A central processing unit and a real-time scheduling method applicable in the CPU are disclosed. At least one of the various embodiments may enable improve load balancing of egress network links by programming network routing tables and conducting diagnostic processes and testing to determine if a programmed network routing table optimally load balances the outgoing the network data traffic among the equal cost next hop egress network links. The optical circulator in accordance with the present invention is a reflection-type optical circulator, in which the paths of throughgoing light rays are folded back upon themselves. The fold lines may transition from non-reinforced to reinforced portions of the blank and a special transition zone is contemplated to accommodate the transition. The preservatives include organic acids and the salts and esters thereof but exclude preservatives which can generate sulfur or chlorine-containing compounds. Rupturing the activator chamber allows activator to combine with the reactant in an exothermic reaction to heat the contents pouch.