Objective. This study aimed to determine the predictors of olfactory improvement after endoscopic sinus surgery among patients with chronic rhinosinusitis with nasal polyps. Method. This prospective cohort study included patients admitted to a university hospital between 2006 and 2012. Assessment using odour identification testing, a sinonasal symptom questionnaire, the Rhinosinusitis Disability Index and mucus biomarker levels was performed at various time points. Correlation of variables with identification score differences at six postoperative time points and at baseline was performed, followed by multiple linear regression to determine significant predictors at each of the six post-operative time points. Results. Baseline absence of acute sinusitis, elevated serpin F2 and anterior rhinorrhoea predict early olfactory improvement, whereas baseline allergic rhinitis predicts late olfactory improvement. Baseline odour identification score was the strongest predictor across all time points. Conclusion. Patients with chronic rhinosinusitis and nasal polyps with worse disease or baseline olfactory function may benefit more from endoscopic sinus surgery in terms of olfactory improvement.

Esta dissertação propõe o desenvolvimento de uma rede neural artificial (RNA) direcionada a ambientes foundation fieldbus para realização do cálculo de vazão em dutos fechados. Para tanto, a metodologia proposta utiliza-se de medidas de pressão, temperatura e pressão diferencial, as quais normalmente estão disponíveis em plantas industriais. A principal motivação do emprego das redes neurais reside no seu baixo custo e simplicidade de implementação, o que possibilita o emprego de apenas blocos fieldbus padrões tornando a metodologia independente do fabricante. Foi utilizada uma rede perceptron multicamadas com algoritmo de treinamento backpropagation de Levenberg-Marquardt. O treinamento foi realizado numa programação elaborada para o software Matlab TM. A arquitetura da rede neural foi determinada por métodos empíricos variando-se o número de neurônios e de camadas neurais até se atingir um erro aceitável na prática. Após esses treinamentos foi desenvolvida uma programação para realizar os cálculos de vazão em um ambiente foundation fieldbus utilizando-se para tanto o software DeltaV TM do fabricante Emerson Process Management. Foram obtidos resultados com erro relativo médio de valor de vazão em torno de 1.43% para um primeiro cenário utilizando uma placa de orifício e ar como fluido, e de 0,073% para um segundo cenário utilizando uma placa de orifício e gás natural como fluido, com relação aos valores obtidos através do instrumento multivariável 3095MV TM do fabricante Rosemount. Os valores de erro encontrados validam o método desenvolvido nessa dissertação. / This dissertation proposes the development of an artificial neural network (ANN) directed to foundation fieldbus environment for calculation of flow in closed ducts. The proposed methodology uses measurements of pressure, temperature and differential pressure, which are usually available in industrial plants. The main motivation of the use of neural networks lies in their low cost and simplicity of implementation, which allows the use of standard fieldbus blocks by just making the method independent of the manufacturer. It was used a multilayer perceptron network with backpropagation training and algorithm from Levenberg-Marquardt. The training was programmed in the software Matlab TM. The architecture of the ANN was determined by empirical methods by varying the number of neurons and neural layers until it reaches an acceptable error. After such trainings, it was developed a program to perform the flow calculations in an foundation fieldbus environment using Emerson Process Management\'s DeltaV TM software. The results were obtained with an average relative error of flow rate of 1.43% for the first scenario using an orifice plate and air as a process fluid, and 0.073% for a second scenario using an orifice plate and natural gas as the fluid related to the values obtained from Rosemount 3095MV TM multivariable instrument. The values of error found validate the method developed in this dissertation.

