TY - JOUR A1 - Schmidt, Daniela A1 - Langen, Karl-J. A1 - Herzog, Hans A1 - Wirths, Jochen A1 - Holschbach, Markus A1 - Kiwit, Jürgen C. W. A1 - Ziemons, Karl A1 - Coenen, Heinz-H. A1 - Müller-Gärtner, Hans-W. T1 - Whole-body kinetics and dosimetry of L-3[123I]-iodo-α-methyltyrosine JF - European Journal of Nuclear Medicine Y1 - 1997 SN - 1619-7089 VL - 24 IS - 9 SP - 1162 EP - 1166 ER - TY - JOUR A1 - Kleines, H. A1 - Ziemons, Karl A1 - Zwoll, K. T1 - Experiences with ATM in a multivendor pilot system at Forschungszentrum Jülich JF - IEEE Transactions on Nuclear Science N2 - The ATM technology for high speed serial transmission provides a new quality of communication by introducing novel features in a LAN environment, especially support of real time communication, of both LAN and WAN communication and of multimedia streams. In order to evaluate ATM for future DAQ systems and remote control systems as well as for a high speed picture archiving and communications system for medical images, Forschungszentrum Julich has build up a pilot system for the evaluation of ATM and standard low cost multimedia systems. It is a heterogeneous multivendor system containing a variety of switches and desktop solutions, employing different protocol options of ATM. The tests conducted in the pilot system revealed major difficulties regarding stability, interoperability and performance. The paper presents motivations, layout and results of the pilot system. Discussion of results concentrates on performance issues relevant for realistic applications, e.g., connection to a RAID system via NFS over ATM Y1 - 1998 SN - 0018-9499 VL - 45 IS - 4 SP - 1867 EP - 1871 ER - TY - JOUR A1 - Weckesser, Martin A1 - Grießmeier, Martin A1 - Schmidt, Daniela A1 - Sonnenberg, Frank A1 - Ziemons, Karl A1 - Kemna, Lars A1 - Holschbach, Marcus A1 - Langen, Karl-J. A1 - Müller-Gärtner, Hans-W. T1 - Iodine-123 α-methyl tyrosine single-photon emission tomography of cerebral gliomas: standardised evaluation of tumour uptake and extent JF - European Journal of Nuclear Medicine N2 - Single-photon emission tomography (SPET) with the amino acid analogue l-3-[123I]iodo-α-methyl tyrosine (IMT) is helpful in the diagnosis and monitoring of cerebral gliomas. Radiolabelled amino acids seem to reflect tumour infiltration more specifically than conventional methods like magnetic resonance imaging and computed tomography. Automatic tumour delineation based on maximal tumour uptake may cause an overestimation of mean tumour uptake and an underestimation of tumour extension in tumours with circumscribed peaks. The aim of this study was to develop a program for tumour delineation and calculation of mean tumour uptake which takes into account the mean background activity and is thus optimised to the problem of tumour definition in IMT SPET. Using the frequency distribution of pixel intensities of the tomograms a program was developed which automatically detects a reference brain region and draws an isocontour region around the tumour taking into account mean brain radioactivity. Tumour area and tumour/brain ratios were calculated. A three-compartment phantom was simulated to test the program. The program was applied to IMT SPET studies of 20 patients with cerebral gliomas and was compared to the results of manual analysis by three different investigators. Activity ratios and chamber extension of the phantom were correctly calculated by the automatic analysis. A method based on image maxima alone failed to determine chamber extension correctly. Manual region of interest analysis in patient studies resulted in a mean inter-observer standard deviation of 8.7%±6.1% (range 2.7%–25.0%). The mean value of the results of the manual analysis showed a significant correlation to the results of the automatic analysis (r = 0.91, P<0.0001 for the uptake ratio; r = 0.87, P<0.0001 for the tumour area). We conclude that the algorithm proposed simplifies the calculation of uptake ratios and may be used for observer-independent evaluation of IMT SPET studies. Three-dimensional tumour recognition and transfer to co-registered morphological images based on this program may be useful for the planning of surgical and radiation treatment. Y1 - 1998 SN - 1619-7089 VL - 25 IS - 2 SP - 150 EP - 156 ER - TY - JOUR A1 - Taylor, J. G. A1 - Schmitz, N. A1 - Ziemons, Karl A1 - Grosse-Ruyken, M.