For a square shaped dislocation loop in Nail with a<100> Burgers vector, a. Write an expression for the self-forces on each of the 4 components of the loop b. Determine the loop size at which the self forces are balanced by the Peierls stress for NiAll. c. Determine the energy of the loop in part (b) d. Compare the energy of the loop in part (c) to the energy of a circular loop enclosing the same area