Operadic deformations as a tool for cogravity

The deformation equation and its integrability condition (Bianchi identity) of a non-(co)associative deformation in operad algebra are found. Based on physical analogies, two ideas ofcogravity equations are proposed. Presented at the 11th Colloquium “Quantum Groups and Integrable Systems”, Prague, 20–22 June 2002.     

Karl Fischer-Reagentien ohne Pyridin (7)

Zusammenfassung Unter Verwendung von Imidazol als Base wurden 6 verschiedene Solvent-Formulierungen hergestellt und erprobt. Wir fanden bei allen Formulierungen eine stöchiometrische Reaktion mit Wasser. Sie sind deshalb als KF-Reagentien geeignet. Die Reagentien ermöglichen eine sehr schnelle Titration und geben stabile Endpunkte. Sie scheinen unbeschränkt lagerfähig zu sein.

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Karl fischer reagents without pyridine (7)Two-component reagents containing imidazole

Summary Six different KF-reagents were prepared using imidazole as base component. All reagents give a stoichiometric reaction with water and can be used for the KF-titration. The reagents show a high speed of reaction and lead to stable endpoints. The shelflife seems to be unlimited.

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Teil 6: Fresenius Z Anal Chem (1982) 310:423–426     

A tabu search procedure for multicommodity location/allocation with balancing requirements

We propose a tabu search heuristic for the location/allocation problem with balancing requirements. This problem typically arises in the context of the medium term management of a fleet of containers of multiple types, where container depots have to be selected, the assignment of customers to depots has to be established for each type of container, and the interdepot container traffic has to be planned to account for differences in supplies and demands in various zones of the geographical territory served by a container shipping company. It is modeled as a mixed integer program, which combines zero-one location variables and a multicommodity network flow structure. Extensive computational results on a set of benchmark problems and comparisons with an efficient dual ascent procedure are reported. These show that tabu search is a competitive approach for this class of problems.     

The Chemistry of Stable Carbenes. Part 2. Benzoin-type condensations of formaldehyde catalyzed by stable carbenes

Stable carbenes derived from thiazole, 1H-imidazole, and 4H-1,2,4-triazole are efficient catalysts for benzointype condensations of formaldehyde. Catalysts derived from N-substituted thiazolium salts trimerize formaldehyde to dihydroxyacetone ( II ). Catalysts based on 1,4-disubstituted 4H-1,2,4-triazol-1-ium salts give glycolaldehyde ( I ) as the main product and no II , whereas N,N′-disubstituted 1H-imidazol-3-ium salts yield mixtures of both products. The isolation of several intermediates in the catalytic cycle provide a better insight into the reaction mechanism.