Some Remarks on the Question of Charge Densities in   Stationary-Current-Carrying Conductors
  Recently, some discussions arose as to the definition of charge and the value of the density of charge in stationary-current-carrying conductors. We stress that the problem of charge definition comes from a misunderstanding of the usual definition. We provide some theoretical elements which suggest that positive and negative charge densities are equal in the frame of the positive ions. 
Liana Baroni (1), Enrico Montanari (2), Alessandro D. Pesci (1) ((1)   University of Bologna and INFN sezione di Bologna, It...