A flexible fixture system for a CNC machine is coupled to a base fixture. Pharmaceutical compositions containing these compounds, methods of using these compounds as inhibitors of nitric oxide synthase and processes for synthesizing these compounds are also described herein. The method also includes determining a rate of change of the water bottom reflection time of each trace and generating a model water velocity and a model water bottom reflection time for each trace midpoint using a preselected function of the water bottom reflection times and the rates of change. The casing of the pump has a slight spiral deviation so that the pump chamber’s radial sidewall flares away from the swept area of the impeller’s vanes to define a fluid outlet that contributes to higher P-Q performance, especially when pumping colder fluids. The apparatus also may include circuits for handling read and write data coupled to the first and second address generating circuits, respectively.