A speech interface for air traffic control terminals

Several issues concerning the current use of speech interfaces are discussed and the design and development of a speech interface that enables air traffic controllers to command and control their terminals by voice is presented. A special emphasis is made in the comparison between laboratory experiments and field experiments in which a set of ergonomics-related effects are detected that cannot be observed in the controlled laboratory experiments. The paper presents both objective and subjective performance obtained in field evaluation of the system with student controllers at an air traffic control (ATC) training facility. The system exhibits high word recognition test rates (0.4% error in Spanish and 1.5% in English) and low command error (6% error in Spanish and 10.6% error in English in the field tests). Subjective impression has also been positive, encouraging future development and integration phases in the Spanish ATC terminals designed by Aeropuertos Españoles y Navegación Aérea (AENA).

Aerial Remote Sensing in Agriculture: A Practical Approach to Area Coverage and Path Planning for Fleets of Mini Aerial Robots

In this paper, a system that allows applying precision agriculture techniques is described. The application is based on the deployment of a team of unmanned aerial vehicles that are able to take georeferenced pictures in order to create a full map by applying mosaicking procedures for postprocessing. The main contribution of this work is practical experimentation with an integrated tool. Contributions in different fields are also reported. Among them is a new one-phase automatic task partitioning manager, which is based on negotiation among the aerial vehicles, considering their state and capabilities. Once the individual tasks are assigned, an optimal path planning algorithm is in charge of determining the best path for each vehicle to follow. Also, a robust flight control based on the use of a control law that improves the maneuverability of the quadrotors has been designed. A set of field tests was performed in order to analyze all the capabilities of the system, from task negotiations to final performance. These experiments also allowed testing control robustness under different weather conditions.

Desarrollo de un datalink con el chip CC1110 de Texas Instruments para UAVs

Se trata de estudiar el comportamiento de un sistema basado en el chip CC1110 de Texas Instruments, para aplicaciones inalámbricas. Los dispositivos basados en este tipo de chips tienen actualmente gran profusión, dada la demanda cada vez mayor de aplicaciones de gestión y control inalámbrico. Por ello, en la primera parte del proyecto se presenta el estado del arte referente a este aspecto, haciendo mención a los sistemas operativos embebidos, FPGAs, etc. También se realiza una introducción sobre la historia de los aviones no tripulados, que son el vehículo elegido para el uso del enlace de datos. En una segunda parte se realiza el estudio del dispositivo mediante una placa de desarrollo, verificando y comprobando mediante el software suministrado, el alcance del mismo. Cabe resaltar en este punto que el control con la placa mencionada se debe hacer mediante programación de bajo nivel (lenguaje C), lo que aporta gran versatilidad a las aplicaciones que se pueden desarrollar. Por ello, en una tercera parte se realiza un programa funcional, basado en necesidades aportadas por la empresa con la que se colabora en el proyecto (INDRA). Este programa es realizado sobre el entorno de Matlab, muy útil para este tipo de aplicaciones, dada su versatilidad y gran capacidad de cálculo con variables. Para terminar, con la realización de dichos programas, se realizan pruebas específicas para cada uno de ellos, realizando pruebas de campo en algunas ocasiones, con vehículos los más similares a los del entorno real en el que se prevé utilizar. Como implementación al programa realizado, se incluye un manual de usuario con un formato muy gráfico, para que la toma de contacto se realice de una manera rápida y sencilla. Para terminar, se plantean líneas futuras de aplicación del sistema, conclusiones, presupuesto y un anexo con los códigos de programación más importantes. Abstract In this document studied the system behavior based on chip CC1110 of Texas Instruments, for wireless applications. These devices currently have profusion. Right the increasing demand for control and management wireless applications. In the first part of project presents the state of art of this aspect, with reference to the embedded systems, FPGAs, etc. It also makes a history introduction of UAVs, which are the vehicle for use data link. In the second part is studied the device through development board, verifying and checking with provided software the scope. The board programming is C language; this gives a good versatility to develop applications. Thus, in third part performing a functionally program, it based on requirements provided by company with which it collaborates, INDRA Company. This program is developed with Matlab, very useful for such applications because of its versatility and ability to use variables. Finally, with the implementation of such programs, specific tests are performed for each of them, field tests are performed in several cases, and vehicles used for this are the most similar to the actual environment plain to use. Like implementing with the program made, includes a graphical user manual, so your understanding is conducted quickly and easily. Ultimately, present future targets for system applications, conclusions, budget and annex of the most important programming codes.

