Bakgrund: Transfemoralt amputerade har nedsatt balans och ökad fallrisk, men väldigt lite forskning är gjord om detta. Inverted pendulum model (IPM) är en balansmodell för icke-amputerade som bygger på ett känt samband mellan Center of Pressure (CoP) och Center of Mass (CoM). Syftet med denna studie är att kinetiskt validera den inverterade pendelmodellen för transfemoralt amputerade. Metod: I studien deltog amputerade (n=5) och en matchande kontrollgrupp (n=5). Man samlade in data genom att deltagarna fick stå stilla på två stycken kraftplattor under tre styckern villkor; öppna ögon, stängda ögon och weight-bearing feedback. Man undersökte sedan korrelationen mellan avståndet från CoM till CoP och CoMacc i både anterioposterior (A/P) riktning samt medio-lateral (M/L) riktning och analyserade datan med trevägsvariansanalys (ANOVA). Resultat: Resultatet visade att det fanns en signifikant interaktionseffekt mellan villkor och position i M/L-riktning. I A/P-riktning fanns det en signifikant interaktionseffekt mellan grupp och position samt villkor och position. Slutsats: Resultatet innebär att IPM är kinetiskt validerat i A/P-riktning sett till hela kroppen men inte på den amputerade sidan. Hur det intakta benet förhåller sig till IPM för amputerade är tvivelaktigt. / Background: It is known that transfemoral prosthesis users lack normal balance control and are more likely to fall. Research on this topic is insufficient. The Inverted Pendulum Model (IPM) is a commonly used biomechanical model for assessment of balance and postural control for healthy individuals based on an assumption that Center of Pressure (CoP) and Center of Mass (CoM) are inter-dependent. The aim of the study is to validate IPM kinetically for transfemoral prosthesis users. Method: Amputees (n=5) and a control group (n=5) participated. During data collection, participants stood on two force plates with eyes open, eyes closed and with weight-bearing feedback. Correlation of the distance CoP-CoM and CoMacc were calculated for anteroposterior and mediolateral directions and evaluated with three-way ANOVA. Result: Results showed significant interaction effects between condition and position plus group and position in anteroposterior direction and condition and group in mediolateral direction. Conclusion: Results indicate kinetic validity of IPM for transfemoral amputees when looking at the whole body but not at the amputated side in the A/P direction. Kinetic validity of IPM for the intact leg is questionable.

Les travaux présentés dans cette thèse constituent une étude sur la possibilité de déposer par pulvérisation plasma des couches minces de TiN sur des fils d'acier inoxydable en défilement. Les aspects technologiques tels que la conception et la construction d'une ligne prototype capable de nettoyer et déposer sur toute la circonférence des substrats cylindriques en mouvement sont présentés. Le développement de procédé dans la chambre de nettoyage par micro-ondes a permis l'amélioration des performances du plasma en termes de densité et de température d'électronique, ce qui a conduit à une amélioration de l'efficacité de nettoyage de substrat en termes de degré de propreté et de temps de traitement requis. D'une manière similaire, le développement de procédé dans la chambre de dépôt a permis de mettre en évidence la limitation majeure du magnétron cylindrique inversée (ICM), soit la très haute température atteinte par le substrat pendant le procédé. Le calcul théorique a permis l'identification de la majeure contribution au chauffage du substrat, et, afin de la réduire, la mise en place d'une solution technique consistant en électrodes supplémentaires, indépendamment polarisées. L'impact de la polarisation des électrodes supplémentaires est présenté en termes de paramètres de procédé (confinement du plasma, redistribution des courants, potentiel de la cible, modes de pulvérisation, temps de traitement plus permis, etc.), et, également, en termes de propriétés de couches déposées (vitesse de dépôt, profil d'épaisseur, composition et stœchiométrie). Basés sur les résultats obtenus dans le magnétron actuel, plusieurs possibilités d'améliorer encore les performances d'une nouvelle chambre de dépôt sont discutées. / This thesis represents a study of the possibility to sputter - deposit titanium nitride thin films on moving stainless steel wires. Technological aspects such as the conception, design and construction of a prototype tool capable of in-line cleaning and deposition all around the circumference of moving cylindrical substrates are presented. The process development in the microwave cleaning chamber allowed the improvement of the plasma performance in terms of density and electron temperature, which lead to improvement of the substrate cleaning efficiency in terms of degree of cleanliness and required process time. Similarly, the process development in the deposition chamber permitted to highlight the major limitation of the inverted cylindrical magnetron (ICM), which is the very high temperature, the substrate reaches during process. Theoretical calculation allowed the identification of the major contribution to substrate heating, and a technical solution consisting of independently biased additional electrodes is proposed in order to reduce it. The impact of the additional electrodes polarization is discussed both in terms of process parameters (plasma confinement, electron current redistribution, target voltage, sputtering modes, longer allowable process time, etc.), and in terms of films properties (deposition rate, thickness profile, composition and stoichiometry). Based on the results obtained in the present ICM, several possibilities to improve the performance of a new magnetron are discussed.

