8,215 research outputs found

    Vibrational relaxation measurements in CO2 USING an induced fluorescence technique

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    Vibrational relaxation measurements in carbon dioxide using induced infrared fluorescence techniqu

    The five-minute oscillations: What's left to be done

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    Current observational methods for studying these oscillations at large horizontal wavenumbers are discussed in detail and several two dimensional power spectra obtained with a CID camera on the main spectrograph of the McMath telescope at Kitt Peak National Observatory are described. The best-resolved observations of the p-mode obtained at chromospheric elevations are also presented. Recent progress in studies of the p-modes at low wavenumbers with full-disk velocity detection schemes is summarized. These full-disk observations of radial and low-degree non-radial modes were shown to place severe constraints on the theoretical calculation of solar interior structure. Progress in making fully-consistent solar models which fit both the high- and low-wave number observations is described. Finally, the observational and theoretical improvements that are necessary for further progress in solar seismology are summarized

    Cathodic electrocatalyst layer for electrochemical generation of hydrogen peroxide

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    A cathodic gas diffusion electrode for the electrochemical production of aqueous hydrogen peroxide solutions. The cathodic gas diffusion electrode comprises an electrically conductive gas diffusion substrate and a cathodic electrocatalyst layer supported on the gas diffusion substrate. A novel cathodic electrocatalyst layer comprises a cathodic electrocatalyst, a substantially water-insoluble quaternary ammonium compound, a fluorocarbon polymer hydrophobic agent and binder, and a perfluoronated sulphonic acid polymer. An electrochemical cell using the novel cathodic electrocatalyst layer has been shown to produce an aqueous solution having between 8 and 14 weight percent hydrogen peroxide. Furthermore, such electrochemical cells have shown stable production of hydrogen peroxide solutions over 1000 hours of operation including numerous system shutdowns

    Infrared emission spectrum and potentials of 0u+0_u^+ and 0g+0_g^+ states of Xe2_2 excimers produced by electron impact

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    We present an investigation of the Xe2_{2} excimer emission spectrum observed in the near infrared range about 7800 cm−1^{-1} in pure Xe gas and in an Ar (90%) --Xe (10%) mixture and obtained by exciting the gas with energetic electrons. The Franck--Condon simulation of the spectrum shape suggests that emission stems from a bound--free molecular transition never studied before. The states involved are assigned as the bound (3)0u+(3)0_{u}^{+} state with 6p[1/2]06p [1/2]_{0} atomic limit and the dissociative (1)0g+(1)0_{g}^{+} state with 6s[3/2]16s [3/2]_{1} limit. Comparison with the spectrum simulated by using theoretical potentials shows that the dissociative one does not reproduce correctly the spectrum features.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

    Pittsburgh\u27s Mt. Lebanon Tunnels- Case History

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    Discussions of basic design philosophy and comparison of alternative contract bid options are presented. Also discussed are descriptions of field monitoring activities with respect to the construction methods, ground response, installation of materials and their performance. Finally, conclusions are reached relative to the NATM philosophy as applied to this project and its place as a design process within the context of United States underground construction practice
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