Control de vibraciones en pasarelas peatonales

En los últimos años se ha construido un gran número de pasarelas peatonales como respuesta a la demanda de nuevas vías de paso en las ciudades. Estas estructuras tienen requisitos constructivos menos exigentes en comparación con otros tipos de puentes, lo cual ha facilitado el desarrollo de diseños con nuevos esquemas resistentes, complicadas geometrías y el empleo de nuevos materiales. En general estas estructuras son esbeltas, ligeras y poco amortiguadas, lo que en ocasiones ha generado problemas de vi-braciones al paso de peatones una vez puestas en servicio. Las normativas actuales son cada vez más sensibles a esta problemática, recomendando diseños cuyas frecuencias naturales deben estar alejadas de los rangos de frecuencia de paso típicos de los peatones y fijando límites de confort en forma de valores máximos de aceleración permitidos, asegurándose así un correcto comportamiento de la estructura. En el presente artículo se analiza esta problemática desde un punto de vista práctico. Para ello se muestran los puntos clave de las normativas y guías de diseño de pasarelas que se pueden encontrar actualmente en la bibliografía, se presentan las técnicas que habitualmente se emplean en el análisis dinámico experimental de estas estructuras, y se comentan las soluciones a las que generalmente se recurre para mejorar su comportamiento dinámico. Por último, se muestran los trabajos llevados a cabo por el Centro Tecnológico CARTIF en colaboración con las Universidades de Valladolid y Castilla-La Mancha en la pasarela peatonal del Museo de la Ciencia de Valladolid. Estos trabajos incluyen: (1) el estudio dinámico de los tres vanos metálicos de dicha pasarela, (2) el diseño e implementación de un amortiguador de masa sintonizado en el vano más sensible a las vibraciones, (3) la implementación de un amortiguador de masa activo utilizando un excitador electrodinámico, y (4) el desarrollo de pruebas para la verificación del estado de servicio de la pasarela. In the last years, a wide number of footbridges have been built as demand response of more direct pathways in cities. These structures have lower building requirements as compared with standard bridges. This circumstance has facilitated the development of new structural design with complex geometries and innovative materials. As a result, these structures may be slender, light and low damped, leading to vibration problems once in service. The current codes take into account this problem, and recommend designs with natural frequencies away from the typical pedestrian pacing rates and fix comfort limits to guarantee the serviceability of the structure.This paper studies this problem from a practical point of view. Thus, the key points of codes and footbridges guidelines are showed, the typical experimental dynamic analysis techniques are presented, and the usual solutions adopted to improve the dynamic performance of these structures are discussed. Finally, the works carried out on the Valladolid Science Museum Footbridge by Centro Tecnológico CARTIF in collaboration with the Universities of Valladolid and Castilla-La Mancha are showed. These works include: (1) the dynamic study of the three steel spans of the footbridge, (2) the design and implementation of a tuned mass damper in the liveliest span, (3) the implementation of an active mass damper using an electrodynamic shaker, and (4) the development of field tests to assess the serviceability of such span.

Localization and Tracking in Energy-Constrained Networks with Dynamic Connectivity

