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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.
201

Zwei Anwendungsbeispiele für Textilbeton

Brameshuber, Wolfgang, Mott, Rebecca 03 June 2009 (has links) (PDF)
In dieser Veröffentlichung werden 2 Anwendungsbeispiele für Textilbeton vorgestellt, ein nachträgliches Abdichtungssystem sowie eine bauteilintegrierte Schalung. Teil 1: Da in vielen Regionen Deutschlands steigende Grundwasserspiegel zu verzeichnen sind und bestehende Gebäude, die nicht für den Belastungsfall „drückendes Wasser“ ausgelegt sind, mit einem tragfähigen nachträglichen Abdichtungssystem ertüchtigt werden müssen, wurde ein entsprechendes Abdichtungssystem aus Textilbeton entwickelt. Durch die Verwendung des Textilbetons ist es möglich, ein Abdichtungssystem mit einer geringen Bauteilstärke von 30 mm im Spritzverfahren herzustellen. Teil 2: Die bauteilintegrierte Schalung (BIS) aus Textilbeton nimmt während der Betonage den Frischbetondruck auf. Im Endzustand bildet sie die Bauteiloberfläche und kann Anforderungen hinsichtlich Tragfähigkeit, Sichtbeton- und Oberflächenqualität sowie Oberflächenausbildung (Farbe, Struktur) erfüllen. BISElemente können werksmäßig wirtschaftlich und qualitativ hochwertig hergestellt werden.
202

Etude des caractéristiques physico-chimiques de nouveaux bétons éco-respectueux pour leur résistance à l'environnement dans le cadre du développement durable

Bur, Nicolas 05 September 2012 (has links) (PDF)
La compréhension des mécanismes à l'origine de la formation de la porosité et de ses propriétés dans les matériaux cimentaires est un enjeu majeur pour l'évaluation de leur durabilité. L'utilisation des laitiers de haut fourneau comme liant hydraulique modifie les phases formées, leur proportion et la microstructure des mortiers et bétons. Il reste un grand nombre de verrous scientifiques à lever concernant les paramètres modifiant les valeurs de porosité, le rayon des capillaires et, par conséquent, la perméabilité. Des échantillons de mortiers ont été réalisés avec différents mélanges de CEM I et de laitiers de haut-fourneau puis différentes cures ont été utilisées afin d'évaluer l'influence de la baisse de la température ou de l'hygrométrie sur la géométrie de leur porosité. Différentes techniques d'analyses de porosité et de perméabilité ont permis de mettre en évidence principalement une augmentation de la porosité totale et libre, des rayons des capillaires et de la perméabilité avec l'augmentation de la proportion de laitier et la diminution de l'hygrométrie. Des observations au microscope électronique à balayage à pression de vapeur d'eau contrôlée ont permis de montrer le lien entre l'ouverture des capillaires et l'hygrométrie. Ainsi les forces exercées par les pressions de disjonction et les pressions capillaires déforment les hydrates de manière à fermer les capillaires avec l'augmentation de l'hygrométrie. La mise au point d'une méthode originale de cartographie de la porosité à partir de données de conductivité thermique a permis de confirmer la présence d'une peau et de déterminer son étendue. Grâce à cette technique, il est possible d'évaluer la distribution des taux de porosité au travers des échantillons. De plus, une nouvelle approche d'analyse a permis de cartographier à partir du même modèle la distribution des proportions relatives de granulats.
203

Submerged Transmission in Wave Energy Converters : Full Scale In-Situ Experimental Measurements

