BACKGROUND: Sepsis is a clinical syndrome characterised by the systemic response to infection. It is a common problem in modern intensive care units and is associated with significant morbidity and mortality. Though the underlying cause of death is often multifactorial, refractory hypotension and cardiovascular collapse are frequently observed in the terminal phases of the condition. The aetiology of these cardiovascular abnormalities is complex but appears to be mediated by a circulating factor(s). The impact of sepsis upon left ventricular systolic function has been studied extensively. This may be because it is more readily assessed than diastolic function. Despite being increasingly appreciated as a contributor to morbidity and mortality in other clinical settings, there are scant data regarding the evaluation of left ventricular diastolic function in sepsis. Review of the haemodynamic monitoring literature reveals that many conventional measures of left ventricular filling, intravascular volume status and fluid responsiveness are influenced by ventricular diastolic (dys)function, such that interpretation can be challenging in critical care settings. In addition, many available techniques, such as pulmonary artery catheterisation, are invasive and potentially associated with risk to the patient. More robust and less invasive measures of left ventricular diastolic function and filling that can be applied within the intensive care unit (ICU) must be developed. The use of cardiac biomarkers, such as B-type natriuretic peptide (BNP), might represent a novel approach to evaluating left ventricular diastolic function and filling. BNP is released by the myocardium in response to wall stretch/tension. It has demonstrated value in the emergency department diagnosis of heart failure but interpretation of plasma BNP concentrations in critical care remains problematic. At least in part, this appears to relate to the significant number of potential confounders in patients with critical illness. Associations between BNP concentration and diastolic function have not previously been evaluated in severe sepsis and septic shock. The overall aim of this thesis is to investigate the usefulness of plasma BNP concentration in the evaluation of left ventricular diastolic function (including ventricular filling) in severe sepsis and septic shock. DIASTOLIC (DYS)FUNCTION IN SEPSIS: Review of the literature reveals that sepsis is associated with a spectrum of diastolic dysfunction. Characterisation of diastolic function in sepsis is challenging. In this regard, tissue Doppler imaging (TDI), offers promise. TDI is an echocardiographic technique that measures myocardial velocities, which are low frequency, high-amplitude signals filtered from conventional Doppler imaging. TDI has gained acceptance amongst cardiologists in the evaluation of diastolic function, particularly as a measure of ventricular relaxation and ventricular filling pressure; however, there are scant data regarding its use in critical care. We analysed echocardiographs from a large heterogeneous cohort of consecutive ICU patients (n=94) who had TDI as part of their clinically requested echocardiography. As well as supporting the feasibility of TDI in critically ill and mechanically ventilated patients, we demonstrated a wide range of TDI variables and a high prevalence of diastolic dysfunction using this modality. RODENT MODELS OF SEPSIS: We also sought to adapt, refine and evaluate rodent models of sepsis. Such models would allow control for a multitude of potential confounders commonly encountered in clinical sepsis. Two commonly employed rodent models of sepsis include caecal ligation and perforation (CLP) and endotoxin infusion. Comparison between CLP, sham and control groups demonstrated no difference in TDI or BNP. The observed changes in echocardiographic diastolic variables did not reflect those expected in sepsis and may be best explained by increases in heart rate rather than diastolic dysfunction per se. Endotoxaemia was associated with changes consistent with impaired myocardial relaxation (TDI) and reversible myocardial injury (histopathology), as expected in sepsis. BNP did not change significantly from baseline. This might be explained by the potential influence of fluid management upon BNP secretion. CLINICAL RESEARCH: The prediction of fluid responsiveness potentially prevents ineffective, excessive or deleterious intravenous fluid administration. Prospective evaluation of plasma BNP concentration in patients with septic shock found that it was not a predictor of a fluid responsive state. Furthermore, elevated BNP did not rule out a favourable response and therefore does not contraindicate a fluid challenge. Both impaired diastolic dysfunction, especially E/e’, and elevated BNP, have been associated with excess mortality in a range of cardiovascular diseases. These have not previously been compared in septic shock. In a cohort of patients with septic shock, E/e’ was a stronger predictor of mortality than cardiac biomarkers, including BNP. Fluid balance was an independent predictor of BNP in septic shock. OVERALL CONCLUSION: BNP appears not to be clinically useful in the evaluation of ventricular filling or diastolic function in sepsis. The association with fluid balance is a new finding and should be evaluated in a wider range of critically ill patients. In contrast to BNP, TDI appears to be a promising bedside tool in the evaluation of diastolic function and should be further evaluated in critical care.

