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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.
41

Experimento de fluxo de sedimentos em um segmento de campo de dunas e?licas costeiras de Jenipabu - Litoral oriental do Rio Grande do Norte.

Malta, J?lia Varella 06 September 2012 (has links)
Made available in DSpace on 2015-03-13T17:08:35Z (GMT). No. of bitstreams: 1 JuliaVM_DISSERT.pdf: 4236567 bytes, checksum: be73f658e3777fffb5d25f1a4d23b8d3 (MD5) Previous issue date: 2012-09-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study analyzed measurements of the aeolian transport using vertical sand traps across the field dunes of Jenipabu, in the municipality of Extremoz, Rio Grande do Norte state to the North of Natal city. These measurements were used as parameters for the sand aeolian transport in the region. Before the field trips a map of landscape units was made. Three visits to the field were done in September 2011 (field a - the 13th, field b - the 21st, field c - the 29th), period of the year with the highest wind speed, and another in December 8th, 2011 (field d ) when the wind speed starts to decrease. The sand traps used were of the type "I" with collecting opening of 25 cm from the surface level, and type "S" with collecting opening of 25 cm located 25 cm from the surface level in six collecting points in two of the visits (fields a and d ), and sand traps of the type "T" with the collecting opening of 50 cm from the surface level in the other field trips (fields "b" and "c"). A set of records was also collected by using a portable meteorological station complemented with information such as frequency and intensity of winds, precipitation and relative air humidity in the region, from the Esta??o Meteorol?gica de Natal , located 12 km from the study area. The sediments collected were treated and the data obtained permitted calculating the ratio of sediment transport. In September, the sedimentation ratio varied from 0.01 to 11.39 kg.m-1.h-1 and in December this ratio varied from 0.33 to 1.30 kg.m-1.h-1 in the type T collectors. In type I collectors they ranged from 0.01 to 11.39 kg.m-1.h-1, while the same parameters varied from 0.01 to 0.73 kg.m-1.h-1 in type S collector. Based on the statistical analysis done, we concluded that the sediment transport increased proportionally to the wind speed 25 cm from the surface. However, this is not true above 25 cm from the surface. The transport of sediments is more intense near the surface where sedimentation ratios greater than 10 kg.m-1.h-1 were found, whilst a maximum value of 3 kg.m-1.h-1 was observed 25 cm below the surface. The volume of sediments collected increases with the increasing wind speed at the surface level, whereas this relationship is opposed far away from that surface / O presente estudo fez a an?lise de medidas de transporte e?lico utilizando coletores de areia verticais (Sand Traps) ao longo de um campo de dunas na praia de Jenipabu, munic?pio de Extremoz no estado do Rio Grande do Norte ao Norte da cidade de Natal. Estas medidas foram utilizadas como par?metro de avalia??o da movimenta??o e?lica nesta regi?o. Tr?s visitas a campo foram realizadas no m?s de setembro de 2011 nos dias 13 (campo "a"), 21 (campo "b") e 29 (campo "c"), per?odo do ano com maiores velocidades de vento e uma em dezembro de 2011 no dia 08 (campo "d"), per?odo onde a velocidade do vento come?a a diminuir. Utilizaram-se coletores tipo "I" com abertura de 25 cm a partir do n?vel da superf?cie e "S" com abertura de 25 cm a 25 cm da superf?cie em seis pontos de coleta em duas das visitas ? campo nos dias 13 de setembro (campo "a") e 08 de dezembro (campo "d"), e tipo "T" com abertura de 50 cm a partir do n?vel da superf?cie nas demais visitas 21 e 29 de setembro (campo "b" e "c") ao longo do Campo de Dunas de Jenipabu. Foram tamb?m coletados dados meteorol?gicos com a utiliza??o de esta??o meteorol?gica port?til e complementados com dados da Esta??o Meteorol?gica de Natal que est? localizada a cerca de 12 km da ?rea de estudo para obter informa??es sobre a frequ?ncia e intensidade dos ventos, precipita??o e umidade relativa do ar da regi?o. Os sedimentos coletados foram tratados e foi calculada a vaz?o de fluxo de sedimentos (taxa de sedimenta??o). Em setembro a taxa sedimenta??o variou de 0,01 at? 11,39 Kg m-1 h-1 e em dezembro entre 0,33 e 1,30 Kg. m-1. h-1 nos coletores tipo "T". Nos coletores tipo "I" esses valores variaram entre 0,01 e 11,39 Kg m-1 h-1, enquanto que nos coletores tipo "S" de 0,01 a 0.73 Kg. m-1. h-1. De acordo com a an?lise estat?stica realisada percebe-se que o transporte de sedimento aumentou proporcionalmente a velocidade do vento em at? 25 cm da superf?cie. Por?m, essa rela??o n?o ? verdadeira acima de 25 cm do n?vel da superf?cie. O transporte de sedimentos ? mais intenso mais pr?ximo ? superf?cie onde foram encontradas taxas de sedimenta??o maiores que 10Kg. m-1. h-1 enquanto que a 25cm de dist?ncia o m?ximo encontrado foi menor que 3Kg. m-1. h-1, a quantidade de sedimento coletados aumenta ? medida que aumenta a velocidade no n?vel da superf?cie, ao se afastar da superf?cie a quantidade de sedimento essa rela??o n?o ? verdadeira
42