A perfuração gástrica por endoscopia é a consequência de alguns de seus procedimentos, e atualmente, com o advento das cirurgias endoscópicas translumenais por orifícios naturais, um meio de manipulação dos órgãos abdominais. Esse é o motivo pelo qual os endoscopistas estão procurando um reparo endoscópico seguro. O objetivo foi avaliar a factibilidade e os resultados do fechamento da abertura gástrica similar àquelas realizadas nos procedimentos cirúrgicos endoscópicos translumenais por orifícios naturais utilizando-se o T-Tag associado à câmara plástica protetora. Sob anestesia geral, dez porcos Landrace foram submetidos a uma perfuração gástrica calibrada em 18 mm de diâmetro. A abertura foi fechada pelo novo método apresentado, composto de fios cirúrgicos conectados em uma âncora metálica (T-Tag) posicionados pela parede gástrica através de uma agulha. Uma câmara protetora plástica foi adaptada à extremidade distal do endoscópio para proteger os órgãos abdominais adjacentes da punção da agulha fora do estômago. Seis dispositivos T-Tag foram posicionados na maioria dos casos e os fios atados com um apertador de nó metálico endoscópico formando três pontos de sutura. O teste de vazamento foi realizado com uma pinça endoscópica e distensão da câmara gástrica com ar. Os animais receberam líquidos no mesmo dia do procedimento. Uma dose de antibiótico diária por dois dias foi administrada. Nenhuma complicação foi detectada no período pós-operatório. Um mês depois, a endoscopia revelou a presença de cicatriz em todos os animais, e a maioria apresentava materiais da sutura aderidos à superfície mucosa da região. A região do antro gástrico apresentava poucas aderências identificadas na laparotomia realizada no mesmo momento. O reparo endoscópico utilizando o T-Tag e a câmara protetora plástica é factível, fácil de ser realizada e seguro. São necessários estudos adicionais para mostrar o real valor desse tipo de procedimento / The endoscopic gastric perforation is a consequence of some endoscopic procedures and now a way to manage abdominal organs. This is the reason why endoscopists are studying a safe endoscopic repair. The objective was to evaluate feasibility and results of the gastric opening closure similar to those performed in natural orifice translumenal endoscopic surgery procedures using T-Tag associated with the plastic protection chamber. Ten Landrace pigs underwent a gastric perforation of 1.8 cm in diameter under general anesthesia. The opening was repaired with stitch assembled in a T-Tag anchor placed through the gastric wall with a needle. A plastic transparent chamber, adapted to the endoscope tip protected the abdominal organs from the needle puncture outside the stomach. Six T-Tags were placed in most cases and the stitches were tied with a metallic tie-knot, forming three sutures. The leakage test was performed with a forceps and by air distention. The animals received liquids in the same operative day. One daily shot antibiotic during two days was used. No complication was detected in the postoperative course. One month later the endoscopy revealed a scar in all animals, and the majority of these with suture material. The antral anterior gastric wall was clear with few adhesions in the laparotomy performed in the same time. The endoscopic repair using T-Tag and a protector chamber is feasible, easy to perform and safe. Further studies are needed to show the real value of this kind of procedure

A medição de vazão de escoamentos multifásicos é uma necessidade constante em diversas atividades industriais como exploração de óleo e gás, controle de linhas de transporte de vapor e monitoramento de sistemas de resfriamento de usinas nucleares. Dentre os meios disponíveis para a realização da medição de vazão mássica, os dispositivos de medição de pressão diferencial constituem um dos métodos mais simples, sendo sua construção, aplicação e operação em escoamentos monofásicos bem conhecidas e definidas por normas técnicas. No entanto, sua aplicação tem sido estendida a escoamentos multifásicos, geralmente estando aliada a uma técnica adicional de medição de fração de vazio ou fração volumétrica das fases. Este trabalho descreve o estudo numérico de escoamentos multifásicos através de medidores de vazão baseados em pressão diferencial como placas de orifício e bocais de vazão de raio longo. Para tal, primeiramente foram conduzidas simulações de escoamentos monofásicos através de placas de orifício e bocais de vazão de raio longo na faixa de número de Reynolds 15.000 500.000. Os resultados de coeficiente de descarga obtidos foram quantitativamente comparados com os valores preditos por norma ISO, apresentando desvio máximo de aproximadamente 4, 9% para as placas e de 1,0% para os bocais. Em uma segunda etapa, escoamentos do tipo gás úmido (wet gas) através de placas de orifício foram simulados através de três abordagens diferentes. Os resultados de vazão mássica total obtidos foram comparados com dados experimentais fornecidos pela PETROBRAS. As abordagens que consideram o escorregamento entre as fases apresentaram previsões mais próximas dos experimentos, com desvio relativo médio de 3,9%, enquanto a modelagem homogênea apresentou um desvio médio de 6, 6%. Nestes estudos, foram também avaliadas