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[Truncated abstract] This thesis consists of six chapters, and the main research contributions are contained in chapters two through five inclusive. The topics addressed in each chapter are distinct, but related, and the specific contributions to knowledge made by the different chapters are related to: (i) understanding more fully the nature of the demand for alcohol; (ii) explaining the relationship between reputation characteristics and consumers’ willingness to pay for wine; (iii) estimating the rate of return to Australian wine; and (iv) using financial analysis to reveal the risk diversification benefits available by including wine in an investment portfolio. The details of each contribution are briefly outlined below. Chapter 2 discusses the nature of the demand for alcohol. The demand for alcoholic beverages is an area much studied, and there are numerous studies estimating the own-price elasticity of alcoholic beverages. A review of relevant published studies indicates reported: beer own-price elasticity estimates range from -.02 to -3.00, with a mean estimate value of -.46, and standard deviation of -.41 (n = 139); wine own-price elasticity estimates range from -.05 to -3.00, with a mean estimate value of -.72, and standard deviation of .53 (n = 140); and spirits own-price elasticity estimates range from -.01 to -2.18, with a mean estimate value of -.74, and standard deviation of .47 (n = 136). Chapter 2 contributes to understanding the demand for alcohol, not by adding yet another set of elasticity estimates to an already substantial literature, but by providing a framework through which all known own-price elasticity estimates can be understood. Specifically, a meta-regression framework is employed to study previously published own-price elasticity estimates. This framework allows the effect of model design attributes to be isolated, and the underlying trend in consumer responses to price changes to be identified.

Les charges réelles d'applications sont souvent dynamiques. Ainsi, le dimensionnement statique de ressources est voué soit au gaspillage, s'il est basé sur une estimation du pire scénario, soit à la dégradation de performance, s'il est basé sur la charge moyenne. Grâce au modèle du cloud computing, les ressources peuvent être allouées à la demande et le dimensionnement adapté à la variation de la charge. Cependant, après avoir exploré les travaux existants, nous avons trouvé que la plupart des outils d'élasticité sont trop génériques et ne parviennent pas à répondre aux besoins spécifiques d'applications particulières. Dans le cadre de ce travail, nous utilisons des boucles autonomiques et diverses techniques d'élasticité afin de rendre élastiques différents types d'applications, à savoir un service de consolidation, un intergiciel de messagerie et une plateforme de traitement de données en temps-réel. Ces solutions élastiques ont été réalisées à partir d'applications libres et leur évaluation montre qu'ils permettent d'économiser les ressources utilisées avec un surcoût minimal. / Real world workloads are often dynamic. This makes the static scaling of resourcesfatally result in either the waste of resources, if it is based on the estimatedworst case scenario, or the degradation of performance if it is based on the averageworkload. Thanks to the cloud computing model, resources can be provisioned ondemand and scaling can be adapted to the variations of the workload thus achievingelasticity. However, after exploring the existing works, we find that most elasticityframeworks are too generic and fail to meet the specific needs of particularapplications. In this work, we use autonomic loops along with various elasticitytechniques in order to render different types of applications elastic, namelya consolidation service, message-oriented middleware and a stream processingplatform. These elastic solutions have been implemented based on open-sourceapplications and their evaluation shows that they enable resources’ economy withminimal overhead.

Master's thesis focuses on numerical modeling of automotive tasks. The text is divided into two main parts. A fuel supply module is the main topic of all numeric analyses of this thesis and it is introduced in the first part. Basics of theoretical continuum mechanics and finite elements method are also explained in the first part. The second part is split into two main topics of the fuel supply module - material damping and contact numerical modeling. Practical reasons for parameter optimization are explained along with particular optimization results and underlying theoretical background.

Made available in DSpace on 2010-04-20T21:00:15Z (GMT). No. of bitstreams: 4 antonioamatheus.pdf.jpg: 10995 bytes, checksum: 1828cb26a193c4d38b615ab0609fe5e2 (MD5) antonioamatheus.pdf.txt: 106415 bytes, checksum: f825bdea8fa1b98bf0a8f186f3f7987b (MD5) antonioamatheus.pdf: 367370 bytes, checksum: f9a03b48130b6bab200082fdcec386e6 (MD5) 1_167577.pdf: 363707 bytes, checksum: baeea326cf89a1805b19cbefeee109b2 (MD5) Previous issue date: 2008-02-26T00:00:00Z / The objective of this study is to analyze the growth of the share of pension funds assets in the GDP, looking for the group of variables that can better explain the observed trend from the beginning of nineties until 2006. This analysis will focus on three groups of variables: economic, social and demographic and structural. This relationship will be empirically demonstrated by the elasticity of the variables over the assets’ share on the GDP, estimated through a time series regression. The main idea is to provide estimators easily to interpret in order to support better policies that will leverage the pension funds coverage in the Brazilian labor-force market. This study differs from the others in three aspects. The first aspect refers to the period of data, a little longer than the others. The second aspect refers to interpolation of missing observations in series, which implies in a better predictive model once there is more data available. The third and last aspect refers to the analyzed group of variables that impact both, the demand and supply of pension funds. / O objetivo deste trabalho é analisar o crescimento dos ativos dos fundos de pensão em relação ao PIB, identificando quais variáveis atuaram de forma mais relevante para o crescimento observado desde o início da década de noventa até o ano de 2006. A relação dessas variáveis com o crescimento dos ativos em relação ao PIB será demonstrada empiricamente através da estimação das elasticidades utilizando modelos regressivos de séries temporais. A idéia principal de se utilizar esta modelagem é o fato dela ser facilmente interpretada, podendo suportar mais claramente a elaboração de políticas que alavanquem o crescimento da cobertura dos fundos de pensão no mercado de trabalho brasileiro. Este trabalho difere dos demais em três aspectos. O primeiro se refere à periodicidade dos dados analisados, sendo a deste trabalho um pouco mais longa que a dos demais. O segundo aspecto concentra-se na interpolação dos dados inexistentes das séries, cujo objetivo é aumentar o poder explicativo das séries com um maior número de observações. Por fim, o terceiro aspecto é o conjunto de variáveis escolhidas, uma vez que engloba tanto aquelas que atuam pelo lado da demanda quando da oferta de fundos de pensão.

