A liquid ejecting apparatus includes a first liquid containing unit containing a liquid therein and a second detachable liquid containing unit containing a liquid therein and having a liquid containing volume smaller than that of the first liquid containing unit. The load of the pad against the substrate, and the rotary speed of the plate, may be varied to control the rate of material removed by the pad. Typically, the fabric matrix of the wet wipe has a capacity of about 125 grams of solution per square meter, and it is impregnated with the aqueous saline solution to a level at or below approximately 80% of the absorbent capacity of the matrix. Thereafter, a supply force is applied on the non-Newtonian fluid to cause the non-Newtonian fluid to flow, whereby the flow is capable of moving the substrate along a direction of the flow. In one embodiment, an identifier for a piece of digital content can be generated using the title of the piece of digital content, the size of the piece of digital content, and a hash of other attributes of the piece of digital content such as title, album, and artist names. That delay may be equal to a delay associated with inputting the clock signal to a last one of the plurality of sense amps, plus a delay of the last sense amp, plus a delay of the data bus.