Abstract: A user of a network-based system may correspond to a user profile that describes the user. The user profile may describe the user using one or more descriptors of items that correspond to the user (e.g., items owned by the user, items liked by the user, or items rated by the user). In some situations, such a user profile may be characterized as a “taste profile” that describes an array or distribution of one or more tastes, preferences, or habits of the user. Accordingly, the user profile machine within the network-based system may generate the user profile by accessing descriptors of items that correspond to the user, clustering one or more of the descriptors, and generating the user profile based on one or more clusters of the descriptors.

Abstract: Continuous preparation of polyisobutylene having a content of terminal double bonds of more than 50% by polymerizing isobutene in the presence of a polymerization catalyst customary therefor, by combining a technical 1-butene-, 2-butene- and isobutene-containing C4 hydrocarbon stream together with a stream of pure isobutene and feeding them into the reaction zone in such a way that the steady-state concentration of the isobutene in the combined stream at the feed point of the combined stream into the reaction zone has an average value of at least 40% by weight, and a polymerization plant therefor.

Abstract: Preparation of isobutene homopolymers having a weight-average molecular weight of 75 000 to 10 000 000 by polymerization of isobutene, by (a) performing the polymerization at ?80° C. to ?190° C., (b) using, as an inert solvent, optionally halogenated C1 to C5 hydrocarbons, (c) using, as a polymerization catalyst, a Lewis acid complex, (d) performing the polymerization in the presence of at least one reaction accelerator in the form of an ethylenically saturated hydrocarbon compound comprising one oxygen atom and no abstractable proton, and (e) performing the polymerization in the presence of at least one chain length regulator comprising one tertiary olefinic carbon atom.

Abstract: Sorbent comprising a solid support material, the surface of which comprises first residues comprising a binuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S, and second residues comprising a mononuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S.

Abstract: A polyisobutylene having a total content of vinylidene double bonds of more than 50 mol % and a number-average molecular weight of 500 to 10 000 daltons, where at least 10% of all the vinylidene double bonds in the polyisobutylene are part of one or more side chains composed of at least 2 carbon atoms from the main polyisobutylene chain. Such a polyisobutylene is suitable for production of fuel and lubricant additives.

Abstract: Sorbent comprising a solid support material, the surface of which comprises first residues comprising a binuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S, and second residues comprising a mononuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S.

Abstract: A polyisobutylene having a total content of vinylidene double bonds of more than 50 mol % and a number-average molecular weight of 500 to 10 000 daltons, where at least 10% of all the vinylidene double bonds in the polyisobutylene are part of one or more side chains composed of at least 2 carbon atoms from the main polyisobutylene chain. Such a polyisobutylene is suitable for production of fuel and lubricant additives.

Abstract: Sorbent comprising a solid support material, the surface of which comprises a first residue comprising a pyridyl ring, whose hydrogen atoms may be substituted, and a second residue comprising a carboxyl group. The first and second residues may be attached to a polymer which coats a carrier, but which polymer is not covalently grafted to the carrier. The sorbents can be used to separate or to increase the concentration and/or purity of a protein or peptide from a mixture containing the same.

Abstract: A catalyst complex composed of boron trifluoride and a cocatalyst mixture of 10 to 90% by weight of a monohydric primary C1- to C20-alcohol and 90 to 10% by weight of a monohydric secondary C3- to C20-alcohol, where the molar ratio of boron trifluoride to the sum of all alcohols is 2:1 to 1:10. This catalyst complex is used in the preparation of high-reactivity isobutene homopolymers having a number-average molecular weight of 300 to 50 000, using, as the feedstock, a C4 hydrocarbon mixture comprising at least 20% by weight of isobutene and a total of at least 10% by weight of other C4 olefins.

Abstract: Sorbent comprising a solid support material, the surface of which comprises first residues comprising a binuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S, and second residues comprising a mononuclear heteroaromatic structure comprising besides carbon atoms at least one of the heteroatoms N, O, S.

Abstract: Sorbent comprising a solid support material, the surface of which comprises a first residue comprising a pyridyl ring, whose hydrogen atoms may be substituted, and a second residue comprising a carboxyl group.

Abstract: Preparation of isobutene homopolymers having a weight-average molecular weight of 75 000 to 10 000 000 by polymerization of isobutene, by (a) performing the polymerization at ?80° C. to ?190° C., (b) using, as an inert solvent, optionally halogenated C1 to C5 hydrocarbons, (c) using, as a polymerization catalyst, a Lewis acid complex, (d) performing the polymerization in the presence of at least one reaction accelerator in the form of an ethylenically saturated hydrocarbon compound comprising one oxygen atom and no abstractable proton, and (e) performing the polymerization in the presence of at least one chain length regulator comprising one tertiary olefinic carbon atom.

Abstract: A catalyst complex composed of boron trifluoride and a cocatalyst mixture of 10 to 90% by weight of a monohydric primary C1- to C20-alcohol and 90 to 10% by weight of a monohydric secondary C3- to C20-alcohol, where the molar ratio of boron trifluoride to the sum of all alcohols is 2:1 to 1:10. This catalyst complex is used in the preparation of high-reactivity isobutene homopolymers having a number-average molecular weight of 300 to 50 000, using, as the feedstock, a C4 hydrocarbon mixture comprising at least 20% by weight of isobutene and a total of at least 10% by weight of other C4 olefins.

Abstract: Continuous preparation of polyisobutylene having a content of terminal double bonds of more than 50% by polymerizing isobutene in the presence of a polymerization catalyst customary therefor, by combining a technical 1-butene-, 2-butene- and isobutene-containing C4 hydrocarbon stream together with a stream of pure isobutene and feeding them into the reaction zone in such a way that the steady-state concentration of the isobutene in the combined stream at the feed point of the combined stream into the reaction zone has an average value of at least 40% by weight, and a polymerization plant therefor.