@misc{DieringerRenzLindeletal.2010, author = {Dieringer, Matthias A. and Renz, Wolfgang and Lindel, Tomasz Dawid and Seifert, Frank and Frauenrath, Tobias and Waiczies, Helmar and von Knobelsdorff-Brenkhoff, Florian and Santoro, Davide and Hoffmann, Werner and Ittermann, Bernd and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {4CH TX/RX Surface Coil for 7T: Design, Optimization and Application for Cardiac Function Imaging}, series = {2010 ISMRM-ESMRMB joint annual meeting}, journal = {2010 ISMRM-ESMRMB joint annual meeting}, issn = {1545-4428}, year = {2010}, abstract = {Practical impediments of ultra high field cardiovascular MR (CVMR) can be catalogued in exacerbated magnetic field and radio frequency (RF) inhomogeneities, susceptibility and off-resonance effects, conductive and dielectric effects in tissue, and RF power deposition constraints, which all bear the potential to spoil the benefit of CVMR at 7T. Therefore, a four element cardiac transceive surface coil array was developed. Cardiac imaging provided clinically acceptable signal homogeneity with an excellent blood myocardium contrast. Subtle anatomic structures, such as pericardium, mitral and tricuspid valves and their apparatus, papillary muscles, and trabecles were accurately delineated.}, language = {en} } @article{GoettscheHoffschmidtSchmitzetal.2010, author = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus}, title = {Solar Concentrating Systems Using Small Mirror Arrays}, series = {Journal of solar energy engineering}, volume = {132}, journal = {Journal of solar energy engineering}, number = {1}, publisher = {ASME}, address = {New York}, issn = {0199-6231}, doi = {10.1115/1.4000332}, pages = {4 Seiten}, year = {2010}, abstract = {The cost of solar tower power plants is dominated by the heliostat field making up roughly 50\% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ~ 20 kg/m² steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m² caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10x10 cm²) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0,5x0,5 m² demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun's path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.}, language = {en} } @article{SpelthahnSchaffrathCoppeetal.2010, author = {Spelthahn, Heiko and Schaffrath, Sophie and Coppe, Thomas and Rufi, Frederic and Sch{\"o}ning, Michael Josef}, title = {Development of an electrolyte-insulator-semiconductor (EIS) based capacitive heavy metal sensor for the detection of Pb2+ und Cd2+ ions}, series = {Physica status solidi (a) : applications and material science}, volume = {207}, journal = {Physica status solidi (a) : applications and material science}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300}, doi = {10.1002/pssa.200983306}, pages = {930 -- 934}, year = {2010}, abstract = {Chalcogenide glass materials as membranes for potentiometric sensors for chemical analysis in solutions have been studied since more than 20 years. In this work, an electrolyte-insulator-semiconductor structure was combined with chalcogenide glass membranes prepared by means of the pulsed laser deposition technique. Depending on the membrane composition a selectivity to different ions (Cd2+ and Pb2+) is achieved. The different sensor membranes have been physically characterised using microscopy, ellipsometry, profilometry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and Rutherford backscattering spectrometry (RBS). The electrochemical behaviour has been investigated via capacitance/voltage (C/V) and constant capacitance (ConCap) measurements and results in a Cd2+ sensitivity of 23.1 ± 0.6 mV per decade in a linear range from 7 × 10-6 to 10-2 mol/l and 24.4 ± 0.5 mV per decade in a linear range from 5 × 10-6 to 10-2 mol/l for Pb2+, respectively.}, language = {en} } @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{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{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{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{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{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} }