TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard A1 - Erpicum, Sebastien A1 - Peltier, Yann A1 - Dewals, Benjamin T1 - Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling JF - Journal of Hydro-environment Research N2 - Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models). KW - coherent structures KW - hydraulic modelling KW - model performance KW - Proper Orthogonal Decomposition KW - Q-criterion Y1 - 2022 U6 - https://doi.org/10.1016/j.jher.2022.03.002 SN - 1570-6443 IS - In Press PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Müller-Veggian, Mattea A1 - Jannsens, R. A1 - Masri, Y. El. A1 - Michel, C. T1 - Untersuchung der Hochspinzustände in ¹⁷⁸,¹⁸⁰ Os JF - Frühjahrstagung ... des Fachausschusses Kernphysik und Hochenergiephysik der DPG (Sektion A: Kernphysik) / Deutsche Physikalische Gesellschaft. 11 (1976) Y1 - 1976 N1 - Verhandlungen der Deutschen Physikalischen Gesellschaft ; 1976=6.R.11,8 SP - 950 ER - TY - THES A1 - Pham, Phu Tinh T1 - Upper bound limit and shakedown analysis of elastic-plastic bounded linearly kinematic hardening structures Y1 - 2011 N1 - Aachen, Techn. Hochsch., Diss., 2011 PB - RWTH Aachen University CY - Aachen ER - TY - JOUR A1 - Tran, Thanh Ngoc A1 - Kreißig, R. A1 - Vu, Duc Khoi A1 - Staat, Manfred T1 - Upper bound limit and shakedown analysis of shells using the exact Ilyushin yield surface JF - Computer & Structures. 86 (2008) Y1 - 2008 SN - 0045-7949 SP - 1683 EP - 1695 ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, Friedhart A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, Ewald T1 - Uranium Toxicity in the State of Punjab in North-Western India T2 - Management of Natural Resources in a Changing Environment N2 - Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity. Y1 - 2015 SN - 978-3-319-12559-6 U6 - https://doi.org/10.1007/978-3-319-12559-6_21 SP - 271 EP - 275 PB - Springer CY - Cham ER - TY - THES A1 - Seifarth, Volker T1 - Ureteral tissue engineering : development of a bioreactor system and subsequent characterization of the generated biohybrids Y1 - 2015 N1 - Duisburg, Essen, Universität Duisburg-Essen, Diss., 2015 PB - Universitätsbibliothek Duisburg-Essen CY - Duisburg ; Essen ER - TY - JOUR A1 - Foltz, Christian A1 - Schneider, Nicole A1 - Wolf, Martin R. A1 - Kausch, Bernhard A1 - Schlick, Christopher A1 - Luczak, Holger ED - Nagl, Manfred T1 - Usability engineering JF - Collaborative and distributed chemical engineering : from understanding to substantial design process support; results of the IMPROVE Project. - (Lecture notes in computer science ; 4970) Y1 - 2008 SN - 978-3-540-70552-9 U6 - https://doi.org/10.1007/978-3-540-70552-9_21 SP - 527 EP - 554 PB - Springer CY - Berlin ER - TY - CHAP A1 - Fuchs, Britta A1 - Ritz, Thomas T1 - Usability for Blended Shopping - Solving Major Flaws by Applying Usability Engineering and Proven Integration Technologies T2 - Proceedings of the 11th International Conference on e-Business, ICE-B 2014, Vienna, Austria Y1 - 2014 SN - 978-989-758-043-7 U6 - https://doi.org/10.5220/0005113502160223 SP - 216 EP - 223 ER - TY - CHAP A1 - Fuchs, Britta A1 - Ritz, Thomas A1 - Strauch, Jakob ED - Obaidat, Mohammad S. T1 - Usability of mobile applications : dissemination of usability engineering in small and medium enterprises T2 - Proceedings of the International Conference on Data Communication Networking, e-Business and Optical Communication Systems : Rome, Italy, 24 - 27 July, 2012 ; [integrated in the ICETE (International Conference on e-Business and Telecommunications)] Y1 - 2012 SN - 978-989-8565-23-5 N1 - Nebentitel: DCNET; ICE-B; OPTICS SP - 272 EP - 277 PB - SciTePress CY - [Lissabon] ER - TY - JOUR A1 - Digel, Ilya A1 - Akimbekov, Nuraly S. A1 - Turalieva, M. A1 - Mansurov, Z. A1 - Temiz Artmann, Aysegül A1 - Eshibaev, A. A1 - Zhubanova, A. T1 - Usage of Carbonized Plant Wastes for Purification of Aqueous Solutions JF - Journal of Industrial Technology and Engineering