A nail-free interchangeable canvas frame is provided, which is adapted to fasten a canvas for a user to work on the canvas. In one embodiment a semiconductor device comprises a substrate, a moveable electrode and a counter electrode, wherein the moveable electrode and the counter electrode are mechanically connected to the substrate. The bar has an end cap having an outer dimension larger than that of the bar and the aperture, with the end cap being situated adjacent the first end of the bar. The heat-transport medium is renewed by allowing inducing a reverse phase transition in the heat-transport medium, permitting the heat-transport medium to repeatedly or continuously undergo the phase transition that causes the temperature differential. An alert is generated to a human operator if the temperature measured does not compare favorably with the desired range. The system memory is accessed by each DSPCoprocessor subsystem through a cache and external memory interface.