@article{DietrichGlamschEhlertetal.2016, author = {Dietrich, Paul M. and Glamsch, Stephan and Ehlert, Christopher and Lippitz, Andreas and Kulak, Nora and Unger, Wolfgang E. S.}, title = {Synchrotron-radiation XPS analysis of ultra-thin silane films: Specifying the organic silicon}, series = {Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces}, volume = {363}, journal = {Applied surface science : a journal devoted to applied physics and chemistry of surfaces and interfaces}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2015.12.052}, pages = {406 -- 411}, year = {2016}, abstract = {The analysis of chemical and elemental in-depth variations in ultra-thin organic layers with thicknesses below 5 nm is very challenging. Energy- and angle-resolved XPS (ER/AR-XPS) opens up the possibility for non-destructive chemical ultra-shallow depth profiling of the outermost surface layer of ultra-thin organic films due to its exceptional surface sensitivity. For common organic materials a reliable chemical in-depth analysis with a lower limit of the XPS information depth z(95) of about 1 nm can be performed. As a proof-of-principle example with relevance for industrial applications the ER/AR-XPS analysis of different organic monolayers made of amino- or benzamidosilane molecules on silicon oxide surfaces is presented. It is demonstrated how to use the Si 2p core-level region to non-destructively depth-profile the organic (silane monolayer) - inorganic (SiO2/Si) interface and how to quantify Si species, ranging from elemental silicon over native silicon oxide to the silane itself. The main advantage of the applied ER/AR-XPS method is the improved specification of organic from inorganic silicon components in Si 2p core-level spectra with exceptional low uncertainties compared to conventional laboratory XPS. (C) 2015 Elsevier B.V. All rights reserved.}, language = {en} } @article{DietrichStreeckGlamschetal.2015, author = {Dietrich, Paul M. and Streeck, Cornelia and Glamsch, Stephan and Ehlert, Christopher and Lippitz, Andreas and Nutsch, Andreas and Kulak, Nora and Beckhoff, Burkhard and Unger, W. E. S.}, title = {Quantification of Silane Molecules on Oxidized Silicon: Are there Options for a Traceable and Absolute Determination?}, series = {Analytical chemistry}, volume = {87}, journal = {Analytical chemistry}, number = {19}, publisher = {American Chemical Society}, address = {Washington}, issn = {0003-2700}, doi = {10.1021/acs.analchem.5b02846}, pages = {10117 -- 10124}, year = {2015}, abstract = {Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXR.F) and X-ray photoelectron spectroscopy (XPS). An areic density of 2-4 silane molecules per nm(2) was calculated from the layer's nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/AR-XPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)-inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceable values for the areic density of silanes containing nitrogen as intrinsic marker are obtained by calibration of the XPS methods with reference-free TXRF. Furthermore, ER/AR-XPS is shown to facilitate the determination of areic densities in (mono)layers made from silanes having no heteroatomic marker other than silicon. After calibration with reference-free TXRF, these areic densities of silane molecules can be determined when using the XPS component intensity of the silane's silicon atom.}, language = {en} } @misc{SheenSanderEibischetal.2004, author = {Sheen, Susanne Fienhold and Sander, Bj{\"o}rn and Eibisch, Frank and Koch, Nicole and Telschow, Stephan and Schwuchow, Franka and Dietrich, Ralf and Lafl{\"o}r, Anja}, title = {Portal alumni}, series = {Das Ehemaligen-Magazin der Universit{\"a}t Potsdam}, volume = {2004}, journal = {Das Ehemaligen-Magazin der Universit{\"a}t Potsdam}, number = {2}, organization = {Stabsstelle Studierendenmarketing/Alumniprogramm Im Auftrag der Pr{\"a}sidentin der Universit{\"a}t Potsdam}, doi = {10.25932/publishup-48114}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-481140}, pages = {58}, year = {2004}, abstract = {Liebe Leserin,lieber Leser,das sind doch gute Nachrichten: Ein Studienabschluss schafft nach einer aktuellen Studie des Hochschul-Informations-Systems (HIS) in Hannover nach wie vor die besten Chancen auf einen Arbeitsplatz. Die Arbeitslosenquote von Akademikern pendelt sich ein halbes Jahr nach dem Examen bei f{\"u}nf Prozent ein. Bei Absolventen einer Lehre liegt sie dagegen doppelt so hoch. Doch auch f{\"u}r Akademiker ist der Einstieg ins Berufsleben kein Selbstl{\"a}ufer mehr. Mit nichts als eingleisigem Fachwissen als Kapital haben es auch Akademiker inzwischen schwer, denn der Arbeitsmarkt hat sich in den letzten Jahren stark ver{\"a}ndert. Welche Ver{\"a}nderungen das sind und wie man am besten darauf reagiert, beleuchtet die Rubrik "wissenstransfer". Das man an der Universit{\"a}t Potsdarn mehr als reines Fachwissen erwerben kann, zeigen die Berichte der Alumni {\"u}ber ihren Berufsweg in der Rubrik "umbr{\"u}che". Von geradlinigen Entwicklungen ist da zu lesen, von entt{\"a}uschten Erwartungen und ergriffenen Chancen. Sie dokumentieren, wie Br{\"u}che im beruflichen Werdegang zwar manchen vom geplanten Weg abkommen ließen, doch auf den pers{\"o}nlich richtigen Pfad fuhrten. Wer sich gerade in der Phase der beruflichen Neuorientierung befindet, oder gerade erst ins Arbeitsleben startet, findet Tipps und Adressen im "wegweiser". Die Redaktion w{\"u}nscht Ihnen viel Vergn{\"u}gen beim Lesen von Portal alumni. Mit den besten Gr{\"u}ßen, Ihr Alumni-Team.