Abstract: The present invention relates to a method and apparatus for replacing a filter placed in a vessel or casing.The filter is placed in a casing, one member of the latter surrounding the filter being slid in order to give access thereto from all sides. Once the new filter has been fitted, it is applied to a frame with the aid of bars having cams, which act on the filter by means of a fastening frame.Application to the filtration of gases containing radioactive dust.

Abstract: The phospholes and P-functional phospholes correspond to the general formula: ##STR1## in which: R.sub.1 and R.sub.2 are identical or different and represent hydrogen or a lower alkyl group of C.sub.1 to C.sub.4 such as a methyl group, and R.sub.3 represents an aryl group (such as --C.sub.6 H.sub.5) or a substituted aryl group (such as --CH.sub.2 C.sub.6 H.sub.5) or an alkyl group (such as --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7 to C.sub.12 H.sub.25) or a --(CH.sub.2).sub.n Z group where Z denotes a function of the --COO-alkyl type (such as --COOC.sub.2 H.sub.5), --CH, --CO-aryl (such as --COC.sub.6 H.sub.5), --CO-alkyl (such as --COCH.sub.3) or --OH and n.gtoreq.1.

Abstract: The invention relates to a process and an apparatus for the replacement of a filter placed between the contaminated area and the uncontaminated area of a vessel.The filter is surrounded by a tightly sealed bag as from the uncontaminated area and this bag is sealingly fixed to the outer periphery of a supporting frame. The filter is removed from the supporting frame and placed on the bottom of the tightly sealed bag, which is welded at two spaced points. The bag is then cut between the two welds so as to obtain a tight diaphragm separating the two areas of the vessel. A supplementary supporting frame is then sealingly fixed to the supporting frame and a new filter is fitted from the uncontaminated area of the vessel. The tight diaphragm is then removed from the contaminated area.

Abstract: A toner dispenser having a rotatable cylindrical dispenser roll and an automatic low toner level indicator comprising a lamp and photocell mounted in opposed walls of the dispenser adjacent the bottom of the dispenser housing. The lamp and photocell are separated from the toner in the dispenser by transparent windows. A wiping arrangement is provided inside the dispenser to periodically clean the windows including wiper pads biased into contact with the windows and movable periodically back and forth across the surface of the windows in response to rotation of the dispenser roll.