55 research outputs found
In situ electron rate effects studies on thermal control coatings Quarterly progress report, 15 Mar. - 15 Jun. 1967
Low energy electron irradiation rate testing of thermal control coatings for spectral reflectance propertie
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
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
Experimental study of effects of simulated neutralized solar wind on white-pigment thermal control coatings
Simulated solar wind effects on thermal control coatings for space fligh
Proton and Electron Effects in Thermal Control Materials Final Report
Radiation effects of electrons and protons on reflectance and degradation properties of specular and diffuse thermal control material
Simulation of space radiation effects on polyimide film materials for high temperature applications
Space environment effects on candidate materials for the solar sail film are determined. Polymers, including metallized polyimides that might be suitable solar radiation receivers, were exposed to combined proton and solar electromagnetic radiation. Each test sample was weighted, to simulate the tension on the polymer when it is stretched into near-planar shape while receiving solar radiation. Exposure rates up to 16 times that expected in Earth orbit were employed, to simulate near-sun solar sailing conditions. Sample appearance, elongation, and shrinkage were monitored, noted, and documented in situ. Thermosetting polyimides showed less degradation or visual change in appearance than thermoplastics
Concept Booklets: Examining the Performance Effects of Journaling of Mathematics Course Concepts
Journaling is an effective tool for writing about mathematics, but research is mixed about the extent to its effectiveness in writing to learn mathematics. This study examined the performance effects of concept booklets on curriculum assessments. Concept booklets are a hybrid style of journal-writing that include responses to journal prompts, diagramming, and traditional note-taking. Prompts were designed to sometimes investigate new concepts and, at other times, to reflect on components of previously learned concepts.
The study, of an experimental design, was carried out at the high school level in honors-level mathematics classes with the independent variable being exposure to the booklets. A unit examination consisting of two parts, the first being traditional curriculum assessment items and the second being composed of nontraditional open-ended problems, was given to both groups. Exam results were analyzed to determine any statistically significant difference between the groups’ performances. Separate analyses of test results were done for sophomores and juniors. Additionally, six examination items were analyzed based on whether an accurate diagram was drawn for the problem. This analysis was performed for the control group, the treatment group, and for the pool of all students in the study.
Results showed significantly better performance by the sophomore subgroup on the entire test as well as both parts. The junior subgroup’s performance reached statistical significance on only the second, open-ended part of the examination. Analysis of diagramming showed significantly better performance on the open-ended questions by students who had provided an accurate diagram of the problem. Potential differences in age between grade levels may have contributed to different results for sophomores and juniors
- …