1
Viktor Weiss: Filtering apparatus and methods of exchanging particulate filter materials. Toren McGeady and Stanger, July 29, 1980: US04214878 (11 worldwide citation)

A filtering apparatus for filtering a fluid comprises two coaxial walls which are provided with openings for the radially-outward passage of the fluid to be filtered, granular filtering material being disposed between the walls. The fluid to be filtered is fed into the space bounded by the inner wal ...


2
Mario Fryberg, Viktor Weiss: Photographic material. Ciba-Geigy, Joseph G Kolodny, March 13, 1984: US04436811 (1 worldwide citation)

Compounds of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 independently of one another are hydrogen, alkyl or alkoxy and R.sub.2 additionally represents a radical of the formula ##STR2## in which R.sub.1 and R.sub.3 have the abovementioned meanings, R.sub.4 is unsubstituted or substitu ...


3
Mario Fryberg, Viktor Weiss: Photographic material. Ciba-Geigy, Joseph G Kolodny, September 11, 1984: US04471048 (1 worldwide citation)

Compounds of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 independently of one another are hydrogen, alkyl or alkoxy and R.sub.2 additionally represents a radical of the formula ##STR2## in which R.sub.1 and R.sub.3 have the abovementioned meanings, R.sub.4 is unsubstituted or substitu ...