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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Emprego da ultrassonografia como método de avaliação dos músculos respiratórios em cães Golden Retriever normais e afetados pela distrofia muscular (GRMD) / Use of ultrasonography as a method of evaluation of respiratory muscles in Golden Retriever dogs affected by muscular dystrophy (GRMD)

Oliveira, Daniela Moraes de 18 December 2012 (has links)
A Distrofia Muscular de Duchenne (DMD) é uma doença genética neuromuscular hereditária, ligada ao cromossomo X, sendo encontrada em seres humanos do sexo masculino em uma taxa de 1 para cada 3500 neonatos. Essa doença muscular é descrita também em outras espécies como o camundongo distrofico (Mdx), cães golden retriever com distrofia muscular GRMD e gatos com distrofia muscular hipertrófica felina (HFMD), os quais apresentam sintomas semelhantes à DMD e por esta razão tem sido amplamente utilizados como modelos experimentais para estudos. Portanto o objetivo deste estudo é avaliar a mobilidade do diafragma, os ciclos respiratórios e a expansão da caixa torácica de cães GRMD afetados e portadores, uma vez que a insuficiência respiratória é a principal causa de mortes em indivíduos acometidos. Para este estudo utilizou-se de avaliação ultrassonográfica dos muscúlos respíratórios (diafragma e intercostais), análises clínicas, e um acompanhamento de análises hematológicas. Como resultado obtido, o movimento de inspiração, expiração e platô, que compõe a mobilidade diafragmática, foi menor no grupo afetado do que nos controles. A fase de platô neste grupo (GRMD) é quase inexistente, indicando que o diafragma destes animais permanece em uma constante movimentação. A frequência respiratória foi 26,93 por minuto para o grupo controle e 15,5 por minuto para o grupo afetado, o qual se encontra abaixo do padrão normal. A movimentação dos m. intercostais apresentou expiração e inspiração respectivamente de: 8,99mm e 8,79mm para o grupo controle e 7,42mm e 7,40mm para o grupo afetado, mostrando que os indivíduos do grupo afetado tem uma menor expansão da caixa torácica e possivelmente um distúrbio na ventilação pulmonar. Conclui-se que a metodologia aplicada neste estudo é um meio viável de acompanhamento e avaliação do sistema respiratório no modelo GRMD, podendo ser adaptado futuramente em outros modelos experimentais da distrofia muscular. / The Duchenne Muscular Dystrophy (DMD) is a genetic neuromuscular disease, linked to chromosome X and is found in human males at a rate of 1 in every 3,500 newborns. This muscle disease is also described in other species such as mouse dystrophic (Mdx), golden retriever dogs with muscular dystrophy GRMD and cats with hypertrophic feline muscular dystrophy (HFMD), which present symptoms similar to DMD and for this reason has been widely used as experimental models for studies. Therefore the objective of this study is to evaluate the mobility of the diaphragm, the respiratory cycles and the expansion of the rib cage GRMD affected dogs and carriers, since respiratory failure the leading cause of death in affected individuals. For this study we used ultrasound evaluation of respiratory muscles (diaphragm and intercostal), clinical analysis, and monitoring of hematological analysis. As a result, the movement of inspiration, expiration and plateau, which comprises the diaphragmatic mobility was lower in the affected group than in controls. The plateau phase in this group (GRMD) is almost nonexistent, indicating that these diaphragm remains in a constant movement. Respiratory rate was 26.93 per minute for the control group and 15.5 minutes for the affected group, which is below the normal standard. The movimentation of the m. intercostal presented expiration and inspiration respectively: 8.99 mm and 8.79 mm for the control group and 7.42 mm and 7.40 mm for the affected group, showing that individuals in the affected group has a lower expansion of the rib cage and possibly a disturbance pulmonary ventilation. It is concluded that the methodology applied in this study is a viable means of monitoring and evaluation of the respiratory system in GRMD model and can be adapted in the future in other experimental models of muscular dystrophy.
62

