Browsing by Subject "Wave functions"
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Item Cluster model calculations for photodisintegration of p6sLi.(Texas Tech University, 1974-08) Wood, Kathryn ElizabethNot availableItem Influence of meso exchange currents on 4He structure(Texas Tech University, 1984-05) Umerah, Gabriel AzukaThe accuracy of measurements with high energy electron scattering experiments reveals data which could no longer be explained in the light of either independent particle shell model or otherwise. We introduce a short-range correlation and meson exchange currents in the S state. We also included the D component to see whether admixture of S and D states has effect on our result. Our result shows meson exchange current has great effect on the nuclear form factor of this nucleus at large momentum transfer.Item Quantum dynamics on adaptive grids : the moving boundary truncation method(2008-12) Pettey, Lucas Richard, 1974-; Wyatt, Robert E. (Robert Eugene)A novel method for integrating the time-dependent Schrödinger equation is presented. The moving boundary truncation (MBT) method is a time-dependent adaptive method that can significantly reduce the number of grid points needed to perform accurate wave packet propagation while maintaining stability. Hydrodynamic quantum trajectories are used to adaptively define the boundaries and boundary conditions of a fixed grid. The result is a significant reduction in the number of grid points needed to perform accurate calculations. A variety of model potential energy surfaces are used to evaluate the method. Excellent agreement with fixed boundary grids was obtained for each example. By moving only the boundary points, stability was increased to the level of the full fixed grid. Variations of the MBT method are developed which allow it to be applied to any potential energy surface and used with any propagation method. A variation of MBT is applied to the collinear H+H₂ reaction (using a LEPS potential) to demonstrate the stability and accuracy. Reaction probabilities are calculated for the three dimensional non-rotating O(³P)+H₂ and O(³P)+HD reactions to demonstrate that the MBT can be used with a variety of numerical propagation techniques.Item Series solutions of third order differential equations(Texas Tech University, 1957-08) Whitworth, Freddy LouzonNot availableItem Simulation of fluid flow in internal combustion engines using wave action simulation(Texas Tech University, 2004-05) Movva, Venkata SumanEngine design is a long and costly process due to the large number of variables that have an effect on the design. Engine Simulation plays a very important role in the development of engines. It helps in analyzing the various engine configurations without actually building the engine. Thus, Engine Simulation helps in reducing the cost and time involved in developing a new engine. Many commercial codes are available in the market to simulate engines. In recent years, Wave Action Models to simulate engines are becoming popular due to their accuracy and robustness and are replacing the old Quasi- Steady and Filling and Emptying Models. There are two parts in engine simulation, fluid flow Simulation and Combustion and Heat Transfer Simulation. In this thesis an attempt has been made to simulate the fluid flow in Internal Combustion Engines and Engine manifolds using Wave Action Simulation. The Non- Linear, Hyperbolic, Partial Differential Equations are solved using the Method of Characteristics (MOC) which is the oldest and the most powerful method to formulate the boundary conditions. A FORTRAN code is developed for obtaining the pressure and velocity of the gas for various boundary conditions. Using the code the pressure and velocity at any point in the manifolds can be obtained. The compression pressure of the cylinder can also be estimated using the code. Pressure and Velocity distributions are obtained from the results obtained from the code clearly show the Wave Action Phenomenon. The results obtained using the Code developed are in excellent agreement with results obtained by other researchers.Item The effect of parity and isospin mixing on the nuclear deformation of 6LI.(Texas Tech University, 1989-05) Giancana, Peter MichaelThe nuclear shell theory has been used extensively and rather successfully to describe nuclear structure and other nuclear properties in general. However, the pure shell model has its limitations, and cannot describe some of the microscopic details of nuclear structure. For example, ordinarily 6Li can be best described in the LS coupled shell model. However, the static electric quadrupole moment of 6Li vanishes in pure LS coupling. A Jastrow-type short range correlation has been introduced into the harmonic oscillator shell model wave function. The intermediate coupling has been used by adding the P and D states to the predominantly ^'^Si ground state wave function, thus mixing different parity and isospin states. The static electric quadrupole, electric hexadecapole and magnetic dipole moments have been computed for the ground state. The electric quadrupole transition width between the 1+, 0 ground state and the 3+ ,0 first excited state (2.184 MeV) has been computed. The magnetic dipole transition width between the l+,0 ground state and the 0+, 1 second excited state (3.56 MeV) has been fitted. The best correlated, parity and isospin mixed wave function yields Q = -0.621 e•mb (-3.57%), µ = 0.892 nm (8.52%), hexadecapole = -0.112 e•fm^4 and r(E2) = 4.31 x lO^-4 eV (-2.05%).