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A fundamental study of the Herschel-Quincke (HQ) tube concept for the reduction of noise in circular ducts is presented here. Recent testing of the Herschel-Quincke tube concept on the Pratt-Whitney JT15D and AlliedSignal TFE731-60 engines showed the potential for the practical application of this approach. A model of the HQ-system has been developed to aid in the design of the system tested. The model has revealed new noise control mechanisms associated to the implementation of multiple HQ-waveguides in a duct in the presence of higher order modes. However, the practical nature of these engine facilities results in limitations with regard to the fundamental research knowledge that could be gained from testing in a more controlled laboratory environment. A series of experiments was conducted at the NASA Langley Research Center 0.30 m ducted fan test facility where detailed modal measurements were performed. The main goals of this research endeavor were to evaluate the accuracy of the previously developed theoretical model and provide insight into the noise control mechanisms. Experiments were performed with different disturbance mode structures, number of HQ tubes and arrays, and axial positions. The modes in the duct were generated with an array of acoustic drivers (no flow case) and measured with logarithmically spaced circumferential and helical microphone arrays located on the duct wall. The modal amplitudes of the incident, transmitted, and reflected modes in the duct were determined from the microphone measurements. This allowed for the comparison of analytical and experimental modal amplitudes, modal powers, total power, and reductions. The results of this study provide insight into the three noise control mechanisms associated with this approach: reflection, circumferential scattering, and radial scattering. Comparison with the experimental results shows that the model accurately predicts the sound power attenuation except near the cut-off frequency of the modes where it tends to overestimate the attenuation. The effect of the number of tubes in the array and its axial position was also evaluated. Overall, the results of this study validate the general modeling approach for the HQ tube concept. / Master of Science

The goal of the splice girder research project 0-6652 funded by the Texas Department of Transportation is to utilize the full potential of splicing prestressed TX girders continuously. The TX girder family of beams is cost effective alone due to their simple, repetitive fabrication, but to truly optimize their potential would be to span several beams together as one continuous unit. The weight and length restrictions allowed by trucks or barges limit the prestressed beam lengths. Therefore, splicing together prestressed beams becomes the solution to the transporting obstacle. As a result, the prestressed girders will be more competitive to other bridge types such as steel I-girders, steel trapezoidal girders, cable-stayed bridges, and concrete segmental bridges. In fact, a prestressed/post-tensioned concrete bridge is preferred over steel designs in highly corrosive environments such as the coast or in snow regions where de-icing chemicals are used. In comparison, to a segmental box girder bridge, the post-tensioned prestressed bridge has reduced complexity due to fewer segments and the number of reduced joints susceptible to corrosion. The issue that arises with splicing prestressed beams is that in the process of connecting them together an opening must be made to install the post-tensioning (PT) steel strands. The openings are created by installing several steel or plastic circular ducts into the web region. Since the post-tensioning results in a reduction of the concrete web region, a modification is necessary to the shear capacity equation. The experimental study performed at the Ferguson Structural Engineering Laboratory consisted of fabricating and testing two full-scale prestressed Tx46 girders. One girder contained a plastic post-tensioning duct with grout and steel strands installed in the web region. The other beam was a standard Tx46 beam fabricated without a duct. Both beams had a reinforced concrete deck installed with an overhang to model an actual bridge section. Furthermore, the purpose of the standard beam was to serve as a direct comparison to the beam with a duct and determine the actual reduction in shear capacity. The research and findings will include the impact of the plastic duct in the Tx46 compared to the control beam. The failure loads of the test specimens will be compared to the current 2012 AASHTO code predictions for shear design. Also, revisions to the AASHTO code will be recommended if necessary. The primary goal of this research was to improve the design and detailing of the skewed end-blocks commonly used in these beams. As U-beams had been in service for several decades without incident, it was anticipated that there would be little need for change in the design, and the findings of the research would involve a slight tweaking to improve the overall performance. / text

