@article{Wrede2016,
  author    = {Wrede, Oliver},
  title     = {Continuity in travel information},
  series = {Information Design Journal},
  volume    = {22},
  journal   = {Information Design Journal},
  number    = {2},
  publisher = {John Benjamins},
  address   = {Amsterdam},
  issn      = {0142-5471},
  doi       = {10.1075/idj.22.2.09wre},
  pages     = {172 -- 178},
  year      = {2016},
  abstract  = {This article discusses the contrast between the information transportation companies provide to travellers and that of their brand messaging. Companies' brand messaging often portrays the service they provide as pleasant, stress free and perfect. Customers and users of the service, on the other hand, often describe their experience of the service as a negative one. This article suggests that the brand value would be greater if transportation companies paid more attention to the users' experience when designing their information systems, particularly in worst case scenarios.},
  language  = {en}
}
@article{NeuJanserKhatibietal.2017,
  author    = {Neu, Eugen and Janser, Frank and Khatibi, Akbar A. and Orifici, Adrian C.},
  title     = {Fully Automated Operational Modal Analysis using multi-stage clustering},
  series = {Mechanical Systems and Signal Processing},
  volume    = {Vol. 84, Part A},
  journal   = {Mechanical Systems and Signal Processing},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0888-3270},
  doi       = {10.1016/j.ymssp.2016.07.031},
  pages     = {308 -- 323},
  year      = {2017},
  language  = {en}
}
@article{FunkeKeinzKustereretal.2016,
  author    = {Funke, Harald and Keinz, Jan and Kusterer, Karsten and Ayed, Anis Haj and Kazari, Masahide and Kitajima, Junichi and Horikawa, Atsushi and Okada, Kunio},
  title     = {Experimental and Numerical Study on Optimizing the Dry Low NOₓ Micromix Hydrogen Combustion Principle for Industrial Gas Turbine Applications},
  series = {Journal of Thermal Science and Engineering Applications},
  volume    = {9},
  journal   = {Journal of Thermal Science and Engineering Applications},
  number    = {2},
  publisher = {ASME},
  address   = {New York, NY},
  issn      = {1948-5093},
  doi       = {10.1115/1.4034849},
  pages     = {021001 -- 021001-10},
  year      = {2016},
  abstract  = {Combined with the use of renewable energy sources for its production, hydrogen represents a possible alternative gas turbine fuel for future low-emission power generation. Due to the difference in the physical properties of hydrogen compared to other fuels such as natural gas, well-established gas turbine combustion systems cannot be directly applied to dry low NOₓ (DLN) hydrogen combustion. The DLN micromix combustion of hydrogen has been under development for many years, since it has the promise to significantly reduce NOₓ emissions. This combustion principle for air-breathing engines is based on crossflow mixing of air and gaseous hydrogen. Air and hydrogen react in multiple miniaturized diffusion-type flames with an inherent safety against flashback and with low NOₓ emissions due to a very short residence time of the reactants in the flame region. The paper presents an advanced DLN micromix hydrogen application. The experimental and numerical study shows a combustor configuration with a significantly reduced number of enlarged fuel injectors with high-thermal power output at constant energy density. Larger fuel injectors reduce manufacturing costs, are more robust and less sensitive to fuel contamination and blockage in industrial environments. The experimental and numerical results confirm the successful application of high-energy injectors, while the DLN micromix characteristics of the design point, under part-load conditions, and under off-design operation are maintained. Atmospheric test rig data on NOₓ emissions, optical flame-structure, and combustor material temperatures are compared to numerical simulations and show good agreement. The impact of the applied scaling and design laws on the miniaturized micromix flamelets is particularly investigated numerically for the resulting flow field, the flame-structure, and NOₓ formation.},
  language  = {en}
}
@article{AyedKustererFunkeetal.2016,
  author    = {Ayed, Anis Haj and Kusterer, Karsten and Funke, Harald and Keinz, Jan},
  title     = {CFD Based Improvement of the DLN Hydrogen Micromix Combustion Technology at Increased Energy Densities},
  series = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)},
  volume    = {26},
  journal   = {American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS)},
  number    = {3},
  publisher = {GSSRR},
  issn      = {2313-4402},
  pages     = {290 -- 303},
  year      = {2016},
