A transportable sign is provided which comprises a base portion, a support portion, and a display portion, In the sign, the display portion comprises a carrier configured to carry a display medium to display an image, e. The HSAFM includes a cantilever, a piezotube, an optical detector, a circuit element, and a feedback controller. Another design provides for a ferrofluid being disposed between the diaphragm and magnets of the electro-dynamic loudspeaker in order to dampen the resonance frequency of the device. The data processing system further comprises a download controller for monitoring the received blocks of data and detecting therein corrupted data associated with a first block of data. A naphtha is separated from the Fischer-Tropsch product and introduced into a naphtha reformer.