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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.
1

Nitrogen Fertilization Studies in Dryland Winter Wheat and Potential Nitrogen Losses from the Soil at the Blue Creek Experimental Station in Northern Utah

Intalop, Subhawat 01 May 1976 (has links)
This study compared the effects of nitrogen sources on the available inorganic soil nitrogen, nitrogen movement, nitrogen losses, and wheat yields when nitrogen fertilizers were applied to soil planted to drylond winter wheat at the Blue Creek Experimental Station in northern Utah. In the fall 1973 soil samplings, the fertilizers producing the largest mineral nitrogen contents in the 0-30 em soil depths were ammonium nitrate >ammonium sulfate > S-cooted urea, when they were broadcast at the practical rate of 56 kg N/ha. There was no increase in the mineral nitrogen at the deeper depths in the fall or at any depth in the following spring. Statistically, the three nitrogen sources did not increase grain yield significantly but did increase grain protein content and nitrogen content in grain. Ammonium nitrate and potassium bromide at the rates of 400 kg N and 200 kg Br/ha were broadcast to soil planted to winter wheat in October 1974. Nitrate-nitrogen and bromide distribution patterns in the soil profile looked alike in May 1975. These showed that their movements were similar. Considerable nitrate-nitrogen (35 percent of the added nitrogen) had moved down below the 120 em depth. The highest nitrate-nitrogen concentrations were found at the 45 to 90 em depth . There seems to be evidence that nitrate-nitrogen and bromide had moved deeper than the 150 em depth. Ammonia- nitrogen losses from nitrogen fertilized soils were conducted in the laboratory. Ammonium sulfate, ammonium nitrate, or urea applied to the soil surface lost ammonia-nitrogen differently. From noncalcareous soil, the ammonia-nitrogen loss was greatest from urea. From calcareous soil or soils receiving carbonates or high soil pH by the addition of sodium hydroxide solution, the greatest losses were from ammonium sulfate. High losses were favored by high temperatures and longer periods of moist soil. The total amounts of water lost from the soil was not closely related to the total ammonia-nitrogen loss during two weeks. No loss of ammonia-nitrogen occurred when nitrogen fertilizers were applied at a 2.5 em depth or deeper. The ammonia-nitrogen losses were also greatly reduced when nitrogen fertilizers applied to the soil surface was followed by irrigation or heavy rainfall. In the field, the higher temperatures increased the ammonia-nitrogen losses from ammonium sulfate, ammonium nitrate, and urea when applied to both a noncalcareous and a calcareous soil . However, the loss from calcareous soil was reduced by irrigation following fertilizer application. No ammonia-nitrogen was observed when ammonium sulfate was applied at a 2. 5 em soil depth, despite of the high soil temperature during the day time in moist soil. Rapid drying of the moist soil surface quickly reduced the losses per day.
2

Potential for CO2 Sequestration and Enhanced Coalbed Methane Production, Blue Creek Field, NW Black Warrior Basin, Alabama

He, Ting 2009 December 1900 (has links)
Carbon dioxide (CO2) is a primary source of greenhouse gases. Injection of CO2 from power plants near coalbed reservoirs is a win-win method to reducing emissions of CO2 to the atmosphere. Limited studies have investigated CO2 sequestration and enhanced coalbed methane production in San Juan and Alberta basins, but reservoir modeling is needed to assess the potential of the Black Warrior basin. Alabama ranks 9th nationally in CO2 emissions from power plants; two electricity generation plants are adjacent to the Black Warrior coalbed methane fairway. This research project was a reservoir simulation study designed to evaluate the potential for CO2 sequestration and enhanced coalbed methane (ECBM) recovery in the Blue Creek Field of Black Warrior basin, Alabama. It considered the injection and production rate, the components of injected gas, coal dewatering, permeability anisotropy, various CO2 soak times, completion of multiple reservoir layers and pressure constraints at the injector and producer. The simulation study was based on a 5-spot well pattern 40-ac well spacing. Injection of 100 percent CO2 in coal seams resulted in average volumes of 0.57 Bcf of sequestered CO2 and average volumes of 0.2 Bcf of enhance methane production for the Mary Lee coal zone only, from an 80-acre 5-spot well pattern. For the entire Blue Creek field of the Black Warrior basin, if 100 percent CO2 is injected in the Pratt, Mary Lee and Black Creek coal zones, enhance methane resources recovered are estimated to be 0.3 Tcf, with a potential CO2sequestration capacity of 0.88 Tcf. The methane recovery factor is estimated to be 68.8 percent, if the three coal zones are completed but produced one by one. Approximately 700 wells may be needed in the field. For multi-layers completed wells, the permeability and pressure are important in determining the breakthrough time, methane produced and CO2 injected. Dewatering and soaking do not benefit the CO2 sequestration process but allow higher injection rates. Permeability anisotropy affects CO2 injection and enhanced methane recovery volumes of the field. I recommend a 5-spot pilot project with the maximum well BHP of 1,000 psi at the injector, minimum well BHP of 500 psi at the producer, maximum injection rate of 70 Mscf/D, and production rate of 35 Mscf/D. These technical results, with further economic evaluation, could generate significant projects for CO2 sequestration and enhance coalbed methane production in Blue Creek field, Black Warrior Basin, Alabama.
3