Inervação do diafragma de ovinos / Innervation of the diaphragm of ovines

Almeida, Ana Elisa Fernandes de Souza 04 September 2002 (has links)
Foram estudados em 30 diafragmas de ovinos (Ovis aries - Linnaeus, 1758) da raça Santa Inês, a origem, divisão e distribuição dos nervos frênicos direito e esquerdo, bem como a participação de outros nervos na inervação do diafragma. Mediante fixação e dissecação das peças foi observado que os nervos frênicos originam-se mais freqüentemente a partir dos ramos ventrais do quinto (C5) e sexto (C6) nervos espinhais cervicais tanto à direita (46,67%) como à esquerda (43,33%). Os nervos frênicos terminam mais constantemente em tronco lombocostal e ramo esternal à direita (40,00%) e em ramos lombar, costal e esternal à esquerda (36,68%). Os ramos lombares dos nervos frênicos inervam à esquerda (96,67%) somente o pilar homolateral do diafragma e à direita (50,00%) fornecem também filetes à veia cava caudal. Os ramos costais dos nervos frênicos inervam à esquerda (90,00%) e à direita (76,67%) somente as regiões dorsal e ventral da pars costalis. Os ramos esternais dos nervos frênicos inervam à direita (100,00%) e à esquerda (83,33%) somente a pars sternalis e a região ventral da pars costalis do mesmo lado. Os nervos intercostais (VIII ao XII pares - 63,33%) contribuem na inervação do diafragma de ovinos da raça Santa Inês. / There were studied 30 diaphragms of ovines from Santa Inês race, their origin, division and the arrangement of the right and left phrenic nerves, as well as the participation of other nerves in the innervation of diaphragm. By fixing and dissecting pieces, it was registered that phrenic neves frequently come from the ventral branches of the fifth (C5) and sixth (C6) cervical spinal nerves as at right (46,67%) as at left (43,33%). The phrenic nerves often result in a lumbocostal trunk and esternal branch at right (40,00%) and in lumbar, costal and esternal branches at left (36,68%). The lumbar branches of phrenic nerves innervate frequently at left (96,67%) only the homolateral pillar of the diaphragma and at right (50,00%) give fillets to vena cava caudalis. The costal branches of phrenic nerves innervate at left (90,00%) and at right (76,67%) only the dorsal and ventral regions of the pars costalis. The esternal branches of the phrenic nerves innervate at right (100,00%) and at left (83,33%) only the pars sternalis and the ventral region of the pars costalis at the same side. The intercostal nerves (VIII to XII pairs - 63,33%) contribute to innervate the diaphragm of ovines of Santa Inês race.
63

Koncept på ett hydrauliskt mothåll / Concept of a hydraulic counter hold

Sharef, Hajan, Potari, Marek January 2016 (has links)
New technology in the automotive industry is the key to success. Therefore, it is appreciated when people come with new design ways to solve problems. This leads to innovation in the automotive industry that will lead to better and more environmentally friendly cars. This report presents a concept on a pushing counter lever spring which provides the same characteristics of force curve as a diaphragm spring in a pressure plate of a car has. The mechanism is to be used for long-term testing and evaluating clutch pedals. The work describes the development process and the manufacture of a prototype. The program Creo (CAD / 3D) is largely used to construct the components. As are the subprograms Mechanism Design and Simulate to simulate the movement and loads. Excel is a great help at the theoretical calculation of the mechanism and to evaluate the theory behind the concept. The result shows how to simulate a diaphragm spring in the pressure plate in a car for long-term testing of clutch pedals. The goal is to accurately mimic the force curve of a diaphragm spring, in order to design better pedals, and thus reduce the weight on the pedals to in turn reduce fuel consumption to protect the environment is one of the most important factors of all in the automotive industry.
64

Ação diafragma de cobertura aplicada às construções em pórtico de madeira / not available

Baraldi, Lívio Túlio 05 October 2001 (has links)
Este trabalho tem como objetivo apresentar uma análise do comportamento de estruturas em pórtico de madeira levando-se em conta a influência da ação diafragma da cobertura, que será verificada por meio da realização de ensaios em painéis de diafragma e por análise numérica. Além disso, apresenta os procedimentos de cálculo para o projeto de edificações considerando a ação diafragma de cobertura. Fornece informações para a produção de estruturas treliçadas de cobertura em nível industrial, utilizando-se chapas com dentes estampados, com maior controle de qualidade técnica dos projetos e economia de material. / The aim of this work is to analyze the behavior of post-frame of timber structures taking in account the influence of the roof diaphragm action, which will be verified by tests in diaphragm panels and in computational theoretical model. Furthermore, it will be show the design criteria considering the diaphragm action. Also, important information is presented for increase the production of trusses for roofs in industrial scale using metal plate connectors in conjunction with a better control of the technical quality of design and economy of material.
65

Comparing a Low-Volume Piezometer to Traditional Wells in Evaluating Hydraulic Lag Caused by Low-Permeability Sediments

