@inproceedings{EngelThieringerTippkoetter2016, author = {Engel, Mareike and Thieringer, Julia and Tippk{\"o}tter, Nils}, title = {Linking bioprocess engineering and electrochemistry for sustainable biofuel production}, series = {Young Researchers Symposium, YRS 2016. Proceedings}, booktitle = {Young Researchers Symposium, YRS 2016. Proceedings}, publisher = {Fraunhofer Verlag}, address = {Karlsruhe}, pages = {49 -- 53}, year = {2016}, abstract = {Electromicrobial engineering is an emerging, highly interdisciplinary research area linking bioprocesses with electrochemistry. In this work, microbial electrosynthesis (MES) of biobutanol is carried out during acetone-butanol-ethanol (ABE) fermentations with Clostridium acetobutylicum. A constant electric potential of -600mV (vs. Ag/AgCl) with simultaneous addition of the soluble redox mediator neutral red is used in order to study the electron transfer between the working electrode and the bacterial cells. The results show an earlier initiation of solvent production for all fermentations with applied potential compared to the conventional ABE fermentation. The f inal butanol concentration can be more than doubled by the application of a negative potential combined with addition of neutral red. Moreover a higher biofilm formation on the working electrode compared to control cultivations has been observed. In contrast to previous studies, our results also indicate that direct electron transfer (DET) might be possible with C. acetobutylicum. The presented results make microbial butanol production economically attractive and therefore support the development of sustainable production processes in the chemical industry aspired by the "Centre for resource-efficient chemistry and raw material change" as well as the the project "NanoKat" working on nanostructured catalysts in Kaiserslautern.}, language = {en} } @misc{TippkoetterPasteurUlber2012, author = {Tippk{\"o}tter, Nils and Pasteur, A. and Ulber, Roland}, title = {Magnetisch abtrennbare Gold-Nanopartikel zur katalytischen Zuckeroxidation}, series = {Chemie Ingenieur Technik}, volume = {84}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201250393}, pages = {1328}, year = {2012}, abstract = {Glucose ist ein prim{\"a}res Zwischenprodukt der Verarbeitung nachwachsender Rohstoffe, wie z. B. Cellulose. Die wertsteigernde Weiterverarbeitung des Monosaccharids erfolgt h{\"a}ufig in Form vonFermentationsprozessen, jedoch kann der Rohstoff auch f{\"u}r zahlreiche chemische Verarbeitungsstufen genutzt werden. Ein großtechnisch relevanter Prozess ist die Herstellung von Glucons{\"a}ure (GS), die u. a. als Nahrungsmittelzusatz (E 574) eingesetzt wird. Die Darstellung der S{\"a}ure erfolgt durch Oxidation von Glucose mit magnetisierbarem Gold-Nano-Katalysator. Die R{\"u}ckgewinnung des Katalysators aus der Reaktionsl{\"o}sung wurde unter Einwirkung eines Magnetfeldgradienten verwirklicht. Die Synthese der magnetischen Goldkatalysatoren (sowohl Tr{\"a}gerpartikel als auch Gold-Nanopartikel) wurde durch nass-chemische F{\"a}llungsreaktionen durchgef{\"u}hrt. Die Charakteristiken der neuen Materialen konnte durch Messungen des PCD-Potenzials, Laserbeugung und REM/EDX untersucht werden. So wurden u. a. Partikeldurchmesser von 25 lm und ein Goldgehaltvon 1,03 \% ermittelt. Weiterhin wurden f{\"u}r die Goldkatalysatoren optimale Reaktionsbedingungen f{\"u}r die Glucoseoxidation im geregelten R{\"u}hrkesselreaktor etabliert. Hierdurch konnten eine Produktselektivit{\"a}t von 100 \% und eine Wiederverwendbarkeit der Partikel {\"u}ber mindestens zehn Zyklen erreicht werden.}, language = {de} } @misc{SiekerTippkoetterUlberetal.2010, author = {Sieker, T. and Tippk{\"o}tter, Nils and Ulber, Roland and Bart, Hans-J{\"o}rg and Heinzle, E.