Obtivemos mapas de Poincaré das linhas de força do campo magnético resultante da superposição linear do campo magnético de um plasma toroidal em equilíbrio com o campo magnético de correntes helicoidais externas. Devido a falta de simetria do campo magnético não podemos definir uma expressão analítica que descreva os mapas; estes foram, então, obtidos pela integração numérica da equação das linhas de força dVET.lxVET.B = 0. Nos mapas de Poincaré aparecem as ilhas magnéticas principais e as ilhas magnéticas secundárias. As ilhas magnéticas secundárias surgem devido a geometria toroidal. Sobre uma mesma superfície ressonante, as ilhas não tem tamanhos iguais. / Poincaré maps of magnetic field lines of a toroidal helical system were made. The magnetic field is a linear superposition of the magnetic fields produced by a toroidal plasma in equilibrium and by external helical currents. We do not have an analytical expression for the Poincaré maps since the magnetic field do not have symmetry. In order to obtain the maps, the equation dl x B = O is numerically integrated. In the Poincaré maps, the principal and the secondary magnetic islands were observed. The islands do not have equal widths in the same resonant surface.

Breathing is a vital phenomenon that implies synergy of various anatomical structures that constitute the thorax. Joint physiology remains a relatively poorly-known component of the overall thorax physiology. Quantitative literature related to in vivo thorax kinematics during breathing is scarce. The present work focuses specifically on developing and applying a methodology to reach this goal. The developed method combined processing of CT data obtained at different lung volumes and infographic techniques. Detailed ranges of motion (ROMs) and axes of movement (mean helical axes, MHAs) were obtained at costovertebral joints in 12 asymptomatic subjects; rib ROMs gradually decrease with increasing rib number; lung volume and rib level have a significant influence on rib ROM; MHAs did not differ between rib levels. In addition, the method was applied on a sample of 10 patients with cystic fibrosis. The pathological condition significantly influenced CVJ ROMs while the orientation of the MHAs did not differ. Finally, the sternal displacement, sternal angle variations and sternocostal joints (SCJ at rib1 to 7) kinematics during breathing motion were analyzed. Rib ranges of motion relative to sternum decreased with increasing rib number similarly to CVJ. Orientation of the MHAs did not differ between SCJ levels. A significant linear correlation was demonstrated between sternum vertical displacement and rib ranges of motion at both CVJ and SCJ. The present work substantially contributes to 3D modelling of human thorax in breathing at a joint level both qualitatively and quantitatively. / Doctorat en Sciences biomédicales et pharmaceutiques (Médecine) / info:eu-repo/semantics/nonPublished

