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298 p., Las aleaciones con memoria de forma son conocidas como SMA por sus siglas en inglés (Shape Memory Alloys) y se caracterizan por tener una transformación martensítica con dos propiedades principales: memoria de forma y efecto superelástico.En la memoria de forma, un objeto en su fase martensita de baja temperatura puede ser deformado fácilmente. Cuando el material se calienta y se forma la fase austenita, esta revierte todas las deformaciones que se habían inducido sobre la martensita. Por otra parte, en el efecto superelástico, los materiales en la fase austenita de alta temperatura pueden ser sometidos a deformaciones muy elevadas que se recuperan totalmente a lretirar las tensiones aplicadas. Estas dos propiedades pueden aprovecharse activamente para generar una fuerza (con la memoria de forma) o para almacenar energía (con el efecto superelástico), lo que convierte a las SMA en materiales inteligentes.A la vista de la gran variedad de las aplicaciones de las SMA, se ha realizado un trabajo en el que se exploran diferentes campos relacionados con este tipo de aleaciones inteligentes:- Las SMA del sistema Cu-Al-Ni han demostrado tener unas muy buenas propiedades. Aunque son aleaciones frágiles en su estado policristalino, alcanzan valores muy elevados de deformación superelástica en estado monocristalino. En este trabajo, se han diseñado, elaborado y caracterizado (tanto la microestructura como las propiedades termomecánicas) SMA cuaternarias monocristalinas para aplicaciones a media y baja temperatura basadas en el sistema del Cu-Al-Ni, al que se le ha añadido un cuarto elemento: Ga, Be, Au o Mn.- Las SMA del sistema binario Ni-Ti son la aleación más utilizada comercialmente, pero por lo general para aplicaciones a temperaturas inferiores a los100 ºC. Por lo tanto, existe un interés por el desarrollo de nuevas aleaciones basadas en el sistema Ni-Ti para aplicaciones a alta temperatura, como es la aleación Ni-Ti-Hf. Se han caracterizado SMA de alta temperatura de N

An approach was proposed to control the displacement of domain walls in magnetic microwires, which are employed in magnetic sensors. The velocity of the domain wall can be altered by the interaction of two magnetic microwires of distinct types. Thorough investigations were conducted utilizing fluxmetric, Sixtus–Tonks, and magneto-optical techniques. The magneto-optical examinations revealed transformation in the surface structure of the domain wall and facilitated the determination of the mechanism of external influence on the movement of domain walls in magnetic microwires.

Magnetic microwires with amorphous structures can present a unique combination of excellent magnetic softness and giant magnetoimpedance (GMI) effects together with reduced dimensions and good mechanical properties. Such unique properties make them suitable for various technological applications. The high GMI effect, observed in as-prepared Co-rich microwires, can be further optimized by postprocessing. However, unexpected magnetic hardening and a transformation of the linear hysteresis loop into a rectangular loop with a coercivity on the order of 90 A/m were observed in several Co-rich microwires upon conventional annealing. Several routes to improve magnetic softness and GMI effect in Fe- and Co-rich magnetic microwires are provided. We observed that stress annealing could remarkably improve the magnetic softness and GMI ratio of Co-rich microwires. Thus, almost unhysteretic loops with a coercivity of 2 A/m and a magnetic anisotropy field of about 70 A/m are achieved in Co-rich microwires stress annealed at appropriate conditions. The observed change in hysteresis loops and the GMI effect is explained by stress-annealing-induced anisotropy, which is affected by the stresses applied during annealing and by the annealing temperature. While as-prepared Fe-rich amorphous microwires present a low GMI effect, appropriate postprocessing (annealing and stress annealing) allows for a remarkable GMI ratio improvement (an order of magnitude). The evaluated dependence of the maximum GMI ratio on frequency allows the identification of the optimal frequency band for the studied samples. The origin of stress-annealing-induced anisotropy and related changes in hysteresis loops and the GMI effect are discussed in terms of the relaxation of internal stresses, “back-stresses”, as well as structural anisotropy.

Penelitian ini bertujuan untuk mengetahui pengaruh dan peningkatan menggunakan model problem based learning terhadap keterampilan berpikir kreatif fisika siswa. Penelitian ini dilakukan pada siswa kelas X SMA. Variabel pada penelitian ini adalah keterampilan berpikir kreatif dan model Problem-Based Learning. Instrument penelitian menggunakan test dalam bentuk essay dengan jumlah 7 soal yang telah dinyatakan valid. Hasil uji analisis covariate menunjukkan lebih kecil dari 0,05, yang berarti terdapat perbedaan keterampilan berpikir kreatif yang diajarkan menggunakan model PBL. Model Problem-Based Learning meningkatkan keterampilan berpikir kreatif lebih baik dibandingkan pembelajaran konvensional. Penggunaan model PBL dapat meningkatkan keterampilan berpikir kreatif kecuali pada indikator berpikir flexibility.

We perform a detailed comparison of the dynamics of cosmic string loops obtained in cosmological field theory simulations with their expected motion according to the Nambu-Goto action. We demonstrate that these loops follow the trajectories predicted within the NG effective theory except in regions of high curvature where energy is emitted from the loop in the form of massive radiation. This energy loss continues for all the loops studied in this simulation until they self-intersect or become small enough that they annihilate and disappear well before they complete a single oscillation. We comment on the relevance of this investigation to the interpretation of the results from cosmological field theory simulations as well as their extrapolation to a cosmological context.