Orientador: Eliane Chaves Jorge / Resumo: Introdução: A sondagem lacrimal tem sido o tratamento de escolha para a obstrução lacrimonasal congênita (OLNC) que não apresenta resolução espontânea. No entanto, não há consenso sobre qual é a melhor época para a realização da sondagem e se ela é melhor do que outras terapias. Objetivo: Avaliar a efetividade da sondagem lacrimal no tratamento da OLNC. Método: Uma revisão sistemática da literatura foi realizada usando plataformas eletrônicas de busca para identificar estudos de OLNC comparando sondagem lacrimal com outros tratamentos ou nenhuma intervenção. A qualidade da evidência foi avaliada pelo sistema GRADE (Grading of Recommendations Assessment, Development and Evaluation). Resultados: Quatro ensaios clínicos randomizados foram incluídos, envolvendo 423 participantes. A metanálise mostrou que não houve diferença estatística na resolução da OLNC entre o grupo submetido à sondagem lacrimal precoce e o submetido à observação/sondagem tardia (2 estudos; RR 1.00 [0.76, 1.33] p=0,99, I2=79%, baixa qualidade de evidência). Nas representações de metanálise, o desfecho taxa de resolução da sondagem tardia comparada à intubação bicanalicular com silicone não teve diferença estatística (1 estudo, RR 0.94 [IC 95% 0.84, 1.06] p=0,31, moderada qualidade de evidência), porém houve diferença no subgrupo das OLNCs complexas, favorecendo a intubação nesses casos (1 estudo; RR 0.56 [0.34, 0.92] p=0,02, moderada qualidade de evidência). Conclusões: A sondagem lacrimal precoce tem a mesma... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: Lacrimal probing has been the treatment of choice for congenital nasolacrimal duct obstruction (CNLDO) that does not have spontaneous resolution. However, there is no consensus about the best time for probing and if it is better than other therapies. Objective: To evaluate the effectiveness of lacrimal probing in the treatment of CNLDO. Method: A systematic review of the literature was performed using electronic search platforms to identify CNLDO studies to compare early or late lacrimal probing with other treatments or no intervention. The quality of the evidence was evaluated by the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). Results: Four randomized clinical trials were included, involving 423 participants. The meta-analysis showed no statistically significant difference between the immediate probing and the observation/ late probing, in the outcome of the CNLDO resolution rate (2 studies, RR 1.00 [0.76, 1.33] p=0,99, I2 = 79%, low quality of evidence). In the meta-analysis representations, the outcome resolution rate of CNLDO comparing late probing and bicanalicular intubation with silicone showed no statistically significant difference (1 study, RR 0.94 [IC 95% 0.84, 1.06] p=0,31, moderate quality of evidence), however there was a difference favoring bicanalicular intubation with silicone in the subgroup complex CNLDOs (1 study; RR 0.56 [0.34, 0.92] p = 0.02, moderate quality of evidence). Conclusions: Early probing has... (Complete abstract click electronic access below) / Mestre

Submitted by Joyce Godoy Farat null (joycegodoyfarat@uol.com.br) on 2017-08-30T01:14:10Z No. of bitstreams: 1 Mestrado_Joyce_Farat.pdf: 2858298 bytes, checksum: af8fea3f1a769a96520bf8b6d1b99814 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-30T17:29:02Z (GMT) No. of bitstreams: 1 farat_jg_me_bot.pdf: 2858298 bytes, checksum: af8fea3f1a769a96520bf8b6d1b99814 (MD5) / Made available in DSpace on 2017-08-30T17:29:02Z (GMT). No. of bitstreams: 1 farat_jg_me_bot.pdf: 2858298 bytes, checksum: af8fea3f1a769a96520bf8b6d1b99814 (MD5) Previous issue date: 2017-08-11 / Introdução: A sondagem lacrimal tem sido o tratamento de escolha para a obstrução lacrimonasal congênita (OLNC) que não apresenta resolução espontânea. No entanto, não há consenso sobre qual é a melhor época para a realização da sondagem e se ela é melhor do que outras terapias. Objetivo: Avaliar a efetividade da sondagem lacrimal no tratamento da OLNC. Método: Uma revisão sistemática da literatura foi realizada usando plataformas eletrônicas de busca para identificar estudos de OLNC comparando sondagem lacrimal com outros tratamentos ou nenhuma intervenção. A qualidade da evidência foi avaliada pelo sistema GRADE (Grading of Recommendations Assessment, Development and Evaluation). Resultados: Quatro ensaios clínicos randomizados foram incluídos, envolvendo 423 participantes. A