A valve system automatically controlled by an expandingcontracting material and method of dispersing fluid through valve system are provided. Corresponding graphic images are allotted to said concrete places, indicating the location of the place in the process, and these images can be displayed in the operating environment of the process control system when the process is running. As the operating member is moved away from the first end or the second end, the first and second audio signals are mixed. The modulated RF carrier signals are radiated by a corresponding plurality of antenna elements coupled to the plurality of polar modulators. The core is substantially thicker than each skin. The temperature of the reaction is easily stabilized and uniform distribution of temperature is obtained in the fluidized catalyst bed.