• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 135
  • 65
  • 52
  • 7
  • 4
  • 4
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 298
  • 116
  • 113
  • 106
  • 101
  • 95
  • 93
  • 75
  • 71
  • 51
  • 42
  • 41
  • 39
  • 39
  • 34
  • 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

Horský hotel / Mountain hotel

Chrobočková, Nikola January 2017 (has links)
The topic of dissertation is project of two- storey mountain hotel in Horní Bečva. Mountain hotel will be used for accommodation and STRAVOVÁNÍ. In basement are four hotel rooms connected by corridor with access to clubroom, fitness room, lounge, sauna and staircase, which is connecting basement and ground floor. In the basement are also rooms for employees, which are office, laundry storage room and cleaning room. In ground floor are rooms for guests, as restaurant, bar, conference room, WC and bicycle and ski room. There are also rooms for employees with separate entrance, which are dressing rooms for men and women, kitchen with storage space. In first floor are hotel rooms, laundry storage room and cleaning room. Mountain hotel has rectangular plan. It has saddle grinder roof.
152

Performance Of Mechanical And Non-mechanical Connections To Gfrp Components

Dike, Nnadozie N 01 January 2012 (has links)
There are presently many solutions to dealing with aging or deteriorated structures. Depending on the state of the structure, it may need to be completely over-hauled, demolished and replaced, or only specific components may need rehabilitation. In the case of bridges, rehabilitation and maintenance of the decks are critical needs for infrastructure management. Viable rehabilitation options include replacement of decks with aluminum extrusions, hybrid composite and sandwich systems, precast reinforced concrete systems, or the use of pultruded fiber-reinforced polymer (FRP) shapes. Previous research using pultruded glass fiber-reinforced polymer (GFRP) decks, focused on behaviour under various strength and serviceability loading conditions. Failure modes observed were specific to delamination of the flexural cross sections, local crushing under loading pads, web buckling and lip separation. However certain failure mechanisms observed from in-situ installations differ from these laboratory results, including behaviour of the connectors or system of connection, as well as the effect of cyclic and torsional loads on the connection. This thesis investigates the role of mechanical and non-mechanical connectors in the composite action and failure mechanisms in a pultruded GFRP deck system. There are many interfaces including top panel to I-beam, deck panel to girder, and panel to panel, but this work focuses on investigating the top panel connection. This is achieved through comparative component level shear, uplift, and flexure testing to characterize failure and determine connector capacity. Additionally, a connection of this GFRP deck system to a concrete girder is investigated during the system-level test. Results show that an epoxy non-mechanical connection may be better than mechanical options in ensuring composite behaviour of the system.
153

Painéis de alta densidade para aplicação em pisos: produção e avaliação de desempenho / High density panels for application in floors: production and performance evaluation

