An ink jet printer stores a waveform and tables. In one embodiment, a shoe is disclosed which includes a tubular outer body that is coupled to a wellbore lining tubing, and a tubular inner body located within the outer body and coupled to fluid supply tubing. A good approximation for a complex spectral representation of the discrete-time signal is obtained by combining two real spectral coefficients, preferably by a weighted linear combination, wherein additionally more degrees of freedom for optimizing the entire system are available. Preferably, the esterification reaction is carried out at the temperature of 200 to 350\xb0 C. The cargo container may include one or two rounded ends.