Cette thèse comprend deux parties principales:La première partie est une étude du problème d'élasticité linéaire en temps par une méthode de Galerkin discontinue (SIPG). Dans cette partie, nous avons toutd'abord obtenu un estimateur a posteriori pour la formulation semi-discrète. En utilisant une technique de reconstruction et des résultats montrés dans le cas stationnaire, on a établi un estimateur a posteriori d'erreur pour le problème d'onde élastique dépendant du temps. Afin de calculer l'estimateur d'erreur lié au cas stationnaire, nous avons présenté deux méthodes, l'une utilisant la technique de la dualité ce qui nous a donné un calcul d'erreur en norme L^2 et l'autre en calculant l'erreur en norme énergie. Pour la discrétisation en temps l'équation, nous utilisons un schéma numérique d'Euler. En utilisant une technique et de reconstruction spatio-temporelle, on propose un nouvel estimateur a posteriori.La deuxième partie a pour but l'établissement d'un développement asymptotiquepour la solution de problème résolvant Stokes avec une petite perturbation dudomaine. Dans ce travail, nous avons appliqué la théorie du potentiel. On a écrit la solution du problème non perturbé et du problème perturbé sous forme d'opérateurs intégraux. En calculant la différence, et en utilisant des propriétés liées aux noyaux des opérateurs on a établi un développement asymptotique de la solution. / This thesis contains two main parts:The first part concerning the discontinuous Galerkin method for the timedependentlinear elasticity problem. In this part, we have derived the a posteriorierror bounds for semi-discrete and fully discrete formulation, by makinguse of the SE reconstruction technique which allows to estimate the errorbound for time-dependent problem through the error estimation of the ascociatedstationary elasticity problem. Then to derive the error bound for thestationary problem, we have presented two methods to obtain two different aposteriori bounds, by L2 duality technique and via energy norm. For fully discretescheme, we make use of the backward-Euler scheme and an appropiatespace-time reconstruction which has the zero-mean value in time.The second part concerning the derivation of an asymptotic expansionfor the solution of Stokes resolvent problem with a small perturbation of thedomain. In this work, we have applied the potential theory, boundary integralequation method and geometric properties of perturbed boundary. Thederivation is rigorous, and this method allows to derive high-order terms inasymptotic expansion. Also, it can be used for many other boundary valueproblems, whenever a suitable potential theory is available.

This thesis contains two parts: theoretical and experimental. In the theoretical part are described materials for production SCC and their effect on the properties of fresh and hardened concrete. Practical part is divided into two experiments. First experiment deals with the design, production and properties of hardened SCC strength classes C16/20, C20/25 and C25/30 with high volume fly ash and inert admixtures. The main endpoints were long-term compressive strength and modulus of elasticity. Second experiment of practical part deals with designs SCC with modulus of elasticity more than 40 kN/mm2.

