han desarrollado varios dispositivos de guía de onda basados en diferentes estructuras de nitruros del grupo III sobre substratos de zafiro y funcionando a 1.55 [my]m. En primer lugar, se han optimizado diferentes guías de onda ópticas basadas en pozos y puntos cuánticos de GaN/AlN para trabajar como absorbentes saturables a través de sus transiciones intersubbanda. Estas guías de onda podrían utilizarse en procesos de conmutación todo-óptica. En segundo lugar, se ha optimizado el crecimiento de AlN por sputtering de radiofrecuencia permitiendo su uso para la fabricación de guías de onda pasivas. El comportamiento óptico lineal de las guías de AlN por sputtering muestra su idoneidad para actuar como interconectores pasivos de bajo coste en un circuito todo-óptico integrado. Por último, se han optimizado dos tipos de guías de onda basadas en InN por sputtering para funcionar como absorbentes saturables inversos mediante procesos de absorción de dos fotones. La respuesta óptica no lineal de ambas guías abre la posibilidad de utilizar estos dispositivos para aplicaciones en limitación todo-óptica a longitudes de onda de telecomunicación

The application of gibberellic acid increases berry size of ‘Emperatriz’ seedless grape

Gibberellic acid (GA3) increases berry size of "Emperatriz" seedless grape, the response depending on the phenological stage of vine at treatment date and on the concentration applied. From berry fruit set to 21 days later, 80 mg/L GA3 increased commercial berry weight by 50%-90%, depending on the year, reaching similar size to that of "Aledo" seeded grape, used as comparison. This effect takes place through: a) a larger berry growth rate; b) an early glucose, fructose and sucrose uptake; c) an increase of absolute glucose and fructose content (mg/berry) of seedless berries up to similar values to those of seeded berries; and d) an increase of absolute berry water content but not of relative content to fresh weight, thus water potential and osmotic potential are not significantly modified by treatments. GA3 does not affect berry pericarp cell number but increases pericarp cell diameter

Monitoring crustal movements and sea level in Lanzarote

The Institute of Astronomy and Geodesy is measuring sea level variations in Lanzarote Island by two automated tide gauges of precision since 1993. In order to obtain "real" sea level variations a permanent GPS station has been installed near the tide gauges. The goal of this GPS station is to measurement vertical crustal movements in order to obtain absolute sea level variations removing these movements from tide gauge data. A vertical tie with high accuracy between the reference point of the pillar where the GPS antenna is installed and the tide gauges bench marks is absolutely necessary. We have carried out this altimetric link yearly since year 2000. Methods of repeated geometric and trigonometric levelling of very short tracts have been used due to the great level difference existent. The control of the local stability of the pillar where the GPS antenna has been established, is carried out by a micro-geodetic control network building around it. This network of 13 benchmarks has been regularly observed by classic and GPS geodetic techniques in years 2000, 2001, 2002, 2003 and 2004. The data of these campaigns have been processed by different types of adjustments in the same reference system. The precision of the measurements and the reliability of the networks have been calculated. In this work the results obtained, the evaluation of the altimetric links and levelling campaigns, and the comparison of the levels of different measurements are presented

Flexibilidad interna en la empresa: alteración sustancial de la condición más beneficiosa sobre la cuantía del salario pactada en contrato de trabajo

La flexibilidad interna en la empresa consiste en un conjunto de facultades del empresario para modificar aspectos de la relación laboral de forma unilateral, para hacer frente a las circunstancias cambiantes propias de un mercado de trabajo en constante evolución, en lugar de acudir a la flexibilidad externa por medio de la extinción de contratos de trabajo. Dentro de estas posibilidades modificativas que la legislación concede al empresario, destacan las modificaciones sustanciales de las condiciones de trabajo, a través de las cuales puede modificar aspectos de la relación contractual relativos a diversas materias, entre las que destaca el sistema de remuneración y la cuantía salarial. Para poder llevar a cabo estas medidas, con la finalidad de mejorar la ventaja competitiva de la empresa, debe acreditar la concurrencia de causas económicas, técnicas, organizativas o de producción. La imprecisión en la regulación del concepto de modificación sustancial, hace necesario acudir a la jurisprudencia para obtener un concepto mejor definido de la modificación sustancial y saber cuándo operan las causas justificadoras de estas medidas. Las últimas reformas legislativas acerca de estos mecanismos flexibilizadores han ampliado notablemente las facultades del empresario, frente a los intereses de los trabajadores, lo que puede dificultar aún más el control judicial de la actuación del empresario que aplica estas medidas.Departamento de Derecho Mercantil, Derecho del Trabajo e Internacional PrivadoGrado en Derech

Estudio de las propiedades y aplicaciones del virus de la pseudorrabia (PRV) cuya expresión inmediatamente temprana es controlada por promotores tumorales humanos

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina Preventiva y Salud Pública y Microbiología . Fecha de lectura: 29-06-2018Este trabajo ha sido financiado por el proyecto del FIS PI0/02788, “Expresión de la proteína quimérica gDB2 de herpes simples tipo 2 por baculovirus y de la proteína IE180 del virus de la pseudorrabia bajo control de promotores tumorales humanos” y por la dotación Ramón y Cajal concedida al Dr. Bruno Sainz

