450 research outputs found
The response of a floating ice sheet to an accelerating line load
The two-dimensional response of a thin, floating sheet of ice to a line load that accelerates from rest at to a uniform velocity V for is determined through an integral-transform solution of the linearized equations of motion. If ā i.e. if the load is impulsively started with velocity V ā the solution exhibits singularities at , the shallow-water-gravity-wave speed, and , the minimum speed for transverse motion of the ice, but these singularities are avoided by the acceleration of the load through the critical speeds
The starfish experiment: a Lagrangian approach
The present paper analyses the free surface deformation of a liquid metal drop under the influence of an alternating magnetic field. The analysis is restricted to the first axi- symmetric mode oscillation. In the low frequency case, the electromagnetic forces are of gradient type and purely oscillatory. Without any viscous damping, it is then possible to build a Lagrangian function, which involves the kinetic energy, the gravitational energy, the surface energy and the electromagnetic energy. The time evolution of the pool height is easily obtained from the Lagrange equation. It is shown that the pool height behaves like a non-linear forced oscillator
Extended neuromuscular blockade with mivacurium following pancuronium
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73891/1/j.1365-2346.1996.00989.x.pd
Experimental Verification of Surface Vehicle Dynamics
Experimental verification of surface vehicle dynamic
Magnetic Flux Braiding: Force-Free Equilibria and Current Sheets
We use a numerical nonlinear multigrid magnetic relaxation technique to
investigate the generation of current sheets in three-dimensional magnetic flux
braiding experiments. We are able to catalogue the relaxed nonlinear force-free
equilibria resulting from the application of deformations to an initially
undisturbed region of plasma containing a uniform, vertical magnetic field. The
deformations are manifested by imposing motions on the bounding planes to which
the magnetic field is anchored. Once imposed the new distribution of magnetic
footpoints are then taken to be fixed, so that the rest of the plasma must then
relax to a new equilibrium configuration. For the class of footpoint motions we
have examined, we find that singular and nonsingular equilibria can be
generated. By singular we mean that within the limits imposed by numerical
resolution we find that there is no convergence to a well-defined equilibrium
as the number of grid points in the numerical domain is increased. These
singular equilibria contain current "sheets" of ever-increasing current
intensity and decreasing width; they occur when the footpoint motions exceed a
certain threshold, and must include both twist and shear to be effective. On
the basis of these results we contend that flux braiding will indeed result in
significant current generation. We discuss the implications of our results for
coronal heating.Comment: 13 pages, 12 figure
On a model mechanism for the spatial patterning of teeth primordia in the Alligator
We propose a model mechanism for the initiation and spatial positioning of teeth primordia in the alligator,Alligator mississippiensis. Detailed embryological studies by Westergaard & Ferguson (1986, 1987, 1990) show that jaw growth plays a crucial role in the developmental patterning of the tooth initiation process. Based on biological data we develop a reaction-diffusion mechanism, which crucially includes domain growth. The model can reproduce the spatial pattern development of the first seven teeth primordia in the lower half jaw ofA. mississippiensis. The results for the precise spatio-temporal sequence compare well with detailed developmental experiments
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