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Analysis of Grain Size Distribution and Hydraulic Conductivity for a Variety of Sediment Types with Application to Wadi SedimentsRosas Aguilar, Jorge 05 1900 (has links)
Grain size distribution, porosity, and hydraulic conductivity from over 400 unlithified sediment samples were analized. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical off sets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, off shore marine, and wadi sediments. Expected hydraulic conductivity estimation errors were reduced. Correction factors were proposed for wadi sediments, taking mud percentage and the standard deviation (in phi units) into account.
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Surface-Water and Groundwater Interactions of a Stream Reach and Proposed Reservoir within the Pascagoula River Basin: George County, MississippiKillian, Courtney 09 May 2015 (has links)
This research had two main objectives: quantify surface-water and groundwater interactions along a stream reach, and determine the hydraulic conductivity at the site where two reservoirs are proposed. The objectives of this research aim to help maintain stream ecology and increase surface water storage for recreational and industrial purposes. The stream reach, located in the Pascagoula River Basin of southeast Mississippi, begins at Lake Okatibbee and terminates at Pascagoula into the Gulf of Mexico. Four USGS continuous gauging stations provided more than forty years of stream discharge data for a hydrograph baselow-recession analysis, which determined the baseflow component within the stream. The analysis showed that baseflow decreases along the stream reach and increases again before reaching the Gulf of Mexico. Thirteen borehole samples were collected at the sites of the proposed reservoirs in George County, Mississippi to determine the hydraulic conductivity of the sediments, which showed high a hydraulic conductivity.
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Temporal variability of riverbed conductance at the Bolton Well Field along the Great Miami River, Southwest Ohio: Characterization of riverbed sediments during low-flow conditionsIdris, Omonigho 04 May 2006 (has links)
No description available.
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Mätning av hydraulisk konduktivitet med Lewis metod : En utvärdering av tillförlitligheten och användbarheten hos en enkel metod för mätning i olika jordarterEriksson, Daniel January 2016 (has links)
The purpose of this study was to evaluate Lewis (2016) simple method to determine hydraulic conductivity in soil samples. This was conducted by comparing Lewis method to a slug-test, Guelph permeameter and calculations from grain size analysis in order to find out if the method is a reliable source for measuring hydraulic conductivity. Other parameters to compare is time consumption, cost effectiveness and area of use. Four different samples were used in the testing, a sand, two tills and pyrite ash (which is a rest product from manufacturing sulfite pulp). The results indicated that measurements in the homogenic sand all methods was in a good range of each other, while in the more heterogenic till the slug-test and Lewis method was close and the calculations from grainsize analysis was much lower. Only grainsize analysis was performed on the pyrite ash and the results was similar to Lewis method. This study shows that Lewis method works well as a reliable source for K measurements and is less time consuming than all the other methods. The material required for the method can be obtained in a hardware store.
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Characterizing low-sulfide instrumented waste-rock piles: image grain-size analysis and wind-induced gas transportChi, Xiaotong January 2010 (has links)
This study is part of the Diavik Waste-Rock Pile Project taking place at the Diavik Diamond Mine in the Northwest Territories, Canada. The project involves the construction of three 15m-scale low sulfide test waste-rock piles and monitoring of fluid flow, geochemical reactions, heat and gas transport within the waste-rock piles and characterization of the physical properties of the waste-rock piles. The focus of this thesis is characterizing grain-size distribution of the waste-rock and quantifying gas transport in the test waste-rock piles.
Grain size of waste rock ranges from millimeters to meters. Sieve analysis typically only provides information of grain size <0.1 m at a single location. A computer program was developed using digital image-processing techniques to obtain a spatial grain-size distribution from photographs of tip faces of the test waste-rock piles acquired in the field. The program characterizes grain size >0.1 m and employs a region-growing algorithm for segmentation of waste-rock grains with pre- and post-processing techniques to improve the accuracy of segmentation. The program was applied to photographs of six different tip faces of the test waste-rock piles. For grain size <0.1 m, data from sieve analyses were attached to the grain-size curves generated from image grain-size analyses to obtain a full spectrum grain-size analyses ranging from boulders to fines. The results show that fine fractions are retained at the top of the tip faces and grain size increases non-linearly from top to bottom of a waste-rock pile. Calculations show that although the greatest mass is associated with the medium and coarse fractions, the greatest surface area is associated with the fine fractions. The results are consistent with field observation that the initial solute concentrations are greatest at the top of the pile and saturated hydraulic conductivity are lower at the top of the pile than in the pile interior. Statistical moments show that the test waste-rock piles have mean grain size of granules and are very poorly sorted, coarse skewed and leptokurtic. Permeability is calculated using empirical formulae and good agreement is obtained between calculated values and field measurements. The heterogeneity of grain size obtained from this study can provide a basis for future modeling efforts.
