379 research outputs found
A Theoretical Study of the Hydrodynamic Performance of an Asymmetric Fixed-Detached OWC Device
The chamber configuration of an asymmetric, fixed-detached Oscillating Water Column (OWC) device was investigated theoretically to analyze its effects on hydrodynamic performance. Two-dimensional linear wave theory was used, and the solutions for the associated radiation and scattering boundary value problems (BVPs) were derived through the matched eigenfunction expansion method (EEM) and the boundary element method (BEM). The results for the hydrodynamic efficiency and other important hydrodynamic properties were computed and analyzed for various cases. Parameters, such as the length of the chamber and the thickness and submergence of the rear and front walls, were varied. The effects on device performance of adding a step under the OWC chamber and reflecting wall in the downstream region were also investigated. A good agreement between the analytical and numerical results was found. Thinner walls and low submergence of the chamber were seen to increase the efficiency bandwidth. The inclusion of a step slightly reduced the frequency at which resonance occurs, and when a downstream reflecting wall is included, the hydrodynamic efficiency is noticeably reduced at low frequencies due to the near trapped waves in the gap between the OWC device and the rigid vertical wall.The current investigation was developed under the framework of the Basque Government (IT1314-19 research group). The authors additionally thank the funding provided by CEMIE-Océano (Mexican Centre for Innovation in Ocean Energy). Project FSE-2014-06-249795 financed by CONACYT-SENER Sustentabilidad Energética
The Juntas out of the Spanish Court: A Perspective from Seville, 17th Century
Los estudios acerca del fenómeno institucional representado por las juntas se han centrado, por lo general, en el ámbito cortesano, asentándose la idea de que estos organismos fueron endémicos de la sede del poder central, íntimamente ligada a la figura real. El presente trabajo, sin embargo, plantea la posi-bilidad de que su desarrollo en el seno de la Monarquía Hispánica se extendiera a otros espacios, como, por ejemplo, Sevilla. Esta ciudad, cabeza del monopolio comercial con las Indias, conoció a lo largo del siglo XVII varias experiencias junteras: la Junta de la Avería, la Junta de Ministros de 1630 y la Junta de la Quietud en 1652. A través del análisis de su estructura, facultades y trayectoria, confrontaremos sus similitudes y dife-rencias, ponderando su importancia en relación con otras instituciones contemporáneasThe studies about the institutional phenomenon represented by the juntas have generally focused on the court environment, establishing the idea that these organizations were endemic to the headquarters of the central power, intimately linked to the royal figure. The present work, however, raises the possibility that its development within the Hispanic Monarchy extended to other spaces, such as, for example, Seville. This city, head of the commercial monopoly with the Indies, met throughout the seventeenth century several assembly experiences: the Junta de la Avería; the Junta de Ministros, in 1630, and the Junta de la Quietud in 1652. Throughout the analysis of its structure, faculties, and trajectory, we will confront its similarities and differences, pondering about its importance in relation to other contemporary institution
Modèles la diversification énergétique en Ibero-Amérique
La subida de los precios del petróleo y el accidente nuclear de Fukushima han sacado de nuevo a la palestra un viejo debate acerca del aumento del abastecimiento de energía; en el presente artículo apoyamos que la mejor solución es la diversificación de las fuentes de energía, promoviendo las fuentes alternativas de energía al petróleo y en general las eficiencia energética. A modo comparativo estudiamos la estructura enérgica de ocho países latinoamericanos (Chile, Venezuela, España, Portugal, México, Brasil, Argentina y Colombia) mencionando las características más importantes de cada uno de ellos.p>Rising oil prices and the Fukushima nuclear accident have brought back to the fore an old debate about the supply of energy, in this paper we think the best solution is to diversify energy sources, promoting alternative energy sources to oil and overall energy efficiency. We have studied the energetic structure of eight Latin American countries (Chile, Venezuela, Spain, Portugal, Mexico, Brazil, Argentina and Colombia) and we have compared them, mentioning the most important features of each.La hausse des prix du pétrole et du Fukushima accident nucléaire ont ramené au premier plan un vieux débat sur la fourniture d’énergie, dans cet article Nous pensons que la meilleure solution consiste à diversifier les sources d’énergie, la promotion de sources d’énergie alternatives au pétrole et au rendement énergétique global. Nous avons étudié la structure énergétique de huit pays d’Amérique latine (Chili, Venezuela, Espagne, Portugal, Mexique, Brésil, Argentine et Colombie) et nous les avons comparés, en mentionnant les caractéristiques les plus importantes de chacun
Procedimiento y sistema ultrasónico de desespumación mediante emisores con placa vibrante escalonada
