Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 17 March 1995:
Vol. 267. no. 5204, pp. 1632 - 1634
DOI: 10.1126/science.267.5204.1632
Prev | Table of Contents | Next

Articles

Granular Convection Observed by Magnetic Resonance Imaging

E. E. Ehrichs 1, H. M. Jaeger 1, Greg S. Karczmar 2, James B. Knight 1, Vadim Yu. Kuperman 2, and Sidney R. Nagel 1

1 James Franck Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA.
2 Department of Radiology, University of Chicago, Chicago, IL 60637, USA.

Vibrations in a granular material can spontaneously produce convection rolls reminiscent of those seen in fluids. Magnetic resonance imaging provides a sensitive and noninvasive probe for the detection of these convection currents, which have otherwise been difficult to observe. A magnetic resonance imaging study of convection in a column of poppy seeds yielded data about the detailed shape of the convection rolls and the depth dependence of the convection velocity. The velocity was found to decrease exponentially with depth; a simple model for this behavior is presented here.

Submitted on September 26, 1994
Accepted on January 23, 1995


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
A theory for particle size segregation in shallow granular free-surface flows.
J.M.N.T Gray and A.R Thornton (2005)
Proc R Soc A 461, 1447-1473
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)