TY - RPRT A1 - Lunn, A. S. A1 - Tittelbach-Helmrich, Klaus A1 - Krause, F.-M. A1 - Becker, T. A1 - Cheetham, B. A1 - Kuhn, M. A1 - Methfessel, Michael A1 - Ettafagh, A. A1 - Secall, M. A1 - Spegel, M. T1 - Design of PAL and Voice Optimisation for WLAN Y1 - 2004 ER - TY - GEN A1 - Blaen, Phillip J. A1 - Kurz, Marie Juliette A1 - Drummond, Jennifer D. A1 - Knapp, Julia L. A. A1 - Mendoza-Lera, Clara A1 - Schmadel, Noah M. A1 - Klaar, Megan A1 - Jäger, Anna A1 - Folegot, Silvia A1 - Lee-Cullin, Joseph A1 - Ward, Adam A1 - Zarnetske, Jay A1 - Datry, Thibault A1 - Milner, Alexander A1 - Lewandowski, Jörg A1 - Hannah, David M. A1 - Krause, Stefan T1 - Woody debris is related to reach-scale hotspots of lowland stream ecosystem respiration under baseflow conditions T2 - Ecohydrology : ecosystems, land and water process interactions, ecohydrogeomorphology KW - Stream metabolism KW - ecosystem respiration Y1 - 2018 U6 - https://doi.org/10.1002/eco.1952 SN - 1936-0592 SN - 1936-0584 ER - TY - GEN A1 - Sullivan, J. T. A1 - Wilks, Regan G. A1 - Winkler, M. T. A1 - Weinhardt, Lothar A1 - Recht, D. A1 - Said, A. J. A1 - Newman, B. K. A1 - Zhang, Y. A1 - Blum, Monika A1 - Krause, S. A1 - Yang, Wan Li A1 - Heske, Clemens A1 - Aziz, M. J. A1 - Bär, Marcus A1 - Buonassisi, T. T1 - Soft x-ray emission spectroscopy studies of the electronic structure of silicon supersaturated with sulfur N2 - We apply soft x-ray emission spectroscopy (XES) to measure the electronic structure of crystalline silicon supersaturated with sulfur (up to 0.7 at. %), a candidate intermediate-band solar cell material. Si L2,3 emission features are observed above the conventional Si valence band maximum, with intensity scaling linearly with S concentration. The lineshape of the S-induced features change across the insulator-to-metal transition, indicating a significant modification of the local electronic structure concurrent with the change in macroscopic electronic behavior. The relationship between the Si L2,3 XES spectral features and the anomalously high sub-band gap infrared absorption is discussed. KW - black silicon KW - solar cells KW - electronic surface structure KW - x-ray emission spectroscopy Y1 - 2011 ER - TY - GEN A1 - Kelleher, Christa A1 - Ward, Adam Scott A1 - Knapp, Julia L. A. A1 - Blaen, Phillip J. A1 - Kurz, Marie Juliette A1 - Drummond, Jennifer D. A1 - Zarnetske, Jay A1 - Hannah, David M. A1 - Mendoza-Lera, Clara A1 - Schmadel, Noah M. A1 - Datry, Thibault A1 - Lewandowski, Jörg A1 - Krause, Stefan T1 - Exploring Tracer Information and Model Framework Trade‐offs to Improve Estimation of Stream Transient Storage Processes T2 - Water Resources Research KW - transient storage modeling KW - smart tracer Y1 - 2019 U6 - https://doi.org/10.1029/2018WR023585 SN - 0043-1397 SN - 1944-7973 VL - 55 IS - 4 SP - 3481 EP - 3501 ER - TY - RPRT A1 - Spegel, M. A1 - Reinhardt, P. A1 - Cheetham, B. A1 - Lunn, A. S. A1 - Krause, F.-M. A1 - Tittelbach-Helmrich, Klaus T1 - Final System Performance and Validation Report Y1 - 2006 ER - TY - RPRT A1 - Spegel, M. A1 - Lunn, A. S. A1 - Krause, F.