}, language = {de} } @article{PatelNoackVacogneetal.2019, author = {Patel, Dhananjay I. and Noack, Sebastian and Vacogne, Charlotte D. and Schlaad, Helmut and Bahr, Stephan and Dietrich, Paul and Meyer, Michael and Thissen, Andreas and Linford, Matthew R.}, title = {Poly(L-lactic acid), by near-ambient pressure XPS}, series = {Surface Science Spectra}, volume = {26}, journal = {Surface Science Spectra}, number = {2}, publisher = {American Institute of Physics}, address = {Melville}, issn = {1055-5269}, doi = {10.1116/1.5110309}, pages = {8}, year = {2019}, abstract = {Near ambient pressure - x-ray photoelectron spectroscopy (NAP-XPS) is a less traditional form of XPS that allows samples to be analyzed at relatively high pressures, i.e., at 2500Pa or higher. With NAP-XPS, one can analyze moderately volatile liquids, biological samples, porous materials, and/or polymeric materials that outgas significantly. In this submission we show C 1s, O 1s, and survey NAP-XPS spectra from poly(L-lactic acid). The C 1s and O 1s envelopes were fit with three and two Gaussian-Lorentzian sum functions, respectively. Water vapor (800Pa) was used as the residual gas for charge compensation, which was confirmed by the sharp peak at 535.0 eV in the O 1s narrow scan. The uniqueness plot corresponding to the C 1s fit shows that the fit parameters had statistical significance. C 1s and O 1s spectra of PLLA damaged by exposure to x-rays for ca. 1 hour are also included. Published by the AVS.}, language = {en} } @article{JainWheelerEssetal.2019, author = {Jain, Varun and Wheeler, Joshua J. and Ess, Daniel H. and Noack, Sebastian and Vacogne, Charlotte D. and Schlaad, Helmut and Bahr, Stephan and Dietrich, Paul and Meyer, Michael and Thissen, Andreas and Linford, Matthew R.}, title = {Poly(gamma-benzyl l-glutamate), by near-ambient pressure XPS}, series = {Surface science spectra : SSS : an international journal \& database devoted to archiving spectra from surfaces \& interfaces}, volume = {26}, journal = {Surface science spectra : SSS : an international journal \& database devoted to archiving spectra from surfaces \& interfaces}, number = {2}, publisher = {American Institute of Physics}, address = {Melville}, issn = {1055-5269}, doi = {10.1116/1.5109121}, pages = {10}, year = {2019}, abstract = {Near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) is a less traditional form of XPS that allows samples to be analyzed at relatively high pressures, i. e., at greater than 2500 Pa. In this study, poly(.- benzyl L- glutamate) (PBLG) with a molar mass of 11.3 kg/mol was analyzed by NAP-XPS; here, we show the survey, C 1s, N 1s, and O 1s narrow scans of PBLG. The C 1s peak envelope was fitted in three different ways, to five, six, or seven synthetic peaks. In each fit, there was also a shake-up signal. The O 1s narrow scan was well fit with three peaks: CZO and CvO in a 1:2 ratio from the polymer, and a higher energy signal from water vapor. Hartree-Fock orbital energies of a model monomer served as a guide to an additional fit of the C 1s envelope.}, language = {en} } @article{SirockoDietrichVeresetal.2013, author = {Sirocko, Frank and Dietrich, Stephan and Veres, Daniel and Grootes, Pieter M. and Schaber-Mohr, Katja and Seelos, Klemens and Nadeau, Marie-Josee and Kromer, Bernd and Rothacker, Leo and Roehner, Marieke and Krbetschek, Matthias and Appleby, Peter G. and Hambach, Ulrich and Rolf, Christian and Sudo, Masafumi and Grim, Stephanie}, title = {Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany}, series = {Quaternary science reviews : the international multidisciplinary research and review journal}, volume = {62}, journal = {Quaternary science reviews : the international multidisciplinary research and review journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0277-3791}, doi = {10.1016/j.quascirev.2012.09.011}, pages = {56 -- 76}, year = {2013}, abstract = {During the last twelve years the ELSA Project (Eifel Laminated Sediment Archive) at Mainz University has drilled a total of about 52 cores from 27 maar lakes and filled-in maar basins in the Eifel/Germany. Dating has been completed for the Holocene cores using 6 different methods (Pb-210 and Cs-137 activities, palynostratigraphy, event markers, varve counting, C-14) In general, the different methods consistently complement one another within error margins. Event correlation was used for relating typical lithological changes with historically known events such as the two major Holocene flood events at 1342 AD and ca 800 BC. Dating of MIS2-MIS3 core sections is based on greyscale tuning, radiocarbon and OSL dating, magnetostratigraphy and