Abstract: A method and apparatus for synthesizing at least one of alkylene oxides and alkylene glycols from lower alkanes and/or lower alkenes. In the preferred embodiment, the apparatus includes a lower alkane/alkene supply; an oxygen supply for providing a source of oxygen; and a metal oxide catalytic reactor. The metal oxide catalytic reactor includes a reactor chamber; and a catalyst in the chamber for reacting the lower alkane/alkene supply with the source of oxygen to convert the lower alkane/alkene by selective partial oxidation to at least one of the alkylene oxides and alkylene glycols. Also, in the preferred embodiment, a separator, downstream from the reactor, separates the alkylene oxides and alkylene glycols from the total product stream and the unconverted reactants.

Abstract: A three-mode analog controller for regulating a signal corresponding to a controller variable to produce a controller output, comprises an integrating circuit, a proportional circuit, and a derivative circuit. The integrating circuit includes a reset adjustment for varying a time constant thereof, the proportional circuit includes a gain adjustment for varying the gain thereof and the derivative circuit includes a rate adjustment for adjusting the rate of derivation of the signal. The gain adjustment comprises a photoresistor associated with a source of light which is provided with varying current corresponding to the signal to vary the resistance of the photoresistor and, thus, the gain value. The reset and rate adjustments may also comprise photoresistors with light sources or may be formed of field affect transistors each controlled by a circuit and remotely located potentiometer or variable voltage source.