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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

Behavior of reinforced concrete beams strengthened using CFRP sheets with superior anchorage devices

Zaki, Mohammed Ameen January 1900 (has links)
Doctor of Philosophy / Department of Civil Engineering / Hayder A. Rasheed / The use of carbon fiber reinforced polymer (CFRP) anchors can improve the performance of reinforced concrete (RC) beams strengthened in flexure with CFRP sheets. This improvement results from delaying or controlling the debonding of FRP sheets at failure. In this research, six full-scale T beams and six full-scale rectangular beams are prepared and tested as two separate series. All the specimens are strengthened identically using three layers of unidirectional CFRP sheets and one layer of bidirectional CFRP sheet. The first strengthened beam in each series is anchored with side GFRP bars inserted longitudinally to both sides of the beam. The second strengthened beam in each series is anchored with GFRP patches applied to both sides of the beam. CFRP spike anchors are utilized for the other beams in the two series. The third beam in each series is secured with CFRP spike anchors of 16 mm diameter at 140 mm spacing along the shear span. The fourth strengthened beam in each series is anchored with CFRP spike anchors of 19 mm diameter at 203 mm spacing along the shear span. Four CFRP anchors are applied to each shear span of the fifth beam in each series with 16 mm- diameter (spaced at 406 mm) to secure the flexural CFRP sheets. An end CFRP anchorage technique is considered for the last beam in each series, which includes installing one CFRP spike anchor placed at 76 mm from the free edge of CFRP sheets. The beams were tested under four-point bending until failure and the results for each series are evaluated. In addition, the outcome is compared with other anchorage techniques that have been examined by some researchers utilizing the same beam geometry and properties. The experimental testing and nonlinear analysis showed improvement in the flexural performance of anchored beams compared with those strengthened beams without anchorage. By attaining debonding or rupture failure modes for the T beams and concrete crushing failure mode for the rectangular specimens, the ultimate sectional force capacity is achieved. Accordingly, the results prove that the anchors offer an effective solution against premature debonding failure.
62

Estudo teórico-experimental de reforço para construções de alvenaria empregando revestimento de argamassa armada

Ramires, Lucas Diemer January 2007 (has links)
O reforço estudado neste trabalho consiste na aplicação de revestimento de argamassa armada sobre paredes de alvenaria danificadas ou não, ou seja, reveste-se a parede de alvenaria existente com argamassa e tela soldada, esta fixada com conectores. É apresentado um procedimento simplificado de projeto visando determinar a capacidade de construções de alvenaria não-armada reforçadas com esta técnica e submetidas a solicitações de membrana, isto é, contidas no plano médio das mesmas, oriundas, por exemplo, de sismos, ventos, recalques, solicitações não previstas, deficiências construtivas, entre outras. Este procedimento foi avaliado através de comparações com resultados disponíveis na literatura e segundo resultados experimentais também desenvolvidos neste trabalho. Foram ensaiados em laboratório dois conjuntos de amostras, cada um composto por paredes com e sem reforço. O primeiro grupo (Serie A) foi composto por paredes de alvenaria cerâmica de vedação ensaiadas à compressão diagonal, enquanto o segundo grupo (Serie B) foi composto por paredes em formato de viga bi-apoiada, também de alvenaria cerâmica de vedação, submetidas à carga concentrada no meio do vão. Constatou-se que as paredes da Serie A experimentaram um aumento de quatro vezes na sua capacidade de carga, enquanto as paredes da Serie B experimentaram um aumento de aproximadamente sete vezes na capacidade de carga. Logo, confirmando evidência experimental disponível na literatura especializada, a técnica utilizada e o procedimento de projeto demonstraram-se eficientes e com grande potencial para aplicação. / The strengthening method studied in this work consists of the application of reinforced mortar (ferrocement) on a masonry wall, in other words, the existent wall, damaged or not, is covered with mortar and a steel welded wire mesh, which is fixed with connectors. A simplified design procedure was presented in order to determine the capacity of constructions of unreinforced masonry with this technique and subjected to in-plane loading, due to earthquakes, winds, displacement of the foundation, non-foreseen loads, constructive deficiencies, among others. This procedure was evaluated through comparisons with available results in the literature and through experimental results, also developed in this dissertation. Two groups of samples were laboratory tested, each one containing walls with and without reinforcement. The first group (Series A) contains walls of perforated ceramic bricks subjected to diagonal compression, while the second group (Series B) contains walls with a pinned-pinned beam shape, also of bricks, subjected to a concentrated load in the middle of the span. It was verified that the walls of Series A presented a four-times increase in the load capacity, while the walls of Series B presented a seven-times increase in the load capacity. Therefore, confirming available experimental evidence in the specialized literature, the technique and the simplified design procedure were demonstrated efficient and with great potential for application.
63

