@article{RuebbelkeVoegeleGrajewskietal.2022, author = {R{\"u}bbelke, Dirk and V{\"o}gele, Stefan and Grajewski, Matthias and Zobel, Luzy}, title = {Hydrogen-based steel production and global climate protection: An empirical analysis of the potential role of a European cross border adjustment mechanism}, series = {Journal of Cleaner Production}, volume = {380}, journal = {Journal of Cleaner Production}, number = {Part 2, Art. Nr.:135040}, publisher = {Elsevier}, issn = {0959-6526}, doi = {10.1016/j.jclepro.2022.135040}, year = {2022}, abstract = {The European Union's aim to become climate neutral by 2050 necessitates ambitious efforts to reduce carbon emissions. Large reductions can be attained particularly in energy intensive sectors like iron and steel. In order to prevent the relocation of such industries outside the EU in the course of tightening environmental regulations, the establishment of a climate club jointly with other large emitters and alternatively the unilateral implementation of an international cross-border carbon tax mechanism are proposed. This article focuses on the latter option choosing the steel sector as an example. In particular, we investigate the financial conditions under which a European cross border mechanism is capable to protect hydrogen-based steel production routes employed in Europe against more polluting competition from abroad. By using a floor price model, we assess the competitiveness of different steel production routes in selected countries. We evaluate the climate friendliness of steel production on the basis of specific GHG emissions. In addition, we utilize an input-output price model. It enables us to assess impacts of rising cost of steel production on commodities using steel as intermediates. Our results raise concerns that a cross-border tax mechanism will not suffice to bring about competitiveness of hydrogen-based steel production in Europe because the cost tends to remain higher than the cost of steel production in e.g. China. Steel is a classic example for a good used mainly as intermediate for other products. Therefore, a cross-border tax mechanism for steel will increase the price of products produced in the EU that require steel as an input. This can in turn adversely affect competitiveness of these sectors. Hence, the effects of higher steel costs on European exports should be borne in mind and could require the cross-border adjustment mechanism to also subsidize exports.}, language = {en} } @article{ThielMufflerTippkoetteretal.2015, author = {Thiel, Alexander and Muffler, Kai and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Hruschka, Steffen M. and Ulber, Roland}, title = {A novel integrated downstream processing approach to recover sinapic acid, phytic acid and proteins from rapeseed meal}, series = {Journal of Chemical Technology and Biotechnology}, volume = {90}, journal = {Journal of Chemical Technology and Biotechnology}, number = {11}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/jctb.4664}, pages = {1999 -- 2006}, year = {2015}, abstract = {BACKGROUND Currently, several techniques exist for the downstream processing of protein, phytic acid and sinapic acid from rapeseed and rapeseed meal, but no technique has been developed to separate all of the components in one process. In this work, two new downstream processing strategies focusing on recovering sinapic acid, phytic acid and protein from rapeseed meal were established. RESULTS The sinapic acid content was enhanced by a factor of 4.5 with one method and 5.1 with the other. The isolation of sinapic acid was accomplished using a zeolite-based adsorbent with high adsorptive and optimal desorption characteristics. Phytic acid was isolated using the anion-exchange resin Purolite A200®. In addition, the processes resulted in two separated protein fractions. The ratios of globulin and albumin ratio to the total protein were 59.2\% and 40.1\%, respectively. The steps were then combined in two different ways: (a) a 'sequential process' using the zeolite and A200 in batch processes; and (b) a 'parallel process' using only A200 in a chromatographic system to separate all of the compounds. CONCLUSIONS It can be concluded that isolation of all three components was possible in both processes. These could enhance the added value of current processes using rapeseed meal as a protein source. © 2015 Society of Chemical Industry}, language = {en} } @article{AlKaidyTippkoetter2016, author = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils}, title = {Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase}, series = {Engineering in Life Sciences}, volume = {16}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/elsc.201400124}, pages = {222 -- 230}, year = {2016}, abstract = {In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1-30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established.}, language = {en} } @article{Ritz2000, author = {Ritz, Thomas}, title = {Information Channels}, series = {Information Technology. Nr. 52 (2000), H. 08. Mai 2000}, journal = {Information Technology. Nr. 52 (2000), H. 08. Mai 2000}, pages = {15 -- 15}, year = {2000}, language = {en} } @article{EngelBayerHoltmannetal.2019, author = {Engel, Mareike and Bayer, Hendrik and Holtmann, Dirk and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Flavin secretion of Clostridium acetobutylicum in a bioelectrochemical system - Is an iron limitation involved?