308 research outputs found
C-shaped specimen plane strain fracture toughness tests
Test equipment, procedures, and data obtained in the evaluation of C-shaped specimens are presented. Observations reported on include: specimen preparation and dimensional measurement; modifications to the standard ASTM E 399 displacement gage, which permit punch mark gage point engagement; and a measurement device for determining the interior and exterior radii of ring segments. Load displacement ratios were determined experimentally which agreed with analytically determined coefficients for three different gage lengths on the inner surfaces of radially-cracked ring segments
Hyperbolic automorphisms and holomorphic motions in C<sup>2</sup>
This article does not have an abstract
Algebraic surfaces holomorphically dominable by C^2
Using the Kodaira dimension and the fundamental group of X, we succeed in
classifying algebraic surfaces which are dominable by C^2 except for certain
cases in which X is an algebraic surface of Kodaira dimension zero and the case
when X is rational without any logarithmic 1-form. More specifically, in the
case when X is compact (namely projective), we need to exclude only the case
when X is birationally equivalent to a K3 surface (a simply connected compact
complex surface which admits a globally non-vanishing holomorphic 2-form) that
is neither elliptic nor Kummer.
With the exceptions noted above, we show that for any algebraic surface of
Kodaira dimension less than 2, dominability by C^2 is equivalent to the
apparently weaker requirement of the existence of a holomorphic image of C
which is Zariski dense in the surface. With the same exceptions, we will also
show the very interesting and revealing fact that dominability by C^2 is
preserved even if a sufficiently small neighborhood of any finite set of points
is removed from the surface. In fact, we will provide a complete classification
in the more general category of (not necessarily algebraic) compact complex
surfaces before tackling the problem in the case of non-compact algebraic
surfaces
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