}, title = {Gr{\"u}ne Bioraffinerie: Ganzheitliche Nutzung von Grassilage f{\"u}r die Herstellung von Grund-und Feinchemikalien}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201050321}, pages = {1564}, year = {2010}, abstract = {Gras hat ein hohes Potenzial als nachwachsender Rohstoff. Bei ungeeigneter Lagerung verderben Gr{\"a}ser allerdings innerhalb weniger Tage. Dieser Nachteil kann durch die Silierung des Grasschnittes behoben werden. Eines der wichtigsten in der Silage enthaltenen Produkte ist die Milchs{\"a}ure. Um diese f{\"u}r weitere Aufarbeitungsschritte zug{\"a}nglich zu machen, wird aus der Silage ein Presssaft hergestellt. Die Milchs{\"a}ure wird aus einem Silagepresssaft mittels Extraktion durch ionische Fl{\"u}ssigkeiten isoliert. Dabei wird zum einen eine reine Milchs{\"a}ure hergestellt, die z. B. f{\"u}r die Herstellung von Polymilchs{\"a}ure genutzt werden kann. Zum anderen wird ein weniger aufgereinigter Extrakt gewonnen, der f{\"u}r die fermentative Produktion von L-Lysin und 1,2-Propandiol genutzt werden soll. Im Rahmen des Projekts erfolgt die gentechnische Optimierung von Corynebacterium glutamicum f{\"u}r die Umsetzung von Milchs{\"a}urezu L-Lysin. Die im nach der Pressung verbleibenden Presskuchen enthaltenen Grasfasern bestehen zu einem großen Teil aus Polysacchariden. Diese werden hydrolysiert und die dabei freigesetzten Zucker zu Grundchemikalien wie Ethanol oder Itakons{\"a}ure fermentiert. Im Rahmen einer vollst{\"a}ndigen Nutzung der Silage wird das Raffinat aus der Milchs{\"a}ureextraktion als Mediumsupplement in der Fermentation eingesetzt, was die Zugabe weiterer Medienbestandteile {\"u}berfl{\"u}ssig macht. Die R{\"u}ckst{\"a}nde der Hydrolysen und Fermentationen sollen dar{\"u}berhinaus f{\"u}r die Herstellung von Biogas genutzt werden.}, language = {de} } @misc{TippkoetterUlber2009, author = {Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Eine magnetische horizontale Wirbelschicht f{\"u}r die Durchmischung und R{\"u}ckhaltung von magnetisierbaren Mikropartikeln im Durchfluss}, series = {Chemie Ingenieur Technik}, volume = {81}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.200950076}, pages = {1168}, year = {2009}, abstract = {Magnetisierbare Partikel als Tr{\"a}ger von Katalysatoren k{\"o}nnen durch Anlegen eines magnetisches Feldes einfach und schnell abgetrennt werden. Die Wiedergewinnung von wertvollen Enzymen unter geringem Energie- und Materialeinsatz der magnetischen Abtrennung er{\"o}ffnet einen Wettbewerbsvorteil f{\"u}r Produktionsprozesse. Die Abtrennung von magnetisierbaren Partikeln vom {\"U}berstand wird {\"u}blicherweise entweder durch Anlegen eines {\"a}ußeren Magnetfelds und der resultierenden Ablagerung der Partikel an den Reaktorw{\"a}nden oder durch Hochgradientenmagnetseparation (HGMS)durchgef{\"u}hrt. Beide Verfahren resultieren meist in der Bildung eines Filterkuchens aus Magnetpartikeln und den Feststoffen des Reaktionsmediums. Das magnetische horizontale Wirbelbett erm{\"o}glicht simultan eine kontinuierliche Reaktionsf{\"u}hrung und die R{\"u}ckhaltung der Partikel im Durchfluss. Die Partikelsuspension fließt durch einen Rohrreaktor, der in einem Magnetfeld mit wechselnden Feldgradienten eingebracht ist. Die {\"A}nderung des Magnetfeldgradienten erfolgt entgegen der Str{\"o}mungsrichtung der Reaktionsl{\"o}sung. Durch alternierende Feldmaxima an den beiden Seiten des Reaktors werden die magnetisierbaren Partikel zu dessen W{\"a}nden gezogen. Bei Umkehrung des Feldes wandern die Partikel an die gegen{\"u}berliegende Reaktorwand. Durch Wahl einer geeigneten Wechselfrequenz kann eine kontinuierliche Durchmischung und R{\"u}ckhaltung der Mikropartikel im durchstr{\"o}mten Rohr erreicht werden. Somit k{\"o}nnen Immobilisierungsreaktionen und Biotransformationen mit den Partikelsystemen im Durchfluss durchgef{\"u}hrt werden.