We study stability of underwater vehicle dynamics for a six-degree-of-freedom vehicle modeled as a neutrally buoyant, submerged rigid body in an ideal fluid. We consider the case in which the center of gravity and the center of buoyancy of the vehicle are noncoincident such that gravity introduces an orientation-dependent moment. Noting that Kirchhoff’s equations of motion for a submerged rigid...

In this review we discuss structure-function relationships of the core complex of photosystem II, as uncovered from analysis of optical spectra of the complex and its subunits. Based on descriptions of optical difference spectra including site directed mutagenesis we propose a revision of the multimer model of the symmetrically arranged reaction center pigments, described by an asymmetric excit...

When an unperturbed Hamiltonian is degenerate and some resonance conditions are satisfied a stochastic web is formed. A classical example of this phenomena is the wave-particle interaction in a constant uniform magnetic field. Recently, Dana has observed that for wide wave packets, the initial position of the cyclotron orbit center, xc. may influence dramatically the diffusion of particles in p...

Markus Kunze1 Mathematisches Institut der Universit at K oln Weyertal 86, D-50931 K oln, Germany email: [email protected] Herbert Spohn Zentrum Mathematik and Physik Department, TU M unchen D-80290 M unchen, Germany email: [email protected] Abstract We consider the Abraham model of a rigid charge distribution coupled to the electromagnetic eld and subject to, on the scal...

We present a theoretical analysis of the mean electron and hole positions in self-assembled InAs-GaAs quantum-dot structures. Because of the asymmetric dot shape, the electron center of mass should be displaced with respect to the hole center of mass in such dots, giving rise to a built-in dipole moment. Theoretical calculations on ideal pyramidal dots predict the electron to be localized above...

Let M be a Kähler compact manifold and let G be a subgroup of its full isometry group. Assume G acts in a Hamilton-ian fashion and that it has a one-dimensional center. In this article we analyze the Kähler reduction M λ and the Kähler cut M λ with respect to the Hamiltonian action of the center Z(G). We prove among other results if K is a compact Lie subgroup of K s , where K s is the semisimp...

Article history: Received 1 May 2011 Accepted 15 February 2012 Available online 16 March 2012 0960-0779/$ see front matter 2012 Elsevier Ltd doi:10.1016/j.chaos.2012.02.010 ⇑ Corresponding author at: Department of Applied E-mail address: [email protected] (P. Y In this paper, we consider bifurcation of limit cycles in planar quadratic Hamiltonian systems with various degree polynomial per...

A Hamiltonian/Lagrangian theory to describe guiding center orbit drift motion that is canonical in Boozer magnetic coordinates is developed to include full electrostatic and electromagnetic perturbed fields in axisymmetric tokamak geometry. Furthermore, the radial component of the equilibrium magnetic field in the covariant representation is retained and the background equilibrium state extends...