The beginning of the 21 st century is characterised, among others, by the evolution in telecommunications. The rapid growth of mobile communications and the variety of applications proposed for the third generation (3G) systems require long operation time, low weight and cost for terminals, as well as improved link quality. For this reason a good efficiency and low profile antennas with low absorption losses by the user are desirable. The Planar Inverted-F Antenna (PIFA) is shown to result into low SAR values and high efficiency when operating in the proximity of the user. Despite these advantages, PIFA is also characterised by narrow bandwidth that limits its practical use. The first part of this work is dedicated to the measurements and evaluation of the radiation characteristics of the PIFA and other wire antennas both in the near and far fields. In addition, novel methods of PIFA tuning are presented. These include the repositioning of the shorting pin and modification of its capacitance. By using these techniques, the effective bandwidth of the PIFA can be increased to satisfy the GSM900 and DCS 1800 system bandwidth requirements. Dual-band and electronically tuned PIFA prototypes are also included. The effects of the handset size on the mass averaged Specific Absorption Rate (SAR), and antenna efficiency are investigated. The appropriate choice of handset can result in up to 30%-reduced peak SAR. The computed SAR values from PIFA are compared with those resulting from the use of a handset equipped with quarter wavelength monopole antenna. A new measure referred to as the 3dB SAR volume is proposed. This measure provides better understanding of the absorbed power distribution in the operator's head. Results obtained in the course of study show that low profile handset antennas, such as the PIFA, present in addition to dual resonance and low reflection losses, reduced SAR values, high efficiency and low 3dB SAR volume. Finally, SAR and 3dB SAR volume values from simulations on 5- and 10- years old child head models are compared with their equivalents for adult models from which appropriate conclusions are drawn.

