Hidrogeologia de les Illes Balears: Les Masses d'aigua càrstiques

[cat] Les aigües subterrànies suposen el 95% dels recursos hídrics de les Illes Balears. Degut a la configuració litològica de l’arxipèlag, la majoria de les aigües subterrànies es localitzen en aqüífers carbonatats que en gran part presenten característiques càrstiques més o menys desenvolupades. De fet 64 de les 90 masses d’aigua subterrànies definides en el Pla Hidrològic de les Illes Balears de 2011 tenen característiques càrstiques. Aquestes masses d’aigua ocupen el 69% de la superfície a Mallorca, el 68% a Menorca, el 67% a Eivissa i el 100% a Formentera. Les particularitats dels aqüífers càrstics fan que la seva gestió sigui més complexa que la dels aqüífers de flux difús. Així degut a que la velocitat d’infiltració i circulació de l’aigua dins d’un aqüífer càrstic sol ser elevada, quan es vol establir la vulnerabilitat a la contaminació d’un aqüífer càrstic és recomanable tenir en consideració el desenvolupament del carst. El mateix ocorre amb els perímetres de protecció de pous de proveïment, el càlcul dels quals s’ha de realitzar amb metodologies diferents a les dels aqüífers de flux difús. L’explotació dels aqüífers càrstics pot accelerar els processos naturals com l’aparició de col·lapses. A Mallorca l’explotació intensiva i estacional de l’aqüífer de Crestatx ha provocat l’aparició de col·lapses que han afectat infraestructures urbanes. D’altra banda a Menorca el descens continuat dels nivells freàtics a l’aqüífer d’Es Migjorn ha accelerat l’aparició de col·lapses que han afectat la qualitat de les aigües d’un pou de proveïment de Es Migjorn Gran.[spa] Las aguas subterráneas suponen el 95% de los recursos hídricos de las Baleares. Debido a la configuración litológica del archipiélago, la mayoría de las aguas subterráneas se localizan en acuíferos carbonatados con características kársticas más o menos desarrolladas. De hecho 64 de las 90 masas de agua subterráneas definidas en el Plan Hidrológico de las Islas Baleares de 2011 tienen características kársticas. Estas masas de agua ocupan el 69% de la superficie en Mallorca, el 68% en Menorca, el 67% en Eivissa y el 100% en Formentera. Las particularidades de los acuíferos kársticos hacen que su gestión sea más compleja que la del resto de acuíferos. Debido a la elevada velocidad de infiltración y circulación del agua en un acuífero kárstico, cuando se quiere establecer la vulnerabilidad a la contaminación de este tipo de acuíferos es recomendable considerar el grado de desarrollo del karst. Lo mismo ocurre con los perímetros de protección de pozos de abastecimiento, el establecimiento de los cuales debe realizarse con metodologías diferentes a las de los acuíferos de flujo difuso. La explotación de los acuíferos kársticos puede acelerar procesos naturales como la aparición de colapsos. En Mallorca la explotación intensiva y estacional del acuífero de Crestatx ha provocado la aparición de colapsos que han afectado infraestructuras urbanas. En Menorca el descenso generalizado de los niveles freáticos en el acuífero de Es Migjorn ha acelerado la aparición de colapsos que han afectado la calidad de las aguas de un pozo de abastecimiento de Es Migjorn Gran.[eng] Groundwaters account for 95% of the water resources in the Balearic Islands. Owing to the lithological configuration of the archipelago, the majority of groundwater aquifers are located in carbonate groundwater bodies with more or less developed karst features. In fact 64 of the 90 groundwater bodies identified in the Balearic Islands Hydrological Plan of 2011 have karst properties. These water bodies occupy 69% of the surface in Mallorca, 68% in Menorca, 67% in Eivissa and 100% in Formentera. The particularities of karst aquifers makes their management more complex than the other aquifers. Due to the high infiltration rate and water circulation in karst aquifers, when establishing the contamination vulnerability of these type of aquifers is recommended to consider the degree of karst development. The same occurs with the protection perimeters of supply wells, the establishment of which should be done with methods different from the used for diffuse flux aquifers. The exploitation of karst aquifers can accelerate natural processes such as the occurrence of collapses. In Mallorca the intensive and seasonal exploitation of the Crestatx aquifer has caused the appearance of collapses that have affected urban infrastructures. In Menorca the general decline of groundwater levels in the Migjorn aquifer has accelerated the occurrence of collapses that have affected the quality of the water from a well supply in Es Migjorn Gran

Design methodology of a non-invasive sensor to measure the current of the output capacitor for a very fast non-linear control