Systems used for target localization, such as goods, individuals, or animals, commonly rely on operational means to meet the final application demands. However, what would happen if some means were powered up randomly by harvesting systems? And what if those devices not randomly powered had their duty cycles restricted? Under what conditions would such an operation be tolerable in localization services? What if the references provided by nodes in a tracking problem were distorted? Moreover, there is an underlying topic common to the previous questions regarding the transfer of conceptual models to reality in field tests: what challenges are faced upon deploying a localization network that integrates energy harvesting modules? The application scenario of the system studied is a traditional herding environment of semi domesticated reindeer (Rangifer tarandus tarandus) in northern Scandinavia. In these conditions, information on approximate locations of reindeer is as important as environmental preservation. Herders also need cost-effective devices capable of operating unattended in, sometimes, extreme weather conditions. The analyses developed are worthy not only for the specific application environment presented, but also because they may serve as an approach to performance of navigation systems in absence of reasonably accurate references like the ones of the Global Positioning System (GPS). A number of energy-harvesting solutions, like thermal and radio-frequency harvesting, do not commonly provide power beyond one milliwatt. When they do, battery buffers may be needed (as it happens with solar energy) which may raise costs and make systems more dependent on environmental temperatures. In general, given our problem, a harvesting system is needed that be capable of providing energy bursts of, at least, some milliwatts. Many works on localization problems assume that devices have certain capabilities to determine unknown locations based on range-based techniques or fingerprinting which cannot be assumed in the approach considered herein. The system presented is akin to range-free techniques, but goes to the extent of considering very low node densities: most range-free techniques are, therefore, not applicable. Animal localization, in particular, uses to be supported by accurate devices such as GPS collars which deplete batteries in, maximum, a few days. Such short-life solutions are not particularly desirable in the framework considered. In tracking, the challenge may times addressed aims at attaining high precision levels from complex reliable hardware and thorough processing techniques. One of the challenges in this Thesis is the use of equipment with just part of its facilities in permanent operation, which may yield high input noise levels in the form of distorted reference points. The solution presented integrates a kinetic harvesting module in some nodes which are expected to be a majority in the network. These modules are capable of providing power bursts of some milliwatts which suffice to meet node energy demands. The usage of harvesting modules in the aforementioned conditions makes the system less dependent on environmental temperatures as no batteries are used in nodes with harvesters--it may be also an advantage in economic terms. There is a second kind of nodes. They are battery powered (without kinetic energy harvesters), and are, therefore, dependent on temperature and battery replacements. In addition, their operation is constrained by duty cycles in order to extend node lifetime and, consequently, their autonomy. There is, in turn, a third type of nodes (hotspots) which can be static or mobile. They are also battery-powered, and are used to retrieve information from the network so that it is presented to users. The system operational chain starts at the kinetic-powered nodes broadcasting their own identifier. If an identifier is received at a battery-powered node, the latter stores it for its records. Later, as the recording node meets a hotspot, its full record of detections is transferred to the hotspot. Every detection registry comprises, at least, a node identifier and the position read from its GPS module by the battery-operated node previously to detection. The characteristics of the system presented make the aforementioned operation own certain particularities which are also studied. First, identifier transmissions are random as they depend on movements at kinetic modules--reindeer movements in our application. Not every movement suffices since it must overcome a certain energy threshold. Second, identifier transmissions may not be heard unless there is a battery-powered node in the surroundings. Third, battery-powered nodes do not poll continuously their GPS module, hence localization errors rise even more. Let's recall at this point that such behavior is tight to the aforementioned power saving policies to extend node lifetime. Last, some time is elapsed between the instant an identifier random transmission is detected and the moment the user is aware of such a detection: it takes some time to find a hotspot. Tracking is posed as a problem of a single kinetically-powered target and a population of battery-operated nodes with higher densities than before in localization. Since the latter provide their approximate positions as reference locations, the study is again focused on assessing the impact of such distorted references on performance. Unlike in localization, distance-estimation capabilities based on signal parameters are assumed in this problem. Three variants of the Kalman filter family are applied in this context: the regular Kalman filter, the alpha-beta filter, and the unscented Kalman filter. The study enclosed hereafter comprises both field tests and simulations. Field tests were used mainly to assess the challenges related to power supply and operation in extreme conditions as well as to model nodes and some aspects of their operation in the application scenario. These models are the basics of the simulations developed later. The overall system performance is analyzed according to three metrics: number of detections per kinetic node, accuracy, and latency. The links between these metrics and the operational conditions are also discussed and characterized statistically. Subsequently, such statistical characterization is used to forecast performance figures given specific operational parameters. In tracking, also studied via simulations, nonlinear relationships are found between accuracy and duty cycles and cluster sizes of battery-operated nodes. The solution presented may be more complex in terms of network structure than existing solutions based on GPS collars. However, its main gain lies on taking advantage of users' error tolerance to reduce costs and become more environmentally friendly by diminishing the potential amount of batteries that can be lost. Whether it is applicable or not depends ultimately on the conditions and requirements imposed by users' needs and operational environments, which is, as it has been explained, one of the topics of this Thesis.

Effects of precooling and degreening treatments on the susceptibility of peach and citrus to handling damage.

Mechanical damage to fruits results from a combination of fruit properties and of damage inflicting effects by the handling equipment. Treatments were applied to fruits which affect mechanical damage susceptibility: precooling for stone fruits and degreening to citrus fruits. Laboratory tests (compression, impact, tumbling, abrasion) and field tests (damage in the handling lines) were applied to (3) peach, (2) apricot, (2) orange and (1) lemon varieties. Hydroor-air-cooling influence positively peach and apricot firmness and cause a significant reduction in: number of bruised fruits, and size of visible bruise, when combined with a low level of loading during handling. Degreening also affects the resistance of citrus fruits to handling, when compared to green fruits.

Propuesta de un sistema para detección precoz de trastornos del lenguaje en niños de 0 a 6 años

