TY - JOUR A1 - Streun, M. A1 - Larue, H. A1 - Parl, C. A1 - Ziemons, Karl T1 - A compact PET detector readout using charge-to-time conversion JF - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The readout of gamma detectors is considerably simplified when the event intensity is encoded as a pulse width (Pulse Width Modulation, PWM). Time-to-Digital-Converters (TDC) replace the conventional ADCs and multiple TDCs can be realized easily in one PLD chip (Programmable Logic Device). The output of a PWM stage is only one digital signal per channel which is well suited for transport so that further processing can be performed apart from the detector. This is particularly interesting for large systems with high channel density (e.g. high resolution scanners). In this work we present a circuit with a linear transfer function that requires a minimum of components by performing the PWM already in the preamp stage. This allows a very compact and also cost-efficient implementation of the front-end electronics. Y1 - 2009 SN - 1082-3654 SP - 1868 EP - 1870 PB - IEEE CY - New York 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 - IEEE Transactions on Nuclear Science 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 field programmable gate array (FPGA). 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. This information is 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 very high count rates to be dealt with. Since this method is to be employed in positron emission tomography (PET), the position of an event is also important. 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 here Y1 - 2001 SN - 0018-9499 VL - 48 IS - 3 SP - 524 EP - 526 ER - TY - JOUR A1 - Heinrich, U. A1 - Blum, A. A1 - Bussmann, N. A1 - Engels, R. A1 - Kemmerling, G. A1 - Weber, S. A1 - Ziemons, Karl T1 - Statistical studies on the light output and energy resolution of small LSO single crystals with different surface treatments combined with various reflector materials JF - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - The optimization of light output and energy resolution of scintillators is of special interest for the development of high resolution and high sensitivity PET. The aim of this work is to obtain statistically reliable results concerning optimal surface treatment of scintillation crystals and the selection of reflector material. For this purpose, raw, mechanically polished and etched LSO crystals (size 2×2×10 mm3) were combined with various reflector materials (Teflon tape, Teflon matrix, BaSO4) and exposed to a 22Na source. In order to ensure the statistical reliability of the results, groups of 10 LSO crystals each were measured for all combinations of surface treatment and reflector material. Using no reflector material the light output increased up to 551±35% by mechanical polishing the surface compared to 100±5% for raw crystals. Etching the surface increased the light output to 441±29%. The untreated crystals had an energy resolution of 24.6±4.0%. By mechanical polishing the surface it was possible to achieve an energy resolution of 13.2±0.8%, by etching of 14.8±0.7%. In combination with BaSO4 as reflector material the maximum increase of light output has been established to 932±57% for mechanically polished and 895±61% for etched crystals. The combination with BaSO4 also caused the best improvement of the energy resolution up to 11.6±0.2% for mechanically polished and 12.2±0.3% for etched crystals. Relating to the light output there was no significant statistical difference between the two surface treatments in combination with BaSO4. In contrast to this, the statistical results of the energy resolution have shown the combination of mechanical polishing and BaSO4 as the optimum. Y1 - 2002 SN - 0168-9002 N1 - Proceedings of the 6th International Conference on Inorganic Scin tillators and their Use in Scientific and Industrial Applications VL - 486 IS - 1-2 SP - 60 EP - 66 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - A PET system with free running ADCs JF - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - A small PET system has been built up with two multichannel photomultipliers, which are attached to a matrix of 64 single LSO crystals each. The signal from each multiplier is being sampled continuously by a 12 bit ADC at a sampling frequency of 40 MHz. In case of a scintillation pulse a subsequent FPGA sends the corresponding set of samples together with the channel information and a time mark to the host computer. The data transfer is performed with a rate of 20 MB/s. On the host all necessary information is extracted from the data. The pulse energy is determined, coincident events are detected and multiple hits within one