An asymmetrical channel implant from source to drain improves short channel characteristics. The apparatus provides a parallel coupling for securely interlocking the outside surfaces of parallel frame members together in a side to side arrangement to form an array with improved structural load distribution. The contact or support surfaces of the balance piston and the apply piston are provided coaxial between the clutch hub and the apply piston support device. A first contact point is connected to an underside of the contact portion and a second contact point is connected to the other terminal. Consequently, it is possible to resolve problems associated with changes in the draft corresponding to the state of the load, without using ballast water. The process is useful for the selective hydrogenation of diolefins having from about 8 to about 19 carbon atoms per molecule to monoolefins.