The combination of non-linear control and linear control proposed in [1] has a very fast transient response (voltage step from 1 V to 1.5 V in 2 mus). In order to achieve this fast transient response the non-linear scheme is based on measuring the current of the output capacitor of a Buck converter. The design of this current sensor is complex due to parasitic effects such as component tolerances (bandwidth and dc gain of the Op-Amp), aging, temperature variation, etc. A design methodology for this current sensor is proposed regarding all these effects. The sensing circuit is designed to mirror the actual capacitor current with a trans-impedance amplifier by matching phase and scaling impedances of the RLC network (C, ESR and ESL of the output capacitor). The proposed methodology has been validated by means of a buck converter switching at 5 MHz. Experimental results validate that the current sensor behaves appropriately under voltage and load step

Metodología de diseño de un sensor de corriente no invasivo para medir la corriente del condensador de salida de un reductor

La combinación del control no-lineal, lineal y lazo de frecuencia propuesto en [2] tiene una rápida respuesta dinámica y frecuencia de conmutación constante (escalón en la tensión de referencia de 1,5 V a 2,5 V en 2 μs). Para alcanzar esta rápida respuesta dinámica el esquema del lazo no-lineal se basa en la medida de corriente del condensador de salida del convertidor reductor. El diseño del sensor de corriente es complejo debido a efectos parásitos como las tolerancias en los componentes (ancho de banda y la ganancia en continua del amplificador operacional), el envejecimiento, la variación de la temperatura, etc. En este artículo se propone una metodología de diseño del sensor de corriente considerando todos estos efectos. El sensor de corriente está diseñado para reproducir la corriente del condensador de salida mediante una red espejo RLC. Para la implementación física del sensor de corriente se usa un amplificador de trans-impedancia. La red espejo se diseña escalando las impedancias, igualando las fases y las mismas constantes de tiempo que las de la impedancia del COUT (C, ESR y ESL del condensador de salida). La metodología de diseño propuesta ha sido validada experimentalmente. El sensor de corriente presenta un buen funcionamiento ante escalones de carga y escalones en la referencia de tensión

Control de histéresis de la corriente del condensador de salida de un reductor operando a frecuencia constante

La combinación del control no-lineal y lineal propuesto en [1] presenta una muy rápida respuesta dinámica (escalones de tensión de 1 V a 1,5 V en 2 μs). Este control se basa en el control de histéresis de la corriente del condensador de salida (Cout ). Sin embargo, el sistema es muy sensible a diferentes efectos parásitos que modifican la frecuencia de conmutación tales como: variación de la tensión de entrada, tensión de salida, etc. En este artículo se propone un lazo de frecuencia adicional para corregir las variaciones de frecuencia y ajustar la frecuencia de conmutación al valor nominal mediante el ajuste de la banda de histéresis. El diseño y análisis del lazo no-lineal, lineal y el lazo de frecuencia son presentados en detalle este artículo. Para la validación experimental se ha construido un convertidor reductor a 5 MHz. La respuesta dinámica del convertidor ante escalones de tensión en la referencia (escalones de 1,5 V a 2,5 V y de 2,5 V a 1,5 V) es rápida y mantiene constante la frecuencia de conmutación en estado estacionario

A very fast control based on hysteresis of the Cout current with a frequency loop to operate at constant frequency

The combination of non-linear control and linear control proposed in [1] provides very fast transient response (voltage step from 1 V to 1.5 V in 2 μs). This non-linear control is based on hysteretic control of the Cout current. This system is very sensitive to effects like aging, temperature, input and output voltage variation, etc., that modify the switching frequency. This paper proposes a frequency loop to avoid the frequency variation and to adjust the switching frequency to the nominal value by changing the hysteretic band. The design and analysis of the nonlinear loop, the voltage loop and frequency loop are presented in detail with a design example. A 5 MHz buck converter is developed and experimental results validate the loops design, obtaining the same fast transient response (from 1.5 V to 2.5 V in 2 μs) but keeping constant the switching frequency in steady state

Generation and Reactivity of Electron-Rich Carbenes on the Surface of Catalytic Gold Nanoparticles

