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Druckbauteile sind essentielle Elemente eines jeden Bauwerks, denn in Form von Stützen oder Wänden tragen sie die Lasten in den Baugrund ab. Heutzutage werden sie zumeist mit einem rechteckigen Querschnitt und konstanten Abmaßen über die Höhe ausgeführt. Bereits runde Stützen stellen eine Ausnahme dar und werden vor allem aus architektonischen Gründen angeordnet. Aber wie würde die möglichst optimale Geometrie eines Druckbauteils aussehen? Im Rahmen des Projekts wurde dieser zentralen Fragestellung nach einer günstigen Adaption der Querschnittsgeometrie von Stützen in Quer- und in Längsrichtung nachgegangen. Wesentliche Zielsetzung war dabei, Stützen so entwerfen und berechnen zu können, dass sie in allen Querschnittsbereichen gleichmäßig ausgelastet sind. Dadurch werden schlankere Bauteile möglich, die aufgrund der Materialersparnis nicht nur zur Schonung unserer natürlichen Ressourcen beitragen, sondern auch wirtschaftlich von Vorteil sind und zu einem ästhetischeren Erscheinungsbild führen. [Aus: Einleitung] / Pressure components are essential elements for any structure, because in the form of columns or walls they transfer the loads into the subsoil. Nowadays, they are usually designed with a constant rectangular cross-section over the full height. Already round columns are an exception and are arranged mainly for architectural reasons. But what would the optimum geometry of a pressure component look like? Within the framework of the project, this central question of a favourable adaptation of the cross-section geometry of columns in transverse and longitudinal direction was investigated. The main objective was to be able to design and calculate columns in such a way that they are equally loaded in all cross-section areas. This enables slimmer components which, due to the material savings, not only contribute to the conservation of our natural resources, but are also economically advantageous and lead to a more aesthetic appearance. [Off: Introduction]

The underlying motives of the research undertaken here are twofold: to obtain a deeper understanding of the dewatering mechanisms at the forming section of a papermaking machine and to develop numerical models that describe the flow through forming fabrics. More comprehensive knowledge of dewatering in the forming section allows suggestions to be made for improvements that reduce the amount of energy used in the process without affecting the quality of the end product.   The objective of this thesis is to answer the following questions: How and why does rewetting occur at the high vacuum suction boxes? How does the structure of the forming fabric affect dewatering at the forming section? Is it possible to create accurate numerical models for forming fabrics, and can these be used to predict the dewatering behaviour of new types of fabrics?   Laboratory and pilot studies simulating high vacuum suction boxes were performed together with numerical modelling of the flow of air and water through both the forming fabric and the paper sheet.   The conclusion drawn from the pilot study is that rewetting significantly lowers the dryness of the paper sheet exiting the suction boxes. The phenomenon is extremely rapid and is most likely driven by capillary forces. The high speed at which this rewetting occurs makes it difficult to impede by placing the suction boxes closer to the couch pick-up: the solution is more likely to be the use of new and improved designs of the forming fabric. The structure of the forming fabric has been shown to affect the dewatering rate at certain conditions of vacuum dewatering, and can possibly be connected partly to the fact that fibres penetrate the surface of the fabric to varying degrees and partly to the flow resistance of the different fabric structures. Numerical models of high accuracy can be constructed and used to predetermine how new fabric designs would affect dewatering at the forming section.   This thesis quantifies aspects of dewatering such as rewetting and the influence of the forming fabric. Understanding these dewatering aspects further provides for the potential enhancement of energy efficiency in the forming section, and thereby the entire papermaking process. The forming fabric can play an important role in improving energy efficiency: rewetting after the high vacuum suction boxes occurs more rapidly than was previously known, so its design might be the only possible way of impeding it. The forming fabric can also improve the rate of dewatering: it is therefore likely that its design will be important in the next stage of developing energy efficiency and thereby play a part in achieving a more sustainable future. / This thesis quantifies aspects of dewatering such as rewetting and the influence of the forming fabric. Understanding these dewatering aspects further provides for the potential enhancement of energy efficiency in the forming section, and thereby the entire papermaking process. The forming fabric can play an important role in improving energy efficiency: rewetting after the high vacuum suction boxes occurs more rapidly than was previously known, so its design might be the only possible way of impeding it. The forming fabric can also improve the rate of dewatering: it is therefore likely that its design will be important in the next stage of developing energy efficiency and thereby play a part in achieving a more sustainable future.

