Potentzia anplifikadoreen behe-maiztasuneko egonkortasun-marjinen zunda bidezko neurketa-sistemaren simulazio eta analisia

[EUS] Gradu Amaierako Lan honetan, [13] lanean proposatzen den teknikaren simulazio bidezko azterketa burutuko da. Lanaren helburu nagusia teknikaren simulazio bankua inplementatzea eta metodologiaren alderdi ezberdinak aztertzea izango da. 2. atalean, xehetasun handiz azalduko dira metodologiaren nondik-norakoak. 3. atalean, inplementazioa nola egin den azalduko da eta simulazioen balioztatzea egingo da. 4. atalean, metodoaren beraren analisia egingo da, alderdi ezberdinak aztertuz; hala nola, kalkulatutako poloen ziurgabetasuna neurketa-erroreen arabera eta neurketa-nodoen aukeraketaren garrantzia. 5. atalean, aztergai den metodoan erabiltzen den inpedantzia altuko zunda beharrean, kontaktu gabeko zunda baten erabileraren aukera aztertuko da. Amaitzeko, 6. atalean, ondorio batzuk aterako dira eta etorkizunerako ireki daitezkeen bideak azalduko dira.[ES] En este Trabajo de Fin de Grado se realizará un estudio simulado de la técnica propuesta en [13]. El objetivo principal del trabajo será implementar el banco de simulación de la técnica y analizar los diferentes aspectos de la metodología. En el apartado 2 se detallarán los pormenores de la metodología. En el apartado 3 se explicará cómo se ha realizado la implementación y se realizará la validación de las simulaciones. En el apartado 4, se realizará un análisis del propio método analizando aspectos como la incertidumbre de los polos calculados en función de los errores de medición y la importancia de la elección de los nodos de medición. En el apartado 5, en lugar de la sonda de alta impedancia utilizada en el método de estudio, se estudiará la posibilidad de utilizar una sonda sin contacto. Para finalizar, en el apartado 6 se extraerán unas conclusiones y se expondrán los caminos que se pueden abrir para el futuro

Forming iron-rich planets with giant impacts

We investigate mantle stripping giant impacts (GI) between super-Earths with masses between 1 and 20M⊕⁠. We infer new scaling laws for the mass of the largest fragment and its iron mass fraction, as well as updated fitting coefficients for the critical specific impact energy for catastrophic disruption, Q∗RD⁠. With these scaling laws, we derive equations that relate the impact conditions, i.e. target mass, impact velocity, and impactor-to-target mass ratio, to the mass and iron mass fraction of the largest fragment. This allows one to predict collision outcomes without performing a large suite of simulations. Using these equations we present the maximum and minimum planetary iron mass fraction as a result of collisional stripping of its mantle for a given range of impact conditions. We also infer the radius for a given mass and composition using interior structure models and compare our results to observations of metal-rich exoplanets. We find good agreement between the data and the simulated planets suggesting that GI could have played a key role in their formation. Furthermore, using our scaling laws we can further constrain the impact conditions that favour their masses and compositions. Finally, we present a flexible and easy-to-use tool that allows one to predict mass and composition of a planet after a GI for an arbitrary range of impact conditions, which, in turn, allows to assess the role of GI in observed planetary systems

DoQA : accessing domain-specific FAQs via conversational QA

The goal of this work is to build conversational Question Answering (QA) interfaces for the large body of domain-specific information available in FAQ sites. We present DoQA, a dataset with 2,437 dialogues and 10,917 QA pairs. The dialogues are collected from three Stack Exchange sites using the Wizard of Oz method with crowdsourcing. Compared to previous work, DoQA comprises well-defined information needs, leading to more coherent and natural conversations with less factoid questions and is multi-domain. In addition, we introduce a more realistic information retrieval (IR) scenario where the system needs to find the answer in any of the FAQ documents. The results of an existing, strong, system show that, thanks to transfer learning from a Wikipedia QA dataset and fine tuning on a single FAQ domain, it is possible to build high quality conversational QA systems for FAQs without in-domain training data. The good results carry over into the more challenging IR scenario. In both cases, there is still ample room for improvement, as indicated by the higher human upperbound

Synergistic theoretical and experimental study on the ion dynamics of bis(trifluoromethanesulfonyl)imide-based alkali metal salts for solid polymer electrolytes

