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El Caballero de Gracia
Get PDFTirso de Molina, seudónimo de fray Gabriel Téllez, considerado uno de los principales dramaturgos del Siglo de Oro, escribió El Caballero de Gracia en 1620 a raíz del fallecimiento de su protagonista, acaso por encargo, pero sin duda como homenaje a su persona. La obra refleja las convenciones estructurales del teatro del momento: de la comedia de capa y espada, la fábula de amores en el intento de casar al Caballero que se propone su cuñado Lamberto, y el tema del honor en el adulterio de Sabina fallido gracias a Jacobo; y de los dramas hagiográficos y de santos, la perseverancia en la defensa de los propósitos religiosos que el protagonista encarnó en su vida y que se concretaron en su ordenación sacerdotal. Aun no siendo un texto de gran calidad, conserva el atractivo suficiente para ser leído por la claridad en la exaltación del personaje y sus motivos, la doctrina, la ironía y el buen humor, además de los aciertos líricos y de la esmerada versificación. Como se trata de una obra literaria no debe de extrañar las faltas presentes respecto de la verdad histórica. Tirso buscó y consiguió poner de relieve la vida santa del Caballero a través de sucesivos episodios
Designing optimal Quantum Key Distribution Networks based on Time-Division Multiplexing of QKD transceivers: qTDM-QKDN
Get PDFTime-sharing of Quantum Key Distribution (QKD) transceivers with the help of optical switches and a central Software-Defined Networking (SDN) controller is a promising technique to better amortize the large investments required to build a Quantum Key Distribution Network (QKDN). In this work, we investigate the implications of introducing Time-Division Multiplexing (TDM) in trusted-relay QKDNs at the wide-area network scale in terms of performance and cost-saving. To this end, we developed both a Mixed Integer Linear Programming (qTDM-MILP) model and a Heuristic Algorithm (qTDM-HA) to solve the allocation of QKD transceivers and network resources for a novel switched QKDN operating scheme: qTDM-QKDN. Our heuristic method provides a close-to-optimal resource planning for the offline problem that computes the minimum number of QKD transceivers and optical switch ports at each node, as well as the number of quantum channels on each link required to satisfy a target set of end-to-end secret-keyrate demands. Moreover, both the model and the heuristic provide the time fractions that each QKD transceiver needs to peer with each neighbor QKD transceiver. We compared our proposed model and heuristic algorithm for cost minimization with non-time sharing QKD transceivers (nTDM) as baseline. The results show that qTDM can achieve substantial cost-savings in the range of 10%–40% compared to nTDM. Furthermore, this work sheds light on the selection of the value for the working cycle T and its influence on network performance.This work has been partially supported by the Horizon EU Program under the ALLEGRO project (GA 101092766), KAT2 Quantum Delta NL, Netherlands, and the Spanish projects ACHILLES, Spain (PID2019-104207RB-I00) and FUN4DATE-REDES, Spain (PID2022-136684OB-C21)
A note on the method of equal shares
No full textThe Method of Equal Shares (ES) is a popular approval-based multi-winner voting rule, which was originally proposed by Peters and Skowron. It satisfies several well-known representation axioms, like extended justified representation (EJR) and priceability, and it can be computed in polynomial time. Further, it has already been employed in several real participatory budgeting elections. In this note, we prove that ES is an instance of the EJR-Exact family of voting rules that also satisfy EJR and were proposed by Aziz et al. 2018 before the work of Peters and Skowron.This work has been partially funded by the “Generation of Reliable Synthetic Health Data for Federated Learning in Secure Data Spaces” Research Project (PID2022-141045OB-C43 (AEI/ERDF, EU)) funded by MICIU/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” by the “European Union”
Alternativas cementantes sostenibles para el almacenamiento de energía térmica: materiales activadosalcalinamente e híbridos basados en escoria