[EN] The reactive nature of carbenes can be modulated, and ultimately reversed, by receiving additional electron density from a metal. Here, it is shown that Au nanoparticles (NPs) generate an electron-rich carbene on surface after transferring electron density to the carbonyl group of an in situ activated diazoacetate, as assessed by Fourier transformed infrared (FT¿IR) spectroscopy, magic angle spinning nuclear magnetic resonance (MAS NMR), and Raman spectroscopy. Density functional theory (DFT) calculations support the observed experimental values and unveil the participation of at least three different Au atoms during carbene stabilization. The surface stabilized carbene shows an extraordinary stability against nucleophiles and reacts with electrophiles to give new products. These findings showcase the ability of catalytic Au NPs to inject electron density in energetically high but symmetrically allowed valence orbitals of sluggish molecules.Financial support by MINECO through the Severo Ochoa program, RETOS program (CTQ2014-55178-R), and Ramon y Cajal Program (to A.L.-P.) is acknowledged. J.O.-M. thanks ITQ for the concession of a contract. We are thankful for the electron microscopy service of UPV.Oliver-Meseguer, J.; Boronat Zaragoza, M.; Vidal Moya, JA.; Concepción Heydorn, P.; Rivero-Crespo, MÁ.; Leyva Perez, A.; Corma Canós, A. (2018). Generation and Reactivity of Electron-Rich Carbenes on the Surface of Catalytic Gold Nanoparticles. Journal of the American Chemical Society. 140(9):3215-3218. https://doi.org/10.1021/jacs.7b13696S32153218140

Potential contribution of distant sources to airborne Betula pollen levels in Northeastern Iberian Peninsula

Betula (birch) pollen is one of the most important causes of respiratory allergy in Northern and Central Europe. While birch trees are abundant inCentral, Northern, and Eastern Europe,theyare scarce inthe Mediterranean territories, especially in the Iberian Peninsula (IP), where they grow only in the northern regions and as ornamental trees in urban areas. However, the airborne birch pollen patterns in Catalonia (Northeastern IP) show abrupt high concentrations in areas withusually low local influence.The intensity of the derived health problemscan beincreasedbyoutbreaksdue to long-range pollen transport. The present work evaluates the different potential contributions to Catalonia from the main source regions: Pyrenees, Cantabria, and the forests of France and Central Europe. To this end, we computed the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back trajectories of air masses associated with the main Betula pollen peaks occurring simultaneously over different Catalan monitoring stations, and we studied their provenance over a 15-year period. The Vielha aerobiological station on the northern slopes of the Central Pyrenees was used to identify the dates of the pollen season in the Pyrenean region. In order to better understand the role of the Pyrenees, whichis thenearest of thefourbirch forested regions, weclassifiedthepollenpeaksinthe other Catalan stations into three groups based onthe relationship between the peak andthe pollenseason in thePyrenees. Our analysis of back-trajectory residence time, combined with the associated pollen concentration, reveals that two principal routes other than the Pyrenean forest sustain the northerly fluxes that enter Catalonia and carry significant concentrations of Betula pollen. This study has also allowed quantifying the differentiated contributions of the potential sourcePeer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarObjectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes TerrestresPostprint (published version

Screening for Prognostic microRNAs Associated with Treatment Failure in Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) treatment with R-CHOP regimen produces 5-year progression-free survival and overall survival of around 60-70%. Our objective was to discover prognostic biomarkers allowing early detection of the remaining 30-40% with poor long-term outcome. For this purpose, we applied a novel strategy: from a cohort of DLBCL patients, treated with standard therapy, a discovery group of 12 patients with poor prognosis (advanced stage III-IV, R-IPI > 2) was formed, consisting of six chemoresistant (refractory/early relapse 3 years) subjects. By using microarray assays, the most differentially expressed miRNAs were defined as an initial set of prognostic miRNA candidates. Their expression was then analyzed in a validation cohort of 68 patients and the three miRNAs with the most significant impact on event-free and overall survival were selected. In the DLBCL cell line U-2932 the transfection with miR-1244 and miR-193b-5p, but not miR-1231, blocked the effect of CHOP on cell viability. A subsequent gene set enrichment analysis in patients revealed the implication of the first two miRNAs in cell cycle control and chemoresistance-related pathways, whereas the last one was involved in immunological processes. In conclusion, this novel strategy identified three promising prognostic markers for DLBCL patients at high risk of failure with standard therapy

Power Balance of a Hybrid Power Source in a Power Plant for a Small Propulsion Aircraft

This paper analyzes two different architectures for a hybrid power source comprising a PEM (Polymer Electrolyte Membrane) fuel cell and a Li ion battery. The hybrid power source feeds the propulsion motor of an all electrical aircraft, the Boeing Fuel Cell Demonstrator. The architectures are an unregulated and a regulated hybrid power source. The regulation is achieved by means of a controllable series boost converter (SBC) connected in series with the fuel cell. Both architectures have been simulated, implemented and tested in the Boeing Fuel Cell Demonstrator Airplane