Long and Lose-Range Terrestrial Photogrammetry for Rocky Landscape Deformation Monitoring

[EN] The paper describes the processing and validation of a series of terrestrial photogrammetric surveys carried out from 2017 to 2020 for monitoring the stability of a cliff in Cortes de Pallás (Spain). The complexity of the target area, which has a strong orography, a water reservoir, and many obstacles such as electrical power lines or vegetation, makes difficult the use of any measurement technique. After considering solutions such as long-range laser scanning or close-range mobile mapping, which were unsatisfactorily tested and therefore rejected for future campaigns, the use of combined short and long terrestrial photogrammetry proved an efficient method for quick and massive monitoring of the entire cliff with an overall accuracy of several centimetres. All the steps undertaken for the centimetre level accuracy deliverables, which include camera calibration, bundle-adjustment, dense point cloud generation, 3D modelling, and validation of the 3D models by using external geodetic information, will be presented. For the sake of conciseness, only results for the last two campaigns (5th and 6th), as well as the comparison between the last (6th) and the first (1st) campaigns, will be discussed. In addition, photogrammetric results will be validated by analyzing the metrics on four target-based micro-geodetic check points, located on key critical areas of the cliff selected by civil and geotechnical engineers from the Department of Roads and Infrastructures.Cabrelles, M.; Lerma, J.; García-Asenjo, L.; Garrigues, P.; Martínez, L. (2023). Long and Lose-Range Terrestrial Photogrammetry for Rocky Landscape Deformation Monitoring. En 5th Joint International Symposium on Deformation Monitoring (JISDM 2022). Editorial Universitat Politècnica de València. 485-491. https://doi.org/10.4995/JISDM2022.2022.1393348549

Diseño y validación de contenido de un videojuego para estimular la memoria episódica en pacientes con deterioro cognitivo leve, subtipo enfermedad de Alzheimer

El objetivo de este estudio es desarrollar un instrumento de intervención que incluye tanto el diseño como el estudio de sus propiedades psicométricas. De primer momento se realizó una revisión de la literatura sobre la memoria episódica, sus alteraciones en el DCL subtipo EA y estrategias de estimulación cognitiva. De igual manera, se tomó en cuenta información de un grupo focal realizado en nueve cuidadores de pacientes con DCL en un hospital de Bogotá, donde se destacaron síntomas de olvido cotidiano como olvido de nombres, números de teléfono y citas médicas

Widely power-tunable polarization-independent ultrafast mode-locked fiber laser using bulk InN as saturable absorber

The growing demand of ultrafast mode-locked fiber lasers in the near infrared has boosted the research activity in this area. One of the most convenient ways to achieve passive mode locking consists of inserting a semiconductor saturable absorber in the laser cavity to modulate the losses. However, in such a configuration, the limited power range of operation is still an unsolved issue. Here we report the fabrication of an ultrafast, high-power, widely power-tunable and non-polarization-dependent mode-locked fiber laser operating at 1.55 μm, using an InN layer as saturable absorber. With post-amplification, this laser delivers 55-fs pulses with a repetition rate of 4.84 MHz and peak power in the range of 1 MW in an all-fiber arrangement

A new ultrafast and high peak power fiber laser operating at 1.5 μm using In N as Saturable Absorber

This work describes a novel ultrafast (<250 fs) fiber laser operating at 1.5 μm and based on InN as saturable absorber (SA). This SA accommodates much higher fluencies than comparable semiconductor or graphene-based SA

High-Throughput System for the Early Quantification of Major Architectural Traits in Olive Breeding Trials Using UAV Images and OBIA Techniques

The need for the olive farm modernization have encouraged the research of more efficient crop management strategies through cross-breeding programs to release new olive cultivars more suitable for mechanization and use in intensive orchards, with high quality production and resistance to biotic and abiotic stresses. The advancement of breeding programs are hampered by the lack of efficient phenotyping methods to quickly and accurately acquire crop traits such as morphological attributes (tree vigor and vegetative growth habits), which are key to identify desirable genotypes as early as possible. In this context, an UAV-based high-throughput system for olive breeding program applications was developed to extract tree traits in large-scale phenotyping studies under field conditions. The system consisted of UAV-flight configurations, in terms of flight altitude and image overlaps, and a novel, automatic, and accurate object-based image analysis (OBIA) algorithm based on point clouds, which was evaluated in two experimental trials in the framework of a table olive breeding program, with the aim to determine the earliest date for suitable quantifying of tree architectural traits. Two training systems (intensive and hedgerow) were evaluated at two very early stages of tree growth: 15 and 27 months after planting. Digital Terrain Models (DTMs) were automatically and accurately generated by the algorithm as well as every olive tree identified, independently of the training system and tree age. The architectural traits, specially tree height and crown area, were estimated with high accuracy in the second flight campaign, i.e. 27 months after planting. Differences in the quality of 3D crown reconstruction were found for the growth patterns derived from each training system. These key phenotyping traits could be used in several olive breeding programs, as well as to address some agronomical goals. In addition, this system is cost and time optimized, so that requested architectural traits could be provided in the same day as UAV flights. This high-throughput system may solve the actual bottleneck of plant phenotyping of "linking genotype and phenotype," considered a major challenge for crop research in the 21st century, and bring forward the crucial time of decision making for breeders