-M. A1 - Wellhausen, T. A1 - Tittelbach-Helmrich, Klaus A1 - Reinhardt, P. A1 - Cheetham, B. T1 - 506746 - WINDECT STP D2.2 Technical Specification of 173, Demonstration System Y1 - 2004 ER - TY - GEN A1 - Bär, Marcus A1 - Schubert, Björn-Arvid A1 - Marsen, Björn A1 - Wilks, Regan G. A1 - Blum, M. A1 - Krause, S. A1 - Pookpanratana, Sujitra A1 - Zhang, Y. A1 - Unold, Thomas A1 - Yang, W. A1 - Weinhardt, Lothar A1 - Heske, Clemens A1 - Schock, Hans-Werner T1 - Cu2ZnSnS4 thin-film solar cell absorbers illuminated by soft x-rays T2 - Journal of Materials Research N2 - In view of the complexity of thin-film solar cells, which are comprised of a multitude of layers, interfaces, surfaces, elements, impurities, etc., it is crucial to characterize and understand the chemical and electronic structure of these components. Because of the high complexity of the Cu2ZnSn(S,Se)4 compound semiconductor absorber material alone, this is particularly true for kesterite-based devices. Hence, this paper reviews our recent progress in the characterization of Cu2ZnSnS4 (CZTS) thin films. It is demonstrated that a combination of different soft x-ray spectroscopies is an extraordinarily powerful method for illuminating the chemical and electronic material characteristics from many different perspectives, ultimately resulting in a comprehensive picture of these properties. The focus of the article will be on secondary impurity phases, electronic structure, native oxidation, and the CZTS surface composition. Y1 - 2012 U6 - https://doi.org/10.1557/jmr.2012.59 SN - 2044-5326 VL - 27 IS - 8 SP - 1097 EP - 1104 ER - TY - CHAP A1 - Bauriegel, E. A1 - Krause, M. A1 - Wiegleb, Gerhard ED - Wiegleb, Gerhard ED - Bröring, Udo ED - Mrzljak, Jadranka ED - Schulz, Friederike T1 - Renaturierung und Initialsetzung von Trockenrasen in der Bergbaufolgelandschaft T2 - Naturschutz in Bergbaufolgelandschaften - Landschaftsanalyse und Leitbildentwicklung Y1 - 2000 SN - 3-7908-1279-X SP - 177 EP - 201 PB - Physica-Verlag CY - Heidelberg ER - TY - CHAP A1 - Reiche, Manfred A1 - Kittler, Martin A1 - Krause, M. A1 - Übensee, Hartmut ED - Cavallini, Anna ED - Estreicher, Stefan K. T1 - Carrier Transport on Dislocations T2 - International Conference on Defects in Semiconductors 2013, proceedings of the 27th International Conference on Defects in Semiconductors, ICDS-2013, Bologna, Italy, 21-26 July 2013 Y1 - 2014 SN - 978-0-7354-1215-6 U6 - https://doi.org/10.1063/1.4865599 PB - AIP Publishing CY - Melville, New York ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Mass, Markus A1 - Krause, Christian A1 - Wolfbeis, Otto S. T1 - Capacitive approach to determine phospholipase A2 activity towards artificial and natural substrates T2 - Analytical Chemistry N2 - A capacitive approach has been employed to develop a novel method to determine phospholipase activity. The sensing electrodes have a structure like Au/S(CH₂)₁₇CH₃/substrate/electrolyte. Hydrolysis of the substrate, mediated by phospholipase A₂, leads to the formation of water-soluble products from the insoluble substrate. This results in desorption of these products into aqueous phase and corresponding increase of the electrode capacitance. The requirement of high water solubility of the reaction products can be achieved in two ways. In the first, short-chain phospholipids are used as the substrate, in which case, water-soluble products are formed and no additional reagents are required to promote desorption of these products. The sensors prepared by this strategy provide sensitive qualitative detection of phospholipases. The second way is based on the use of a water-soluble acceptor (for example, β-cyclodextrin) to solubilize the products of hydrolysis. It allows semiquantitative detection of phospholipase activity toward long-chain