3,090 research outputs found

    Analytical study of laser supported combustion waves in hydrogen

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    A one-dimensional energy equation, with constant pressure and area, was used to model the LSC wave. This equation balances convection, conduction, laser energy absorption, radiation energy loss and radiation energy transport. Solutions of this energy equation were obtained to give profiles of temperature and other properties, as well as the relation between laser intensity and mass flux through the wave. The flow through the LSC wave was then conducted through a variable pressure, variable area streamtube to accelerate it to high speed, with the propulsion application in mind. A numerical method for coupling the LSC wave model to the streamtube flow was developed, and a sample calculation was performed. The result shows that 42% of the laser power has been radiated away by the time the gas reaches the throat. It was concluded that in the radially confined flows of interest for propulsion applications, transverse velocities would be less important than in the unconfined flows where air experiments have been conducted

    Let\u27s Keep What We Have Until We Get More to Keep

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    Some New Developments in Road Construction and Maintenance

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    The Highway Game - Offense vs. Defense

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    Effects of an undergraduate program to integrate academic learning and service: cognitive, prosocial cognitive, and identity outcomes

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    The present study investigated the effects of key characteristics of service-learning experiences (such as autonomy, instructional support for the experience, and so on) on the cognitive, moral, and ego identity development of undergraduates. Participants in service-learning courses and control students wrote pre- and post-responses to social problems. Service-learning students· also completed weekly journals and an evaluation of their experiences. Results revealed significant gains for the service-learning participants on certain cognitive dimensions, such as awareness of multidimensionality. Aspects of the experience predicted cognitive gains as well as gains in prosocial reasoning. Paired 1-tests revealed significant increases in prosocial decision-making, prosocial reasoning and identity processing

    Proposal for a study of computer mapping of terrain using multispectral data from ERTS-A for the Yellowstone National Park test site

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    The author has identified the following significant results. A terrain map of Yellowstone National Park showed plant community types and other classes of ground cover in what is basically a wild land. The map comprised 12 classes, six of which were mapped with accuracies of 70 to 95%. The remaining six classes had spectral reflectances that overlapped appreciably, and hence, those were mapped less accurately. Techniques were devised for quantitatively comparing the recognition map of the park with control data acquired from ground inspection and from analysis of sidelooking radar images, a thermal IR mosaic, and IR aerial photos of several scales. Quantitative analyses were made in ten 40 sq km test areas. Comparison mechanics were performed by computer with the final results displayed on line printer output. Forested areas were mapped by computer using ERTS data for less than 1/4 the cost of the conventional forest mapping technique for topographic base maps
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