Motion detection can be achieved either with mechanisms sensitive to a target's velocity, or sensitive to change in a target's position. Using a procedure to dissociate these two provided by Nakayama and Tyler (Vis Res 1981;21:427-433), we explored detection of first-order (luminance-based) and various second-order (texture-based and stereo-based) motion. In the first experiment, observers view...

We present a detailed numerical study of a microscopic artificial swimmer realized recently by Dreyfus in experiments [Dreyfus, Nature 437, 862 (2005)]. It consists of an elastic filament composed of superparamagnetic particles that are linked together by DNA strands. Attached to a load particle, the resulting swimmer is actuated by an oscillating external magnetic field so that it performs a n...

The analysis of a new viscometer that takes the form of an oscillating plate, fabricated from silicon using the methods of micro-electro-mechanical-systems (MEMS) is considered. The instrument is designed principally for experimental use in the oil industry. The plate is 1.6mm wide, 2.4mm long, and 20μm thick. It is suspended from a 0.4mm thick support by 48 square cross-section legs, each of l...

Biological motion observation has been recognized to produce dynamic change in sensorimotor activation according to the observed kinematics. Physical plausibility of the spatial-kinematic relationship of human movement may play a major role in the top-down processing of human motion recognition. Here, we investigated the time course of scalp activation during observation of human gait in order ...

The classical hydrogen atom is examined for the situation where a circularly polarized electromagnetic plane wave acts on a classical charged point particle in a near-circular orbit about an infinitely massive nucleus, with the plane wave normally incident to the plane of the orbit. The effect of the phase α of the polarized wave in relation to the velocity vector of the classical electron is e...

13 Milling is a critical process for controlling the properties of the granules produced by roll 14 compaction. In the current study, the positron emission particle tracking (PEPT) technique was 15 used to examine the milling kinematics of roll compacted ribbons at various milling speeds. 16 Microcrystalline cellulose (MCC, Avicel PH-102) was used as the model feed material and a 17 radioactive...

Data are presented of experiments with turbulent open channel flow over rough surfaces and large relative submergence, which are conducted in two series with different geometric boundary conditions. During the experiments an oscillating fluid motion in the uppermost filter layer is visualised by the injection of a tracer dye. It is shown that this oscillating fluid motion is driven by highly un...

For the eventual use as regards wave generation and damping, we investigate oscillating contact lines on vertical walls. Stainless steel is used rather than the glass of Ting and Perlin [J. Fluid Mech. 295 (1995) 263] for the vertically sinusoidally oscillating plate over a large range of Reynolds numbers. The non-wetting stainless steel minimizes the static meniscus ignored in our analysis. Ot...

Under sustained pumping, kinetics of macroscopic nonlinear biochemical reaction systems far from equilibrium either can be in a stationary steady state or can execute sustained oscillations about a fixed mean. For a system of two dynamic species X and Y, the concentrations n(x) and n(y) will be constant or will repetitively trace a closed loop in the (n(x), n(y)) phase plane, respectively. We s...