}, language = {en} } @misc{TippkoetterSiekerWiesenetal.2014, author = {Tippk{\"o}tter, Nils and Sieker, T. and Wiesen, S. and Duwe, A. and Roth, J. and Ulber, Roland}, title = {Simultane Saccharifizierung und Fermentierung (SSF) sowie Produktion von Aceton, Butanol, Ethanol (ABE) und Dicarbons{\"a}uren aus technischer Cellulose}, series = {Chemie Ingenieur Technik}, volume = {86}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201450297}, pages = {1518}, year = {2014}, abstract = {Technische Cellulose wurde als m{\"o}glicher Rohstoff zur fermentativen Produktbildung untersucht. Hierf{\"u}r wird Cellulose in der Lignocellulose-Bioraffinerie hergestellt und daraus Hydrolysat gewonnen. Die Pr{\"u}fung der technischen Hydrolysate als Substrate erfolgte anhand eines breiten Spektrums an Bioprodukten, von Kraftstoffen wie Ethanolund Butanol, bis zu den Dicarbons{\"a}uren Itacon- und Bernsteins{\"a}ure. Dabei werden Bakterien, Hefen und Pilze als Produktionsorganismen eingesetzt. Die einzelnen Herstellverfahren stellen unterschiedliche Anforderungen an die Substrathandhabung. Im Fall der Ethanol- und Butanol-Gewinnung kann eine simultane Saccharifizierung und Fermentierung (SSF) durchgef{\"u}hrt werden. Aufgrund der Produkttoxizit{\"a}t erfordert die Butanol-Herstellung dabei eine In-situ-Produktabtrennung durch L{\"o}semittelimpr{\"a}gnierte Partikel. Die Herstellung der beiden Dicarbons{\"a}uren unterscheidet sich in der Sensitivit{\"a}t der verwendeten Mikroorganismen gegen{\"u}ber Inhibitoren, die in Spuren im Hydrolysat enthalten sind. Die Bernteins{\"a}urebildung mit Actinobacillussuccinogenes kann mit unbehandeltem Hydrolysat erfolgen. Dagegen erfordert die Gewinnung von Itacons{\"a}ure mit A. terreus eine Detoxifizierung des Hydrolysats. Insgesamt konnte gezeigt werden, dass s{\"a}mtliche Bioraffinerie-Hydrolysate als Substrate f{\"u}r unterschiedliche Fermentationen geeignet sind.}, language = {de} } @misc{WiesenTippkoetterDuweetal.2012, author = {Wiesen, S. and Tippk{\"o}tter, Nils and Duwe, A. and Ulber, Roland}, title = {Aceton-Butanol-Ethanol (ABE)-Fermentation von Organosolv-Holzhydrolysaten}, series = {Chemie Ingenieur Technik}, volume = {84}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201250262}, pages = {1308}, year = {2012}, abstract = {Die L{\"o}sungsmittelherstellung durch Clostridien konnte wirtschaftlich nicht mit der chemischen Synthese von L{\"o}sungsmitteln auf Erd{\"o}lbasis konkurrieren und wurde in den fr{\"u}hen 1960er Jahren nahezu vollst{\"a}ndig eingestellt. Das Interesse an nachwachsenden Rohstoffen hat in den letzten Jahren zu einem Wiederaufleben der ABE-Fermentation gef{\"u}hrt. Aufgrund seiner h{\"o}heren Energiedichte im Vergleich zu Ethanol ist Biobutanol als Energietr{\"a}gerbesonders interessant und bietet sich z. B. als Produkt einer Bioraffinerie der 2. Generation an. F{\"u}r die beschriebenen Experimente wird durch das Organosolv-Verfahren aufgeschlossenes Buchenholz verwendet. Der Faserstoff wird mithilfe von CTec2-Enzymen hydrolysiert, wobei der erhaltene {\"U}berstand eine Glucosekonzentration von 66 g L⁻¹ aufweist. Auf der Basis dieses Materials k{\"o}nnen mit Clostridium acetobutylicum Butanol-Ausbeuten erzielt werden, die mit denen unter Verwendung von reinen Zuckern vergleichbar sind. Dem Problem der hohen Produktinhibierung wird mit einer In-situ-Produktaufarbeitung begegnet. Mithilfe von L{\"o}sungsmittelimpr{\"a}gnierten Partikeln (SIPs) kann die Produktausbeute drastisch gesteigert werden, indem die gebildeten L{\"o}sungsmittel durch das auf dem Partikel impr{\"a}gnierte L{\"o}sungsmittel w{\"a}hrend der Fermentation extrahiert werden. Zudem wird hierdurch die weitere Produktaufarbeitungstark vereinfacht.}, language = {de} } @article{FrauenrathNiendorfKob2008, author = {Frauenrath, Tobias and Niendorf, Thoralf and Kob, Malte}, title = {Acoustic method for synchronization of Magnetic Resonance Imaging (MRI)}, series = {Acta Acustica}, volume = {94}, journal = {Acta Acustica}, number = {1}, publisher = {Hirzel}, address = {Stuttgart}, issn = {1861-9959}, doi = {10.3813/AAA.918017}, pages = {148 -- 155}, year = {2008}, abstract = {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.