A packing for biologically treataing waste water in a percolating filter comprising randomly packed extruded hollow cylindrical pieces of an organic polymeric material, the wall of each cylindrical piece being provided, throughout its length, as a plurality of corrugations which lie in planes which are transverse to or oblique to the main axis of the cylindrical piece.

Culture media for the cultivation of mycoplasms comprising an aqueous dispersion of amino acids, carbohydrates, yeast extract, inorganic salts, and lecithin.

An atomizer for spraying a liquid medium, having a nozzle body which has connections for the liquid to be sprayed and for compressed air. The nozzle body is mounted for universal movement by means of two rings connected by rotary pins to one another and to the nozzle body. The nozzle is driven in a predetermined path by a guide shaft in cooperation with an eccentrically-mounted follower ring.

A medium for effecting heat bonding between two surfaces of material comprising a carrier sheet one side of which carries layers of a heat bonding substance and of a pressure sensitive adhesive, such layers being arranged that they both present exposed surfaces.

A magnetic recording medium for use in recording short-wavelength which is excellent in easiness of marking by a black or dark color marking material, in easiness and validity of discrimination of the mark, and in antistatic effect can be prepared by providing a magnetizable layer on one side of a non-magnetizable plastic film and providing a layer having a surface electric resistance of below 1 .times. 10.sup.9 ohm on the opposite side and further, a white or light color layer thereon.

A selective medium was developed for the isolation of Streptococcus mutans from human dental plaque. Mitis-salivarius agar was modified by adding 0.2 units/ml bacitracin and by increasing the sucrose concentration to 20 percent. The selective agents allowed the undiminished recovery of Strep.mutans with maximum inhibition of the balance of the streptococcal flora normally encountered on this medium.

This invention relates to a culture medium for the rapid differentiation and identification of bacteria belonging to the family Enterobacteriaceae.

A magnetic recording medium comprising a plastic base and an adherent coating comprising acicular gamma ferric oxide having an appreciable content of ferrous iron dispersed in a resinous binder consisting essentially of a polyurethane resin, a copolymer of vinylidene chloride and acrylonitrile, a diimide, a divalent lead salt, a free radical chain reaction inhibitor and a dispersant is described.

A sampling device for separating particles entrained in a gaseous medium including a plurality of plates spaced from each other a prescribed distance with each of the plates defining a plurality of jet impaction apertures therethrough with the apertures of each plate staggered with respect to the apertures of the plates adjacent thereto so that the entrained particles will be separated by jet impaction by each plate on the next downstream plate, a collection substrate carried by the upstream sid...

A fluid pressure control device for controlling a servo motor is disclosed, the control device being provided with at least one pressure control valve for controlling pressure in a working chamber of the servo motor and transmitting a thrust corresponding to the pressure in the working chamber back to a power input member; operation of the pressure control valve being derived from the power input member through a lost motion coupling means.