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Arbitrary and Rigorous Aperture Illumination Synthesis in Huygens’ Metasurface-Based Leaky-Wave Antennas.
Full text linkOmega-type bianisotropic Huygens’ metasurfaces offer a novel approach for controlling the aperture field distribution of leaky-wave antennas. This paper presents a methodology utilizing a parallel-plate waveguide with a metasurface as its top plate. Previous limitations on constant leakage factor are addressed using a slowly varying amplitude approximation in order to satisfy Maxwell’s wave equation, enabling the design of the radiation pattern. A semi-analytical algorithm is employed to obtain the required multi-layer unit-cell geometries. Here, the inter-layer coupling is taken into account, enabling an efficient synthesis of these antennas. Several designs presenting different pointing angles and aperture field distributions are carried out, showing very good agreement between theory and realistic simulations without further full-wave optimization. Finally, the design process is experimentally validated through several prototypes, whose measurements are shown and discussed. These results, demonstrating straightforward semi-analytical synthesis of versatile aperture profiles, would significantly broaden the applicability of such antennas in next-generation wireless systems.This work was supported by the Spanish Ministry of Universities under Grant FPU20/03240 and by MICIU/AEI/10.13039/501100011033 and ERDF/EU under Grant PID2022-141193OB-I00. Funding for open access charge: Universidad de Málaga/CBUA
¿Cómo influye la (in)competencia lingüística de los estudiantes de turismo en la elección de asignaturas impartidas en inglés?
Full text linkEste trabajo pretende aportar al escaso conocimiento existente en esta línea de investigación, desde el prisma de la influencia del conocimiento previo del estudiante en inglés para matricularse en asignaturas cursadas en inglés, lengua franca del sector turístico. Concretamente, se consideran en este estudio diferentes medidas del conocimiento de idiomas: el nivel competencial reportado por los propios estudiantes, el nivel certificado (según el Marco Europeo Común de Referencia para los idiomas (CEFR)) y la experiencia previa de asistencia a cursos impartidos en inglés (ej., bachillerato internacional o bilingüe). Estas variables, entre otras, son empleadas en este estudio para identificar su impacto sobre la autopercepción de ser suficientemente competente para superar las asignaturas impartidas en inglés
Metal-Only 3D Unit Cell for Reflectarrays with Independent Dual-Band Operation.
Full text linkhttps://openpolicyfinder.jisc.ac.uk/id/publication/3355This paper presents a metal-only reflectarray based on a 3D unit cell with dual-band capability. The 3D unit cell is a square waveguide whose vertical walls include resonator elements with independent frequency performance. Different resonator geometries are analyzed to obtain a reflected phase variation in the target frequency band and to be feasible for 3-D manufacturing. C-shaped, triangle-shaped, and circle-shaped resonators are selected to obtain the required phase shift in reflection. A reflectarray (RA) prototype is designed, including pairs of resonators where the C-shaped resonator controls the low-frequency band, and the triangle resonators do so for the high-frequency band. The main reflected beam directions for each frequency band are different to show the independent phase tuning of the resonators. The prototype is manufactured using stereolithography (SLA) with a subsequent silver coating. Measured results show realized gains of 21.2 dBi in the 18 GHz band and 23.63 dBi in the 26.75 GHz band, with a good agreement with the simulated results
Probabilistic Methods for Robotic Gas Source Localization.
Full text linkThe field of robotics is a complex one. Many things can go wrong when an autonomous machine interacts with the real world, from sensors producing unreliable measurements to actuators behaving in unpredictable manners. A robot operating with such unreliable tools must account for the uncertainty that they cause in its estimations of the state of the world.
Probabilistic robotics is an approach that embraces this uncertainty by modeling all the knowledge and estimation processes of the robot with the formal tools of probability theory. This creates a rigorous, robust way of handling uncertainty even as the complexity of the problems increases. Such an approach is beneficial in most cases, but becomes crucial when the information that the robot obtains can only be related to the state it tries to estimate through unreliable models.
One such problem is gas source localization (GSL), where a robot equipped with a gas sensor and an anemometer must solve a fluid dynamics problem to figure out which point in the environment a gas is being emitted from. Due to the complexity of the phenomenon of gas dispersion, GSL techniques must make assumptions and simplifications to be able to reason about it, which increases uncertainty.
In this thesis, we tackle the subject of source localization with an autonomous mobile robot from the perspective of probabilistic robotics. We explain the difficulties the problem presents, and propose solutions based on probabilistic modeling and Bayesian reasoning
Análisis descriptivo de pacientes con insuficiencia cardiaca hospitalizados por covid-19 en España. Registro semicovid-19.