This dissertation examines the effects of physician ownership of hospitals on the quality of patient-centric care in the U.S. The health care sector in the U.S. is becoming more aligned with markets and in turn, with consumers’ preferences. In consumer driven service industries, consumer satisfaction is considered a key criterion to judge quality. In the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) patient satisfaction surveys, physician-owned hospitals (POHs) get more top 5-Star ratings than other hospitals. However, it is not known whether higher perceived patient satisfaction is because of better inpatient experience or due to better health related outcomes. Ratings also do not clarify variations between specialty and general service POHs. The study compares the quality of care in POHs with that in other major forms of hospitals (corporate-owned, and not-for-profit). The Affordable Care Act (ACA) regulated physician ownership of hospitals due to concerns that physicians’ profit motive might negatively affect the quality of care. This non-experimental study used bivariate and multivariate analyses to examine variation in the quality of care among types of hospitals in 2017 and 2018 using patient satisfaction and clinical outcomes as indicators of quality. This study used two samples, a full and a restricted sample. Full sample compared all POHs (specialty and general service) with other hospitals. Restricted sample included only general service hospitals. Patients in POHs were found to have higher perceived satisfaction, and viewed providers’ practices more favorably in the full sample. In the restricted sample, however, not-for-profit (NFP) hospitals provided relatively better care. Corporate-owned hospitals had lowest patient satisfaction and poorest outcomes. Results indicate POHs are competitive with not-for-profit hospitals on patient satisfaction dimension of quality care. Multivariate analyses suggest that the effects of physician ownership go away when mediation by providers’ practices is considered. NFP hospitals, however, continue to provide better overall value of care. The results do not support reconsideration of the ACA restrictions on POHs. Patient satisfaction may be contingent upon patient-centric practices than type of hospital, but hospital ownership may affect preference for some practices over others. Outcomes may not matter when patients’ perceptions measure quality. / Ph. D. / The health care sector is becoming more closely linked to markets, and consumer experience and satisfaction, like any other consumer services industry due to growing influence of for-profit hospitals and hospital forms. Physician-owned hospitals are a relatively new form of hospitals in the U.S. Along with more traditional not-for-profit and corporate-owned hospitals; physician-owned hospitals compete for patients and patient dollars. Many physician-owned hospitals are specialty and surgical hospitals, in addition to general service hospitals. According to federal government surveys, patients usually perceive medical care provided by physician-owned hospitals to be of superior quality to that of other kinds of hospital. However, physician-owned hospitals are a type of for-profit hospital, and it is not clearly known if general service physician owned hospitals provide similar care as specialty hospitals. This research compared possible quality differences between specialty and general service physician-owned hospitals as well as with corporate-owned and not-for-profit hospitals. The results indicate that patients’ perceptions of quality of care are not consistent for physician-owned specialty and general service hospitals; the higher patient perception ratings for physician-owned hospitals reflect the better performance of specialty hospitals. In comparison with other hospitals, not-for-profit hospitals seem to provide better quality of care (tapped by both patient satisfaction and clinical outcomes) than for-profit hospitals. Corporate-owned hospitals were found to have lowest quality of care. Patients should consider tradeoffs between having better inpatient experiences and better outcomes of care.