}, language = {en} } @inproceedings{EggertSchadeBroehletal.2024, author = {Eggert, Mathias and Schade, Maximilian and Br{\"o}hl, Florian and Moriz, Alexander}, title = {Generating synthetic LiDAR point cloud data for object detection using the Unreal Game Engine}, series = {Design Science Research for a Resilient Future (DESRIST 2024)}, booktitle = {Design Science Research for a Resilient Future (DESRIST 2024)}, editor = {Mandviwalla, Munir and S{\"o}llner, Matthias and Tuunanen, Tuure}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-61174-2 (Print)}, doi = {10.1007/978-3-031-61175-9_20}, pages = {295 -- 309}, year = {2024}, abstract = {Object detection based on artificial intelligence is ubiquitous in today's computer vision research and application. The training of the neural networks for object detection requires large and high-quality datasets. Besides datasets based on image data, datasets derived from point clouds offer several advantages. However, training datasets are sparse and their generation requires a lot of effort, especially in industrial domains. A solution to this issue offers the generation of synthetic point cloud data. Based on the design science research method, the work at hand proposes an approach and its instantiation for generating synthetic point cloud data based on the Unreal Engine. The point cloud quality is evaluated by comparing the synthetic cloud to a real-world point cloud. Within a practical example the applicability of the Unreal Game engine for synthetic point cloud generation could be successfully demonstrated.}, language = {de} } @misc{GraesslRenzHezeletal.2012, author = {Gr{\"a}ßl, Andreas and Renz, Wolfgang and Hezel, Fabian and Frauenrath, Tobias and Pfeiffer, Harald and Hoffmann, Werner and Kellmann, Peter and Martin, Conrad and Niendorf, Thoralf}, title = {Design, evaluation and application of a modular 32 channel transmit/receive surface coil array for cardiac MRI at 7T}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {Cardiac MR (CMR) at ultrahigh (≥7.0 T) fields is regarded as one of the most challenging MRI applications. At 7.0 T image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Detrimental effects bear the potential to spoil the signal-to-noise (SNR) and contrast-to-noise (CNR) benefits of cardiac MR (CMR) at 7.0 T. B₁⁺-inhomogeneities and signal voids represent the main challenges. Various pioneering coil concepts have been proposed to tackle these issues, enabling cardiac MRI at 7.0 T. This includes a trend towards an ever larger number of transmit and receive channels. This approach affords multi-dimensional B₁⁺ modulations to improve B₁⁺ shimming performance and to enhance RF efficiency. Also, parallel imaging benefits from a high number of receive channels enabling two-dimensional acceleration. Realizing the limitations of existing coil designs tailored for UHF CMR and recognizing the opportunities of a many element TX/RX channel architecture this work proposes a modular, two dimensional 32-channel transmit and receive array using loop elements and examines its efficacy for enhanced B¹+ homogeneity and improved parallel imaging performance.}, language = {en} } @misc{TkachenkovonKnobelsdorffBrenkenhoffKleindienstetal.2012, author = {Tkachenko, Valeriy and von Knobelsdorff-Brenkenhoff, Florian and Kleindienst, Denise and Winter, Lukas and Rieger, Jan and Frauenrath, Tobias and Dieringer, Matthias A. and Santoro, Davide and Niendorf, Thoralf and Schulz-Menger, Jeanette}, title = {Cardiovasular MR at 7Tesla: assessment of the right ventricle}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {The assessment of the right ventricle (RV) is a challenge in today's cardiology, but of growing clinical impact regarding patient prognosis in different cardiac diseases. The detection and differentiation of small wall motion abnormalities may help to enhance