Abstract: To provide a simple and compact fuel cell system that prevents degradation of the performance of a fuel cell stack due to accumulation of impurities and improves fuel efficiency by reducing discharge of a fuel gas. An impurity storage section 30 that communicates with an outlet of an anode gas passage of each cell 20 and stores an impurity in a fuel gas is formed in a fuel cell stack 2. The volume of the impurity storage section 30 is preferably larger than the volume of a fuel gas inlet manifold 26.

Abstract: A source position detecting method and a communications system, communications equipment and relay suitable for implementing this method. When relaying a coded data signal from one individual network to another individual network, a first relay, for instance, increases the length of preambles by 1 and when relaying to the next individual network, a second relay, for instance, decreases the length of preambles by 2. Increment/decrement processing of the length of preambles can be carried out without decoding the main body of the coded data signal. Alternatively, preamble duration shortening accompanying the relay can be utilized and signal distortions accompanying signal transmission such as group delay and signal strength attenuation can also be utilized. Without processing the data at the relay, the destination equipment can obtain data concerning the position of the source equipment which transmitted the data signal, such as data concerning the transmission route of the data signal.

Abstract: A pressure vibration damping device in a liquid supply passage for supplying a liquid from a pump to a hydraulic device such as a fluid pressure type suspension of a vehicle, including a pressure pulse absorbing means adapted to be able to accept and return a small amount of the liquid from and to said liquid supply passage so as to absorb momentary changes in the flow rate of the liquid in the liquid supply passage, and a liquid column vibration damping means adapted to be able to apply a substantial flow resistance principally to a high velocity flow of the liquid in the liquid supply passage at a part thereof between the pump and the pressure pulse absorbing means, the high flow velocity being due to pulse flows of the liquid induced by a resonance of pulsating output of the pump and the pressure pulse absorbing means and substantially higher than a mean flow velocity of the liquid corresponding to a normal rate of supply of the liquid through the liquid supply passage.