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 12 of 12 for “"Frozen ground"”.
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Improving The Palmer Drought Severity Index By Incorporating Snow And Frozen Ground
… of consideration for snow and the treatment of ground status. In this study, a simplified snow model is included in the self-calibrated PDSI model, which is run in a monthly time step over the continental United States (CONUS) for the past 32 years (1979 - 2010). In the modified PDSI model, the …
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The Du Toitskloof Tunnel project : the construction of the (south) soft ground tunnel, Western Cape, South Africa
… on the excavation and construction of the soft ground tunnel, by means of artificial ground freezing for ground support and stabilisation. The soft ground section of the tunnel being situated at the Western portal, and forming approximately 168 metres of the four kilometre main tunnel. The …
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The permafrost problem
Thesis (B.S.)--Michigan State College of Agriculture and Applied Science, 1948
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Impact of permafrost dynamics on Arctic groundwater ow systems with application to the evolution of spring and lake taliks
Groundwater ow in permafrost is restricted to unfrozen zones, known as taliks. There is an interaction between groundwater ow and heat ow, because the permafrost distribution determines the occurrence of groundwater, but groundwater also contributes to advective heat transport in uencing the …
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Organic Contaminant Release from Melting Snow
… the melt water runs off as overland flow over frozen ground, pollutants are directly transferred into catchment streams, and their water quality is affected most. Melt water flow along the soil subsurface dilutes and buffers organic contaminant loads. The findings of this laboratory study may …
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Measurement and Simulation of Preferential Flow in Frozen Soils
The infiltrability of frozen soils strongly influences the partitioning of snowmelt and hydrological functioning of cold regions. Preferential flow in macropores may enhance infiltration into frozen soil, but flow dynamics are complicated by coupled water and heat transfer processes. Field studies …
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Experimental investigation of soil volume changes during freezing and thawing
… with focus on frost heave and thaw settlement. Ground freezing is a natural phenomenon that affects civil engineering projects, especially in cold regions or where artificial ground freezing (AGF) is employed. Freezing causes water in the soil pores to turn into ice, which expands, leading to …
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Rapid bioluminometric enumeration of microorganisms in ground beef
… for estimating total bacterial counts in ground beef. Minimum sensitivity was found to be 10⁶ cfu/g using a double filtration procedure for sample preparation. Although ATP content per cfu decreased approximately 10 fold during storage, correlation of total aerobic plate count (APC) with …
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Methanogens from Siberian permafrost as models for life on Mars : response to simulated martian conditions and biosignature characterization
… as we know it. The occurrence of permanently frozen ground – permafrost, is a common phenomenon on Mars and it shows multiple morphological analogies with terrestrial permafrost. Despite the extreme inhospitable conditions, highly diverse microbial communities inhabit terrestrial permafrost in …
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The seasonal dynamics of Arctic surface hydrology in permafrost environments
… warming, and in some regions even thawing, the frozen ground. Permafrost is a carbon sink. The thermal state of the ground therefore has important implications on carbon exchange with the atmo- sphere. Permafrost thaw mobilises previously sequestered carbon stocks, potentially turning these high …
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Response of Soil and Water Quality to Winter Manure Application from Small Agricultural Watersheds in South Dakota
… in the state during the winter months when the ground is frozen. Thus, producers are left with the options such as storing the manure over a longer period until summer or spreading on snow or frozen ground. Storing manure for longer duration leads to increased risks of concentrated spills into …
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Dynamics of residual non-aqueous phase liquids in porous media subject to freeze-thaw
This project concerns the effect of freeze-thaw cycles on the pore-scale structure of nonaqueous phase liquid (NAPL) contaminants in water-saturated porous media. This problem is of critical importance to the entrapment of such contaminants in cold temperate, polar and high altitude regions, and …