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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Influência do toro mandibular na atividade eletromiográfica dos músculos da mastigação / Influence of mandibular torus on electromyographic activity of the mastication muscles

José Mendes da Silva 07 August 2014 (has links)
O toro é uma excrescência óssea convexa, com crescimento lento, considerado de origem congênita, benigno, também denominado de exostose, com pouca significância clínica, sendo necessária sua remoção quando dificulta a confecção de prótese totais, parciais ou removíveis e a posição da língua, interferindo na fala ou ainda, dificultam a intubação cirúrgica. O objetivo deste trabalho foi analisar, por meio da eletromiografia, o padrão de comportamento (morfológico e funcional) da atividade dos músculos masseter e temporal nas condições posturais da mandíbula como o Repouso, Protrusão, Máxima Interscupidação Habitual (MIH), Apertamento Dental com Parafilme M®, Lateralidades Direita e Esquerda. O presente estudo também propôs analisar a eficiência dos ciclos mastigatórios e para tanto, foi utilizado a avaliação da mastigação habitual e não habitual por meio da integral da envoltória do sinal eletromiográfico obtido dos músculos masseter e temporal durante a mastigação habitual de uvas passas e amendoim e da mastigação não-habitual de Parafilme M®, considerando a presença ou não do toro mandibular. Diante dos resultados obtidos no presente trabalho foi possível concluir que, de um modo geral, houve aumento na atividade eletromiográfica nos músculos masseteres de indivíduos portadores de toro mandibular (Grupo Casos) quando comparado aos indivíduos do Grupo Controles nas condições clínicas de protrusão, lateralidades direita e esquerda, máxima intercuspidação habitual (MIH), apertamento dental com parafilme M®. Na mastigação com parafilme M®, mastigação com amendoins e mastigação com uvas passas verificou-se aumento da atividade para os músculos temporais e masseteres, evidenciando que a presença de toro mandibular está associada a alterações no padrão de ativação da musculatura mastigatória nas condições posturais da mandíbula e na mastigação. / The torus is a convex bony outgrowth, considered congenital, benign, also called exostosis, with little clinical significance, necessitating its removal difficult when the making of complete dentures, removable partial or tongue position and interfering speech or hinder surgical intubation. The aim of this study was to analyze, using electromyography, the default behavior (morphological and functional) of activity of the masseter and temporal muscles in conditions mandible posture as Home, protrusion, Maximum Interscupidação Habitual (MIH), Dental Clenching with Parafilm M®, lateral excursion (right and left). This study also proposed to analyze the efficiency of the mastigatory cycles. Therefore, we used the evaluation of usual mastication and unusual mastication through the envoltory integral of the EMG signal obtained from the masseter and temporalis muscles during mastication of raisins and peanuts and unusual chewing Parafilm M®, considering the presence or no in mandibular torus. Given the results obtained in this study it was concluded that, in general, increased the EMG activity in the masseter muscles of patients with mandibular torus (Group Case) when compared to individuals of the Group Controls in the mandible clinical conditions as protrusion, lateral excursion (right and left), maximum intercuspation (MIH), clenching with parafilm M®. There was an increase in EMG activity of the temporal and masseter muscles during mastication with parafilm M®, mastication with peanuts and mastication with raisins, showing that the presence of mandibular torus is associated with changes in the default activation of masticatory muscle in conditions mandible posture and chewing.
52

Elliptic Tori in p-adic Orthogonal Groups

Chinner, Trinity 29 September 2021 (has links)
In this thesis, we classify up to conjugacy the maximal elliptic toral subgroups of all special orthogonal groups SO(V), where (q,V) is a 4-dimensional quadratic space over a non-archimedean local field of odd residual characteristic. Our parameterization blends the abstract theory of Morris with a generalization of the practical work performed by Kim and Yu for Sp(4). Moreover, we compute an explicit Witt basis for each such torus, thereby enabling its concrete realization as a set of matrices embedded into the group. This work can be used explicitly to construct supercuspidal representations of SO(V).
53

Redistribution of Tensors for Distributed Contractions

Nikam, Akshay Machhindra 02 June 2014 (has links)
No description available.
54

Finite Element Modeling and Active Control of an Inflated Torus Using Piezoelectric Devices

