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Settlement Behavior of a Sandy Loam Due to Suction Changes Associated with Simulated Artificial Tree RootsAreghan, Joseph I 19 November 2012 (has links)
Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction.
In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.
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Técnica de replicação de raízes dentárias em resina composta fotopolimerizável a partir de molde de resina acrílica autopolimerizável / Root tooth replication technique in photo polymerized composite resin made by means of an acrylic resin mold by self polymerized resinCamargo, Sergio Luiz da Silveira 08 February 2011 (has links)
Pelas fraturas que sofrem os dentes caninos, torna-se necessário tratá-los endodonticamente, e repará-los proteticamente. Porém, novas fraturas coronais, com ou sem perda de coroa metálica podem se repetir. Muitas técnicas restauradoras priorizam os dentes com maior percentual de porção coronal, porque a extensa área de coroa remanescente assegura execução facilitada, favorecendo a recuperação do elemento dental e garantindo sucesso do assentamento da peça metálica. As pesquisas realizadas para se conseguir novos tratamentos utilizam dentes naturais para simular a realidade. Não há banco de dentes rotineiro na Odontologia Veterinária. O uso de dentes naturais de animais encontra restrições por conta da grande diversidade de raças e de porte entre cães, consequentemente no tamanho e na anatomia dos dentes. Existe ainda a carência de disponibilidade de amostras naturais na quantidade necessária para desenvolver tais estudos. O material artificial capaz de substituir os dentes naturais pode estar nas resinas compostas fotopolimerizáveis que apresentam propriedades mecânicas semelhantes às da dentina. Para se replicar o dente natural em resina composta, foi criado um molde em resina acrílica transparente. A literatura deste assunto é escassa ou mesmo inexiste. Com a construção de dentes artificiais muitas pesquisas podem ser realizadas, pois as amostras dentárias serão padronizadas de acordo com a necessidade de cada estudo a ser desenvolvido. Neste trabalho objetivou-se reproduzir quarenta dentes artificiais (réplicas) para demonstrar a possibilidade do padrão de cópia a partir do uso de um molde de resina acrílica. Os resultados mostraram que as réplicas foram similares ao dente natural. / Due to the fractures that canine teeth suffer, it is necessary to treat these teeth endodonticaly and restore them prosthetically (with pin, post core and metallic crown) in its coronal portion. However a new coronal fracture can happen with or without loss of the prosthodontic work. Many of the techniques aim at the teeth with larger extension of remaining area of crown, which favors the crown preparation and fixation of the prosthesis. Many researches use natural teeth to simulate the real conditions. In Veterinary Dentistry there is no routine bank of teeth. However there is a variety of dog breeds with different sizes, as well as a great variety in extension of the teeth. Additionally there is large numbers of natural teeth available enough for use in all researches. The material that can substitute the natural teeth seems to be the photo polymerized composite resin, which has similar mechanical properties to dentin. To replicate the natural teeth in composite resin, a mold was created in acrylic transparent resin. Literature of this subject is spares or inexistent. With artificial replication of teeth many researches can be achieved, once the samples of teeth can be standardized, according to which study. This project aimed to reproduce 40 replicas to demonstrate the possibility of copy from a transparent acrylic mold. Results showed that the replicas were similar to the natural tooth.
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Settlement Behavior of a Sandy Loam Due to Suction Changes Associated with Simulated Artificial Tree RootsAreghan, Joseph I 19 November 2012 (has links)
Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction.
In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.
