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Dissertations / Theses on the topic 'Tee joints'
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Read, Paul John Charles Lewis. "Fatigue characterisation of FRP structural tee joints." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242730.
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Earl, Jacqueline Sonia. "The influence of hygrothermal ageing on polymeric composite sandwich materials and structures." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342836.
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Kang, Chew Ting. "Ultimate strength of Double-Tee tubular joints under combined brace and chord loading." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364210.
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Brooke, Stephen John. "The application of high power lasers to the welding of tee section joints in ship production." Thesis, University of Newcastle Upon Tyne, 1987. http://hdl.handle.net/10443/830.
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The use of computers by naval architects has revolutionised ship design and -construction management. The use of high power laser technology could similarly revolutionise production processes to produce a quantum leap in productivity. Facilitating low heat input materials processing, the laser is suited to various cutting, welding and heat treatment applications in shipbuilding to increase productivity through improved product accuracy. From these processes, the Author has concentrated on the application of high power lasers to the welding of tee section joints - the most common joint configuration in ship structures - by a single sided method (skid welding) to give both the lowest possible heat input and greatest flexibility. -Using a lOkW laser, single pass fully penetrating skid welds may be produced for joints in plate of up to 15mm thick, but using this size of laser, production parameter envelopes to produce visually and structurally sound joints reduce in size as plate thickness increases to greater than 10mm. It is shown that fully penetrating laser skid welds produced in steel conventionally used for surface vessel construction are of superior structural quality to fillet welds as required by classification society rules. The work has shown that achieving process consistency in an automated production based skid welding workstation operating with existing levels of joint tolerance will be dependent not only on well designed laser and beam delivery harware but also on suitable on-line adaptive control systems. It has been demonstrated that by employing laser skid welding for steelwork fabrication, an increase in productivity can be gained, principally through increased processing speed and improved product accuracy.
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Chlosta, Alexander. "Analysis of Prestressed Concrete Deck Bulb Tee Girder Bridges with Ultra-High Performance Concrete Longitudinal Joints." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1574349161211748.
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Waymark, Claire Marie. "Joint validation of HIRDLS and TES." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531808.
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Bary, Abdouraman. "Etude par TEM et EBIC des joints, sous-joints et précipités dans le silicium polycristallin POLIX." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37611619w.
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Bary, Abdouraman. "Etude par tem et ebic des joints, sous-joints et precipites dans le silicium polycristallin polix." Caen, 1989. http://www.theses.fr/1989CAEN2031.
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La structure cristallographique des principaux defauts presents dans les lingots bruts de silicium polycristallin de type polix a ete etudiee par microscopie electronique en transmission (met). Une methode analytique a permis de determiner de facon tres precise des parametres qui caracterisent les joints de grains et les sous-joints. Les precipites presents dans ce materiau ont ete egalement caracterises. Parallelement a cette description structurale, l'activite electrique de ces defauts a ete etudiee au moyen de la microscopie electronique a balayage (meb) par la technique du courant induit par faisceau d'electrons (ebic). Des mesures quantitatives de vitesses de recombinaison des porteurs de charge electrique minoritaires sur les defauts ont ete realisees. Il a ete mis en evidence le role determinant des facteurs chimiques, la segregation d'impuretes et surtout la precipitation sur l'activite ebic des defauts. Ces phenomenes sont cependant modules par les facteurs structuraux
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Dong, Fangxiao. "KINETICS OF WEDGE-TEE JOINT FORMATION DURING BRAZING OF AN ALUMINUM ALLOY UNDER CONTROLLED ATMOSPHERE." UKnowledge, 2013. http://uknowledge.uky.edu/me_etds/23.
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This work involves investigation of the kinetics data of a joint formation during aluminum alloy brazing. Data was generated by several groups of experiments conducted under conditions of a controlled oxygen level of the background brazing atmosphere. Generated data are examined to identify the phases of the joint formation and the time frame of its evolution. Specifically, the triple line kinetics data are analyzed to verify whether a power law between (1) the triple line of the molten metal preceding joint formation and (2) the formation time can be established for each formation phase. In addition, both initial and residual clad thicknesses on brazing sheets are studied to check phenomenologically an impact of silicon diffusion on joint formation. Formation shapes are also inspected in order to study if a 2-D configuration of joint formation is present. The kinetics data from different sets of experiments under adverse atmosphere conditions are compared to understand the impact of oxygen level on joint formation. This study is not necessarily aimed at building a mathematical model for T-Joint formation during brazing process, but intends to understand possible influential parameters on the development of the formation.
KEYWORDS: Aluminum Brazing, Kinetics, T-Joint, Background Atmosphere, Capillary Flow.
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Runte, David E. "Fundamental frequencies of I-joist, solid-sawn wood joist, and truss floors based of tee-beam modeling /." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-09192009-040550/.
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Fernandes, Monica Lente. "Relação do exame físico e ultrassonográfico do segmento lombo-sacro-ilíaco e do disco invertebral da articulação lombossacral com desempenho atlético em equinos." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-07072014-145019/.
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As dores lombares acometem a maioria dos atletas, inclusive os equinos. Somente o exame clínico não é suficiente para identificar a localização exata do foco doloroso. O diagnóstico definitivo só é atingido através da utilização dos meios diagnósticos complementares, neste caso, a ultrassonografia. Caso sejam constatadas anomalias discal lombossacras e/ou artropatias ITLS e/ou SI, o veterinário ainda não é capaz de quantificar a influência destas sobre o desempenho atlético do cavalo de esporte. Face a esta dúvida, objetivou-se estabelecer uma relação entre os achados dos exames físicos e ultrassonográficos, executados em 200 cavalos atletas, de quatro raças diferentes (Trote Francês, Quarto de Milha, Puro Sangue Inglês e Cavalos de Sela Francesa e Brasileiro de Hipismo). Todos os animais estavam em treinamento, participando de provas, e não apresentavam claudicação. Após exame físico, os animais foram avaliados ultrassonograficamente, por via transretal, para visualização do aspecto ventral do disco LS (L6-S1), das articulações intertransversas (ITLS) e sacroilíacas (SI), direitas e esquerdas. Para a avaliação transretal os animais foram colocados em tronco de contenção, não tendo sido observada necessidade de sedação ou emprego de outros métodos físicos. Ato contínuo foi introduzido um transdutor linear de 5-7,5 MHz e imagens do disco lombossacro, das articulações intertransversas lombossacras e sacroilíacas foram obtidas. A determinação do número de animais que apresentavam alterações durante os exames de inspeção, palpação, mobilização e avaliação dinâmica assim como a caracterização dos tipos de anomalias discais (T1, T2, T3 e T4) e artropatias ITLS e SI, sugere que durante a execução do exame físico, cavalos que não apresentem sinais clínicos não devem ser descartados de possuírem algum tipo de anomalia discal lombossacra e/ou atropatias ITLS e/ou SI. Observou-se também que as artropatias SI podem afetar o desempenho dos cavalos de trote atrelado, já para as artropatias ITLS e anomalias LS não houve significância quanto às suas influências aos achados no desempenho.Back pain affects most athletes, including horses. The clinical examination alone is not sufficient to identify the exact location of the painful focus. The definitive diagnosis is only achieved by using complementary diagnostic tools, in the case of this study the ultrasonography. Lumbosacral anomalies and intertransverse lumbosacral and sacroiliac arthropathies, if detected ultrasonographicaly, do not directly input in loss of performance or locomotor impairment. In order to assess this issue, this study aimed to establish a relationship between the findings of physical and ultrasound examinations, performed on 200 horses athletes, from 4 different breeds, French Trotters, Quarter Horse, Thoroughbred Horses and Show Jumpers. After physical examination, the animals were evaluated by a transrectal approach with ultrasonography and the images collected were, ventral aspect of the disc LS (L6-S1), intertransverse joints (ITLS) and sacroiliac (SI), right and left. To perform this evaluation, the animals were placed in the containment trunk with any sedation methods. Immediately thereafter introduced a 5 - 7.5 MHz linear transducer, images of lumbosacral, intertransverse lombossacral and sacroiliac joints were obtained. The determination of number of animals showing abnormalities during clinical examination of inspection, palpation, mobilization and dynamic examination as well as the characterization of the types of disc anomalies (T1, T2, T3 and T4) and arthropathies ITLS and SI, enabled the realization of the following framework, where even the patient, during the execution of the clinical examination, will not provide a positive signals for certain tests, this does not rule out the possibility it has some kind of anomaly in LS joint and/or arthropathy ITLS and/or SI. It was also observed that the arthropathy of SI can affect the performance of French Trotters, and anomalies of ITLS and LS have no significance or influence on athletic performance.
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Tiss, Amal. "Joint Reconstruction of Longitudinal Positron Emission Tomography Studies for Tau Protein Imaging." Electronic Thesis or Diss., Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2019SORUS387.pdf.
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L’accumulation des filaments appariés en hélices de la protéine tau (PHF tau) entraine un déclin cognitif rencontré dans la démence causée par la maladie d’Alzheimer (MA). Le radiotraceur 18F AV-1451, utilisé dans la tomographie par émission de positons (TEP), permet l’observation de la protéine tau in vivo. Pour déterminer le taux de dépôt des PHF tau dans le cerveau, l'approche classique consiste à effectuer deux scans séparés de 2 à 3 ans et à reconstruire les images TEP séparément. L’image différence obtenue souffre d’une grande variation dans l’intensité du signal. Un essai clinique nécessiterait alors un échantillon plus large pour déceler une différence significative entre un groupe recevant un traitement potentiel et un groupe contrôle. Notre nouvelle approche vise à reconstruire l’image différence directement des données TEP pour réduire la variance en introduisant une dépendance temporelle linéaire et en considérant la différence entre les doses injectées et le recalage entre les deux images. Pour valider la méthode, nous simulons différents niveaux de dépôt accru des PHF tau en créant une image artificielle à partir de données réelles d’un patient. Nous appliquons ensuite la méthode aux données de 123 sujets : 109 sains, 10 atteints de trouble cognitif léger et 4 souffrants de MA. La reconstruction jointe montre un meilleur contraste dans l'image différence créée par les simulations numériques et une variance considérablement réduite dans le changement du ratio de la valeur de fixation normalisée chez les sujets. La variance réduite de notre méthode entraine un échantillon plus petit pour un potentiel essai clinique contre la MAThe accumulation of the paired helical filament tau protein leads to the cognitive decline seen in Alzheimer’s disease (AD). The Positron Emission Tomography tracer, [18F]-AV-1451, permits the observation of PHF tau in vivo. To determine the rate of tau deposition in the brain, the conventional approach involves scanning the subject two times (2-3 years apart) and reconstructing the images separately. Region-specific rates of accumulation are derived from the difference image which suffers from an increased intensity variation making this approach inadequate for clinical trial looking at the effect of a candidate drug on tau because the increased variation leads to a higher sample size required. We propose a joint longitudinal image reconstruction where the tau deposition difference image is reconstructed directly from measurements leading to a lower intensity variation. This approach introduces a linear temporal dependency and accounts for spatial alignment, and the different injected doses. We validate the reconstruction method by simulating higher tau accumulation in real data at different intensity levels. We additionally reconstruct the data from 123 subjects: 109 healthy subjects, 10 suffering from mild cognitive impairment, and 4 diagnosed with AD. The joint reconstruction shows better contrast in the difference image obtained by the numerical simulations and a drastically reduced variance in the change of the Standard Uptake Value Ratio among subjects. The decreased variance of our method leads to a smaller sample size for a potential clinical trial evaluating the effect of a candidate drug against AD
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Satouri, Jamil. "Méthode d'éléments spectraux avec joints pour des géométries axisymétriques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2010. http://tel.archives-ouvertes.fr/tel-00815022.
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Dans cette thèse on s'est intéressé aux problèmes tridimensionnels de Laplace et de stokes dans des domaines axisymétriques. Ces problèmes sont réduits, sans approximation et par des développements en coefficients de Fourier en une famille dénombrable de problèmes bidimensionnels. Les domaines qu'on a considéré présentent des singularités géométriques et sont décomposés de façons non nécessairement conformes. Les non conformités sur les interfaces entre les sous domaines sont traités par la méthode des joints. La méthode de base de discrétisation est la méthode spectrale. On a montre alors des résultats d'approximation optimaux, proches de ceux trouves lors de l'approximation conformes avec des contraintes de continuités sur les interfaces. Ceci prouve encore une fois l'efficacité de la méthode des joints.
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Paccou, Elie. "Etude de l'évolution des propriétés mécaniques et de la sensibilité à la fissuration intergranulaire en fonction de la microstructure d'irradiation d'un acier 304 irradié aux ions lourds." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30119.