Las Tecnologías de la Información y las Comunicaciones han propiciado avances en el contexto de la salud tanto en la gestión efectiva de información socio‐sanitaria de forma electrónica, como en la provisión de servicios de e‐salud y telemedicina. Los antecedentes de investigación publicados en esta área corroboran este hecho presentando las mejoras experimentadas en la atención de la población y en la provisión de servicios sanitarios. La atención temprana, cuyos principios científicos se fundamentan en los campos de la pediatría, neurología, psicología, psiquiatría, pedagogía, fisiatría y lingüística, entre otros, tiene como finalidad ofrecer a los niños con déficit o con riesgo de padecerlos un conjunto de acciones optimizadoras y compensadoras, que faciliten su adecuada maduración en todos los ámbitos y que les permita alcanzar el máximo nivel de desarrollo personal y de integración social. La detección de posibles alteraciones en el desarrollo infantil es un aspecto clave de la atención temprana en la medida en que puede posibilitar la puesta en marcha de diversos mecanismos de actuación disponibles en las entidades implicadas, valiosos para la calidad de vida de la persona. Cuanto antes se realice la detección, existen mayores garantías de prevenir patologías añadidas, lograr mejoras funcionales y posibilitar un ajuste más adaptativo entre el niño y su entorno. El objetivo de la investigación presentada en esta tesis doctoral es analizar, diseñar, verificar y validar un sistema de información abierto, basado en conocimiento, que facilite efectivamente a los profesionales que trabajan con la población infantil entre 0 y 6 años la detección precoz de posibles trastornos del lenguaje. Desde el punto de vista metodológico, la Ingeniería del Conocimiento ofrece un marco conceptual sólido que permite desarrollar y validar Sistemas de Ayuda a la Toma de Decisiones distribuidos y escalables, capaces de ayudar al pediatra de Atención Primaria y al educador infantil en la detección precoz de posibles trastornos del lenguaje en niños. La evaluación del sistema se ha realizado de forma incremental mediante el diseño y validación de pruebas de campo experimentales consistentes en la evaluación de niños en dos escenarios distintos: la escuela infantil y el centro de atención temprana. Los experimentos realizados en poblaciones distintas con alrededor de 344 niños durante 2 años, han permitido contrastar la buena adecuación del sistema propuesto a las necesidades de detección de los profesionales que trabajan con niños entre 0 y 6 años. La tesis resultante ha permitido caracterizar el uso del sistema en entornos reales, conocer la aceptación entre los usuarios y su impacto en la provisión de un servicio de atención temprana como el descrito para el correcto seguimiento del desarrollo del lenguaje en los niños, además de proponer un nuevo modelo de atención y evaluación cooperativa que permita incrementar el conocimiento experimental existente al respecto. ABSTRACT The Information and Communication Technology have led to advances in the context of health both in the effective management of socio‐health information electronically, and in the provision of e‐health and telemedicine. The history of research published in this area confirm this fact by presenting the improvements in the care of the population and the provision of health services. Early attention, whose scientific principles are based on the fields of pediatrics, neurology, psychology, psychiatry, pedagogy, physical medicine and linguistics, among others, aims to provide children with deficits or risk of suffering a set of enhancer actions, which facilitate adequate maturation in all areas and allow them to achieve the highest level of personal development and social integration. The detection of possible changes in child development is a key aspect of early intervention to the extent that it can enable the implementation of different mechanisms of action available to the entities involved, valuable to the quality of life of the person. The earlier the detection is made, there are more guarantees added to prevent diseases, achieving functional improvements and enable a more adaptive fit between the child and his environment. The aim of the research presented is to analyze, design, verify and validate an open information system, based on knowledge, which effectively provide professionals working with the child population between 0 and 6 years, in processes of early detection of language disorders. From the methodological point of view, Knowledge Engineering provides a solid conceptual framework to develop and validate a distributed and scalable decision support systems aim to assist pediatricians and language therapists at early identification and referral of language disorder in childhood. The system evaluation was performed incrementally with the design and validation of consistent experimental field tests in the assessment of children in two different scenarios: the nursery and early intervention center. Experiments in different populations with about 344 children over 2 years, allowed to testing the adequacy of the proposed good detection needs of professionals working with children between 0 and 6 years old system. The resulting thesis has allowed to formalizing the system at real environments and to identifying the acceptance by users as well as its impact on the provision of an early intervention service, such as the one described for the proper monitoring of language development in children. In addition, it proposes a new model of care and cooperative evaluation that lets to increase the existing experimental knowledge about it.

