The Minimal Genus of Homology Classes in a Finite 2-Complex

We study surface representatives of homology classes of finite complexes which minimize certain complexity measures, including its genus and Euler characteristic. Our main result is that up to surgery at nullhomotopic curves minimizers are homotopic to cellwise coverings to the 2-skeleton. From this we conclude that the minimizing problem is in general algorithmically undecidable, but can be solved for 2-dimensional CAT(-1)-complexes

Der Nachhaltigkeit von Immobilien einen finanziellen Wert geben : Economic Sustainability Indicator ESI® Überarbeitung 2011/12

Das CCRS hat – gemeinsam mit Partnern aus Wissenschaft und Praxis – Grundlagen für ein Verständnis der Nachhaltigkeit von Immobilien aus finanzieller Sicht erarbeitet und mit den ESI®-Indikatoren für MFH, Büro- und Verkaufsflächen ein Instrument geschaffen, mit welchem die finanzielle Nachhaltigkeit von Immobilien gemessen werden kann

Synthesis of Boltorn 1,2,3-triazole dendrimers by click chemistry

Second-, third-, and fourth-generation hyperbranched aliphatic polyols namely Boltorn® H20, Boltorn H30, and Boltorn H40 were endcapped with azido and activated acetylenic groups in good to excellent yields (75-95%) following an acid catalyzed procedure. The resultant terminally functionalized dendritic azido and acetylenic groups undergo 1,3-dipolar cycloaddition using methyl (or ethyl) propiolate and benzyl azide, respectively, under catalytic or noncatalytic conditions below 40 °C to yield 1,2,3-triazole dendrimeric polymers in 82-95% yield, under extremely mild conditions that could be applied for compounds sensitive to acid, base, or heat. The dendritic azido and activated acetylenic derivatives may act as novel scaffolds to tune the mechanical properties of different polymers. © 2009 Wiley Periodicals, Inc