50,925 research outputs found
Formal Desingularization of Surfaces - The Jung Method Revisited -
In this paper we propose the concept of formal desingularizations as a
substitute for the resolution of algebraic varieties. Though a usual resolution
of algebraic varieties provides more information on the structure of
singularities there is evidence that the weaker concept is enough for many
computational purposes. We give a detailed study of the Jung method and show
how it facilitates an efficient computation of formal desingularizations for
projective surfaces over a field of characteristic zero, not necessarily
algebraically closed. The paper includes a generalization of Duval's Theorem on
rational Puiseux parametrizations to the multivariate case and a detailed
description of a system for multivariate algebraic power series computations.Comment: 33 pages, 2 figure
Stress corrosion crack inhibiting method for titanium
Addition of oxyanions to liquid solvents in excess of the number of chloride, bromide, or iodide ions present prevents cracking of titanium-aluminum alloys under exposure to aqueous and other solvent environments. The molar concentration of oxyanion is set from 10 to 100 times higher than concentration of halide ions
Method of inhibiting stress corrosion cracks in titanium alloys Patent
Method to prevent stress corrosion cracking in titanium alloy
Adjoint Computation for Hypersurfaces Using Formal Desingularizations
We show how to use formal desingularizations (defined earlier by the first
author) in order to compute the global sections (also called adjoints) of
twisted pluricanonical sheaves. These sections define maps that play an
important role in the birational classification of schemes.Comment: 10 page
On supercorrelated systems and phase space entrainment
It is demonstrated that power-laws which are modified by logarithmic
corrections arise in supercorrelated systems. Their characteristic feature is
the energy attributed to a state (or value of a general cost function) which
depends nonlinearly on the phase space distribution of the constituents. A
onedimensional dissipative deterministic model is introduced which is attracted
to a supercorrelated state (phase space entrainment). Extensions of this
particular model may have applications in the study of transport and
equilibration phenomena, particularly for supply and information networks, or
for chemical and biological nonequilibrium systems, while the qualitative
arguments presented here are believed to be of more general interest.Comment: 12 pages - some technical material removed from second version,
several explanatory comments and references added instea
Stress corrosion cracking of titanium alloys - Potential transients at open circuit during SCC and pitting corrosion, and chloride absorption during formation of TiO sub 2 Quarterly progress report, Jul. 1 - 30 Sep. 1967
Stress corrosion cracking of titanium alloys and chloride absorption during formation of titanium oxid
Stress corrosion cracking of titanium alloys heat treatment effects, SCC velocity in various solvents and electrochemical kinetics with Ti - 8-1-1 alloy Quarterly progress report, 1 Oct. - 31 Dec. 1966
Stress corrosion cracking of titanium alloy
Magnetic fields in merging spirals - the Antennae
We present an extensive study of magnetic fields in a system of merging
galaxies. We obtained for NGC4038/39 (the Antennae) radio total intensity and
polarization maps at 8.44, 4.86 and 1.49GHz using the VLA in the C and D
configurations. The radio thermal fraction was found to be about 50% at
10.45GHz, higher than in normal spirals. The mean total magnetic fields in both
galaxies are about two times stronger (20microG) than in normal spirals.
However,the degree of field regularity is rather low, implying tangling of the
regular component in regions with interaction-enhanced star formation. Our data
combined with those in HI, Halpha, X-rays and in far infrared allow us to study
local interrelations between different gas phases and magnetic fields. We
distinguish several radio-emitting regions with different physical properties
and at various evolutionary stages. The whole overlapping region shows a
coherent magnetic field structure, probably tracing the line of collision
between the arms of merging spirals while the total radio emission reveals
hidden star formation nests. The southern part of it is a particularly intense
merger-triggered starburst. Highly tangled magnetic fields reach there
strengths of 30microG, even larger than in both individual galaxies, possibly
due to compression of the original fields pulled out from the parent disks. In
the northeastern ridge, away from star-forming regions, the magnetic field is
highly coherent with a strong regular component of 10microG tracing gas
shearing motions along the tidal tail. Modelling Faraday rotation data show
that we deal with a three-dimensionally curved structure of magnetic fields,
becoming almost parallel to the sky plane in the southeastern part of the
ridge.Comment: Accepted for publication in AA, 16 pages including 16 figures,
high-res version at http://www.oa.uj.edu.pl/~chris/publ/4038.ps.g
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