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L'IASCC est un phénomène de fragilisation observé dans les aciers austénitiques inoxydable utilisés comme éléments de structures internes des REP. L'ampleur et les caractéristiques du phénomène dépendent du matériau lui-même, du milieu primaire REP, de l'irradiation neutronique et des sollicitations mécaniques diverses que ces éléments subissent. La dégradation d'un de ces contributeurs permet de limiter ou de faire disparaître la sensibilité à la fissuration intergranulaire. Bien que des contributeurs tels que la localisation de la déformation et la ségrégation intergranulaire aient été identifiés, le rôle de la microstructure d'irradiation dans la sensibilisation d'un matériau à ce phénomène n'est pas totalement établi à ce jour. Le rôle des nanocavités d'irradiation sur l'IASCC, notamment celles situées aux joints de grain est questionné. Dans cette thèse, un acier austénitique inoxydable 304L a été soumis à différentes conditions d'irradiation dans le but de déterminer l'influence du durcissement, de la localisation et l'effet des cavités d'irradiation sur la fragilisation de ce matériau. Les échantillons d'acier ont été irradiés aux ions fer 10 MeV avec ou sans ajout d'hélium et sous deux températures différentes, 450° et 600°C. Les températures et l'ajout d'hélium permettent de modifier les microstructures d'irradiation. Une dose d'irradiation importante est nécessaire pour la germination de cavités, mais la taille et la densité de celles-ci ainsi que des boucles de Frank générées dépendent, bien entendu, des conditions d'irradiation employées. L'étude de la sensibilité des matériaux irradiés a montré que la microstructure ayant subi le plus fort durcissement est la plus sensible à la fissuration intergranulaire bien que celle-ci puisse apparaître après un faible durcissement. La microstructure d'irradiation, notamment la présence de cavités, semble réduire la sensibilité à la fissuration par une limitation de la localisation de la déformation ou par leur effet adoucissant. Dans cette étude, la présence de cavités aux joints de grain n'augmente pas la sensibilité à la fissuration intergranulaire. Pour l'étude du durcissement induit par irradiation, nous avons développé et réalisé des essais de microcompression in situ en MEB sur les matériaux irradiés aux ions. Ces essais en glissement simple montrent un effet important de la taille des micropiliers non irradiés, qui est atténué voire complétement annihilé par l'effet durcissant de la microstructure d'irradiation. Ces essais de microcompression conduisent à des résultats cohérents avec ceux établis par nanoindentation. Pour mieux comprendre l'effet de localisation de la déformation, nous avons fait varier la taille de grains du matériau à l'étude. Lorsque celle-ci diminue, la déformation se concentre d'autant plus sur les grains à forts facteurs de Schmid. De plus, la sensibilité à la fissuration diminue lorsque la taille de grain augmente, ce qui montre un effet du ratio entre la profondeur d'irradiation et la taille moyenne des grainsIASCC is a phenomenon of embrittlement observed in stainless austenitic steels used as internal structural elements of PWRs. The magnitude and the characteristics of the phenomenon depend on the material, the PWR environment, the neutron irradiation and the mechanical stresses that these elements undergo. The degradation of one of these contributors makes it possible to limit or eliminate the sensitivity to intergranular cracking. Although contributors such as deformation localization and intergranular segregation have been identified, the role of the irradiation microstructure on the susceptibility to this phenomenon of a material is not fully established. The role of irradiation nanocavities on IASCC, especially those located at grain boundaries is questioned. In this thesis, a 304L stainless steel austenitic was subjected to different irradiation conditions in order to determine the influence of the hardening, the localization and the effect of the irradiation cavities on the embrittlement of this material. The steel samples were irradiated with 10 MeV iron ions with or without helium and under two different temperatures, 450 ° and 600 ° C. These parameters made it possible to modify the microstructures of irradiation. The size and density of the cavities and the Frank loops generated are linked to the irradiation conditions employed. The study of the susceptibility of the irradiated samples has shown that the microstructure that underwent the strongest hardening is the most sensitive to intergranular cracking, although this susceptibility may appear after a weak hardening. The irradiation microstructure, in particular the presence of cavities, seems to reduce the sensitivity to cracking by limiting the location of the deformation or by their softening effect. In this study, the presence of cavities at grain boundaries does not increase sensitivity to intergranular cracking. For the study of radiation-induced hardening, we have developed and realized in situ microcompression tests in SEM on ion-irradiated materials. These simple slip tests show a significant effect of the size of unirradiated micropiliers, which is attenuated or completely annihilated by the hardening effect of the irradiation microstructure. These microcompression tests lead to results consistent with those established by nanoindentation. To better understand the localization effect of the deformation, we varied the grain size of the material under study. When this decreases, the deformation concentrates even more on grains with strong Schmid factors. In addition, the sensitivity to cracking decreases as the grain size increases, showing an effect of the ratio between the irradiation depth and the average grain size
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Berthou, Matthieu. "Fiabilité des assemblages sans plomb en environnement sévère." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00991011.
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Le mémoire porte sur l'étude de la fiabilité des assemblages utilisant des alliages de brasure sans-plomb en environnement sévère pour des applications électroniques. Une méthode de préparation métallographique fiable et reproductible en vue de l'analyse microstructurale est présentée. L'effet du vieillissement thermique statique sur l'évolution microstructurale de billes de brasure en SAC, la tenue à la fatigue mécanique des assemblages brasés et l'étude de l'endommagement thermomécanique sont développés. Le seul effet notable constaté après vieillissement thermique est l'augmentation des épaisseurs des intermétalliques de contact. A la suite de sollicitations mécaniques, les ruptures sont plus souvent observées dans les pistes que dans les brasures, et ne permettent pas d'incriminer des éléments de la microstructure brasée comme facteurs déterminant de propagation des fissures. Les sollicitations thermomécaniques conduisent à une recristallisation, et les fissures se propagent alors le long des joints de grains recristallisés.
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Leyland, Patricia E. "An analysis of the acquisition process of the Joint Fires Network/Tactical Exploitation System-Navy." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FLeyland.pdf.
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Huťka, Pavel. "Deformačně napěťová analýza TEP kyčelního kloubu – typ Santori." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-378901.
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Submitted Diploma thesis deals with stress-strain analysis of deformation proximal end of femur with applied total hip joint endoprosthesis (replacement) – shortcut type. To identify deformation and tensity (stress) was used computational simulation by method of final elements. Have been created two computational models TEP- type Santori and type DePuy Proxima. Geometry model Santori was created on low level model geometry through the use of X-ray photograph. Principle of geometry model type DePuy Proxima was real Femoral stem endoprosthesis which was scanned on scanner ATOS. Geometry of both these replacements were set up in program Rhinoceros 4.0 and then execute in program CatiaV5R17. Data for geometry model of femur were gained from CT chains. Material model of femur have been crated in two variants. The first one looks at structure bone tissues and the second one were created by Gruen´s zones. Femoral Stem was weighted by static equivalent resultant force acting in hip joint. Computational model of system and self solution, including depiction results, was done by ANSYS Workbench 11.0 for four model variants.
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Rýdel, Jiří. "Deformačně napěťová analýza TEP kyčelního kloubu – typ Mayo." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-378907.
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This diploma thesis deals with hip endoprothesis, primarily with endoprothesis conservative Mayo. A part of this paper considers a study aimed at an anatomy, types and modern trends in endoprothetic. On the basis of this study, gained CT data and the help of systems Ansys Workbench, Rhino Ceros and Catia there was made a model of proximal part of femur and TEP Conservative Mayo. A computational model was build up afterwards, which was used for a stress-train analysis.
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CREUZE, Jérôme. "Des surfaces aux joints de grains : la ségrégation dans tous ses états." Phd thesis, Université Paris Sud - Paris XI, 2000. http://tel.archives-ouvertes.fr/tel-00001572.
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Grand nombre des propriétés des alliages dépend de la structure et de la composition chimique des défauts. Dans ce contexte, nous avons étudié la ségrégation interfaciale d'un système présentant une forte démixtion en volume et une tendance à ségréger en surface (i.e. Cu/Ag), par simulations Monte Carlo avec déplacements et un modèle d'Ising effectif sur réseau rigide. Les interfaces considérées sont le joint de grains de flexion Sigma=5 (310) <001> ainsi que les surfaces (001) et (310). Les résultats obtenus en Monte Carlo pour le joint de grains montrent l'existence d un composé ordonné bi-dimensionnel dans le plan du joint... dans un système à tendance à la démixtion ! Pour la surface (001), nous montrons l'apparition d une surstructure cristallographique illustrant le couplage complexe entre ségrégation et modification structurale. L analyse par le modèle sur réseau rigide nous a permis de déterminer les forces motrices de ségrégation intergranulaire et superficielle. Le couplage des deux méthodes a mis en évidence le rôle important de l'entropie vibrationnelle dans la ségrégation intergranulaire, alors qu'elle peut être négligée pour la ségrégation superficielle. L'évaluation de l'entropie vibrationnelle de ségrégation doit tenir compte des couplages entre vibrateurs premiers voisins (le modèle d Einstein ne pouvant donc être utilisé) et de la dilatation thermique différentielle à proximité du joint de grains. Nous avons alors utilisé l'approche analytique pour déterminer les isothermes de ségrégation intergranulaire. Nous avons ainsi mis en évidence une transition de phase du premier ordre à caractère multicouche. Un comportement identique est obtenu pour la surface (310), les interactions inter-plan étant à l'origine de ces transitions. Cet aspect multicouche de la ségrégation intergranulaire a été confirmé par des simulations Monte Carlo montrant de plus l'apparition d un phénomène de mouillage, le joint de grains initial se scindant en deux interfaces séparées par une phase métastable.
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Tkadlec, Tadeáš. "Analýza mazání TEP kyčle s využitím fluorescenční mikroskopie." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-377516.
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This diploma thesis deals with an experimental analysis of lubrication of total hip joint replacement using fluorescence microscopy, focusing on so-called soft bearing pairs. Experiments were realized using a hip joint simulator, which was modified and refined for fluorescence microscopy. The aim of this diploma thesis was to determine the effect of the individual components of the synovial fluid on the lubrication mechanisms. For this purpose, different model fluids were designed to represent the composition of proteins and other synovial fluid constituents to elucidate the effect of albumin, -globulin and hyaluronic acid on the resulting lubrication performance. The experiments were separate into two categories different in type of load, dynamic (representative walking) and combined (representing standing with short walk). The experimental results were time-dependent fluorescence intensity values, representing dimensionless film thickness parameters. The values were recorded on the graphs and supplemented with fluorescence images taken during the characteristic sections of the measurements. The measured data was subsequently confronted with previously published articles. It was found that the dominant constituent responsible form film thickness is albumin, while -globulin and hyaluronic acid forms thin stable layer enhancing adsorption ability of albumin which contributes to increase of film thickness eventually.
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Přikryl, Adam. "Posouzení opotřebení extrahovaných polyetylenů TEP kyčle pomocí optických metod." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241862.
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An experimental methodology for wear assessment of extracted polyethylene hip implants was designed in this diploma thesis. Methodology uses optical 3D scanner and optical profilometer for analysis of wear. Designed methodology for wear analysis was validated by gravimetric method. The results of validation were in good agreement with the increase of wear rate. Validation results show that the methodology is not suited for wear assessment of metal and ceramic implants which have small wear rates. On the other hand the methodology is more than useful for wear assessment of polyethylene implants. Designed methodology for wear assessment was applied on the set of thirteen extracted polyethylene hip implants. Results of the wear analysis were wear volumes and linear wear noted in the wear maps. Roughness of the surface was measured on explanted cups and results were noted in the roughness map. On articulating surface of the cups different areas were observed for measured roughness. Those areas were described as area with machining marks from manufacturing process, polished area from combination of abrasive and adhesive wear, polished area from micro-contact fatigue and area including plastic deformation.
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Iwaza, Lana, and Lana Iwaza. "Joint Source-Network Coding & Decoding." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00855787.
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While network data transmission was traditionally accomplished via routing, network coding (NC) broke this rule by allowing network nodes to perform linear combinations of the upcoming data packets. Network operations are performed in a specific Galois field of fixed size q. Decoding only involves a Gaussian elimination with the received network-coded packets. However, in practical wireless environments, NC might be susceptible to transmission errors caused by noise, fading, or interference. This drawback is quite problematic for real-time applications, such as multimediacontent delivery, where timing constraints may lead to the reception of an insufficient number of packets and consequently to difficulties in decoding the transmitted sources. At best, some packets can be recovered, while in the worst case, the receiver is unable to recover any of the transmitted packets.In this thesis, we propose joint source-network coding and decoding schemes in the purpose of providing an approximate reconstruction of the source in situations where perfect decoding is not possible. The main motivation comes from the fact that source redundancy can be exploited at the decoder in order to estimate the transmitted packets, even when some of them are missing. The redundancy can be either natural, i.e, already existing, or artificial, i.e, externally introduced.Regarding artificial redundancy, we choose multiple description coding (MDC) as a way of introducing structured correlation among uncorrelated packets. By combining MDC and NC, we aim to ensure a reconstruction quality that improves gradually with the number of received network-coded packets. We consider two different approaches for generating descriptions. The first technique consists in generating multiple descriptions via a real-valued frame expansion applied at the source before quantization. Data recovery is then achieved via the solution of a mixed integerlinear problem. The second technique uses a correlating transform in some Galois field in order to generate descriptions, and decoding involves a simple Gaussian elimination. Such schemes are particularly interesting for multimedia contents delivery, such as video streaming, where quality increases with the number of received descriptions.Another application of such schemes would be multicasting or broadcasting data towards mobile terminals experiencing different channel conditions. The channel is modeled as a binary symmetric channel (BSC) and we study the effect on the decoding quality for both proposed schemes. Performance comparison with a traditional NC scheme is also provided.Concerning natural redundancy, a typical scenario would be a wireless sensor network, where geographically distributed sources capture spatially correlated measures. We propose a scheme that aims at exploiting this spatial redundancy, and provide an estimation of the transmitted measurement samples via the solution of an integer quadratic problem. The obtained reconstruction quality is compared with the one provided by a classical NC scheme.
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Letellier, Laurence. "Etude des joints de grains et interphases dans les superalliages Astroloy par microscopie électronique et tomographie atomique." Rouen, 1994. http://www.theses.fr/1994ROUES067.
