TY - JOUR A1 - Hötter, Jan-Steffen A1 - Fateri, Miranda A1 - Gebhardt, Andreas T1 - Prozessoptimierung des SLM-Prozesses mit hoch-reflektiven und thermisch sehr gut leitenden Materialien durch systematische Parameterfindung und begleitende Simulationen am Beispiel von Silber JF - RTejournal - Forum für Rapid Technologie N2 - Additive Manufacturing durch Aufschmelzen von Metallpulvern hat sich auf breiter Front als Herstellverfahren, auch für Endprodukte, etabliert. Besonders für die Variante des Selective Laser Melting (SLM) sind Anwendungen in der Zahntechnik bereits weit verbreitet und der Einsatz in sensitiven Branchen wie der Luftfahrt ist in greifbare Nähe gerückt. Deshalb werden auch vermehrt Anstrengungen unternommen, um bisher nicht verarbeitete Materialien zu qualifizieren. Dies sind vorzugsweise Nicht-Eisen- und Edelmetalle, die sowohl eine sehr hohe Reflektivität als auch eine sehr gute Wärmeleitfähigkeit aufweisen – beides Eigenschaften, die die Beherrschung des Laser-Schmelzprozesses erschweren und nur kleine Prozessfenster zulassen. Die Arbeitsgruppe SLM des Lehr- und Forschungsgebietes Hochleistungsverfahren der Fertigungstechnik hat sich unter der Randbedingung einer kleinen und mit geringer Laserleistung ausgestatteten SLM Maschine der Aufgabe gewidmet und am Beispiel von Silber die Parameterfelder für Einzelspuren und wenig komplexe Geometrien systematisch untersucht. Die Arbeiten wurden von FEM Simulationen begleitet und durch metallographische Untersuchungen verifiziert. Die Ergebnisse bilden die Grundlage zur schnellen Parameterfindung bei komplexen Geometrien und bei Veränderungen der Zusammensetzung, wie sie bei zukünftigen Legierungen zu erwarten sind. Die Ergebnisse werden exemplarisch auf unterschiedliche Geometrien angewandt und entsprechende Bauteile gezeigt. N2 - Additive manufacturing by melting of metal powders is a method that has been established even for the manufacturing of final products. In particular, Selective Laser Melting (SLM) is currently applied for prosthetic dentistry. In the near future, this technology will access sensitive industries like aerospace engineering. This leads to the need to process new materials. Therefore, especially non-ferrous metals and noble metals must be determined and qualified. These materials have in common a very high reflectivity and an excellent thermal conductivity. In general, these two properties counteract the control of the melt pool and contribute to very narrow process windows. The “SLM” research team of the Aachen University of Applied Science, AcUAS (FH Aachen) systematically investigated process parameter fields for silver. The work focused on a small SLM desktop machine with comparably low laser power. The results are verified using FEA and metallographic inspections and will support future set-ups for complex geometries. Furthermore, the obtained parameter fields are applied to make different geometric objects and to manufactured parts, which are presented. KW - SLM KW - Selektives Laser Schmelzen KW - Silber Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0009-2-33639 SN - 1614-0923 VL - 9 IS - 1 SP - 1 EP - 14 PB - Fachhoschule Aachen CY - Aachen 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 - BOOK A1 - Mandelartz, Johannes T1 - Der Sekundäraluminium-Stoffstrom in Deutschland unter transporttechnischen und logistischen Gesichtspunkten KW - Aluminium KW - Recycling KW - Materialfluss KW - Logistik KW - Transport Y1 - 2000 SN - 3-86073-672-8 N1 - Zugl.: Aachen, Techn. Hochsch., Diss. N1 - Technische Hochschule Aachen / Lehrstuhl und Institut für Bergwerks- und Hüttenmaschinenkunde: Aachener Beiträge zur angewandten Rechnertechnik des Institutes für Bergwerks- und Hüttenmaschinenkunde ; 40 PB - Mainz CY - Aachen ER - TY - CHAP A1 - Mandelartz, Johannes T1 - VDI-Richtlinien – mit Technischen Regeln Wirtschaftlichkeit erhöhen und Standards setzen T2 - Betriebliche Instandhaltung N2 - Der Verein Deutscher Ingenieure e.V. (VDI) ist ein gemeinnütziger, wirtschaftlich und politisch unabhängiger, technisch-wissenschaftlicher Verein von Ingenieuren und Naturwissenschaftlern. Mit über 137 000 persönlich zugeordneten Mitgliedern ist er eine der größten Ingenieur-Vereinigungen Europas und gilt in Deutschland als führender Sprecher der Technik und der Ingenieure. 