This video shows why you cant always trust all information on the internet, as well as shows the basics of torque wrenches and a few oddball calculations you might run across when building custom things.
Underground mine ventilation. Underground mine ventilation provides a flow of air to the underground workings of a mine of sufficient volume to dilute and remove dust and noxious gases (typically NOx, SO2, methane, CO2 and CO) and to regulate temperature.
assist-control ventilation. A type of mechanical ventilation with a minimum frequency of respirations determined by ventilator settings. It also permits the patient to initiate ventilation at the same tidal volume or pressure as set on the ventilator. See also: ventilation.