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			PHYSICAL MATHEMATICS SEMINAR


TOPIC:		GRANULAR MATTER WITH ATTRACTION


SPEAKER::	ARSHAD KUDROLLI
		Department of Physics
		Clark University
			and
		Department of Mathematics
		Massachusetts Institute of Technology

ABSTRACT:

Granular matter have been the topic of a considerable number of
inter-disciplinary investigations because of the fascinating properties
exhibited by them and their importance in industrial and geophysical
situations. However most of the studies have focused on non-cohesive
granular matter.  We will discuss a series of experiments where attractive
forces are also present between particles.  If a small amount of liquid is
introduced in a granular mixture, capillary bridges introduce attractive
forces.  We will discuss the effect of the cohesivity on the angle of
repose and segregation of granular matter.  In a second series of
experiments, we will discuss the effect of magnetizing the granular
particles.  The experimental system consists of magnetized steel beads
that are supplied energy by vertical vibrations.  For high amplitudes of
vibration, a gas of beads is observed, but as the amplitude is lowered,
the magnetized particles are observed to form clusters.  We use high speed
imaging to measure the positions to understand the structure of the
clusters.  A detailed understanding of the properties this system may also
help us understand the novel properties shown by ferrofluids and electro
rheological fluids.


DATE:		Tuesday, October 2, 2001

TIME:		2:30 PM

LOCATION:	Building 2, Room 338


Refreshments will be served at 3:30 PM in Room 2-349


Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA  02139