as estruturas desenvolvidas no escoamento através de visualizações da distribuição de fases. São também apresentadas duas sugestões para complementação da caracterização de um escoamento multifásico: (1) a introdução da informação de fração de vazio na formulação apresentada por Paz (2011) e (2) a análise estatística do sinal de pressão diferencial em placas de orifício. Com relação ao primeiro item, comparações quantitativas com dados experimentais sugeriram que a alternativa apresentada é viável para operações de monitoramento da produção. Já o último estudo mostrou qualitativamente a influência da quantidade de líquido na flutuação da pressão diferencial / The flowrate measurement of multiphase flows is a constant need at many industrial activities such as oil and gas exploration, steam transport lines control and monitoring of nuclear plants cooling systems. Within the available means for performing flowrate measurement, the differential pressure devices constitute one of the simplest methods, with their construction, application and operation in single phase flows being well known and defined by technical standards. However, their application has been extended to multiphase flows, usually being allied to a void fraction or phase volume fraction measurement technique. This work describes a numerical study of multiphase flows through differential pressure-based flowrate meters such as orifice plates and long radius nozzles. Firstly simulations of single phase flows through orifice plates and long radius nozzles were conducted in the Reynolds number range 15.000500.000. The obtained results of discharge coefficients were quantitatively compared to ISO Standard predicted values, showing a maximum deviation of approximately 4,9% for the orifice plates and of 1,0% for the nozzles. In a second stage, wet gas flows through orifice plates were simulated by means of three approaches. The calculated results of total mass flowrate were compared to experimental data provided by PETROBRAS. The approaches that considered the slip between phases provided the closest results to the experiments, with a mean relative error of 3, 9%, while the homogeneous modeling presented an error of 6, 6%. In these studies, the structures developed within the domain were also evaluated through the visualization of the phases distribution. Two suggestions for complementing the characterization of a multiphase flow are presented: (1) the introduction of void fraction information into the formulation presented by Paz (2011) and (2) the statistical analysis of the orifice plate pressure drop signal. Regarding the first item, quantitative comparison with experimental data suggested that the presented alternative is viable for production monitoring operations. The last study qualitatively revealed the influence of the liquid loading in the pressure drop fluctuation.

A medição de vazão de escoamentos multifásicos é uma necessidade constante em diversas atividades industriais como exploração de óleo e gás, controle de linhas de transporte de vapor e monitoramento de sistemas de resfriamento de usinas nucleares. Dentre os meios disponíveis para a realização da medição de vazão mássica, os dispositivos de medição de pressão diferencial constituem um dos métodos mais simples, sendo sua construção, aplicação e operação em escoamentos monofásicos bem conhecidas e definidas por normas técnicas. No entanto, sua aplicação tem sido estendida a escoamentos multifásicos, geralmente estando aliada a uma técnica adicional de medição de fração de vazio ou fração volumétrica das fases. Este trabalho descreve o estudo numérico de escoamentos multifásicos através de medidores de vazão baseados em pressão diferencial como placas de orifício e bocais de vazão de raio longo. Para tal, primeiramente foram conduzidas simulações de escoamentos monofásicos através de placas de orifício e bocais de vazão de raio longo na faixa de número de Reynolds 15.000 500.000. Os resultados de coeficiente de descarga obtidos foram quantitativamente comparados com os valores preditos por norma ISO, apresentando desvio máximo de aproximadamente 4, 9% para as placas e de 1,0% para os bocais. Em uma segunda etapa, escoamentos do tipo gás úmido (wet gas) através de placas de orifício foram simulados através de três abordagens diferentes. Os resultados de vazão mássica total obtidos foram comparados com dados experimentais fornecidos pela PETROBRAS. As abordagens que consideram o escorregamento entre as fases apresentaram previsões mais próximas dos experimentos, com desvio relativo médio de 3,9%, enquanto a modelagem homogênea apresentou um desvio médio de 6, 6%. Nestes estudos, foram também avaliadas as estruturas desenvolvidas no escoamento através de visualizações da distribuição de fases. São também apresentadas duas sugestões para complementação da caracterização de um escoamento multifásico: (1) a introdução da informação de fração de vazio na formulação apresentada por Paz (2011) e (2) a análise estatística do sinal de pressão diferencial em placas de orifício. Com relação ao primeiro item, comparações quantitativas com dados experimentais sugeriram que a alternativa apresentada é viável para operações de monitoramento da produção. Já o último estudo mostrou qualitativamente