}, series = {Bioelectrochemistry}, journal = {Bioelectrochemistry}, number = {In Press, Accepted Manuscript}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1567-5394}, doi = {10.1016/j.bioelechem.2019.05.014}, year = {2019}, language = {en} } @article{RensVarzinczakMeyeretal.2010, author = {Rens, Gavin and Varzinczak, Ivan and Meyer, Thomas and Ferrein, Alexander}, title = {A Logic for Reasoning about Actions and Explicit Observations}, series = {AI 2010: Advances in Artificial Intelligence 23rd Australasian Joint Conference, Adelaide, Australia, December 7-10, 2010. Proceedings}, journal = {AI 2010: Advances in Artificial Intelligence 23rd Australasian Joint Conference, Adelaide, Australia, December 7-10, 2010. Proceedings}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-17431-5}, pages = {395 -- 404}, year = {2010}, language = {en} } @article{HeuermannSchiek1995, author = {Heuermann, Holger and Schiek, Burkhard}, title = {The double-LNN Calibration technique for scattering parameter measurements of microstrip devices}, series = {Conference proceedings}, journal = {Conference proceedings}, publisher = {NEXUS House}, address = {Kent}, pages = {343 -- 347}, year = {1995}, language = {en} } @article{KronhardtAlexopoulosReisseletal.2014, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Sattler, Johannes Christoph and Hoffschmidt, Bernhard and H{\"a}nel, Matthias and Doerbeck, Till}, title = {High-temperature thermal storage system for solar tower power plants with open-volumetric air receiver simulation and energy balancing of a discretized model}, series = {Energy procedia}, volume = {49}, journal = {Energy procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102 (E-Journal) ; 1876-6102 (Print)}, doi = {10.1016/j.egypro.2014.03.094}, pages = {870 -- 877}, year = {2014}, abstract = {This paper describes the modeling of a high-temperature storage system for an existing solar tower power plant with open volumetric receiver technology, which uses air as heat transfer medium (HTF). The storage system model has been developed in the simulation environment Matlab/Simulink®. The storage type under investigation is a packed bed thermal energy storage system which has the characteristics of a regenerator. Thermal energy can be stored and discharged as required via the HTF air. The air mass flow distribution is controlled by valves, and the mass flow by two blowers. The thermal storage operation strategy has a direct and significant impact on the energetic and economic efficiency of the solar tower power plants.}, language = {en} } @article{Laack2013, author = {Laack, Walter van}, title = {Why natural constants are as they are}, series = {British journal of arts and social sciences}, volume = {Vol. 15}, journal = {British journal of arts and social sciences}, number = {Nr. 2}, publisher = {BritishJournal Publ. Inc}, address = {London}, issn = {2046-9578 (E-Journal)}, pages = {198 -- 203}, year = {2013}, language = {en} } @article{FerreinNiemuellerSteinbauer2010, author = {Ferrein, Alexander and Niem{\"u}ller, Tim and Steinbauer, Gerald}, title = {Team Zadeat 2010 : application for participation}, pages = {5 Seiten}, year = {2010}, language = {en} } @article{Heuermann1996, author = {Heuermann, Holger}, title = {Sure Methods of On-Wafer Scattering Parameter Measurements with Self-Calibration Procedures}, pages = {136 -- 145}, year = {1996}, language = {en} } @article{OertelBung2015, author = {Oertel, Mario and Bung, Daniel Bernhard}, title = {Stability and scour development of bed material on crossbar block ramps}, series = {International journal of sediment research}, volume = {30}, journal = {International journal of sediment research}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1001-6279}, doi = {10.1016/j.ijsrc.2014.12.003}, pages = {344 -- 350}, year = {2015}, abstract = {Block ramps are ecologically oriented drop structures with adequate energy dissipation and partially moderate flow velocities. A special case is given with crossbar block ramps, where the upstream and downstream level difference is reduced by a series of basins. To prevent the total structure from failing, the stability of single boulders within the crossbars and the bed material in between must be guaranteed. The present paper addresses the stability of bed material and scour development for various flow regimes. Any bed material erosion may affect the stability of the crossbar boulders, which in turn can result in major damages of the ramp. Therefore new design approaches are developed to choose an appropriate bed material size and to avoid failures of crossbar block ramp structures.}, language = {en} } @article{HoffmannRohrbachUhletal.2022, author = {Hoffmann, Andreas and Rohrbach, Felix and Uhl, Matthias and Ceblin, Maximilian and Bauer, Thomas and Mallah, Marcel and Jacob, Timo and Heuermann, Holger and Kuehne, Alexander J. C.}, title = {Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing}, series = {Journal of Applied Polymer Science}, volume = {139}, journal = {Journal of Applied Polymer Science}, number = {37}, publisher = {Wiley}, issn = {0021-8995 (Print)}, doi = {10.1002/app.52887}, pages = {1 -- 9}, year = {2022}, abstract = {Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance.}, language = {en} } @article{FerreinDyllaLakemeyer2003, author = {Ferrein, Alexander and Dylla, Frank and Lakemeyer, Gerhard}, title = {Specifying Multirobot Coordination in ICPGolog - From Simulation towards Real Robots / Dylla, Frank ; Ferrein, Alexander ; Lakemeyer, Gerhard}, pages = {1 -- 10}, year = {2003}, language = {en} } @article{StaatHeitzer1997, author = {Staat, Manfred and Heitzer, M.}, title = {Limit and Shakedown Analysis for Plastic Safety of Complex Structures}, series = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]}, journal = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]}, address = {Lyon}, pages = {33 -- 40}, year = {1997}, language = {en} } @article{Heuermann2003, author = {Heuermann, Holger}, title = {GSOLT: the calibration procedure for all multi-port vector network analyzers}, series = {IEEE MTT-S International Microwave Symposium digest : Philadelphia, Pennsylvania, 8 - 13 June 2003 ; [including: 2003 International Microwave Symposium digest, vol. 1-3, RF Integrated Circuit Symposium digest, Automatic RF Techniques Group Symposium digest . Vol. 3}, journal = {IEEE MTT-S International Microwave Symposium digest : Philadelphia, Pennsylvania, 8 - 13 June 2003 ; [including: 2003 International Microwave Symposium digest, vol. 1-3, RF Integrated Circuit Symposium digest, Automatic RF Techniques Group Symposium digest . Vol. 3}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {0-780-37696-X}, pages = {1815 -- 1818}, year = {2003}, language = {en} } @article{Heuermann1997, author = {Heuermann, Holger}, title = {Microwave On-Wafer Measurements with Activ Needle Probe Tips}, pages = {208 -- 214}, year = {1997}, language = {en} } @article{StulpeGudderHagler1988, author = {Stulpe, Werner and Gudder, S. and Hagler, J.