@inproceedings{9755, author = {{Kraft , Verena and Bauch, C. and Nückel, M. and Hemsel, Tobias}}, booktitle = {{19. Gemeinschaftstagung LICHT 2010}}, title = {{{Konzeption und Aufbau eines Langzeitforschungsstandes zur lichttechnischen Charakterisierung von organischen Leuchtdioden (OLEDs)}}}, year = {{2010}}, } @article{9756, abstract = {{Dieser Beitrag fasst die bekannten analytischen Berechnungsmethoden für piezoelektrische Ultraschallverbundschwinger zusammen und gibt anhand typischer Beispiele Anleitungen zur Lösung theoretischer und technischer Fragen bei deren Entwicklung. Zunächst werden die passiven, in der Regel metallischen Komponenten von Verbundschwingern als Stab- oder Plattensysteme mit homogen verteilten Feder-, Masse und Dämpfungseigenschaften beschrieben. Hier breitet sich die Schwingungsenergie in Form stehender und fortschreitender Wellen zum akustischen Verbraucher hin aus. Es folgt eine gleichwertige und schaltungstreue Darstellung durch elektrische oder mechanische Vierpole, die für den Entwicklungsingenieur leichter zu handhaben sind und in Netzwerken direkt mit Masons Ersatzschaltung des piezoelektrischen Wandlers gekoppelt werden können. Danach werden die wichtigsten, messtechnisch zugänglichen Parameter anhand eines in Resonanznähe zulässigen Ersatzmodells mit konzentrierten elektrischen bzw. mechanischen Komponenten definiert. Als Schwerpunkt wird anschließend deren analytische Berechnung und messtechnische Verifizierung an typischen Beispielen demonstriert. Es folgen wichtige technische Informationen über Frequenzkorrekturen, Schallgeschwindigkeitsdispersion, Leistungs- und Belastbarkeitsgrenzen der Komponenten und andere wertvolle praktische Hinweise.}}, author = {{Lierke, Ernst-Günter and Littmann, Walter and Hemsel, Tobias}}, issn = {{1948-5719}}, journal = {{Veröffentlichung der Universität Paderborn}}, title = {{{Zur Theorie der piezoelektrischen Ultraschallverbundschwinger mit praktischen Schlussfolgerungen für den Entwicklungsingenieur}}}, year = {{2010}}, } @article{9757, author = {{Lucinskis, Raimundas and Mazeika, Dalius and Hemsel, Tobias and Bansevicius, Ramutis}}, issn = {{1948-5719}}, journal = {{MECHANIKA}}, title = {{{The experimental research of piezoelectric actuator with two vectors of polarization direction}}}, year = {{2010}}, } @article{9758, abstract = {{As a lead-free piezoelectric ceramics, (K,Na)NbO$_{3}$ is a promising material because of its good piezoelectric properties. In this study, (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics were synthesized from a KNbO$_{3}$ and NaNbO$_{3}$ mixture powder prepared by the hydrothermal reaction. The hydrothermal reaction enables the production of high quality powder for the ceramics fabrication process. To obtain (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics, these two powders KNbO$_{3}$ and NaNbO$_{3}$ were mixed and then sintered together. X-Ray diffraction analysis revealed that the solid solution ceramics (K$_{1-x}$Na$_{x}$)NbO$_{3}$ was produced by the sintering process. The K/Na ratio in (K$_{1-x}$Na$_{x}$)NbO$_{3}$ ceramics was optimized for the best piezoelectric properties. The optimized forms was (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$, which showed the following piezoelectric properties; k$_{33}$=0.56, d$_{33}$=114pC/N. In addition, the ferroelectric properties, P$_{r}$=7.72mC/cm$^{2}$, E$_{c}$=857V/mm, and the Curie temperature T$_{c}$=420$_{o}$C were also measured.}}, author = {{Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}}, issn = {{1948-5719}}, journal = {{Journal of Korean Physical Society}}, keywords = {{Lead-free piezoelectric material, KNN, Hydrothermal method}}, number = {{4}}, pages = {{924--928}}, title = {{{Hydrothermal (K1-xNax)NbO3 Lead-free Piezoelectric Ceramics}}}, doi = {{10.3938/jkps.57.924}}, volume = {{57}}, year = {{2010}}, } @article{9759, abstract = {{Among various lead-free piezoelectric materials, (K,Na)NbO$_{3}$ is a very promising candidate. In this study, (K,Na)NbO$_{3}$ ceramics were sintered from mixed (K,Na)NbO$_{3}$ and NaNbO$_{3}$ powders prepared by hydrothermal reaction. These two powders were mixed with distilled water in a KNbO$_{3}$/NaNbO$_{3}$ molar ratio of 1. After sintering the mixed powder, the solid solution of (Na,K)NbO$_{3}$ ceramics was obtained. The electrical properties such as the electromechanical coupling factors k$_{p}$ and k$_{33}$, the mechanical quality factor, Q$_{m}$, and the piezoelectric constant d$_{33}$ of the sintered (K,Na)NbO$_{3}$ ceramics were 0.32, 0.48, 71 (radial mode), 118 ((33)mode), and 107 pC/N, respectively.