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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.
151

Computational and Experimental Study on the Behavior of Diaphragms in Steel Buildings

Wei, Gengrui 03 February 2022 (has links)
The lateral force resisting system (LFRS) of a steel building consist of two parts, i.e., a vertical LFRS such as braced frames or shear walls, and a horizontal LFRS with diaphragms playing a crucial role. There are various types of floor and roof diaphragms in steel buildings, such as concrete-filled steel deck diaphragms for the floor system and bare steel deck diaphragms for the roof system of a typical steel braced frame building, and standing seam roof diaphragms for a typical metal building. Compared to vertical elements of a building's LFRS, our understanding of the horizontal elements, i.e., the diaphragms, is grossly lacking. The motivation for this work comes from the gaps identified in the research, including the lack of generally adopted acceptance criteria and modeling protocols for seismic performance-based design of bare steel deck and concrete-filled steel deck diaphragms through linear and nonlinear analysis, the need to better understand the complex behavior of concrete-filled steel deck diaphragms with irregular configurations such as reentrant corners and openings under lateral loading, the absence of appropriate Rs values for the alternative diaphragm seismic design approach in the current building code that considers diaphragm inelasticity, and the demand for understanding the in-plane behavior of a standing seam roof system and its use in lateral bracing of rafters in metal buildings. A series of computational and experimental studies were conducted to investigate the behavior of diaphragms in buildings systems, including: 1) development of acceptance criteria and modeling protocol for performance-based seismic design of bare and concrete-filled steel deck diaphragms using a database of existing cantilever diaphragm tests; 2) a computational study on the nonlinear behavior of diaphragms with irregular configurations under lateral loading using high-fidelity finite element models validated against experiment test results; 3) investigation of the seismic behavior and performance of steel buildings with buckling restrained braced frames that considers different diaphragm design approaches and diaphragm inelasticity using nonlinear three-dimensional (3D) computational models; and 4) an experimental study that investigated the in-plane behavior of full-scale standing seam roof assemblies and their use in lateral bracing of rafters in metal building systems. The results of these studies contribute to a better understanding of the behavior of diaphragms in steel buildings and lead to several recommendations for diaphragm design. Firstly, a series of m-factors (ductility measures) and nonlinear modeling parameters (multi-linear cyclic backbone curves) were determined for bare steel deck diaphragms and concrete-filled steel deck diaphragms. These new provisions are recommended for adoption in ASCE 41 / AISC 342, which allows the use of ductility in steel deck diaphragms for their design and retrofits. Secondly, results of the finite element analysis on concrete-filled steel deck diaphragms revealed a concentrated distribution of shear transfer through the shear connections on the collectors of the diaphragm near braced frames and a stress concentration in the composite slab near reentrant corners and openings. Thirdly, results of eigenvalue analyses with nonlinear 3D building models showed that the consideration of diaphragm flexibility led to an increase in first mode period between 13% and 48%. A comparison of results from pushover analyses and response history analyses indicated that even though the pushover analyses (based on a first mode load pattern) identified the BRBF as being weaker than the diaphragms and therefore dominating the inelastic pushover behavior, response history analyses demonstrated that the diaphragms can experience substantial inelasticity during a dynamic response. The response history results also suggest that there would be a significant difference in seismic behavior of buildings modeled as two-dimensional (2D) planar frames as compared to the 3D structures modeled herein. Furthermore, the observed final collapse mode involves an interaction between large BRBF story drifts combined with diaphragm deformations that are additive and exacerbate second order effects leading to collapse. The computed adjusted collapse margin ratios for all buildings satisfied the FEMA P695 criteria for acceptance. Therefore, it is concluded that the alternative diaphragm design procedure with the proposed Rs values (Rs = 2 for concrete-filled steel deck diaphragm and Rs = 2.5 for bare steel deck diaphragm) are reasonable for use in design of these types of structures. Lastly, the effects of different standing seam roof configurations (panel type, clip type, thermal insulation, and purlin spacing) on the in-plane stiffness and strength of the standing seam roof system were investigated through an experimental testing program, and a method was described to use these experimental results in the calculations of required bracing for metal building rafters. / Doctor of Philosophy / A diaphragm is a horizontal structural component (e.g. floors and roof) that transfers lateral forces induced by wind or earthquakes to the vertical portions (e.g. frames and walls) of the lateral force resisting system (LFRS) of the building. There are various types of floor and roof diaphragms in steel buildings, such as concrete-filled steel deck diaphragms for the floor system and bare steel deck diaphragms for the roof system of a typical steel braced frame building, and standing seam roof diaphragms for a typical metal building. Compared to vertical elements of a building's LFRS, our understanding of the horizontal elements, i.e., the diaphragms, is grossly lacking. To address the research gaps in understanding the behavior of diaphragms and utilizing them in building design, this work presents a series of computational and experimental studies. In the first study, past experimental test data were analyzed to develop acceptance criteria and modeling protocol for performance-based seismic design of steel deck diaphragms. In the second study, finite element analyses were conducted to understand the nonlinear behavior of concrete-filled steel deck diaphragms subjected to in-plane lateral loading. In the third study, nonlinear three-dimensional computational building models were developed to investigate the seismic behavior and performance of steel buildings with different diaphragm design approaches and diaphragm inelasticity. In the fourth study, experimental testing on full-scale standing seam roof assemblies was conducted to investigate their in-plane behavior and their use in lateral bracing of rafters in metal building systems. The results of these studies contribute to a better understanding of the behavior of diaphragms in steel buildings and lead to several recommendations for diaphragm design.
152