141 p., En nuestro planeta podemos ver agua en todas sus formas: gaseosa en las nubes, sólida en los glaciares, o líquida en ríos o mares. El agua es trascendental para la vida en la tierra ya que regula la temperatura del medio ambiente adecuadamente y, por lo tanto, se convierte en un factor que determina la supervivencia de la fauna y flora. En los seres humanos, el agua está directamente relacionada con el transporte de nutrientes, la eliminación de toxinas o la lubricación de tejidos participando en las reacciones químicas y en las reacciones metabólicas. Sin agua no podríamos además criar animales, cultivar, lavar los alimentos o mantener una buena higiene.Hasta el siglo XX el agua se ha considerado un recurso inagotable. Sin embargo, el crecimiento de la población mundial y el cambio climático han provocado que en el siglo XXI se haya convertido en un bien escaso. Además, el agua disponible está contaminada fundamentalmente por actividades humanas como la agricultura, ganadería, industria y, parcialmente por razones naturales como erupciones volcánicas. En este contexto se ha vuelto crucial disponer de metodologías o sistemas que permitan de una manera eficiente y económica descontaminar o remediar el agua que disponemos.Esta tesis se centrará en el desarrollo de adsorbentes para la remediación de agua dulce contaminada. Si bien existen muchos tipos de contaminantes diferentes, me concentraré en los llamados ¿contaminantes emergentes¿, una colección de moléculas presente en agua dulce que engloban los productos de cuidado personal, fármacos, plaguicidas y otros productos químicos industriales. De hecho, durante 2023 las regulaciones europeas y españolas del agua para consumo incluirán una extensa lista de estos contaminantes.Los metales pesados proceden de fuentes naturales (como la erosión de rocas compuestas por metales pesados o las erupciones volcánicas) o por actividad humana (la minería y los vertidos industriales). El consumo prolongado de agua contaminada por

209 p., This doctoral thesis was realized at the frontier between Liquid-Phase Transmission Electron Microscopy (LP-TEM) and Microfluidics. It contributes to the elevation of LP-TEM to a quantitative experimental technique for the study of nanoscale dynamics in liquid environments by applying concepts established in microfluidics.A workflow combining numeric modelling and experiments was elaborated. The workflow reveals and quantifies the effect of structural elements of microfluidic LP-TEM reactors on mass transport. Moreover, the effect of flow on the radiolysis reaction network was analysed. The acquired knowledge led to the development of customized LP-TEM mixing reactors with optimized mass transport.This manuscript derives general guidelines for LP-TEM flow experiments and showcases model experiments to demonstrate the progress towards quantitative LP-TEM studies.

125 p., Las proteínas son biopolímeros esenciales en todos los organismos vivos encargadas de un gran número de funciones. Tradicionalmente, el paradigma estructura-función dictaba que todas las proteínas debían encontrarse plegadas ya que solo así serían capaces de ejercer su función. Posteriormente, se ha descubierto un tipo de proteínas llamadas intrínsecamente desordenadas (o IDPs) que no se encuentran plegadas en su estado fisiológico. Debido a su desorden estructural, estas proteínas son capaces de adoptar diferentes configuraciones y unirse a diferentes proteínas. Esto les confiere una gran versatilidad funcional, y en consecuencia están muy presentes en vías de señalización y regulación celular. En esta tesis nos centraremos en el estudio de la unión de dos IDPs, HIF-1¿ y CITED2, a uno de los ocho dominios de la proteína de unión a CREB (CREB binding protein o CBP). Este dominio llamado TAZ1regula la activación del mecanismo de hipoxia en el organismo cuando la cantidad de oxígeno tisular es demasiado baja. En condiciones normales HIF-1 se hidroxila con la presencia de oxígeno y es degradado por el proteasoma, sin embargo cuando no hay oxígeno esta proteína no se puede hidroxilar,acumulándose y uniéndose a TAZ1. Esto provoca la activación de un gran número de genes relacionados con la supervivencia celular. Algunos de estos genes son utilizados por las células tumorales para sobrevivir, ya que al estar alejadas del torrente sanguíneo también tienen problemas similares a las células en condiciones hipóxicas. Por esta razón es que el bloqueo de la interacción de estas dos proteínas seria muy beneficioso.

232 p., Actualmente la producción de agua potable mediante la desalinización por membranas es un proceso eficiente pero que sufre una fuerte limitación: el ensuciamiento o ¿fouling¿ de membranas. La industria no puede detectar este problema con la suficiente anticipación como para poder planificar los procesos de limpieza de las membranas de forma anticipada y minimizar así los daños intrínsecamente asociados, como los residuos generados y el elevado coste energético. Las técnicas convencionales de detección y monitorización del fouling no tienen la sensibilidad suficiente como para poder dar una respuesta que permita tomar acciones y optimizar así el proceso de producción de agua. Es por ello, que el objetivo de este trabajo es investigar si las limitaciones de los métodos convencionales se pueden superar por combinar dos técnicas sensibles a fenómenos de superficie: la microbalanza de cristal de cuarzo con monitorización de la disipación (QCM-D) y la resonancia de plasmones superficiales multi-paramétrica (MP-SPR). Se pudo demostrar con éxito que la combinación QCM-D/MP-SPR permite caracterizar la acumulación de incluso las primeras capas de fouling a nivel nanométrico y por lo tanto, posee una sensibilidad lo suficientemente grande como para anticipar la necesidad de limpiar las membranas antes de que el flujo de agua del permeado disminuya. Estos métodos además permitieron testar diferentes estrategias de limpieza de membranas de forma eficiente tanto en términos de tiempo como de material. Finalmente, la tesis discute críticamente la aplicabilidad de un dispositivo basado en estas técnicas en un entorno industrial relevante.

152 p., Water, the most abundant molecule in our planet, is truly and empirically accepted as an essential component to sustain life on Earth. The extraordinary properties of this unique and universal "matrix of life" have served over this quarter century, as the driving force -for theoreticians and experimentalists- to perform novel research on the structural basis and molecular dynamics taking place in very different environments. Even today, scientists are still discovering new phenomena in water, especially at the nanoscale.When referred to bio-systems, water is usually seen as the liquid environment -or "matrix"- where physical and chemical processes take place. Here, the molecules of life are thought of being wet - this is, completely immersed in liquid water or, in other words, in fully hydrated conditions. While this is true for most living cells, a surprising number of processes require merely traces of water, which could be vapor or a layer as thin as nanometers. Indeed, this is observed in situations in which, because of extremes of either heat or cold, liquid water is scarce. Here, the hydration layer of the molecules - understood as an entity that differs from bulk water - should confer certain stability to keep the biomolecules still functional; and the processes taking place at the air interface should play a prominent role.In this direction, the transmission of many airborne viruses - through respiratory droplets (e.g. aerosols) - requires, actually, survival in dry conditions. Influenza A virus (IAV), is one of the best-known cases, for which the transmission and thus survival is tightly connected to seasonal factors. Seasonal epidemics generally occur during winter, when air temperature and humidity are low. Under these conditions, the respiratory droplets must confer some structural stability to the contained viruses; membrane collapse, for example, should be in principle avoided. However, this assumption is yet poorly understood and experimental data bas

