A milling device is disclosed for the preparation of microscopy specimens or other surface science applications through the use of ion bombardment. One example method comprises, adjusting engine injection timing based on a first temperature of a first intake of the first bank and a second temperature of a second intake of the second bank. A quantization table level is selected from a quantization table that includes at least one level, and information identifying the selected level is placed into an information stream. The surgical instrument may also comprise a handle connected to a proximate end of the shaft. The invention also broadly comprises a surgical assemblies control service head designed to house powered surgical devices and a vacuum-filtering system for the treatment of air contamination caused by surgical procedures. The compounds of the invention are of use in both therapeutic and diagnostic methods.