1980-1989 Theses (MU)
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Item Structure and dynamics of unique bluegill populations(University of Missouri--Columbia, 1982) Hillman, W. Phillip; Anderson, Richard O."Introduction: The impetus for this research was the question of why there are so few small impoundments in the Midwest which produce bluegills (Lepomis macrochirus) 20 cm and longer. Populations containing fish of this size in any reasonable numbers must be considered unique. In order to have the best fishing quality for any species, population structures providing appropriate numbers of an adequate range of quality sizes must be sustained. This study is basically a description of nine small impoundments which had a history of producing bluegills 20 cm and longer. The study objectives were: 1. to evaluate bluegill population structure and functional characteristics in small impoundments that have a history of producing fish 20 cm and longer in Missouri; 2. to characterize habitat conditions of such impoundments; 3. to assess the food habits of three bluegill size groups; and 4. to develop functional models for a largemouth bass and bluegill community, which would include some percentage of bass and bluegills greater than 38 and 20 cm, respectively. Bluegills are ubiquitous in all facets of small impoundment fisheries management and research endeavors. No efforts have focused upon characteristics that may distinguish populations which sustain fish of exceptional sizes. The fact that 20-cm bluegills are unique in midwestern small impoundments was supported by the results of the 1973-1974 Central States Pond Management Work Group project where only 5 of 38 ponds exhibited appreciable numbers of bluegills 20 cm and longer. The aim of this research was to answer why this is so and to postulate whether management can improve this situation."--Page 1.Item Preparation and properties of lithium aluminate supported electrolytic tiles for electrochemical concentrators(University of Missouri--Columbia, 1980) Besselsen, Rebecca Kaye; Winnick, Jack"An electrochemical gas concentrator effects the removal of a specified gas (such as carbon dioxide or sulfur dioxide) by an electrochemical process. This electrochemical transfer takes place across the electrode electrolyte-electrode interfaces in an electrochemical cell. The advent of a viable gas concentration process effecting removal by electrochemical transfer requires the development of a reliable, cost-effective system. Examination and optimization of cell ccmponents, processing parameters of said components, and cell operation variables are an essential portion of this development. In aqueous electrochemical concentrators, the electrolyte is dispersed in a solvent, water. However, in molten salt concentration cells (and fuel cells), the electrolyte is contained in a ceramic matrix struc ture. The stability, both physical and chemical, of this matrix-electrolyte combination, called the electrolytic tile, is extremely important to (1) the operation and performance of the cell. Currently, there is a fundamental need to understand the factors which determine the stability of the electrolytic tile in the operating environment. Processing techniques need to be developed for preparing the tile and its components which will consistently yield tiles with sufficient physical and chemical stability to achieve high performance and long endurance. The suitability of a chemical compound to act as a support matrix for an electrolyte is governed by its physical and chemical character in the operating system. Magnesium oxide was used as the electrolyte support (1) medium in early developmental work of the molten carbonate fuel cell. The magnesium oxide-alkali carbonate (electrolyte) mixture formed a (2) stiff paste at cell operating temperatures. However, it was soon determined that magnesium oxide is chemically active in the molten carbonate environment (3). Thus, effort was directed towards finding a support material that is both chemically inert and physically stable in the molten carbonate environment of a fuel cell. Broers and co-workers determined that lithium aluminate possessed these requirements and suggested its use as the support medium for molten carbonate electrolytes (1). A mixture of lithium aluminate and dilithium oxide is commercially available (Alfa Division, Ventron Corp., chemical analysis: 78.6% LiA102/21.4% Li20). However, due to the lack of a supply of relatively pure lithium aluminate, there is a need to develop a process for its formation and to understand the relationship between process variables and final product characteristics. Much of the developmental work in this area has been concerned with the optimization of a procedure to manufacture tile powder containing both lithium aluminate and the binary alkali carbonate eutectic used as the electrolyte in the molten carbonate fuel cell. Due to the dual function of lithium aluminate as the support medium for electrolytes for both the carbon dioxide and sulfur dioxide molten salt concentrators, it is necessary to obtain and optimize an electrolyte-free lithium aluminate production method. The final product characteristics produced in such a method play an important role in determining the properties of the electrolytic tile and thus, have sane important effects on the performance and long-term stability of the tile in the operating environment of a molten salt electrochemical concentrator."--Introduction.Item Natural lactic and Candida tropicalis ATCC 9968 fermentation of corn meal and its effect on relative nutritive value, thiamin, niacin and riboflavin(University of Missouri--Columbia, 1982) Baseler, Mary E.; Fields, Marion L."Most of the world’s population relies upon high carbohydrate foods for a large percentage of its diet. Currently, about 70% of the world’s dietary protein comes from cereals, vegetables and legumes (Pimental et al., 1975). Corn (Zea mays), long a cereal staple for humans, is the third ranking food crop in developing countries (Hanson, 1974). It is the primary cereal grain grown in much of Africa and Latin America. According to Wilkes (1972), corn is the single largest harvest in the United States. The widespread cultivation of corn is a reflection, not only of its use as a human food, but also of its role as a feed for livestock and as a raw material for many industrial products. A plant of remarkable adaptability and versatility, maize provides high yields of food energy per hectare. Yet, termed the "poor man’s cereal" (FAO, 1953), excessive human consumption of corn is associated with the classical deficiency disease pellagra. Corn’s nutritional importance is intensely magnified in populations where there is limited consumption of animal protein foods. West (1969) stated that in devel oping countries, people are usually dependent upon a single ceral as the staple in their diet. This cereal then becomes a major source of protein as well as calories. An example of this is the diet consumed by most Latin American rural poor. According to Bressani (1975), 72% of the diet is maize, 8% consists of beans and the remaining 20% is made up of tubers, vegetables and sugar. Such a monotonous assortment of foods only increases the risk that people will not consume sufficient amounts of all needed nutrients."--Introduction.Item The fracture resistance of experimental alloy and Class U carbon steel wrought railroad wheels(University of Missouri--Columbia, 1986) Roland, John Russel; Bowles, C. QuintonMechanical and metallographic testing was used to relate fracture toughness to the mechanical properties and the metallurgical characteristics of Class U carbon steel wrought wheels and an experimental alloy wrought wheel. The study was performed to determine how variations in carbon content and alloy addition influenced these relationships. The results of the research suggest the chromium addition found in the experimental alloy and the variation in prior austenite grain size had little effect on toughness. Carbon content reduction and the resulting amount of proeutectoid ferrite in the microstructure were found to be the principal factors controlling fracture toughness of the wrought steel wheels.Item An ecological study of loggerhead shrikes in central Missouri(University of Missouri--Columbia, 1982) Kridelbaugh, Alan Lee"The objectives of this study were to: 1. Document the population decline and current distribution of loggerhead shrikes in Missouri. 2. Investigate the nesting ecology of loggerhead shrikes in Missouri. 3. Determine habitat selection by loggerhead shrikes in the breeding season. 4. Investigate food habits of loggerhead shrikes in the breeding season. 5. Propose management guidelines to halt the decline of loggerhead shrikes in Missouri."--Page 5.