Get PDFThe transition to sustainable energy highlights the importance of thermal energy storage (TES) systems, particularly in concentrated solar power plants. While Portland cement has shown potential in TES applications, its high CO2 emissions limit its sustainability. Therefore, this research examines alternative cementitious materials, specifically alkali-activated (AAM) and hybrid alkaline materials (HM), which use blast furnace slag as a binder and incorporate recycled aggregates such as glass waste and electric arc furnace slag.These alternatives not only demonstrate enhanced thermal and mechanical stability up to 500 degrees C but also exhibit improved energy efficiency. Finite Element Method simulations indicate that these alternatives can reduce TES system volume and improve heat transfer efficiency. Additionally, Life Cycle Assessment highlights significant reductions in carbon and water footprints. This study provides insights into the use of AAM and HM mortars as viable, lower-impact alternatives that align with sustainability goals in renewable energy applications.La transición hacia energías sostenibles resalta la importancia de los sistemas de almacenamiento de energía térmica (TES), especialmente en centrales termosolares. Aunque el cemento Portland ha mostrado potencial en estas aplicaciones, sus altas emisiones de CO₂ limitan su aplicación. Por ello, esta revisión analiza materiales cementantes alternativos, específicamente materiales activados alcalinamente (AAM) y morteros híbridos (HM),que emplean escoria de alto horno como conglomerante e incluyen áridos reciclados como residuos de vidrio y escoria de horno de arco eléctrico. Estos materiales no solo ofrecen mayor estabilidad térmica y mecánica hasta 500 °C, sino también una eficiencia energética superior. Las simulaciones mediante el Método de Elementos Finitos sugieren que estas alternativas pueden reducir el volumen del sistema TES y mejorar la transferencia de calor. Además, el Análisis de Ciclo de Vida destaca reducciones significativas en huellas de carbono y agua, alineándose con los objetivos de sostenibilidad en aplicaciones de energía renovable.This study was funded by MCIN/AEI /10.13039/501100011033 and Europe Union NextGenerationEU/PRTR under the National Project TED2021-130633B-I00 and under the National ProjectPID2021-125810OB-C22. This work has been supported by the Madrid Government (Comunidad deMadrid-Spain) under the Multiannual Agreement with UC3M (CALHORIA-CM-UC3M)
A severing rate model for tape tethers based on experimental ballistic equations
No full textA model for the severing rate of tape-like tethers under the impact of small space debris is presented and combined with three ballistic limit equations already proposed in the literature. One of them is based on the classical assumption that particles with 1/3 of the width of the tether can sever it. The other two rely on experimental and numerical results and take into account the impactor-to-tether relative velocity. As a result, the severing rate formula is a triple integral involving the differential flux of debris as a function of the debris size, velocity and impact angle. In order to evaluate the severing rate, a database of the differential flux for different orbit altitudes and inclinations was constructed by using Master 8.03. After implementing and verifying a numerical code, several parametric analyses were conducted to understand the effect of the three ballistic limit equations and the impoverished state of the space debris population on the severing rate. As compared with the simple 1/3 ballistic limit equation, the severing rates found with the two experimental ballistic limit equations are a factor of two lower (or more, depending on the orbit) for the same debris flux and similar among them. However, the growth of the space debris flux over the last decade counteracted this improvement; the severing rate found with the updated debris flux database and the experimental ballistic limit equations is similar to the one found in the past by using older epochs and the classical tether cut assumption.This project has received funding from the European Innovation Council (EIC) under the European Union’s Horizon Europe Programme (Grant agreement No. 101058166, E.T.PACK-F project)
Los mecanismos alternativos a la Jurisdicción para la resolución de conflictos en la empresa familiar argentina
No full textPrograma de Doctorado en Derecho por la Universidad Carlos III de MadridPresidente: Juan Carlos Veiga.- Secretario: Bernardo Pedro Carlino.- Vocal: Marta García Mandaloni
Regional Heterogeneity and Warming Dominance in the contiguous United States
