Evidence for electron transfer between graphene and non‐covalently bound π‐systems

Hybridizing graphene and molecules possess a high potential for developing materials for new applications. However, new methods to characterize such hybrids must be developed. Herein, the wet‐chemical non‐covalent functionalization of graphene with cationic π‐systems is presented and the interaction between graphene and the molecules is characterized in detail. A series of tricationic benzimidazolium salts with various steric demand and counterions was synthesized, characterized and used for the fabrication of graphene hybrids. Subsequently, the doping effects were studied. The molecules are adsorbed onto graphene and studied by Raman spectroscopy, XPS as well as ToF‐SIMS. The charged π‐systems show a p‐doping effect on the underlying graphene. Consequently, the tricationic molecules are reduced through a partial electron transfer process from graphene, a process which is accompanied by the loss of counterions. DFT calculations support this hypothesis and the strong p‐doping could be confirmed in fabricated monolayer graphene/hybrid FET devices. The results are the basis to develop sensor applications, which are based on analyte/molecule interactions and effects on doping

Diel changes in bulk and single-cell bacterial heterotrophic activity in winter surface waters of the northwestern Mediterranean Sea

14 pages, 8 figures, 2 tablesTwo diel cycle studies were conducted to determine the effect of day–night light changes on winter bacterial activity in the coastal Mediterranean (Blanes Bay Microbial Observatory). Bacterial abundances, bacterial heterotrophic activity, and flagellate grazing counts were determined at 4-h intervals during two 3-d periods separated by 2 d. Twice a day, the single-cell activity of major bacterial groups was further analyzed by applying microautoradiography combined with catalyzed reporter deposition-fluorescence in situ hybridization. During the first cycle, all the measured parameters (including the number of active cells in most groups) varied synchronously, with higher values at night and lower during the day. An episode of strong winds between the two studied periods disrupted this periodicity at the onset of the second cycle. The bulk incorporation of 3H-leucine recovered the diel pattern after 2 d, mostly driven by the activity of Gammaproteobacteria. Among the possibilities considered, the observed nighttime increases in the grazing activity of heterotrophic nanoflagellates appeared to partially drive the activity of all bacterial taxa through potential periodic release of dissolved organic matterThis work has been supported by the Spanish Ministry of Science and Innovation (MICINN)through the projects ‘‘Fuentes de Materia Orgánica, Diversidad microbiana y funcionamiento (respiración y Uso del carbono) del ecosistema marino pelágico costero’’ (MODIVUS) (Ciencias y Tecnologías Marinas-CTM2005-04795/MAR) and ‘‘Surface Mixing Modulation of the Exposure to solar Radiation’’ (SUMMER) (Ciencias y Tecnologías Marinas-CTM2008-03309/MAR)Peer reviewe

Monitoring of the primary drying of a lyophilization process in vials

An innovative and modular system (LyoMonitor) for monitoring the primary drying of a lyophilization process in vials is illustrated: it integrates some commercial devices (pressure gauges, moisture sensor and mass spectrometer), an innovative balance and a manometric temperature measurement system based on an improved algorithm (DPE) to estimate sublimating interface temperature and position, product temperature profile, heat and mass transfer coefficients. A soft-sensor using a multipoint wireless thermometer can also estimate the previous parameters in a large number of vials. The performances of the previous devices for the determination of the end of the primary drying are compared. Finally, all these sensors can be used for control purposes and for the optimization of the process recipe; the use of DPE in a control loop will be shown as an exampl

Presence of 5-hydroxyguaiacyl units as native lignin constituents in plants as seen by Py-GC/MS

Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080-Seville, Spain 2Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain E-mail address: [email protected] (J.C. del Río)The presence of 5-hydroxyguaiacyl moieties in the lignin from several plants has been assessed by Py-GC/MS. Different woody (eucalypt) and nonwoody (flax, hemp, kenaf, jute, sisal and abaca) angiosperms were selected for this study. The pyrolysis of whole fibers released lignin-derived products with p-hydroxyphenyl, guaiacyl and syringyl structures. Indeed, a series of compounds having a 5-hydroxyguaiacyl nuclei, including 3-methoxycatechol, 5-vinyl-3-methoxycatechol and 5-propenyl-3-methoxycatechol, were detected and identified in all samples, although in lower amounts than the normal guaiacyl and syringyl compounds. The analysis of the lignins isolated from the same plants also indicated the presence of 5-hydroxyguaiacyl moieties in the isolated lignins. These compounds are supposed to arise from the pyrolysis of 5-hydroxyguaiacyl moieties, which are supposed to be native constituents of lignin in plants forming benzodioxane substructures.This study has been supported by the Spanish Ministerio de Ciencia y Tecnología (MCyT) and FEDER funds (project AGL2005-01748) and the EU project BIORENEW (NMP2-CT-2006-026456). We thank CELESA S.A. (Tortosa, Spain) for providing the nonwoody plant samples, and ENCE for providing the eucalypt wood sample.Peer reviewe

Factors Affecting the Use of Impedance Spectroscopy in the Characterisation of the Freezing Stage of the Lyophilisation Process: the Impact of Liquid Fill Height in Relation to Electrode Geometry

The file attached to this record is the authors final peer reviewed version. The final publishers version can be found by following the DOI link

Schöne Geschichte? Ästhetische (Vor-) Urteile in der Denkmalpflege

Einführende Gedanken anlässlich des Symposiums «Nachdenken über Denkmalpflege» (Teil 5): «Schöne Geschichte? Ästhetische Urteile in der Denkmalpflege», Essen/Ruhr, 1. April 2006. Denkmalpflegerische Methodendiskussion kann nicht das Ästhetische als das Schöne, Angenehme und Gefällige zur zentralen Kategorie einer Denkmalpflege machen, die sich dann wieder ganz ungeniert "schöpferische" Denkmalpflege nennen dürfte. Notwendig ist aber eine dialektische Ästhetik in der Denkmalpflege, die sich mit a l l en Tatsachen der sinnlichen Wahrnehmungen abgibt und diese im Begriff hat eine Ästhetik, die um die Gleichzeitigkeit von Anziehung und Abstoßung im Akt der Wahrnehmung weiß und mit dieser Ambivalenz rational umzugehen versteht, insbesondere dann, wenn Substanzerhaltung unweigerlich ästhetische Konsequenzen für das Denkmal und damit gestalterische Probleme erzeugt. Diese wollen nicht beschwiegen, sondern erörtert werden. Daher ist es an der Zeit, den halbierten Begriff des Ästhetischen, der offensichtlich die in der Denkmalpflege übliche antiästhetische Abwehrhaltung provoziert hat, aufzubrechen und gewissermaßen um die dunkle Seite des Ästhetischen zu ergänzen