TY  - JOUR
A1  - Becker, Meike
A1  - Frauenrath, Tobias
A1  - Hezel, Fabian
A1  - Krombach, Gabriele A.
A1  - Kremer, Ute
A1  - Koppers, Benedikt
A1  - Butenweg, Christoph
A1  - Goemmel, Andreas
A1  - Utting, Jane F.
A1  - Schulz-Menger, Jeanette
A1  - Niendorf, Thoralf
T1  - Comparison of left ventricular function assessment using phonocardiogram- and electrocardiogram-triggered 2D SSFP CINE MR imaging at 1.5 T and 3.0 T
JF  - European Radiology
N2  - Objective: As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to interference from electromagnetic fields (EMF) and to magneto-hydrodynamic (MHD) effects increases and with it the motivation for a CMR triggering alternative. This study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects (n=14). Methods: Quantitative analysis of 2D CINE steady-state free precession (SSFP) images was conducted to compare ACT’s performance with vector ECG (VCG). Endocardial border sharpness (EBS) was examined paralleled by quantitative LV function assessment. Results: Unlike VCG, ACT provided signal traces free of interference from EMF or MHD effects. In the case of correct Rwave recognition, VCG-triggered 2D CINE SSFP was immune to cardiac motion effects—even at 3.0 T. However, VCG-triggered 2D SSFP CINE imaging was prone to cardiac motion and EBS degradation if R-wave misregistration occurred. ACT-triggered acquisitions yielded LV parameters (end-diastolic volume (EDV), endsystolic volume (ESV), stroke volume (SV), ejection fraction (EF) and left ventricular mass (LVM)) comparable with those derived fromVCG-triggered acquisitions (1.5 T: ESVVCG=(56± 17) ml, EDVVCG=(151±32)ml, LVMVCG=(97±27) g, SVVCG=(94± 19)ml, EFVCG=(63±5)% cf. ESVACT= (56±18) ml, EDVACT=(147±36) ml, LVMACT=(102±29) g, SVACT=(91± 22) ml, EFACT=(62±6)%; 3.0 T: ESVVCG=(55±21) ml, EDVVCG=(151±32) ml, LVMVCG=(101±27) g, SVVCG=(96±15) ml, EFVCG=(65±7)% cf. ESVACT=(54±20) ml, EDVACT=(146±35) ml, LVMACT= (101±30) g, SVACT=(92±17) ml, EFACT=(64±6)%). Conclusions: ACT’s intrinsic insensitivity to interference from electromagnetic fields renders
KW  - Magnetic resonance imaging (MRI)
KW  - MR-stethoscope
KW  - Magnetic field strength
KW  - Left ventriular function
KW  - Cardiovascular MRI
Y1  - 2010
U6  - http://dx.doi.org/10.1007/s00330-009-1676-z
SN  - 1432-1084 (Onlineausgabe)
SN  - 0938-7994 (Druckausgabe)
VL  - 20
SP  - 1344
EP  - 1355
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Evers, Jörg
A1  - Fleischhaker, Robert
A1  - Pálffy, A.
A1  - Keitel, C.
T1  - Light propagation : From atomic to nuclear quantum optics
T2  - Modern optics and photonics: atoms and structured media
Y1  - 2010
SN  - 978-981431327-8
U6  - http://dx.doi.org/10.1142/9789814313278_0001
SP  - 3
EP  - 15
PB  - World Scientific Publishing Co.
ER  - 
TY  - JOUR
A1  - Fleischhaker, Robert
A1  - Evers, Jörg
A1  - Dey, Tarak N.
T1  - Phase modulation induced by cooperative effects in electromagnetically induced transparency
JF  - Physical Review A - Atomic, molecular, and optical physics
N2  - We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium.
Y1  - 2010
U6  - http://dx.doi.org/10.1103/PhysRevA.82.013815
SN  - 1050-2947
VL  - 82
IS  - 1
PB  - AIP Publishing
CY  - Melville, NY
ER  - 
TY  - CHAP
A1  - Reindl, Lukas
A1  - Park, Jin
A1  - Norda, Hannah
A1  - Butenweg, Christoph
T1  - Seismic design of masonry walls subject to out-of-plane bending
T2  - Proceedings of the Tenth International Conference on Computational Structures Technology : Valencia, Spain, 14 - 17 September 2010 / organised in association with: Universidad Politecnica de Valencia ... Ed. by B. H. V. Topping ...
