@article{KernKloetersPferdemenges2010, author = {Kern, Alexander and Kl{\"o}ters, Georg and Pferdemenges, J{\"o}rg}, title = {Optimised protection against lightning for the signalling and safety systems of level crossings on non-electrified railway lines}, series = {RTR : European Rail Technology Review}, volume = {50}, journal = {RTR : European Rail Technology Review}, number = {2}, publisher = {DVV Media Group}, address = {Hamburg}, issn = {0079-9548}, year = {2010}, language = {en} } @article{TemizArtmannBaşkurtEdremitlioglu1994, author = {Temiz Artmann, Ayseg{\"u}l and Ba{\c{s}}kurt, Oǧuz Kerim and Edremitlioglu, M.}, title = {In vitro effects of in vivo activated leukocytes on red blood cell filterability and lipid peroxidation. Baskurt, O.K.; Edremitlioglu, M.; Temiz, A.}, series = {Clinical Hemorheology. 14 (1994), H. 4}, journal = {Clinical Hemorheology. 14 (1994), H. 4}, pages = {591 -- 596}, year = {1994}, language = {en} } @article{SponagelBaroudSteffenetal.2002, author = {Sponagel, Stefan and Baroud, Gamal and Steffen, T. and Wu, J.}, title = {Parameter identification for cement infiltration of osteoporotic bone}, series = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, journal = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, publisher = {Balkema}, address = {Lisse [u.a.]}, isbn = {90-5809-394-8}, pages = {55 -- 58}, year = {2002}, language = {en} } @article{KernSchelthoffMathieu2010, author = {Kern, Alexander and Schelthoff, Christof and Mathieu, Moritz}, title = {Probability of lightning strikes to air-terminations of structures using the electro-geometrical model theory and the statistics of lightning current parameters}, publisher = {IEEE}, address = {New York}, isbn = {978-88-905519-0-1}, doi = {10.1109/ICLP.2010.7845757}, pages = {750-1 -- 750-8}, year = {2010}, abstract = {Planning the air-terminations for a structure to be protected the use of the rolling-sphere method (electro-geometrical model) is the best way from the physics of lightning point-of-view. Therefore, international standards prefer this method. However, using the rolling-sphere method only results in possible point-of-strikes on a structure without giving information about the probability of strikes at the individual points compared to others.}, language = {en} } @article{Naujokat2010, author = {Naujokat, Anke}, title = {Ut rhetorica architectura - Leon Battista Alberti´s Technique of Architectural Collage / Leon Battista Albertis architektonische Collagetechnik}, series = {Candide : journal for architectural knowledge}, volume = {2}, journal = {Candide : journal for architectural knowledge}, publisher = {RWTH Aachen}, address = {Aachen}, issn = {1869-6465}, pages = {73 -- 100}, year = {2010}, abstract = {Leon Battista Alberti, probably the most innovative architect of early Renaissance Italy, has always fascinated scholars by virtue of the striking interpenetration of theory and practice manifest in his work. As an architect, Alberti was an autodidact. Without the benefit of the formative influence of a master or design education, the roots of his conception of architecture lie in his intellectual formation through humanistic rhetoric. The present study demonstrates with reference to a specific project — the Tempietto of the Holy Sepulchre in Florence — how Alberti's humanist approach conditioned his method of architectural design.}, language = {en} } @article{TemizArtmannBaşkurtMeiselman1998, author = {Temiz Artmann, Ayseg{\"u}l and Ba{\c{s}}kurt, Oǧuz Kerim and Meiselman, H. J.}, title = {Effect of superoxide anions on red blood cell rheologic properties. Baskurt, O. K.; Temiz, A.; Meiselman, H. J.}, series = {Free Radical Biology and Medicine. 24 (1998), H. 1}, journal = {Free Radical Biology and Medicine. 24 (1998), H. 1}, isbn = {0891-5849}, pages = {102 -- 110}, year = {1998}, language = {en} } @article{TemizArtmannBaşkurtMeiselman1997, author = {Temiz Artmann, Ayseg{\"u}l and Ba{\c{s}}kurt, Oǧuz Kerim and Meiselman, H. J.}, title = {Red blood cell aggregation in experimental sepsis . Baskurt, O. K.; Temiz, A.; Meiselman, H. J.}, series = {Journal of Laboratory and Clinical Medicine. 130 (1997), H. 2}, journal = {Journal of Laboratory and Clinical Medicine. 130 (1997), H. 2}, isbn = {0022-2143}, pages = {183 -- 190}, year = {1997}, language = {en} } @article{KernSchelthoffMathieu2010, author = {Kern, Alexander and Schelthoff, Christof and Mathieu, Moritz}, title = {Die dynamische Blitzkugel : Wahrscheinlichkeitsberechnung f{\"u}r Blitzeinschl{\"a}ge in Geb{\"a}ude}, series = {de - Fachzeitschrift f{\"u}r das Elektrohandwerk}, journal = {de - Fachzeitschrift f{\"u}r das Elektrohandwerk}, number = {13-14}, publisher = {H{\"u}thig}, address = {Heidelberg}, issn = {2509-517X}, pages = {24 -- 29}, year = {2010}, language = {de} } @article{TemizArtmannBaşkurtEdremitlioglu1995, author = {Temiz Artmann, Ayseg{\"u}l and Ba{\c{s}}kurt, Oǧuz Kerim and Edremitlioglu, M.}, title = {Effect of erythrocyte deformability on myocardial hematocrit gradient. Baskurt, O.K.; Edremitlioglu, M.; Temiz, A.}, series = {American Journal of Physiology: Heart and Circulatory Physiology. 268 (1995), H. 1}, journal = {American Journal of Physiology: Heart and Circulatory Physiology. 268 (1995), H. 1}, isbn = {0363-6135}, pages = {260 -- 264}, year = {1995}, language = {en} } @article{WagnerMiyamotoSchoeningetal.2010, author = {Wagner, Torsten and Miyamoto, Ko-ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Novel combination of digital light processing (DLP) and light-addressable potentiometric sensors (LAPS) for flexible chemical imaging}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2010.09.161}, pages = {520 -- 523}, year = {2010}, abstract = {Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach of read out in a light-addressable potentiometric sensor (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device which allows fast and flexible generation of light patterns. With the help of these light patterns the sensor surface of the LAPS device can be read out sequentially in a raster like scheme (scanning LAPS). The DLP approach has several advantages compared to conventional scanning LAPS set-ups, e.g., the spot size, the shape and the intensity of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of measurement.