TY - CHAP A1 - Müller-Veggian, Mattea A1 - Kops, Elena Rota A1 - Quin, Peng A1 - Herzog, Hans T1 - MRI Based Attenuation Correction for Brain PET Images T2 - Advances in medical engineering / [3rd RPT - Remagener Physiktage together with the Second Scientific Workshop of Medical Robotics, Navigation and Visualization ... Remagen ... 7.-9. März 2007]. Thorsten M. Buzug (ed.) Part 1. N2 - This work describes a procedure to yield attenuation maps from MR images which are used for the absorption correction (AC) of brain PET data. Such an approach could be mandatory for future combined PET and MRI scanners, which probably do not include a transmission facility. T1-weighted MR images were segmented into brain tissue, bone, soft tissue, and sinus; attenuation coefficients corresponding to elemental composition and density as well as to 511 keV photon energy were respectively assigned. Attenuation maps containing up to four compartments were created and forward projected into sinograms with attenuation factors which then were used for AC during reconstruction of FDG-PET data. The commonly used AC based on a radioactive (68Ge) transmission scan served as reference. The reconstructed radioactivity values obtained with the MRI-based AC were about 20% lower than those obtained with PET-based AC if the skull was not taken into account. Considering the skull the difference was still about 10%. Our investigations demonstrate the feasibility of a MRI-based AC, but revealed also the necessity of a satisfying delineation of bone thickness which tends to be underestimated in our first approach of T1-weighted MR image segmentation. Y1 - 2007 SN - 978-3-540-68763-4 U6 - https://doi.org/10.1007/978-3-540-68764-1_15 N1 - Springer proceedings in physics ; 114 SP - 93 EP - 97 PB - Springer CY - Berlin ER - TY - CHAP A1 - Helmig, Ilka ED - Klanten, Robert T1 - Tristan und Isolde, Samson und Dalila, Capriccio : 3D illustration for posters of Cologne Opera T2 - Papercraft [1] : design and art with paper KW - Papierkunst Y1 - 2009 SN - 978-3-89955-251-5 SP - 202 PB - Gestalten Verlag CY - Berlin ER - TY - CHAP A1 - Boonzaaijer, Karel A1 - Helmig, Ilka T1 - 2D Room : cardboard installation T2 - Papercraft [1] : design and art with paper KW - Papierkunst Y1 - 2009 SN - 978-3-89955-251-5 SP - 206 PB - Gestalten Verlag CY - Berlin ER - TY - CHAP A1 - Helmig, Ilka A1 - Boonzaaijer, Karel T1 - Growing 48 hours : design experiment in an aircraft hangar ... T2 - Papercraft [1] : design and art with paper KW - Papierkunst KW - Aktionskunst KW - Studienarbeit Y1 - 2009 SN - 978-3-89955-251-5 SP - 224 PB - Gestalten Verlag CY - Berlin ER - TY - CHAP A1 - Helmig, Ilka T1 - Friendship : editorial illustration T2 - Papercraft 2 : design and art with paper KW - Papierkunst KW - Illustration Y1 - 2011 SN - 978-3-89955-333-8 SP - 237 PB - Gestalten Verlag CY - Berlin ER - TY - CHAP A1 - Helsper, Christoph A1 - Fissan, H. J. A1 - Franzen, H. ED - Benarie, Michel M. T1 - Particle Size Distributions of Combustion Aerosols T2 - Atmospheric Pollution 1978 : Proceedings of the 13th International Colloquium; 25-28 April 1978; Paris, France; Edited by Michel M. Benarie N2 - It has been observed that carcinogenic polycyclic aromatic hydrocarbons (PAH) are present in the atmosphere. Combustion processes are considered the most important sources for PAH. Among these, the burning of coal produces the highest emission, but in cities with high traffic density and low meteorological exchange activities, vehicle emissions determine the immission situation, especially in narrow streets. For estimating the potential health effects caused by PAH, it is sufficient to characterize the emission of PAH with respect to their physical state, concentrations, and, as far as the particulate phase is concerned, size distribution. The size distribution is important for transport phenomena, inhalation, and deposition in the respiratory tract. These parameters mainly depend on the combustion system, on system operating conditions, on the exhaust system, and on exhaust cooling conditions. At exhaust-gas temperatures in the range of ambient air temperatures, almost the whole emission of PAH is made up of particulate matter. Y1 - 1978 SN - 0-444-41691-9 U6 - https://doi.org/10.1016/S0166-1116(08)71583-8 SP - 263 EP - 266 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Bechstedt, U. A1 - Berg, Georg P. A. A1 - Hacker, U. A1 - Hardt, Arno A1 - Hürlimann, W. A1 - Maier, R. A1 - Martin, S. A1 - Meissburger, J. A1 - Römer, J. G. M. A1 - Possen, P. von A1 - Sagefka, T. T1 - BIG KARL and COSY T2 - The art and science of magnet design. A Festschrift in honor of Klaus Halbach. Vol. 1 Y1 - 1995 SP - 19 EP - 28 PB - Lawrence Berkeley Lab., Univ. of California CY - Berkeley, CA. ER - TY - CHAP A1 - Cresser, J. D. A1 - Häger, J. A1 - Leuchs, G. A1 - Rateike, Franz-Matthias A1 - Walther, H. T1 - Resonance fluorescence of atoms in strong monochromatic laser fields T2 - Dissipative systems in quantum optics. Ed. by Rodolfo Bonifacio. Topics in current physics. Vol. 27 N2 - The investigation of atomic resonance fluorescence has always been of special interest as a means for the determination of atomic parameters. In addition, information on the interaction mechanism between atoms and radiation can be obtained. In the standard fluorescence experiment the frequency distribution of the incident photons is larger than the natural width of the respective transition; as a consequence the correlation time in the photon-atom interaction is determined by the lifetime of the atoms in the excited state. With the development of lasers and especially of tunable dye lasers in recent years it became possible to study the case where the incident radiation has a spectral distribution which is narrower than the natural width. This corresponds to a correlation time of the incoming light wave which is much longer than the excited-state lifetime. In this chapter a survey of experiments on the resonance fluorescence of atoms in monochromatic laser fields will be given. Y1 - 1982 SN - 978-3-642-81719-9 U6 - https://doi.org/10.1007/978-3-642-81717-5_3 SP - 21 EP - 59 PB - Springer CY - Berlin ER - TY - CHAP A1 - Weber, Hans-Joachim T1 - Applied physics of compressible and incompressible fluids T2 - Critical care nephrology / [Hrsg.:] Claudio Ronco and Rinaldo Bellomo Y1 - 1998 SN - 978-94-010-6306-7 SP - 63 EP - 84 PB - Springer CY - Dordrecht ER - TY - CHAP A1 - Dikta, Gerhard T1 - Fundamentals of applied probability and basic statistics T2 - Critical care nephrology / [Hrsg.:] Claudio Ronco and Rinaldo Bellomo Y1 - 1998 SN - 978-94-010-6306-7 SP - 51 EP - 61 PB - Springer CY - Dordrecht ER -