Strömstedt, Erland January 2012 (has links)
Different wave power technologies are in development around the world in different stages of prototype testing. So far only a few devices have been deployed offshore at full scale for extended periods of time. Little data is published about how these different devices perform. This thesis presents results from experiments with the full-scale offshore wave energy converters at the Lysekil research site on the Swedish west coast. The theories, experiments, measurements, performance evaluations and developments of the submerged transmission in the direct driven permanent magnet linear generator are in focus. The reciprocating submerged transmission fulfills the purpose of transmitting the absorbed mechanical wave energy through the capsule wall into the generator, while preventing the seawater from entering the capsule and reducing the life time of the converter. A measuring system with seven laser triangulation sensors has been developed to measure small relative displacements between piston rod and seal housing in the submerged transmission with excellent accuracy for the purpose of evaluating both functional behavior and successive wear in-situ. A method for calculating relative tilt angles, azimuth angles, differential tilt angles, and successive wear in the submerged transmission has been developed. Additional sensors systems have been installed in the converter enabling correlation and a thorough investigation into the operating conditions of the transmission and the converter. The thesis presents unique results from the measurements. A data acquisition system transmits the signals from the converter on the seabed to an onshore measuring station. Results are presented in time-, frequency- and the time-frequency domain. The results have given important information for further development of the submerged transmission, which is important to the survivability of the system. The thesis describes the status of research, and is a step that may influence future designs of wave energy devices for reaching survivability and a cost-effective renewable energy system. / <p>Published is a preprint version of the full text and should be combined by the errata.</p> / The Lysekil Wave Power Project
204

Nuu-Chah-Nulth labour relations in the pelagic sealing industry, 1868-1911

Crockford, Cairn Elizabeth January 1996 (has links) (PDF)
No description available.
205

Synthesis and Characterization of Ordered Mesoporous Silica with Controlled Macroscopic Morphology for Membrane Applications

January 2011 (has links)
abstract: Ordered mesoporous materials have tunable pore sizes between 2 and 50 nm and are characterized by ordered pore structures and high surface areas (~1000 m2/g). This makes them particularly favorable for a number of membrane applications such as protein separation, polymer extrusion, nanowire fabrication and membrane reactors. These membranes can be fabricated as top-layers on macroporous supports or as embedded membranes in a dense matrix. The first part of the work deals with the hydrothermal synthesis and water-vapor/oxygen separation properties of supported MCM-48 and a new Al-MCM-48 type membrane for potential use in air conditioning systems. Knudsen-type permeation is observed in these membranes. The combined effect of capillary condensation and the aluminosilicate matrix resulted in the highest separation factor (142) in Al-MCM-48 membranes, with a water vapor permeance of 6×10-8mol/m2&#61655;Pa&#61655;s. The second part focuses on synthesis of embedded mesoporous silica membranes with helically ordered pores by a novel Counter Diffusion Self-Assembly (CDSA) method. This method is an extension of the interfacial synthesis method for fiber synthesis using tetrabutylorthosilicate (TBOS) and cetyltrimethylammonium bromide (CTAB) as the silica source and surfactant respectively. The initial part of this study determined the effect of TBOS height and humidity on fiber formation. From this study, the range of TBOS heights for best microscopic and macroscopic ordering were established. Next, the CDSA method was used to successfully synthesize membranes, which were characterized to have good support plugging and an ordered pore structure. Factors that influence membrane synthesis and plug microstructure were determined. SEM studies revealed the presence of gaps between the plugs and support pores, which occur due to shrinking of the plug on drying. Development of a novel liquid deposition method to seal these defects constituted the last part of this work. Post sealing, excess silica was removed by etching with hydrofluoric acid. Membrane quality was evaluated at each step using SEM and gas permeation measurements. After surfactant removal by liquid extraction, the membranes exhibited an O2 permeance of 1.65x10-6mol/m2.Pa.s and He/O2 selectivity of 3.30. The successful synthesis of this membrane is an exciting new development in the area of ordered mesoporous membrane technology. / Dissertation/Thesis / Ph.D. Chemical Engineering 2011
206

A Systematic Evaluation of Fault Seal Integrity in the southern Pletmos Basin, offshore South Africa: A 3D Multidisciplinary Modelling Approach

