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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.
91

Performance Capabilities of Light-Frame Shear Walls Sheathed With Long OSB Panels

Bredel, Daniel 13 June 2003 (has links)
In this investigation, thirty-six shear walls measuring 8 feet (2.4 m) in width and possessing heights of 8, 9 and 10 feet (2.4, 2.7 and 3.0 m) were subjected to the reversed, cyclic loading schedule of the standard CUREE protocol in order to determine the performance capabilities of shear walls greater than 8 feet (2.4 m) in height sheathed with long panels. Of the thirty-six walls, a total of twelve walls measuring 9 and 10 feet (2.7 and 3.0 m) in height were sheathed with 4 x 8 feet (1.2 x 2.4 m) panels which required additional blocking members between the studs of the frame. Values obtained from the tests performed on these walls provided a direct comparison to those obtained from the walls of equal height, but sheathed with a long panel capable of spanning the entire height of the wall. The capabilities of long panels were investigated when used as the sheathing elements of shear walls with and without a mechanical hold-down device attached to the base of the end stud. An advantage of the long panel was investigated in which it was extended past the bottom plate and down onto the band joist to determine if significant resistance to the uplift present in walls without mechanical hold-down devices could be provided. Also, the effects of orienting the fibers of a 4 x 9 feet (1.2 x 2.7 m) panel in the alternate direction were examined. Average values of the parameters produced by walls sheathed with long panels either matched or exceeded those of its counterpart sheathed with 4 x 8 feet (1.2 x 2.4 m) panels in all configurations except the 10 feet (3.0 m) tall wall without hold-down devices. In fact, 4 x 9 feet (1.2 x 2.7 m) panels increased the performance of 9 feet (2.7 m) tall walls equipped with hold-down restraint significantly. Extending the long panels past the bottom plate and down onto the band joist improved the performance of both 8 and 9 feet (2.4 and 2.7 m) tall prescriptive shear walls significantly. Walls sheathed with panels made of fibers oriented in the alternate direction performed identically to those sheathed with panels of typical fiber orientation until the point of peak load. Once peak load was reached, walls sheathed with panels of alternate oriented fibers failed in a more sudden and brittle manner. / Master of Science
92

In Search of Equilibrium: Containers of Light

Kamat, Smruti 21 September 2005 (has links)
The goal of this thesis is to find that point of equilibrium in a composition where nothing can be added and nothing can be taken away. Each and every element is vital and any addition or subtraction will disturb this equilibrium. The nature of this investigation requires a program where simplicity is a virtue. The word temple is derived from 'temnere', which means to cut, to take away. I understand this as a process of subtracting to create meaning out of something that would otherwise have been inert matter. The program proposes a sequence of three distinct spaces for contemplation, and welcomes people of any faith. While it is impossible to meet the exact requirements of each religion, there is a common thread that ties all sacred spaces together. The goal of this project is to create a silent meditative environment by bringing into play essential qualities of the space itself such as material and light. / Master of Architecture
93

Vattentäta betongkonstruktioner utsatta för tvångskrafter : Finit elementanalys av tvångsfördelning för vanliga typfall / Waterproof concrete structures exposed to restraint forces : Finite element analysis of restraint distribution for common cases