metanálise mostrou que não houve diferença estatística na resolução da OLNC entre o grupo submetido à sondagem lacrimal precoce e o submetido à observação/sondagem tardia (2 estudos; RR 1.00 [0.76, 1.33] p=0,99, I2=79%, baixa qualidade de evidência). Nas representações de metanálise, o desfecho taxa de resolução da sondagem tardia comparada à intubação bicanalicular com silicone não teve diferença estatística (1 estudo, RR 0.94 [IC 95% 0.84, 1.06] p=0,31, moderada qualidade de evidência), porém houve diferença no subgrupo das OLNCs complexas, favorecendo a intubação nesses casos (1 estudo; RR 0.56 [0.34, 0.92] p=0,02, moderada qualidade de evidência). Conclusões: A sondagem lacrimal precoce tem a mesma chance de sucesso terapêutico que a tardia na OLNC (baixa qualidade de evidência); a sondagem tardia tende a ter a mesma chance de sucesso terapêutico que a intubação bicanalicular com silicone na OLNC simples (moderada qualidade de evidência); a taxa de sucesso da sondagem tardia tende a ser inferior à da intubação bicanalicular com silicone em casos de OLNCs complexas (moderada qualidade de evidência). / Introduction: Lacrimal probing has been the treatment of choice for congenital nasolacrimal duct obstruction (CNLDO) that does not have spontaneous resolution. However, there is no consensus about the best time for probing and if it is better than other therapies. Objective: To evaluate the effectiveness of lacrimal probing in the treatment of CNLDO. Method: A systematic review of the literature was performed using electronic search platforms to identify CNLDO studies to compare early or late lacrimal probing with other treatments or no intervention. The quality of the evidence was evaluated by the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). Results: Four randomized clinical trials were included, involving 423 participants. The meta-analysis showed no statistically significant difference between the immediate probing and the observation/ late probing, in the outcome of the CNLDO resolution rate (2 studies, RR 1.00 [0.76, 1.33] p=0,99, I2 = 79%, low quality of evidence). In the meta-analysis representations, the outcome resolution rate of CNLDO comparing late probing and bicanalicular intubation with silicone showed no statistically significant difference (1 study, RR 0.94 [IC 95% 0.84, 1.06] p=0,31, moderate quality of evidence), however there was a difference favoring bicanalicular intubation with silicone in the subgroup complex CNLDOs (1 study; RR 0.56 [0.34, 0.92] p = 0.02, moderate quality of evidence). Conclusions: Early probing has the same chance of therapeutic success as the late probing in CNLDO (low quality of evidence); late probing tends to have the same chance of therapeutic success as bicanalicular silastic intubation in CNLDO (moderate quality of evidence); the success rate of late probing tends to be lower than the therapeutic success of bicanalicular intubation with silastic in cases of complex CNLDO (moderate quality of evidence).

Submitted by Verônica Esteves (vevenesteves@gmail.com) on 2018-01-11T14:41:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Orlando Siqueira.pdf: 2924925 bytes, checksum: c32bce21e6c777f33da53c373787cb05 (MD5) / Approved for entry into archive by Verônica Esteves (vevenesteves@gmail.com) on 2018-01-11T14:41:40Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Orlando Siqueira.pdf: 2924925 bytes, checksum: c32bce21e6c777f33da53c373787cb05 (MD5) / Made available in DSpace on 2018-01-11T14:41:40Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese Orlando Siqueira.pdf: 2924925 bytes, checksum: c32bce21e6c777f33da53c373787cb05 (MD5) Previous issue date: 2017 / Universidade Federal Fluminense. Hospital Universitário Antônio Pdro / Introdução: A anastomose término-terminal no tratamento da lesão das vias biliares durante a colecistectomia laparoscópica tem sido associada à formação de estenose. O objetivo deste estudo foi investigar experimentalmente o efeito do tratamento oral com tamoxifeno (tmx) sobre a fibrose, o colágeno e o transforming growth factor TGF-β1, - β2 e - β3 na anastomose da via biliar principal de porcos. Métodos: Vinte e seis porcos foram divididos em três grupos [sham (n = 8), controle (n = 9) e tmx (n = 9)]. Os ductos biliares foram seccionados e anastomosados nos grupos controle e tmx. Tmx (40 mg / dia) foi administrado oralmente ao grupo tmx, e os animais foram eutanasiados após 60 dias. A fibrose foi analisada pela coloração com tricromo de Masson. Picrosirius red foi utilizado para quantificar o teor total de colágeno e a proporção de colágeno tipo I / III. A expressão de mRNA do TGF-β1, -β2 e - β3 foi quantificada usando a reação em cadeia da polimerase em tempo real (qRT-PCR). Resultados: Os grupos de controle e estudo apresentaram fibrose maior do que o grupo