The problem of finding packings of congruent circles in a circle, or, equivalently, of spreading points in a circle, is considered. Two packing algorithms are discussed, and the best packings found of up to 65 circles are presented.

Cold rolling behaviours of a commercial pure titanium have been studied by means of transmission electron microscopy. The results indicates: (1) In cold rolled titanium, there are a number of tangled dislocations which have often been observed in cold worked face centered cubic metals. (2) In 16.7% cold rolled Ti, imperfect structures with a high concentration of tangled dislocations were obser...

We obtain the complete space of solutions, in the two-dimensional O(3) nonlinear sigma model, which are foliated by Villarceau circles. In particular, we prove the existence of solitons that admit a foliation by nonparallel circles. This contrasts with the Plateau context, where solitons foliated by nonparallel circles cannot exist. These solitons carry topological charges that are holographica...