@article{AnikFrohberg1983, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Investigation of the thermodynamics of oxygen and the determination of phase boundaries in the system copper-oxygen-bismuth at 12000C}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {8}, issn = {0044-3093}, pages = {530 -- 534}, year = {1983}, language = {en} } @article{FrohbergAnik1983, author = {Frohberg, Martin G. and Anik, Sabri}, title = {The application of a quadi-chemical lattice model to binary metallic solvents containing oxygen in higher concentrations}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {74}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {10}, issn = {0044-3093}, pages = {665 -- 666}, year = {1983}, language = {en} } @article{AnikFrohberg1984, author = {Anik, Sabri and Frohberg, Martin G.}, title = {Investigations of the thermodynamics of oxygen and the determination of the miscibility gap in the system copper-oxygen-lead at 12000C}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {75}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {8}, issn = {0044-3093}, pages = {586 -- 589}, year = {1984}, language = {en} } @article{FrohbergAnik1985, author = {Frohberg, Martin G. and Anik, Sabri}, title = {The calculation of component activities of binary metallic melts from their gas solubilities}, series = {Zeitschrift f{\"u}r Metallkunde}, volume = {76}, journal = {Zeitschrift f{\"u}r Metallkunde}, number = {2}, issn = {0044-3093}, pages = {135 -- 137}, year = {1985}, language = {en} } @article{BohrnMuchaWerneretal.2013, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and Trattner, Barbara and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and St{\"u}tz, Evamaria and Schmitt-Landsiedel, Doris and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment}, series = {Sensors and actuators. B: Chemical}, volume = {Vol. 182}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, pages = {58 -- 65}, year = {2013}, language = {en} } @article{MiyamotoIchimuraWagneretal.2013, author = {Miyamoto, Ko-ichiro and Ichimura, Hiroki and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {189}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.04.057}, pages = {240 -- 245}, year = {2013}, abstract = {The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation.}, language = {en} } @article{JensKaldenhoffKirschnerHermannsetal.2014, author = {Jens, Otto and Kaldenhoff, E. and Kirschner-Hermanns, R. and M{\"u}hl, Thomas and Klinge, Uwe}, title = {Elongation of textile pelvic floor implants under load is related to complete loss of effective porosity, thereby favoring incorporation in scar plates}, series = {Journal of biomedical materials research. Part A}, volume = {102}, journal = {Journal of biomedical materials research. Part A}, number = {4}, publisher = {Wiley}, address = {New York}, issn = {1552-4965}, doi = {10.1002/jbm.a.34767}, pages = {1079 -- 1084}, year = {2014}, abstract = {Use of textile structures for reinforcement of pelvic floor structures has to consider mechanical forces to the implant, which are quite different to the tension free conditions of the abdominal wall. Thus, biomechanical analysis of textile devices has to include the impact of strain on stretchability and effective porosity. Prolift® and Prolift + M®, developed for tension free conditions, were tested by measuring stretchability and effective porosity applying mechanical strain. For comparison, we used Dynamesh-PR4®, which was designed for pelvic floor repair to withstand mechanical strain. Prolift® at rest showed moderate porosity with little stretchability but complete loss of effective porosity at strain of 4.9 N/cm. Prolift + M® revealed an increased porosity at rest, but at strain showed high stretchability, with subsequent loss of effective porosity at strain of 2.5 N/cm. Dynamesh PR4® preserved its high porosity even under strain, but as consequence of limited stretchability. Though in tension free conditions Prolift® and Prolift + M® can be considered as large pore class I meshes, application of mechanical strain rapidly lead to collapse of pores. The loss of porosity at mechanical stress can be prevented by constructions with high structural stability. Assessment of porosity under strain was found helpful to define requirements for pelvic floor devices. Clinical studies have to prove whether devices with high porosity as well as high structural stability can improve the patients' outcome.