No full textClimate change exhibits substantial variability across both space and time, requiring mitigation and adaptation strategies that effectively address challenges at global and local scales. Accurately capturing this variability is essential for assessing climate impacts, attributing underlying causes, and formulating effective policies. This study introduces simple yet robust quantitative methods to detect local warming, distinguish among different types of warming, and compare warming trends across contiguous U.S. states using the concept of warming dominance. In contrast to traditional approaches that focus solely on average temperatures, our analysis rigorously and systematically examines the entire distribution of daily temperatures for the contiguous United States from 1950 to 2021. The results reveal that, while 44% of states show no statistically significant warming based on average temperature trends, a much larger proportion—84%—exhibit warming when assessing various quantiles of the distribution. These findings underscore the substantial heterogeneity in warming patterns: some states, such as those located in the so-called “Warming Hole,” display no evidence of warming at any quantile; others experience more pronounced warming in either the lower or upper tails of the temperature distribution; and a few states show consistent warming across all quantiles. The study concludes by identifying which states exhibit warming dominance over others and which appear comparatively less affected. These insights are particularly important in the United States, where climate policy is formulated and implemented at both federal and state levels.This research was supported by financial contributions from the Spanish Ministry of Science and Innovation, the Spanish State Research Agency (MCIN/AEI/10.13039/501100011033), and the European Regional Development Fund (ERDF, EU) through grants
PID2020-114646RB-C44, PID2023-150095NB-C44, PID2023-147593NB-I00, and CEX2021-001181 (María de Maeztu). Additional support was provided by the Spanish Ministry of Science and Innovation, the State Research Agency (MCIN/AEI /10.13039/501100011033), and the European Union’s NextGenerationEU/ PRTR under grant TED2021-129784B-I00, as well as by the Community of Madrid through grants
EPUC3M11 and V PRICIT
Cooling rate control combined with refractory Mo and/or V addition to enhance the mechanical properties of CoCrFeMnNi alloy
No full textThis work shows that optimum combination of cooling rate control and refractory Mo and/or V element addition to the CoCrFeMnNi (Cantor) HEA enables to develop novel high-strength hierarchical microstructures consisting of FCC, o phase and finely dispersed precipitates. This has been achieved by casting CoCrFeMnNiV0.5, CoCrFeMnNiMo0.5 and CoCrFeMnNiV0.5Mo0.5 at. % HEAs at a cooling rate of 1000K/s. Since this cooling rate is relatively fast, it enables to retain the Mo and/or V alloying elements in solid solution in the FCC phase. The phenomenon of solid solution hardening contributes to a decrease in the maximum indentation depth from 100um for CoCrFeMnNi, to 89um and 85um for the FCC and o phases, respectively in the CoCrFeMnNiV0.5Mo0.5 at. % HEA. The novel microstructures additionally improve the wear resistance, particularly regarding the scratch hardness number, from Hs=2.74GPa for CoCrFeMnNi, to 4.19GPa for CoCrFeMnNiV0.5, 4.78GPa for CoCrFeMnNiMo0.5 and 6.85GPa for CoCrFeMnNiMo0.5V0.5 thus making these alloys of potential interest for engineering components subjected to load and wear.Sergio González is grateful to the Spanish Ministry of Science, Innovation and Universities for the financial support through the “Beatriz Galindo” Program (BG23/00159)
Exploring the survival of premixed hydrogen flames below the lean flammability limit
Get PDFUltra-lean hydrogen flames, which can ignite unintentionally due to leaks near a heat or power source, pose significant safety risks. This study investigates why flames propagate at equivalence ratios below the theoretical flammability limit ( = 0.255), where the equilibrium temperature equals the crossover temperature. To find the answer, we use detailed chemistry to numerically study the conditions that explain recent experimental observations of flame propagation in confined channels at equivalence ratios < 0.2. Our simulations consider a two-dimensional geometry of two parallel plates separated by a small distance to form a straight channel. Adiabatic and isothermal boundary conditions are considered at the walls to evaluate the effect of heat losses on the survival of the flame. The flame curvature, caused by the confinement within the narrow channel, leads to the formation of a high-temperature region near the center of the channel. This region is surrounded by unburned gas flowing close to the channel walls. The reaction is then sustained by the hydrogen that diffuses from the low-temperature region to the reactive front. This behavior is unique to fuels or fuel blends with sufficiently high mass diffusivity and does not occur when the Lewis number is near or above unity. A new scaling, that accounts for the flame curvature to define the characteristic velocity and lengths scales, is proposed to describe the flame dynamics at equivalence ratios near the flammability limit. According to our calculations, self-sustained 2D hydrogen flames may exist at equivalence ratios as low as = 0.15, a threshold determined by the existence of a stationary flat flame that is unaffected by heat losses.This work was funded by the Regional Government of Madrid and by MCIN of Spain with funding from European Union NextGenerationEU (No. PRTR-C17.I1) and by Agencia Estatal de Investigación under projects, Spain PID2022-139082NB-C51 and TED2021-129446B-C41 (MICINN/FEDER, UE)
