Abstract: Cleaning apparatus, and a method of utilization of the apparatus, cleans an object with a moving surface, such as a roll. The cleaning apparatus includes a nozzle head with a suction nozzle and a jet nozzle for emitting a liquid jet towards the roll. A sub-pressure is maintained in a chamber of the suction nozzle in order to evacuate liquid and released impurities with the aid of air flowing through a gap between the roll and the orifice edge. The jet nozzle is spaced from the inside of the suction nozzle and at the center of the suction nozzle to form a circumferential passage, the passage communicating with an evacuation pipe. The nozzle head also includes a structure to supply compressed air into the chamber through the gap in order to encounter and carry with it toward the passage liquid and impurities, cooperating with the suction effect maintained in the chamber and the evacuation pipe. The compressed air also has the advantage of drying the roll treated with liquid.

Abstract: An apparatus for determining the content of an element having an atomic number higher than 47, in a sample volume, in particular for determining the concentration of an X-ray contrast agent in vivo, employs a radiation source for such excitation of the element in the sample volume with collimated radiation that the element emits its characteristic X-ray radiation. An NaI(T1) scintillation detector is directed towards the sample volume for receiving X-ray radiation therefrom at an angle of from 90.degree. to 135.degree. in relation to the excitation radiation. Both the energy of Copton-scattered photons in the sample and the difference between this energy and 28.5 KeV must be clearly distinguished from the characteristic energy of the element concerned.