TY - JOUR A1 - Frauenrath, Tobias A1 - Fuchs, Katharina A1 - Dieringer, Matthias A. A1 - Özerdem, Celal A1 - Patel, Nishan A1 - Renz, Wolfgang A1 - Greiser, Andreas A1 - Elgeti, Thomas A1 - Niendorf, Thoralf T1 - Detailing the use of magnetohydrodynamic effects for synchronization of MRI with the cardiac cycle: A feasibility study JF - Journal of Magnetic Resonance Imaging N2 - Purpose: To investigate the feasibility of using magnetohydrodynamic (MHD) effects for synchronization of magnetic resonance imaging (MRI) with the cardiac cycle. Materials and Methods: The MHD effect was scrutinized using a pulsatile flow phantom at B0 = 7.0 T. MHD effects were examined in vivo in healthy volunteers (n = 10) for B0 ranging from 0.05–7.0 T. Noncontrast-enhanced MR angiography (MRA) of the carotids was performed using a gated steady-state free-precession (SSFP) imaging technique in conjunction with electrocardiogram (ECG) and MHD synchronization. Results: The MHD potential correlates with flow velocities derived from phase contrast MRI. MHD voltages depend on the orientation between B0 and the flow of a conductive fluid. An increase in the interelectrode spacing along the flow increases the MHD potential. In vivo measurement of the MHD effect provides peak voltages of 1.5 mV for surface areas close to the common carotid artery at B0 = 7.0 T. Synchronization of MRI with the cardiac cycle using MHD triggering is feasible. MHD triggered MRA of the carotids at 3.0 T showed an overall image quality and richness of anatomic detail, which is comparable to ECG-triggered MRAs. Conclusion: This feasibility study demonstrates the use of MHD effects for synchronization of MR acquisitions with the cardiac cycle. J. Magn. Reson. Imaging 2012;36:364–372. © 2012 Wiley Periodicals, Inc. Y1 - 2012 U6 - https://doi.org/10.1002/jmri.23634 SN - 1522-2586 VL - 36 IS - 2 SP - 364 EP - 372 PB - Wiley-Liss CY - New York ER - TY - JOUR A1 - Kern, Alexander A1 - Schelthoff, Christof A1 - Mathieu, Moritz T1 - Detaillierte Berechnung der Einfangwirksamkeiten von Fangeinrichtungen JF - Elektro-Praktiker N2 - Im Beitrag wird zunächst das Verfahren eines dynamischen elektro-geometrischen Modells vorgestellt. Dieses arbeitet im Gegensatz zum klassischen Blitzkugel-Verfahren nicht mit konstanten Radien; vielmehr wird der Radius der Blitzkugel variiert. Dabei werden ausschließlich vorhandene und in internationalen Normen anerkannte Ergebnisse, blitzphysikalische Grundlagen und Untersuchungen verwendet, und auf deren Grundlage ein numerisches Verfahren erarbeitet. Mit dem dynamischen elektro-geometrischen Modell werden dann einige Beispiele des Schutzes mit Fangstangen, die gemäß dem klassischen Blitzkugel-Verfahren nach DIN EN 62305-3 für die Schutzklassen I – II – III – IV geplant sind, untersucht. Es wird gezeigt, dass die Einfangwirksamkeiten wesentlich höher sind als in der Normenreihe DIN EN 62305 selbst angegeben. Grund dafür ist die Tatsache, dass das Blitzkugel-Verfahren sehr konservativ aufgebaut ist und dem Planer von Blitzschutzsystemen nur die möglichen Stellen für einen Einschlag aufzeigt, ohne eine Bewertung der Einschlagshäufigkeit zu liefern. Andererseits bedeutet dies jedoch, dass man mit dem klassischen Blitzkugel-Verfahren stets auf der „sicheren Seite“ liegt. Y1 - 2012 SN - 0013-5569 VL - 66 IS - 4 PB - Huss Medien CY - Berlin ER - TY - CHAP A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Stütz, Evamaria A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Detection of toxic chromium species in water using cellbased sensor systems Y1 - 2012 SN - 978-3-9813484-2-2 U6 - https://doi.org/10.5162/IMCS2012/P2.1.14 SP - 1364 EP - 1367 ER - TY - CHAP A1 - Hartmann, Axel A1 - Kallweit, Stephan A1 - Feldusen, Antje A1 - Schröder, Wolfgang T1 - Detection of upstream propagating sound waves at buffet flow using high-speed PIV BT - 16th International Symposium on Applications of Laser Techniques to Fluid Mechanics ; 9th to 12th July 2012 Lisbon, Portugal Y1 - 2012 N1 - Aerodynamisches Institut ; International Symposium on Applications of Laser Techniques to Fluid Mechanics <16, 2012, Lissabon> ER - TY - BOOK A1 - Gell, Sebastian T1 - Determinants of earnings