Abstract: A vessel for bulk materials is described whose level can be continuously determined from outside during the filling or emptying process. To this end, at least one AE (acoustic emission) transducer is mounted at each of the levels of the vessel which determine full or empty states. An acoustic waveguide is provided between the two AE transducers defining full and empty states. Preferably, however, the vessel wall serves as an acoustic waveguide. The AE transducers are connected with an electronic signal processing unit which determines the movement of the bulk material by localization from the difference between the arrival times of the signals generated by friction noises of the bulk material at the acoustic waveguide, which are detected by the two AE transducers.

Abstract: Bone replacement or prosthesis anchoring material on the basis of sintered calcium phosphates which consists of a mixture of calcium phosphates with low or high-molecular-weight organic substances. More specifically, the anchoring material consists of a mixture of calcium phosphates composed of CaO and P.sub.2 O.sub.5 in a quantitative ratio of 2:1 to 4:1 with biodegradable polymers in a ratio of 10:1 to 1:1 of phosphate to polymer and is implantable as a solid body. A method for the production of the material wherein calcium phosphate with a porosity of 15 to 30 volume percent is used and its pores are filled by impregnation with polymer material.