sham, e o grupo de estudo apresentou fibrose menor do que o grupo controle (p = 0,011). Os grupos controle e tmx apresentaram maior teor total de colágeno do que o grupo sham (p = 0,003) e não houve diferença significativa entre os grupos controle e tmx. A proporção de colágeno tipo I / III foi maior no grupo controle do que nos grupos sham e tmx (p = 0,015) e não houve diferença significativa entre os grupos sham e tmx. Não houve diferenças significativas na expressão de mRNA de TGF-β1, -β2 e -β3 entre os grupos (p> 0,05). Conclusões: Tmx diminuiu a fibrose e impediu a alteração na proporção de colágeno tipo I / III causada pelo procedimento. / Introduction: End-to-end anastomosis in the treatment of bile duct injury during laparoscopic cholecystectomy has been associated with the formation of stenosis. The aim of this study was to experimentally investigate the effect of oral treatment with tamoxifen (tmx) on fibrosis, collagen and transforming growth factor TGF-β1, - β2 and – β3 on anastomosis of the common bile duct in pigs. Methods: Twenty-six pigs were divided into three groups (sham (n = 8), control (n = 9) and tmx (n = 9)). The bile ducts were sectioned and anastomosed in the control and tmx groups. Tmx (40 mg / day) was administered orally to the tmx group, and the animals were euthanized after 60 days. Fibrosis was analyzed by Masson's trichrome staining. Picrosirius red was used to quantify the total collagen content and the proportion of collagen type I / III. Expression of TGF-β1, -β2 and -β3 mRNA was quantified using the real-time polymerase chain reaction (qRT-PCR). Results: The control and study groups presented higher fibrosis than the sham group, and the study group had lower fibrosis than the control group (p = 0.011). The control and tmx groups presented higher total collagen content than the sham group (p = 0.003) and there was no significant difference between the control and tmx groups. The proportion of type I / III collagen was higher in the control group than in the sham and tmx groups (p = 0.015) and there was no significant difference between the sham and tmx groups. There were no significant differences in TGF-β1, -β2 and -β3 mRNA expression between the groups (p> 0.05). Conclusions: Tmx decreased fibrosis and prevented the change in the proportion of collagen type I / III caused by the procedure.

In search for quieter engines there is a need for a better understanding of the acoustic properties of engine intake and exhaust system components. Besides mufflers which have the purpose of reducing pressure pulses originating from the internal combustion (IC) engine, there are many components in a modern car exhaust and intake system, e.g., air-filters, coolers, catalytic converters, particulate filters - all having an effect on the pressure pulses or sound field in the system. In this work the focus is on the turbocharged IC-engine where both, sound scattering (reflection and transmission) and sound generation from automotive turbochargers are studied. In addition, sound reflection from an open ended pipe, such as the tailpipe of an IC-engine exhaust is investigated.             Accurate and efficient methods to fully characterize turbochargers by measuring the acoustic two-port have been developed.  Compared to earlier work, a number of modifications are suggested for improving the quality of the results. A study on three different automotive turbochargers is also presented, including data for sound scattering for both the compressor and turbine. The results for the transmission of sound, which is of interest for the ability of a turbocharger to reduce noise coming from the engine, is plotted for all tested cases against a dimensionless frequency scale (Helmholtz-number). This makes it possible to generalize the result in order to draw conclusions about the behavior for any turbocharger.              The sound generation was also studied and three different methods to estimate the sound power are suggested. The methods were used to investigate sound generation at different operating points and identify source mechanisms for a turbocharger compressor.             An accurate method for measuring the reflection of plane acoustic waves from a pipe termination in a duct with hot gas flow has been developed and tested. Representing the acoustical conditions at an exhaust tail-pipe, the data obtained is important for effective modeling of exhaust systems. The experimental results of the reflection coefficient were compared with Munt`s theory on flow duct openings. The measurements were carried out for air jet velocities up to Mach 0.4 and for flow temperatures up to 100°C in order to study temperature effects on the reflection properties. It was concluded, that the experimental results agree well with the Munt theory.