2,922 research outputs found
Evolution of Plastic Strain During a Flow Forming Process
The distribution of equivalent plastic strain through the thickness of
several AISI 1020 steel plates formed under different conditions over a smooth
cylindrical mandrel using a single-roller forward flow forming operation was
studied by measuring the local micro-indentation hardness of the deformed
material. The equivalent plastic strain was higher at the inner and outer
surfaces and lowest at the center of the workpiece. Empirical expressions are
presented which describe the contribution of the roller and mandrel to the
total local equivalent plastic strain within the flow formed part. The
dependence of these expressions upon the thickness reduction during flow
forming is discussed.Comment: 13 pages, 9 figure
Heavy quark action on the anisotropic lattice
We investigate the improved quark action on anisotropic lattice as a
potential framework for the heavy quark, which may enable precision computation
of hadronic matrix elements of heavy-light mesons. The relativity relations of
heavy-light mesons as well as of heavy quarkonium are examined on a quenched
lattice with spatial lattice cutoff 1.6 GeV and the
anisotropy . We find that the bare anisotropy parameter tuned for the
massless quark describes both the heavy-heavy and heavy-light mesons within 2%
accuracy for the quark mass , which covers the charm quark
mass. This bare anisotropy parameter also successfully describes the
heavy-light mesons in the quark mass region within the
same accuracy. Beyond this region, the discretization effects seem to grow
gradually. The anisotropic lattice is expected to extend by a factor the
quark mass region in which the parameters in the action tuned for the massless
limit are applicable for heavy-light systems with well controlled systematic
errors.Comment: 11 pages, REVTeX4, 11 eps figure
Quenched charmonium spectrum on anisotropic lattices
We present the results of quenched charmonium spectrum for S- and P-states,
obtained by a relativistic heavy quark method on anisotropic lattices.
Simulations are carried out using the standard plaquette gauge action and a
meanfield-improved clover quark action at --6 GeV with the
renormalized anisotropy fixed to . We study the scaling
of our fine and hyperfine mass splittings, and compare with previous results.Comment: Lattice 2000 (Heavy Quark Physics), 4 pages, 6 eps figures,
LaTeX(espcrc2.sty
Magnetoresistance, specific heat and magnetocaloric effect of equiatomic rare-earth transition-metal magnesium compounds
We present a study of the magnetoresistance, the specific heat and the
magnetocaloric effect of equiatomic Mg intermetallics with , Eu, Gd, Yb and , Au and of GdAuIn. Depending on the
composition these compounds are paramagnetic (, Yb) or they
order either ferro- or antiferromagnetically with transition temperatures
ranging from about 13 to 81 K. All of them are metallic, but the resistivity
varies over 3 orders of magnitude. The magnetic order causes a strong decrease
of the resistivity and around the ordering temperature we find pronounced
magnetoresistance effects. The magnetic ordering also leads to well-defined
anomalies in the specific heat. An analysis of the entropy change leads to the
conclusions that generally the magnetic transition can be described by an
ordering of localized moments arising from the half-filled
shells of Eu or Gd. However, for GdAgMg we find clear evidence
for two phase transitions indicating that the magnetic ordering sets in
partially below about 125 K and is completed via an almost first-order
transition at 39 K. The magnetocaloric effect is weak for the antiferromagnets
and rather pronounced for the ferromagnets for low magnetic fields around the
zero-field Curie temperature.Comment: 12 pages, 7 figures include
A Study of Meson Correlators at Finite Temperature
We present results for mesonic propagators in temporal and spatial directions
at T below and above the deconfining transition in quenched QCD. Anisotropic
lattices are used to get enough information in the temporal direction. We use
the Wilson fermion action for light quarks and Fermilab action for heavy
quarks.Comment: LATTICE 99 (finite temperature and density), 3 pages, LaTeX with 3
eps figures, espcrc2.sty, psfig.st
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