This thesis begins by introducing the concept of a rigid quasilocal frame (RQF) as a geometrically natural way to define an extended system in the context of the dynamical spacetime of general relativity. An RQF is defined as a two-parameter family of timelike worldlines comprising the worldtube boundary of the history of a finite spatial volume with the rigidity conditions that the congruence of worldlines is expansion-free (the ``size'' of the system is not changing) and shear-free (the ``shape'' of the system is not changing). We demonstrate that this frame exists in flat and arbitrary curved spacetimes and, moreover, exhibits the full six motional time-dependent degrees of freedom we are familiar with from Newtonian mechanics. The latter result is intimately connected with the fact that a spatial slice through the RQF - having a two-sphere topology - always admits precisely six conformal Killing vector (CKV) fields (three boosts and three rotations) associated with the action of the Lorentz group on a two-sphere. These CKVs, along with the four-velocity of observers on the RQF, are then used to quasilocally define the energy, momentum, and angular momentum inside an RQF without relying on the pre-general relativistic practice of appealing to spacetime symmetries. These quasilocal definitions for energy, momentum, and angular momentum also involve replacing the local matter-only stress-energy-momentum (SEM) tensor with the Brown-York matter plus gravity boundary SEM tensor. This allows for the construction of completely general conservation laws which describe the changes in a system in terms of fluxes across the boundary. Furthermore, since an RQF is a congruence with zero expansion and shear only relevant fluxes appear in these conservation laws - that is, fluxes due merely to changes in the size or shape of the boundary are eliminated. These resulting fluxes are simple, exact, and quantified in terms of operationally-defined geometrical quantities on the boundary and we show that they explain at a deeper level the mechanisms behind gravitational energy and momentum transfer by way of the equivalence principle. In particular, when we accelerate relative to a mass, the energy changes at a rate proportional to our acceleration times the momentum (and we propose an exact gravitational analogue of the electromagnetic Poynting vector to capture this idea). Similarly, the momentum of that object changes at a rate proportional to our acceleration times the energy. This new insight has fascinating consequences for how we should understand everyday occurrences like a falling apple - that is, the change in energy of the apple involves frame dragging while the change in momentum involves extrinsic curvature effects near the apple. Our naive general relativistic intuition tells us that these quantities should be so tiny that they should be negligible and, indeed, they are tiny but they are multiplied by huge numbers to give rise to macroscopic effects. This is how general relativity universally explains the transfer of energy and momentum but we needed rigid quasilocal frames to uncover this beautiful property of nature. Using the RQF formalism we also investigate a variety of specific problems. In particular, while looking at time-dependent rotations we discover that the reason Ehrenfest's rigid rotating disk paradox has gone unsolved for so long is that rotation introduces a subtle non-locality in time. By this we mean that, in order to maintain rigidity while undergoing time-dependent rotation, one needs to know, not only the instantaneous rotation rate, but the entire history of the motion. This makes it impossible to keep a volume of observers rigid but is doable with an RQF. We also consider RQFs in the small-sphere limit to derive many of our results and one example with particularly interesting consequences involves Bell's spaceship accelerating through an electromagnetic field. Here, we show that the change in electromagnetic energy inside the spaceship is made up of two pieces: the usual electromagnetic Poynting flux accounts for half the change while the gravitational Poynting vector equally contributes to make up the other half. This means that electromagnetism in flat spacetime generically does not tell you what is actually going on. Rather, the curvature due to the electromagnetic field necessitates a fully general relativistic treatment to get the whole story. We also use the RQF linear momentum conservation law in the context of stationary observers and fields to derive, for the first time, an exact fully general relativistic analogue of Archimedes' law. In essence, this law demonstrates that the weight of the matter and gravitational fields contained in a finite region of space is supported by the stresses (buoyant forces) acting on the boundary of that region. Furthermore, in a post-Newtonian approximation, we derive a simple set of quasilocal conservation laws which describe non-relativistic systems bound by mutual gravitational attraction. In turn, we use these laws to obtain expressions for the rates of gravitational energy and angular momentum transfer between two tidally interacting bodies - that is, the tidal heating and tidal torque - without the need to define unphysical pseudotensors. Moreover, the RQF approach explains these transfers of energy and momentum again, not as the difference of forces acting on a tidal bulge, but instead more fundamentally in the language of the equivalence principle in terms of ``accelerations relative to mass''. Throughout this work we demonstrate that the RQF approach always gives very simple, geometrical descriptions of the physical mechanisms at work in general relativity. Given that this approach also includes both matter and gravitational energy, momentum, and angular momentum and does not rely on spacetime symmetries to define these quantities, we argue that we are seeing here strong evidence that the universe is actually quasilocal in nature. We are really deeply ingrained with a local way of thinking, so shifting to a quasilocal mindset will require great effort, but we contend that it ultimately leads to a deeper understanding of the universe.