matrix can be identified. In order to achieve a narrow time window the pulse starting time is refined further than the resolution of the time mark (=25 ns) would allow. This is possible by interpolating between the pulse samples. First data obtained from this system will be presented. The system is part of developments for a much larger system and has been created to study the feasibility and performance of the technique and the hardware architecture. Y1 - 2002 SN - 0168-9002 N1 - Proceedings of the 6th International Conference on Inorganic Scin tillators and their Use in Scientific and Industrial Applications VL - 486 IS - 1-2 SP - 18 EP - 21 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - Coincidence detection by digital processing of free-running sampled pulses JF - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - Coincident events in two scintillator crystals coupled to photomultipliers (PMT) are detected by processing just the digital data of the recorded pulses. For this purpose the signals from both PMTs are continuously sampled by free-running ADCs at a sampling rate of 40 MHz. For each sampled pulse the starting time is determined by processing the pulse data. Even a fairly simple interpolating algorithm results in a FWHM of about 2 ns. Y1 - 2002 SN - 0168-9002 VL - 487 IS - 3 SP - 530 EP - 534 ER - TY - JOUR A1 - Khodaverdi, M. A1 - Pauly, F. A1 - Schroder, G. A1 - Ziemons, Karl A1 - Sievering, R. A1 - Halling, H. T1 - Preliminary studies of a micro-CT for a combined small animal PET/CT scanner JF - 2001 IEEE Nuclear Science Symposium Conference Record, Vol. 3 N2 - We are developing an X-ray computed tomography (CT) system which will be combined with a high resolution animal PET system. This permits acquisition of both molecular and anatomical images in a single machine. In particular the CT will also be utilized for the quantification of the animal PET data by providing accurate data for attenuation correction. A first prototype has been built using a commercially available plane silicon diode detector. A cone-beam reconstruction provides the images using the Feldkamp algorithm. First measurements with this system have been performed on a mouse. It could be shown that the CT setup fulfils all demands for a high quality image of the skeleton of the mouse. It is also suited for soft tissue measurements. To improve contrast and resolution and to acquire the X-ray energy further development of the system, especially the use of semiconductor detectors and iterative reconstruction algorithms are planned. Y1 - 2002 SN - 1082-3654 SP - 1605 EP - 1606 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - A PET system based on data processing of free-running sampled pulses JF - 2001 IEEE Nuclear Science Symposium Conference Record, Vol. 2 N2 - Within the developments for the Crystal Clear small animal PET project (CLEARPET) a dual head PET system has been established. The basic principle is the early digitization of the detector pulses by free running ADCs. The determination of the γ-energy and also the coincidence detection is performed by data processing of the sampled pulses on the host computer. Therefore a time mark is attached to each pulse identifying the current cycle of the 40 MHz sampling clock. In order to refine the time resolution the pulse starting time is interpolated from the samples of the pulse rise. The detector heads consist of multichannel PMTs with a single LSO scintillator crystal coupled to each channel. For each PMT only one ADC is required. The position of an event is obtained separately from trigger signals generated for each single channel. An FPGA is utilized for pulse buffering, generation of the time mark and for the data transfer to the host via a fast I/O-interface. Y1 - 2002 SN - 1082-3654 SP - 693 EP - 694 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Saleh, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - Pulse shape discrimination of LSO and LuYAP scintillators for depth of interaction detection in PET JF - 2002 IEEE Nuclear Science Symposium Conference Record, Vol. 3 N2 - A feasible way to gain the depth of interaction information in a PET scanner is the use of phoswich detectors. In general the layer of interaction is identified front the pulse shape of the corresponding scintillator material. In this work pulses from LSO and LuYAP crystals were investigated in order to find a practical method of distinguishing. It turned out that such a pulse processing could he kept simple due to an additional slow component in the light decay of the LuYAP pulse. At the same time the short decay time guarantees that the major amount of the light output is still collected within a short pulse recording time. Y1 - 2003 SN - 1082-3654 SP - 1636 EP - 1639 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Saleh, H. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - Pulse shape discrimination of LSO and LuYAP scintillators for depth of interaction detection in PET JF - IEEE Transactions on Nuclear Science N2 - A feasible way to gain the depth of interaction information in a positron emission tomography scanner is the use of phoswich detectors. In general, the layer of interaction is identified from the pulse shape of the corresponding scintillator material. In this work, pulses from LSO and LuYAP crystals were investigated in order to find a practical method of distinguishing. It turned out that such a pulse processing could be kept simple because of an additional slow component in the light decay of the LuYAP pulse. At the same time, the short decay time guarantees that the major amount of the light output is still collected within a short pulse recording time. Y1 - 2003 SN - 0018-9499 VL - 50 IS - 3 SP - 344 EP - 347 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Brökel, M. A1 - Fuss, L. A1 - Larue, H. A1 - Parl, C. A1 - Zimmermann, E. A1 - Ziemons, Karl A1 - Halling, H. T1 - The ClearPET data acquisition JF - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 5 N2 - Within the Crystal Clear Collaboration a modular system for a small animal PET scanner (ClearPET™) has been developed. The modularity allows the assembly of scanners of different sizes and characteristics in order to fit the specific needs of the individual member institutions. Now a first demonstrator is being completed in Julich. The system performs depth of interaction detection by using a phoswich arrangement combining LSO and LuYAP scintillators which are coupled to multi-channel photomultipliers (PMTs). A free-running ADC digitizes the signal from the PMT and the complete scintillation pulses are sampled by an FPGA and sent with 20 MB/S to a PC for preprocessing. The pulse provides information about the gamma energy and the scintillator material which identifies the interaction layer. Furthermore, the exact pulse starting time is obtained from the sampled data. This is important as no hardware coincidence detection is implemented. All single events are recorded and coincidences are identified by software. An advantage of that is that the coincidence window and the dimensions of the field of view can be adjusted easily. The ClearPET™ demonstrator is equipped with 10240 crystals on 80 PMTs. This paper presents an overview of the data acquisition system. Y1 - 2004 SN - 1082-3654 SP - 3097 EP - 3100 ER - TY - JOUR A1 - Christ, D. A1 - Hollendung, A. A1 - Larue, H. A1 - Parl, C. A1 - Streun, M. A1 - Weber, S. A1 - Ziemons, Karl A1 - Halling, H. T1 - Homogenization of the MultiChannel PM gain by inserting light attenuating masks JF - 2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4 N2 - MultiChannel Photomultipliers (PM), like the R7600-00-M64 or R5900-00-M64 from Hamamatsu, are often chosen as photodetectors in high-resolution positron emission tomography (PET). A major problem of this PM is the nonuniform channel gain. In order to solve this problem, light attenuating masks were created. The aim of the masks is a homogenization of the output of all 64 channels using different hole sizes at the channel positions. The hole area, which is individually defined for the different channels, is inversely proportional to the channel gain. The measurements by inserting light attenuating masks improved a homogenization to a ratio of 1:1.2. Y1 - 2004 SN - 1082-3654 SP - 2382 EP - 2385 ER - TY - JOUR A1 - Streun, M. A1 - Christ, D. A1 - Hellendung, A. A1 - Larue, H. A1 - Ziemons, Karl A1 - Halling, H. T1 - Effects of crosstalk and gain nonuniformity using multichannel PMTs in the Clearpet® scanner JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment N2 - The ClearPET® scanners developed by the Crystal Clear Collaboration use multichannel PMTs as photodetectors with scintillator pixels coupled individually to each channel. In order to localize an event each channel anode is connected to a comparator that triggers when the anode signal exceeds a common predefined threshold. Two major difficulties here are crosstalk of light and the gain nonuniformity of the PMT channels. Crosstalk can generate false triggering in channels adjacent to the actual event. On the one hand this can be suppressed by sufficiently increasing the threshold, but on the other hand a threshold too high can already prevent valid events on the lower gain channels from being detected. Finally, both effects restrict the dynamic range of pulse heights that can be processed. The requirements to the dynamic