a influência da quantidade de líquido na flutuação da pressão diferencial / The flowrate measurement of multiphase flows is a constant need at many industrial activities such as oil and gas exploration, steam transport lines control and monitoring of nuclear plants cooling systems. Within the available means for performing flowrate measurement, the differential pressure devices constitute one of the simplest methods, with their construction, application and operation in single phase flows being well known and defined by technical standards. However, their application has been extended to multiphase flows, usually being allied to a void fraction or phase volume fraction measurement technique. This work describes a numerical study of multiphase flows through differential pressure-based flowrate meters such as orifice plates and long radius nozzles. Firstly simulations of single phase flows through orifice plates and long radius nozzles were conducted in the Reynolds number range 15.000500.000. The obtained results of discharge coefficients were quantitatively compared to ISO Standard predicted values, showing a maximum deviation of approximately 4,9% for the orifice plates and of 1,0% for the nozzles. In a second stage, wet gas flows through orifice plates were simulated by means of three approaches. The calculated results of total mass flowrate were compared to experimental data provided by PETROBRAS. The approaches that considered the slip between phases provided the closest results to the experiments, with a mean relative error of 3, 9%, while the homogeneous modeling presented an error of 6, 6%. In these studies, the structures developed within the domain were also evaluated through the visualization of the phases distribution. Two suggestions for complementing the characterization of a multiphase flow are presented: (1) the introduction of void fraction information into the formulation presented by Paz (2011) and (2) the statistical analysis of the orifice plate pressure drop signal. Regarding the first item, quantitative comparison with experimental data suggested that the presented alternative is viable for production monitoring operations. The last study qualitatively revealed the influence of the liquid loading in the pressure drop fluctuation.

Esta dissertação propõe o desenvolvimento de uma rede neural artificial (RNA) direcionada a ambientes foundation fieldbus para realização do cálculo de vazão em dutos fechados. Para tanto, a metodologia proposta utiliza-se de medidas de pressão, temperatura e pressão diferencial, as quais normalmente estão disponíveis em plantas industriais. A principal motivação do emprego das redes neurais reside no seu baixo custo e simplicidade de implementação, o que possibilita o emprego de apenas blocos fieldbus padrões tornando a metodologia independente do fabricante. Foi utilizada uma rede perceptron multicamadas com algoritmo de treinamento backpropagation de Levenberg-Marquardt. O treinamento foi realizado numa programação elaborada para o software Matlab TM. A arquitetura da rede neural foi determinada por métodos empíricos variando-se o número de neurônios e de camadas neurais até se atingir um erro aceitável na prática. Após esses treinamentos foi desenvolvida uma programação para realizar os cálculos de vazão em um ambiente foundation fieldbus utilizando-se para tanto o software DeltaV TM do fabricante Emerson Process Management. Foram obtidos resultados com erro relativo médio de valor de vazão em torno de 1.43% para um primeiro cenário utilizando uma placa de orifício e ar como fluido, e de 0,073% para um segundo cenário utilizando uma placa de orifício e gás natural como fluido, com relação aos valores obtidos através do instrumento multivariável 3095MV TM do fabricante Rosemount. Os valores de erro encontrados validam o método desenvolvido nessa dissertação. / This dissertation proposes the development of an artificial neural network (ANN) directed to foundation fieldbus environment for calculation of flow in closed ducts. The proposed methodology uses measurements of pressure, temperature and differential pressure, which are usually available in industrial plants. The main motivation of the use of neural networks lies in their low cost and simplicity of implementation, which allows the use of standard fieldbus blocks by just making the method independent of the manufacturer. It was used a multilayer perceptron network with backpropagation training and algorithm from Levenberg-Marquardt. The training was programmed in the software Matlab TM. The architecture of the ANN was determined by empirical methods by varying the number of neurons and neural layers until it reaches an acceptable error. After such trainings, it was developed a program to perform the flow calculations in an foundation fieldbus environment using Emerson Process Management\'s DeltaV TM software. The results were obtained with an average relative error of flow rate of 1.43% for the first scenario using an orifice plate and air as a process fluid, and 0.073% for a second scenario using an orifice plate and natural gas as the fluid related to the values obtained from Rosemount 3095MV TM multivariable instrument. The values of error found validate the method developed in this dissertation.