Varanda, Luciano Donizeti 12 September 2016 (has links)
Temas relacionados ao desenvolvimento de novos materiais têm sido cada vez mais abordados e discutidos, num contexto em que questões como meio ambiente, sociedade, economia de energia e aproveitamento de resíduos, vêm se tornando relevantes. Neste cenário, faz-se necessário estudar aplicações de insumos alternativos na produção de pisos de madeira, tanto para reduzir o consumo de essências tropicais quanto para suprir o aumento da demanda de madeira nas indústrias deste segmento. O objetivo deste estudo foi produzir painéis de partículas homogêneos de alta densidade, com resíduos de madeira de Pinus elliottii e casca de aveia (Avena sativa), aderidos sob pressão com dois tipos de adesivo, poliuretano à base de óleo de mamona e melamina formaldeído, nos percentuais de 11 e 13%, e avaliar o desempenho físico-mecânico de tais painéis para aplicação em pisos. O desempenho físico-mecânico dos painéis (Planejamento I - 20 tratamentos) foi avaliado com base nas normas ABNT NBR 14810 (2006 e 2013). Realizou-se análise de variância (ANOVA) para testar a influência dos fatores individuais (percentual de casca de aveia, percentual de adesivo e tipo de adesivo), além das interações entre tais fatores (dois a dois e três a três) nas propriedades físico-mecânicas dos painéis. Também foi avaliado o desempenho para pisos, tanto dos painéis (Planejamento II - 12 tratamentos) quanto de três espécies de madeira tropical (Angelim Vermelho, Dinizia excelsa; Cumaru, Dipteryx odorata e Jatobá, Hymenaea sp.), segundo diversas normas relacionadas a pisos de madeira. Os resultados apontaram propriedades físico-mecânicas dos painéis, em alguns tratamentos superiores aos requisitos estipulados por normas nacionais e internacionais. Quanto ao desempenho para pisos, os painéis apresentaram desempenho semelhante as três espécies de madeira, na maioria das propriedades avaliadas. A análise de porosimetria por intrusão de mercúrio confirmou a similaridade entre os painéis (do Planejamento II) e as três espécies de madeira avaliadas, evidenciando a potencialidade dos painéis produzidos para aplicação na indústria de pisos engenheirados. / Matters related to the development of new materials have been increasingly addressed and discussed in a context where issues such as the environment, society, energy and waste recovery economy, is becoming relevant. In this scenario, it is necessary to study alternative inputs for applications in the production of wood floors, both to reduce the consumption of tropical essences as to meet the increasing demand for wood in industries in this segment. The aim this study was to produce high density homogeneous particleboard with waste wood of Pinus elliottii and oat hulls (Avena sativa), adhered under pressure with two types of adhesive, castor oil-based polyurethane and melamine formaldehyde, the percentage of 11 and 13%, and evaluate the physical and mechanical performance of such panels for use in floors. The physical-mechanical performance of the panels (Planning I - 20 treatments) was evaluated based on the NBR 14810 (2006 and 2013) standards. We conducted an analysis of variance (ANOVA) to evaluate the influence of individual factors (oat hulls percentage, adhesive percentage and type of adhesive), and the interactions between these factors (two by two and three by three) on the physical properties-mechanical panels. It was also evaluated the performance for floors, both panels (Planning II - 12 treatments) as three species of tropical wood (Angelim Vermelho, Dinizia excelsa; Cumaru, Dipteryx odorata e Jatobá, Hymenaea sp.), according to various standards related to wood floors. The results indicated physical and mechanical properties of the panels, in some treatments superior to the requirements stipulated by national and international standards. As for performance flooring, panels statistically equivalent to the three species of wood, most of the evaluated properties. Porosimetry analysis by mercury intrusion confirmed the similarity between the panels (from Planning II) and the three wood species evaluated, demonstrating the potential of the panels produced for use in the flooring industry engineered.
154

Whereabouts : en tillflyktsort / Whereabouts : a hideaway

Sandqvist, Karin January 2013 (has links)
Jag har valt att kalla mitt projekt ”Whereabouts”, vilket betyder plats eller tillhåll. Och det är just en plats som jag försöker skapa i mitt examensarbete. Arbetet handlar om textil i rum och hur jag kan använda mig utav textil för att bygga upp en rumslighet. Fokus ligger på offentlig miljö, och hur jag i en sådan miljö kan skapa en plats för avskildhet och lugn. Lite som ett gömställe att fly till när omgivningen blir stökig och orolig. Det hela resulterar i en rumsavdelare i form av ett textilt tak och golv.Kärnan i projektet är att utforska hur jag kan skapa rumslighet, eller snarare illusionen av rumslighet då jag inte använder mig av några väggar som stänger av flödet i rummet. Istället undersöker jag om det skapas en känsla av att kliva in i ett annat område eller rum genom att föra in ett extra, lägre tak över ett begränsat område. Om det skapas en annan atmosfär under taket. För att ytterligare bygga på detta, arbetar jag även fram ett golv, som fungerar som en avspegling av taket och därmed binder ihop golv och tak.“Whereabouts” is a hideaway, a place to escape to when the surroundings are noisy and unrestful. With a room divider, in the form of a textile ceiling and floor, a place of serenity is created in the public room. Inspired by the spatiality created underneath the tree crown and of the light that seeps through the leaves, “Whereabouts” forms a more natural atmosphere in an otherwise artificial context.The work revolves around the use of textiles in interiors and how I can create spatiality, or rather the illusion of it, not using any walls. Instead, I examine whether the use of a ceiling and floor can create a different atmosphere and a sense of space. / Program: Textildesignutbildningen
155