Spencer, John M 02 April 2008 (has links)
Traditionally-constructed wells are commonly used to measure hydraulic head in all saturated systems, even in fine-grained sediments. Previous studies (Hvorslev 1951, Penman 1961) have shown that time lag in response to head changes between traditional wells and the surrounding fine-grained sediments can be a significant source of error. Time lag is caused by the time required for water to flow into or out of the well to reflect the appropriate change in head. A low-volume piezometer was constructed to measure changes in hydraulic head without requiring a change in fluid volume within the piezometer by directly measuring pore pressure in the surrounding sediments. The low-volume piezometer used a commercially-available pressure transducer that is hydraulically connected to the surrounding sediment by a porous-ceramic cylinder. The device is attached to a drive point that allows for quick insertion without creating excessive over-pressure so that equilibrium is achieved rapidly. The low-volume piezometer was inserted near traditionally-constructed wells in 3-4 m thick, saturated clay in west-central Florida. The low-volume piezometer was field tested to compare measured pore pressures with observed levels in traditionally-constructed wells. The comparison highlights any head difference between the two methods, and determines if there is a time lag between the two measurement methods and its magnitude. The low-volume piezometer was installed next to a traditionally-constructed well and heads in both wells were monitored for three months. Results show that the low-volume piezometer can take up to a month to reach equilibrium. Using Hvorslev's equations, traditionally-constructed wells have time lag of roughly 6 orders of magnitude greater than the low-volume piezometer. If this is correct, it could take up to 83,000 years for a traditionally-constructed well to reach equilibrium. However, when a trend analysis is performed on the hydrographs from the low-volume piezometer and the two traditional wells, the correlation coefficients are 0.95 and 0.96. The very strong correlation suggests that the low-volume piezometer and the traditional wells both respond similarly to changes in head. More field data need to be collected, but it appears that contrary to theory, time lag in traditionally-constructed wells may be negligible.
66

Forced Vibration Testing and Analysis of Pre- and Post- Retrofit Buildings

Jacobsen, Erica Dawn 01 June 2011 (has links)
ABSTRACT Forced Vibration Testing and Analysis of Pre- and Post- Retrofit Buildings Erica Dawn Jacobsen The primary goal of the thesis was to detect the retrofit through vibration testing of both buildings. The secondary goal focused on correctly identifying the behavior of the building through FVT, comparing that behavior to computational model predictions, and determining the necessary level of detail to include in the computational modeling. Forced vibration testing (FVT) of two stiff-wall/flexible-diaphragm buildings yielded natural frequencies and mode shapes for the two buildings. The buildings were nearly identical with the exception that one had been retrofitted. Both buildings were comprised of concrete shearwalls and steel moment frames in the north/south direction and moment frames in the east/west direction. The retrofit strengthened the moment connections and added braces to the perimeter walls in the east/west direction. The natural frequencies were found through FVT by setting a 30-lb shaker on the roof of both buildings and sweeping through a range of frequencies in both the east/west and north/south directions. Accelerometers were placed on the building to detect the accelerations. The peaks on the Fast Fourier Transform (FFT) graphs indicated the frequencies at which the structure resonated. Mode shapes were tested for by placing the shaker in a position ideal for exciting the mode and setting the shaker to the natural frequency detected from the FFT graphs. The accelerometers were placed around the roof of the building to record the mode shape. After testing, computational models were created to determine if the models could accurately predict the frequencies and mode shapes of the buildings as well as the effect of the retrofit. A series of increasingly complex computational models, ranging from hand calculations to 3D models, were created to determine the level of detail necessary to predict the building behavior. Natural frequencies were the primary criteria used to determine whether the model accurately predicted the building behavior. The mid-diaphragm deflection and base shear from spectral analysis were the final criteria used to compare these select models. It was determined that in order to properly capture the modal behavior of the building, the sawtooth framing, major beams, and the lateral-force-resisting-system (LFRS) must be modeled. Though the mode shape of the building is dominated by the flexible diaphragm, the LFRS is necessary to model to accurately predict both the natural frequency of the building as well as the diaphragm deflection.
67

Experimental Determination of the Stiffness and Strength of Continuity Tie Connections in Large Wood Roof Dipahragms, and Impact on the Collective Chord Model

Yarber, Caroline Nicole 01 August 2012 (has links)
The goal of this thesis is to determine whether continuity ties in large wood diaphragms are stiff enough to engage and provide diaphragm flexural stiffness in a collective chord model. Four series of continuity tie assemblies using Simpson Strong-Tie steel connectors were tested to determine the stiffness of each assembly. The results found from testing were applied to an example building and then analyzed using both the traditional chord method and the collective chord method. The completed analysis on a typical size warehouse building showed that the collective chord model will act inadvertently on an existing building designed with a traditional chord, or alternatively will potentially act intentionally in the design of a new building. The relative stiffness of the continuity ties will determine if they engage and allow them to act collectively. The testing and analysis completed creates a basis for further research into the actual static and dynamic behavior of these diaphragms. The collective chord model does seem to be a reasonable approximation for how diaphragms actually behave. If more research is conducted into different shaped and sized buildings to confirm that the collective chord model will work on most buildings then it will be a more accurate way to design new diaphragms and analyze existing diaphragms than the current traditional model.
68

