This thesis focuses on the study of the size effect in the elastic-viscoplastic response of pure face centered cubic polycrystalline materials. First, the effect of vacancy diffusion is studied via the use of a two-phase self-consistent scheme in which the inclusion phase represents grain interiors and the matrix phase represents grain boundaries. The behavior of the inclusion phase is driven by the activity of dislocations, described with typical strain hardening laws, and by the activity of Coble creep. The behavior of the matrix phase is modeled as elastic-perfect plastic. This model is then extended to account for the possible activity of Lifschitz sliding. The active role of grain boundaries to the viscoplastic deformation is studied with the introduction of a novel method allowing the scale transition from the atomistic scale to the macroscopic scale. A model describing the mechanism of grain boundary dislocation emission and penetration is informed with molecular simulations and finite element simulations. The macroscopic response of the material is then predicted with use of several self-consistent schemes, among which two novel three-phases schemes are introduced. The most refined micromechanical scheme proposed is based on a two-phase representation of the material and is valid in the elastic-viscoplastic regime and accounts for the effect of slightly weakened interfaces.

none

In this research project composed of multiple case studies, I focused on how bona fide virtual groups appropriated multiple media to facilitate group boundary construction and boundary management, which are preconditions of group identity formation. Specific topics explored in the study included how virtual groups socially constructed their group boundaries through recurring patterns of media use as well as other communication practices, how the group boundaries were preserved and blurred in both internal and external communication, and how bona fide groups managed dialectal tensions in interacting with external groups. To explore those research questions, I conducted four in-depth case studies of real life groups operating in natural contexts. Multiple qualitative methods of data collection were employed in the study and a modified grounded theory method was used in analyzing the collected data. As a result, the study found that the groups studied constructed group boundaries through communication practices such as making sense of common goals, negotiation of task jurisdiction with other interlocking groups, distinguishing patterns of ingroup interaction from those of outgroup interactions, and through developing group specific patterns and norms of media combination and media use. Group boundaries were preserved when the influence of outgroup members were constrained through media use, such as excluding them from team conference calls, filtering messages from external groups or members, and using boundary spanners to interact with external members. Group boundaries were blurred when intergroup communication impacted internal dynamics and when norms and practices were transferred from other contexts into a given group context. The study suggested that technology adaptation and boundary management occurred simultaneously. In addition, the groups experienced dialectical tensions in face of the permeability of group boundaries and developed communication tactics to deal with those tensions. Theoretical implications of the study were also discussed.

In this dissertation, we consider various aspects of the boundary behavior of holomorphic functions of several complex variables. In dimension one, a characterization of the radial limit zero sets of nonconstant holomorphic functions on the disc has been given by Lusin, Privalov, McMillan, and Berman. In higher dimensions, no such characterization is known for holomorphic functions on the unit ball B. Rudin posed the question as to the existence of nonconstant holomorphic functions on the ball with radial limit zero almost everywhere. Hakim, Sibony, and Dupain showed that such functions exist. Because the characterization in dimension one involves both Lebesgue measure and Baire category, it is natural to also ask whether there exist nonconstant holomorphic functions on the ball having residual radial limit zero sets. We show here that such functions exist. We also prove a higher dimensional version of the Lusin-Privalov Radial Uniqueness Theorem, but we show that, in contrast to what is the case in dimension one, the converse does not hold. We show that any characterization of radial limit zero sets on the ball must take into account the "complex structure" on the ball by giving an example that shows that the family of these sets is not closed under orthogonal transformations of the underlying real coordinates. In dimension one, using the theorem of McMillan and Berman, it is easy to see that radial limit zero sets are not closed under unions (even finite unions). Since there is no analogous result in higher dimensions of the McMillan and Berman result, it is not obvious whether the radial limit zero sets in higher dimensions are closed under finite unions. However, we show that, as is the case in dimension one, these sets are not closed under finite unions. Finally, we show that there are smooth curves of finite length in S that are non-tangential limit uniqueness sets for holomorphic functions on B. This strengthens a result of M. Tsuji.

Thesis (M.S. in Meteorology and Oceanography)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Shaw, W.J. Second Reader: Nuss, W.A. "September 1990." Description based on title screen as viewed on December 29, 2009. DTIC Identifier(s): Marine atmospheres, marginal ice zones, geostropic wind, atmospheric boundary layer, stratus clouds, cumulus clouds, stratocumulus clouds, wind velocity, temperature inversion, air ice interactions. Author(s) subject terms: Marginal ice zone. Includes bibliographical references (p. 45-46). Also available in print.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 125-136).

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 184-197).

Thesis (M. Sc.)--York University, 1997. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 84-91). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL:http://wwwlib.umi.com/cr/yorku/fullcit?pMQ27395.

Thesis (M. Sc.)--York University, 1999. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 138-141). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ39212.

Thesis (M.S.)--Mississippi State University. Department of Mechanical Engineering. / Title from title screen. Includes bibliographical references.