ENERGETIC BIOCIDAL MATERIALS AND SPORE NEUTRALIZATION

The objective of this dissertation is to explore a more accurate and versatile approach to investigating the neutralization of spores suffered from ultrafast heating and biocide based stresses, and further to explore and understand novel methods to supply ultrafast heating and biocides through nanostructured energetic materials A surface heating method was developed to apply accurate (± 25 ˚C), high heating rate thermal energy (200 - 800 ˚C, ~103 - ~105 ˚C/s). Uniform attachment of bacterial spores was achieved electrophoretically onto fine wires in liquids, which could be quantitatively detached into suspension for spore enumeration. The spore inactivation increased with temperature and heating rate, and fit a sigmoid response. The neutralization mechanisms of peak temperature and heating rate were correlated to the DNA damage at ~104 ˚C/s, and to the coat rupture by ultrafast vapor pressurization inside spores at ~105 ˚C/s. Humidity was found to have a synergistic effect of rapid heating and chlorine gas to neutralization efficiency. The primary neutralization mechanism of Cl2 and rapid heat is proposed to be chlorine reacting with the spore surface. The stress-kill correlation above provides guidance to explore new biocidal thermites, and to probe mechanisms. Results show that nano-Al/K2S2O8 released more gas at a lower temperature and generated a higher maximum pressure than the other nano-Al/oxysalts. Given that this thermite formulation generates the similar amount of SO2 as O2, it can be considered as a potential candidate for use in energetic biocidal applications. The reaction mechanisms of persulfate and other oxysalts containing thermites can be divided into two groups, with the reactive thermites (e.g. Al/K2S2O8) that generate ~10× higher of pressure and ~10× shorter of burn time ignited via a solid-gas Al/O2 reaction, while the less reactive thermites (e.g. Al/K2SO4) following a condensed phase Al/O reaction mechanism. These different ignition mechanisms were further re-evaluated by investigating the roles of free and bound oxygen. A constant critical reaction rate for ignition was found which is independent to ignition temperature, heating rate and free vs. bound oxygen.

INNOVATIONS IN FRENCH CHAMBER MUSIC AND MÉLODIE (1886 – 1962) – A COLLABORATIVE PIANIST’S PERSPECTIVE

French chamber music in the last quarter of the nineteenth century displayed significant advances in musical innovations and technical developments. As the Parisian public began to favor instrumental music and mélodie over opera, vocal and chamber music with piano became one of the main genres to express French composers’ creativity and individuality. The composers Franck, Debussy, Fauré, Duparc, Ravel, Chausson and Poulenc were the major contributors to this unusually creative period in French music. French mélodies of this period blend precision with lyricism, and demand the performer’s elegance and wit. They show careful settings of the French language’s rhythmic subtleties and increased expressiveness in and importance of the piano accompaniment. The chamber works of this period demanded superior pianistic and instrumental virtuosity while displaying wide ranges of sonority, multiple tone colors, and rhythmic fluidity. The three recitals which comprise this dissertation project were performed at the University of Maryland Gildenhorn Recital Hall on 27 October 2006, All Nations Mission Church (Dayton, NJ) on 5 December 2009, and the Leah M. Smith Lecture Hall of the University of Maryland on 11 May 2010. The repertoire included Poulenc’s Sonata for Oboe and Piano (1962) with oboist Yeongsu Kim, French mélodies by Fauré, Chausson, Debussy, Ravel and Duparc with soprano Jung-A Lee and baritone Hyun-Oh Shin, Poulenc’s Sextet for Piano, Flute, Oboe, Clarinet, Bassoon and Horn (1932-1939) with flutist Katrina Smith, clarinetist Jihoon Chang, bassoonist Erich Heckscher, hornist Heidi Littman and oboist Yeongsu Kim, Debussy’s Sonata for Cello and Piano (1915) with cellist Ji-Sook Shin, Poulenc’s Sonata for Violin and Piano (1942-1949) with violinist Ji-Hee Lim, Franck’s Sonata for Violin and Piano (1886) with violinist Na-Young Cho, Ravel’s Piano Trio (1915) with cellist Ji-Sook Shin and violinist Yu-Jeong Lee and Ravel’s Sonata for Violin and Piano (1927) with violinist Yu-Jeong Lee. The recitals were recorded on compact discs and are archived within the Digital Repository at the University of Maryland (DRUM).

The Application of an Exogenous Linear and Radial Electrical Field to an In Vitro Chronic Diabetic Ulcer Model for Evaluation as a Potential Treatment

Chronic diabetic ulcers affect approximately 15% of patients with diabetes worldwide. Currently, applied electric fields are being investigated as a reliable and cost-effective treatment. This in vitro study aimed to determine the effects of a constant and spatially variable electric field on three factors: endothelial cell migration, proliferation, and angiogenic gene expression. Results for a constant electric field of 0.01 V demonstrated that migration at short time points increased 20-fold and proliferation at long time points increased by a factor of 1.40. Results for a spatially variable electric field did not increase directional migration, but increased proliferation by a factor of 1.39 and by a factor of 1.55 after application of 1.00 V and 0.01 V, respectively. Both constant and spatially variable applied fields increased angiogenic gene expression. Future research that explores a narrower range of intensity levels may more clearly identify the optimal design specifications of a spatially variable electric field.