Péče o ventilovaného spinálního pacienta v České republice / Care of ventilator-dependent patient with spinal cord injury in Czech republic

Plecháčková, Kristýna January 2010 (has links)
Thesis "Care of ventilator-dependent patienl wilh spinal cord injury in Czech republic" deals with problems of high cervica\ spinal cord les ion wilh diaphragm para\ysis. Generally introduces clinical manifestation of the spinal cord injury, classifícation of spinal cord lesions and statistical data regarding the incidence, prevalence and etiology. In more detail focuses on respiratory problems. Contains survey of most conunon respiratory complications in ventilator-dependent quadriplegic patients and infonn about the possibililies of respiralory physiotherapy. The practical part provides the first description of the Czech population of pentaplegics. Truough case studies indroduces health and livíng conditíons of persons wíth high spinal cord lesion and need of mechanical ventilation. Powered by TCPDF (www.tcpdf.org)
153

Vliv změny posturální stability na sílu respiračních svalů / Influence of postural stability changes on respiratory muscle strenght

Dařinová, Jitka January 2015 (has links)
The presented thesis is focused on the influence of postural stability changes on respiratory muscle strength. The aim of this thesis was to determinate whether the respiratory muscle strength will change during the increased demands on postural stability, and if so, then how exactly. The theoretical part summarized the findings about the diaphragm and its postural stabilizing function, about the connection between breathing and postural control as well as about the influence of body position on respiratory muscle strength. In the practical part of the thesis, the values of the maximal respiratory mouth pressures were measured (PI max and PE max) on 21 healthy subjects ranging from 20 to 26 years of age using the spirometer in three postural situations - standing, standing on the balance surface and standing on the balance surface with no visual control. Throughout the whole group, there were no significant statistical differences ( p ≥ 0,05 ) in the outcome values of the measured postural situations. Two trends were observed in the changes of values of PI max and PE max. During the increased demands for postural stability the value of PI max was higher for 29% and lower for 71% of the measured individuals. The value of PE max was higher for 33% and lower for 67% of the measured individuals. This...
154

Stanovení nových referenčních hodnot maximálních inspiračních a expiračních tlaků a hodnot PO.1 u normální populace ve věkovém rozmezí 16 až 17 let / Definition of new referential values of maximum inspiratory and expiratory pressures and P0.1 values in normal population of the 16 - to - 17 age range

