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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.
511

Pore-scale analysis of thermal remediation of NAPL-contaminated subsurface environments

Ahn, Min 15 May 2009 (has links)
The possible benefits of thermal remediation of NAPL-contaminated subsurface were analyzed at pore-scale. Force balance analysis was performed to provide the insight and information on the critical conditions for the blob mobilization. First, the critical blob radius for blob mobilization was calculated in terms of blob radius, temperature, and water velocity. Temperature increase enhanced the blob mobilization along with the decrease of interfacial tension. Water velocity increase also enhanced the blob mobilization. Critical water velocity provided the critical condition for the initiation of blob mobilization to distinguish singlet and doublet in blob size. Second, the terminal (or steady state) blob velocity at the steady state blob motion was determined. Increases of temperature and water velocity raised the terminal blob velocity. When the observation of blob mobilization moved from REV scale (macroscale) to pore-scale, terminal blob velocity showed the different phenomena according to the change of oil saturation. At macro-scale, the terminal blob velocity was smaller than water velocity by an order or two. However, the terminal blob velocity reached to water velocity at pore-scale. This investigation would provide the better understanding on the pore-scale analysis of residual NAPL blob mobilization by thermal remediation. Additionally, the pore-scale analysis developed in this study would be incorporated into a general conservation equation in terms of the accumulation of multiple blobs. It would derive continuumaveraged equations that accurately represent pore-level physics. In conclusion, the study on the critical conditions for the initiation of blob mobilization as a single discrete blob would have some contribution to the transport and fate of NAPL contaminant and the desired subsurface remediation.
512

Laboratory Study Investigating the Three-dimensional Turbulence and Kinematic Properties Associated with a Breaking Solitary Wave

Swigler, David Townley 2009 August 1900 (has links)
A laboratory experiment was performed to investigate the three-dimensional turbulence and kinematic properties that develop due to a breaking solitary and an irregular shallow water bathymetry. A large basin equipped with a piston-type wavemaker was used to generate the wave, while the free surface elevations and fluid velocities were measured using wave gauges and three-dimensional acoustic-Doppler velocimeters (ADVs), respectively. From the free surface elevations, the evolution and runup of the wave was revealed; while from the ADVs, the velocity and turbulent energy was determined to identify specific turbulent events and coherent structures. It was found that shoaling was confined to areas with gentler sloping bathymetry near the basin side walls and the runup shoreward of the still water shoreline was not uniform. The runup was characterized by a jetting mechanism caused by the convergence of water mass near the basin centerline as the wave refracted during breaking. The jetting mechanism caused the greatest cross-shore velocities to be located near the basin centerline. The greatest turbulent events were well correlated to borefronts, resembling hydraulic jumps, where the greatest shear and fluid accelerations occurred. Because of an abrupt change in the bathymetry, a coherent structure developed which was found to have a three-dimensional flow field. It was proposed that variations in the internal flow with depth were due to the orientation of multiple vortex rings.
513

Effects of Winter Overseeding and Three-demensional Clipping Management on Warm-season Turfgrasses