Y1 - 2013 VL - 2 IS - 07 SP - 47 EP - 54 ER - TY - CHAP A1 - Ulmer, Jessica A1 - Braun, Sebastian A1 - Cheng, Chi-Tsun A1 - Dowey, Steve A1 - Wollert, Jörg T1 - Usage of digital twins for gamification applications in manufacturing T2 - Procedia CIRP Leading manufacturing systems transformation – Proceedings of the 55th CIRP Conference on Manufacturing Systems 2022 N2 - Gamification applications are on the rise in the manufacturing sector to customize working scenarios, offer user-specific feedback, and provide personalized learning offerings. Commonly, different sensors are integrated into work environments to track workers’ actions. Game elements are selected according to the work task and users’ preferences. However, implementing gamified workplaces remains challenging as different data sources must be established, evaluated, and connected. Developers often require information from several areas of the companies to offer meaningful gamification strategies for their employees. Moreover, work environments and the associated support systems are usually not flexible enough to adapt to personal needs. Digital twins are one primary possibility to create a uniform data approach that can provide semantic information to gamification applications. Frequently, several digital twins have to interact with each other to provide information about the workplace, the manufacturing process, and the knowledge of the employees. This research aims to create an overview of existing digital twin approaches for digital support systems and presents a concept to use digital twins for gamified support and training systems. The concept is based upon the Reference Architecture Industry 4.0 (RAMI 4.0) and includes information about the whole life cycle of the assets. It is applied to an existing gamified training system and evaluated in the Industry 4.0 model factory by an example of a handle mounting. KW - Gamification KW - Digital Twin KW - Support System Y1 - 2022 U6 - https://doi.org/10.1016/j.procir.2022.05.044 SN - 2212-8271 N1 - 55th CIRP Conference on Manufacturing Systems, Jun 29, 2022 - Jul 01, 2022, Lugano, Switzerland VL - 107 SP - 675 EP - 680 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Haselgruber, Nikolaus A1 - Mautner, Karin A1 - Thiele, Jan T1 - Usage Space Analysis for Reliability Testing JF - Quality and Reliability Engineering International N2 - During the development process of a complex technical product, one widely used and important technique is accelerated testing where the applied stress on a component is chosen to exceed the reference stress, i.e. the stress encountered in field operation, in order to reduce the time to failure. For that, the reference stress has to be known. Since a complex technical product may fail regarding numerous failure modes, stress in general is highly dimensional rather than scalar. In addition, customers use their products individually, i.e. field operation should be described by a distribution rather than by one scalar stress value. In this paper, a way to span the customer usage space is shown. It allows the identification of worst case reference stress profiles in significantly reduced dimensions with minimal loss of information. The application example shows that even for a complex product like a combustion engine, stress information can be compressed significantly. With low measurement effort it turned out that only three reference stress cycles were sufficient to cover a broad range of customer stress variety. Y1 - 2010 U6 - https://doi.org/10.1002/qre.1155 SN - 1099-1638 N1 - Special Issue: Business and Industrial Statistics: Developments and Industrial Practices in Quality and Reliability VL - 26 IS - 8 SP - 877 EP - 885 PB - Wiley CY - New York ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Sun, Q. A1 - Meireles, I. A1 - Matos, J. A1 - Viseu, T. T1 - USBR type III stilling basin performance for steep stepped spillways T2 - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto Y1 - 2012 SN - 978-989-8509-01-7 ER - TY - JOUR A1 - Scherer, Ulrich W. A1 - Baltensperger, Urs A1 - Ammann, Markus A1 - Bochert, Ulrich K. T1 - Use of 13N for Studies of the Selective Reduction of NO by NH3 over Vanadia/Titania Catalyst at Very Low Reactant Concentrations / Urs Baltensperger, Markus Ammann, Ulrich K. Bochert, Bernd Eichler, Heinz W. Gäggeler, Dieter T. Jost, Joseph A. Kovacs, An JF - Journal of Physical Chemistry. 