NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Stability limits for bioconvective fractals - Microgravity prospectsFractal objects are delicate aggregates which show self-similar behavior and vanishing density for increasing length scales. In practice real fractals in nature however possess only a limited region of verifiable self-similarity. As natural fractal objects increase in size, they become easier to disrupt mechanically. Herein the effects of thermal vibrations and gravity are investigated as deforming forces on fractal aggregation. Example calculations are carried out on a biological fractal formed from the surface aggregation of various cells such as alga and bacteria. For typical cell parameters, the predicted diameter of this so-called 'bioconvective' fractal agrees well with the observed limits of about 5 cm. On earth, this size represents an experimental maximum for finding bioconvective fractal objects. To extend this size range of fractals available for statistical study, a reduced gravity environment offers one way to achieve larger fractals. For these enhanced sizes, the present scaling predicts that microgravity can yield up to a 35-fold improvement in extending statistical resolution.
Document ID
19920052161
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Noever, David A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 15, 2013
Publication Date
March 1, 1992
Publication Information
Publication: Microgravity Science and Technology
Volume: 5
ISSN: 0938-0108
Subject Category
Materials Processing
Accession Number
92A34785
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available