Functional inks for light-based 3D printing are actively being searched for being able to exploit all the potentialities of additive manufacturing. Herein, a fast visible-light photopolymerization process is showed of conductive PEDOT:PSS hydrogels. For this purpose, a new Type II photoinitiator system (PIS) based on riboflavin (Rf), triethanolamine (TEA), and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated for the visible light photopolymerization of acrylic monomers. PEDOT:PSS has a dual role by accelerating the photoinitiation process and providing conductivity to the obtained hydrogels. Using this PIS, full monomer conversion is achieved in less than 2 min using visible light. First, the PIS mechanism is studied, proposing that electron transfer between the triplet excited state of the dye (3Rf*) and the amine (TEA) is catalyzed by PEDOT:PSS. Second, a series of poly(2-hydroxyethyl acrylate)/PEDOT:PSS hydrogels with different compositions are obtained by photopolymerization. The presence of PEDOT:PSS negatively influences the swelling properties of hydrogels, but significantly increases its mechanical modulus and electrical properties. The new PIS is also tested for 3D printing in a commercially available Digital Light Processing (DLP) 3D printer (405 nm wavelength), obtaining high resolution and 500 µm hole size conductive scaffolds.

Waterborne polyurethane dispersions (WPUs) are environmentally friendly coatings since they present low amount of volatile organic compound amounts (VOCs). In the majority of the WPUs the dispersions are balanced with anionic groups and accordingly their stability at low pH is limited. In order to this drawback to be solved, in this work a tertiary amine containing chain extender (triethanolamine, TEOA) was introduced together with a conventional internal emulsifier (carboxylic acid) in acrylic end-capped polyurethane dispersions giving rise to amphoteric UV curable WPUs. After adding a radical photo-initiator and film formation, the coatings were cured under UV irradiation. The properties of amphoteric and anionic dispersions were compared. The best properties were obtained for the samples containing a 1/1 amine/acid molar ratio. Thus, while the anionic dispersions coagulated at low pH values, the 1/1 amphoteric dispersion showed high stability to pH changes. After curing this sample with UV irradiation, the gel content of the film was higher and the water vapour transmission rate was lower than that of the anionic polyurethane because of the strong acid/base interaction. The results showed that the amphoteric WPUs are promising for various applications, offering stability over a wider pH range than traditional formulations.

We reveal the feasibility of the localized surface plasmon resonance in a system of Bi nanoparticles embedded into an AlxGa1−xAs semiconductor matrix. With an ab initio determined dielectric function for bismuth and well-known dielectric properties of AlxGa1−xAs solid solution, we performed calculations of the optical extinction spectra for such metamaterial using Mie’s theory. The calculations demonstrate a strong band of the optical extinction using the localized surface plasmons near a photon energy of 2.5 eV. For the semiconducting matrices with a high aluminum content x > 0.7, the extinction by plasmonic nanoparticles plays the dominant role in the optical properties of the medium near the resonance photon energy

New material solutions are searched for the manufacturing and safety of current batteries. Herein, an extrusion printable polymer separator for lithium batteries based on single-ion polymer electrolytes is presented. The polymer electrolytes are based on methacrylic polymeric nanoparticles (NPs) functionalized with a lithium sulfonamide group combined with different organic plasticizers such as sulfolane and carbonates. The synthesis of the polymer NPs is carried out by emulsion copolymerization of methyl methacrylate and lithium sulfonamide methacrylate in the presence of a crosslinker, resulting in particle sizes of less than 30 nm, as shown by electron microscopy. Then polymer electrolytes are prepared by mixing polymer NPs with varying lithium sulfonamide content and different plasticizers such as carbonates and sulfolane. The polymer electrolytes show ionic conductivities between 2.9 × 10−4 and 2.3 × 10−5 S cm−1 at 85 °C with the highest values for the small-sized NPs with the highest lithium content. As a proof-of-concept application, layer-by-layer printing of a sulfolane-based polymer electrolyte is evaluated via direct ink writing directly onto classic battery electrodes. The electrochemical characterization of the printed solid electrolyte indicates favorable properties, ionic conductivity, lithium transfer number, electrochemical stability window, and cyclability in lithium symmetrical cells, to be used in lithium batteries.

Despite the increasing availability of genomic data and enhanced data analysis procedures, predicting the severity of associated diseases remains elusive in the absence of clinical descriptors. To address this challenge, we have focused on the KV7.2 voltage-gated potassium channel gene (KCNQ2), known for its link to developmental delays and various epilepsies, including self-limited benign familial neonatal epilepsy and epileptic encephalopathy. Genome-wide tools often exhibit a tendency to overestimate deleterious mutations, frequently overlooking tolerated variants, and lack the capacity to discriminate variant severity. This study introduces a novel approach by evaluating multiple machine learning (ML) protocols and descriptors. The combination of genomic information with a novel Variant Frequency Index (VFI) builds a robust foundation for constructing reliable gene-specific ML models. The ensemble model, MLe-KCNQ2, formed through logistic regression, support vector machine, random forest and gradient boosting algorithms, achieves specificity and sensitivity values surpassing 0.95 (AUC-ROC > 0.98). The ensemble MLe-KCNQ2 model also categorizes pathogenic mutations as benign or severe, with an area under the receiver operating characteristic curve (AUC-ROC) above 0.67. This study not only presents a transferable methodology for accurately classifying KCNQ2 missense variants, but also provides valuable insights for clinical counseling and aids in the determination of variant severity. The research context emphasizes the necessity of precise variant classification, especially for genes like KCNQ2, contributing to the broader understanding of gene-specific challenges in the field of genomic research. The MLe-KCNQ2 model stands as a promising tool for enhancing clinical decision making and prognosis in the realm of KCNQ2-related pathologies.

