Variabilidad espacio-temporal de los nutrientes inorgánicos y orgánicos en cinco rías gallegas (Noroeste España)

The spatial variability of inorganic (nitrate, nitrite, ammonium, phosphate and silicate) and organic (dissolved organic carbon) nutrients in five Galician rias (Vigo, Pontevedra, Arousa, Muros and Ares-Betanzos) was assessed by considering average values for the upwelling and downwelling periods. Inner stations were significantly different from middle and outer stations, especially during the downwelling period. Spatial differences between the five rías, tested by means of a multivariate analysis, were found in both periods. The behaviour of inorganic and organic nutrient variables was also significantly different between periods with and without shellfish harvesting closures due to the occurrence of toxic phytoplankton species.La variación espacial de los nutrientes inorgánicos (nitrato, nitrito, amonio, fosfato y silicato) y orgánicos (carbono orgánico disuelto) fue evaluado en las cinco rías gallegas (Vigo, Pontevedra, Arousa, Muros y Ares-Betanzos), considerando los valores medios para los periodos de afloramiento y hundimiento. Las estaciones estuáricas se separaron significativamente de las estaciones intermedias y oceánicas, especialmente durante el periodo de hundimiento. Se encontró para ambos periodos una variabilidad espacial entre las cinco rías, comprobada mediante análisis multivariante. El comportamiento de los nutrientes inorgánicos y orgánicos fue significativamente diferente cuando comparamos periodos con y sin cierres debidos a eventos o episodios de fitoplancton tóxico

MAR INTERMEDIO. DESARROLLO TEÓRICO- PRÁCTICO DE UN PROYECTO DE ENSAYO AUDIOVISUAL

[EN] This Final Project revolves around the phenomenon of human displacement: the aproach to the issue is carried in two planes, theoretical and iconic, coming to meet and merge under an audiovisual format. The paper focuses primarily on concepts such as nation-state, crossing personal and others’ reflections on their visible physical boundaries, id est, about borders and social conflicts they generate. Then, encourages a dialogue between these concepts using audiovisual practice from a heuristic perspective, understanding that freedom that characterizes this film mode is the best way forward, by contrast and as politics strategy itself, to rigid and coercive forms in question.[ES] Este Trabajo Final de Grado gira en torno al fenómeno de los desplazamientos humanos: la aproximación al tema se efectúa en dos planos, teórico e icónico, que vienen a encontrarse y fundirse bajo un formato audiovisual. El trabajo profundiza en primer lugar sobre conceptos como el de estado-nación, cruzando reflexiones personales y ajenas acerca de sus delimitaciones físicas visibles, es decir, acerca de las fronteras y de los conflictos sociales que generan. Seguidamente, alienta un diálogo entre estos conceptos empleando la práctica audiovisual desde una perspectiva ensayística, entendiendo que la libertad que caracteriza esta modalidad fílmica es la mejor manera de remitir, por contraste y como estrategia política en sí misma, a las formas rígidas y coercitivas puestas en cuestión.López Doval, L. (2016). MAR INTERMEDIO. DESARROLLO TEÓRICO- PRÁCTICO DE UN PROYECTO DE ENSAYO AUDIOVISUAL. http://hdl.handle.net/10251/76229.TFG

Numerical modelling of the hydrodynamic ram phenomenon

12 pages, 16 figures.Hydrodynamic ram (HRAM) is a phenomenon that occurs when a high-kinetic energy object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure, increasing the risk of catastrophic failure and excessive structural damage. This is of particular concern in the design of wing fuel tanks for aircraft since it has been identified as one of the important factors in aircraft vulnerability. In the present paper, the commercial finite-element code LS-DYNA has been used to simulate an HRAM event created by a steel spherical projectile impacting a water-filled aluminium square tube. Two different formulations (ALE and SPH) are employed to reproduce the event. Experimental tests which indicate the pressure at different points of the fluid, displacement of the walls and cavity evolution for different impact velocities are compared with the numerical results in order to assess the validity and accuracy of both ALE and SPH techniques in reproducing such a complex phenomenon.Publicad

Experimental analysis of fluid-filled aluminium tubes subjected to high-velocity impact

11 pages, 20 figures.Hydrodynamic ram (HRAM) is a phenomenon that occurs when a high-energy object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure increasing the risk of catastrophic failure and excessive structural damage. It is of particular concern in the design of wing fuel tanks for aircraft since it has been identified as one of the important factors in aircraft vulnerability. For the present work, water-filled aluminium square tubes (6063-T5) were subjected to impact by steel spherical projectiles (12.5 mm diameter) at impact velocities of 600–900 m/s. The aluminium tubes were filled at different volumes to study how an air layer inside the tank might influence the impact behaviour. The test boxes were instrumented with five strain gauges and two pressure transducers. The formation process of the cavity was recorded with a high-speed camera. This work presents the results of these tests.This research was done with the financial support of the Spanish Ministry of Education under Project reference DPI2005-06769, and of the University Carlos III of Madrid and Comunidad Autónoma de Madrid under project reference CCG07-UC3M/DPI-3395.Publicad

Experimental study of CFRP fluid-filled tubes subjected to high-velocity impact

In recent years, vulnerability against high-velocity impact loads has become an increasingly critical issue in the design of composite aerospace structures. The effects of Hydrodynamic Ram (HRAM), a phenomenon that occurs when a high-energy object penetrates a fluid-filled container, are of particular concern in the design of wing fuel tanks for aircraft because it has been identified as one of the important factors in aircraft vulnerability. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure, increasing the risk of catastrophic failure and excessive structural damage. For the present work, water-filled CFRP square tubes were subjected to an impact of steel spherical projectiles (12.5 mm diameter) at impact velocities of 600–900 m/s. The CFRP tubes were filled to different volumes to examine how volume might influence the tank behavior. The composite test boxes were instrumented with six strain gauges and two pressure transducers, and the formation process of the cavity was recorded using a high-speed camera. The damage produced in the tubes was then analyzed, and differences were found according to the testing conditions. This work presents the results of these tests.The authors would like to acknowledge the Center for the Development of Industrial Technology (CDTI) of Spain and to the company AERNNOVA Aerospace for the financial support for this research.Publicad

