Nous étudions dans ce mémoire de thèse les états diexcités 1po de l'atome d'hélium, situés au voisinage de son seuil de double ionisation (79 eV), atteints par absorption d'un photon. Ces états diexcités sont soit les états du double continuum situés au-dessus du seuil de double ionisation soit les états doublements excités situés en dessous. Ces deux types d'états diexcités sont dégénérés aux états du continuum simple avec ou sans excitation de l'ion résiduel He+ et sont donc fortement couplés à ces derniers. Dans un processus de photoabsorption à un photon, ces états ne peuvent être accessibles que grâce aux corrélations électroniques du système. Le travail que nous avons réalisé s'inscrit dans une démarche qui vise à étudier tous ces états par une seule et même méthode contrairement aux travaux antérieurs où les méthodes se spécialisaient dans le traitement d'un seul type d'état.<br />Nous utilisons pour cela la méthode HRM-SOW (Hyperspherical R-Matrix with Semiclassical Outgoing Waves), initialement dédiée à l'étude du double continuum de He.<br />Dans ce travail, elle est étendue à la description du continuum simple avec ou sans excitation. Ainsi, nous avons pu calculer les sections efficaces de photoionisation simple avec ou sans excitation jusqu'à n=50 de He à 100meV seulement au dessous de son seuil de double ionisation. Une analyse détaillée en ondes partielles a permis de mettre en évidence le rôle des corrélation angulaires et radiales dans les états du simple continuum de He. Nous avons ensuite établi une relation de continuité entre la photoionisation double et la photoionisation simple avec une excitation infinie de l'ion résiduel He+. la méthode HRM-SOW permet également de calculer la section efficace intégrée de double photoionisation avec une grande précision y compris à très basse énergie. Nous l'avons donc appliquée pour différentes énergies de photon au voisinage du seuil afin de tester la loi de seuil de Wannier. Les résultats obtenus sont en accord d'une part avec les prédictions théoriques de Wannier, d'autre part avec les résultats expérimentaux. La méthode HRM-SOW apparaît donc comme une méthode complète au dessus du seuil de double ionisation. <br />Nous avons poursuivi ce travail en amorçant l'étude des états doublement excités autoionisants. Ceux ci se manifestent comme des résonances dans les sections efficaces d'ionisation sous le seuil de double ionisation. Nos calculs de sections efficaces partielles intégrées et différentielles nous ont permis d'identifier ce type d'états dans la région allant jusqu'au cinquième d'ionisation simple. Certains ont été observés pour la première fois.

A constitutive model has been developed to model the shock response of single crystal aluminum from peak pressures ranging from 2-110 GPa. This model couples a description of higher-order thermoelasticity with a dislocation-based viscoplastic formulation, both of which are formulated for single crystals. The constitutive model has been implemented using two numerical methods: a plane wave method that tracks the propagating wave front; and an extended one-dimensional, finite-difference method that can be used to model spatio-temporal evolution of wave propagation in anisotropic materials. The constitutive model, as well as these numerical methods, are used to simulate shock wave propagation in single crystals, polycrystals, and pre-textured polycrystals. Model predictions are compared with extensive existing experimental data and are then used to quantify the influence of the initial material state on the subsequent shock response. A coarse-grained model is then proposed to capture orientation-dependent deformation heterogeneity, and is shown to replicate salient features predicted by direct finite-difference simulation of polycrystals in the weak shock regime. The work in this thesis establishes a general framework that can be used to quantify the influence of initial material state on subsequent shock behavior not only for aluminum single crystals, but for other face-centered cubic and lower symmetry crystalline metals as well.