Kálalová, Tereza January 2014 (has links)
The purpose of this thesis is to define norms for inspiratory (Pimax) and expiratory (Pemax) pressures and mouth occlusion pressure (P0.1) in healthy white population of the 16-17 age group in the Czech Republic, specifically the capital city of Prague and its close vicinity. Furthermore, this work aspires to ascertain whether there is a correlation between the respiratory pressures, P0.1 and selected anthropometric and pulmonary values. In order to define the norms, 79 children were tested, including 41 boys and 38 girls 16 to 17 years old. After establishing the subjects' case histories, anthropometric, spirometric inspiratory, expiratory and forced vital capacity measurements were made. The study defined the norms of respiratory pressures and P0.1 in 16 to 17-year-old boys and girls, thus achieving its main goal. Furthermore, a difference was found between the average measured Pimax and Pemax values for boys and girls, with the boys showing higher values comparing with the girls. The study did not ascertain a correlation between respiratory pressures, P0.1 and selected anthropometric values (age, height, weight, BMI, BSA). No correlation was found between respiratory pressures and static pulmonary volumes. Powered by TCPDF (www.tcpdf.org)
155

Tvarové změny v axiálním systému při respiraci / Shape changes in the axial system during respiration

Slawiková, Eliška January 2012 (has links)
The name of the work: Shape changes in the axial system during respiration Goal of the work: the main objective is to perform a case study of brass parameters and changes the shape of the trunk during the ventilation maneuver, prepare the correct methodology of research and to conduct separate measurements. The thesis will be divided into two parts, the first will contain the theoretical background to the subject, in the second part will then be described by the research, where I measured the change in the volume of the lungs in relation to time, assess the impact of implemented ventilation maneuver on the individual probands and examine the respiratory dynamics in selected ventilation maneuver. Methods: in the framework of the fulfilment of the tasks of this work have been carried out experiments with the use of 3D kinematic record with Qualisys and spirometric measurement. The experiment involved three probands aged 20 to 40 specific common features. Each of the proband performed during the measurement of quiet breathing, maximum inhalation and exhalation and ventilation maneuver. Measurements were carried out in one day under standard conditions, measurements made on the day of probands quiet breathing, maximum inhalation and exhalation and ventilation maneuver (5 min total). Data records were...
156

Differences during quiet standing when breathing abdominally

Gantar, Sebastjan January 2016 (has links)
Title: Differences in postural activity during quiet standing when breathing abdominally. Aim and purpose: Aim of this study was to examine the effects of abdominal breathing on selected muscles and stability during quiet standing to find empirical evidence if it can reduce the strain and change the activity pattern, which erect standing demands from the muscles. Methods and materials: This thesis begins with an introduction to theoretical part in which we gathered all the already existing and written information needed to form the knowledge base for our experiment. Continuing in 9th chapter, methodology and experiment procedure are described where we measured muscle activity using surface EMG and to monitor changes in stability we used force- plate for posturography where only linear parameters were acquired. Both devices were used simultaneously while the subject was in quiet stance for a period of 90 seconds. Results: Results shown decrease in most of the muscles, with a higher increase in body sway in medio- lateral than in antero-posterior direction. Signal didn't change to a more distinct wave-like pattern of rhythmic oscillations, as we had thought it would. Keywords: Posture, quiet standing, abdominal breathing, diaphragm, system interrelation, EMG, posturography
157

Mobilidade diafragmática em pacientes com DPOC: avaliação ultra-sonográfica do deslocamento crânio-caudal do ramo esquerdo da veia porta / Diaphragm mobility in COPD patients: ultrasound assessment of the craniocaudal displacement of the left branch of the portal vein

