Description: Aerogels are highly porous, low dielectric constant (low k) materials being considered by the semiconductor industry as an interlayer dielectric. Low k materials are needed to overcome capacitance problems that limit device feature sizes. Precursors triethoxyfluorosilane (TEFS) and tetraethoxysilane (TEOS) were used to prepare bulk aerogels. Samples were prepared by sol-gel methods, and then carbon dioxide supercritically-dried. Effects of varying the water to precursor ratio were studied with respect to aerogel properties and microstructure. Methods of analysis for this study include FTIR-ATR, TEM, RBS, EDS, SEM, dielectric constant determination by impedance and surface area by gas adsorption. Si-F bonds were determined to be present in both acid- and base-catalyzed TEFS as well as HF-catalyzed TEOS. Fluorine promotes a fractal network microstructure as opposed to a particle-like microstructure. Surface area and dielectric constant were determined to increase slightly with increases in the water to precursor ratio.

Description: This study illustrates the changing nature of organized crime at both national and international levels. Organized crime groups have changed in that they have entered the realm of high technology. In response this change, the use of new or modified analytical tools is suggested to enhance law enforcement efforts. This study highlights the problems of, and offers particular solutions for information analysis in its use in the fight against organized crime. Ultimately, it is argued that combined crime and intelligence analysis can be an effective and efficient method for the detection and prevention of modern organized crime.

Description: The first part of this paper describes the Meissner effect in superconductors which serves as the most definitive evidence for superconductivity. It is shown that the microwave perturbation technique may be used to demonstrate this effect. By measuring the changes of resonant frequency and inverse quality factor Q of a microwave cavity with a small volume of sample loading, the Meissner effect can be shown by using the Slater perturbation equation. The experimental system is described with details and the basic principle of each component discussed. The second part of this work describes the technique employed to do the actual measurements. The experiments were conducted on samples of Gallium Arsenide (GaAs) and lead zirconate titanate (PZT) to look for the possible high temperature superconductivity properties. Results of these experiments are presented and discussed. Conclusion and suggestions to future exploration are made.

Description: This thesis examines the issue of Texas annexation from the viewpoints of two southern cities: Richmond, Virginia, and New Orleans, Louisiana. It looks primarily at four major newspapers, two in each city: the Richmond Enquirer and the Richmond Whig; and the New Orleans Times-Picayune and the New Orleans Whig. These four newspapers were examined thoroughly from January 1844 to July 1845. In addition to the above newspapers, the Congressional Globe and national voting patterns on Texas annexation were examined. Analysis of the editorial articles in the above newspapers offers the best possibility of understanding public sentiment toward Texas annexation and the presidential election of 1844. The evidence examined in this study indicates that Texas annexation became a decisive issue in the presidential election of 1844. It also shows that, although the press and elements within both Democratic and Whig parties were aware that the slavery question was intricately linked to the Texas annexation issue, slavery and sectional politics were not the primary factors influencing annexation. Ultimately, fundamental concerns regarding western expansion in general, especially for the Whigs, and political party loyalty proved the decisive factors in the presidential election of 1844 and Texas annexation. The evidence gathered in this study ...

Description: Media sociologists have produced much research on the systems of production of media content. Photojournalism, however, largely has been ignored in these studies. This paper presents the findings of an ethnographic study of work routines and photojournalism practices at three newspapers. The study explored the extent to which routines and practices are affected by professional norms and values and organizational needs and beliefs. The study also explored how these factors influence the content and aesthetic qualities of newspaper photographs. Findings suggest that photo editors and photojournalists operate under many of the same constraints as other media workers. The findings also show that photojournalists are socialized to newspapers. expectations by fellow photographers and photo editors. To gauge professional accomplishments, photojournalists rely on peers, professional organizations and competitions.