Le projet de thèse, mené en collaboration avec le laboratoire Medesis Pharma, porte sur la mise au point de deux formulations pharmaceutiques, une microémulsion inverse et un gel colloïdal, à base de Pécéol®, lécithine, éthanol et eau. Le lithium indiqué dans le traitement de maladies neurodégénératives a été utilisé comme un modèle de principe actif hydrophile dans le cadre de ce projet. Ce travail a été initié par l’étude du comportement de phases du mélange quaternaire Pécéol®/lécithine/éthanol/eau, mettant essentiellement l’accent sur les différents paramètres impliqués dans les transitions de phases, dans le but de déterminer le rôle du Pécéol® et de la lécithine dans la structuration du système.- L’étude des propriétés structurales de la microémulsion, dans le domaine riche en Pécéol®, a montré que la structure du système n’est pas cohérente avec un modèle classique de micelles sphériques, l’hypothèse d’une structure localement lamellaire a été proposée. Les propriétés de solubilisation de la microémulsion ont été évaluées par l’élaboration d’une série de diagrammes de phases pseudo-ternaires, en faisant varier le rapport éthanol/lécithine. Une efficacité optimale a été obtenue pour un rapport éthanol/lécithine égal à 40/60. La formulation optimisée est capable d’incorporer efficacement le lithium (Li), à des concentrations acceptables sans altérer la stabilité du système. L’étude des propriétés d’incorporation du Li dans la microémulsion a montré que le mécanisme d’encapsulation est compatible avec un modèle d’interactions de type drug-surfactant. Les résultats des études de stabilité de la microémulsion vide et chargée en Li menées selon les conditions ICH sont satisfaisants.- La structuration du gel clair, dans le domaine riche en lécithine, a été suivie par des analyses de rhéologie et de microscopie en lumière polarisée en fonction du rapport lécithine/Pécéol®. Les résultats ont montré que les propriétés rhéologiques du gel peuvent être modifiées en ajustant le rapport lécithine/Pécéol®. La caractérisation de la structure du gel clair par diffraction de rayons X aux petits angles (SAXS) et cryofracture conjuguée à la microscopie électronique en transmission (FF-TEM) a mis en évidence une structure anisotrope hexagonale H2. Alors que dans le domaine riche en eau, une structure anisotrope hexagonale inverse H2 et lamellaire Lα a été mise en évidence. Les propriétés rhéologiques modulables du gel dans le domaine riche en lécithine ainsi que sa grande capacité de rétention d’eau, sont particulièrement intéressantes pour une application du gel clair dans le domaine de pharmaceutique et/ou cosmétique. / This thesis project, carried out in collaboration with Medesis Pharma laboratory, is about the development of two pharmaceutical formulations, a reverse microemulsion and a colloidal gel, based on Pécéol®, lécithine, ethanol and water. The indicated lithium in the treatment of neurodegenerative diseases has been used as a hydrophilic principal active model for this project. This work started with the study of the phase behavior of the four component system Pécéol®/lecithin/éthanol/water, focusing primarily on the various parameters involved in phase transitions in order to determine the role of Pécéol® and lecithin in the structuring of the system.- The study of the structural properties of the reverse microemulsion, in the Pécéol® rich domain, showed that the system structure is not coherent with a classical model of spherical micelles, a hypothesis of a local lamellar structure was proposed. The solubilization properties of the microemulsion were evaluated following the development of a series of pseudo-ternary phase diagrams, by varying the ethanol/lecithin ratio. Optimal efficiency was obtained for an ethanol/lecithin ratio of 40/60. The optimized formulation is capable of effectively incorporating lithium (Li) to acceptable concentrations without altering the stability of the system. The study of the incorporation properties of Li in the microemulsion has shown that the encapsulation mechanism is compatible with drug-surfactant binding model. The results of the stability studies of the free and Li loaded microemulsion, conducted according to ICH conditions, are satisfactory.- The gel structuring was followed, in the lecithin rich domain, through rheological and optical microscopy analyses, according to lecithin/Pécéol® ratio. Results showed that the rheological properties of the gel can be modified by adjusting the lecithin/Pécéol® ratio. Moreover, the characterization of the gel structure through Small Angle X-Ray Scattering (SAXS) and Freeze Fracture-Transmission Electron Microscopy (FF-TEM) showed an inverse hexagonal phase H2. While, in the water rich region, an inverse hexagonal H2 and lamellar Lα phases were identified. The adjustable rheological properties of the clear gel, and its great water solubilisation capacity, are particularly interesting for the application of the gel in pharmaceutical and/or cosmetic fields.

