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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.
41

Efeito do envelhecimento em diferentes soluções sobre a resistência de união em reparos com resina composta Bulk Fill. / Effect of aging on different solutions on bond strength in repairs with composite resin Bulk Fill

Rosa, Saulo Vinicius da 03 March 2017 (has links)
Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-05-15T19:35:27Z No. of bitstreams: 2 Saulo Vinicius da Rosa.pdf: 2244692 bytes, checksum: e13fed6b2f75e2fa2861bf064a121ca7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-15T19:35:27Z (GMT). No. of bitstreams: 2 Saulo Vinicius da Rosa.pdf: 2244692 bytes, checksum: e13fed6b2f75e2fa2861bf064a121ca7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-03 / Bulk fill resins can be used as dentin replacements, requiring coating by another composite resin, such as a nano-hybrid resin, or they can be used without the need for a new composite resin for their protection. The objective of this work was to evaluate the bond strength of repairs made between different composite resins, after aging in different solutions. Five composite resins were used, one conventional and four bulk fill composites. 2x2x5 mm CP were made in silicone mold and aged for 30 days, after which the resins were given the surface treatment and soon after the repair, becoming a CP with 2x2x10mm. All the resins were combined. The mean values obtained for each test specimen were submitted to the Shapiro Kruskall Wallis test, followed by the Dunn test, p <0.05. The results showed that, after aging in distilled water, Aura bulk fill as base showed statistical differences when compared to the composite resins Z350 (1.27 + 0.95) and Tetric Ceram bulk fill (3.72 + 1.74), the composite resin Tetric Ceram bulk fill used as a base showed that there was statistical difference when Filtek bulk fill composite resin 4,81 (+1,20) was used and when Z350 resin (2.22 + 0.63) and Tetric Ceram bulk fill (2.54 + 0.52). After aging in water / ethanol solution, no statistically significant differences were found between all possible combinations. After aging in nitric acid solution, when Aura bulk fill was used as base there were statistical differences between the repair with Tetric Ceram bulk fill (4.02 + 0.82) and Z350 (1.71 + 1.09 ), when Filtek bulk fill used as base there were statistical differences between Z350 (2.30 + 0.62) and Filtek bulk fill 4.02 (+1.85) used for the repair, with Tetric ceram bulk fill as base there were statistical differences when compared to the composite resin Filtek bulk fill 4,04 (+1,07) and Z350 (1,99 + 0,76). According to the results obtained it was possible to verify that, in the majority of the comparisons made among the composite resins evaluated in this study, the composite resins bulk fill obtained better values of bond strength when the composite resins themselves were united bulk fill and the worst values when they received the repair with the composite resin when immersed in acidic solutions and distilled water, it was not possible to observe statistically significant differences when immersing in water / ethane. / As resinas “bulk fill” podem ser utilizadas como substitutas da dentina, necessitando de recobrimento por outra resina composta, como uma resina nano- híbrida, ou ainda podem ser utilizadas sem a necessidade de uma nova resina composta para sua proteção. O objetivo desse trabalho foi avaliar a resistência de união de reparos confeccionados entre diferentes resinas compostas, após envelhecimento em diferentes soluções. Foram utilizadas cinco resinas compostas, sendo uma convencional e quatro resinas compostas “bulk fill”. Foram confeccionados CP de 2x2x5 mm em molde de silicone e envelhecidas por 30 dias, após esse período as resinas receberam o tratamento de superfície e logo após o reparo, tornando-se um CP com 2x2x10mm. Todas as resinas foram combinadas entre si. Os valores médios obtidos para cada corpo de prova foram submetidos ao teste de Shapiro Kruskall Wallis, seguido do pós teste de Dunn, p < 0,05. Os resultados mostraram que após o envelhecimento em água destilada, a Aura bulk fill como base mostrou diferenças estatísticas quando comparadas as resinas compostas Z350 (1,27+0,95) e Tetric Ceram bulk fill (3,72+1,74), a resina composta Tetric Ceram bulk fill utilizada como base mostrou que houve diferença estatística quando utilizada a resina composta Filtek bulk fill 4,81(+1,20) e quando utilizada a resina Z350 (2,22+0,63) e Tetric Ceram bulk fill (2,54+0,52). Após o envelhecimento em solução água/etanol não foram encontradas diferenças estatisticamente significantes entre todas as combinações possíveis. Após o envelhecimento em solução de ácido nítrico, quando a Aura bulk fill foi utilizada como base houve diferenças estatísticas entre o reparo com a Tetric Ceram bulk fill (4,02+0,82) e a Z350 (1,71+1,09), já quando Filtek bulk fill utilizada como base houve diferenças estatísticas entre a Z350 (2,30+0,62) que e a Filtek bulk fill 4,02(+1,85) usadas para o reparo, com a Tetric ceram bulk fill como base houve diferenças estatísticas quando comparadas a resina composta Filtek bulk fill 4,04(+1,07) e a Z350 (1,99+0,76). De acordo com os resultados obtidos foi possível verificar que, na maioria das comparações realizadas entre as resinas compostas avaliadas nesse estudo, as resinas compostas bulk fill obtiveram melhores valores de resistência a união quando unidas as próprias resinas compostas bulk fill e os piores valores quando receberam o reparo com a resina composta quando imersas em soluções ácidas e na água destilada, já na imersão em água/etano não foi possível observar diferenças estatisticamente significantes.
42

