A Simple Algorithm for the Nucleolus of Airport Profit Games

In this paper we present a procedure for calculating the nucleolus for airport profit games which are a generalization of the airport cost games.     

Mössbauer and XRD Characterization of the Mineral Matter of Coal from the Guachinte Mine in Colombia

The aim of this work was the characterization and differentiation, using Mössbauer spectroscopy (MS) and X-ray diffraction (XRD), of coal samples with different ash and sulfur contents obtained in three places corresponding at cuts in different seams from the Guachinte mine, Valle, Colombia. The mineral phases identified by XRD were in general kaolinite, quartz, pyrite and gypsum, and in particular dolomite and calcite. MS confirms the presence of pyrite and kaolinite, besides evidences the additional presence of jarosite which was not detected by the XRD results due their low amounts. In the high mineral matter ash sample quartz and hematite was identified by XRD, the last one confirmed by MS results. A second phase in this sample was detected by Mössbauer spectroscopy, which could be superparamagnetic hematite. Rietveld refinement for XRD pattern from a sample is reported.

     

Nouveau fondement fonctionnel de la Mécanique

Sans résumé Mémoire transmis par C. Truesdell     

Étude de la phényl-2 oxine et de ses chélates: Préparation et propriétés des phényl-2 oxinates

The authors have studied the potentiometric curves obtained during the neutralization, in dilute alcoholic media, of acid solutions containing 2-phenyl-8-quinolinol and metallic cations, with sodium hydroxide. By thermogravimetric analysis the number of water molecules and regions of stability for hydrates and anhydrous compounds were also established.Moreover these results were compared with those previously obtained for oxinates and methyl-2 oxinates.     

Synthesis of seven-membered ring glycals via endo-selective alkynol cycloisomerization

[reaction: see text] Alkynyldiols 1 undergo cycloisomerization to the corresponding seven-membered cyclic enol ethers 2 under tungsten carbonyl catalysis. This novel transformation proceeds with good yields and virtually complete regioselectivity for all diastereomers of 1, favoring the product 2 resulting from endo-mode cyclization. The unexpected regioselectivity may be dependent on the presence of the dioxolane structure tethering the terminal alkyne and diol functional groups.     

Temperature effects in proton exchanged LiNbO<Subscript>3</Subscript> waveguides

Temperature effects on single, homogeneous phases of proton exchanged LiNbO₃ waveguides have been studied. The refractive index of -phase guides on z-cut and x-cut congruent substrates monotonically increases with temperature, the thermo-optical coefficient being similar to that of the substrate. In ₂-phases on z-cut congruent substrates and in ₁-phases on z-cut and x-cut congruent and quasi-stoichiometric substrates, the thermo-optical coefficient is smaller than that of the substrate below 60 °C and higher above this temperature. A rather similar effect has been observed in ₁-phases on z-cut and x-cut congruent substrates in the linear expansion coefficient. The microscopic origin of the phase transition is not known for the moment. PACS Provide PACS codes please.     

Rearrangement of 2-quinolyl- and 1-isoquinolylcarbenes to naphthylnitrenes

2-quinolylcarbene 23 and 1-isoquinolylcarbene 33 are generated by flash vacuum thermolysis (FVT) of the corresponding triazolo[1,5-a]quinoline and triazolo[5,1-a]isoquinoline 19 and 29, as well as 2-(5-tetrazolyl)quinoline and 1-(5-tetrazolyl)isoquinoline 20 and 30, respectively. These carbenes rearrange to 1- and 2-naphthylnitrene 21 and 31, respectively, and the nitrenes are also generated by FVT of 1- and 2-naphthyl azides 18 and 28. The products of FVT of both the nitrene and carbene precursors are the 2- and 3-cyanoindenes 26 and 27 together with the nitrene dimers, viz. azonaphthalenes 25 and 35, and the H-abstraction products, aminonaphthalenes 24 and 34. All the azide, triazole, and tetrazole precursors yield 3-cyanoindene 26 as the principal ring contraction product under conditions of low FVT temperature (340-400 degrees C) and high pressure (1 Torr N(2) as carrier gas for the purpose of collisional deactivation). This ring contraction reaction is strongly subject to chemical activation, which caused extensive isomerization of 3-cyanoindene to 2-cyanoindene under conditions of low pressure (10(-3) Torr). 2-Cyanoindene is calculated to be ca. 1.7 kcal/mol below 3-cyanoindene in energy; accordingly, high-temperature FVT of these cyanoindenes always gives mixtures of the two compounds with the 2-cyano isomer dominating. Photolysis of trizolo[1,5-a]quinoline 19 and triazolo[5,1-a]isoquinoline 29 in Ar matrixes causes partial ring opening to the corresponding 2-diazomethylquinoline 19' and 1-diazomethylisoquinoline 29'. The photolysis of the former gives rise to a small amount of the cyclic ketenimine 22, the intermediate connecting 2-quinolylcarbene and 1-naphthylnitrene.