  abstract  = {Combined with the use of renewable energy sources for its production, Hydrogen represents a possible alternative gas turbine fuel within future low emission power generation. Due to the large difference in the physical properties of Hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for Dry Low NOx (DLN) Hydrogen combustion. Thus, the development of DLN combustion technologies is an essential and challenging task for the future of Hydrogen fuelled gas turbines. The DLN Micromix combustion principle for hydrogen fuel has been developed to significantly reduce NOx-emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized diffusion-type flames. The major advantages of this combustion principle are the inherent safety against flash-back and the low NOx-emissions due to a very short residence time of reactants in the flame region of the micro-flames. The Micromix Combustion technology has been already proven experimentally and numerically for pure Hydrogen fuel operation at different energy density levels. The aim of the present study is to analyze the influence of different geometry parameter variations on the flame structure and the NOx emission and to identify the most relevant design parameters, aiming to provide a physical understanding of the Micromix flame sensitivity to the burner design and identify further optimization potential of this innovative combustion technology while increasing its energy density and making it mature enough for real gas turbine application. The study reveals great optimization potential of the Micromix Combustion technology with respect to the DLN characteristics and gives insight into the impact of geometry modifications on flame structure and NOx emission. This allows to further increase the energy density of the Micromix burners and to integrate this technology in industrial gas turbines.},
  language  = {en}
}
@article{OrzadaJohstMaderwaldetal.2013,
  author    = {Orzada, Stephan and Johst, S{\"o}ren and Maderwald, Stefan and Bitz, Andreas and Solbach, Klaus and Ladd, Mark E.},
  title     = {Mitigation of B1(+) inhomogeneity on single-channel transmit systems with TIAMO},
  series = {Magnetic Resonance in Medicine},
  volume    = {70},
  journal   = {Magnetic Resonance in Medicine},
  number    = {1},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.24453},
  pages     = {290 -- 294},
  year      = {2013},
  language  = {en}
}
@article{OrzadaMaderwaldPoseretal.2012,
  author    = {Orzada, S. and Maderwald, S. and Poser, B. A. and Johst, S. and Kannengiesser, S. and Ladd, M. E. and Bitz, Andreas},
  title     = {Time-interleaved acquisition of modes: an analysis of SAR and image contrast implications},
  series = {Magnetic Resonance in Medicine},
  volume    = {67},
  journal   = {Magnetic Resonance in Medicine},
  number    = {4},
  publisher = {Wiley-Liss},
  address   = {New York},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.23081},
  pages     = {1033 -- 1041},
  year      = {2012},
  abstract  = {s the magnetic field strength and therefore the operational frequency in MRI are increased, the radiofrequency wavelength approaches the size of the human head/body, resulting in wave effects which cause signal decreases and dropouts. Especially, whole-body imaging at 7 T and higher is therefore challenging. Recently, an acquisition scheme called time-interleaved acquisition of modes has been proposed to tackle the inhomogeneity problems in high-field MRI. The basic premise is to excite two (or more) different Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-1 modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In this work, the impact of time-interleaved acquisition of mode on image contrast as well as on time-averaged specific absorption rate is addressed in detail. Time-interleaved acquisition of mode is superior in Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-2 homogeneity compared with conventional radiofrequency shimming while being highly specific absorption rate efficient. Time-interleaved acquisition of modes can enable almost homogeneous high-field imaging throughout the entire field of view in PD, T2, and T2*-weighted imaging and, if a specified homogeneity criterion is met, in T1-weighted imaging as well.},
  language  = {en}
}
@article{KobusBitzUdenetal.2012,
  author    = {Kobus, Thiele and Bitz, Andreas and Uden, Mark J. van and Lagemaat, Miram W. and Rothgang, Eva and Orzada, Stephan and Heerschap, Arend and Scheenen, Tom W. J.},
  title     = {In vivo 31P MR spectroscopic imaging of the human prostate at 7 T: safety and feasibility},
  series = {Magnetic Resonance in Medicine},
  volume    = {68},
  journal   = {Magnetic Resonance in Medicine},
  number    = {6},
  publisher = {Wiley-Liss},
  address   = {New York},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.24175},
  pages     = {1683 -- 1695},
  year      = {2012},
  abstract  = {31P MR spectroscopic imaging of the human prostate provides information about phosphorylated metabolites that could be used for prostate cancer characterization. The sensitivity of a magnetic field strength of 7 T might enable 3D 31P MR spectroscopic imaging with relevant spatial resolution in a clinically acceptable measurement time. To this end, a 31P endorectal coil was developed and combined with an eight-channel 1H body-array coil to relate metabolic information to anatomical location. An extensive safety validation was performed to evaluate the specific absorption rate, the radiofrequency field distribution, and the temperature distribution of both coils. This validation consisted of detailed Finite Integration Technique simulations, confirmed by MR thermometry and Burn:x-wiley:07403194:media:MRM24175:tex2gif-stack-1 measurements in a phantom and in vivo temperature measurements. The safety studies demonstrated that the presence of the 31P endorectal coil had no influence on the specific absorption rate levels and temperature distribution of the external