@inproceedings{GallAbelAhlbrinketal.2010, author = {Gall, Jan and Abel, Dirk and Ahlbrink, Nils and Pitz-Paal, Robert and Andersson, Joel A. E. and Diehl, M. and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Hoffschmidt, Bernhard}, title = {Simulation and control of solar thermal power plants}, series = {International Conference on Renewable Energies and Power Quality : ICREPQ '10 : Granada 23rd - 25th March 2010}, booktitle = {International Conference on Renewable Energies and Power Quality : ICREPQ '10 : Granada 23rd - 25th March 2010}, pages = {1 -- 5}, year = {2010}, language = {en} } @inproceedings{FunkeRobinsonHendricketal.2010, author = {Funke, Harald and Robinson, A. E. and Hendrick, P. and Wagemakers, R.}, title = {Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fuelled µ-Scale Gas Turbine}, series = {Conference Proceedings ASME Turbo Expo 2010: Power for Land, Sea, and Air. Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology}, booktitle = {Conference Proceedings ASME Turbo Expo 2010: Power for Land, Sea, and Air. Volume 5: Industrial and Cogeneration; Microturbines and Small Turbomachinery; Oil and Gas Applications; Wind Turbine Technology}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4400-7}, doi = {10.1115/GT2010-23453}, pages = {587 -- 596}, year = {2010}, abstract = {For more than a decade up to now there is an ongoing interest in small gas turbines downsized to micro-scale. With their high energy density they offer a great potential as a substitute for today's unwieldy accumulators, found in a variety of applications like laptops, small tools etc. But micro-scale gas turbines could not only be used for generating electricity, they could also produce thrust for powering small unmanned aerial vehicles (UAVs) or similar devices. Beneath all the great design challenges with the rotating parts of the turbomachinery at this small scale, another crucial item is in fact the combustion chamber needed for a safe and reliable operation. With the so called regular micromix burning principle for hydrogen successfully downscaled in an initial combustion chamber prototype of 10 kW energy output, this paper describes a new design attempt aimed at the integration possibilities in a μ-scale gas turbine. For manufacturing the combustion chamber completely out of stainless steel components, a recuperative wall cooling was introduced to keep the temperatures in an acceptable range. Also a new way of an integrated ignition was developed. The detailed description of the prototype's design is followed by an in depth report about the test results. The experimental investigations comprise a set of mass flow variations, coupled with a variation of the equivalence ratio for each mass flow at different inlet temperatures and pressures. With the data obtained by an exhaust gas analysis, a full characterisation concerning combustion efficiency and stability of the prototype chamber is possible. Furthermore the data show a full compliance with the expected operating requirements of the designated μ-scale gas turbine.}, language = {en} } @inproceedings{FunkeBoernerRobinsonetal.2010, author = {Funke, Harald and B{\"o}rner, Sebastian and Robinson, A. and Hendrick, P. and Recker, E.}, title = {Low NOx H2 combustion for industrial gas turbines of various power ranges}, year = {2010}, language = {en} } @inproceedings{FrickeHoffschmidt2010, author = {Fricke, Barbara and Hoffschmidt, Bernhard}, title = {Ecobalance of a solar thermal tower power plant with volumetric receiver}, series = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France}, booktitle = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France}, publisher = {Soc. OSC}, address = {Saint Maur}, pages = {87 -- 88}, year = {2010}, 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} } @misc{FrauenrathRenzRiegeretal.2010, author = {Frauenrath, Tobias and Renz, Wolfgang and Rieger, Jan and G{\"o}mmel, Andreas and Butenweg, Christoph and Niendorf, Thoralf}, title = {High Spatial Resolution 3D MRI of the Larynx Using a Dedicated TX/RX Phased Array Coil at 7.0T}, series = {2010 ISMRM-ESMRMB joint annual meeting}, journal = {2010 ISMRM-ESMRMB joint annual meeting}, issn = {1545-4428}, year = {2010}, abstract = {MRI holds great potential for elucidating laryngeal and vocal fold anatomy together with the assessment of physiological processes associated in human phonation. However, MRI of human phonation remains very challenging due to the small size of the targeted structures, interfering signal from fat, air between the vocal folds and surrounding muscles and physiological motion. These anatomical/physiological constraints translate into stringent technical requirements in balancing, scan time, image contrast, immunity to physiological motion, temporal resolution and spatial resolution. Motivated by these challenges and limitations this study is aiming at translating the sensitivity gain at ultra-high magnetic fields for enhanced high spatial resolution 3D imaging of the larynx and vocal tract. To approach this goal a dedicated two channel TX/RX larynx coil is being proposed.