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La sonde atomique et la microscopie électronique ont été utilisées parallèlement afin d'étudier la microstructure et la composition des joints de grains rectilignes et dentelés d'un superalliage à base nickel Astroloy. Les microanalyses à la sonde atomique ont révélé une ségrégation de bore, molybdène et un peu de carbone aux joints homophases ou hétérophases, dentelés ou rectilignes. Un important enrichissement en chrome est également observé aux joints '/'. La quantification de la ségrégation intergranulaire a pu être réalisée en utilisant la sonde atomique tomographique. L'épaisseur de la zone ségrégée a pu être estimée à environ 5A pour les joints dentelés. Les mécanismes de ségrégation ont été étudiés. En décomposant étape par étape le traitement thermique, nous avons montré que la majeure partie de la ségrégation intergranulaire avait lieu pendant le refroidissement entre 1150°C et 800°C. Concernant la comparaison entre joints rectilignes et joints dentelés, les taux de ségrégation par unité de surface sont les mêmes. Seul un changement dans la répartition spatiale des atomes au joint a été observé. Une étude des interfaces /' et de la composition de la phase dans un superalliage monocristallin (mc2) flué nous a permis de proposer une interprétation de la formation des plaquettes ' sous contrainte
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Jégou, Hervé. "Codes robustes et codes joints source-canal pour transmission multimédia sur canaux mobiles." Rennes 1, 2005. https://tel.archives-ouvertes.fr/tel-01171129.
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Cette thèse propose des codes robustes et des codes conjoint source / canal pour transmettre des signaux multimédia sur des canaux bruités. Nous proposons des codes entropiques offrant une résistance intrinsèque aux données prioritaires. Ces codes sont étendus pour exploiter la dépendance temporelle du signal. Un nouveau modèle d'état est ensuite proposé et analysé pour le décodage souple de codes à longueur variable avec une contrainte de longueur. Il permet de régler finement le compromis performance de décodage/complexité. Nous proposons également de séparer, au niveau du codage entropique, les étapes de production des mots de codes et de paquétisation. Différentes stratégies de construction de train binaire sont alors proposées. Enfin, la représentation en arbre binaire des codes entropiques est étendue en considérant des règles de réécriture. Cela permet d'obtenir en particulier des codes qui offrent des meilleures performances en décodage souple.
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Camelo, Lianna Silva. "Determinantes do desempenho em joint ventures brasileiras." Universidade de Fortaleza, 2017. http://dspace.unifor.br/handle/tede/104180.
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Previous issue date: 2017-08-29International Joint Ventures appear as an alternative to sharing costs and reducing risks to enter in globalized marketplace if compared with mergers and acquisitions. However, the plenty failure rates show that despite the lot of researches about this theme, there are some gaps that when explored could contribute to increase the success occurrence in this business. The general objective of this master¿s thesis is to identify the relevance of the Brazilian¿s IJV performance determinants in terms of organizational life cycle and evaluate how the cultural diversity determinant could contribute to increase the business results. To this end two papers were developed. In the first paper, the performance determinants relevance was investigated in terms of organizational life cycle, on the basis of this theme¿s specialists. In the second paper, it was developed the research about the cultural diversity determinant in terms of how this factor could be the raw material to increase the performance. The results show that the Joint Venture could priories actions involved to the efficient integration between the partner¿s resources, as well as, the customers and suppliers satisfaction and implement strategies to eliminate the competition action, since this is the most relevant determinants independent of the organizational life cycle. However, to this efficient integration happened, the Joint Venture needs to overcome the faced difficulties by the cultural diversity implementing management diversity strategies. Keywords: Joint Venture. Performance determinants. Cultural diversity.
Joint Ventures Internacionais caracterizam-se como uma alternativa de menor custo e risco para a inserção no mercado globalizado quando comparado com fusões e aquisições. Contudo, o grande índice de insucesso em alianças deste tipo mostra que apesar da ampla gama de pesquisas sobre o tema, ainda existem lacunas que quando exploradas podem contribuir para elevar a margem de sucesso neste tipo de negócio. A dissertação tem como objetivo geral identificar a relevância dos determinantes do desempenho de JVI fundadas no Brasil em função do seu ciclo de vida, avaliando como o determinante diversidade cultural pode alavancar resultados para a organização. Para isso foram desenvolvidos dois artigos. No artigo I foi investigada a relevância dos determinantes do desempenho em função do seu ciclo de vida com base na opinião de especialistas na área. No artigo II foi realizado um aprofundamento do determinante diversidade cultural a partir da investigação de como este fator por constituir-se em matéria-prima para a alavancagem do desempenho. Os resultados evidenciam a Joint Venture deve priorizar a estruturação de ações voltadas para a integração eficiente entre os recursos dos sócios, bem como a satisfação de clientes e fornecedores e estratégias para monitorar e mitigar as ações da concorrência, já que estes são os determinantes mais relevantes, independente do seu estágio no ciclo de vida organizacional. Contudo, para que esta integração eficiente ocorra, a JV precisa superar as dificuldades encontradas pela diversidade cultural implementando estratégias voltadas para garantir uma gestão eficiente dessa diversidade. Palavras-chave: Joint Venture. Determinantes de performance. Diversidade cultural.
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Billy, Frédéric. "Analyse de l'effet des surfaces texturées dans un film mince : application aux joints d'étanchéités." Phd thesis, Université de Poitiers, 2005. http://tel.archives-ouvertes.fr/tel-00012160.
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Le but de l'étude présentée est l'analyse d'un écoulement turbulent au sein d'un joint annulaire texturé. Le stator est usiné de centaines de trous cylindriques dont la profondeur peut atteindre 20 fois l'épaisseur du film. L'analyse de l'écoulement a été réalisée à l'aide de la résolution des équations complètes de Navier Stokes et d'une étude expérimentale complémentaire.Une première approche bidimensionnelle a permis la mise en évidence de l'apparition de deux phénomènes dus à la prise en compte des effets d'inerties : un effet de traînée provenant de la présence des cavités ainsi que l'existence d'un cisaillement fluide important au sein de la couche de mélange s'établissant au niveau de l'interface cavité-film mince. La validation des résultats numériques 2D a été réalisée avec succès grâce à la conception et la fabrication d'un banc d'essais original. Ce dispositif permet d'entreprendre des mesures PIV dans un écoulement de Couette en canal rainuré allant jusqu'à des régimes fortement turbulent (Re=10000). La modularité du montage a été prise en compte afin de pouvoir tester d'autres types de textures à l'avenir.
La deuxième étape a été la résolution des équations de Reynolds dans un canal équivalent où la texture est remplacée par son effet à travers une modification des lois de frottement du rotor et du stator, ainsi que par la prise en compte de l'effet de traînée comme un terme source. Des simulations tridimensionnelles, basée sur une configuration réaliste, ont été effectuées afin d'extraire les données nécessaires pour la modification des modèles de calcul du film mince. Les grandes différences par rapport aux anciens modèles sont que les lois de frottements du rotor et su stator sont calculées séparément et que la variation de l'épaisseur du film est prise en compte.
Les calculs montrent une amélioration des résultats pour les coefficients de raideur directe, de raideur croisée et d'amortissement direct, avec cependant une surestimation de ce dernier.
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El, Rhabi Mohammed. "Analyse Numérique et discrétisation par éléments spectraux avec joints des équations tridimensionnelles de l'électromagnétisme." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2002. http://tel.archives-ouvertes.fr/tel-00002224.
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Cette thèse a pour objet l'analyse et la discrétisation numérique des équations tridimensionnelles de l'électromagnétisme. Ces travaux débutent par l'étude de ces équations dans un domaine b orné multiplement connexe. Un théorème d'existence général a été établi, en proposant une nouvelle approche du problème, en le reformulant à l'aide d'un opérateur approprié, tenant compte des omplexités géométriques du domaine. Dans la suite, après avoir donnée un résultat de régularité, on propose une approximation numérique de la solution par une méthode spectrale. La méthode est, d'une part, analysée numériquement dans le cas d'une décomposition conforme du domaine, et d'autre, implantée dans le cadre d'un code 3D. Des tests numériques illustrant les prévisions théoriques sont exposés et comparés à ceux obtenus par une méthode d'éléments finis de type P1 qu'on présentera sommairement. En outre, les quatre premières valeurs propres du problème discret sont calculées et comparées à celui du spectre exact. La dernière partie de cette thèse est consacrée à l'étude d'une décomposition de domaine par une méthode spectrale avec joints pour le problème de Maxwell. Il est utile de souligner que les paramètres physiques sont considérés dans cette partie comme pouvant être hétérogènes. On applique cette méthode à un problème type présenté. Ce dernier permet d'unifier deux approches qui habituellement sont distinguées: le problème d'évolution de Maxwell, et le problème de Maxwell en régime harmonique. Des estimations d'erreurs sont démontrées, elles reposent sur un lemme, qui est une variante du second lemme de Strang, permettant de décomposer l'erreur en la somme de trois erreurs principales: l'erreur sur la meilleure approximation, l'erreur de consistance et l'erreur d'intégration numérique. Cette dernière étant obtenue de ma ière classique, les deux autres erreurs ont nécessité une recherche plus approfondie, notamment, la définition d'opérateurs discrets et un Lemme d'augmentation de degré pour l'erreur sur la meilleure approximation. Enfin des courbes d'erreurs et des tests numériques sont exposés validant un code de calcul tridimensionnel développé pour l'approximation de la solution du problème type (pour des paramètres physiques homogènes et hétérogènes).
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Daveau, Gaël. "Interaction dislocations - joints de grains en déformation plastique monotone : étude expérimentale et modélisations numériques." Phd thesis, Ecole Centrale Paris, 2012. http://tel.archives-ouvertes.fr/tel-00740650.
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Modéliser la déformation plastique des polycristaux est un objectif majeur de la science des matériaux. Tous les modèles actuels comportent une partie phénoménologique n'ecessitant un ajustement de paramètres sur des résultats expérimentaux. Cette thèse vise à mettre en place un nouveau modèle, justifié physiquement, sans paramètre ajustable et adapté à la modélisation du polycristal CFC en sollicitation monotone. Afin de mesurer les champs mécaniques à l'échelle du micromètre, des mesures de microdiffraction Laue ont été réalisées sur un tricristal de cuivre à une faible déformation plastique. Ces mesures nous renseignent sur les mécanismes plastiques intervenant très près des joints de grains et définissent des états de référence pour les simulations. On montre principalement que la déformation plastique s'accompagne d'un stockage de dislocations géométriquement nécessaires (GND) aux joints de grains, en relation avec l'apparition de contraintes internes à longue distance. Des simulations de Dynamique des Dislocations dans des bicristaux ont 'et'e réalisées afin de caractériser les phénomènes physiques mis en œuvre. Ces simulations confirment que l'interaction dislocations - joints de grains s'accompagne d'un stockage de GND sous la forme de microstructures tridimensionnelles très inhomogènes. Les propriétés mécaniques induites par ce phénomène complexe peuvent être quantifiées par des lois continues élaborées à partir de l'approximation théorique d'un empilement unidimensionnel. Les lois de comportement ainsi définies ont ensuite été incorporées dans une modélisation micromécanique de plasticité cristalline, jusqu'ici dédiée au monocristal CFC. Le modèle ainsi construit a maintenant la capacité de prédire les mesures réalisées sur le tricristal de cuivre. Nous avons ainsi mis en place un modèle physiquement justifié et adapté 'a la modélisation du polycristal CFC en sollicitation monotone.
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Bartošík, Jan. "Vliv velikosti hlavice na procesy tření a mazání v TEP kyčle." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231946.
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This diploma thesis concerns itself with the experimental study of friction and lubrication in the artificial hip joint depending on the head size. Measurements were made in a hip joint simulator based on the principle of pendulum. For the friction measurements artificial joints, made from three material combinations and two diameters, from two companies were used. The measurements show that the material combination has a more significant effect to friction coefficient than the head size. Using a bigger head size shows a decrease in friction coefficient for all material combinations when compared to a smaller head size. For the measurement of lubrication film the colorimetric interferometry was applied. A metal-on-glass contact pair was used, where the glass cups were made according to the real measurements of the joint cups. Four types of hip replacements with diameters of 28 and 36 mm with two different diametral clearance were measured during a constant motion of 210 seconds. Measurements show, that the lubrication film in the hip joint with a small diametral clearance increases very fast over the 800 nm value. Contact surfaces in the hip joint with a large diametral clearance aren’t separated by the lubrication film, resulting in a damage of the chromium coating in cup. A thick lubrication film results in a higher friction coefficient, when compared with hip joints with a very thin or no lubrication film.
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Vu, Xuan Thang. "Joint Network / Channel Decoding over Noisy Wireless Networks." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01060330.
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Network coding (NC) has gained much research attention as a potential candidate to solve the demand for higher spectral e ciency of modern wireless communications. Many research papers have investigated the performance of NC-aided networks such as throughput and outage capacity. However, the analysis of NC in practical systems where NC is combined with other techniques such as channel coding is still immature to fully understand its potential performance. In this thesis, we aim to design high performance receivers and analyze its performance for network-coded cooperative networks in practical scenarios. Firstly, we propose two Iterative Network/Channel Decoding (INCD) algorithms for the Multiple-Access Relay Channel (MARC) with two notable relaying schemes named Decode-and-Forward (DF) and Demodulate-and-Forward (DMF). The INCD algorithm operates based on turbo-like decoding methods and reduces the impact of the error propagation problem with the aid of a channel-aware receiver design. Both perfect Channel State Information (CSI) and imperfect CSI at the receiver side are investigated. We propose a practical method that forwards the quantized version of the relay decoding errors to the destination. It is shown that the proposed algorithms achieve full diversity gain and signi cantle outperforms solutions which do not take care of error propagation. We also show that the number of pilot symbols a ects only the coding gain but has a negligible impact on the diversity order, while the quantization level a cts both the diversity and coding gain. Secondly, we propose a Near Optimal Joint Network/Channel Decoding (NOJNCD) algorithm for the MARC that allows to analyze the system Bit Error Rate (BER). The NOJNCD algorithm performs network decoding and channel decoding in one decoding step of the super code, which comprises of all trellis states of individual code at the sources via NC. Furthermore, NC combined with Relay Selection (RS) is considered and the achievable diversity order is studied with the aid of outage analysis. We analytically show that Single Relay Selection (SRS) always achieves a diversity order two and Multiple Relay Selection (MRS) can achieve full diversity gain only when the number of selected relays exceeds the number of the sources. Last but not least, we propose a so-called partial relaying protocol to improve the spectral e ciency for channel coding assisted relay networks. Closed-form expression of the BER and the system diversity order are computed for partial relaying. We show, by analysis and simulations, that with a proper Convolutional Code (CC), partial relaying can achieve full diversity gain and same coding gain as the classical (full) relaying protocol in nite signal-to-noise ratio region while it obtains a better spectrum usage. Moreover, we propose a new protocol based on partial relaying in opportunistic relaying cooperative networks and show that this protocol signi cantly outperforms the NC-based cooperation in some circumstances.