Because the electronic properties of semiconducting polymers are inexorably linked to their solid-state microstructure, it is imperative to understand their complex crystallization processes fully. For example, poly(2,5-bis(3-alkylthiophen-2-yl)-thieno-[3,2-b]thiophene) (PBTTT), which is frequently considered a model system for highly ordered semicrystalline semiconducting polymers, can exhibit two distinct semi-crystalline thin film morphologies: the so-called terrace-phase, which features high charge carrier mobility (>1 cm2 V−1 s−1), and the ribbon-phase with much poorer properties. The achievement of one or the other depends on the temperature at which the polymer is thermally annealed. Our results evidence that PBTTT is in the liquid state at those “annealing temperatures” and, therefore, the achievement of the terrace- or ribbon phases depends, in fact, on the distinct structural configuration of liquid PBTTT chains at each temperature (before crystallization). Motivated by this observation, we investigate the complex crystallization kinetics of spun cast PBTTT thin films crystallized from those liquid states. We achieve this using a methodology that combines fast scanning calorimetry, X-ray scattering, and optical microscopy. We demonstrate that a preexisting smectic order enhances crystal nucleation rate, speeding up the crystallization kinetics at the early stages of phase transformation. More interestingly, our analysis reveals a complex crystallization kinetics in PBTTT, which differs from the typical crystallization behavior of commodity polymers. These results evidence that the crystallization of semiconducting polymers occurs quite differently to that of most commodity polymers, highlighting (once again) the necessity to conduct more fundamental investigations on the structure development of this important class of polymers.

Thermally activated delayed fluorescence (TADF) has emerged as one of the most promising strategies in the quest for organic light emitting diodes with optimal performance. This computational study dissects the mechanistic intricacies of the central photophysical step, reverse intersystem crossing (rISC) in N and B doped triangulenes as potential multi-resonance TADF compounds. Optimal molecular patterns conducive to efficient rISC, encompassing dopant atom size, number, and distribution, are identified. Additionally, we assess various electronic structure methods for characterizing TADF-relevant molecular systems. The findings identify the distinct role of the direct and mediated mechanisms in rISC, and provide insights into the design of advanced TADF chromophores for next-generation OLED technology.

180 p., Esta tesis se centra en el estudio de materiales ferromagnéticos bidimensionales. En concreto, en las aleaciones superficiales de Tierra Rara (RE) y Metal Noble (NM) y su interacción con monocapas (ML) de moléculas magnéticas. Las aleaciones superficiales de Tierra Rara (RE) y Metal Noble (NM) se han producido mediante la evaporación de RE sobre las superficies Au(111) y Ag(111). Posteriormente se han evaporado térmicamente las monocapas de CuPc y TbPc2. Su estructura tanto de las aleaciones superficiales como de las monocapas depositadas encima se ha estudiado mediante microscopia de efecto túnel (STM) y difracción de electrones de baja energía (LEED). La estructura electrónica tanto de las aleaciones superficiales como las capas de moléculas se ha estudiado mediante varias variante de photoemisión (PES): de rayos-X (XPS) resonante (res-PES) y resuelta en angulo (ARPES). El comportamiento magnético de las aleaciones se ha estudiado mediante dicroísmo magnético de Rayos X (XMCD). También se ha usado XMCD para el estudio del acoplo magnético entre las moléculas y las aleaciones superficiales

Solid polymer electrolytes that combine both a high lithium-ion transference number and mechanical properties at high temperatures are searched for improving the performance of batteries. Here, we show a salt-free all-polymer nanocomposite solid electrolyte for lithium metal batteries that improves the mechanical properties and shows a high lithium-ion transference number. For this purpose, lithium sulfonamide-functionalized poly(methyl methacrylate) nanoparticles (LiNPs) of very small size (20–30 nm) were mixed with poly(ethylene oxide) (PEO). The morphology of all-polymer nanocomposites was first investigated by transmission electron microscopy (TEM), showing a good distribution of nanoparticles (NPs) even at high contents (50 LiNP wt %). The crystallinity of PEO was investigated in detail and decreased with the increasing concentration of LiNPs. The highest ionic conductivity value for the PEO 50 wt % LiNP nanocomposite at 80 °C is 1.1 × 10–5 S cm–1, showing a lithium-ion transference number of 0.68. Using dynamic mechanic thermal analysis (DMTA), it was shown that LiNPs strengthen PEO, and a modulus of ≈108 Pa was obtained at 80 °C for the polymer nanocomposite. The nanocomposite solid electrolyte was stable with respect to lithium in a Li||Li symmetrical cell for 1000 h. In addition, in a full solid-state battery using LiFePO4 as the cathode and lithium metal as the anode, a specific capacity of 150 mAhg–1 with a current density of 0.05 mA cm–2 was achieved.

A simple and novel setup for high-frequency dielectric spectroscopy of materials has been developed using a portable vector network analyzer. The measurement principle is based on radio-frequency reflectometry, and both its capabilities and limitations are discussed. The results obtained on a typical liquid crystal prove that the device can provide reliable spectra between 107 Hz and 109 Hz, thus extending the capabilities of conventional impedance analyzers.

This review describes the dynamic phenomena in the atmosphere of Mars that are visible in images taken in the visual range through cloud formation and dust lifting. We describe the properties of atmospheric features traced by aerosols covering a large range of spatial and temporal scales, including dynamical interpretations and modelling when available. We present the areographic distribution and the daily and seasonal cycles of those atmospheric phenomena. We rely primarily on images taken by cameras on Mars Express.

Transitioning to more ambitious electrode formulations facilitates developing high-energy density cells, potentially fulfilling the demands of electric car manufacturers. In this context, the partial replacement of the prevailing anode active material in lithium-ion cells, graphite, with silicon-based materials enhances its capacity. Nevertheless, this requires adapting the rest of the components and harmonizing the electrode integration in the cell to enhance the performance of the resulting high-capacity anodes. Herein, starting from a replacement in the standard graphite anode recipe with 22% silicon suboxide at laboratory scale, the weight fraction of the electrochemically inactive materials was optimized to 2% carbon black/1% dispersant/3% binder combination before deriving an advantage from including single-wall carbon nanotubes in the formulation. In the second part, the recipe was upscaled to a semi-industrial electrode coating and cell assembly line. Then, 1 Ah lithium-ion pouch cells were filled and tested with different commercial electrolytes, aiming at studying the dependency of the Si-based electrodes on the additives included in the composition. Among all the electrolytes employed, the EL2 excelled in terms of capacity retention, obtaining a 48% increase in the number of cycles compared to the baseline electrolyte formulation above the threshold capacity retention value (80% state of health).

