• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 45
  • 18
  • 12
  • 6
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 163
  • 30
  • 16
  • 13
  • 12
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 10
  • 10
  • 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.
121

PADRÕES NORMATIVOS, ENSAIOS EXPERIMENTAIS E ANÁLISE DA PERFORMANCE ACÚSTICA DE TELHAS SANDUÍCHE / REGULATORY STANDARDS, TESTING AND EXPERIMENTAL ANALYSIS OF ACOUSTIC PERFORMANCE OF SANDWICH TILES

Andrade, Bruna Fuzzer de 26 January 2016 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / In urban areas, where noise is significant, the facades and roofs must submit a performance capable of ensuring insulation required for the acoustic comfort of the users. The roof, although important elements of the envelope of buildings, has been little studied in Acoustics. The validity of ISO 15575 Residential Buildings - Performance impacted mainly the construction industry suppliers, who needed to characterize their products and systems. Also in 2015 came the NBR 16373 - tiles and thermoacoustic panels - Performance requirements. This Thesis aimed to establish a methodology to analyse the acoustic performance for sandwich tiles considering regulatory standards and experimental trials. It started from the requirements of ISO 16373 for performing absorption tests and sound transmission loss of sandwich type of shingle tiles + EPS. The experimental procedure used to determine the sound absorption coefficient (α) was the method of the reverberation chamber in a diffuse field standardized by ASTM C423. The results showed behaviour with greater absorption (0.29) in a narrow band around 250 Hz and stabilized above 1600 Hz, with values similar to 0.06. These factors mean rank 1 according to the NBR 16373, in other words, the worst performance scale. Regarding the sound insulation test, performed according to ISO 10140 in reverberation room, it was quantified the Weighted Sound Reduction Index, Rw = 20 dB, above the expected performance because resulted close to the performance of other more valued tile commercially. The information given on NBR 16373: 2015 for the experimental analysis of sandwich tile are very incomplete, so difficult the tests. To facilitate implementation, minimizing errors due to erroneous interpretations of the techniques involved standards, we established a specific analysis methodology for trials in shingles or tiles. Therefore, it is proposed that the adequacy of samples of the tests, the individual analysis of each material that compose the shingle and evaluation of the two faces of the composite tiles, in order that they may have different types of finish (liner, liner-film, perforated panel, among others) and therefore the analysis of the lower tile becomes effective in assisting in the determination of the acoustic conditioning of the interior environments. Another suggestion is the evaluation of the rain impact noise on tiles. Finally, we reiterate the importance of the technical product information are clear and complete, allowing consumers to obtain adequate acoustic performance in their buildings. / Em áreas urbanas, onde o ruído é significativo, as fachadas e coberturas devem apresentar um desempenho capaz de garantir a isolação necessária para o conforto acústico dos usuários. As coberturas, embora sejam elementos importantes da envoltória das edificações, tem sido pouco estudadas na área de Acústica. A vigência da NBR 15575 Edificações habitacionais Desempenho impactou, principalmente, o setor de fornecedores da construção civil, que necessitaram caracterizar seus produtos e sistemas. Além disso, em 2015, surgiu a NBR 16373 Telhas e painéis termoacústico Requisitos de desempenho. A presente Dissertação teve como objetivo principal estabelecer uma metodologia de análise da performance acústica para telhas sanduíche, considerando padrões normativos e ensaios experimentais. Partiu-se das exigências da NBR 16373 para a execução dos ensaios de absorção e perda de transmissão sonora das telhas sanduíche do tipo telha + EPS. O procedimento experimental utilizado para a determinação do Coeficiente de Absorção Sonora (α) foi o método da câmara reverberante em campo difuso, normatizado pela ASTM C423. Os resultados mostraram um comportamento com maior absorção (0,29) numa faixa estreita em torno de 250 Hz e uma estabilização acima de 1600 Hz, com valores similares a 0,06. Tais coeficientes significam classificação 1, de acordo com a NBR 16373, ou seja, o pior desempenho da escala. No que tange ao ensaio de isolamento sonoro, executado de acordo com a ISO 10140, em câmara reverberante, foi quantificado o Índice de Redução Sonora Ponderado, Rw= 20 dB, desempenho acima do esperado, pois resultou próximo ao desempenho de outra telha mais valorizada comercialmente. As informações constantes na NBR 16373:2015 para a análise experimental da telha sanduíche são muito incompletas, por isso dificultam a realização dos ensaios. Para facilitar a execução, minimizando os erros decorrentes de interpretações equivocadas das normas técnicas envolvidas, estabeleceu-se uma metodologia de análise específica para ensaios realizados em telhas ou coberturas. Assim, propõe-se a adequação das amostras dos ensaios, a análise individual de cada material que compõe a telha e a avaliação das duas faces das telhas compostas, tendo em vista que elas podem possuir diferentes tipos de acabamento (forro, forro-filme, painel perfurado, entre outros) e, por isso, a análise da parte inferior da telha torna-se eficaz no auxílio da determinação do condicionamento acústico no interior de ambientes. Outra sugestão é a avaliação do ruído de impacto da chuva em telhas. Por fim, reitera-se a importância de que as informações técnicas sobre os produtos sejam claras e completas, permitindo que os consumidores finais possam obter um adequado desempenho acústico em suas edificações.
122