}}, author = {{Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Hemsel, Tobias}}, issn = {{1948-5719}}, journal = {{Materials Letters}}, keywords = {{Lead-free piezoelectric material, (K, Na)NbO$_{3}$ ceramics, Sintering solid solution, Piezoelectric properties}}, number = {{2}}, pages = {{125--128}}, title = {{{(K,Na)NbO3 lead-free piezoelectric ceramics synthesized from hydrothermal powders}}}, doi = {{10.1016/j.matlet.2009.10.012}}, volume = {{64}}, year = {{2010}}, } @inproceedings{9760, abstract = {{Self-optimizing systems are able to adapt their behavior autonomously according to their current self-determined objectives. Unforeseen influences could lead to dependability-critical behavior of the system. Methods are required which secure self-optimizing systems during operation. These methods to increase the dependability of the system should already be taken into consideration in the design process. This paper presents a guideline for the dependability-oriented design of self-optimizing systems, which integrates established classical methods like failure mode and effects analysis as well as methods based on self-optimization. On the one hand self-optimization is used to increase the dependability of the system by integrating objectives like safety, availability, and reliability to the objectives of the system. On the other hand methods are required to ensure the self-optimization itself. As basis for this guideline serves the principle solution of the system. The six phases of the guideline extend the design process and lead to an enhanced principle solution. Additionally, the guideline illustrates phases to implement and validate the self-optimizing system. The proposed guideline is applied to an innovative rail-bound vehicle, called RailCab, which is equipped with self-optimizing function modules.}}, author = {{Sondermann-Wölke, Christoph and Hemsel, Tobias and Sextro, Walter and Gausemeier, Jürgen and Pook, Sebastian}}, booktitle = {{Industrial Informatics (INDIN), 2010 8th IEEE International Conference on}}, keywords = {{RailCab, dependability-critical behavior, dependability-oriented design, failure mode, rail-bound vehicle, secure self-optimizing systems, self-optimizing function modules, optimisation, railways, self-adjusting systems}}, pages = {{739 --744}}, title = {{{Guideline for the dependability-oriented design of self-optimizing systems}}}, doi = {{10.1109/INDIN.2010.5549490}}, year = {{2010}}, } @article{9761, abstract = {{New mechatronic systems, called self-optimizing systems, are able to adapt their behavior according to environmental, user and system specific influences. Self-optimizing systems are complex and due to their non-deterministic behavior comprise hidden risks, which cannot be foreseen in the design phase of the system. Therefore, modifications of the ISO 17359 condition monitoring policy for being able to cope with this new kind of systems are presented. Besides avoiding critical situations evoked by self-optimization, the proposed concept uses self-optimization to increase the dependability of the system. This concept is applied to the active guidance module of an innovative rail-bound vehicle. First test drives provide information for the enhancement of the implementation of realtime switching to appropriate control strategies. The different control strategies are investigated in detail. It is illustrated that influences on the system like different track sections or the desired velocity of the RailCab effect the system and can lead to a higher amount of flange contacts, which indicate higher wear and thus a reduction of the availability of the system. Therefore, these influences should be minded within the condition monitoring policy. Consequently, this article presents the condition monitoring policy for self-optimizing function modules and its application to the active railway guidance module.