Abstract: An apparatus (10) is provided for determining the flow rate of a gas. The apparatus comprises a housing (12) forming a vaporization chamber (14) for converting a fluid into a gas vapor when subjected to heat (22). An oscillation flow meter is formed within the housing (12), thereby being integrated with the vaporization chamber, for receiving the gas vapor and providing a frequency signal (60) indicative of the rate of flow of the gas vapor.

Abstract: An apparatus (10) is provided for determining the flow rate of a gas. The apparatus comprises a housing (12) forming a vaporization chamber (14) for converting a fluid into a gas vapor when subjected to heat (22). An oscillation flow meter is formed within the housing (12), thereby being integrated with the vaporization chamber, for receiving the gas vapor and providing a frequency signal (60) indicative of the rate of flow of the gas vapor.

Abstract: A polymer electrolyte membrane fuel cell stack (52) includes a plurality of membrane electrode assemblies (12) having evenly distributed fuel concentration across an anode (24), and efficient cooling across a cathode (26). A first plate (14) has a fuel side (28) with a plurality of serpentine channels (40) formed therein for distributing fuel across the anode (24), and a second plate (16) has an oxidant side (30) with oxidant channels (42) formed therein for distributing an oxidant across the cathode (26). The membrane electrode assembly (12) has an even fuel concentration thereacross, and the oxidant is routed through the cell (10) at least twice for absorbing heat prior to being distributed across the cathode (26).