According to an embodiment, the present invention provide a method for fabricating a copper indium diselenide semiconductor film using a self cleaning furnace. In various embodiments, an implement for drinking andor eating generally includes at least one tube having at least one inner fluid flow passage therethrough in which fluid may be received and delivered through the at least one inner fluid flow passage. The user can be a set of users or an automated program. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. The duty ratio andor the pulse height of the pulse voltage is changed according to the control signal.