61 research outputs found
Microstructure and Mechanical Properties of the in situ Β-Si 3 N 4 /Α′-SiAlON Composite
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65911/1/j.1151-2916.1994.tb04604.x.pd
Dynamic polarizability of rotating particles in electrorheological fluids
A rotating particle in electrorheological (ER) fluid leads to a displacement
of its polarization charges on the surface which relax towards the external
applied field , resulting in a steady-state polarization at an angle
with respect to . This dynamic effect has shown to affect the ER
fluids properties dramatically. In this paper, we develop a dynamic effective
medium theory (EMT) for a system containing rotating particles of finite volume
fraction. This is a generalization of established EMT to account for the
interactions between many rotating particles. While the theory is valid for
three dimensions, the results in a special two dimensional configuration show
that the system exhibits an off-diagonal polarization response, in addition to
a diagonal polarization response, which resembles the classic Hall effect. The
diagonal response monotonically decreases with an increasing rotational speed,
whereas the off-diagonal response exhibits a maximum at a reduced rotational
angular velocity comparing to the case of isolated rotating
particles. This implies a way of measurement on the interacting relaxation
time. The dependencies of the diagonal and off-diagonal responses on various
factors, such as , the volume fraction, and the dielectric contrast,
are discussed.Comment: 6 pages, 4 figures, accepted to J. Phys. Chem.
Cubic-to-Tetragonal ( t ') Transformation in Zirconia-Containing Systems
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66338/1/j.1151-2916.1992.tb05546.x.pd
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