Three Essays on Social Evaluations
Get PDFThis dissertation comprises three studies at the intersection of organization theory and strategy, examining how firms communicate their social or strategic positions to the market, how various audiences receive such positions, and taken together, how they translate into firm performance. Focusing on settings in creative and cultural markets, the essays address the following questions: (1) How does communicating informational attributes (such as service features or operational updates) influence consumer perceptions of authenticity and firm performance? (2) How do consumers respond to organizations that take a public stance on a social cause, and do these responses differ for supportive, opposing, or neutral audiences — especially in politically polarized contexts? (3) What happens when there is a misalignment between an organization’s intended category positioning and how audiences perceive it, and does the nature of this misalignment (opportunistic vs. innovative) affect performance outcomes?
In the first essay (co-authored with Samira Reis and Alicia Barroso), we investigate the role of informative publicity in shaping perceptions of authenticity and subsequent performance of organizations. While authenticity is a valued identity trait that can confer competitive advantage, highly authentic organizations often feel constrained in how they engage consumers for fear of seeming inauthentic. Using a quantitative analysis of restaurant performance and leveraging a quasi-natural experiment on Yelp (the introduction of COVID-19 “pickup and delivery” highlight tags on the platform), we find that when businesses broadcast informational updates (e.g. service availability and safety measures), it increases customer engagement and popularity. However, this comes with a paradoxical trade-off: such informational messaging diminishes consumers’ perceptions of the restaurant’s authenticity. Moreover, we observe that the boost to performance (e.g. increased reviews or ratings) from informative publicity materializes only for restaurants that were previously perceived as having low or moderate authenticity. Highly authentic restaurants, in contrast, risk performance declines. These results extend research on authenticity in organizational identity by demonstrating the unintended consequences of information-sharing strategies, offering practical implications for managers of authentic brands on balancing authenticity and outreach.
In the second essay (co-authored with Samira Reis and Alicia Barroso), we examine how organizations' public stances on social causes affects consumer evaluations, focusing on the case of businesses self-declaring as women-owned. Identifying as a women-owned business (WOB) is not inherently a political statement, but in today’s polarized climate around gender equality, this disclosure can be interpreted as an ideological stance. We consider how different consumer groups—supporters, opponents, and nonparticipants—respond to such messaging, with particular attention to nonparticipants, individuals who remain uninvolved with social causes. We argue that while such messaging fosters loyalty among aligned consumers, it also risks alienating opponents and discouraging nonparticipants. Importantly, the reaction of the neutral majority depends on the broader environment: under high polarization, even previously neutral consumers are pushed to take sides, thereby intensifying the effect of organizations taking a stance. Using the 2019 introduction of a “Women-Owned Business” attribute on Yelp as a quasi-experimental setting, we analyze Yelp data to assess how the adoption of this attribute by women-owned businesses influences consumer ratings and reviews. We contribute to understanding how organizational communication of social positions can transform audience composition and behavior, and we reveal that rising societal polarization intensifies these effects by reducing the middle-ground of indifferent consumers.Programa de Doctorado en Empresa y Finanzas / Business and Finance por la Universidad Carlos III de MadridPresidente: Gaël Le Mens.- Secretaria: Mercedes Esteban Bravo.- Vocal: Ying L