Roundnesses

If you mean circularities, why not say so? "Roundnesses" is rather informal and out of place in something scholarly.

Their mean circularities at the moment when the tumors reach the boundaries of the simulation domain are slightly larger

Table 6 and Figure 3 show the mean circularities as a function of time

sorted by mean circularities

quotient of the mean circularities

Our subhaloes have mean circularities between 0.6 to 0.7 where sampling is high, with a redshift zero mean L/Lcirc = 0.64 for r < rvir

The pulverized toner and spherical toner had mean circularities of 0.91 and 0.98, respectively

Thanks very much Contrex. I didn't know that the word circularity was preferred to roundness. I looked up dental research articles written by native EN speakers with the word circularity or roundness, and could not find any with circularity but found one with roundness: http://www.ncbi.nlm.nih.gov/pubmed/19912375

But if you say circularity is fine, I will use it instead.

I checked, and found that roundness and circularity are oftenly used interchangeably. However in engineering roundness relates to three dimensional solids whereas circularity relates to plane (flat) figures.

Thanks again. Circularity is the word I need then because the article talks about the circularity of a perpendicular section of the root canal.

I used the wrong word when I wrote 'solid'. Roundness can apply to a cavity or tunnel or hole as well as a solid object. As you note, a plane section would be said to have a degree of circularity.