The utilization of extra-high-voltage underground power cables
over distances greater than 100 miles presents serious problems relative
to the voltage and current limits of such cables. These problems
are directly associated with the fixed amount of capacitance inherent
in long cable lines. As a result, large charging currents are
characteristic...
The focus of this thesis is a study of the thermodynamics and
the transport of oxygen in yttrium-doped cubic zirconia (Zr0₂). This
material is representative of other ceramics with the same crystal
structure (Y-Ce0₂ etc.). The Monte Carlo technique as developed by
Metropolis et al. is used to calculate thermodynamical...
Total energy calculations based on density functional theory are generally a good
approach to obtain the properties of solids. The local density approximation (LDA) is
widely used for calculating the ground state properties of electronic systems; for excited
states the errors are in general unknown. The important aspects of LDA...
Experimental data on the structural phase changes in zirconia are summarized. The computational techniques of molecular dynamics are reviewed and equations of motion are formulated which allow the study of phase changes as a function of temperature and pressure. The molecular dynamics program NPT which was written for this purpose...
Molecular dynamics is a technique in which the
trajectories of a group of particles are calculated as a
function of time by integrating the equations of motion. In
this thesis we study the use of molecular dynamics for atoms
in a crystal.
A model is introduced which describes interactions of...
The magnetocrystalline anisotropy energy (MAE) for fcc Ni and bcc Fe is calculated as the difference of single particle energy eigenvalue sums using a tight-binding model. For nickel we predict a MAE of -0.15 eV and the wrong easy axis, for iron we find a MAE of -0.7 eV with...
Immersion energies of atoms in a jellium environment were calculated using density functional theory and the Kohn-Sham (KS) equations. It was found that the KS scheme does not destroy an existing axial symmetry of the electron structure of the impurity atom. The definition of phase shifts was extended to those...
A large amount of research has been done in which the magnetocrystalline anisotropy energy for fcc Ni and bcc Fe was calculated based on the electronic structure of these elements. Unfortunately; the results of these studies don't agree with each other and also differ from the experimental observation. In a...