Effects of Architectural Features of Air-Permeable Roof Cladding Materials on Wind-Induced Uplift Loading

Li, Ruilong 23 April 2012 (has links)
Widespread damage to roofing materials (such as tiles and shingles) for low-rise buildings, even for weaker hurricanes, has raised concerns regarding design load provisions and construction practices. Currently the building codes used for designing low-rise building roofs are mainly based on testing results from building models which generally do not simulate the architectural features of roofing materials that may significantly influence the wind-induced pressures. Full-scale experimentation was conducted under high winds to investigate the effects of architectural details of high profile roof tiles and asphalt shingles on net pressures that are often responsible for damage to these roofing materials. Effects on the vulnerability of roofing materials were also studied. Different roof models with bare, tiled, and shingled roof decks were tested. Pressures acting on both top and bottom surfaces of the roofing materials were measured to understand their effects on the net uplift loading. The area-averaged peak pressure coefficients obtained from bare, tiled, and shingled roof decks were compared. In addition, a set of wind tunnel tests on a tiled roof deck model were conducted to verify the effects of tiles’ cavity internal pressure. Both the full-scale and the wind tunnel test results showed that underside pressure of a roof tile could either aggravate or alleviate wind uplift on the tile based on its orientation on the roof with respect to the wind angle of attack. For shingles, the underside pressure could aggravate wind uplift if the shingle is located near the center of the roof deck. Bare deck modeling to estimate design wind uplift on shingled decks may be acceptable for most locations but not for field locations; it could underestimate the uplift on shingles by 30-60%. In addition, some initial quantification of the effects of roofing materials on wind uplift was performed by studying the wind uplift load ratio for tiled versus bare deck and shingled versus bare deck. Vulnerability curves, with and without considering the effects of tiles’ cavity internal pressure, showed significant differences. Aerodynamic load provisions for low-rise buildings’ roofs and their vulnerability can thus be more accurately evaluated by considering the effects of the roofing materials.
123

Qallaline. Les revêtements céramiques des fondations beylicales tunisoises du XVIIIe siècle / Qallaline. Ceramic tile panelling in XVIIIth century Tunisian Beylical architecture