Rigid polyurethane foam is a polymeric material which is widely used for thermal insulation in building construction and other applications. Given recent emphasis on energy conservation and efficiency, there has been continuous growth in its use over the years. This raises significant fire safety concerns since polyurethanes are inherently very flammable and prone to release toxic gases as the foam thermally decomposes and burns. To improve fire safety characteristics by reducing ignitability and flammability of the foams, various flame retardants (FR) have been introduced into base foam formulations. But with the introduction of FR agents, there has been rising concern within the fire safety community and general public regarding the overall benefits versus detrimental impacts of even commonly used FR agents. In the case of rigid polyurethane foam, however, such an assessment is difficult as there are few cross comparisons in the literature that detail the impacts of different concentrations of common fire retardants, such as brominated, phosphorus-based and expandable graphite agents, on the fire behavior, smoke development and toxic gas production for even single base foam formulations. The present experimental work focuses on a systematic evaluation of these factors using three common, commercial fire retardants added in concentrations of 0%wt, 10%wt and 20%wt to a single formulation of rigid polyurethane foam. Cone calorimeter and smoke density tests are used to simulate well ventilated and poorly ventilated fire conditions during material fire performance assessment, while FTIR, Novatech P 695 gas analyzers and TD-GC/MS methods are used to investigate the gases evolved during oxidative pyrolysis and combustion of the samples. Concentration measurements of principal fire gases such as CO, CO2, reduced O2, and NOx are combined with more detailed investigation of the volatile organic compounds generated during the fire testing. Use of gas absorption sampling followed by off-line Thermal Desorption/Gas Chromatography/Mass Spectrometry (TD-GC-MS) analysis for identification of toxic gases has proven of significant benefit in this application. The full set of data obtained provides a more comprehensive identification of the evolved products during three characteristic periods in the combustion process. As such, it expands current knowledge and provides valuable new insight and understanding of thermal degradation, combustion and smoke development, as well as overall fire performance, of fire retarded rigid polyurethane foams in well-ventilated and poorly ventilated environments.

The aims of the thesis were to study the response of temporary soil-filled walls both experimentally and numerically, and to develop an efficient and accurate analytical model to predict 2-D planar response from blast loading which could be used to efficiently calculate a pressure-impulse (P-I) curve. An explicit finite element (FE) formulation was constructed using LS-Dyna software, and two analytical models were also derived and presented: a Rigid-Body Rotation model as a preliminary model, and the Rigid-Body Hybrid model as the proposed model of this thesis. Seven full-scale experiments which consisted of blast loading simple free-standing soil-filled Hesco Bastion (HB) walls are presented. Apart from comparison of an experimental result where the soil-fill in the wall possessed sizable cohesion, the response of the Rigid-Body Hybrid model was in very good agreement with the experiments overall (within 10 %). A soil sensitivity study was conducted and overall very good agreement was reached between the Rigid-Body Hybrid model in comparison with the FE model in its ability to capture differences in displacement-time histories from differences in soil parameters. Comparison with the FE model for different height-to-width ratios of walls showed that the Rigid-Body Hybrid model was within 10 % for all rotation angles and predictions of critical overturning impulse for height-to-width ratios of walls . P-I curves were developed using the analytical and FE models for the three different wall configurations studied in the experiments. The results demonstrated that the proposed Rigid-Body Hybrid model is useful for calculating a P-I curve for a HB wall efficiently and yielded very accurate results (within 5 % for the impulse asymptotes).

Dissertation (Ph. D.)--University of Akron, Dept. of Electrical and Computer Engineering, 2008. / "December, 2008." Title from electronic dissertation title page (viewed 12/29/2008) Advisor, Nathan Ida; Committee members, Robert J. Veillette, George C. Giakos, Jiang John Zhe, Gerald W. Young; Department Chair, Jose Alexis De Abreu-Garcia; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

No description available.