}, language = {en} } @article{AbouzarPedrazaSchoeningetal.2010, author = {Abouzar, Maryam H. and Pedraza, A. M. and Sch{\"o}ning, Michael Josef and Poghossian, Arshak}, title = {Label-free DNA hybridization and denaturation detection by means of field-effect nanoplate SOI capacitors functionalized with gold nanoparticles}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2010.09.259}, pages = {918 -- 921}, year = {2010}, abstract = {A new approach for a label-free electrical detection of DNA hybridization and denaturation using an array of individually addressable field-effect nanoplate SOI (silicon-on-insulator) capacitors functionalized with gold nanoparticles is presented. By using a constant-capacitance measuring setup in a differential mode, signal changes of ∼110 mV and ∼70 mV have been registered after the DNA hybridization and denaturation events, respectively.}, language = {en} } @article{Esch2010, author = {Esch, Thomas}, title = {Trends in der Nutzfahrzeugantriebstechnik}, series = {Motortechnische Zeitschrift (MTZ)}, volume = {71}, journal = {Motortechnische Zeitschrift (MTZ)}, number = {10}, publisher = {Springer Nature}, address = {Basel}, issn = {0024-8525}, doi = {10.1007/bf03225608}, pages = {652 -- 658}, year = {2010}, abstract = {Umweltzonen und Fahrverbote, kletternde Dieselpreise und steigende Straßenbenutzungsgeb{\"u}hren setzen dem Transportgewerbe aktuell schwer zu. Nutzfahrzeughersteller und Partner finden auf diese Herausforderungen neue Antworten mit der Erf{\"u}llung der EEV-Grenzwerte (Enhanced Environmentally Friendly Vehicle) als den gegenw{\"a}rtig anspruchsvollsten europ{\"a}ischen Abgasstandard f{\"u}r Lkw und Busse.}, language = {de} } @article{BienerSasseWemhoff2010, author = {Biener, Ernst and Sasse, Torsten and Wemhoff, Thomas}, title = {Deponie auf Deponie - Technische und genehmigungsrechtliche Aspekte}, series = {Band 19: Abschluss und Rekultivierung von Deponien und Altlasten 2010 : Die Umsetzung der neuen Deponieverordnung - praktische Erfahrungen im Vollzug und erste {\"A}nderungsverordnung zur neuen DepV ; Beitr{\"a}ge zum Seminar am 13. und 14. Oktober 2010 in Karlsruhe}, journal = {Band 19: Abschluss und Rekultivierung von Deponien und Altlasten 2010 : Die Umsetzung der neuen Deponieverordnung - praktische Erfahrungen im Vollzug und erste {\"A}nderungsverordnung zur neuen DepV ; Beitr{\"a}ge zum Seminar am 13. und 14. Oktober 2010 in Karlsruhe}, editor = {Egloffstein, Thomas}, publisher = {ICP-Eigenverlag}, address = {Karlsruhe}, isbn = {978-3-939662-08-2}, pages = {73 -- 84}, year = {2010}, language = {de} } @article{GronsfeldSparlaWeinnhold2010, author = {Gronsfeld, Richard and Sparla, Peter and Weinnhold, Wolfgang}, title = {Airborne und terrestrisches Laserscanning - neue Tools f{\"u}r den Talsperrenbetreiber?}, series = {Wasserwirtschaft}, volume = {100}, journal = {Wasserwirtschaft}, number = {4}, publisher = {Springer Vieweg}, address = {Wiesbaden}, issn = {0043-0978}, doi = {10.1007/BF03241621}, pages = {80 -- 82}, year = {2010}, language = {de} } @article{ThelenPaschmannHamelmann2010, author = {Thelen, Jan and Paschmann, Hans and Hamelmann, Dirk}, title = {Zielsichere Herstellung und Anwendung von Fl{\"u}ssigboden}, series = {bi-UmweltBau}, journal = {bi-UmweltBau}, publisher = {bi-Medien-GmbH}, address = {Kiel}, issn = {2509-2685}, pages = {48 -- 49}, year = {2010}, language = {de} } @article{BerretzSkorupaSanderetal.2010, author = {Berretz, Frank and Skorupa, Sascha and Sander, Volker and Belloum, Adam}, title = {Towards an actor-driven workflow management system for grids}, series = {Proceedings of 2010 International Symposium on Collaborative Technologies and Systems}, journal = {Proceedings of 2010 International Symposium on Collaborative Technologies and Systems}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4244-6619-1}, doi = {10.1109/CTS.2010.5478458}, pages = {611 -- 616}, year = {2010}, abstract = {Currently, most workflow management systems in Grid environments provide push-oriented job distribution strategies, where jobs are explicitly delegated to resources. In those scenarios the dedicated resources execute submitted jobs according to the request of a workflow engine or Grid wide scheduler. This approach has various limitations, particularly if human interactions should be integrated in workflow execution. To support human interactions with the benefit of enabling inter organizational computation and community approaches, this poster paper proposes the idea of a pull-based task distribution strategy. Here, heterogeneous resources, including human interaction, should actively select tasks for execution from a central repository. This leads to special demands regarding security issues like access control. In the established push-based job execution the resources are responsible for granting access to workflows and job initiators. In general this is done by access control lists, where users are explicitly mapped to local accounts according to their policies. In the pull-based approach the resources actively apply for job executions by sending requests to a central task repository. This means that every resource has to be able to authenticate against the repository to be authorized for task execution. In other words the authorization is relocated from the resources to the repository. The poster paper introduces current work regarding to the mentioned security aspects in the pull-based approach within the scope of the project "HiX4AGWS".