Estudo teórico-experimental de reforço para construções de alvenaria empregando revestimento de argamassa armada

Ramires, Lucas Diemer January 2007 (has links)
O reforço estudado neste trabalho consiste na aplicação de revestimento de argamassa armada sobre paredes de alvenaria danificadas ou não, ou seja, reveste-se a parede de alvenaria existente com argamassa e tela soldada, esta fixada com conectores. É apresentado um procedimento simplificado de projeto visando determinar a capacidade de construções de alvenaria não-armada reforçadas com esta técnica e submetidas a solicitações de membrana, isto é, contidas no plano médio das mesmas, oriundas, por exemplo, de sismos, ventos, recalques, solicitações não previstas, deficiências construtivas, entre outras. Este procedimento foi avaliado através de comparações com resultados disponíveis na literatura e segundo resultados experimentais também desenvolvidos neste trabalho. Foram ensaiados em laboratório dois conjuntos de amostras, cada um composto por paredes com e sem reforço. O primeiro grupo (Serie A) foi composto por paredes de alvenaria cerâmica de vedação ensaiadas à compressão diagonal, enquanto o segundo grupo (Serie B) foi composto por paredes em formato de viga bi-apoiada, também de alvenaria cerâmica de vedação, submetidas à carga concentrada no meio do vão. Constatou-se que as paredes da Serie A experimentaram um aumento de quatro vezes na sua capacidade de carga, enquanto as paredes da Serie B experimentaram um aumento de aproximadamente sete vezes na capacidade de carga. Logo, confirmando evidência experimental disponível na literatura especializada, a técnica utilizada e o procedimento de projeto demonstraram-se eficientes e com grande potencial para aplicação. / The strengthening method studied in this work consists of the application of reinforced mortar (ferrocement) on a masonry wall, in other words, the existent wall, damaged or not, is covered with mortar and a steel welded wire mesh, which is fixed with connectors. A simplified design procedure was presented in order to determine the capacity of constructions of unreinforced masonry with this technique and subjected to in-plane loading, due to earthquakes, winds, displacement of the foundation, non-foreseen loads, constructive deficiencies, among others. This procedure was evaluated through comparisons with available results in the literature and through experimental results, also developed in this dissertation. Two groups of samples were laboratory tested, each one containing walls with and without reinforcement. The first group (Series A) contains walls of perforated ceramic bricks subjected to diagonal compression, while the second group (Series B) contains walls with a pinned-pinned beam shape, also of bricks, subjected to a concentrated load in the middle of the span. It was verified that the walls of Series A presented a four-times increase in the load capacity, while the walls of Series B presented a seven-times increase in the load capacity. Therefore, confirming available experimental evidence in the specialized literature, the technique and the simplified design procedure were demonstrated efficient and with great potential for application.
64

Estudo teórico-experimental de reforço para construções de alvenaria empregando revestimento de argamassa armada

Ramires, Lucas Diemer January 2007 (has links)
O reforço estudado neste trabalho consiste na aplicação de revestimento de argamassa armada sobre paredes de alvenaria danificadas ou não, ou seja, reveste-se a parede de alvenaria existente com argamassa e tela soldada, esta fixada com conectores. É apresentado um procedimento simplificado de projeto visando determinar a capacidade de construções de alvenaria não-armada reforçadas com esta técnica e submetidas a solicitações de membrana, isto é, contidas no plano médio das mesmas, oriundas, por exemplo, de sismos, ventos, recalques, solicitações não previstas, deficiências construtivas, entre outras. Este procedimento foi avaliado através de comparações com resultados disponíveis na literatura e segundo resultados experimentais também desenvolvidos neste trabalho. Foram ensaiados em laboratório dois conjuntos de amostras, cada um composto por paredes com e sem reforço. O primeiro grupo (Serie A) foi composto por paredes de alvenaria cerâmica de vedação ensaiadas à compressão diagonal, enquanto o segundo grupo (Serie B) foi composto por paredes em formato de viga bi-apoiada, também de alvenaria cerâmica de vedação, submetidas à carga concentrada no meio do vão. Constatou-se que as paredes da Serie A experimentaram um aumento de quatro vezes na sua capacidade de carga, enquanto as paredes da Serie B experimentaram um aumento de aproximadamente sete vezes na capacidade de carga. Logo, confirmando evidência experimental disponível na literatura especializada, a técnica utilizada e o procedimento de projeto demonstraram-se eficientes e com grande potencial para aplicação. / The strengthening method studied in this work consists of the application of reinforced mortar (ferrocement) on a masonry wall, in other words, the existent wall, damaged or not, is covered with mortar and a steel welded wire mesh, which is fixed with connectors. A simplified design procedure was presented in order to determine the capacity of constructions of unreinforced masonry with this technique and subjected to in-plane loading, due to earthquakes, winds, displacement of the foundation, non-foreseen loads, constructive deficiencies, among others. This procedure was evaluated through comparisons with available results in the literature and through experimental results, also developed in this dissertation. Two groups of samples were laboratory tested, each one containing walls with and without reinforcement. The first group (Series A) contains walls of perforated ceramic bricks subjected to diagonal compression, while the second group (Series B) contains walls with a pinned-pinned beam shape, also of bricks, subjected to a concentrated load in the middle of the span. It was verified that the walls of Series A presented a four-times increase in the load capacity, while the walls of Series B presented a seven-times increase in the load capacity. Therefore, confirming available experimental evidence in the specialized literature, the technique and the simplified design procedure were demonstrated efficient and with great potential for application.
65

