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The thesis deals with headstock and spindle of the universal turning center. In the introduction part is a destription of the headstock morfology. It describe how the spindle and headstock can be solved in terms of its bearing, installation, used clamping interface, lubrrication, cooling and sealing. The second part is devoted to the universals turning machines which are available on the market. In the final part is the practical solution of the headstock and spindle on which can be performed for milling and drilling operation instead of turning.

The purpose of this thesis is to design system for automatic exchange of spindle heads shared by several machines. Spindle heads are transported between these machines and placed to the position for exchange. The system also allows storing of heads. Requirements for system are load capacity of 2 000 kg and placing a spindle head to the exchange position with precision of ± 0,02 mm. The thesis consists of three parts. The first part involves search of head exchange principles and shows possible ways to transport heads and other elements that could be used in the system. In the next part are several possible solutions introduced and the selection of the best one is made. The last part contains the design of the chosen solution, visualisation, description and calculations. The result is design of two solutions which are described in this work.

This thesis deals with mechanical design of right-angle manual milling head for headstock of horizontal boring machine of Fermat production. The thesis includes research of milling head types, Fermat production heads, but also heads of competition companies with similar parameters like designed head. Design part of thesis is about describing used components of chosen solution. The thesis includes also technical report describing calculation of load spectrum from machining, design of gears, calculation of reactions in spindle bearings, spindle deformation and control of spindle bearings. The end of the thesis describes financial evaluation including also comparation with competitive milling heads with similar parameters.

This thesis deals with conceptual design of spindle speeder head for headstock of horizontal boring machine of FERMAT Company. The thesis includes research part, which is initially given to horizontal boring machines and their accessories and continues with an overview and comparison of spindle speeders that are currently on the market. The work includes technical report, which is aimed on design of the belt drive including the idler pulley. Design of belt drive is based on the output of the calculation program developed by manufacturer of synchronous belts. Calculation part, mainly focused on the spindle and its bearings, is preceded by a part in which are calculated cutting forces for two technological operations. Calculation of the spindle part contains strength calculation of the spindle and equivalent basic rating life of spindle bearings, including calculating of radial stiffness at the spindle nose and calculation of optimal distance between the spindle bearings. At the end of the technical report is a financial summary, description of used components and the chosen design solution. The drawings which are based on model assembly processed in 3D CAD system, contains a drawing of the entire device and drawings of selected components.

