El éxito de la fecundación humana depende, entre otros eventos moleculares, de la capacidad de los espermatozoides para llevar a cabo de forma adecuada la capacitación. Este proceso implica una serie de cambios bioquímicos en los espermatozoides para favorecer su interacción con el gameto femenino. Aunque es posible capacitar las células in vitro, el tiempo óptimo para que un espermatozoide complete la capacitación en estas condiciones sigue siendo objeto de debate debido a la falta de biomarcadores de capacitación adecuados. Los estudios en esta área, se han centrado en aquellos receptores espermáticos implicados en la interacción entre gametos. En particular, el complejo molecular formado por la proteína de choque térmico A2 (HSPA2; del inglés heat shock protein A2), la molécula de adhesión a hialuronidasa 1 (SPAM1; del inglés sperm adhesion molecule 1) y la proteína arilsulfatasa A (ARSA; del inglés arylsulfatase A), ha sido estudiado por varios grupos de investigación debido a su participación en el reconocimiento del ovocito por parte del espermatozoide. Los estudios más relevantes sobre la ubicación de este complejo se basan en la evidencia de la colocalización de estas proteínas en la región periacrosomal de la cabeza espermática. Sin embargo,Esta premisa es controvertida, ya que otros autores han encontrado una asociación entre diferentes áreas de distribución de HSPA2 en la cabeza del espermatozoide y la fertilidad. A pesar del importante papel que desempeña este complejo proteico durante la unión del espermatozoide a la zona pelúcida del ovocito (ZP), aún no se ha ilustrado el grado de dependencia del tiempo de capacitación sobre la presencia y distribución de una topografía específica en la superficie espermática de estas proteínas. Con esta premisa, en la presente tesis evaluamos la influencia del tiempo de capacitación in vitro en la localización y distribución de HSPA2 y ARSA en la cabeza de espermatozoides humanos. De esta manera, y mediante microscopía de fluorescencia, se evaluó la presencia de HSPA2 y ARSA en donantes normozoospérmicos2 tanto antes como tras la capacitación in vitro durante una y cuatro horas. Además, se utilizó la microscopía electrónica de campo de alta resolución (FE-SEM; microscopía electrónica de barrido de emisión de campo; del inglés field emission scanning electron microscopy) para cuantificar la densidad de ARSA y la localización específica de esta proteína en los diferentes dominios de la membrana espermática antes y después de la capacitación in vitro durante una y cuatro horas. Con respecto al porcentaje de células positivas para HSPA2, no se observaron diferencias significativas entre las poblaciones analizadas antes y después de una hora de capacitación. No obstante, observamos un porcentaje significativamente mayor de células marcadas con HSPA2 tras cuatro horas de capacitación in vitro. A pesar de que no se pudo determinar un patrón de distribución de HSPA2 predominante en las células que fueron positivas antes de la capacitación, el patrón de distribución mayoritario después de la capacitación fue de fluorescencia en la banda ecuatorial y el acrosoma. Al estudiar la distribución de ARSA se observó un aumento significativo en el porcentaje de células positivas para esta proteína tras la capacitación, pero sin diferencias entre una y cuatro horas de incubación. Al igual que ocurría con HSPA2, el análisis mediante microscopía de fluorescencia no mostró un patrón mayoritario de distribución de ARSA en la subpoblación espermática previa a la capacitación, mientras que, tras este proceso las células presentaron de manera predominante un marcaje intenso en la región acrosomal. Por otra parte, el análisis mediante microscopía electrónica de barrido de emisión de campo mostró una agregación de ARSA en la región periacrosomal tras la capacitación. Nuestros resultados apuntan que el complejo formado por HSPA2, ARSA y SPAM1 requiere más de una hora de capacitación in vitro para distribuirse correctamente en la cabeza espermática. Además, el presente estudio proporciona evidencias sólidas de la utilidad de HSPA2 y ARSA como biomarcadores de capacitación, sugiriendo su uso como biomarcadores suplementarios al clásico análisis seminal previo a una técnica de reproducción artificial. / Este trabajo de investigación ha sido subvencionado por la Cátedra Human Fertility de la Universidad de Alicante y los proyectos de I+D+i ViGrob-186 y UAIND17-03.

