Turing Pattern Formation by the CIMA Reaction in a Chemical System Consisting of Quaternary Alkyl Ammonium Cationic Groups

2011 ◽  
Vol 115 (14) ◽  
pp. 3959-3963 ◽  
Author(s):  
Kouichi Asakura ◽  
Ryo Konishi ◽  
Tomomi Nakatani ◽  
Takaya Nakano ◽  
Masazumi Kamata
Keyword(s):  
Pattern Formation ◽  
Chemical System ◽  
Turing Pattern ◽  
Alkyl Ammonium ◽  
Cima Reaction

scholarly journals Spatial Heterogeneity and Imperfect Mixing in Chemical Reactions: Visualization of Density-Driven Pattern Formation

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Sabrina G. Sobel ◽  
Harold M. Hastings ◽  
Matthew Testa
Keyword(s):  
Pattern Formation ◽  
Salt Water ◽  
Model System ◽  
Reaction Vessel ◽  
Chemical System ◽  
Industrial Processes ◽  
History Of ◽  
Convection Rolls ◽  
Belousov Zhabotinsky Reaction ◽  
Complex Ion

Imperfect mixing is a concern in industrial processes, everyday processes (mixing paint, bread machines), and in understanding salt water-fresh water mixing in ecosystems. The effects of imperfect mixing become evident in the unstirred ferroin-catalyzed Belousov-Zhabotinsky reaction, the prototype for chemical pattern formation. Over time, waves of oxidation (high ferriin concentration, blue) propagate into a background of low ferriin concentration (red); their structure reflects in part the history of mixing in the reaction vessel. However, it may be difficult to separate mixing effects from reaction effects. We describe a simpler model system for visualizing density-driven pattern formation in an essentially unmixed chemical system: the reaction of pale yellow Fe3+ with colorless SCN− to form the blood-red Fe(SCN)2+ complex ion in aqueous solution. Careful addition of one drop of Fe(NO3)3 to KSCN yields striped patterns after several minutes. The patterns appear reminiscent of Rayleigh-Taylor instabilities and convection rolls, arguing that pattern formation is caused by density-driven mixing.

scholarly journals Mechanism of Trees / Bushes Like Pattern in Chemical System

2009 ◽  
Vol 6 (3) ◽  
pp. 819-829
Author(s):  
P. K. Srivastava ◽  
Narendra Yadav
Keyword(s):  
Pattern Formation ◽  
Ir Spectra ◽  
Succinic Acid ◽  
Ammonium Sulphate ◽  
Cyclic Compound ◽  
Chemical System ◽  
Powder Spectrum ◽  
Initial Concentration ◽  
X Ray ◽  
Type Pattern

Trees / bushes like pattern have been investigated in succinic acid + ethylacetoacetate + BrO3−+ Fe (phen)3+2+ Ce+4+ H2SO4system at 30 °C in a petridish after 6 hours. These patterns are dependent on initial concentration of reactants and temperature. The system first shows fast appearing / disappearing blue and red pattern then bifurcate into concentric waves and finally shows a tree / bushes type pattern which grows in length and breadth against time. Microphotographs of trees / bushes pattern, succinic acid and ceric ammonium sulphate shows that a new compound has been formed which is responsible for this pattern. It is further confirmed by X-ray powder spectrum of trees / bushes pattern material and succinic acid. IR spectra of pattern material show that presence of cyclic compound in which Ce+4ion coordinated by hydroxyethylacetoacetate. A tentative mechanism of pattern formation is proposed.

Chaotic turing pattern formation in spatiotemporal systems

2006 ◽  
Vol 1 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Jing-hua Xiao ◽  
Hai-hong Li ◽  
Jun-zhong Yang ◽  
Gang Hu
Keyword(s):  
Pattern Formation ◽  
Turing Pattern
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