A method includes forming a gate stack to cover a middle portion of a semiconductor fin, and doping an exposed portion of the semiconductor fin with an n-type impurity to form an n-type doped region. In one embodiment, for example, the computer is configured to determine the total amount of flux additions to achieve a desired sulfur percentage as part of a steel desulfurization process. Parts of the air sampling system may be externally mounted to the inlet system, allowing for an operator to access the sampling coupons, while the inlet system operates. These ratios, I1079 nmI1340 nm, may vary from about 0. When the working catheter is locked in the operative position, the working catheter extends through the guide lumen of the guide catheter and out of the distal guide orifice of the guide catheter, and the distal working orifice of the working catheter is positioned outside of the guide catheter.