}, language = {en} } @article{ZiemonsHeinrichsStreunetal.2004, author = {Ziemons, Karl and Heinrichs, U. and Streun, M. and Pietrzyk, Uwe}, title = {Validation of GEANT3 simulation studies with a dual-head PMT ClearPET™ prototype}, series = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 5}, journal = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 5}, issn = {1082-3654}, pages = {3053 -- 3056}, year = {2004}, abstract = {The ClearPET™ project is proposed by working groups of the Crystal Clear Collaboration (CCC) to develop a 2nd generation high performance small animal positron emission tomograph (PET). High sensitivity and high spatial resolution is foreseen for the ClearPET™ camera by using a phoswich arrangement combining mixed lutetium yttrium aluminum perovskite (LuYAP:Ce) and lutetium oxyorthosilicate (LSO) scintillating crystals. Design optimizations for the first photomultiplier tube (PMT) based ClearPET camera are done with a Monte-Carlo simulation package implemented on GEANT3 (CERN, Geneva, Switzerland). A dual-head prototype has been built to test the frontend electronics and was used to validate the implementation of the GEANT3 simulation tool. Multiple simulations were performed following the experimental protocols to measure the intrinsic resolution and the sensitivity profile in axial and radial direction. Including a mean energy resolution of about 27.0\% the simulated intrinsic resolution is about (1.41±0.11)mm compared to the measured of (1.48±0.06)mm. The simulated sensitivity profiles show a mean square deviation of 12.6\% in axial direction and 3.6\% in radial direction. Satisfactorily these results are representative for all designs and confirm the scanner geometry.}, language = {en} } @article{KhodaverdiChatziioannouWeberetal.2005, author = {Khodaverdi, M. and Chatziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, Uwe}, title = {Investigation of different MicroCT scanner configurations by GEANT4 simulations}, series = {IEEE Transactions on Nuclear Science}, volume = {52}, journal = {IEEE Transactions on Nuclear Science}, number = {1}, isbn = {0018-9499}, pages = {188 -- 192}, year = {2005}, abstract = {This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.}, language = {en} } @article{SchollSchubertZieneretal.2010, author = {Scholl, Ingrid and Schubert, Nicole and Ziener, Pascal and Pietrzyk, Uwe}, title = {GPU-basiertes Volumenrendering von multimodalen medizinischen Bilddaten in Echtzeit}, series = {Bildverarbeitung f{\"u}r die Medizin 2010}, journal = {Bildverarbeitung f{\"u}r die Medizin 2010}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-11967-5}, pages = {400 -- 404}, year = {2010}, abstract = {Die vorliegende Arbeit zeichnet sich dadurch aus, dass registrierte unsegmentierte Volumina aus multimodalen Bilddatens{\"a}tzen (z.B. MRT, PET) gleichzeitig in einer 3D-Rekonstruktion visualisiert werden und in Echtzeit manipuliert werden k{\"o}nnen. Erm{\"o}glicht wird die Echtzeitf{\"a}higkeit durch die Programmierung der Algorithmen zur direkten Volumenvisualisierung auf der Grafikkarte mittels der neuen CUDA-Technologie. Die Zuordnung der Farbeigenschaften wird {\"u}ber 1D-Transferfunktionen f{\"u}r jedes Volumen getrennt gesteuert. So k{\"o}nnen durch die interaktive Ver{\"a}nderung der 1D-Transferfunktion Detailinformationen aus den zwei Bilddatens{\"a}tzen getrennt kontrolliert werden und die Vorteile der verschiedenen Bildmodalit{\"a}ten in einer Visualisierung genutzt werden. Mittels dieses interaktiven Frameworks k{\"o}nnen neue Erkenntnisse insbesondere {\"u}ber neurodegenerativen Erkrankungen gewonnen werden.}, language = {de} } @article{BlomeChiconeHehletal.2010, author = {Blome, Hans-Joachim and Chicone, Carmen and Hehl, Friedrich W. and Mashhoon, Bahram}, title = {Nonlocal modification of Newtonian gravity}, series = {Physical Review D}, volume = {81}, journal = {Physical Review D}, number = {6}, publisher = {American Physical Society}, address = {Melville, NY}, issn = {0556-2821}, doi = {10.1103/PhysRevD.81.065020}, year = {2010}, abstract = {The Newtonian regime of a recent nonlocal extension of general relativity is investigated. Nonlocality is introduced via a scalar "constitutive" kernel in a special case of the translational gauge theory of gravitation, namely, the teleparallel equivalent of general relativity. In this theory, the nonlocal aspect of gravity simulates dark matter. A nonlocal and nonlinear generalization of Poisson's equation of Newtonian gravitation is presented. The implications of nonlocality for the gravitational physics in the solar system are briefly studied.}, language = {en} } @article{Timme2010, author = {Timme, Michael}, title = {K{\"u}ndigung des Mietverh{\"a}ltnisses wegen nicht gezahlter Kosten eines Rechtsstreits}, series = {Monatsschrift f{\"u}r deutsches Recht}, volume = {64}, journal = {Monatsschrift f{\"u}r deutsches Recht}, number = {19}, publisher = {Verlag Dr. Otto Schmidt}, address = {K{\"o}ln}, issn = {0340-1812}, doi = {10.9785/ovs-mdtr-2010-1089}, pages = {1089 -- 1091}, year = {2010}, abstract = {Der BGH hat entschieden, dass ein Vermieter einen Wohnraummietvertrag nicht deshalb k{\"u}ndigen kann, weil der Mieter die Prozesskosten eines fr{\"u}heren, auf Zahlungsverzug gest{\"u}tzten R{\"a}umungsprozesses nicht begleicht. Der folgende Beitrag beleuchtet die Konsequenzen dieser Entscheidung f{\"u}r die mietvertragliche Praxis}, language = {de} } @article{KowollikSchnitzlerBisellietal.2010, author = {Kowollik, Silvia and Schnitzler, Thomas and Biselli, Manfred and Krueger, R. and Zang, Werner and Peuscher, A. and Schillberg, S. and Fischer, R.