303 research outputs found
SNAP-8 corrosion program Quarterly progress report, period ending 31 May 1965
Differences in corrosion and mass transfer rates in corrosion loops for SNAP-8 system and effectiveness of cold trapping in reducing hydrogen concentratio
Snap-8 corrosion program quarterly progress report, period ending 28 feb. 1965
SNAP-8 corrosion program - hydrogen solubility in sodium-potassium, permeability of hydrogen and deuterum through stainless steel, and phase equilibri
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Examination of corrosion specimens from slurry blanket mockup run SM-5
Generally low attack rates were displayed by specimens of type 347 stainless steel, titanium RC-55, and nket pe 347 stainless steel suffered more severe attack dut to erosive action by the slurry. Specimens SA-212-B carbon steel displayed attack rates of 230 to 300 mpy. (auth
Summary of specimen corrosion data from slurry blanket mock-up run SM-3
Examination of corrosion specimens from the 948 hour slurry blanket mock- up Run SM-3 lndicated generally low attack rates on type 347 stainless steel, titanium -75A, and Zircaloy-2. The upstream coupon of the array, of type 347 stainless steel, suffered moderate but more severe attack. Coupons of SA-212 grade B carbon steel were severely attacked. No stress corrosion cracking was noted on samples, placed in the pressurizer, of types 347 and AM 350 stainless steels, titanium aluminum--vanadium alloy, or Zircaloy-2. (auth
Examination of corrosion specimens from slurry blanket mockup run SM-4
Generally low attack rates were displayed by specimens of type 347 stainless steel, titanium-75A, and Zircaloy-2 which were exposed for 2396 hr in slurry blanket mock-up Run SM-4. The leading coupon of the array, of type 347 stainless steel, suffered more severe attack are to erosive action by the slurry. Coupons of SA-212-B carbon steel were consumed during the run. No stress corrosion cracking was noted on samples, placed in the pressurizer, of types 347 and AM 350 stainless steels, titanium-6A14V alloy, or Zircaloy-2. (auth
Generalized Holographic Cosmology
We consider general black hole solutions in five-dimensional spacetime in the
presence of a negative cosmological constant. We obtain a cosmological
evolution via the gravity/gauge theory duality (holography) by defining
appropriate boundary conditions on a four-dimensional boundary hypersurface.
The standard counterterms are shown to renormalize the bare parameters of the
system (the four-dimensional Newton's constant and cosmological constant). We
discuss the thermodynamics of cosmological evolution and present various
examples. The standard brane-world scenarios are shown to be special cases of
our holographic construction.Comment: 15 pages, 5 figure
Classical Integrability of the Squashed Three-sphere, Warped AdS3 and Schroedinger Spacetime via T-Duality
We discuss the integrability of 2d non-linear sigma models with target space
being the squashed three-sphere, warped anti-de Sitter space and the
Schroedinger spacetime. These models can be obtained via T-duality from
integrable models. We construct an infinite family of non-local conserved
charges from the T-dual Lax currents, enhancing the symmetry of warped anti-de
Sitter space and the Schroedinger spacetime to sl2(R)+sl2(R).Comment: 29 Pages, 3 appendices. Minor changes: added references, footnot
Gravity in the 3+1-Split Formalism II: Self-Duality and the Emergence of the Gravitational Chern-Simons in the Boundary
We study self-duality in the context of the 3+1-split formalism of gravity
with non-zero cosmological constant. Lorentzian self-dual configurations are
conformally flat spacetimes and have boundary data determined by classical
solutions of the three-dimensional gravitational Chern-Simons. For Euclidean
self-dual configurations, the relationship between their boundary initial
positions and initial velocity is also determined by the three-dimensional
gravitational Chern-Simons. Our results imply that bulk self-dual
configurations are holographically described by the gravitational Chern-Simons
theory which can either viewed as a boundary generating functional or as a
boundary effective action.Comment: 25 pages; v2: minor improvements, references adde
Holographic Reconstruction and Renormalization in Asymptotically Ricci-flat Spacetimes
In this work we elaborate on an extension of the AdS/CFT framework to a
subclass of gravitational theories with vanishing cosmological constant. By
building on earlier ideas, we construct a correspondence between Ricci-flat
spacetimes admitting asymptotically hyperbolic hypersurfaces and a family of
conformal field theories on a codimension two manifold at null infinity. By
truncating the gravity theory to the pure gravitational sector, we find the
most general spacetime asymptotics, renormalize the gravitational action,
reproduce the holographic stress tensors and Ward identities of the family of
CFTs and show how the asymptotics is mapped to and reconstructed from conformal
field theory data. In even dimensions, the holographic Weyl anomalies identify
the bulk time coordinate with the spectrum of central charges with
characteristic length the bulk Planck length. Consistency with locality in the
bulk time direction requires a notion of locality in this spectrum.Comment: 44 pages, 4 figures. v2: minor changes in section
Tomimatsu-Sato geometries, holography and quantum gravity
We analyze the Tomimatsu-Sato spacetime in the context of the
proposed Kerr/CFT correspondence. This 4-dimensional vacuum spacetime is
asymptotically flat and has a well-defined ADM mass and angular momentum, but
also involves several exotic features including a naked ring singularity, and
two disjoint Killing horizons separated by a region with closed timelike curves
and a rod-like conical singularity. We demonstrate that the near horizon
geometry belongs to a general class of Ricci-flat metrics with
symmetry that includes both the extremal Kerr and
extremal Kerr-bolt geometries. We calculate the central charge and temperature
for the CFT dual to this spacetime and confirm the Cardy formula reproduces the
Bekenstein-Hawking entropy. We find that all of the basic parameters of the
dual CFT are most naturally expressed in terms of charges defined intrinsically
on the horizon, which are distinct from the ADM charges in this geometry.Comment: 20+1 pages, 3 figures, changed title, expanded discussion, matches
version published in CQ
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