range are not low as the ClearPET® scanners detect the depth of interaction by phoswich pixels consisting of LSO and Lu0.7Y0.3AP, two scintillators with different light yields. We will present a model to estimate the achievable dynamic range and show solutions to increase it. Y1 - 2005 SN - 0168-9002 N1 - Proceedings of the 7th International Conference on Inorganic Scintillators and their Use in Scientific and Industrial Applications VL - 537 IS - 1-2 SP - 402 EP - 405 ER - TY - JOUR A1 - Beer, S. A1 - Streun, M. A1 - Hombach, T. A1 - Buehler, J. A1 - Jahnke, S. A1 - Khodaverdi, M. A1 - Larue, H. A1 - Minwuyelet, S. A1 - Parl, C. A1 - Roeb, G. A1 - Schurr, U. A1 - Ziemons, Karl T1 - Design and initial performance of PlanTIS: a high-resolution positron emission tomograph for plants JF - Physics in Medicine and Biology N2 - Positron emitters such as 11C, 13N and 18F and their labelled compounds are widely used in clinical diagnosis and animal studies, but can also be used to study metabolic and physiological functions in plants dynamically and in vivo. A very particular tracer molecule is 11CO2 since it can be applied to a leaf as a gas. We have developed a Plant Tomographic Imaging System (PlanTIS), a high-resolution PET scanner for plant studies. Detectors, front-end electronics and data acquisition architecture of the scanner are based on the ClearPET™ system. The detectors consist of LSO and LuYAP crystals in phoswich configuration which are coupled to position-sensitive photomultiplier tubes. Signals are continuously sampled by free running ADCs, and data are stored in a list mode format. The detectors are arranged in a horizontal plane to allow the plants to be measured in the natural upright position. Two groups of four detector modules stand face-to-face and rotate around the field-of-view. This special system geometry requires dedicated image reconstruction and normalization procedures. We present the initial performance of the detector system and first phantom and plant measurements. Y1 - 2010 U6 - https://doi.org/10.1088/0031-9155/55/3/006 SN - 1361-6560 VL - 55 IS - 3 SP - 635 EP - 646 PB - IOP CY - Bristol ER - TY - JOUR A1 - Herzog, Hans A1 - Pietrzyk, Uwe A1 - Shah, N. Jon A1 - Ziemons, Karl T1 - The current state, challenges and perspectives of MR-PET JF - Neuroimage N2 - Following the success of PET/CT during the last decade and the recent increasing proliferation of SPECT/CT, another hybrid imaging instrument has been gaining more and more interest: MR-PET. First combined, simultaneous PET and MR studies carried out in small animals demonstrated the feasibility of the new approach. Concurrently, some prototypes of an MR-PET scanner for simultaneous human brain studies have been built, their performance is being tested and preliminary applications have already been shown. Through this pioneering work, it has become clear that advances in the detector design are necessary for further optimization. Recently, the different issues related to the present state and future prospects of MR-PET were presented and discussed during an international 2-day workshop at the Forschungszentrum Jülich, Germany, held after, and in conjunction with, the 2008 IEEE Nuclear Science Symposium and Medical Imaging Conference in Dresden, Germany on October 27–28, 2008. The topics ranged from small animal MR-PET imaging to human MR-BrainPET imaging, new detector developments, challenges/opportunities for ultra-high field MR-PET imaging and considerations of possible future research and clinical applications. This report presents a critical summary of the contributions made to the workshop. Y1 - 2010 U6 - https://doi.org/10.1016/j.neuroimage.2009.10.036 SN - 1053-8119 VL - 49 IS - 3 SP - 2072 EP - 2082 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Parl, C. A1 - Larue, H. A1 - Streun, M. A1 - Ziemons, Karl T1 - Double-side-readout technique for SiPM-matrices JF - 2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - In our case the double-side-method is used to minimize the complexity of a matrix-readout. Here the number of channels is reduced to 2√N̅. It is also possible to benefit from the method in a single pixel readout system. One signal can be used to measure position and energy of the event, the other one can be applied to a fast trigger-circuit at the same time. In a next step we will investigate timing behavior and electrical crosstalk of the circuit. Y1 - 2011 SN - 1095-7863 SP - 1486 EP - 1487 PB - IEEE CY - New York ER - TY - GEN A1 - Achten, Richard A1 - Bauer, Andreas A1 - Bertram, Walter A1 - Cremer, Markus A1 - Daemen, Jos A1 - Dehnhardt, Markus A1 - Fleischer, Manfred A1 - Kirchner, Peter A1 - Leyendecker, Marco A1 - Pietrzyk, Uwe A1 - Schmitz, Jakob A1 - Ziemons, Karl A1 - Zilles, Karl T1 - Vorrichtung zum Halten eines lebenden Objektes bei physiologischen Messungen N2 - Die vorliegende Erfindung betrifft eine Vorrichtung zum Halten eines lebenden Objektes bei physiologischen Messungen mit einem Basiselement und Mitteln zum Arretieren des lebenden Objektes, die atraumatische Ohrenhalter sowie ein Mundstück aufweisen, das mit einer Aussparung für die Zähne des Lebewesens versehen ist, mit einem Masseanteil von wenigstens 95% an glasfaserverstärktem Kunststoff. Y1 - 2005 N1 - Patent Anmelder : Forschungszentrum Jülich GmbH SP - 1 EP - 17 ER - TY - GEN A1 - Rongen, Heinz A1 - Ziemons, Karl A1 - Schiek, Michael A1 - Tass, Alexander T1 - Vorrichtung zur Messung biomedizinischer Daten eines Probanden und Verfahren zur Simulation des Probanden mit in Echtzeit verarbeiteten Daten T1 - Device for measuring biomedical data from a testee and method for stimulating the testee with data processed in real-time N2 - Die Erfindung betrifft eine Vorrichtung zur Messung biomedizinischer Daten eines Probanden, mit einem Messsystem zur Erhebung der Daten sowie einer ersten Hardware-Komponente zur Aufzeichnung der Daten. In einer Verbindungsleitung zur Übertragung der Daten vom Messsystem zur ersten Hardware-Komponente zur Aufzeichnung der Daten ist erfindungsgemäss ein Mittel zur galvanischen Auftrennung der Daten angeordnet. Auf diese Weise ist wenigstens die Duplizierung der Daten für Datenverarbeitungszwecke gewährleistet. Die auf diese Weise verarbeiteten Daten werden für ein Verfahren zur Echtzeit-Stimulation eines Probanden genutzt. Y1 - 2006 N1 - Auch veröffentlicht als EP2007276 ; US2009069662 ; US8301222 ; JP2009535071 ; WO2007118443 ; AT 533401 SP - 1 EP - 12 ER - TY - BOOK A1 - Simonis, Rainer T1 - Experimentelle Darstellung von Kr/Xe-Hydrat bei Drücken bis 160 bar KW - Krypton KW - Xenon KW - krypton xenon hydrate Y1 - 1985 N1 - Zugl.: Aachen, Techn. Hochsch., Diss. N1 - Berichte der Kernforschungsanlage Jülich ; 1995 PB - Zentralbibliothek d. Kernforschungsanlage CY - Jülich ER - TY - BOOK A1 - Simonis, Rainer A1 - Brücher, Heiner T1 - Verhalten von radioaktivem Krypton-85 in der Tiefsee : Abschlußbericht für d. Berichtszeitraum 1.10.1980 - 31.3.1983 KW - Krypton-85 Y1 - 1984 N1 - Spezielle Berichte der Kernforschungsanlage Jülich ; 267 PB - Zentralbibliothek d. Kernforschungsanlage CY - Jülich ER - TY - PAT A1 - Hofbauer, Peter A1 - Härtel, Günter A1 - Lösing, Karl-Heinrich A1 - Dorner, Robert A1 - Simonis, Rainer A1 - Schulte, Erasmus T1 - Brennstoffeinspritzsystem für Brennkraftmaschinen : Offenlegungsschrift DE 3833215 A1 ; Offenlegungstag: 28.12.89 N2 - Es wird ein Brennstoffeinspritzsystem für Brennkraftmaschinen vorgeschlagen, bei dem ein definiertes Teil eines fest vorgegebenen Brennstoffvolumens durch die Druckerhöhung innerhalb einer brennstoffeinschließenden Kammer eine definierte Brennstoffmenge über jeweils ein Rückschlagventil abgespritzt wird. Ein elektronisches Steuergerät berechnet die Dauer und/oder Intensität und gegebenenfalls die Impulsfolge eines zum Beispiel zur Verdampfung einer bestimmten Brennstoffmenge erforderlichen Laserimpulses. Das System kann für Ein- oder Mehrstelleinspritzung Verwendung finden. KW - Brennkraftmaschine KW - Brennstoffeinspritzsystem Y1 - 1989 PB - Deutsches Patent- und Markenamt CY - München ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Suso, Henri-Pierre A1 - Rysstad, Gunnar A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes JF - Physica status solidi (a) N2 - A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests. KW - calorimetric gas sensor;hydrogen peroxide;wireless sensor system Y1 - 2013 U6 - https://doi.org/10.1002/pssa.201200920 SN - 1862-6319 VL - 210 IS - 5 SP - 877 EP - 883 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Larue, H. A1 - Parl, C. A1 - Ziemons, Karl T1 - The data acquisition system of ClearPET neuro - a small animal PET scanner JF - IEEE Transactions on Nuclear Science N2 - The Crystal Clear Collaboration has developed a modular system for a small animal PET scanner (ClearPET). The modularity allows the assembly of scanners of different sizes and characteristics in order to satisfy the specific needs of the individual member institutions. The system performs depth of interaction detection by using a phoswich arrangement combining LSO and LuYAP scintillators which are coupled to Multichannel Photomultipliers (PMTs). For each PMT a free running 40 MHz ADC digitizes the signal and the complete scintillation pulse is sampled by an FPGA and sent with 20 MB/s to a PC for preprocessing. The pulse provides information about the gamma energy and the scintillator material which identifies the interaction