-L. A1 - Gruber, O. A1 - Müller-Gärtner, H.-W. A1 - Shah, N. J. T1 - The network of brain areas involved in the motion aftereffect JF - Neuroimage N2 - A network of brain areas is expected to be involved in supporting the motion aftereffect. The most active components of this network were determined by means of an fMRI study of nine subjects exposed to a visual stimulus of moving bars producing the effect. Across the subjects, common areas were identified during various stages of the effect, as well as networks of areas specific to a single stage. In addition to the well-known motion-sensitive area MT the prefrontal brain areas BA44 and 47 and the cingulate gyrus, as well as posterior sites such as BA37 and BA40, were important components during the period of the motion aftereffect experience. They appear to be involved in control circuitry for selecting which of a number of processing styles is appropriate. The experimental fMRI results of the activation levels and their time courses for the various areas are explored. Correlation analysis shows that there are effectively two separate and weakly coupled networks involved in the total process. Implications of the results for awareness of the effect itself are briefly considered in the final discussion. Y1 - 2000 SN - 1053-8119 VL - 11 IS - 4 SP - 257 EP - 270 ER - TY - JOUR A1 - Fink, G. R. A1 - Marshall, J. C. A1 - Shah, N. J. A1 - Weiss, P.H. A1 - Halligan, P. W. A1 - Grosse-Ruyken, M. A1 - Ziemons, Karl A1 - Zilles, K. A1 - Freund, H. J. T1 - Line bisection judgments implicate right parietal cortex and cerebellum as assessed by fMRI JF - Neurology Y1 - 2000 SN - 1526-632X VL - 54 IS - 6 SP - 1324 EP - 1331 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - Pulse recording by free-running sampling JF - 2000 IEEE Nuclear Science Symposium Conference Record, Vol. 2 N2 - Pulses from a position-sensitive photomultiplier (PS-PMT) are recorded by free running ADCs at a sampling rate of 40 MHz. A four-channel acquisition-board has been developed which is equipped with four 12 bit-ADCs connected to one FPGA (field programmable gate array). The FPGA manages data acquisition and the transfer to the host computer. It can also work as a digital trigger, so a separate hardware-trigger can be omitted. The method of free running sampling provides a maximum of information, besides the pulse charge and amplitude also pulse shape and starting time are contained in the sampled data. These informations are crucial for many tasks such as distinguishing between different scintillator materials, determination of radiation type, pile-up recovery, coincidence detection or time-of-flight applications. The absence of an analog integrator allows coping with very high count rates. Since this method is going to be employed in positron emission tomography (PET), the position of an event is another important information. The simultaneous readout of four channels allows localization by means of center-of-gravity weighting. First results from a test setup with LSO-scintillators coupled to the PS-PMT are presented Y1 - 2000 SN - 1082-3654 SP - 9/179 EP - 9/181 ER - TY - JOUR A1 - Pieper, Martin A1 - Klein, Peter T1 - A simple and accurate numerical network flow model for bionic micro heat exchangers JF - Heat mass transfer Y1 - 2011 SN - 0947-7411 VL - 47 IS - 5 SP - 491 EP - 503 PB - Springer CY - Berlin ER - TY - JOUR A1 - Pieper, Martin A1 - Klein, Peter T1 - Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media JF - Heat mass transfer N2 - Often, detailed simulations of heat conduction in complicated, porous media have large runtimes. Then homogenization is a powerful tool to speed up the calculations by preserving accurate solutions at the same time. Unfortunately real structures are generally non-periodic, which requires unpractical, complicated homogenization techniques. We demonstrate in this paper, that the application of simple, periodic techniques to realistic media, that are just close to periodic, gives accurate, approximative solutions. In order to obtain effective parameters for the homogenized heat equation, we have to solve a so called “cell problem”. In contrast to periodic structures it is not trivial to determine a suitable unit cell, which represents a non-periodic media. To overcome this