Sistema portátil de medida de dispositivos sometidos a ensayos en campo

El proyecto fin de carrera “Sistema Portátil de Medida de Dispositivos Sometidos a Ensayos en Campo” es un proyecto acometido para el desarrollo y evaluación de un sistema de medición portátil y confiable, que permita la realización de mediciones de curvas I-V en campo, en condiciones reales de funcionamiento. Dado que la finalidad de este proyecto fin de carrera es la obtención de un sistema para la realización de mediciones en campo, en la implementación del proyecto se tendrán como requisitos principales de diseño el tamaño, la fuente de alimentación, el peso del sistema, además de la fiabilidad y una relativa precisión en la realización de mediciones. Durante la realización de este proyecto y dados los requerimientos anteriores de portabilidad y fiabilidad, se ha buscado ofrecer una solución de compromiso diseñando un equipamiento que sea realizable, que cumpla con los objetivos anteriores con un coste que no sea elevado y con la característica de que disponga de una facilidad de manejo que permita a cualquier usuario la utilización del mismo. El sistema final diseñado está basado en el dispositivo de adquisición de datos MyDAQ de National Instruments que permite la realización de múltiples tipos de mediciones. En base a este dispositivo de adquisición de datos, se ha diseñado un sistema de medición con una arquitectura que se implementa a través de un ordenador portátil, con un software de medición instalado que recopila e interpreta los datos, y que alimenta y controla al dispositivo a través del puerto USB. El sistema también implementa una carga variable que permite la medición de la curva I-V en iluminación de células o mini-paneles fotovoltaicos. Este diseño permite que para la realización de las mediciones de las curvas I-V en iluminación en campo sólo se requiera conectar el dispositivo de adquisición a un PC portátil con batería y a la carga variable. Aunque este diseño es específico para la medición de células solares se ha implementado de forma que pueda extrapolarse fácilmente a otro tipo de medición de tensión y corriente. Para la comprobación de la precisión del sistema portátil de medidas, durante el proyecto se ha procedido a la comparación de los resultados obtenidos del sistema diseñado con un equipo de caracterización en laboratorio. Dicho sistema de alta exactitud permite cuantificar la degradación real de la célula y establecer una comparación de mediciones con el sistema portátil de medida, ofreciendo resultados satisfactorios en todas las mediciones realizadas y permitiendo concluir la evaluación del sistema portátil como apto para las mediciones de dispositivos en campo. El proceso de evaluación del equipamiento diseñado consistiría en la medida de la curva I-V en laboratorio de un dispositivo fotovoltaico con instrumentación de alta precisión y condiciones controladas de luz y temperatura de un dispositivo, célula o mini-panel. Tras la medida inicial las células se instalarían en campo y se realizaría una caracterización periódica de los dispositivos mediante el sistema portátil de medida, que permitiría evidenciar si en la curva I-V bajo iluminación existe degradación, y en qué zona de la curva. Al finalizar el ensayo o en periodos intermedios se desmontarían los dispositivos para volver a medir la curva I-V con exactitud en laboratorio. Por tanto el sistema portátil de medida, debe permitir evaluar la evolución de la curva I-V en condiciones ambientales similares a obtenidas en medidas anteriores, y a partir de la misma determinar el modo de degradación del dispositivo, no siendo necesaria una elevada precisión de medida para ofrecer resultados exactos de degradación, que sólo podrán medirse en el laboratorio. ABSTRACT. The final degree project "Portable Measurement System For Devices Under Field Tests" is a project undertaken for the development and evaluation of portable and reliable measurement equipment, which allows the realization of I-V curve measurements in field conditions actual operation. Since the purpose of this final project is to obtain a system for conducting field measurements in the implementation of the project will have as main design requirements for size, power supply, system weight, plus reliability and precision relative to the taking of measurements. During the development of this project and given the above requirements portability and reliability, has sought to offer a compromise designing equipment that is achievable, that meets the above objectives with a cost that is not high and the feature that available management facility that allows any user to use it. The final system is designed based on the acquisition device MyDAQ NI data that allows the execution of multiple types of measurements. Based on this data acquisition device, we have designed a measurement system with an architecture that is implemented via a laptop, with measurement software installed that collects and interprets data, and feeds and controls the device through the USB port. The system also implements a variable load which allows measurement of the I-V curve lighting photovoltaic cells. This design allows performing measurements of I-V curves in lighting field is only required to connect the device to purchase a laptop with a battery and variable load. Although this design is specific for the measurement of solar cells has been implemented so that it can easily be extrapolated to other types of measuring voltage and current. To test the accuracy of the portable measurement system during the project has been carried out to compare the results of the designed system, a team of laboratory characterization. This system of high accuracy to quantify the actual degradation of the cell and a comparison of measurements with portable measurement system, providing satisfactory results in all measurements and allowing complete portable system assessment as suitable for measurements of devices field. The evaluation process designed equipment would be far laboratory I-V curve of a photovoltaic device with high precision instrumentation controlled light and temperature of a device, panel or mini-cell conditions. After initial measurement cells settle in a periodic field and device characterization will be achieved through the portable measurement system, which would show whether the I-V curve under illumination degradation exists, and in which area of the curve. At the end of the trial or in interim periods devices to remeasure the I-V curve accurately in laboratory dismount. Therefore the portable measurement system should allow evaluating the evolution of the I-V curve similar to previous measurements obtained in ambient conditions, and from it determine the mode of degradation of the device, not a high measurement accuracy to be necessary to provide degradation accurate results, which can only be measured in the laboratory.