Lors de leur construction, les structures massives (ex. les enceintes de confinement des centrales nucléaires) sont soumises à des déformations dues à l’hydratation du béton. En effet, d’une part la réaction chimique du ciment avec l’eau est exothermique et thermo activée, ce qui induit des déformations de dilatation puis de contraction. D’autre part une dépression capillaire étant créée par la consommation d’eau due à l’hydratation du ciment, des déformations de contraction se produisent. Lorsqu’elles sont empêchées par la partie de la structure déjà construite, ces déformations volumiques induisent des contraintes de compression puis de traction pouvant causer une fissuration traversante augmentant alors sensiblement la perméabilité du béton. Mon travail de thèse a consisté à caractériser le comportement au jeune âge du matériau que l’on utilise (basé sur la formulation utilisée lors de la construction d’une enceinte) puis à mettre au point un essai permettant d’étudier la fissuration d’une éprouvette de béton soumise à des déformations empêchées lors de son durcissement. Ce nouvel essai est en fait une évolution de l’essai à l’anneau de retrait gêné permettant de prendre également en compte les déformations d’origine thermique. Les essais de caractérisation concernent essentiellement, d’un point de vue macroscopique, le retrait (endogène et thermique), le fluage (propre et thermique transitoire) et l’évolution des caractéristiques mécaniques (résistance à la compression, à la traction et module d’élasticité). La campagne d’essais réalisée avec ce nouveau dispositif, appelé essai à l’anneau thermique actif, et l’analyse numérique de ces essais par des simulations aux éléments finis (basées sur un modèle viscoélastique endommageable introduisant un couplage entre le fluage et l’endommagement) a permis d’évaluer ce couplage, d’identifier la diminution de résistance en traction due à une reprise de bétonnage et de quantifier l’effet des armatures sur le comportement du béton. Des mesures de transfert d’air sec à travers une éprouvette fissurée ont également été réalisées sur ce dispositif. Finalement, des simulations numériques d’ouvrages massifs ont mis en exergue l’influence des conditions de restriction du retrait sur le faciès d’endommagement et l’influence du couplage fluage fissuration sur le calcul des ouvertures de fissures. / At early-age, massive concrete structures (ex. nuclear power plant) are submitted to strains due to the hydration reaction. If they are restrained, crossing cracks can occurs. This cracking may increase significantly the concrete wall permeability. The objectives of this work was to characterize the early age concrete behavior (thermal and endogenous shrinkage, basic and thermal transient creep, mechanical characteristic evolution) as well as develop a new device to study the early age cracking of a concrete structure submitted to restrained shrinkage.The experimental campaign achieved with this new device (called thermal active ring test) and the numerical analysis of the test thanks to finite element simulations allows us to evaluate the coupling betwwen creep and damage, to identify the tensile strength decrease due to construction joints and to quantify the effect of reinforcement on the concrete behaviour. Moreover, with this device, permeability measurements have been performed on a cracked specimen. Finally, numerical simulations of massive structures highlight the influence of boundary conditions for restrained shrinkage and the influence of the coupling between creep and damage on the damage pattern.

The diploma thesis deals with the literary texts and their adequacy. It researches what features make kids books appropriate for the development of reading in the fifth grade of primary school. The attention is focused on reader's development and demands of literary texts. The action research gives the overview of one group of readers. Their favourite titles are assesed according to their adequacy. Bonnie Campbell Hill's Developmental Continuums are the main component for defining the criteria of the literary text. The selected texts considered according to their adequacy take place in a suggestion for teachers who want to deal with the level of kids books for their pupils. How to plan and then reflect the pupils reading performance with the knowledge of developmental continuums indicates the practical class.

Molecular dynamics simulations are an important tool for the study of biological systems, such as biomembranes. The missing electronic polarization in classical non- polarizable force fields, however, produces significant inaccuracies in the interactions of membranes with charged particles, such as ions. In this work, we implement the missing electronic polarization effects into CHARMM36 force field for phospatidylcholine lipids. This implementation is done in the mean field way by using electronic continuum correction (ECC) model. We will validate the strength of ion-membrane interactions using the electrometer concept. This concept connects the response of choline order parameters of lipid molecules with the amount of charge present in the surface of the membrane. Keywords: phosphatydylcholine, calcium ions, sodium ions, electronic continuum cor- rection, electrometer concept 1

A Shock wave as represented by the Riemann problem and a Point-blast explosion are two key phenomena involved in a supernova explosion. Any hydrocode used to simulate supernovae should be subjected to tests consisting of the Riemann problem and the Point-blast explosion. L. I. Sedov's solution of Point-blast explosion and Gary A. Sod's solution of a Riemann problem have been re-derived here from one dimensional fluid dynamics equations . Both these problems have been solved by using the idea of Self-similarity and Dimensional analysis. The main focus of my research was to subject the CHIMERA supernova code to these two hydrodynamic tests. Results of CHIMERA code for both the blast wave and Riemann problem have then been tested by comparing with the results of the analytic solution. / by Abu Salah M. Ahsan. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

