Described herein is an implementation of a technology for managing credentials. The filter assembly includes a heating system to heat the filter medium. The IPU includes a central processing unit and a monitor electrically connected to the CPU. In the next step of this method, a urea compound is blended with a nano-clay material to produce a second blend and compression molded. Thus, the key can be removed from the core when the card is inserted, and the block locks the card and does not permit removal of the card. The alteration of the one or more environmental parameters in a specifically timed manner can be used to induce and maintain synchronous cell division.