Made available in DSpace on 2014-06-12T22:57:41Z (GMT). No. of bitstreams: 2 arquivo2789_1.pdf: 1384050 bytes, checksum: e0bdedf479359d1e99e0933285066c05 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / A assistência ventilatória mecânica (AVM) controlada induz profundas alterações na musculatura diafragmática, causando a chamada disfunção diafragmática induzida pela ventilação mecânica (DDIV). Essas alterações parecem poder ser atenuadas quando utilizados modos com participação da atividade diafragmática, como o de Pressão de Suporte (PSV). O objetivo do trabalho foi avaliar os efeitos do modo ventilatório controlado por pressão controlada (PCV-C) e do modo PSV sobre a histologia e morfometria do músculo diafragma de ratos. Ratos (n = 18) da linhagem Wistar foram incluídos nesse estudo prospectivo. Após injeção intraperitoneal de anestésico e sedativo, os ratos foram distribuídos no grupo controle (RE) e para receber AVM por 6 horas no modo PCV-C e no modo PSV. Após esse período, os animais foram eutanasiados, o diafragma retirado e encaminhado para a análise histológica e morfométrica. Os resultados revelaram uma redução da área das fibras musculares de 15% no grupo PCV-C em comparação ao controle (p<0,001) e de 10% quando comparado ao grupo PSV (p<0,05). Já com relação ao diâmetro menor das fibras musculares observou-se uma redução de 9% do grupo PCV-C em comparação ao controle (p<0,001) e de 6% em relação ao grupo PSV (p<0,05). Quando avaliada a área dos mionúcleos, notou-se uma redução de 16% desse parâmetro no grupo PCV-C, comparado ao PSV (p<0,05). Não houve diferença significativa no perímetro dos mionúcleos entre os grupos estudados (p>0,05). O grupo PCV-C apresentou atrofia muscular em um período curto de ventilação mecânica. O modo PSV parece atenuar os efeitos da DDIV, sendo uma alternativa eficiente no controle da atrofia muscular decorrente do uso do suporte ventilatório

No description available.

This dissertation explores beta dose profile of microspheres packed in arteries, various source geometries of 142Pr that can be used for therapeutic purpose, and dose backscatter factors for selected beta sources. A novel treatment method by injecting microspheres into feeding arteries of arteriovenous malformation (AVM) is under pre-clinical investigation. To optimize radiation dose to the clinically important area, i.e. arterial wall, preliminary dosimetric studies were needed. Monte Carlo calculations were performed for several geometries simulating arteries filled with microspheres packed by random packing methods. Arterial radii used in the simulation varied from 50 mm to 3 mm; microsphere radii varied from 10 mm to 0.7 mm. Dose varied significantly as a function of microsphere size, for constant arterial sizes. For the same sizes of arteries, significant dose increase was observed because of inter-artery exposure for large arteries (> 0.1 cm rad.) filled with large microspheres (> 0.03 cm rad.). Dose increase between small arteries (0.03 cm rad.) was less significant. The dose profiles of prototype 142Pr beta brachytherapy sources were calculated using MCNP 4C Monte Carlo code as well as dose point kernel (DPK) for selected cases. Dose profiles were similar to beta sources currently used indicating that 142Pr can substitute for current sources for certain cases and the DPK was closely matched with MCNP result. Backscattering of electrons is a prominent secondary effect in beta dosimetry. The backscattering is closely correlated with factors such as geometry of source and scattering material, and composition of scattering material. The backscattering factors were calculated for selected beta sources that are currently used as well as potentially useful sources for therapeutic purpose. The factors were calculated as a function of distance from the interface between water and scatterers. These factors were fit by a simple function for future incorporation into a DPK code. Backscattering effect was significant for short distance from the surface of interface between water and scattering material.