Álvarez Dopico, Ilham 28 November 2010 (has links)
Ce travail porte sur la production de carreaux de céramique des ateliers de la ville de Tunis, dits Qallaline, du XVIIIe siècle et sur leur application dans l’architecture beylicale contemporaine. La première partie de ce volume contient l’étude monographique de cette production céramique et privilège la mise en contexte historique et spatiale avec la fixation d’une chronologie raisonnée, l’établissement d’une typologie systématique des modèles de carreaux, l’analyse iconographique des motifs déployés sur les revêtements céramiques, avec l’étude de l’origine des motifs employés et de leur évolution, et finalement la définition des influences subies par les ateliers tunisois. Aussi, il est question de sa distribution à l’intérieur de la Régence ottomane de Tunis et de son exportation vers les Régences voisines ainsi que l’usage et les pratiques associées à l’emploi des revêtements céramiques tunisois dans l’architecture contemporaine dans l’Afrique du Nord. La deuxième partie de ce volume contient un catalogue des modèles de carreaux et de panneaux céramiques qui propose une classification ouverte et qui ne se cantonne pas au descriptif pour aborder l’interprétation. L’étude et la description formelle de cette production céramique concluent avec la définition stylistique de Qallaline comme expression d’un art ottoman provincial. / This PhD deals with the production of ceramic tiles from XVIII th century Tunisian Qallaline workshops and its use in the Beylical architecture of the time. The first part consist of a monographic study of this ceramics production, which, in turns, enables us to contextualize it both historically and geographically by means of setting a contrasted chronology and establishing a systematic typology of the different tile models. It also includes an iconographic analysis of the patterns present in the ceramic panelling, together with the study of their origin and evolution. Then, we focus on the foreign influences affecting Tunisian workshops. Finally, the distribution of this ceramic panelling within the Ottoman Regency of Tunisia and in the surrounding Regencies, as well as the use and practices associated with such Tunisian panelling in Northern African architecture in the XVIIIth century are also studied. The second part contains a catalogue of the different tiles and tile panels. This catalogue offers an open classification, which means that it does not consider only the mere description of the items it contains when giving an interpretation. The formal description and the study of this ceramics production has enabled us to define Qallaline from a stylistic point of view as an expression of Ottoman provincial art.
124

Problematika využití surovin na bázi skelných recyklátů / The study of utilization of raw materials based on glass recyclate

Bajer, Tomáš January 2018 (has links)
Presented work deals with the problem of solar glass waste recycling. In theoretical part recent EU regulation regarding waste management is presented. Different ways of PV panels recycling are explained as well as raw materials for glass production are listed. Differences between regular and solar glass is explained. In experimental part different recipes using solar glass waste and polymer binders are presented. Grindability was tested on specimen tiles. Potential of solar glass waste for manufacturing products with acoustic properties was examined.
125

Evaluating the Effects of Legacy Phosphorus on Dissolved Reactive Phosphorus Losses in Tile-Drained Systems

