published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 173-184).

Thesis (doctoral)--Rheinische Friedrich-Wilhelms-Universität Bonn, 2002. / Includes bibliographical references (p. 113-119).

The beet-boot and said-shed continua were created in 2001. Each continuum has 13 stimuli and there are a total of four continua (one each of beet-boot and said-shed for a female and a male speaker). There are two kinds of files in this archive, parameter and audio. The parameter files have the .doc extension, but they are text files that serve as input to a Klatt synthesizer rather than Microsoft Word files. The audio files are Microsoft .wav files that have the .wav extension. / NIDCD (No. DC003007)

No description available.

The energy convergence of mixed methods of approximate analysis for problems involving linear self-adjoint operators is investigated. A new energy product and the associated energy norm are defined for such indefinite systems and then used in establishing the strain energy convergence and estimation of error for problems in continuum mechanics. In the process, the completeness requirements are laid out for approximate solutions. Also established is the mean convergence of the basic variable e.g. displacements and stresses. After accomplishing a new mathematical framework for the mixed methods in continuum, the theory is then extended to the finite element method. The completeness requirements, convergence criteria and the effect of continuity requirements on convergence are established. The flexibility offered by the mixed methods in incorporating the boundary con ditions is also demonstrated. For stress singular problems, the strain energy convergence is established and an energy release method for determining the crack intensity factor K. is presented. A detailed eigenvalue-eigenvector analysis of the mixed finite element matrix is carried out for various combinations of interpolations for the plane stress linear elasticity and the linear part of the Navier-Stokes equations. Also discussed is its relation to the completeness requirements. Finally, numerical results are obtained from applying the mixed finite element method to several examples. These include beam bending, a plane stress square plate with parabolically varying end loads, a plane stress cantilever and plane strain stress concentration around a circular hole. A plane stress example of a square plate with symmetric edge cracks is also solved to study the strain energy convergence. Lastly, two rectangular plates, one with symmetric edge cracks and the other with a central crack are considered to determine the crack intensity factor K. In most of the examples, the strain energy convergence rates are predicted and compared with the numerical results, and excellent agreement is observed. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

In this thesis, the first-order and higher-order interferences on the total (Coulomb+nuclear), Coulomb and nuclear breakup cross sections in the 15C+208Pb, 11Be+208Pb breakup reactions are first studied at 68 MeV/u incident energy. It is shown that the first-order interference reduces by more than 60% the total breakup cross sections, by less than 3% the Coulomb breakup cross sections and by more than 85% the nuclear breakup cross sections, for both reactions. On the other hand, the high-order interference is found to reduce by less than 9% the total breakup cross section, less than 1% the Coulomb breakup cross section and less than 7% the nuclear breakup cross section for the 15C+208Pb reaction. For the 11Be+208Pb reaction however, the high-order interference reduces by less than 7% the total breakup cross section, by less than 1% the Coulomb breakup cross section and by less than 4% the nuclear breakup cross section. It is finally shown that even at first-order, the incoherent sum of the nuclear breakup cross sections is more important than the incoherent sum of the Coulomb breakup cross sections for the two reactions. The role of the diagonal and off-diagonal continuum-continuum couplings on total, Coulomb and nuclear breakup cross sections is also investigated for the 8B+58Ni, 8B+208Pb and 19C+208Pb at 29.3, 170.3 MeV and 1273 MeV incident energies respectively. Qualitatively, we found that, the diagonal continuum-continuum couplings are responsible for the large reduction of the differential total and nuclear breakup cross sections at backward angles. At forward angles, this reduction is due to the off-diagonal continuum-continuum couplings. In the absence of these couplings, the nuclear breakup is the more dominant process, while when they are included, the Coulomb breakup becomes dominant. This shows that, the nuclear breakup is more affected by the continuum-continuum couplings than its Coulomb counterpart. Quantitatively, we found that, the off-diagonal countinuum-countinuum couplings reduce by 13.39%, 12.71% and 11.11% the total breakup cross sections for the 8B+58Ni, 8B+208Pb and 19C+208Pb reactions, respectively. / Physics / D. Phil. (Physics)

No description available.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy