Selective hydrogenation of a gasoline cut containing polyunsaturated hydrocarbons containing at least 2 carbon atoms per molecule and having an end point of 250\xb0 C. A brake material is sandwiched between the drum and a tension band to provide adjustable resistance to rotation of the drum. The adder is configured to sum the digital samples, and the summed digital samples define a mass spectrum. A shunting diode is coupled between the switch and the input inductor. When the consecutive counter reaches a first predetermined value, the non-consecutive counter is incremented and the consecutive counter is reset to zero. Also provided is a candle comprising such a container, wherein the first portion contains candle wax, lamp oil or petroleum gel, and a wick.