Embodiments of the present invention are directed toward a photoluminescent article comprising at least one host material and at least one color tunable photoluminescent dye. The axis of the pin or pins is situated below the axis of the motor of the shearer’s ranging arm. Thus, different protein samples can be supplied with the appropriate amounts of electrical energy for isoelectric focusing, so as to produce the optimal protein focusing effects and ensure that the focusing of protein in a gel will not be adversely affected by an otherwise insufficient or excessive supply of electrical energy. Another aspect of the invention is directed toward an aircraft system having an airfoil and a leading edge device movable between at least a retracted position and an extended position along a motion path having two segments.