Abstract: A method and arrangement for the nondestructive determination of a property of an object including a conveyer for movably supporting the object. A testing unit, including a movable member and a stroking body, is mounted adjacent the conveyer. The conveyer moves the object into and then out of engagement with the movable member. When the object is out of engagement with the movable member, it is physically impacted by the stroking body causing the object to freely vibrate at at least one natural resonant frequency mode. A detector detects the vibration of the object resulting from the physical impact on the object by the stroking body. A computer coupled to the detector processes the detector output and determines the properties of the object.

Abstract: The invention provides a method for reducing the emission of NO.sub.x in a pressurized fluidized bed combustion process comprising (a) combusting reaction products in the presence of a sulfur absorbent in a pressurized fluidized bed at a pressure of at least 5 bar to form a flue gas comprising dust particles and an initial concentration of NO.sub.x, (b) reacting the NO.sub.x in the flue gas with a substance which reduces NO.sub.x in a first reaction zone to form a flue gas which has a lower NO.sub.x concentration as compared to its initial NO.sub.x concentration, wherein the absolute pressure of the flue gas is at least 5 bar and the temperature of the flue gas is at least 450.degree. C. in the first reaction zone, and (c) reducing the NO.sub.x concentration in the flue gas provided by step (b) in a second reaction zone by contacting the gas with a solid surface comprised of flue gas dust particles.