the differentiation of cardiomyopathies including Arrhythmogenic Rightventricular Cardiomyopathy. Cardiovascular magnetic resonance (CMR) at 1.5T is the accepted gold standard for RV quantification. The higher spatial resolution achievable at ultrahigh field strength (UHF) offers the potential to gain new insights into the structure and function of the RV. To approach this goal accurate RV chamber quantification at 7T has to be proven. Consequently this study examines the feasibility of assessment of RV dimensions and function at 7T using improved spatial resolution enabled by the intrinsic sensitivity gain of UHF CMR. For this purpose, a dedicated 16 channel TX/RX RF coil array is used together with 2D CINE fast gradient echo (FGRE) imaging. For comparison RV chamber quantification is conducted at 1.5T using a SSFP based state of the art clinical protocol.}, language = {en} } @misc{FrauenrathFuchsHezeletal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Hezel, Fabian and Dieringer, Matthias A. and Rieger, Jan and Niendorf, Thoralf}, title = {Improved cardiac triggering by combining multiple physiological signals: a cardiac MR feasibility study at 7.0 T}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {In current clinical cardiovascular MR (CMR) practice cardiac motion is commonly dealt with using ECG based synchronization. However, ECG is corrupted by magneto-hydrodynamic (MHD) effects in magnetic fields. This leads to artifacts in the ECG trace and evokes severe T-wave elevations, which might be misinterpreted as R-waves resulting in erroneous triggering. At (ultra)high field strengths, the propensity of ECG recordings to MHD effects is further pronounced. Pulse oximetry (POX) being inherently sensitive to blood oxygenation provides an alternative approach for cardiac gating. However, due to the travel time of the blood the peak of maximum oxygenation and hence the trigger is delayed by approx. 300 ms with respect to the ECG's R-wave. Also the peak of maximum oxygenation shows a jitter of up to 65 ms. Alternative triggering approaches include acoustic cardiac triggering (ACT). In current clinical practice cardiac gating / triggering commonly relies on using single physiological signals only. Realizing this limitation this study proposes a combined triggering approach which exploits multiple physiological signals including ECG, POX or ACT to track cardiac activity. The feasibility of the coupled approach is examined for LV function assessment at 7.0 T. For this purpose, breath-held 2D-CINE imaging in conjunction with cardiac synchronization was performed paralleled by real time logging of physiological waveforms to track (mis)synchronization between the cardiac cycle and data acquisition. Combinations of the ECG, POX and ACT signals were evaluated and processed in real time to facilitate reliable trigger information.}, language = {en} } @misc{FrauenrathPfeifferHezeletal.2012, author = {Frauenrath, Tobias and Pfeiffer, Harald and Hezel, Fabian and Dieringer, Matthias A. and Winter, Lukas and Gr{\"a}ßl, Andreas and Santoro, Davide and {\"O}zerdem, Celal and Renz, Wolfgang and Greiser, Andreas and Niendorf, Thoralf}, title = {Lessons learned from cardiac MRI at 7.0 T: LV function assessment at 3.0 T using local multi-channel transceiver coil arrays}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {Cardiac MR (CMR) is of proven clinical value but also an area of vigorous ongoing research since image quality is not always exclusively defined by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Recent developments of CMR at 7.0 T have been driven by pioneering explorations into novel multichannel transmit and receive coil array technology to tackle the challenges B1+-field inhomogeneities, to offset specific-absorption rate (SAR) constraints and to reduce banding artifacts in SSFP imaging. For this study, recognition of the benefits and performance of local surface Tx/Rx-array structures recently established at 7.0 T inspired migration to 3.0 T, where RF inhomogeneities and SAR limitations encountered in routine clinical CMR, though somewhat reduced versus the 7.0 T situation, remain significant. For all these reasons, this study was designed to build and examine the feasibility of a local four channel Tx/Rx cardiac coil array for anatomical and functional cardiac imaging at 3.0 T. For comparison, a homebuilt 4 channel Rx cardiac coil array exhibiting the same geometry as the Tx/Rx coil and a Rx surface coil array were used.