Drag-reduction techniques capable of reducing the level of turbulent friction through wall-parallel movement of the wall are described, with special emphasis placed on spanwise movement. The discussion is confined to active open-loop control strategies, although feedback control is briefly mentioned with regard to peculiarities of spanwise sensing and/or actuation. Theoretical considerations ar...

Drag-reduction techniques capable of reducing the level of turbulent friction through wall-parallel movement of the wall are described, with special emphasis placed on spanwise movement. The discussion is confined to active open-loop control strategies, although feedback control is briefly mentioned with regard to peculiarities of spanwise sensing and/or actuation. Theoretical considerations ar...

Contents Introduction Time locked perceptual fading induced by visual transients Perceptual alternation induced by visual transients Visual transients and change detection Visual transients reveal the veridical position of a moving object Perceptual manifestations of rapid neural plasticity: visual motion priming, rapid motion aftereffect and perceptual sensitization. Disruption of stabilizatio...

Abstract Oscillating electric fields are present in many different kinds of plasmas and can modify the radiated line shape. An accurate characterization their effect is difficult since they act simultaneously with fluctuating microfield electrons ions. We propose to address these simultaneous effects by a computer simulation plasma particles motion coupled numerical integration Schrödinger equa...

We study the steady state behaviour of a confined quantum Brownian particle subjected to a space-dependent, rapidly oscillating time-periodic force. To leading order in the period of driving, the result of the oscillating force is an effective static potential which has a quantum dissipative contribution, VQD, which adds on to the classical result. This is shown using a coherent state represent...

In systems where one coordinate undergoes periodic oscillation, the net displacement in any other coordinate over a single period is shown to be given by differentiation of the action integral associated with the oscillating coordinate. This result is then used to demonstrate that the action integral acts as a Hamiltonian for slow coordinates providing time is scaled to the "tick time" of the o...

In this study, we manipulated the swimming direction of bacteria and controlled the switching off movement by using dc and ac galvanotaxis. The microstructures blotted by Serratia marcescens could be spontaneously manipulated and switched off at the desired position. The optimum ac frequency for switching off the microstructural motion was 7 Hz. We built a mathematical model to analyze and unde...

Inspired by rattleback toys, we created small chiral wires that rotate in a preferred direction on a vertically oscillating platform and quantified their motion with experiment and simulation. We demonstrate experimentally that angular momentum of rotation about particle centers of mass is converted to collective angular momentum of center-of-mass motion in a granular gas of these wires, and we...

Synovial joints are loaded by weight bearing, stretching, and fluid-driven shear. To simulate in vitro fluid-driven shear, we developed an "oscillating Couette flow mechanical shear loader". Oscillating Couette flow mimics relative motion of articular surfaces; hence, characterizing flow-induced shear by the loader enhances understanding of mechanotransduction in the joint tissue. Here, the ana...

A solid body undergoing oscillatory motion in a fluid generates an oscillating flow. Oscillating flows in Newtonian fluids were first treated by G.G. Stokes in 1851. Since then, this problem has attracted much attention, mostly due to its technological significance. Recent advances in micro- and nanotechnology require that this problem be revisited: miniaturized mechanical resonators with linea...