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Simões, Carla Costa. "A joint venture contratual e o direito concorrencial." Universidade Presbiteriana Mackenzie, 2012. http://tede.mackenzie.br/jspui/handle/tede/1066.
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Previous issue date: 2012-09-04The contractual joint venture comes from an association of interests synthesized in a contract, which will determine all wills and goals of co-venturers. The connection between contractual joint venture and competition law occurs when a non corporate joint venture s creation, being a contractual legal instrument as is, can be adjusted by the parties as best fit them. Such a contractual association may aim to infringe freedom of competition, which affects the economic power, and, as a result of the relationship merely contractual, it is difficult for the State to monitor this conduct.
A joint venture contratual advém de uma associação de interesses sintetizada em um contrato, que determinará todas as vontades e objetivos dos coventurers. A ligação do instituto da joint venture contratual com o direito da concorrência ocorre na medida em que a criação de uma non corporate joint venture, sendo um instrumento jurídico contratual como é, pode ser ajustada pelas partes como melhor lhes aprouverem. Tal associação contratual poderá ter como objetivo infringir a livre concorrência, o que afeta o Poder Econômico, e, em razão da relação meramente contratual, é difícil para o Estado fiscalizar este tipo de conduta.
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Ravaud, Romain. "Etude analytique des systèmes magnétomécaniques sans fer : application au haut-parleur guidé par joints de ferrofluide." Phd thesis, Université du Maine, 2009. http://tel.archives-ouvertes.fr/tel-00441482.
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Cette thèse a pour objet la modélisation analytique des systèmes à aimants permanents. Leurs caractérisations supposent la détermination du champ magnétique qu'ils produisent et des énergies spécifiques mises en jeu. Les premiers travaux français réalisés par Durand en 1960 concernent principalement le calcul de champ créé par des aimants parallélépipédiques (structures planes) et des anneaux aimantés axialement. Les expressions analytiques des forces et couples, publiées par G. Akoun et J. P. Yonnet, et plusieurs études analytiques menées par F. Bancel et G. Lemarquand, dès les années 80-90, dénotent un intérêt manifeste pour l'optimisation des structures à aimants permanents. Les progrès de fabrication des aimants ouvrent alors des perspectives industrielles notables. Dès la fin des années 90, E. P. Furlani, B. Azzerbonni, E. Cardelli ou encore J.P. Selvaggi, S. Salon et M. V. K. Chari proposent des approches semi-analytiques et des développements sériels pour calculer le champ magnétique créé par des structures à topologie cylindrique. Dans ce prolongement, nous exposons dans cette thèse les expressions analytiques du champ magnétique créé par des anneaux de polarisation radiale. Ces modèles analytiques nous permettent d'évaluer le champ magnétique en tout point de l'espace. De façon connexe, nous établissons les formules du champ magnétique créé par un anneau aimanté axialement sous une forme plus générale que celle établie par Durand. De façon concomitante, S. I. Babic et C. Akyel développent en 2008 des modèles analytiques simplifiés du champ créé par des anneaux aimantés radialement et axialement. Dans un second temps, nous présentons les expressions du champ magnétique créé par des tuiles aimantées radialement, axialement et orthoradialement. Ces expressions sont basées sur des intégrales elliptiques incomplètes pour le cas des polarisations axiale et radiale. Dans le cas de la polarisation orthoradiale, l'expression du champ magnétique ne nécessite pas l'utilisation de fonctions spéciales. Notons que ces aimants à topologie courbe sont largement utilisés dans la conception de machines électriques, d'accouplements ou encore de capteurs. Néanmoins, les aimants en forme de tuiles sont généralement fabriqués avec des aimantations uniformes pour des raisons technologiques et économiques. Ainsi, les tuiles conjecturées à aimantation radiale, orthoradiale ou axiale ont usuellement une aimantation uniforme. Cette caractéristique d'uniformité engendre des ondulations de champ qui dépendent du nombre de tuiles utilisées. En conséquence, nous présentons les expressions du champ magnétique créé par des tuiles aimantées uniformément dans toutes les directions. Nous comparons les aimantations uniformes et idéales (radiale, orthoradiale et axiale) pour déterminer l'influence de l'uniformité de l'aimantation sur les caractéristiques du champ magnétique produit. Ces expressions nous permettent de modéliser et d'optimiser les structures de Halbach et de prédire les effets notoires résultants de l'uniformité de l'aimantation. Ces mêmes effets sont étudiés dans le cadre des structures dédiées à l'Imagerie par Résonance Magnétique. On propose ainsi un modèle analytique général permettant de reconstruire le champ magnétique produit par un assemblage d'aimants à aimantations tournantes uniformes. Les expressions exactes des forces, raideurs et couples s'exerçant entre anneaux et tuiles aimantées radialement, axialement ou uniformément, sont établies afin d'étudier tout dispositif constitué d'aimants permanents. Des modèles semi-analytiques aboutissent à l'optimisation d'accouplements magnétiques, de paliers passifs constitués d'anneaux et d'actionneurs linéaires. La deuxième partie de cette thèse traite de l'étude d'un haut-parleur sans fer. La présence du fer dans les pièces polaires est un inconvénient majeur dans la conception de moteurs de haut-parleurs électrodynamiques. Une nouvelle structure de haut-parleur sans fer, développée par G.~Lemarquand, permet de s'affranchir des non-linéarités engendrées par le fer et les suspensions périphériques. Ces suspensions sont remplacées par un ou plusieurs joints de ferrofluide dont le comportement mécanique dépend intrinsèquement du champ magnétique produit par sa structure. Les travaux antérieurs sur les ferrofluides (notamment R. E. Rosensweig) concernent essentiellement leurs propriétés d'étanchéité et thermiques. Nous envisageons dans cette thèse d'utiliser le ferrofluide pour ses propriétés mécaniques. Les outils analytiques caractérisant les champs magnétiques créés par des aimants permanents sont utilisés dans le cadre de l'étude de haut-parleurs sans fer. En effet, les expressions analytiques du champ magnétique conduisent à un modèle énergétique décrivant les propriétés mécaniques d'un joint de ferrofluide guidant le piston émissif d'un haut-parleur sans fer. Ce modèle est basé sur l'interaction du champ produit par la structure et l'aimantation saturée des particules ferromagnétiques du ferrofluide. La pression magnétique dans ce joint fixe ses raideurs radiale et axiale, son volume, sa forme et sa répartition dans l'entrefer du haut-parleur. La validité de ce modèle est confirmée par des mesures expérimentales. L'ensemble des travaux présentés dans ce mémoire fonde une démarche d'analyse des systèmes à aimants basée sur un mode opératoire exclusivement analytique. D'un côté, les modèles exacts des champs suggèrent des optimisations précises et rapides des dispositifs magnétomécaniques. D'autre part, appliqués au dimensionnement d'un joint de ferrofluide, ces modèles permettent des études paramétriques sur l'évolution de la pression du ferrofluide dans un entrefer en fonction des dimensions des aimants utilisés.
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Caggegi, Carmelo, and Carmelo Caggegi. "Experimental analysis of the efficiency of carbon fiber anchors applied over CFRP to firebrick bonded joints." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00861023.
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In these recent years, the strengthening of masonry building has known a massive use of CFRP sheets. Those composite materials glued on the elements to reinforce are exposed to prematurely debonding crisis due to a tension load which is much smaller than the tensile strength of the CFRP. A way to upgrade failure load of CFRP-to-support bonded joint is to reinforce the cohesion between the fibers and the support by the use of mechanicals anchors built with the same fibers of the composite and fastened in the support like "nails". Research on the use of anchors for masonry supports has been limited and, in this framework, there are no experimental analyses related to the design and the placement of fiber anchors. The aim of this thesis is to provide experimental data to quantify the efficiency of the carbon fiber anchors applied on a reinforced fire brick. This is a ground work to study CFRP to masonry bonded joint fastened by fiber "nails". Specifically, the analysis of the displacement and the strain fields of the reinforced surface have been realized by means of Digital Image Correlation (DIC), an optical appealing method never used to study a FRP to support bonded joint fastened by FRP anchor. The research demonstrates that the use of the CFRP anchor increases the resistance and the ductility of the reinforcements. The latter are important to augment the mechanical features of the structural members and, especially, to increase the safety of people during earthquakes by avoiding the brittle collapse of the strengthened elements. The digital image correlation has been a good tool for the strain field analysis; strengths and weaknesses of this method have been evaluated
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Silva, Maíra Jéssika Fernandes. "Corporate venturing externo: o impacto das aquisições e joint ventures no desempenho das empresas." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6316.
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External Corporate Venturing is one of the dimensions of corporate entrepreneurship, entrepreneurship practiced by existing companies. Through external corporate venturing companies seek survival, consolidation in the market in which they operate, explore new markets and obtain better financial returns. For the practice of external corporate venturing companies can make acquisitions, joint ventures, licensing, mergers and corporate venture capital transactions. This study focused on acquisitions and joint ventures as external corporate venturing practices. The impact of these practices on business performance is still inconclusive, so the aim of this study was to assess the impact of external corporate venturing in the performance of large companies. For this, we used secondary data disclosed by companies in the consumer discretionary sector and non-cyclical listed on the Bolsa de Valores de São Paulo (Bovespa). We analyzed the relevant facts disclosed in Comissão de Valores Mobiliários (CVM) for the collection of data on the ad acquisitions and joint ventures undertaken by those companies during the years 2010-2014, and the financial statements on the Bovespa for the collection financial data for performance measurement. The data were analyzed by regression data into fixed effect and random effect panel. Regression models were estimated with the performance variables return on assets (ROA) and return on equity (ROE). The results indicate that the realization of acquisition and joint venture operations have no statistically significant impact on ROA and ROE of large companies listed on the Bovespa. Although the results are not consistent with some previous studies on the topic, present contributions to the theory and practice, especially regarding the aspect of time that can be decisive in the relationship between acquisitions and joint venture operations and performance. For future studies recommended a bigger time horizon and verification of goals and strategies that companies have to invest in acquisitions and joint venture operations, because if adopted for the purpose of short-term financial returns may not be the most suitable .
O corporate venturing externo é uma das dimensões do empreendedorismo corporativo, o empreendedorismo praticado por empresas já existentes. Por meio do corporate venturing externo as empresas buscam a sobrevivência, consolidação no mercado em que atuam, exploração de novos mercados e obtenção de melhores retornos financeiros. Para a prática do corporate venturing externo as empresas podem realizar operações de aquisições, joint ventures, licenciamentos, fusões e corporate venture capital. Este estudo enfocou as aquisições e joint ventures como práticas de corporate venturing externo. O impacto destas práticas no desempenho das empresas ainda é inconclusivo, assim o objetivo deste estudo foi verificar qual o impacto do corporate venturing externo no desempenho das grandes empresas. Para isso, foram utilizados dados secundários divulgados pelas empresas dos setores de consumo cíclico e não cíclico listadas na Bolsa de Valores de São Paulo (Bovespa). Analisou-se os fatos relevantes divulgados na Comissão de Valores Mobiliários (CVM) para a coleta de dados referentes aos anúncios de aquisições e joint ventures realizados por essas empresas durante os anos de 2010 a 2014, e os demonstrativos contábeis na Bovespa para a coleta de dados financeiros para a mensuração do desempenho. Os dados foram analisados por meio de regressão com dados em painel de efeitos fixos e efeitos aleatórios. Os modelos de regressão foram estimados com as variáveis de desempenho retorno sobre o ativo (ROA) e retorno sobre o patrimônio líquido (ROE). Os resultados indicam que a realizaçao de operações de aquisição e joint ventures não apresentam impactos significativos estatisticamente no ROA e no ROE das grandes empresas listadas na Bovespa. Apesar dos resultados não serem condizentes com alguns estudos realizados anteriormente sobre o tema, apresentam contribuições para a teoria e para a prática, principalmente em relação ao aspecto do tempo que pode ser determinante na relação entre operações de aquisições e joint ventures e desempenho. Para estudos futuros recomenda-se um horizonte temporal maior e a verificação dos objetivos e estratégias que as empresas possuem ao investir em operações de aquisições e joint ventures, pois se forem adotadas com o objetivo de retornos financeiros a curto prazo podem não ser as mais indicadas.
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Oliva, Victor Hugo Gaitán. "Propagação de fraturas em juntas rugosas não-persistentes." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-01032005-172004/.
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O presente trabalho foi realizado para estudar o efeito sobre a propagação de fraturas em juntas não-persistentes quando existe uma variação da rugosidade nas juntas. Para esta abordagem, foram analisados os modos de coalescência, o ângulo de início das fraturas, a resistência à compressão e deformação de modelos de argamassa contendo juntas não-persistentes e submetidos a estados biaxiais de tensão. Na literatura especializada encontram-se vários trabalhos que estudam o comportamento de juntas lisas não-persistentes. Infelizmente, este tipo de juntas não leva em conta os efeitos da dilatância e do aumento do atrito. Neste estudo, desenvolveu-se um método para produzir juntas rugosas não-persistentes dentro dos moldes de argamassa. Desta forma, conseguiu-se comparar os diferentes modos de ruptura, tanto para as juntas lisas como as rugosas. A configuração geométrica usada foi de 15 juntas com 'alfa' = 54 graus; 'beta' = 60 graus; Lj = Lb = 50mm e d = 25mm. Onde 'alfa' é o ângulo gerado entre o plano de uma junta e o plano formado entre as pontas de juntas não-coplanares, 'beta' é a inclinação da junta com respeito ao plano de tensão maior, Lb denota à distância entre juntas paralelas coplanares, Lj é o comprimento da junta e d é a distância entre juntas paralelas não coplanares. Estes parâmetros mantiveram-se constantes em todos os ensaios, tanto para as juntas lisas (JRC = 0) como as rugosas (JRC = 6,96 e JRC = 12,25). Usando os parâmetros acima mencionados, observou-se que o tipo de ruptura sempre aconteceu por escalonamento. Para as amostras contendo as juntas lisas, JRC = 0, o mecanismo principal de coalescência entre as juntas é a tração. Para estas juntas, os ângulos de início das fraturas, em média, resultaram de 64º e 65º para esquerda e direita, respectivamente. Em média, a resistência a compressão normalizada ('sigma'nor = 'sigma'1 - 'sigma'2 / 'sigma'cs; onde 'sigma'1 e 'sigma'2 são as tensões principais e 'sigma'cs é a resistência média à compressão simples) destes corpos de prova resultou ter o valor mais baixo, 'sigma'nor = 0,52, e a maior deformação, 'épsilon' = 0,0057. No caso das juntas com JRC = 6,7, a coalescência ocorreu tanto por tração como por cisalhamento, descrevendo um caminho ondulante entre as pontas das juntas. O ângulo médio de início das fraturas foi de 40º para o lado esquerdo e 48º para o lado direito. A resistência média normalizada destes corpos a compressão foi de 'sigma'nor = 0,54 e uma deformação de 'épsilon' = 0,0053. Com as juntas com JRC = 12,3, a coalescência também apresentou ambos os mecanismos, tração e cisalhamento, seguindo uma direção inclinada no início e trajetória reta no meio. Os ângulos de início obtidos foram 5º no lado esquerdo e 20º do lado direito. Os valores maiores de resistência média normalizada e o valor médio menor de deformação foram obtidos nestes tipo de juntas, sendo estes de 'sigma'nor = 0,59 e 'épsilon' = 0,0045. Verificou-se então que a rugosidade tem uma grande influência sobre a propagação da fratura, afetando grandemente o modo de coalescência, o ângulo de início de propagação das fraturas e a resistência e deformação total dos corpos de provaThe present experimental study was conducted to investigate the effect of joint roughness on the fracture propagation of models with non persistent joints. For this approach the parameters investigated are : coalescence, the crack initiation angle, the compressive strength and deformation of the mortar samples containing non-persistent rough joints under biaxial loading. There are many works in specialized literature that study the behavior of non-persistent smooth joints, unfortunately, this kind of approach does not take into account the effect of the dilation and the increase of friction due to the joint roughness. In this study, a new method was developed to produce non-persistent rough joints inside the mortar models. With this method it was possible to compare the different paths of rupture generated for the smooth and for the rough joints. Each sample had 15 joints with 'alfa' = 54º; 'beta' = 60º; Lj = Lb = 50mm and d = 25mm. Where 'alfa' is the formed angle between the joint plane and the plane generated by two non coplanar joint tips, 'beta' is the joint inclination angle with the principal plane stress, Lb is the distance between coplanar joints, Lj is the length of the joint, d is the distance between two non-coplanar joints. These parameters remained constant in all the tests; the only variation permitted was in the joint roughness : from smooth joints (JRC = 0) to rough joints (JRC = 6,96 and JRC = 12,25). Using the mentioned parameters before it was always obtained the stepping failure. For the samples containing smooth joints, JRC = 0, the main mechanism of coalescence is tension. For these joints the average crack initiation angles, had resulted of 64º and 65º for left and right side, respectively. The average normalized compression strength ('sigma'nor = 'sigma'1 - 'sigma'2 / 'sigma'cs; where 'sigma'1 and 'sigma'2 are the principal stresses and 'sigma'cs is the average compression strength) of these tests resulted to have the lowest value, 'sigma'nor = 0,52, and the highest deformation, 'épsilon' = 0,0057. In the case of joints with JRC = 6,7; the mechanisms of coalescence are tension and shear, growing in a waving path between the joint tips. The average crack initiation angle was of 40º for the left side and 48º for the right side of the joint. The average normalized compression strength of these tests was of 'sigma'nor = 0,54 and deformation 'épsilon' = 0,0053. With joints having JRC = 12,3; the coalescence also presents both mechanisms, tension and shear, following a direction inclined in the beginning and a straight line in the middle of the way. The crack initiation angles had been : 5º in the left side and 20º of the right side. The highest values of average normalized strength resistant and the lowest average value of deformation were found in this type of joint, being of 'sigma'nor = 0,59 e 'épsilon' = 0,0045 respectively. With this approach, it was verified that the joint roughness influence the fracture propagation, affecting the coalescence, the crack initiation angle, the resistance and total deformation of the tested specimens
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Felix, Valtuir Barbosa. "Prevalência de disfunção temporomandibular em pacientes com Síndrome de Moebius: aspectos clínicos e imaginológicos." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/23/23141/tde-18082010-120618/.
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A síndrome de Moebius (SM) é pouco freqüente e caracterizada por paralisia total ou parcial de certos pares cranianos, obrigatoriamente VI e VII, podendo associar-se a outras anormalidades. Clinicamente ocorre falta de expressão facial, hipoplasia da língua, micrognatia, lábio curto e maloclusão. Disfunção temporomandibular (DTM) não tem sido estudada em pacientes com SM. O objetivo deste estudo é conhecer a prevalência de DTM em pacientes com SM e comparar a incidência e tipo de DTM com um grupo controle. Para tanto, foi realizado um estudo clínico caso controle observacional randomizado, no Centro de Atendimento a Pacientes Especiais (CAPE) da Faculdade de Odontologia da Universidade de São Paulo (FOUSP), entre julho de 2007 e dezembro de 2009, que avaliou 101 pacientes divididos em dois grupos: Grupo de estudo (GE) composto por 36 pacientes com SM, sendo 16 do gênero masculino e 20 do gênero feminino, com idade média de 10,2 anos, variando de 3 a 18 anos de idade; e grupo controle (GC) composto por 65 pacientes sem SM e sem nenhuma deformidade crânio facial, sendo 36 do gênero masculino e 29 do gênero feminino, com idade média de 10,7 anos, variando entre 3 e 18 anos. Nossos resultados mostraram que dos 36 pacientes do GE, 20 tinham DTM ou sinal de DTM (bruxismo). Desses 20 pacientes com DTM, 15 realizaram tomografias computadorizadas de ATM (TCs). Dos 65 pacientes do GC, 8 tinham DTM ou sinal de DTM (bruxismo) e 6 concordaram em realizar as TCs. Foram obtidas imagens volumétricas multiplanares e 3D. As alterações morfológicas indicando processo degenerativo encontrado nos exames de imagem encontradas nos dois grupos foram semelhantes. Concluimos que DTM é mais freqüente em pacientes com SM e que o diagnóstico em idade tenra pode representar uma oportunidade de prevenção e tratamento precoce da doença evitando seqüelas futuras. Por esta razão a avaliação da ATM deve ser incluída no exame clínico odontológico rotineiro de pacientes com a SM.Moebius syndrome (MS) is rare and characterized by partial or total paralysis of some cranial nerves, unavoidably VI and VII, and may be associated with other abnormalities. The clinical aspects include lack of facial expression, hypoplasia of the tongue, micrognathia, short lip and malocclusion. Temporomandibular Joint disorders (TMJ) has not been studied in patients with MS. The aim of this study is to assess the prevalence of TJD in patients with MS and to compare the incidence and type of TMJ with a control group. We conducted a case-control randomized observational clinical study at the Special Care Dentistry Center, Dental School, University of São Paulo, between July 2007 and December 2009, which evaluated 101 patients divided into two groups: Study group (SG), composed of 36 patients with MS, 16 males and 20 females, mean age 10.2 years, ranging from 3 to18 years of age, and the control group (CG) composed of 65 patients without MS and with no craniofacial deformity, 36 male and 29 female, mean age 10.7 years, ranging between 3 and 18 years. Among 36 patients of the SG, 20 had TMJ. Among them, 15 were submitted to computed tomography (CT). Of the 65 CG patients, 8 had TMJ and 6 were submitted to CTs. Volumetric multiplanar and 3D images were obtained. The morphological changes of the TMJ demonstrating the pattern of the degenerative process found in patients with SM was similar to that found in people from control group. We concluded that the prevalence of TMJ in patients with MS is higher in SM patients and the diagnosis at an early age may represent an opportunity for prevention and early treatment of disease by avoiding future sequels. For this reason the evaluation of the TMJ should be included in routine clinical dental examination of patients with MS.
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Mendonça, Giselle Bonifácio Neves. "Goniometria em cães da raça Rottweiler." Universidade Federal de Goiás, 2009. http://repositorio.bc.ufg.br/tede/handle/tde/2876.
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Dissertacao_Giselle_Mendonca.pdf: 1021339 bytes, checksum: 1524c07974484631f5d2ebb69ce0400a (MD5)Made available in DSpace on 2014-08-01T14:44:05Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertacao_Giselle_Mendonca.pdf: 1021339 bytes, checksum: 1524c07974484631f5d2ebb69ce0400a (MD5) Previous issue date: 2009
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Goniometry has been used in canine orthopedics to assess clinics, surgical and/or therapy physical treatment efficacy involving shoulder, elbow, carpal, hip, stifle and tarsal. However, in dogs this procedure is few studied and validated to scientifics researches. The purposes of this experiment were to estimate the maximum flexion and extension angle of shoulder, elbow, carpus, hip, stifle and tarsus and carpus adduction and abduction in dogs with breed Rottweiler, compare goniometric joint measurements obtained from no sedated, sedated and measurements made in radiography, and compare this goniometric joint measurements between males and females. The goniometric assess was accomplished by universal plastic goniometer, in 11 dogs Rottweilers, clinically healthy, in Goiânia-GO. One examiner accomplished assess, tree times, in each joint position (flexion and extension of shoulder, elbow, carpal, hip, stifle and tarsal, as well as carpus adduction and abduction) before and after dogs sedation. Also, accomplished measurements from radiographs taken of these joint positions while dogs were sedated, totalizing 1386 measurements. To compare the joint goniometric measure mean of animal nonsedated, sedated and radiographs was used the Friedman test. To compare the goniometry between males and females was used the t test. The differences were considered significant at values of p 0,05, for all comparisons. The results indicated that joint measurements did not differ significantly when compared goniometric measurements in nonsedated dogs, sedated and radiographs, for all joints positions evaluated, exception for shoulder and stifle extension and carpus adduction. Also, no significant differences were identified between the sexes, exclusion the shoulder extension in sedated dogs and carpus abduction in radiographs taken.
A goniometria tem sido usada na ortopedia canina para avaliar a eficácia do tratamento clínico, cirúrgico e/ou fisioterapêutico envolvendo o ombro, cotovelo, carpo, quadril, joelho e tarso. Entretanto, em cães, este procedimento é pouco estudado e validado por pesquisas científicas. Este experimento teve como objetivos estimar o ângulo máximo de flexão e extensão do ombro, cotovelo, carpo, quadril, joelho e tarso e adução e abdução do carpo de cães da raça Rottweiler, comparar as medidas goniométricas das articulações obtidas dos animais não-sedados, sedados e medidas obtidas por radiografias e comparar as medidas goniométricas destas articulações entre machos e fêmeas. Realizou-se a avaliação goniométrica, utilizando goniômetro de plástico universal, em 11 cães Rottweilers, clinicamente saudáveis, em Goiânia-GO. Um examinador realizou a avaliação, três vezes, em cada posição articular (flexão e extensão do ombro, cotovelo, carpo, quadril, joelho e tarso, bem como adução e abdução do carpo) antes e após sedação dos cães. Também foram realizadas medidas de radiografias tomadas destas posições articulares enquanto os cães estavam sedados, totalizando 1386 medidas. Para comparar a média das medidas goniométricas das articulações de animais não-sedados, sedados e radiografias, utilizou-se o teste de Friedman. Para comparar a goniometria entre machos e fêmeas utilizou-se o teste t. As diferenças foram consideradas significantes nos valores de p 0,05, para todas as comparações. Os resultados indicaram que as medidas articulares não diferiram significativamente quando se compararam medidas gonioméricas de cães não-sedados, sedados e radiografias, para todos os posicionamentos articulares avaliados, com exceção da extensão do ombro e joelho e adução do carpo. Também não foram identificadas diferenças significativas entre os sexos, com ressalva da extensão do ombro em cães sedados e da abdução do carpo tomada nas radiografias.
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Tomadon, Aniele. "Avaliação da terapia fotodinâmica em modelo experimental de artrite por paracoccidioides brasiliensis." Universidade Estadual do Oeste do Parana, 2016. http://tede.unioeste.br:8080/tede/handle/tede/668.