Following the notion of $p$-adic analytic differential operators introduced by Ardakov--Wadsley, we establish a number of properties for coadmissible $\wideparen{\mathcal{D}}$-modules on rigid analytic spaces. Our main result is a $\wideparen{\mathcal{D}}$-module analogue of Kiehl's Proper Mapping Theorem, considering the 'naive' pushforward from $\wideparen{\mathcal{D}}_X$-modules to $f_*\wideparen{\mathcal{D}}_X$-modules for proper morphisms $f: X\to Y$. Under assumptions which can be naturally interpreted as a certain properness condition on the cotangent bundle, we show that any coadmissible $\wideparen{\mathcal{D}}_X$-module has coadmissible higher direct images. This implies among other things a purely geometric justification of the fact that the global sections functor in the rigid analytic Beilinson--Bernstein correspondence preserves coadmissibility, and we are able to extend this result to arbitrary twisted $\wideparen{\mathcal{D}}$-modules on analytified partial flag varieties. Our results rely heavily on the study of completed tensor products for $p$-adic Banach modules, for which we provide several new exactness criteria. We also show that the main results of Ardakov--Wadsley on the algebraic structure of $\wideparen{\mathcal{D}}$ still hold without assuming the existence of a smooth Lie lattice. For instance, we prove that the global sections $\wideparen{\mathcal{D}}_X(X)$ form a Frechet--Stein algebra for any smooth affinoid $X$.

O colapso traqueal é caracterizado por alterações tanto anatômicas como histológicas da cartilagem hialina dos anéis traqueais e do músculo traqueal dorsal, ocasionando colapso dinâmico da traqueia durante o ciclo respiratório. A etiologia do colapso de traqueia é desconhecida e provavelmente multifatorial. O esforço repetido das vias respiratórias causa inflamação crônica da mucosa traqueal, manifestando assim a tosse, que exacerba o processo inflamatório. O colapso de traqueia manifesta um sinal clínico importante chamado síndrome de angústia respiratória. Geralmente acomete cães de raça miniatura ou toy, sendo mais observado em cães de idade média, ou idosos. O procedimento traqueoscópico é considerado padrão ouro no diagnóstico para àqueles animais com alterações respiratórias, em especial nos casos de colapso traqueal. A intervenção cirúrgica objetiva estabilizar a cartilagem da traqueia e o músculo traqueal. O avanço da tecnologia possibilitou o desenvolvimento de próteses (stents) de materiais diversos. A finalidade do uso do stent é manter o suporte cartilaginoso, eventualmente perdido pela via aérea. Em função disso, o objetivo deste trabalho foi de descrever e avaliar a colocação de stents intraluminais autoexpansivos de nitinol (liga de titânioníquel), no interior do lúmen traqueal de cães com colapso de traqueia pela técnica de traqueoscopia, e também avaliar as complicações trans e pós-operatórias, com acompanhamento periódico dos pacientes. Foram incluídos neste trabalho sete cães, com peso corporal inferior a 5kg, com diagnóstico clínico, radiográfico e endoscópico de colapso traqueal cervicotorácico e intratorácico, atendidos no HCV-FAVET/UFRGS. Os critérios de inclusão avaliados foram: manifestação de dispneia e tosse, tratamento clínico sem remissão dos sinais e colapso de traqueia grau III ou IV. O procedimento foi realizado utilizando o método diagnóstico de traqueoscopia rígida, sem o auxílio de fluroscopia, para a colocação dos stents, na tentativa de corrigir o defeito traqueal destes animais. Foi realizada radiografia cervicotorácica em todos os cães, em duas posições em ângulo de 90º, para avaliação do posicionamento do stent e da correção do defeito traqueal logo após o procedimento. Este exame foi igualmente realizado, aos 15 dias e mensalmente, até término do período de avaliação, de sete meses. Os animais foram submetidos à traqueoscopia aos 50 dias e aos sete meses após a colocação do stent, para avaliar a presença de colapso em outra região traqueal e/ou de brônquios ocorrência de fraturas do stent em quatro cães e presença de tecido de granulação. Pelas avaliações radiográficas e traqueoscópicas não foi evidenciada ocorrência de migração do stent em nenhum cão, mas fratura em quatro deles. Foi observada presença de tecido de granulação excessivo em todos eles. Neste estudo, a técnica de colocação de stent intraluminal autoexpansivo de nitinol por meio de traqueoscopia sem o uso de fluroscopia é considerada efetiva, pois houve melhora na qualidade, mas não