2 resultados para NANOCOMPOSITE SPHERES

em DRUM (Digital Repository at the University of Maryland)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This dissertation project explored the spheres of influence on art song by Nadia Boulanger, Erik Satie, and Claude Debussy within Boulangeries, Les Six, and Les Apaches. After World War I, American composers flocked to Paris to study with Boulanger. Boulanger gave her students the confidence to explore their native talents instead of mimicking foreign models. Works by Aaron Copland, Virgil Thomson, Theodore Chanler, John Duke, and Richard Hundley were included in the first dissertation recital on January 31, 2010: The Legacy of Nadia Boulanger: Her Influence on American Song Composers. Satie established a new modern French musical style, and was a catalyst for the formation of Les Six. Ned Rorem came to Paris, and had a close association with Les Six. Works by Satie, and three members of Les Six, Francis Poulenc, Arthur Honegger, Darius Milhaud; and Rorem were featured in the second recital on September 1, 2010: Satie, Selected Members of Les Six, and Rorem in Paris. Debussy was one of the most significant French composers in the late nineteenth century, predating Boulanger and Satie. Young composers exploring new directions were inspired by Debussy, forming the group Les Apaches. The final recital, April 7, 2011, featured works by Debussy and two members of Les Apaches, Maurice Ravel and Manuel de Falla: Debussy: A Catalyst for Les Apaches, Ravel and Falla. Falla‘s less well-known repertoire was presented. This dissertation showed the influence of these three major figures and that they embraced innovation in their own time, along with their followers. Recordings of these three performances may be obtained from the Michelle Smith Performing Arts Library in Clarice Smith Performing Arts Center at the University of Maryland, College Park.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nanocomposite energetics are a relatively new class of materials that combine nanoscale fuels and oxidizers to allow for the rapid release of large amounts of energy. In thermite systems (metal fuel with metal oxide oxidizer), the use of nanomaterials has been illustrated to increase reactivity by multiple orders of magnitude as a result of the higher specific surface area and smaller diffusion length scales. However, the highly dynamic and nanoscale processes intrinsic to these materials, as well as heating rate dependencies, have limited our understanding of the underlying processes that control reaction and propagation. For my dissertation, I have employed a variety of experimental approaches that have allowed me to probe these processes at heating rates representative of free combustion with the goal of understanding the fundamental mechanisms. Dynamic transmission electron microscopy (DTEM) was used to study the in situ morphological change that occurs in nanocomposite thermite materials subjected to rapid (10^11 K/s) heating. Aluminum nanoparticle (Al-NP) aggregates were found to lose their nanostructure through coalescence in as little as 10 ns, which is much faster than any other timescale of combustion. Further study of nanoscale reaction with CuO determined that a condensed phase interfacial reaction could occur within 0.5-5 µs in a manner consistent with bulk reaction, which supports that this mechanism plays a dominant role in the overall reaction process. Ta nanocomposites were also studied to determine if a high melting point (3280 K) affects the loss of nanostructure and rate of reaction. The condensed phase reaction pathway was further explored using reactive multilayers sputter deposited onto thin Pt wires to allow for temperature jump (T-Jump) heating at rates of ~5x10^5 K/s. High speed video and a time of flight mass spectrometry (TOFMS) were used to observe ignition temperature and speciation as a function of bilayer thickness. The ignition process was modeled and a low activation energy for effective diffusivity was determined. T-Jump TOFMS along with constant volume combustion cell studies were also used to determine the effect of gas release in nanoparticle systems by comparing the reaction properties of CuO and Cu2O.