Neste trabalho, uma análise quantitativa e qualitativa para a estabilização dinâmica de um pêndulo invertido com uma força externa senoidal aplicada no ponto de suspensão é feita. Inicialmente, a perturbação externa é composta de um único cosseno, então uma generalização é feita, usando uma soma de N cossenos com diferentes amplitudes e frequências. Aproximações são testadas e o tempo durante o qual o pêndulo invertido permanece estável é explorado quando N é grande, a fim de recuperar o padrão do caso onde N = 1. O caso específico de oscilações periódicas e quase periódicas, quando N = 2, é analisado e diagramas de estabilidade considerando diferentes frequências e amplitudes são estudados. Depois, um ruído Gaussiano additivo é adicionado ao sistema para que a degradação dos diagramas de estabilidade gerados por variâncias diferentes possam ser estudados. Todos os pontos deste trabalho são corroborados por simulações, as quais integram numericamente as equações de movimento do sistema através do método de Runge-Kutta de quarta ordem. Os algoritmos e detalhes extras dos métodos de integração usados são explorados numa publicação deste trabalho, a qual está apresentada, nesta dissertação, como um apêndice. / In this work a quantitative and qualitative analysis of the dynamical stabilization of an inverted pendulum with a sinusoidal external perturbation applied at the suspension point is made. Initially, the external perturbation is composed of a single cosine, then a generalization is made using a sum of N cosines with different amplitudes and frequencies. Approximations are tested, and the time for which the inverted pendulum remains stable is explored when N is large, in order to recover the pattern of the case when N = 1. The specific case of periodic and almost periodic oscillations, when N = 2, is analysed and stability diagrams considering different frequencies and amplitudes are studied. Later, an additive Gaussian noise is added to the system so the degradation of the stability diagrams generated by different variances can be studied. All points of this work are corroborated by simulations, which numerically integrate the system’s equation of motion through a fourth order Runge-Kutta method. Algorithms and extra details on the integration methods used are explored in a publication of this work, which is presented in this thesis as an appendix.

Neste trabalho, uma análise quantitativa e qualitativa para a estabilização dinâmica de um pêndulo invertido com uma força externa senoidal aplicada no ponto de suspensão é feita. Inicialmente, a perturbação externa é composta de um único cosseno, então uma generalização é feita, usando uma soma de N cossenos com diferentes amplitudes e frequências. Aproximações são testadas e o tempo durante o qual o pêndulo invertido permanece estável é explorado quando N é grande, a fim de recuperar o padrão do caso onde N = 1. O caso específico de oscilações periódicas e quase periódicas, quando N = 2, é analisado e diagramas de estabilidade considerando diferentes frequências e amplitudes são estudados. Depois, um ruído Gaussiano additivo é adicionado ao sistema para que a degradação dos diagramas de estabilidade gerados por variâncias diferentes possam ser estudados. Todos os pontos deste trabalho são corroborados por simulações, as quais integram numericamente as equações de movimento do sistema através do método de Runge-Kutta de quarta ordem. Os algoritmos e detalhes extras dos métodos de integração usados são explorados numa publicação deste trabalho, a qual está apresentada, nesta dissertação, como um apêndice. / In this work a quantitative and qualitative analysis of the dynamical stabilization of an inverted pendulum with a sinusoidal external perturbation applied at the suspension point is made. Initially, the external perturbation is composed of a single cosine, then a generalization is made using a sum of N cosines with different amplitudes and frequencies. Approximations are tested, and the time for which the inverted pendulum remains stable is explored when N is large, in order to recover the pattern of the case when N = 1. The specific case of periodic and almost periodic oscillations, when N = 2, is analysed and stability diagrams considering different frequencies and amplitudes are studied. Later, an additive Gaussian noise is added to the system so the degradation of the stability diagrams generated by different variances can be studied. All points of this work are corroborated by simulations, which numerically integrate the system’s equation of motion through a fourth order Runge-Kutta method. Algorithms and extra details on the integration methods used are explored in a publication of this work, which is presented in this thesis as an appendix.