}, language = {en} } @article{MelissOesterwindVoss1975, author = {Meliß, Michael and Oesterwind, Dieter and Voß, Alfred}, title = {Non-nuclear and non-fossil energy resources and their possibilities for future power generation}, series = {Kerntechnik}, volume = {17}, journal = {Kerntechnik}, number = {7}, publisher = {De Gruyter}, address = {Berlin}, issn = {0932-3902}, doi = {10.18419/opus-8093}, pages = {301 -- 306}, year = {1975}, abstract = {It must be stressed that the assessment of the exploitation possibilities of the energy resources discussed in this paper requires further studies. With this proviso, the situation can be provisionally summarised as follows: The total potential of known geothermal steam sources is only 64 GW. Geothermal energy could therefore only make a significant contribution to covering the worldwide power needs if we succeed in exploiting dry geothermal reservoirs. Exploitation of tidal energy is limited to a few geographically favourable locations. The power generation potential at these locations is only about 64 GW. An important drawback of tidal power is discontinuous power generation. Large scale exploitation of wind, wave and glacier energy, and of ocean heat, requires solution of a number of technological problems. The environmental effects of exploitation of these energy resources are to some extent of a qualitatively different nature from those of operation of fossil-fuel-fired and of nuclear power plants. The scanty knowledge in this area often results in these effects being underestimated. In any case, however, it would be deliberately misleading to postulate that any form of power generation is possible without some detrimental effects on the environment. It may be stated in conclusion that, owing to their small potential or to the as yet insufficiently advanced technological development, none of the energy resources discussed in this paper can make a significant contribution to the solution of middle-term energy supply problems, i.e., to a rapid replacement of mineral oil and natural gas.}, language = {en} } @article{FerreinMeyer2012, author = {Ferrein, Alexander and Meyer, Thomas}, title = {A Brief Overview of Artificial Intelligence in South Africa}, series = {AI Magazine}, volume = {33}, journal = {AI Magazine}, number = {1}, publisher = {AAAI}, address = {Menlo Park}, issn = {0738-4602}, doi = {10.1609/aimag.v33i1.2357}, pages = {99 -- 101}, year = {2012}, abstract = {South Africa in recent years is the establishment of a number of research hubs involved in AI activities ranging from mobile robotics and computational intelligence, to knowledge representation and reasoning, and human language technologies. In this survey we take the reader through a quick tour of the research being conducted at these hubs, and touch on an initiative to maintain and extend the current level of interest in AI research in the country.}, language = {en} } @article{AbulnagaPinkenburgSchiffelsetal.2013, author = {Abulnaga, El-Hussiny and Pinkenburg, Olaf and Schiffels, Johannes and E-Refai, Ahmed and Buckel, Wolfgang and Selmer, Thorsten}, title = {Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli}, series = {Journal of bacteriology}, volume = {195}, journal = {Journal of bacteriology}, number = {16}, issn = {1098-5530 [E-Journal]}, pages = {3704 -- 3713}, year = {2013}, language = {en} } @article{AbdelLatifPeekenBenner1985, author = {Abdel-Latif, Lotfie Ahmed and Peeken, Heinz and Benner, Joachim}, title = {Thermohydrodynamic analysis of thrust-bearing with circular pads running on bubbly oil (BTHD-theory)}, series = {Journal of tribology}, volume = {107}, journal = {Journal of tribology}, number = {4}, isbn = {0742-4787}, issn = {1528-8897}, pages = {527 -- 537}, year = {1985}, language = {en} } @article{MelissSpaete2000, author = {Meliß, Michael and Sp{\"a}te, Frank}, title = {The solar heating system with seasonal storage at the Solar-Campus J{\"u}lich}, series = {Solar energy. Vol. 69 (2000), iss. 6}, journal = {Solar energy. Vol. 69 (2000), iss. 6}, issn = {0038-092X}, pages = {525 -- 533}, year = {2000}, language = {en} } @article{RensFerrein2013, author = {Rens, Gavin and Ferrein, Alexander}, title = {Belief-node condensation for online POMDP algorithms}, publisher = {IEEE}, address = {New York}, pages = {1 -- 7}, year = {2013}, abstract = {Slightly extended version of the paper accepted at the Robotics and Artificial Intelligence Workshop, a special track of IEEE AFRICON-2013, held in Mauritius, 9-12 September 2013}, language = {en} } @article{KirsteinMuellerWaleckiMingersetal.2012, author = {Kirstein, Simon and M{\"u}ller, Karsten and Walecki-Mingers, Mark and Deserno, Thomas M.