Squeeze Film Dampers (SFD) provide viscous damping in rotor bearing systems to reduce lateral vibration amplitudes and to isolate mechanical components. Aircraft engine shafts, often supported on roller bearings, operate at high rotational speeds and are susceptible to large amplitude shaft whirl due to rotor imbalance. SFDs aid to reduce such large whirl amplitudes while also eliminating rotor instabilities. he current work quantifies experimentally the forced performance of two parallel squeeze SFDs separated by a central groove. Force coefficients are identified in a specialized SFD test rig constructed to undergo similar operating and loading conditions as in jet engines. Of interest is to quantify the effect of a central feed groove on the forced performance of SFDs and to validate predictions from a computational tool. The test rig comprises of an elastically supported bearing structure and one of two journals. Tests are conducted on two open ends SFDs, both with diameter D and nominal radial clearance c; each damper with two parallel film land lengths L= 1/5 D and 2L, separated by a feed groove of width L and depth 3/4 L. ISO VG 2 grade lubricant oil flows into the central groove via 3 orifices, 120 degrees apart, and then through the film lands to finally exit to ambient. In operation, a static loader pulls the bearing to various static off center positions with respect to the stationary journal, and electromagnetic shakers (2,200 N) excite the test system with single frequency loads over a frequency range to generate rectilinear, circular and elliptical orbits with specified motion amplitudes. A frequency domain method identifies the SFD mechanical parameters, viz., stiffness, damping, and added mass coefficients. The long damper generates 7 times more direct damping and 2 times more added mass compared to the short length damper. The damping coefficients are sensitive to the static eccentricity (up to 50 percent c) while showing lesser dependency on the amplitude of whirl motion (up to 20 percent c). On the other hand, added mass coefficients are nearly constant with static eccentricity and decrease with higher amplitudes of motion. The magnitudes of identified cross-coupled coefficients are insignificant for all imposed operating conditions for either damper. Large dynamic pressures recorded in the central groove demonstrate the groove does not isolate the film lands by merely acting as a source of lubricant, but contributes to the generation of large added mass coefficients. The recorded dynamic pressures in the film lands and central groove do not evidence lubricant vapor or gas cavitation for the tested static eccentricities and amplitudes of motion. The direct damping coefficients for both dampers are independent of excitation frequency over the frequency range of the tests. Predictions derived from a novel SFD computational tool that includes flow interactions in the central groove and oil supply orifices agree well with the experimental force coefficients for both dampers. The current work advances the state of the art in SFDs for jet engines.

As the most commonly diseased valve of the heart, the mitral valve has been the subject of extensive research for many years. Prior research has focused on the development of surgical repair techniques and mainly consists of in vivo clinical studies into the efficacy and long-term effects of different procedures. There is a need for a means of studying the mitral valve ex vivo, incorporating patient data and the effects of different repair techniques on the valve prior to surgery. In this study, a method was developed for reconstructing the mitral valve from patient-specific data. Three-dimensional transthoracic and transesophageal echocardiography (3D-TTE and 3D-TEE) were used to obtain ultrasound images from a normal subject and a patient with mitral valve regurgitation. Geometric information was extracted from the images defining the primary structures of the mitral valve and a special program in MATLAB was created to automatically construct a finite element model of a valve. A dynamic finite element analysis solver, LS-DYNA 971, was used to simulate the dynamics of the valves and the non-linear, anisotropic behaviour of biological tissue. The two models were successful in simulating the dynamics of the mitral valve, with the subject model displaying normal function and the patient model showing the dysfunction displayed in the ultrasound images. A method was then developed to modify the original patient model, in a way that maintains its patient-specific nature, to model mitral valve repair. Four mitral valve repair techniques were simulated using the patient model: the annuloplasty ring, the double-orifice Alfieri stitch, the paracommissural Alfieri stitch, and the quadrangular resection. The former was coupled with the other three techniques, as is standard protocol in mitral valve repair. The effects of these techniques on the mitral valve were successfully determined, with varying degrees of improvement in valve function.