Atomistic computer simulations were performed using embedded atom method interatomic potentials in α-Fe with impurities and defects. The effects of intergranular carbon on fracture toughness and the mechanisms of fracture were investigated. It was found that as the average grain size changes the dominant energy release mechanism also changes. Because of this the role of the intergranular carbon changes and these mechanisms compete affecting the fracture toughness differently with changing grain size. Grain boundary accommodation mechanisms are seen to be dominant in the fracture of nanocrystalline α-Fe. To supplement this work we investigate grain boundary sliding using the Σ = 5,(310)[001] symmetrical tilt grain boundary. We observe that in this special boundary sliding is governed by grain boundary dislocation activity with Burgers vectors belonging to the DSC lattice. The sliding process was found to occur through the nucleation and glide of partial grain boundary dislocations, with a secondary grain boundary structure playing an important role in the sliding process. Interstitial impurities and vacancies were introduced in the grain boundary to study their role as nucleation sites for the grain boundary dislocations. While vacancies and H interstitials act as preferred nucleation sites, C interstitials do not. / Ph. D.

A system was developed for the controlled expression of genes in Azotobacter vinelandii by using genomic fusions to the sucrose catabolic regulon. This system was used for the functional analysis of the A. vinelandii isc genes, whose products are involved in the maturation of [Fe-S] proteins. For this analysis the scrX gene, contained within the sucrose catabolic regulon, was replaced by the A. vinelandii iscS, iscU, iscA, hscB, hscA, fdx, iscX gene cluster, resulting in duplicate genomic copies of these genes, one whose expression is directed by the normal isc regulatory elements (Pisc) and the other whose expression is directed by the scrX promoter (PscrX). Functional analysis of [Fe-S] protein maturation components was achieved by placing a mutation within a particular Pisc-controlled gene with subsequent repression of the corresponding PscrX-controlled component by growth on glucose as the carbon source. This experimental strategy was used to show that IscS, IscU, HscBA and Fdx are essential in A. vinelandii and that their depletion results in a deficiency in the maturation of aconitase, an enzyme that requires a [4Fe-4S] cluster for its catalytic activity. Depletion of IscA results in null growth only when cells are cultured under conditions of elevated oxygen, marking the first null phenotype associated with the loss of a bacterial IscA-type protein. Furthermore, the null growth phenotype of cells depleted for HscBA could be partially reversed by culturing cells under conditions of low oxygen. These results are interpreted to indicate that HscBA and IscA could have functions related to the protection or repair of the primary IscS/IscU machinery when grown under aerobic conditions. Conserved amino acid residues within IscS, IscU, and IscA that are essential for their respective functions and/or display a partial or complete dominant-negative growth phenotype were also identified using this system. Inactivation of the IscR repressor protein resulted in a slow growth phenotype that could be specifically attributed to the elevated expression of an intact [Fe-S] cluster biosynthetic system. This system was also used to investigate the extent to which the two [Fe-S] biosynthetic systems in A. vinelandii, Nif and Isc, can perform overlapping functions. Under normal laboratory growth conditions, no cross-talk between the two systems could be detected. However, elevated expression of Isc components as a consequence of inactivation of the IscR repressor protein results in a modest ability of the Isc [Fe-S] protein maturation components to replace the function of Nif-specific [Fe-S] protein maturation components. Similarly, when expressed at very high levels the Nif-specific [Fe-S] protein maturation components could functionally replace the Isc components. Oxygen levels were also found to affect the ability of the Nif and Isc systems to perform common functions. Nevertheless, the lack of significant reciprocal cross-talk between the Nif and Isc systems when they are produced only at levels necessary to satisfy their respective physiological functions, indicates a high level of target specificity with respect to [Fe-S] protein maturation. / Ph. D.