[pt] Entre materiais renováveis de baixo impacto ambiental o bambu se destaca devido ao seu crescimento rápido, alta resistência à tração, baixo peso específico e flexibilidade. É um material compósito natural com fibras longas alinhadas unidirecionalmente, anisotrópico, que não está sendo usado amplamente nas construções civis por razão de falta de informações técnico-científicas. O bambu é um material inteligente com a distribuição das fibras longitudinais como functionally graded composite material (FGM). O objetivo deste trabalho é continuação dos estudos sobre o comportamento de bambu para aplicação nas obras de engenharia, que inicio na PUC-Rio em 1979. Neste estudo específico foi observado comportamento de bambu da espécie Phyllostachys pubescens (Mosô) (através dos ensaios experimentais) sujeito a carga de torção e flexão pura (realizados com utilização do sistema de reconhecimento de imagem) e simulações computacionais em programa de elementos finitos Abaqus. Os ensaios foram feitos para os corpos de prova inteiros (de 1 metro de comprimento) e os mesmos corpos de prova foram posteriormente fissurados no meio, alargando a fissura para cada ensaio até a ruptura. / [en] Among renewable materials with low environmental impact bamboo stands out because of rapid growth, high tensile strength, low specific weight and flexibility. It is a natural composite anisotropic material with unidirectionally aligned long fibers, which is not widely used in civil construction yet due to lack of technical and scientific information. Bamboo is an intelligent material with the distribution of longitudinal fibers as functionally graded composite material (FGM). The objective of this work is to continue the study the behavior of bamboo for application to engineering works, which started at PUC-Rio in 1979. In this specific study was observed the behavior of Moso bamboo (Phyllostachys pubescens) through the experimental observation of pure torsion and bending (realized with utilization of image recognition system) and computer simulations in finite element program Abaqus. The tests were done for the whole bamboo specimens (1 meter long) and the same specimens were subsequently cracked in the middle extending the crack for each test until failure.

Today's classroom is evolving on a myriad of levels. As class size increases, learning space decreases and diversity extremes are introduced, yet educators must use materials that address all types oflearners. The specific needs of students as well as the varied skills required for mastery on state standardized tests require educators, children and parents to look towards technology for answers. This study attempts to contribute a view of new educationally based e-merging technology being presented for use in the elementary education classroom. This study also looks at the Section 508 Compliance and its role in utilizing technology to make information available for all. The Section 508 Compliance relates to all government funded materials and their ability to be accessed and utilized by the public. With the United States increasingly diverse population and implementation of inclusion in classrooms, we have a noteworthy amount of students and educators who could benefit from this technology. Specifically, this study examines how diverse classrooms and students' individual needs are to be met with technology and that this technology will be employed with the Section 508 Compliance. As a nation we need to better prepare our future generations with a sturdy foundation of skills and tools to allow our students to excel in the learning and working environment. By showcasing the needs of children, the laws enacted, and the technology resources to educate, this thesis provides the reader with a global perspective on integrating technology and instruction for all students. Enforcing the Section 508 Compliance so that e-businesses must comply with technology-based innovations that will allow educators the resources to benefit all learners.

[pt] Elementos de paredes finas com seções transversais abertas têm sido amplamente empregados em aplicações de engenharia. Embora as aplicações convencionais e os códigos de projeto se concentrem predominantemente em elementos de aço, observa-se um interesse crescente no uso de materiais alternativos, especialmente compósitos. Entre estes, polímeros reforçados com fibra (FRP) têm sido cada vez mais empregados devido às suas propriedades benéficas. No entanto, a natureza ortotrópica das colunas FRP, produzidas através de pultrusão, apresenta um desafio, uma vez que as prescrições convencionais de projeto para estruturas de aço não podem ser aplicadas diretamente. Assim, mais pesquisas são essenciais para fornecer normas de projeto confiáveis para membros estruturais em FRP. Entre as geometrias tradicionais de seção aberta, seções cantoneira têm sido comumente empregadas. Apesar de sua simplicidade geométrica, colunas com seção cantoneira apresentam uma flambagem estrutural e um comportamento dinâmico complexos, que decorre do fato de tais colunas apresentarem diferentes modos de deformação, função de suas propriedades geométricas e materiais, incluindo interação modal, principalmente entre os modos de flexão e torção. Este trabalho se concentra na investigação das características de flambagem e vibração de colunas pultrudadas FRP com seção cantoneira, abrangendo seções de abas iguais e desiguais, e abrangendo colunas curtas a