Análisis mediante elementos finitos del comportamiento de losas de hormigón armado sometidas a explosiones

Se presenta en este trabajo una investigación sobre el comportamiento de losas de hormigón armado sometidas a explosiones y la simulación numérica de dicho fenómeno mediante el método de los elementos finitos. El trabajo aborda el estudio de la respuesta de dichos elementos estructurales por comparación entre los resultados obtenidos en ensayos reales a escala 1:1 y los cálculos realizados mediante modelos de ordenador. Este procedimiento permite verificar la idoneidad, o no, de estos últimos. Se expone en primer lugar el comportamiento mecánico de los modelos de material que son susceptibles de emplearse en la simulación de estructuras mediante el software empleado en la presente investigación, así como las diferentes formas de aplicar cargas explosivas en estructuras modeladas mediante el método de los Elementos Finitos, razonándose en ambos casos la elección llevada a cabo. Posteriormente, se describen los ensayos experimentales disponibles, que tuvieron lugar en las instalaciones del Laboratorio de Balística de Efectos, perteneciente al Instituto Tecnológico de la Marañosa (ITM), de Madrid, para estudiar el comportamiento de losas de hormigón armado a escala 1:1 sometidas a explosiones reales. Se ha propuesto un método de interpretación del nivel de daño en las losas mediante el martillo de Schmidt, que posteriormente permitirá comparar resultados con los modelos de ordenador realizados. Asimismo, se propone un método analítico para la determinación del tamaño óptimo de la malla en las simulaciones realizadas, basado en la distribución de la energía interna del sistema. Es conocido que el comportamiento de los modelos pueden verse fuertemente influenciados por el mallado empleado. Según el mallado sea “grosero” o “fino” el fallo puede no alcanzarse o hacerlo de forma prematura, o excesiva, respectivamente. Es más, algunos modelos de material contemplan una “regularización” del tamaño de la malla, pero en la presente investigación se evidencia que dicho procedimiento tiene un rango de validez limitado, incluso se determina un entorno óptimo de valores. Finalmente, se han elaborado los modelos numéricos con el software comercial LS-DYNA, contemplando todos los aspectos reseñados en los párrafos anteriores, procediendo a realizar una comparación de los resultados obtenidos en las simulaciones con los procedidos en los ensayos reales a escala 1:1, observando que existe una muy buena correlación entre ambas situaciones que evidencian que el procedimiento propuesto en la investigación es de todo punto adecuado para la simulación de losas de hormigón armado sometidas a explosiones. ABSTRACT This doctoral thesis presents an investigation on the behavior of reinforced concrete slabs subjected to explosions along with the numerical simulation of this phenomenon by the finite elements method. The work involves the study of the response of these structural elements by comparing the results of field tests at full scale and the calculations performed by the computer model. This procedure allows to verify the appropriateness or not of the latter. Firstly, the mechanical behavior of the material models that are likely to be used in the modelling of structures is explained. In addition, different ways of choosing explosive charges when conducting finite element methods are analyzed and discussed. Secondly, several experimental tests, which took place at the Laboratorio de Balística de Efectos at the Instituto Tecnológico de la Marañosa (ITM), in Madrid, are described in order to study the behavior of these reinforced concrete slabs. A method for the description of the slab damage level by the Schmidt hammer is proposed, which will make possible to compare the modelling results extracted from the computation experiments. Furthermore, an analytical method for determining the optimal mesh size to be used in the simulations is proposed. It is well known that the behavior of the models can be strongly influenced by the mesh size used. According to this, when modifiying the meshing density the damaged cannot be reached or do it prematurely, or excessive, respectively. Moreover, some material models include a regularization of the mesh size, but the present investigation evidenced that this procedure has a limited range of validity, even an optimal environment values are determined. The method proposed is based on the distribution of the internal energy of the system. Finally, several expecific numerical models have been performed by using LS-DYNA commercial software, considering all the aspects listed in the preceding paragraphs. Comparisons of the results extracted from the simulations and full scale experiments were carried out, noting that there exists a very good correlation between both of them. This fact demonstrates that the proposed research procedure is highly suitable for the modelling of reinforced concrete slabs subjected to blast loading.

Biomass and essential oil yields of cornmint (Mentha arvensis L.) grown in the irrigation area of Río Dulce, Santiago del Estero, Argentina.

The aim of this study is to determine the yield and composition of the essential oil of cornmint (Mentha arvensis L.) grown in the irrigation area of Santiago del Estero, Argentina. Field tests were carried out under irrigation conditions, harvesting when 70% flowering was reached (in the summer and at the end of the winter seasons). Essential oil yields were 2% in the first cut and 1.6% in the second cut, respectively, the major constituents of the essential oil being menthol, menthone, isomenthone and menthofuran. In both cases, a high concentration of menthol was obtained, although during the winter the content decreased, increasing the concentration of menthofuran. It is concluded that during the summer a higher yield and better quality of essential oil are produced.

