Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 268-278). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 268-278). Also available on the Internet.

published_or_final_version / Journalism and Media Studies Centre / Doctoral / Doctor of Philosophy

Communication scholarship on black journalists has mostly focused on their lack of empowerment and the constraints that prevent them from engaging as full partners in the journalism industry, which has been shown to be ambivalent about the role of race in professional work. Racial discourse studies assert that blacks have little say in their representation by the media, where African Americans and other minority groups are treated as the negative “them” rather than the positive mainstream “us.” This dissertation examines journalism and racial discourse from a little-explored perspective in both fields: that of elite black columnists, who have the platform and autonomy to discuss news in general and race in particular from an African-American point of view. This dissertation examined the work of 11 African-American columnists who have won the Pulitzer Prize for commentary or write for one of the country’s highest-circulation publications. After textual analyses of more than 3,000 of their columns and in-depth, elite interviews with five columnists, this study found that elite black columnists wrote extensively and strategically about race at a level previously unrecognized in academia. The study found that the columnists heavily relied on biography and history in constructing a black narrative, which is not usually associated with journalistic work but helped them make sense of the black experience and to explain it to their mostly white readership. The research also identified six related frames the columnists used to provide context to news coverage about black America. Three frames explained the “problem people” image of black America: the devaluation of black life, misrepresentation, and destructive racial discourse. Three were correctives to that image: the raising of critical racial consciousness (while unmasking whiteness), black responsibility and black pride, and reverence for the Constitution and American ideals. The findings showed that elite black columnists were actively engaged in what could be called an antiracist racial project: to not only counter inequality and misrepresentation but also to battle the forces within discourse that feed the “us” vs. “them” ideology. / text

A reactive distillation column for the alkylation of benzene with long chain linear olefin was studied. The study involved design, construction, experimentation, and simulation of the column. Establishing the design required study of reaction rates, thermodynamic relationships, and packing structures. A heuristic was developed for the design of such columns. This heuristic involved estimating an amount of catalyst loading and subsequently determining the operating parameters for a column. This method is particularly applicable to systems with high concentrations of inert feeds. A column was constructed following the design. Data was collected from the column and compared to simulations. The simulations were performed with Aspen Plus RADFRAC. In this manner, the data was used to validate the commercial steady state models for reactive distillation. In addition, dynamic simulations of the system were performed. These dynamic simulations provided insight into more design considerations. For example, steady state simulations indicated an optimal feed stage based on steady state conversion of the olefin. However, the dynamic simulations showed a potential disadvantage to the utilization of the optimal feed stage. With some disturbances, a column configured with the feed stage with the highest steady state conversion also deviated from the steady state faster and with greater amplitude than other configurations. These considerations were further explored in developing a control scheme for reactive distillation columns. Control of reactive distillation differs from traditional distillation in that one control variable is conversion. Traditional distillation generally focuses on production rates and product purity. To this end, control schemes were analyzed and dynamic simulations were performed. These simulations showed an advantage to a variable pairing in which duty is paired with conversion. The conversion was inferred from a stage temperature in the reactive zone. In addition, distillate rate may be paired with product composition. In conclusion, the reactive distillation column design for long chain olefin alkylation of benzene requires careful estimation of catalyst requirements and valid simulation tools. In addition, dynamic response should be considered in the design. Finally, a simple inferential control scheme may be adequate. / text

Fiber Reinforced Polymer (FRP) sheets can provide incredible structural strength while weighing only a fraction as much as steel. When applied to piles the FRP provides strengthening through both concrete confinement and tensile reinforcement. Mainly used in structural repair, its application is relatively simple in theory. However, many factors(some avoidable, some not) can interfere with the bond between FRP and concrete. When this bond is interrupted the strength of the repair becomes compromised.This thesis examines 2 new methods of improving FRP bond to concrete piles during the time the resin is curing. These methods are compared using 3 types of testing, both nondestructive and otherwise: acoustic analysis, infrared thermography, and pull-off testing. Therefore not only FRP bond improvement techniques are compared but also the techniques for bond evaluation. Findings have shown a definite correlation between non destructive testing and destructive pull-off testing, as well as bond improvement both above and below the waterline when a pressure bag system is used.

Not available / text

In steel moment resisting frames, the region of the column located within the beam-column joint is known as the panel zone. When a steel moment resisting frame is subjected to lateral load, due to wind or seismic loads, the panel zone is subject to high shear. In some cases, the shear in the panel zone is sufficiently high that the panel zone must be reinforced to increase its stiffness and/or strength. This is normally accomplished by welding doubler plates to the column in the panel zone region. Doubler plates can be a costly feature in steel moment resisting frames because of the substantial amount of welding involved. There has been a large amount of past research that has investigated the required shear strength and stiffness of the panel zone region to establish a basis for sizing doubler plates. However, very little past research has investigated the details of attaching doubler plates to columns. These attachment details can have a significant influence on the structural performance of panel zone and on cost. The overall goal of this research was to conduct preliminary finite element studies that provide insight into several key issues related to the attachment of doubler plates to columns and to identify issues that require further research. The research involved finite element modeling of a simplified representation of beam-to-column joint subjected to monotonic loading. A total of twenty-one analysis cases with different doubler plate attachment details were studied. Issues that were investigated included the effect of welding different edges of the doubler plate to the column (horizontal edges only, vertical edges only, and all four sides), the effect of extending the doubler plate beyond the panel zone region, and the effect of providing two thinner doubler plates of equivalent total thickness on both sides of the column web instead of one thick doubler plate on one side of the column web. In addition, the forces developed in the doubler plate welds were computed from the finite element analysis and compared with current building code requirements for the design of these welds. Observations and preliminary design recommendations on these issues are provided in this thesis, along with recommendations for further research. / text

published_or_final_version / abstract / toc / Civil Engineering / Doctoral / Doctor of Philosophy

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