A thin layer medium for use in molecular diffusion or affinity separation processes having a layer of hydrated gel material, the surface of which is scored or cross-scored at intervals of 0.05 to 1 millimeter. The medium may be maintained wet until used or it may be dried for storage and rehydrated before use.

A culturing article according to which one part of a wick is placed in engagement with a body fluid in order to check for the presence of suspected microorganisms. An opposed part of the wick is maintained out of engagement with the body fluid, so that by capillary action the body fluid will progress along the wick from the one part toward the opposed part thereof. The progress of the body fluid from the one part toward the opposed part of the wick is limited to achieve a density gradient accord...

Sensible coatings comprised of a colored sensible material in a binder of aminotriazine resin and a polymeric material are disclosed. The coatings can be placed on a transfer base such as polyethylene terephthalate and transferred to enpaneled plastic card bases. These machine sensible cards are resistant to scratching and other surface damage. The sensible coating is easily transferred in one step and permanently heat sealed in a second step.

A flexible grinding tool made up a synthetic resin impregnated fiberglass mat with a layer of abrasive grains attached to both surfaces of the mat by a synthetic resin binder containing short fibers of glass, asbestos, ceramic material or graphite therein.

Stable suspensions of solid particles are formed by dispersing the particles in a pseudoplastic aqueous medium containing in solution xanthan gum and at least one non-ionic water-soluble polymer, exemplified by guar gum, in proportions providing an unexpectedy high ratio of yield point to plastic viscosity. The medium is especially useful in the planting of seeds which may be pre-germinated.

A method and apparatus of producing a filter medium of a relatively strong substrate and a fibrous felt layer bonded to the substrate by needle punching the felt through the substrate and fusing the fibers protruding through the perforations to the substrate and each other.

A heat curable coating medium for use in the formation of a cured, highly cross-linked, polymeric coating on a substrate. The coating medium comprises an aromatic diamide diacid diamine formed as the reaction product of an aromatic diamine and an aromatic dianhydride, in the molar ratio of two-to-one respectively, in a solvent.

Disclosed is a filter medium for removing contaminants, including gels, from molten polymers. The medium contains layers of sintered metal fibers having diameters of 50 microns or less. At least two adjacent layers are separated by a screen, and the screen and layers are bonded together by compression and sintering. Preferably the layers include from 35 to 60 volume percent fibers. The filter medium is graded so that the polymer as it flows through the medium encounters fiber layers having pores...

A recording medium consists of a composite amorphous magnetic material layer comprising a rare earth metal and an iron family metal, the composition ratio thereof being nonuniform in the perpendicular direction. Because of the nonuniform composition ratio, a minute magnetic domain can be formed stably, so that thermo magnetic recording at extremely high density and sensitivity can be effected. Where GdFe is employed as a suitable material, the thickness of a portion of the magnetic layer, which ...

A nutrient medium is presented for the cultivation of microorganisms. The nutrient medium is used in the determination of activity of a therapeutically-active substance against an infective microorganism.