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[SPA] Si imaginamos el mercado como un circuito en el que diferentes agentes actúan entre ellos para obtener un beneficio económico, podemos decir que, las empresas forman parte de este circuito junto a otros agentes (como los hogares, el estado, las entidades bancarias, inversores…etc.). Que alguno de esos agentes deje de existir afecta desde una perspectiva económica a los que permanecen en el circuito (deflación, desempleo, disminución de la actividad productiva), incluso a otros agentes del mismo tipo (pérdida de proveedores), aun perteneciendo a otros países (disminución del comercio internacional). En este sentido, y por ubicarnos en un sistema capitalista, analizamos la situación en la que las empresas dejan de existir por ser un aspecto de importancia fundamental en ámbitos políticos y socioeconómicos. El objetivo de esta tesis es determinar la combinación de condiciones financieras necesarias que hacen que las empresas fracasen. Además, examinamos si estas condiciones varían ante shocks externos inesperados y difíciles de predecir como es el caso de la crisis derivada de la situación de la pandemia del Covid. Para ello, desarrollamos una metodología basada en análisis simbólico, a partir del cual caracterizamos el proceso de fracaso empresarial en base a la información que obtenemos a partir de los ratios financieros. En particular, superamos las limitaciones derivadas de la aplicación de técnicas de análisis cualitativo comparativo de conjuntos difusos (fsQCA) respecto a su carácter subjetivo mediante la aplicación de algoritmos de Big Data basados en el análisis simbólico, y la utilización de herramientas de estadística tradicional. Además, aplicamos herramientas de clusterización con el fin de identificar características financieras comunes en las distintas empresas que determinamos como fracasadas en el proceso anterior. Esto nos ayuda a identificar distintos procesos de fracaso empresarial. Este procedimiento propuesto se aplica posteriormente para com, [ENG] If we imagine the market as a circuit in which different agents act among themselves to obtain an economic benefit, we can say that companies form part of this circuit together with other agents (such as households, the state, banks, investors, etc.). If any of these agents cease to exist, from an economic perspective, this affects those who remain in the circuit (deflation, unemployment, decrease in productive activity), and even other agents of the same type (loss of suppliers), even if they belong to other countries (decrease in international trade). In this sense, and because we are located in a capitalist system, we analyse the situation in which companies cease to exist because they are of fundamental importance in political and socio-economic spheres. The objective of this thesis is to determine the combination of necessary financial conditions that cause firms to fail. In addition, we examine whether these conditions vary in the face of unexpected and hard-to-predict external shocks such as the crisis resulting from the Covid pandemic situation. To this end, we develop a methodology based on symbolic analysis, from which we characterise the process of business failure based on the information we obtain from financial ratios. In particular, we overcome the limitations derived from the application of fuzzy set comparative qualitative analysis (fsQCA) techniques with respect to their subjective character by applying Big Data algorithms based on symbolic analysis, and the use of traditional statistical tools. In addition, we apply clustering tools in order to identify common financial characteristics in the different companies that we determined as failures in the previous process. This helps us to identify different processes of business failure. This proposed procedure is then applied to test whether the typology of business failure processes has changed before and after Covid. Subsequently, we develop an empirical analysis applying the previously descri

The main objective of this work is to investigate the expected success of the application of Landing Obligation in the Spanish bottom trawl fleet operating in North-western Iberian waters (ICES divisions 27.8.c and 27.9.a). This fleet is composed by three trawling metiers: bottom otter trawl targeting demersal fish species (OTB_DEF), bottom otter trawl targeting mixed pelagic and demersal species (OTB_MPD) and pair bottom trawl targeting mixed pelagic and demersal species (PTB_MPD). Discards data from 2009 until 2021, obtained through the DCF Spanish at-sea sampling programme, was analysed in order to determine if the LO has had some effect on the discards of frequently caught species (those present in at least 30% of the hauls). For this, we have stratified the historical series into three periods: prior to the LO (2009-2014), transition period (2015-2018) and full implementation (2019-2022). Regarding the species, they were split into two groups: regulated species (with TAC) and non-regulated species (without management measures). For metiers OTB_DEF and OTB_MPD, the data shows a decrease in the discards during the transition period, being this reduction more clear after full implementation of the LO in 2019. Interestingly this appears to happen not just for regulated species but also for those taxa without TAC. For PTB_MPD, discards decrease does not appear to be as clear as in the other two metiers, but a reduction has been also noted mainly after 2019.

A list of new tests for serial dependence based on ordinal patterns is provided. These new methods rely exclusively on the order structure of the data sets. Hence, the novel tests are stable under monotone transformations of the time series and robust against small perturbations or measurement errors. The standard asymptotic distributions are given, and their finite sample behavior under linear and non-linear departures from the null of independence are studied. Moreover, it is proved that under mild conditions, any ordinal-pattern-based test is nuisance free, which is appealing for modeling, as these tests can eventually be used as misspecification tests. This property is also analyzed for finite samples and illustrated through an empirical application. Much of the discussion is based on a detailed combinatorial analysis of ordinal pattern probabilities.

