16,376 research outputs found

    Commentary on the 1985 NASA/Vanderbilt Symposium on Future Hypervelocity Flight Requirements

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    The discussion, started in Semiannual Status Report Number 1, on aerothermal problems of hypervelocity flight and experiments that may lead to significant improvements in analytical/computational predictive methods, continues. The commentary is based on presentations made by speakers at a symposium on this subject held in December 1985. Symposium participants focused on the serious deficiencies that exist in knowledge of real-gas, nonequilibrium thermochemical-kinetic processes, catalytic processes, surface and shock slip, gas/surface interaction, boundary layer transition, and vortical leeside flows under hypervelocity conditions. Programs of laboratory research and computations leading toward in-flight experiments were recommended. Feasibility of appropriate measurement techniques for the flight environment was assessed and problems for study in that area identified. A synopsis of the oral presentations is given

    A simulation study of Large Area Crop Inventory Experiment (LACIE) technology

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    The author has identified the following significant results. The LACIE performance predictor (LPP) was used to replicate LACIE phase 2 for a 15 year period, using accuracy assessment results for phase 2 error components. Results indicated that the (LPP) simulated the LACIE phase 2 procedures reasonably well. For the 15 year simulation, only 7 of the 15 production estimates were within 10 percent of the true production. The simulations indicated that the acreage estimator, based on CAMS phase 2 procedures, has a negative bias. This bias was too large to support the 90/90 criterion with the CV observed and simulated for the phase 2 production estimator. Results of this simulation study validate the theory that the acreage variance estimator in LACIE was conservative

    Quantitative determination of stratospheric aerosol characteristics

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    There are no author-identified significant results in this report

    Ocean properties

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    The author has identified the following significant results. Results of testing the CP program indicate that the best results can be obtained in the near infrared water bands. The absorption due to water vapor and carbon dioxide in the thermal infrared band appeared to be less reliable in comparison to spacecraft-acquired data and band models. Comparisons of laboratory carbon dioxide transmission in the thermal infrared band show good agreement except in regions where lines are known to be missing. The comparison of ozone transmission at a wavelength of 9.6 micrometers to laboratory data showed unexceptedly large differences

    Continuation of development of nitrides for space nuclear reactors

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    Alloy nitrides (U,Zr), (U,Ce), and (U,Y) were prepared and exposed to vacuum at temperatures to 1700 C (1973 K) and compared with pure UN. Weight loss data and physical observations showed that the alloy samples were more stable than UN. In weight loss, (U,Zr)N was 3 times as stable as UN at 1600 C (1873 K) for 100 hr at 0.000002 torr (0.000266n/sq.m.)

    Economic restructuring in New York State

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    When economic activity slows down, labor markets may undergo extensive structural change-the permanent reallocation of workers across industries. Job losses can be heavy, and creating new jobs and retraining displaced workers to fill them can take time. A high degree of restructuring may help to explain why New York State's most recent downturn persisted for well over two years. Subseries: Second District Highlights.Employment - New York (State) ; Labor market - New York (State) ; Industries - New York (State) ; Federal Reserve District, 2nd

    Exploring The Neural Correlates of Reading Comprehension and Social Cognition Deficits in College Students with ADHD

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    Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, impulsivity, and hyperactivity. Symptoms of this disorder have been shown to adversely impact academic and social functioning of those with ADHD. College students with ADHD, compared to their non-ADHD peers, are at increased risk for academic and social difficulties. Given the reading-intensive and socially-driven environment of the college campus, empirical literature examining the reading comprehension and social cognition of college students are wanting. The current investigation utilized the Nelson-Denny Reading Test (NDRT) and Faux Pas Recognition test (FPRT) to assess reading comprehension and social cognition, respectively, in college students with (n = 3) and without ADHD (n = 9). The Short Story Task (SST) was administered during functional magnetic resonance imaging (fMRI) to examine neural correlates of narrative comprehension and theory of mind (ToM) while reading short fictional stories of varying prose complexity. The ADHD and control groups did not differ in IQ, GPA, or scores of NDRT, FPRT, or SST, suggesting that they had comparable academic performance, narrative comprehension, and social cognition. The fMRI analysis of SST showed that the ADHD group demonstrated increased activation in the left anterior cingulate (ACC) and parahippocampal gyrus (PHG) while reading the complex story compared to the simple story. This differential activation was not observed in the CTRL group, suggesting that the ADHD group required more neural resources to process the emotional components of the complex story to achieve the comparable performance on the SST. The ADHD group additionally exhibited lower activation in the narrative comprehension and ToM networks (medial prefrontal cortex, Broca’s area, angular gyri). Collectively, these results indicate that while ADHD and CTRL groups did not differ behaviorally, they exhibit differential neural activation patterns in tasks related to narrative comprehension and social cognition. Further investigations may inform the development of educational and psychosocial interventions to improve academic and social functioning in young adults with ADHD

    The role of freestream turbulence scale in subsonic flow separation

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    The ojective of this work is the clarification of the role of freestream turbulence scale in determining the location of boundary layer separation. An airfoil in subsonic wind tunnel flow is the specific case studied. Hot-film and hot-wire anemometry, liquid-film visualization and pressure measurements are the principal diagnostic techniques in use. The Vanderbilt University subsonic wind tunnel is the flow facility being used
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