Ce travail de thèse porte sur l’étude de la cinématique 3D du rachis cervical supérieur ainsi que<p>sur l’analyse des bras de levier des muscles sous-occipitaux postérieurs, par le développement<p>de différentes méthodes contribuant à la modélisation anatomique du mouvement.<p>La première partie de ce travail s’oriente vers l’étude des mouvements de flexion extension, de<p>rotation axiale et de flexion latérale ainsi que des axes qui y sont rapportés. Pour ce faire, deux<p>protocoles ont été développés sur préparations anatomiques, l’un visant à analyser les<p>mouvements discrets à partir de différentes attitudes du rachis cervical supérieur et l’autre<p>s’intéressant aux mouvements instantanés. Ceux-ci ont permis de mettre en évidence une<p>orientation et une position de l’axe hélicoïdal dépendantes du mouvement, du segment étudié<p>et de sa position spatiale.<p>En deuxième intention, nous nous sommes intéressés aux propriétés biomécaniques musculaires<p>de cette région, et en particulier à l’étude des bras de levier. Deux méthodes de calcul<p>distinctes ont été utilisées, montrant chacune des résultats différents d’un point de vue<p>quantitatif mais relativement similaires au niveau qualitatif.<p>Pour terminer, nous avons exploité ces méthodes afin d’apprécier leur faisabilité dans le cadre<p>d’une évaluation fonctionnelle in vivo. Il en ressort une concordance de résultats cinématiques<p>par rapport aux études susmentionnées, permettant d’entrevoir des perspectives cliniques<p>encourageantes.<p>Par ailleurs, la modélisation musculo-squelettique 3D pourrait également contribuer à la<p>compréhension du dysfonctionnement cinématique du rachis cervical supérieur./ <p><p>This thesis concerns 3D kinematics analysis of the upper cervical spine (UCS) and computation of the posterior suboccipital muscle moment arms as well the development of different methods contributing to anatomical modeling and motion representation. The first part of this work is focused on the kinematics of flexion extension, axial rotation and lateral bending of the UCS. Two protocols were developed and applied in anatomical specimens, one to analyze discrete movements in different attitudes of upper cervical spine and the second concerned instantaneous motions. In addition to usual range of motion data, orientation and position of helical axes was computed for each motion type and UCS joint segment.<p>In the second part, we were interested in posterior suboccipital muscle biomechanical properties, particularly in the study of moment arms. Two different calculation methods were used, each showing different results from a quantitative point of view but quite similar in quality. Finally, we used these methods to assess their feasibility for in vivo functional assessment. The latter showed a concordance of kinematic results compared to the above studies, offering insight and clinical perspectives. In addition, musculoskeletal modelling 3D could also contribute to understanding of the kinematic features of upper cervical spine disorders.<p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Les travaux de cette thèse ont eu pour but la conception de guides d'onde dans des verres de chalcogénure, par une technique de photo-inscription. Celle-ci consiste à focaliser un laser femtoseconde dans le matériau et de l'interaction lumière-matière, il en résulte une variation d'indice de réfraction (Δn) permanente. Cette technique est rapide, en une seule étape et ne nécéssite pas l'intervention de processus chimique. De plus, elle permet la réelle conception de dispositifs en trois dimensions. Deux verres ont été étudiés, le GeGaS et l'As₂S₃. Les phénomènes responsables de ces modifications ont été étudiés et décrits pour chacun des verres. Dans le premier verre, la propagation d'un faisceau sous la forme de filament a été mise en évidence. Du déplacement des charges, il découle une modification de la structure du réseau vitreux qui conduit à une variation d'indice positive. Cette As₂S₃ a été étudiée et il a été montré que son amplitude est contrôlable au travers du taux de répétition du laser ou de la vitesse de déplacement de l'échantillon, alors que son diamètre reste constant indépendamment des conditions expérimentales. Dans le deuxième verre, des effets d'origine thermique ont été mis en évidence. Pour ce verre d'As₂S₃, alors que les Δn obtenues classiquement sont négatives, l'utilisation d'une trajectoire hélicoïdale innovante a mené à la réalisation de guides d'onde. Après une analyse systématique des différents paramètres expérimentaux, une maîtrise de l'amplitude de Δn et du diamètre du guide a été obtenue. Ainsi, des guides d'ondes monomodes, avec des propriétés équivalentes à l'état de l'art, ont été réalisé en une seule étape. / This thesis aimed at the waveguide conception in chalcogenide glass, with a photo-writing technique. This one consists on a laser focus into the material, from the light-matter interaction it results a permanent refractive index variation (Δn). This technique is fast, single step and it doesn't require any chemical process intervention. Furthermore it really enables the three dimensional devices design. Two glasses were studied, one is the GeGaS and the other the As₂S₃. The responsible phenomena of these modifications was studied and described for each of the glasses. In the first one, the beam propagation on a filament form was highlighting. From the charge displacement, it ensues a modification of the glassy network structure which leads to a positive index variation. This Δn was studied and it was shown that its amplitude is controllable trhough the laser repetition rate or with the sample displacement velocity while its diameter remains constant independently of the experimental conditions. Into the second glass, effects of thermal origin were highlighted. For this As₂S₃ glass, while classical photo-writing Δn are negative, the use of an innovative helical trajectory led to the waveguide conception. After a systematic analysis of the experimental parameter influence, a control of the Δn amplitude and of the waveguide diameter was obtaines. So, monomode waveguides, with equivalent properties to the state-of-the-art, were realized in a single step.

Ce travail de thèse porte sur les propriétés de stabilité des tourbillons hélicoïdaux, structures que l'on retrouve notamment dans le sillage des rotors d'hélicoptères et d'éoliennes.Dans une première partie, le développement spatio-temporel de l'instabilité d'appariement est caractérisé à l'aide d'un code numérique pseudo-spectral pour une allée infinie d'anneaux tourbillonnaires. On montre que ce modèle axisymétrique d'écoulement est en effet une bonne approximation du système hélicoïdal dans la limite des grands rayons et petits pas d’hélice. Dans ces conditions, et en utilisant un adimensionnement judicieux, on obtient également que le résultat théorique pour le taux de croissance spatio-temporel obtenu pour une double allée de tourbillons ponctuels s’avère être une bonne prédiction pour le cas hélicoïdal.Dans une seconde partie, on décrit comment un ou plusieurs tourbillons hélicoïdaux ont pu être générés de façon très peu perturbée à l’aide de modèles réduits de rotors dans le canal hydrodynamique du laboratoire. Grâce à l’introduction de perturbations d’amplitudes et de fréquences soigneusement contrôlées, le taux de croissance de l’instabilité d’appariement a pu être mesuré et comparé aux résultats théoriques. L’évolution non linéaire de ces perturbations ainsi que d’autres modes instables, à plus petites longueurs d’onde, ont également pu être observés expérimentalement pour la première fois.Enfin, ces résultats ont été appliqués au cas des rotors d’hélicoptères pour la prédiction du régime de Vortex Ring State (VRS) et à la transition vers la turbulence du sillage des éoliennes. / This thesis is devoted to the stability properties of helical vortices, which are of interest for applications such as helicopter and wind turbine wakes.In a first part, the spatio-temporal development of the pairing instability is characterised for an infinite array of vortex rings, using a pseudo-spectral numerical code. We show that this axisymmetric flow model is indeed a good approximation of the helical system in the limit of large helix radius and small pitch. Under these assumptions, and by using appropriate dimensionless variables, we also show that the theoretical result concerning the spatio-temporal growth rate for a double row of point vortices represents a good prediction for the helical case.In a second part, we describe how one or several helical vortices were generated in a carefully controlled way using small-scale rotor models in the water channel of the laboratory. Introducing perturbations with well-defined amplitudes and frequencies, the growth rate of the pairing instability could be measured experimentally and compared to theoretical predictions. The non-linear evolution of these perturbations, as well as other unstable modes of smaller wavelengths, were also observed experimentally for the first time.Finally, these results were applied to helicopter wakes for the prediction of the Vortex Ring State (VRS) regime and to the transition to turbulence in wind turbine wakes.