O incremento nos padrões de consumo de energia elétrica e o fácil acesso a diversas tecnologias eletroeletrônicas têm contribuído para a superação anual dos índices de consumo de eletricidade. Tendo em vista que esse insumo ainda não é economicamente armazenável em larga escala, se faz necessário manter o equilíbrio em tempo real entre a oferta/demanda mais perdas. Entretanto, a maioria dos consumidores brasileiros atendidos em baixa tensão paga tarifas baseadas nos custos médios, os quais ocultam os efeitos da alta concentração de consumo de eletricidade em determinados horários do dia. Nesse contexto, o presente estudo analisa o impacto que Programas de Resposta à Demanda (PRD), baseado em tarifas com diferenciação horária, exercem sobre o desempenho dos sistemas de distribuição. A metodologia proposta utiliza o conceito de elasticidade-preço da demanda de energia elétrica, por meio de uma abordagem matricial e permite representar diferentes tipos de consumidores. A partir de uma análise de sensibilidade dos estudos de casos, verificou-se a influência dos parâmetros que compõem as equações do PRD proposto. Para avaliar o desempenho do modelo, foram feitos estudos numéricos usando uma versão modificada do sistema teste IEEE de 34 nós. A análise de sensibilidade entre os estudos de caso apresentou uma avaliação do percentual de adesão dos consumidores, bem como o comportamento das perdas ativas mensais e do perfil de tensão. Os resultados obtidos no presente estudo evidenciam a validade da abordagem proposta, a partir de uma formulação simplificada, além de demonstrar a potencial aplicabilidade a casos reais. / Power consumption behavior increase and easy access to electroelectronics technologies had contributed to annual power consumption rates surpass. As there is not yet an economically sustainable way to store electric power it is necessary to maintain the balance between offer and power demand (considering losses). Brazilian customers majority supplied in low voltage are charged by its mean power consumption masking peak consumption in certain periods of the day. Within this reality the present work analysis the impact of Demand Response Programs (DRP) using Time-Of-Use tariff (TOU) over the power distribution system’s performance. The proposed methodology applies the concept of Price Elasticity demand and uses the representation of different consumers’ types in a matrix approach. The DRP parameters’ variation impact was checked using a sensitivity analysis. In order to evaluate the performance of the proposed model numerical studies were done using the IEEE 34 modified node test feeder. A sensitivity analysis among the case studies presents the customers adherence percentage and the monthly active power losses and voltage profile. The methodology's results besides supporting the proposal approach from a simplified formulation show the potential use on real cases.

Made available in DSpace on 2016-12-23T13:51:51Z (GMT). No. of bitstreams: 1 Dissertacao Ana Paula Coelho Duarte.pdf: 2045883 bytes, checksum: 83ad2c04d2aba1d3d47b92dfb5d4359c (MD5) Previous issue date: 2011-07-05 / Amostras de madeira foram submetidas a ensaio de determinação de rigidez à flexão e à compressão paralela às fibras. A deflexão sofrida pela amostra foi medida por intermédio de relógio comparador (como na norma NBR 7190), para efeito de comparação e por meio de imagens digitais colhidas por câmera. As imagens também permitiram determinar a equação da linha elástica e o ângulo de curvatura apresentada pela amostra a cada valor de carga. Essas quatro metodologias para obter deformações permitiram calcular, portanto, o módulo de elasticidade de quatro maneiras. Mediu-se também a deformação específica de corpos-de-prova submetidos à compressão, seja pela maneira tradicional, com extensômetros elétricos, como de modo diferente, por análise de imagens. Concluiu-se que a análise de imagens permite inferir com exatidão o valor da rigidez, quando se usam a medida da deflexão no centro do vão ou quando se obtém por regressão os parâmetros utilizados na derivação da curva elástica. A definição do ângulo de curvatura por interpretação das imagens nem sempre apresentou bons resultados. Amostras maiores de madeira talvez permitam maior precisão nessa definição. Os resultados do cálculo da rigidez por compressão da madeira foram pouco satisfatórios, isso certamente porque a deformação é excepcionalmente pequena. Uma câmera de maior qualidade ótica será suficiente para resolver essa falha / Wood samples were submitted to standard bending and compression tests to determine their stiffness. To compare values, modulus of elasticity was first measured using a dial gage (in bending) or strain-gage (in compression). The samples were filmed at the same time and the film, captured by a Leica V-lux-20, yielded still images in the .jpg format, that were later analysed using a MatLab program. In the case of bending, three values of MOE were obtained from each image and compared to the first. One of the new methods, that permitted to calculate the deflection at the center of the sample in the image, gave values that were very close to those given by the dial. Data were also collected from the images that allowed the calculation by regression analysis of the elastic curve of the beam. MOE values so obtained were also very similar to those of the dial, with a few exceptions. The angle that subtended the curvature of the deflected beam was also found from the images, but gave MOE values quite different, in most cases. It is presumed, in this case, that the sample (a 2 by 2 by 24 cm parallelepiped) was probably too small to allow calculating with precision the lines by regression. In compression, the technique used here, the filming of two parallel lines that should become closer as the sample was loaded, did not also give good estimates of MOE. The calculated strain should amount here to only about 2 or 3 pixels, too few to guarantee a precise capture by the camera. The techniques used in this work are simple, the necessary equipment, cheap, and only one person is needed. A better camera will certainly be sufficient to make them practical and precise