Disclosed is a multiple-gate transistor that includes a channel region and source and drain regions at ends of the channel region. The melting point of the first conductive body exceeds the melting point of the second conductive body. A vapor retardant facing layer is bonded to at least one of the major surfaces of the mat. Both silicas are rendered cationic. The first clamping member and the second clamping member of each clamping assembly are capable of moving toward each other for clamping a workpiece. The umbilical may be made from composite materials and it may be a neutrally buoyant in any well fluids present.