De Barros Cruz, Julio Cesar, Paunovic, Marijana January 2019 (has links)
Betong är ett av de mest använda byggnadsmaterialen i dagens samhälle. Några av anledningarna till detta är att den har lång livslängd, är naturligt material som är 100 % återvinningsbart samt ej lättantändligt material. Även om betong har många fördelar så är den inte helt idealisk eftersom den har en låg draghållfasthet. En betongkonstruktion kan spricka på grund av förhindrade rörelser som skapar dragspänningar. Förhindrade rörelser kallas för tvång och kan beskrivas i form av en tvångsfaktor. I detta examensarbete definieras tvångsfaktor som en spänningskvot mellan påtvingade spänningar och påtvingade spänningar vid fullständigt tvång. Fastlåsningsgrad, rörelsemöjlighet och styvhetsrelation mellan det nygjutna elementet och motgjutningen är avgörande parametrar vid beräkning av tvång och ett typiskt fall kan exempelvis vara en vägg gjuten mot grund. En helt förhindrad konstruktion kan ha en tvångsfaktor som är lika med 1 medan en konstruktion som kan röra sig fritt kan ha en tvångsfaktor som är lika med 0. En relativ lägre tvångsfaktor fås däremot om krypningseffekten beaktas eftersom den har gynnsam inverkan på tvånget. Betongen kan spricka på grund av tvånget och om sprickan inte är förväntad eller är större än den förväntade för den dimensionerade lasten då betraktas den som skada. Att förhindra vattengenomträngning eller läckage innebär dessutom att genomgående sprickor i vattentäta betongkonstruktioner bör undvikas. Det är således viktigt att beakta tvånget vid sprickriskanalyser av vattentäta betongkonstruktioner. Syftet med det här examensarbetet var att undersöka tvånget utifrån flera aspekter vilket gjorde att arbetet uppdelades i 3 analyser. Analys 1 syftade på att bekräfta de typiska fallen som anges i eurokoden SS-EN 1992–3 samt att utvärdera angivna tvångsfaktorer vid beräkning av tvångsdeformationer. Följaktligen användes finita elementprogram för modellering av de fallen från eurokoden och samtidigt gjordes handberäkningar för att komplettera analysen. I analys 2 studerades hur tvånget påverkas mellan konstruktionsdelar med ändring av bärverksdimensioner. Bärverket som studerades var vägg gjuten mot bottenplatta. Föränderliga parametrar var plattans bredd och tjocklek samt väggens höjd och tjocklek. Samtidigt togs ändring av konstruktionens längd som en påverkande faktor. Slutligen gjordes sprickviddsberäkningar avseende böjande moment och krympning i analys 3 för att få fram armeringsmängderna som skulle klara sprickviddskravet för vattentäta betongkonstruktioner. Detta åstadkoms enligt två olika beräkningsmetoder: Eurokodens och Engströms (2014). Dessa beräkningar visade även en jämförelse i armeringsmängd vid användning av tvångsfaktorer hämtad från eurokoden och tvångsfaktorer framräknad enligt FE-analyserna. Resultaten från analys 1 visade att variationen av beräknade tvångsfaktorer inte motsvarade helt den variationen som anges i SS-EN 1992–3 men avvek inte alldeles för mycket. Det fanns dock några enstaka fall där avvikelser var märkbara och därmed erfordras en noggrannare undersökning. Analys 2 visade att ökning av väggens volym minskar tvånget mot plattan men att en motsatt effekt fås för ökning av plattans volym. Det visade sig dessutom att en längre konstruktion orsakar större tvång mellan själva konstruktionsdelar. Slutsatsen från analys 3 var att skillnaden i genererad armeringsmängd var nästan proportionell i procentsats mot skillnaden i tvångsfaktor. Olika beräkningsmetoder resulterade dock i armeringsmängder som inte var jämförbara. Jämförelsen mellan de två beräkningsmetoderna var inte heller syftet med detta examensarbete utan endast ett försök att få en insyn i hur de olika metoderna är uppbyggda. / Concrete is one of the most widely used building materials in society today. Some of the reasons for this are that it has a long life, is a natural material that is 100% recyclable and non-flammable material. It has many advantages, but it is not entirely ideal due to its low tensile strength. A concrete structure may crack due to restrained movements which creates tensile stresses. Restrained movements are called restraint which can be described in the form of restraint factor. In this thesis, restraint factor is defined as a ratio between the actual imposed stress and the imposed stress at full restraint. The degree of fixity, movement possibility and stiffness relation between the newly casted element and the adjacent old structure are crucial parameters in the calculation of restraint and a typical case is, for example, a wall-on-slab cast. A completely restrained construction has a restraint factor equal to 1, while a structure that can move freely has a restraint factor equal to 0. However, a relative lower restraint factor is obtained if the creep effect is considered, since it has a positive influence on the restraint. The concrete may crack due to the restraint and if the crack is not expected or is larger than the expected for the dimensioned load then it is considered as damage. Preventing water penetration or leakage also means that through cracks in waterproof concrete structures should be avoided. Therefore, it is important to consider the restraint on fracture risk analyzes of waterproof concrete structures. The purpose of this thesis was to investigate the restraint based on several aspects, which meant that the work was divided into 3 analyses. Analysis 1 had as purpose to confirm typical cases specified in Eurocode SS-EN 1992–3 and to evaluate the stated restraint factors that the Eurocode proposes should be used in calculations of restraint deformations. For that matter, finite element program was used for modeling the cases from the Eurocode and at the same time hand calculations were made to supplement the analysis. Analysis 2 consisted of examining how the restraint between structural parts is affected by changing dimensions of the structure. The construction being studied was wall-on-slab cast. Variable parameters were the width and thickness of the slab, as well as the height and thickness of the wall. At the same time, changing the length of the construction was taken as an affecting factor. Lastly, crack width calculations for bending moments and shrinkage were made in analysis 3 to obtain the amount of reinforcement that meet the crack width requirement for waterproof concrete structures. This was done according to two different calculation methods: Eurocodes and Engström’s (2014). These calculations also showed a comparison in the amount of reinforcement when using restraint factors derived from Eurocode and restraint factors calculated according to the FE analyses. The results from analysis 1 showed that the variation of restraint factors calculated did not completely correspond to the variation stated in SS-EN 1992–3 but did not deviate too much. However, there were a few cases where deviations were noticeable and therefore a more detailed examination is required. Analysis 2 showed that increasing the volume of the wall reduces the restraint against the slab, but an opposite effect was obtained by increasing the volume of the slab. At the same time, it was found that a longer construction causes greater restraint between the actual components. The conclusion from analysis 3 was that the difference in generated amount of reinforcement was almost proportional in percentage to the difference in restraint factor. However, using different calculation methods resulted in amounts of reinforcement that were not comparable. Comparison between the two calculation methods was not the purpose of this thesis, but merely an attempt to gain an insight into how the different methods are structured.
94