natural substrates. The reaction kinetics for this case was found to be monoexponential and linearly dependent on the phospholipase concentration. The detection limit of this method, as tested with phospholipase A₂ from bee venom and soy bean lecithin as the substrate, is ∼0.5 ng/mL (500 μunits/mL). Y1 - 1998 U6 - https://doi.org/10.1021/ac980102w SN - 0003-2700 SN - 1520-6882 VL - 70 IS - 17 SP - 3674 EP - 3678 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Krause, Christian A1 - Heckmann, Klaus Dietrich T1 - Capacitive detection of adsorption/desorption on hydrophobized gold electrodes: an application for surfactants adsorption and phospholipase assay T2 - Chimica Chronica, New Series Y1 - 1996 VL - 25 SP - 179 EP - 194 ER - TY - GEN A1 - Krause, Christian A1 - Mirsky, Vladimir M. A1 - Heckmann, Klaus Dietrich T1 - Capacitive detection of surfactant adsorption on hydrophobized gold electrodes T2 - Langmuir N2 - Nonspecific adsorption of surfactants on polycrystalline gold electrodes, covered by a chemically adsorbed monomolecular layer of octadecanethiol, was studied by means of capacitive measurements. Homologous series of fatty acids (from decane to tetradecane acids) and dodecanepyridinium chloride were used as surfactants. The behavior of the electrode was completely different in the first and subsequent cycles of adsorption/desorption. In the first adsorption cycle, an initial capacitance jump at low concentrations (<10 μM) occurs, while later the curves show the usual saturation behavior. The first surfactant layer could not be completely desorbed; only the electrode capacitance shown after the jump was reached. Subsequent cycles do not reveal any capacitance jumps and were completely reversible. Adsorption curves in the series of monoalkyl acids are shifted according to the Traube rule. A comparison with the surfactant adsorption at the air/water interface has been done. Y1 - 1996 U6 - https://doi.org/10.1021/la9601869 SN - 0743-7463 VL - 12 IS - 25 SP - 6059 EP - 6064 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Krause, Christian A1 - Heckmann, Klaus Dietrich T1 - Capacitive sensor for lipolytic enzymes T2 - Thin Solid Films N2 - The preparation of the capacitive biosensor for monitoring the activity of enzymes (lipases, phospholipases, etc.) hydrolysing waterinsoluble substrates into water-soluble products is described. The sensor is based on a sandwich-like structure: Au/S(CH₂)₁₇CH₁/substrate/electrolyte. Hydrolysis of the substrate leads to the formation of water-soluble products and desorption of these compounds from the electrode. When the product formation is the rate-limiting step of this process, the desorption rate is determined by the enzyme activity. The desorption can be easily monitored as an increase of the electrode capacitance. By following this principle it was possible to develop a sensor monitoring phospholipase A₂ activity even at the 50 pg ml-1 level. KW - Phospholipase AZ KW - Enzyme assay KW - Capacitive sensor KW - Self-assembly layer Y1 - 1996 U6 - https://doi.org/10.1016/S0040-6090(95)08485-1 SN - 0040-6090 VL - 284-285 SP - 939 EP - 941 ER - TY - GEN A1 - Mirsky, Vladimir M. A1 - Riepl, Michael A1 - Krause, Christian A1 - Novotny, Ivan A1 - Splonskowski, Markus A1 - Rehacek, Vlastimil A1 - Tvarozek, Vladimir A1 - Hummel, Helmut A1 - Wolfbeis, Otto S. T1 - Thin film electrodes for capacitive chemo- and biosensors: an optimization of the electrodes