26,320 research outputs found

    Technical summary of accomplishments made in preparation for the USSR barley exploratory experiment

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    The highlights of the work accomplished under each subcomponent of the U.S.S.R. Barley Pilot Experiment, which is scheduled for completion in 1984, are summarized. A significant amount of developmental system implementation activity was in the final stages of preparation prior to the rescoping of project tasks. Unpublished materials which are significant to this exploratory experiment are incorporated into the appendixes

    Single-stage experimental evaluation of boundary layer bleed techniques for high lift stator blades. Compressors design

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    Design and evaluation of stator blades for use in boundary layer bleed techniques in axial flow compresso

    Single-stage experimental evaluation of boundary layer blowing techniques for high lift stator blades. 1 - Compressor design

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    Boundary layer blowing techniques for high lift stator blades in axial flow compressor

    Asymptotic analysis of a secondary bifurcation of the one-dimensional Ginzburg-Landau equations of superconductivity

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    The bifurcation of asymmetric superconducting solutions from the normal solution is considered for the one-dimensional Ginzburg--Landau equations by the methods of formal asymptotics. The behavior of the bifurcating branch depends on the parameters d, the size of the superconducting slab, and κ\kappa, the Ginzburg--Landau parameter. The secondary bifurcation in which the asymmetric solution branches reconnect with the symmetric solution branch is studied for values of (κ,d)(\kappa,d) for which it is close to the primary bifurcation from the normal state. These values of (κ,d)(\kappa,d) form a curve in the κd\kappa d-plane, which is determined. At one point on this curve, called the quintuple point, the primary bifurcations switch from being subcritical to supercritical, requiring a separate analysis. The results answer some of the conjectures of [A. Aftalion and W. C. Troy, Phys. D, 132 (1999), pp. 214--232]

    Asymptotic analysis of a system of algebraic equations arising in dislocation theory

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    The system of algebraic equations given by\ud \ud ∑j=0,j≠insgn(xi−xj)/∣xi−xj∣a=1,i=1,2,…n,x0=0,\sum_{j=0, j \neq i}^n sgn(x_i - x_j) / |x_i - x_j|^a = 1, i = 1, 2, \ldots n, x_0 = 0,\ud \ud appears in dislocation theory in models of dislocation pile-ups. Specifically, the case a = 1 corresponds to the simple situation where n dislocations are piled up against a locked dislocation, while the case a = 3 corresponds to n dislocation dipoles piled up against a locked dipole.\ud \ud We present a general analysis of systems of this type for a > 0 and n large. In the asymptotic limit n -> ∞, it becomes possible to replace the system of discrete equations with a continuum equation for the particle density. For 0 < a < 2, this takes the form of a singular integral equation, while for a > 2 it is a first-order differential equation. The critical case a = 2 requires special treatment but, up to corrections of logarithmic order, it also leads to a differential equation.\ud \ud The continuum approximation is only valid for i not too small nor too close to n. The boundary layers at either end of the pile-up are also analyzed, which requires matching between discrete and continuum approximations to the main problem

    Population polygons of tektite specific gravity for various localities in australasia

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    Comparison of specific gravity of tektites from australia, asia, texas, and czechoslovaki

    Adaptive optics near-IR imaging of NGC2992 - unveiling core structures related to radio figure-8 loops

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    We present near-IR adaptive optics, VLA radio and HST optical imaging of the nearby Seyfert galaxy NGC2992. Spiral structure and an extension to the West are traced down to the core region at the limiting resolution of our near-IR images. A faint, diffuse loop of near-IR and radio emission is also observed to the north, embedded within the prominent 2 arcsec radio loop previously observed to the northwest. Near-IR color maps, and CO narrowband imaging, are then used to identify which regions may not be purely reddened stellar populations. Our new data provide evidence that the VLA radio-loop morphology in the shape of a figure-8 represents two components superimposed: 1) outflow bubbles out of the plane of the disk, coincident with the extended emission line region (EELR); 2) star formation along the spiral arm within the galaxy disk and through the dust lane. The near-IR continuum emission associated with the outflowing radio bubbles suggest that the radio loops are driven by the active nucleus.Comment: 10 pages, 9 figures, accepted in MNRA

    Quantifying fusion born ion populations in magnetically confined plasmas using ion cyclotron emission

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    Ion cyclotron emission (ICE) offers unique promise as a diagnostic of the fusion born alpha-particle population in magnetically confined plasmas. Pioneering observations from JET and TFTR found that ICE intensity PICEP_{ICE} scales approximately linearly with the measured neutron flux from fusion reactions, and with the inferred concentration, nα/nin_\alpha/n_i, of fusion-born alpha-particles confined within the plasma. We present fully nonlinear self-consistent kinetic simulations that reproduce this scaling for the first time. This resolves a longstanding question in the physics of fusion alpha-particle confinement and stability in MCF plasmas. It confirms the magnetoacoustic cyclotron instability (MCI) as the likely emission mechanism and greatly strengthens the basis for diagnostic exploitation of ICE in future burning plasmas
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