97 (1993) Y1 - 1993 SN - 0022-3654 SP - 12325 EP - 12330 ER - TY - GEN A1 - Varriale, Ludovica A1 - Kuka, Katrin A1 - Tippkötter, Nils A1 - Ulber, Roland T1 - Use of a green biomass in a biorefinery platform T2 - Chemie Ingenieur Technik N2 - 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. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255095 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1299 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Zhubanova, Azhar A. A1 - Mansurov, Zulkhair A. A1 - Digel, Ilya T1 - Use of Advanced Nanomaterials for Bioremediation of Contaminated Ecosystems T2 - Carbon Nanomaterials in Biomedicine and the Environment N2 - This chapter shows that nanomaterials obtained by high-temperature carbonization of inexpensive plant raw material such as rice husk, grape seeds, and walnut shells can serve as a basis for the production of highly efficient microbial drugs, biodestructors, biosorbents, and biocatalysts, which are promising for the remediation of the ecosystem contaminated with heavy and radioactive metals, oil and oil products. A strong interest in engineering zymology is dictated by the necessity to address the issues of monitoring enzymatic processes, treatment, and diagnosis of a number of common human diseases, environmental pollution, quality control of pharmaceuticals and food. Nanomaterials obtained by high-temperature carbonization of cheap plant raw material such as-rice husks, grape seeds and walnut shells, can serve as a basis for creating of highly effective microbial preparations-biodestructors, biosorbents and biocatalysts, which are promising for the use of contaminated ecosystems, and for restoration of human intestine microecology. Y1 - 2020 SN - 978-981-4800-27-3 U6 - https://doi.org/10.1201/9780429428647-18 SP - 353 EP - 378 PB - Jenny Stanford Publishing CY - Singapore ER - TY - JOUR A1 - Akimbekov, Nuraly S. A1 - Zhubanova, A. A. A1 - Mansurov, Z. A. A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Use of Carbonized Rise Shell for the local treatment of wounds JF - Eurasian ChemTech Journal N2 - On the model of musculocutaneous wound in rats, the effect of applicative sorption by carbonized rise shell (CRS) on the healing of festering wound was studied. It has been shown, that cytological changes end with rapid scar formation. The use of CRS at the period of severe purulent wound contributes to its favorable course, prevents the development of complications of the animals from sepsis. Y1 - 2010 U6 - https://doi.org/10.18321/ectj35 SN - 2522-4867 VL - 12 IS - 2 SP - 133 EP - 138 PB - Institute of Combustion Problems CY - Almaty ER - TY - JOUR A1 - Siqueira, Jose R. A1 - Maki, Rafael M. A1 - Paulovich, Fernando V. A1 - Werner, Frederik A1 - Poghossian, Arshak A1 - Oliveira, Maria C. F. de A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Use of Information Visualization Methods Eliminating Cross Talk in Multiple Sensing Units Investigated for a Light-Addressable Potentiometric Sensor JF - Analytical Chemistry (2010) Y1 - 2010 SN - 0003-2700 SP - 61 EP - 65 ER - TY - JOUR A1 - Scheer, Nico A1 - Campos-Ortega, José A. T1 - Use of the Gal4-UAS technique for targeted gene expression in the zebrafish JF - Mechanism of Development Y1 - 1999 U6 - https://doi.org/10.1016/S0925-4773(98)00209-3 SN - 0925-4773 VL - 80 IS - 2 SP - 153 EP - 158 ER - TY - JOUR A1 - Garhofer, Gerhard A1 - Bek, Toke A1 - Boehm, Andreas G. A1 - Gherghel, Doina A1 - Grundwald, Juan