no aumento de expectativa de vida desses cães. / The tracheal collapse is a disease characterized by both anatomical and histological changes in the hialine cartilage of the tracheal rings and the dorsal muscle, causing dynamic collapse of the trachea during the respiratory cycle. The etiology of tracheal collapse is unknown and probably multifactorial. Repeated airway stress causes chronic inflammation of the tracheal mucosa, thus manifesting cough, which exacerbates the inflammatory process. The collapse of the trachea demonstrates a significant clinical sign called respiratory distress syndrome. Usually affects breeds miniature or toy, more observed in middle-age or elderly. The tracheoscopic procedure is considered the gold standard in diagnosis for those animals with respiratory changes, especially in cases of tracheal collapse. The surgery aims to stabilize the cartilage of the trachea and tracheal muscle. The advancement of technology has enabled the development of prostheses (stents) of various materials. The purpose of a stent to keep the cartilaginous support is eventually lost by air. As a result, the objective of this study was to describe and evaluate the placement of intraluminal autoexpansives nitinol stents (nickel-titanium alloy), inside the tracheal lumen of dogs with tracheal collapse by tracheoscopy technique and also evaluate complications trans and postoperative, with periodic patient monitoring. This work seven dogs whith body weight less than 5kg, with clinical, radiographic and endoscopic diagnosis of cervicalthoracic and intrathoracic tracheal collapse seen at HCV-FAVET/UFRGS were included. Inclusion criteria were: manifestation of dyspnea and cough, clinical treatment without remission of sings and collapsing trachea grade III or IV. The procedure was performed using the diagnostic method of rigid tracheoscopy, without the aid of fluoroscopy for the placement of stents in an attempt to correct the tracheal defect of these animals. Cervicalthoracic radiography was performed in all dogs, in two positions at 90 °, to evaluate the positioning of the stent and the fix tracheal defect after the procedure. This examination was also performed at 15 days and monthly until the end of the evaluation period of seven months. The animals underwent tracheoscopy at 50 days and at seven months after stent placement, to assess the presence of tracheal collapse in another and / or bronchi occurrence of stent fractures in four dogs and the presence of granulation tissue region. By radiographic and reviews tracheoscopycs was not evidence of stent migration occurred in any dog, but fracture in four of them. Presence of excessive granulation tissue was observed in all of them. In this study, the technique of placing intraluminal autoexpansive nitinol stenting through tracheoscopy without the use of fluoroscopy is considered effective because there was an improvement in quality, but not the increase in life expectancy of these dogs.

O colapso traqueal é caracterizado por alterações tanto anatômicas como histológicas da cartilagem hialina dos anéis traqueais e do músculo traqueal dorsal, ocasionando colapso dinâmico da traqueia durante o ciclo respiratório. A etiologia do colapso de traqueia é desconhecida e provavelmente multifatorial. O esforço repetido das vias respiratórias causa inflamação crônica da mucosa traqueal, manifestando assim a tosse, que exacerba o processo inflamatório. O colapso de traqueia manifesta um sinal clínico importante chamado síndrome de angústia respiratória. Geralmente acomete cães de raça miniatura ou toy, sendo mais observado em cães de idade média, ou idosos. O procedimento traqueoscópico é considerado padrão ouro no diagnóstico para àqueles animais com alterações respiratórias, em especial nos casos de colapso traqueal. A intervenção cirúrgica objetiva estabilizar a cartilagem da traqueia e o músculo traqueal. O avanço da tecnologia possibilitou o desenvolvimento de próteses (stents) de materiais diversos. A finalidade do uso do stent é manter o suporte cartilaginoso, eventualmente perdido pela via aérea. Em função disso, o objetivo deste trabalho foi de descrever e avaliar a colocação de stents intraluminais autoexpansivos de nitinol (liga de titânioníquel), no interior do lúmen traqueal de cães com colapso de traqueia pela técnica de traqueoscopia, e também avaliar as complicações trans e pós-operatórias, com acompanhamento periódico dos pacientes. Foram incluídos neste trabalho sete