Low speed aerodynamic characteristics of the GD/C B-18E3 booster

A 0.02 scale model of the B-18E3 space shuttle booster was tested in a low speed wind tunnel to evaluate the low speed aerodynamic charactersitics. The basic configuration, including build-up, was tested at a Mach number of 0.201 and Reynolds number per foot of 1.39 million. The normal angle-of-attack range was -4 to +24 degrees in 2 degree increments, at sideslip angles of 0 and 5 degrees. Some lateral data were obtained at the sideslip angle range of -6 to 10 degrees at angles-of attack of 0, 10, and 15 degrees. Data were obtained for canard, split elevon, and split rudder deflections

Chaotic string-capture by black hole

We consider a macroscopic charge-current carrying (cosmic) string in the background of a Schwarzschild black hole. The string is taken to be circular and is allowed to oscillate and to propagate in the direction perpendicular to its plane (that is parallel to the equatorial plane of the black hole). Nurmerical investigations indicate that the system is non-integrable, but the interaction with the gravitational field of the black hole anyway gives rise to various qualitatively simple processes like "adiabatic capture" and "string transmutation".Comment: 13 pages Latex + 3 figures (not included), Nordita 93/55

Mass of Rotating Black Holes in Gauged Supergravities

The masses of several recently-constructed rotating black holes in gauged supergravities, including the general such solution in minimal gauged supergravity in five dimensions, have until now been calculated only by integrating the first law of thermodynamics. In some respects it is more satisfactory to have a calculation of the mass that is based directly upon the integration of a conserved quantity derived from a symmetry principal. In this paper, we evaluate the masses for the newly-discovered rotating black holes using the conformal definition of Ashtekar, Magnon and Das (AMD), and show that the results agree with the earlier thermodynamic calculations. We also consider the Abbott-Deser (AD) approach, and show that this yields an identical answer for the mass of the general rotating black hole in five-dimensional minimal gauged supergravity. In other cases we encounter discrepancies when applying the AD procedure. We attribute these to ambiguities or pathologies of the chosen decomposition into background AdS metric plus deviations when scalar fields are present. The AMD approach, involving no decomposition into background plus deviation, is not subject to such complications. Finally, we also calculate the Euclidean action for the five-dimensional solution in minimal gauged supergravity, showing that it is consistent with the quantum statistical relation.Comment: Typos corrected and references update

Transonic Elastic Model for Wiggly Goto-Nambu String

The hitherto controversial proposition that a ``wiggly" Goto-Nambu cosmic string can be effectively represented by an elastic string model of exactly transonic type (with energy density $U$ inversely proportional to its tension $T$) is shown to have a firm mathematical basis.Comment: 8 pages, plain TeX, no figure

Geometric scaling in high-energy QCD at nonzero momentum transfer

We show how one can obtain geometric scaling properties from the Balitsky-Kovchegov (BK) equation. We start by explaining how, this property arises for the b-independent BK equation. We show that it is possible to extend this model to the full BK equation including momentum transfer. The saturation scale behaves like max(q,Q_T) where q is the momentum transfer and Q_T a typical scale of the target.Comment: 4 pages, 2 figures. Talk given by G. Soyez at the "Rencontres de Moriond", 12-19 March 2005, La Thuile, Ital

A Killing tensor for higher dimensional Kerr-AdS black holes with NUT charge

In this paper, we study the recently discovered family of higher dimensional Kerr-AdS black holes with an extra NUT-like parameter. We show that the inverse metric is additively separable after multiplication by a simple function. This allows us to separate the Hamilton-Jacobi equation, showing that geodesic motion is integrable on this background. The separation of the Hamilton-Jacobi equation is intimately linked to the existence of an irreducible Killing tensor, which provides an extra constant of motion. We also demonstrate that the Klein-Gordon equation for this background is separable.Comment: LaTeX, 14 pages. v2: Typo corrected and equation added. v3: Reference added, introduction expanded, published versio

Control of gradient-driven instabilities using shear Alfv\'en beat waves

A new technique for manipulation and control of gradient-driven instabilities through nonlinear interaction with Alfv\'en waves in a laboratory plasma is presented. A narrow field-aligned density depletion is created in the Large Plasma Device (LAPD), resulting in coherent unstable fluctuations on the periphery of the depletion. Two independent kinetic Alfv\'en waves are launched along the depletion at separate frequencies, creating a nonlinear beat-wave response at or near the frequency of the original instability. When the beat-wave has sufficient amplitude, the original unstable mode is suppressed, leaving only the beat-wave response at a different frequency, generally at lower amplitude.Comment: Submitted for Publication in Physical Review Letters. Revision 2 reflects changes suggested by referees for PRL submission. One figure removed, several major changes to another figure, and a number of major and minor changes to the tex

Sprayable low density ablator and application process

A sprayable, low density ablative composition is described consisting esentially of: (1) 100 parts by weight of a mixture of 25-65% by weight of phenolic microballoons, 0-20% by weight of glass microballoons, 4-10% by weight of glass fibers, 25-45% by weight of an epoxy-modified polyurethane resin, 2-4% by weight of a bentonite dispersing aid, and 1-2% by weight of an alcohol activator for the bentonite; (2) 1-10 parts by weight of an aromatic amine curing agent; and (3) 200-400 parts by weight of a solvent

Separability and Killing Tensors in Kerr-Taub-NUT-de Sitter Metrics in Higher Dimensions

A generalisation of the four-dimensional Kerr-de Sitter metrics to include a NUT charge is well known, and is included within a class of metrics obtained by Plebanski. In this paper, we study a related class of Kerr-Taub-NUT-de Sitter metrics in arbitrary dimensions D \ge 6, which contain three non-trivial continuous parameters, namely the mass, the NUT charge, and a (single) angular momentum. We demonstrate the separability of the Hamilton-Jacobi and wave equations, we construct a closely-related rank-2 Staeckel-Killing tensor, and we show how the metrics can be written in a double Kerr-Schild form. Our results encompass the case of the Kerr-de Sitter metrics in arbitrary dimension, with all but one rotation parameter vanishing. Finally, we consider the real Euclidean-signature continuations of the metrics, and show how in a limit they give rise to certain recently-obtained complete non-singular compact Einstein manifolds.Comment: Author added, title changed, references added, focus of paper changed to Killing tensors and separability. Latex, 13 page