637 research outputs found

    Thin film heat transfer gage is stable at higher temperatures

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    Thin film convective heat transfer gage functions effectively for prolonged periods at temperatures up to 1000 degrees F. An initial resistance shift does not inhibit the performance or accuracy of the gages, as the original resistance-temperature relationship remains unchanged

    Substituting gold for silver improves electrical connections

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    In attaching external leads to thin film sensors of platinum ribbon, liquid gold is applied to each end of the ribbon and the leads are soldered to the cured gold. The cured and soldered liquid gold shows no tendency to migrate and retains initial resistance characteristics when exposed to elevated temperatures

    The effect of free-stream turbulence on heat transfer to a strongly accelerated turbulent boundary layer

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    Free-stream turbulence effects on heat transfer to strongly accelerated turbulent boundary laye

    Design documentation and test hardware for an engineering model of a Serpentuator Final report

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    Design, fabrication, and testing of Serpentuator model for intervehicular performanc

    Vibration-tolerant narrow-linewidth semiconductor disk laser using novel frequency-stabilisation schemes

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    This paper will present developments in narrow-linewidth semiconductor-disk-laser systems using novel frequency-stabilisation schemes for reduced sensitivity to mechanical vibrations, a critical requirement for mobile applications. Narrow-linewidth single-frequency lasers are required for a range of applications including metrology and high-resolution spectroscopy. Stabilisation of the laser was achieved using a monolithic fibre-optic ring resonator with free spectral range of 181 MHz and finesse of 52 to act as passive reference cavity for the laser. Such a cavity can operate over a broad wavelength range and is immune to a wide band of vibrational frequency noise due to its monolithic implementation. The frequency noise of the locked system has been measured and compared to typical Fabry-Perot-locked lasers using vibration equipment to simulate harsh environments, and analysed here. Locked linewidths of < 40 kHz have been achieved. These developments offer a portable, narrow-linewidth laser system for harsh environments that can be flexibly designed for a range of applications

    Using livestock wastewater with SDI: a status report after three seasons

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    Presented at the Central Plains irrigation short course and exposition on February 5-6, 2001 at the Holiday Inn in Kearney, Nebraska.Using subsurface drip irrigation (SDI) with lagoon wastewater has many potential advantages. The challenge is to design and manage the SDI system to prevent emitter clogging. A study was initiated in 1998 to test the performance of five types of driplines (with emitter flow rates of 0.15, 0.24, 0.40, 0.60, and 0.92 gal/hr-emitter) with lagoon wastewater. A disk filter (200 mesh, with openings of 0.003 inches) was used and shock treatments of chlorine and acid were injected periodically. Over the course of three seasons (1998-2000) a total of approximately 52 inches of irrigation water has been applied through the SDI system. The flow rates of the two smallest emitter sizes, 0.15 gal/hr-emitter and 0.24 gal/hr-emitter have decreased approximately 30% during the three seasons, indicating some emitter clogging. The three largest driplines (0.40, 0.60, and 0.92 gal/hr-emitters) have had less than 5% reduction in flow rate. The disk filter and automatic backflush controller have performed adequately with the beef livestock wastewater in all three years. Based on these results, the use of SDI with beef lagoon wastewater shows promise. However, the smaller emitter sizes normally used with groundwater sources in western Kansas may be risky for use with lagoon wastewater and the long-term (> 3 growing seasons) effects are untested

    Proceedings of the 24th annual Central Plains irrigation conference

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    Presented at Proceedings of the 24th annual Central Plains irrigation conference held on February 21-22 in Colby, Kansas.Includes bibliographical references

    A Pilot Survey of an M Dwarf Flare Star with Swift's UV Grism

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    The near-ultraviolet (NUV) spectral region is a useful diagnostic for stellar flare physics and assessing the energy environment of young exoplanets, especially as relates to prebiotic chemistry. We conducted a pilot NUV spectroscopic flare survey of the young M dwarf AU Mic with the Neil Gehrels Swift Observatory's UltraViolet and Optical Telescope. We detected four flares and three other epochs of significantly elevated count rates during the 9.6 hours of total exposure time, consistent with a NUV flare rate of ∼\sim0.5 hour−1^{-1}. The largest flare we observed released a minimum energy of 6×\times1033^{33} erg between 1730-5000 \r{A}. All flares had durations longer than the ∼\sim14-17 minute duration of each Swift visit, making measuring total flare energy and duration infeasible.Comment: Published in Research Notes of the AAS (RNAAS

    Strong Continuum-continuum Couplings In The Direct Ionization Of Ar And He Atoms By 6-MeV/u U38+ And Th38+ Projectiles

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    Doubly differential cross sections have been measured as a function of the electron energy and observation angle for electron emission following collisions of 6-MeV/u U38+ and Th38+ on He and Ar. The electron-emission data show an enhancement at forward angles and a decrease at backward angles with respect to scaled-cross-section results based on the Born approximation. Comparison with classical-trajectory Monte Carlo calculations suggests that the deviation from the Born approximation can be explained by continuum-continuum couplings. By comparing with previously published data, we found that the forward enhancement as well as the backward decrease follow a q/vp (q,vp are the projectile charge and velocity) scaling. © 1989 The American Physical Society
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