Contribuições à análise de pavimentos de edifícios em laje nervurada / Contributions for analysis of building floors in waffle slab

Barbirato, Carlos Braz Cordeiro 04 April 1997 (has links)
Este trabalho trata da análise elástico-linear de pavimentos de edifícios de concreto armado em laje nervurada e, em especial, lajes lisas com vigas nas bordas. Inicialmente desenvolve-se um pré-processador dedicado a esse sistema estrutural com todas as facilidades que permitem sua modelagem rápida e eficiente. Os dados de entrada são baseados quase que exclusivamente no fornecimento dos contornos dos capitéis e do pavimento, sendo que este último é discretizado em segmentos retilíneos que devem ser paralelos aos eixos do sistema cartesiano. Com um mínimo de informações, esse pré-processador executa a montagem do arquivo de dados, definindo automaticamente elementos de barra para as nervuras, elementos de placa para os capitéis e realizando todos os ajustes necessários para a modelagem do pavimento a ser analisado com a utilização de um sistema em Elementos Finitos. Com a utilização dessa ferramenta, desenvolve-se um estudo de alguns casos de pavimentos típicos, objetivando-se, em especial, uma comparação entre a análise através de elementos de barra e placa e o procedimento simplificado de se considerar apenas elementos finitos de placa com rigidez equivalente. Para facilitar a análise dos resultados apresenta-se um pós-processador que permite a visualização tridimensional dos esforços solicitantes e deslocamentos obtidos. / This work deals with the linearly elastic analysis of reinforced concrete building floors in waffle slab, emphasizing flat slabs with beams at the edges. lnitially it is developed a pre-processor dedicated to this structural system, with all facilities that allows a quick and efficient modeling. The input data are based on the supplying of the the drop-panels and the floor contours, and this last one is discretized in right segments that must be parallel with the axes of the Cartesian system. With few informations, this pre-processor performs the assemblage data files, defining automatically bar elements to the ribs, plate elements to the drop-panels and realizing all the necessary adjustments in the model to be analyzed by a Finite Element system. With the utilization of the mentioned tool, it is presented a study of some typical floors, enhancing a comparison between the analysis using bar and plate elements and the simplified process with equivalent rigidity plate elements. In order to facilitate the analysis of the results it is also presented a pos-processor that allows a tridimensional visualization of internal forces and displacements.
156

Impacto da Utilização de Pavimentação Permeável em Áreas Urbanas na Recuperação de Bacias Hidrográficas / Use of Impact Permeable Paving in Urban Areas in Recuperção Watershed