}, language = {en} } @misc{LindelGreiserWaxmanetal.2012, author = {Lindel, Tomasz Dawid and Greiser, Andreas and Waxman, Patrick and Dietterle, Martin and Seifert, Frank and Fontius, Ulrich and Renz, Wolfgang and Dieringer, Matthias A. and Frauenrath, Tobias and Schulz-Menger, Jeanette and Niendorf, Thoralf and Ittermann, Bernd}, title = {Cardiac CINE MRI at 7 T using a transmit array}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {With its need for high SNR and short acquisition times, Cardiac MRI (CMR) is an intriguing target application for ultrahigh field MRI. Due to the sheer size of the upper torso, however, the known RF issues of 7T MRI are also most prominent in CMR. Recent years brought substantial progress but the full potential of the ultrahigh field for CMR is yet to be exploited. Parallel transmission (pTx) is a promising approach in this context and several groups have already reported B1 shimming for 7T CMR. In such a static pTx application amplitudes and phases of all Tx channels are adjusted individually but otherwise imaging techniques established in current clinical practice 1.5 T and 3 T are applied. More advanced forms of pTx as spatially selective excitation (SSE) using Transmit SENSE promise additional benefits like faster imaging with reduced fields of view or improved SAR control. SSE requires the full dynamic capabilities of pTx, however, and for the majority of today's implemented pTx hardware the internal synchronization of the Tx array does not easily permit external triggering as needed for CMR. Here we report a software solution to this problem and demonstrate the feasibility of CINE CMR at 7 T using a Tx array.}, language = {en} } @misc{WaicziesKuehneWinteretal.2013, author = {Waiczies, Helmar and K{\"u}hne, Andr{\´e} and Winter, Lukas and Frauenrath, Tobias and Hoffmann, Werner and Ittermann, Bernd and Waiczies, Sonia and Niendorf, Thoralf}, title = {Towards theranostics of rheumatoid arthritis: 1H/19F imaging of non-steroidal anti-inflammatory drugs in hand and wrist at 7 Tesla}, series = {2013 ISMRM Annual Meeting Proceedings}, journal = {2013 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2013}, abstract = {We have developed a double-tuned ¹H/¹⁹F birdcage resonator dedicated for hand and wrist imaging at 7 T to locally image non-steroidal anti-inflammatory drugs (NSAID) such as 2-{[3-(Trifluoromethyl) phenyl]amino}benzoic acid. The preliminary in vivo images acquired by the double-tuned ¹H/¹⁹F birdcage resonator demonstrate the feasibility for ¹H/¹⁹F hand- and wrist-imaging at 7 T. While the diagnostic quality of the coil needs to be assessed in patients with inflammatory rheumatoid disease, first ¹⁹F images of the NSAID are encouraging, and point towards the prospect of applying ¹⁹F-MRI to visualize and quantify the concentration of therapeutically-active compound at the sites of inflammation.