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Full-Text Articles in Applied Mathematics

Energy Functional For Nuclear Masses, Michael Giovanni Bertolli Dec 2011

Energy Functional For Nuclear Masses, Michael Giovanni Bertolli

Doctoral Dissertations

An energy functional is formulated for mass calculations of nuclei across the nuclear chart with major-shell occupations as the relevant degrees of freedom. The functional is based on Hohenberg-Kohn theory. Motivation for its form comes from both phenomenology and relevant microscopic systems, such as the three-level Lipkin Model. A global fit of the 17-parameter functional to nuclear masses yields a root- mean-square deviation of χ[chi] = 1.31 MeV, on the order of other mass models. The construction of the energy functional includes the development of a systematic method for selecting and testing possible functional terms. Nuclear radii are computed within …


Transverse Waves In Simulated Liquid Rocket Engines With Arbitrary Headwall Injection, Charles Toufic Haddad Dec 2011

Transverse Waves In Simulated Liquid Rocket Engines With Arbitrary Headwall Injection, Charles Toufic Haddad

Masters Theses

This work introduces a closed-form analytical solution for the transverse vorticoacoustic wave in a circular cylinder with arbitrary headwall injection. This particular configuration mimics the conditions leading to the onset of traveling radial and tangential waves in a simple liquid rocket engine (LRE). Assuming a short cylindrical chamber with an injecting headwall, regular perturbations are used to linearize the problem’s mass, momentum, energy, ideal gas and isentropic relations. A Helmholtz decomposition is subsequently applied to the first-order disturbance equations, thus giving rise to a compressible, inviscid and acoustic set that is responsible for driving the unsteady motion and to an …


Electronic Excitations In Ytio3 Using Tddft And Electronic Structure Using A Multiresolution Framework, William Scott Thornton Aug 2011

Electronic Excitations In Ytio3 Using Tddft And Electronic Structure Using A Multiresolution Framework, William Scott Thornton

Doctoral Dissertations

We performed ab initio studies of the electronic excitation spectra of the ferro- magnetic, Mott-insulator YTiO3 using density functional theory (DFT) and time- dependent density functional theory (TDDFT). In the ground state description, we included a Hubbard U to account for the strong correlations present within the d states on the cation. The excitation spectra was calculated using TDDFT linear response formalism in both the optical limit and the limit of large wavevector transfer. In order to identify the local d-d transitions in the response, we also computed the density response of YTiO3 using a novel technique where the basis …