29,634 research outputs found

    Aerodynamic stability analysis of NASA J85-13/planar pressure pulse generator installation

    Get PDF
    A digital computer simulation model for the J85-13/Planar Pressure Pulse Generator (P3 G) test installation was developed by modifying an existing General Electric compression system model. This modification included the incorporation of a novel method for describing the unsteady blade lift force. This approach significantly enhanced the capability of the model to handle unsteady flows. In addition, the frequency response characteristics of the J85-13/P3G test installation were analyzed in support of selecting instrumentation locations to avoid standing wave nodes within the test apparatus and thus, low signal levels. The feasibility of employing explicit analytical expression for surge prediction was also studied

    Specific volumes of the Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 alloy in the liquid, glass, and crystalline states

    Get PDF
    The specific volumes of the Zr41.2Ti13.8CU12.5Ni10.0Be2.25 alloy as a function of temperature, T, are determined by employing an image digitizing technique and numerical calculation methods applied to the electrostatically levitated spherical alloy. The linear fitting of the volumes of the alloy in the liquid, V-l, glass, V-g, and crystalline V-c, states in the temperature ranges shown in parentheses are V-l(T) = 0.1583 + 8.877 x 10(-6)T(cm^(3)/g) (700-1300 K); V-g(T) = 0.1603 + 5.528 x 10^(-6)T (400-550 K); V-c(T) = 0.1583 + 6.211 x 10(-6)T(400-850 K). The average volume thermal expansion coefficients within the temperature ranges are determined to be 5.32, 3.39, and 3.83 x 10^(-5) (1/K) for the liquid, glass, and crystalline states, respectively

    Angular Normal Modes of a Circular Coulomb Cluster

    Full text link
    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

    The Overlap of Interstitial Cystitis/Painful Bladder Syndrome and Overactive Bladder

    Get PDF
    Results of this study suggest that patients who have failed therapies for overactive bladder might be more effectively treated using therapies directed towards uroepithelial dysfunction and neural upregulation associated with interstitial cystitis

    Effective nucleon-nucleon interactions and nuclear matter equation of state

    Get PDF
    Nuclear matter equations of state based on Skyrme, Myers-Swiatecki and Tondeur interactions are written as polynomials of the cubic root of density, with coefficients that are functions of the relative neutron excess δ\delta. In the extrapolation toward states far away from the standard one, it is shown that the asymmetry dependence of the critical point (ρc,δc\rho_c, \delta_c) depends on the model used. However, when the equations of state are fitted to the same standard state, the value of δc\delta_c is almost the same in Skyrme and in Myers-Swiatecki interactions, while is much lower in Tondeur interaction. Furthermore, δc\delta_c does not depend sensitively on the choice of the parameter γ\gamma in Skyrme interaction.Comment: 15 pages, 9 figure

    Interference measurements of non-Abelian e/4 & Abelian e/2 quasiparticle braiding

    Full text link
    The quantum Hall states at filling factors ν=5/2\nu=5/2 and 7/27/2 are expected to have Abelian charge e/2e/2 quasiparticles and non-Abelian charge e/4e/4 quasiparticles. For the first time we report experimental evidence for the non-Abelian nature of excitations at ν=7/2\nu=7/2 and examine the fermion parity, a topological quantum number of an even number of non-Abelian quasiparticles, by measuring resistance oscillations as a function of magnetic field in Fabry-P\'erot interferometers using new high purity heterostructures. The phase of observed e/4e/4 oscillations is reproducible and stable over long times (hours) near ν=5/2\nu=5/2 and 7/27/2, indicating stability of the fermion parity. When phase fluctuations are observed, they are predominantly π\pi phase flips, consistent with fermion parity change. We also examine lower-frequency oscillations attributable to Abelian interference processes in both states. Taken together, these results constitute new evidence for the non-Abelian nature of e/4e/4 quasiparticles; the observed life-time of their combined fermion parity further strengthens the case for their utility for topological quantum computation.Comment: A significantly revised version; 54 double-column pages containing 14 pages of main text + Supplementary Materials. The figures, which include a number of new figures, are now incorporated into the tex
    corecore