Pauline Kageha Welikhe (8803301) 07 May 2020 (has links)
<p>Eutrophication due to phosphorus (P) enrichment continues to be a primary water quality concern affecting freshwater and marine estuaries around the world. Excessive anthropogenic P inputs, driven by the need to meet the rising food and energy demands of a growing and increasingly urbanized population, have resulted in the buildup of P creating legacy (historical) P pools in agricultural landscapes. There is growing evidence that remobilization of accumulated legacy P can interfere with conservation efforts aimed at curbing eutrophication and improving water quality. Less is known about the magnitude and effects of these legacy P pools on dissolved reactive P (DRP) losses in tile-drained systems. This dissertation consists of three separate inquiries into how legacy P may affect DRP losses in tile drains. In the first inquiry, we examined the possibility of developing a suitable pedo-transfer function (pedoTF) for estimating P sorption capacity (PSC). Subsequent PSC-based indices (Phosphorus Saturation Ratio (PSR) and Soil Phosphorus Storage Capacity (SPSC)) were evaluated using daily water quality data from an in-field laboratory. The pedoTF derived from soil aluminum and organic matter accurately predicted PSC (R<sup>2</sup> = 0.60). Segmented-line models fit between PSR and soluble P (SP) concentrations in both desorption assays (R² = 0.69) and drainflows (R² = 0.66) revealed apparent PSR thresholds in close agreement at 0.21 and 0.24, respectively. Linear relationships were observed between negative SPSC values and increasing SP concentrations (R² = 0.52 and R<sup>2</sup> =0.53 respectively), and positive SPSC values were associated with very low SP concentrations in both desorption assays and drainflows. Zero SPSC was suggested as a possible environmental threshold. Thus, PSC-based indices determined using a pedoTF could estimate the potential for SP loss in tile drains. Also, both index thresholds coincided with the critical soil test P level for agronomic P sufficiency (22 mg kg<sup>-1</sup> Mehlich 3 P) suggesting that the agronomic threshold could serve as an environmental P threshold. In the second inquiry, PSC- based indices in addition to other site characteristics present in a P index (PI), were used as inputs in the development of a multi-layer feed-forward artificial neural network (MLF-ANN). The MLF-ANN was trained, tested, and validated to evaluate its performance in predicting SP loss in tile drains. Garson’s algorithm was used to determine the weight of each site characteristic. To assess the performance of ANN-generated weights, empirical data from an in-field laboratory was used to evaluate the performance of an unweighted PI (PI<sub>NO</sub>), a PI weighted using Lemunyon and Gilbert weights (PI<sub>LG</sub>), and an ANN-weighted PI (PI<sub>ANN</sub>) in estimating SP losses in tile effluent. The MLF-ANN provided reliable predictions of SP concentrations in tile effluent (R<sup>2</sup> = 0.99; RMSE = 0.0024). Soil test P, inorganic fertilizer application rate (FPR), SPSC, PSR, and organic P fertilizer application rate (OPR), with weights of 0.279, 0.233, 0.231, 0.097, and 0.084, respectively, were identified as the top five site characteristics with the highest weights explaining SP loss in tile discharge. These results highlighted the great contribution of both contemporary and legacy P sources to SP concentrations in tile discharge. Also, PI<sub>ANN </sub>was the only PI with a significant exponential relationship with measured annual SP concentrations (R<sup>2 </sup>= 0.60; p < 0.001). These findings demonstrated that MLF-ANNs coupled with Garson’s algorithm, can accurately quantify weights for individual site characteristics and develop PIs with a strong correlation with measured SP in tile discharge. Finally, in the third inquiry, we compared DRP loads and flow-weighted mean DRP (FDRP) concentrations in P source and P sink soils and evaluated the predominant DRP concentration – discharge (C-Q) behavior in these soils on a daily and event scale. At the daily scale, C-Q patterns were linked to the soil P status whereby a chemostatic and dilution behavior was observed for P source and P sink soils, respectively. At the event scale, C-Q patterns were linked to soil P status, flow path connectivity, and mixing of event water, matrix water, and rising shallow groundwater. The predominant anti-clockwise rotational pattern observed on P source soils suggested that, as the discharge event progressed, contributions from P poor waters including matrix and shallow groundwater resulted in lower DRP concentrations on the rising limb compared to the falling limb. However, the variable flushing and dilution behavior observed on the rising limb suggested that, in addition to discharge and soil P status, rapid exchanges between P pools, the magnitude of discharge events (Q), and the relative number of days to discharge peak (D<sub>rel</sub>) also regulated DRP delivery. On the other hand, the predominant non-hysteretic C-Q behavior in P sink soils suggest that DRP loss from these soils can be discounted. Our collective results highlight the need for nutrient and conservation practices focused on P drawdown, P sequestration, and P supply close to the crop needs, which will likely be required to convert P sources to sinks and to avoid the conversion of P sinks to sources. </p>
126

Časová kalibrace kalorimetru ATLAS/Tilecal pomocí jetů / Tine calibration of the ATLAS Tile Calorimeter using jets

Poláček, Stanislav January 2020 (has links)
The ATLAS experiment is one of the two general-purpose detectors at the Large Hadron Collider at CERN near Geneva. The goals of this particle physics experiment are the search for new physics phenomena and precision measurement of the particle interactions. Tilecal is the central hadronic calorimeter of the ATLAS. The calorimeter time calibration is important for the time-of-flight measurement of particles (used in some analyses) as well as for the actual energy reconstruction. 1
127