Fontanier, Charles H. 2010 May 1900 (has links)
Perennial ryegrass (Lolium perenne L.) is commonly overseeded into hybrid bermudagrass [Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy] turfs during autumn in the southern United States. Overseeding can provide a green, actively-growing turf throughout the winter dormancy period. Improved persistence of perennial ryegrass cultivars has increased management inputs during the spring transition period. Lower input turf systems that provide acceptable winter overseeding quality are preferred, and research aimed at evaluating alternative overseeding species are warranted. Grooming reel attachments allowing for threedimensional clipping management (3DCM) have become increasingly used by turf managers for reducing grain and thatch, but scientific information on best management practices and canopy effects of 3DCM-grooming are lacking. A field study was conducted at the Texas A&M Turfgrass Field Laboratory in College Station, TX (30.6191 degrees N, 96.3576 degrees W), to investigate the effects of overseeding using annual (Lolium multiflorum Lam.) and perennial ryegrasses on 3DCM-groomed and non-groomed fairway turfs of 'Tifway' hybrid bermudagrass, zoysiagrass [Zoysia matrella (L.) Merr. 'Cavalier'], and seashore paspalum (Paspalum vaginatum Sw. 'Sea Isle 1'). The study was arranged as a randomized complete block split-split-plot with three replications. Species whole main plots were split into three grooming intervals, which were further split into four overseeding treatments. Data were collected assessing visual turf quality, visual turf cover, leaf area index, clipping yield, shoot density, and biomass partitioning. Results indicate annual ryegrass alone and an annual/perennial ryegrass overseeding mix provided acceptable turf quality, but did not improve turf recovery over perennial ryegrass alone in 'Tifway' or 'Sea Isle 1' turfs. In 'Cavalier' turfs, summer quality was affected by overseeding treatment as follows: control > annual > annual/perennial > perennial. The overseeding tolerance of the warm-season turfgrasses was as follows: 'Sea Isle 1' > 'Tifway' > 'Cavalier'. Differences in canopy architecture of warm-season turfgrasses were related to the overseeding tolerance of each species and used to explain plant competition during the spring transition period. Grooming by 3DCM improved late-season turf quality and reduced scalping in 'Tifway'. Overseeding establishment and canopy architecture were not affected by 3DCM.
514

The Venetian Galley of Flanders: From Medieval (2-Dimensional) Treatises to 21st Century (3-Dimensional) Model

Higgins, Courtney Rosali 2012 May 1900 (has links)
Nautical archaeologists and scholars often try to recreate how ships were built and maneuvered. Due to the delicate nature of older wooden vessels, there is often little archaeological evidence remaining to aid in these studies, and researchers must supplement what little they have with other resources, such as texts. By using computer programs to synthesize and enhance the information in the texts, scholars can better understand the vessel and explore questions that even hull remains may not be able to address. During the High to Late Middle Ages, Venice was a key city for trade and commerce. Its location on the Adriatic Sea connected merchants throughout mainland Europe and the Mediterranean Sea. Since its founding in the low Middle Ages, Venice has been connected to the sea, leading to a long history of seafaring and shipbuilding. By the end of the Middle Ages, Venice had established several trade routes throughout the Mediterranean and Black Seas, and one long sea route into the Atlantic, to Lisbon, Flanders, and London. Although no archaeological evidence of these galleys have been found, several contemporary texts describe the merchant galleys of the 15th century. Two of these texts, dating to the first half of the 15th century discuss the dimensions the galley: The book of Michael of Rhodes and the book of Giorgio "Trombetta" da Modone. Perhaps complementary copies of the same original, these texts contain enough information to reconstruct a 3-dimensional model of the galley of Flanders's hull, in this case using off-the-shelf software ((Rhinoceros). From this computer model the vessel can then be analyzed for volumetric information in order to better understand the hull capacity and how the ship was laden.
515

On Design of new Complementary Codes

Yang, Chih-yuan 02 September 2005 (has links)
In this thesis, we propose a new way to generate orthogonal code distinct from complete complementary (CC) code and Super CC code but it still have ideal auto-correlation and cross-correlation property. We also introduce the concept of correlation and propose six rules to determine if the code generated by different ways are the same.After that we use the rules on orthogonal matrix and find a new way to generate orthogonal matrix different from Hadamard marix. Then we will use this marix in 2-D orthogonal variable spreading factor (OVSF) code and generate similar codes.
516

Generating Implicit Functions Model from Triangles Mesh Model by Using Genetic Algorithm

Chen, Ya-yun 09 October 2005 (has links)
The implicit function model is nowadays generally applied to a lot of fields that need 3D, such as computer game, cartoon or for specially effect film. So far, most hardware are still to support the polygon-mesh model but not implicit function model, so polygon-mesh model is still the mainstream of computer graphics. However, translation between the two representation models becomes a new research topic. This paper presents a new method to translate the triangles mesh model into the implicit functions model. The main concept is to use the binary space-partitioning tree to divide the points and patches in the triangle mesh model to create a hierarchical structure. For each leaf node in this hierarchical structure, we would generate a corresponding implicit function. These implicit functions are generated by the genetic algorithm. And the internal nodes in this hierarchical structure are blended by the blending operators. The blending operators make the surface become smooth and continual. The method we proposed reduces the data in a large amount because we only save the coefficients of the implicit surface. And the genetic algorithm can avoid the high computing complexity.
517