Le travail décrit dans ce manuscrit est consacré à la synthèse et à la caractérisation structurale d'une nouvelle famille de γ-amino acides hétérocycliques contraints, les ATCs (acides 4-Amino-(méthyl)-1,3-Thiazole-5-Carboxyliques). Ces monomères sont construits autour d'un noyau thiazole inséré entre les carbones Cα-Cβ permettant de limiter la valeur de l'angle dièdre ζ à 0°. La présence de deux points de substitution, sur le carbone γ asymétrique et en position 2 du noyau aromatique, autorise une large diversification structurale des ATCs. Des séries d'oligomères, i.e. dimères, tétramères et hexamères solubles dans les solvants organiques halogénés, dans les alcools et dans l'eau ont été synthétisées par couplages peptidiques. La conformation adoptée par ces séquences a été déterminée en solution par RMN 1D et 2D associées à des techniques de modélisation sous contraintes RMN. Nous avons montré que les oligomères d'ATCs s'arrangeaient en hélices 39 droites, présentant un pas de 11,8 Å. La conformation hélicoïdale est stabilisée par un réseau de liaisons hydrogène de type CO(i)…NH(i+2) s'établissant tout au long de la séquence, faisant entrer les oligomères d'ATCs dans le monde des foldamères. Des mesures de dichroïsme circulaire ont permis d'apprécier la stabilité conformationnelle des édifices et l'analyse à l'état solide par diffraction des rayons X a confirmé l'arrangement observé par RMN. Dans une seconde partie nous avons étudié le rôle structurant d'un motif ATC placé au sein d'une petite séquence peptidique. Nous montrons au travers d'expériences RMN et de calculs théoriques que la configuration du monomère d'ATC conditionne la conformation de peptides hybrides αγαα en solution. En termes d'application nous décrivons l'utilisation du motif ATC comme mime de coude pour concevoir un analogue fonctionnel de la gramicidine S, un cyclodécapeptide symétrique antibactérien. La dernière partie de ce travail concerne nos efforts pour développer, à partir des connaissances acquises quant à la structure tridimensionnelle des oligomères d'ATCs, des inhibiteurs de l'interaction protéine-protéine STAT6-NCoA-1. / The work described herein is devoted to the synthesis and the structural characterization of a new family of heterocyclic constrained γ-amino acids, named ATCs (4-Amino-(methyl)-1,3-Thiazole-5-Carboxylic acids). These building-blocks are built around a thiazole ring inserted between the Cα-Cβ carbons allowing the limitation of the ζ dihedral angle value to 0°. The presence of two diversification points both on the γ asymmetric carbon and on the position 2 of the aromatic ring, allows a large structural diversification of the ATCs. Series of oligomers consisting in dimers, tetramers and hexamers soluble in halogenated solvents, alcools and water have been synthesized according to peptide chemistry. The conformations of the sequences have been studied by various NMR experiments associated to modelling studies led under NMR constraints. The ATC oligomers adopt a right 39 helical shape, owning a pitch of 11.8 Å which has been confirmed by crystallography. The helix is stabilized by a conserved hydrogen bond pattern between CO(i)…NH(i+2) occurring all along the sequence axis. Circular dichroism measures have been done to check the conformational stability of the architectures. In the second part of the manuscript, we demonstrate by NMR and theoretical computing that when included in a short peptide sequence, ATCs could act as turns. The derived application consists in optimizing the biological behaviour of the ATC moiety as a turn mimetic thanks to the design and the antibacterial evaluation of a gramicidin S analogue. Based on our knowledge about the three-dimensional structure of ATC oligomers, the last part of this work deals with our efforts to develop inhibitors of protein-protein interaction STAT6-NCoA-1.

