Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 187 for “"Canopies"”.
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Turbulent flows over canopies
In this thesis, turbulent flows over canopies in the sparse and dense regimes are examined using direct numerical simulation. The term `canopy' is used to refer to tall roughness elements in the flow. Sparse canopies typically have large element spacings and allow turbulent eddies to penetrate …
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Residence time in coastal canopies
Aquatic canopies provide important ecosystem services such as improved water quality, oxygen flux, sediment stabilisation and trapping and recycling of nutrients. The ecological health of coastal canopies and the significant ecosystem services they provide depends largely on the continuous exchange …
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On the hydrodynamics of flexible vegetation canopies
Aquatic vegetation canopies, including seagrasses, provide a host of ecosystem services within coastal environments. The environmental, social, and economic benefits are primarily controlled by the detailed interactions between hydrodynamics and canopy properties, which governs energy cascades and …
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Transport in random cylinder arrays : a model for aquatic canopies
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2002.
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Multiple scattering of microwaves from soil surface and vegetation canopies
A multiple scattering radiative transfer model is developed for use in global retrieval algorithms of microwave geophysical parameters. This attempts to both improve soil moisture and vegetation attenuation and scattering parameter retrievals under moderate to dense canopy covers and capture the …
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Snowfall Interception and Ablation in Needleleaf Canopies: Observations and Model Development
… global landmass. Here, interception by forest canopies plays a crucial role in the terrestrial water cycle and land-atmosphere energy exchanges. Global changes in climate and vegetation cover have the potential to alter how snowfall is intercepted and subsequently partitioned between …
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Net Radiation, Visible Radiation, Apparent Photosynthesis and Evapotranspiration in Soybean Canopies
Made available in DSpace on 2014-12-10T17:12:29Z (GMT). No. of bitstreams: 1 6607814.pdf: 2573138 bytes, checksum: 41b1929b0390a6e7448a705f8d6f4c75 (MD5) Previous issue date: 1966
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Detection and Analysis of Coherent Structures within and above Tall-vegetated Canopies
… flow in the proximity to tall-vegetated canopies. Although coherent structures have called increasing attention of the turbulence community during the past decades, the basic mechanisms of their emergence, their contributions to exchange processes and their importance for conventional …
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Estimation of biophysical properties of woodland canopies using LiDAR and hyperspectral imagery
Vegetation canopies represent the interface between the atmosphere and the biosphereand play an important role in determining energy and mass exchange. Accuratecharacterisation of vegetation canopy characteristics is therefore important tounderstand these processes, and remote sensing has been used …
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A Study of Bio-Inspired Canopies for the Reduction of Roughness Noise
… crops. Analogous surface treatments (suspended canopies) were designed which simulated the most essential geometric features of the velvety down material. The Virginia Tech Anechoic Wall-Jet Facility was used to perform far-field noise and surface pressure fluctuation measurements in the …
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Hydrodynamic Effects of Salt Marsh Canopies and their Prediction using Remote Sensing Techniques
… determining fluid momentum losses in salt marsh canopies. These results led to the development of a new empirical based model using vertical measures of biomass and approach (incident) velocity which can accurately (R2 0.71) predict flow momentum losses. This suggests that the characteristic …
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Rainfall redistribution and change of water quality in tropical forest canopies : patterns and persistence
Motivations and research objectives: During the passage of rain water through a forest canopy two main processes take place. First, water is redistributed; and second, its chemical properties change substantially. The rain water redistribution and the brief contact with plant surfaces results in a …
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Flow and solute transport in random cylinder arrays : a model for emergent aquatic plant canopies
… and solute transport in idealized emergent plant canopies. This thesis presents laboratory measurements of the mean drag, turbulence structure and intensity, and lateral dispersion of passive solute in arrays of randomly-distributed cylinders, a model for emergent, rigid aquatic plants. Mean drag …
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Identification of Disease Stress in Turfgrass Canopies Using Thermal Imagery and Automated Aerial Image Analysis
… asymptomatic tall fescue and creeping bentgrass canopies showed differences as well (p<0.0492). The second project attempted to isolate spring dead spot from aerial imagery of bermudagrass golf course fairways using a Python script. Aerial images from unmanned aerial vehicle flights were …
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Quantifying structural change in UK woodland canopies with a dual-wavelength full-waveform terrestrial laser scanner
Vegetation structure provides a direct link between forest ecosystem productivity and earth-atmosphere fluxes, and is both a result and driver of these interactions. Therefore, the ability to collect objective, quantitative and three-dimensional measurements of vegetation structure is essential, …
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Assessing ice storm damage to hardwood forest canopies using the Advanced Solid-State Array Spectroradiometer (ASAS) and Landsat TM imagery
<p>A major ice storm in January 1998 damaged 17 million acres of forestland in the Northeastern United States and Quebec Province. In July 1998 the airborne multiangle hyperspectral sensor, Advanced Solid-State Array Spectroradiometer (ASAS), acquired imagery for nine ice damaged target areas in …
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Variations in needle morphology and anatomy as related to variations in photosynthetic potential within loblolly pine (Pinus taeda L.) canopies
… for foliage from six positions within the canopies of three Loblolly Pine trees. The six positions represented two distinct lightning conditions, open and closed grown, and three vertical positions, top, middle and bottom on the canopies of the three trees. Only foliage of the first flush …
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Field Studies of Light Relationships as Affecting Seed Yields and Photosynthesis of Individual Leaves Within Canopies of Soybeans (Glycine Max (L.) Merrill)
Made available in DSpace on 2014-12-10T17:12:36Z (GMT). No. of bitstreams: 1 6812138.pdf: 3387904 bytes, checksum: 1740934bd2ae539a3499fdb7941778a5 (MD5) Previous issue date: 1968
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