Yamaguti, Wellington Pereira dos Santos 22 June 2007 (has links)
O objetivo desse estudo foi avaliar a relação da mobilidade diafragmática com a função pulmonar e a força muscular respiratória em indivíduos com DPOC, utilizando a mensuração ultra-sonográfica do deslocamento crânio-caudal do ramo esquerdo da veia porta. Foram estudados 54 pacientes portadores de DPOC com hiperinsuflação pulmonar e 20 sujeitos saudáveis. Os parâmetros avaliados foram: mobilidade diafragmática, função pulmonar e as pressões respiratórias máximas. Pacientes com DPOC apresentaram menor mobilidade do diafragma (36,46 ± 10,90 mm) quando comparados a indivíduos saudáveis (46,33 ± 9,47) (p = 0,001). Nos indivíduos portadores de DPOC foram verificadas uma forte correlação com os parâmetros da função pulmonar que quantificam o aprisionamento de ar (VR: r = -0,60; p < 0,001; VR/CPT: r = -0,72; p < 0,001), uma moderada correlação com a obstrução de vias aéreas (VEF1: r = 0,55, p < 0,001; resistência das vias aéreas: r = -0,32, p = 0,02) e uma fraca correlação com a hiperinsuflação pulmonar (CPT: r = -0,28, p = 0,04). Não foi observada relação entre a mobilidade do diafragma e a força muscular respiratória (PImax: r = -0,11 e p = 0,43; PEmax: r = 0,03 e p = 0,80). Nossos resultados sugerem que a redução da mobilidade do diafragma em pacientes com DPOC ocorre principalmente devido ao aprisionamento de ar, não sendo influenciada pela hiperinsuflação pulmonar ou pela força muscular respiratória. / The purpose of this study was to use ultrasound to measure the craniocaudal displacement of the left branch of the portal vein in order to evaluate the relationship between pulmonary function and diaphragm mobility, as well as that between respiratory muscle strength and diaphragm mobility, in COPD patients. We studied 54 COPD patients with pulmonary hyperinflation, together with 20 healthy subjects. Pulmonary function, maximal respiratory pressures, and diaphragm mobility were evaluated. COPD patients presented less diaphragm mobility than did healthy individuals (36.46 +/- 10.90 mm vs. 46.33 +/- 9.47 mm, respectively) (p = 0.001). In COPD patients, we found that diaphragm mobility correlated strongly with pulmonary function parameters that quantify air trapping (RV: r = -0.60; p < 0.001; RV/TLC: r = -0.76; p < 0.001), moderately with airway obstruction (FEV1: r = 0.55, p < 0.001; airway resistance: r = -0.32, p = 0.02), and weakly with pulmonary hyperinflation (TLC: r = -0.28, p = 0.04). No relationship was observed between diaphragm mobility and respiratory muscle strength (maximal inspiratory pressure: r = -0.11 and p = 0.43; maximal expiratory pressure: r = 0.03 and p = 0.80). The results of this study suggest that the reduction in diaphragm mobility in COPD patients occurs mainly due to air trapping and is not influenced by respiratory muscle strength or pulmonary hyperinflation.
158

Estudo do padrão respiratório, movimentação toracoabdominal e ventilação em pacientes portadores de doença pulmonar obstrutiva crônica durante respiração diafragmática / Study of respiratory pattern, thoracoabdominal motion and ventilation in patients with chronic obstructive pulmonary disease during diaphragmatic breathing