}, title = {Robust adaptive flow line detection in sewer pipes}, series = {Automation in construction}, journal = {Automation in construction}, number = {21}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7891 (E-Journal) ; 0926-5805 (Print)}, doi = {10.1016/j.autcon.2011.05.009}, pages = {24 -- 31}, year = {2012}, abstract = {As part of a novel approach to automatic sewer inspection, this paper presents a robust algorithm for automatic flow line detection. A large image repository is obtained from about 50,000 m sewers to represent the high variability of real world sewer systems. Automatic image processing combines Canny edge detection, Hough transform for straight lines and cost minimization using Dijkstra's shortest path algorithm. Assuming that flow lines are mostly smoothly connected horizontal structures, piecewise flow line delineation is reduced to a process of selecting adjacent line candidates. Costs are derived from the gap between adjacent candidates and their reliability. A single parameter α enables simple control of the algorithm. The detected flow line may precisely follow the segmented edges (α = 0.0) or minimize gaps at joints (α = 1.0). Both, manual and ground truth-based analysis indicate that α = 0.8 is optimal and independent of the sewer's material. The algorithm forms an essential step to further automation of sewer inspection.}, language = {en} } @article{SchiffelsPinkenburgScheldenetal.2013, author = {Schiffels, Johannes and Pinkenburg, Olaf and Schelden, Maximilian and Aboulnaga, El-Hussiny A. A. and Baumann, Marcus and Selmer, Thorsten}, title = {An innovative cloning platform enables large-scale production and maturation of an oxygen-tolerant [NiFe]-hydrogenase from cupriavidus necator in Escherichia coli}, series = {PLOS one. 2013}, journal = {PLOS one. 2013}, publisher = {Public Library of Science}, address = {San Francisco, California}, issn = {1932-6203}, doi = {10.1371/journal.pone.0068812}, year = {2013}, language = {en} } @article{SommerGerlingPredel1984, author = {Sommer, Ferdinand and Gerling, Ulrich and Predel, Bruno}, title = {On the evaluation of interchange energies and the equilibrium-constant from mixing enthalpies of a regular associated solution-comment}, series = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 75, H. 11}, journal = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 75, H. 11}, issn = {0044-3093 ; 0179-4841}, pages = {898}, year = {1984}, language = {en} } @article{ArpshofenPoolSommeretal.1983, author = {Arpshofen, Ingo and Pool, M. J. and Sommer, Ferdinand and Gerling, Ulrich and Predel, Bruno and Schultheiss, Emil}, title = {Determination of the integral mixing enthalpies in the Cu-Pd-Si liquid ternary alloy system at 1600 K}, series = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 1}, journal = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 1}, issn = {0044-3093 ; 0179-4841}, pages = {25 -- 32}, year = {1983}, language = {en} } @article{GerlingPoolPredel1983, author = {Gerling, Ulrich and Pool, M. J. and Predel, Bruno}, title = {A contribution to the associate model for binary liquid alloys = Ein Beitrag zum Assoziat-Modell f{\"u}r bin{\"a}re fl{\"u}ssige Legierungen}, series = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 9}, journal = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 9}, issn = {0044-3093 ; 0179-4841}, pages = {616 -- 619}, year = {1983}, language = {en} } @article{SommerGerlingPredel1984, author = {Sommer, F. and Gerling, Ulrich and Predel, Bruno}, title = {Comments on 'On the evaluation of interchange energies and the equilibrium constant from mixing enthalpies of a regular associated solution' by S. Lele, G.V.S. Sastry, and P. Ramachandrarao = Kommentar zu 'Zur Berechnung der Wechselwirkungsenergien und der Gleichgewichtskonstanten aus Mischungsenthalpien in regul{\"a}ren assoziierten L{\"o}sungen' von S. Lele, G.V.S. Sastry und P. Ramachandrarao}, series = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 75, H. 6}, journal = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 75, H. 6}, issn = {0044-3093 ; 0179-4841}, pages = {449 -- 454}, year = {1984}, language = {en} } @article{LueckGerlingPredel1989, author = {L{\"u}ck, Reinhard and Gerling, Ulrich and Predel, Bruno}, title = {An entropy paradox of the association model}, series = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 80, H. 4}, journal = {Zeitschrift f{\"u}r Metallkunde : international journal of materials research and advanced techniques. Bd. 80, H. 4}, issn = {0044-3093 ; 0179-4841}, pages = {270 -- 275}, year = {1989}, language = {en} } @article{HardtMartinMeissburgeretal.1978, author = {Hardt, Arno and Martin, S. and Meißburger, J. and Retz, R. and Wimmer, J.