2,914 research outputs found

    A survey of eight successful enrichment programs.

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    Thesis (Ed.M.)--Boston Universit

    Constant Enough: On The Kinds Of Perceptual Constancy Worth Having

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    This chapter argues that whereas perceptual experience is underconstant in one sense, it is virtually constant insofar as it is functionally stable and predictable. The possibility of distinguishing perception and cognition is explored in experiments on the perception of surface orientation. These experiments are related to the study of self-motion perception and space perception. An experiment comparing monocular and binocular perception of hills revealed perceptual differences, between-subjects, that were masked in within-subject comparisons by metacognitive strategies. A second experiment found that participants wearing heavy backpacks gave (cognitively) elevated slope estimates only because of experimental demands not physical ones. Perceptual experience is informative about perceptual processing, but reports of experience are subject to cognitive contamination. True perceptual experience may be virtually constant insofar as the perceptual consequences of actions can be correctly anticipated

    Cuphea Yields in Iowa, 2002

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    Cuphea is a potential source of lauric and capric acids, which are medium-chain-length fatty acids. They are used to manufacture various products such as detergents (lauric) and high quality lubricants (capric). The fatty acids are contained in oils that are produced and stored in cuphea seeds. Currently, all of the lauric acid used for detergents is derived from imported palm and coconut oils. There is no domestic source of this fatty acid, which is a dilemma that U.S. industries, such as Proctor & Gamble and ADM, would like to resolve

    System Noise Assessment and the Potential for a Low Noise Hybrid Wing Body Aircraft with Open Rotor Propulsion

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    An aircraft system noise assessment was conducted for a hybrid wing body freighter aircraft concept configured with three open rotor engines. The primary objective of the study was to determine the aircraft system level noise given the significant impact of installation effects including shielding the open rotor noise by the airframe. The aircraft was designed to carry a payload of 100,000 lbs on a 6,500 nautical mile mission. An experimental database was used to establish the propulsion airframe aeroacoustic installation effects including those from shielding by the airframe planform, interactions with the control surfaces, and additional noise reduction technologies. A second objective of the study applied the impacts of projected low noise airframe technology and a projection of advanced low noise rotors appropriate for the NASA N+2 2025 timeframe. With the projection of low noise rotors and installation effects, the aircraft system level was 26.0 EPNLdB below Stage 4 level with the engine installed at 1.0 rotor diameters upstream of the trailing edge. Moving the engine to 1.5 rotor diameters brought the system level noise to 30.8 EPNLdB below Stage 4. At these locations on the airframe, the integrated level of installation effects including shielding can be as much as 20 EPNLdB cumulative in addition to lower engine source noise from advanced low noise rotors. And finally, an additional set of technology effects were identified and the potential impact at the system level was estimated for noise only without assessing the impact on aircraft performance. If these additional effects were to be included it is estimated that the potential aircraft system noise could reach as low as 38.0 EPNLdB cumulative below Stage 4

    Geologic mapping of the Urvara and Yalode Quadrangles of Ceres

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    We conducted geologic mapping of the Urvara (Ac-13) and Yalode (Ac-14) Quadrangles (21–66°S, 180–360°E) of the dwarf planet Ceres utilizing morphologic, topographic, and compositional information acquired by NASA's Dawn mission. The geologic characteristics of the two large impact basins Urvara (170 km diameter) and Yalode (260 km diameter) and their surroundings were investigated using Dawn Framing Camera datasets, including Survey (415 m/pixel), HAMO (140 m/pixel), and LAMO (35 m/pixel) images and mosaics, color and color ratio images, and DTMs derived from stereo-photogrammetry. Geologic mapping demonstrates that impact cratering has dominated the geologic history of the Urvara and Yalode Quadrangles, with early cratered terrain formation followed by formation of the large basins and widespread emplacement of basin-related smooth material. Impact craters display a wide range of preservation states from nearly completely buried/degraded forms to more recent pristine craters with terraced inner walls and lobate ejecta deposits. Cross-cutting relationships and morphologic signatures show that the Urvara impact followed the Yalode impact, consistent with ages derived from crater size-frequency distributions (580 ± 40 Ma for Yalode and 550 ± 50 Ma for Urvara). Observed differences in basin materials and rim morphology suggest heterogeneities in the substrate excavated by impact. Smooth deposits that cover large areas of the quadrangles, including the basin floors, rims, and exterior zones, are interpreted to be dominated by Urvara ejecta but Yalode ejecta and localized ice-rich flow material may be minor components. Geologic mapping results and simulations of ejecta emplacement suggest that Urvara and Yalode ejecta deposits extend for large distances (more than two crater diameters from the basin centers) and may serve as important stratigraphic markers for the geologic record of Ceres
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