Y1  - 2010
SN  - 978-1-905088-36-2
U6  - http://dx.doi.org/10.4203/ccp.93.348
SP  - Paper 348
PB  - Civil-Comp Press
CY  - Kippen
ER  - 
TY  - CHAP
A1  - Gellert, Christoph
A1  - Park, Jin
A1  - Butenweg, Christoph
T1  - Seismic safety verification of masonry structures
T2  - Proceedings of the Eight International Masonry Conference : held in Dresden from 4th to 7th of July 2010 / [International Masonry Society ; Technische Universität Dresden]. Ed. by: Wolfram Jäger ... Volume 1. (Masonry / International Masonry Society Special Publication ; 11)
Y1  - 2010
SN  - 978-3-00-031381-3
SP  - 813
EP  - 822
PB  - ARGE 8IMC Dresden
CY  - Radebeul
ER  - 
TY  - CHAP
A1  - Frauenrath, Tobias
A1  - Gömmel, Andreas
A1  - Butenweg, Christoph
A1  - Otten, Mario
A1  - Niendorf, Thoralf
T1  - 3D mapping of vocal fold geometry during articulatory maneuvers using ultrashort echo time imaging at 3.0 T
T2  - ISMRM-ESMRMB joint annual meeting 2010 : Stockholm, Sweden, 1 - 7 May 2010. Band 4
Y1  - 2010
SN  - 978-1-617-82008-3
SP  - 3087
PB  - Curran
CY  - Red Hook, NY
ER  - 
TY  - CHAP
A1  - Gömmel, Andreas
A1  - Niendorf, Thoralf
A1  - Frauenrath, Tobias
A1  - Otten, Mario
A1  - Butenweg, Christoph
A1  - Kob, Malte
T1  - 3D vocal fold geometry mapping using Magnetic Resonance Imaging
T2  - Fortschritte der Akustik : 36. Deutsche Jahrestagung für Akustik ; 15.-18. März 2010, [Berlin ; DAGA 2010] / DEGA ... Wiss. Ed. Michael Möser ... Band 1
Y1  - 2010
SN  - 978-3-9808659-8-2
SP  - 271
EP  - 272
PB  - Deutsche Gesellschaft für Akustik
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Vogt, C.
A1  - Mottaghy, Darius
A1  - Wolf, A.
A1  - Rath, V.
A1  - Pechnig, R.
A1  - Clauser, C.
T1  - Reducing temperature uncertainties by stochastic geothermal reservoir modelling
JF  - Geophysical Journal International
N2  - Quantifying and minimizing uncertainty is vital for simulating technically and economically successful geothermal reservoirs. To this end, we apply a stochastic modelling sequence, a Monte Carlo study, based on (i) creating an ensemble of possible realizations of a reservoir model, (ii) forward simulation of fluid flow and heat transport, and (iii) constraining post-processing using observed state variables. To generate the ensemble, we use the stochastic algorithm of Sequential Gaussian Simulation and test its potential fitting rock properties, such as thermal conductivity and permeability, of a synthetic reference model and—performing a corresponding forward simulation—state variables such as temperature. The ensemble yields probability distributions of rock properties and state variables at any location inside the reservoir. In addition, we perform a constraining post-processing in order to minimize the uncertainty of the obtained distributions by conditioning the ensemble to observed state variables, in this case temperature. This constraining post-processing works particularly well on systems dominated by fluid flow. The stochastic modelling sequence is applied to a large, steady-state 3-D heat flow model of a reservoir in The Hague, Netherlands. The spatial thermal conductivity distribution is simulated stochastically based on available logging data. Errors of bottom-hole temperatures provide thresholds for the constraining technique performed afterwards. This reduce the temperature uncertainty for the proposed target location significantly from 25 to 12 K (full distribution width) in a depth of 2300 m. Assuming a Gaussian shape of the temperature distribution, the standard deviation is 1.8 K. To allow a more comprehensive approach to quantify uncertainty, we also implement the stochastic simulation of boundary conditions and demonstrate this for the basal specific heat flow in the reservoir of The Hague. As expected, this results in a larger distribution width and hence, a larger, but more realistic uncertainty estimate. However, applying the constraining post-processing the uncertainty is again reduced to the level of the post-processing without stochastic boundary simulation. Thus, constraining post-processing is a suitable tool for reducing uncertainty estimates by observed state variables.
Y1  - 2010
U6  - http://dx.doi.org/10.1111/j.1365-246X.2009.04498.x
SN  - 1365-246X
VL  - 181
IS  - 1
SP  - 321
EP  - 333
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - CHAP
A1  - Feldhusen, Jörg
A1  - Brezing, Alexander Nikolaus
A1  - Pütz, Claus
A1  - Wählisch, Georg
T1  - Multi-system CAD-teaching in large classes
T2  - When design education and design research meet : proceedings of the 12th International Conference on Engineering and Product Design Education, Norwegian University of Science and Technology (NTNU) Trondheim, Norway, 2nd - 3rd September 2010 ; [E&PDE]
Y1  - 2010
SN  - 978-1-904670-19-3
SP  - 204
EP  - 209
PB  - Design Society
CY  - Glasgow
ER  - 
TY  - CHAP
A1  - Goldbach, Daniel
A1  - Ament, Christoph
ED  - Scharff, Peter
T1  - Stabilized reversing with vehicle trailer combinations
T2  - Crossing borders within the ABC : automation, biomedical engineering and computer science; proceedings; 55. IWK Internationales Wissenschaftliches Kolloquium; 13 - 17 September 2010, Ilmenau
Y1  - 2010
SN  - 978-3-938843-53-6
SP  - 352
EP  - 357
PB  - Verl. ISLE
CY  - Ilmenau
ER  -