}, title = {The cryopump system of the QQDDQ magnet spectrometer BIG KARL}, series = {Vacuum}, volume = {28}, journal = {Vacuum}, number = {10-11}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-2715 (E-Journal); 0042-207X (Print)}, doi = {10.1016/S0042-207X(78)80026-8}, pages = {483}, year = {1978}, abstract = {Cryopumps without liquid nitrogen shielding are used to provide a vacuum of 10-6 torr in the spectrometer. The vacuum system is subdivided in three sections that can be separated by valves. The first section (scattering chamber) has a volume of 60 l, two rotation transmissions with 35 cm dia and a sliding seal that allows a rotation of 160° without deteriorating the vacuum. The second section includes the vacuum chambers inside the magnets with 6 × 80 cm cross-section and a length of 1200 cm. The third section (detector box) has a volume of 4300 l and contains a moveable detector system. The gas inside the detector with a pressure of 760 torr is separated from the vacuum by a 15 μm mylar foil with an area of 300 cm2. The detector box can be valved off by a valve with the dimension of 10 × 100 cm. The layout of system is given. The instrumentation and the interlock system are described. First experiences with this system are presented.}, language = {en} } @article{BergDemarteauHardtetal.1982, author = {Berg, G. P. A. and Demarteau, M. and Hardt, Arno and H{\"u}rlimann, W. and Martin, S. A. and Meissburger, J. and Oelert, W. and Seyfart, H. and Styczen, B. and K{\"o}hler, M. and Oelrich, I. and Scheerer, J.}, title = {High resolution spectroscopy of 102Ru(d, p)103Ru and 104Ru(p, d)103Ru reactions}, series = {Nuclear Physics A. Vol. 379, iss. 1}, journal = {Nuclear Physics A. Vol. 379, iss. 1}, issn = {1873-1554 (E-Journal); 0375-9474 (Print)}, pages = {93 -- 109}, year = {1982}, language = {en} } @article{MartinHardtMeissburgeretal.1983, author = {Martin, Siegfried A. and Hardt, Arno and Meissburger, J{\"u}rgen and Berg, Georg P. A. and Hacker, Ulrich and H{\"u}rlimann, Werner and R{\"o}mer, Josef G. M. and Sagefka, Thomas and Retz, Adolf and Schult, Otto W. B.}, title = {The QQDDQ magnet spectrometer "BIG KARL"}, series = {Nuclear instruments and methods in physics research. Vol. 214, iss. 2-3}, journal = {Nuclear instruments and methods in physics research. Vol. 214, iss. 2-3}, issn = {0029-554x (E-Journal); 1872-9606 (E-Journal); 0167-5087 (Print)}, pages = {281 -- 303}, year = {1983}, language = {en} } @article{MartinBergHackeretal.1985, author = {Martin, S. A. and Berg, G. P. A. and Hacker, U. and Hardt, Arno and K{\"o}hler, M. and Meißburger, J. and Osterfeld, F. and Prasuhn, D. and Riepe, G. and Rogge, M. and Schult, O. W. B. and Speth, J. and Turek, P. and Gaul, G. and Hagedoorn, H. and Heide, J. A. van der and Hinterberger, F. and Huber, M. and Jahn, R. and Mayer-Kuckuk, T. and Poth, H. and Paetz gen. Schieck, H.}, title = {COSY - a cooler synchrotron and storage ring}, series = {IEEE transactions on nuclear science. Vol. 32, iss. 5}, journal = {IEEE transactions on nuclear science. Vol. 32, iss. 5}, issn = {1558-1578 (E-Journal); 0018-9499 (Print)}, pages = {2694 -- 2696}, year = {1985}, language = {en} } @article{BechstedtHaasHackeretal.1985, author = {Bechstedt, U. and Haas, H. and Hacker, U. and Hardt, Arno and Henn, K. and Martin, S. and Wimmer, J.}, title = {Magnets for the German Spallation Source SNQ}, series = {IEEE transactions on nuclear science. Vol. 32, iss. 5}, journal = {IEEE transactions on nuclear science. Vol. 32, iss. 5}, issn = {1558-1578 (E-Journal); 0018-9499 (Print)}, pages = {3631 -- 3633}, year = {1985}, language = {en} } @article{MakovickaGaertnerHardtetal.1997, author = {Makovicka, C. and G{\"a}rtner, G. and Hardt, Arno and Hermann, W. and Wiechert, D. U.}, title = {Impregnated cathode surface investigations by SFM/STM and SEM/EDX}, series = {Applied surface science. Vol. 111}, journal = {Applied surface science. Vol. 111}, issn = {1873-5584 (E-Journal); 0169-4332 (Print)}, pages = {70 -- 75}, year = {1997}, language = {en} } @article{SchultSistemichHardt1995, author = {Schult, O. W. B. and Sistemich, K. and Hardt, Arno}, title = {Plans for investigations of subthreshold K+ production in p+A collisions / O. W. B. Schult [u.a.]}, series = {Nuclear Physics A. Vol. 583}, journal = {Nuclear Physics A. Vol. 583}, issn = {1873-1554 (E-journal); 0375-9474 (Print)}, pages = {629 -- 632}, year = {1995}, language = {en} } @article{BalewskiBrauksiepeHardt1997, author = {Balewski, J. and Brauksiepe, S. and Hardt, Arno}, title = {Threshold measurements at the internal experimental facility COSY-11 / J. Balewski [u.a.]