Fernandes, Marcelo 11 January 2008 (has links)
Introdução: A respiração diafragmática (RD) é uma técnica que integra um conjunto de ações de auto-cuidado no programa de reabilitação pulmonar com objetivo de melhorar a mecânica ventilatória e reduzir a dispnéia em pacientes com doença pulmonar obstrutiva crônica (DPOC). No entanto, questiona-se sua indicação e seus efeitos. Nesse contexto avaliamos o efeito da RD no padrão respiratório, movimento toracoabdominal e ventilação em pacientes com DPOC. Método: Foram estudados 44 indivíduos entre 45 e 75 anos conforme o grau de obstrução da via aérea (VEF1), divididos em grupos controle, DPOC moderado e DPOC grave. Avaliou-se padrão respiratório, movimento toracoabdominal e ventilação por meio de sistemas de pletismografia respiratória por indutância (Respitrace) e análise metabólica de gases (MGC) durante 10 minutos. Após quatro minutos de respiração tranqüila os indivíduos realizavam dois minutos de respiração diafragmática e novamente, quatro de respiração tranqüila. Dispnéia foi avaliada antes, durante e após a RD (escala de Borg modificada). Mobilidade diafragmática foi avaliada utilizando radiografias de tórax. Resultados: Verificou-se aumento do volume corrente e redução da freqüência respiratória durante a RD a partir da elevação do fluxo inspiratório médio e do tempo inspiratório. Houve maior participação do compartimento abdominal com o grupo moderado apresentando incoordenação. A ventilação pulmonar se elevou em associação à redução na ventilação em espaço morto, no equivalente ventilatório para o gás carbônico, e elevação da saturação periférica de oxigênio. Mobilidade diafragmática, ausência de dispnéia, menor grau de hipoxemia e movimento toracoabdominal coordenado associaram-se ao melhor desempenho da RD. Conclusões: A respiração diafragmática é capaz de promover melhora no padrão respiratório e eficiência ventilatória sem conduzir a dispnéia naqueles pacientes com sistema muscular respiratório preservado. / Introduction: Diaphragmatic breathing (DB) is a technique which is part of a set of self-care actions in the lung rehabilitation program for the purpose of improving the ventilatory mechanical and reducing dyspnea. There are doubts, however, as to its effects and recommended use. In this context we assessed the effect of the DB on respiratory pattern, thoracoabdominal motion and ventilation in patients with chronic pulmonary obstructive disease (COPD). Method: Forty-four subjects aged between 45 and 75 years were studied according to the degree of obstruction of the airway (FEV1). This group was subdivided into three: a control group and two others, respectively, of moderate and severe COPD. Their breathing pattern, thoracoabdominal motion and ventilation by means of respiratory inductive plethysmograph (Respitrace) and metabolic analysis of gases (MGC) systems were assessed during ten minutes. After four minutes of quiet breathing, the subjects would perform two minutes of the DB and four other minutes of quiet breathing. Dyspnea was assessed before, during and after diaphragmatic breathing (modified Borg scale). Diaphragmatic mobility was assessed by thoracic radiography. Results: An increase in tidal volume and a reduction in breathing frequency were found during DB as from the rise in mean inspiratory flow and inspiratory time. There was greater participation of the abdominal compartment with the moderate group presenting asynchronous motion. The pulmonary ventilation increased together with the reduction of the ventilation in the dead space and of the ventilatory equivalent for carbonic gas, with the increase in arterial oxygen saturation. Diaphragmatic mobility, absence of dyspnea, minor degree of hypoxemia and coordinated thoracoabdominal motion were associated with the better DB performance. Conclusions: Diaphragmatic breathing is capable of promoting an improvement in the breathing pattern and ventilatory efficiency without provoking dyspnea in patients whose muscular respiratory system has been preserved.
159

Programa de Apoio Respiratório Sonorizado: processo de aprendizado de cantores populares / Voiced Breathing Support Program: the learning process of popular singers