Evaluating drainage water recycling in tile-drained systems

Benjamin D Reinhart (8071469) 03 December 2019 (has links)
<p>Drainage water recycling (DWR) is the practice of capturing, storing, and reusing subsurface drained agricultural water to support supplemental irrigation and has recently been proposed as a practice for improving the crop production and water quality performance in the tile-drained landscape of the U.S. Midwest. This study describes the development of a modeling framework to quantify the potential irrigation and water quality benefits of DWR systems in tile-drained landscapes and the application of the model using ten years of measured weather, tile drain flow and nutrient concentrations, water table, and soil data from two sites in the U.S. Midwest. From this modeling framework, the development and testing of an open-source online tool is also presented.</p><p></p><p>A spreadsheet model was developed to track water flows between a reservoir and drained and irrigated field area at each site. The amount of tile drain flow and associated nutrient loads that could be captured from the field and stored in the reservoir was estimated to calculate the potential water quality benefits of the system. Irrigation benefits were quantified based on the amount of applied irrigation annually. A reservoir size representing 6% to 8% of the field area with an average depth of 3.05 m was sufficient in meeting the annual irrigation requirements during the 10-year period at each site. At this reservoir size, average annual nitrate-N loads were reduced by 20% to 40% and soluble reactive phosphorus loads by 17% to 41%. Variability in precipitation within and across years, and differences in soil water characteristics, resulted in a wide range of potential benefits at the two sites.</p><p>An online tool was developed from the model, and a variance-based global sensitivity analysis was conducted to determine influential and low-sensitivity input parameters. The input parameter, depth of root zone, was the most influential input parameter suggesting that the estimation of total available water for the field water balance is a critical component of the model. Input settings describing the irrigation management and crop coefficients for the initial establishment and mid-season crop growth periods were also influential in impacting the field water balance. Reservoir seepage rate was influential in regard to the reservoir water balance, particularly at larger reservoir sizes. Sensitivity analysis results were used to develop a user-interface for the tool, Evaluating Drainage Water Recycling Decisions (EDWRD).</p><p>This study shows that DWR is capable of providing both irrigation and water quality benefits in the tile-drained landscape of the U.S. Midwest. The developed modeling framework supports future research on the development of strategies to implement and manage DWR systems, and the online tool serves as a resource for users to increase their awareness and understanding of the potential benefits of this novel practice.</p><p></p>
128

Movements

Johnsson, Anders January 2019 (has links)
This thesis project explores the question of the death of architecture; the declaration of the lost abilities of architecture to achieve political influence and the architect as a social actor. As I have found myself in agreement with this Tafurian perspective on the subject, I wanted to use this thesis project to explore the question of architecture and its political potential, as well as breaking from the paralyzing condition of the incentives of architecture's incapabilities. This, in suggesting that architecture can act as a catalyst for doing things differently. The project investigates, on the one hand,  how a building can encourage political action and engagement, and, on the other, how ideological ideas and intentions can concretize spatially, materially and aesthetically, The project is an design exploration concretized in a specific architectural proposal – a building for a political organization operating in the city of Stockholm.
129

[pt] COMPÓSITOS LAMINADOS ARTESANAIS DERIVADOS DO FIBROBARRO APLICADOS COMO REVESTIMENTOS E VEDAÇÕES EM ESTRUTURAS ADAPTÁVEIS DE BAMBU E EM SISTEMAS DE COBERTURAS RESIDENCIAIS / [en] HANDMADE ROLLED DERIVED FIBROBARRO APPLIED AS COATINGS AND SEALS IN ADAPTIVE STRUCTURES OF BAMBOO