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Técnica de replicação de raízes dentárias em resina composta fotopolimerizável a partir de molde de resina acrílica autopolimerizável / Root tooth replication technique in photo polymerized composite resin made by means of an acrylic resin mold by self polymerized resinSergio Luiz da Silveira Camargo 08 February 2011 (has links)
Pelas fraturas que sofrem os dentes caninos, torna-se necessário tratá-los endodonticamente, e repará-los proteticamente. Porém, novas fraturas coronais, com ou sem perda de coroa metálica podem se repetir. Muitas técnicas restauradoras priorizam os dentes com maior percentual de porção coronal, porque a extensa área de coroa remanescente assegura execução facilitada, favorecendo a recuperação do elemento dental e garantindo sucesso do assentamento da peça metálica. As pesquisas realizadas para se conseguir novos tratamentos utilizam dentes naturais para simular a realidade. Não há banco de dentes rotineiro na Odontologia Veterinária. O uso de dentes naturais de animais encontra restrições por conta da grande diversidade de raças e de porte entre cães, consequentemente no tamanho e na anatomia dos dentes. Existe ainda a carência de disponibilidade de amostras naturais na quantidade necessária para desenvolver tais estudos. O material artificial capaz de substituir os dentes naturais pode estar nas resinas compostas fotopolimerizáveis que apresentam propriedades mecânicas semelhantes às da dentina. Para se replicar o dente natural em resina composta, foi criado um molde em resina acrílica transparente. A literatura deste assunto é escassa ou mesmo inexiste. Com a construção de dentes artificiais muitas pesquisas podem ser realizadas, pois as amostras dentárias serão padronizadas de acordo com a necessidade de cada estudo a ser desenvolvido. Neste trabalho objetivou-se reproduzir quarenta dentes artificiais (réplicas) para demonstrar a possibilidade do padrão de cópia a partir do uso de um molde de resina acrílica. Os resultados mostraram que as réplicas foram similares ao dente natural. / Due to the fractures that canine teeth suffer, it is necessary to treat these teeth endodonticaly and restore them prosthetically (with pin, post core and metallic crown) in its coronal portion. However a new coronal fracture can happen with or without loss of the prosthodontic work. Many of the techniques aim at the teeth with larger extension of remaining area of crown, which favors the crown preparation and fixation of the prosthesis. Many researches use natural teeth to simulate the real conditions. In Veterinary Dentistry there is no routine bank of teeth. However there is a variety of dog breeds with different sizes, as well as a great variety in extension of the teeth. Additionally there is large numbers of natural teeth available enough for use in all researches. The material that can substitute the natural teeth seems to be the photo polymerized composite resin, which has similar mechanical properties to dentin. To replicate the natural teeth in composite resin, a mold was created in acrylic transparent resin. Literature of this subject is spares or inexistent. With artificial replication of teeth many researches can be achieved, once the samples of teeth can be standardized, according to which study. This project aimed to reproduce 40 replicas to demonstrate the possibility of copy from a transparent acrylic mold. Results showed that the replicas were similar to the natural tooth.
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Settlement Behavior of a Sandy Loam Due to Suction Changes Associated with Simulated Artificial Tree RootsAreghan, Joseph I January 2012 (has links)
Shallow foundations rested on Leda clay that are widely distributed in Eastern Canada exhibit shrinkage characteristics and are prone to differential settlements. Due to this reason, significant repairs are necessary to the foundations and basements of residential structures constructed in Leda clay deposits. Differential settlements are commonly attributed to the changes in the natural water content of soils associated with water infiltration, evaporation or plant transpiration (i.e., tree-roots-suction). Various research studies have been undertaken to estimate the possible settlements of shallow foundations associated with the water infiltration or evaporation. Several thumb rules have been proposed through research studies, providing recommendations with respect to the distance at which trees must be planted as a function of their heights at maturity such that differential settlements can be avoided. However, limited studies have been carried out to estimate or model the settlements of shallow foundations taking into account the influence of tree-roots-suction.
In the present research program, a comprehensive experimental study regarding the deformation characteristics of a sandy loam soil from Ottawa due to tree-root-suction is undertaken, using specially designed equipment. The study has been undertaken using a sandy loam soil so that the testing program can be conducted in a shorter period of time. An artificial rooting system (ARS) was designed and placed in a specially designed tank at the University of Ottawa to simulate tree-roots-suction and measure soil surface settlements associated with a decrease in natural water content (or increase in soil suction) using particle image velocimetry (PIV) technique. The ARS consists of an artificial root, suction generator, matric suction and volumetric water content monitoring devices. The variation of matric suction and volumetric water content are monitored at various depths using the instrumentation of the ARS. Based on the results of the experimental studies, a methodology is proposed to model the settlement behaviour of sandy loam soils due to suction from ARS, using commercial finite element software, SEEP/W and SIGMA/W (i.e. software package of GeoStudio 2007). The study offers a reasonably good comparison between the measured surface settlements and those estimated using the finite element modelling analysis. The modelling methodology presented in this thesis is promising and may be extended for estimating the settlement behaviour associated with the tree roots suction of Leda clay deposits and to other soils.
