We present an effective technique for suppressing the vortex-induced vibrations of bluff bodies by eliminating the von Kármán street formed in their wake. Specifically, we find that small amounts of combined windward suction and leeward blowing around the body modify the wake instability and lead to suppression of the fluctuating lift force. Three-dimensional simulations and stability analysis ...

Optical and vibrational properties of novel self-assembled silver nanocolumns are studied experimentally and theoretically. The split of the surface plasmon resonance into transverse and longitudinal modes verifies the one-dimensional character of the nanocolumns. In this work, we have identified the acoustic vibration modes of the nanocolumns using Raman scattering, as spheroid-like modes (l =...

this paper deals with new method for designing the tuned mass dampers (tmd) with considering both transient and steady state responses, simultaneously. this formulation is presented for undamped vibrations. for this purpose, the absolute value of the structural displacement ratio is minimized numerically. this procedure leads to optimum value of tmd's specifications. for numerical verification,...

The stretching and bending vibrations of methane are studied in the framework of a symmetryadapted algebraic model. The model is based on the realization of the one-dimensional Morse potential in terms of a U(2) algebra. For the 45 observed energies we obtain a fit with a r.m.s. deviation of 1.11 cm which is an order of magnitude better than in any previous algebraic calculation. PACS numbers: ...

Three-dimensional (3D) reconstruction experiments were carried out by observing high-resolution 3D electrostatic potential distributions of Pt nanoparticles using off-axis electron holographic tomography. These Pt nanoparticles were mounted on the surfaces of amorphous silicon pillars. In order to realize high-resolution observation, we developed a mechanically stable 3D specimen holder with sm...

Nanoelectromechanical systems were fabricated from single- and multilayer graphene sheets by mechanically exfoliating thin sheets from graphite over trenches in silicon oxide. Vibrations with fundamental resonant frequencies in the megahertz range are actuated either optically or electrically and detected optically by interferometry. We demonstrate room-temperature charge sensitivities down to ...

We present an adequate analytical approach to the description of nonlinear vibration with strong energy exchange between weakly coupled oscillators and oscillatory chains. The fundamental notion of the limiting phase trajectory (LPT) corresponding to complete energy exchange is introduced. In certain sense this is an alternative to the nonlinear normal mode (NNM) characterized by complete energ...

Neural network-based adaptive control is considered for active control of a highly flexible truss structure which may be used to support solar sail membranes. The objective is to suppress unwanted vibrations in SAFE (Solar Array Flight Experiment) boom_ a test-bed located at NASA. Compared to previous tests that restrained truss structures in planar motion, full three dimensional motions are te...

Constrained dynamics on finite-dimensional trial manifolds of quantum state vectors appears in time-dependent variational calculations. This work presents a requantization method, by which properties of the exact eigenstates can be retrieved from the phase portrait of such approximations. Applications to the coherent states dynamics, small amplitude vibrations and collective rotations, show tha...

We show that the recombination kinetics of two-dimensional electrons with acceptor bound holes is a sensitive probe of the local spatial structure of the electronic system. Using the time resolved magnetoluminescence, we extract the regime of the electron Wigner solid and establish its local configuration consistent with the triangular lattice model. Up to the melting point, the amplitude of th...