This thesis is on the Navier-Stokes equations which model the motion of compressible viscous fluid. A minimum principle on the temperate variable is established. Under the thermo-insulated boundary conditions and some reasonable assumptions on the solution, the minimum of the temperature does not increase. To our best knowledge, that's the first result on the minimum principle of the temperature variable in the compressible Navier-Stokes equation. As an application of the minimum principle, global in time existence of the weak solution for the Navier-Stokes equations is established when the viscosities and heat conductivity are power functions of the temperature. In this model the temperature is coupled with density which may have vacuum or concentration and the heat conductivity has possible degeneracy. However the temperature is proved to obey the minimum principle, which secured the dissipative mechanism of the system, and paved the road to the existence theory.

Falls among older adults (age 65 years and older) residing in personal care homes (PCHs) are an important health concern. Atypical antipsychotic drugs (AADs) have been shown to be associated with fall risk among older adults. However, previous studies face some methodological limitations that affect the quality, consistency, and comparability of these studies. Therefore, a population-based study was undertaken to examine the effect of AAD use on the risk of falling among older PCH residents. A nested case-control study was conducted using the administrative healthcare records and Minimum Data Set for PCHs (MDS) housed at the Manitoba Centre for Health Policy in the Faculty of Medicine, University of Manitoba. The study period was from April 1, 2005 to March 31, 2007. Cases (n=626) were fallers as recorded in MDS. Using incidence density sampling, each case was matched to four controls on length of PCH stay, age, and sex (n=2,388). Exposure to AADs was obtained from the Drug Program Information Network database. Conditional logistic regression was used to model the effects of AAD use on the risk of falling while accounting for matching and for confounding of other covariates. While the adjusted odds of falling was statistically greater for AAD users versus nonusers (adjusted odds ratio = 1.60, 95% CI 1.10-2.32), this association was type and dose dependent. Compared to nonusers, the odds of falling was greater for quetiapine users, regardless of this drug's dose, and high dose risperidone users. On the other hand, low dose risperidone and olanzapine, irrespective of drug dose, use was not associated with the risk of falling. Furthermore, the effect of AAD use, in general, on the risk of falling was significantly greater for people with wandering problems (adjusted odds ratio = 1.84, 95% CI 1.09-3.09). Despite some methodological limitations, this research has provided some unique findings that enhance our understanding of AAD use as a fall risk factor. Study findings allow policymakers to further develop evidence-based interventions specific to AADs in order to better manage falls in the PCH setting. However, a great deal of research is still needed to address other important unanswered questions.

Over 95% of imports entering the United States from outside North America arrive via cargo containers by sea at 329 ports of entry. The current layered approach for the detection only scans 5% of cargo bound for the United States. This is inadequate to protect our country. This research involved the building of a gamma-ray radiation detection system used for cargo scanning. The system was mounted on a spreader bar crane (SBC) at the Port of Tacoma (PoT) and the applicability and capabilities of the system were analyzed. The detection system provided continuous count rate and spectroscopic data among three detectors while operating in an extreme environment. In a separate set of experiments, 60Co and 137Cs sources were positioned inside a cargo container and data were recorded for several count times. The Monte Carlo N-Particle (MCNP) code was used to simulate a radioactive source inside an empty cargo container and the results were compared to experimentally recorded data. The detection system demonstrated the ability to detect 60Co, 137Cs, 192Ir, highly-enriched uranium (HEU), and weapons-grade plutonium (WGPu) with minimum detectable activities (MDA) of 5.9 ± 0.4 microcuries (μCi), 19.3 ± 1.1 μCi, 11.7 ± 0.6 μCi, 3.5 ± 0.3 kilograms (kg), and 30.6 ± 1.3 grams (g), respectively. This system proved strong gamma-ray detection capabilities, but was limited in the detection of fissile materials Additional details of this system are presented and advantages of this approach to cargo scanning over current approaches are discussed.

The minimum degree spanning tree problem is a widely studied NP-hard variation of the minimum spanning tree problem, and a generalization of the Hamiltonian path problem. Most of the work done on the minimum degree spanning tree problem has been on approximation algorithms, and very little work has been done studying graph classes where this problem may be polynomial time solvable. The Hamiltonian path problem has been widely studied on graph classes, and we use classes with polynomial time results for the Hamiltonian path problem as a starting point for graph class results for the minimum degree spanning tree problem. We show the minimum degree spanning tree problem is polynomial time solvable for chain graphs. We then show this problem is polynomial time solvable on bipartite permutation graphs, and that there exist minimum degree spanning trees of these graphs that are caterpillars, and that have other particular structural properties.

Thesis (PhD)--University of South Australia, 1998

Thesis (PhD)--University of South Australia, 1998

Thesis (Ph. D.)--University of Sydney, 1987. / Includes bibliographical references (leaves 285-286).

Thesis (Ph. D.)--Harvard University, 1995. / Includes bibliographical references (leaves 166-177).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

University, Diss., 2003--Dortmund.