Abstract: A method for determining the permeability of a petroliferous reservoir comprising injecting a tagged organic molecule into the reservoir at a first location, and detecting a signal associated with tagged organic molecule at a second location in the reservoir, wherein the tagged organic molecule comprises a radionuclide having a half-life of less than a month. In certain embodiments, the tagged organic molecule comprises a radionuclide selected from the group consisting of iodine-131 and fluorine-18.

Abstract: This invention provides certain polycarbonates and polycarbonate blends useful in optical article applications. In a preferred embodiment, copolymers of, for example, certain ortho substituted bisphenol A-based polycarbonates and bisphenol A, optionally further comprising polycarbonate residues derived from ortho subsitituted spirobiindane compounds and alkylene or cycloalkylene diacid moieties. In a further embodiment, the invention provides copolymers of certain ortho-substituted bisphenol A moieties and ortho-substituted spirobiindane moieties. Also provided are optical articles comprised of the copolymers and blends of the invention. We have found that such copolymers and blends exhibit superior dimensional stability when exposed to water or moisture.

Abstract: Aliphatic tricarboxylic acids, as exemplified by 9-carboxy-1,18-octadecanedioic acid, may be prepared by the biotransformation of an olefinic monocarboxylic acid such as oleic acid to the corresponding olefinic dicarboxylic acid, preferably 1,18-octadec-9-enedioic acid, in the presence of a strain of yeast, such as a strain of Candida tropicalis, followed by the carboxylation of the olefinic dicarboxylic acid by reaction with carbon monoxide and water in the presence of a catalyst. The product tricarboxylic acids are useful as branching agents for polycarbonates.

Abstract: The invention relates to polycarbonates comprising: (a) carbonate structural units corresponding to structure (I) where R1, R2, R3, and R4 are independently selected from the group consisting of C1-C6 alkyl, R5 is C1-C3 alkyl and n is 0, 1 or 2, and (b) carbonate structural units corresponding to structure (II):  where R6, R7, R10 and R11 are independently C1-C6 alkyl, R8 and R9 are independently H or C1-C5 alkyl, R12 is H or C1-C3 alkyl and n is 0, 1 or 2; where the polycarbonate has a glass transition temperature of from about 120° C. to about 185° C. and a water absorption of less than about 0.33%. This invention further relates to method of making these polycarbonates, optical articles made from these polycarbonates, and methods of making optical articles from these polycarbonates.

Abstract: The invention relates to polycarbonates suitable for use in optical articles, and methods for making such polycarbonates. The polycarbonates may comprise residues of m,p-BPA and SBI.

Abstract: The crystallinity of an amorphous precursor polycarbonate is enhanced by contact in the liquid or vapor state with a non-solvent which may be water, an alkanol or a mixture thereof and which is dialkyl carbonate-free. Contact temperatures are at least about 75.degree. C. and are further defined by the relationshipT.sub.c .gtoreq.T.sub.b -z,wherein T.sub.c is the contact temperature, T.sub.b is the boiling point of the non-solvent at the contact pressure employed (both in degrees C.) and z is a constant whose value is 60.

Abstract: The invention relates to polycarbonates suitable for use in optical articles; the polycarbonates contain residues of alicyclic bisphenols and have properties particularly suited for use in high density optical data storage media. The polycarbonates further contain residues of other monomers, such as SBI and its derivatives; bisphenols, such as bisphenol A; CD-1 and its derivatives or some combination of each.

Abstract: A method of systemically controlling endoparasites and ectoparasites of warm-blooded animals by orally or percutaneously administering to the animal a parasiticidally effective amount of an acyl urea compound.

Abstract: A method of systemically controlling endoparasites and ectoparasites of warm-blooded animals by orally or percutaneously administering to the animal a parasiticidally effective amount of an acyl urea compound.

Abstract: Polyimides, especially thermoset polyimides such as those prepared by the reaction of p-phenylenediamine with 4,4'-hexafluoroisopropylidenebis(phthalic anhydride) and nadic ester, are converted to monomers which may be recycled for polyimide synthesis by heating with a solution of an alkali metal hydroxide, such as lithium hydroxide or sodium hydroxide, in a dipolar aprotic solvent such as N-methylpyrrolidone. The products are the diamine and the tetracarboxylic acid alkali metal salt corresponding to the dianhydride.