As formulações baseadas na mecânica do contínuo, embora precisas até certo ponto, por vezes não podem ser utilizadas, ou não são conceitualmente corretas para o entendimento de fenômenos em escalas reduzidas. Estas limitações podem aparecer no estudo dos fenômenos tribológicos em escala nanométrica, que passam a necessitar de novos métodos experimentais, teóricos e computacionais que permitam explorar estes fenômenos com a resolução necessária. Simulações atomísticas são capazes de descrever fenômenos em pequena escala, porém, o número necessário de átomos modelados e, portanto, o custo computacional - geralmente torna-se bastante elevado. Por outro lado, os métodos de simulação associados à mecânica do contínuo são mais interessantes em relação ao custo computacional, mas não são precisos na escala atômica. A combinação entre essas duas abordagens pode, então, permitir uma compreensão mais realista dos fenômenos da tribologia. Neste trabalho, discutem-se os conceitos básicos e modelos de atrito em escala atômica e apresentam-se estudos, por meio de simulação numérica, para a análise e compreensão dos mecanismos de atrito e desgaste no contato entre materiais. O problema é abordado em diferentes escalas, e propõe-se uma abordagem conjunta entre a Mecânica do Contínuo e a Dinâmica Molecular. Para tanto, foram executadas simulações numéricas, com complexidade crescente, do contato entre superfícies, partindo-se de um primeiro modelo que simula o efeito de defeitos cristalinos no fenômeno de escorregamento puro, considerando a Dinâmica Molecular. Posteriormente, inseriu-se, nos modelos da mecânica do contínuo, considerações sobre o fenômeno de adesão. A validação dos resultados é feita pela comparação entre as duas abordagens e com a literatura. / Formulations based on continuum mechanics are generally accurate in a macroscale level, but sometimes cannot be used, or it is not conceptually correct to use for the understanding of small scale phenomena. These limitations may be observed in the study of tribological phenomena at the nanoscale, which may consequently require new experimental, theoretical and computational methods in order to analyze these phenomena with the required resolution. Atomistic simulations may describe phenomena at small scale, but the required number of atoms to be modeled, i.e. the computational cost, usually becomes very high. Moreover, simulation methods associated with continuum mechanics (such as the Finite Element Method - FEM) are more interesting in relation to computational cost, but they are not accurate for atomic scale studies. The combination of these two approaches can then enable a more realistic understanding of tribological phenomena. This work discusses the basic concepts of friction and models for friction at atomic scale. This work also presents studies, by means of numerical simulation, for the analysis of friction and wear mechanisms in the contact of materials. The problem is approached considering different scales, and basing the analysis both on Continuum Mechanics and Molecular Dynamics (MD). For both methods, numerical simulations with increasing complexity were conducted to reproduce the contact between surfaces, starting from an initial model that simulates the effect of crystalline defects during the MD analysis of pure slip. In a second stage, adhesion phenomenon were implemented through continuum mechanics models. The validation of the models and the coupling between the two approaches were conducted by comparison with literature.

Nesta dissertação, propomos um método que combina a técnica de varredura-Z e a luz branca supercontínua gerada em uma fibra fotônica para caracterizar o espectro de não-linearidades de amostras. O espectro não-linear fornece informações cruciais a respeito da característica, da origem e do potencial da não-linearidade para aplicação em dispositivos. Neste sentido, a luz branca supercontínua aliada à técnica de varredura-Z vem permitir uma rápida determinação de espectros numa banda larga. Neste trabalho, a luz branca foi gerada numa fibra fotônica comercial bombeada por pulsos de femtossegundo de um oscilador laser de Ti:safira. Tanto os lasers de femtosegundo quanto as fibras fotônicas estão se tornando cada vez mais acessíveis. Ademais, a técnica de varredura-Z é um método bastante conhecido para a determinação de não-linearidades devido à sua simplicidade e precisão. Dessa forma, aliamos essas vantagens para fazer um aparato simples, compacto e de baixo custo. Em geral, a determinação do espectro de não-linearidades necessita de sistemas lasers complexos que possam sintonizar o comprimento de onda. O método de varredura-Z de luz branca desenvolvido aqui foi usado para medir o espectro não-linear do corante disperse red 13 (DR13) em metanol. Esse corante possui um efeito não-linear absortivo (absorção saturada) bem caracterizado, sendo um bom material não apenas para calibração, mas também para testar nosso sistema experimental. Os resultados experimentais comprovaram a viabilidade do sistema para caracterização de amostras com efeitos não-lineares absortivos intensos. / In this dissertation, we proposed a method that combines the Z-scan technique and the white-light continuum generated by a photonic crystal fiber to characterize the nonlinear spectrum of materials. The nonlinear spectrum provides crucial information on the characteristic, the origin and the potential of the nonlinearity for devices application. In this sense, the white-light continuum allied to the Z-scan technique allows fast spectra determination in a broad spectral range. In this work, the white light was generated in a commercial photonic crystal fiber pumped by femtosecond pulses from a Ti:sapphire laser oscillator. Both the femtosecond lasers and the photonic crystal fibers are becoming more accessible. In addition, the Z-scan technique is a well-known method for nonlinearities determination due to its simplicity and precision. In this way, we merged these advantages to make a simple, compact and low-cost apparatus for studying nonlinear samples. In general, the nonlinear spectrum determination requires complex laser systems which are able to tune the wavelength. The white-light Z-scan method we developed here was used to measure the nonlinear spectrum of disperse red 13 (DR13) dye in methanol. This dye presents a well-characterized absorcive nonlinear effect (saturable absorption), being a good material not only to calibrate, but also to test our experimental setup. The experimental results confirmed the viability of the setup for characterizing samples with strong nonlinear absorption effect.

