9,967 research outputs found

    Universal Charge-Radius Relation for Subatomic and Astrophysical Compact Objects

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    Electron-positron pair creation in supercritical electric fields limits the net charge of any static, spherical object, such as superheavy nuclei, strangelets, and Q-balls, or compact stars like neutron stars, quark stars, and black holes. For radii between 4×1024\times10^2 fm and 10410^4 fm the upper bound on the net charge is given by the universal relation Z=0.71RfmZ=0.71R_{fm}, and for larger radii (measured in fm or km) Z=7×10−5Rfm2=7×1031Rkm2Z = 7 \times 10^{-5} R_{fm}^2 = 7 \times 10^{31} R_{km}^2. For objects with nuclear density the relation corresponds to Z≈0.7A1/3Z \approx 0.7 A^{1/3} (108<A<101210^{8} < A < 10^{12}) and Z≈7×10−5A2/3Z \approx 7\times10^{-5} A^{2/3} (A>1012A > 10^{12}), where AA is the baryon number. For some systems this universal upper bound improves existing charge limits in the literature

    Transient engine simulation program. NERVA program

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    IBM 7094 transient engine simulation program for NERV

    Topological equivalence of crystal and quasicrystal band structures

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    A number of recent articles have reported the existence of topologically non-trivial states and associated end states in one-dimensional incommensurate lattice models that would usually only be expected in higher dimensions. Using an explicit construction, we here argue that the end states have precisely the same origin as their counterparts in commensurate models and that incommensurability does not in fact provide a meaningful connection to the topological classification of systems in higher dimensions. In particular, we show that it is possible to smoothly interpolate between states with commensurate and incommensurate modulation parameters without closing the band gap and without states crossing the band gap.Comment: 7 pages, 9 figures. Editors' Suggestio

    Angular Normal Modes of a Circular Coulomb Cluster

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    We investigate the angular normal modes for small oscillations about an equilibrium of a single-component coulomb cluster confined by a radially symmetric external potential to a circle. The dynamical matrix for this system is a Laplacian symmetrically circulant matrix and this result leads to an analytic solution for the eigenfrequencies of the angular normal modes. We also show the limiting dependence of the largest eigenfrequency for large numbers of particles

    Is There a Future Audience for Small Market Broadcast Television News?

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    Local television stations, especially in smaller markets of 100,000 to 200,000 TV homes, are constantly looking for adults between the ages of 25- 54 to watch their TV newscasts. TV stations must nurture younger audiences (of adults 18-34) to grow into older, desired audiences of loyal TV news viewers. Because of technological innovations such as the Internet, Facebook and Twitter, younger audiences are spending less time watching local TV news. Existing research on younger audiences has largely focused on news consumption in general (TV, radio, newspaper, Internet), used more of a national news focus, and was often conducted in large U.S. markets. This thesis asked 354 people, aged 18-34, about local TV news consumption in smaller, Midwest television markets. The survey also asked respondents what might encourage them to watch more local TV news. Results indicate the younger audience for local TV news is shrinking, but there are positive signs for local TV stations hoping to increase the size of those young audiences for the future. Adviser: Bernard J. McCo

    Is There a Future Audience for Small Market Broadcast Television News?

    Get PDF
    Local television stations, especially in smaller markets of 100,000 to 200,000 TV homes, are constantly looking for adults between the ages of 25- 54 to watch their TV newscasts. TV stations must nurture younger audiences (of adults 18-34) to grow into older, desired audiences of loyal TV news viewers. Because of technological innovations such as the Internet, Facebook and Twitter, younger audiences are spending less time watching local TV news. Existing research on younger audiences has largely focused on news consumption in general (TV, radio, newspaper, Internet), used more of a national news focus, and was often conducted in large U.S. markets. This thesis asked 354 people, aged 18-34, about local TV news consumption in smaller, Midwest television markets. The survey also asked respondents what might encourage them to watch more local TV news. Results indicate the younger audience for local TV news is shrinking, but there are positive signs for local TV stations hoping to increase the size of those young audiences for the future. Adviser: Bernard J. McCo

    Characterization and evaluation of acid rain in East Central Florida from 1978 to 1987: Ten year summary report

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    Rainfall was collected on the University of Central Florida (UCF) campus near Orlando since July 1977 and at the Kennedy Space Center (KSC), Florida since August 1977. Since November 1983, the KSC site has been affiliated with the National Atmospheric Deposition Network. Annual volume weighted pH was slightly above the 10 year mean of 4.58 during four of the past five years. Nitrate concentrations have risen somewhat during recent years while excess sulfate concentrations have remained below the 10 year mean during four of the past years. These observations hold for both the UCF and KSC data. The distribution of individual sample pH was nearly identical at UCF and KSC. Stepwise regression suggests that sulfate, nitrate, ammonium ion, and calcium play major roles in the description of rainwater acidity. Annual acid deposition and annual rainfall have varied from 30 to 50 meq/m2-yr and 100 to 180 cm/yr, respectively. Sea salt comprises about 25 percent (UCF) and greater than 50 percent (KSC) of total ionic composition
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