This dissertation studies the micromechanical behavior of high-performance carbon fiber-reinforced polymer (CFRP) composites through high-fidelity numerical simulations. We investigated multiple transverse cracking of cross-ply CFRP laminates on the microstructure level through simulating large numerical models. Such an investigation demands an efficient numerical framework along with significant computational power. Hence, an efficient numerical framework was developed for simulating 2-D representations of CFRP composites' microstructure. The framework utilizes a nonlinear interface-enriched generalized finite element method (IGFEM) scheme which significantly decreases the computational cost. The framework was also designed to be fast and memory-efficient to enable simulating large numerical models. By utilizing the developed framework, the impacts of a few parameters on the evolution of transverse crack density in cross-ply CFRP laminates were studied. The considered parameters were characteristics of fiber/matrix cohesive interfaces, matrix stiffness, $0^{circ}$~plies longitudinal stiffness. We also developed a micromechanical framework for efficient and accurate simulation of damage propagation and failure in aligned discontinuous carbon fiber-reinforced composites under loading along the fibers' direction. The framework was validated based on the experimental results of a recently developed 3-D printed aligned discontinuous carbon fiber-reinforced composite as the composite of interest. The framework was then utilized to investigate the impacts of a few parameters of the constitutive equations on the strength and failure pattern of the composites of interest. This dissertation also contributes towards improving the computational efficiency of CFRP composites' simulations. We exhaustively investigated the cause of a convergence difficulty in finite element analyses caused by cohesive zone models (CZMs) which are commonly used to simulate fiber/matrix interfaces in CFRP composites. The CZMs' convergence difficulty significantly increases the computational burden. For the first time, we explained the root of the convergence difficulty and proposed a simple technique to overcome the convergence issue. The proposed technique outperformed the existing methods in terms of accuracy and computational cost. We also proposed a deep learning framework for predicting full-field distributions of mechanical responses in 2-D representations of CFRP composites based on the geometry of the microstructures. The deep learning framework can be used as a surrogate to the expensive and time-consuming finite element simulations. The proposed framework was able to accurately predict the stress distribution at an early stage of damage initiation and the failure pattern in representations of CFRP composites microstructure under transverse tension. / Doctor of Philosophy / Carbon fiber-reinforced polymers (CFRPs) are materials that are lightweight with excellent mechanical performance. Hence, these materials have a wide range of applications in various industries such as aerospace, automotive, and civil engineering. The extensive use of CFRPs has made them an active area of research and there have been great efforts to better understand and improve the mechanical properties of these materials over the past few decades. Therefore, CFRP materials and their manufacturing process are constantly changing and new types of CFRPs are kept being developed. As a result, the mechanical behavior of CFRPs needs to be exhaustively investigated to provide guidelines for their optimal engineering design and indicate the future direction of manufacturing improvements. This dissertation studied the mechanical behavior of CFRPs through high-fidelity simulations. Two types of CFRP were investigated: laminates and 3-D printed CFRPs. Laminates are the most popular type of CFRPs which are commonly used to construct the body of aircraft. 3-D printed CFRPs are new types of material that are gaining traction due to their ability to construct structures with complex geometries at high speed and without direct human supervision. The numerical simulations of CFRPs under mechanical loading are time-consuming and require significant computational power even when run on a supercomputer. Hence, this dissertation also contributes to improving the computational efficiency of numerical simulations. To decrease the computational cost, we proposed a technique that can significantly speed up the numerical simulations of CFRPs. Moreover, we utilized artificial intelligence to develop a new framework that can be substituted for the expensive and time-consuming conventional numerical simulations to quickly predict specific mechanical responses of CFRPs.

