TY - JOUR A1 - Tippkötter, Nils A1 - Deterding, A. A1 - Ulber, Roland T1 - Determination of acetic acid in fermentation broth by gas-diffusion technique JF - Engineering in Life Sciences N2 - Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents. Y1 - 2008 U6 - https://doi.org/10.1002/elsc.200820227 VL - 8 IS - 1, Special Issue: Technical Systems for the Use in Life Sciences SP - 62 EP - 67 ER - TY - JOUR A1 - Heuermann, Holger A1 - Sadeghfam, Arash T1 - Electrically tunable bandpass filter with integrated carrier suppression for UHF RFID systems / Sadeghfam, Arash ; Heuermann, Holger JF - European Conference on Wireless Technology, 2008. EuWiT 2008. Y1 - 2008 SN - 978-2-87487-008-8 SP - 306 EP - 309 ER - TY - JOUR A1 - Heuermann, Holger T1 - Calibration of a Network Analyzer Without a Thru Connection for Nonlinear and Multiport Measurements JF - IEEE Transactions on Microwave Theory and Techniques. 56 (2008), H. 11, 1 Y1 - 2008 SN - 0018-9480 SP - 2505 EP - 2510 ER - TY - JOUR A1 - Stulpe, Werner A1 - Busch, Paul T1 - The structure of classical extensions of quantum probability theory JF - Journal of Mathematical Physics. 49 (2008), H. 3 Y1 - 2008 SN - 1089-7658 N1 - 032104 SP - 1 EP - 22 ER - TY - JOUR A1 - Ciobanu, Octavian A1 - Staat, Manfred A1 - Rahimi, Alireza T1 - The use of open source software in biomechanical finite element analysis JF - Buletinul Institutului Politehnic din Iaşi / Universitatea Tehnică Gh. Asachi, Iaşi Secţia 5, Construcţii de maşini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta Y1 - 2008 SN - 1011-2855 VL - 54 IS - 7/8 SP - 213 EP - 220 ER - TY - JOUR A1 - Bialonski, Stephan A1 - Allefeld, Carsten A1 - Wellmer, Jörg A1 - Elger, Christian E. A1 - Lehnertz, Klaus T1 - An approach to identify synchronization clusters within the epileptic network JF - Klinische Neurophysiologie Y1 - 2008 U6 - https://doi.org/10.1055/s-2008-1072881 VL - 39 IS - 1 SP - A79 ER - TY - JOUR A1 - Frauenrath, Tobias A1 - Niendorf, Thoralf A1 - Kob, Malte T1 - Acoustic method for synchronization of Magnetic Resonance Imaging (MRI) JF - Acta Acustica N2 - Magnetic Resonance Imaging (MRI) of moving organs requires synchronization with physiological motion or flow, which dictate the viable window for data acquisition. To meet this challenge, this study proposes an acoustic gating device (ACG) that employs acquisition and processing of acoustic signals for synchronization while providing MRI compatibility, immunity to interferences with electro-magnetic and acoustic fields and suitability for MRI at high magnetic field strengths. The applicability and robustness of the acoustic gating approach is examined in a pilot study, where it substitutes conventional ECG-gating for cardiovascular MR. The merits and limitations of the ACG approach are discussed. Implications for MR imaging in the presence of physiological motion are considered including synchronization with other structure- or motion borne sounds. Y1 - 2008 U6 - https://doi.org/10.3813/AAA.918017 SN - 1861-9959 VL - 94 IS - 1 SP - 148 EP - 155 PB - Hirzel CY - Stuttgart ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios A1 - Baltzopoulos, Vasilios T1 - Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo JF - Journal of Biomechanics Y1 - 2008 U6 - https://doi.org/10.1016/j.jbiomech.2008.04.020 SN - 0021-9290 VL - 41 SP - 2211 EP - 2218 ER - TY - JOUR A1 - Jeromin, Günter Erich T1 - Superabsorbed alcohol dehydrogenase—a new catalyst for asymmetric reductions JF - Biotechnology Letters. 31 (2009), H. 11 Y1 - 2009 SN - 0141-5492 SP - 1717 EP - 1721 ER - TY - JOUR A1 - Enning, Manfred A1 - Baier, M. T1 - Energetic and operational use of FlexCargoRail freight wagons in the single wagon load traffic / Baier, M. ; Enning, M. JF - Towards zero emission : EVS 24, the 24th International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium & Exhibition, Stavanger, Norway, May 13 - 16, 2009 ; symposium proceedings / organised by AVERE ... Robert Stüssi [Hrsg.] Y1 - 2009 N1 - European Association of Electric Road Vehicles ; EVS ; (24 : ; 2009.05.13-16 : ; Stavanger) CY - Stavanger ER -