Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xii, 169 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 65-75).

Thesis (Ph. D.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains ix, 106 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of California, 1925. / Hilgardia, a journal of agricultural science, v. 2, no. 14. April, 1927, with a special thesis t.p. attached to the cover. "Literature cited": p. 527-528.

Thesis (M.E.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 133-135). Also available via the World Wide Web.

No description available.

Thesis (MTech(Chemical Engineering))--Cape Technikon, Cape Town, 2001 / Although numerous methods exist to treat mine water that is rich in CaS04 they all have inherent disadvantages. A means of treating acid mine drainage is by forming a precipitate known as ettringite. Ettringite is a low solubility calcium hydrosulphoaluminate that is stable between pH values of 11.4 and 124. Ettringite is made up of calcium, sulphate, aluminium and a large amount of water. The formation of this precipitate is a result of calcium sulphate which is brought into contact with an aluminium containing agent. Decomposition of ettringite takes place by reducing the pH to a near neutral value. A 5 stage process is proposed to treat acid mine drainage of which the formation of ettringite forms the cornerstone of this process. The process incorporates the formation of more than one precipitate, namely; metal hydroxides, gypsum, CaS04 and CaCOJ. To facilitate the formation of ettringite, gibbsite is recycled as a result of ettringite being decomposed. The results obtained in this paper are as a result of modeling this process on an Aspen Plus simulator. The simulation package is useful for investigating how this process behaves under non-ideal conditions and under various sensitivities. The process and its behavioral patterns are also analyzed in order to ascertain its economic viability.

The application of nitrogen (N) fertilizers and manure to agricultural soil is essential for crop production, but has in turn introduced environmental impacts including: eutrophication, contamination of groundwater, freshwater acidification, and an increase in greenhouse gas emissions. The movement of nitrogen was observed following liquid swine manure applications at six fields in Winchester, ON employing controlled tile drainage and denitrifying bioreactors. The manure was mainly in the form of ammonium during application where it was transformed to other N species including nitrate and nitrous oxide (N2O) by microbial activity in soil. Large soil N2O fluxes occurred in fields throughout 2012 and 2013, and total N of soil in the fields was enriched in 15N, indicating denitrification. Soil nitrate was also leached and collected by drainage tiles, and a portion of the tile water was treated by denitrifying bioreactors. Previous studies have demonstrated that denitrification of nitrate in bioreactors elicits the production of N2O, which is emitted from the overlying soil surface and/or is released as dissolved N2O in tile effluent. In this study, it is found that a decrease in nitrate was associated with decreasing levels of nitrous oxide during a rain event, and no significant N2O flux was recorded above bioreactors throughout either year. The δ15N and δ18O signatures of nitrate did not change significantly following bioreactor treatment and did not exhibit the 15N and 18O enrichment that is characteristic of denitrification. The data demonstrates that the decrease in nitrate through the bioreactors was due to dilution, likely from the accumulation of rainfall in reactor beds employing controlled tile drainage. Further work is needed to examine the conditions under which dilution may occur in place of denitrification.

A computer-aided design scheme for both man-made and natural runoff systems is presented. The model uses linear programming to solve Muskingum routing equations through a drainage system, and provides design information through post-optimality (sensitivity) analysis. With the objective of minimizing the peak outflow from the system and using hydrograph ordinates as the decision variables, the output of the linear programming analysis shows the extent that each flow ordinate at every node in the network influences the peak flow at some downstream location. This information can aid the user in speeding up the design process to arrive at an efficient design - i.e., one which either minimizes construction costs or reduces the potential risk of flood damage. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Drainage water management via controlled drainage (CD) and subirrigation (SI) has shown positive effects on water quality. To determine the impact of CD and SI in the Red River Valley (RRV), data from two fields, each with CD and SI, were analyzed. Water samples taken during SI from a North Dakota field during 2012-2018 were significantly different from those taken during CD and free drainage (FD). This was likely due to the SI water source of marginal quality, which also impacted soil quality near the drain tile. Three Minnesota fields were compared during 2013-2019, each with differing drainage practices. Results from a rainfall event showed an intermediate water table depth in the CD and SI field, along with a higher phosphate but lower nitrate concentration in surface runoff samples compared to subsurface drainage samples. Despite differences found between these fields, correlation between drainage practice and crop yield was not present.

Background and Purpose: Percutaneous transhepatic biliary drainage remains a painful procedure in many cases despite the routine use of large amounts of intravenous sedation. We present a feasibility study of thoracic paravertebral blocks in an effort to reduce pain during and following the procedure and reduce requirements for intravenous sedation. Methods: Ten consecutive patients undergoing biliary drainage procedures received fluoroscopically guided paravertebral blocks and then had supplemental intravenous sedation as required to maintain patient comfort. Levels T8-T9 and T9-T10 on the right were targeted with 10-20 ml of 0.5% bupivacaine. Sedation requirements and pain levels were recorded. Results: Ten biliary drainage procedures in 8 patients were performed for malignancy in 8 cases and for stones in 2. The mean midazolam use was 1.13 mg IV, and the mean fentanyl requirement was 60.0 μg IV in the block patients. Two episodes of hypotension, which responded promptly to volume replacement, may have been related to the block. No serious complications were encountered. The mean pain score when traversing the chest wall, liver capsule, and upon entering the bile ducts was 0.1 on a scale of 0 to 10, with 1 patient reporting a pain level of 1 and 9 reporting 0. The mean peak pain score, encountered when manipulating at the common bile duct level or when addressing stones there, was 5.4 and ranged from 0 to 10. Conclusions: Thoracic paravertebral block with intravenous sedation supplementation appears to be a feasible method of pain control during biliary interventions.