problem, we give a rule of thumb on how to choose a good cell. Finally we demonstrate the efficiency of our method for virtually generated foams as well as real foams and compare these results to periodic structures. Y1 - 2012 U6 - https://doi.org/10.1007/s00231-011-0879-4 SN - 0947-7411 VL - 48 IS - 2 SP - 291 EP - 300 PB - Springer CY - Berlin ER - TY - JOUR A1 - Pieper, Martin A1 - Klein, Peter T1 - Numerical solution of the heat equation with non-linear, time derivative-dependent source term JF - International Journal for Numerical Methods in Engineering N2 - The mathematical modeling of heat conduction with adsorption effects in coated metal structures yields the heat equation with piecewise smooth coefficients and a new kind of source term. This term is special, because it is non-linear and furthermore depends on a time derivative. In our approach we reformulated this as a new problem for the usual heat equation, without source term but with a new non-linear coefficient. We gave an existence and uniqueness proof for the weak solution of the reformulated problem. To obtain a numerical solution, we developed a semi-implicit and a fully implicit finite volume method. We compared these two methods theoretically as well as numerically. Finally, as practical application, we simulated the heat conduction in coated aluminum fibers with adsorption in the zeolite coating. Copyright © 2010 John Wiley & Sons, Ltd. Y1 - 2010 U6 - https://doi.org/10.1002/nme.2937 SN - 0029-5981 VL - 84 IS - 10 SP - 1205 EP - 1221 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Pieper, Martin T1 - Nonlinear integral equations for an inverse electromagnetic scattering problem JF - Journal of Physics Conference Series. 124 (2008) Y1 - 2008 SN - 1742-6596 ER - TY - JOUR A1 - Pieper, Martin A1 - Ivanyshyn, Olha T1 - Nonlinear integral equations for a 3D inverse acoustic scattering problem : abstract / O. Ivanyshyn and M. Pieper Y1 - 2008 N1 - World Congress on Computational Mechanics <8, 2008, Venedig> ; European Congress on Computational Methods in Applied Sciences and Engineering <5, 2008, Venedig> ER - TY - JOUR A1 - Ewe, Hendrik A1 - Klein, Peter A1 - Pieper, Martin A1 - Füldner, G. T1 - Heat conductivity in sintered aluminium fibers JF - Cellular metals for structural and functional applications : CELLMET 2008 ; proceedings of the International Symposium on Cellular Metals for Structural and Functional Applications held October 8 - 10, 2008 in Dresden, Germany / ed. by Günter Stephani Y1 - 2009 SP - 187 EP - 193 PB - Fraunhofer IFAM CY - Dresden ER - TY - JOUR A1 - Pieper, Martin T1 - Multiobjective optimization with expensive objectives applied to a thermodynamic material design problem JF - Proceedings in applied mathematics and mechanics : PAMM. 11 (2011), H. 1 Y1 - 2011 SN - 1617-7061 SP - 733 EP - 734 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Fateri, Miranda A1 - Hötter, Jan-Steffen A1 - Gebhardt, Andreas T1 - Experimental and Theoretical Investigation of Buckling Deformation of Fabricated Objects by Selective Laser Melting JF - Physics Procedia N2 - Although Selective Laser Melting (SLM) process is an innovative manufacturing method, there are challenges such as inferior mechanical properties of fabricated objects. Regarding this, buckling deformation which is caused by thermal stress is one of the undesired mechanical properties which must be alleviated. As buckling deformation is more observable in hard to process materials, silver is selected to be studied theoretically and experimentally for this paper. Different scanning strategies are utilized and a Finite Element Method (FEM) is applied to calculate the temperature gradient in order to determine its effect on the buckling deformation of the objects from experiments. Y1 - 2012 U6 - https://doi.org/10.1016/j.phpro.2012.10.062 SN - 1875-3892 N1 - Part of special issue "Laser Assisted Net shape Engineering 7 (LANE 2012)" VL - 39 SP - 464 EP - 470 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Werner, Frederik A1 - Takenaga, Shoko A1 - Taki, Hidenori A1 - Sawada, Kazuaki A1 - Schöning, Michael Josef T1 - Comparison of label-free ACh-imaging sensors based on CCD and LAPS JF - Sensors and Actuators B: Chemical (2012) N2 - Semiconductor-based chemical imaging sensors, like the light-addressable potentiometric sensor (LAPS) or