Referencia OEPM: P200202113.-- Fecha de solicitud: 13/09/2002.-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).Procedimiento y sistema ultrasónico de desespumación mediante emisores con placa vibrante escalonada (ver figura en archivo de texto adjunto). El objeto de esta solicitud de patente es un dispositivo ultrasónico que permite eliminar espumas y controlar su crecimiento en grandes contenedores. El dispositivo emplea emisores sónicos y/o ultrasónicos del tipo placa vibrante escalonada, especiales para radiar altas intensidades acústicas en gases, los cuales, al estar libremente suspendidos en un soporte giratorio con rotación variable controlada, generan en su movimiento por acción de la fuerza centrífuga un recorrido complejo de los haces acústicos emitidos que permite barrer la superficie sobre la que se forma la espuma. Por efecto de la alta intensidad acústica ( >170 dB ref. 2.10^-4 μbar) gran parte de las burbujas de la espuma se van rompiendo casi instantáneamente al paso del haz ultrasónico.Peer reviewe
The Influence of the Chamber Configuration on the Hydrodynamic Efficiency of Oscillating Water Column Devices
Based on the two-dimensional linear wave theory, the effects of the front wall thickness and the bottom profile of an Oscillating Water Column (OWC) device on its efficiency were analyzed. Using the potential flow approach, the solution of the associated boundary value problem was obtained via the boundary element method (BEM). Numerical results for several physical parameters and configurations were obtained. The effects of the front wall thickness on the efficiency are discussed in detail, then, various configurations of the chamber bottom are presented. A wider efficiency band was obtained with a thinner front wall. In a real scenario having a thinner front wall means that such a structure could have less capacity to withstand the impact of storm waves. Applying the model for the case of the Mutriku Wave Energy Plant (MWEP), findings showed that the proposed bottom profiles alter the efficiency curve slightly; higher periods of the incoming water waves were found. This could increase the efficiency of the device in the long-wave regime. Finally, the numerical results were compared with those available in the literature, and were found to be in good agreement.The present research has been developed under the framework of CEMIE-Océano (Mexican Centre for Innovation in Ocean Energy). Project FSE-2014-06-249795 financed by CONACYT-SENER- Sustentabilidad Energética. In addition, the authors would like also to express their gratitude for the funding provided by the UPV/EHU [PPGA20/26 research group] and the Basque Government (IT1314-19 research group)
Polarization and hate speech with gender bias associated with politics: analysis of interactions on Twitter
The spread of hate speech through social media contributes to poisoning the public sphere and undermining the quality of liberal democracies. This type of discourse is particularly virulent against the political class and against feminism. Taking this reality as a starting point, this research will attempt to identify the gender bias in hate speech in the political sphere: do female politicians receive more verbal attacks than their male counterparts, not because they are politicians, but because they are women? Do female politicians receive more emotional polarity in the mentions they receive on Twitter than their male counterparts? Through discourse analysis using PLN techniques for emotion detection and text mining on a corpus of 3,483,232 tweets collected from 20 accounts of Spanish politicians, it is found that the messages received by women politicians concentrate more emotional polarity than men’s, but not more hatred, which is slightly higher in men. It also confirms that sexist and misogynist expressions are used to denigrate women and, by extension, feminism, which makes hate speech a type of information disorder.La propagación de discursos de odio a través de las redes sociales contribuye a intoxicar la esfera pública y a mermar la calidad de las democracias liberales. Este tipo de discursos es singularmente virulento contra la clase política y contra el feminismo. Partiendo de esta realidad, la presente investigación tratará de delimitar el sesgo de género en el discurso de odio en el ámbito político. ¿Reciben las mujeres políticas más agresiones verbales que sus homólogos varones, no por su condición de políticas, sino por su condición de mujeres? ¿Concentran las mujeres políticas más polaridad emocional que los hombres en las menciones que reciben en Twitter? A través del análisis del discurso operado con técnicas de PLN para la de detección de las emociones y de la minería de texto sobre un corpus de 3.483.232 de tuits recolectados de 20 cuentas de políticos españoles, se confirma que los mensajes que reciben las mujeres políticas concentran mayor polaridad emocional que los de los hombres, pero no más odio, que es un poco superior en los hombres. También se confirma que las expresiones sexistas y misóginas son empleadas para denigrar a las mujeres y, por extensión, al feminismo, lo que convierte al discurso del odio en un tipo de desorden informativo
Benchmarking biomedical text mining web servers at BioCreative V.5: the technical Interoperability and Performance of annotation Servers - TIPS track
The TIPS track consisted in a novel experimental task under the umbrella
of the BioCreative text mining challenges with the aim to, for the first time
ever, carry out a text mining challenge with particular focus on the continuous
assessment of technical aspects of text annotation web servers, specifically of
biomedical online named entity recognition systems.
