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 - 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 - CHAP A1 - Staat, Manfred A1 - Heitzer, Michael T1 - The restricted influence of kinematic hardening on shakedown loads N2 - Structural design analyses are conducted with the aim of verifying the exclusion of ratcheting. To this end it is important to make a clear distinction between the shakedown range and the ratcheting range. In cyclic plasticity more sophisticated hardening models have been suggested in order to model the strain evolution observed in ratcheting experiments. The hardening models used in shakedown analysis are comparatively simple. It is shown that shakedown analysis can make quite stable predictions of admissible load ranges despite the simplicity of the underlying hardening models. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis. Both give identical or similar shakedown ranges. Structural shakedown analyses show that the loading may have a more pronounced effect than the hardening model. KW - Biomedizinische Technik KW - Einspielen KW - Shakedown KW - Ratcheting KW - Bruchmechanik KW - shakedown KW - material shakedown KW - linear kinematic hardening KW - nonlinear kinematic hardening KW - ratchetting Y1 - 2002 ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. T1 - Limit and Shakedown Analysis with Uncertain Data JF - Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed] Y1 - 2002 SN - 3-540-42889-5 SP - 241 EP - 254 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Staat, Manfred T1 - Some Achievements of the European Project LISA for FEM Based Limit and Shakedown Analysis JF - Computational mechanics : developments and applications, 2002 : presented at the 2002 ASME Pressure Vessels and Piping Conference, Vancouver, British Columbia, Canada, August 5 - 9. / Badie, N. [ed] Y1 - 2002 SN - 0791846520 N1 - Serie PVP ; vol. 441. SP - 177 EP - 185 PB - American Society of Mechanical Engineers CY - New York ER - TY - JOUR A1 - Sponagel, Stefan A1 - Baroud, G. A1 - Steffen, T. A1 - Wu, J. T1 - Parameter identification for cement infiltration of osteoporotic bone JF - Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ... Y1 - 2002 SN - 90-5809-394-8 SP - 55 EP - 58 PB - Balkema CY - Lisse [u.a.] ER - TY - JOUR A1 - Selmer, Thorsten A1 - Willanzheimer, Angela A1 - Hetzel, Marc T1 - Propionate CoA-transferase from Clostridium propionicum. Cloning of the gene and identification of glutamate 324 at the active site JF - European Journal of Biochemistry. 269 (2002), H. 1 Y1 - 2002 SN - 0014-2956 SP - 372 EP - 380 ER - TY - JOUR A1 - Selmer, Thorsten A1 - Netz, Daili Jacqueline Aguilar A1 - Pohl, Regula A1 - Beck-Sickinger, Annette G. T1 - Biochemical characterisation and genetic analysis of aureocin A53, a new, atypical bacteriocin from Staphylococcus aureus / Netz, Daili Jacqueline Aguilar ; Pohl, Regula ; Beck-Sickinger, Annette G. ; Selmer, Thorsten ; Pierik, Antonio J. ; Carmo de Frei JF - Journal of Molecular Biology. 319 (2002), H. 3 Y1 - 2002 SN - 0022-2836 SP - 745 EP - 756 ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Wang, Josepf A1 - Krause, Robin A1 - Block, Kirstin A1 - Musameh, Mustafa A1 - Mulchandani, Ashok A1 - Mulchandani, Priti A1 - Chen, Wilfred T1 - Dual amperometric-potentiometric biosensor detection system for monitoring organophosphorus neurotoxins JF - Analyica Chimica Acta. 469 (2002), H. 2 Y1 - 2002 SN - 0378-4304 SP - 197 EP - 203 ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Simonis, Anette A1 - Ruge, Christian A1 - Ecken, Holger A1 - Müller-Veggian, Mattea A1 - Lüth, Hans T1 - A (bio-)chemical Field-effect Sensor with Macroporous Si as Substrate Material and a SiO₂ / LPCVD-Si₃N₄ Double Layer as pH Transducer JF - Sensors. 2 (2002), H. 1 N2 - Macroporous silicon has been etched from n-type Si, using a vertical etching cell where no rear side contact on the silicon wafer is necessary. The resulting macropores have been characterised by means of Scanning Electron Microscopy (SEM). After etching, SiO₂ was thermally grown on the top of the porous silicon as an insulating layer and Si₃N₄ was deposited by means of Low Pressure Chemical Vapour Deposition (LPCVD) as transducer material to fabricate a capacitive pH sensor. In order to prepare porous biosensors, the enzyme penicillinase has been additionally immobilised inside the porous structure. Electrochemical measurements of the pH sensor and the biosensor with an Electrolyte/Insulator/Semiconductor (EIS) structure have been performed in the Capacitance/Voltage (C/V) and Constant capacitance (ConCap) mode. Y1 - 2002 SN - 1424-8220 U6 - http://dx.doi.org/10.3390/s20100011 SP - 11 EP - 22 ER -