Thesis (Ph.D.) -- University of Texas at Dallas, 2005 / Includes vita. Includes bibliographical references (leaves 102-107)

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 177-185).

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: Hydrogen bonding; octupolar; nonlinear optics; crystal engineering. Includes bibliographical references (p.).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 164-174).

Copies of author's previously published works inserted. Bibliography: p. 119-127. This thesis demonstrates the combined use of stimulated Brillouin scattering (SBS) for aberration correction, auto alignment and pulse compression as an ideal technology for studies of nonlinear optical processes, in particular nonlinear optical scattering (NLS).

No description available.

A number of metallophthalocyanines (MPcs) and metal-free phthalocyanines (H₂Pcs) have been synthesized and characterized using various characterization tools such as ¹H-NMR, TOF mass spectrometry, FT-IR, UV-visible spectrophotometry and CHNS elemental analysis. Some of the MPcs were covalently linked to nanomaterials such as silica nanoparticles (SiNPs), single-walled carbon nanotubes (SWCNTs), magnetite nanoparticles (MNPs) and quantum dots (QDs), or embedded in polymer thin-films using poly(methyl methacrylate) (PMMA) and poly(acrylic acid) (PAA) as the polymer sources. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), thermogravimetry analysis and X-ray diffractometry. The nonlinear optical (NLO) properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. In general, most of the investigated MPcs showed good optical limiting behaviors, except for a few, like the non-peripherally-substituted 2-pyridyloxy phthalocyanines, which showed inhibited NLO response as a result of the ring-strain effects. The absence of a metal center was found to greatly reduce the inherent high nonlinearities expected of some of the phthalocyanine complexes. The octaphenoxy derivatives (61a – 61e) were found to exhibit reverse saturable absorption (RSA) that depends on the singlet-singlet transitions, hence making them less reliable optical limiters. The optical limiting properties of the MPcs were improved in the presence of nanomaterials such as the QDs, MNPs and SWCNTs, with MPc-QDs showing the best optical limiting behavior of the three. SiNPs have no significant effect on the optical limiting behavior of the MPcs. The optical limiting properties of the MPcs were greatly enhanced in the presence of PMMA or PAA polymers. The PAA polymer showed better optical limiting behavior compared to PMMA

In this work I study certain aspects of qualitative behaviour of solutions to nonlinear PDEs. The thesis consists of introduction and three parts. In the first part I study solutions of Emden-Fowler type elliptic equations in nondivergence form. In this part I establish the following results; 1. Asymptotic representation of solutions in conical domains; 2. A priori estimates for solutions to equations with weighted absorption term; 3. Existence and nonexistence of positive solutions to equations with source term in conical domains. In the second part I study regularity properties of nonlinear degenerate parabolic equations. There are two results here: A Harnack inequality and the H51der continuity for solutions of weighted degenerate parabolic equations with a time-independent weight from a suitable Muckenhoupt class; A new proof of the Holder continuity of solutions. The third part is propedeutic. In this part I gathered some facts and simple proofs relating to the Harnack inequality for elliptic equations. Both divergent and nondivergent case are considered. The material of this chapter is not new, but it is not very easy to find it in the literature. This chapter is built entirely upon the so-called "growth lemma" ideology (introduced by E.M. Landis).

Dissertation submitted in compliance with the requirements for Masters Degree in Technology in Electrical Engineering (Light Current) at Technikon Natal, 1998. / Designing compensators in the frequency domain is a complicated problem even for linear systems that have dead time. The situation is far more difficult if the system is also nonlinear. This study introduces a new method for the design of compensators for time-invariant, nonlinear systems that have dead time. The method is based on an optimization approach and utilizes large signal linearization methodology. / M