[ES] En la presente invención, se describe un nuevo procedimiento de síntesis del material intercrecido CHA/AEI en su forma zeolítica utilizando un único agente director de estructura orgánico (ADEO), mucho más sencillo que las mezclas descritas hasta el momento, y en ausencia de aniones fluoruro en el medio de síntesis. En la presente invención también se describe el material obtenido con dicho procedimiento y su uso como catalizador en diversos procesos catalíticos, como metanol a olefinas, y la reducción catalítica selectiva (RCS) de distintos óxidos de nitrógeno (NOx) en emisiones gaseosas., [EN] The present invention relates to a new method for synthesising CHA/AEI intergrown material in its zeolitic form using a single organic structure-directing agent (OSDA), which is much simpler than previously described mixtures, and in which the synthesis medium is free of fluoride anions. The present invention also relates to the material obtained with said method and the use thereof as a catalyst in various catalytic processes, such as the methanol-to-olefin process, and the selective catalytic reduction (SCR) of different nitrogen oxides (NOx) in gaseous emissions., [FR] La présente invention porte sur un nouveau procédé de synthèse du matériau entrecroisé CHA/AEI dans sa forme zéolithique au moyen d'un agent directeur unique de structure organique (ADEO), beaucoup plus simple que les mélanges décrits jusqu'à ce jour, et en l'absence d'anions fluorure dans le milieu de synthèse. L'invention porte également sur le matériau obtenu au moyen dudit procédé et sur son utilisation comme cstalyseur dans divers processus catalytiques, comme la conversion de méthanol en oléfines et la réduction catalytique sélective (RCS) de différents oxydes d'azote (NOx) en émissions gazeuses.

Zeolites span a large variety of microporous crystal structures, making them useful materials for catalysis and separations. However, controlling phase competition in their synthesis often requires organic structure-directing agents (OSDAs) to selectively crystallize the desired topologies. Whereas computational design of OSDAs can help in selecting adequate candidates for zeolite synthesis, machine-generated templates are often complex or expensive. In this work, we use shape and binding metrics to propose templates for over 100 zeolites and to rationalize dual-OSDA approaches. Starting from OSDAs from the literature, promising templates were selected for zeolites ranging from clathrasil frameworks to extra large-pore structures. Selectivity maps derived from phase competition metrics show that small- and medium-pore zeolites tend to be more shape-selective toward their templates than their large-pore counterparts. Finally, shape and volume descriptors allow identification of OSDAs that may act as synergistic pore-fillers for different cavities of zeolites. The application of this theory is demonstrated for the case of the KFI zeolite, which may be synthesized using tetraethylammonium and OSDAs repurposed from high-silica LTA synthesis as dual OSDAs. This work may help in the discovery of new synthesis routes for known zeolites using shape descriptors and repurposed OSDAs.

A novel ab initio methodology based on high-throughput simulations has permitted designing unique biselective organic structure-directing agents (OSDAs) that allow the efficient synthesis of CHA/AEI zeolite intergrowth materials with controlled phase compositions. Distinctive local crystallographic ordering of the CHA/AEI intergrowths was revealed at the nanoscale level using integrated differential phase contrast scanning transmission electron microscopy (iDPC STEM). These novel CHA/AEI materials have been tested for the selective catalytic reduction (SCR) of NOx, presenting an outstanding catalytic performance and hydrothermal stability, even surpassing the performance of the well-established commercial CHA-type catalyst. This methodology opens the possibility for synthetizing new zeolite intergrowths with more complex structures and unique catalytic properties.

As one of the most influential scientists in the field of heterogeneous catalysis and materials science, Prof. Avelino Corma has made significant contributions in many diverse fields, spanning over solid catalysts for petrochemistry, solid catalysts for production of fine chemicals, synthesis of microporous and mesoporous materials, development of inorganic-organic hybrid materials, supported metal catalysts (from isolated metal atoms to nanoclusters and nanoparticles) and photochemistry with solid materials. These experimental approaches are complemented with characterization of solid materials with advanced spectroscopy and microscopy techniques as well as theoretical calculations/modeling. The aim of this Account is to overview Avelino's distinguished scientific career and highlight the most remarkable achievements made in his research activities during >40 years. We attempt to show the evolution of Avelino's research topics in his group throughout his career and the approaches that Avelino has chosen to tackle the challenges encountered. The research paradigm developed by Avelino and his team can be inspiring to the researchers in the field of materials science who are striving to translate the knowledge generated in fundamental studies into practical applications for addressing the new scientific challenges encountered in building a sustainable world.

Computer-assistance allows selecting the most adequate low-cost organic structure directing agents (OSDAs) for the crystallization of Al-rich CHA-type zeolites. The host-guest stabilization energies of tetraethylammonium (TEA), methyltriethylammonium (MTEA) and dimethyldiethylammonium (DMDEA), in combination with Na, were first theoretically evaluated. This “ab-initio” analysis reveals that two TEA show a serious steric hindrance in a cha cavity, whereas two MTEA would present excellent host-guest confinements. The synthesis of Al-rich CHA-type zeolites has been accomplished using TEA and MTEA. Electron diffraction and high-resolution transmission electron microscopy reveal large CHA-domains with narrow faulted GME-domains in the CHA-type material synthesized with TEA, confirming the better OSDA-directing roles of MTEA cations towards the cha cavity, in good agreement with DFT calculations. Cu-exchanged Al-rich CHA-type samples achieved with MTEA and TEA show excellent catalytic activity and hydrothermal stability for the selective catalytic reduction (SCR) of NOx with ammonia under conditions relevant for future heavy duty diesel conditions.