}, title = {An Uncertainty Relation for Joint Position-Momentum Measurements}, series = {Foundations of Physics Letters. 1 (1988), H. 3}, journal = {Foundations of Physics Letters. 1 (1988), H. 3}, isbn = {1572-9524}, pages = {287 -- 292}, year = {1988}, language = {en} } @article{HeuermannLuenebach2005, author = {Heuermann, Holger and L{\"u}nebach, M.}, title = {A Novel Dual-Mode-Design for Push-Push Oscillators with Improved Phase Noise Performance. Heuermann, Holger; L{\"u}nebach, M.}, series = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 1}, journal = {Conference proceedings : 3 - 7 October 2005, CNIT la D{\´e}fense, Paris, France; [comprises the] 35th European Microwave Conference 2005 ; The European Conference on Wireless Technology 2005 ; European Radar Conference 2005 ; GAAS 2005, The European Gallium A. Vol. 1}, publisher = {Horizon House Publ}, address = {London}, isbn = {2-9600551-0-1}, pages = {4 pp.}, year = {2005}, language = {en} } @article{GoettscheGabryschSchilleretal.2004, author = {G{\"o}ttsche, Joachim and Gabrysch, K. and Schiller, H. and Kauert, B. and Schwarzer, Klemens}, title = {Energetic Effects of demand - controlled ventilation retrofitting in a biochemical laboratory building}, series = {AIVC publications [Elektronische Ressource] / Air Infiltration and Ventilation Centre}, journal = {AIVC publications [Elektronische Ressource] / Air Infiltration and Ventilation Centre}, publisher = {INIVE EEIG}, address = {Brussels}, pages = {50}, year = {2004}, language = {en} } @article{Ritz2002, author = {Ritz, Thomas}, title = {Modelling Production of personalized information services and their delivery on multiple distribution channels}, series = {Personalization Techniques in Electronic Publishing on the Web. Workshop in the Framework of the 2nd international conference on Adaptive Hypermedia and adaptive web based systems (AH2002) in Malaga (ES)}, journal = {Personalization Techniques in Electronic Publishing on the Web. Workshop in the Framework of the 2nd international conference on Adaptive Hypermedia and adaptive web based systems (AH2002) in Malaga (ES)}, pages = {19 -- 30}, year = {2002}, language = {en} } @article{SiekerNeunerDimitrovaetal.2011, author = {Sieker, Tim and Neuner, Andreas and Dimitrova, Darina and Tippk{\"o}tter, Nils and Muffler, Kai and Bart, Hans-J{\"o}rg and Heinzle, Elmar and Ulber, Roland}, title = {Ethanol production from grass silage by simultaneous pretreatment, saccharification and fermentation: First steps in the process development}, series = {Engineering in Life Sciences}, volume = {11}, journal = {Engineering in Life Sciences}, number = {4}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/elsc.201000160}, pages = {436 -- 442}, year = {2011}, abstract = {Grass silage provides a great potential as renewable feedstock. Two fractions of the grass silage, a press juice and the fiber fraction, were evaluated for their possible use for bioethanol production. Direct production of ethanol from press juice is not possible due to high concentrations of organic acids. For the fiber fraction, alkaline peroxide or enzymatic pretreatment was used, which removes the phenolic acids in the cell wall. In this study, we demonstrate the possibility to integrate the enzymatic pretreatment with a simultaneous saccharification and fermentation to achieve ethanol production from grass silage in a one-process step. Achieved yields were about 53 g ethanol per kg silage with the alkaline peroxide pretreatment and 91 g/kg with the enzymatic pretreatment at concentrations of 8.5 and 14.6 g/L, respectively. Furthermore, it was shown that additional supplementation of the fermentation medium with vitamins, trace elements and nutrient salts is not necessary when the press juice is directly used in the fermentation step.}, language = {en} } @article{SchaelAtanasyanBerdugoetal.2019, author = {Schael, S. and Atanasyan, A. and Berdugo, J. and Bretz, T. and Czupalla, Markus and Dachwald, Bernd and Doetinchem, P. von and Duranti, M. and Gast, H. and Karpinski, W. and Kirn, T. and L{\"u}belsmeyer, K. and Ma{\~n}a, C. and Marrocchesi, P.S. and Mertsch, P. and Moskalenko, I.V. and Schervan, T. and Schluse, M. and Schr{\"o}der, K.-U. and Schultz von Dratzig, A. and Senatore, C. and Spies, L. and Wakely, S.P. and Wlochal, M. and Uglietti, D. and Zimmermann, J.}, title = {AMS-100: The next generation magnetic spectrometer in space - An international science platform for physics and astrophysics at Lagrange point 2}, series = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, volume = {944}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, number = {162561}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-9002}, doi = {10.1016/j.nima.2019.162561}, year = {2019}, language = {en} } @article{GrajewskiHronTurek2005, author = {Grajewski, Matthias and Hron, Jaroslav and Turek, Stefan}, title = {Dual weighted a posteriori error estimation for a new nonconforming linear finite element on quadrilaterals}, series = {Applied Numerical Mathematics}, volume = {54}, journal = {Applied Numerical Mathematics}, number = {3-4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-9274}, doi = {10.1016/j.apnum.2004.09.016}, pages = {504 -- 518}, year = {2005}, abstract = {After a short introduction of a new nonconforming linear finite element on quadrilaterals recently developed by Park, we derive a dual weighted residual-based a posteriori error estimator (in the sense of Becker and Rannacher) for this finite element. By computing a corresponding dual solution we estimate the error with respect to a given target error functional. The reliability and efficiency of this estimator is analyzed in several numerical experiments.