The following is an article from The Annals of Improbable Research, now in all-pdf form. Get a subscription now for only $25 a year!
Research involving, or said to involve, centrifugal force
compiled by Katherine Lee, Improbable Research staff
Far-Flung Centrifugal Distribution of Fresh vs. Aged Poultry Litter
“Centrifugal Spreader Mass and Nutrients Distribution Patterns for Application of Fresh and Aged Poultry Litter,” W. D. Temple, M. Skowrońska, and A. A. Bomke, Journal of Environmental Management, vol. 139, 2014, pp. 200–7. (Thanks to Marcin Klejman for bringing this to our attention.) The authors, at the University of British Columbia, Canada and the University of Life Sciences in Lublin, Poland, report:
“Poultry litter (PL) consists of chicken or turkey manure, feathers and bedding material which is typically wood shavings, sawdust, wheat straw, peanut hulls or rice hulls.... A spin-type centrifugal spreader was evaluated using fresh and aged poultry litter... Relative to the aged litter, the broadcast fresh litter resulted in higher coefficients of variation (CV) over its transverse distance, a narrower calculated space distance between passes for uniform spread and lower soil available N [nitrogen] concentrations.... [Our] results suggest that poultry litter should be allowed to age before broadcast application is attempted.”
Detail from the study “Centrifugal Spreader Mass and Nutrients Distribution Patterns for Application of Fresh and Aged Poultry Litter.”
“Centrifugal and Centripetal Forces in Personality Development,” Leo Kanner, The Quarterly Journal of Child Behavior, vol. 2, 1950, p. 353.
Using a Centrifuge to Decapitate an Ant
“The Exoskeletal Structure and Tensile Loading Behavior of an Ant Neck Joint,” Vienny Nguyen, Blaine Lilly and Carlos Castro, Journal of Biomechanics, vol. 47, no. 2, January 22, 2014, pp 497–504. The authors, at Ohio State University, report:
Live ant specimens were tested in a custom-built, open centrifuge following previous investigations of attachment forces of arboreal ants (Federleetal, 2000). Based on Wojtusiak (1995), we used 7g as the minimum performance requirement for the centrifuge.... Prior to testing, ants were anesthetized in a 30ºF chamber until immobile. Samples were fixed at the mouth to a disk using glue and accelerant with the head pointing towards the center of the disk.... Ant specimens were subjected to incremental loads by increasing rotation speed by 15 rps every 12s up to 215 rps, corresponding to a maximum force of 3400 times the weight of the ant.... SEM [scanning electron microscope]
Detail from the study “The Exoskeletal Structure and Tensile Loading Behavior of an Ant Neck Joint." micrographs of ruptured specimens revealed that failure occurred at the neck–head transition.
This article is republished with permission from the May-June 2014 issue of the Annals of Improbable Research.
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