Constructive hierarchy through entitlement: inequality in lithic resource access among the ancient Maya of Blue Creek, Belize

Barrett, Jason Wallace 17 February 2005 (has links)
This dissertation tests the theory that lithic raw materials were a strategic resource among the ancient Maya of Blue Creek, Belize that markedly influenced the development of socio-economic hierarchies at the site. Recent research has brought attention to the role of critical resource control as a mechanism contributing to the development of political economies among the ancient Maya. Such research has been primarily focused on the control of access to water and agricultural land. The examination of lithic raw materials as a critical economic resource is warranted as stone tools constituted a fundamental component of the ancient Maya economy. My research objectives include measuring raw material variability in the Blue Creek settlement zone and its immediate environs, assessing the amount of spatial and temporal variability present in the distribution of various raw materials, determining the degree to which proximity to a given resource influenced the relative level of its use, and testing whether differential resource access relates to variability in aggregate expressions of wealth. To meet these objectives, I examined 2136 formal stone tools and 24,944 pieces of debitage from excavations across the Blue Creek settlement zone, and I developed a lithic raw material type collection using natural outcrops. Significant spatial and temporal differences were observed in the use of various raw materials. Control of critical resources under conditions of scarcity is shown to have caused social stratification among the ancient Maya of Blue Creek. Initial disparities in use-right arrangements based on first occupancy rights produced substantial, accumulative inequality in economic capability and subsequent achievements. During the Early Classic period, these disproportionate allowances ultimately undermined the more egalitarian structure observed during the Preclassic. The Early Classic period at Blue Creek is characterized by increasing extravagance among the elites and increasing disenfranchisement throughout the hinterlands when compared to earlier periods. This suggests that elites at the site only became fully able to convert their resource monopolies into substantial gains in power, prestige, and wealth during the Classic period.
4

Nitrogen Fertilization Studies in Dryland Winter Wheat and Potential Nitrogen Losses from the Soil at the Blue Creek Experimental State in Northern Utah

Intalap, Subhawat 01 May 1976 (has links)
This study compared the effects of nitrogen sources on the available inorganic soil nitrogen, nitrogen movement, nitrogen losses, and wheat yields when nitrogen fertilizers were applied to soil planted to dryland winter wheat at the Blue Creek Experimental Station in northern Utah. In the fall 1973 soil samplings, the fertilizers producing the largest mineral nitrogen contents in the 0-30 cm soil depths were ammonium nitrate >ammonium sulfate > S-coated urea, when they were broadcast at the practical rate of 56 kg N/ha. There was no increase in the mineral nitrogen at the dee per depths in the fall or at any depth in the following spring. Statistically, the three nitrogen sources did not increase grain yield significantly but did increase grain protein content and nitrogen content in grain. Ammonium nitrate and potassium bromide at the rates of 400 kg N and 200 kg Br/ha were broadcast to soil planted to winter wheat in October 1974. Nitrate-nitrogen and bromide distribution patterns in the soil profile looked alike in May 1975. These showed that their movements were similar. Considerable nitrate-nitrogen (35 percent of the added nitrogen) had moved down below the 120 cm depth. The highest nitrate-nitrogen concentrations were found at the 45 to 90 cm depth. There seems to be evidence that nitrate-nitrogen and bromide had moved deeper than the 150 cm depth. Ammonia-nitrogen losses from nitrogen fertilized soils were conducted in the laboratory. Ammonium sulfate, ammonium nitrate, or urea applied to the soil surface lost ammonia-nitrogen differently. From noncolcoreous soil, the ammonia-nitrogen loss was greatest from urea. From calcareous soil or soils receiving carbonates or high soil pH by the addition of sodium hydroxide solution, the greatest losses were from ammonium sulfate. High losses were favored by high temperatures and longer periods of moist soil. The total amounts of water lost from the soil was not closely related to the total ammonia-nitrogen loss during two weeks. No loss of ammonia-nitrogen occurred when nitrogen fertilizers were applied at a 2.5 em depth or deeper. The ammonia-nitrogen losses were also greatly reduced when nitrogen fertilizers applied to the soil surface was followed by irrigation or heavy rainfall. In the field, the higher temperatures increased the ammonia-nitrogen losses from ammonium sulfate, ammonium nitrate, and urea when applied to both a noncalcareous and a calcareous soil. However, the loss from calcareous soil was reduced by irrigation following fertilizer application. No ammonia-nitrogen was observed when ammonium sulfate was applied to o 2.5 cm soil depth, despite of the high soil temperature during the day time in moist soil. Rapid drying of the moist soil surface quickly reduced the losses per day.

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