Electronic Theses, Dissertations, and Records of Study (2002-present)

Recent Submissions

• Epifaunal Assemblages on Deep-water Corals in Roatan, Honduras

  Lavelle, Katherine (August 2012)

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  Abstract:

  Deep-water corals provide complex habitat structure for diverse assemblages of invertebrates and fishes. Similar to shallow coral reefs, oyster reefs, and seagrass beds, these complex biogenic structures serve many ecosystem functions: (a) as prey items; (b) sites for reproduction; (c) feeding stations, elevating suspension feeders above the benthos; and (d) refuges from predation. Because deep-sea corals provide some of the only three-dimensional habitats in the deep-sea, they may host distinct assemblages of epifauna. Non-destructive video surveys of deep-water coral assemblages were made to depths of 700 m at eight sites off Roatan, Honduras in May and December, 2011. Abundance, species richness, and distribution of epifauna were measured for 305 corals. We observed sixteen morphospecies of coral and twenty-six morphospecies of epifauna. Coral and epifaunal abundances were highest in the 335-449 m depth zone. Some epifauna had high fidelity for a single coral species or for a few species of similar morphological complexity. Other coral species had overlapping assemblages of habitat generalists. This is the first research on the biodiversity of deep-sea coral communities in Roatan, Honduras, and provides information on the assemblages, their depth distributions and ecological interactions.

  URI:

  http://hdl.handle.net/1969.1/148466

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  Lavelle.pdf   (1.692Mb)
• Pilot-Scale Demonstration of hZVI Process for Treating Flue Gas Desulfurization Wastewater at Plant Wansley, Carrollton, GA

  Peddi, Phani 1987- (December 2011)

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  Abstract:

  The hybrid Zero Valent Iron (hZVI) process is a novel chemical treatment platform that has shown great potential in our previous bench-scale tests for removing selenium, mercury and other pollutants from Flue Gas Desulfurization (FGD) wastewater. This integrated treatment system employs new iron chemistry to create highly reactive mixture of Fe^0, iron oxides (FeOx) and various forms of Fe (II) for the chemical transformation and mineralization of various heavy metals in water. To further evaluate and develop the hZVI technology, a pilot-scale demonstration had been conducted to continuously treat 1-2 gpm of the FGD wastewater for five months at Plant Wansley, a coal-fired power plant of Georgia Power. This demonstrated that the scaled-up system was capable of reducing the total selenium (of which most was selenate) in the FGD wastewater from over 2500 ppb to below 10 ppb and total mercury from over 100 ppb to below 0.01 ppb. This hZVI system reduced other toxic metals like Arsenic (III and V), Chromium (VI), Cadmium (II), Lead (II) and Copper (II) from ppm level to ppb level in a very short reaction time. The chemical consumption was estimated to be approximately 0.2-0.4 kg of ZVI per 1 m^3 of FGD water treated, which suggested the process economics could be very competitive. The success of the pilot test shows that the system is scalable for commercial application. The operational experience and knowledge gained from this field test could provide guidance to further improvement of technology for full scale applications. The hZVI technology can be commercialized to provide a cost-effective and reliable solution to the FGD wastewater and other metal-contaminated waste streams in various industries. This technology has the potential to help industries meet the most stringent environmental regulations for heavy metals and nutrients in wastewater treatment.

  URI:

  http://hdl.handle.net/1969.1/148465

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  Peddi.pdf   (1.263Mb)
• Performance of Assisted History Matching Techniques When Utilizing Multiple Initial Geologic Models

  Aggarwal, Akshay (December 2011)

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  Abstract:

  History matching is a process wherein changes are made to an initial geologic model of a reservoir, so that the predicted reservoir performance matches with the known production history. Changes are made to the model parameters which include rock and fluid parameters (viscosity, compressibility, relative permeability, etc.) or properties within the geologic model. Assisted History Matching (AHM) provides an algorithmic framework to minimize the mismatch in simulation, and aids in accelerating this process. The changes made by AHM techniques, however, cannot ensure a geologically consistent reservoir model. In fact, the performance of these techniques depends on the initial starting model. In order to understand the impact of the initial model, this project explored the performance of the AHM approach using a specific field case, but working with multiple distinct geologic scenarios. This project involved an integrated seismic to simulation study, wherein I interpreted the seismic data, assembled the geological information, and performed petrophysical log evaluation along with well test data calibration. The ensemble of static models obtained was carried through the AHM methodology. I used sensitivity analysis to determine the most important dynamic parameters that affect the history match. These parameters govern the large scale changes in the reservoir description and are optimized using the Evolutionary Strategy Algorithm. Finally, the streamline based techniques were used for local modifications to match the water cut well by well. The following general conclusions were drawn from this study- a) The use of multiple simple geologic models is extremely useful in screening possible geologic scenarios and especially for discarding unreasonable alternative models. This was especially true for the large scale architecture of the reservoir. b) The AHM methodology was very effective in exploring a large number of parameters, running the simulation cases, and generating the calibrated reservoir models. The calibration step consistently worked better if the models had more spatial detail, instead of the simple models used for screening. c) The AHM methodology implemented a sequence of pressure and water cut history matching. An examination of specific models indicated that a better geologic description minimized the conflict between these two match criteria.

  URI:

  http://hdl.handle.net/1969.1/148464

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  Aggarwal.pdf   (5.549Mb)
• Challenges and Techniques for Personal Environment Management

  Zacchi, Anna 1967- (December 2011)

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  Abstract:

  People today use the computer for many simultaneous work projects and activities. The traditional file system was developed for storing and retrieving files and it and the desktop have not evolved with users' practices. The first part of the dissertation presents a user study that generates a better understanding of the issues and practices regarding the organization of documents in support of activities. The second part provides the design of an environment to organize information based on an activity paradigm as opposed to an archiving paradigm and delivers the instantiation and the evaluation of a system based on such a design. The system, called Docksy, provides an environment structured in workspaces. Each workspace is segmented in areas or panels. Users can use documents as elements to structure their workflow or to manage their activities by separating files in the different panels, and by adding comments, tags, and flags. The Docksy design aims to create a flexible, lightweight environment that is easy to use and can be incorporated into users' daily practice, old or new. Such a system could be used to learn about users' practices and their evolution. Docksy was therefore developed for a double purpose; the short term purpose of testing new features (panels, comments, flags, and tags) and the long term purpose of facilitating learning about user practices. A study of Docksy use was conducted in which twenty participants used Docksy for at least two weeks and they were then interviewed. The study showed that participants valued the panels and the comment features. The results of the study showed the potential for changing users' practice and the potential for the system to be adopted by users.

  URI:

  http://hdl.handle.net/1969.1/148463

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  Zacchi.pdf   (6.008Mb)
• I. A1,3-Strain Enabled Retention of Chirality During Bis-Cyclization of β-Ketoamides: Asymmetric Synthesis and Bioactivity of Salinosporamide A and Derivatives II. Optimization of an Organic Syntheses: Asymmetric Nucleophile-Catalyzed Aldol- Lactonization of Aldehyde Acids

  Nguyen, Henry (December 2010)

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  Abstract:

  The potential of human 20S proteasome inhibitors continues to be of interest for anticancer chemotherapy and the recent FDA approval of bortezomib (Velcade) validates the proteasome as a target for cancer chemotherapy. Salinosporamide A, a marine unique bicycle [3.2.0] Beta-lactone-containing natural product, is not only a potent nanomolar inhibitor of the human proteasome but also active against bortezomibresistant multiple myeloma cells. The racemic and asymmetric syntheses of salinosporamide A and derivatives were targeted. In this dissertation, we successfully accomplished the shortest route to date with only a 9-step total synthesis of (–)-salinosporamide A. The conciseness of this strategy arises from the key bis-cyclization of a Beta-keto tertiary amide, amenable to gram scale, constructs both the Gamma-lactam and the fused-Beta-lactone in one operation with high enantiopurity, which was enabled by A^1,3-strain. Several derivatives were synthesized and their inhibition activity toward chymotripsin-like, caspase-like, and trypsin-like of the human 20S proteasome was evaluated. This dissertation also included a successfully optimized Organic Syntheses procedure for asymmetric synthesis of (1S,5R)-6-oxaspiro[bicyclo[3.2.0]heptane-3,2'- [1,3]dioxolan]-7-one via the nucleophile-catalyzed aldol-lactonization.

  URI:

  http://hdl.handle.net/1969.1/148462

  Files in this item: 1

  Nguyen.pdf   (6.543Mb)