}, series = {Nuclear physics A. Vol. 626, iss. 1-2}, journal = {Nuclear physics A. Vol. 626, iss. 1-2}, issn = {1873-1554 (E-Journal) ; 0375-9474 (Print)}, pages = {85 -- 92}, year = {1997}, language = {en} } @article{BarsovBechstedtHardt2001, author = {Barsov, S. and Bechstedt, U. and Hardt, Arno}, title = {ANKE, a new facility for medium energy hadron physics at COSY-J{\"u}lich / S. Barsov [u.a.]}, series = {Nuclear instruments and methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Vol. 462, iss. 3}, journal = {Nuclear instruments and methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. Vol. 462, iss. 3}, issn = {0167-5087 (Print) ; 0168-9002 (E-journal)}, pages = {364 -- 381}, year = {2001}, language = {en} } @article{MuribGrinsvenGrietenetal.2013, author = {Murib, M. S. and Grinsven, B. van and Grieten, L. and Janssens, S. D. and Vermeeren, V. and Eersels, K. and Broeders, J. and Ameloot, Marcel and Michiels, L. and Ceuninck, W. De and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, Patrick}, title = {Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates}, series = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, journal = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, publisher = {Wiley-VCH}, address = {Berlin}, issn = {0031-8965}, pages = {911 -- 917}, year = {2013}, language = {en} } @article{HuckSchiffelsHerreraetal.2013, author = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201200900}, pages = {926 -- 931}, year = {2013}, abstract = {Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the "welfare" of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis-Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.}, language = {en} } @article{SchusserLeinhosBaeckeretal.2013, author = {Schusser, Sebastian and Leinhos, Marcel and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200941}, pages = {905 -- 910}, year = {2013}, abstract = {Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution.}, language = {en} } @article{PoghossianWeilCherstvyetal.2013, author = {Poghossian, Arshak and Weil, M. and Cherstvy, A. G. and Sch{\"o}ning, Michael Josef}, title = {Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices}, series = {Analytical and bioanalytical chemistry}, volume = {405}, journal = {Analytical and bioanalytical chemistry}, number = {20}, publisher = {Springer}, address = {Berlin}, issn = {1432-1130 ; 1618-2642}, doi = {10.1007/s00216-013-6951-9}, pages = {6425 -- 6436}, year = {2013}, abstract = {The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance-voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.}, language = {en} } @article{WernerWagnerYoshinobuetal.2013, author = {Werner, Frederik and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Frequency behaviour of light-addressable potentiometric sensors}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200929}, pages = {884 -- 891}, year = {2013}, abstract = {Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.}, language = {en} } @article{LindemannRunge1997, author = {Lindemann, Markus and Runge, Alexander}, title = {Permanent IT-support in electronic commerce transactions}, series = {Electronic markets : the international journal of networked business. Vol. 7 (1997), iss. 1}, journal = {Electronic markets : the international journal of networked business. Vol. 7 (1997), iss. 1}, issn = {1422-8890}, pages = {18 -- 20}, year = {1997}, language = {en} } @article{LindemannSchmid1999, author = {Lindemann, Markus and Schmid, Beat F.}, title = {Framework for specifying, building and operating electronic markets}, series = {International journal of electronic commerce. Vol. 3 (1998/99), No. 2}, journal = {International journal of electronic commerce. Vol. 3 (1998/99), No. 2}, issn = {1086-4415}, pages = {7 -- 21}, year = {1999}, language = {en} } @article{PalmerLindemann2003, author = {Palmer, J. W. and Lindemann, Markus}, title = {Business models and market mechanisms : evaluating efficiency in consumer electronic markets}, series = {Data base and advanced information systems. Bd. 34 (2003), H. 2}, journal = {Data base and advanced information systems. Bd. 34 (2003), H. 2}, issn = {0105-9912}, pages = {23 -- 38}, year = {2003}, language = {en} } @article{FischerDoerenJanke1981, author = {Fischer, W. A. and D{\"o}ren, Horst-Peter and Janke, Dieter}, title = {Aluminium nitride probes for application in iron melts}, series = {Archiv f{\"u}r das Eisenh{\"u}ttenwesen. 52 (1981), H. 3}, journal = {Archiv f{\"u}r das Eisenh{\"u}ttenwesen. 