Mhlambi, Sanelisiwe January 2017 (has links)
Magister Scientiae - MSc (Earth Science) / The syn-rift succession encompasses the primary exploration target in the southern Pletmos Basin. Several fault-bounded structural traps that contain gas accumulations have been discovered within this succession. Likewise, ubiquitous residual gas shows have been encountered in most drilled wells. Yet, the impact of faults on fluid flow is poorly understood. Therefore, this study aspires to predict, and where possible, quantify fault seal integrity and sealing capacities of some of the major prospect-bounding faults. A multi-disciplinary research strategy was employed in order to fulfil the study objectives. Fault mapping and geo-cellular modelling using geostatistical algorithms were undertaken to provide the basic geometric and structural input for more advanced fault seal analysis applications. Juxtaposition analysis was carried out to identify zones with a high probability to seal (or leak) and as the first-order tool for predicting fault seal potential. Threshold pressures, hydrocarbon column heights, cross-fault permeability and transmissibility were used to estimate the sealing capacities of the faults. In addition to juxtaposition and customary fault-rock properties, the study also analysed parameters that can be deemed to be representative of cross-fault fluid flow (i.e. effective cross-fault permeability and transmissibility; ECFP and ECFT). Finally, modelling of the geo-history facilitated the validation of the properties that underpinned fault seal analysis studies. The Ga-Q and proposed Ga-K prospects along with their main bounding faults formed the foci of the fault seal analysis results. The analysed faults showed excellent initial sealing potential due to either favourable juxtaposition or shale gouge development. Nonetheless, predicted hydrocarbon column heights and threshold pressures were low suggesting that the seal integrity of the analysed faults is predisposed to failure. In addition, high predicted fault permeability and transmissibility values signify the presence of open and permeable fracture networks within the fault zones. Thus, it is proposed that the faults are very likely to have leaked during hydrocarbon migration and filling of traps resulting in empty or under-filled hydrocarbon reservoirs.
207

Estudo das ligações entre pilares de concreto e alvenaria cerâmica de vedação

Jodas, Marcela [UNESP] 19 December 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:25:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-19Bitstream added on 2014-06-13T20:13:41Z : No. of bitstreams: 1 jodas_m_me_ilha.pdf: 1356266 bytes, checksum: 018e99760788ea15eba777612fafa224 (MD5) / Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA) / As estruturas de concreto armado vêm se tornando cada vez mais esbeltas, aliadas ao menor tempo de execução das edificações e aos menores prazos de execução da fixação da alvenaria na estrutura, cada vez com mais freqüência observa-se a formação dos estados patológicos nas alvenarias. As estruturas de concreto armado apresentam progressivamente deformações mais acentuadas, fazendo com que as paredes de vedação trabalhem, oferecendo resistência a esses deslocamentos surgindo assim patologias que se apresentam na forma de fissuras na interface pilar/alvenaria. Desse modo, surge a necessidade de estudos das ligações empregadas na interface pilar/alvenaria, que têm por objetivo “solidarizar” estrutura e alvenaria, distribuindo as deformações excessivas da estrutura que se traduzem na forma de fissuras e com isso diminuir a ocorrência de patologias nas alvenarias de vedação. Para tal, foram desenvolvidos ensaios de diferentes formas de ligação da interface pilar/alvenaria de modo a avaliar a eficiência dos dispositivos empregados no mercado da construção de edifícios de São Paulo atualmente, como a tela metálica eletrosoldada. Numa primeira etapa foram realizados ensaios de arrancamento direto à tração, de modo a se estudar o comportamento do dispositivo quando submetido ao esforço de tração. Foram ensaiados também prismas de alvenaria, com diferentes dispositivos de ligação inseridos de modo a se avaliar as resistências à tração das ancoragens inseridas na junta de argamassa, e numa terceira etapa, foram realizados ensaios em pequenas paredes, para se determinar o desempenho das ancoragens na ligação de paredes e pilares de concreto armado, na situação real. / Structures of reinforced concrete are becoming more slender, associated to the short time of building construction and with the lesser periods of masonry fixation in the structure, each time with more frequency can be observed the formation of pathological state in masonry. The structures of reinforced concrete progressively presents more accentuated deformation, making masonry to work, offering strength to these displacements, creating pathology that appears like cracks in the interface of column/masonry. Thus, it is necessary to study the bonds used in the interface column/masonry, wich has as objective “join” the structure and the masonry, spreading the excessive deformations of the structure that comes up as cracks, and diminishing the occurrence of damages in the forbid masonry. In order to do this, different tests in the interface column/masonry were developed in order to evaluate the efficiency of device used in the civil construction in São Paulo, as tela metálica eletrosoldada. In the first step, pull-out tests were done to sutdy the behavior of the device when submitted to a tensile strength. Prisms were also tested, with different kinds of bond gadgets inserted in order to evaluate the resistance in a traction of devices in the anchorages inserted in the grouts, and in a third step, small walls were tested to analyze the behavior of anchorages in the bond of wall and column, in the real situation.
208

