494 research outputs found

    Mark Twain\u27s \u3cem\u3eRoughing It\u3c/em\u3e: A Humorist\u27s Darker Side

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    Roughing It was based rather roughly on a period of Twain’s life that began in 1861, when Twain went west with his brother Orion. Orion had been appointed Secretary of the Nevada territory with the help of friend who had a friend in Lincoln’s new cabinet. Twain had just faded quietly out of the Confederate army after suffering from boils and a sprained ankle and never firing a shot. For a while out west, Twain prospected for silver around Virginia City; then for about two years he was a reporter for the Virginia City Territorial Enterprise. In 1864 he drifted on to San Francisco, where he was a reporter and a free-lance writer. In 1866 he was sent to the Hawaiian Islands by the Sacramento Union. The period covered by the book ends with his return to San Francisco, his first success as a lecturer, and his boarding ship for the voyage that was to take him to New York and his career as one of America’s most famous writers. The stretch between the inception and the publishing of Roughing It – from the beginning of 1870 to February 1872 – was for Twain one of protracted crisis

    Implications of Public Opinion for Space Program Planning, 1980 - 2000

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    The effect of public opinion on future space programs is discussed in terms of direct support, apathy, or opposition, and concern about the tax burden, budgetary pressures, and national priorities. Factors considered include: the salience and visibility of NASA as compared with other issues, the sources of general pressure on the federal budget which could affect NASA, the public's opinions regarding the size and priority of NASA'S budget, the degree to which the executive can exercise leverage over NASA's budget through influencing or disregarding public opinion, the effects of linkages to other issues on space programs, and the public's general attitudes toward the progress of science

    Identification of the ns and nd Rydberg states of O2 for n=3–5

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    The 4s‐3d and 5s‐4dRydberg complexes of diatomic oxygen have been studied by (2+1) resonance‐enhanced multiphoton ionization of the X  3∑ g − ground state of O2. We have located and identified at least two vibrational levels of each of the following states: Three of four expected 4sσ Π states; all four expected 5sσ Π states; 18 of 22 expected 3d states (with only the states of the 3dσ orbital remaining unobserved); and 5 of the 10 predicted 4dπ states. State assignments were assisted by the following: the results of rotational cooling and laser polarization experiments which facilitated the rotational analysis, band positions, band intensities, and parameterized calculations. The experimentally determined state locations are compared with the state locations obtained from ab initio calculations. We have carried out isotope experiments and rotational linewidth analysis to study in some detail the mixing between the Rydberg states and the repulsive valence states as well as the mixing between the Rydberg states themselves. We conclude that direct predissociation dominates indirect predissociation as a dissociative mechanism, but there is evidence of Δv≠0 interactions which perturb the rotational structure of the 3dπ∑ and Δ states. The relative intensities of the states detected are found to span a range in excess of 104 with the nsσ Π states being the weakest and the ndπ ∑ states being the strongest. Photoionization of the ndπ ∑ states appears to be most affected by the shape resonance in the continuum. Our measurements confirm the expectation that many of the properties of the Rydberg states in the same series scale as (n*)−3

    Identification of the nd Δ and Σ States and the 1,3Φ←←X  3Σ− g Transition of O2 by Resonant Multiphoton Ionization

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    Spectra of the 3dRydberg state region of O2 have been obtained by two‐photon resonant ionization of the ground electronic state. By varying the rotational distribution and radiation polarization, all observed bands were identified and attributed to excitation of Σ, Δ, and Φ states. Earlier assignments were corrected. The Δ and Φ assignments are complete while the Σ assignments are so far incomplete

    Emission factors for open and domestic biomass burning for use in atmospheric models

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    Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially true for non-methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New EF should improve regional to global BB emissions estimates and therefore, the input for atmospheric models. In this work we present an up-to-date, comprehensive tabulation of EF for known pyrogenic species based on measurements made in smoke that has cooled to ambient temperature, but not yet undergone significant photochemical processing. All EFs are converted to one standard form (g compound emitted per kg dry biomass burned) using the carbon mass balance method and they are categorized into 14 fuel or vegetation types. Biomass burning terminology is defined to promote consistency. We compile a large number of measurements of biomass consumption per unit area for important fire types and summarize several recent estimates of global biomass consumption by the major types of biomass burning. Post emission processes are discussed to provide a context for the emission factor concept within overall atmospheric chemistry and also highlight the potential for rapid changes relative to the scale of some models or remote sensing products. Recent work shows that individual biomass fires emit significantly more gas-phase NMOC than previously thought and that including additional NMOC can improve photochemical model performance. A detailed global estimate suggests that BB emits at least 400 Tg yr^(−1) of gas-phase NMOC, which is almost 3 times larger than most previous estimates. Selected recent results (e.g. measurements of HONO and the BB tracers HCN and CH_3CN) are highlighted and key areas requiring future research are briefly discussed
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