425 p., Las tecnologías de fabricación han sido transformadas por los avances en la fabricación aditiva. Esta técnica revolucionaria minimiza el desperdicio, permite la producción de estructuras complejas y producción a medida. Esto mejora la eficiencia de recursos, reduce el inventario excesivo y promueve la sostenibilidad. Sin embargo, la fabricación aditiva basada en luz se enfrenta un desafío importante debido a la baja degradabilidad y reciclabilidad de los materiales utilizados en la fotopolimerización.Abordar este problema implica diversificar los materiales y formulaciones fotopolimerizables, el cual a sido el enfoque central de este estudio. En este sentido, se han introducido estrategias no radicalarias para la preparación de materiales poliméricos por medio de irradiación de luz con degradabilidad y reciclabilidad mejorada. Por ello, este trabajo incluye el estudio de varios de estos sistemas y su implementación en fotoimpresión en tanque exponiendo los limites y virtudes de los sistemas reportados.

Metalloenzymes are able to catalyze complex biochemical reactions in cellular (aqueous) media with high efficiency. In recent years, a variety of metal-containing single-chain nanoparticles (SCNPs) have been synthesized as simplified metalloenzyme-mimetic nano-objects. However, most of the metal-containing SCNPs reported so far contained complexed metal ions but not metal nanoclusters (NCs) with diameter <5 nm, which could be used as powerful, emerging catalysts. Herein, we report the synthesis of gold nanoclusters (Au-NCs) within SCNPs and the further use of Au-NCs/SCNPs as catalytic nanoreactors in water. We demonstrate that a common motif contained in several drugs (i.e., the aminophenyl–oxazolidinone fragment present in Rivaroxaban, Sutezolid, and Linezolid) can be efficiently prepared in water from a hydrophobic precursor compound by using the Au-NCs/SCNPs as efficient catalytic nanoreactors. In summary, this work paves the way forthe synthesis of metal–NCs/SCNPs for advanced catalysis in aqueous media.

The non-destructive detection of defects in materials, such as cracks, delaminations and others, is a critical issue to be addressed in many technological applications like automotive, aeronautical or aerospace industries. In this frame, lock-in infrared thermography is identified as a highly suitable solution offering not only a qualitative detection of the defects but also their quantitative characterization. With the goal of maximizing its capabilities on the crack detection and characterization, in this work, a dimensionless numerical global sensitivity analysis of the lock-in infrared thermography is developed. First, a complete dimensionless reformulation of the thermographic investigation is provided, not only limited to the defect geometrical parameters, but also including the corresponding experimental parameters. As a consequence, the constraints of particular experimental setups or material properties can be removed by means of an appropriate choice of length, time and temperature scales. This leads to a set of dimensionless parameters and equations which preserve the full physical information of the experiment. The resulting model has been numerically solved and successfully validated by using experimental thermographic data over laboratory calibrated cracked material samples. Second, the developed dimensionless numerical model has been used as input for a global sensitivity analysis able to determine the correlations between the proposed dimensionless parameters and their corresponding impact on the thermographic results. Furthermore, the ranges of sensitivity and predominance of each dimensionless parameter are obtained, which provide quantitative parametric selection criteria for a maximized efficiency and accuracy on the thermographic crack detection and characterization.

Article published in Journal of Energy Storage Volume 84, Part B, 20 April 2024, 110675, Addition of different types of phase change materials (PCMs) to cement-based materials for thermal energy storage has been broadly investigated in the literature. Many studies have researched the addition of organic PCMs and the thermal performance of the PCM-cement system. However, drawbacks such as leakage and poor thermal conductivity of the PCMs have stimulated studies to improve thermal properties within the PCM-cement system. Among the different solutions, addition of carbonous materials (such as graphite and carbon nanotubes) to improve thermal conductivity of the PCMs have been investigated. In the current work, an innovative system that contains microencapsulated PCMs (MPCMs) and purposely synthesized reduced graphene oxide (rGO) has been designed and assessed. The addition of rGO has two aims. The first one is to speed up the heat storage/release velocity by improving the thermal conductivity of the whole system. The second one is to improve the electrical conductivity of the system in order to actively (by applying voltage) be able to turn on the thermal storage/release feature. Up to the authors' knowledge, this is a novel approach for the development of active PCM-cement based thermal energy storage systems. Furthermore, in the present study, the use of paraffinic PCMs was compared with that of biobased PCMs in order to provide a more sustainable solution to the design of cement-based elements for buildings applications. A comprehensive thermal characterization (heat storage capacity, thermal conductivity and diffusivity) has been carried out as well as microstructural characterization. Moreover, broadband dielectric spectroscopy was used to characterize the electrical conductivity of the novel MPCM-rGO-cement system.

Topologically non-trivial magnetization configurations in ferromagnetic materials on the nanoscale, such as hopfions, skyrmions, and vortices, have attracted considerable attention of researchers during the last few years. In this article, by applying the theory of micromagnetism, I demonstrate that the toroidal hopfion magnetization configuration is a metastable state of a thick cylindrical ferromagnetic nanodot or a nanowire of a finite radius. The existence of this state is a result of the competition among exchange, magnetostatic, and magnetic anisotropy energies. The Dzyaloshinskii–Moriya exchange interaction and surface magnetic anisotropy are of second importance for the hopfion stabilization. The toroidal hopfion metastable magnetization configuration may be reached in the process of remagnetizing the sample by applying an external magnetic field along the cylindrical axis.

Eisenbud–Wigner–Smith delay and the Larmor time give different estimates for the duration of a quantum scattering event. The difference is most pronounced in the case where the de Broglie wavelength is large compared to the size of the scatterer. We use the methods of quantum measurement theory to analyse both approaches and to decide which one of them, if any, describes the duration a particle spends in the region that contains the scattering potential. The cases of transmission, reflection, and three-dimensional elastic scattering are discussed in some detail.

The primary challenge in the field of high-temperature superconductivity in hydrides is to achieve a superconducting state at ambient pressure rather than the extreme pressures that have been required in experiments so far. Here, we propose a family of compounds, of composition Mg2XH6 with X = Rh, Ir, Pd, or Pt, that achieves this goal. These materials were identified by scrutinizing more than a million compounds using a machine-learning accelerated high-throughput workflow. We predict that their superconducting transition temperatures are in the range of 45–80 K, or even above 100 K with appropriate electron doping of the Pt compound. These results indicate that, although very rare, high-temperature superconductivity in hydrides is achievable at room pressure.