Gava Junior, Wilson 28 July 2010 (has links)
Made available in DSpace on 2016-04-27T18:12:47Z (GMT). No. of bitstreams: 1 Wilson Gava Junior.pdf: 1334336 bytes, checksum: d3d92d3bb204a4bb2373747afd19403a (MD5) Previous issue date: 2010-07-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / INTRODUCTION: in the singing voice field, the relationships established between the singer s mastering of breathing and vocal emission have always been widely discussed with different points of view. In this matter, breath support is one of the main agents. It is important to note that there are few studies that contribute with practical models designed towards the learning of this ability. AIM: to analyze the Voiced Breathing Support Program (PARS), developed by the author, through the learning process of three popular singers. METHODS: an initial interview was performed to select the subjects, and three professional popular singers, with different characteristics, were chosen to take part in the study. The PARS was developed, individually, in weekly one-hour encounters, in three interdependent phases (awareness, development and sedimentation). Throughout the process, a log of each encounter was filled in, and the audio files were registered, for each singer. Perceptive parameters of voice were also analyzed and compared before and after the program. RESULTS: Subject one had a learning process which involved all levels of knowledge and provided a change in attitude regarding breath support establishment. This subject finished all three phases of the PARS in the expected time-span. There were observed improvements in body aspects, the articulation was more precise, there was an increase of five half-tones in vocal tessitura, and stability in tuning at the end of the program. In the learning process of singer two, different awareness strategies were deeded. This subject needed a higher number of encounters in development and sedimentation phases in order to learn breath support. The parameters that were improved at the end of the PARS were: breathing, breath coordination while singing, resonance, articulation and vocal tessitura, which increased six half-tones. The process of subject three presented difficulties that were basically related to awareness and anatomic and physiologic limitations. They influenced the subject s not being able to obtain a change in attitude in order to learn breath support. Subject three accomplished the awareness and development phases in a higher number of encounters. The awareness phase was not finished and the subject did not acquire breath support. This singer maintained inadequate parameters at the end of the PARS, with only a discrete improvement in tuning. FINAL COMMENTS: Of the three subjects in this study, two established breath support through the PARS. The learning process for each subject occurred in different ways, despite the diversity of each studied subject. There was a link established between knowing and performing, and this promoted a change in attitude regarding respiratory aspects. As far as the vocal aspects, for two singers there were improvements in resonance, articulation, vocal tessitura and tuning / INTRODUÇÃO: no campo da voz cantada, as relações estabelecidas entre o domínio da respiração e a emissão vocal do cantor sempre foram assuntos geradores de polêmica. Nesse ponto, o apoio respiratório é um dos principais agentes. Vale ressaltar, também, que poucos estudos apresentaram propostas práticas direcionadas para seu aprendizado. OBJETIVO: analisar o Programa de Apoio Respiratório Sonorizado (PARS), criado pelo pesquisador, por meio do processo de aprendizado de três cantores populares. MÉTODOS: foi realizada uma entrevista inicial para seleção, na qual três cantores populares profissionais, com diferentes características, foram escolhidos. O PARS foi desenvolvido, de forma individual, em encontros semanais de uma hora de duração, em três fases complementares (sensibilização, desenvolvimento e sedimentação). Para cada cantor, durante todo o processo, foi elaborado um diário dos encontros e registros em áudio. Também, foram analisados e comparados parâmetros perceptivos da voz, antes do inicio do programa e depois. RESULTADOS: o sujeito um teve um processo de aprendizado que envolveu todos os níveis de conhecimento e promoveu uma mudança de atitude com relação ao estabelecimento do apoio. Esse sujeito concluiu três fases do PARS dentro do período esperado. Foram observadas melhoras nos aspectos corporais, articulação ficou mais precisa, houve ampliação de cinco semitons na tessitura vocal e estabilidade na afinação ao final do PARS. No processo de aprendizado, do segundo cantor, foram necessárias estratégias diferenciadas para a propriocepção. Esse sujeito necessitou de um número maior de encontros nas fases de desenvolvimento e sedimentação para aprender o apoio respiratório. Os parâmetros com mudança positiva, ao final do PARS, foram: respiração, coordenação pneumofonoarticulatória, ressonância, articulação e tessitura vocal, com ampliação de seis semitons. O processo do sujeito três apresentou dificuldades, em relação, basicamente, a propriocepção e a limitações anatomofisiológicas. Essas influenciaram para que o sujeito não conseguisse uma mudança de atitude para o aprendizado do apoio. O sujeito três realizou as fases de sensibilização e desenvolvimento em um número maior de encontros. A fase de sensibilização não foi concluída e o sujeito não adquiriu o apoio respiratório. O cantor manteve parâmetros inadequados ao final do PARS, com apenas uma discreta melhora na afinação. CONSIDERAÇÕES FINAIS: dos três sujeitos do estudo, dois estabeleceram o apoio respiratório por meio do PARS. O processo de aprendizado de cada um ocorreu de forma distinta, a despeito da diversidade de cada sujeito pesquisado. Estabeleceu-se um enlace entre o saber e o fazer, de forma a promover uma mudança de atitude com relação aos aspectos respiratórios. Com relação aos aspectos vocais, para dois cantores ocorreram melhoras na ressonância, na articulação, na tessitura e na afinação
160

L’association entre la fonction diaphragmatique préopératoire et le développement de complications respiratoires de la chirurgie cardiaque

Cavayas, Yiorgos Alexandros 04 1900 (has links)
No description available.

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