Le fuseau mitotique assure la ségrégation des chromatides sœurs et le maintien de la poïdie des cellules filles. Le fuseau est composé de microtubules dynamiques (qui polymérisent et dépolymérisent continuellement), de nombreux moteurs moléculaires, d'agents de réticulations et de régulateurs. Bien que la structure du fuseau au niveau moléculaire soit connue, son fonctionnement reste délicat à comprendre, et nécessite la prise en compte de la dynamique de ses composants et leurs interactions. Les approches utilisées pour répondre à ces problématiques sont jusqu'à maintenant plutôt des approches in silico et in vitro. Il manque aujourd'hui une caractérisation de la mécanique du fuseau dans son contexte physiologique. Nous proposons une méthode non invasive basée sur de l'analyse d'image, combiné à une modélisation heuristique pour mesurer les paramètres mécaniques durant toute la division. Nous suivons les pôles du fuseau marqués par protéine fluorescente avec un taux acquisition rapide et une bonne résolution spatiale ce qui nous permet d'accéder aux fluctuations de longueur du fuseau in vivo. Avec la transformée de Fourier aux temps courts, nous calculons leurs densités spectrales de puissances — leurs signatures mécaniques. Ces spectres sont alors ajustés avec un modèle Kelvin — Voigt avec inertie (un ressort, un amortisseur et un terme inertiel en parallèle). Nous avons validé la méthode par des expériences numériques où nous retrouvons les évolutions des paramètres sur des données simulées et la calibration a été réalisée par l'utilisation de la rupture du fuseau induite par micro chirurgie laser ou par la génétique. Nous avons caractérisé le fuseau de l'embryon unicellulaire du nématode C. elegans. La méthaphase apparaît dominée par l'amortisseur, ce qui est cohérent avec la lente élongation du fuseau que nous observons. Mais contraste l'idée répandue de l'existence d'un mécanisme de maintien de la longueur du fuseau durant la métaphase. Au passage en anaphase, les trois paramètres mécaniques chutent, avant de réaugmenter environ 50 secondes après la transition pour réatindre un régime dominé de nouveau par l'amortisseur, ce qui suggère que les microtubules interpolaires jouent un rôle mineur durant l'élongation du fuseau en début d'anaphase. Dans la perspective de comprendre le lien entre la mécanique du fuseau et les interactions des acteurs moléculaires, nous avons partiellement supprimé un gène par sous-structure du fuseau. Nous avons alors retrouvé des comportements connus avec une perspective augmentée offerte par notre méthode. Cette méthode, ne va pas seulement permettre la compréhension fondamentale de la mécanique du fuseau, en remplaçant la modélisation du fuseau basé uniquement sur la longueur, mais aussi d'aller vers la prise en compte de la robustesse de fonctionnement du fuseau mitotique face aux défauts tel que la polyou l'aneuploïdie. / The mitotic spindle ensures the correct segregation of the sister chromatids to maintain ploidy in daughter cells. The spindle comprises dynamical microtubules (alternating polymerizing and depolymerizing), a variety of molecular motors, crosslinker and the regulators. Although the molecular grounds of spindle structure is well known, the link to its functions remain elusive, calling for including the dynamics of its components and their interactions. These questions were mostly investigated by in silico or in vitro approaches. But a detailed characterizing of spindle mechanics, in physiological conditions, is missing. We propose an image processing based, non invasive, method combined to an heuristic model to measure mechanical parameters of the mitotic spindle along time. We tracked fluorescently labeled spindle pole at high temporal and spatial resolution and measured the variations of spindle length, in vivo. We computed their power density spectrum using short time Fourier transform (sliding window) — a blueprint of spindle mechanics. Such a spectrum is then fitted with a Kelvin —Voigt model with inertia (a spring, a damper, an inertial element in parallel). We validated this method by recovering the mechanical parameters over time from simulated data and calibrated it uses laser and genetically induced spinlde cut. We characterized the mitotic spindle of the one-cell embryo of nematode C. elegans. Metaphase appeared dominated by damping element, consistent with the slow spindle elongation observed. But in contrast with the common thought that a mechanism maintains the spindle length during metaphase. At anaphase onset, all three parameters collapsed, before increasing about 50s later to reach a regime where damping dominated again, suggesting the overlapping spinlde microtubules may play a minor role in early anaphase spinlde elongation. In perspective of understanding how spindle mechanics emerge of molecular players interactions, we depleted one gene per splindle sub-structure — overlapped microtubules, kinetochore microtubules, central spindle and astral microtubules. We succefully recovered some known behavior but with the augmented insight offered by our method. This method paves the way not only towards understanding the fundamentals of spindle mechanics, superseding the degenerated modeling based on the sole spindle length but also towards acounting for spindle functional robustness towards defect as polyor aneuploidy.