Proteomic analysis of nitrile-induced proteins in Klebsiella oxytoca

Chou, Shu-min 06 September 2006 (has links)
The cyanide-degradation bacteria Klebsiella oxytoca SYSU-110 was isolated from the waste water of a metal-plating plant in southern Taiwan. K. oxytoca can utilize many nitrile compounds [including acetonitrile (100 mM), benzonitrile (1 mM), butyronitrile (100 mM), glutaronitrile (50 mM), methacrylnitrile (100 mM), phenylacetonitrile (1 mM), propionitrile (25 mM), succinonitrile (25 mM) and valeronitrile (50 mM)] as its sole nitrogen source. In this study, we found out that K. oxytoca was capable of degrading acetonitrile and propionitrile. Frome GC analysis, we recognized amide was an intermediate compound, while the carboxylic acid and ammonia were the final end-products. Therefore, we presume that K. oxytoca biodegraded nitrile compounds by two enzymes, the nitrile hydratase and amidase. We also analyzed the total cell proteins by 2-D polyacrylamide gel electrophoresis after the cells were cultured in medium containing 25mM succinonitrile. There were 23 proteins could be induced or overexpressed by nitrile and we had identified 11 by Mascot Peptide mass Fingerprint and Blast. Six proteins that can protect the cells from oxidative damage are: superoxide dismutase, glutathione s-transferase, dyp-type peroxidase, metal binding protein PsaA (that can transport metal ions into the cells), LraI, and FepA (used to transport inorganic ions into the cells). Three enzymes glutamine synthetase, methylenetetrahydrofolate reductase,¡@and dihydroxyacid dehydratase were used to synthesize amino acids. One protein was identified as ribosomal protein L9. The last identified protein is nucleoside triphosphates kinase which can convert nucleoside diphosphates to nucleoside triphosphates non-specifically. From the activity analysis, superoxide dismutase and glutathione S-transferase activities were escalated when the cells were cultured in 25mM succinonitrile, and the concentration of ROS has rise. These results suggested that succinonitrile could cause oxidative damage to the cells and induce some anti-oxidative damage proteins to protect them.
518

Exotic Smooth Structures On Non-simply Connected 4-manifolds

Topkara, Mustafa 01 March 2010 (has links) (PDF)
In this thesis, we study exotic smooth structures on 4-manifolds with finite fundamental groups. For an arbitrary finite group G, we construct an infinite family of smooth 4-manifolds with fundamental group G, which are all homeomorphic but mutually non-diffeomorphic, using the small symplectic manifold with arbitrary fundamental group constructed by S. Baldridge and P. Kirk, together with the methods of A. Akhmedov, R.&amp / #221 / . Baykur and D. Park for constructing infinite families of exotic simply connected 4-manifolds. In the final chapter, pairs of small exotic 4-manifolds with a cyclic fundamental group of any odd order are constructed.
519

ADVANCED NEW NEUROSURGICAL PROCEDURE USING INTEGRATED SYSTEM OF INTRAOPERATIVE MRI AND NEURONAVIGATION WITH MULTIMODAL NEURORADIOLOGICAL IMAGES

WAKABAYASHI, TOSHIHIKO, FUJII, MASAZUMI, KAJITA, YASUKAZU, NATSUME, ATSUSHI, MAEZAWA, SATOSHI, YOSHIDA, JUN 09 1900 (has links)
No description available.
520

THREE-DIMENSIONAL COMPUTED TOMOGRAPHIC ANALYSIS FOR PLACEMENT OF MAXILLOFACIAL IMPLANTS AFTER MAXILLECTOMY

KANEDA, TOSHIO, SAWAKI, YOSHIHIRO, UEDA, MINORU 25 November 1993 (has links)
No description available.

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