5,538 research outputs found
Electromagnetic wave energy conversion research
Known electromagnetic wave absorbing structures found in nature were first studied for clues of how one might later design large area man-made radiant-electric converters. This led to the study of the electro-optics of insect dielectric antennae. Insights were achieved into how these antennae probably operate in the infrared 7-14um range. EWEC theoretical models and relevant cases were concisely formulated and justified for metal and dielectric absorber materials. Finding the electromagnetic field solutions to these models is a problem not yet solved. A rough estimate of losses in metal, solid dielectric, and hollow dielectric waveguides indicates future radiant-electric EWEC research should aim toward dielectric materials for maximum conversion efficiency. It was also found that the absorber bandwidth is a theoretical limitation on radiant-electric conversion efficiency. Ideally, the absorbers' wavelength would be centered on the irradiating spectrum and have the same bandwith as the irradiating wave. The EWEC concept appears to have a valid scientific basis, but considerable more research is needed before it is thoroughly understood, especially for the complex randomly polarized, wide band, phase incoherent spectrum of the sun. Specific recommended research areas are identified
A survey of elementary school banking in New England
Thesis (Ed.M.)--Boston Universit
LIBRA: An inexpensive geodetic network densification system
A description is given of the Libra (Locations Interposed by Ranging Aircraft) system, by which geodesy and earth strain measurements can be performed rapidly and inexpensively to several hundred auxiliary points with respect to a few fundamental control points established by any other technique, such as radio interferometry or satellite ranging. This low-cost means of extending the accuracy of space age geodesy to local surveys provides speed and spatial resolution useful, for example, for earthquake hazards estimation. Libra may be combined with an existing system, Aries (Astronomical Radio Interferometric Earth Surveying) to provide a balanced system adequate to meet the geophysical needs, and applicable to conventional surveying. The basic hardware design was outlined and specifications were defined. Then need for network densification was described. The following activities required to implement the proposed Libra system are also described: hardware development, data reduction, tropospheric calibrations, schedule of development and estimated costs
Growth of Bluegill, Largemouth Bass, and Channel Catfish in Relation to Fish Abundances, Food Availability, and Other Limnological Variables
Bluegill, largemouth bass, and channel catfish are widely distributed and popular sports species. We assessed growth of sympatric populations of these species in 14 reservoirs throughout Illinois, and attempted to relate growth to environmental factors. Principal components analysis (PCA) classified the lakes using 20 morphometric and limnological variables. We examined growth rate relationships with the principal components, via correlations, and also developed simple and multiple regression models using individual variables. Using size-specific growth for two size classes, percent littoral zone of a lake was correlated with growth of both channel catfish (300 and 450 mm) and small bluegill (50 mm). Lake latitude was correlated with growth of large bluegill (150 mm). There were no significant correlations for either size of largemouth bass (100 and 250 mm). Our empirical relationships provide working models of fish growth and suggest testable hypotheses for future study. The models, when tested against independent data sets, will provide managers with useful tools for making inexpensive, a priori assessments of a fishery resource
Fake Characters: Real Suffering
In this paper, I was asked to describe positive or negative literacy sponsors I have encountered in my life
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