A total of 13 teams registered annotation servers, implemented in various programming
languages, supporting up to 12 different general annotation types. The
continuous evaluation period took place from February to March 2017. The systematic
and continuous evaluation of server responses accounted for testing periods
of low activity and moderate to high activity. Moreover three document
provider settings were covered, including also NCBI PubMed. For a total of
4,092,502 requests, the median response time for most servers was below 3.74 s
with a median of 10 annotations/document. Most of the servers showed great
reliability and stability, being able to process 100,000 requests in 5 days.info:eu-repo/semantics/publishedVersio
Dissociation of a Strong Acid in Neat Solvents: Diffusion Is Observed after Reversible Proton Ejection Inside the Solvent Shell
This is the peer-reviewed version of the following article:
The Journal of Physical Chemistry B 2013, 117, 14065–14078, DOI: 10.1021/jp4042765, which has been published in final form at https://pubs.acs.org/doi/abs/10.1021/jp4042765.
This article may be used for non-commercial purposes onlyStrong-acid dissociation was studied in alcohols. Optical excitation of the cationic photoacid N-methyl-6-hydroxyquinolinium triggers proton transfer to the solvent, which was probed by spectral reconstruction of picosecond fluorescence traces. The process fulfills the classical Eigen–Weller mechanism in two stages: (a) solvent-controlled reversible dissociation inside the solvent shell and (b) barrierless splitting of the encounter complex. This can be appreciated only when fluorescence band integrals are used to monitor the time evolution of the reactant and product concentrations. Band integrals are insensitive to solvent dynamics and report relative concentrations directly. This was demonstrated by first measuring the fluorescence decay of the conjugate base across the full emission band, independently of the proton-transfer reaction. Multiexponential decay curves at single wavelengths result from a dynamic red shift of fluorescence in the course of solvent relaxation, whereas clean single exponential decays are obtained if the band integral is monitored instead. The extent of the shift is consistent with previously reported femtosecond transient absorption measurements, continuum theory of solvatochromism, and molecular properties derived from quantum chemical calculations. In turn, band integrals show clean biexponential decay of the photoacid and triexponential evolution of the conjugate base in the course of the proton transfer to solvent reaction. The dissociation step follows the slowest stage of solvation, which was measured here independently by picosecond fluorescence spectroscopy in five aliphatic alcohols. Also, the rate constant of the encounter-complex splitting stage is compatible with proton diffusion. Thus, for this photoacid, both stages reach the highest possible rates: solvation and diffusion control. Under these conditions, the concentration of the encounter complex is substantial during the earliest nanosecondWe thank the Spanish Government and the European Regional Development Fund (grant nos. CTQ2010-17835, CTQ2010-17026, and CTQ2011-29311-C02-01) and the Xunta de Galicia (grants nos. CN 2012/314, 2012-PG237, GPC2013/052 and INCITE09 314 252 PR) for financial support of our work. J.L.P.L. thanks the Spanish Ministry of Economy and Competitiveness for funding through the Ramon y Cajal ́
Programm 2009. M.V. and C.C.B. thank the Spanish Government for funding through the FPU program. A. B. thanks the Segundo Gil Dávila Foundation for financial supportS
La teledetección como herramienta para ordenación rural sostenible en entidades locales menores
La ordenación territorial puede considerarse como una disciplina científica, una técnica administrativa y una práctica política concebida como actuación interdisciplinaria y global cuyo objetivo es un desarrollo equilibrado de las regiones y la organización física del espacio según un concepto rector. La ordenación debe ser democrática, global, funcional y prospectiva, en sentido de considerar las tendencias socioeconómicas, culturales y ambientales, a largo plazo
- …