A1 - Jeppesen, Peter A1 - Kergoat, Hélène A1 - Kotliar, Konstantin A1 - Lanzl, Ines A1 - Lovasik, John V. A1 - Nagel, Edgar A1 - Vilser, Walthard A1 - Orgul, Selim A1 - Schmetterer, Leopold T1 - Use of the retinal vessel analyzer in ocular blood flow research JF - Acta Ophthalmol N2 - The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed. Y1 - 2010 U6 - https://doi.org/10.1111/j.1755-3768.2009.01587.x SN - 1755-3768 VL - 88 IS - 7 SP - 717 EP - 722 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Using a cell-based gas biosensor for investigation of adverse effects of acetone vapors in vitro JF - Biosensors and Bioelectronics. 40 (2013), H. 1 Y1 - 2013 SN - 0956-5663 SP - 393 EP - 400 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Schreiber, Marc A1 - Barkschat, Kai A1 - Kraft, Bodo T1 - Using Continuous Integration to organize and monitor the annotation process of domain specific corpora T2 - 5th International Conference on Information and Communication Systems (ICICS) : 1-3 April 2014, Irbid, Jordanien Y1 - 2014 SN - 978-1-4799-3022-7 U6 - https://doi.org/10.1109/IACS.2014.6841958 SP - 1 EP - 6 ER - TY - JOUR A1 - Ferrein, Alexander A1 - Fritz, Christian A1 - Lakemeyer, Gerhard T1 - Using Golog for Deliberation and Team Coordination in Robotic Soccer / Ferrein, Alexander ; Fritz, Christian ; Lakemeyer, Gerhard JF - Künstliche Intelligenz : KI. 19 (2005), H. 1 Y1 - 2005 SN - 0933-1875 SP - 24 EP - 30 ER - TY - JOUR A1 - Biener, Ernst A1 - Sasse, T. A1 - Wernhoff, T. T1 - Using harbour dredged material for combination sealing of the former Bockhorner Weg disposal site in Bremen, Germany JF - Proceedings of the International Harbour Congress. 13 (2003) Y1 - 2003 N1 - International Harbour Congress <13, 2003, Antwerpen> SP - 101 EP - 109 ER - TY - CHAP A1 - Rausch, Lea A1 - Friesen, John A1 - Altherr, Lena A1 - Pelz, Peter F. ED - Kliewer, Natalia ED - Ehmke, Jan Fabian ED - Borndörfer, Ralf T1 - Using mixed-integer programming for the optimal design of water supply networks for slums T2 - Operations Research Proceedings 2017 N2 - The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh. Y1 - 2018 SN - 978-3-319-89919-0 (Print) SN - 978-3-319-89920-6 (Online) U6 - https://doi.org/10.1007/978-3-319-89920-6_68 N1 - International Conference of the German Operations Research Society (GOR), Freie Universiät Berlin, Germany, September 6-8, 2017. SP - 509 EP - 516 PB - Springer CY - Cham ER - TY - CHAP A1 - Funke, Harald A1 - Esch, Thomas A1 - Roosen, Peter ED - Bartz, Wilfried J. T1 - Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship T2 - Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009 N2 - The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 % v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security. Y1 - 2009 SN - 978-3-924813-75-8 SP - 237 EP - 244 PB - Technische Akademie Esslingen (TAE) CY - Ostfildern ER - TY - CHAP A1 - Franzen, Julian A1 - Stecken, Jannis A1 - Pfaff, Raphael A1 - Kuhlenkötter, Bernd T1 - Using the Digital Shadow for a Prescriptive Optimization of Maintenance and Operation : The Locomotive in the Context of the Cyber-Physical System T2 - Advances in Production, Logistics and Traffic N2 - In competition with other modes of transport, rail freight transport is looking for solutions to become more attractive. Short-term success can be achieved through the data-driven optimization of operations and maintenance as well as the application of novel strategies such as prescriptive maintenance. After introducing the concept of prescriptive maintenance, this paper aims to prove that vehicle-focused applications of this approach indeed have the potential to increase attractiveness. However, even greater advantages can be activated if data from the horizontal network of the vehicle is available. Drawing on the state of the art in research and technology in the field of cyber-physical systems (CPS) as well as digital twins and shadows, our