We studied Ni2FeSi-, Co2FeSi-, and Co2MnSi-based full-Heusler alloy glass-coated microwires with the same geometric parameters, i.e., fixed nucleus and total diameters, prepared using the Taylor–Ulitovsky method. The fabrication of X2YZ (X = Co and Ni, Y = Fe and Mn, and Z = Si)-based glass-coated microwires with fixed geometric parameters is quite challenging due to the different sample preparation conditions. The XRD analysis showed a nanocrystalline microstructure for all the samples. The space groups Fm3¯m (FCC) and Im3¯m (BCC) with disordered B2 and A2 types are observed for Ni2FeSi and Co2FeSi, respectively. Meanwhile, a well-defined, ordered L21 type was observed for Co2MnSi GCMWs. The change in the positions of Ni, Co and Mn, Fe in X2YSi resulted in a variation in the lattice cell parameters and average grain size of the sample. The room-temperature magnetic behavior showed a dramatic change depending on the chemical composition, where Ni2FeSi MWs showed the highest coercivity (Hc) compared to Co2FeSi and Co2MnSi MWs. The Hc value of Ni2FeSi MWs was 16 times higher than that of Co2MnSi MWs and 3 times higher than that of Co2FeSi MWs. Meanwhile, the highest reduced remanence was reported for Co2FeSi MWs (Mr = 0.92), being about 0.82 and 0.22 for Ni2FeSi and Co2MnSi MWs, respectively. From the analysis of the temperature dependence of the magnetic properties (Hc and Mr) of X2YZ MWs, we deduced that the Hc showed a stable tendency for Co2MnSi and Co2FeSi MWs. Meanwhile, two flipped points were observed for Ni2FeSi MWs, where the behavior of Hc changed with temperature. For Mr, a monotonic increase on decreasing the temperature was observed for Co2FeSi and Ni2FeSi MWs, and it remained roughly stable for Co2MnSi MWs. The thermomagnetic curves at low magnetic field showed irreversible magnetic behavior for Co2MnSi and Co2FeSi MWs and regular ferromagnetic behavior for Ni2FeSi MWs. The current result illustrates the ability to tailor the structure and magnetic beha

As-prepared Fe-rich microwires with perfectly rectangular hysteresis loops present magnetization reversal through fast domain wall propagation, while the giant magnetoimpedance (GMI) effect in Fe-rich microwires is rather low. However, the lower cost of Fe-rich microwires makes them attractive for magnetic sensors applications. We studied the effect of conventional (furnace) annealing and Joule heating on magnetic-propertied domain wall (DW) dynamics and the GMI effect in two Fe microwires with different geometries. We observed that magnetic softness, GMI effect and domain wall (DW) dynamics can be substantially improved by appropriate annealing. Observed experimental results are discussed considering the counterbalance between the internal stresses relaxation and induced magnetic anisotropy associated with the presence of an Oersted magnetic field during Joule heating.

In this article, we study the effect of annealing temperature and applied stress on the magnetic properties of Fe71.80B13.27Si11.02Nb2.99Ni0.92 and Co65.34Si12.00B10.20Cr8.48Fe3.90Mo0.08 microwires. An anomalous behavior of the coercive field is observed while applying stress, indicating nontrivial changes in the microwire magnetic anisotropy. The effect of applied stimuli on the magnetic anisotropy and magnetostriction constant in both microwires is also discussed.

[EN] Hybrid organic-inorganic metal halide perovskites have emerged as promising materials in the development of optoelectronic devices, namely due to their high optical absorption coefficient, tuneable bandgap and charge carrier mobility. However, more efforts are needed to improve their stability against oxygen, moisture and light and find new ways to modulate their optical properties. In this work, we study the photoluminescence properties of lead-bromide-based layered (2D) perovskites with different composition and dimensionality as bulk crystals and mechanically exfoliated flakes. We highlight the tuning of the photoluminescence emission of 2D metal halide perovskites by design and enhance their ambient stability by encapsulating the exfoliated flakes with h-BN flakes. Finally, we carry out the fabrication of heterostructures using as building blocks perovskite flakes showing how to further modulate the photoluminescence emission colour.

Magnetotactic bacteria Magnetospirillum magneticum AMB-1 have been cultured using three different media: magnetic spirillum growth medium with Wolfe’s mineral solution (MSGM + W), magnetic spirillum growth medium without Wolfe’s mineral solution (MSGM – W), and flask standard medium (FSM). The influence of the culture medium on the structural, morphological, and magnetic characteristics of the magnetosome chains biosynthesized by these bacteria has been investigated by using transmission electron microscopy, X-ray absorption spectroscopy, and X-ray magnetic circular dichroism. All bacteria exhibit similar average size for magnetosomes, 40–45 nm, but FSM bacteria present slightly longer subchains. In MSGM + W bacteria, Co2+ ions present in the medium substitute Fe2+ ions in octahedral positions with a total Co doping around 4–5%. In addition, the magnetic response of these bacteria has been thoroughly studied as functions of both the temperature and the applied magnetic field. While MSGM – W and FSM bacteria exhibit similar magnetic behavior, in the case of MSGM + W, the incorporation of the Co ions affects the magnetic response, in particular suppressing the Verwey (∼105 K) and low temperature (∼40 K) transitions and increasing the coercivity and remanence. Moreover, simulations based on a Stoner–Wolhfarth model have allowed us to reproduce the experimentally obtained magnetization versus magnetic field loops, revealing clear changes in different anisotropy contributions for these bacteria depending on the employed culture medium. Finally, we have related how these magnetic changes affect their heating efficiency by using AC magnetometric measurements. The obtained AC hysteresis loops, measured with an AC magnetic field amplitude of up to 90 mT and a frequency, f, of 149 kHz, reveal the influence of the culture medium on the heating properties of these bacteria: below 35 mT, MSGM – W bacteria are the best heating mediators, but above 60 mT, FSM and MSGM + W bacteria

Magnetic hybrid metal–organic interfaces possess a great potential in areas such as organic spintronics and quantum information processing. However, tuning their carrier injection barriers on-demand is fundamental for the implementation in technological devices. We have prepared hybrid metal–organic interfaces by the adsorption of copper phthalocyanine CuPc on REAu2 surfaces (RE = Gd, Ho and Yb) and studied their growth, electrostatics and electronic structure. CuPc exhibits a long-range commensurability and a vacuum level pinning of the molecular energy levels. We observe a significant effect of the RE valence of the substrate on the carrier injection barrier of the hybrid metal–organic interface. CuPc adsorbed on trivalent RE-based surfaces (HoAu2 and GdAu2) exhibits molecular level energies that may allow injection carriers significantly closer to an ambipolar injection behavior than in the divalent case (YbAu2).