longas. Para isso, são desenvolvidos modelos de dimensão reduzida (ROMs) baseados na teoria clássica não linear de placas (CPT) proposta por von Kármán. A seção cantoneira é modelada como duas placas, com restrições de continuidade imposta na ligação entre ambas. Utilizando o software GBTul, é conduzida uma investigação abrangente da participação modal nos modos de flambagem e vibração. Com base nesta análise, o campo de deslocamentos de cada placa para todos os ROMs é aproximado por funções de interpolação derivadas analiticamente, que são usadas para discretizar o sistema contínuo com base no método de Ritz. Pela aplicação do princípio de Hamilton, os problemas de autovalor e equações não lineares de movimento são derivados. São realizadas análises paramétricas dimensionais e adimensionais, com cargas críticas e frequências de vibração comparadas favoravelmente com os resultados do GBTul. Caminhos pós-flambagem são explorados resolvendo-se os sistemas de equações de equilíbrio não lineares para cada ROM. A influência dos parâmetros geométricos e materiais na rigidez pós-flambagem é investigada, juntamente com a sensibilidade às imperfeições geométricas iniciais. Finalmente, a estabilidade de colunas sob carregamento axial harmônico é avaliada resolvendo-se numericamente as equações não lineares de movimento usando-se o método Runge-Kutta de quarta ordem. As regiões de instabilidade paramétrica são determinadas em função da frequência e magnitude da força de excitação harmônica, considerando a influência do material, do amortecimento e da geometria da seção transversal. Os diagramas de bifurcação são obtidos empregando-se o método da força bruta e técnicas de continuação, esclarecendo as bifurcações associadas aos limites de instabilidade paramétrica. A evolução das bacias de atração de soluções coexistentes é investigada, proporcionando uma avaliação da integridade dinâmica. Os resultados demonstram que a coluna pode perder estabilidade sob níveis de carga bem abaixo da carga estática de flambagem e, portanto, os projetistas devem ter cautela ao trabalhar com essas estruturas sujeitas a cargas axiais variáveis no tempo. / [en] Thin-walled elements with open cross sections have been widely employed in engineering applications. While conventional applications and design codes predominantly focus on steel members, a growing interest has emerged in exploring alternative materials, particularly composites. Among these, fiber reinforced polymer (FRP) has witnessed increased application owing to its advantageous properties. However, the orthotropic nature of FRP columns, produced through pultrusion, presents a challenge as conventional design prescriptions for structural steel cannot be directly applied. Thus, further research is essential to derive reliable design rules for FRP members. In the realm of traditional open section geometries, angle sections have been commonly employed. Despite their geometric simplicity, angles exhibit a complex structural buckling and dynamic behaviour which arises from the fact that such columns may undergo different deformation modes, according to their geometric and material properties, with modal interaction observed, particularly between flexural and torsional modes. This work focuses on investigating the buckling and vibration characteristics of pultruded FRP angle sections, encompassing both equal and unequal-leg sections, and spanning short to long columns. For this, reduced order models (ROMs) are developed based on the classical von Kármán nonlinear plate theory (CPT). The angle section is modelled as two plates, with continuity constraints considered at the common boundary. Utilizing GBTul software, a comprehensive investigation of modal participation in linear buckling and vibration modes is conducted. Based on this analysis, the plate displacement field for each ROM is approximated by suitable analytically derived interpolating functions, which are used to discretize the continuous system on the basis of the Ritz energy method. By application of Hamilton s principle, the eigenvalue problems and nonlinear equations of motion are derived. Parametric dimensional and nondimensional analyses are carried out, with critical loads and vibration frequencies compared favorably with GBTul results. Post-buckling paths are explored by solving the systems of nonlinear equilibrium equations for each ROM. The influence of geometric and material parameters on post-buckling stiffness is investigated, along with the sensitivity to initial geometrical imperfections. Finally, the stability of the columns under harmonic axial loading is assessed by numerically solving the nonlinear equations of motion using the fourth-order Runge-Kutta method. Parametric instability regions are determined as a function of the frequency and magnitude of the harmonic excitation force, considering the influence of material, damping, and cross-sectional geometry. Bifurcation diagrams are obtained employing the brute force method and continuation techniques, clarifying the bifurcations associated to the parametric instability boundaries. The evolution of basins of attraction of coexisting solutions is investigated, providing an evaluation of dynamic integrity. The results demonstrate that the column may lose stability at load levels well below the static buckling loads and, therefore, designers must exercise caution when working with these structures subjected to time-varying axial loads.