31,915 research outputs found
Workshop on Applications of Phase Diagrams in Metallurgy and Ceramics
A workshop was held to assess the current national and international status of phase diagram determinations and evaluations for alloys, ceramics, and semiconductors; to determine the needs and priorities, especially technological, for phase diagram determinations and evaluations; and to estimate the resources being used and potentially available for phase diagram evaluation. Highlights of the workshop, description of a new poster board design used in the poster sessions, lists of attendees and demonstrations, the program, and descriptions of the presentations are included
Electrodynamics of Bose-Einstein condensates in angular motion
A theory determining the electric and magnetic properties of vortex states in
Bose-Einstein condensates (BECs) is presented. The principal ingredient is the
Lagrangian of the system which we derive correct to the first order in the
atomic centre of mass velocity. For the first time using centre of mass
coordinates, a gauge transformation is performed and relevant relativistic
corrections are included. The Lagrangian is symmetric in the electric and
magnetic aspects of the problem and includes two key interaction terms, namely
the Aharanov-Casher and the Roentgen interaction terms. The constitutive
relations, which link the electromagnetic fields to the matter fields via their
electric polarisation and magnetisation, follow from the Lagrangian as well as
the corresponding Hamiltonian. These relations, together with a generalised
Gross-Pitaevskii equation, determine the magnetic (electric) monopole charge
distributions accompanying an order n vortex state when the constituent atoms
are characterised by an electric dipole (magnetic dipole). Field distributions
associated with electric dipole active (magnetic dipole active) BECs in a
vortex state are evaluated for an infinite- and a finite-length cylindrical
BEC. The predictd monopole charge distributions, both electric and magnetic,
automatically satisfy the requirement of global charge neutrality and the
derivations highlight the exact symmetry between the electric and magnetic
properties. Order of magnitude estimates of the effects are given for an atomic
gas BEC, superfluid helium and a spin-polarised hydrogen BEC.Comment: 23 pages, 2 figures, submitted to Journal of Optics
Computer program offers new method for constructing periodic orbits in nonlinear dynamical systems
Computer program uses an iterative method to construct precisely periodic orbits which dynamically approximate solutions that converge to precise dynamical solutions in the limit of the sequence. The method used is a modification of the generalized Newton-Raphson algorithm used in analyzing two point boundary problems
Method for constructing periodic orbits in nonlinear dynamic systems
Method is modification of generalized Newton-Ralphson algorithm for analyzing two-point boundary problems. It constructs sequence of solutions that converge to precise dynamic solution in the sequence limit. Program calculates periodic orbits in either circular or elliptical restricted three-body problems
Study made of resistance of stainless steels to zinc-vapor corrosion
Study of the corrosion resistance of several stainless steels to zinc vapor revealed that some stainless steels could be employed for use in zinc processing equipment housings or vapor lines
Use of steel and tantalum apparatus for molten Cd-Mg-Zn alloys
Steel and tantalum apparatus contains various ternary alloys of cadmium, zinc, and magnesium used in pyrochemical processes for the recovery of uranium-base reactor fuels. These materials exhibit good corrosion resistance at the high temperatures necessary for fuel separation in liquid metal-molten salt solvents
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