Search results for "Planar network"

showing 2 items of 2 documents

Structural investigations on diorganotin and triorganotin(IV) phosphomycin derivatives.

2008

Abstract Four new diorganotin(IV), (R = Me, Bu), and triorganotin(IV), (R = Me, Ph), derivatives of the phosphomycin disodium salt antibiotic[(1R,2S)-1,2-epoxypropylphosphonate]Na2 have been synthesized and their solid state configuration studied by X-ray crystallography, FT-IR, Mossbauer, UV–Vis spectroscopies. The X-ray diffraction investigation, performed on the bis[trimethyltin(IV)]phosphomycin, showed that the coordination geometry at all the Sn atoms is trigonal bipyramidal. The structure of the complex forms an unusual polymeric zig-zag planar network. The FT-IR and the 119Sn Mossbauer studies supported the formation of trigonal bipyramidal (Tbp) molecular structures, both in the dio…

Lattice dynamicsPlanar networkChemistrySolid-statePOTENTIOMETRIC AND SPECTROPHOTOMETRIC TITRATIONSFT-IRInorganic ChemistryCrystallographyTrigonal bipyramidal molecular geometrySettore CHIM/03 - Chimica Generale E InorganicaORGANOTINMOSSBAUERMössbauer spectroscopyX-RAYMaterials ChemistryOrganotin FT-IR Mossbauer X-ray Potentiometric and spectrophotometric titrationsPhysical and Theoretical ChemistryCoordination geometry
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On the hardness of evaluating criticality of activities in a planar network with duration intervals

2003

Complexity results for problems of evaluating the criticality of activities in planar networks with duration time intervals are presented. We show that the problems of asserting whether an activity is possibly critical, and of computing bounds on the float of an activity in these networks are NP-complete and NP-hard, respectively.

Planar networkFloat (project management)PlanarCriticalityComputer scienceDuration timeApplied MathematicsReal-time computingManagement Science and Operations ResearchDuration (project management)Industrial and Manufacturing EngineeringSoftwareSimulationOperations Research Letters
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