work serves to design a system of systems for the horizontal interconnection of a rail vehicle and to conceptualize a draft for a digital twin of a locomotive. Y1 - 2019 SN - 978-3-030-13535-5 U6 - https://doi.org/10.1007/978-3-030-13535-5_19 SP - 265 EP - 276 PB - Springer CY - Cham ER - TY - JOUR A1 - Zange, Jochen A1 - Schopen, Kathrin A1 - Albracht, Kirsten A1 - Gerlach, Darius A. A1 - Frings-Meuthen, Petra A1 - Maffiuletti, Nicola A. A1 - Bloch, Wilhelm A1 - Rittweger, Jörn T1 - Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial JF - Plos one Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0171562 VL - 12 IS - 2 ER - TY - JOUR A1 - Hüning, Felix T1 - Using Trench PowerMOSFETs in Linear Mode JF - Power Electronics Europe (2012) N2 - If we think about applications for modern Power MOSFETs using trench technology, running them in linear mode may not be top of the priority list. Yet there are multiple uses for Trench Power MOSFETs in linear mode. In fact, even turning the device on and off in switching applications is a form of linear operation. Also, these components can be run in linear mode to protect the device against voltage surges. This article will illustrate the factors that need to be considered for linear operation and show how Trench Power MOSFETs are suited to it. Y1 - 2012 SN - 1748-3530 SP - 27 EP - 29 PB - DFA Media CY - Tonbridge ER - TY - JOUR A1 - Wagner, Torsten A1 - Miyamoto, K. A1 - Werner, Frederik A1 - Schöning, Michael Josef A1 - Yoshinobu, T. T1 - Utilising Digital Micro-Mirror Device (DMD) as Scanning Light Source for Light-Addressable Potentiometric Sensors (LAPS) Y1 - 2011 U6 - https://doi.org/10.1166/sl.2011.1620 VL - 9 IS - 2 SP - 812 EP - 815 PB - American Scientific Publishers CY - Stevenson Ranch, Calif. ER - TY - CHAP A1 - Azar, Fouad A1 - Digel, Ilya ED - Staat, Manfred ED - Erni, Daniel T1 - Utilization of fluorescence spectroscopy and neural networks in clinical analysis T2 - 3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen N2 - Fluorescence topography of human urine in combination with learning algorithms can provide a variant pattern recognition method in analytical clinical chemistry and, eventually, diagnosis. Y1 - 2019 SN - 978-3-940402-22-6 U6 - https://doi.org/10.17185/duepublico/48750 SP - 40 EP - 41 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - GEN A1 - Krafft, Simone A1 - Kuka, Katrin A1 - Ulber, Roland A1 - Tippkötter, Nils T1 - Utilization of Lolium perenne varieties as a renewable substrate for single-cell proteins, lactate, and composite materials T2 - Chemie Ingenieur Technik N2 - 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. Y1 - 2022 U6 - https://doi.org/10.1002/cite.202255306 SN - 0009-286X SN - 1522-2640 (eISSN) N1 - ProcessNet and DECHEMA‐BioTechNet Jahrestagungen 2022 together with 13th ESBES Symposium 2022, 12. - 15. September 2022, Eurogress Aachen VL - 94 IS - 9 SP - 1303 EP - 1304 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Blome, Hans-Joachim A1 - Priester, Wolfgang T1 - Vacuum energy in cosmic dynamics JF - Astrophysics and Space Science. 117 (1985), H. 2 Y1 - 1985 SN - 0004-640X SP - 327 EP - 335 ER - TY - JOUR A1 - Hagemann, Hans-Jürgen A1 - Ihrig, H. T1 - Valence change and phase stability of 3d-doped BaTiO3 annealed in oxygen and hydrogen. Hagemann, H. J.; Ihrig, H. JF - Physical Review B.. 20 (1979), H. 9 Y1 - 1979 SN - 1095-3795 SP - 3871 EP - 3878 ER - TY - JOUR A1 - Müller, Martin A1 - Hirschfeld, Julian A1 - Lambertz, Rita A1 - Schulze Lohoff, Andreas A1 - Lustfeld, Hans A1 - Pfeifer, Heinz A1 - Reißel, Martin T1 - Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks JF - Journal of power sources N2 - In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents. Y1 - 2014 U6 - https://doi.org/10.1016/j.jpowsour.2014.08.045 SN - 1873-2755 (E-Journal); 0378-7753 (Print) VL - 272 SP - 225 EP - 232 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Müller, Tim M. A1 - Schmitt, Andreas A1 - Leise, Philipp A1 - Meck, Tobias A1 - Altherr, Lena A1 - Pelz, Peter F. A1 - Pfetsch, Marc E. T1 - Validation of an optimized resilient water supply system T2 - Uncertainty in Mechanical Engineering N2 - Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems. KW - Optimization KW - Mixed-integer nonlinear programming KW - Water distribution system KW - Resilience KW - Validation Y1 - 2021 SN - 978-3-030-77255-0 SN - 978-3-030-77256-7 U6 - https://doi.org/10.1007/978-3-030-77256-7_7 N1 - Proceedings of the 4th International Conference on Uncertainty in Mechanical Engineering (ICUME 2021), June 7–8, 2021 SP - 70 EP - 80 PB - Springer CY - Cham ER - TY - JOUR A1 - Ziemons, Karl A1 - Heinrichs, U. A1 - Streun, M. A1 - Pietrzyk, U. T1 - Validation of GEANT3 simulation studies with a dual-head PMT ClearPET™ prototype JF - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 5 N2 - The ClearPET™ project is proposed by working groups of the Crystal Clear Collaboration (CCC) to develop a 2nd generation high performance small animal positron emission tomograph (PET). High sensitivity and high spatial resolution is foreseen for the ClearPET™ camera by using a phoswich arrangement combining mixed lutetium yttrium aluminum perovskite (LuYAP:Ce) and lutetium oxyorthosilicate (LSO) scintillating crystals. Design optimizations for the first photomultiplier tube (PMT) based ClearPET camera are done with a Monte-Carlo simulation package implemented on GEANT3 (CERN, Geneva, Switzerland). A dual-head prototype has been built to test the frontend electronics and was used to validate the implementation of the GEANT3 simulation tool. Multiple simulations were performed following the experimental protocols to measure the intrinsic resolution and the sensitivity profile in axial and radial direction. Including a mean energy resolution of about 27.0% the simulated intrinsic resolution is about (1.41±0.11)mm compared to the measured of (1.48±0.06)mm. The simulated sensitivity profiles show a mean square deviation of 12.6% in axial direction and 3.6% in radial direction. Satisfactorily these results are representative for all designs and confirm the scanner geometry. Y1 - 2004 SN - 1082-3654 SP - 3053 EP - 3056 ER - TY - JOUR A1 - German, Laura A1 - Mikucki, Jill A. A1 - Welch, Susan A. A1 - Welch, Kathleen A. A1 - Lutton, Anthony A1 - Dachwald, Bernd A1 - Kowalski, Julia A1 - Heinen, Dirk A1 - Feldmann, Marco A1 - Francke, Gero A1 - Espe, Clemens A1 - Lyons, W. Berry T1 - Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry JF - International Journal of Environmental Analytical Chemistry N2 - Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe’s sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2−+NO3− from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica. Y1 - 2021 U6 - https://doi.org/10.1080/03067319.2019.1704750 SN - 0306-7319 VL - 101 IS - 15 SP - 2654 EP - 2667 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Jablonowski, Nicolai David A1 - Kollmann, Tobias A1 - Nabel, Moritz A1 - Damm, Tatjana A1 - Klose, Holger A1 - Müller, Michael A1 - Bläsing, Marc A1 - Seebold, Sören A1 - Krafft, Simone A1 - Kuperjans, Isabel A1 - Dahmen, Markus A1 - Schurr, Ulrich T1 - Valorization of Sida (Sida hermaphrodita) biomass for multiple energy purposes JF - GCB [Global Change Biology] Bioenergy N2 - The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha⁻¹, whereas the highest dry matter of 70% to 80% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha⁻¹; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500 °C, associated with a net calorific value of 16.5–17.2 MJ kg⁻¹. All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications. Y1 - 2016 U6 - https://doi.org/10.1111/gcbb.12346 SN - 1757-1707 (online) SN - 1757-1693 (print) N1 - Special Issue: Perennial biomass crops for a resource constrained world VL - 9 IS - 1 SP - 202 EP - 214 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Yazdanbakhsh, Pedram