A memory device and a method of controlling an input signal of the memory device. Plunger pumps so constructed are relatively resistant to fatigue failure because of stress reductions, and they may incorporate a variety of valve styles, including top and lower stem-guided valves and crow-foot-guided valves, in easily-maintained configurations. Arrays formed of such memory cells and non-volatile memory cells are also disclosed. 1 percent by weight to about 10 percent by weight of an acetate salt, about 0. The metallic sealing element forms the sealing surface around said inner border of the seat surface, and the synthetic sealing element forms the sealing surface towards the outer border of the seat surface. The proximal end has a housing enclosing a fluid pressure chamber therein.