Towards 4D MVCBCT for lung tumor treatment

Chen, Mingqing 01 July 2012 (has links)
Currently in our clinic, a mega-voltage cone beam computed tomography (MVCBCT) scan is performed before each treatment for patient localization. For non-small cell lung cancer (NSCLC) patients, a strain gauge is used as an external surrogate to indicate tumor motion in both the planning stage and the treatment stage. However, it is likely that the amplitude of tumor motion varies between treatment fractions without a corresponding change in the surrogate signal. Motion amplitude larger than what was planned may underdose the tumor and overexpose normal tissues. The overall objective of this project is to extend the capabilities of MVCBCT for respiratory motion management by taking advantage of 2D projection images. First, a new method was developed to detect ipsi-lateral hemi-diaphragm apex (IHDA) motion along superior-inferior (SI) direction in 3D. Then a respiratory correlated reconstruction method was implemented and verified. This method is able to create MVCBCT volume in the full exhale (FE) and the full inhale (FI) phases, respectively. The diaphragm to tumor motion ratio (DTMR) was derived by quantifying the absolute position of the tumor and IHDA in these two volumes. The DTMR and the extracted IHDA motion were further used to calibrate the strain gauge signal. Second, an organ motion detection approach was developed, in which the detection is converted into an optimal interrelated surface detection problem. The framework was first applied to tumor motion extraction, which enables accurate detection for large tumors (with a diameter not smaller than 1.9cm). The framework was then applied to lung motion extraction and the extracted lung motion model was used to create a series of displacement vector fields for a motion compensated (MC) reconstruction. The accuracy of both tumor extraction and the MC approach was validated, which shows their clinical feasibility. Last but not least, a novel enhancement framework was developed. The aim of this approach is to eliminate the overlapping tissues and organs in the CBCT projection images. Though scattering and noise is the major problem, the proposed method is able to achieve enhanced projection images with a higher contrast to noise ratio (CNR) without compromising detection accuracy on tumors and IHDA.
69

PRESSURE MEASUREMENT INSTRUMENTATION IN A HIGH TEMPERATURE MOLTEN SALT TEST LOOP

Ritchie, John Andrew 01 December 2010 (has links)
A high temperature molten salt test loop that utilizes FLiNaK (LiF-NaF-KF) at 700ºC has been proposed by Oak Ridge National Laboratory (ORNL) to study molten salt flow characteristics through a pebble bed for applications in high temperature thermal systems, in particular the Pebble Bed – Advanced High Temperature Reactor (PB-AHTR). The University of Tennessee Nuclear Engineering Department has been tasked with developing and testing pressure instrumentation for direct measurements inside the high temperature environment. A nickel diaphragm based direct contact pressure sensor is developed for use in the salt. Capacitive and interferometric methods are used to infer the displacement of the diaphragm. Two sets of performance data were collected at high temperatures. The fiber optic, Fabry-Perot interferometric sensor was tested in a molten salt bath. The capacitive pressure sensor was tested at high temperatures in a furnace under argon cover gas.
70

Numerical Assessment Of Negative Skin Friction Effects On Diaphragm Walls

Gencoglu, Cansu 01 January 2013 (has links) (PDF)
Within the confines of this study, numerical simulations of time dependent variation of downdrag forces on the diaphragm walls are analyzed for a generic soil site, where consolidation is not completed. As part of the first generic scenario, consolidation of a clayey site due to the application of the embankment is assessed. Then two sets of diaphragm walls, with and without bitumen coating, are analyzed. For comparison purposes, conventional analytical calculation methods (i.e., rigid-plastic and elastic-plastic soil models) are also used, the results of which, establish a good basis of comparison with finite-element based simulation results. Additionaly, the same generic cases are also analyzed during the stages of excavation, when diaphragm walls are laterally loaded. As the concluding remark, on the basis of time dependent stress and displacement responses of bitumen coated and uncoated diaphragm walls, it was observed that negative skin friction is a rather complex time-dependent soil-structure and loading interaction problem. This problem needs to be assessed through methods capable of modeling the complex nature of the interaction. Current analytical methods may significantly over-estimate the amount of negative skin friction applied on the system, hence they are judged to be over-conservative. However, if negative skin friction is accompanied by partial unloading as expected in diaphragm walls or piles used for deep excavations, then they may be subject to adverse combinations of axial load and moment, which may produce critical combinations expressed in interaction diagrams. Neglecting the axial force and moment interaction may produce unconservative results.

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