Contribuição ao estudo do fosfogesso comparativamente a algumas propriedades do gesso mineral

Brondino, João Ailton 16 June 2014 (has links)
Made available in DSpace on 2016-06-02T20:09:22Z (GMT). No. of bitstreams: 1 6502.pdf: 4166416 bytes, checksum: ff381c88fdd0ab873e2762ec96c7288f (MD5) Previous issue date: 2014-06-16 / Financiadora de Estudos e Projetos / The phosphogypsum is calcium sulfate (gypsum chemical), generated as waste in industrial production of phosphoric acid, the main raw material for the production of phosphate fertilizers. Is generated on a large scale, and to produce one ton of phosphoric acid are generated many tons of phosphogypsum, depending on the composition of the phosphate rock used. In Brazil are generated annually million tons and disposed in landfill or dumpsites sites without suitable destination for the volume generated, which represents a major environmental liability and worsens, progressively, with the need for increased food production. Thus, this research aimed to determine a relationship between temperature and phosphogypsum the calcination time, to study the possibility of adapting their use in construction. For this, calcined phosphogypsum samples were produced with different combinations of temperature and time, and, then were used in the preparation of the molded specimens. These were evaluated in mechanical tests (compressive strength and tensile strength in bending) and physical (water absorption). The best combination of temperature and calcination time was 159°C and 120 minutes, results that expressed the highest mechanical resistance to bending and compression, and the water absorption index met the Brazilian standards adopted in the recommendations for blocks concrete and blocks ceramic. The scientific contribution of this work will be important not only for building, but for the sustainability of the planet, because an industrial waste that is generated in large quantities, can become raw material for the production of building components for buildings, will avoid the need of new controlled landfill sites for its disposal and also, where an industrial residue replaces a raw material, it is noteworthy that, besides the use and eliminate waste landfills, we will stop exploring the raw material replaced, prolonging the "lifespan" the same and/or preserving of areas exploration. / O fosfogesso é um sulfato de cálcio (gesso químico), gerado como resíduo na produção industrial de ácido fosfórico, principal matéria-prima para a produção de fertilizantes fosfatados. É gerado em grande escala, sendo que para produzir uma tonelada de ácido fosfórico são geradas muitas toneladas de fosfogesso, dependendo da composição da rocha fosfática utilizada. No Brasil são geradas anualmente milhões de toneladas e dispostas em aterros a céu aberto, sem destino adequado para o volume gerado, o que representa um grande passivo ambiental e que se agrava, progressivamente, com a necessidade do aumento da produção de alimentos. Assim, essa pesquisa teve como objetivo determinar uma relação entre a temperatura e o tempo de calcinação do fosfogesso para estudar a possibilidade de adequar a sua utilização na construção civil. Para isso, foram produzidas amostras de fosfogesso calcinado com diferentes combinações de temperatura e tempo, e que foram utilizadas na preparação dos corpos de prova. Estes foram avaliados em testes mecânicos (resistência à compressão e à tração na flexão) e físicos (absorção de água). A melhor combinação entre temperatura e tempo de calcinação foi 159°C e 120 minutos, resultados que expressaram as maiores resistências mecânicas à flexão e à compressão, e o índice de absorção de água atendeu às normas brasileiras adotadas nas recomendações para blocos de concreto e blocos cerâmicos. A contribuição científica deste trabalho será importante não só para a construção civil, mas para a sustentabilidade do planeta, pois um resíduo industrial que é gerado em grande quantidade, poderá se tornar matéria-prima para a confecção de elementos construtivos para edificações, evitará a necessidade de novos aterros controlados para a sua disposição e também, sempre que um resíduo industrial substitui uma matéria prima, é importante salientar que, além do uso do resíduo e eliminação de aterros, deixamos de prospectar a matéria prima substituída, prolongando a vida útil da mesma e/ou preservando áreas de exploração.
209

Envelhecimento populacional e reforma da política de aposentadoria no regime geral de previdência social