eight-channel 1H array coil. To stay within a 10 g averaged local specific absorption rate of 10 W/kg, a maximum time-averaged input power of 33 W for the 1H array coil was allowed. For transmitting with the 31P endorectal coil, our safety limit of less than 1°C temperature increase in vivo during a 15-min MR spectroscopic imaging experiment was reached at a time-averaged input power of 1.9 W. With this power setting, a second in vivo measurement was performed on a healthy volunteer. Using adiabatic excitation, 3D 31P MR spectroscopic imaging produced spectra from the entire prostate in 18 min with a spatial resolution of 4 cm3. The spectral resolution enabled the separate detection of phosphocholine, phosphoethanolamine, inorganic phosphate, and other metabolites that could play an important role in the characterization of prostate cancer.},
  language  = {en}
}
@article{OrzadaMaderwaldPoseretal.2010,
  author    = {Orzada, Stephan and Maderwald, Stefan and Poser, Benedikt Andreas and Bitz, Andreas and Quick, Harald H. and Ladd, Mark E.},
  title     = {RF excitation using time interleaved acquisition of modes (TIAMO) to address B1 inhomogeneity in high-field MRI},
  series = {Magnetic Resonance in Medicine},
  volume    = {64},
  journal   = {Magnetic Resonance in Medicine},
  number    = {2},
  publisher = {Wiley-Liss},
  address   = {New York},
  issn      = {1522-2594},
  doi       = {10.1002/mrm.22527},
  pages     = {327 -- 333},
  year      = {2010},
  abstract  = {As the field strength and, therefore, the operational frequency in MRI is increased, the wavelength approaches the size of the human head/body, resulting in wave effects, which cause signal decreases and dropouts. Several multichannel approaches have been proposed to try to tackle these problems, including RF shimming, where each element in an array is driven by its own amplifier and modulated with a certain (constant) amplitude and phase relative to the other elements, and Transmit SENSE, where spatially tailored RF pulses are used. In this article, a relatively inexpensive and easy to use imaging scheme for 7 Tesla imaging is proposed to mitigate signal voids due to B1 field inhomogeneity. Two time-interleaved images are acquired using a different excitation mode for each. By forming virtual receive elements, both images are reconstructed together using GRAPPA to achieve a more homogeneous image, with only small SNR and SAR penalty in head and body imaging at 7 Tesla.},
  language  = {en}
}
@article{UmutluBitzMaderwaldetal.2013,
  author    = {Umutlu, Lale and Bitz, Andreas and Maderwald, Stefan and Orzada, Stephan and Kinner, Sonja and Kraff, Oliver and Brote, Irina and Ladd, Susanne C. and Schroeder, Tobias and Forsting, Michael},
  title     = {Contrast-enhanced ultra-high-field liver MRI: a feasibility trial},
  series = {European Journal of Radiology},
  volume    = {82},
  journal   = {European Journal of Radiology},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0720-048X},
  doi       = {10.1016/j.ejrad.2011.07.004},
  pages     = {760 -- 767},
  year      = {2013},
  language  = {en}
}
@article{YazdanbakhshSolbachBitz2012,
  author    = {Yazdanbakhsh, Pedram and Solbach, Klaus and Bitz, Andreas},
  title     = {Variable power combiner for RF mode shimming in 7-T MR imaging},
  series = {IEEE Transaction on Biomedical Engineering},
  volume    = {59},
  journal   = {IEEE Transaction on Biomedical Engineering},
  number    = {9},
  publisher = {IEEE},
  address   = {New York},
  issn      = {1558-2531},
  doi       = {10.1109/TBME.2012.2205926},
  pages     = {2549 -- 2557},
  year      = {2012},
  abstract  = {This contribution discusses the utilization of RF power in an MRI system with RF mode shimming which enables the superposition of circularly polarized modes of a transmit RF coil array driven by a Butler matrix. Since the required power for the individual modes can vary widely, mode-shimming can result in a significant underutilization of the total available RF power. A variable power combiner (VPC) is proposed to improve the power utilization: it can be realized as a reconfiguration of the MRI transmit system by the inclusion of one additional matrix network which receives the power from all transmit amplifiers at its input ports and provides any desired (combined) power distribution at its output ports by controlling the phase and amplitude of the amplifiers' input signals. The power distribution at the output ports of the VPC is then fed into the "mode" ports of the coil array Butler matrix in order to superimpose the spatial modes at the highest achievable power utilization. The VPC configuration is compared to the standard configuration of the transmit chain of our MRI system with 8 transmit channels and 16 coils. In realistic scenarios, improved power utilization was achieved from 17\% to 60\% and from 14\% to 55\% for an elliptical phantom and a region of interest in the abdomen, respectively, and an increase of the power utilization of 1 dB for a region of interest in the upper leg. In general, it is found that the VPC allows significant improvement in power utilization when the shimming solution demands only a few modes to be energized, while the technique can yield loss in power utilization in cases with many modes required at high power level.},
  language  = {en}
}