The air intake apparatus provides for additional auxiliary air to a wood or pellet burning stove. The methods and systems may vaporize the cellulose in a continuous steam reactor at a temperature of about 400-550\xb0 C. A display image control device performs a coordinate conversion between the coordinate system of the ultrasound image and a coordinate system of the medical image and displays a deformed image based on the deformation calculation and the other image about a same cross-section on a display device. In single microphone hearing instruments, the microphone signal and a delayed version of this signal are used to improve wind noise detection and reduction. In the event of a positive torque request, the fuel mass to be supplied is increased in order to enrich the air-fuel mixture. Other systems and methods are also provided.