}, language = {en} } @article{DachwaldSeboldt2003, author = {Dachwald, Bernd and Seboldt, Wolfgang}, title = {Solar sailcraft of the first generation mission applications to near-earth asteroids}, year = {2003}, language = {en} } @article{CapitainWagnerHummeletal.2021, author = {Capitain, Charlotte and Wagner, Sebastian and Hummel, Joana and Tippk{\"o}tter, Nils}, title = {Investigation of C-N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion}, series = {Waste and Biomass Valorization}, volume = {12}, journal = {Waste and Biomass Valorization}, publisher = {Springer Nature}, address = {Cham}, issn = {1877-265X}, doi = {10.1007/s12649-020-01110-5}, pages = {1761 -- 1779}, year = {2021}, language = {en} } @article{FerreinSteinbauerVassos2012, author = {Ferrein, Alexander and Steinbauer, Gerald and Vassos, Stavros}, title = {Action-Based Imperative Programming with YAGI}, pages = {24 -- 31}, year = {2012}, abstract = {Many tasks for autonomous agents or robots are best described by a specification of the environment and a specification of the available actions the agent or robot can perform. Combining such a specification with the possibility to imperatively program a robot or agent is what we call the actionbased imperative programming. One of the most successful such approaches is Golog. In this paper, we draft a proposal for a new robot programming language YAGI, which is based on the action-based imperative programming paradigm. Our goal is to design a small, portable stand-alone YAGI interpreter. We combine the benefits of a principled domain specification with a clean, small and simple programming language, which does not exploit any side-effects from the implementation language. We discuss general requirements of action-based programming languages and outline YAGI, our action-based language approach which particularly aims at embeddability.}, language = {en} } @article{DefosseKleinschmidtSchmutzetal.2022, author = {Defosse, Jerome and Kleinschmidt, Joris and Schmutz, Axel and Loop, Torsten and Staat, Manfred and Gatzweiler, Karl-Heinz and Wappler, Frank and Schieren, Mark}, title = {Dental strain on maxillary incisors during tracheal intubation with double-lumen tubes and different laryngoscopy techniques - a blinded manikin study}, series = {Journal of Cardiothoracic and Vascular Anesthesia}, volume = {36}, journal = {Journal of Cardiothoracic and Vascular Anesthesia}, number = {8, Part B}, publisher = {Elsevier}, address = {New York, NY}, issn = {1053-0770}, doi = {10.1053/j.jvca.2022.02.017}, pages = {3021 -- 3027}, year = {2022}, language = {en} } @article{ArtmannDigelZerlinetal.2009, author = {Artmann, Gerhard and Digel, Ilya and Zerlin, Kay and Maggakis-Kelemen, Christina and Linder, Peter and Porst, Dariusz and Kayser, Peter and Stadler, David and Dikta, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Hemoglobin senses body temperature}, series = {European Biophysics Journal}, volume = {38}, journal = {European Biophysics Journal}, number = {5}, isbn = {0175-7571}, pages = {589 -- 600}, year = {2009}, language = {en} } @article{DemirciTrzewikLinderetal.2004, author = {Demirci, T. and Trzewik, J. and Linder, Peter and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Mechanical Stimulation of 3T3 Fibroblasts Activates Genes: Real Time PCR Products and Suppliers by Comparison}, series = {Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2}, journal = {Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2}, isbn = {0932-4666}, pages = {1046 -- 1047}, year = {2004}, language = {en} } @article{KowalskiLinderZierkeetal.2016, author = {Kowalski, Julia and Linder, Peter and Zierke, S. and Wulfen, B. van and Clemens, J. and Konstantinidis, K. and Ameres, G. and Hoffmann, R. and Mikucki, J. and Tulaczyk, S. and Funke, O. and Blandfort, D. and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecker, S. and Plescher, Engelbert and Sch{\"o}ngarth, Sarah and Dachwald, Bernd and Digel, Ilya and Artmann, Gerhard and Eliseev, D. and Heinen, D. and Scholz, F. and Wiebusch, C. and Macht, S. and Bestmann, U. and Reineking, T. and Zetzsche, C. and Schill, K. and F{\"o}rstner, R. and Niedermeier, H. and Szumski, A. and Eissfeller, B. and Naumann, U. and Helbing, K.}, title = {Navigation technology for exploration of glacier ice with maneuverable melting probes}, series = {Cold Regions Science and Technology}, journal = {Cold Regions Science and Technology}, number = {123}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0165-232X}, doi = {10.1016/j.coldregions.2015.11.006}, pages = {53 -- 70}, year = {2016}, abstract = {The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.}, language = {en} } @article{HandtkeSchroeterJuergenetal.2014, author = {Handtke, Stefan and Schroeter, Rebecca and J{\"u}rgen, Britta and Methling, Karen and Schl{\"u}ter, Rabea and Albrecht, Dirk and Hijum, Sacha A. F. T. van and Bongaerts, Johannes and Maurer, Karl-Heinz and Lalk, Michael and Schweder, Thomas and Hecker, Michael and Voigt, Birgit}, title = {Bacillus pumilus reveals a remarkably high resistance to hydrogen peroxide provoked oxidative stress}, series = {PLOS one}, volume = {9}, journal = {PLOS one}, number = {1}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0085625}, pages = {e85625}, year = {2014}, abstract = {Bacillus pumilus is characterized by a higher oxidative stress resistance than other comparable industrially relevant Bacilli such as B. subtilis or B. licheniformis. In this study the response of B. pumilus to oxidative stress was investigated during a treatment with high concentrations of hydrogen peroxide at the proteome, transcriptome and metabolome level. Genes/proteins belonging to regulons, which are known to have important functions in the oxidative stress response of other organisms, were found to be upregulated, such as the Fur, Spx, SOS or CtsR regulon. Strikingly, parts of the fundamental PerR regulon responding to peroxide stress in B. subtilis are not encoded in the B. pumilus genome. Thus, B. pumilus misses the catalase KatA, the DNA-protection protein MrgA or the alkyl hydroperoxide reductase AhpCF. Data of this study suggests that the catalase KatX2 takes over the function of the missing KatA in the oxidative stress response of B. pumilus. The genome-wide expression analysis revealed an induction of bacillithiol (Cys-GlcN-malate, BSH) relevant genes. An analysis of the intracellular metabolites detected high intracellular levels of this protective metabolite, which indicates the importance of bacillithiol in the peroxide stress resistance of B. pumilus.