Nonprofit organizations facing competition : the application of United States, European and German competition law to not-for-profit entities /

Cicoria, Cristiana. January 1900 (has links) (PDF)
Univ., Diss.--Hamburg, 2005. / Literaturverz. S. 259 - 286.
95

Potentieller Wettbewerb und Marktbeherrschung : eine Untersuchung zum deutschen, europäischen und US-amerikanischen Kartellrecht /

Gey, Peter. January 2004 (has links) (PDF)
Univ., Diss. u.d.T.: Gey, Peter: Die Bedeutung des potentiellen Wettbewerbs bei der Bestimmung marktbeherrschender Stellungen im deutschen, europäischen und US-amerikanischen Kartellrecht--Hamburg, 2004.
96

Análise numérico-experimental de vigas de concreto armado com restrições axial e rotacional em situação de incêndio. / Experimental and numerical analysis of reinforced concrete beams with axial and rotational restraints in fire.

Albuquerque, Gabriela Bandeira de Melo Lins de 09 May 2018 (has links)
As vigas de concreto armado sofrem deformações térmicas em situação de incêndio. Os comprimentos dos vãos se alongam resultando no deslocamento horizontal de seus respectivos apoios e elas passam a fletir de forma acentuada, o que gera a rotação nos mesmos. Se essas deformações forem impedidas pelas próprias condições de apoio da peça ou devido a elementos estruturais circundantes, por exemplo, esforços adicionais passarão a atuar nas vigas, modificando seu desempenho frente ao fogo. Estudos apontam que os efeitos desses esforços podem ser benéficos à resistência ao fogo (RF) das vigas aquecidas, contudo, nas poucas pesquisas voltadas à análise experimental dessa questão, as restrições foram admitidas apenas de forma isolada, i.e., ou as vigas estavam submetidas a restrições axiais ou a rotacionais. O efeito conjunto, mais representativo ao que ocorre na realidade, e a consideração de diferentes níveis de rigidezes impostos às deformações, foram avaliados em investigações numéricas sem dados experimentais apropriados para a validação dos resultados. Na presente Tese de Doutorado, avaliou-se experimentalmente o desempenho de vigas de concreto mediante a realização de ensaios de flexão em elementos em escala real e sob diferentes condições de apoio: sem restrições às deformações, com restrições apenas axiais e com restrições tanto axiais quanto rotacionais. Relativamente aos elementos restringidos, foram analisados dois níveis de rigidezes axial, 0,02 e 0,04EA/l, e rotacional, 1 e 2EI/l. Também houve ensaios de referência em vigas simplesmente apoiadas à temperatura ambiente para a verificação dos carregamentos e modos de ruptura. Os dados experimentais obtidos para diferentes esquemas estáticos de vigas motivaram a concepção de modelos numéricos que fossem representativos do comportamento dos mesmos. Com o auxílio do programa de computador DIANA, que tem base no método dos elementos finitos, foram criados modelos para as vigas ensaiadas à temperatura ambiente e ao fogo. Eles foram idealizados com a consideração de diversas propriedades características do comportamento não linear dos materiais e conduziram a boas correlações quando os seus resultados foram comparados aos obtidos em laboratório. A principal conclusão deste estudo numérico-experimental foi que a RF das vigas de concreto armado sempre aumentam quando admitido qualquer tipo de restrição (somente axial ou axial mais rotacional). Além disso, ao se fixar um valor para a restrição rotacional, as vigas com nível de restrição axial mais elevado apresentaram RF maiores do que aquelas com nível mais brando. O mesmo se verificou ao fixar a restrição axial e variar a rotacional. Vigas nos quais o efeito conjunto das restrições foi admitido conduziram a maiores RF do que aquelas apenas com restrição axial. Para a maior parte dos casos estudados, os aumentos das RF se mostraram significativos quando confrontados às vigas sem restrições. Assim, confirmou-se que os métodos simplificados normatizados que não consideram os efeitos provenientes das mesmas no dimensionamento para a situação de incêndio das vigas de concreto armado estão a favor da segurança. Os resultados numérico-experimentais aqui apresentados podem auxiliar na concepção de ferramentas alternativas