Model validation of a well-known class of solid polymer electrolyte (SPE) is utilized to predict the ionic structure and ion dynamics of alternative alkali metal ions, leading to advancements in Na-, K-, and Cs-based SPEs for solid-state alkali metal batteries. A comprehensive study based on molecular dynamics (MD) is conducted to simulate ion coordination and the ion transport properties of poly(ethylene oxide) (PEO) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt across various LiTFSI concentrations. Through validation of the MD simulation results with experimental techniques, we gain a deeper understanding of the ionic structure and dynamics in the PEO/LiTFSI system. This computational approach is then extended to predict ion coordination and transport properties of alternative alkali metal ions. The ionic structure in PEO/LiTFSI is significantly influenced by the LiTFSI concentration, resulting in different lithium-ion transport mechanisms for highly concentrated or diluted systems. Substituting lithium with sodium, potassium, and cesium reveals a weaker cation-PEO coordination for the larger cesium-ion. However, sodium-ion based SPEs exhibit the highest cation transport number, indicating the crucial interplay between salt dissociation and cation-PEO coordination for achieving optimal performance in alkali metal SPEs.The research was supported by funding as a part of the DESTINY PhD program, funded by the European Union's Horizon2020 research and innovation program under the Marie Skłodowska-Curie Actions COFUND (Grant No. 945357), and funding through the Basque Government PhD Grant. The authors also acknowledge funding from ‘Departamento de Educación, Política Lingüística y Cultura del Gobierno Vasco’ (Grant No. IT1358-22), the Basque Government (PRE_2022_1_0034), and thank SGI/IZO-SGIker UPV/EHU for providing supercomputing resources

TOI-431/HIP 26013: A super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431 b is a super-Earth with a period of 0.49 d, a radius of 1.28 ± 0.04 R, a mass of 3.07 ± 0.35 M, and a density of 8.0 ± 1.0 g cm-3; TOI-431 d is a sub-Neptune with a period of 12.46 d, a radius of 3.29 ± 0.09 R, a mass of 9.90+1.53-1.49 M, and a density of 1.36 ± 0.25 g cm-3. We find a third planet, TOI-431 c, in the High Accuracy Radial velocity Planet Searcher RV data, but it is not seen to transit in the TESS light curves. It has an Msin i of 2.83+0.41-0.34 M, and a period of 4.85 d. TOI-431 d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterization, while the super-Earth TOI-431 b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431 b is a prime TESS discovery for the study of rocky planet phase curves.Fil: Osborn, Ares. University of Warwick; Reino UnidoFil: Armstrong, David J. University of Warwick; Reino UnidoFil: Cale, Bryson. George Mason University; Estados UnidosFil: Brahm, Rafael. Universidad Adolfo Ibañez; Chile. Instituto de Astrofísica; ChileFil: Wittenmyer, Robert A. University Of Southern Queensland; AustraliaFil: Dai, Fei. Division Of Geological And Planetary Sciences; Estados UnidosFil: Crossfield, Ian J. M. University of Kansas; Estados UnidosFil: Bryant, Edward M. University of Warwick; Reino UnidoFil: Adibekyan, Vardan. Universidad de Porto; PortugalFil: Cloutier, Ryan. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Collins, Karen A. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Delgado Mena, E.. Universidad de Porto; PortugalFil: Fridlund, Malcolm. Leiden University; Países Bajos. Chalmers University of Technology; SueciaFil: Hellier, Coel. Keele University; Reino UnidoFil: Howell, Steve B. NASA Ames Research Center; Estados UnidosFil: King, George W. University of Warwick; Reino UnidoFil: Lillo Box, Jorge. Consejo Superior de Investigaciones Científicas. Centro de Astrobiología; EspañaFil: Otegi, Jon. Universidad de Ginebra; Suiza. Universitat Zurich; SuizaFil: Sousa, S.. Universidad de Porto; PortugalFil: Stassun, Keivan G. Vanderbilt University; Estados UnidosFil: Matthews, Elisabeth C. Universidad de Ginebra; Suiza. Massachusetts Institute of Technology; Estados UnidosFil: Ziegler, Carl. University of Toronto; CanadáFil: Ricker, George. Massachusetts Institute of Technology; Estados UnidosFil: Vanderspek, Roland. Massachusetts Institute of Technology; Estados UnidosFil: Latham, David W. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Seager, S.. Massachusetts Institute of Technology; Estados UnidosFil: Winn, Joshua N.. University of Princeton; Estados UnidosFil: Jenkins, Jon M. NASA Ames Research Center; Estados UnidosFil: Acton, Jack S. University of Leicester; Reino UnidoFil: Addison, Brett C. University Of Southern Queensland; AustraliaFil: Diaz, Rodrigo Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Físicas. - Universidad Nacional de San Martín. Instituto de Ciencias Físicas; Argentin