52 (1981), H. 3}, issn = {0003-8962}, pages = {91 -- 98}, year = {1981}, language = {en} } @article{ItabashiKosakaMiyamotoetal.2013, author = {Itabashi, Akinori and Kosaka, Naoki and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {High-speed chemical imaging system based on front-side-illuminated LAPS}, series = {Sensors and actuators B: Chemical}, volume = {182}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077}, doi = {10.1016/j.snb.2013.03.016}, pages = {315 -- 321}, year = {2013}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the spatial distribution of specific ions on the sensing surface. The conventional chemical imaging system based on the light-addressable potentiometric sensor (LAPS), however, required a long time to obtain a chemical image, due to the slow mechanical scan of a single light beam. For high-speed imaging, a plurality of light beams modulated at different frequencies can be employed to measure the ion concentrations simultaneously at different locations on the sensor plate by frequency division multiplex (FDM). However, the conventional measurement geometry of back-side illumination limited the bandwidth of the modulation frequency required for FDM measurement, because of the low-pass filtering characteristics of carrier diffusion in the Si substrate. In this study, a high-speed chemical imaging system based on front-side-illuminated LAPS was developed, which achieved high-speed spatiotemporal recording of pH change at a rate of 70 frames per second.}, language = {en} } @article{FeuchtSchoenbachLanzletal.2013, author = {Feucht, Nikolaus and Sch{\"o}nbach, Etienne Michael and Lanzl, Ines and Kotliar, Konstantin and Lohmann, Chris Patrick and Maier, Mathias}, title = {Changes in the foveal microstructure after intravitreal bevacizumab application in patients with retinal vascular disease}, series = {Clinical Ophthalmology}, volume = {7}, journal = {Clinical Ophthalmology}, publisher = {Dove Medical Press}, address = {Auckland, New Zealand}, issn = {1177-5483}, pages = {173 -- 178}, year = {2013}, language = {en} } @article{KotliarHanssenEberhardtetal.2013, author = {Kotliar, Konstantin and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Schmaderer, Christoph and Halle, Martin and Heemann, Uwe and Baumann, M.}, title = {Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects}, series = {Microcirculation}, journal = {Microcirculation}, publisher = {Wiley}, address = {Malden}, issn = {1549-8719}, year = {2013}, language = {en} } @article{ReisertSchneiderGeissleretal.2013, author = {Reisert, Steffen and Schneider, Benno and Geissler, Hanno and Gompel, Matthias van and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Multi-sensor chip for the investigation of different types of metal oxides for the detection of H2O2 in the ppm range}, series = {physica status solidi (a)}, volume = {210}, journal = {physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, pages = {898 -- 904}, year = {2013}, abstract = {In this work, a multi-sensor chip for the investigation of the sensing properties of different types of metal oxides towards hydrogen peroxide in the ppm range is presented. The fabrication process and physical characterization of the multi-sensor chip are described. Pure SnO2 and WO3 as well as Pd- and Pt-doped SnO2 films are characterized in terms of their sensitivity to H2O2. The sensing films have been prepared by drop-coating of water-dispensed nano-powders. A physical characterization, including scanning electron microscopy and X-ray diffraction analysis of the deposited metal-oxide films, was done. From the measurements in hydrogen peroxide atmosphere, it could be shown, that all of the tested metal oxide films are suitable for the detection of H2O2 in the ppm range. The highest sensitivity and reproducibility was achieved using Pt-doped SnO2. Calibration plot of a SnO2, WO3, Pt-, and Pd-doped SnO2 gas sensor for H2O2 concentrations in the ppm range.}, language = {en} } @article{HennemannKohlReisertetal.2013, author = {Hennemann, J{\"o}rg and Kohl, Claus-Dieter and Reisert, Steffen and Kirchner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Copper oxide nanofibres for detection of hydrogen peroxide vapour at high concentrations}, series = {physica status solidi (a)}, volume = {210}, journal = {physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201200775}, pages = {859 -- 863}, year = {2013}, abstract = {We present a sensor concept based on copper(II)oxide (CuO) nanofibres for the detection of hydrogen peroxide (H2O2) vapour in the percent per volume (\% v/v) range. The fibres were produced by using the electrospinning technique. To avoid water condensation in the pores, the fibres were initially modified by an exposure to H2S to get an enclosed surface. By a thermal treatment at 350 °C the fibres were oxidised back to CuO. Thereby, the