Diniz, Matheus Brito Nunes 03 June 2016 (has links)
Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-09-29T13:30:30Z No. of bitstreams: 1 arquivototal.pdf: 2273676 bytes, checksum: 395afcdce6b9bf66887ff35fee446def (MD5) / Made available in DSpace on 2017-09-29T13:30:30Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2273676 bytes, checksum: 395afcdce6b9bf66887ff35fee446def (MD5) Previous issue date: 2016-06-03 / Faced with the continuing decline in population work mass activity, in contrast to the growing number of retirees, the financial and actuarial balance of the entire system of public security is called into question, demanding measures to enable the rebalancing of this scale. The question becomes even more delicate by the political and ideological choice of the brazilian constituent legislator, which adopted a pay-as-you-go system of social security financing model, sustained by the principle of social solidarity and dependent on social contributions made by the economically active population to accomplish their commitments. Thus, the objective is to study some of the major legal reforms suggested within the retirement policy for age and contribution time now practiced by RGPS, especially because of Brazil's new age setting, whose population undergoes with a fast aging process. Through an essentially bibliographic research, there has been produced an analysis of the problems above, in attempt to highlight the main aspects that may lead to the affirmation of a social security currently lagging in structural terms. It is observed that, while a neuralgic public policy for the country, RGPS has not followed the national demographic dynamics. Facing that process undergoes, inevitably, by reviewing the rules of access to retirement by age and contribution time, that is, which is presented as a measure of adaptation of RGPS rules to the new characteristics of a people living longer and better. In addition to its perfect compatibility with the brazilian legal system, these changes also represent a rereading of the breakthrough concept of social protection, in which the tightening of the rules means, in Brazil and in other countries experiencing the same phenomenon, the preservation of pension system for future generations. / Diante da contínua redução da massa trabalhadora em atividade, em contraposição ao número crescente de aposentados, o equilíbrio financeiro e atuarial de todo o sistema público de previdência é posto em xeque, demandando, nessa esteira, medidas que possibilitem o reequilíbrio dessa balança. A questão se torna ainda mais delicada pela escolha político-ideológica do legislador constituinte brasileiro, que adotou a repartição simples como sistema de financiamento dos gastos previdenciários, modelo este calcado no postulado da solidariedade social e dependente das contribuições sociais vertidas pela população economicamente ativa para a quitação de seus compromissos. Desse modo, objetiva-se estudar algumas das principais de reformas jurídicas sugeridas no seio da política de aposentadoria por idade e por tempo de contribuição ora praticada pelo RGPS, sobretudo em face da nova configuração etária brasileira, cuja população passa por rápido processo de envelhecimento. Através de uma pesquisa essencialmente bibliográfica, produziu-se uma análise sobre a referida problemática, procurando realçar os principais aspectos que podem conduzir à afirmação de uma previdência social atualmente defasada em termos estruturais. Observa-se que, enquanto política pública nevrálgica para o país, o RGPS não tem acompanhado a dinâmica demográfica nacional. O enfrentamento a esse processo passa, inevitavelmente, pela revisão das regras de acesso à aposentadoria por idade e por tempo de contribuição, que se apresenta como medida de adaptação das regras do RGPS às novas características de um povo que vive por mais tempo e com mais qualidade. Além de sua compatibilidade com o ordenamento jurídico pátrio, tais mudanças representam, também, uma releitura da noção de avanço na proteção social, no qual o endurecimento das regras significa, no caso brasileiro e nos demais países que passam pelo mesmo fenômeno, a preservação do sistema previdenciário para as futuras gerações.
210

Desenvolvimento de selantes vitrocerâmicos para uso em SOFC pertencentes ao sistema BAS (BaO-Alsub(2)0sub(3)-SiOsub(2)) modificados com Bsub(2)Osub(3) / Development of glass ceramic sealants for use in SOFC belonging to BAS (BaO-Alsub(2)0sub(3)-SiOsub(2)) system modified with Bsub(2)Osub(3)

SILVA, MAVIAEL J. da 10 April 2015 (has links)
Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-04-10T16:38:07Z No. of bitstreams: 0 / Made available in DSpace on 2015-04-10T16:38:07Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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