4,049 research outputs found

    Unique research challenges for high-speed civil transports

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    Market growth and technological advances are expected to lead to a generation of long-range transports that cruise at supersonic or even hypersonic speeds. Current NASA/industry studies will define the market windows in terms of time frame, Mach number, and technology requirements for these aircraft. Initial results indicate that, for the years 2000 to 2020, economically attractive vehicles could have a cruise speed up to Mach 6. The resulting research challenges are unique. They must be met with technologies that will produce commercially successful and environmentally compatible vehicles where none have existed. Several important areas of research were identified for the high-speed civil transports. Among these are sonic boom, takeoff noise, thermal management, lightweight structures with long life, unique propulsion concepts, unconventional fuels, and supersonic laminar flow

    Genetics of the Multiple Endocrine Neoplasia Type 2B Syndrome

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    Multiple endocrine neoplasia type 2B (MEN 2B) is similar to MEN 2A in that both autosomal dominant syndromes include medullary thyroid cancers and pheochromocytomas. It is distinct in that MEN 2B patients have much earlier age of onset with more aggressive tumors and mucosa/neuromas of the lips and tongue. The neuromas allow ascertainment generally before age 5. Studies of two and three generations of 14 MEN 2B families disclosed close linkage of the MEN 2B gene to DNA markers to which MEN2A had been linked. Multipoint analysis utilizing additional results in three generations of a 15th family have disclosed a peak total lod score of 8.89 at the midpoint between the centromere markers D10ZJ and RBP3 on the long arm (band q11). One recombinant was observed between D10ZJ and MEN28, but this individual was not recombinant with D10S94. These studies suggest physical proximity of MEN2A and MEN28 but do not establish allelism for the gene(s)

    Design, Testing And Commissioning Of A Synchronous Motor-Gear-Axial Compressor.

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    LecturePg. 97-112This paper presents the design features involved in providing two air compressor trains at high efficiency. Testing and commissioning data are also presented, including specific electrical requirements; foundation and assembly features; grade maintained air filter designs at 0.5 in. water drop; torsional features not using soft elastomeric couplings; bearing designs for motor, gear and compressors; and test and commissioning data. The test and commissioning data include torsional data, alignment heat rise data, torsional-lateral interaction on run-up, quadrant inlet vane surge tests with flow and vibration responses, eccentricity plots of journals in bearing, transient responses through criticals, and correlations of predicted vs. actual rotor dynamics responses

    A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

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    Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

    A Spitzer IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. II. IC 1613

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    We present Spitzer Space Telescope IRAC photometry of the Local Group dwarf irregular galaxy IC 1613. We compare our 3.6, 4.5, 5.8, and 8.0 micron photometry with broadband optical photometry and find that the optical data do not detect 43% and misidentify an additional 11% of the total AGB population, likely because of extinction caused by circumstellar material. Further, we find that a narrowband optical carbon star study of IC 1613 detects 50% of the total AGB population and only considers 18% of this population in calculating the carbon to M-type AGB ratio. We derive an integrated mass-loss rate from the AGB stars of 0.2-1.0 x 10^(-3) solar masses per year and find that the distribution of bolometric luminosities and mass-loss rates are consistent with those for other nearby metal-poor galaxies. Both the optical completeness fractions and mass-loss rates in IC 1613 are very similar to those in the Local Group dwarf irregular, WLM, which is expected given their similar characteristics and evolutionary histories.Comment: Accepted by ApJ, 26 pages, 10 figures, version with high-resolution figures available at: http://webusers.astro.umn.edu/~djackson
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