Modélisation complexe des interactions entre la végétation et le déplacement des sédiments

Gauvin-Bourdon, Phillipe 05 1900 (has links)
Les environnements arides végétalisés seront parmi les environnements les plus impactés par la désertification dans le cadre du changement climatique. Ces environnements légèrement végétalisés sont caractérisés par une balance précaire entre un état de résilience et de vulnérabilité qui est intrinsèquement menacé par la désertification pouvant potentiellement mener à une augmentation du transport des sédiments éolien et une dégradation des environnements. Le nombre d’interactions présentes entre la végétation, la pluie, le transport des sédiments et la présence d’herbivore en milieu aride, ainsi que leur nature non-linéaire rend difficile de représenter ces interactions à l’aide de modèle physique et mathématique. La modélisation complexe est mieux adaptée à la représentation des interactions complexes entre la végétation, la pluie, le transport des sédiments et la présence d’herbivores dans les systèmes arides. Un nombre considérable d’études ont utilisées les modèles complexes pour étudier l’effet de la végétation sur le transport des sédiments ou l’effet de la présence d’herbivore sur la végétation, mais peu d’études ont utilisées une approche intégrant ces trois composantes en un même modèle. Un nouveau modèle d’herbivorie basé sur l’agent (GrAM) est présenté sous forme d’extension du modèle ViSTA_M17 et permet une meilleure représentation de l’impact des régimes de pâturage en environnement aride végétalisé. Cet ajout ayant un modèle complexe de transport des sédiments et de végétation déjà établit vise présenter un modèle hybride pouvant représenter l’impact de l’herbivorie sur la composition végétale et le transport des sédiments en environnement aride à l’échelle du paysage. Le développement du nouveau module à l’intérieur de la structure du modèle ViSTA original a souligné certaines limites de ce dernier, notamment une sensitivité importante de la végétation et de la force de cisaillement du vent. Le modèle ViSTA_GrAM répond à certaines limites du modèle original par l’intégration d’un nouveau module d’herbivorie et présente une avancée vers une modélisation environnementale englobante permettant une meilleure compréhension des dynamiques spatiales et temporelles des environnements arides. L’approche englobante utilisée par le modèle ViSTA_GrAM est bénéfique à la prise de décision, puisqu’elle offre un outil permettant d’explorer les réponses des environnements arides à un changement de leur végétation, leur régime de pluie, leur régime de transport des sédiments ou leur régime d’herbivorie. Les modèles complexes et l’exploration de scénarios futurs des environnements arides peuvent permettre d’améliorer la gestion de ces mêmes environnements. / Vegetated arid environments will be among one of the most affected by desertification as a result of climate change. These sparsely vegetated regions exhibit a delicate balance of resilience and vulnerability that are profoundly challenged by desertification, potentially producing an important positive feedback leading to increased aeolian activity and therefore land degradation. The high level of interaction between rainfall, vegetation, sediment transport and grazing in these arid environments and the non-linear nature of these interactions make them difficult to predict by traditional mathematical modeling mean. Complex modeling, on the other hand, offer better representation of the intricate relation between vegetation, rainfall, sediment transport and grazing in an arid environment system. A sizable amount of studies has been conducted with complex models to explore the effect of vegetation on sediment transport or grazing effect on vegetation, but few have used a truly integrative approach where all tree components were represented in a complex model. This research present a novel agent-based model (GrAM) integrated as an extension to already complete sediment transport-vegetation complex model (ViSTA) allowing a more refined representation of grazer’s impact in vegetated arid environments. This addition to the ViSTA model is aimed to combine a land management and systematic approach in a coupled model, to represent, at a landscape level, the impact of grazing on the composition of vegetation and sediment movement in arid environments. The development of this new module within the original ViSTA model, has highlighted some limitations of this model, most notably concerning its sensitivity to vegetation and wind shear. The ViSTA_GrAM model addresses these limitations through integrating a new module of grazing as the next step toward an integrated modelling effort that permits models to effectively increase our spatial and temporal understanding of arid environments vegetation, sediment transport and grazing dynamics. Integrative approach, like the one provided by the ViSTA_GrAM model, is beneficial to decision making by providing tools to investigate the response of an arid environment to different state of their vegetation, rainfall regime, wind stress and grazing regime. By developing complex modeling in arid environment and exploring various future scenarios for arid environment, we hope to lead to better management plan of those same environment.
43

A Comparative Sustainability Study for Treatment of Domestic Wastewater: Conventional Concrete and Steel Technology vs. Vegetated Sand Beds (VSB’s) and Their Relative Differences in CO2 Production