Background: Foamy viruses (FVs) have developed a unique budding strategy within the retrovirus family. FV release requires co-expression and a highly specific interaction between capsid (Gag) and glycoprotein (Env), which cannot be complemented by heterologous Env proteins. The interaction domain in FV Env has been mapped in greater detail and resides mainly in the N-terminal tip of the cytoplasmic domain of the Env leader peptide subunit. In contrast, the corresponding domain within Gag is less well defined. Previous investigations suggest that it is located within the N-terminal part of the protein. Results: Here we characterized additional Gag interaction determinants of the prototype FV (PFV) isolate using a combination of particle release, GST pull-down and single cycle infectivity analysis assays. Our results demonstrate that a minimal PFV Gag protein comprising the N-terminal 129 aa was released into the supernatant, whereas proteins lacking this domain failed to do so. Fine mapping of domains within the N-terminus of PFV Gag revealed that the N-terminal 10 aa of PFV Gag were dispensable for viral replication. In contrast, larger deletions or structurally deleterious point mutations in C-terminally adjacent sequences predicted to harbor a helical region abolished particle egress and Gag – Env protein interaction. Pull-down assays, using proteins of mammalian and prokaryotic origin, support the previous hypothesis of a direct interaction of both PFV proteins without requirement for cellular cofactors and suggest a potential direct contact of Env through this N-terminal Gag domain. Furthermore, analysis of point mutants within this domain in context of PFV vector particles indicates additional particle release-independent functions for this structure in viral replication by directly affecting virion infectivity. Conclusions: Thus, our results demonstrate not only a critical function of an N-terminal PFV Gag motif for the essential capsid - glycoprotein interaction required for virus budding but also point out additional functions that affect virion infectivity.

Master`s thesis solves technological processes rehabilitation of masonry reconstruction historically protected building. Describes the restoration of masonry using the electroosmotic system and by using helical reinforcement masonry of reinforcement, then it is also in this master`s thesis time and financial plan, site facilities and complementary features.

The thesis is focused on the technology of manufacturing of helical flute in the frame servomotor of austenitic chromium-nickel steel with improved machinability. One part of this thesis is a theoretical analysis of stainless steel and more detailed analysis of machined steel SANMAC 304L. The thesis also analyzes the current way of machining in the company VUES Brno s.r.o. and suggests new innovative ways of manufacturing helical flute. Innovative proposals include a technological procedure and a choice of instruments and tools for turning and milling. The means of manufacturing are evaluated from an economic and technical point of view. Conclusion of this thesis contains the assessment of the current way of machining with innovative designs.

Many industries including the medical, aerospace, and automobile industries have increasingly adopted the use of shape memory alloys (SMAs) for a plethora of applications due to their unique thermomechanical properties. From the commercially available SMAs in the market, binary NiTi SMAs have shown the most desirable properties. However, SMA properties can be significantly affected by the fabrication process. One of the most familiar applications of NiTi SMAs is in the design of actuating devices where the shape memory effect properties are highly advantageous. Spring NiTi SMA actuators are among the most commonly used and are generally made by torsion loading a straight wire. Consequently, stress concentrations are formed causing a reduction in recovery force. Other methods for producing springs and other NiTi SMA components is the fast emerging manufacturing method of additive manufacturing (AM). AM often uses metal powders to produce the near-net shape components. A major challenge for SMAs, in particular, is their well-known composition sensitivity. Therefore, it is critical to control composition in NiTi SMAs. In this thesis, a novel method for processing NiTi SMAs for pre-alloyed NiTi SMA powders and springs is presented. A low pressure and low temperature hydriding-pulverization-dehydriding method is used for preparing the pre-alloyed NiTi SMA powders with well-controlled compositions, size, and size distributions from wires. By hydrogen charging as-drawn martensitic NiTi SMA wires in a heated H3PO4 solution, pulverizing, and dehydriding, pre-alloyed NiTi powders of various well-controlled sizes are produced. In addition, a low pressure and low temperature hydriding-dehydriding method is used for producing NiTi SMA helixes from wires. The helix pattern in the pre-alloyed NiTi SMA wires was obtained by hydrogen charging NiTi SMA 500 μm diameter wires at different time intervals, followed by dehydriding to remove the hydrogen. The wires, powders, and resulting helixes were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD). The relationship between the wire diameter, powder particle size, and helix geometry as a function of hydrogen charging time is investigated. Lastly, the recovery behavior due to the shape memory effect is also investigated after dehydriding.