1856 gegründet, hat er viele für die Technik wesentliche Entwicklungen in Gang gesetzt, so im Bereich der technischen Überwachung, der technischen Regelsetzung und Normung, der Arbeitsstudien, im gewerblichen Rechtsschutz und im Patentwesen. Seit seiner Gründung sieht es der VDI als seine Aufgabe, "das Zusammenwirken aller geistiger Kräfte der Technik im Bewusstsein ethischer Verantwortung zu fördern" und die Lebensmöglichkeiten aller Menschen durch Entwicklung und sinnvoller Anwendung technischer Mittel zu verbessern. Y1 - 2009 SN - 978-3-642-00502-2 U6 - https://doi.org/10.1007/978-3-642-00502-2_26 SP - 311 EP - 317 PB - Springer CY - Berlin [u.a.] ER - TY - BOOK A1 - Reichel, Jens A1 - Müller, Gerhard A1 - Mandelartz, Johannes T1 - Betriebliche Instandhaltung KW - Unternehmen KW - Produktionssystem KW - Instandhaltung Y1 - 2009 SN - 978-3-642-00502-2 PB - Springer CY - Berlin [u.a.] 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 - Khodaverdi, M. A1 - Chatziioannou, A. F. A1 - Weber, S. A1 - Ziemons, Karl A1 - Halling, H. A1 - Pietrzyk, U. T1 - Investigation of different MicroCT scanner configurations by GEANT4 simulations JF - IEEE Transactions on Nuclear Science N2 - This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material. Y1 - 2005 SN - 0018-9499 VL - 52 IS - 1 SP - 188 EP - 192 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 - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 49 (1997), H. 4 Y1 - 1997 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) N1 - Printausg. in der Bibliothek: 61 Z 609-1997 SP - 68 EP - 75 ER - TY - JOUR A1 - Meliß, Michael T1 - Aktuelle Aspekte der Windkraftnutzung JF - Energiewirtschaftliche Tagesfragen. Jg. 47 (1997), H. 9 Y1 - 1997 SN - 0013-743X SP - 531 EP - 532 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 - Jens, Otto A1 - Kaldenhoff, E. A1 - Kirschner-Hermanns, R. A1 - Mühl, Thomas A1 - Klinge, Uwe T1 - Elongation of textile pelvic floor implants under load is related to complete loss of effective porosity, thereby favoring incorporation in scar plates JF - Journal of biomedical materials research. Part A N2 - Use of textile structures for reinforcement of pelvic floor structures has to consider mechanical forces to the implant, which are quite different to the tension free conditions of the abdominal wall. Thus, biomechanical analysis of textile devices has to include the impact of strain on stretchability and effective porosity. Prolift® and Prolift + M®, developed for tension free conditions, were tested by measuring stretchability and effective porosity applying mechanical strain. For comparison, we used Dynamesh-PR4®, which was designed for pelvic floor repair to withstand mechanical strain. Prolift® at rest showed moderate porosity with little stretchability but complete loss of effective porosity at strain of 4.9 N/cm. Prolift + M® revealed an increased porosity at rest, but at strain showed high stretchability, with subsequent loss of effective porosity at strain of 2.5 N/cm. Dynamesh PR4® preserved its high porosity even under strain, but as consequence of limited stretchability. Though in tension free conditions Prolift® and Prolift + M® can be considered as large pore class I meshes, application of mechanical strain rapidly lead to collapse of pores. The loss of porosity at mechanical stress can be prevented by constructions with high structural stability. Assessment of porosity under strain was found helpful to define requirements for pelvic floor devices. Clinical studies have to prove whether devices with high porosity as well as high structural stability can improve the patients' outcome. Y1 - 2014 U6 - https://doi.org/10.1002/jbm.a.34767 SN - 1552-4965 VL - 102 IS - 4 SP - 1079 EP - 1084 PB - Wiley CY - New York ER - TY - CHAP A1 - Faber, Christian T1 - Solare Großbäckerei in Burkina Faso als Beispiel eines solaren Prozesswärmesystems T2 - 14. Symposium Thermische Solarenergie : 12. bis 14. Mai 2004, Kloster Banz, Bad Staffelstein / OTTI-Kolleg Technik, Energie, Management Y1 - 2004 SN - 3-934681-33-6 SP - 500 EP - 505 PB - OTTI-Energie-Kolleg CY - Regensburg ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Vieira, Maria Eugenia A1 - Müller, Christoph A1 - Lehmann, Harry A1 - Coutinho, Lecimara T1 - Modular solar thermal desalination system with flat plate collector T2 - RIO 3 - World Climate & Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ... Y1 - 2003 SN - 85-902710-2-1 SP - 281 EP - 286 PB - Krauter CY - Rio de Janeiro 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 - CHAP A1 - Schütz, P. A1 - Breuer, M. A1 - Höfken, Hans-Wilhelm A1 - Schuba, Marko T1 - Malware proof on mobile phone exhibits based on GSM/GPRS traces T2 - The Second International Conference on Cyber Security, Cyber Peacefare and Digital Forensic (CyberSec 2013) : 04.03. - 06.03.2013, Kuala Lumpur, Malaysia Y1 - 2013 SN - 978-0-9853483-7-3 SP - 89 EP - 96 PB - The Society of Digital Information and Wireless Communication ER -