Transient distributions ensuing when ultracentrifugal equilibrium is disturbed by a substantial increase in speed

Abstract

An infinite series solution to the Mason–Weaver approximation to the Lamm equation is given for the case in which a system at equilibrium in the ultracentrifuge is suddenly rotated at a considerably higher speed. The greatest rate of change of concentration occurs initially at the meniscus, but later the rate of change becomes less than that in the center of the column where initially it is relatively small. Curves are presented from which to calculate, for a wide variety of conditions, the time at which it is most advantageous to transfer the level of observation from the center of the column to the meniscus. The actual rates of change of concentration at these levels at these times are tabulated. Hence, in experiments of this type interference fringes can be identified unequivocally from a limited number of photographs.