Reabilitação de paredes de alvenaria pela aplicação de revestimentos resistentes de argamassa armada. / Rehabilitation of masonty walls by the application of resistant ferrocement overlays.

Fabiana Lopes de Oliveira 18 April 2001 (has links)
O presente trabalho apresenta os resultados obtidos na pesquisa sobre o uso de revestimentos resistentes de argamassas de cimento e areia na reabilitação de paredes de alvenaria, quando solicitadas à compressão axial, compressão diagonal e flexão de painéis. Os ensaios foram baseados nas normas NBR 8949, ASTM 519 e NBR 14322 respectivamente. O objetivo dos ensaios realizados foi observar o comportamento estrutural de paredes de blocos de concreto revestidas com diversos tipos de argamassa de cimento e areia, os quais resultaram de combinações de argamassa de resistência baixa ou mais elevada, telas de aço soldadas, fibras de aço, fibras de polipropileno e conectores de cisalhamento. Os modelos dos ensaios de compressão axial tinham dimensões de 39 x 81 cm e foram confeccionados em gabaritos de aço para uma maior precisão durante o assentamento. Para os ensaios de compressão diagonal foram idealizados gabaritos de madeira para confecção e transporte dos modelos cujas dimensões eram de 80 x 80 cm. Nos ensaios de flexão as paredes (80 x 1,60) foram ensaiadas com a face maior na posição horizontal com duas situações de carregamento. Depois de terminados estes ensaios e analisados os resultados foi realizada também uma série de ensaios sobre painéis de alvenaria, submetidos a forças distribuídas numa região pequena do topo da parede e ensaiados em três situações diferentes: paredes íntegras, reabilitadas e reforçadas. A decisão de ensaiar painéis com aberturas se deu pela intenção de criar situações de desvio de tensões no plano da parede, provocando esforços de compressão, tração e cisalhamento. Todos os ensaios foram realizados com uso de equipamento hidráulico servo-controlado INSTRON, controlando-se a velocidade de deslocamento, o que permitiu observar o comportamento das paredes após à sua resistência de pico. Pode-se dizer que a técnica em estudo apresenta diversos aspectos interessantes, que podem ser explorados tanto na reabilitação (reforço ou reparo) de estruturas de alvenaria, como na execução de estruturas novas com exigências especiais de desempenho. / This paper reports on the results of a study about the use of resistant overlays of cement and sands mortars in the rehabilitation of masonry walls subjected to axial and diagonal compression and flexure. The tests were carried out according to the NBR8949, ASTM 519 and NBR 14322 codes. The purpose of the tests was to observe the structural behavior of concrete block walls covered with several combinations of materials: plain mortar with two different strengths, welded steel mesh, steel fibers, polypropylene fibers and shear connectors. The dimensions of the specimens subjected to axial compression tests were 390 x 810 mm. They were built inside steel templates for a better precision during their construction. Wooden templates were set up for the diagonal compression tests to build and transport the 800 x 800 mm specimens. In the flexure tests, the walls (800 x 1600 mm) were tested with the larger side in the horizontal position, using two loading situations. After the conclusion of these tests and an analysis of the results, a series of tests was carried out on masonry panels subjected to loads distributed over a small area at the top of the wall. Three different situations were tested, i.e., undamaged walls, rehabilitated walls and reinforced walls. The decision to test panels with openings was based on the idea of creating situations to deviate the stresses in the plane of the wall, thereby inducing compression, tension and shear. All the tests were performed using an universal servo-controlled INSTRON machine to control the displacement speed, allowing the observation of the behavior of the walls after their peak resistance. Based on this study, it can be stated that this technique offers several interesting aspects that may be applied both in the rehabilitation (strengthening or repair) of masonry structures and in the construction of new structures with special performance requirements.
66

The Strengthening Marriage and Relationships Training (SMART) Florida Project: Year 3 Impacts and Outcomes