A1 - Solbach, Klaus A1 - Bitz, Andreas T1 - Variable power combiner for RF mode shimming in 7-T MR imaging JF - IEEE Transaction on Biomedical Engineering N2 - This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers’ input signals. The power distribution at the output ports of the VPC is then fed into the “mode” ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17% to 60% and from 14% to 55% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level. Y1 - 2012 U6 - https://doi.org/10.1109/TBME.2012.2205926 SN - 1558-2531 VL - 59 IS - 9 SP - 2549 EP - 2557 PB - IEEE CY - New York ER - TY - JOUR A1 - Conzen, Catharina A1 - Albanna, Walid A1 - Weiss, Miriam A1 - Kürten, David A1 - Vilser, Walthard A1 - Kotliar, Konstantin A1 - Zäske, Charlotte A1 - Clusmann, Hans A1 - Schubert, Gerrit Alexander T1 - Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes JF - Translational Stroke Research N2 - Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5–14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome. Y1 - 2018 U6 - https://doi.org/10.1007/s12975-017-0585-8 SN - 1868-601X IS - 9 SP - 284 EP - 293 PB - Springer Nature CY - Cham ER - TY - CHAP A1 - Blum, Yannik A1 - Albanna, Walid A1 - Benninghaus, Anne A1 - Kotliar, Konstantin ED - Staat, Manfred ED - Erni, Daniel T1 - Vasomotion in retinal vessels of patients presenting post hemorrhagic hydrocephalus following subarachnoid hemorrhage T2 - 3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen N2 - Clearance of blood components and fluid drainage play a crucial role in subarachnoid hemorrhage (SAH) and post hemorrhagic hydrocephalus (PHH). With the involvement of interstitial fluid (ISF) and cerebrospinal fluid (CSF), two pathways for the clearance of fluid and solutes in the brain are proposed. Starting at the level of capillaries, flow of ISF follows along the basement membranes in the walls of cerebral arteries out of the parenchyma to drain into the lymphatics and CSF [1]–[3]. Conversely, it is shown that CSF enters the parenchyma between glial and pial basement membranes of penetrating arteries [4]–[6]. Nevertheless, the involved structures and the contribution of either flow pathway to fluid balance between the subarachnoid space and interstitial space remains controversial. Low frequency oscillations in vascular tone are referred to as vasomotion and corresponding vasomotion waves are modeled as the driving force for flow of ISF out of the parenchyma [7]. Retinal vessel analysis (RVA) allows non-invasive measurement of retinal vessel vasomotion with respect to diameter changes [8]. Thus, the aim of the study is to investigate vasomotion in RVA signals of SAH and PHH patients. Y1 - 2019 SN - 978-3-940402-22-6 U6 - https://doi.org/10.17185/duepublico/48750 SP - 38 EP - 39 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - JOUR A1 - Giresini, Linda A1 - Sassu, Mauro A1 - Butenweg, Christoph A1 - Alecci, Valerio A1 - De Stefano, Mario T1 - Vault macro-element with equivalent trusses in global seismic analyses JF - Earthquakes and Structures N2 - This paper proposes a quick and simplified method to describe masonry vaults in global seismic analyses of buildings. An equivalent macro-element constituted by a set of six trusses, two for each transverse, longitudinal and diagonal direction, is introduced. The equivalent trusses, whose stiffness is calculated by fully modeled vaults of different geometry, mechanical properties and boundary conditions, simulate the vault in both global analysis and local analysis, such as kinematic or rocking approaches. A parametric study was carried out to investigate the influence of geometrical characteristics and mechanical features on the equivalent stiffness values. The method was numerically validated by performing modal and transient analysis on a three naves-church in the elastic range. Vibration modes and displacement time-histories were compared showing