Control of insect vectors and plant viruses in protected crops by novel pyrethroid-treated nets

Long-lasting insecticide-treated nets (LLITNs) constitute a novel alternative that combines physical and chemical tactics to prevent insect access and the spread of insect-transmitted plant viruses in protected enclosures. This approach is based on a slow-release insecticide-treated net with large hole sizes that allow improved ventilation of greenhouses. The efficacy of a wide range of LLITNs was tested under laboratory conditions against Myzus persicae, Aphis gossypii and Bemisia tabaci. Two nets were selected for field tests under a high insect infestation pressure in the presence of plants infected with Cucumber mosaic virus and Cucurbit aphid-borne yellows virus. The efficacy of Aphidius colemani, a parasitoid commonly used for biological control of aphids, was studied in parallel field experiments.

Educational Project for the Teaching of Control of Electric Traction Drives

Electric vehicles constitute a multidisciplinary subject that involves disciplines such as automotive, mechanical, electrical and control engineering. Due to this multidisciplinary technical nature, practical teaching methodologies are of special relevance. Paradoxically, in the past, the training of engineers specializing in this area has lacked the practical component represented by field tests, due to the difficulty of accessing real systems. This paper presents an educational project specifically designed for the teaching and training of engineering students with different backgrounds and experience. The teaching methodology focuses on the topology of electric traction drives and their control. It includes two stages, a simulation computer model and a scaled laboratory workbench that comprises a traction electrical drive coupled to a vehicle emulator. With this equipment, the effectiveness of different traction control strategies can be analyzed from the point of view of energy efficiency, robustness, easiness of implementation and acoustic noise.

Contribute to the Study of Vertical Distribution of Conventional No-Till Seeders and Spatial Variability of Seed Depth Placement of Maize in Alentejo, Portugal

Entre os vários fatores que contribuem para a produção de uma cultura de milho, a distribuição vertical dos semeadores avaliada através da localização da semente em profundidade é um fator-chave, especialmente na técnica de sementeira direta. Simultaneamente, dada a complexidade dos ecossistemas naturais e agrícolas em sistemas de agricultura de conservação, a gestão diferenciada e localizada das parcelas assume um importante papel na análise e gestão da variabilidade das propriedades do solo e estabelecimento das culturas, nomeadamente utilizando informação geo referenciada e tecnologia expedita. Assim, o principal objetivo desta Tese foi a avaliação em culturas de milho da variabilidade espacial da localização de semente em profundidade e estabelecimento da cultura em sementeira direta usando sistemas convencionais de controlo de profundidade, tendo-se comparado com diferentes sistemas de mobilização e recorrendo a tecnologias de agricultura de precisão. Os ensaios decorreram na região Mediterrânea do Alentejo, em propriedades agrícolas no decorrer das campanhas de 2010, 2011, 2012 e 2015 em 6 diferentes campos experimentais. O trabalho experimental consistiu em ensaios com avaliações in loco do solo e cultura, consumo de combustível das operações e deteção remota. Os resultados obtidos indicam que não só o sistema de mobilização afetou a localização da semente em profundidade, como em sementeira direta a profundidade de sementeira foi afetada pelo teor de humidade do solo, resistência do solo à profundidade e velocidade da operação de sementeira. Adicionalmente observaram-se condições heterogéneas de emergência e estabelecimento da cultura afetadas por condições físicas de compactação do solo. Comparando os diferentes sistemas de mobilização, obteve-se uma significativa redução de combustível para a técnica de sementeira direta, apesar de se terem observado diferenças estatísticas significativas considerando diferentes calibrações de profundidade de sementeira Do trabalho realizado nesta Tese ressalva-se a importância que as tecnologias de agricultura de precisão podem ter no acompanhamento e avaliação de culturas em sementeira direta, bem como a necessidade de melhores procedimentos no controlo de profundidade dos semeadores pelo respetivos operadores ou ao invés, a adoção de semeadores com mecanismos ativos de controlo de profundidade. ABSTRACT Among the various factors that contribute towards producing a successful maize crop, seeders vertical distribution evaluated through seed depth placement is a key determinant, especially under a no-tillage technique. At the same time in conservation agriculture systems due to the complexity of natural and agricultural ecosystems site specific management became an important approach to understand and manage the variability of soil properties and crop establishment, especially when using geo spatial information and affording readily technology Thus, the main objective of this Thesis was to evaluate the spatial variability of seed depth placement and crop establishment in maize crops under no-tillage conditions compared to different tillage systems, using conventional seed depth control no till seeders and precision farming technologies. Trials were carried out in the Mediterranean region of Alentejo, in private farms along the sowing operations season over the years 2010, 2011, 2012 and 2015 in 6 different experimental fields. Experimental work covered field tests with in loco soil and crop evaluations, fuel operation evaluations and aerial sensing. The results obtained indicate that not only tillage system affected seed depth placement but under no till conditions seed depth was affected by soil moisture content, soil resistance to penetration and seeders forward speed. In addition uneven crop seedling and establishment depended on seed depth placement and could be affected by physical problems of compaction layers. Significant reduction in fuel consumption was observed for no till operations although significant differences observed according to different setting calibrations of seed depth control. According to the results, precision agriculture is an important tool to evaluate crops under no till conditions and seed depth mechanisms should be more accurate by the operators or is determinant the adoption of new active depth control technology to improve seeders performance.

