18,399 research outputs found

    UNCERTAINTY IN STATIC PRESSURE CORRECTION IN A SUBSONIC WIND TUNNEL

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    The static pressure p on the subsonic Wind Tunnel of the Aerodynamic Testing Laboratory of the Institute of Aeronautics and Space IAE, Aerospace Technical Center CTA, is measured using an absolute pressure sensor, located on the upper test section wall. This measurement is not taken at the same location as the one where the model is mounted during the actual wind tunnel test. This fact raises the need for a correction during data reduction. The identification and evaluation of the associated error source is important because the static pressure is an input quantity for the calculation of the total pressure pt, Mach number M and density ρ during the test. The present paper is concerned with the determination of the relationship between the static pressure measured on the tunnels upper wall and that at the model location, and with the analysis of the uncertainty propagation for the measured flow parameters

    SP-Sephadex equilibrium chromatography of bradykinin and related peptides: Application to trypsin-treated human plasma

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    An analytical method is deseribed for the separation of bradykinin, Lys-bradykinin, and Met-Lys-bradykinin by equilibrium chromatography on SP-Sephadex C-25 eluted in 0.02 Tris-HCl buffer, pH 8.10, 0.12 NaCl. A second elution buffer, 0.02 Tris-HCl buffer, pH 7.70, 0.06 NaCl, serves as a second parameter for the identification of bradykinin and also separates the hormone from plasma bradykinin-potentiating peptides. Ten to one-hundred nanomoles of each peptide can be recovered in high yields, identified by elution position, and measured by bioassay with the isolated guinea pig ileum. The identification of bradykinin as the peptide released by trypsin acting on acid-denatured plasma is documented as an illustration of the method

    Short small-polaron lifetime in the mixed-valence perovskite Cs2_2Au2_2I6_6 from high-pressure pump-probe experiments

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    We study the ultrafast phonon response of mixed-valence perovskite Cs2_2Au2_2I6_6 using pump-probe spectroscopy under high-pressure in a diamond anvil cell. We observed a remarkable softening and broadening of the Au - I stretching phonon mode with both applied pressure and photoexcitation. Using a double-pump scheme we measured a lifetime of the charge transfer excitation into single valence Au2+^{2+} of less than 4 ps, which is an indication of the local character of the Au2+^{2+} excitation. Furthermore, the strong similarity between the pressure and fluence dependence of the phonon softening shows that the inter-valence charge transfer plays an important role in the structural transition.Comment: 4 pages, 4 figure

    Caracterização molecular e morfológica do agente etiológico da pinta preta em solanáceas no Brasil.

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    Este trabalho objetivou realizar a caracterização molecular e morfológica de isolados de Alternaria obtidos de solanáceas.Resumo 504_1
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