A key structure is provided, including a substrate, a key cap, a first link, and a second link pivotally connected to the first link. An integrated process includes introducing the feedstock and hydrogen into a first hydrocracking reaction zone containing a first hydrocracking catalyst to produce a first zone effluent. A controller for generating a temperature set point is connected to the temperature sensor and responsive to the test signal for selectively controlling a power level applied to the heating element in order to control a rate at which energy is transferred to the test specimens.