}, title = {Die Rolle des Respirationsquotienten in der Zellkulturfermentation}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {Chemie Ingenieur Tec}, doi = {10.1002/cite.201050393}, pages = {1505 -- 1506}, year = {2010}, abstract = {In der biopharmazeutischen Industrie werden rekombinante Proteine und monoklonale Antik{\"o}rper in Zellkulturfermentationen produziert, da nur humane oder tierische Zelllinien {\"u}ber die F{\"a}higkeit der Glykosylierung verf{\"u}gen. Um hohe Produktausbeuten in ausgezeichneter Qualit{\"a}t zu erzielen, ist eine funktionst{\"u}chtige Prozesskontrolle unerl{\"a}sslich. Hierzu wurde in Kooperation mit der Firma Hitec Zang GmbH die HiSense� Pr{\"a}zisionsabgasanalytik entwickelt, die auf Basis der vollautomatischen Ermittlung des Respirationsquotienten (RQ; Verh{\"a}ltnis vonKohlendioxidbildungsrate (CER) zu Sauerstoffaufnahmerate (OTR)) einen Fermentationsprozess nicht-invasiv {\"u}berwacht. Der RQ kann in Hybridoma- und CHO-Zellen (s. Abb.) in sowohl serumhaltigen als auch serumfreien Medien erfolgreich ermittelt werden. Hier spiegeln die CER und die OTR das Wachstumsverhalten der kultivierten CHO-Zellen wider. Der RQ nimmt dabei Werte zwischen 0,9 und 1,2 an. Dies l{\"a}sst auf verschiedene Stoffwechselaktivit{\"a}ten schließen. Da die momentane industrielle Prozesskontrolle auf gemessenen Sauerstoffaufnahmeraten oder entsprechende Offline-Analytiken der Metaboliten basieren, soll durch die vollautomatische RQ-Ermittlung ein neues Verfahren zur Fermentations{\"u}berwachung etabliert werden. Bisher war diese, in bakteriellen Kultivierungen standardisierte Methode, aufgrund der schwierigen CER-Berechnung bei Zellkulturen keine ad{\"a}quate Alternative.}, language = {de} } @article{ZiemonsBruyndonckxPerezetal.2008, author = {Ziemons, Karl and Bruyndonckx, P. and Perez, J. M. and Pietrzyk, Uwe and Rato, P. and Tavernier, S.}, title = {Beyond ClearPET: Next Aims}, series = {5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro Symposium Proceedings ISBI 2008}, journal = {5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro Symposium Proceedings ISBI 2008}, isbn = {978-1-4244-2003-2}, pages = {1421 -- 1424}, year = {2008}, abstract = {The CRYSTAL CLEAR collaboration, in short CCC, is a consortium of 12 academic institutions, mainly from Europe, joining efforts in the area of developing instrumentation for nuclear medicine and medical imaging. In the framework of the CCC a high performance small animal PET system, called ClearPET, was developed by using new technologies in electronics and crystals in a phoswich arrangement combining two types of lutetium- based scintillator materials: LSO:Ce and LuYAP:Ce. Our next aim will be the development of hybrid image systems. Hybrid MR-PET imaging has many unique advantages for brain research. This has sparked a new research line within CCC for the development of novel MR-PET compatible technologies. MRI is not as sensitive as PET but PET has poorer spatial resolution than MRI. Two major advantages of PET are sensitivity and its ability to acquire metabolic information. To assess these innovations, the development of a 9.4T hybrid animal MR-PET scanner is proposed based on an existing 9.4T MR scanner that will be adapted to enable simultaneous acquisition of MR and PET data using cutting- edge technology for both MR and PET.}, language = {en} } @article{KhodaverdiChaziioannouWeberetal.2004, author = {Khodaverdi, M. and Chaziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, Uwe}, title = {Investigation of different microCT scanner configurations by GEANT4 simulations}, series = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4}, journal = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4}, issn = {1082-3654}, pages = {2989 -- 2993}, year = {2004}, abstract = {This study has been performed to design the combination of the new ClearPET TM (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal Positron Emission Tomography (PET) system, with a microComputed Tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.}, language = {en} } @article{SchmittSchollCaietal.2010, author = {Schmitt, Robert and Scholl, Ingrid and Cai, Yu and Xia, Ji and Dziwoki, Paul and Harding, Martin and Pavim, Alberto}, title = {Machine vision system for inline inspection in carbide insert production}, series = {Proceedings of the 36th International MATADOR Conference}, journal = {Proceedings of the 36th International MATADOR Conference}, publisher = {Springer}, address = {Berlin}, isbn = {978-1-84996-431-9}, doi = {10.1007/978-1-84996-432-6_77}, pages = {339 -- 342}, year = {2010}, abstract = {In steps of the production chain of carbide inserts, such as unloading or packaging, the conformity test of the insert type is done manually, which causes a statistic increase of errors due to monotony and fatigue of the worker and the wide variety of the insert types. A machine vision system is introduced that captures digital frames of the inserts in the production line, analyses inspects automatically and measures four quality features: coating colour, edge radius, plate shape and chip-former geometry. This new method has been tested on several inserts of different types and has shown that the prevalent insert types can be inspected and robustly classified in real production environment and therefore improves the manufacturing automation.}, language = {en} } @article{WagnerWernerMiyamotoetal.2010, author = {Wagner, Torsten and Werner, Frederik and Miyamoto, Ko-ichiro and Ackermann, Hans-Josef and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {FPGA-based LAPS device for the flexible design of sensing sites on functional interfaces}, series = {Physica Status Solidi (A)}, volume = {207}, journal = {Physica Status Solidi (A)}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300}, doi = {10.1002/pssa.200983320}, pages = {844 -- 849}, year = {2010}, abstract = {The development of new interfaces for (bio-)chemical sensors requires comprehensive analyses and testing. The light-addressable potentiometric sensor (LAPS) can be used as a platform to investigate the sensitivity of a newly developed interface towards (bio-)chemical agents. LAPS measurements are spatially resolved by utilisation of focused light beams to define individual measurement spots. In this work, a new digitally modulated LAPS set-up based on an FPGA design will be introduced to increase the number of measurement spots, to shorten the measurement time and to improve the measurement accuracy.}, language = {en} } @article{BerretzSkorupaSanderetal.2011, author = {Berretz, Frank and Skorupa, Sascha and Sander, Volker and Belloum, Adam and Bubak, Marian}, title = {Actor-Driven Workflow Execution in Distributed Environments}, series = {Euro-Par 2010 Parallel Processing Workshops : HeteroPAR, HPCC, HiBB, CoreGrid, UCHPC, HPCF, PROPER, CCPI, VHPC ; Ischia, Italy, August 31 - September 3, 2010 ; revised selected papers / Mario R. Guarracino ... (eds.)