}, language = {en} } @article{RossiWinandsButenweg2022, author = {Rossi, Leonardo and Winands, Mark H. M. and Butenweg, Christoph}, title = {Monte Carlo Tree Search as an intelligent search tool in structural design problems}, series = {Engineering with Computers : An International Journal for Simulation-Based Engineering}, volume = {38}, journal = {Engineering with Computers : An International Journal for Simulation-Based Engineering}, number = {4}, editor = {Zhang, Jessica}, publisher = {Springer Nature}, address = {Cham}, issn = {1435-5663}, doi = {10.1007/s00366-021-01338-2}, pages = {3219 -- 3236}, year = {2022}, abstract = {Monte Carlo Tree Search (MCTS) is a search technique that in the last decade emerged as a major breakthrough for Artificial Intelligence applications regarding board- and video-games. In 2016, AlphaGo, an MCTS-based software agent, outperformed the human world champion of the board game Go. This game was for long considered almost infeasible for machines, due to its immense search space and the need for a long-term strategy. Since this historical success, MCTS is considered as an effective new approach for many other scientific and technical problems. Interestingly, civil structural engineering, as a discipline, offers many tasks whose solution may benefit from intelligent search and in particular from adopting MCTS as a search tool. In this work, we show how MCTS can be adapted to search for suitable solutions of a structural engineering design problem. The problem consists of choosing the load-bearing elements in a reference reinforced concrete structure, so to achieve a set of specific dynamic characteristics. In the paper, we report the results obtained by applying both a plain and a hybrid version of single-agent MCTS. The hybrid approach consists of an integration of both MCTS and classic Genetic Algorithm (GA), the latter also serving as a term of comparison for the results. The study's outcomes may open new perspectives for the adoption of MCTS as a design tool for civil engineers.}, language = {en} } @article{SadykovDigelTemizArtmannetal.2009, author = {Sadykov, Rustam and Digel, Ilya and Temiz Artmann, Ayseg{\"u}l and Porst, Dariusz and Linder, Peter and Kayser, Peter and Artmann, Gerhard and Savitskaya, Irina and Zhubanova, Azhar}, title = {Oral lead exposure induces dysbacteriosis in rats}, series = {Journal of Occupational Health. 51 (2009) (2009), H. 1}, journal = {Journal of Occupational Health. 51 (2009) (2009), H. 1}, isbn = {1348-9585}, pages = {64 -- 73}, year = {2009}, language = {en} } @article{TrzewikTemizArtmannLinderetal.2004, author = {Trzewik, J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Linder, Peter and Demirci, T. and Digel, Ilya and Artmann, Gerhard}, title = {Evaluation of lateral mechanical tension in thin-film tissue constructs}, series = {Annals of Biomedical Engineering. 32 (2004), H. 9}, journal = {Annals of Biomedical Engineering. 32 (2004), H. 9}, isbn = {1573-9686}, pages = {1243 -- 1251}, year = {2004}, language = {en} } @article{BhattaraiJabbariAndingetal.2018, author = {Bhattarai, Aroj and Jabbari, Medisa and Anding, Ralf and Staat, Manfred}, title = {Surgical treatment of vaginal vault prolapse using different prosthetic mesh implants: a finite element analysis}, series = {tm - Technisches Messen}, volume = {85}, journal = {tm - Technisches Messen}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {2196-7113}, doi = {10.1515/teme-2017-0115}, pages = {331 -- 342}, year = {2018}, abstract = {Particularly multiparous elderly women may suffer from vaginal vault prolapse after hysterectomy due to weak support from lax apical ligaments. A decreased amount of estrogen and progesterone in older age is assumed to remodel the collagen thereby reducing tissue stiffness. Sacrocolpopexy is either performed as open or laparoscopic surgery using prosthetic mesh implants to substitute lax ligaments. Y-shaped mesh models (DynaMesh, Gynemesh, and Ultrapro) are implanted in a 3D female pelvic floor finite element model in the extraperitoneal space from the vaginal cuff to the first sacral (S1) bone below promontory. Numerical simulations are conducted during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues are modeled as incompressible, isotropic hyperelastic materials whereas the meshes are modeled either as orthotropic linear elastic or as isotropic hyperlastic materials. The positions of the vaginal cuff and the bladder base are calculated from the pubococcygeal line for female pelvic floor at rest, for prolapse and after repair using the three meshes. Due to mesh mechanics and mesh pore deformation along the loaded direction, the DynaMesh with regular rectangular mesh pores is found to provide better mechanical support to the organs than the Gynemesh and the Ultrapro with irregular hexagonal mesh pores. Insbesondere {\"a}ltere, mehrgeb{\"a}hrende Frauen leiden h{\"a}ufiger an einem Scheidenvorfall nach einer Hysterektomie aufgrund der schwachen Unterst{\"u}tzung durch laxe apikale B{\"a}nder. Es wird angenommen, dass eine verringerte Menge an {\"O}strogen und Progesteron im h{\"o}heren Alter das Kollagen umformt, wodurch die Gewebesteifigkeit reduziert wird. Die Sakrokolpopexie ist eine