Santos, Cristiano de Assumpção 07 April 2016 (has links)
Made available in DSpace on 2017-07-10T15:14:38Z (GMT). No. of bitstreams: 1 Cristiano.pdf: 1521067 bytes, checksum: 8be179f3b8b51910029f0a61831b2fc6 (MD5) Previous issue date: 2016-04-07 / Urbanization and the disorderly occupation of cities have created many environmental problems, ranging from floods to climate change in large urban centers. Among the causes of these occurrences is mainly soil sealing in cities, that occurs by interference and man's need to use more space. The more waterproofed the surface of urban areas, higher runoff, and this, in turn, due to the adopted public politics and the lack of planning, are transferred to adjacent watersheds, causing, these problems such as floods and silting of rivers. The impermeabilized surfaces end up affording a smaller charge of watersheds, transferring to other river basins the amount of water that it should be restored in the region, that way impair the recovery of the basins where the percolations occur. This study is a comparison between two existing technologies in commercially known market as "paver" and "draining floor", and point which of these can help in the recovery of watersheds and, consequently, reduce the problems caused by surface runoff in urban areas. To reach the result precipitations were simulated using a sprinkler infiltrometer in intensities corresponding to 45mm.h-1, 60mm.h-1 and 90mm.h-1, and occurred in lysimeters where the coverages match the public walks characteristics using the technologies to be analyzed as ground cover. This experiment showed that the permeable concrete parts (draining floor) and concrete parts gaskets extended (paver) has percolation rate likened to grass cover and thus can be used as technologies for water infiltration into the soil aiding in the recovery of watersheds in urban areas / A urbanização e a ocupação desordenada das cidades criaram diversos problemas ambientais, que vão desde enchentes até alterações climáticas nos grandes centros urbanos. Entre as causas destas ocorrências está, principalmente, a impermeabilização dos solos nas cidades, que ocorre pela interferência e necessidade do homem em utilizar mais espaço. Quanto mais impermeabilizada a superfície das regiões urbanas, maior o escoamento superficial, e este, por sua vez, devido às políticas públicas adotadas e à falta de planejamento, são transferidos para bacias adjacentes, trazendo problemas a estas, como enchentes e assoreamentos dos rios. As superfícies impermeabilizadas acabam proporcionando uma menor recarga das bacias hidrográficas, transferindo para outras bacias a quantidade de água que deveria ser reposta naquela região, desta forma prejudicam a recuperação das bacias onde ocorrem as percolações. O presente estudo faz um comparativo entre duas tecnologias existentes no mercado comercialmente conhecidos como paver e o piso drenante , e apontará qual destas pode auxiliar na recuperação das bacias hidrográficas e, consequentemente, reduzir os problemas causados pelo escoamento superficial nas regiões urbanas. Para chegar ao resultado foram simuladas precipitações utilizando um infiltrômetro de aspersão em intensidades correspondentes à 45 mm.h-1, 60 mm.h-1 e 90 mm.h-1, e ocorreram em lisímetros onde as coberturas correspondem as características de passeios públicos utilizando as tecnologias a serem analisadas como cobertura de solo. Este experimento apontou que as peças de concreto permeável (piso drenante) e as peças de concreto com juntas alargadas (paver) têm taxa de percolação assemelhada a cobertura de grama e desta forma podem ser utilizadas como tecnologias para infiltração de água no solo auxiliando na recuperação das bacias hidrográficas das zonas urbanas.
157

Prédiction et estimation de très faibles taux d'erreur pour des chaînes de communication codées.

Kakakhail, Shahkar 10 January 2010 (has links) (PDF)
Dans cette thèse, nous abordons le sujet d'optimisation des méthodes utlisées pour l'évaluation de performance des codes correcteurs d'erreurs. La durée d'une simula- tion Monte Carlo pour estimer le taux d'erreurs dans un système de communication augmente exponentiellement avec l'accroissement du Rapport Signal sur Bruit (RSB). Importance Sampling (IS) est une des techniques qui permettent à réduire le temps de ces simulations. Dans ce travail, on a étudié et mis en oeuvre une version avancée d'IS, appelé Adaptive Importance Sampling (AIS), pour l'évaluation efficace des codes cor- recteurs d'erreurs aux taux d'erreur très bas. D'abord, nous présentons les inspirations et motivations en analysant différentes approches actuellement mises en pratique. On s'intéresse plus particulièrement aux méthodes inspirées de la physique statistique. Ensuite, basé sur notre analyse qualita- tive, nous présentons une méthode optimisée, appelé la méthode de Fast Flat Histogram (FFH) qui est intrinsèquement très générique. La méthode emploie l'algorithme de Wang-Landau, l'algorithme de Metropolis-Hastings et les chaines de Markov. Elle fonctionne dans le cadre de l'AIS et nous donne un gain de simulation satisfaisant. Différents paramètres sont utilisés pour assurer une précision statistique suffisante. L'extension vers d'autres types de codes correcteurs d'erreurs est directe. Nous présentons les résultats pour les codes LDPC et turbocodes ayant dif- férentes tailles et différents rendements. Par conséquent, nous montrons que la méthode FFH est générique et valable pour une large gamme des rendements, tailles et structures. De plus, nous montrons que la méthode FFH est un outil puissant pour trouver des pseudocodewords dans la région de RSB élévé en appliquant l'algorithme de décodage Belief Propagation aux codes LDPC.
158

