Resonant pattern formation in a chemical system
Article Abstract:
An experiment was conducted to determine the effect of a periodic, external, optical force applied to spiral wave patterns in an artificially created reaction-diffusion system composed of a porous membrane disk placed between two reservoirs of light-sensitive, Belousov-Zhabotinsky reagents. Results indicate that as the forcing frequency is changed, the resulting resonant interactions lead to a transformation of the spiral waves into maze-like, standing-wave patterns. Periodic forcing frequently occurs in nature and thus could produce similar resonant pattern formations in chemical or biological media.
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:
Controlling chaos in the Belousov-Zhabotinsky reaction
Article Abstract:
A new map-based, proportional-feedback algorithm can be used to impose order on the chaotic Belousov-Zhabotinsky (BZ) reaction. BZ is an oscillatory chemical system whose chaos results from the interaction of Ce(IV)/Ce(III), CH2(COOH)2, BrO3- and H2SO4. The algorithm gives stability to BZ by exploiting the tendency of chaotic systems to become regular when near a fixed point on the next-amplitude map that is associated with an unstable periodic orbit.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1993
User Contributions:
Comment about this article or add new information about this topic:
Competition exposed by knight?
Article Abstract:
Sanderson and colleagues have re-evaluated biogeogaphical data, and Jared Diamond's interpretation, on bird species on islands around New Guinea. They used a recursive algorithm, known as the knight's tour, to produce a genuinely null model. The results conclude that species pairs not occurring together, are as frequent as expected by chance, but those occurring together twice fall outside computed 99% confidence limits and are improbably rare.
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:
- Abstracts: Pattern formation in semiconductors. Vestal voyagers unveiled. Non-thermal melting in semiconductors measured at femtosecond resolution
- Abstracts: Elephant and rhinoceros conservation in Kenya. African Elephant Conservation Act. Natural variation in horn size and social dominance and their importance to the conservation of black rhinoceros
- Abstracts: Hydrostatic locomotion in a limbless tetrapod. Independent evolution of running in vampire bats. Wing bone stresses in free flying bats and the evolution of skeletal design for flight
- Abstracts: Enhancing protein C interaction with thrombin results in a clot-activated anticoagulant. The thrombin paradox
- Abstracts: Communal nesting patterns in mice implicate MHC genes in kin recognition. Female anti-male attack