geometry T2 - Materials Science Forum KW - Biosensor KW - Capacitance KW - Chemical Sensors KW - Electrode Y1 - 1998 U6 - https://doi.org/10.4028/www.scientific.net/MSF.287-288.423 SN - 1662-9752 VL - 287-288 SP - 423 EP - 426 ER - TY - GEN A1 - Shrestha, Krishna Prasad A1 - Eckart, Sven A1 - Elbaz, Ayman M. A1 - Giri, Binod Raj A1 - Fritsche, Chris A1 - Seidel, Lars A1 - Roberts, William L. A1 - Krause, Hartmut A1 - Mauß, Fabian T1 - A comprehensive kinetic model for dimethyl ether and dimethoxymethane oxidation and NOx interaction utilizing experimental laminar flame speed measurements at elevated pressure and temperature T2 - Combustion and Flame N2 - Laminar flame speeds of dimethyl ether and dimethoxymethane at pressures from 1 to 5 bar and initial temperatures from 298 to 373 K were determined experimentally using a constant volume spherical vessel and a heat flux burner setup. This study is the first to report dimethoxymethane laminar flame speeds at a pressure higher than 1 bar. Using these experimental data along with data available in the literature, a new kinetic model for the prediction of the oxidation behavior of dimethyl ether and dimethoxymethane in freely propagating and burner stabilized premixed flames, in shock tubes, rapid compression machines, flow reactors, and a jet-stirred reactor has been developed. The experimental results from the present work and literature are interpreted with the help of the derived kinetic model. This newly developed reaction mechanism considers the redox chemistry of NOx to accommodate the influence of the oxygen level on the onset of fuel conversion and interconversion of NO and NO2. The current model suggests that an increased O2 level promotes the HO2 production, which in turn leads to the formation of OH radicals, which promotes the combustion of the fuel/air mixture under lean conditions. The increase of OH radical concentrations is mainly via the NO/NO2 interconversion reaction channel, NO+HO2=NO2+OH, NO2+H=NO+OH, CH3OCH3+NO2=CH3OCH2+HONO, followed by the thermal decomposition of HONO. This work extends the kinetic database and helps to improve the understanding of dimethyl ether and dimethoxymethane combustion behavior. The kinetic model presented in this work can serve as a base model for hydrocarbons and oxygenated fuels higher than C2. KW - Dimethyl ether KW - Dimethoxymethane KW - Laminar flame speed KW - Kinetic modeling KW - NOx Y1 - 2020 U6 - https://doi.org/10.1016/j.combustflame.2020.04.016 SN - 1556-2921 VL - 218 SP - 57 EP - 74 ER - TY - PAT A1 - Beyer, T. A1 - Krause, F.-M. A1 - Methfessel, Michael A1 - Tittelbach-Helmrich, Klaus A1 - Lunn, A. S. T1 - Verfahren für drahtlosen Handover bei Datenströmen über WLAN Systeme Y1 - 2005 ER - TY - PAT A1 - Becker, T. A1 - Krause, F.-M. A1 - Methfessel, Michael A1 - Tittelbach-Helmrich, Klaus T1 - Verfahren zum Betreiben einer Datenverbindung Y1 - 2004 ER - TY - PAT A1 - Becker, T. A1 - Krause, F.-M. A1 - Methfessel, Michael A1 - Tittelbach-Helmrich, Klaus A1 - Lunn, A. S. T1 - Verfahren für drahtlosen Handover bei Datenströmen über WLAN Systeme Y1 - 2004 ER - TY - RPRT A1 - Methfessel, Michael A1 - Krause, F.-M. A1 - Tittelbach-Helmrich, Klaus T1 - Research Report on Power Consumption, Deliverable D3.3.4 Y1 - 2005 ER - TY - PAT A1 - Becker, T. A1 - Krause, F.-M. A1 - Methfessel, Michael A1 - Tittelbach-Helmrich, Klaus T1 - Verfahren zum Betreiben einer Datenverbindung Y1 - 2005 ER -