The effects of mechanical alloying milling time and carbon concentration on microstructural evolution and hardness of high-carbon Fe-C alloys were investigated. Mechanical alloying and powder metallurgy methods were used to prepare the samples. Mixtures of elemental powders of iron and 1.4, 3, and 6.67 wt.% pre-milled graphite were milled in a SPEX mill with tungsten milling media for up to 100h. The milled powders were then cold-compacted and pressure-less sintered between 900°C and 1200°C for 1h and 5h followed by furnace cooling. Milled powders and sintered samples were characterized using X-ray diffraction, differential scanning calorimetry, Mossbauer spectroscopy, scanning and transmission electron microscopes. Density and micro-hardness were measured. The milled powders and sintered samples were studied as follows: In the milled powders, the formation of Fe_3 C was observed through Mossbauer spectroscopy after 5h of milling and its presence increased with milling time and carbon concentration. The particle size of the milled powders decreased and tended to become more equi-axed after 100h of milling. Micro-hardness of the milled powders drastically increased with milling time as well as carbon concentration. A DSC endothermic peak around 600°C was detected in all milled powders, and its transformation temperature decreased with milling time. In the literature, no explanation was found. In this work, this peak was found to be due to the formation of Fe_3 C phase. A DSC exothermic peak around 300°C was observed in powders milled for 5h and longer; its transformation temperature decreased with milling time. This peak was due to the recrystallization and/or recovery α-Fe and growth of Fe_3 C . In the sintered samples, almost 100% of pearlitic structure was observed in sintered samples prepared from powders milled for 0.5h. The amount of the pearlite decreased with milling time, contrary to what was found in the literature. The decrease in pearlite occurred at the same time as an increase in graphite-rich areas. With milling, carbon tended to form graphite instead of Fe_3 C. Longer milling time facilitated the nucleation of graphite during sintering. High mount of graphite-rich areas were observed in sintered samples prepared from powders milled for 40h and 100h. Nanoparticles of Fe_3 C were observed in a ferrite matrix and the graphite-rich areas in samples prepared from powders milled for 40h and 100h. Micro-hardness of the sintered samples decreased with milling time as Fe_3 C decreased. The green density of compacted milled powders decreased with milling time and the carbon concentration that affected the density of sintered samples. / Ph. D.

New developments often lack regional identity and distinctiveness of place. Before the industrial revolution, landscapes were the result of social, cultural and environmental constraints. Currently, a strong sense of place is lacking in many American cities. Santa Fe, New Mexico, as an example, faces the challenge of integrating new development with existing historic areas. While the downtown central core of Santa Fe has a distinctive and unique character, the outlying fringes of Santa Fe County are being developed in ways that undermine the sense of place that is valued by its residents and visitors. Current county development patterns do not meld with the intimate, small-scale character of the older neighborhoods in the downtown central core areas of the city. To address this issue, this thesis uses theory related to sense of place to identify distinctive characteristics that can be adapted for projects outside Santa Fe's central core. The study uses a mixed method approach, including a literature review and field study methods to assess Santa Fe's distinctive physical characteristics. The results are a set of contemporary community design guidelines for the Santa Fe, New Mexico region that address sense of place in the following categories: (a) Spatial Planning and Architecture: street design characteristics and their physical relationship to architecture; (b) Environmentally Responsive Architecture: architecture design characteristics that respond to the regional environment and Santa Fe Style; (c) Decorative Architectural Details: architectural detail design characteristics that respond to the regional vernacular and the Santa Fe Style; (d) Integration of Architecture and Landscape: open space design the physical relationship between the local landscape and architecture; and, (e) Landscape and Cultural Character: regional landscape and art design characteristics that respond to Santa Fe's environment and culture. The resulting design principles are expressed as guidelines to support sense of place and their application to new development in Santa Fe County. / Master of Landscape Architecture

Carbon fiber reinforced polymers (CFRP), which can be used to strengthen and repair damaged steel structures, have gained popularity in recent years. On the one hand, CFRP has demonstrated substantial advantages over conventional reinforcing techniques like welding and bolting, such as light weight, high strength, and corrosion resistance. Additionally, the CFRP application process is relatively easy, rapid, and labor-intensive. On the other hand, failure is more likely to happen at the bond interface due to the high strength characteristics of steel and CFRP. Thus, studying the bond behavior and failure mechanism of CFRP strengthened steel structures as well as the variables that are crucial to the bond quality. Prior to implementing these elements in an actual construction, it is necessary to thoroughly study the factors affecting this bond strength. Despite the fact that some theoretical predictive modeling for the strength between steel/CFRP joints under various loading situations has been published, in this work, by using finite element modelling, one may compute the failure loads and effective length of the steel/CFRP specimens quickly, simply and accurately. Additionally, factors affecting these parameters are also investigated in this study. / Master of Science / Structural Steel deteriorates over time. Due to this, engineers are constantly on the look-out for cheap and easy ways to repair and maintain these structures. One of the methods is the use of carbon fibred polymer or CFRP. In the literature, it has been frequently documented that CFRPs can make existing structures stronger. Additionally, CFRP has the advantages of not corroding and prevents the structure from becoming significantly heavier. Due to this high strength of CFRP, the failure occurs at the steel-CFRP interface and thus this bond and the factors affecting this bond needs to be studied. One way to do this is experimental testing and another way is finite element modelling which can give you data that is harder to get using experimental testing. Thus, this study focuses on finite element modelling of these joints and how it can be used for studying these joints.

