@article{BongaertsEsserLorbachetal.2011, author = {Bongaerts, Johannes and Esser, Simon and Lorbach, Volker and Al-Momani, L{\´o}ay and M{\"u}ller, Michael A. and Franke, Dirk and Grondal, Christoph and Kurutsch, Anja and Bujnicki, Robert and Takors, Ralf and Raeven, Leon and Wubbolts, Marcel and Bovenberg, Roel and Nieger, Martin and Sch{\"u}rmann, Melanie and Trachtmann, Natalie and Kozak, Stefan and Sprenger, Georg A. and M{\"u}ller, Michael}, title = {Diversity-oriented production of metabolites derived from chorismate and their use in organic synthesis}, series = {Angewandte Chemie International Edition}, volume = {Vol. 50}, journal = {Angewandte Chemie International Edition}, number = {Iss. 34}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-3773 (E-Journal); 0570-0833 (Print); 1433-7851 (Print)}, pages = {7781 -- 7786}, year = {2011}, 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{NguyenXuanRabczukNguyenThoietal.2011, author = {Nguyen-Xuan, H. and Rabczuk, T. and Nguyen-Thoi, T. and Tran, Thanh Ngoc and Nguyen-Thanh, N.}, title = {Computation of limit and shakedown loads using a node-based smoothed finite element method}, series = {International Journal for Numerical Methods in Engineering}, volume = {90}, journal = {International Journal for Numerical Methods in Engineering}, number = {3}, publisher = {Wiley}, address = {Weinheim}, issn = {1097-0207}, doi = {10.1002/nme.3317}, pages = {287 -- 310}, year = {2011}, abstract = {This paper presents a novel numerical procedure for computing limit and shakedown loads of structures using a node-based smoothed FEM in combination with a primal-dual algorithm. An associated primal-dual form based on the von Mises yield criterion is adopted. The primal-dual algorithm together with a Newton-like iteration are then used to solve this associated primal-dual form to determine simultaneously both approximate upper and quasi-lower bounds of the plastic collapse limit and the shakedown limit. The present formulation uses only linear approximations and its implementation into finite element programs is quite simple. Several numerical examples are given to show the reliability, accuracy, and generality of the present formulation compared with other available methods.}, language = {en} } @article{BaeckerPouyeshmanSchnitzleretal.2011, author = {B{\"a}cker, Matthias and Pouyeshman, S. and Schnitzler, Thomas and Poghossian, Arshak and Wagner, Patrick and Biselli, Manfred and Sch{\"o}ning, Michael Josef}, title = {A silicon-based multi-sensor chip for monitoring of fermentation processes}, series = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, journal = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, publisher = {Wiley}, address = {Weinheim}, isbn = {1862-6319}, pages = {1364 -- 1369}, year = {2011}, language = {en} } @article{OrzadaBitzSchaeferetal.2011, author = {Orzada, Stephan and Bitz, Andreas and Sch{\"a}fer, Lena C. and Ladd, Susanne C. and Ladd, Mark E. and Maderwald, Stefan}, title = {Open design eight-channel transmit/receive coil for high-resolution and real-time ankle imaging at 7 T}, series = {Medical Physics}, volume = {38}, journal = {Medical Physics}, number = {3}, publisher = {Wiley}, address = {Hoboken}, issn = {2473-4209}, doi = {10.1118/1.3553399}, pages = {1162 -- 1167}, year = {2011}, abstract = {Purpose: At 1.5 T, real-time MRI of joint movement has been shown to be feasible. However, 7 T, provides higher SNR and thus an improved potential for parallel imaging acceleration. The purpose of this work was to build an open, U-shaped eight-channel transmit/receive microstrip coil for 7 T MRI to enable high-resolution and real-time imaging of the moving ankle joint. Methods: A U-shaped eight-channel transmit/receive array for the human ankle was built.urn:x-wiley:00942405:mp3399:equation:mp3399-math-0001-parameters and urn:x-wiley:00942405:mp3399:equation:mp3399-math-0002-factor were measured. SAR calculations of different ankle postures were performed to ensure patient safety. Inhomogeneities in the transmit field consequent to the open design were compensated for by the use of static RF shimming. High-resolution and real-time imaging was performed in human volunteers. Results: The presented array showed good performance with regard to patient comfort and image quality. High acceleration factors of up to 4 are feasible without visible acceleration artifacts. Reasonable image homogeneity was achieved with RF shimming. Conclusions: Open, noncylindrical designs for transmit/receive coils are practical at 7 T and real-time imaging of the moving joint is feasible with the presented coil design.}, language = {en} } @article{ElQuardiStreckertBitzetal.2011, author = {El Quardi, A. and Streckert, J. and Bitz, Andreas and M{\"u}nkner, S. and Engel, J. and Hansen, V.