satisfying agreement between the complete and the simplified models. This procedure is particularly useful in engineering practice because it allows to assess, in a simplified way, the effectiveness of strengthening interventions for reducing horizontal relative displacements between vault supports. KW - vault KW - macro-element KW - equivalent stiffness KW - truss KW - churches Y1 - 2017 U6 - https://doi.org/10.12989/eas.2017.12.4.409 SN - 2092-7614 (Print) SN - 2092-7622 (Online) VL - 12 IS - 4 SP - 409 EP - 423 PB - Techno-Press CY - Taejŏn ER - TY - JOUR A1 - Pieper, Martin T1 - Vector hyperinterpolation on the sphere JF - Journal of approximation theory. 156 (2009), H. 2 Y1 - 2009 SN - 0021-9045 SP - 173 EP - 186 ER - TY - JOUR A1 - Heuermann, Holger A1 - Ibrahim, Irfan A1 - Hillebrand, J. T1 - Vector-Signal-Generator with Two ¿¿-PLL's / Ibrahim, I. ; Hillebrand, J. ; Heuermann, H. JF - European Conference on Wireless Technologies, 2007. ECWT 2007 ; 8 - 10 October 2007 Munich, Germany Y1 - 2007 SN - 978-2-87487-003-3 SP - 1 EP - 4 ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel Bernhard T1 - Vectrino profiler spatial filtering for shear flows based on the mean velocity gradient equation JF - Journal of Hydraulic Engineering N2 - A new methodology is proposed to spatially filter acoustic Doppler velocimetry data from a Vectrino profiler based on the differential mean velocity equation. Lower and upper bounds are formulated in terms of physically based flow constraints. Practical implementation is discussed, and its application is tested against data gathered from an open-channel flow over a stepped macroroughness surface. The method has proven to detect outliers occurring all over the distance range sampled by the Vectrino profiler and has shown to remain applicable out of the region of validity of the velocity gradient equation. Finally, a statistical analysis suggests that physically obtained bounds are asymptotically representative. Y1 - 2018 U6 - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001485 SN - 0733-9429 N1 - Article number 04018037 VL - 144 IS - 7 PB - ASCE CY - Reston, Va. ER - TY - CHAP A1 - Döring, Bernd A1 - Ziller, Claudia A1 - Hortmanns, M. T1 - Ventilation of double facades by external dynamic wind pressure T2 - 11th International Conference on Wind Engineering. 1 Y1 - 2003 SP - 721 EP - 730 PB - The Wind Science and Engineering Research Center CY - Lubbock, Tex. ER - TY - CHAP A1 - Tewari, Udit A1 - Neshvad, Surena A1 - Goldbach, Daniel A1 - Sachau, Jürgen T1 - Verification and Implementation of Pseudo-Random-Binary-Sequences for Online Determination of Grid Impedance Spectrum T2 - International Conference on Renewable Energies and Power Quality (ICREPQ´15), La Conuna, Spain, 25th to 27th March, 2015 Y1 - 2015 ER - TY - JOUR A1 - Helsper, Christoph A1 - Fißan, H. J. A1 - Muggli, J. A1 - Scheidweiler, A. T1 - Verification of Ionization Chamber Theory JF - Fire Technology. 19 (1983), H. 1 Y1 - 1983 SN - 1572-8099 SP - 14 EP - 21 ER - TY - JOUR A1 - Heierli, Joachim A1 - Purves, Ross S. A1 - Felber, Andreas A1 - Kowalski, Julia T1 - Verification of nearest-neighbours interpretations in avalanche forecasting JF - Annals of Glaciology N2 - This paper examines the positive and negative aspects of a range of interpretations of nearest-neighbours models. Measures-oriented and distributionoriented verification methods are applied to categorial, probabilistic and descriptive interpretations of nearest neighbours used operationally in avalanche forecasting in Scotland and Switzerland. The dependence of skill and accuracy measures on base rate is illustrated. The purpose of the forecast and the definition of events are important variables in determining the quality of the forecast. A discussion of the application of different interpretations in operational avalanche forecasting is presented. KW - avalanche Y1 - 2004 SN - 1727-5644 VL - 38 IS - 1 SP - 84 EP - 88 ER -