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Previous issue date: 2016-02-01Conselho Nacional de Desenvolvimento Científico e Tecnológico
Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis, is one of the most prevalent systemic mycosis in Latin America. Infection can occur accidentally through direct inoculation or mainly through inhalation of propagules of P. brasiliensis, which are installed initially in the lungs and can spread to organs and tissues of the host. In the acute form of the disease the major clinical manifestation is the febrile lymphoproliferative syndrome, occurring osteoarticular involvement; the same for the chronic form, in which 60% of cases, bone and joint changes usually treated for extended periods with conventional antifungal agents. Drug therapy is the most widely used to treatment the disease, however, high costs, poor adherence to treatment and adverse side effects, take the need to search for alternative therapies such as photodynamic (PDT), which has low cost and toxicity, local action and does not induce resistance to microorganisms. In vitro studies have shown positive results of PDT against various fungi, but there are no in vivo reports on its action in the control of P. brasiliensis. In this sense, the present study aimed to evaluate the PDT response in an experimental model of arthritis by P. brasiliensis. For this purpose, male Wistar rats (n = 42) were divided into groups submitted to inoculation with P. brasiliensis and PBS (control) in the right knee joint. After the development of arthritis, the mice were treated from the eighth to the eleventh day to the therapy: Groups L40 and L120 laser treated at dosages of 40 and 120 J/cm2, AM group treated with the photosensitizer methylene blue and PDT40 and PDT120 groups treated with PDT at doses of 40 and 120 J/cm2. The laser and AM therapies were used individually as a control for PDT. The groups were evaluated: edema, by measuring the lateral-lateral diameter of the joint; the intensity of arthritis, for histopathology and titration of anti-gp43 antibody by ELISA. The results showed that the edema formation was lower in the groups treated with PDT 40 and 120 J/cm2 (p = 0.8359 and p = 0.7167, respectively). The analysis of the intensity of arthritis as assessed by histopathology showed that the group treated with PDT 120 J/cm2 had the lowest morphological changes in the joint. Titration of anti-gp43 antibodies, showed the highest production of specific antibodies in the yeast group, but the differences were not significant when comparing the groups. Thus, the morphological evidence of normal tissue recovery aspects, the joint subjected to PDT 120 J/cm2, revealed the potential use of this therapy in reducing arthritis caused by P. brasiliensis
A Paracoccidioidomicose (PCM), causada pelo fungo dimórfico Paracoccidioides brasiliensis, é uma das micoses sistêmicas de maior prevalência na América Latina. A infecção pode ocorrer acidentalmente por inoculação direta ou, principalmente, através da inalação de propágulos de P. brasiliensis, que se instalam inicialmente nos pulmões e podem se disseminar para órgãos e tecidos do hospedeiro. Na forma aguda da doença a principal manifestação clínica é a síndrome linfoproliferativa febril, podendo ocorrer acometimento osteoarticular; o mesmo para a forma crônica, onde em 60% dos casos há alterações ósseas e articulares, geralmente tratadas por longos períodos com antifúngicos convencionais. A terapia medicamentosa é a mais utilizada para o controle da doença, entretanto, custos elevados, baixa adesão ao tratamento e efeitos colaterais adversos, levam a necessidade de se pesquisar terapias alternativas, como a fotodinâmica (TFD), que apresenta baixo custo e toxicidade, ação local e não induz resistência aos microorganismos. Estudos in vitro têm demonstrado resultados positivos da TFD contra diversos fungos, mas não existem relatos in vivo sobre sua ação no controle de P. brasiliensis. Nesse sentido, o presente estudo objetivou avaliar a resposta da TFD em modelo experimental de artrite por P. brasiliensis. Para tanto, ratos Wistar machos (n=42), foram distribuídos em grupos submetidos à inoculação de P. brasiliensis e PBS (controle) na articulação do joelho direito. Após o desenvolvimento da artrite, os grupos foram tratados, do oitavo ao décimo primeiro dia com as terapias: grupos L40 e L120 tratados com laser nas dosagens de 40 e 120 J/cm2, grupo AM tradado com o fotossensibilizador azul de metileno e grupos TFD40 e TFD120 tratados com TFD nas dosagens de 40 e 120 J/cm2. Os tratamentos com laser e AM foram utilizados de forma individual como controle para a TFD. Nos grupos foram avaliados: o edema, através da medida do diâmetro látero-lateral da articulação; a intensidade da artrite, por exame histopatológico e a titulação do anticorpo anti-gp43, por ELISA. Os resultados mostraram que, a formação do edema foi menor nos grupos tratados com TFD 40 e 120 J/cm2 (p=0,8359 e p=0,7167, respectivamente). A análise da intensidade da artrite, revelou que o grupo tratado com TFD 120 J/cm2 apresentou as menores alterações morfológicas na articulação. A titulação de anticorpos anti-Gp43, demonstrou a maior produção de anticorpos específicos no grupo levedura, porém as diferenças não foram significativas na comparação entre os demais grupos. Assim, as evidências morfológicas de recuperação de aspectos teciduais normais, na articulação submetida a TFD 120 J/cm2, revelaram o potencial uso desta terapia na redução da artrite causada por P. brasiliensis.
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Hakim, Iman, and Robin Harris. "Joint effects of citrus peel use and black tea intake on the risk of squamous cell carcinoma of the skin." BioMed Central, 2001. http://hdl.handle.net/10150/610367.
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BACKGROUND:Differences in tea drinking habits and/or citrus peel use are likely to vary by populations and could contribute to the inconsistencies found between studies comparing their consumption and cancer risk.METHODS:A population-based case-control study was used to evaluate the relationships between citrus peel use and black tea intake and squamous cell carcinoma (SCC) of the skin. Moreover, we assessed the independent and interactive effects of citrus peel and black tea in the development of SCC.RESULTS:Hot and iced teas were consumed by 30.7% and 51.8% of the subjects, respectively. Peel consumption was reported by 34.5% of subjects. Controls were more likely than were cases to report citrus peel use (odds ratio (OR) = 0.67) and hot tea intake (OR = 0.79). After adjustment for hot and iced tea intake, the ORs associated with citrus peel use were 0.55 and 0.69, respectively, whereas the corresponding adjusted ORs for hot and iced tea intake after adjustment for citrus peel use were 0.87 and 1.22 respectively. Compared with those who did not consume hot black tea or citrus peel, the adjusted ORs associated with sole consumption of hot black tea or citrus peel were 0.60 and 0.30, respectively. Subjects who reported consumption of both hot black tea and citrus peel had a significant marked decrease (OR= 0.2295% CI = 0.10 - 0.51) risk of skin SCC.CONCLUSION:These results indicate that both citrus peel use and strong (hot) black tea have independent potential protective effects in relation to skin SCC.
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Angélico, Ricardo Afonso. "Study of resistance welded composite joints: from the manufacturing process to the mechanical behaviour." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-14122017-111250/.
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This study is dedicated to thermoplastic composite joints obtained by an electrical resistance welding procedure. This welding process consists in joining two substrates with an electrical resistor which acts as a heating element melting the polymer substrates. The substrates considered herein are 2mm thick 7-layer hybrid composites, with the following stacking sequence ([0°/90°]G, [0°/90°]C, [45°]C, [0°/90°]C, [45°]C, [0°/90°]C, [0°/90°]G), where G and C denote plies with PPS matrix reinforced by continuous glass or carbon bres, respectively. The heating element is a stainless metallic grid surrounded by two PPS amorphous lms. For a better understanding of the the time evolution of the temperature eld in the welded zone, a heat transfer model was developed in nite element code Abaqus®. The prediction capabilities of the numerical tool were validated by comparing the numerical results with thermocouple measurements. The thermal properties required by the nite element model, viz. the specic heat and the thermal conductivities, were identied from DSC tests and from an inverse identication procedure, respectively. The inverse identication procedure is based on a Levenberg-Marquart algorithm applied to the analysis of specic experiments instrumented with thermocouples and an infra-red camera. Thermal or/and mechanical analyses of anisotropic composite laminates can lead to high computational costs even for linear analyses. Proper Generalized Decomposition constitutes a promising tool to reduce computational costs for multi-dimensional problems such as multi-parametric problems typical of manufacturing process simulations and/or problems with dierent length scales typical of composite laminates. To demonstrate its capabilities and its eciency {including in terms of computation costs for small size problems- PGD technique is applied to the solution of an axisymmetric heat transfer problem. Specimens were manufactured (with a laboratory welding machine designed and built during this study) with dierent processing parameters - eating element geometry, intensity of the electrical current, time evolution of the pressure. DCB specimens were tested to characterize the mechanical toughness under mode I. The analysis with the compliance method of the tests results exhibits two non-negligible energy dissipation mechanisms, related to crack creation and localized plastic deformation, respectively. An original model developed within the internal variable thermodynamics framework is proposed and used to describe the R-curves representative of the ductile behaviour of the DCB specimens. A rst sensitivity analysis of the processing parameters on the joint fracture toughness exhibits the key role of the pressure applied onto the joint during the cooling phase of the welding process.Este estudo é dedicado a juntas de compósitos termoplásticos soldadas pelo processo de soldagem por resistência elétrica. Este processo consiste em unir dois substratos com um resistor elétrico que atua como um elemento de aquecimento que funde o polímero dos substratos. Os substratos considerados neste trabalho são laminados compósitos híbridos, constituídos de 7 camadas que totalizam 2 mm de espessura, com a seguinte sequencia de empilhamento ([0°/90°]G, [0°/90°]C, [45°]C, [0°/90°]C, [45°]C, [0°/90°]C, [0°/90°]G), onde G e C denotam camadas de PPS reforçadas com fibra de vidro ou carbono, respectivamente. O elemento de aquecimento utilizado é uma malha metálica de aço inoxidável entre dois filmes de PPS (amorfos). Para um melhor entendimento do histórico do campo de temperatura na região soldada, um modelo de transferência de calor foi desenvolvido no pacote de elementos nitos Abaqus®. As capacidades de predição de temperatura do modelo computacional foram validadas a partir da comparação com resultados experimentais de termopares. As propriedades térmicas do modelo em elementos nitos, viz. o calor específico e as condutividades térmicas, foram identificadas a partir de ensaios DSC e de um procedimento de identificação inverso, respectivamente. O procedimento de identificação inversa foi baseado no algoritmo de Levenberg-Marquart aplicado na análise de experimentos específicos intrumentados com termopares e com uma câmera infra-vermelha. A análise térmica ou/e mecânica de laminados compósitos anisotropos podem apresentar elevados cusos computacionais, mesmo para análises lineares. A técnica PGD (Proper Generalized Decomposition) é uma ferramenta promissora na redução de custos computacionais de problemas multidimensionais, tópicos de simulação do processo de manufatura, e/ou problemas multi-escalas, tópico de laminados compósitos. Para demonstrar sua capacidade e sua eficiência, a técnica PGD é aplicada na solução de um problema axissimétrico de transferência de calor. Corpos-de-prova foram fabricados (com a máquina de soldagem laboratorial desenvolvida e construída durante este estudo) com diferentes parâmetros de processamento - geometria do elemento de aquecimento, intensidade da corrente elétrica, histórico de pressão. Corpos-de-prova DCB foram testados para caracterizar a resistência mecânica à propagação de trinca em modo I. A análise com o método da exibilidade dos resultados mostram dois mecanismos predominantes de dissipação de energia, correlatos com a criação da trinca e a localização de deformação plástica, respectivamente. Um modelo original desenvolvido baseado nas variáveis internas termodinâmicas é proposto e usado para descrição das curvas-R representativas do comportamento dúctil dos corpos-de-prova DCB. Uma primeira análise de sensibilidade da resistência à fratura ao variar os parâmetros de processamento mostra que a pressão aplicada na junta durante a etapa de resfriamento desempenha papel fundamental na resistência final da junta.
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Furuta, Fernanda. "Estudo da consolidação proporcional nas empresas que atuam no mercado brasileiro." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/12/12136/tde-05102006-174105/.
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Não existe consenso em relação à melhor forma de reconhecimento de investimentos em joint ventures na demonstração contábil consolidada da investidora. Há necessidade de adoção de uma única prática contábil, já que a falta de padronização do tratamento contábil de investimentos com controle compartilhado prejudica a comparabilidade das demonstrações contábeis consolidadas de empresas que adotam abordagens diferentes. Este trabalho tem como objetivo avaliar tanto os reflexos da adoção da consolidação proporcional nas demonstrações contábeis da investidora quanto da não adoção desse método quando há investimento de controle compartilhado. O Lucro Líquido e o Patrimônio Líquido são os únicos valores que devem ser iguais nessas demonstrações. A pesquisa empírica testou se há diferenças significativas entre os valores das contas ao ser feita adoção ou não da consolidação proporcional. O levantamento de dados foi realizado por meio do banco de dados da Fundação Instituto de Pesquisas Contábeis, Atuariais e Financeiras- FIPECAFI/FEA USP, que é utilizado na edição da Revista Exame ? Melhores e Maiores. Inicialmente, foram pesquisadas as empresas que atuam no mercado brasileiro e que, no período de 1996 a 2003, apresentaram investimento com controle compartilhado. Posteriormente, na pesquisa empírica foram utilizados os dados de 2000 a 2003 que totalizaram 34 demonstrações contábeis e, a partir dessas demonstrações, foi calculado como seriam os valores caso não fosse feita a consolidação proporcional. Utilizou-se o teste não paramétrico de Wilcoxon e os resultados indicaram que ao nível de significância de 5%, há diferenças significativas entre os valores do ativo circulante, do realizável a longo prazo, do passivo circulante, do exigível de longo prazo, das vendas líquidas, do custo da mercadorias vendidas ou custo do produtos vendidos ou custo dos serviços prestados, do capital circulante liquido, do capital de terceiros sobre capital próprio, da liquidez corrente, da liquidez geral e da margem líquida, obtidos aplicando-se a consolidação proporcional e não a aplicando. Esses resultados confirmam a controvérsia existente na literatura acadêmica em relação às divergências de um método em relação ao outro, em termos de controle e definição de ativo e exigibilidade. Apesar de os testes estatísticos sugerirem que não há diferença significativa na composição do endividamento não é possível generalizar que seus valores não sejam diferentes. Os resultados obtidos, neste trabalho, indicam que a adoção de uma abordagem de consolidação ou outra pode fazer com que o usuário da demonstração contábil interprete de forma diferente as demonstrações consolidadas de empresas que possuem investimentos em joint venture.There is no consensus on the best way of recognizing investments in joint ventures in the investing company?s financial statement. One single accounting practice needs to be adopted, as the lack of a standardized accounting treatment for investments in cases of shared control impairs the comparability of consolidated financial statements issued by companies that adopt different approaches. This study aims to evaluate the reflexes of adopting ? or not - the proportional consolidation method in the investing company?s financial statements in case of shared control investments. In these statements, Net Profit and Net Equity are the only figures that have to be equal. An empirical study tested for significant differences between the figures of accounts with or without proportional consolidation. Data were collected from the database of the Institute for Accounting, Actuarial and Financial Research Foundation - FIPECAFI/FEA USP, which is used to publish the magazine Exame ? Melhores e Maiores. First, we examined companies active in the Brazilian market who presented shared control investments between 1996 and 2003. Next, in the empirical study, we used data from 2000 to 2003, totaling 34 financial statements, which were used for calculating figures with and without proportional consolidation. Wilcoxon?s non-parametrical test was used with a significance level of 5%. Results indicated significant differences in current and long-term assets, current and long-term liabilities, net sales, cost of goods sold or cost of products sold or cost of services rendered, working capital, index of capital of third-party investors on own capital, current and general liquidity and net margin, when calculated with and without the proportional consolidation method. These results confirm the controversy in academic literature about the differences between one method and another in terms of control and definition of assets and liabilities. Although statistical tests suggest that there is no significant difference in the composition of indebtedness, it cannot be generalized that there are no differences between the figures. The results of this study indicate that, due to the adoption of a specific consolidation approach, financial statement users may give a different interpretation to the consolidated statements of companies with joint venture investments.