Three new brown dwarfs and a massive hot Jupiter revealed by TESS around early-type stars

Context. The detection and characterization of exoplanets and brown dwarfs around massive AF-type stars is essential to investigate and constrain the impact of stellar mass on planet properties. However, such targets are still poorly explored in radial velocity (RV) surveys because they only feature a small number of stellar lines and those are usually broadened and blended by stellar rotation as well as stellar jitter. As a result, the available information about the formation and evolution of planets and brown dwarfs around hot stars is limited. Aims. We aim to increase the sample and precisely measure the masses and eccentricities of giant planets and brown dwarfs transiting early-type stars detected by the Transiting Exoplanet Survey Satellite (TESS). Methods. We followed bright (V 6200 K that host giant companions (R > 7 R⊕) using ground-based photometric observations as well as high precision radial velocity measurements from the CORALIE, CHIRON, TRES, FEROS, and MINERVA-Australis spectrographs. Results. In the context of the search for exoplanets and brown dwarfs around early-type stars, we present the discovery of three brown dwarf companions, TOI-629b, TOI-1982b, and TOI-2543b, and one massive planet, TOI-1107b. From the joint analysis of TESS and ground-based photometry in combination with high precision radial velocity measurements, we find the brown dwarfs have masses between 66 and 68 MJup, periods between 7.54 and 17.17 days, and radii between 0.95 and 1.11 RJup. The hot Jupiter TOI-1107b has an orbital period of 4.08 days, a radius of 1.30 RJup, and a mass of 3.35 MJup. As a by-product of this program, we identified four low-mass eclipsing components (TOI-288b, TOI-446b, TOI-478b, and TOI-764b). Conclusions. Both TOI-1107b and TOI-1982b present an anomalously inflated radius with respect to the age of these systems. TOI-629 is among the hottest stars with a known transiting brown dwarf. TOI-629b and TOI-1982b are among the most eccentric brown dwarfs. The massive planet and the three brown dwarfs add to the growing population of well-characterized giant planets and brown dwarfs transiting AF-type stars and they reduce the apparent paucity

Constraining Exoplanet Structure and Composition: Linking Theory & Observations

Since the discovery of first exoplanet by the end of the twentieth century, technological advancements have hugely extended our understanding of planetary systems. The large number of discovered exoplanets has unveiled a staggering diversity in their nature, leading to the surprising conclusion that our Solar System may not be a typical system. One of the key objective of planetary science is to understand the composition and internal structure of planets, which can then be linked to their formation and evolution path. The characterization of exoplanet interior results challenging, and requires a strong interaction between theory and observations. A combination of several detection techniques is needed to infer planet fundamental parameters as the mass, radius, or equlibrium temperature, and these observables allow to put constraints on theoretical models. On the other hand, theoretical models are crucial to guide observational campaigns. This thesis represents an effort to advance in the interplay between observations and theory to understand the underlying nature of planets. A substantial part of this work is dedicated to the investigation of the exoplanet demography. We are entering an era in which we can compare and classify exoplanet in distinct populations based on many parameters as mass, radius, incoming radiation, stellar type, etc. We present a new as reliable as possible exoplanet catalog based on robust mass and radius measurements. This revisited catalog allows to identify trends and exoplanet subpopulations that were not seen before. The large exoplanet diversity also extend to the architecture of multi-planetary systems. We also use the revisited exoplanet catalog to perform an in-depth analysis of the similarity in mass, radius, and density of multi-planetary systems. Besides the demographic studies, we have also focused on the characterization of the internal structure of individual planets. Building on a previous structure model, we updated several parts of the core, water and volatile envelope models, and use it to characterize various discovered exoplanets. We also use these internal models to study several aspects that affect the characterization of super-Earths and sub-Neptunes, such as observational uncertainties, location in the mass-radius diagram, or model assumptions. This thesis aims to be an additional step towards a deeper understanding of the exoplanetary nature.</p