Návrh nových laboratorních úloh v síťovém simulátoru OMNeT++ / New laboratory exercises in OMNeT++ network simulator

Vlašín, Martin January 2016 (has links)
Diploma thesis deals with creating four laboratory tasks using simulation tool OMNeT++ and Inet Framework extension. Subject matter of these designed tasks is focused on routing protocols, providing quality of service, computer networking technologies used in local area networks and comparison of active networking devices. First task contains the comparison of behaviour and routing techniques between protocols RIPv2 and OSPFv2, including the effect of dividing OSPF network into smaller areas. Second task is focused on various techniques for controlling quality of service, namely FIFO queue, PQ and WFQ. Main goal is the comparison of results, that define quality of network services. Third task compares networking technologies, Ethernet and WLAN, parameters of transmission. Fourth task offers comparison of networking devices, hub, switch and router. This paper also contains required theory of network technologies and software tools used for executing simulations.
43

Imagerie sismique quantitative de la marge convergente d'Equateur-Colombie : Application des mèthodes tomographiques aux données de sismique réflexion multitrace et réfraction-réflexion grand-angle des campagnes SISTEUR et SALIERI

Agudelo, William 08 July 2005 (has links) (PDF)
Mon travail de thèse se propose d'étudier la structure, les propriétés physiques et les processus géodynamiques de la zone de subduction d'Equateur-Colombie grâce à l'adaptation et le développement d'outils d'imagerie sismique (inversion de formes d'ondes 'alias' tomographie en diffraction) et à leur application aux données de sismique marine multitrace (MCS) et grand-angle OBS (WA) acquises en Equateur-Colombie pendant les campagnes SISTEUR et SALIERI. Ces outils m'ont permis de réaliser une imagerie fine et quantitative à trois niveaux : l'imagerie superficielle (~ 0-3 km), l'imagerie à profondeur intermédiaire (~ 3-10 km) et l'imagerie profonde (~ 10-30 km). Dans le domaine superficiel, j'ai effectué une cartographie fine et quantitative des propriétés physiques des sédiments au voisinage du BSR (Bottom Simulating Reflector), interpreté comme la base de stabilité des hydrates de gaz. Sur le profil SIS-40 situé sur la marge sud de la Colombie, j'ai pu identifier la présence de failles qui perturbent localement le BSR. Les résultats présentés sous la forme d' une série de logs adjacents de l'image migrée en profondeur, montrent que certaines régions du BSR sont caractérisées par une augmentation de la vitesse (1470-1650 m/s), indiquant la présence d'une faible quantité d'hydrates de gaz au dessus du BSR; d'autres zones situées immédiatement sous le BSR sont caractérisées par une diminution de la vitesse (~1200 m/s), liée à la présence de gaz libres piégés sous la couche d'hydrate de gaz. A des profondeurs moyennes j'ai étudié la structure du chenal de subduction (profil SIS-72). Le chenal constitue la limite mécanique entre la plaque chevauchante et la plaque plongeante. Il est délimité à son toit par un fort réflecteur interprété comme le décollement interplaque et à sa base par le toit très réflectif de la croûte océanique en subduction. L'imagerie fine et quantitative des propriétés physiques du décollement interplaque permet de mieux comprendre le rôle de la circulation des fluides et des variations lithologiques et physiques, sur le couplage mécanique inter-plaque. En raison de la sensibilité de la méthode de tomographie en diffraction au macro-modèle de vitesse, un code de correction de ce modèle a été implémenté, afin d'obtenir des images tomographiques fiables (i.e. géométrie et amplitudes correctes). Du fait de la bande passante limitée de la source et de la longueur du dispositif d'acquisition limitée à 4.5 km, les images tomographiques ont une résolution spatiale limitée : l'image tomographique présente un déficit des petits et grands nombre d'onde (fréquences spatiales) limitant ainsi l' interprétation géologique des paramètres physiques cartographiés. Un traitement spécifique basé sur la modélisation des traces sismiques a été implémenté. L'image tomographique, traitée comme une série de traces verticales, constitue la donnée observée. L'espace des modèles est constitué par un ensemble de modèles impulsionnels et unidimensionnels de Terre construits aléatoirement. Ces modèles sont dégradés par convolution avec une estimation de l'ondelette source afin de fournir une représentation synthétique de l'image tomographique « observée ». La minimisation de la fonction coût entre les traces migrées et les traces synthétiques est effectuée dans le cadre d'une inversion globale par recuit simulé (VFSA= « Very Fast Simulated Annealing »). Le modèle moyen issu de cette procédure fournit un modèle 2D fin de vitesse, fonction de la profondeur et comparable à la limite de la résolution théorique de la source. A l'issue de ce traitement, des perturbations de vitesse positives sont mises en évidence au toit de la croûte, et d'autres négatives accompagnent certains segments du niveau du décollement. Ces dernières sont probablement associées à la présence de fluides. Le domaine plus profond a été étudié à partir des données MCS et WA dans le double but (1) d'améliorer la résolution spatiale des images sismiques du Moho et du contact interplaque en relation avec la zone sismogène, et (2) de détecter la présence d'anomalies crustales de vitesse et d'analyser leur relation avec les zones d'aspérité sismologiques. L'utilisation conjointe des données de sismique MCS et WA a été mise en oeuvre pour prolonger vers le bas les images de sismique verticale et tenter ainsi d'établir une relation entre les processus profonds et les manifestations en surface. L'application de la chaîne de traitement au profil SIS-44 a permis d'obtenir un modèle de vitesse bien contraint jusqu'à 25 km de profondeur. Ce modèle met en évidence des réflecteurs profonds (Moho et contact interplaque ) et des réflecteurs plus superficiels (splay fault), dont l'interprétation était initialement incertaine sur les images migrées en temps.
44