The relationship between social experience and action in the context of recurrent disasters is often thought of in terms of adaptation. This study problematises this assumption from an anthropological perspective by analysing the memoryscape that mediates past experiences of disasters. The inquiry is based on translocal and transtemporal ethnographic fieldwork conducted in 2004-2011 in the flood-prone city of Santa Fe in Argentina. The study examines how past flooding is remembered by flood victims in the middle- and low-income districts and by activists of the protest movement that emerged in the wake of the 2003 flood. It deals with flood memory in the local bureaucracy, in local historiography, myths and popular culture. The analysis reveals that the Santafesinian flood memoryscape is dynamically configured by evocative, reminiscent and commemorative modes of remembering, which are expressed in multiple forms, ranging from memorials and rituals to bureaucratic documents, infrastructure and everyday practices. The study addresses the relationship between memory, morality and social inequality and discusses the implications for questions regarding vulnerability, resilience and adaptation.

Des films et revêtements composés de phases et composés intermétalliques présentent des propriétés et des combinaisons de propriétés attractives qui ne sont que très partiellement explorées aujourd’hui. Ils sont porteurs de solutions potentielles pour conférer à des matériaux avancés des multifonctionnalités nécessaires dans pratiquement toutes les industries manufacturières et deviennent ainsi source de rupture et d’innovation. Cette situation prévaut pour le système Al-Cu-Fe, au sein duquel même les binaires à base d’Al présentent des propriétés remarquables. Si des techniques de dépôt physique en phase vapeur sont le plus souvent utilisées pour l’élaboration de tels films et revêtements métalliques, l’utilisation de procédés de dépôt chimique en phase vapeur à partir de précurseurs métalorganiques (MOCVD) permettrait à terme le traitement et la fonctionnalisation de surfaces de géométrie complexe. Le présent travail s’inscrit dans cette logique. Il vise la mise au point de procédés MOCVD de films d’Al, de Cu et de Fe. Ces procédés doivent être compatibles afin de constituer la base pour l’élaboration de protocoles complexes permettant le codépôt ou le dépôt séquentiel de ces éléments. La MOCVD d’Al à partir de dimethylethyl amine alane (DMEAA) a été adaptée pour satisfaire les contraintes de codépôt, pour valider le dispositif expérimental utilisé pour le dépôt des films unaires et binaires, pour valider certains aspects mécanistiques du dépôt et pour illustrer la capacité de la technique de couvrir de manière conforme des surfaces de géométrie complexe. Le protocole mise au point permet d’opérer à une pression de 10 Torr, dans une fenêtre de températures entre 160 °C et 240 °C. La modélisation du procédé permet son optimisation dans ces conditions, conduisant à des films d’épaisseur uniforme sur une surface de diamètre 58 mm. La microstructure désordonnée des films est améliorée par un prétraitement plasma des substrats d’acier 304L in situ avant dépôt.Le besoin d’utiliser des précurseurs de Cu et de Fe exemptes d’oxygène (en vue d’un codépôt avec Al) a conduit à tester pour ces deux éléments la famille originale des composés moléculaires à base de ligands amidinates. Il est montré que des films purs de Cu sont obtenus entre 200 °C et 350 °C à partir de [Cu(i-Pr-Me-AMD)]2 dans une phase gazeuse riche en hydrogène, la limite entre les régimes cinétique et diffusionnel étant à 240 °C. Le criblage de précurseurs analogues pour Fe a révélé que, dans les mêmes conditions, le composé [Fe(tBu-MeAMD)2] conduit à des films contenant Fe, Fe4N ainsi qu’à des carbures Fe3C et Fe4C.Des bicouches de Cu et Al ont été déposées à partir des protocoles mis au point. Leur recuit post dépôt a été suivi in situ par diffraction de rayons X et par mesure de la résistance électrique. Il a permis de stabiliser des phases θ-Al2Cu, η-AlCu et, pour la première fois reportée dans la littérature, de la phase approximante γ-Al4Cu9. Il a été démontré que la technique MOCVD associée avec des recuits post dépôt est une méthode appropriée pour obtenir des films composés d’alliages intermétalliques. Des dépôts conformes de tels