A hydraulically actuated friction coupling comprises a hollow case, an output shaft drivingly connected to the case, a friction clutch pack for selectively engaging and disengaging the case and the output shaft, and a hydraulic clutch actuator. A plasma is generated from the gases within the chamber. A handle is attached with a hinge to the mounting plate and rests within the recessed area when it is not being used. The dipsticks specifically bind a lipoprotein or apolipoprotein when dipped into a protein sample. In the photo detector, at least a part of a resonance region formed by the periodic structure is included in the photoelectric conversion layer of the photo detector. When in the second position, the first plate and the second plate are situated such that the first cylindrical member and the second cylindrical member would be in proper placement for joining.