Thesis (Ph. D.)--University of Wyoming, 2005. / Title from PDF title page (viewed on March 10, 2008). Includes bibliographical references (p. 89-96).

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on June 26, 2008). Includes bibliographical references (p. 169-177).

Thesis (Ph. D.)--University of Wyoming, 2005. / Title from PDF title page (viewed on Feb. 22, 2008). Includes bibliographical references (p. 75-87).

Thesis (M. Ag. Sc.)--University of Adelaide, Dept. of Entomology, 1985. / Mounted illus. Includes bibliographical references (leaves 141-153).

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on June 26, 2008). Includes bibliographical references.

This thesis uses multiscale computational modelling to find the fundamental principles that govern defects forming during the operation of new electro-optical devices and the processing of spider silk fibers. The generalized approach developed in this thesis bridges engineering devices and biological processes based on liquid crystalline materials. / Three types of defects are encountered: inversion walls, lines and points. Inversion wall defects are found in the electro-optical device when a nematic thin film undergoes a temperature-induced surface anchoring transition. Point defects naturally occur in the tubular extrusion duct of spiders, while line defects present close topological connections with point defects and are widespread in many high-performance industrial fibers. Three models are used in this thesis and their usage is dependent on the characteristics of the defects studied. / In the case of inversion wall defects, computational modelling is used to verify, complement and analyze experimental measurements made with fluorescence confocal polarizing microscopy by our collaborator at the Georgia Institute of Technology. The various simulation results agree and explain very well experimental observations and provide a thorough understanding of the wall defects behavior. A computational technique is developed to enable the precise determination of the interaction between the liquid crystal and the device substrate. Understanding the behavior of wall defects and estimating interfacial properties are indispensable to the development and optimization of the electro-optical device as they affect properties like temperature of operation, switching voltages and response time. / Computational modelling is also used to investigate the behavior of nematic point defects confined in cylindrical cavities as observed along spiders' spinning apparatus, and to examined textural connections with other well know structures seen in industrial fibers. The various scenarios investigated include: interactions between point defects, topological transformations between point, line and ring defects as well as interactions between ring defects. The simulation results agree and complement previous investigations but also offer a new fundamental understanding on the nature and stability of defects in cylindrical cavities. Understanding the behavior of nematic point and line defects in cylindrical geometries is important as they play a fundamental role in the processing of natural and industrial high-performance fibers.

A synthetic analog of a spider silk protein (M4) was studied. Langmuir films were made and an inflexion in the isotherm indicated conformational changes upon compression. Deposition onto solid substrates was most successful using a hydrophobic substrate and the Langmuir-Schaeffer method. AFM was used to image the surface, which was mesh like and did not show any indication of order. / Gold nanoparticles were produced in the presence of the protein and protein solutions were added to read made nanoparticles for the purpose of displacing the weak ligands present. CD measurements were performed on the protein solutions to study its conformation. Nanoparticle size information was obtained from TEM images. DLS was used to determine if the protein was affected by the addition of the gold nanoparticles. Precipitation of the protein was shown not to affect the nanoparticles.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 86-95). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 86-95). Also available on the Internet.

Silks from araneoid spiders have become an active area of research for material scientists, biochemists, and molecular biologists. Mechanical properties of spider silk such as elasticity, tensile strength, and toughness make the manufacturing of silk for medical sutures, body armor, ropes and other synthetic material applications great possibilities. The difficulties of having a black widow spider farm to harvest silk, due to their cannibalistic nature, make recombinant expression of silk proteins a fundamental goal of spider silk research. In order to express silk fibers, cDNAs encoding the corresponding silk fiber products must first be isolated and identified. One of the first steps in gene identification relies on the identification of the proteins in the silk fibers. No previous study has demonstrated the molecular constituents of gumfooted lines. In the course of this research, the core fibroins in the gumfooted lines were identified to be members of the Major Ampullate Spidroin family (MaSp), using mass spectrometry. This research was the first to identify the core fibroins of the gumfooted lines. Novel peptide fragments from solubilized gumfooted lines were acquired from manual de novo MSIMS sequencing after in-gel tryptic digestion. These peptide fragments showed post-translational modifications consistent with glycosylation, which aligns with the reported chemical properties of glue proteins. Novel peptide sequences were also acquired from the attachment discs as well as novel scanning electron microscopy images and reveal, for the first time, the physical attributes and molecular properties of threads attached to the surface of an immobilized structure. This study was the first to identify the molecular constituents of the attachment discs.