}, journal = {Euro-Par 2010 Parallel Processing Workshops : HeteroPAR, HPCC, HiBB, CoreGrid, UCHPC, HPCF, PROPER, CCPI, VHPC ; Ischia, Italy, August 31 - September 3, 2010 ; revised selected papers / Mario R. Guarracino ... (eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-21877-4}, pages = {287 -- 294}, year = {2011}, language = {en} } @article{GerhardsSkorupaSanderetal.2011, author = {Gerhards, M. and Skorupa, Sascha and Sander, Volker and Pfeiffer, P. and Belloum, Adam}, title = {Towards a security framework for a WS-HumanTask processor}, series = {7th International Conference on Network and Service Management (CNSM), 2011 Paris}, journal = {7th International Conference on Network and Service Management (CNSM), 2011 Paris}, publisher = {IEEE}, address = {New York}, isbn = {978-3-901882-44-9}, pages = {1 -- 5}, year = {2011}, language = {en} } @article{BernauKnoedlerEmontsetal.2022, author = {Bernau, C. R. and Kn{\"o}dler, Matthias and Emonts, Jessica and J{\"a}pel, Ronald Colin and Buyel, Johannes Felix}, title = {The use of predictive models to develop chromatography-based purification processes}, series = {Frontiers in Bioengineering and Biotechnology}, journal = {Frontiers in Bioengineering and Biotechnology}, number = {10}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-4185 (online-ressource)}, doi = {10.3389/fbioe.2022.1009102}, pages = {25 Seiten}, year = {2022}, abstract = {Chromatography is the workhorse of biopharmaceutical downstream processing because it can selectively enrich a target product while removing impurities from complex feed streams. This is achieved by exploiting differences in molecular properties, such as size, charge and hydrophobicity (alone or in different combinations). Accordingly, many parameters must be tested during process development in order to maximize product purity and recovery, including resin and ligand types, conductivity, pH, gradient profiles, and the sequence of separation operations. The number of possible experimental conditions quickly becomes unmanageable. Although the range of suitable conditions can be narrowed based on experience, the time and cost of the work remain high even when using high-throughput laboratory automation. In contrast, chromatography modeling using inexpensive, parallelized computer hardware can provide expert knowledge, predicting conditions that achieve high purity and efficient recovery. The prediction of suitable conditions in silico reduces the number of empirical tests required and provides in-depth process understanding, which is recommended by regulatory authorities. In this article, we discuss the benefits and specific challenges of chromatography modeling. We describe the experimental characterization of chromatography devices and settings prior to modeling, such as the determination of column porosity. We also consider the challenges that must be overcome when models are set up and calibrated, including the cross-validation and verification of data-driven and hybrid (combined data-driven and mechanistic) models. This review will therefore support researchers intending to establish a chromatography modeling workflow in their laboratory.}, language = {en} } @article{FredebeulKreinKnoben2010, author = {Fredebeul-Krein, Markus and Knoben, Werner}, title = {Long term risk sharing contracts as an approach to establish public-private partnerships for investment into next generation access networks}, series = {Telecommunications Policy}, volume = {34}, journal = {Telecommunications Policy}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0308-5961}, doi = {10.1016/j.telpol.2010.07.011}, pages = {528 -- 539}, year = {2010}, abstract = {This paper develops an investment/pricing model for the deployment of basic broadband networks which, along with other applications, is applicable to public-private partnership projects. In particular, a new investment model is suggested to be used for finance deployment over a longer term by enabling both private and public investors to participate in the roll-out of next generation access (NGA) infrastructure. This so-called "long-term risk sharing concept" has several notable benefits compared with the traditional regulatory approach. Above all, the model enables both private operators and public authorities to share the risk of investing in NGA infrastructure. Thus the model offers a way for public authorities to achieve a timely and countrywide roll-out of NGA networks, including in areas where NGA investment would otherwise not occur.}, language = {en} } @article{FredebeulKrein2010, author = {Fredebeul-Krein, Markus}, title = {Wirtschaftskrise : Staatliche F{\"o}rderung von glasfaserbasierten Breitbandnetzen?}, series = {Wirtschaftsdienst}, volume = {90}, journal = {Wirtschaftsdienst}, number = {2}, publisher = {ZBW}, address = {Berlin}, issn = {0043-6275}, pages = {113 -- 117}, year = {2010}, abstract = {Glasfaserbasierte Breitbandnetze werden in Deutschland auch aufgrund der Wirtschaftskrise nur sehr z{\"o}gerlich ausgebaut. Markus Fredebeul-Krein h{\"a}lt eine staatliche Subventionierung der Breitbandnetze nur bedingt f{\"u}r gerechtfertigt. Private Investoren ben{\"o}tigen jedoch dringend Planungssicherheit durch verl{\"a}ssliche Regulierungsvorschriften.}, language = {de} } @article{SchlamannYoonMaderwaldetal.2009, author = {Schlamann, M. and Yoon, M.-S. and Maderwald, S. and Pietrzyk, Thomas and Bitz, Andreas and Gerwig, M. and Forsting, M. and Ladd, S. C. and Ladd, M. E. and Kastrup, O.}, title = {Auswirkungen der Magnetresonanztomografie auf die Elektrophysiologie des motorischen Kortex: eine Studie mit transkranieller Magnetstimulation}, series = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren}, volume = {181}, journal = {R{\"o}Fo - Fortschritte auf dem Giebiet der R{\"o}ntgenstrahlen und der bildgebenden Verfahren}, number = {3}, publisher = {Thieme}, address = {Stuttgart}, issn = {1438-9029}, doi = {10.1055/s-0028-1109038}, pages = {215 -- 219}, year = {2009}, language = {de} } @article{GerhardsSkorupaSanderetal.2011, author = {Gerhards, M. and Skorupa, Sascha and Sander, Volker and Belloum, Adam and Vesunin, D. and Benabdelkader, A.