Strengthening existing steel bridge girders by the use of post-installed shear connectors

Kwon, Gun Up, 1977- 28 September 2012 (has links)
A number of older bridges built before the 1970’s were constructed with floor systems consisting of a non-composite concrete slab over steel girders. Many of these bridges do not satisfy current load requirements and may require replacement or strengthening. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders to permit the development of composite action. This dissertation describes a research program investigating methods to develop composite action in existing non-composite floor systems by the use of postinstalled shear connectors. Three types of post-installed shear connection methods were investigated. These methods are referred to as the double-nut bolt, the high tension friction grip bolt, and the adhesive anchor. These post-installed shear connectors were tested under static and fatigue loading, and design equations for ultimate strength and fatigue strength were developed. These post-installed shear connectors showed significantly higher fatigue strength than conventional welded shear studs widely used for new construction. The superior fatigue strength of these post-installed shear connectors enables strengthening of existing bridge girders using partial composite design, thereby requiring significantly fewer shear connectors than possible with conventional welded shear studs. Five full-scale non-composite beams were constructed and four of these were retrofitted with post-installed shear connectors and tested under static load. The retrofitted composite beams were designed as partially composite with a 30-percent shear connection ratio. A non-composite beam was also tested as a baseline specimen. Test results of the full-scale composite beams showed that the strength and stiffness of existing non-composite bridge girders can be increased significantly. Further, excellent ductility of the strengthened partially composite girders was achieved by placing the postinstalled shear connectors near zero moment regions to reduce slip at the steel-concrete interface. Parametric studies using the finite element program ABAQUS were also conducted to investigate the effects of beam depth, span length, and shear connection ratio on the system behavior of strengthened partially composite beams. The studies showed that current simplified design approaches commonly used for partially composite beams in buildings provide good predictions of the strength and stiffness of partially composite bridge girders constructed using post-installed shear connectors. / text
159

Framtidens Flexibla Sporthall : För mer tidseffektiva sporthallar / The future flexible indoor sport accomodation : A proposal for more efficient use of sport facilities