films peuvent ainsi être envisagés pour des nombreuses applications. / Films and coatings intermetallic phases and intermetallic compounds present proprieties and combination of proprieties which are just partially explored today. They carry potential solutions to confer multifunctionality for advanced materials needed by industries and become a source of disruption and innovation. This situation prevails for the Al-Cu-Fe, in which even the binary Al-based exhibit remarkable properties. While techniques of physical vapor deposition are most often used for the development of such films and metallic coatings, the use of processes of chemical vapor deposition from metallorganic precursors (MOCVD) lead to the treatment and functionalization of surfaces with complex geometry. The present work joins in this logic.It aims at the development of MOCVD processes of Al, Cu and Fe films. These processes must be compatible to constitute the base for the elaboration of complex protocols allowing the codeposition or the sequential deposition of these elements. The MOCVD of Al from dimethylethyl amine alane (DMEAA) was adapted to satisfy the constraints of codeposition to validate the experimental device. Used for the deposition of unary and binary films, to validate certain aspects mechanistic of the deposition and to illustrate the capacity of the technique to cover in a shape way surfaces of complex geometry. The protocol development allows to operate at pressure of 10 Torr, in a window of temperatures between 160 °C and 240 °C. The modeling of the process allows its optimization in these conditions, leading to films with uniform thickness. The disorderly microstructure of these films is improved by a plasma pretreatment of the substrate of 304L steel in situ before deposition. The need to use precursors of Cu and Fe-free oxygen (for a co-deposition with Al) has led to testing for these two elements the original family of molecular compounds based ligands AMIDINATES. It is shown that pure Cu films are obtained between 200 ° C and 350 ° C from [Cu (i-Pr-Me-AMD)]2 in a gaseous phase rich in hydrogen, the boundary between the kinetic schemes and diffusion regyme being at 240 ° C. Screening similar to Fe precursors revealed that, under the same conditions, the compound [Fe (tBu-MeAMD)2] leads to films containing Fe, as well as Fe4N carbides Fe3C and Fe4C. Bilayers of Cu and Al were deposited from the protocols developed. Their post deposition annealing was followed by in situ X-ray diffraction and by measuring the electrical resistance. It has stabilized θ-Al2Cu, η-AlCu phases and, for the first time reported in the literature, the approximant phase γ-Al4Cu9. It was demonstrated that the MOCVD technique associated with post-deposition annealing is a suitable method to obtain films composed of intermetallic alloys. Deposits conform such films can thus be considered for many applications.

Master of Science / Department of Agronomy / Dorivar A. Ruiz Diaz Suarez / Soybeans have expanded into Western Kansas during the last 50 years, increasing in area by 14,500%. There are several limitations that come with trying to grow soybeans in this region, including fertility constraints, moisture stress, and improper use of fertilizers. However, the largest constraint at this time seems to be the presence of micronutrient deficiencies, specifically iron. This thesis has an introduction, and three major chapters.The objective of the first study on agronomics was the evaluation of the effect of Fe fertilizer application using foliar and seed-applied methods in combination with variety selection for Fe deficiency management of soybean grown under irrigated conditions in Western Kansas. The second study uses multivariate analysis as an exploratory tool useful in determining simultaneous observation and analysis of more than one variable in a multidimensional space. Factor analysis is used to find underlying factors that one variable alone cannot measure. The objective of this study was to determine the underlying factors and the multi-linear models that are associated with soil parameters that can create Fe chlorosis in the Great Plains. The third study looked at different application rates of seed-applied Fe fertilizer to try and determine the optimum application rate for application of chelated Fe in Western Kansas.