Desarrollo de estructuras nanofotonicas de campo cercano para intensificacion localizada de luz en celulas solares de banda intermedia - Near-field nanophotonic structures for localized light enhancement in intermediate band solar cells

This doctoral thesis explores some of the possibilities that near-field optics can bring to photovoltaics, and in particular to quantum-dot intermediate band solar cells (QD-IBSCs). Our main focus is the analytical optimization of the electric field distribution produced in the vicinity of single scattering particles, in order to produce the highest possible absorption enhancement in the photovoltaic medium in their surroundings. Near-field scattering structures have also been fabricated in laboratory, allowing the application of the previously studied theoretical concepts to real devices. We start by looking into the electrostatic scattering regime, which is only applicable to sub-wavelength sized particles. In this regime it was found that metallic nano-spheroids can produce absorption enhancements of about two orders of magnitude on the material in their vicinity, due to their strong plasmonic resonance. The frequency of such resonance can be tuned with the shape of the particles, allowing us to match it with the optimal transition energies of the intermediate band material. Since these metallic nanoparticles (MNPs) are to be inserted inside the cell photovoltaic medium, they should be coated by a thin insulating layer to prevent electron-hole recombination at their surface. This analysis is then generalized, using an analytical separation-of-variables method implemented in Mathematica7.0, to compute scattering by spheroids of any size and material. This code allowed the study of the scattering properties of wavelengthsized particles (mesoscopic regime), and it was verified that in this regime dielectric spheroids perform better than metallic. The light intensity scattered from such dielectric spheroids can have more than two orders of magnitude than the incident intensity, and the focal region in front of the particle can be shaped in several ways by changing the particle geometry and/or material. Experimental work was also performed in this PhD to implement in practice the concepts studied in the analysis of sub-wavelength MNPs. A wet-coating method was developed to self-assemble regular arrays of colloidal MNPs on the surface of several materials, such as silicon wafers, amorphous silicon films, gallium arsenide and glass. A series of thermal and chemical tests have been performed showing what treatments the nanoparticles can withstand for their embedment in a photovoltaic medium. MNPs arrays are then inserted in an amorphous silicon medium to study the effect of their plasmonic near-field enhancement on the absorption spectrum of the material. The self-assembled arrays of MNPs constructed in these experiments inspired a new strategy for fabricating IBSCs using colloidal quantum dots (CQDs). Such CQDs can be deposited in self-assembled monolayers, using procedures similar to those developed for the patterning of colloidal MNPs. The use of CQDs to form the intermediate band presents several important practical and physical advantages relative to the conventional dots epitaxially grown by the Stranski-Krastanov method. Besides, this provides a fast and inexpensive method for patterning binary arrays of QDs and MNPs, envisioned in the theoretical part of this thesis, in which the MNPs act as antennas focusing the light in the QDs and therefore boosting their absorption

Study on the response of IFMIF fission chambers to mixed neutron-gamma fields: PH-2 experimental tests

The engineering design of fissionchambers as on-line radiation detectors for IFMIF is being performed in the framework of the IFMIF-EVEDA works. In this paper the results of the experiments performed in the BR2 reactor during the phase-2 of the foreseen validation activities are addressed. Two detectors have been tested in a mixedneutron-gamma field with high neutron fluence and gamma absorbed dose rates, comparable with the expected values in the HFTM in IFMIF. Since the neutron spectra in all BR2 channels are dominated by the thermal neutron component, the detectors have been surrounded by a cylindrical gadolinium screen to cut the thermal neutron component, in order to get a more representative test for IFMIF conditions. The integrated gamma absorbed dose was about 4 × 1010 Gy and the fast neutron fluence (E > 0.1 MeV) 4 × 1020 n/cm2. The fissionchambers were calibrated in three BR2 channels with different neutron-to-gamma ratio, and the long-term evolution of the signals was studied and compared with theoretical calculations