Clues to Quasar Broad Line Region Geometry and Kinematics

We present evidence that the high-velocity CIV lambda 1549 emission line gas of radio-loud quasars may originate in a disk-like configuration, in close proximity to the accretion disk often assumed to emit the low-ionization lines. For a sample of 36 radio-loud z~2 quasars we find the 20--30% peak width to show significant inverse correlations with the fractional radio core-flux density, R, the radio axis inclination indicator. Highly inclined systems have broader line wings, consistent with a high-velocity field perpendicular to the radio axis. By contrast, the narrow line-core shows no such relation with R, so the lowest velocity CIV-emitting gas has an inclination independent velocity field. We propose that this low-velocity gas is located at higher disk-altitudes than the high-velocity gas. A planar origin of the high-velocity CIV-emission is consistent with the current results and with an accretion disk-wind emitting the broad lines. A spherical distribution of randomly orbiting broad-line clouds and a polar high-ionization outflow are ruled out.Comment: 5 Latex pages, 1 figure, accepted for publication in ApJ Letter

Radio imaging of core-dominated high redshift quasars

VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum quasars, consistent with these objects being observed at sight lines close to their (relativistic, $\gamma \approx$ 4-7) jet axes. The usefulness of the radio source orientation indicator R_V, being defined as ratio of radio core and rest frame optical V-band luminosity, is confirmed.Comment: 11 pages, 11 postscript figures, uses aa.cls 4.03 for LaTeX2e To appear in Astronomy and Astrophysic

Functional polyether-based materials: from synthesis to controlled cellular uptake and self-healing coatings

Die vorliegende Dissertation beschreibt die Synthese Poly(ethylen oxid) (PEO) – basierter Materialien durch lebende anionische Ringöffnungspolymerisation (AROP). Die synthetisierten Polymere konnten gezielt Funktionalisiert und in einem breiten Anwendungsfeld zum Einsatz gebracht werden. Poly(ethylenoxid)-block-Poly(allylglycidylether)-block-Poly(t-butylglycidylether) (PEO-b-PAGE-b-PtBGE) Triblock-Terpolymere wurden für die Untersuchung der Selbstassemblierung in wässriger Lösung genutzt. Weiterhin wurden die PAGE Segmente funktionalisiert um Ladungen in das Triblock-Terpolymer einzuführen. Die erhaltenen Materialien wurden anschließend als Plattform für die Herstellung von funktionalen sub-30 nm Mizellen genutzt und die Zellaufnahme studiert. Als weiteres Monomer wurde Furfurylglycidylether (FGE) durch die AROP kontrolliert polymerisiert und die Furaneinheiten durch Diels-Alder Reaktionen ([4+2] Cycloaddition) funktionalisiert. Selbstassemblierung von Poly(ethylenoxid)-block-Poly(furfurylglycidylether) (PEO-b-PFGE) führte in wässriger Lösung zu sphärischen Mizellen, deren PFGE-Kern durch eine Diels-Alder Reaktion reversibel verlinkt werden konnte. Weiterhin wurden PFGE und PEO-b-PFGE Polymere für die Herstellung selbstheilender Beschichtungen verwendet. Dabei konnte das reversible vernetzen/entnetzen demonstriert werden, welches in eine Änderung der Materialhärte resultierte. Es wurde demonstriert, dass PEO-b-PFGE Beschichtungen in der Lage sind, Kratzer mit einer Tiefe von bis zu 6 µm und einer Breite von 1.7 mm zu heilen. Weiterhin konnte FGE als effizientes Terminierungsreagenz für die lebende anionische Polymerisation genutzt und Poly(2-vinylpyridin)-block-Poly(ethylenoxid) (P2VP-b-PEO) Blockcopolymere mit einer einzelnen FGE-Einheit an der Blockgrenze hergestellt werden. Die Furangruppe wurde danach zur Anbindung eines fluoreszierenden Farbstoffs sowie für die kovalente Beschichtung von Gold-Nanopartikeln durch Diels-Alder Reaktionen genutzt

Phase diagram of an extended quantum dimer model on the hexagonal lattice

We introduce a quantum dimer model on the hexagonal lattice that, in addition to the standard three-dimer kinetic and potential terms, includes a competing potential part counting dimer-free hexagons. The zero-temperature phase diagram is studied by means of quantum Monte Carlo simulations, supplemented by variational arguments. It reveals some new crystalline phases and a cascade of transitions with rapidly changing flux (tilt in the height language). We analyze perturbatively the vicinity of the Rokhsar-Kivelson point, showing that this model has the microscopic ingredients needed for the "devil's staircase" scenario [E. Fradkin et al., Phys. Rev. B 69, 224415 (2004)], and is therefore expected to produce fractal variations of the ground-state flux.Comment: Published version. 5 pages + 8 (Supplemental Material), 31 references, 10 color figure

Conceptualization and implementation of a regional groundwater model for the Neckar catchment in the framework of an integrated regional model

International audienceJoint modelling of surface and subsurface systems is necessary to assess the quantity and quality of the water resources in a watershed. Therefore, it is widely applied in integrated regional models. The presented study deals with groundwater modelling within the framework of the integrated regional model MOSDEW, which is being developed for the Neckar catchment in Germany with the objective of contributing to the implementation of the EU Water Framework Directive (EU-WFD) (www.rivertwin.org). The groundwater model aims at obtaining a better understanding of the groundwater recharge processes and at evaluating the groundwater resources on watershed scale. In this paper the developed coupling method is described. Furthermore the groundwater model construction based on the available database and first calibration results are presented