We studied the magnetic properties of a glass-covered amorphous microwire that was stress-annealed at temperatures distributed along the microwire length. The Sixtus-Tonks, Kerr effect microscopy and magnetic impedance techniques have been applied. There was a transformation of the magnetic structure across the zones subjected to annealing at different temperatures. The annealing temperature distribution induces the graded magnetic anisotropy in the studied sample. The variety of the surface domain structures depending on the longitudinal location has been discovered. Spiral, circular, curved, elliptic and longitudinal domain structures coexist and replace each other in the process of magnetization reversal. The analysis of the obtained results was carried out based on the calculations of the magnetic structure, assuming the distribution of internal stresses.

The influence of Joule heating on magnetic properties, giant magnetoimpedance (GMI) effect and domain wall (DW) dynamics of Fe75B9Si12C4 glass-coated microwires was studied. A remarkable (up to an order of magnitude) increase in GMI ratio is observed in Joule heated samples in the frequency range from 10 MHz to 1 GHz. In particular, an increase in GMI ratio, from 10% up to 140% at 200 MHz is observed in Joule heated samples. Hysteresis loops of annealed samples maintain a rectangular shape, while a slight decrease in coercivity from 93 A/m to 77 A/m, after treatment, is observed. On the other hand, a modification of MOKE hysteresis loops is observed upon Joule heating. Additionally, an improvement in DW dynamics after Joule heating is documented, achieving DW propagation velocities of up to 700 m/s. GMI ratio improvement along with the change in MOKE loops and DW dynamics improvement have been discussed considering magnetic anisotropy induced by Oersted magnetic fields in the surface layer during Joule heating and internal stress relaxation. A substantial GMI ratio improvement observed in Fe-rich Joule-heated microwires with a rectangular hysteresis loop and fast DW propagation, together with the fact that Fe is a more common and less expensive metal than Co, make them suitable for use in magnetic sensors.

Amorphous magnetic microwires can be suitable for a variety of technological applications due to their excellent magnetic softness and giant magnetoimpedance (GMI) effect. Several approaches for optimization of soft magnetic properties and GMI effect of magnetic microwires covered with an insulating, flexible, and biocompatible glass coating with tunable magnetic properties are overviewed. The high GMI effect and soft magnetic properties, achieved even in as-prepared Co-rich microwires with a vanishing magnetostriction coefficient, can be further improved by appropriate heat treatment (including stress-annealing and Joule heating). Although as-prepared Fe-rich amorphous microwires exhibit low GMI ratio and rectangular hysteresis loops, stress-annealing, Joule heating, and combined stress-annealed followed by conventional furnace annealing can substantially improve the GMI effect (by more than an order of magnitude).

[EN] In intermetallic compounds with zero orbital momentum (L = 0) the magnetic anisotropy and the electronic band structure are interconnected. Here, we investigate this connection in divalent Eu and trivalent Gd intermetallic compounds. We find by x-ray magnetic circular dichroism an out-of-plane easy magnetization axis in two-dimensional atom-thick EuAu2. Angle-resolved photoemission spectroscopy and density-functional theory prove that this is due to strong f-d band hybridization and Eu2+ valence. In contrast, the easy in-plane magnetization of the structurally equivalent GdAu2 is ruled by spin-orbit-split d bands, notably Weyl nodal lines, occupied in the Gd3+ state. Regardless of the L value, we predict a similar itinerant electron contribution to the anisotropy of analogous compounds.

[EN] We report on the influence of graded magnetic anisotropy designed by stress-annealing of magnetic microwire at variable annealing temperature on domain wall propagation. We found that the domain wall propagation in a medium with graded magnetic anisotropy is substantially nonuniform. Domain wall can be trapped in the microwire region with strong enough stress-annealing induced magnetic anisotropy. On the other hand, faster domain wall propagation and a decrease in the domain wall length are observed in the region with moderate stress-annealing induced magnetic anisotropy. Beneficial effect of stress annealing on the domain wall dynamics is associated with the induced transverse magnetic anisotropy in the outer domain which affects the travelling domain wall in a similar way as application of transversal bias magnetic field. Observed decreasing of the half-width of the electromagnetic force (EMF) peak in stress-annealed microwires can be associated to the decreasing of the characteristic domain wall length.

The present work reports on a detailed discussion about the synthesis, characterization, and luminescence properties of three pairs of enantiopure 3D metal–organic frameworks (MOFs) with general formula {[Ln2(L/D-tart)3(H2O)2]·3H2O}n (3D_Ln-L/D, where Ln = Sm(III), Eu(III) or Gd(III), and L/D-tart = L- or D-tartrate), and ten pairs of enantiopure 2D coordination polymers (CPs) with general formula [Ln(L/D-Htart)2(OH)(H2O)2]n (2D_Ln-L/D, where Ln = Y(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III) or Yb(III), and L/D-Htart = hydrogen L- or D-tartrate) based on single-crystal X-ray structures. Enantiopure nature of the samples has been further corroborated by Root Mean Square Deviation (RMSD) as well as by circular dichroism (CD) spectra. Solid-state emission spectra of Eu(III), Tb(III), and Dy(III)-based compounds confirm the occurrence of ligand-to-metal charge transfers in view of the characteristic emissions for these lanthanide ions, and emission decay curves were also recorded to estimate the emission lifetimes for the reported compounds. A complete theoretical study was accomplished to better understand the energy transfers occurring in the Eu-based counterparts, which allows for explaining the different performances of 3D-MOFs and 2D-layered compounds. As inferred from the colorimetric diagrams, emission characteristics of Eu-based 2D CPs depend on the temperature, so their luminescent thermometry has been determined on the basis of a ratiometric analysis between the ligand-centered and Eu-centered emission. Finally, a detailed study of the polarized luminescence intensity emitted by the samples is also accomplished to support the occurrence of chiro-optical activity.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) is a bio-based polyester with the potential to replace some common polymers of fossil origin. However, PHBH presents serious limitations, such as low stiffness, tendency to undergo crystallization over long time periods and low resistance to thermal degradation during processing. In this work, we studied the use of alumina nanowires to generate PHBH–alumina nanocomposites, modifying the properties of PHBH to improve its usability. Solvent casting and melt blending were used to produce the nanocomposites. Then, their physicochemical properties and aquatic toxicity were measured. Finally, LCA was used to evaluate and compare the environmental impacts of several scenarios relevant to the processing and end of life (EoL) conditions of PHBHs. It was observed that, at low concentrations (3 wt.%), the alumina nanowires have a small positive impact on the stiffness and thermal degradation for the samples. However, for higher concentrations, the observed effects differed for each of the applied processing techniques (solvent casting or melt blending). The toxicity measurements showed that PHBH alone and in combination with alumina nanowires (10 wt.%) did not produce any impact on the survival of brine shrimp larvae after 24 and 48 h of exposure. The 18 impact categories evaluated by LCA allowed defining the most environmentally friendly conditions for the processing and EoL of PHBHs, and comparing the PHBH-related impacts to those of some of the most common fossil-based plastics. It was concluded that the preferable processing technique for PHBH is melt blending and that PHBH is unquestionably more environmentally friendly than every other analyzed plastic.

