Interpretation of alpha-epsilon graph for pairSpringSliderDashpot collision model
 

One of the (very important!) required parameters in the pairSpringSliderDashpot model for lagrangian particle tracking and collisions is "alpha", which relates to the coefficient of restitution, epsilon. After much searching, I have found the original paper that the collision model seems to be based on.
https://www.sciencedirect.com/scienc...3259109288030L


However, the graph (attached below) relating alpha to epsilon is a bit hard to interpret. The x-axis seems to shift between different scales. Any insights on how to interpret the data? Is it linear in each section, or perhaps alternating between linear and logarithmic?

Any ideas will be appreciated. Thank you!

Attachment 95361