144 research outputs found
Experimental in situ investigation of the effects of protons, ultraviolet radiation, and temperature on thermophysical properties of solar cell filters and other spacecraft materials
In situ determination of effects of ultraviolet radiation, solar wind protons, and temperature on thermophysical properties of solar cell filters and other spacecraft material
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Developing High School Multiple Intelligence Learning Centers: An Action Research Project in History.
Research that provides results which can be almost instantaneously put into use is looked on by some teachers as a path to better student learning. Accordingly, action research is a form of critical reflection that some experts believe can achieve instant change. Although, action research is sometimes denigrated as lacking in precision, the critical reflection necessary in any well done action research project demonstrates that such research while, not quantitatively rigorous can still be qualitatively useful. As such, the author discusses her own implementation of MI learning centers as a form of action research in the classroom
Effects of high energy simulated space radiation on polymeric second-surface mirrors
A radiation effects experimental program was performed, in which second surface mirror type thermal control coatings were exposed to ultraviolet radiation, electrons, and protons simultaneously. Stability was assessed by making periodic spectral reflectance measurements in situ (and in air after testing for comparison). Solar absorption coefficients were derived by computer. Many of the exposed materials showed large amounts of degradation in reflectance absorptance, principally due to the electron exposure. A series of tests was conducted, leading to the identification of a modified second surface mirror that shows considerable improvement and promise for stability during thermal control applications in a charged particle space radiation environment
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Erin Gruwell and The Freedom Writers: Two Books Reviewed
Two books, “The Freedom Writers Diary: How a Teacher and 150 Teens Used Writing to Change Themselves and the World Around Them,” by the Freedom Writers and Erin Gruwell, and “Teach With Your Heart,” also by Erin Gruwell will be reviewed herein. Together, they weave an integrated tale of discovery and self-actualization. This is true for both the students who undergo catharsis with diary entries in “The Freedom Writers Diary,” and for Ms. Gruwell who learns more deeply about who she is as a teacher, a professor, and a person, through a heartfelt journey to help 150 at-risk students find authenticity in learning in “Teach With Your Heart”
Study of space environment effects on thermal control coatings - Dependence of thermal control coating degradation upon electron energy Final report
Hemispherical spectral reflectance in vacuum for thermal coating degradation using electron energ
Effects of control inputs on the estimation of stability and control parameters of a light airplane
The maximum likelihood parameter estimation technique was used to determine the values of stability and control derivatives from flight test data for a low-wing, single-engine, light airplane. Several input forms were used during the tests to investigate the consistency of parameter estimates as it relates to inputs. These consistencies were compared by using the ensemble variance and estimated Cramer-Rao lower bound. In addition, the relationship between inputs and parameter correlations was investigated. Results from the stabilator inputs are inconclusive but the sequence of rudder input followed by aileron input or aileron followed by rudder gave more consistent estimates than did rudder or ailerons individually. Also, square-wave inputs appeared to provide slightly improved consistency in the parameter estimates when compared to sine-wave inputs
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Review of Books by Visual/Media Literacy Author, Thomas West
Thomas West’s: In the Mind’s Eye: Visual Thinkers, Gifted People with Learning Disabilities, Computer Images, and the Ironies of Creativity, and Thinking Like Einstein: Returning to Our Visual Roots with the Emerging Revolution in Computer Information Visualization
A comparison of results from two simulators used for studies of astronaut maneuvering units
A comparison of the results from a fixed-base, six-degree-of -freedom simulator and a moving-base, three-degree-of-freedom simulator was made for a close-in, EVA-type maneuvering task in which visual cues of a target spacecraft were used for guidance. The maneuvering unit (the foot-controlled maneuvering unit of Skylab Experiment T020) employed an on-off acceleration command control system operated entirely by the feet. Maneuvers by two test subjects were made for the fixed-base simulator in six and three degrees of freedom and for the moving-base simulator in uncontrolled and controlled, EVA-type visual cue conditions. Comparisons of pilot ratings and 13 different quantitative parameters from the two simulators are made. Different results were obtained from the two simulators, and the effects of limited degrees of freedom and uncontrolled visual cues are discussed
Effects of terraces on submerged aquatic vegetation in shallow marsh ponds in coastal southwest Louisiana
The wetlands of coastal Louisiana are disappearing at a rate of 65 to 80 km2yr-1. Most of the loss is the conversion of emergent marsh to shallow marsh ponds. Terracing is one restoration technique that has been used frequently in recent years. Terraces are small intertidal ridges built in shallow marsh ponds to reduce wave action. It is assumed that this will slow erosion of adjacent emergent marsh and increase Submerged Aquatic Vegetation (SAV) production, a key habitat component for many marsh fauna. Yet both relevant previous studies failed to show that terraces increased SAV abundance. In April of 2004 this study was initiated to test this assumption. Three study sites with paired terraced and unterraced ponds were selected in southwest Louisiana; two at Rockefeller State Wildlife Refuge and one at Sabine National Wildlife Refuge. SAV abundance was estimated every other month for one year. SAV biomass and frequency were significantly higher in terraced ponds. SAV frequency in unterraced ponds averaged 20% (SE 13 to 33%) but frequency for unterraced ponds was 9% (SE 5 to 14%). Terraced ponds had approximately three and half times the biomass of unterraced ponds. This indicates that terraces improve SAV production as had been suspected. Turbidity and organic matter content were lower in terraced ponds indicating a possible causal mechanism. My results confirm some assumptions of wetland restoration planners who have used terraces
Modeling Satellite Formations In The Presence Of Perturbations
The potential benefits of autonomous satellite formation flying in such areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite formations. The purpose of this paper is to develop and describe a numerical simulation of the orbital environment including central force field perturbations and atmospheric drag effects which will be a useful analytical tool for investigating issues relating to maintaining satellite formations in low-earth-orbit. Many of the studies done in this area confine their research to circular orbits, with and without perturbation effects. This study will investigate apply orbital dynamic equations to the problem of maintaining satellite formations in both circular and elliptical orbits, with and without the presence of J2 gravity perturbation effects and atmospheric drag. This effort is primarily focused on modeling the orbital mechanics of one and two satellites in the presence of J2 and drag perturbations This effort is being performed as part of a multi-disciplined University of Central Florida KnightSat project, sponsored by the Air Force, to develop a two-satellite formation in the nanosatellite class, for investigating issues related to using formation satellites for remote earth sensing, to develop three-dimensional mapping
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