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-15T17:53:44Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) A_Marques_PhD_thesis_2016_FINAL.pdf: 9324057 bytes, checksum: 92c1de27f6fa947d7e6b3e74ae09a849 (MD5) / Made available in DSpace on 2016-08-15T17:53:46Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) A_Marques_PhD_thesis_2016_FINAL.pdf: 9324057 bytes, checksum: 92c1de27f6fa947d7e6b3e74ae09a849 (MD5) Previous issue date: 2015-02-15 / capes / Cromossomos holocêntricos são caracterizados pela ausência de constrição primária e apresentam normalmente a proteína centromérica CENH3 distribuída ao longo de um eixo em cada cromátide. Embora muitos organismos com cromossomos monocêntricos apresentem sequências de DNA centroméricas específicas e associadas com a CENH3, nenhuma sequência centromérica havia sido identificada em organismos com cromossomos holocêntricos até o momento. Além disso, vários estudos reportam adaptações meióticas em espécies com cromossomos holocêntricos. Sendo observada em alguns casos uma inversão da ordem dos eventos meióticos (meiose invertida ou pós-reducional). Assim, o presente trabalho objetivou estudar a organização centromérica e a meiose de espécies com cromossomos holocêntricos do gênero Rhynchospora (Cyperaceae). Foi realizada uma análise citogenômica da organização e composição dos holocentrômeros de Rhynchospora pubera (2n = 10), sendo reportada a primeira descoberta de sequências centroméricas em espécies com cromossomos holocêntricos. Foi observado que os holocentrômeros de R. pubera são compostos principalmente por arranjos de DNA satélite (Tyba) e retroelementos centroméricos (CRRh) distribuídos pelo genoma. A análise detalhada da sucessão dos eventos meióticos de R. pubera e R. tenuis (2n = 4) reportou uma prófase inicial semelhante a de monocêntricos. No entanto, foi verificado que as cromátides-irmãs separam para polos opostos durante a anáfase I e os homólogos segregam somente durante a meiose II, comprovando uma meiose invertida para ambas as espécies. Curiosamente, durante a meiose de R. pubera foi observado uma organização diferencial dos centrômeros. Ao contrário do observado em mitose, durante meiose não foi observado a formação de holocentrômeros em forma de linha, sendo, na verdade, observado estruturas centroméricas aglomeradas. O restabelecimento de holocentrômeros em forma de linha se deu durante a primeira mitose do pólen. / Holocentric chromosomes are characterized by the absence primary constriction and normally show the centromeric protein CENH3 distributed along the axis of each chromatid. Although many monocentric organisms show centromere-specific DNA sequences associated to CENH3, no centromeric sequences had been identified in any holocentric organism so far. Furthermore, many studies report meiotic adaptations in holocentric species. In some cases is observed an inversion of the order of meiotic events. This type of meiosis has been named of inverted or post-reductional meiosis and would be exclusive of holocentric organisms. Thus, the present work aimed to study the centromere organization and meiosis of holocentric species of the genus Rhynchospora (Cyperaceae). A cytogenomic analysis of the composition and organization of the holocentromeres of Rhynchospora pubera (2n = 10) has been performed, being reported the first centromeric sequences from a holocentric species. It was observed that the holocentromeres of R. pubera are composed mainly by arrays of satellite DNA (Tyba) and centromeric retrotransposons (CRRh) distributed genomewide. The detailed analysis of the succession of meiotic events of R. pubera and R. tenuis (2n = 4) demonstrated an early meiotic prophase similar to that of monocentric. However, it was verified that sister chromatids separate to opposite poles during anaphase I, while homologs only segregate at meiosis II. These results prove the inverted meiosis for both species. Curiously, it was observed during meiosis of R. pubera a differential organization of centromere units. In contrast to the observed in mitosis, during meiosis we did not observed the formation of line-like holocentromeres, being in fact observed the formation of cluster-like holocentromeres. The reestablishment of a line-like holocentromere occurred during the first pollen mitosis.

