Fingering in granular flows
Article Abstract:
Granular material flow on inclined planes is complex, and shows many different flow regimes, particle segregation effects and instabilities. Industrial processing of powders and knowledge of geophysical instabilities such as avalanches and landslides can be enhanced by a better understanding of granular material flow. An experimental set up showing such instabilities is described that demonstrates how the front divides rapidly into fingers. This is induced by size segregation, developing during the flow, not surface tension as with liquids.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
Nonlinear modes of vibration
Article Abstract:
Linear systems with n degrees of freedom have n fundamental vibration modes. The system motion can occur as a linear combination of fundamental modes. The combination principle is not thought to hold for nonlinear systems. However H. Hofer, K. Wysocki and E. Zehnder have provided evidence that certain convex systems having two degrees of freedom, must have either two periodic orbits, or infinitely many.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
User Contributions:
Comment about this article or add new information about this topic:
Patterns in the sand
Article Abstract:
A new model of vibrated granular material, using high-speed photography, examines the physical mechanisms responsible for the complex wave patterns of hexagons, stripes and squares. The model examines the role of the horizontal motions of the grains, which, unlike the vertical dynamics, is ill understood, and provides fresh insights into pattern formation.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Seismicity and stress rotation in a granular model of the brittle crust. Long-period volcano seismicity: its source and use in eruption forecasting
- Abstracts: Managing plant communities. Center for Plant Conservation
- Abstracts: Fixing all the parts. NMFS steers marine issues at COP10
- Abstracts: The role of urine marking in the foraging behavior of least chipmunks. Olfactory nest recognition by British storm-petrel chicks
- Abstracts: Suffering demand curves and welfare: a reply to Houston. The cost of peripheral males in a brook trout mating system