Plasma Discharges in Gas Bubbles in Liquid Water: Breakdown Mechanisms and Resultant Chemistry.

The use of atmospheric pressure plasmas in gases and liquids for purification of liquids has been investigated by numerous researchers, and is highly attractive due to their strong potential as a disinfectant and sterilizer. However, the fundamental understanding of plasma production in liquid water is still limited. Advancements in the field will rely heavily on the development of innovative diagnostics. This dissertation investigates several aspects of electrical discharges in gas bubbles in water. Two primary experimental configurations are investigated: the first allows for single bubble breakdown analysis through the use of an acoustic trap. The second experiment investigates the resulting liquid phase chemistry that is driven by a dielectric barrier discharge in the bulk liquid. Breakdown mechanisms of attached and unattached gas bubbles in liquid water were investigated using the first device. The breakdown scaling relation between breakdown voltage, pressure and dimensions of the discharge was studied and a Paschen-like voltage dependence was discovered. High-speed photography suggests the phenomenon of electrical charging of a bubble due to a high voltage pulse, which can be significant enough to prevent breakdown from occurring. The resulting liquid-phase chemistry of the plasma-bubble system was also examined. Plasma parameters such as electron density, gas temperature, and molecular species production are found to have both a time-dependence and gas dependence. These dependencies afford effective control over plasma-driven decomposition. The effect of plasma-produced radicals on various wastewater simulants is studied. Various organic dyes, halogenated compounds, and algae water are decomposed and assessed. Toxicology studies with melanoma cells exposed to plasma-treated dye solutions are completed; treated dye solution were found to be non-toxic. Thirdly, the steam plasma system was developed to circumvent the acidification associated with gas-feed discharges. This steam plasma creates its own gas pocket via field emission. This steam plasma has strong decontamination properties, with continued decomposition of contaminants lasting beyond two weeks. Finally, a “two-dimensional bubble” was developed and demonstrated as a novel diagnostic device to study the gas-water interface, the reaction zone. This device is shown to provide convenient access to the reaction zone and decomposition of various wastewater simulants is investigated.PhDNuclear Engineering and Radiological SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/116739/1/sngucker_3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/116739/2/sngucker_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/116739/3/sngucker_1.pd

The Invading Fly: Innovative Pest Management Solutions for Control of Bactrocera Invadens in Pemba, Zanzibar

An integrated pest management study was conducted targeting the invasive fruit fly, Bactrocera invadens, on the island of Pemba, Zanzibar. Male annihilation technique (MAT) traps were set in geographically dispersed sites featuring mango fruit hosts. Three locally sourced essential oils,eucalyptus citriodora, clove and lemongrass were tested against the standard attractant methyl eugenol. Rainfall quantities at each site were collected and interviews with local farmers were conducted on the subject of B. invadens infestation and management. Over the course of the two week study, April 2nd to April 18th, 2014, methyl eugenol baited traps had an average catch of 2465.75 flies per trap, which was significantly different than the 331.45 and 141.7 average fruit fly catch for eucalyptus citriodora oil and clove oil respectively. Lemongrass lagged even further with behind with a negligible number of five flies captured during the entirety of the study. These results represent the effectiveness of eucalyptus citriodora and clove oil as attractants in an integrated pest management (IPM) strategy to combat the infestation by this prolific invasive pest

Dieulouard – Pré Maillot (phase 1)

Identifiant de l'opération archéologique : 137061 Date de l'opération : 2008 (EX) Le projet de création d'une gravière sur la commune de Dieulouard a fait l'objet d'un diagnostic archéologique au lieu-dit Pré Maillot,sur une emprise de 10,4 ha. Trois blocs architecturaux en calcaire blanc local ont été prélevés dans les niveaux de remblais, liés au creusement du canal, mais aucune structure archéologique n'a pu être décelée in situ

A Stochastic Shell Model of Turbulence: Numerical and Analytical Results

We consider an inviscid shell model of turbulence with the addition of Itô and Stratonovich multiplicative stochastic forcing. Numerical simulations are performed for both models that show dissipation of energy at an algebraic rate. A comparison between the Itô and Stratonovich effects is examined. Positivity of solutions is discussed and demonstrated numerically

Blénod-lès-Pont-à-Mousson – ZAC Les Longues Rayes

Identifiant de l'opération archéologique : 137011 Date de l'opération : 2008 (EX) Le diagnostic archéologique réalisé au lieu-dit de la ZAC Les Longues Rayes,sur une superficie de 81 520 m2, a permis de mettre au jour plusieurs vestiges archéologiques, liés à une nécropole du Campaniforme d'une part et d'autre part à un habitat protohistorique caractérisé par une période d'occupation longue, qui s'étend du Bronze final à La Tène B-C. La présence d'un drain en tegulaen limite d'emprise témoign..

Simulated Beam Extraction Performance Characterization of a 50-cm Ion Thruster Discharge

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97099/1/AIAA2012-3795.pd

Complete 1H and 13C NMR assignments of a series of pergalloylated tannins

Tannins are secondary metabolites widely distributed in the plant kingdom.1 A common feature of tannins is their phenolic units, which can be linked together to form highly diverse chemical structures.2 Because these compounds constitute an important fraction of the food and beverage ingested,3 they have been thoroughly studied for their biological effects.4-6 Recently, we have performed a phytochemical study on Cornus canadensis, an abundant flowering plant growing wild in North America and giving edible fruits.7 A preliminary bioactivity screening was performed and revealed that an extract from C. canadensis was active toward Herpes simplex virus type 1.8 Following bioassay-guided fractionations, hydrolyzable tannins were identified.9 One of these compounds, namely, 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG), has been the subject of several pharmaceutical studies as recently reviewed by Zhang.10 The biological and medicinal properties of PGG are diverse and include anticancer, antioxidant, antimutagenic, anti-inflammatory, anti-allergic, hypocholesterolemic, anticoagulation, antinephrolithiasis, anticonvulsion, antiviral, and antibacterial activities. Furthermore, a series of PGG analogs were synthesized and found to be an optimal scaffold to stimulate glucose transport in adipocytes.11 Some of these compounds were also prepared in our laboratory in order to assess their antiherpetic activities. Because these analogs were only partially characterized by NMR,11 we would like to report herein the complete 1H and 13C assignments of pergalloylated D-glucose (1), D-mannose (2), D-galactose (3), D-xylose (4), L-ribose (5), L-arabinose (6), L-rhamnose (7), and D-fucose (8) by using a combination of one-dimensional and two-dimensional NMR experiments