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Innovations in Musical Texture and Aural Perspective: Steven Mackey's See Ya Thursday for Solo Marimba

Description: This dissertation and accompanying lecture recital explore the unique textural features in the works of Steven Mackey as exhibited in See Ya Thursday (1993).A rigorous formal, harmonic, and motivic analysis will highlight the compositional characteristics of textural structure and aural perspective that exist in the work. Illumination of these compositional elements can help to identify and minimize the technical complexities that exist within this piece for the performer. In addition, this document provides brief biographical information on Steven Mackey and his works, and on See Ya Thursday as it relates to other pieces in the advanced marimba literature. Finally, it is the aim of the author to add a resource to the relatively limited amount of research on Steven Mackey with this analysis of See Ya Thursday.
Date: August 2013
Creator: Hall, David Porter
Partner: UNT Libraries

Temporal and Spatial Comparisons of Ambient Toxicity of the Trinity River in Relationship to an Effluent

Description: A toxicological study was initiated because of concerns about allegations that the Texas Water Commission that effluent from the Dallas Central Wastewater Treatment Plant, which discharges into the Trinity River, was affecting downstream water quality. Monthly, flow-weighted composite effluent samples were collected. Grab samples were also collected upstream and downstream from the effluent from April 1989 to August 1991. Toxicity tests were conducted on these samples using Ceriodaphnia dubia as the test organism. Samples were collected four times during this study in which rainfall occurred prior to sampling. In every instance, this "first flush" of the watershed during a rising hydrograph was toxic to C. dubia upstream. Analyzing toxicity by season resulted in a statistically significantly lower neonate production in the effluent than in the river samples during the months of June, July, and August. This impact on neonate production was suspected of being caused by organic pesticides which are used for insect control on lawns. The effluent was never acutely toxic to C. dubia. Primarily, toxic occurrences in either the effluent or the river samples were primarily of a chronic nature. Overall, survival of C. dubia was affected more frequently at the upstream site than in the effluent or the downstream site. Because EPA's Phase I Acute Toxicity Identification Evaluations (TIEs) methods were designed for identifying acute toxicity, two alternative strategies were attempted to identify chronic toxicity. The first attempt was the modification of the phase I acute TIE methodologies. This was done by processing more sample through the phase I characterization tests. This approach was inadequate due to toxicity that occurred during the last several days of the seven-day C. dubia reproduction test. The second strategy for identifying chronic toxicity within a TIE involved the use of freeze concentration. During this preliminary investigation ofthe efficiency of freeze concentration, ...
Date: December 1993
Creator: Hall, David B., 1958-
Partner: UNT Libraries