14,008 research outputs found

    Biology of the Genus \u3ci\u3eHemileuca\u3c/i\u3e (Lepidoptera: Saturniidae) in Michigan

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    The habitats and host plants of buckmoths (Hemileuca: Saturniidae: Hernileucinae) in Michigan are described and compared to those of the three species known from eastern North America, H. maia, H. nevadensls, and H. lucina. Michigan populations show variation in host plant and habitat use spanning the entire range of all three species. The presence of transitional phenotypes and the host plant and habitat data suggest that Michigan populations are a single, variable species. These things combined with the intermediate geographical location of Michigan\u27s populations call into question the taxonomic distinctness of the three eastern buckmoth species

    Collapsible loop antenna for space vehicle Patent

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    Collapsible, space erectable loop antenna system for space vehicl

    Trace Metals and Major Elements in Water-Soluble Rocks of Northwest Arkansas

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    Trace metals in limestone are potential water contaminants because they can enter the ground water when the limestone is dissolved by carbonic acid and other naturally occurring acids. Four local limestones, the St. Joe and Pitkin Formations (Mississippian) and the Brentwood and Kessler Members of the Bloyd Formation (Pennsylvanian) were sampled in a five county area in Northwest Arkansas. Atomic absorption analyses were made for Na, K, Mg, Ca, Zh, Cu, Ba, Fe, Co, Cr, Ni, Mn, Li and Sr on the acid soluble material of the samples. All the limestones are relatively pure CaCO3 with Pitkin the purest, 93.4%. Calcium and acid soluble material values varied only 3-5% from the average among the limestones whereas 71-108% variation occurred for Fe, Mn, K and Cr. Other elements showed intermediate variations. Only Fe and Mn are present on the average in the limestones at concentration levels which might lead to contamination of ground water to undesirably high levels. Analyses compare well with the reported average limestone except for acid insoluble elements which were not dissolved in our scheme and lithium (1.5 ppm average vs 20 in reference). Ratios of Sr/Ca and Mg/Ca were similar to reported values for limestones of comparable geologic age. Maxima in the areal variation of these ratios occurred at about the same latitude for three of the formations. The areal variation of Fe/Ca and Mn/Ca was also determined for the four limestone formations. Interelement correlations in the limestones showed: Na, Sr, Li, Fe and Zn contents increased with Mg content; Mn and Cr increased with Fe content. Indications were obtained that detrital and other materials not in the calcite structure can be determined by their relative insolubility in acetic acid compared to hydrochloric acid

    True and False Foodplants of \u3ci\u3eCallosamia Promethea\u3c/i\u3e (Lepidoptera: Saturniidae) in Southern Michigan

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    A survey in 1980 of the associations of over 400 cocoons of Callosamia promethea Drury in vegetation along and adjacent to southern Michigan roadsides gave evidence for seven species of true larval foodplants (not including two others known in the area from other studies) and 17 species of false foodplants, the latter determined by the (1) rarity of their association with cocoons, (2) only one or two cocoons per plant, and (3) their proximity to a well known true foodplant. Three species, sassafras, black cherry, and buttonbush, are evidently the most important true foodplants in this area. Comparisons are made of the foodplants in terms of past literature, geography, and taxonomic relationships

    An Analytical Study of T-38 Drag Reduction in Tight Formation Flight

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    This thesis explores the benefits of flying in a tight formation, mimicking the natural behavior of migratory birds such as geese. The first phase of the research was to determine an optimal position for the wingman of a tight formation flight of T-38 Talon aircraft using the HASC95 vortex lattice code. A second wingman was then added to determine the benefit derived by increasing formation size. The second wingman was predicted to derive an even greater induced drag benefit than the first wingman for T-38s operating at Mach 0.54 at a 10,000-foot altitude. The predicted values were 17.5% savings for the second wingman versus 15% for the first wingman. The flight test phase flew two and three-ship formations to validate the computational work. The results of the two-ship flight tests showed with 80% confidence that the wingman saved fuel in the predicted optimal position (86% wingspan lateral spacing). This position yielded actual fuel savings of 8.8% 5.0% versus the predicted 15%. The other lateral positions did not show a statistically significant fuel savings. The flight test team felt that the three-ship formation data was inconclusive due to the difficulty of trying to fly a stable position as the third aircraft in the formation without station-keeping ability
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