cães, com peso corporal inferior a 5kg, com diagnóstico clínico, radiográfico e endoscópico de colapso traqueal cervicotorácico e intratorácico, atendidos no HCV-FAVET/UFRGS. Os critérios de inclusão avaliados foram: manifestação de dispneia e tosse, tratamento clínico sem remissão dos sinais e colapso de traqueia grau III ou IV. O procedimento foi realizado utilizando o método diagnóstico de traqueoscopia rígida, sem o auxílio de fluroscopia, para a colocação dos stents, na tentativa de corrigir o defeito traqueal destes animais. Foi realizada radiografia cervicotorácica em todos os cães, em duas posições em ângulo de 90º, para avaliação do posicionamento do stent e da correção do defeito traqueal logo após o procedimento. Este exame foi igualmente realizado, aos 15 dias e mensalmente, até término do período de avaliação, de sete meses. Os animais foram submetidos à traqueoscopia aos 50 dias e aos sete meses após a colocação do stent, para avaliar a presença de colapso em outra região traqueal e/ou de brônquios ocorrência de fraturas do stent em quatro cães e presença de tecido de granulação. Pelas avaliações radiográficas e traqueoscópicas não foi evidenciada ocorrência de migração do stent em nenhum cão, mas fratura em quatro deles. Foi observada presença de tecido de granulação excessivo em todos eles. Neste estudo, a técnica de colocação de stent intraluminal autoexpansivo de nitinol por meio de traqueoscopia sem o uso de fluroscopia é considerada efetiva, pois houve melhora na qualidade, mas não no aumento de expectativa de vida desses cães. / The tracheal collapse is a disease characterized by both anatomical and histological changes in the hialine cartilage of the tracheal rings and the dorsal muscle, causing dynamic collapse of the trachea during the respiratory cycle. The etiology of tracheal collapse is unknown and probably multifactorial. Repeated airway stress causes chronic inflammation of the tracheal mucosa, thus manifesting cough, which exacerbates the inflammatory process. The collapse of the trachea demonstrates a significant clinical sign called respiratory distress syndrome. Usually affects breeds miniature or toy, more observed in middle-age or elderly. The tracheoscopic procedure is considered the gold standard in diagnosis for those animals with respiratory changes, especially in cases of tracheal collapse. The surgery aims to stabilize the cartilage of the trachea and tracheal muscle. The advancement of technology has enabled the development of prostheses (stents) of various materials. The purpose of a stent to keep the cartilaginous support is eventually lost by air. As a result, the objective of this study was to describe and evaluate the placement of intraluminal autoexpansives nitinol stents (nickel-titanium alloy), inside the tracheal lumen of dogs with tracheal collapse by tracheoscopy technique and also evaluate complications trans and postoperative, with periodic patient monitoring. This work seven dogs whith body weight less than 5kg, with clinical, radiographic and endoscopic diagnosis of cervicalthoracic and intrathoracic tracheal collapse seen at HCV-FAVET/UFRGS were included. Inclusion criteria were: manifestation of dyspnea and cough, clinical treatment without remission of sings and collapsing trachea grade III or IV. The procedure was performed using the diagnostic method of rigid tracheoscopy, without the aid of fluoroscopy for the placement of stents in an attempt to correct the tracheal defect of these animals. Cervicalthoracic radiography was performed in all dogs, in two positions at 90 °, to evaluate the positioning of the stent and the fix tracheal defect after the procedure. This examination was also performed at 15 days and monthly until the end of the evaluation period of seven months. The animals underwent tracheoscopy at 50 days and at seven months after stent placement, to assess the presence of tracheal collapse in another and / or bronchi occurrence of stent fractures in four dogs and the presence of granulation tissue region. By radiographic and reviews tracheoscopycs was not evidence of stent migration occurred in any dog, but fracture in four of them. Presence of excessive granulation tissue was observed in all of them. In this study, the technique of placing intraluminal autoexpansive nitinol stenting through tracheoscopy without the use of fluoroscopy is considered effective because there was an improvement in quality, but not the increase in life expectancy of these dogs.

