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 141 for “"depressions"”.
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Classification of infiltration characteristics of depressions in landfill covers using uncalibrated, thermal-infrared imagery
… of the design is the collection of runoff in depressions developed in the cover.
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Comparison of Two Algorithms for Removing Depressions and Delineating Flow Networks From Grid Digital Elevation Models
… to hydrologic and nonpoint source modeling. The depressions which are frequently present in DEMs may represent the actual topography, but are often the result of errors. Creating a depression-free surface is commonly required prior to deriving flow direction, flow accumulation, flow network, and …
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The importance of fine-scale flow processes and food availability in the maintenance of soft-sediment communities
… between microdepositional environments (small depressions) and non-trapping environments (flush treatments). Depressions have been observed to trap passive particles, and these experiments were therefore designed to test whether settling larvae would be trapped in depressions like passive …
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Pans of the southern Kalahari, Botswana
… shallow sub circular to sub elliptical isolated depressions, on the southern side of which is an area of fringing dunes, indicative of a deflation origin for the pan depressions. Analysis of the distribution of the pans shows that they are strongly clustered but do not form aligned groupings. Two …
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Failure of laterally crushed aluminum tubes under combined bending and tension
… locations. The local wall thinning develops into depressions with a width of the order of the shell wall thickness. As crushing progresses the depressions deepen, increase their span, become neck-like and develop inclined failures. The crushing was terminated when the first of four such …
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Nutrient cycles across topography in drainage-impaired Corn Belt soils
… human and environmental health. Topographic depressions in the US Corn Belt have documented impacts on hydrology, crop production, soil characteristics, and soil microbial communities. These topographic features also likely impact nutrient leaching rates and nitrous oxide (N2O) production. …
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Model Estimation of Depression-focused Groundwater Recharge and its Variability in the Canadian Prairies
… topographical variations containing numerous depressions. These depressions play an important role in the hydrology of the prairie region by storing runoff water and replenishing groundwater through focused infiltration termed as depression-focused groundwater recharge. This study investigated …
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Characterization of Surface Karst Using LiDAR and Field Traverses, Fort Hood Military Installation, Coryell County, Texas
… (LiDAR) data to characterize surface karst depressions, create a set of new and refined filters and buffering mechanisms to remove non-karst depressions, and determine the accuracy of the model. LiDAR data was used to create a digital elevation model (DEM), which was used to extract areas …
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Delineation of Karst Potential Using LiDAR and GIS Analyses, Fort Hood Military Installation, Texas
… fill and extract areas with localized depressions at sub-meter scale. The resulting polygons were processed through a series of filters that isolated depressions outside the influence of non-karst features and with a depth greater than the vertical accuracy of the LiDAR survey. A karst …
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A comparison of virginiamycin and a lactobacillus probiotic as feed additives for swine and the effects of virginiamycin supplementation and crowding stress on swine performance
… m nursery pens from six to 12 caused significant depressions in final weight, daily gain, feed intake, and feed efficiency. Virginiamycin supplementation significantly improved final weight, daily gain and feed efficiency. In two starter trials, reducing space allowance from .24 to .12 m² per pig …
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Dynamics of inorganic soil-nitrogen age in intensively managed landscape
… age model, we aim to understand how topographic depressions and tile drains drive the spatial heterogeneity of nutrient concentration and age distribution over agricultural fields. Towards this objective, we develop a model for nitrogen age by considering various transformations associated with …
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The Description and Interpretation of a Tertiary Siliceous Rock in Western North Dakota
… by an extensive shallow basin with local depressions. Sediments deposited in these depressions were silicifed by the precipitation of ground water-transported silica. Precipitation of this silica, in the form of chert and secondary overgrowths, was facilitated by an acidic environment at …
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Climatic factors influencing Last Glacial Maximum and modern glacial conditions in the tropical and subtropical Andes
… Maximum (LGM) equilibrium line altitude (ELA) depressions to be approximately 600 m in the tropics and 800 m in the subtropics, consistent with studies that suggest the subtropical Andes were glaciated at LGM. While previous studies have found that the subtropical Andes are presently …
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The geology of the Newburg-South Westhope oil fields, Bottineau County, North Dakota
… beds.</p> <p>The two fields are marked with depressions formed as a result of the dissolving of deep seated, presumably Devonian, salt beds and complementary gradual subsidence of overlying sediments. Two stages of salt solution are recognized, a pre-Spearfish stage which is reflected in …
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Delineation of Surface Water Features Using RADARSAT-2 Imagery and a TOPAZ Masking Approach over the Prairie Pothole Region in Canada
… world. In the PPR of North America, topographic depressions are common, and they are an essential water storage element in the regional hydrological system. The accurate delineation of surface water bodies is important for a variety of reasons, including conservation, environmental management, …
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Data driven modeling of corn yield: a machine learning approach
… yield is high. Corn yield is higher in gentle depressions as compared to steep slopes and very deep depressions. Further, very high and very low precipitation during the emergence stage (VE) is most likely to lead to lower yield. The model described in this study can also be used to develop …
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Soils and morphology of Carolina bays, Eastern Shore, Virginia
… apparently associated with larger less distinct depressions. The restriction of bay size by associated land surface may be evidenced by a number of small bays occurring on the narrow peninsula south of Wachapreague and the lack of large bays (over 2 miles in length) in the study area. Truncation …
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Where the Ice Ends: Calving and Ice-Ocean Interactions at Helheim Glacier and Beyond
… at Helheim Glacier. We find that surface depressions appear at a consistent spot near a subglacial ridge upflow from Helheim Glacier's terminus. The subsequent calving events from these surface depressions and non-surface-depression calving events did not have a sustained increase in …
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Phonon scattering from monovalent substitutional impurities in sodium chloride
… but the other seven systems investigated showed depressions of the conductivity curves on eith~r .,side of the maximum, or on both. -2- In the present work, the Callaway analysis has been extende4 to be valid at higher temperatures by relaxing the Debye approximation. Using the shell model of the …
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