para a consideração dos efeitos das restrições em projeto. / Reinforced concrete beams are submitted to thermal deformations when exposed to fire. The lengths of the spans elongate, a fact that triggers the horizontal displacement of their supports, and they begin to bend sharply, resulting in their rotation. If these deformations are hindered by the support conditions of the element or by surrounding structural elements, for instance, additional efforts will act on the beams in order to modify their performance when facing the action of fire. Studies have pointed out that the effects of such efforts may be beneficial to the fire resistance of the beams; however, in the few researches focused on the experimental analysis of this issue, the restraints were admitted only in an isolated way, i.e., the beams were either submitted to axial or to rotational restraints. Their coupled effect, more representative of what occurs in reality, and the consideration of different stiffness levels imposed on the deformations, were evaluated in numerical investigations, without suitable experimental data for validating the results, though. In this PhD Thesis, the performance of concrete beams was evaluated experimentally by performing bending tests on full-scale elements under different support conditions: unrestrained, only with axial restraints and with both axial and rotational restraints. Regarding the restrained elements, two levels of axial and rotational stiffness were analyzed, 0.02 and 0.04EA/l; 1 and 2EJ/l. There were also reference tests on simply supported beams at ambient temperature to check the load-bearing capacities and failure modes. The experimental data obtained for different beam static schemes still motivated the conception of numerical models that would be representative of their behavior. With the aid of the DIANA software, which is based on the finite element and displacement methods, beam models to represent beams tested at ambient temperature and in fire conditions were created. These models were implemented considering several properties that characterize the nonlinear behavior of the materials and led to good correlations when their results were compared to those obtained in the laboratory. The main conclusion of this experimental and numerical study was that the fire resistance of RC beams always increases when any type of restraint (axial or axial plus rotational) is introduced. In addition, by fixing the rotational stiffness, the beams with higher axial stiffness level presented higher fire resistance than those with the lower level. The same was observed by fixing the axial stiffness and varying the rotational stiffness. Beams in which the combined effect of the restraints was admitted led to higher resistances than those with only axial restraint. For most of the studied situations, the increases of the resistances showed to be significant when confronted with the ones for unrestrained beams. Thus, it was confirmed that the standard simplified methods that allow the non-consideration of these effects during the fire design of the RC beams lead to conservative results. The numerical and experimental results presented herein may aid in the conception of alternative tools that allow applying restraint effects to design.
97

Strukturkrisenkartelle im deutschen und europäischen Kartellrecht /

Jürgens, Robert. January 2007 (has links)
Universiẗat, Diss., 2006--Köln.
98

Die neue Schirm-Gruppenfreistellungsverordnung (EG) Nr. 2790/1999 der Kommission : zu den Ursachen der weitreichenden Reform der EG-Wettbewerbspolitik gegenüber vertikalen Wettbewerbsbeschränkungen und deren materiellrechtlichen Grenzen /

Rütters, Silke, January 2002 (has links) (PDF)
Univ., Diss.--Köln, 2001. / Literaturverz. S. 209 - 223.
99

Die Anwendung der Artikel 81 und 82 EGV durch die französischen Behörden und Gerichte /

Crozals, Cyrille de. January 2003 (has links) (PDF)
Univ., Diss.--Köln, 2002.
100

Einseitige Massnahmen in Abgrenzung zum europäischen Kartellverbot /

Schwinn, Hannes. January 2009 (has links)
Thesis (doctoral)--Universität, Heidelberg, 2007. / Includes bibliographical references.

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