7,507 research outputs found

    High temperature thermocouple operates in reduction atmosphere

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    Thermocouple continuously measures a flowing gas up to 4500 degrees F in a hazardous environment. The thermocouple combines rhenium and tungsten in the probe, housing, and swaged extension lead. The wires extend continuously from the cold junction to the probe tip to eliminate errors from secondary thermocouple effects

    Biodiversity as an index of regime shift in the eastern Bering Sea

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    Data collected from an annual groundf ish survey of the eastern Bering Sea shelf from 1975 to 2002 were used to estimate biomass and biodiversity indexes for two fish guilds: f latfish and roundfish. Biomass estimates indicated that several species of f latfish (particularly rock sole, arrowtooth flounder, and f lathead sole), several large sculpins (Myoxocephalus spp.), bigmouth (Hemitripterus bolini), and skates (Bathyraja spp.) had increased. Declining species included several f latfish species and many smaller roundfish species of sculpins, eelpouts (Lycodes spp.), and sablefish (Anoplopoma fimbria). Biodiversity indexes were calculated by using biomass estimates for both guilds from 1975 through 2002 within three physical domains on the eastern Bering Sea shelf. Biodiversity trends were found to be generally declining within the roundfish guild and generally increasing within the f latfish guild and varied between inner, middle, and outer shelf domains. The trends in biodiversity indexes from this study correlated strongly with the regime shift reported for the late 1970s and 1980s

    Causes of failure of airship shed

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    The causes of the collapse of airship shed, which was being taken down at Niediergorsdorf, are discussed. This shed, which was built of iron, was 184 m long, 28 m high, and 35 m wide. The demolition of the shed had been assigned to unskilled men who proceeded to remove certain key structural supports, leaving the structure in such a condition that relatively small eccentricities of the columns or spans or of lateral forces could easily have caused the columns or spans to break down. A small gust of wind would have perhaps sufficed to bring the building down. An analysis is also given of the suction effects on the roof of an air shed in Staaken. The damage to this shed, which occurred during a storm, was due to the fact that the shed had no opening in its top for equalizing the air pressure within and without. The location of the plates blown off the roof correspond to the point of greatest suction

    High-temperature rapid-response thermocouple for reducing atmospheres

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    Thermocouple measures continuously in flowing gaseous hydrogen at temperatures up to 4000 deg F, in environments made hazardous by radiation, and where rapid response and calibration reproducibility are critically important. Thermocouple wires extend continuously, without splice or foreign material, from cold junction to probe's tip

    Existence of global strong solutions in critical spaces for barotropic viscous fluids

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    This paper is dedicated to the study of viscous compressible barotropic fluids in dimension N2N\geq2. We address the question of the global existence of strong solutions for initial data close from a constant state having critical Besov regularity. In a first time, this article show the recent results of \cite{CD} and \cite{CMZ} with a new proof. Our result relies on a new a priori estimate for the velocity, where we introduce a new structure to \textit{kill} the coupling between the density and the velocity as in \cite{H2}. We study so a new variable that we call effective velocity. In a second time we improve the results of \cite{CD} and \cite{CMZ} by adding some regularity on the initial data in particular ρ0\rho_{0} is in H1H^{1}. In this case we obtain global strong solutions for a class of large initial data on the density and the velocity which in particular improve the results of D. Hoff in \cite{5H4}. We conclude by generalizing these results for general viscosity coefficients
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