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Le, Floch Edith. "Méthodes multivariées pour l'analyse jointe de données de neuroimagerie et de génétique." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00753829.
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L'imagerie cérébrale connaît un intérêt grandissant, en tant que phénotype intermédiaire, dans la compréhension du chemin complexe qui relie les gènes à un phénotype comportemental ou clinique. Dans ce contexte, un premier objectif est de proposer des méthodes capables d'identifier la part de variabilité génétique qui explique une certaine part de la variabilité observée en neuroimagerie. Les approches univariées classiques ignorent les effets conjoints qui peuvent exister entre plusieurs gènes ou les covariations potentielles entre régions cérébrales.Notre première contribution a été de chercher à améliorer la sensibilité de l'approche univariée en tirant avantage de la nature multivariée des données génétiques, au niveau local. En effet, nous adaptons l'inférence au niveau du cluster en neuroimagerie à des données de polymorphismes d'un seul nucléotide (SNP), en cherchant des clusters 1D de SNPs adjacents associés à un même phénotype d'imagerie. Ensuite, nous prolongeons cette idée et combinons les clusters de voxels avec les clusters de SNPs, en utilisant un test simple au niveau du "cluster 4D", qui détecte conjointement des régions cérébrale et génomique fortement associées. Nous obtenons des résultats préliminaires prometteurs, tant sur données simulées que sur données réelles.Notre deuxième contribution a été d'utiliser des méthodes multivariées exploratoires pour améliorer la puissance de détection des études d'imagerie génétique, en modélisant la nature multivariée potentielle des associations, à plus longue échelle, tant du point de vue de l'imagerie que de la génétique. La régression Partial Least Squares et l'analyse canonique ont été récemment proposées pour l'analyse de données génétiques et transcriptomiques. Nous proposons ici de transposer cette idée à l'analyse de données de génétique et d'imagerie. De plus, nous étudions différentes stratégies de régularisation et de réduction de dimension, combinées avec la PLS ou l'analyse canonique, afin de faire face au phénomène de sur-apprentissage dû aux très grandes dimensions des données. Nous proposons une étude comparative de ces différentes stratégies, sur des données simulées et des données réelles d'IRM fonctionnelle et de SNPs. Le filtrage univarié semble nécessaire. Cependant, c'est la combinaison du filtrage univarié et de la PLS régularisée L1 qui permet de détecter une association généralisable et significative sur les données réelles, ce qui suggère que la découverte d'associations en imagerie génétique nécessite une approche multivariée.
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Duriez, Jérôme. "Stabilité des massifs rocheux : une approche mécanique." Phd thesis, Grenoble INPG, 2009. http://tel.archives-ouvertes.fr/tel-00462072.
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Résumé La prédiction efficace des éboulements rocheux constitue un des moyens pour se prémunirvis-à-vis du risque naturel représenté par les chutes de blocs. Les joints rocheux jouant un rôle décisif dans le déclenchement de ces éboulements, il faut décrire du mieux possible le comportement mécanique de ceux-ci, et en particulier leur rupture. Une nouvelle loi de comportement de joint rocheux, incrémentalement non linéaire, est ainsi proposée, parallèlement à l'utilisation du critère du “travail du second ordre” pour détecter les conditions impliquant un éboulement. La définition de la loi se base sur un modèle numérique de joint rocheux, utilisant la méthode aux Éléments Discrets via le code Yade. Une fois le comportement des joints rocheux investigué grâce à ce modèle numérique (en lien avec des résultats expérimentaux), et la loi définie puis validée, cette-dernière est étudiée vis-à-vis de ce critère du travail du second ordre. L'existence de “directions instables” de sollicitation, susceptibles d'entraîner la rupture du joint rocheux avant le critère de Mohr-Coulomb, est ainsi mise en évidence. Ces directions instables dépendent tout particulièrement des couplages entre les directions normale et tangentielle du joint rocheux. Une falaise existante est enfin analysée : les “Gorges de Valabres”, situées dans les Alpes-Maritimes. L'analyse est effectuée en utilisant la nouvelle loi de comportement, et le critère du travail du second ordre, dans le cadre d'un modèle numérique discret de la falaise. On observe alors que des sollicitations du chargement simulé correspondent pour certains joints à des directions instables.
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Vincent, Sylvie. "Influence du prétraitement thermique sur les propriétés électriques du dioxyde d'étain polycristallin. Application à la détection du méthane." Grenoble INPG, 1992. http://tel.archives-ouvertes.fr/tel-00844425.
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Nous avons étudié l'influence de certains paramètres sur la conductance électrique du dioxyde d'étain polycristallin, propriété utilisée pour la détection des gaz. Une première partie est consacrée a l'étude de l'influence du traitement thermique sur les caractéristiques morphologiques du matériau (taille des grains, porosité. . . ) Et sur ses performances électriques en présence de gaz varies (air, méthane, dioxyde de carbone,. . . ). Les résultats obtenus montrent l'influence des conditions de préparation du matériau sur ses performances électriques (sélectivité, stabilité. . . ) Et toute l'importance du contrôle de ces traitements préalables (mise en forme, traitement thermique. . . ). Une seconde partie est consacrée à la compréhension des mécanismes physico-chimiques a l'origine des performances électriques. Les résultats expérimentaux obtenus (chromatographie, thermogravimétrie, calorimétrie, conductance électrique), couples a une modélisation cinétique mathématique des phénomènes nous permettent d'envisager certaines hypothèses préférentiellement a d'autres au sujet des mécanismes qui provoquent les variations de conductance électrique.
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Alhajaya, Mohammed. "Exercise, neuromuscular control and performance, and stability of the knee joints." Thesis, Bangor University, 2004. https://research.bangor.ac.uk/portal/en/theses/exercise-neuromuscular-control-and-performance-and-stability-of-the-knee-joints(67ac5512-a776-42a9-8fe5-f727198582ad).html.
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In spite of an accumulating volume of information about injury to the musculoskeletal system in recent years, little scrutiny has been focused on the cause and prevention of injury. The large number of injuries to the knee joint and the anterior cruciate ligament ACL ligament in particular, is an alarming sign of the seriousnesso f this problem facing recreational and athletic people around the world. The large number of injuries appears to arise from an unfavourable interaction between `static' connective tissue-related and 'dynamic' muscle-related stabilisers of the joint system (Gleeson et al., 1998; Myers and Lephart, 2000). The functional stability is mediated ultimately by the neuromuscular system (Myers and Lephart, 2000) and it is important therefore to understand the function of the neuromuscular system as fully as possible in order to affect the aetiology and likelihood of injury favourably. The neuromuscular system includes biological 'machinery' offering capability for neuromuscular control (proprioception) and neuromuscular performance (motor actions). The neuromuscular control was quantified by newly-developed and laboratory-based assessmentsin volving the dynamic muscular reproduction of a `blind' target force and the error associated with such efforts may provide greater efficacy of measurement compared to those tests used in contemporary practice which may not indicate an individual's true functional capability to resist injury threats, in particular, to assessth e muscular dynamic intensity associatedw ith sporting endeavours which may functional capability to resist injury threats may be compromised. This thesis is presented as a series of three studies. The aim of this study was to examine between-day reproducibility and single measurement reliability of objective and self-perceived indices of force error in the knee flexors and extensors in men. Results showed that the reproducibility and single-measuremenrt eliability of objective (CE%, VE %) and self-perceived performance (SPCE% and SPVE %) during between-daya ssessmentso f neuromuscularc ontrol NCA1, NCA2 and NCA3 offered compromised precision and efficacy. These indices of performance should be deployed cautiously within both case-study and inter-individual comparisons and must rely on multiple-trial protocols to achieve acceptable levels of measurement precision in such circumstances. The aim of the second study was to examine the effects of serial bouts of acute fatiguing exercise on objective and self-perceived indices of neuromuscular control and performance of the knee flexors in men. In summary, results showed that despite substantial fatigue-related strength and muscle activation impairments, neuromuscular control as measured objectively by NCAI, NCA3 or RJA was not influenced significantly by the fatigue task intervention and that capability in this aspect of neuromuscular control was preserved in response to this type of exercise stress. Furthermore, constant error associated with self-perceived performance was similarly not influenced significantly by the fatigue task intervention. It is plausible that in ordert o provideo ptimump rotectiono f synovialj oints, neuromusculacro ntrol of the kneef lexorsm ay be preservedp referentiallyt o neuromusculapre rformance whenc hallengedb y fatigue-relatede xercises tresses. The third study assessedc oncomitant effects of an episodeo f muscle damage interspersed amongst serial bouts of fatigue on objective and self-perceived indices of neuromuscular control and performance of the knee flexors. This type of exercise perturbation reflects that associated with acute, transient and metabolically-focused effects (fatigue) and that during a more prolonged, mechanical type of disruption to the muscle (EIMD). It was likely to mimic some of the patterns of exercise inherent in sports and training practice and may serve to disrupt dynamic stabilization around the knee joint. Results showed that despite substantial EIMD and fatigue-related strength impairments (the former confirmed in this experiment by means of indirect physiological descriptive variables including a reduced range of movement and an increase in pain upon active movement of the affected limb), neuromuscular control as measured by objective and self-perceived indices of constant and variable error in assessment protocols NCA 2, NCA3 and DNCA was not influenced significantly by the EIMD and fatigue task intervention. It was notable that capability in this aspect of neuromuscular control was preserved in response to this type of exercise perturbation in the three different modes of objective assessments of neuromuscular control used in this study.
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Stamato, Guilherme Corrêa. "Ligações em estruturas de madeira compostas por chapas de madeira compensada." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-03062016-100611/.
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As estruturas de madeira composta com alma em compensado já vem sendo amplamente utilizadas em diversos países onde as estruturas de madeira estão tecnologicamente mais desenvolvidas, oferecendo aos engenheiros civis mais uma opção de sistema construtivo eficiente, seguro e duradouro. Nesse trabalho são apresentados estudos teóricos e experimentais referentes às estruturas de madeira compostas utilizando compensado nas almas, e em especial as estruturas cuja ligação alma mesa é feita por pinos metálicos. O objetivo desse trabalho é desenvolver critérios de dimensionamento dessas estruturas para serem aplicados no Brasil. Vários critérios de dimensionamento de elementos compostos foram encontrados na bibliografia, alguns com simplificações que desconsideram efeitos de composição parcial e outros mais completos, que consideram deformações por cisalhamento, composição parcial etc. Com os resultados dos ensaios de vigas compostas pregadas foi possível comparar valores experimentais com resultados teóricos, concluiu-se que os critérios de dimensionamento do EUROCODE 5 são adequados. Os ensaios de rigidez de nó de pórtico de seção composta permitiram o desenvolvimento de metodologia para o cálculo da rigidez dessas ligações, visto que não existe formulação equivalente na bibliografia internacional. Concluiu-se que as ligações por pinos metálicos apresentam boa eficiência para serem utilizadas nas seções compostas com alma em compensado. As ligações de nó de pórtico com ligação alma/mesa pregadas podem ser consideradas rígidas na maioria dos casos estudados.Plywood webbed structures have been applied in at several countries where timber structures are commonly used, giving civil engineers and builders one more option when looking for a safe, efficient and durable construction system. This work presents theoretical and experimental studies about plywood-webbed structures, with emphasis on nailed plywood webbed structures. The aim of this work is to develop design criteria for these structures to be used in Brazil. Several design criteria where found in the bibliography, some of them using simplifications for shear deflexions and joint deformations. Experimental results of nailed plywood webbed beams were compared with theoretical values from formulations found in the bibliography, concluding that EUROCODE 5 gives the best design criteria for nailed composite beams. Based on plywood webbed knee joints tests, a methodology to calculate the joint rigidity was proposed. The conclusions show the efficiency of this system and that nailed plywood webbed knee joints can be considered fixed for the majority of the specimens tested.
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Flor, Felipe Rendeiro. "Damage monitoring in composite structures via vibration based method: metal-composite bonded joints and sandwich structures." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-04042016-161659/.