Lewis, Jackson A. 20 December 2000 (has links)
Satellite antenna design requirements are driving the satellite size to proportions that cannot be launched into space using current technology. In order to reduce the launch size and mass of satellites, inflatable structures, also known as gossamer structures, are being considered. Inflatable space-based structures are susceptible to vibration disturbance due to their low stiffness and damping. This thesis discusses the structural dynamics and vibration suppression via piezoelectric actuators, using active control of an inflatable torus. A commercial finite element package, ANSYS, is used to model the inflated torus. The effect of torus aspect ratio and inflation pressure on the vibratory response of the structure is investigated. The interaction with the torus of the surface-mounted piezoelectric patches, made of PVDF, is modeled using Euler-Bernoulli beam theory. A state space representation is created of the model in modal space and modal truncation is performed. Traditional control tools are used to suppress vibration in the structure. First observer-based full state feedback is used, then direct output velocity feedback is explored. The aspect ratio of the torus is found to significantly influence the mode shapes. Toroids of small aspect ratios, skinny toroids, act like rings, but the mode shapes of toroids with large aspect ratios are much more complicated. For toroids of small aspect ratios, increasing the inflation pressure simply results in stiffening the ring, thereby increasing the natural frequencies. Increasing the pressure in toroids with large aspect ratios changes both the mode shapes and natural frequencies. The passive effect of PVDF on the dynamics of the torus is small, the mode shapes do not change and the frequencies are only slightly reduced. Active control of toroids with small aspect ratios using piezoelectric devices is effective. It may be more difficult to control toroids with large aspect ratios because the mode shapes are much more complicated than the simple ring modes found in toroids with small aspect ratios. / Master of Science
55

Eigenspectra for Correlating Cosmic Microwave Background Temperature Data

Osborne, Joshua C. P. 01 February 2019 (has links)
No description available.
56

Remodelage osseux et pathologies oro-faciales / Bone remodeling and oro-facial pathologies

Kün-Darbois, Daniel 13 November 2017 (has links)
Un 1er travail a étudié les effets osseux mandibulaires de l’injection unilatérale dans les muscles masticateurs de toxine botulique (BTX) chez le rat adulte. Ceci entraine une perte osseuse mandibulaire condylienne et alvéolaire homolatérale importante. Une hypertrophie osseuse de l’enthèse d’insertion mandibulaire du muscle digastrique a été observée et pourrait correspondre à une étiologie pour les tori. Les effets de la BTX sur le cartilage articulaire condylien mandibulaire dans le même modèle animal ont été recherchés par analyse microtomographique du cartilage articulaire après augmentation de contraste à l’acétate d’uranyle. Aucune différence d’épaisseur cartilagineuse n’a été mise en évidence entre les groupes contrôles et BTX.Le 3ème travail a consisté en l’étude histologique et microtomographique des tori mandibulaires chez l’homme.Les tori sont différents des exostoses des os longs par plusieurs caractéristiques (dont l’absence de Fe et Al dans la matrice osseuse) et une asymétrie du remodelage osseux a été mise en évidence.La 4ème partie a consisté en l’étude de la qualité osseuse et de la microvascularisation alvéolaire dans un modèle animal d’ostéonécrose mandibulaire (ONM) aux bisphosphonates (BP). Des signes cliniques et microtomographiques d’ONM ont été observés dans la majorité des cas. La minéralisation osseuse était plus élevée après imprégnation en BP. La microvascularisation osseuse alvéolaire apparaissait augmentée après avulsion dentaire chez les animaux contrôles mais pas chez les animaux ayant reçu des BP témoignant ainsi d’un effet anti angiogénique in vivo des BP qui pourrait jouer un rôle dans la physiopathologie de l’ONM. / First, bone changes at the mandible were studied after a unilateral botulinum toxin (BTX) injection in masticatory muscles in adult rats. A major alveolar and condylar bone loss was evidenced. The occurrence of a hypertrophic bone metaplasia at the digastric muscle enthesis was evidenced as well. This could constitute an etiological factor for tori. Then, condylar articular cartilage changes at the mandible were studied in the same BTX animal model, using microtomography after contrast enhancement of cartilage with uranyl acetate. Cartilage thickness measurement showed no difference when comparing control and BTX groups.A third work studied mandibular tori in human using histologic and microtomographic techniques. Tori appeared different from long bone exostoses by several characteristics (absence of Fe and Al in the bone matrix) and a specific asymmetric bone remodeling was evidenced.The fourth part consisted in the study of alveolar mandibular vascularization and quality of the bonematrix in an animal model of osteonecrosis of the jaws(ONJ) after bisphosphonates (BP) injections. Clinical and microtomographic signs of ONJ were found in mostof the cases. An increased mineralization of the alveolar bone was observed after BP impregnation. Microvascularization was increased after tooth extraction in the alveolar bone of control animals but it was impaired in ZA treated rats. Such an in vivo antiangiogenic effect of BPs could play a role in the pathophysiology of ONJ.
57