Sistema integrado para tomada de decis?o espacial em situa??es de derramamento de ?leo no litoral norte do Estado do RN

Souza, Clen?bio Feitosa de 09 October 2006 (has links)
Made available in DSpace on 2015-03-13T17:08:40Z (GMT). No. of bitstreams: 1 ClenubioFS.pdf: 1330843 bytes, checksum: f44365144a87dbadb85a95129360dfdc (MD5) Previous issue date: 2006-10-09 / The northern coast of Rio Grande do Norte State (RN) shows areas of Potiguar basin with high activity in petroleum industry. With the goal of avoiding and reducing the accident risks with oil it is necessary to understand the natural vulnerability, mapping natural resources and monitoring the oil spill. The use of computational tools for environmental monitoring makes possible better analyses and decisions in political management of environmental preservation. This work shows a methodology for monitoring of environment impacts, with purpose of avoiding and preserving the sensible areas in oil contact. That methodology consists in developing and embedding an integrated computational system. Such system is composed by a Spatial Decision Support System (SDSS). The SDSS shows a computational infrastructure composed by Web System of Geo-Environmental and Geographic Information - SWIGG , the System of Environmental Sensibility Maps for Oil Spill AutoMSA , and the Basic System of Environmental Hydrodynamic ( SisBAHIA a System of Modeling and Numerical Simulating SMNS). In a scenario of oil spill occurred coastwise of Rio Grande do Norte State s northern coast, the integration of such systems will give support to decision agents for managing of environmental impacts. Such support is supplied through a system of supporting to spatial decisions / O litoral norte do Estado do Rio Grande do Norte (RN) apresenta ?reas da bacia Potiguar com intensa atividade da ind?stria petrol?fera. Com a finalidade de prevenir e minimizar os riscos de acidentes com ?leo, faz-se necess?rio compreender a vulnerabilidade natural, mapear os recursos naturais e monitorar os derrames de ?leo. O uso de ferramentas computacionais para o monitoramento ambiental, possibilita uma melhor an?lise e tomada de decis?o no planejamento de pol?ticas de conserva??o ambiental. A presente disserta??o apresenta uma metodologia de trabalho para o monitoramento de impactos ambientais, com o prop?sito de avaliar e proteger as regi?es sens?veis ao contato do ?leo. A metodologia consiste em desenvolver e implantar um sistema integrado, constituindo um Sistema de Apoio ? Decis?o Espacial (SADE). O SADE apresenta uma infra-estrutura computacional composta pelo SWIGG (Sistema Web de Informa??es Geogr?ficas e Geoambientais), o AutoMSA (Automatizador de Mapas de Sensibilidade Ambiental para derramamentos de ?leo) e o Sistema BAse de HIdrodin?mica Ambiental (SisBAHIA um Sistema de Modelagem e Simula??o Num?rica - SMSN). Num cen?rio de derramamento de ?leo ocorrido pr?ximo ?s ?reas costeiras do litoral norte do Estado do RN a integra??o destes sistemas disponibilizar? aos agentes respons?veis pelo gerenciamento dos danos ambientais, um sistema de suporte a tomada de decis?o espacial
45

