250 research outputs found
Interfacial Dynamics of Perylene Derivatives Attached to Metal Oxide Particle and Nanorod Films
No full textPhoto induced electron transfer and recombination was investigated for molecular absorbers covalently bound to metal oxide films [1]. Two perylene derivatives with different anchor bridge groups, propionic acid and acrylic acid, exhibiting a model character for the strong and weak electronic coupling case were studied on different nano structured architectures. In this contribution, we will present time resolved data obtained from fs transient absorption on sensitized TiO2 and ZnO colloidal and nanorod films. The dynamics of the initial electron injection and early back transfer is compared for the different electrode substrates and chromophores. In a systematic approach the decay of the excited state was measured simultaneously with the rise of the cationic state of the perylene derivatives employing fs pump pulses and a time zero corrected fs white light probe continuum spectrally covering both states. The addressed absorption bands are energetically well separated and represent a complementary temporal measure for the interfacial electron transfer reaction. The experiments show less an influence of the nature of the different nanometer sized architectural structures than of the semiconductor electronic properties as for example the respective specific density of states available for the electron transfer. We have also investigated the effect of co adsorbates on the ultrafast electron injection and early recombination dynamics by changing the chemical environment from UHV to inert gases and solvents of different polarity [2]. The presence of the various non reactive species significantly slows down the electron transfer reaction which can be explained by adsorbate induced surface dipoles that shift the electronic energy levels and modify the density of electronic semiconductor states that couple to the molecular electronic states involved in the electron transfer. [1] The Ultrafast Temporal and Spectral Characterization of Electron Injection from Perylene Derivatives into ZnO and TiO2 Colloidal Films J. M. Szarko, A. Neubauer, A. Bartelt, L. Socaciu Siebert, F. Birkner, K. Schwarzburg, T. Hannappel, R. Eichberger; J. Phys. Chem. C 112, 10542 2008 [2] Influence of TiO2 Perylene Interface Modifications on Electron Injection and Recombination Dynamics A Bartelt, R. Schütz, A. Neubauer, T. Hannappel, R. Eichberger; J. Phys. Chem.C , accepte
Effect of body size on mercury concentrations in shoreline spiders
No full textRecently, shoreline spiders have been proposed as biosentinels of mercury (Hg) contamination in the environment. Shoreline spiders become contaminated with Hg by feeding on Hg-contaminated emergent aquatic insects. Although body size is known to affect Hg bioaccumulation in other organisms (e.g. fish), few studies have tested the effect of body size on Hg concentrations in shoreline spiders. In this study, we determined the effect of body size on Hg concentrations in 6 taxa of shoreline spiders (Araneidae, Tetragnatha spp., Salticidae, Pardosa spp., Rabidosa spp. and Schizocosa spp.) from 14 human-made ponds at the LBJNG, Texas. Average concentrations of total-Hg (THg) were significantly different between spider taxa. We found that concentrations of THg in spiders increased significantly with body size (measured by tibia + patella length of the first leg) for Araneidae, Tetragnatha spp., Salticidae and Pardosa spp. This study indicates that Hg accumulation in shoreline spiders differs between spider taxa and within taxa by spider size
J. S. Bach - Johannespassion : Palmsonntag, den 21. März, abends 8 Uhr im Kaisersaal der Städt. Tonhalle
No full textW[alter ] Sturm, Wiesbaden, Evangelist ; Th[eo] Hannappel, Wiesbaden, Christus ; S[ophie] Hoepfel, Frankfurt a. M., Sopran ; L[illy] Neitzer, Berlin, Alt ; S[iegfried] Tappolet, Köln, Baß. Chor und Orchester des Bachvereins, Leitung: Dr. Josep Neyses. Bachverein in Verbindung mit der N. S. KulturgemeindeErscheinungsjahr und Vornamen der Interpreten aus Konzertprogramm entnomme
Photoelectron spectroscopy data of InP(100) surfaces in contact with water and oxygen
No full textRaw photoelectron spectroscopy data files (XPS and UPS) of InP(100) surfaces before and after adsorption of water and oxygen in ultra-high vacuum. The data was used to produce the graphs in the article M. M. May, H.-J. Lewerenz, and T. Hannappel. “Optical in situ Study of InP(100) Surface Chemistry: Dissociative Adsorption of Water and Oxygen”. Journal of Physical Chemistry C 118(33) (2014), pp. 19032–19041. doi:10.1021/jp502955m. Further details can be found in the README.md.</p
The Transnationalisation of Criminal Law in the Nineteenth and Twentieth Century. Political Crime, Police Cooperation, Security Regimes and Normative Orders
No full textDistribution of Thymosin beta 4 in Vertebrate Classes
No full textA peptide containing 43 amino acid residues, rich in glutamic acid and lysine, was originally isolated from calf thymus and designated thymosin beta 4 [T.L.K. Low, S. -K. Hu, and A. L. Goldstein (1981) Proc. Nat. Acad. Sci. USA 78, 1162-1166]. However, thymosin beta 4 was also shown to be present in other tissues of rats and mice, with highest concentrations in spleen and peritoneal macrophages [E. Hannappel, G.-J. Xu, J. Morgan, J. Hempstead, and B.L. Horecker (1982), Proc. Nat. Acad. Sci. USA 79, 2172-2175]. We have now identified the same peptide in tissues of other mammalian species and other vertebrate classes, including birds and amphibia. Exceptions are the rabbit and bony fish, where thymosin beta 4 is replaced by different peptides, similar in size and in amino acid sequence. None of these peptides was detected in several invertebrates or in the protozoan, Tetrahymena pyriformis. In subcellular fractionation of rat spleen, thymosin beta 4 was recovered in the cytosol
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