}, title = {HisT/PLIER : A Two-Fold Provenance Approach for Grid-Enabled Scientific Workflows Using WS-VLAM}, series = {12th IEEE/ACM International Conference on Grid Computing (GRID), 2011}, journal = {12th IEEE/ACM International Conference on Grid Computing (GRID), 2011}, publisher = {IEEE}, address = {New York}, doi = {10.1109/Grid.2011.39}, pages = {224 -- 225}, year = {2011}, language = {en} } @article{FredebeulKrein2010, author = {Fredebeul-Krein, Markus}, title = {Die Abschaffung der Studiengeb{\"u}hren ist der falsche Weg!}, series = {Der Ordnungspolitische Kommentar}, journal = {Der Ordnungspolitische Kommentar}, year = {2010}, language = {de} } @article{EmontsBuyel2023, author = {Emonts, Jessica and Buyel, Johannes Felix}, title = {An overview of descriptors to capture protein properties - Tools and perspectives in the context of QSAR modeling}, series = {Computational and Structural Biotechnology Journal}, journal = {Computational and Structural Biotechnology Journal}, number = {21}, publisher = {Research Network of Computational and Structural Biotechnology}, address = {Gotenburg}, issn = {2001-0370 (online-ressource)}, doi = {10.1016/j.csbj.2023.05.022}, pages = {3234 -- 3247}, year = {2023}, abstract = {Proteins are important ingredients in food and feed, they are the active components of many pharmaceutical products, and they are necessary, in the form of enzymes, for the success of many technical processes. However, production can be challenging, especially when using heterologous host cells such as bacteria to express and assemble recombinant mammalian proteins. The manufacturability of proteins can be hindered by low solubility, a tendency to aggregate, or inefficient purification. Tools such as in silico protein engineering and models that predict separation criteria can overcome these issues but usually require the complex shape and surface properties of proteins to be represented by a small number of quantitative numeric values known as descriptors, as similarly used to capture the features of small molecules. Here, we review the current status of protein descriptors, especially for application in quantitative structure activity relationship (QSAR) models. First, we describe the complexity of proteins and the properties that descriptors must accommodate. Then we introduce descriptors of shape and surface properties that quantify the global and local features of proteins. Finally, we highlight the current limitations of protein descriptors and propose strategies for the derivation of novel protein descriptors that are more informative.}, language = {en} } @article{FredebeulKrein2010, author = {Fredebeul-Krein, Markus}, title = {Sollen die Studiengeb{\"u}hren wieder abgeschafft werden?}, series = {Bildungsgerechtigkeit in der Begabtenf{\"o}rderung. Ein Widerspruch in sich?}, journal = {Bildungsgerechtigkeit in der Begabtenf{\"o}rderung. Ein Widerspruch in sich?}, editor = {Bartoldus, Beate and John-Ohnesorg, Marei}, publisher = {Friedrich-Ebert-Stiftung}, address = {Berlin}, isbn = {978-3-86872-423-3}, pages = {124 -- 129}, year = {2010}, abstract = {In den letzten Jahren haben in Deutschland mehrere Bundesl{\"a}nder Studiengeb{\"u}hren eingef{\"u}hrt. Seitdem wird in der Politik heftig {\"u}ber das F{\"u}r und Wider diskutiert. Von den Gegnern wird h{\"a}ufig das Argument vorgebracht, Studiengeb{\"u}hren seien sozial ungerecht und w{\"u}rden insbesondere einkommensschwache Bev{\"o}lkerungsschichten von einem Studium abhalten. Best{\"a}tigt werden sie von den Zahlen aus Umfragen, denen zufolge {\"u}ber 70 Prozent derjenigen, die sich gegen ein Studium entscheiden, finanzielle Gr{\"u}nde f{\"u}r einen Studienverzicht anf{\"u}hren. Bef{\"u}rworter halten dem entgegen, Studiengeb{\"u}hren seien angesichts knapper {\"o}ffentlicher Kassen unbedingt notwendig, da nur so die Qualit{\"a}t der Lehre aufrechterhalten bzw. verbessert werden k{\"o}nne. Zudem w{\"u}rden Studiengeb{\"u}hren die sozialen Bildungsbarrieren keineswegs erh{\"o}hen, was auch daran erkennbar sei, dass infolge der Studiengeb{\"u}hren die Zahl der Studierenden nicht zur{\"u}ckgegangen ist. Der vorliegende Artikel leistet einen Beitrag zu dieser Debatte, indem er die an einer Hochschule in Nordrhein-Westfalen gesammelten Erfahrungen mit Studiengeb{\"u}hren auswertet}, language = {de} } @article{HirschfeldLustfeldReisseletal.2010, author = {Hirschfeld, Julian A. and Lustfeld, Hans and Reißel, Martin and Steffen, Bernhard}, title = {A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack}, series = {International Journal of Energy Research}, volume = {34}, journal = {International Journal of Energy Research}, number = {3}, publisher = {Wiley}, address = {London}, issn = {0363-907X}, doi = {10.1002/er.1662}, pages = {293 -- 301}, year = {2010}, abstract = {A novel scheme for detecting inhomogeneous internal currents in a fuel cell stack is presented. In this paper the scheme is investigated for the case that the flow field plates consist of graphite. Then plates of high conductivity, e.g. aluminium between the flow field plates together with small slits in these plates have three effects: (a) Whenever a local inhomogeneity of the electric current occurs at a particular cell in the stack, this will induce a surface current close to that cell perpendicular to the averaged current. This current can be detected. (b) The plates of high conductivity completely prevent the inhomogeneities from spreading to neighbouring cells. (c) Even at the particular cell the inhomogeneity is suppressed as far as possible. Thus this scheme leads to much better diagnostic possibilities and at the same time reduces electric instabilities to an extent, where they probably become harmless. This scheme will first be explained for a simple model to clarify the idea. However, very precise three dimensional computations using realistic parameters are presented, corroborating the results of the simple model.