Philosophiae Doctor - PhD / The fascinating optical properties of metallic nanostructures, dominated by collective oscillations of free electrons known as plasmons, open new opportunities for the development of devices fabrication based on noble metal nanoparticle composite materials. This thesis demonstrates a low-cost and versatile technique to produce stimuli-responsive ultrafast plasmonic nanostructures with reversible tunable optical properties. Albeit challenging, further control using thermal external stimuli to tune the local environment of gold nanoparticles embedded in VO2 host matrix would be ideal for the design of responsive functional nanocomposites. We prepared Au-VO2 nanocomposite thin films by the inverted cylindrical reactive magnetron sputtering (ICMS) known as hollow cathode magnetron sputtering for the first time and report the reversible tuning of surface plasmon resonance of Au nanoparticles by only adjusting the external temperature stimuli. The structural, morphological, interfacial analysis and optical properties of the optimized nanostructures have been studied. ICMS has been attracting much attention for its enclosed geometry and its ability to deposit on large area, uniform coating of smart nanocomposites at high deposition rate. Before achieving the aforementioned goals, a systematic study and optimization process of VO2 host matrix has been done by studying the influence of deposition parameters on the structural, morphological and optical switching properties of VO2 thin films. A reversible thermal tunability of the optical/dielectric constants of VO2 thin films by spectroscopic ellipsometry has been intensively also studied in order to bring more insights about the shift of the plasmon of gold nanoparticles imbedded in VO2 host matrix. / South Africa

The diploma thesis deals with control of rotary inverted pendulum - Furuta pendulum. Solution for power electronics, sensors and coupling with PC is described, identification of parameters and nonlinear simulation model in Matlab/Simulink and SimMechanics toolbox is presented. Second type Lagrange equation is used for determination of equations of motion. Controll system based on state-space model of mechanism and LQR algorithm for design of state-space controller is used and switching between swing-up cotroller a stabilizing state-space control is achieved according to actual angular position of pendulum's angle. Input integrator eliminating steady state error was used with success.

This study focuses on the investigation of the key parameters that determine the optical and electrical characteristics of inverted top-emitting organic light emitting diodes (OLED). A co-deposition of small molecules in vacuum is used to establish electrically doped films that are applied in n-i-p layered devices. The knowledge about the functionality of each layer and parameter is important to develop efficient strategies to reach outstanding device performances. In the first part, the thin film optics of top-emitting OLEDs are investigated, focusing on light extraction via cavity tuning, external outcoupling layers (capping layer), and the application of microlens films. Optical simulations are performed to determine the layer configuration with the maximum light extraction efficiency for monochrome phosphorescent devices. The peak efficiency is found at 35%, while varying the thickness of the charge transport layers, the semitransparent anode, and the capping layer simultaneously. Measurements of the spatial light distribution validate, that the capping layer influences the spectral width and the resonance wavelength of the extracted cavity mode, especially for TM polarization. Further, laminated microlens films are applied to benefit from strong microcavity effects in stacked OLEDs by spatial mixing of external and to some extend internal light modes. These findings are used to demonstrate white top-emitting OLEDs on opaque substrates showing power conversion efficiencies up to 30 lm/W and a color rendering index of 93, respectively. In the second part, the charge carrier management of n-i-p layered diodes is investigated as it strongly deviates from that of the p-i-n layered counterparts. The influence of the bottom cathode material and the electron transport layer is found to be negligible in terms of driving voltage, which means that the assumption of an ohmic bottom contact is valid. The hole transport and the charge carrier injection at the anode is much more sensitive to the evaporation sequence, especially when using hole transport materials with a glass transition temperature below 100°C. As a consequence, thermal annealing of fabricated inverted OLEDs is found to drastically improve the device electronics, resulting in lower driving voltages and an increased internal efficiency. The annealing effect on charge transport comes from a reduced charge accumulation due to an altered film morphology of the transport layers, which is proven for electrons and for holes independently. The thermal treatment can further lead to a device degradation. Finally, the thickness and the material of the blocking layers which usually control the charge confinement inside the OLED are found to influence the recombination much more effectively in inverted OLEDs compared to non-inverted ones.