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Quantitative measures of disorder in biological oscillations and their implications for bioreactor operation
Author(s) -
Patnaik Pratap R.
Publication year - 2007
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.91
Subject(s) - noise (video) , inflow , monotonic function , continuous flow , bioreactor , biological system , statistical physics , environmental science , physics , control theory (sociology) , computer science , mathematics , mechanics , biology , mathematical analysis , artificial intelligence , botany , image (mathematics) , control (management)
Under realistic conditions, biological oscillations show fluctuations around time‐varying deterministic values. These fluctuations are often created by noise from the environment, and they vary randomly with time. With continuous flow microbial cultures, the feed stream is a major source of noise. While the detrimental effects of noise inflow are known, quantitative measures of their effects are not established. Such indexes are important because, apart from distortions, noise may displace a fermentation into an undesirable state or into chaos. Using Saccharomyces cerevisiae as an example, four measures of the effect of noise are proposed and their physical implications for the operation of continuous cultures are discussed. It is shown that, like monotonic cultures studied earlier, noise‐affected oscillating cultures too can be analyzed usefully through their fractal dimensions. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.