An object of the present invention is to provide an accumulator including a flow damper which is capable of performing a control so that a vortex may not be formed in a vortex chamber at the time of a large flow injection without requiring huge labors and fabrication costs. The method further includes forming an isolation buried layer in the substrate under at least a portion of the first circuit section and forming a conductive layer on a surface of the substrate, the conductive layer overlaying at least a portion of the first circuit section. Each hopper section includes a controllable discharge opening that permits precise control of the amount of each concrete color that is discharged from the hopper. In addition, the surface of the silica precipitate formed may be modified by the addition of surface modifying agents, during synthesis to further enhance the desired reinforcing properties of the precipitated silica. Metal shields are formed between adjacent wordlines and substantially parallel to the wordlines to shield the floating gates of adjacent cells. A method of using a purification system to process fatty materials, such as oils, edible oils, fats, and similar materials, is also disclosed.