Abstract: A system for extraction of metal out from a liquid solution. The system may include a housing and a filter. The housing may have an inlet and an outlet. The filter may be carried by the housing, and the filter may include a sorption media that may comprise a graphene oxide material. The filter may be in fluid communication with the inlet and the outlet of the housing. The liquid solution may comprise a liquid solution that contains at least one metal. The housing may be shaped as a cartridge. The inlet may be configured to be removably engaged in fluid communication with an external apparatus that may provide a source of the liquid solution.

Abstract: A telephone call restricting apparatus for preventing toll calls and including circuitry for sequentially decoding the signals representing each digit of a telephone number, storing the first seven decoded digit signals in binary and converting the stored signals into decimal number signals, a comparator for comparing the decimal number signals corresponding to the appropriate digits of the telephone number with permissable local central exchange digits stored in a programmed memory device, a 90 detector and 0/1 detector for detecting long distance calls, an 800 detector and a 555 detector for detecting toll free long distance calls and logic responsive to both the comparator and the detectors and operative to abort unapproved toll calls.