Hinton, Ginny, Nelson, Nelly, Visconti, Brian, Harris, Victor W. 13 April 2019 (has links)
Abstract not available.
67

Informing BPM practice in Emergency Units of South African hospitals for improved patient flow

Loriston, Izienne P 17 August 2018 (has links)
Globally, higher healthcare demand strains existing systems, already overburdened by a lack of resources and funding while longer life expectancy and increased disease burden force higher patient loads. A majority of the South African population is medically uninsured and therefore depend on emergency care; consequently, the healthcare service demand easily exceeds available acute care to prevent life threat. When this happens, emergency centres suffer from overcrowding and long patient waiting times, which increases morbidity and mortality, associated patient risk. Moreover, critical resources such as staff and hospital beds are required for an even flow of patients through hospitals, but are distributed inefficiently. The South African healthcare system configuration therefore delays access to and compromises the delivery of equitable, unbiased life-saving healthcare in an environment moreover challenged by economic pressures. This calls for sustainable, cost-effective reform. Therefore, more efficient healthcare can save more lives by improving access to life-saving care. Research on current Healthcare Information Systems (HIS) shows an incoherent knowledge body with conceptual gaps in theories on healthcare, which disengages transformation potential. Comprehensive reform tactics thus require a priori concept discovery and diagnostics to make research practically useful. The systematic use of BPM theories allowed for the qualitative assessment of as-is process activity at patient touch-points at three hospitals – two public and one private – in the Western Cape of South Africa. Because a strategic Information Systems (IS) methodology, Business Process Management (BPM) poses business process activity improvement, this research draws from successful BPM activity as a means to improve patient flow processes in Emergency Centres (ECs). Success is evaluated by drawing from empirically supported enabler categories and prescriptive guidelines because BPM practice is not yet fully understood. The results show a clear correlation between the improvement areas at the three hospitals; improvements on aspects of actions and decisions taken during patient-flow process activity, therefore support a pragmatic approach to reform. The data confirms disparity between public and private healthcare. Healthcare appears to be a “doctor driven” service, which, based on qualitative decision-making, navigates patients along defined flows, enabled by supporting human capital and hospital assets. Optimal patient flow is a product of symbiotic working relationships and depends on efficient integration with wider hospital functions. Shorter waiting times and hospital stays reduce process burden. This leads to more efficient resource usage and regulated access to healthcare. However, integrated healthcare reform must consider the time demands and rigidity of clinical processes. The challenge lies in finding the space to invite parallel business agility to drive the reform of the stricken healthcare industry in South Africa.
68

Project Manager Strategies for Strengthening Communications Within Project Teams

Taylor, Christine 01 January 2018 (has links)
Communication inefficiencies are among the reasons for poor or substandard performances in project teams. The purpose of this multiple case study was to explore the strategies used by project managers in the health care industry to strengthen communication within project teams. The conceptual framework for the study was McQuail's mass communication theory and Craig's communication theory. Participants of the study were 4 project managers from 2 leading medical supply companies located in the mid-Atlantic region of the United States. Data were collected using semistructured interviews and a review of company documents. The summarized interview responses were validated by participants through the use of member checking. The 3 key themes that emerged from thematic data analysis highlighted strategies that project managers used to strengthen communications with project teams: communication planning, management, and ethics. Project managers can use the study's findings to increase team members' motivation, improve project results, and bolster organizational profitability, which may positively contribute to the growth, development, and betterment of the communities served by their companies.
69

Ego Strengthening Hypnotic Suggestions Versus Specific Hypnotic Suggestions in the Treatment of Obesity

Hutchison, Richard A. 01 May 1981 (has links)
A comparison was made of two types of hypnotic suggestions. Twenty seven subjects in two groups participated in eight weekly one-hour group hypnotic sessions. All subjects were given the Minnesota Multiphasic Personality Inventory, the Tennessee Self-Concept Scale, and were weighed pre, post and at four month follow-up. Both types of hypnotic suggestions were equally effective in helping individuals lose weight. The average weight loss was 10 pounds at follow up. Both groups showed improvement on the personality tests. Those who received the ego-strengthening hypnotic suggestions showed more improvement and more long lasting improvement than did those who received the specific hypnotic suggestions.
70

Příprava Al2O3 keramiky se zvýšenými mechanickými vlastnostmi / Processing of reinforced alumina ceramics

Kachlík, Martin January 2010 (has links)
Literature review of processing and toughening of bulk Al2O3 ceramics was performed. Based on performed experiments, optimal technological conditions of infiltration of alumina ceramics by nickel oxide and zirconia dioxide were found. These approaches were used for preparation of toughened alumina. The properties of sintered alumina matrix composites were discussed from the point of view of their hardness, bending strength, microstructure and phase composition.

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