layer. Furthermore, the exact pulse starting time is obtained from the sampled data. This is important as no hardware coincidence detection is implemented. All single events are recorded and coincidences are identified by software. The system in Jülich (ClearPET Neuro) is equipped with 10240 crystals on 80 PMTs. The paper will present an overview of the data acquisition system. Y1 - 2006 SN - 0018-9499 VL - 53 IS - 3 SP - 700 EP - 703 ER - TY - JOUR A1 - Khodaverdi, M. A1 - Weber, S. A1 - Streun, M. A1 - Parl, C. A1 - Ziemons, Karl T1 - High resolution imaging with ClearPET™ Neuro - first animal images JF - 2005 IEEE Nuclear Science Symposium Conference Record, Vol. 3 N2 - The ClearPET™ Neuro is the first full ring scanner within the Crystal Clear Collaboration (CCC). It consists of 80 detector modules allocated to 20 cassettes. LSO and LuYAP:Ce crystals in phoswich configuration in combination with position sensitive photomultiplier tubes are used to achieve high sensitivity and realize the acquisition of the depth of interaction (DOI) information. The complete system has been tested concerning the mechanical and electronical stability and interplay. Moreover, suitable corrections have been implemented into the reconstruction procedure to ensure high image quality. We present first results which show the successful operation of the ClearPET™ Neuro for artefact free and high resolution small animal imaging. Based on these results during the past few months the ClearPET™ Neuro System has been modified in order to optimize the performance. Y1 - 2006 SN - 1082-3654 SP - 1641 EP - 1644 ER - TY - JOUR A1 - Streun, M. A1 - Brandenburg, G. A1 - Khodaverdi, M. A1 - Larue, H. A1 - Parl, C. A1 - Ziemons, Karl T1 - Timemark correction for the ClearPET™ scanners JF - 2005 IEEE Nuclear Science Symposium Conference Record, Vol. 4 N2 - The small animal PET scanners developed by the Crystal Clear Collaboration (ClearPETtrade) detect coincidences by analyzing timemarks which are attached to each event. The scanners are able to save complete single list mode data which allows analysis and modification of the timemarks after data acquisition. The timemarks are obtained from the digitally sampled detector pulses by calculating the baseline crossing of the rising edge of the pulse which is approximated as a straight line. But the limited sampling frequency causes a systematic error in the determination of the timemark. This error depends on the phase of the sampling clock at the time of the event. A statistical method that corrects these errors will be presented Y1 - 2006 SN - 1082-3654 SP - 2057 EP - 2060 ER - TY - CHAP A1 - Gerhards, Michael A1 - Sander, Volker A1 - Belloum, Adam T1 - Seamlessly enabling the use of cloud resources in workflows T2 - Cloud Computing 2013 : The Fourth International Conference on Cloud Computing, GRIDs, and Virtualization : May 27 - June 1, 2013 - Valencia, Spain Y1 - 2013 SN - 978-1-61208-271-4 SP - 108 EP - 114 PB - Curren CY - Red Hook, NY ER - TY - JOUR A1 - Miyamoto, Ko-ichiro A1 - Ichimura, Hiroki A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel JF - Sensors and actuators. B: Chemical N2 - The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation. Y1 - 2013 U6 - https://doi.org/10.1016/j.snb.2013.04.057 SN - 1873-3077 (E-Journal); 0925-4005 (Print) N1 - Part of special issue "Selected Papers from the 26th European Conference on Solid-State Transducers" VL - 189 SP - 240 EP - 245 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Trattner, Barbara A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Stütz, Evamaria A1 - Schmitt-Landsiedel, Doris A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment JF - Sensors and actuators. B: Chemical Y1 - 2013 SN - 1873-3077 (E-Journal); 0925-4005 (Print) VL - Vol. 182 SP - 58 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Kayatekin, Muammer B. A1 - Uysal, N. A1 - Resmi, H. T1 - Does antioxidant supplementation alter the effects of acute exercise on erythrocyte aggregation, deformability and endothelium adhesion in untrained rats? Kayatekin, Muammer B.; Uysal N.; Resmi, H.; Bediz, Seref C.; Temiz Artmann, A.; Genç, S.; Tugyan, K. JF - International Journal for Vitamin and Nutrition Research. 75 (2005), H. 4 Y1 - 2005 SN - 0300-9831 SP - 243 EP - 250 ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Resmi, Halil A1 - Akhunlar, Hülya A1 - Güner, Gül T1 - In vitro effects of high glucose concentrations on membrane protein sulfhydryl oxidation, G-actin and deformability of human erythrocytes. Resmi, Halil ; Akhunlar, Hülya ; Temiz Artmann, Aysegül ; Güner, Gül JF - Cell biochemistry and function. 