2,844 research outputs found
Automatic sample rotator for metallographic polishing
Simple, inexpensive device can be attached to most metallographic sample polishing tables. It provides a suitable surface finish for microscopic examination or photography of surface details of the samples
Radiocarbon dating of deep-sea corals
Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow ^(14)C to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagnetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO_2. A survey of modern samples from the full Δ^(14)C gradient in the deep ocean demonstrates that the coralline CaCO_3 records the radiocarbon value of the dissolved inorganic carbon
SU(2) Skyrme Vortices
A regular method for constructing vortex-like solutions with cylindrical
symmetry to the equations of the SU(2) Skyrme chiral model is proposed. A
numerical estimate for the length density of mass is given
Electrodynamic Limit in a Model for Charged Solitons
We consider a model of topological solitons where charged particles have
finite mass and the electric charge is quantised already at the classical
level. In the electrodynamic limit, which physically corresponds to
electrodynamics of solitons of zero size, the Lagrangian of this model has two
degrees of freedom only and reduces to the Lagrangian of the Maxwell field in
dual representation. We derive the equations of motion and discuss their
relations with Maxwell's equations. It is shown that Coulomb and Lorentz forces
are a consequence of topology. Further, we relate the U(1) gauge invariance of
electrodynamics to the geometry of the soliton field, give a general relation
for the derivation of the soliton field from the field strength tensor in
electrodynamics and use this relation to express homogeneous electric fields in
terms of the soliton field.Comment: 13 pages, 4 figures, Introduction and Section II (Model Lagrangian)
rewritten, new chapters concerning electrodynamic limit and discussion of
causality inserte
Lagrangian formulation for noncommutative nonlinear systems
In this work we use the well known formalism developed by Faddeev and Jackiw
to introduce noncommutativity within two nonlinear systems, the SU(2) Skyrme
and O(3) nonlinear sigma models. The final result is the Lagrangian
formulations for the noncommutative versions of both models. The possibility of
obtaining different noncommutative versions for these nonlinear systems is
demonstrated.Comment: 8 pages. Revex 4.
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