Abstract: A level indicator providing a digital display of gravity-related attitude comprises a capacitive gravimeter pickup assembly the complementary capacitor pair of which are alternately switched, on an equal-time basis, into an R.C. oscillator circuit. Concurrently, each oscillator pulse train is switched, respectively, into the up- and down-mode of reversible counting means to yield a net oscillator frequency difference directly, digitally indicative of the degree of departure from a gravity-referenced level condition.

Abstract: Polymerization of an ethylenically unsaturated compound is achieved by means of free radical initiators derived from the reaction of an aldehyde/bisulfite adduct with cupric ions resulting from electrolysis involving a copper anode. By including a photoconductive cathode in the system image-wise light exposure effects the formation of polymeric images in the polymerizable composition.

Abstract: A photopolymerizable composition useful in photo-imaging processes comprises an ethylenically unsaturated polymerizable compound and a photo-initiator comprising a combination of a photoreducible dye and an alkanolamine. The composition is substantially insensitive to visible light when in an acidic pH condition, yet may be made highly sensitive to visible light upon adjustment to a condition of alkaline pH. Imaging materials may be repeatedly sensitized and desensitized by pH adjustment and multiple-spaced exposures made prior to final washoff development processing.

Abstract: Polymerization of an ethylenically unsaturated compound is achieved by means of free radical initiators derived from the reaction of an aldehyde/bisulfite adduct with cupric ions resulting from electrolysis involving a copper anode. By including a photoconductive cathode in the system image-wise light exposure effects the formation of polymeric images in the polymerizable composition.

Abstract: Material useful in electropolymerization processes comprises a conductive support and a layer thereon of a composition comprising a polymerizable monomer and polymerization catalyst precursor which is a combination of an alkali metal nitrite and a primary aromatic amine. Electrolysis of the composition results in diazotization of the amine with subsequent electrolytic generation of polymerization-inducing free radicals. The anodic reaction ensures polymerization at and bonding of the resulting polymer to the support sheet of the material even when used in conjunction with zinc oxide photoconductor cathode layers. The material is particularly useful in negative-working imagery and in the preparation of patterned resist layers.

Abstract: A precise indexing detent comprises a pair of grooved members the plane groove faces of which define a polyhedron within which there may be positioned a sphere in surface contact with all such faces. A detent member comprising a spherical section is situated in close association with the grooved members to govern the positional indexing of movable apparatus parts as in a level-transit surveying instrument or drafting machine protractor head.

Abstract: Material useful in electropolymerization processes comprises a conductive support and a layer thereon of a composition comprising a polymerizable monomer and polymerization catalyst precursor which is a combination of an alkali metal nitrite and a primary aromatic amine. Electrolysis of the composition results in diazotization of the amine with subsequent electrolytic generation of polymerization-inducing free radicals. The anodic reaction ensures polymerization at and bonding of the resulting polymer to the support sheet of the material even when used in conjunction with zinc oxide photoconductor cathode layers. The material is particularly useful in negative-working imagery and in the preparation of patterned resist layers.

Abstract: Diazotype material includes a light-sensitive diazonium compound of the general formula ##SPC1##Wherein:R.sub.1 and R.sub.2 are substituted or unsubstituted alkyl, aralkyl, or cycloalkyl groups, or form, with the nitrogen atom, a heterocyclic radical, which may be substituted;R.sub.3 is hydrogen or the group OR.sub.6 ;R.sub.4 and R.sub.5 are hydrogen, halogen, alkyl, or OR.sub.6 groups;R.sub.6 is alkyl; or fluorinated alkyl, alkenyl, cycloalkyl, or cycloalkenyl; andX is the anion of the diazonium compound;At least one of the radicals R.sub.4 and R.sub.5 is hydrogen; and at least one of the radicals R.sub.3, R.sub.4, and R.sub.5 is one of said fluorinated radicals, at least one of said fluorinated radicals being further substituted by other halogen atoms, hydroxy groups, acyloxy groups, alkoxy groups, alkylated or acylated amino groups, or aryl radicals.