}, language = {en} } @article{FrauenrathHezelRenzetal.2010, author = {Frauenrath, Tobias and Hezel, Fabian and Renz, Wolfgang and de Geyer d'Orth, Thibaut and Dieringer, Matthias and von Knobelsdorf-Brenkenhoff, Florian and Prothmann, Marcel and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla}, series = {Journal of Cardiovascular Magnetic Resonance}, volume = {12}, journal = {Journal of Cardiovascular Magnetic Resonance}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1532-429X}, doi = {10.1186/1532-429X-12-67}, year = {2010}, abstract = {Background To demonstrate the applicability of acoustic cardiac triggering (ACT) for imaging of the heart at ultrahigh magnetic fields (7.0 T) by comparing phonocardiogram, conventional vector electrocardiogram (ECG) and traditional pulse oximetry (POX) triggered 2D CINE acquisitions together with (i) a qualitative image quality analysis, (ii) an assessment of the left ventricular function parameter and (iii) an examination of trigger reliability and trigger detection variance derived from the signal waveforms. Results ECG was susceptible to severe distortions at 7.0 T. POX and ACT provided waveforms free of interferences from electromagnetic fields or from magneto-hydrodynamic effects. Frequent R-wave mis-registration occurred in ECG-triggered acquisitions with a failure rate of up to 30\% resulting in cardiac motion induced artifacts. ACT and POX triggering produced images free of cardiac motion artefacts. ECG showed a severe jitter in the R-wave detection. POX also showed a trigger jitter of approximately Δt = 72 ms which is equivalent to two cardiac phases. ACT showed a jitter of approximately Δt = 5 ms only. ECG waveforms revealed a standard deviation for the cardiac trigger offset larger than that observed for ACT or POX waveforms. Image quality assessment showed that ACT substantially improved image quality as compared to ECG (image quality score at end-diastole: ECG = 1.7 ± 0.5, ACT = 2.4 ± 0.5, p = 0.04) while the comparison between ECG vs. POX gated acquisitions showed no significant differences in image quality (image quality score: ECG = 1.7 ± 0.5, POX = 2.0 ± 0.5, p = 0.34). Conclusions The applicability of acoustic triggering for cardiac CINE imaging at 7.0 T was demonstrated. ACT's trigger reliability and fidelity are superior to that of ECG and POX. ACT promises to be beneficial for cardiovascular magnetic resonance at ultra-high field strengths including 7.0 T.}, language = {en} } @inproceedings{FrauenrathGoemmelButenwegetal.2010, author = {Frauenrath, Tobias and G{\"o}mmel, Andreas and Butenweg, Christoph and Otten, Mario and Niendorf, Thoralf}, title = {3D mapping of vocal fold geometry during articulatory maneuvers using ultrashort echo time imaging at 3.0 T}, series = {ISMRM-ESMRMB joint annual meeting 2010, Band 4}, booktitle = {ISMRM-ESMRMB joint annual meeting 2010, Band 4}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Society of Magnetic Resonance in Medicine}, isbn = {978-1-617-82008-3}, pages = {3087}, year = {2010}, language = {en} } @misc{FrauenrathBeckerHezeletal.2010, author = {Frauenrath, Tobias and Becker, Meike and Hezel, Fabian and Krombach, Gabriele A. and Kremer, Ute and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Comparison of Left Function Assessment Using Phonocardiogram and Electrocardiogram Triggered 2D SSFP CINE MR Imaging at 1.5 T and 3.0 T}, series = {2010 ISMRM-ESMRMB joint annual meeting}, journal = {2010 ISMRM-ESMRMB joint annual meeting}, issn = {1545-4428}, year = {2010}, abstract = {As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to distortions and mistriggering increases and with it the motivation for a cardiac triggering alternative. Hence, this study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects at 1.5T and 3.0T.}, language = {en} } @article{FontivonArxGarciaGonzalezetal.2010, author = {Fonti, Patrick and von Arx, Georg and Garc{\´i}a-Gonz{\´a}lez, Ignacio and Eilmann, Britta and Sass-Klaassen, Ute G. W. and G{\"a}rtner, Holger and Eckstein, Dieter}, title = {Studying global change through investigation of the plastic responses of xylem anatomy in tree rings}, series = {New Phytologist}, volume = {185}, journal = {New Phytologist}, number = {1}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1469-8137 (Online)}, doi = {10.1111/j.1469-8137.2009.03030.x}, pages = {42 -- 53}, year = {2010}, abstract = {Variability in xylem anatomy is of interest to plant scientists because of the role water transport plays in plant performance and survival. Insights into plant adjustments to changing environmental conditions have mainly been obtained through structural and functional comparative studies between taxa or within taxa on contrasting sites or along environmental gradients. Yet, a gap exists regarding the study of hydraulic adjustments in response to environmental changes over the lifetimes of plants. In trees, dated tree-ring series are often exploited to reconstruct dynamics in ecological conditions, and recent work in which wood-anatomical variables have been used in dendrochronology has produced promising results. Environmental signals identified in water-conducting cells carry novel information reflecting changes in regional conditions and are mostly related to short, sub-annual intervals. Although the idea of investigating environmental signals through wood anatomical time series goes back to the 1960s, it is only recently that low-cost computerized image-analysis systems have enabled increased scientific output in this field. We believe that the study of tree-ring anatomy is emerging as a promising approach in tree biology and climate change research, particularly if complemented by physiological and ecological studies. This contribution presents the rationale, the potential, and the methodological challenges of this innovative approach.}, language = {en} }