A method to select ions based on their electrical mobility is described. The first electrode with an array of carbon nonotubes and the second electrode are positioned to produce an air gap between the first electrode with an array of carbon nonotubes and the second electrode. Each data packet may include a transaction type field that includes data indicative of a first size of a payload of the respective data packet and a second size of an error control code in the respective data packet. The titanium dioxide pigment of the present invention has characteristics peculiar to anatase type, for example, optical characteristics such as bluish color tone and physical characteristics such as low hardness, and furthermore has high opacity which is not possessed by conventional anatase type titanium oxide pigments.