23 (2005), H. 3 Y1 - 2005 SN - 0263-6484 SP - 163 EP - 168 ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Cavdar, C. A1 - Yenicerioglu, Y. A1 - Caliskan, S. T1 - The effects of intravenous iron treatment on oxidant stress and erythrocyte deformability in haemodialysis patients. Cavdar, C.; Temiz, A.; Yenicerioglu, Y.; Caliskan, S.; Celik, A.; Sifil, A.; Onvural, B.; Camsari, T. JF - Scandinavian Journal of Urology and Nephrology. 37 (2003), H. 1 Y1 - 2003 SN - 0036-5599 SP - 77 EP - 82 ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Yolcuoglu, B. A1 - Onal, M. A. A1 - Sipahi, O. T1 - The effect of skin transplantation on tumour growth in mice. Yolcuoglu, B.; Onal, M. A.; Sipahi, O.; Temiz, A.; Pekcetin, C.; Acikgöz, O.; Kar, H.; Güre A. JF - The American Journal of Surgery. 178 (1999), H. 4 Y1 - 1999 SN - 0002-9610 SP - 329 EP - 330 ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Ates, H. A1 - Üretmen, Ö. A1 - Andac, K. T1 - Erythrocyte deformability in high-tension and normal tension glaucoma. Ates, H.; Üretmen, Ö.; Temiz, A.; Andac, K. JF - International Ophthalmology. 22 (1998), H. 1 Y1 - 1998 SN - 0165-5701 SP - 7 EP - 12 ER - TY - JOUR A1 - Temiz Artmann, Aysegül A1 - Akhisaroglu, M. A1 - Sercan, Z. A1 - Kayatekin, B. M. T1 - Adhesion of Erythrocytes to Endothelial Cells After Acute Exercise: Differences in Red Blood Cells from Juvenile and Adult Rats. Temiz Artmann, A.; Akhisaroglu, M.; Sercan, Z.; Kayatekin, BM.; Yorukoglu, K.; Kirkali, G. JF - Physiological Research (2005) Y1 - 2005 SN - 0862-8408 N1 - pre-press article ER - TY - JOUR A1 - Sponagel, Stefan A1 - Akbay, U. T1 - Über den Relaxationseinfluß auf die Stabilität der ebenen Couette-Strömung. Akbay, U. ; Sponagel, S. JF - Rheologica Acta. 23 (1984), H. 2 Y1 - 1984 SN - 0035-4511 SP - 177 EP - 184 ER - TY - JOUR A1 - Pawelke, Siegfried A1 - Butzer, Paul L. T1 - Ableitungen von trigonometrischen Approximationsprozessen JF - Acta scientiarum mathematicarum / Institutum Bolyaianum Universitatis Szegediensis Y1 - 1967 SN - 0001-6969 VL - 28 IS - 1-2 SP - 173 EP - 183 PB - n.a. CY - Szeged ER - TY - JOUR A1 - Pawelke, Siegfried A1 - Butzer, Paul L. T1 - Semi-groups and resolvent operators JF - Archive for Rational Mechanics and Analysis KW - Resolvent Operator KW - Electromagnetism KW - Complex System KW - Neural Network KW - Nonlinear Dynamics Y1 - 1968 U6 - https://doi.org/10.1007/BF00250941 SN - 0003-9527 VL - 30 IS - 2 SP - 127 EP - 147 PB - Springer CY - Berlin ER - TY - JOUR A1 - Pawelke, Siegfried A1 - Berens, H. A1 - Butzer, Paul L. T1 - Limitierungsverfahren von Reihen mehrdimensionaler Kugelfunktionen und deren Saturationsverhalten JF - Publications of the Research Institute for Mathematical Sciences, Series A N2 - Die vorliegende Arbeit untersucht das approximationstheoretische Verhalten von Summationsprozessen von Reihen von Kugelfunktionen, sogenannten Laplace-Reihen. Zunächst wird die Theorie der besten Approximation auf der Kugel, also die Erweiterung der Sätze von D. Jackson und S. Bernstein, skizziert. Nimmt man nun spezielle Verfahren zur Summation von Laplace-Reihen, dann lassen sich auch hier Sätze vom Jacksonschen und Bernsteinschen Typ beweisen. Darüber hinaus zeigen viele Verfahren ein Saturationsverhalten, d.h. es gibt eine nur vom Verfahren abhängige optimale Approximationsordnung. Das Saturationsproblem besteht nun darin, diejenige Klasse von Funktionen (Saturationsklasse) zu bestimmen, welche genau von der optimalen Ordnung approximiert werden. Y1 - 1968 U6 - https://doi.org/10.2977/prims/1195194875 SN - 0034-5318 VL - 4 IS - 2 SP - 201 EP - 268 PB - EMS Press CY - Zürich ER - TY - BOOK A1 - Pawelke, Siegfried T1 - Saturation und Approximation bei Reihen mehrdimensionaler Kugelfunktionen Y1 - 1969 PB - Techn. Hochsch. CY - Aachen ER - TY - JOUR A1 - Pawelke, Siegfried T1 - Ein Satz von Jacksonschen Typ für algebraischen Polynome JF - Acta scientiarum mathematicarum / Bolyai Institute, University of Szeged Y1 - 1972 SN - 0001-6969 IS - 33 SP - 323 EP - 336 PB - n.a. CY - Szeged ER - TY - JOUR A1 - Pawelke, Siegfried T1 - Über die Approximationsordnung bei Kugelfunktionen und algebraischen Polynomen JF - Tohoku Mathematical Journal (2) N2 - Für die Approximation stetiger, 2π-periodischer Funktionen auf der reellen Achse durch trigonometrische Polynome wurde ein direkter Satz von D. Jackson 1911 [8] und die Umkehrung von S. N. Bernstein 1912 [1] bewiesen und die Ergebnisse von A. Zygmund [25] 1945 verallgemeinert. 