8 research outputs found
Granular discharge and clogging for tilted hoppers
We measure the flux of spherical glass beads through a hole as a systematic
function of both tilt angle and hole diameter, for two different size beads.
The discharge increases with hole diameter in accord with the Beverloo relation
for both horizontal and vertical holes, but in the latter case with a larger
small-hole cutoff. For large holes the flux decreases linearly in cosine of the
tilt angle, vanishing smoothly somewhat below the angle of repose. For small
holes it vanishes abruptly at a smaller angle. The conditions for zero flux are
discussed in the context of a {\it clogging phase diagram} of flow state vs
tilt angle and ratio of hole to grain size
Breaking of general rotational symmetries by multi-dimensional classical ratchets
We demonstrate that a particle driven by a set of spatially uncorrelated,
independent colored noise forces in a bounded, multidimensional potential
exhibits rotations that are independent of the initial conditions. We calculate
the particle currents in terms of the noise statistics and the potential
asymmetries by deriving an n-dimensional Fokker-Planck equation in the small
correlation time limit. We analyze a variety of flow patterns for various
potential structures, generating various combinations of laminar and rotational
flows.Comment: Accepted, Physical Review
Control of absolute negative mobility via noise recycling procedure
Absolute negative mobility (ANM) is investigated in a spatially-periodic symmetric system
under the influence of noise consisting of the superposition of a white Gaussian noise
with the same noise delayed by time Ï„. The effects of the noise intensity
σ, the time delay τ and feedback intensity
ϵ in the noise recycling are discussed. It is found that the noise
intensity σ and time delay τ can induce the phenomenon
of ANM, while the feedback intensity ϵ can not induce it. This phenomenon
of ANM can be tested in the setup consisting of a resistively and capacitively shunted
Josephson junction device by using a vertical cavity surface emitting laser to generate
the noise recycling procedure