Abstract: In a device for determining the ozone concentration by utilizing the surface chemiluminescence effect having a fan (13), a chemiluminescence element (8), a photomultiplier (6), a temperature sensor (16), and control electronics (12), an airflow generated by a fan (13) passes via a suction pipe (7) and an adjoining light trap system (17) through a venturi-shaped channel structure (2) along a metal block (9) in which a temperature sensor (16) is housed. The device is calibrated with respect to the temperature dependence of the reaction of a chemiluminescence disc (8) attached to the bottom of the metal block by determining the output voltage of a photomultiplier (6) in dependence on the temperature at a predetermined ozone concentration in the measured air.

Abstract: The present invention relates to laser dyes having improved characteristics comprising substituted and unsubstituted ring-bridged p-oligophenylenes having at least four and no more than 8 phenyl groups. These improved laser dyes can be excited by pump lasers and are capable of producing stimulated coherent emission in the near ultraviolet range, particularly in the range below 400 nm, and have improved photostability. The p-oligophenylenes used according to the invention have the following characteristics:(a) the number of bridges is a number from 1 to 7 but only one bridge exists between two adjacent phenylene groups;(b) each bridge in the O,O'-cis position engages two adjacent phenylene groups;(c) the bridges represent the same and/or different species from a defined group; and(d) the phenylene rings may either be unsubstituted, except for the bridges, or one or several phenylene rings in the molecule, independent of whether they are bridged or not, may have one or two radicals R.sub.

Abstract: Solid radioactive waste is incorporated in glass, ceramic or basaltic blocks which are conditioned in waste waters or sludges prior to placement in ultimate storage. The conditioning has the dual benefit of reducing the radioactivity of the radioactive waste and of purifying the waste water or of purifying and facilitating the filterability of the sludge. Such purifying is enhanced by concurrent treatment with oxygen or an oxygen-containing gas and/or with a substance which is readily reduced to radicals.