Gas transport analysis focused on 1) substantiating the relationship between wind flow external to the waste-rock pile and gas pressures within the pile, 2) determining the gas flow regime in the pile, and 3) quantifying the temporal variation in wind speed and direction and determining the relevant time scales. Differential gas pressures were measured in 2008 at 49 locations within one of the three test waste-rock piles and 14 locations on the surface of the pile at one-minute intervals. Wind speed and direction were measured at 10-min intervals. Correlations between wind vectors and pressure measurements show that the wind influences pressure fluctuations in the test pile. The strength of the correlation is roughly inversely proportional to the distance between measurement ports and the atmospheric boundary. The linear relationship between internal pressure measurements and surface pressure measurements demonstrate that gas flow is Darcian within the test waste-rock pile. Spectral analysis of wind data and a one-dimensional analytical solution to the flow equations show that the persistence of wind in a certain direction has most pronounced effects on transient gas flow within the pile. The penetration depth of wind-induced gas pressure wave is a function of the periodicity of the wind and permeability of the waste-rock pile.
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A Geomorphological Assessment of Armored Deposits Along the Southern Flanks of Grand Mesa, CO, USABrunk, Timothy J. 2010 May 1900 (has links)
A series of deposits, located along the southern flanks of Grand Mesa, Colorado, and extending to the south, are problematic, and the processes related to emplacement are not understood. The overall area is dominated by two landform systems, Grand Mesa, which supported a Pleistocene ice cap, and the North Fork Gunnison River drainage. Thus, one has to ask: Are these deposits the result of the melting of the ice cap or are they fluvial terraces associated with the evolution of the ancestral Gunnison River? The goal of this research was to map the areal extent of the deposits and to interpret the formation and climatic significance in understanding the evolution of the Pleistocene landscape in the region.
An extensive exposure, parallel to State Highway 65 near Cory Grade, was used for detailed description and sampling. Three additional exposures, ~10 to 20 km (~6 to 12 mi) were used to extend the areal extent of sampling. The study area was mapped using aerial photography and traditional field mapping aided by GPS. From the field work, a detailed stratigraphic column, including lithology and erodability, was constructed. Vertical exposures of the deposits were described, mapped, and recorded in the field and using detailed photo mosaics. Samples were collected from each stratum of the deposits for grain-size, shape, and sorting analyses. Five distinct depositional facies were identified.
Sieve analysis on collected samples shows that four distinct grain-sizes occur in the outcrops; coarse sand, very-coarse sand, granule, and pebble and boulder. Mean grain-sizes range from 0.0722 to 0.9617, -0.0948 to -0.9456, -1.0566 to -1.9053, and -2.0050 to -3.4643, respectively.
Glacio-fluvial depositional environments were identified and supported with observations of sedimentary structures and clast composition. Two major environments of deposition are recorded in the deposits; fluvial deposits from glacial outburst floods, and debris flow deposits. Imbrication of clasts in the strata suggests the flow came from the direction of Grand Mesa to the north. Facies and subsequent sequences were constructed to portray evidence that supports the glacio-fluvial mode of deposition.
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Research of Neural Network Applied on Seabed Sediment RecognitionLee, Po-Yi 07 June 2000 (has links)
Along with advancement of human industrialization, pollution in the ocean is getting worse. Moreover, the overfishing through the years has caused catastrophic damage to the ocean eco-system. In order to avoid exhaustion of fishery resource, many concepts of planned administrative fishery has become popular, and thereamong, ocean ranch draws the most attention. Artificial reef plays a key role in an ocean ranch, which starts with incubating brood fish in the laboratory. Often, the brood fish will grow in the cage near coast till proper size, then be released to the artificial reef. If fish groups do not disperse and multiply, the artificial reef can be considered successful. The success of the artificial reef relies on the stable foundation. Consequently, the composition of seabed sediment under the planned site should be investigated thoroughly before hand. This research introduced a remote investigation method, which an active sonar, depth sounder, was used to emit and collect acoustic signals. By using the signals reflected from the seabed, the sediment composition can be analyzed.
However, all acoustic signals are subjected to noise through propagation, and distorted somehow. Therefore, certain signal pre-processing should be applied to the received signal, and representative characteristics can be extracted from it. In this research, the recognition platform was built on artificial neural network (ANN) in this research.