tephrochronology. The lithological changes in the sediment cores demonstrate a sequence of events similar to the North Atlantic rapid climate variability of the Last Glacial Cycle. The warmest of the MIS3 interstadials was GI14, when a forest with abundant spruce covered the Eifel area from 55 to 48 ka BP, i.e. during a time when also other climate archives in Europe suggested very warm conditions. The forest of this "Early Stage 3 warm phase" developed subsequently into a steppe with scattered birch and pine, and finally into a glacial desert at around 25 ka BP. Evidence for Mono Lake and Laschamp geomagnetic excursions is found in two long cores. Several large eruptions during Middle and Late Pleistocene (Ulmener Maar - 11,000 varve years BP, Laacher See - 12,900 varve years BP, Mosenberg volcanoes/Meerfelder Maar 41-45 cal ka BP, Dumpel Maar 116 ka BP, Glees Maar - 151 ka BP) produced distinct ash-layers crucial for inter-core and inter-site correlations. The oldest investigated maar of the Eifel is Ar-40/Ar-39 dated to the time older than 520 ka BP.}, language = {en} } @article{BormanndeBritoCharchousietal.2018, author = {Bormann, Helge and de Brito, Mariana Madruga and Charchousi, Despoina and Chatzistratis, Dimitris and David, Amrei and Grosser, Paula Farina and Kebschull, Jenny and Konis, Alexandros and Koutalakis, Paschalis and Korali, Alkistis and Krauzig, Naomi and Meier, Jessica and Meliadou, Varvara and Meinhardt, Markus and Munnelly, Kieran and Stephan, Christiane and de Vos, Leon Frederik and Dietrich, J{\"o}rg and Tzoraki, Ourania}, title = {Impact of Hydrological Modellers' Decisions and Attitude on the Performance of a Calibrated Conceptual Catchment Model}, series = {Hydrology}, volume = {5}, journal = {Hydrology}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2306-5338}, doi = {10.3390/hydrology5040064}, pages = {13}, year = {2018}, abstract = {In this study, 17 hydrologists with different experience in hydrological modelling applied the same conceptual catchment model (HBV) to a Greek catchment, using identical data and model code. Calibration was performed manually. Subsequently, the modellers were asked for their experience, their calibration strategy, and whether they enjoyed the exercise. The exercise revealed that there is considerable modellers' uncertainty even among the experienced modellers. It seemed to be equally important whether the modellers followed a good calibration strategy, and whether they enjoyed modelling. The exercise confirmed previous studies about the benefit of model ensembles: Different combinations of the simulation results (median, mean) outperformed the individual model simulations, while filtering the simulations even improved the quality of the model ensembles. Modellers' experience, decisions, and attitude, therefore, have an impact on the hydrological model application and should be considered as part of hydrological modelling uncertainty.}, language = {en} } @article{ChaurasiaDietrichRosswog2021, author = {Chaurasia, Swami Vivekanandji and Dietrich, Tim and Rosswog, Stephan}, title = {Black hole-neutron star simulations with the BAM code}, series = {Physical review : D, Particles, fields, gravitation, and cosmology}, volume = {104}, journal = {Physical review : D, Particles, fields, gravitation, and cosmology}, number = {8}, publisher = {American Physical Society}, address = {Ridge, NY}, issn = {2470-0010}, doi = {10.1103/PhysRevD.104.084010}, pages = {15}, year = {2021}, abstract = {The first detections of black hole-neutron star mergers (GW200105 and GW200115) by the LIGO-Virgo-Kagra Collaboration mark a significant scientific breakthrough. The physical interpretation of pre- and postmerger signals requires careful cross-examination between observational and theoretical modelling results. Here we present the first set of black hole-neutron star simulations that were obtained with the numerical-relativity code BAM. Our initial data are constructed using the public LORENE spectral library, which employs an excision of the black hole interior. BAM, in contrast, uses the moving-puncture gauge for the evolution. Therefore, we need to "stuff" the black hole interior with smooth initial data to evolve the binary system in time. This procedure introduces constraint violations such that the constraint damping properties of the evolution system are essential to increase the accuracy of the simulation and in particular to reduce spurious center-of-mass drifts. Within BAM we evolve the Z4c equations and we compare our gravitational-wave results with those of the SXS collaboration and results obtained with the SACRA code. While we find generally good agreement with the reference solutions and phase differences less than or similar to 0.5 rad at the moment of merger, the absence of a clean convergence order in our simulations does not allow for a proper error quantification. We finally present a set of different initial conditions to explore how the merger of black hole neutron star systems depends on the involved masses, spins, and equations of state.}, language = {en} }