visible pores disappear which was verified by SEM analysis. The fibres show a decrease of resistance with increasing H2O2 concentration which is due to the fact that hydrogen peroxide is an oxidising gas and CuO a p-type semiconductor. The sensor shows a change of resistance within the minute range to the exposure until the maximum concentration of 6.9\% v/v H2O2. At operating temperatures below 450 °C the corresponding sensor response to a concentration of 4.1\% v/v increases. The sensor shows a good reproducibility of the signal at different measurements. CuO seems to be a suitable candidate for the detection of H2O2 vapour at high concentrations. Resistance behaviour of the sensor under exposure to H2O2 vapours between 2.3 and 6.9\% v/v at an operating temperature of 450 °C.}, language = {en} } @article{NomdedeuWillenSchiefferetal.2012, author = {Nomdedeu, Mar Monsonis and Willen, Christine and Schieffer, Andre and Arndt, Hartmut}, title = {Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web}, series = {Marine Biology}, volume = {159}, journal = {Marine Biology}, number = {11}, publisher = {Springer}, address = {Berlin}, issn = {1432-1793}, doi = {10.1007/s00227-012-1966-x}, pages = {2423 -- 2430}, year = {2012}, abstract = {The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming.}, language = {en} } @article{HeinzelSchaeferMuelleretal.2010, author = {Heinzel, Alexander and Sch{\"a}fer, Ralf and M{\"u}ller, Hans-Wilhelm and Schieffer, Andre and Ingenhag, Ariane and Northoff, Georg and Franz, Matthias and Hautzel, Hubertus}, title = {Differential modulation of valence and arousal in high-alexithymic and low-alexithymic individuals}, series = {Neuroreport}, volume = {21}, journal = {Neuroreport}, number = {15}, publisher = {Lippincott Williams \& Wilkins}, address = {London}, issn = {1473-558X}, doi = {10.1097/WNR.0b013e32833f38e0}, pages = {998 -- 1002}, year = {2010}, abstract = {High-alexithymic individuals are characterized by an impaired ability to identify and communicate emotions whereas low-alexithymic individuals have a wide-ranging ability to deal with emotions. This study examined the hypothesis that valence and arousal modifications of emotional stimuli differentially modulate cortical regions in high-alexithymic and low-alexithymic individuals. To this end, 28 high-alexithymic and 25 low-alexithymic individuals were investigated with event-related fMRI using visual emotional stimuli. We found differential neural activations in the dorsal anterior cingulate, the insula and the amygdala. We suggest that these differences may account for the impaired ability of high-alexithymic individuals to appropriately handle emotional stimuli.}, language = {en} } @article{HeinzelSchaeferMuelleretal.2010, author = {Heinzel, Alexander and Sch{\"a}fer, Ralf and M{\"u}ller, Hans-Wilhelm and Schieffer, Andre and Ingenhag, Ariane and Eickhoff, Simon B. and Northoff, Georg and Franz, Matthias and Hautzel, Hubertus}, title = {Increased Activation of the Supragenual Anterior Cingulate Cortex during Visual Emotional Processing in Male Subjects with High Degrees of Alexithymia: An Event-Related fMRI Study}, series = {Psychotherapy and Psychosomatics}, volume = {79}, journal = {Psychotherapy and Psychosomatics}, number = {6}, publisher = {Karger}, address = {Basel}, issn = {0033-3190}, doi = {10.1159/000320121}, pages = {363 -- 370}, year = {2010}, abstract = {Background: One of the most prominent neurobiological models of alexithymia assumes an altered function of the anterior cingulate cortex (ACC) as the crucial neural correlate of alexithymia. So far functional imaging studies have yielded inconclusive results. Therefore, we tested this hypothesis in healthy alexithymics and nonalexithymics in an event-related fMRI study. Methods: Thirty high- and 30 low-alexithymic right-handed male subjects (selected by the 20-item Toronto Alexithymia Scale, TAS-20) were investigated with event-related fMRI using a picture viewing paradigm. The stimuli consisted of happy, fearful and neutral facial expressions (Ekman-Friesen) as well as positive, negative and neutral pictures from the International Affective Picture System. Results: Contrasting the high-alexithymic with the low-alexithymic group we observed increased activation of the supragenual ACC for different emotional valences as well as for different emotional stimuli. Moreover, there was a positive correlation of the ACC with the individual TAS-20 scores but no correlations with the individual Beck Depression Inventory scores. Additionally, there was no difference in activity of the amygdala. Conclusions: We demonstrated that the supragenual ACC is constantly activated more strongly in alexithymic subjects and that this activation is related to the symptoms of alexithymia and not to associated symptoms such as depression. Therefore, our findings support the hypothesis of an altered function of the ACC in alexithymia.