Sudoku Variants on the Torus

Wyld, Kira A 01 January 2017 (has links)
This paper examines the mathematical properties of Sudoku puzzles defined on a Torus. We seek to answer the questions for these variants that have been explored for the traditional Sudoku. We do this process with two such embeddings. The end result of this paper is a deeper mathematical understanding of logic puzzles of this type, as well as a fun new puzzle which could be played.
58

Finding obstructions within irreducible triangulations

Campbell, Russell J. 01 June 2017 (has links)
The main results of this dissertation show evidence supporting the Successive Surface Scaffolding Conjecture. This is a new conjecture that, if true, guarantees the existence of all the wye-delta-order minimal obstructions of a surface S as subgraphs of the irreducible triangulations of the surface S with a crosscap added. A new data structure, i.e. an augmented rotation system, is presented and used to create an exponential-time algorithm for embedding graphs in any surface with a constant-time check of the change in genus when inserting an edge. A depiction is a new formal definition for representing an embedding graphically, and it is shown that more than one depiction can be given for nonplanar embeddings, and that sometimes two depictions for the same embedding can be drastically different from each other. An algorithm for finding the essential cycles of an embedding is given, and is used to confirm for the projective-plane obstructions, a theorem that shows any embedding of an obstruction must have every edge in an essential cycle. Obstructions of a general surface S that are minor-minimal and not double-wye-delta-minimal are shown to each have an embedding on the surface S with a crosscap added. Finally, open questions for further research are presented. / Graduate
59

Nullification of Torus Knots and Links

Bettersworth, Zachary S 01 July 2016 (has links)
Knot nullification is an unknotting operation performed on knots and links that can be used to model DNA recombination moves of circular DNA molecules in the laboratory. Thus nullification is a biologically relevant operation that should be studied. Nullification moves can be naturally grouped into two classes: coherent nullification, which preserves the orientation of the knot, and incoherent nullification, which changes the orientation of the knot. We define the coherent (incoherent) nullification number of a knot or link as the minimal number of coherent (incoherent) nullification moves needed to unknot any knot or link. This thesis concentrates on the study of such nullification numbers. In more detail, coherent nullification moves have already been studied at quite some length. This is because the preservation of the previous orientation of the knot, or link, makes the coherent operation easier to study. In particular, a complete solution of coherent nullification numbers has been obtained for the torus knot family, (the solution of the torus link family is still an open question). In this thesis, we concentrate on incoherent nullification numbers, and place an emphasis on calculating the incoherent nullification number for the torus knot and link family. Unfortunately, we were unable to compute the exact incoherent nullification numbers for most torus knots. Instead, our main results are upper and lower bounds on the incoherent nullification number of torus knots and links. In addition we conjecture what the actual incoherent nullification number of a torus knot will be.
60

Inexistência de difusão sublinear para uma classe de homeomorfismos do toro / Inexistence of sublinear diffusion for a class of torus homeomorphisms

Salomão, Guilherme Silva 30 January 2019 (has links)
No presente trabalho iremos provar, usando a folheação de Brouwer-Le Calvez e a teoria de forcing dela derivada, que dado um homeomorfismo f do toro isotópico à identidade tal que seu conjunto de rotação é um segmento de reta com inclinação irracional e tendo 0 como um ponto extremal, então f não possui difusão sublinear na direção perpendicular à direção do conjunto de rotação / In the present work we will prove, using the Brouwer-Le Calvez foliation and the forcing theory derived from it, that given a torus homeomorphism f isotopopic to the identity such that its rotation set is a line segment with irrational slope and 0 is an extreme point, then f does not have sublinear diffusion in the direction perpendicular to the direction of the rotation set.

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