}, language = {en} } @article{ScholzLeyDachwaldetal.2010, author = {Scholz, A. and Ley, Wilfried and Dachwald, Bernd and Miau, J. J. and Juang, J. C.}, title = {Flight results of the COMPASS-1 picosatellite mission}, series = {Acta Astronautica}, volume = {76}, journal = {Acta Astronautica}, number = {9-10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0094-5765}, doi = {10.1016/j.actaastro.2010.06.040}, pages = {1289 -- 1298}, year = {2010}, abstract = {The mission of the COMPASS-1 picosatellite is to take pictures of the earth, to validate a space-borne GPS receiver developed by the German Aerospace Center, and to verify the proper operation of the magnetic attitude control system in orbit. The spacecraft was launched on April 28, 2008 from the Indian space port Sriharikota, as part of the PSLV-C9 world record launch that simultaneously brought ten satellites into orbit. The mission operations were carried out from the ground stations in Aachen and Tainan. Arising difficulties in the communication link were overcome with the support of individuals from the amateur radio community. After several months of mission operation, abundant housekeeping and mission data has been commanded, received and analyzed and is presented in this paper.}, language = {en} } @article{HirschfeldLustfeldReisseletal.2010, author = {Hirschfeld, Julian A. and Lustfeld, Hans and Reißel, Martin and Steffen, Bernhard}, title = {Tomographic diagnostics of current distributions in a fuel cell stack}, series = {International Journal of Energy Research}, volume = {34}, journal = {International Journal of Energy Research}, number = {3}, publisher = {Wiley}, address = {London}, issn = {0363-907X}, doi = {10.1002/er.1634}, pages = {284 -- 292}, year = {2010}, abstract = {A novel tomographic scheme for analysing the state of any single membrane electrode assembly (MEA) in a stack is suggested. Plates of very high conductivity placed between every fuel cell and slitted in an appropriate manner cause surface currents at well-defined locations of the stack. We show that knowing these surface currents, information about anomalies of the currents in a MEA can be obtained using the methods of tomography. The results are mathematically not unique. However, when assuming plausible defect structures, one can exclude improbable deficiencies by applying a special form of simulated annealing. We present numerical calculations of typical examples demonstrating that the essential defects of the MEA in any single cell of the stack can be detected and their extent can be determined.}, language = {en} } @article{HeinrichsPietrzykZiemons2003, author = {Heinrichs, U. and Pietrzyk, Uwe and Ziemons, Karl}, title = {Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3}, series = {IEEE Transactions on Nuclear Science}, volume = {50}, journal = {IEEE Transactions on Nuclear Science}, number = {5}, isbn = {0018-9499}, pages = {1428 -- 1432}, year = {2003}, abstract = {Within the Crystal Clear Collaboration (CCC), four centers are developing second generation high performance small animal positron emission tomography (PET) scanners for different kinds of animals and medical applications. The first prototypes are photomultiplier tube (PMT)-based systems including depth of interaction (DOI) detection by using a phoswich layer of lutetium oxyorthosilicate (LSO) and lutetium yttrium aluminum perovskite (LuYAP). The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in fields of view (FOVs) caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN, Geneva, Switzerland) was used.}, language = {en} } @article{FredebeulKrein2010, author = {Fredebeul-Krein, Markus}, title = {Studiengeb{\"u}hren sind sozial gerecht}, series = {INSM-{\"O}konomenblog}, journal = {INSM-{\"O}konomenblog}, publisher = {INSM}, address = {Berlin}, year = {2010}, language = {de} } @article{MuellerHirschfeldLambertzetal.2014, author = {M{\"u}ller, Martin and Hirschfeld, Julian A. and Lambertz, Rita and Schulze Lohoff, Andreas and Lustfeld, Hans and Pfeifer, Heinz and Reißel, Martin}, title = {Validation of a novel method for detecting and stabilizing malfunctioning areas in fuel cell stacks}, series = {Journal of power sources}, volume = {272}, journal = {Journal of power sources}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2755 (E-Journal); 0378-7753 (Print)}, doi = {10.1016/j.jpowsour.2014.08.045}, pages = {225 -- 232}, year = {2014}, abstract = {In this paper a setup for detecting malfunctioning areas of MEAs in fuel cell stacks is described. Malfunctioning areas generate electric cross currents inside bipolar plates. To exploit this we suggest bipolar plates consisting not of two but of three layers. The third one is a highly conducting layer and segmented such that the cross currents move along the segments to the surface of the stack where they can be measured by an inductive sensor. With this information a realistic model can be used to detect the malfunctioning area. Furthermore the third layer will prevent any current inhomogeneity of a malfunctioning cell to spread to neighbouring cells in the stack. In this work the results of measurements in a realistic cell setup will be compared with the results obtained in simulation studies with the same configuration. The basis for the comparison is the reliable characterisation of the electrical properties of the cell components and the implication of these results into the simulation model. The experimental studies will also show the limits in the maximum number of segments, which can be used for a reliable detection of cross currents.}, language = {en} } @article{MangHodeniusSchmitzRodeetal.2009, author = {Mang, Thomas and Hodenius, Michael A. J. and Schmitz-Rode, Thomas and Baumann, Martin and Ivanova, Gergana and Wong, John Erik and Haulena, Friedhelm and Soenen, Stefaan J. H. and de Cuyper, Marcel}, title = {Absorption of 10-hydroxycamptothecin into the coat of magnetoliposomes / Hodenius, M. A. J. ; Schmitz-Rode, T. ; Baumann, M. ; Ivoanova, G. ; Wong, J. E. ; Mang, T. ; Haulena, F. ; Soenen, S. J. H. ; De Cuyper, M.