3,649 research outputs found

    Analytical study of control devices for high amplitude combustion instability Quarterly report

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    Mathematical model and analysis of combustion processes in annular rocket engines for control of high amplitude combustion instabilit

    A study of high frequency nonlinear combustion instability in baffled annular liquid propellant rocket motors, volume 1 Final report, 25 Aug. 1969 - 25 Sep. 1970

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    High frequency nonlinear combustion instability in baffled annular liquid propellant rocket engines - Vol.

    Nonlinear combustion instability in liquid-propellant rocket motors Final report

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    Mathematical models of nonlinear combustion instabilities in liquid propellant rocket engin

    A study of high frequency nonlinear combustion instability in baffled annular liquid propellant rocket motors

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    Computer program contains mathematical model which provides relationship between engine gas dynamics and combustion processes. Mathematically simulated explosions initiate gas disturbances. Design methods for damping disturbances can be studied to prevent future engine shutdown or destruction

    Temperature sensitivity of the pyloric neuromuscular system and its modulation by dopamine

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    We report here the effects of temperature on the p1 neuromuscular system of the stomatogastric system of the lobster (Panulirus interruptus). Muscle force generation, in response to both the spontaneously rhythmic in vitro pyloric network neural activity and direct, controlled motor nerve stimulation, dramatically decreased as temperature increased, sufficiently that stomach movements would very unlikely be maintained at warm temperatures. However, animals fed in warm tanks showed statistically identical food digestion to those in cold tanks. Applying dopamine, a circulating hormone in crustacea, increased muscle force production at all temperatures and abolished neuromuscular system temperature dependence. Modulation may thus exist not only to increase the diversity of produced behaviors, but also to maintain individual behaviors when environmental conditions (such as temperature) vary

    Maestras Dedicadas: A Portrait of Chicana Teacher Activism in Troubled Times

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    Two researchers document how veteran Chicana teacher activists, who have taught more than 15 years, remain in the classroom and challenge the pedagogy of control in urban schools. Our findings show that networking and relationships for Chicana teacher activists is developed on the basis of a common political agenda and a love of children. All of these teachers assist their students in retaining their Chicana/o language, culture, and Chicana/o identity is of primary importance and subversively alter the standardized curriculum to do so. The testimonios of these maestras dedicadas provide insights into the daily challenges veteran Chicana teachers face while negotiating the classroom during these troubled times. The seasoned activists also offer advice to new teacher activists

    A Statistical Treatment of the Gamma-Ray Burst "No Host Galaxy" Problem: II. Energies of Standard Candle Bursts

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    With the discovery that the afterglows after some bursts are coincident with faint galaxies, the search for host galaxies is no longer a test of whether bursts are cosmological, but rather a test of particular cosmological models. The methodology we developed to investigate the original "no host galaxy" problem is equally valid for testing different cosmological models, and is applicable to the galaxies coincident with optical transients. We apply this methodology to a family of models where we vary the total energy of standard candle bursts. We find that total isotropic energies of E<2e52~erg are ruled out while log(E)~53 erg is favored.Comment: To appear in Ap.J., 514, 15 pages + 7 figures, AASTeX 4.0. Revisions are: additional author, updated data, and minor textual change
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