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The present document covers the studies over Structural Health Monitoring systems via vibration based methods. The topic is organized in two parallel studies. The first one analyzes the integrity of metal-composite single lap bonded joints. The second one approaches similar analyses for sandwich structures. The monitoring was made by investigating the dynamic response both computationally and experimentally to verify the reliability of applying vibration based SHM procedures, specifically with the objective of identifying the presence of debonding damage. The dynamic responses were obtained via accelerometers and piezoelectric sensors placed on top of the investigated structures (on the outward surface). The purpose for the accelerometers is to provide reference data for the analyses involving the piezoelectric sensors. Different metrics of damage identification were investigated, all working over a determined frequency range. They quantify the damage by analyzing either the magnitudes or phase angles of the dynamic responses among the undamaged and damage structures. This present work proposed modifications to some methodologies of damage quantification found in the literature and compared the results. The new metrics offered more reliable values for the damage quantification on several of the analyses. It was verified that the metrics are valid for the scenarios observed in the present study. The experimental analyses showed also the influence on the dynamic response due to the position of small elastomeric elements. In regards to the finite element analyses, the computational models showed similar results to the experimental data, the more accurate ones being the models for the bonded joints. For the computational models, improvements can be applied into the piezoelectric sensor (e.g. by using new finite element formulations), as well as the region of debonding (e.g. by using contact algorithms). It is important to highlight that the elastic properties of the skins for the sandwich structure were obtained by the literature, so the model can be improved in the future by applying properties obtained experimentally.Esta dissertação aborda os estudos realizados no campo de Sistemas de Monitoramento da Integridade Estrutural por meio de métodos baseados em vibrações. O tópico abordado é organizado em dois estudos paralelos. O primeiro é relativo ao monitoramento da integridade de juntas coladas metal-compósito. O segundo versa sobre análises semelhantes em estruturas sanduíche. O monitoramento foi executado através das análises das assinaturas dinâmicas das estruturas, tanto computacionalmente quanto experimentalmente, visando avaliar a capacidade de metodologias vibracionais de SHM em detectar dano de descolamento. As respostas dinâmicas foram obtidas por meio de acelerômetros e sensores piezelétricos dispostos sobre a superfície das estruturas avaliadas. Os acelerômetros fornecem dados de referência para as análises realizadas com base nas respostas do sensor piezelétrico. Diferentes métricas de identificação de dano são abordadas, sendo que todas estão baseadas em análise no domínio da frequência, utilizando parâmetros de magnitude ou ângulo de fase das estruturas danificadas e intactas. O presente trabalho propôs alterações em algumas das metodologias encontradas na literatura e comparou os resultados das métricas originais com as modificadas. As métricas modificadas apresentaram resultados mais consistentes em vários cenários de análise. Constatou-se também que as métricas abordadas mostram-se válidas para os casos observados no presente estudo. As análises experimentais também evidenciaram a influência na assinatura dinâmica da estrutura sanduíche causada pelo posicionamento de pequenos elementos elastoméricos. Com relação às análises via elementos finitos, os modelos computacionais apresentaram resultados similares aos obtidos experimentalmente, sendo os da junta colada os mais precisos. Tais modelos computacionais podem ser melhorados no futuro por meio de uma modelagem mais detalhada dos elementos piezelétricos (por exemplo: por meio de novas formulações), como também da região de descolamento (por exemplo: por meio da implementação de algoritmos de contato). Deve-se ressaltar também que as propriedades elásticas das lâminas externas da estrutura sanduíche foram obtidas da literatura, assim sendo, o modelo poderá ser melhorado em estudos futuros por meio do emprego de propriedades obtidas experimentalmente.
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Veiga, Ana Carolina Rocha. "Estudo retrospectivo de casuística, abrangendo metodologia diagnóstica da osteoartrite em eqüinos." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/10/10136/tde-16052007-091454/.
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Nos eqüinos, as articulações sinoviais são submetidas a graus variáveis de estresse físico, de acordo com o tipo de movimento executado. Com o trabalho ou treinamento intenso, o aumento da carga imposta aos seus tecidos pode provocar sinovite mecanicamente induzida, com produção e liberação de citocinas, e conseqüentemente estimulação de metaloproteinases e de outros componentes inflamatórios. Estes eventos podem acarretar em desequilíbrio entre os processos de síntese e degradação de proteoglicanos e glicosaminoglicanos da matriz cartilagínea, levando a osteoartrite. Perante a magnitude de ocorrência de osteoartrite em eqüinos atletas, teve-se como objetivo caracterizar a população de cavalos, com diagnóstico firmado de osteoartrite, atendida junto ao Serviço de Clínica Médica de Eqüinos do Hospital Veterinário (HOVET) da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ/USP), em um período de 10 anos. O levantamento da casuística foi executado através da análise de fichas de registro dos casos antigos. A amostragem foi composta envolvendo a totalidade de casos de eqüídeos, com diagnóstico firmado da doença articular, arrolando-se e analisando-se dados referentes a: espécie, idade, sexo, peso, raça, atividade esportiva, início e evolução da doença, tipo de manifestação clínica, e exames radiográficos. Foram analisados 152 prontuários de eqüídeos acometidos por osteoartrite. Observou-se que a maioria tratava-se de animais da espécie eqüina, com idade média de 8 anos, macho ou fêmea, das raças Quarto de Milha, Mangalarga Paulista e sem raça definida, pesando em torno de 420kg, praticantes de romaria ou provas de Quarto de Milha.O tempo médio entre o início da sintomatologia de osteoartrite e o atendimento hospitalar foi de 7,7 meses.A análise estatística não mostrou relação entre presença de claudicação, dor palpável, sensibilidade em casco, sensibilidade muscular, teste de flexão positiva e atividade exercida (p>0,05). Porém, mostrou correlação entre a presença de edema/calor e atividade exercida (p<0,05). Também não mostrou relação entre dor palpável, edema/calor, sensibilidade de casco, sensibilidade muscular, e claudicação (p>0,05). Mediante os resultados obtidos pela avaliação radiográfica dos pacientes acometidos por osteoartrite, notou-se que não houve relação direta entre o menor e maior escore em relação à presença ou não de claudicação. Concluiu-se que o perfil do paciente, acometido por osteoartrite, mais freqüentemente atendido pelo Serviço de Clínica Médica de Eqüinos ? HOVET ? USP trata-se da espécie eqüina, da raça Quarto de Milha, 8 anos de idade, 420 kg, praticante de provas de Quarto de Milha.The equine sinovial joints are submitted do different degrees of physical stress, depending on the movement performed. With work and hard training, the increase on the loads applied to its tissues maycause mechanically induced synovitis, with production and release of cytokines, and consequently metalloproteinases stimulation and other inflammatory components. These events may lead to anunbalance between the synthesis and degradation processes, of proteoglycan and glicosaminoglycan of the cartilaginous matrix, leading to the osteoarthritis. Regarding the magnitude of the osteoarthritis incidence on athletic horses, our goal is to characterize the horse population with confirmed osteoarthritis diagnoses examined by the Equine Internal Medicine Service at the Veterinary Hospital at the College of Veterinary Medicine and Animal Science of University of São Paulo, in a 10 year period. The retrospective study was performed through the analysis of documented cases. The sampling included the totality of equide cases with confirmed joint disease diagnosis and analyzed considering: age, sex, breed, sportive activity, beginning and evolution of the disease, clinical signs observed and radiographic exam. One hundred and fifty two (152) equides hospital forms with confirmed osteoarthritis were analyzed .It was found that most cases were equines, with an average age of 8 years, either male or female, with the predominance of Quarter Horses, Mangalarga Paulista and Mixed Breds, weighing around 420Kg, used for long distance rides or western activities. The average time between the beginning of the osteoarthritis clinical signs and the referring to the hospital was 7,7 months. The statistical analysis did not show relation between lameness, palpable pain, hoof sensitivity, muscular pain, positive flexion test and use (p>0,05). Although, its howed a relation between edema /heat and use (p<0,05). No relation was found between palpable pain, edema/heat, hoof and muscular pain and lameness (p<0,05). The results found in the radiographic evaluation of the animals with osteoarthritis showed no direct relation between the radiographic score and lameness. The animals with osteoarthritis more frequently sent to the Equine Internal Medicine Service -HOVET-USP, is equine , Quarter Horse, 8 years old, 420Kg, used in western competitions.
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Brunetière, Noël. "Etude théorique et expérimentale du comportement thermohydrodynamique des garnitures d'étanchéité." Phd thesis, Université de Poitiers, 2001. http://tel.archives-ouvertes.fr/tel-00003542.
Full textAbstract:
Les garnitures d'étanchéité sont utilisées pour assurer l'étanchéité d'arbres tournants lorsque les conditions de vitesse, de pression et de température ne permettent pas l'utilisation de joints classiques en élastomère. Pour un fonctionnement optimal, les deux bagues constituant une garniture doivent être séparées par un film fluide très mince afin d'éviter l'usure des faces du joint tout en limitant la fuite à une valeur acceptable. L'élévation de température due au frottement visqueux modifie considérablement les conditions de lubrification de l'interface du joint. Les phénomènes thermiques jouent donc un rôle essentiel dans les joints d'étanchéité à faces radiales et constituent le sujet de recherche de cette thèse de doctorat. Une analyse bibliographique approfondie a permis de définir les hypothèses nécessaires à une modélisation théorique du comportement thermoélastohydrodynamique des garnitures d'étanchéité. Les équations de conservation dans le film fluide ont été établies puis discrétisées par la méthode des éléments finis dans l'hypothèse d'un fonctionnement stationnaire. La résolution de l'équation de l'énergie a nécessité l'utilisation d'un schéma numérique adapté aux problèmes de convection. Les échanges de chaleur avec les anneaux du joint et les déformations thermoélastiques sont pris en compte par la méthode des coefficients d'influence. Un algorithme itératif permet la détermination des champs tridimensionnels de pression, de vitesse et de température au sein du film fluide dans le cas d'écoulement laminaire et turbulent. L'étude paramétrique réalisée avec le modèle numérique contribue à une meilleure connaissance de l'influence des conditions de fonctionnement, des paramètres de conception et des défauts géométriques sur les performances d'une garniture d'étanchéité. En outre, des relevés de température effectués par thermographie infrarouge sur un joint expérimental développé à cet effet, ont permis de valider le modèle numérique.
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Gaffard, Vincent. "Étude expérimentale et modélisation du comportement, de l'endommagement et de la rupture en fluage de joints soudés en acier 9Cr1Mo-NbV." Phd thesis, École Nationale Supérieure des Mines de Paris, 2004. http://tel.archives-ouvertes.fr/tel-00162118.
Full textAbstract:
Les aciers inoxydables martensitiques au chrome sont développés depuis les années 70 avec pour objectif aujourd'hui de les utiliser comme matériau de structure dans les centrales thermiques (Circuits de refroidissement, turbine) et nucléaires (Cuve du réacteur...). L'acier de l'étude i.e. l'acier 9Cr1Mo-NbV est déjà utilisé dans des centrales thermiques principalement en Angleterre et au Japon. Compte tenu de l'importance des composants, l'assemblage par soudage est une technique largement utilisée. Un intérêt tout particulier est porté dans cette étude à l'évaluation de la durée de vie des composants soudés en acier 9Cr1Mo-NbV après la constatation de plusieurs ruptures en service prématurées au niveau des soudures.L'étude réalisée avait donc pour objectif d'identifier expérimentalement et de modéliser le comportement, l'endommagement et la rupture en fluage haute température (typiquement dans le domaine de température 450°C - 650°C) de composants soudés en acier 9Cr1Mo-NbV.
Pour cette étude, le métal de base a d'abord été étudié comme matériau de référence. Il est notamment démontré que les résultats expérimentaux à 1000 heures ne peuvent pas être utilisés, comme il est usuel de le faire, pour prédire la durée de vie en fluage à 100000 heures. La raison de cette impossibilité est l'existence d'un changement de mécanisme de comportement et d'endommagement aux temps longs. Pour représenter ce changement de mécanisme, un modèle de fluage couplant comportement et endommagement et intégrant plusieurs mécanismes de déformation a été développé suivant les développements de la mécanique des milieux poreux initiés par Gurson. Le modèle a été identifié sur la base de résultats expérimentaux sur diverses géométries d'éprouvettes permettant notamment de prendre en compte les effets de la triaxialité sur le développement de l'endommagement. L'étude a par ailleurs mis en évidence une bonne capacité du modèle à prédire les lieux de rupture ainsi que l'amorçage et la propagation stable de fissure.
L'attention a ensuite été portée à la tenue en fluage des composants soudés qui présentent une résistance au fluage très inférieure à celle du métal de base due à la faiblesse de la zone affectée thermiquement (ZAT). Pour ce faire, deux niveaux d'investigation ont du être explorés. D'une part, le soudage induit des modifications métallurgiques et donc des modifications locales des propriétés mécaniques du métal de base : c'est un effet matériau. D'autre part, les différences de propriétés mécaniques rendent complexes l'état de chargement de l'assemblage soudé : c'est un effet de structure.
L'effet matériau a été étudié en identifiant la ZAT faible des composants soudés, en la reproduisant sur échantillons massifs, puis en testant des éprouvettes de fluage usinées dans ces mêmes échantillons massifs. Il a été ainsi possible d'utiliser le modèle multi-mécanismes développé pour l'étude sur métal de base afin de modéliser le comportement et l'endommagement de fluage haute température de la ZAT faible dans toute la gamme de contrainte.
Finalement, des calculs éléments finis multi-matériaux ont été réalisés en considérant le composant soudé comme l'assemblage de trois microstructures : le métal d'apport, le métal de base et la ZAT faible dont les équations constitutives respectives ont été intégrées aux calculs. Il a ainsi été possible d'identifier les effets de type structure mais surtout de prédire la durée de vie des composants soudés en acier 9Cr1Mo-NbV y compris pour des composants industriels.