offene oder laparoskopische Operation, die mit prothetischen Netzimplantaten durchgef{\"u}hrt wird, um laxe B{\"a}nder zu ersetzen. Y-f{\"o}rmige Netzmodelle (DynaMesh, Gynemesh und Ultrapro) werden in einem 3D-Modell des weiblichen Beckenbodens im extraperitonealen Raum vom Vaginalstumpf bis zum Promontorium implantiert. Numerische Simulationen werden w{\"a}hrend des Valsalva-Man{\"o}vers mit geschw{\"a}chtem Gewebe durchgef{\"u}hrt, das durch eine reduzierte Gewebesteifigkeit modelliert wird. Die Gewebe werden als inkompressible, isotrop hyperelastische Materialien modelliert, w{\"a}hrend die Netze entweder als orthotrope linear elastische oder als isotrope hyperlastische Materialien modelliert werden. Die Positionen des Vaginalstumpfs, der Blase und der Harnr{\"o}hrenachse werden anhand der Pubococcygeallinie aus der Ruhelage, f{\"u}r den Prolaps und nach der Reparatur unter Verwendung der drei Netze berechnet. Aufgrund der Netzmechanik und der Netzporenverformung bietet das DynaMesh mit regelm{\"a}ßigen rechteckigen Netzporen eine bessere mechanische Unterst{\"u}tzung und eine Neupositionierung des Scheidengew{\"o}lbes, der Blase und der Urethraachse als Gynemesh und Ultrapro mit unregelm{\"a}ßigen hexagonalen Netzporen.}, language = {en} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel Bernhard}, title = {Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment}, series = {International Journal of Multiphase Flow}, volume = {100}, journal = {International Journal of Multiphase Flow}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2017.12.011}, pages = {127 -- 142}, year = {2018}, abstract = {A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades.}, language = {en} } @article{BirgelLeschingerWegmannetal.2018, author = {Birgel, Stefan and Leschinger, Tim and Wegmann, Kilian and Staat, Manfred}, title = {Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model}, series = {tm - Technisches Messen}, volume = {85}, journal = {tm - Technisches Messen}, number = {5}, publisher = {De Gruyter}, address = {Berlin}, issn = {2196-7113}, doi = {10.1515/teme-2017-0114}, pages = {321 -- 330}, year = {2018}, abstract = {Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus. Mit der Software OpenSim und {\"u}berpr{\"u}ften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen f{\"u}r den Supraspinatus und Deltoideus. Zus{\"a}tzlich wird der Einfluss auf die Gelenkstabilit{\"a}t betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus.}, language = {en} } @article{IkenBronderGoretzkietal.2019, author = {Iken, Heiko and Bronder, Thomas and Goretzki, Alexander and Kriesel, Jana and Ahlborn, Kristina and Gerlach, Frank and Vonau, Winfried and Zander, Willi and Schubert, J{\"u}rgen and Sch{\"o}ning, Michael Josef}, title = {Development of a Combined pH- and Redox-Sensitive Bi-Electrode Glass Thin-Film Sensor}, series = {physica status solidi a : applications and materials sciences}, volume = {216}, journal = {physica status solidi a : applications and materials sciences}, number = {12}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201900114}, pages = {1 -- 8}, year = {2019}, language = {en} } @article{KurzLinderTrzewiketal.2010, author = {Kurz, R. and Linder, Peter and Trzewik, J{\"u}rgen and R{\"u}ffer, M. and Artmann, Gerhard and Digel, Ilya and Rothermel, A. and Robitzki, A. and Temiz Artmann, Ayseg{\"u}l}, title = {Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes}, series = {Medical and Biological Engineering and Computing}, volume = {48}, journal = {Medical and Biological Engineering and Computing}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {1741-0444}, doi = {10.1007/s11517-009-0552-y}, pages = {59 -- 65}, year = {2010}, abstract = {The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure. This biaxial strain distribution is rather similar the beating, blood-filled heart. The setup allowed presetting the mechanical residual stress level externally by adjusting the centre deflection, thus, mimicking hypertension in vitro. Tension was measured as oscillating differential pressure change between chamber and environment. A 0.5-mm thick collagen-cardiac myocyte tissue construct induced after 2 days of culturing (initial cell density 2 x 10(4) cells/ml), a mechanical tension of 1.62 +/- 0.17 microN/mm(2). Mechanical load is an important growth regulator in the developing heart, and the orientation and alignment of cardiomyocytes is stress sensitive. Therefore, it was necessary to develop the CellDrum technology with its biaxial stress-strain distribution and defined mechanical boundary conditions. Cells were exposed to strain in two directions, radially and circumferentially, which is similar to biaxial loading in real heart tissues. Thus, from a biomechanical point of view, the system is preferable to previous setups based on uniaxial stretching.}, language = {en} } @article{KapplerTanudyayaSchmittTippkoetteretal.2007, author = {Kappler-Tanudyaya, Nathalie and Schmitt, Heike and Tippk{\"o}tter, Nils and Meyer, Lina and Lenzen, Sigurd and Ulber, Roland}, title = {Combination of biotransformation and chromatography for the isolation and purification of mannoheptulose}, series = {Biotechnology Journal}, volume = {2}, journal = {Biotechnology Journal}, number = {6}, issn = {1860-7314}, doi = {10.1002/biot.200700004}, pages = {692 -- 699}, year = {2007}, abstract = {Mannoheptulose is a seven-carbon sugar. It is an inhibitor of glucose-induced insulin secretion due to its ability to selectively inhibit the enzyme glucokinase. An improved procedure for mannoheptulose isolation from avocados is described in this study (based upon the original method by La Forge). The study focuses on the combination of biotransformation and downstream processing (preparative chromatography) as an efficient method to produce a pure extract of mannoheptulose. The experiments were divided into two major phases. In the first phase, several methods and parameters were compared to optimize the mannoheptulose extraction with respect to efficiency and purity. In the second phase, a mass balance of mannoheptulose over the whole extraction process was undertaken to estimate the yield and efficiency of the total extraction process. The combination of biotransformation and preparative chromatography allowed the production of a pure mannoheptulose extract. In a biological test, the sugar inhibited the glucokinase enzyme activity efficiently.