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Vergleichende Untersuchung zur Applikation von Kalziumhydroxideinlagen / Comparative Examination of Application Techniques of Calcium HydroxideStaemmler, Kai 19 March 2012 (has links)
No description available.
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Vergleichende In-Vitro-Studie zur Applikation von Kalziumhydroxid-Einlagen mit verschiedenen Techniken und Medikamenten / Comparative in vitro study on the application of calcium hydroxide deposits with different techniques and drugsPietzarka, Katharina 25 March 2014 (has links)
Ziel der Studie: Das Ziel der Studie war es, verschiedene Applikationsmethoden und Medikamente auf die erzielbare Homogenität der Füllung bei der Einbringung einer Kalziumhydroxid-Paste in den Wurzelkanal zu untersuchen. Weiterhin sollte die Untersuchung für zwei verschiedene Präparationsgrößen des Wurzelkanals erfolgen.
Material und Methode: Für die Versuche wurden 160 konfektionierte Wurzelkanalmodelle verwendet, die vor ihrer Verwendung auf die apikale Gängigkeit überprüft wurden. Anschließend erfolgte die randomisierte Aufteilung der Proben gemäß den Präparationsgrößen 35 und 45 in zwei Hauptgruppen (n = 80), die wiederum in jeweils vier Untergruppen (n = 20) aufgeteilt wurden. Die jeweils 80 künstlichen Wurzelkanäle der beiden Hauptgruppen wurden standardisiert bis zur Größe 35 und bis zur Größe 45 präpariert.
Die so präparierten Wurzelkanalmodelle wurden mit verschiedenen Medikamenten und Methoden jeweils für die Größe 35 und 45 gefüllt. Die erste Untergruppe wurde mit Hypocal gefüllt und anschließend mit einem Wattepellet verdichtet. Die zweite Untergruppe wurde mit Hypocal gefüllt, das anschließend mit einer Papierspitze im Kanal verteilt wurde, mit Hypocal nachappliziert und abschließend mit einem Wattepellet verdichtet. Die Applikationsmethode der dritten Untergruppe entspricht der Methode der ersten Gruppe, jedoch wurde Ultracal als Medikament genutzt. Die vierte Untergruppe wurde äquivalent zur zweiten Untergruppe mit Ultracal gefüllt.
Die Wurzelkanalmodelle wurden geröntgt und mit Hilfe eines Score-Systems von zwei kalibrierten Untersuchern ausgewertet. Die Ergebnisse wurden nach einem nichtparametrischen Rangverfahren für longitudinale Daten für die Kriterien „Vollständigkeit der Füllung“, „Qualität im apikalen Bereich“, „Überpressung“, „Blasengröße“ und „Füllung des Apex“ ausgewertet. Weiterhin wurden Paarvergleiche der Applikationsmethoden „Hypocal/Wattepellet“, „Ultracal/Wattepellet“, „Hypocal mit Verdichtung durch eine Papierspitze“ und „Ultracal mit Verdichtung durch eine Papierspitze“ für multiples Testen adjustiert nach Tukey angestellt. Die Untersuchungen wurden getrennt für die Größen 35 und 45 durchgeführt.
Ergebnis: Es konnte nachgewiesen werden, dass keine Medikament-Applikations-Kombination in allen Kriterien generell eine vollständige, nicht-überpresste und blasenfreie Füllung gewährleistet. Weiterhin wurde aufgezeigt, dass die signifikant beste Füllqualität durch eine 3-malige Applikation der Kalziumhydroxid-Paste mit anschließender Verdichtung mit einem Wattepellet erreicht wurde. Es lag kein signifikanter Unterschied zwischen den beiden Kalziumhydroxid-Medikamenten hinsichtlich der Füllqualität vor.
Schlussfolgerung: Die beste Füllqualität wurde unabhängig vom Medikament nach 3-maliger Applikation des Kalziumhydroxids und anschließender Verdichtung mit einem Wattepellet erzielt.
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