Aurora A (AurA) is an important mitotic kinase mainly studied for its involvement in cell cycle progression, centrosome maturation, mitotic spindle pole organization and bipolar spindle formation. It localizes to duplicated centrosomes and spindle microtubules (MTs) during mitosis where it regulates various factors participating in metaphase spindle formation. AurA is degraded late in mitosis suggesting that it might also have a function in anaphase. In this study we focused in understanding AurA function during anaphase in two different experimental systems. First, we kept AurA active in cycled Xenopus egg extracts and found that MTs maintained their mitotic organization longer throughout mitotic exit. We also observed chromosome segregation defects and problematic nuclear envelope formation. These observations indicate that AurA activity needs to be down-regulated for the transition from metaphase back to interphase. To get insights into the role of AurA during metaphase-anaphase transition we initially asked whether its kinase activity is still necessary for the maintenance of the metaphase spindle. We saw that the inhibition of AurA kinase activity in metaphase resulted to a collapse of the established metaphase spindle in HeLa cells. Indicating that AurA activity is necessary for the metaphase spindle maintenance. Then, we looked whether AurA kinase activity is still necessary during anaphase. We inhibited AurA at the onset of anaphase in Hela cells and found that anaphase spindles were smaller. We also observed that the MT structure responsible for anaphase spindle elongation, the central spindle, was defectively assembled and organized. Moreover, in cells where AurA was inhibited segregation of chromosomes was defective. These results indicate that AurA kinase activity is necessary for anaphase spindle elongation, central spindle assembly and organization and chromosome segregation. To understand further how AurA regulates anaphase spindle formation we looked known AurA substrates. We depleted TACC3, a known AurA substrate involved in MT formation earlier in mitosis and observed that TACC3 depletion phenocopied AurA inhibition. This indicates that TACC3 has a function in MT organization and chromosome segregation during anaphase and this function could possibly be regulated by AurA. In this study we have demonstrated that AurA activity is essential for metaphase spindle maintenance. We also found that during anaphase when AurA is either maintained active or inhibited MT organization is greatly affected and chromosome segregation is defective. Suggesting that AurA activity needs to be tightly controlled during anaphase for a correct completion of mitosis. / Aurora A (AurA) es una quinasa mitótica importante que se ha estudiado principalmente en su papel durante la progresión del ciclo celular, la maduración del centrosoma, la organización y la formación del polo y del huso mitótico. Durante la mitosis, AurA se localiza en los centrosomas duplicados y en los microtúbulos (MTs) del huso y se ha observado que regula varios factores que participan en la formación del huso mitótico. AurA se degrada al final de la mitosis indicando que pueda tener una función durante la anafase. En este estudio nos hemos centrado en la comprensión de la función de AurA durante la anafase en dos sistemas experimentales diferentes. En primer lugar, utilizando extractos de huevos de Xenopus hemos mantenido AurA activa durante la transición de metafase a anafase y hemos visto que los MTs del huso mitótico mantienen su organización durante más tiempo. También hemos observado que cuando AurA se mantiene activa existen defectos en la segregación cromosómica y la formación de la membrana nuclear. Esto indica que la actividad de AurA tiene un papel regulador sobre los MTs y la chromatina durante la transición de la metafase a la interfase. Para entender cual es la función de AurA durante la transición de metafase a anafase primero hemos estudiado si la actividad de la quinasa es necesaria para el mantenimiento del huso mitótico. Hemos visto que la inhibición de la actividad quinasa AurA resultó en el colapso del huso durante la metafase en células HeLa. Esto indica que la actividad de AurA es necesaria para el mantenimiento del huso mitótico de metafase. A continuación hemos analizamos si la actividad quinasa de AurA sigue siendo necesaria para la anafase. Para ello hemos inhibido AurA en células Hela al inicio de la anafase. En estas condiciones los husos de la anafase son más pequeños y la estructura de los MTs responsable del alargamiento del huso mitótico durante la anafase, el huso central, se organiza defectuosamente. Además, se encontraron errores durante la segregación de los cromosomas. Estos resultados indican que la actividad quinasa de AurA es necesaria para el alargamiento del huso durante la anafase y la organización y segregación cromosómica. Para entender el mecanismo de la función de AurA durante la anafase hemos estudiado a sustratos de AurA. Al estudiar TACC3 , un sustrato conocido de AurA que participa en la formación de MTs en las fase iniciales de la mitosis hemos encontrado que su eliminación de células HeLa produce el mismo fenotipo que la inhibición de AurA. Esto indica que TACC3 tiene una función en la organización de MT y la segregación de cromosomas durante la anafase y que esta función podría estar regulada por la quinasa AurA. En este estudio hemos demostrado que la actividad quinasa de AurA es esencial para el mantenimiento del huso mitótico. También hemos encontrado que durante la anafase cuando la quinasa AurA se mantiene activa o se inhibe la organización de los MTs del huso mitótico se ve muy afectada y los cromosomas se segregan defectuosamente. Por tanto los resultados de este estudio indican que la actividad quinasa de AurA está estrechamente controlada durante la anafase para el correcto cumplimiento de la mitosis.