}, title = {New fin-line devices for radiofrequency exposure of small biological samples in vitro allowing whole-cell patch clamp recordings}, series = {Bioelectromagnetics}, volume = {32}, journal = {Bioelectromagnetics}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-186X}, doi = {10.1002/bem.20621}, pages = {102 -- 112}, year = {2011}, abstract = {The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin-line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately Pin = 50 mW, Pin = 19 mW, and Pin = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF-induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10\% from the intended solution volume yielded a calculated SAR deviation of 8\% from the desired value. A maximum ±10\% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located.}, language = {en} } @article{TippkoetterWollnyKampeisetal.2011, author = {Tippk{\"o}tter, Nils and Wollny, S. and Kampeis, P. and Oster, J. and Schneider, H. and Ulber, Roland}, title = {Magnetseparation von Proteinen : Separation von Zielmolek{\"u}len durch hochselektive Aptamere}, series = {GIT Labor-Fachzeitschrift}, volume = {55}, journal = {GIT Labor-Fachzeitschrift}, number = {10}, publisher = {Wiley}, address = {Weinheim}, pages = {666}, year = {2011}, abstract = {Durch die Kombination von Oligonukleotid-Liganden (Aptameren) hoher Bindungsaffinit{\"a}ten mit hochselektiv abtrennbaren magnetisierbaren Mikropartikeln wird eine einstufige Separation von Zielmolek{\"u}len aus mikrobiologischen Produktionsans{\"a}tzen m{\"o}glich. Die Aptamere werden hierf{\"u}r reversibel auf den Partikeloberfl{\"a}chen gebunden und f{\"u}r die spezifische Isolierung von Bioprodukten eingesetzt. Die Abtrennung der beladenen Partikel erfolgt durch einen neuen Rotor-Stator-Separator mit Hochgradient-Magnetfeld.}, language = {de} } @article{HaselgruberMautnerThiele2010, author = {Haselgruber, Nikolaus and Mautner, Karin and Thiele, Jan}, title = {Usage Space Analysis for Reliability Testing}, series = {Quality and Reliability Engineering International}, volume = {26}, journal = {Quality and Reliability Engineering International}, number = {8}, publisher = {Wiley}, address = {New York}, issn = {1099-1638}, doi = {10.1002/qre.1155}, pages = {877 -- 885}, year = {2010}, abstract = {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.}, language = {en} } @article{PieperKlein2010, author = {Pieper, Martin and Klein, Peter}, title = {Numerical solution of the heat equation with non-linear, time derivative-dependent source term}, series = {International Journal for Numerical Methods in Engineering}, volume = {84}, journal = {International Journal for Numerical Methods in Engineering}, number = {10}, publisher = {Wiley}, address = {Chichester}, issn = {0029-5981}, doi = {10.1002/nme.2937}, pages = {1205 -- 1221}, year = {2010}, abstract = {The mathematical modeling of heat conduction with adsorption effects in coated metal structures yields the heat equation with piecewise smooth coefficients and a new kind of source term. This term is special, because it is non-linear and furthermore depends on a time derivative. In our approach we reformulated this as a new problem for the usual heat equation, without source term but with a new non-linear coefficient. We gave an existence and uniqueness proof for the weak solution of the reformulated problem. To obtain a numerical solution, we developed a semi-implicit and a fully implicit finite volume method. We compared these two methods theoretically as well as numerically. Finally, as practical application, we simulated the heat conduction in coated aluminum fibers with adsorption in the zeolite coating. Copyright © 2010 John Wiley \& Sons, Ltd.}, language = {en} } @article{TippkoetterRoikaewUlberetal.2010, author = {Tippk{\"o}tter, Nils and Roikaew, Wipa and Ulber, Roland and Hoffmann, Alexander and Denzler, Hans-J{\"o}rg and Buchholz, Heinrich}, title = {Paracoccus denitrificans for the effluent recycling during continuous denitrification of liquid food}, series = {Biotechnology Progress}, volume = {26}, journal = {Biotechnology Progress}, number = {3}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {8756-7938}, doi = {10.1002/btpr.384}, pages = {756 -- 762}, year = {2010}, abstract = {Nitrate is an undesirable component of several foods. A typical case of contamination with high nitrate contents is whey concentrate, containing nitrate in concentrations up to 25 l. The microbiological removal of nitrate by Paracoccus denitrificans under formation of harmless nitrogen in combination with a cell retention reactor is described here. Focus lies on the resource-conserving design of a microbal denitrification process. Two methods are compared. The application of polyvinyl alcohol-immobilized cells, which can be applied several times in whey feed, is compared with the implementation of a two step denitrification system. First, the whey concentrate's nitrate is removed by ion exchange and subsequently the eluent regenerated by microorganisms under their retention by crossflow filtration. Nitrite and nitrate concentrations were determined by reflectometric color measurement with a commercially available Reflectoquant® device. Correction factors for these media had to be determined. During the pilot development, bioreactors from 4 to 250 mg·L-1 and crossflow units with membrane areas from 0.02 to 0.80 m2 were examined. Based on the results of the pilot plants, a scaling for the exemplary process of denitrifying 1,000 tons per day is discussed.}, language = {en} }