O colapso traqueal é caracterizado por alterações tanto anatômicas como histológicas da cartilagem hialina dos anéis traqueais e do músculo traqueal dorsal, ocasionando colapso dinâmico da traqueia durante o ciclo respiratório. A etiologia do colapso de traqueia é desconhecida e provavelmente multifatorial. O esforço repetido das vias respiratórias causa inflamação crônica da mucosa traqueal, manifestando assim a tosse, que exacerba o processo inflamatório. O colapso de traqueia manifesta um sinal clínico importante chamado síndrome de angústia respiratória. Geralmente acomete cães de raça miniatura ou toy, sendo mais observado em cães de idade média, ou idosos. O procedimento traqueoscópico é considerado padrão ouro no diagnóstico para àqueles animais com alterações respiratórias, em especial nos casos de colapso traqueal. A intervenção cirúrgica objetiva estabilizar a cartilagem da traqueia e o músculo traqueal. O avanço da tecnologia possibilitou o desenvolvimento de próteses (stents) de materiais diversos. A finalidade do uso do stent é manter o suporte cartilaginoso, eventualmente perdido pela via aérea. Em função disso, o objetivo deste trabalho foi de descrever e avaliar a colocação de stents intraluminais autoexpansivos de nitinol (liga de titânioníquel), no interior do lúmen traqueal de cães com colapso de traqueia pela técnica de traqueoscopia, e também avaliar as complicações trans e pós-operatórias, com acompanhamento periódico dos pacientes. Foram incluídos neste trabalho sete cães, com peso corporal inferior a 5kg, com diagnóstico clínico, radiográfico e endoscópico de colapso traqueal cervicotorácico e intratorácico, atendidos no HCV-FAVET/UFRGS. Os critérios de inclusão avaliados foram: manifestação de dispneia e tosse, tratamento clínico sem remissão dos sinais e colapso de traqueia grau III ou IV. O procedimento foi realizado utilizando o método diagnóstico de traqueoscopia rígida, sem o auxílio de fluroscopia, para a colocação dos stents, na tentativa de corrigir o defeito traqueal destes animais. Foi realizada radiografia cervicotorácica em todos os cães, em duas posições em ângulo de 90º, para avaliação do posicionamento do stent e da correção do defeito traqueal logo após o procedimento. Este exame foi igualmente realizado, aos 15 dias e mensalmente, até término do período de avaliação, de sete meses. Os animais foram submetidos à traqueoscopia aos 50 dias e aos sete meses após a colocação do stent, para avaliar a presença de colapso em outra região traqueal e/ou de brônquios ocorrência de fraturas do stent em quatro cães e presença de tecido de granulação. Pelas avaliações radiográficas e traqueoscópicas não foi evidenciada ocorrência de migração do stent em nenhum cão, mas fratura em quatro deles. Foi observada presença de tecido de granulação excessivo em todos eles. Neste estudo, a técnica de colocação de stent intraluminal autoexpansivo de nitinol por meio de traqueoscopia sem o uso de fluroscopia é considerada efetiva, pois houve melhora na qualidade, mas não no aumento de expectativa de vida desses cães. / The tracheal collapse is a disease characterized by both anatomical and histological changes in the hialine cartilage of the tracheal rings and the dorsal muscle, causing dynamic collapse of the trachea during the respiratory cycle. The etiology of tracheal collapse is unknown and probably multifactorial. Repeated airway stress causes chronic inflammation of the tracheal mucosa, thus manifesting cough, which exacerbates the inflammatory process. The collapse of the trachea demonstrates a significant clinical sign called respiratory distress syndrome. Usually affects breeds miniature or toy, more observed in middle-age or elderly. The tracheoscopic procedure is considered the gold standard in diagnosis for those animals with respiratory changes, especially in cases of tracheal collapse. The surgery aims to stabilize the cartilage of the trachea and tracheal muscle. The advancement of technology has enabled the development of prostheses (stents) of various materials. The purpose of a stent to keep the cartilaginous support is eventually lost by air. As a result, the objective of this study was to describe and evaluate the placement of intraluminal autoexpansives nitinol stents (nickel-titanium alloy), inside the tracheal lumen of dogs with tracheal collapse by tracheoscopy technique and also evaluate complications trans and postoperative, with periodic patient monitoring. This work seven dogs whith body weight less than 5kg, with clinical, radiographic and endoscopic diagnosis of cervicalthoracic and intrathoracic tracheal collapse seen at HCV-FAVET/UFRGS were included. Inclusion criteria were: manifestation of dyspnea and cough, clinical treatment without remission of sings and collapsing trachea grade III or IV. The procedure was performed using the diagnostic method of rigid tracheoscopy, without the aid of fluoroscopy for the placement of stents in an attempt to correct the tracheal defect of these animals. Cervicalthoracic radiography was performed in all dogs, in two positions at 90 °, to evaluate the positioning of the stent and the fix tracheal defect after the procedure. This examination was also performed at 15 days and monthly until the end of the evaluation period of seven months. The animals underwent tracheoscopy at 50 days and at seven months after stent placement, to assess the presence of tracheal collapse in another and / or bronchi occurrence of stent fractures in four dogs and the presence of granulation tissue region. By radiographic and reviews tracheoscopycs was not evidence of stent migration occurred in any dog, but fracture in four of them. Presence of excessive granulation tissue was observed in all of them. In this study, the technique of placing intraluminal autoexpansive nitinol stenting through tracheoscopy without the use of fluoroscopy is considered effective because there was an improvement in quality, but not the increase in life expectancy of these dogs.

No description available.