We have examined the relative abilities of Hartree-Fock, density-functional theory (DFT), and coupled-cluster theory in describing second-order (pseudo) Jahn-Teller (SOJT) effects, perhaps the most commonly encountered form of symmetry breaking in polyatomic molecules. As test cases, we have considered two prototypical systems: the 2Sigmau+ states of D( infinity h) BNB and C3+ for which interac...

This paper explores the driving mechanisms for structural transitions of atomic clusters between oblate and prolate isomers. We employ the hyperspherical coordinates to investigate structural dynamics of a seven-atom cluster at a coarse-grained level in terms of the dynamics of three gyration radii and three principal axes, which characterize overall mass distributions of the cluster. Dynamics ...

The introduction of telemanipulator systems into cardiac surgery enables the heart surgeon to perform sophisticated mini-invasive and endoscopic procedures with high precision under stereoscopic view. At present, the commercially available robotic surgical systems do not dispose of force feedback for the operating surgeon. The lack of haptic (force or tactile) feedback causes damage of tissue a...

The surprising incidence of nonlethal skeletal fractures implies that many organisms operate near their upper performance limits, yet we know little about the loads at which biological structures break or about the material properties of those structures. In addition, biologically realistic estimates of how closely normal maximal loads approach breaking strengths (i.e., safety factors) remain e...

Following a field-theoretical approach, we study the scalar Casimir effect upon perfectly conducting cylindrical shell in presence of spontaneous Lorentz symmetry breaking. The field is modeled by Lorentz-breaking extension theory for real quantum bulk regions. corresponding Green's functions satisfying Dirichlet boundary conditions on are derived explicitly. We express pressure (i.e. vacuum ex...

We study in detail the ratchetlike dynamics of topological solitons in homogeneous nonlinear Klein-Gordon systems driven by a biharmonic force. By using a collective coordinate approach with two degrees of freedom, namely the center of the soliton, X(t), and its width, l(t), we show, first, that energy is inhomogeneously pumped into the system, generating as result a directed motion; and, secon...