VICENTE JESUS DOS SANTOS RAMILO 24 September 2019 (has links)
[pt] A pesquisa aborda métodos e técnicas para desenvolvimento de compósitos laminados concebidos a partir de materiais naturais, derivados de técnicas construtivas vernaculares e mais especificamente de técnica denominada de Fibrobarro, direcionadas às comunidades rurais. Estas técnicas utilizam materiais encontrados na natureza e em especial no próprio LILD, modos de fazer comuns das regiões rurais, seguindo a metodologia empírica, traduzida em novos conceitos de design participativo, que determina vivências e convivências que influenciam as relações sociais de ensino e trabalho destas comunidades. O conjunto de métodos e técnicas utilizados ao longo da pesquisa contribui para o processo de desenvolvimento dos compósitos, no qual se aplica a metodologia projetual do LILD, que segue o uso de tecnologias limpas de baixo impacto ambiental e o uso de materiais regionais, objetivando a sustentabilidade no processo e no uso. Os resultados obtidos nos ensaios e experimentos, ao longo da pesquisa, demonstraram a existência de possibilidade de aplicação destes materiais feitos com terra crua, fibras naturais e poliuretano vegetal para atenderem demandas reais na construção de objetos de design e arquitetura, gerando novos materiais e técnicas que substituam as demandas tradicionais que usam materiais convencionais. Descobriu-se no material enorme potencial de uso, tanto em processos bioconstrutivos, que utilizam estruturas adaptáveis feitas com bambu; sujeitos a menores carregamentos como revestimento e vedação, tais como painéis e divisórias e mais especificamente como telhas em sistemas de coberturas residenciais; como em processos construtivos convencionais. / [en] The research deals with methods and techniques for development of composites laminates designed from natural materials, derived from vernacular building techniques and more specifically of technique called Fibrobarro, directed at rural communities. These techniques use materials found in nature and in particular own LILD, ways of doing common rural regions, following the empirical methodology, translated into new concepts of participatory design, which determines experiences and relationships that influence the social relations of teaching and work of these communities. The set of methods and techniques used throughout the research contributes to the development process of composites, in which applies the design methodology of LILD, which follows the use of clean technologies for low environmental impact and the use of materials regional, aiming at sustainability in the process and in use. The results obtained in the tests and experiments, over the poll, demonstrated the existence of possibility of application of these materials made with raw land, natural fibers and vegetal polyurethane to meet actual demands in the construction of objects of design and architecture, creating new materials and techniques that replace traditional demands that use conventional materials. It was discovered in the huge potential of material use, both in bioconstructives processes, which use adaptive structures made with bamboo; subject to smaller shipments as coating and sealing, such as panels and partitions and more specifically as tiles in residential roofing systems; as in conventional construction processes.
130

Demonstrating reliableinstrumentation in theATLAS Tile Calorimeter : Fault tolerance and redundancy in hardware and firmwarefor the Phase-II Demonstrator project in preparation forHigh Luminosity LHC at CERN

Åkerstedt, Henrik January 2024 (has links)
The Large Hadron Collider at CERN is scheduled to undergo upgrades in 2026-2028 to significantly increase its luminosity. These upgrades, while providing the experiments with a higher collision rate, pose a number of challenges to the design of the hardware and software in the detectors. The Tile Calorimeter (a scintillating sampling calorimeter read out by photomultiplier tubes) at the ATLAS experiment will have its read-out electronics completely replaced to enable performance and reliability improvements.  Advances in electronics, new requirements due to the luminosity upgrade as well as lessons learned from the current readout scheme drove development with the goals to partition the readout into small independent units with full granularity readout and a robust mitigation strategy for radiation induced errors. To verify the functionality of the new system while retaining backward compatibility a "Demonstrator'' has been developed to emulate the current functionality while using new and improved hardware. The board responsible for managing digitized calorimeter data and communicating with the off-detector electronics, called the DaughterBoard, is the main focus of this thesis. It has two electrically isolated sides for redundancy where each side consists of voltage regulators, two optical transceivers, a GigaBit transceiver chip (for clocking and configuration) and a Kintex FPGA for data processing. In addition to data management and transmission, the FPGA (and every other component) needs to be able to withstand the effects of radiation both in terms of total dose (ionization and displacement damage) and due to single event effects. The DaughterBoard was developed with this in mind and has undergone several radiation tests during its development to verify reliability and fault tolerance. / CERN

Page generated in 0.4376 seconds