}, series = {Colloids and Surfaces A: Physicochemical and Engineering Aspects. 343 (2009), H. 1-3}, journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects. 343 (2009), H. 1-3}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0927-7757}, pages = {20 -- 23}, year = {2009}, language = {en} } @article{ReisselLustfeldHirschfeldetal.2009, author = {Reißel, Martin and Lustfeld, Hans and Hirschfeld, Julian A. and Steffen, Bernhard}, title = {Uniqueness of magnetotomography for fuel cells and fuel cell stacks / Lustfeld, H. ; Hirschfeld, J. ; Reißel, M ; Steffen, B.}, series = {Journal of Physics A: Mathematical and Theoretical. 42 (2009), H. 495205}, journal = {Journal of Physics A: Mathematical and Theoretical. 42 (2009), H. 495205}, isbn = {0022-3689}, pages = {9 S.}, year = {2009}, language = {en} } @article{ReisselLustfeldSteffenetal.2009, author = {Reißel, Martin and Lustfeld, Hans and Steffen, Bernhard and Schmidt, U.}, title = {Reconstruction of Electric Currents in a Fuel Cell by Magnetic Field Measurements / Lustfeld, H. ; Reißel, M. ; Steffen, B. ; Schmidt, U.}, series = {Journal of fuel cell science and technology}, volume = {Vol. 6}, journal = {Journal of fuel cell science and technology}, number = {Iss. 2}, isbn = {1550-624X}, pages = {021012-1 -- 021012-8}, year = {2009}, language = {en} } @article{ReisselHirschfeldLustfeldetal.2009, author = {Reißel, Martin and Hirschfeld, Julian A. and Lustfeld, Hans and Steffen, Bernhard}, title = {Magnetotomography and Electric Currents in a Fuel Cell / Lustfeld, H. ; Reißel, M. ; Steffen, B.}, series = {Fuel Cells. 9 (2009), H. 4}, journal = {Fuel Cells. 9 (2009), H. 4}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {1615-6854}, pages = {474 -- 481}, year = {2009}, language = {en} } @article{LustfeldHirschfeldReisseletal.2011, author = {Lustfeld, Hans and Hirschfeld, Julian A. and Reißel, Martin and Steffen, Bernhard}, title = {Enhancement of precision and reduction of measuring points in tomographic reconstructions}, series = {Physics Letters A}, volume = {375}, journal = {Physics Letters A}, number = {8}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0375-9601}, pages = {1167 -- 1171}, year = {2011}, language = {en} } @article{Schermutzki2010, author = {Schermutzki, Margret}, title = {In Modulen lehren, lernen und pr{\"u}fen}, series = {In Modulen lehren, lernen und pr{\"u}fen. Herausforderungen an die Hochschuldidaktik}, journal = {In Modulen lehren, lernen und pr{\"u}fen. Herausforderungen an die Hochschuldidaktik}, editor = {Terbuyken, Gregor}, publisher = {Evangelische Akademie Loccum}, address = {Rehburg-Loccum}, isbn = {978-3-8172-7809-1}, pages = {81 -- 106}, year = {2010}, language = {de} } @article{SchneiderSchneider2010, author = {Schneider, Bettina and Schneider, Wilhelm}, title = {Die Konzernrechnungslegung}, series = {Das Wirtschaftsstudium : wisu}, volume = {39}, journal = {Das Wirtschaftsstudium : wisu}, number = {7}, publisher = {Lange}, address = {D{\"u}sseldorf}, issn = {0340-3084}, pages = {938 -- 942}, year = {2010}, language = {de} } @article{HeinrichsPietrzykZiemons2003, author = {Heinrichs, U. and Pietrzyk, Uwe and Ziemons, Karl}, title = {Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3}, series = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, issn = {1082-3654}, pages = {682 -- 686}, year = {2003}, abstract = {Within the Crystal Clear Collaboration four centres are developing 2nd generation high performance small animal PET scanners for different kinds of animals and medical applications. The first prototypes are PMT-based systems including depth of interaction (DOI) detection by using a phoswich layer of LSO and LuYAP. The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in FOVs caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN) was used. The simulations have shown that all PMT designs with one-to-one coupling of crystals have a very nonlinear axial sensitivity profile. By shifting every other PMT 1/4 of a PMT length in axial direction the sampling of the FOVs became more homogeneous. At an energy threshold of 350keV the regression coefficient increases from 0.818 for the non-shifted to 0.993 for the shifted design. Simulations of a point source centred in the FOV (threshold: 350keV) resulted in sensitivities of 4.2\% for a 4×20PMT (LSO/LuYAP a 10mm) and 3.8\% for a 4×16PMT (LSO/LuYAP a 8mm) ring design. The 3D-MLEM reconstruction of a point source shows the enormous improvement of resolution using a crystal double layer with DOI (3.1mm at 40mm from CFOV) instead of a 20mm single layer (11.9mm).}, language = {en} } @article{LustfeldPithanReissel2012, author = {Lustfeld, Hans and Pithan, C. and Reißel, Martin}, title = {Metallic electrolyte composites in the framework of the brick-layer model}, series = {Journal of the European Ceramic Society}, volume = {32}, journal = {Journal of the European Ceramic Society}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-2219}, doi = {10.1016/j.jeurceramsoc.2011.10.017}, pages = {859 -- 864}, year = {2012}, abstract = {It is well known that the already large dielectric constants of some electrolytes like BaTiO₃ can be enhanced further by adding metallic (e.g. Ni, Cu or Ag) nanoparticles. The enhancement can be quite large, a factor of more than 1000 is possible. The consequences for the properties will be discussed in the present paper applying a brick-layer model (BLM) for calculating dc-resistivities of thin layers and a modified one (PBLM) that includes percolation for calculating dielectric properties of these materials. The PBLM results in an at least qualitative description and understanding of the physical phenomena: This model gives an explanation for the steep increase of the dielectric constant below the percolation threshold and why this increase is connected to a dramatic decrease of the breakdown voltage as well as the ability of storing electrical energy. We conclude that metallic electrolyte composites like BaTiO₃ are not appropriate for energy storage.}, language = {en} }