}, language = {en} } @misc{RothkranzKrafftTippkoetter2022, author = {Rothkranz, Berit and Krafft, Simone and Tippk{\"o}tter, Nils}, title = {Media optimization for sustainable fuel production: How to produce biohydrogen from renewable resources with Thermotoga neapolitana}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255305}, pages = {1298 -- 1299}, year = {2022}, abstract = {Hydrogen is playing an increasingly important role in research and politics as an energy carrier of the future. Since hydrogen has commonly been produced from methane by steam reforming, the need for climate-friendly, alternative production routes is emerging. In addition to electrolysis, fermentative routes for the production of so-called biohydrogen are "green" alternatives. The application of microorganisms offers the advantage of sustainable production from renewable resources using easily manageable technologies. In this project, the hyperthermophilic, anaerobic microorganism Thermotoga neapolitana is used for the productio nof biohydrogen from renewable resources. The enzymatically hydrolyzed resources were used in fermentation leading to yield coefficients of 1.8 mole H₂ per mole glucose when using hydrolyzed straw and ryegrass supplemented with medium, respectively. These results are similar to the hydrogen yields when using Thermotoga basal medium with glucose (TBGY) as control group. In order to minimize the supplementation of the hydrolysate and thus increase the economic efficiency of the process, the essential media components were identified. The experiments revealed NaCl, KCl, and glucose as essential components for cell growth as well as biohydrogen production. When excluding NaCl, a decrease of 96\% in hydrogen production occured.}, language = {en} } @misc{VarrialeKukaTippkoetteretal.2022, author = {Varriale, Ludovica and Kuka, Katrin and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Use of a green biomass in a biorefinery platform}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255095}, pages = {1299}, year = {2022}, abstract = {The emerging environmental issues due to the use of fossil resources are encouraging the exploration of new renewable resources. Biomasses are attracting more interest due to the low environmental impacts, low costs, and high availability on earth. In this scenario, green biorefineries are a promising platform in which green biomasses are used as feedstock. Grasses are mainly composed of cellulose and hemicellulose, and lignin is available in a small amount. In this work, a perennial ryegrass was used as feedstock to develop a green bio-refinery platform. Firstly, the grass was mechanically pretreated, thus obtaining a press juice and a press cake fraction. The press juice has high nutritional values and can be employed as part of fermentation media. The press cake can be employed as a substrate either in enzymatic hydrolysis or in solid-state fermentation. The overall aim of this work was to demonstrate different applications of both the liquid and the solid fractions. For this purpose, the filamentous fungus A. niger and the yeast Y. lipolythica were selected for their ability to produce citric acid. Finally, the possibility was assessed to use the press juice as part of fermentation media to cultivate S. cerevisiae and lactic acid bacteria for ethanol and lactic acid fermentation.}, language = {en} } @misc{KrafftKukaUlberetal.2022, author = {Krafft, Simone and Kuka, Katrin and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Utilization of Lolium perenne varieties as a renewable substrate for single-cell proteins, lactate, and composite materials}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255306}, pages = {1303 -- 1304}, year = {2022}, abstract = {Lolium perenne (perennial ryegrass) is aproductive and high-quality forage grass indigenous to Southern Europe, temperate Asia, and North Africa. Nowadays it is widespread and the dominant grass species on green areas in temperate climates. This abundant source of biomass is suitable for the development of bioeconomic processes because of its high cellulose and water-soluble carbohydrate content. In this work, novel breeds of the perennial ryegrass are being examined with regards to their quality parameters and biotechnological utilization options within the context of bioeconomy. Three processing operations are presented. In the