Among many network algorithm modes, this research chose the widely used backpropagation learning algorithm to be the main structure in ANN. The goal of this research was to discriminate among three seabed sediments: fine sand, medium sand, and rock. During the signal processing, characteristics were extracted by using peak value selection method. Selected major frequency peaks were fed into the network to train and learn. According to partial error relation between recognition and practical result, weights of the network were adjusted for improving successful ratio. Finally, a reliable acoustic wave signal recognition system was constructed.
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Provenance and Depositional History of Late Pleistocene New Jersey Shelf SedimentsTurner, Roxie Jessica 12 May 2005 (has links)
Pleistocene New Jersey shelf sedimentology is strongly influenced by glacially driven sea level changes. A combination of regressive shoreline processes, subaerial exposure, fluvial downcutting, and deposition and reworking during transgression has influenced the NJ shelf sediment composition. Sediment provenance and transport history may be determined on a shelf environment through analysis of grain size distribution, heavy mineral content, magnetic mineral concentrations, and isotopic dating methods. A combination of surface grab and stratigraphic samples were analyzed within the study area. Relatively high percentages of heavy minerals were found in the 2 phi and 3 phi size fractions and hornblende grains provided K-Ar age values indicating two groups of sediment sources. The first source is Grenville with apparent ages above 900 Ma deposited during marine OIS 1. The second source is a mixed assemblage of Grenvillian and Paleozoic sources deposited during marine OIS 3, with apparent ages of approximately 850 ± 20 Ma.
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Characterizing low-sulfide instrumented waste-rock piles: image grain-size analysis and wind-induced gas transportChi, Xiaotong January 2010 (has links)
This study is part of the Diavik Waste-Rock Pile Project taking place at the Diavik Diamond Mine in the Northwest Territories, Canada. The project involves the construction of three 15m-scale low sulfide test waste-rock piles and monitoring of fluid flow, geochemical reactions, heat and gas transport within the waste-rock piles and characterization of the physical properties of the waste-rock piles. The focus of this thesis is characterizing grain-size distribution of the waste-rock and quantifying gas transport in the test waste-rock piles.
Grain size of waste rock ranges from millimeters to meters. Sieve analysis typically only provides information of grain size <0.1 m at a single location. A computer program was developed using digital image-processing techniques to obtain a spatial grain-size distribution from photographs of tip faces of the test waste-rock piles acquired in the field. The program characterizes grain size >0.1 m and employs a region-growing algorithm for segmentation of waste-rock grains with pre- and post-processing techniques to improve the accuracy of segmentation. The program was applied to photographs of six different tip faces of the test waste-rock piles. For grain size <0.1 m, data from sieve analyses were attached to the grain-size curves generated from image grain-size analyses to obtain a full spectrum grain-size analyses ranging from boulders to fines. The results show that fine fractions are retained at the top of the tip faces and grain size increases non-linearly from top to bottom of a waste-rock pile. Calculations show that although the greatest mass is associated with the medium and coarse fractions, the greatest surface area is associated with the fine fractions. The results are consistent with field observation that the initial solute concentrations are greatest at the top of the pile and saturated hydraulic conductivity are lower at the top of the pile than in the pile interior. Statistical moments show that the test waste-rock piles have mean grain size of granules and are very poorly sorted, coarse skewed and leptokurtic. Permeability is calculated using empirical formulae and good agreement is obtained between calculated values and field measurements. The heterogeneity of grain size obtained from this study can provide a basis for future modeling efforts.
Gas transport analysis focused on 1) substantiating the relationship between wind flow external to the waste-rock pile and gas pressures within the pile, 2) determining the gas flow regime in the pile, and 3) quantifying the temporal variation in wind speed and direction and determining the relevant time scales. Differential gas pressures were measured in 2008 at 49 locations within one of the three test waste-rock piles and 14 locations on the surface of the pile at one-minute intervals. Wind speed and direction were measured at 10-min intervals. Correlations between wind vectors and pressure measurements show that the wind influences pressure fluctuations in the test pile. The strength of the correlation is roughly inversely proportional to the distance between measurement ports and the atmospheric boundary. The linear relationship between internal pressure measurements and surface pressure measurements demonstrate that gas flow is Darcian within the test waste-rock pile. Spectral analysis of wind data and a one-dimensional analytical solution to the flow equations show that the persistence of wind in a certain direction has most pronounced effects on transient gas flow within the pile. The penetration depth of wind-induced gas pressure wave is a function of the periodicity of the wind and permeability of the waste-rock pile.
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Temporal variability of riverbed conductance at the Bolton well field along the Great Miami River, southwest Ohio characterization of riverbed sediments during low-flow conditions /Idris, Omonigho. January 2006 (has links)
Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2006. / Title from first page of PDF document. Includes bibliographical references (p. 33-35).
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