Flow Structure and fluid transport via advection around pectoral fin of larval ZebraFish are studied numerically using Immersed Boundary Method, Lagrangian Coherent Structure, passive particle tracing, vortex core evolution and four statistically defined mixing numbers. Experimental fish kinematics for nominal swimming case are obtained from previous researchers and numerically manipulated to analyze the role of different body motion kinematics, Reynolds number and fin morphology on flow structure and transport. Hyperbolic strain field and vortex cores are found to be effective particle transporter and their relative strength are driving force of varying flow structure and fluid transport. Translation and lateral undulation of fish; as a combination or individual entity, has coherent advantages and drawbacks significant enough to alter the nature of fluid advection. Reynolds number increase enhances overall fluid transport and mixing in varying order for different kinematics and nominal bending position of fin has average transport capability of other artificially induced fin morphology. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

O que hoje se denomina Mon coeur mis à nu é um conjunto de notas, aforismos bombásticos, ideias de capítulos por vir, agrupados e encadernados por Poulet-Malassis após a morte de Charles Baudelaire. Em 1887, Eugène Crépet publica a obra pela primeira vez, sob o título factício Journaux intimes. Os gestos editoriais pelos quais passou desde então tendem a conter seus inacabamentos, seja recorrendo à denominação diário íntimo, seja apagando editorialmente marcas da materialidade manuscrita e da provisoriedade de toda proposta de ordenação das notas. Mais recentemente, dois marcos começam a apontar para a dimensão inacabada de Mon coeur mis à nu, ainda que circunscritos a certa concepção filológica do processual: a noção de poética do rascunho, cunhada por Béatrice Didier ao tratar dos escritos póstumos de Baudelaire, e a edição diplomática de 2001, realizada por Claude Pichois para a editora suíça Droz. Tomando a retradução como estratégia de tradução, propõem-se nesta tese duas traduções simultâneas de Mon coeur mis à nu: uma tradução manuscrítica (voltada para a materialidade do manuscrito e sua transcrição-tradução) e um comentário do original como possibilidade de escrita tradutória (voltado para a necessidade de traçar linhas de força que rompam com a ordenação arbitrária de Malassis e desenhem outras relações possíveis, sem cair, em contrapartida, na falsa solução da desordenação absoluta e primordial). Mon coeur mis à nu apresenta uma escrita de cólera, que tem relação, por sua vez, com a teatralidade (a encenação de certa postura encolerizada, desagradável e chocante) e com a fusée (o aforismo incendiário, o processo de escrita que, atravessado pela cólera, faz-se projeto inacabado, promessa de explosão, projetos-projéteis lançados sobre a página contra a França, a modernidade, a canaille littéraire). Por fim, propomos a noção de contínuo do rascunho, que nos permite construir estratégias de edição e tradução que levem em consideração os inacabamentos de Mon coeur mis à nu, seu aspecto manuscrito, sua dispersão, seu efeito processual, sua cólera que, no limite, se volta contra a própria possibilidade de obra acabada. / The todays so-called Mon coeur mis à nu is a compound of notes, bombastic aphorisms, ideas for chapters to come, combined and bound by Poulet-Malassis after Charles Baudelaires death. In 1887, Eugène Crépet publishes the work for the first time under the sham title of Journaux intimes. The editorial gestures by which the work has passed ever since tend to contain its unfinishments, by means of denominating it intimal journal or by editorially erasing marks of the handwritten materiality and of the fugacity of any suggested organization of the notes. More recently, two milestones begin to highlight Mon coeur mis à nus unfinished dimension, albeit limited to a certain philological conception of the processual: the notion of draft poetics, initiated by Béatrice Didier approaching Baudelaires posthumous writings, and the 2001 diplomatic edition prepared by Claude Pichois for Droz, a Belgian publishing house. Understanding retranslation as a translation strategy, this thesis proposes two simultaneous translations for Mon coeur mis à nu: a manuscriptical translation (aiming the handwritten materiality and its transcription-translation) and a commentary of the original as a possibility of translational writing (aiming the necessity of tracing lines of force that break Malassis arbitrary ordering and redraw other possible relations, without succumbing, in return, to the false solution of the absolute and primeval disorder). Mon coeur mis à nu presents a wrathful writing related to, on the other hand, the theatricality (the mis-en-scène of a certain rabid, unpleasant, shocking posture) and the fusée (the incendiary aphorism, the writing process that, traversed by cholera, produces itself as an unfinished project, a promise of explosion, projects-projectiles launched over the page against France, the modernity, the canaille littéraire). Finally, we offer the notion of draft continuum, that allows us to build strategies of edition and translation that consider Mon coeur mis à nus unfinishments, its handwritten aspect, its dispersion, its processual effect, its cholera that, to the limit, turns against the possibility itself of being a finished work.