¿Qué hace un psicopedagogo como tú en un sitio como éste?: una experiencia de intervención psicopedagógica en la materia de nuevas tecnologías aplicadas a la educación

[Abstract] En el presente trabajo se recoge una novedosa experiencia sobre la realización de prácticas de Psicopedagogía en un contexto universitario: la Escuela Universitaria de Formación del Profesorado, y más concretamente en la materia troncal de Nuevas Tecnologías aplicadas a la Educación. El alumnado de esta materia presenta ciertas carencias que requieren de una intervención psicopedagógica directa, en el sentido de que la materia de Nuevas Tecnologías tiene una parte importante de contenidos procedimentales que requieren del dominio de ciertas habilidades técnicas con el manejo de medios audiovisuales e informáticos. El diseño e implementación de las intervenciones psicopedagógicas que dieran respuesta a estas necesidades resultó una tarea ardua y difícil. Esto fue así, tanto por la inexperiencia de los participantes como por la falta de referentes anteriores en el ámbito de la intervención psicopedagógica universitaria

Numerical Analysis of the Hydrodynamic Ram Phenomenon in Aircraft Fuel Tanks

Hydrodynamic ram (H RAM) is a phenomenon that occurs when a high-energetic object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure, increasing the risk of catastrophic failure and excessive structural damage on adjacent components. It is of particular concern in the design of wing fuel tanks for aircraft because it has been identified as one of the important factors in aircraft vulnerability. To study the aforementioned phenomenon, water-filled aluminum tubes (to different volume percentages) were subjected to impact of spherical projectiles. This work is focused on the analysis of energies, momenta, and pressure contours obtained by means of a previously developed and validated numerical model to achieve a better understanding of the fluid/structure interaction problem that takes place during the HRAM phenomenon.This research was done with the financial support of the Spanish Ministry of Science and Innovation under Project references DPI/2008-06408 and DPI/2010-15123, and of the Region of Madrid and University Carlos III of Madrid under Project reference CCG10-UC3M/DPI-4694Publicad

Transient Propagation and Scattering of Quasi-Rayleigh Waves in Plates: Quantitative comparison between Pulsed TV-Holography Measurements and FC(Gram) elastodynamic simulations

We study the scattering of transient, high-frequency, narrow-band quasi-Rayleigh elastic waves by through-thickness holes in aluminum plates, in the framework of ultrasonic nondestructive testing (NDT) based on full-field optical detection. Sequences of the instantaneous two-dimensional (2-D) out-of-plane displacement scattering maps are measured with a self-developed PTVH system. The corresponding simulated sequences are obtained by means of an FC(Gram) elastodynamic solver introduced recently, which implements a full three-dimensional (3D) vector formulation of the direct linear-elasticity scattering problem. A detailed quantitative comparison between these experimental and numerical sequences, which is presented here for the first time, shows very good agreement both in the amplitude and the phase of the acoustic field in the forward, lateral and backscattering areas. It is thus suggested that the combination of the PTVH system and the FC(Gram) elastodynamic solver provides an effective ultrasonic inspection tool for plate-like structures, with a significant potential for ultrasonic NDT applications.Comment: 46 pages, 16 figures, corresponding author Jos\'e Carlos L\'opez-V\'azquez, [email protected]. Changes: 1st, 4th, 5th paragraphs (intro), 3rd, 4th paragraphs (sec. 4); [59-60] cited only in appendixes; old ref. [52] removed; misprints corrected in the uncertainty of c_L (subsec. 3.1), citation to fig. 10 (sec. 4), size of images (caption fig.15); reference to Lam\'e constants removed in subsec. 3.

Multilevel Multiphase Feedforward Space-Vector Modulation Technique

Multiphase converters have been applied to an increasing number of industrial applications in recent years. On the other hand, multilevel converters have become a mature technology mainly in medium- and high-power applications. One of the problems of multilevel converters is the dc voltage unbalance of the dc bus. Depending on the loading conditions and the number of levels of the converter, oscillations appear in the dc voltages of the dc link. This paper presents a feedforward modulation technique for multilevel multiphase converters that reduces the distortion under balanced or unbalanced dc conditions. The proposed modulation method can be applied to any multilevel-converter topology with any number of levels and phases. Experimental results are shown in order to validate the proposed feedforward modulation technique.Ministerio de Ciencia e Innovación DPI2009-07004Ministerio de Eduación y Ciencia TEC2007-6187

Numerical modeling and measurement by pulsed television holography of ultrasonic displacement maps in plates with through-thickness defects

We present a novel numerical modeling of ultrasonic Lamb and Rayleigh wave propagation and scattering by through-thickness defects like holes and slots in homogeneous plates, and its experimental verification in both near and far field by a self-developed pulsed TV holography system. In contrast to rigorous vectorial formulation of elasticity theory, our model is based on the 2-D scalar wave equation over the plate surface, with specific boundary conditions in the defects and plate edges. The experimental data include complex amplitude maps of the out-of-plane displacements of the plate surface, obtained by a two-step spatiotemporal Fourier transform method. We find a fair match between the numerical and experimental results, which allows for quantitative characterization of the defects