Abstract: A magnetorheological fluid damping system includes a hydraulic cylinder, a piston head, a piston rod, and a porous valve. The hydraulic cylinder is configured for disposing magnetorheological fluid therein. The piston head is disposed within the hydraulic cylinder and has first and second sides defining first and second chambers within the hydraulic cylinder. The piston head is configured to be in sliding engagement with the hydraulic cylinder. The piston rod is connected to the piston head. The porous valve includes a magnetorheological fluid pathway, has first and second fluid connections, and is configured to dampen the flow of the magnetorheological fluid between the first and second fluid connections in accordance with a magnetic field. The first fluid connection is fluidly connected to the first chamber and the second fluid connection is fluidly connected to the second chamber. The magnetorheological fluid pathway at least partially directs magnetorheological fluid flow through a porous media.

Abstract: A single enclosure (10), which satisfies the needs of portability, is closeable into a suitcase-type cabinet with a tractable carrying handle. Specifically, a keyboard enclosure (14) is hinged (16) to a main frame enclosure (12) in such a manner that it is possible to fold the keyboard up against the main frame and to latch (40) the two together.