TY - JOUR A1 - Prume, Klaus A1 - Roelofs, Andreas A1 - Schmitz, Thorsten A1 - Reichenberg, Bernd T1 - Compensation of the Parasitic Capacitance of a Scanning Force Microscope Cantilever Used for Measurements on Ferroelectric Capacitors of Submicron Size by Means of Finite Element Simulations / Prume, Klaus ; Roelofs, Andreas ; Schmitz, Thorsten ; Reichenb JF - Japanese Journal of Applied Physics. 41 (2002), H. 11B Y1 - 2002 SN - 0021-4922 SP - 7198 EP - 7201 ER - TY - JOUR A1 - Knüppel, Mark T1 - Pro-Forma-Angaben JF - Handbuch der Bilanzierung : das gesamte Wissen zur Rechnungslegung nach HGB, EStG und IFRS / Federmann, Rudolf ; Gnam, Arnulf ; Ammedick, Oliver Y1 - 2002 N1 - Aktuelle Informationen in Erg.-Lfg. 122 [nicht mehr vorhanden] SP - 1950 EP - 1952 PB - Haufe CY - Freiburg ER - TY - BOOK A1 - Damrau, Karin A1 - Pasing, Anton T1 - Unschärferelationen : Experiment Raum = Uncertainty principles / Hrsg.: Karin Damrau; Anton Markus Pasing. [Bearb.: Bernd Wylicil. Übers.: Annette Wiethüchter] Y1 - 2002 SN - 3-932509-09-9 PB - Nelte CY - Wiesbaden ER - TY - JOUR A1 - Öhlschläger, Peter A1 - Michel, Nico A1 - Osen, Wolfram A1 - Freyschmidt, Eva-Jasmin T1 - T cell response to human papillomavirus 16 E7 in mice: comparison of Cr release assay, intracellular IFN-gamma production, ELISPOT and tetramer staining / Michel, Nico ; Öhlschläger, Peter ; Osen, Wolfram ; Freyschmidt, Eva-Jasmin ; Gutöhrlein, Heidrun ; JF - Intervirology. 45 (2002) Y1 - 2002 SN - 1423-0100 SP - 290 EP - 299 ER - TY - JOUR A1 - Pfeiffer, Johann T1 - Gute Chancen im Maschinenbau JF - Aachener Nachrichten / Aachener Zeitung : Sonderbeil. (2002) Y1 - 2002 PB - - ER - TY - JOUR A1 - Pfeiffer, Johann T1 - Gute Chancen im Maschinenbau JF - Rheinische Post : Sonderbeil. (2002) Y1 - 2002 ER - TY - JOUR A1 - Pfeiffer, Johann T1 - Chancen im Maschinenbau JF - Fachblatt : Journal der Fachhochschule Aachen . 2002 (2002), H. 1 Y1 - 2002 SP - 2 PB - - 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 -