88 p. Los capítulos 3,4,5,6 y 7 están sujetos a confidencialidad por parte de la autora, Las aleaciones con memoria de forma (SMA: Shape Memory Alloys) presentan unatransformación martensítica termoelástica que les confiere las propiedades de Memoria deForma (MF) y efecto superelástico (ES). Esta transformación es reversible y se define porcuatro temperaturas: Ms (martensite start) y Mf (martensite finish) durante el enfriamiento, y As(austenite start) y Af (austenite finish) durante el calentamiento. Estas propiedades pueden serutilizadas para generar una fuerza o movimiento (MF) y almacenar energía (ES) razones por lascuales las SMAs son denominadas materiales inteligentes. Hasta ahora se ha prestado muy pocaatención al desarrollo de SMAs con muy bajas temperaturas de transformación que permitanexplotar sus potenciales aplicaciones a temperaturas criogénicas. Es por ello, que a partir delconocimiento de las aleaciones de Cu-Al-Ni y Cu-Al-Be se ha elaborado una nueva familia dealeaciones cuaternaria de Cu-Al-Ni-Be y posteriormente sus correspondientes monocristalesque transforman hasta por debajo del nitrógeno líquido. A continuación se han caracterizado suspropiedades térmicas a partir de ensayos de DSC y resistividad a bajas temperaturas, técnicaque ha sido desarrollada en el marco de este trabajo. Las propiedades mecánicas se hancaracterizado mediante ensayos de deformación bajo carga y superelásticos. Por último, se harealizado la caracterización microestructural mediante ensayos de calentamiento-enfriamientoin-situ en el microscopio óptico y en el microscopio eléctronico de barrido.

257 p., The chemistry of the lithium salt employed plays a pivotal role in dictating the physico-chemical and electrochemical performance of any solid polymer electrolytes (SPEs), and thus also influences the performance of solid-state lithium metal batteries (SSLMBs). The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, first suggested as salt for SPEs in 1986, possesses low lattice energy and the TFSI' anion has a large structural flexibility, both due to the anion¿s highly delocalized negative charge and flexible center [e.g., ¿SO2¿N(¿)¿SO2¿] and has therefore been commonly used for SPE-based SSLMBs. However, low lithium-ion transference number (TLi+) and poor solid electrolyte interphase (SEI) creating properties, resulting in severe cell polarization and simultaneously notorious dendritic growth on the Li° anode. Therefore, in this thesis, several novel lithium salts were designed and synthesized to suppress anionic mobility and enhance TLi+, but without sacrificing significantly the ionic conductivity, and simultaneously with the aim of forming excellent SEI layers on the Li° anode to improve interfacial compatibility and stability towards Li° anode.

Capítuldo 5 confidencial pendiente de patente. Tesis completa 159 p. Tesis censurada 143, [ES]Las superficies expuestas al ambiente presentan una gran tendencia a atraer suciedad. Teniendo en cuenta que son éstas las que definen la mayor parte de las propiedades de los materiales, tanto la presencia como la acumulación de suciedad suponen un impacto negativo en numerosas aplicaciones ya que pueden generar importantes riesgos para la seguridad y la salud, así como, afectar negativamente al rendimiento, requiriendo costosas operaciones de mantenimiento. En los últimos años, la industria ha mostrado un gran interés en el desarrollo de soluciones capaces de preservar limpias las superficies. Tradicionalmente, las superficies repelentes se han obtenido mediante el efecto de la superhidrofobicidad. Sin embargo, su ineficacia para repeler líquidos de baja energía superficial y la fragilidad de ciertas micro/nanoestructuras necesarias pueden limitar su aplicación. En este contexto, el desarrollo de recubrimientos omnifóbicos de baja adhesión puede aportar numerosos beneficios en distintas aplicaciones de sectores muy diversos. Esta tesis persigue desarrollar nuevas estrategias para la obtención de superficies repelentes, focalizando el trabajo en alcanzar soluciones robustas con buenas prestaciones de durabilidad que sean capaces de responder a varias fuentes de contaminación simultáneamente. Para ello, el potencial que ofrece la nanotecnología se utiliza desde dos aproximaciones diferentes: a través de la estructuración superficial ymediante la incorporación de nanoobjetos como vectores para introducir nuevas funcionalidades, siendo el objetivo final desarrollar superficies omnifóbicas con propiedades diseñadas a medida que den respuesta a las necesidades de la industria.

150 p., Esta tesis se focaliza en el estudio del transporte eléctrico y térmico debido a electrones en el estado estacionario mediante la Teoría Funcional de la Densidad (DFT) desde un punto de vista teórico. Por un lado el estudio se centra en el desarrollo de un marco teórico (iq-DFT) el cual permite describir correctamente no solo la densidad, si no también la corriente eléctrica y la corriente de calor. Además, diferentes cantidades físicas como los coeficientes de transporte o la función espectral fuera del equilibrio se derivan de manera teórica en el formalismo propuesto. Por otro lado, esta tesis focaliza el estudio en sistemas fuertemente correlacionados. Generalmente, se ha considerado que estos sistemas no pueden ser correctamente descritos mediante DFT. En la presente tesis se estudian y construyen funcionales de intercambio y correlación de sistemas modelos Hamiltonianos que permiten describir correctamente el régimen de fuerte correlación.

Los capítulos: resumen, capítulo 4 y conclusiones están sujetos a confidencialidad por la autora. 277 p.