}, language = {en} } @article{GoettenHavermannBraunetal.2021, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach}, series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, journal = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2021-1535}, pages = {1 -- 12}, year = {2021}, language = {en} } @article{GoettscheReillyWittwer1991, author = {G{\"o}ttsche, Joachim and Reilly, S. and Wittwer, Volker}, title = {Advanced window systems and building energy performance / S. Reilly ; J. G{\"o}ttsche ; V. Wittwer}, series = {Solar World Congress, 1991 : proceedings of the biennial congress of the International Solar Energy Society, Denver, Colorado, USA, 19-23 August 1991 / ed. by M. E. Arden ...}, journal = {Solar World Congress, 1991 : proceedings of the biennial congress of the International Solar Energy Society, Denver, Colorado, USA, 19-23 August 1991 / ed. by M. E. Arden ...}, publisher = {Pergamon Press}, address = {Oxford [u.a.]}, isbn = {0-08-041690-X}, pages = {3211 -- 3216}, year = {1991}, language = {en} } @article{KurulganDemirciDemirciLinderetal.2012, author = {Kurulgan Demirci, Eylem and Demirci, Taylan and Linder, Peter and Trzewik, J{\"u}rgen and Gierkowski, Jessica Ricarda and Gossmann, Matthias and Kayser, Peter and Porst, Dariusz and Digel, Ilya and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {rhAPC reduces the endothelial cell permeability via a decrease of contractile tensions induced by endothelial cells}, series = {Journal of Bioscience and Bioengineering}, volume = {113}, journal = {Journal of Bioscience and Bioengineering}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1347-4421}, doi = {10.1016/j.jbiosc.2012.03.019}, pages = {212 -- 219}, year = {2012}, abstract = {All cells generate contractile tension. This strain is crucial for mechanically controlling the cell shape, function and survival. In this study, the CellDrum technology quantifying cell's (the cellular) mechanical tension on a pico-scale was used to investigate the effect of lipopolysaccharide (LPS) on human aortic endothelial cell (HAoEC) tension. The LPS effect during gram-negative sepsis on endothelial cells is cell contraction causing endothelium permeability increase. The aim was to finding out whether recombinant activated protein C (rhAPC) would reverse the endothelial cell response in an in-vitro sepsis model. In this study, the established in-vitro sepsis model was confirmed by interleukin 6 (IL-6) levels at the proteomic and genomic levels by ELISA, real time-PCR and reactive oxygen species (ROS) activation by florescence staining. The thrombin cellular contraction effect on endothelial cells was used as a positive control when the CellDrum technology was applied. Additionally, the Ras homolog gene family, member A (RhoA) mRNA expression level was checked by real time-PCR to support contractile tension results. According to contractile tension results, the mechanical predominance of actin stress fibers was a reason of the increased endothelial contractile tension leading to enhanced endothelium contractility and thus permeability enhancement. The originality of this data supports firstly the basic measurement principles of the CellDrum technology and secondly that rhAPC has a beneficial effect on sepsis influenced cellular tension. The technology presented here is promising for future high-throughput cellular tension analysis that will help identify pathological contractile tension responses of cells and prove further cell in-vitro models.}, language = {en} } @article{RingersBialonskiEgeetal.2023, author = {Ringers, Christa and Bialonski, Stephan and Ege, Mert and Solovev, Anton and Hansen, Jan Niklas and Jeong, Inyoung and Friedrich, Benjamin M. and Jurisch-Yaksi, Nathalie}, title = {Novel analytical tools reveal that local synchronization of cilia coincides with tissue-scale metachronal waves in zebrafish multiciliated epithelia}, series = {eLife}, volume = {12}, journal = {eLife}, publisher = {eLife Sciences Publications}, issn = {2050-084X}, doi = {10.7554/eLife.77701}, pages = {27 Seiten}, year = {2023}, abstract = {Motile cilia are hair-like cell extensions that beat periodically to generate fluid flow along various epithelial tissues within the body. In dense multiciliated carpets, cilia were shown to exhibit a remarkable coordination of their beat in the form of traveling metachronal waves, a phenomenon which supposedly enhances fluid transport. Yet, how cilia coordinate their regular beat in multiciliated epithelia to move fluids remains insufficiently understood, particularly due to lack of rigorous quantification. We combine experiments, novel analysis tools, and theory to address this knowledge gap. To investigate collective dynamics of cilia, we studied zebrafish multiciliated epithelia in the nose and the brain. We focused mainly on the zebrafish nose, due to its conserved properties with other ciliated tissues and its superior accessibility for non-invasive imaging. We revealed that cilia are synchronized only locally and that the size of local synchronization domains increases with the viscosity of the surrounding medium. Even though synchronization is local only, we observed global patterns of traveling metachronal waves across the zebrafish multiciliated epithelium. Intriguingly, these global wave direction patterns are conserved across individual fish, but different for left and right noses, unveiling a chiral asymmetry of metachronal coordination. To understand the implications of synchronization for fluid pumping, we used a computational model of a regular array of cilia. We found that local metachronal synchronization prevents steric collisions, i.e., cilia colliding with each other, and improves fluid pumping in dense cilia carpets, but hardly affects the direction of fluid flow. In conclusion, we show that local synchronization together with tissue-scale cilia alignment coincide and generate metachronal wave patterns in multiciliated epithelia, which enhance their physiological function of fluid pumping.