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Physical Sciences and Mathematics

Masters Theses & Specialist Projects

1979

Western Kentucky University

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Ecotypic Differentiation Of Andropogon Virginicus L. In Relation To Strip Mine Spoil Banks, Valina Kay Hurt May 1979

Ecotypic Differentiation Of Andropogon Virginicus L. In Relation To Strip Mine Spoil Banks, Valina Kay Hurt

Masters Theses & Specialist Projects

Reciprocal plantings of populations of broomsedge, taken from an abandoned strip mine and from an abandoned farm plot in south central Kentucky, on strip mine spoil and abandoned field soil resulted in patterns of populations differentiation. Clonal plantings of populations from strip mine habitats and old field development appeared equal in height and biomass when grown on old field soils in both field trials and growth chamber studies. Populations when planted in strip mine soils in field trials and controlled growth experiments. Later flowering in strip mine populations may be a key to survival strategy in the harsh microclimates of …


Simulative Investigation Of The Detection Of Modes Of Luminosity Variation In Astrophysical Sources, James Collins May 1979

Simulative Investigation Of The Detection Of Modes Of Luminosity Variation In Astrophysical Sources, James Collins

Masters Theses & Specialist Projects

Five astronomical data analysis methods were evaluated, using computer simulation techniques, for minimum detection levels, periodicity detection, and parameter estimation sensitivities. The evaluation of these methods was accomplished using three basic waveforms with the addition of ten “random” noise samples from a Gaussian distribution of known parameters. The chi-square and t-test methods were evaluated in detecting low-amplitude variability and brightness level shifts. Results indicate both methods have a strong dependence on the estimation of the standard deviation (σ) where a 0.1 change in σ will affect detection rates by ten to twenty-five percent at the ninety-five percent confidence level. The …