}, language = {en} } @article{KirchnerOberlaenderSusoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suso, Henri-Pierre and Rysstad, Gunnar and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes}, series = {Physica status solidi (a)}, volume = {210}, journal = {Physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201200920}, pages = {877 -- 883}, year = {2013}, abstract = {A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests.}, language = {en} } @article{GebhardtFateri2013, author = {Gebhardt, Andreas and Fateri, Miranda}, title = {3D printing and its applications}, series = {RTejournal - Forum f{\"u}r Rapid Technologie}, volume = {10}, journal = {RTejournal - Forum f{\"u}r Rapid Technologie}, number = {1}, publisher = {Fachhochschule Aachen}, address = {Aachen}, issn = {1614-0923}, url = {http://nbn-resolving.de/urn:nbn:de:0009-2-35626}, year = {2013}, abstract = {Eine zunehmende Anzahl von Artikeln in Publikumszeitschriften und Journalen r{\"u}ckt die direkte Herstellung von Bauteilen und Figuren immer mehr in das Bewusstsein einer breiten {\"O}ffentlichkeit. Leider ergibt sich nur selten ein einigermaßen vollst{\"a}ndiges Bild davon, wie und in welchen Lebensbereichen diese Techniken unseren Alltag ver{\"a}ndern werden. Das liegt auch daran, dass die meisten Artikel sehr technisch gepr{\"a}gt sind und sich nur punktuell auf Beispiele st{\"u}tzen. Dieser Beitrag geht von den Bed{\"u}rfnissen der Menschen aus, wie sie z.B. in der Maslow'schen Bed{\"u}rfnispyramide strukturiert dargestellt sind und unterstreicht dadurch, dass 3D Printing (oder Additive Manufacturing resp. Rapid Prototyping) bereits alle Lebensbereiche erfasst hat und im Begriff ist, viele davon zu revolutionieren.}, language = {en} } @article{ParlLarueStreunetal.2011, author = {Parl, C. and Larue, H. and Streun, M. and Ziemons, Karl}, title = {Double-side-readout technique for SiPM-matrices}, series = {2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)}, journal = {2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)}, publisher = {IEEE}, address = {New York}, issn = {1095-7863}, pages = {1486 -- 1487}, year = {2011}, abstract = {In our case the double-side-method is used to minimize the complexity of a matrix-readout. Here the number of channels is reduced to 2√N̅. It is also possible to benefit from the method in a single pixel readout system. One signal can be used to measure position and energy of the event, the other one can be applied to a fast trigger-circuit at the same time. In a next step we will investigate timing behavior and electrical crosstalk of the circuit.}, language = {en} } @article{HerzogPietrzykShahetal.2010, author = {Herzog, Hans and Pietrzyk, Uwe and Shah, N. Jon and Ziemons, Karl}, title = {The current state, challenges and perspectives of MR-PET}, series = {Neuroimage}, volume = {49}, journal = {Neuroimage}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1053-8119}, doi = {10.1016/j.neuroimage.2009.10.036}, pages = {2072 -- 2082}, year = {2010}, abstract = {Following the success of PET/CT during the last decade and the recent increasing proliferation of SPECT/CT, another hybrid imaging instrument has been gaining more and more interest: MR-PET. First combined, simultaneous PET and MR studies carried out in small animals demonstrated the feasibility of the new approach. Concurrently, some prototypes of an MR-PET scanner for simultaneous human brain studies have been built, their performance is being tested and preliminary applications have already been shown. Through this pioneering work, it has become clear that advances in the detector design are necessary for further optimization. Recently, the different issues related to the present state and future prospects of MR-PET were presented and discussed during an international 2-day workshop at the Forschungszentrum J{\"u}lich, Germany, held after, and in conjunction with, the 2008 IEEE Nuclear Science Symposium and Medical Imaging Conference in Dresden, Germany on October 27-28, 2008. The topics ranged from small animal MR-PET imaging to human MR-BrainPET imaging, new detector developments, challenges/opportunities for ultra-high field MR-PET imaging and considerations of possible future research and clinical applications. This report presents a critical summary of the contributions made to the workshop.}, language = {en} }