Complexity of a one-to-one meeting scheduling problem with two types of actors

This article deals with a new scheduling problem that arises in the organization of one-to-one meetings in parallel. We first introduce applications of one-to-one meeting scheduling problems. Then, we give an overview of the relevant complexity results. We then prove several complexity results for different versions of the problem.     

Bridged 3,3″′-didodecylquaterthiophene-based dimers: design,synthesis, and optoelectronic properties

Five functionalized quaterthiophene dimers including a non-conjugated bridge have been designed and efficiently synthesized. The synthetic pathways explored toward these dimers revealed unexpected features, such as the direct formation of secondary and tertiary quaterthiophene amines through a procedure initially developed for the preparation of primary amine exclusively. All these dimers possess a promising potential for the elaboration of semiconducting materials with a charge transport of higher dimensionality compared to quaterthiophene.     

Complexation Behavior of Phosphate and Phosphazene Derivatives Containing Three or Six Benzo-15-crown-5 Cavities

Tris(benzocrown ether)s 2a , b X = P(NMeN=CH-B15C5) 3 (X=O, S) and tri[bis(benzocrown ether)] [N=P(NMeN=CH-B15C5) 2 ] 3 3 strongly chelate with alkali metal salts and their efficiency and selectivity in binding these salts are compared with those of the monomeric crown 1 . Data obtained from salt distribution equilibrium in water-chloroform show these ligands to be excellent extracting agents, especially for K + and Rb + . Furthermore, compound 3 is able to transport K + selectively.     

Determination of the rheological properties of aqueous solutions of branched PEO‐PPO‐PEO copolymers. Confrontation with small‐angle neutron scattering studies.

The physico‐chemical properties of Tetronic^® 908 in aqueous solution have been explored on a wide range of temperature and concentration. This system presents interesting rheological properties depending on the polymer concentration in solution, and temperature. For weight percentage p comprised between 5% and 20%, the viscosity of the solution passes through a maximum. Small angle neutron scattering experiments show that the increase in the viscosity is due to the progressive aggregation of the chains. For higher weight percentages, the viscosity of the system diverges and the mixture becomes “gel‐like”. SANS studies of the same solution indicate that the micelles are organized in a cubic structure. We have developed a model which suitably describes the SANS curves of the system in the region where micelles are formed. It allows the calculation of several parameters (volume fraction of the micelles, size, composition). The evolution of these parameters with temperature and polymer concentration is detailed. Comparisons with models of literature are discussed.     

Electron-induced mass spectrometry of 1,2-dihydropyridine derivatives

The electron-induced mass spectrometry of 1-substituted-4-phenyl-1,2-dihydropyridines is characterized by a [M-1] peak that accounts for the base peak, and a fragment corresponding to the loss of the N-substituent in every example examined.