1949 stellte M. Zamansky [25] eine Beziehung zwischen der Approximationsordnung und dem Wachstum bezϋglich n der Ableitungen der Approximationspolynome her; auf die Approximationsordnung für die Ableitungen der Funktion schloβ S. B. Steckin 1951. Die Umkehrung des Ergebnisses von M. Zamansky bewies G. Sunouchi 1968 [21,22], womit die Aquivalenz aller Aussagen gezeigt ist. Die Übertragung der Ergebnisse auf Approximationsoperatoren in Banachräumen stammt von K. Scherer und P. L. Butzer [3, 4], wobei gewisse Voraussetzungen an die Operatorfolge (eine verallgemeinerte Bernsteinsche Ungleichung und eine sogenannte Jacksonsche Ungleichung) gestellt werden. An die Stelle der strukturellen Eigenschaften der Funktion, die durch das Verhalten des Stetigkeitsmoduls der Funktion charakterisiert werden, treten in allgemeinen Banachräumen Eigenschaften des von J. Peetre [17] eingefϋhrten K-Funktionals. In dieser Arbeit wird die Approximation von Funktionen, die auf der Einheitskugel Sᵏ im Rᵏ definiert sind, durch Linearkombinationen von Kugelfunktionen untersucht. Es wird für diesen Fall eine Bernstein-Ungleichung und die Jackson-Ungleichung bewiesen, wenn man die Ableitung durch den Laplace-Operator auf Sᵏ ersetzt. Damit ist der oben zitierte allgemeine Satz von Butzer-Scherer anwendbar. Weiter kann man hier an Stelle des K-Funktionals einen verallgemeinerten Stetigkeitsmodul setzen. Anschlieβend wird der Spezialfall der zonalen Funktionen und ihre Approximation durch algebraische Polynome untersucht. Y1 - 1972 SN - 0040-8735 U6 - https://doi.org/10.2748/tmj/1178241489 VL - 24 IS - 3 SP - 473 EP - 486 PB - Tohoku University CY - Sendai ER - TY - CHAP A1 - Pawelke, Siegfried ED - Ciesielski, Zbigniew T1 - Approximationstheorie mit Hilfe von Jacobi-Polynomen und Kugelfunktionen T2 - Proceedings of the conference jointly organized by the Mathematical Institute of the Polish Academy of Sciences and the Institute of Mathematics of the Adam Mickiewicz University, held in Poznan, 22-26 August, 1972 Y1 - 1975 SN - 90-277-0483-X SP - 157 EP - 173 PB - Reichel CY - Dordrecht ER - TY - JOUR A1 - Pawelke, Siegfried T1 - Weak smoothness conditions for the uniform convergence of Fourier-Jacobi series JF - Functiones et Approximatio. Commentarii Mathematici. 9 (1980) Y1 - 1980 SN - 0208-6573 N1 - Zentralblatt MATH: http://www.emis.de/MATH-item?0471.42018 SP - 9 EP - 13 ER - TY - JOUR A1 - Turek, Monika A1 - Ketterer, Lothar A1 - Claßen, Melanie A1 - Berndt, Heinz A1 - Elbers, Gereon A1 - Krüger, Peter A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Development and Electrochemical Investigations of an EIS-(Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection JF - Sensors Y1 - 2007 SN - 1424-8220 VL - 7 IS - 8 SP - 1415 EP - 1426 ER - TY - JOUR A1 - Wagner, Torsten A1 - Molina, Roberto A1 - Yoshinobu, Tatsuo A1 - Kloock, Joachim P. A1 - Biselli, Manfred A1 - Canzoneri, Michele A1 - Schnitzler, Thomas A1 - Schöning, Michael Josef T1 - Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications JF - Electrochimica Acta. 53 (2007), H. 2 Y1 - 2007 SN - 0013-4686 SP - 305 EP - 311 ER - TY - JOUR A1 - Pawelke, Siegfried A1 - Schmitt, W. A1 - Meissen, Th. T1 - Aachen 3D finger. 3D digitizer for application in dentistry / Schmitt, W. ; Pawelke, S. ; Meissen, Th. JF - Biomedizinische Technik. 35 (1990), H. 4 Y1 - 1990 SN - 0013-5585 SP - 69 EP - 71 ER - TY - JOUR A1 - Pawelke, Siegfried T1 - Note on Jackson and Bernstein type approximation theorems in the case of approximation by algebraic polynomial in the spaces L and C JF - Studia Scientiarum Mathematicarum Hungarica. 36 (2000), H. 3-4 Y1 - 2000 SN - 0081-6906 SP - 353 EP - 358 ER - TY - JOUR A1 - Sander, Volker A1 - Erwin, Dietmar A1 - Huber, Valentina T1 - High-performance computer management based on Java JF - Future Generation Computer Systems. 15 (1999), H. 3 Y1 - 1999 SN - 0167-739X SP - 425 EP - 432 ER - TY - JOUR A1 - Sander, Volker A1 - Foster, Ian A1 - Roy, Alain A1 - Winkler, Linda T1 - A differentiated services implementation for high-performance TCP flows JF - Computer Networks. 34 (2000), H. 6 Y1 - 2000 SN - 1389-1286 SP - 915 EP - 929 ER - TY - JOUR A1 - Sander, Volker A1 - Czajkowski, K. A1 - Foster, I. A1 - Kesselman, C. T1 - SNAP: A Protocol for Negotiating Service Level Agreements and Coordinating Resource Management in Distributed Systems / Czajkowski, K. ; Foster, I. ; Kesselman, C. ; Sander, V. ; Tuecke, S. JF - Job Scheduling Strategies for Parallel Processing : 8th InternationalWorkshop, JSSPP 2002 Edinburgh, Scotland, UK, July 24, 2002. Revised Papers Y1 - 2002 SN - 3-540-00172-7 N1 - Lecture Notes in Computer Science ; 2537 ; JSSPP <8, 2002, Edinburgh > SP - 153 EP - 183 PB - Springer CY - Berlin ER - TY - BOOK A1 - Sander, Volker T1 - Design and evaluation of a bandwidth broker that provides network quality of service for grid applications Y1 - 2003 SN - 3-00-010002-4 N1 - NIC series ; 16 ; Zugl. Aachen, Techn. Hochsch., Diss., 2002 PB - John von Neumann Institute for Computing (NIC) CY - Jülich ER -