}, language = {en} } @article{DemirciTrzewikLinderetal.2004, author = {Demirci, T. and Trzewik, J. and Linder, Peter and Digel, Ilya and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Mechanical Stimulation of 3T3 Fibroblasts Activates Genes: ITGB5 and p53 Responses as Quantified on the mRNA Level}, series = {Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2}, journal = {Biomedizinische Technik . 49 (2004), H. Erg.-Bd. 2}, isbn = {0932-4666}, pages = {1030 -- 1031}, year = {2004}, language = {en} } @article{LuftBremenLuft2023, author = {Luft, Angela and Bremen, Sebastian and Luft, Nils}, title = {A cost/benefit and flexibility evaluation framework for additive technologies in strategic factory planning}, series = {Processes}, volume = {11}, journal = {Processes}, number = {7}, publisher = {MDPI}, address = {Basel}, issn = {2227-9717}, doi = {10.3390/pr11071968}, pages = {Artikel 1968}, year = {2023}, abstract = {There is a growing demand for more flexibility in manufacturing to counter the volatility and unpredictability of the markets and provide more individualization for customers. However, the design and implementation of flexibility within manufacturing systems are costly and only economically viable if applicable to actual demand fluctuations. To this end, companies are considering additive manufacturing (AM) to make production more flexible. This paper develops a conceptual model for the impact quantification of AM on volume and mix flexibility within production systems in the early stages of the factory-planning process. Together with the model, an application guideline is presented to help planners with the flexibility quantification and the factory design process. Following the development of the model and guideline, a case study is presented to indicate the potential impact additive technologies can have on manufacturing flexibility Within the case study, various scenarios with different production system configurations and production programs are analyzed, and the impact of the additive technologies on volume and mix flexibility is calculated. This work will allow factory planners to determine the potential impacts of AM on manufacturing flexibility in an early planning stage and design their production systems accordingly.}, language = {en} } @article{AsanteAsamaniKleefeldWade2020, author = {Asante-Asamani, E.O. and Kleefeld, Andreas and Wade, B.A.}, title = {A second-order exponential time differencing scheme for non-linear reaction-diffusion systems with dimensional splitting}, series = {Journal of Computational Physics}, volume = {415}, journal = {Journal of Computational Physics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9991}, doi = {10.1016/j.jcp.2020.109490}, year = {2020}, abstract = {A second-order L-stable exponential time-differencing (ETD) method is developed by combining an ETD scheme with approximating the matrix exponentials by rational functions having real distinct poles (RDP), together with a dimensional splitting integrating factor technique. A variety of non-linear reaction-diffusion equations in two and three dimensions with either Dirichlet, Neumann, or periodic boundary conditions are solved with this scheme and shown to outperform a variety of other second-order implicit-explicit schemes. An additional performance boost is gained through further use of basic parallelization techniques.}, language = {en} } @article{RauschHarbrechtKahmannetal.2020, author = {Rausch, Valentin and Harbrecht, Andreas and Kahmann, Stephanie Lucina and Fenten, Thomas and Jovanovic, Nebojsa and Hackl, Michael and M{\"u}ller, Lars P. and Staat, Manfred and Wegmann, Kilian}, title = {Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws}, series = {The Journal of Hand Surgery}, volume = {45}, journal = {The Journal of Hand Surgery}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0363-5023}, doi = {10.1016/j.jhsa.2020.04.010}, pages = {987.e1 -- 987.e8}, year = {2020}, abstract = {Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.}, language = {en} } @article{MuschallikKippReckeretal.2020, author = {Muschallik, Lukas and Kipp, Carina Ronja and Recker, Inga and Bongaerts, Johannes and Pohl, Martina and Gelissen, Melanie and Sch{\"o}ning, Michael Josef and Selmer, Thorsten and Siegert, Petra}, title = {Synthesis of α-hydroxy ketones and vicinal diols with the Bacillus licheniformis DSM 13T butane-2, 3-diol dehydrogenase}, series = {Journal of Biotechnology}, volume = {202}, journal = {Journal of Biotechnology}, number = {Vol. 324}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {2590-1559}, doi = {10.1016/j.jbiotec.2020.09.016}, pages = {61 -- 70}, year = {2020}, abstract = {The enantioselective synthesis of α-hydroxy ketones and vicinal diols is an intriguing field because of the broad applicability of these molecules. Although, butandiol dehydrogenases are known to play a key role in the production of 2,3-butandiol, their potential as biocatalysts is still not well studied. Here, we investigate the biocatalytic properties of the meso-butanediol dehydrogenase from Bacillus licheniformis DSM 13T (BlBDH). The encoding gene was cloned with an N-terminal StrepII-tag and recombinantly overexpressed in E. coli. BlBDH is highly active towards several non-physiological diketones and α-hydroxyketones with varying aliphatic chain lengths or even containing phenyl moieties. By adjusting the reaction parameters in biotransformations the formation of either the α-hydroxyketone intermediate or the diol can be controlled.}, language = {en} }