The invention relates to a method of producing a protein of interest, comprising making a non-human transgenic mammal that produces said protein in its milk, obtaining said milk from the non-human transgenic mammal and purifying said protein of interest from the milk. One feature is that the magnetic structures are configured to help minimize the winding’s AC losses, improving the system’s efficiency. The system may determine the flame-sensing rod contamination, the stray capacitance of the flame sensing system, and compensate for stray capacitance in the flame sensing system. An anti-wetting coating including a perfluorinated alkene compound on at least a surface around the nozzle is formed on an exposed surface of the printhead. Examples of fluid properties based on which the device can direct fluid include fluid density, fluid velocity, fluid viscosity, and Reynolds number of the fluid flow. At ground level, a portion of the curtain is attached to the head of the curtain mount.