En milieu aqueux, les verres nucléaires AVM présentent de grandes différences de comportement à l'altération, malgré de faibles variations de composition. La vitesse résiduelle d'altération de ces verres est contrôlée par deux phénomènes, qui sont la précipitation de phases secondaires de type hectorites alumineuses, qui en altérant le gel protecteur, augmentent la vitesse résiduelle d'altération du verre, et, la diffusion de l'eau à travers un gel plus ou moins protecteur. Le magnésium, contenu dans ces verres, facilite la précipitation de ces phases secondaires, mais s'incorpore également dans le gel, augmentant son pouvoir de passivation. La prédominance de l'un ou l'autre de ces phénomènes dépend de la composition initiale du verre, du pH de la solution, des conditions d'altération. Altérés en eau souterraine de stockage (riche en Mg et Ca), les verres AVM s'altèrent moins qu'en eau pure, et ce malgré la précipitation de phases secondaires. Le calcium s'incorpore dans le gel, à la place du sodium et du magnésium, augmentant son pouvoir de passivation. Nous avons adapté le modèle géochimique d'altération des verres GRAAL, aux verres AVM. Malgré ses limites, ce modèle nous permet de rendre compte des différences de comportement entre les verres AVM, selon leur composition, ainsi que de proposer un modèle opérationnel de l'altération des verres AVM. / During their aqueous alteration, AVM French nuclear glasses exhibit a large range of behaviour, in spite of a small range of composition. AVM glasses alteration rates are controlled by two phenomena: (i) precipitation of secondary phases, mostly aluminous hectorites, and (ii) diffusion of water across a more or less protective gel. The magnesium contained in these glasses increases the precipitation of these secondary phases, leading to a partial or total dissolution of the gel layer. This dissolution increases the glass alteration rates. On the other hand, Mg also incorporates in the gel, increasing his passivation properties. The predominance of one of these two phenomena depends on the initial composition of the glass, the pH of the solution, and the alteration conditions. In presence of Bure geological disposal site water (Mg and Ca rich), AVM glasses undergo less alteration than in initially pure water, in spite of larger amounts of secondary phase precipitates. This results from incorporation of calcium in the gel instead of sodium and magnesium, improving its passivating properties. We have adapted the geochemical GRAAL model for AVM glasses. In spite of its limitations, this model allows us to describe the differences of behaviour between these glasses, in function of their composition. Moreover, GRAAL can be proposed as a basis of a future operational model for predicting the alteration of AVM glasses.

Tamil cinema is marked by its remarkable output of films and reception across the globe. More than 5000 films were produced in Tamil during the last century alone, and Tamil films have a longer and denser history of reception among the South East Asian diaspora--in countries like Sri Lanka, Malaysia and Singapore, mainly among the Tamilians and other South Indians--than films made in any other Indian language. The studios of Madras, arguably the most influential in shaping a film industry in terms of its form and content outside the classical Hollywood system, were at the center of Tamil cinema's productivity during the defining decades of the 1940s and 50s, a period marked by British Rule, the Second World War, India's independence, and the electoral politics of the Dravidian movement. However, a sustained and scholarly study of this history has been marked by its absence, primarily due to the enormity of the task, the challenges associated with data collection, and the availability of archival materials. Therefore, my primary objective in this dissertation is to fill this void, and study the most eventful period in the history of the Madras studios (1940-57) when they produced their landmark and seminal films. An understanding of the history of the studios and a detailed reading of their major films sheds light on the complex intersection of the cultural, economic, and political factors which shaped the studios and their owners, and the type of productions they were interested in. Tamil cinema is often criticized as verbose and theatrical mainly due to lack of parallel and art cinema movements like in neighboring states of Kerala and Karnataka. The "Madrasi Picture" has become the convenient way to label a melodramatic tearjerker juxtaposed with comedy. My challenge to this perception in this thesis, therefore, is to foreground Tamil Cinema's theatrical roots embedded in folk traditions and the Parsi theatre, and its ability to navigate through multiple influences, and yet retain a specificity of its own in terms of innovative genres, narrative devices, and formats which keep significantly influencing Indian popular cinema.

An average-value model of a rotating rectifier circuit in a brushless excitation system is set forth, where a detailed simulation is required to extract the essential averaged-model parameters using numerical averaging. In the proposed approach, a synchronous machine model with saturation and cross saturation and an arbitrary rotor network representation that uses a voltage-behind-reactance representation for the field winding of the main machine is proposed. This allows the field winding to be represented as branches in a circuit solver, permitting straightforward simulation with connected circuitry. Also a brushless exciter model is introduced to be compatible with the averaged-model, where the exciter armature windings are represented using a voltage-behind-reactance formulation. The resulting average-value model is verified in time domain against detailed simulation, and its validity is demonstrated in all rectifier modes of operation.

Predictions of market values are important for investment decisions and risk management of banking institutions, developers and, last but not least, households. Increased access to real estate market data and reducing valuatin costs were one of the most important reasons to be interested in developing and subsequent using of automated valuation models (AVM) worldwide. However, the implementation of AVM in the Czech Republic is still limited to a minimum. The aim of the thesis is to theoretically describe some alternative statistical methods used by AVM, such as fuzzy logic, ANN, spatial econometrics or hedonic models, characterize AVM, their use and analyze their current application in the Czech Republic and outline further possible development.

No description available.

This thesis covers recent advances in the adjoint variable method for the sensitivity estimations through time-domain electromagnetic simulations. It considers both frequency-independent and frequency-dependent response functions, and at the same time, provides a novel adjoint treatment for addressing dispersive sensitivity parameters in the material constitutive relation. With this proposed adjoint technique, response sensitivities with respect to all N sensitivity parameters can be computed through at most one extra simulations regardless of the value of N. This thesis also extends the existing adjoint technique to estimate all N^2 second-order sensitivity entries in the response Hessian matrix through N additional simulations. All adjoint sensitivity techniques presented in this thesis are numerically validated through various practical examples. Comparison shows that our produced adjoint results agree with those produced through central finite-difference approximations or through exact analytical approaches. / Dissertation / Doctor of Engineering (DEng)

No description available.