Seismic structure, gas hydrate, and slumping studies on the Northern Cascadia margin using multiple migration and full waveform inversion of OBS and MCS data

Yelisetti, Subbarao 05 November 2014 (has links)
The primary focus of this thesis is to examine the detailed seismic structure of the northern Cascadia margin, including the Cascadia basin, the deformation front and the continental shelf. The results of this study are contributing towards understanding sediment deformation and tectonics on this margin. They also have important implications for exploration of hydrocarbons (oil and gas) and natural hazards (submarine landslides, earthquakes, tsunamis, and climate change). The first part of this thesis focuses on the role of gas hydrate in slope failure observed from multibeam bathymetry data on a frontal ridge near the deformation front off Vancouver Island margin using active-source ocean bottom seismometer (OBS) data collected in 2010. Volume estimates (∼ 0.33 km^3) of the slides observed on this margin indicate that these are capable of generating large (∼ 1 − 2 m) tsunamis. Velocity models from travel time inversion of wide angle reflections and refractions recorded on OBSs and vertical incidence single channel seismic (SCS) data were used to estimate gas hydrate concentrations using effective medium modeling. Results indicate a shallow high velocity hydrate layer with a velocity of 2.0 − 2.1 km/s that corresponds to a hydrate concentration of 40% at a depth of 100 m, and a bottom simulating reflector (BSR) at a depth of 265 − 275 m beneath the seafloor (mbsf). These are comparable to drilling results on an adjacent frontal ridge. Margin perpendicular normal faults that extend down to BSR depth were also observed on SCS and bathymetric data, two of which coincide with the sidewalls of the slump indicating that the lateral extent of the slump is controlled by these faults. Analysis of bathymetric data indicates, for the first time, that the glide plane occurs at the same depth as the shallow high velocity layer (100±10 mbsf). In contrast, the glide plane coincides with the depth of the BSR on an adjacent frontal ridge. In either case, our results suggest that the contrast in sediments strengthened by hydrates and overlying or underlying sediments where there is no hydrate is what causing the slope failure on this margin. The second part of this dissertation focuses on obtaining the detailed structure of the Cascadia basin and frontal ridge region using mirror imaging of few widely spaced OBS data. Using only a small airgun source (120 cu. in.), our results indicate structures that were previously not observed on the northern Cascadia margin. Specifically, OBS migration results show dual-vergence structure, which could be related to horizontal compression associated with subduction and low basal shear stress resulting from over-pressure. Understanding the physical and mechanical properties of the basal layer has important implications for understanding earthquakes on this margin. The OBS migrated image also clearly shows the continuity of reflectors which enabled the identification of thrust faults, and also shows the top of the igneous oceanic crust at 5−6 km beneath the seafloor, which were not possible to identify in single-channel and low-fold multi-channel seismic (MCS) data. The last part of this thesis focuses on obtaining detailed seismic structure of the Vancouver Island continental shelf from MCS data using frequency domain viscoacoustic full waveform inversion, which is first of its kind on this margin. Anelastic velocity and attenuation models, derived in this study to subseafloor depths of ∼ 2 km, are useful in understanding the deformation within the Tofino basin sediments, the nature of basement structures and their relationship with underlying accreted terranes such as the Crescent and the Pacific Rim terranes. Specifically, our results indicate a low-velocity zone (LVZ) with a contrast of 200 m/s within the Tofino basin sediment section at a depth 600 − 1000 mbsf over a lateral distance of 10 km. This LVZ is associated with high attenuation values (0.015 − 0.02) and could be a result of over pressured sediments or lithology changes associated with a high porosity layer in this potential hydrocarbon environment. Shallow high velocities of 4 − 5 km/s are observed in the mid-shelf region at depths > 1.5 km, which is interpreted as the shallowest occurrence of the Eocene volcanic Crescent terrane. The sediment velocities sharply increase about 10 km west of Vancouver Island, which probably corresponds to the underlying transition to the Mesozoic marine sedimentary Pacific Rim terrane. High attenuation values of 0.03 − 0.06 are observed at depths > 1 km, which probably corresponds to increased clay content and the presence of mineralized fluids. / Graduate / 0373 / 0372 / 0605 / subbarao@uvic.ca

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