Made available in DSpace on 2016-12-08T16:44:51Z (GMT). No. of bitstreams: 1 PGPV15MA177.pdf: 752563 bytes, checksum: 4fce88fb9643f9cfe11263390f3012f4 (MD5) Previous issue date: 2015-04-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nowadays Brazil is self sustaining in apple. The production is located in micro regions in Southern Brazil, in Santa Catarina and Rio Grande do Sul State. The technology and innovation need to be allied of the technicians and growers, responsible for the nacional production. The decision of which training system that will be used, it is one of the decisions that needs to do at planning to plant a new orchard. Is there so many training systems around the world. The choosed system wills interfer directlly in the profitability of the orchard. Nationally, the traditional system used is central leader system, with some changes, depending on the region that it is installed. With those informations, the aim of this study was evaluate different training systems in trials that combine the two most growed cultivars, Gala and Fuji, combined with the two most used rootstocks, M.9 and Marubakaido with interstem of M.9. The training systems evaluated were Vertical Axis, Tall Spindle and Solaxe at Vacaria-RS. The study concludes that Kiku-8®‟, grafted on M.9 tends to be a bi-annual bearing in all systems, the same cultivar was more vigorous when grafted on Marubakaido‟ trained in Vertical Axis. Maxi Gala‟ showed more vigour when trained in Vertical Axis in both rootstocks. All systems did not have effect in fruit quality parameters, like total soluble solids, flesh firmness and fruit size. It is necessary more labor hours Solaxe System in the most part of the combinations.The choice of which training system is the best to use, needs to be embased with data of more years of study / O Brasil é autossustentável em maçãs. A produção está concentrada em micro regiões no Sul do Brasil, nos estados de Santa Catarina e Rio Grande do Sul. A tecnologia e inovação devem ser aliadas dos técnicos e produtores responsáveis pela produção nacional. A decisão de qual sistema de condução é um dos intens a ser planejados antes mesmo da implantação do pomar. Diversos são os sistemas de condução existentes, existindo diferentes preferências nas diversas regiões produtoras ao redor do mundo. O sistema de condução escolhido vai inferir diretamente na rentabilidade do pomar. Nacionalmente o sistema de condução tradicional é em líder central, variando sua forma conforme local e tecnologia empregada. A partir dessas considerações objetivouse nesse trabalho avaliar diferentes sistemas de condução que utilizam líder central, em experimentos combinados com as cultivares mais produzidas no país, Gala e Fuji e com dois dos portaenxertos, M.9 e Marubakaido com interenxerto de M.9. Os sistemas de condução são o Vertical Axis, Solaxe e Tall Spindle, no município de Vacaria (RS). Pode-se concluir neste estudo que Kiku-8®‟ enxertado sobre M.9 mostra tendência a alternância de produção em todos os sistemas de condução, a mesma foi mais vigorosa quando enxertada sobre Marubakaido‟ e conduzida em Vertical Axis. Para a Maxi Gala‟ também o sistema Vetical Axis foi o qu mais induziu vigor nos dois portaenxertos utilizados. Os sistemas de condução não interferem nos fatores de qualidade de frutos como teor de sólidos solúveis, firmeza de polpa e tamanho de fruto. É necessário maior número de horas de mãode- obra no sistema Solaxe na maior parte das combinaçõe. A decisão para seleção de sistemas de condução terá que ser feita com base em resultados de mais safras

During embryogenesis, a single cell gives rise to a multi-cellular embryo through successive rounds of cell division. As cells become smaller, cellular organelles adapt their sizes accordingly. The size of the mitotic spindle—the microtubule-based structure controlling these divisions—is particularly important as it determines the distance over which chromosomes are segregated. To perform its function properly, spindle size scales with cell size. However, we still lack a mechanistic understanding of the underlying microtubule-based processes that regulate spindle scaling. In this thesis, I combined quantitative microscopy and laser ablation in zebrafish embryos and Xenopus laevis egg extract encapsulated in oil droplets. My measurements revealed the influence of microtubule length dynamics, transport, and nucleation on cell size-dependent spindle scaling. Strikingly, I discovered a hierarchical regulation of spindle size. In large cells, microtubule nucleation exclusively scales spindle size relative to cell size by changing the number of microtubules within the spindle. In small cells, microtubule dynamics fine-tune spindle size by modulating microtubule length. To understand the mechanism of spindle scaling, I proposed a theoretical model based on a limiting number of microtubule nucleators and microtubule-associated proteins that regulate microtubule length. The transition from nucleation- to dynamics-based scaling requires that microtubule number and the number of microtubule-associated proteins that promote microtubule growth scale differently with cell size. This can be achieved by sequestering an inhibitor of microtubule nucleation to the cell membrane, which is consistent with my measurements of microtubule nucleation. The differential regimes of spindle scaling modulated by microtubule nucleation and dynamics imply a gradual change in spindle architecture, which may ensure faithful chromosome segregation by spindles of all sizes.

This master thesis deals with the construction of multi-functional machining centre. The theoretical part describes the history of lathes, trends in production of lathes and individual machine parts. The practical part is the structural design of the spindle with positioning in the C axis, the second spindle (including drive in Z axis) and the turret (including drive in the X and Z axis). A 3-D model of the entire lathe assembly modeled in Autodesk Inventor 2010 is also included.