A polypropylene composition for injection-molded drainage systems comprising 78-84 wt % of a crystalline propylene polymer, 8 to less than 13 wt % of an elastomeric copolymer and 8 to less than 13 wt % of polyethylene. The method may be exploited for finely tuning the impedance of semiconductor components or devices, by modifying the dopant profile of a region of low dopant concentration by diffusion of dopants from adjacent regions of higher dopant concentration through the melting action of a focused heating source, for example a laser. in centralized or distributed environments. The content receiver is configured to recombine the plurality of transponder signals to regenerate the digital data signal. A compensation voltage can also be applied to interior memory cells to equalize their erase behavior with end memory cells.