As the most commonly diseased valve of the heart, the mitral valve has been the subject of extensive research for many years. Prior research has focused on the development of surgical repair techniques and mainly consists of in vivo clinical studies into the efficacy and long-term effects of different procedures. There is a need for a means of studying the mitral valve ex vivo, incorporating patient data and the effects of different repair techniques on the valve prior to surgery. In this study, a method was developed for reconstructing the mitral valve from patient-specific data. Three-dimensional transthoracic and transesophageal echocardiography (3D-TTE and 3D-TEE) were used to obtain ultrasound images from a normal subject and a patient with mitral valve regurgitation. Geometric information was extracted from the images defining the primary structures of the mitral valve and a special program in MATLAB was created to automatically construct a finite element model of a valve. A dynamic finite element analysis solver, LS-DYNA 971, was used to simulate the dynamics of the valves and the non-linear, anisotropic behaviour of biological tissue. The two models were successful in simulating the dynamics of the mitral valve, with the subject model displaying normal function and the patient model showing the dysfunction displayed in the ultrasound images. A method was then developed to modify the original patient model, in a way that maintains its patient-specific nature, to model mitral valve repair. Four mitral valve repair techniques were simulated using the patient model: the annuloplasty ring, the double-orifice Alfieri stitch, the paracommissural Alfieri stitch, and the quadrangular resection. The former was coupled with the other three techniques, as is standard protocol in mitral valve repair. The effects of these techniques on the mitral valve were successfully determined, with varying degrees of improvement in valve function.

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Civil Engineering in the Faculty of Engineering at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014 / The current problems of orifice, nozzle and Venturi flow meters are that they are limited to turbulent flow and the permanent pressure drop produced in the pipeline. To improve these inadequacies, converging-diverging (C-D) tubes were manufactured, consisting of symmetrical converging and diverging cones, where the throat is the annular section between the two cones, with various angles and diameter ratios to improve the permanent pressure loss and flow measurement range. The objective of this study was firstly to evaluate the permanent pressure loss, secondly to determine the discharge coefficient values for various C-D tubes and compare them with the existing differential pressure flow meter using Newtonian and non-Newtonian fluids, and finally to assess the performance of these differential pressure flow meters. The tests were conducted on the multipurpose test rig in the slurry laboratory at the Cape Peninsula University of Technology. Newtonian and non-Newtonian fluids were used to conduct experiments in five different C-D tube flow meters with diameter ratios (β) of 0.5, 0.6 and 0.7, and with angles of the wall to the axis of the tube (θ) of 15°, 30° and 45°. The results for each test are presented firstly in the form of static pressure at different flow rates. It was observed that the permanent pressure loss decreases with the flow rate and the length of the C-D tube. Secondly, the results are presented in terms of discharge coefficient versus Reynolds number. It was found that the Cd values at 15° drop earlier than at 30° and 45°; when viscous forces become predominant, the Cd increases with increasing beta ratio. The Cd was found to be independent of the Reynolds number for Re>2000 and also a function of angle and beta ratio. Preamble Performance of a symmetrical converging-diverging tube differential pressure flow meter Finally, the error analyses of discharge coefficients were assessed to determine the performance criteria. The standard variation was found to increase when the Reynolds number decreases. The average discharge coefficient values and their uncertainties were determined to select the most promising C-D tube geometry. An average Cd of 0.96, with an uncertainty of ±0.5 % for a range of Reynolds numbers greater than 2,000 was found. The comparison between C-D tubes 0.6(15-15) and classical Venturi flow meters reveals that C-D 0.6(15-15) performs well in turbulent range and shows only a slight inaccuracy in laminar. This thesis provides a simple geometrical differential pressure flow meter with a constant Cd value over a Reynolds number range of 2000 to 150 000.