first process, the perennial ryegrass is pretreated by pressing or hydrothermal extraction to derive glucosevia subsequent enzymatic hydrolysis of cellulose. A yield of up to 82 \% glucose was achieved when using the hydrothermal ex-traction as pretreatment. In a second process, the ryegrass is used to produce lactic acid in high concentrations. The influence of the growth conditions and the cutting time on the carboxylic acid yield is investigated. A yield of lactic acid of above 150 g kg⁻¹ dry matter was achieved. The third process is to use Lolium perenne as a substrate in the fermentation of K. marxianus for the microbial production of single-cell proteins. The perennial ryegrass is screw-pressed and the press juice is used as medium. When supplementing the press juice with yeast media components, a biomass concentration of up to 16 g L⁻¹ could be achieved.}, language = {en} } @misc{BraunKrafftTippkoetter2022, author = {Braun, Lena and Krafft, Simone and Tippk{\"o}tter, Nils}, title = {Combined supercritical carbon dioxide extraction and chromatography of the algae fatty linoleic and linolenic acid}, series = {Chemie Ingenieur Technik}, volume = {94}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.202255308}, pages = {1304}, year = {2022}, abstract = {A method for the integrated extraction and separation of fatty acids from algae using supercritical CO2 is presented. Desmodesmus obliquus and Chlorella sorokiniana were used as algae. First, a method for chromatographic separation of fatty acids of different degrees of saturation was established and optimized. Then, an integrated method for supercritical extraction was developed for both algal species. It was also verified whether prior cell disruption was beneficial for extraction. In developing the method for chromatographic separation, statistical experimental design was used to determine the optimal parameter settings. The methanol content in the mobile phase proved to be the most important parameter for successful separation of the three unsaturated fatty acids oleic acid, linoleic acid, and linolenic acid. Supercritical extraction with dried algae showed that about four times more fatty acids can be extracted from C. sorokiniana relative to the dry mass used.}, language = {en} } @techreport{Tippkoetter2021, author = {Tippk{\"o}tter, Nils}, title = {TreBec - Herstellung eines Mehrwegbechers aus Treber : Sachbericht zum Verwendungsnachweis}, publisher = {FH Aachen}, address = {J{\"u}lich}, doi = {10.2314/KXP:1858723302}, pages = {10 Seiten}, year = {2021}, abstract = {Laufzeit des Vorhabens und Berichtszeitraum: 01.10.2020-30.09.2021}, language = {de} } @article{Timme2024, author = {Timme, Michael}, title = {Kaufvertrag: Das Zusammentreffen von Beschaffenheitsvereinbarung und Gew{\"a}hrleistungsausschluss - ein Spannungsverh{\"a}ltnis}, series = {Monatsschrift f{\"u}r Deutsches Recht}, volume = {78}, journal = {Monatsschrift f{\"u}r Deutsches Recht}, number = {12}, publisher = {Verlag Dr. Otto Schmidt}, address = {K{\"o}ln}, issn = {2194-4202 (online)}, doi = {10.9785/mdtr-2024-781203}, pages = {745 -- 748}, year = {2024}, abstract = {Wer A sagt, muss zumindest im Kaufrecht nicht immer B sagen: Es kommt nicht selten vor, dass sich in einem Kaufvertrag einerseits ein wirksamer Ausschluss der Gew{\"a}hrleistung des Verk{\"a}ufers f{\"u}r Sachm{\"a}ngel findet, die Parteien aber andererseits gleichwohl eine Beschaffenheitsvereinbarung f{\"u}r bestimmte Eigenschaften vertraglich festlegen. In diesem Problemfeld f{\"u}hrt eine aktuelle Entscheidung des BGH zu weiteren Kl{\"a}rungen f{\"u}r die Praxis (BGH, Urt. v. 10.4.2024 - VIII ZR 161/23, MDR 2024, 706). Der folgende Beitrag setzt sich mit den vielf{\"a}ltigen Aspekten der Entscheidung auseinander und erl{\"a}utert, aus welchen Gr{\"u}nden der BGH dem K{\"a}ufer einige goldene Br{\"u}cken f{\"u}r einen Schadensersatzanspruch gebaut hat.}, language = {de} }