Abstract: Systems and methods for digital ID sharing are disclosed. One disclosed method includes receiving a first digital ID comprising a verified credential of a first user; receiving a second digital ID comprising a verified credential of a second user, verifying a relationship between the first user and the second user, linking the first digital ID to the second digital ID; and outputting a verification message associated with the first digital ID and the second digital ID.

Abstract: A cleaning apparatus for cleaning the burning chambers of engines to remove carbon monoxide deposits and other accumulated residue therefrom. The apparatus includes a holding tank for containing a predetermined amount of cleaning solvent, a nozzle having a nozzle tip with a discharge outlet and a suction inlet, a supply line connecting between the holding tank and the outlet and a first pump for transferring solvent under pressure from the holding tank for discharge from the outlet into the burning chamber. A return line connects between the inlet of the nozzle and the holding tank and includes a second pump connected in-line for creating a suction at the inlet, causing solvent to be transferred back to the holding tank. An air supply line from a compressor connects to the solvent supply line via a three-way valve for selective discharge of pressurized air into the burning chamber to facilitate drying thereof after washing with the solvent.