The present invention relates, inter alia, to copolymers, preferably conjugated polymers, formulations comprising the copolymers and electronic devices comprising the copolymers. The method may further include assigning a pair identifier to the device-to-device pair. The elastic member is interconnected with the arbor such that rotation of the arbor in a loading direction loads the elastic member. Deflection of the follower is used to operate a hydraulic valve which, in turn, is used as a control cylinder to raise or lower an adjacent dog member. Liquid manure can also be transferred between the tanks to thereby achieve a pre-determined weight distribution between the tanks.