the pH-imaging sensor based on a charge-coupled device (CCD), are becoming a powerful tool for label-free imaging of biological phenomena. We have proposed a polyion-based enzymatic membrane to develop an acetylcholine (ACh) imaging sensor for neural cell-activity observations. In this study, a CCD-type ACh-imaging sensor and a LAPS-type ACh-imaging sensor were fabricated and the prospect of both sensors was clarified by making a comparison of their basic characteristics. Y1 - 2013 SN - 0925-4005 VL - 177 SP - 745 EP - 752 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Wosnitza, Franz A1 - Hilgers, Hans Gerd T1 - Energieeffizienz und Energiemanagement : ein Überblick heutiger Möglichkeiten und Notwendigkeiten Y1 - 2012 SN - 978-3-8348-1941-3 N1 - eISBN 978-3-8348-8671-2 PB - Springer Spektrum CY - Wiesbaden ER - TY - BOOK A1 - Janser, Frank A1 - Havermann, Marc T1 - Inkompressible Strömungen Y1 - 2012 SN - 978-3-86130-446-3 N1 - Strömungslehre und Aerodynamik PB - Mainz CY - Aachen ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Suco, Henri-Pierre A1 - Rysstad, Gunnar A1 - Schöning, Michael Josef T1 - Monitoring the microbicidal effectiveness of gaseous hydrogen peroxide in sterilisation processes by means of a calorimetric gas sensor JF - Food control N2 - In the present work, a novel method for monitoring sterilisation processes with gaseous H2O2 in combination with heat activation by means of a specially designed calorimetric gas sensor was evaluated. Therefore, the sterilisation process was extensively studied by using test specimens inoculated with Bacillus atrophaeus spores in order to identify the most influencing process factors on its microbicidal effectiveness. Besides the contact time of the test specimens with gaseous H2O2 varied between 0.2 and 0.5 s, the present H2O2 concentration in a range from 0 to 8% v/v (volume percent) had a strong influence on the microbicidal effectiveness, whereas the change of the vaporiser temperature, gas flow and humidity were almost negligible. Furthermore, a calorimetric H2O2 gas sensor was characterised in the sterilisation process with gaseous H2O2 in a wide range of parameter settings, wherein the measurement signal has shown a linear response against the H2O2 concentration with a sensitivity of 4.75 °C/(% v/v). In a final step, a correlation model by matching the measurement signal of the gas sensor with the microbial inactivation kinetics was established that demonstrates its suitability as an efficient method for validating the microbicidal effectiveness of sterilisation processes with gaseous H2O2. KW - hydrogen peroxide KW - sterilisation KW - Bacillus atrophaeus KW - calorimetric gas sensor Y1 - 2012 U6 - https://doi.org/10.1016/j.foodcont.2012.11.048 SN - 0956-7135 VL - 31 IS - 2 SP - 530 EP - 538 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Börner, Sebastian A1 - Funke, Harald A1 - Hendrick, P. A1 - Recker, E. T1 - LES of Jets In Cross-Flow and Application to the “Micromix” Hydrogen Combustion T2 - XIX International Symposium on Air Breathing Engines 2009 (ISABE 2009) : Proceedings of a meeting held 7-11 September 2009, Montreal, Canada Y1 - 2009 SN - 9781615676064 SP - 1555 EP - 1561 ER - TY - CHAP A1 - Kowalski, Julia A1 - Bartelt, Perry A1 - McElwaine, J. T1 - Two-phase debris flow modeling T2 - Geophysical Research Abstracts Y1 - 2007 N1 - A-08119 ER - TY - CHAP A1 - Kowalski, Julia A1 - McElwaine, J. T1 - Two-phase debris flow modeling T2 - Geophysical Research Abstracts Y1 - 2008 N1 - A-01048 ER - TY - CHAP A1 - Olaru, Alexandra Maria A1 - Kowalski, Julia A1 - Sethi, Vaishali A1 - Blümich, Bernhard T1 - Fluid Transport in Porous Media probed by Relaxation-Exchange NMR T2 - 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec. Y1 - 2011 N1 - H12B-07; American Geophysical Union ER - TY - JOUR A1 - Ziemons, Karl T1 - Jet production and fragmentation properties in deep inelastic muon scattering JF - Zeitschrift für Physik C : Particles and Fields Y1 - 1987 SN - 0170-9739 N1 - European Muon Collaboration VL - 36 IS - 4 SP - 527 EP - 543 ER - TY - JOUR A1 - Ziemons, Karl T1 - A measurement of the spin asymmetry of the structure function g1 in deep inelastic muon-proton scattering JF - Physics Letters B N2 - The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured over a large x range (0.01