forecast error, earnings forecast revision and earnings forecast accuracy N2 - ​Earnings forecasts are ubiquitous in today’s financial markets. They are essential indicators of future firm performance and a starting point for firm valuation. Extremely inaccurate and overoptimistic forecasts during the most recent financial crisis have raised serious doubts regarding the reliability of such forecasts. This thesis therefore investigates new determinants of forecast errors and accuracy. In addition, new determinants of forecast revisions are examined. More specifically, the thesis answers the following questions: 1) How do analyst incentives lead to forecast errors? 2) How do changes in analyst incentives lead to forecast revisions?, and 3) What factors drive differences in forecast accuracy? Y1 - 2012 SN - 978-3-8349-3936-4 SN - 978-3-8349-3937-1 U6 - https://doi.org/10.1007/978-3-8349-3937-1 N1 - Titel in der Buchreihe: Quantitatives Controlling PB - Springer Gabler CY - Wiesbaden ER - TY - JOUR A1 - Hasan, Istabrak A1 - Keil, Ludger A1 - Staat, Manfred A1 - Wahl, Gerhard A1 - Bourauel, Christoph T1 - Determination of the frictional coefficient of the implant-antler interface : experimental approach JF - Biomedical Engineering / Biomedizinische Technik N2 - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens. Y1 - 2012 SN - 1862-278X VL - 57 IS - 5 SP - 359 EP - 363 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Wagner, Torsten A1 - Werner, Frederik A1 - Miyamoto, Ko-Ichiro A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - Development and characterisation of a compact light-addressable potentiometric sensor (LAPS) based on the digital light processing (DLP) technology for flexible chemical imaging JF - Sensors and Actuators B: Chemical N2 - Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device, which allows fast and flexible generation of light patterns. With the help of these light patterns, the sensor surface of the LAPS device can be addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface. Y1 - 2012 U6 - https://doi.org/10.1016/j.snb.2010.12.003 SN - 0925-4005 N1 - Part of special issue "Eurosensors XXIV, 2010" VL - 170 SP - 34 EP - 39 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Kirsanov, Dmitry A1 - Legin, Andrey A1 - Osterrath, Thomas A1 - Schubert, Jürgen A1 - Zander, Willi A1 - Schöning, Michael Josef T1 - Development of a thin-film sensor array for analytical monitoring of heavy metals in aqueous solutions JF - Physica Status Solidi (a) N2 - In industrial processes there is a variety of heavy metals (e.g., copper, zinc, cadmium, and lead) in use for wires, coatings, paints, alloys, batteries, etc. Since the application of these transition metals for industry is inevitable, it is a vital task to develop proper analytical techniques for their monitoring at low activity levels, especially because most of these elements are acutely toxic for biological organisms. The determination of ions in solution by means of a simple and inexpensive sensor array is, therefore, a promising task. In this work, a sensor array with heavy metal-sensitive chalcogenide glass membranes for the simultaneous detection of the four ions Ag⁺, Cu2⁺, Cd2⁺, and Pb2⁺ in solution is realized. The results of the physical characterization by means of microscopy, profilometry, Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM) as well as the electrochemical characterization by means of potentiometric measurements are presented. Additionally, the possibility to expand the sensor array by polymeric sensor membranes is discussed. Y1 - 2012 SN - 1862-6319 U6 - https://doi.org/10.1002/pssa.201100733 VL - 209 IS - 5 SP - 885 EP - 891 PB - Wiley-VCH CY - Weinheim ER - TY - BOOK A1 - Hoepner, Gert A1 - Schminke, Lutz H. T1 - Dialog-Marketing und E-Commerce : ein anwendungsorientiertes und konzeptionelles Kompendium für Praxis und Ausbildung Y1 - 2012 SN - 978-3-942171-23-6 PB - Uni-ed. GmbH CY - Berlin ER - TY - JOUR A1 - Ellrich, Thomas A1 - Lind, Thorsten Patric T1 - Die 'kalte Zwangsverwaltung' durch den Insolvenzverwalter JF - Forderungs-Praktiker : WIKI Y1 - 2012 IS - 1 SP - 16 EP - 21 PB - FCH CY - Heidelberg ER -