Full text linkLa prevalencia de insuficiencia cardiaca (IC) en nuestro entorno presenta un marcado incremento, debido principalmente al envejecimiento de la población, así como a los avances terapéuticos frente a esta enfermedad y a las comorbilidades asociadas. Actualmente, la IC se considera un problema de salud pública de primer orden en los países desarrollados, representando uno de los principales motivos de hospitalización en nuestro medio. Todo ello hace necesario un adecuada prevención, un diagnóstico temprano y un correcto tratamiento basado en el abordaje precoz, integral y continuado del paciente. Los pacientes con IC presentan una serie de características que los hacen más vulnerables y expuestos a una mayor morbimortalidad por la COVID-19 respecto a los individuos infectados por SARS-CoV-2 sin IC. Sin embargo, disponemos de pocos estudio sobre pacientes con IC hospitalizados por COVID-19. En consecuencia, sería conveniente conocer las características clínicas de los pacientes con IC hospitalizados por COVID-19 e identificar los factores de riesgo de mortalidad durante el ingreso. Por ello, hemos realizado el presente trabajo que pretende conocer las características de los pacientes ingresados por COVID-19 que presentaban IC previamente al ingreso, con el fin de identificar al momento del ingreso factores predictores de mal pronóstico intrahospitalario, y la respuesta a distintos tratamientos farmacológicos
Micro-CT reconstruction reveals new information about the phylogenetic position and locomotion of the Early Cretaceous bird Iberomesornis romerali
Full text linkThe enantiornithine Iberomesornis romerali from the Lower Cretaceous site of Las Hoyas (Spain) was originally described more than 35 years ago. As one of the first known articulated partial skeletons of this clade, I. romerali has been critical to our understanding of early avian systematics. Due to its preservation as a largely two-dimensional slab specimen, previous anatomical descriptions were unable to fully capture its anatomy. Here, we present new anatomical data based on micro-computed tomography of the holotype. We reconstruct five previously poorly known osteological elements, i.e., cervical vertebrae, pygostyle, coracoid, furcula, and humerus. Re-evaluation of these elements resulted in revised scorings for 15 morphological characters commonly used for cladistic analysis of Aves. The results of the modified character matrix support Iberomesornis in a derived position within Enantiornithes, close to the Longipterygidae. In addition, new findings in the coracoid and humerus reveal well-developed muscles for the elevation (i.e., supracoracoideus) and flexion–extension (extensor carpi radiale) of the wing. The new evidences, together with the typical enantiornithine furcula and the small size of the holotype, suggest that I. romerali was capable of flapping flight.Funding for open access charge: Universidad de Málaga / CBU
Síntesis de nuevos materiales basados en minerales de la arcilla. Aplicaciones ambientales y químicas.
No full textLa tesis titulada "Síntesis de nuevos materiales basados en minerales de la arcilla. Aplicaciones ambientales y químicas" aborda el desarrollo y la caracterización de materiales derivados de arcillas, como zeolitas, para aplicaciones sostenibles en catálisis, captura de CO2 y gestión de residuos peligrosos como el asbesto.
El trabajo explora métodos avanzados para modificar arcillas (como la pilarización y la creación de heteroestructuras porosas) con el objetivo de convertir biomasa lignocelulósica en productos químicos de alto valor, como γ-valerolactona y levulinatos de alquilo, mediante procesos catalíticos eficientes. También investiga la síntesis de zeolitas a partir de filosilicatos para la captura de CO2, destacando el impacto de los tratamientos ácidos y las condiciones hidrotérmicas en la mejora de su capacidad adsorbente.
Un capítulo destacado se centra en el tratamiento del crisotilo, un mineral fibroso de asbesto, mediante métodos ácidos asistidos por microondas. Este enfoque transforma el crisotilo en un material amorfo y poroso, reduciendo su patogenicidad y ofreciendo una solución efectiva para la gestión segura de residuos de asbestos.
Los resultados demuestran que las arcillas pilareadas y las heteroestructuras porosas optimizan la conversión de furfural en compuestos de valor añadido, siendo los catalizadores basados en circonio los más efectivos. En la captura de CO2, las zeolitas sintetizadas a partir de caolinita y montmorillonita muestran una adsorción significativamente superior a la de arcillas tratadas. Los tratamientos de crisotilo logran una reducción drástica de su toxicidad en tiempos cortos, aumentando la porosidad y eliminando componentes nocivos.
