1,915 research outputs found
One parameter family of Compacton Solutions in a class of Generalized Korteweg-DeVries Equations
We study the generalized Korteweg-DeVries equations derivable from the
Lagrangian: where the usual fields of the
generalized KdV equation are defined by . For an
arbitrary continuous parameter we find compacton solutions
to these equations which have the feature that their width is independent of
the amplitude. This generalizes previous results which considered . For
the exact compactons we find a relation between the energy, mass and velocity
of the solitons. We show that this relationship can also be obtained using a
variational method based on the principle of least action.Comment: Latex 4 pages and one figure available on reques
Universal scaling and ferroelectric hysteresis regimes in the giant squid axon propagating action potential: a Phase Space Approach
The experimental data for the giant squid axon propagated action potential is
examined in phase space. Plots of capacitive and ionic currents vs. potential
exhibit linear portions providing temperature dependent time rates and maximum
conductance constants for sodium and Potassium channels. First order phase
transitions of ionic channels are identified. Incorporation of time rates into
Avrami equations for fractions of open channels yields for each channel a
temperature independent dimensionless constant that is close in value to the
fine structure constant. It also reveals temperature independent scaling
exponents. Evidence is presented that the action potential traverses a
ferroelectric hysteresis loop. This results in a second order phase transition
polarization flip at the peak of the action potential, followed by closing of
sodium and opening of potassium channels, and finally closing the loop by
reversing the polarization flip as the resting potential is reached. The
existence of this hysteresis loop for the giant squid action potential suggests
the possibility of neurons with two stable states, the basis for memory storage
and retrieval.Comment: 19 pages, 6 figure
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