Milch, Alicia M 13 July 2016 (has links)
Conventional wastewater treatment in the U.S. is an energy dependent and carbon dioxide emitting process. Typical mechanical systems consume copious amounts of energy, which is most commonly produced from fossil fuel combustion that results in the production of CO2. The associated organic load is also metabolized by microorganisms into CO2 and H2O. As the desire to reduce CO2 output becomes more prominent, it is logical to assess the costs of conventional treatment methods and to compare them to alternative, more sustainable technology. Vegetated Sand Bed (VSB) and Reed Bed (RB) systems are green technologies that provide environmentally superior treatment to conventional systems at a fraction of the cost both environmentally and economically. Using mass balance equations the net CO2 produced from wastewater treatment at 3 conventional facilities, (Amherst, MA, Ithaca, NY and Shelburne-Buckland, MA) and 3 VSBs, (Lloyd, NY, Shushufindi Slaughterhouse, Ecuador and Shushufindi Municipal Facility, Ecuador), will be estimated. Carbon dioxide sources considered are BOD5 microbial respiration, power demand, and sludge treatment. Using the BOD5 reduction and the average daily flow from each of the conventional facilities, hypothetical VSB and RB systems will be sized for the 3 conventional systems. The land area for each hypothetical VSB and RB and the CO2 reduction for equal treatment are estimated for each conventional facility. Estimates of annual CO2 production for Amherst, Ithaca, and Shelburne-Buckland, are 3,021 metric tons, 5,575 metric tons, and 158 metric tons of, respectively. The annual CO2 reduction potential for the conventional facilities Amherst, Ithaca, and Shelburne-Buckland, when compared to VSB and RB technology is estimated to be 74.0%, 83.2%, and 86.3% respectively. VSB and RB technology also provide promising results for sustainable wastewater treatment and reuse. Ammonium and nitrate reduction at the Joseph Troll Turf Plot VSBs were 72% and 88% respectively. The mean ammonium microbial growth rate constant was – 0.14 d-1 and the mean nitrate microbial growth rate constant was – 0.23 d-1. The implications are ammonium and nitrate reduction is possible with VSB and RB technology. Further investigation to understand the processes and fate of nitrogen including separate testing of ammonium and nitrate reduction are recommended.
44

Dětský domov / Children's Home

Chrbolková, Erika January 2022 (has links)
The thesis focuces on project documentation for a construction project with the aim to design home for children under institutional care. Located on the outskirts of Skuteč, the building is three-storey, detached and partially basemented. The basement area lays on the slab foundations and the first floor on strip foundations. Vertical structures are made of ceramic blocks and local reinforced concrete columns while horizontal structures are made of reinforced concrete slabs and wooden trusses over the gym. The building is covered by a vegetated flat roof. The building houses six residential units for six family groups with a total capacity of 43 children. The basement includes gym and fitness with technical facilities. The first floor consists of three residential units, changing rooms for the gym and kitchen with facilities. The second floor houses remaining three residential units, offices and the refectory. The upper floor is used for children´s education and entertainment.
45

Budova občanské vybavenosti / Civic amenities building

Plášková, Věra January 2022 (has links)
The thesis deals with the design of a two-storey L-shaped smart building for amenities with a low energy consumption concept in mind. The ground floor will be used as a café and technical facilities. The second floor is designed for a small design office. The first part of the thesis is devoted to the architectural and structural design. The selected load-bearing system is a wall system made of Silka sand-lime blocks. The floor and roof are designed of prestressed reinforced concrete panels Spiroll. Stone wool is used as the main thermal insulation. The flat roof is designed green extensive. The second part of the thesis deals with the building environment technology, which will use energy from photovoltaic panels and will be supplied with heat from a local central heat source. Air exchange is provided by two HVAC units. Cooling is designed as a VRF system with refrigerant. The third part of the thesis deals with the acoustic assessment. The main topic is optimizing the reverberation time in the open space office. For the preparation of the thesis, the Archicad and Autocad software, MS Excel and Word or Deksoft were used.
46

Obecní úřad s mateřskou školou / Municipal authority with nursery school

Müller, David January 2022 (has links)
The subject of my diploma thesis is a new-building of a municipal authority with a nursery school in Obora near Boskovice. The objects are statically and operationally separated from each other, but they formo ne unit. The building is located on the corner of the village in a flat terrain and thus forms the dominant feature of the village and a landmark. The target of the design was to create a building that will harmoniously connect to the surrounding buildings, public spaces and the school garden. The municipal authority has a rectangular floor plan, two-storey, basement, covered with a sloping roof, the building has a designed elevator. In the basement there are cellars of local associations, on the ground floor there is information center, a municipal library and on the first floor there is a municipal office with a registry office and a ceremonial hall. The attic can be used in the future for municipal apartments for rent. An official board with a public space is designed ahead of the municipal office. A photovoltaic power plant will be located on the roof of the municipal office. The nursery school has a trapezoidal floor plan, ground floor, no basement, covered with a vegetated flat roof. In the nursery school there is a children's day room with a storage room, storage of mattresses, teaching aids, food preparation, technical and hygienic facilities. The structural systém of both objects is longitudinal, wall. The underground part of the municipal office is designed in a white concrete tub system. The vertical load-bearing constructions are made from cut ceramic blocks. The horizontal constructions in the municipal office are monolithic, ferroconcrete, and in the nursery school they are prefabricated, ferroconcrete. The project was made in AutoCad software application, 3D model in 3D modelling computer program SketchUp.

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