En conjunto, esta investigación aporta soluciones innovadoras y sostenibles en catálisis, captura de carbono y gestión de residuos, con implicaciones relevantes para la industria y el medio ambiente
Mejorando las habilidades comunicativas y conductuales en niños de habla española con trastorno del espectro autista utilizando SymboTalk y EC+: Un estudio piloto
No full textEste manuscrito es la versión aceptada (postprint) del artículo publicado en la Revista de Logopedia, Foniatría y Audiología. https://openpolicyfinder.jisc.ac.uk/id/publication/17746- Introduction: Autism spectrum disorder (ASD) is a neurological condition that impacts receptive and expressive communication as well as behavior. In this context, augmentative and alternative communication (AAC) strategies are increasingly integrated with information and communication technologies (ICT). ICT supports have significantly advanced AAC interventions, incorporating tools, software, and digital apps to facilitate information processing in educational and therapeutic settings. Despite the benefits, the wide range of these supports raises concerns about proper usage and optimal alignment with specific needs.
- Method: This pilot study evaluated the impact of an intervention with two different AAC with assistance (AAC+a) on 40 participants with ASD Level 3 within a Spanish-speaking context: communication board from the SymboTalk platform and list-form from the multimodal EC+ app. These supports were implemented using the aided augmented input strategy, an intervention methodology that utilizes these supports to facilitate functional communication by combining visual and oral input.
- Results: After 16 weeks, significant improvements in expressive and receptive communication were observed using the communication board support, although the other resource also proved to be a favorable support for the intervention. No differences were found between groups in behavioral outcomes and modes of communication.
- Conclusions: The results highlight the effectiveness of these supports, emphasizing the importance of teaching communication skills and implementing this strategy in a Spanish-speaking context. This consideration is crucial given the unique characteristics of this context and its potential impact on children with ASD and complex communication needs.Vicerrectorado de Investigación Universidad de Málaga [Vice-rectorate for Research University of Malaga]. II Own Research Plan (Project B4-2023-18 and Project B2-2022-02
Overcoming the Passivity Bounds in Communications Systems with Spacetime Modulations.
Full text linkIn this paper, we exploit the extra degrees of freedom associated with including time as a design variable to create communication scenarios beyond the physical bounds of passive structures. We particularize the results to a time-modulated diffractive one-dimensional grating. By tuning the temporal modulation, we show that two different scenarios can lead to the same output angles but with different output frequencies or incidence angles. These results illustrate the potential of these metastructures as diffractive beamformers and frequency mixers.This work has been supported by grant TED2021-129938BI00 funded by MCIN/AEI/10.13039/501100011033 and by
the European Union NextGenerationEU/PRTR. It has also
been supported by grants PID2020-112545RBC54, PDC2022-
133900-I00, PDC2023-145862-I00, and IJC2020-043599-I,
funded by MCIN/AEI/10.13039/501100011033 and by the
European Union NextGenerationEU/PRT
Ecomodernism: Sustainability and Human Flourishing.
No full textWhat is ecomodernism? Where did it come from? What are its values? What could be the strongest defense of these values to overcome the current stalemate and polarization in environmental politics? This thesis investigates the origins and values of ecomodernism and offers a normative account of these values.
Part I (The Origins of Ecomodernism) explores where ecomodernism comes from. It explains that ecomodernism builds from something. Consequently, it provides a historical account of its precursors and development in Chapter 1. It also starts to justify its uniqueness as an environmental discourse in relation to reformist environmental discourses such as ecological modernization. To provide a thorough exhaustive exposition of these origins, I detail in Chapter 2 how and why ecomodernism also starts in opposition to something. Namely, the broadly accepted concept of limits as understood by radical and mainstream Western environmentalism.
Part II (The Values of Ecomodernism) systematizes ecomodernism. It contains the argument that ecomodernism has four core values: Pragmatism, unorthodox Prometheanism, modernization, and weak Anthropocentrism. Pragmatism, unorthodox Prometheanism and modernization make up the “modernism” of ecomodernism. I argue that the meanings of these concepts are complex and diverse, and should be taken into account to make sense of ecomodernism. Weak Anthropocentrism makes up the “eco” of ecomodernism. It involves a new set of human-nature relationships, whose virtues and limitations are analyzed and reconceptualized in detail.
In Part III (The Ethics and Political Theory of Ecomodernism) I outline my own version of ecomodernism. I argue in Chapter 5 that breakthrough technologies can help to promote just ecological transitions by extending human substantive freedoms if they are followed by rational consumption of critical ecosystem goods and services