Ferngren, Jenny January 2015 (has links)
This report contains a developing project about a future indoor sport center. The project should provide inspiration on how to shorten set-up times between different sports. The client for the project is the municipality of Karlstad and the project is a thesis for the Bachelor of Science in Innovation and Design, 2015. The Municipality of Karlstad feels that today's accommodations are not used as desired and they find it difficult to get in many different sports under one roof. The main goal of the project was to reduce the set-up times between different sports. As a second goal, all the ideas that came up during the project were gathered, drawn and displayed in an idea bank, to provide further inspiration. The third goal was to make a model to visualize the solutions of a future sports hall. The dimensions 90x55 was used to allow maximum dimension of the model in the thesis. The facility was suggested by the municipality to be divided into two parts, where one side was for ball sports and the other for physical education and martial arts. Focus of the project became the part of physical education and martial arts, since that area currently is the least developed. The project is based on interviews and field trips to sport facilities. This was the main contribution towards the creation of the model. A model helps to gain understanding and visualizes how the proposed solutions and ideas would work. The final model shows solutions that allow more types of gymnastics with for example jumping pits and trapezes integrated underneath the sport accommodations floors. Dancing mats can be rolled out mechanically to reduce muscular use. Another solution that also reduces muscular use is a tool-treadmill running over half the facility. Martial arts are located on top of the flexible floors but also under the floor just like the trapeze does. All solutions are designed to operate by the press of a button. The thesis has followed the product development process. By benchmarking and interviews, the model evolved to the needs of the users desires. The inspiration that the municipality wished to get is considered fulfilled by the model and the idea bank. / Denna rapport behandlar ett utvecklingsprojekt om framtidens sporthall, ett projekt som skall ge inspiration om hur ställtiderna kan förkortas emellan olika sporter. Uppdragsgivaren är Karlstads Kommun och projektet är ett examensarbete för Högskoleingenjörsprogrammet i Innovationsteknik och design, 2015. Karlstads Kommun upplever att dagens hallar inte används under maximal tid och de tycker att det är svårt att få in många olika sporter under ett tak. Målen med projektet har varit att göra en modell för att visualisera de lösningar en framtida sporthall skulle kunna äga. Alla idéer som kom upp under projektet gestaltades i projektets andra mål, en idébank för att kunna ge vidare inspiration. Ett tredje mål var att minska ställtiden mellan de olika sporterna. Ett maximalt yttre mått har funnits till hallen, 90x55 meter. Hallen är tänkt att delas upp i två delar där en sida gällde för bollsporter och den andra för gymnastik samt mattsporter 1). Fokus i projektet kom att hamna på delen med gymnastik och mattsporter, då den delen är minst utvecklad i dagens läge. Arbetet byggdes på de önskningar som kommit fram från intervjuer och studiebesök och den största vinsten av insikt gavs från tillverkning av modellen. Modellbygge är ett sätt att visa för utomstående hur idéer skall kunna fungera. Genom en iterativ process för att testa sina idéer i en modell kan stora summor pengar sparas genom att hitta de brister som annars kan ha vart svåra att upptäcka. I den slutgiltiga modellen ses lösningar som gör det möjligt för fler typer av gymnastik med t.ex. hoppgropar och trapetser integrerat under hallens golv. Dansvåder och ett redskapsrullband rullas ut mekaniskt för att minska fysiskt belastning av kroppen. Mattsporterna är placerade över gymnastikens flexibla golv men även under golvet precis som med trapetserna. Alla lösningar är tänkta att tjänstgöra genom knapptryckning. Arbetet har följt produktutvecklingsprocessen och genom benchmarking och intervjuer har modellen utvecklats till behovet efter användarnas önskan. Den inspiration som kommunen önskat sig anses uppfyllas genom modell och idébank. 1) Mattsporter - Ett samlingsnamn i denna rapport för kampsporter. I rapporten inkluderar mattsporter Judo, Jiujitsu, brottning och karate.
160

Vibration characteristics of steel-deck composite floor systems under human excitation

De Silva, Sandun S. January 2007 (has links)
Steel-deck composite floor systems are being increasingly used in high-rise building construction, especially in Australia, as they are economical and easy to construct. These composite floor systems use high strength materials to achieve longer spans and are thus slender. As a result, they are vulnerable to vibration induced under service loads. These floors are normally designed using static methods which will not reveal the true behaviour and miss the dynamic amplifications resulting in inappropriate designs, which ultimately cause vibration and discomfort to occupants. At present there is no adequate design guidance to address the vibration in these composite floors, due to a lack of research information, resulting in wasteful post event retrofits. To address this gap in knowledge, a comprehensive research project is presented in this thesis, which investigated the dynamic performance of composite floors under various human induced loads. A popular type of composite floor system was selected for this investigation and subjected to load models representing different human activities. These load models have variable parameters such as load intensity, activity type (contact ratio), activity frequency and damping and are applied as pattern loads to capture the maximum responses in terms of deflections and accelerations. Computer models calibrated against experimental results are used in the analysis to generate the required information. The dynamic responses of deflections and accelerations are compared with the serviceability deflection limits and human comfort levels (of accelerations) to assess these floor types. This thesis also treats the use of visco-elastic (VE) dampers to mitigate excessive vibrations in steel-deck composite floors. VE damper properties have been presented and their performances in reducing the excessive vibrations have been assessed this thesis. The results identified possible occupancies under different loading conditions that can be used in planning, design and evaluation. The findings can also be used to plan retrofitting measures in problematic floor systems.

Page generated in 0.0539 seconds