}}, author = {{Sondermann-Wölke, Christoph and Sextro, Walter}}, journal = {{International Journal On Advances in Intelligent Systems}}, keywords = {{dependability, condition monitoring, selfoptimization, active railway guidance module}}, number = {{1 - 3}}, pages = {{65 -- 74}}, title = {{{Integration of Condition Monitoring in Self-optimizing Function Modules Applied to the Active Railway Guidance Module}}}, volume = {{3}}, year = {{2010}}, } @inproceedings{9762, abstract = {{Die erweiterten Möglichkeiten der Informationsverarbeitung mechatronischer Systeme erlauben es, mechatronische Systeme selbstoptimierend zu gestalten. Dabei bezieht sich die Selbstoptimierung auf die Fähigkeit des Systems, sich an die aktuelle Umfeldsituation anzupassen; wobei das System im Allgemeinen mehrere relevante Ziele verfolgt. Wurde eine Umfeldveränderung bemerkt, so müssen diese Ziele an die neue Situation angepasst und das resultierende Verhalten ausgewählt werden. In diesem Beitrag wird das selbstoptimierende Spurführungsmodul näher untersucht. Das Spurführungsmodul ist Bestandteil eines innovativen schienengebundenen Verkehrssystems, genannt RailCab, und dient zur Lenkung des einzelnen Fahrzeugs. Ziele des Spurführungsmoduls bestehen darin, die Verlässlichkeit des Spurführungsmoduls zu erhöhen sowie möglichst wenig Energie zu verbrauchen. Um kritische Systemzustände zu erkennen bzw. frühzeitig zu verhindern wird eine Vorgehensweise zur Einrichtung einer Zustandsüberwachung für selbstoptimierende Systeme beschrieben. Diese wird auf dem realen Versuchsträger im Maßstab 1:2,5 implementiert. Die Auswertung von Versuchsfahrten zeigt, dass gerade beim Auftreten eines Fehlers das Umschalten vom Ziel ''Energieverbrauch minimieren`` auf das Ziel ''Verlässlichkeit maximieren`` sinnvoll ist.}}, author = {{Sondermann-Wölke, Christoph and Sextro, Walter and Geisler, Jens and Trächtler, Ansgar}}, booktitle = {{Entwurf mechatronischer Systeme}}, editor = {{Gausemeier, Jürgen and Rammig, Frans Josef and Trächtler, Ansgar}}, keywords = {{Selbstoptimierung, Spurführungsmodul}}, pages = {{411 -- 420}}, title = {{{Experimentelle Untersuchung der Selbstoptimierung innerhalb des RailCab-Spurführungsmoduls}}}, volume = {{272}}, year = {{2010}}, } @inproceedings{9763, abstract = {{Recent advances in information processing enable new kinds of technical systems, called self-optimizing systems. These systems are able to adapt their objectives and their behavior according to the current situation and influences autonomously. This behavior adaptation is non-deterministic and hence self-optimization is a risk to the system, e.g. if the result of the self-optimization process does not match the suddenly changed situation. In contrary, self-optimization could be used to increase the dependability by pursuing objectives like reliability and availability. In our preceding publications we introduced the so called multi-level dependability concept to cope with this new kind of systems (cf. [6]). This concept comprises the monitoring of the system behavior, the classification of the current situation, and the selection of the appropriate measure, if reliability limits are exceeded. In this paper we present for the first time experimental results. The dependability concept is implemented in the self-optimizing active guidance system of a railway vehicle. The test drives illustrate clearly that the proposed concept is able to cope with, e.g., sensor failures, and is able to increase the reliability and availability of the active guidance module.}}, author = {{Sondermann-Wölke, Christoph and Geisler, Jens and Sextro, Walter}}, booktitle = {{Reliability and Maintainability Symposium (RAMS), 2010 Proceedings - Annual}}, issn = {{0149-144X}}, keywords = {{availability, dependability concept, multilevel dependability concept, railway vehicle, reliability, self optimizing active guidance system, self optimizing railway guidance system, situation classification, system behavior monitoring, optimal control, railways, reliability theory, self-adjusting systems}}, pages = {{1 --6}}, title = {{{Increasing the reliability of a self-optimizing railway guidance system}}}, doi = {{10.1109/RAMS.2010.5448080}}, year = {{2010}}, } @article{9764, author = {{Tomberger, Christoph and Dietmaier, Peter and Martin, Rosenberger and Sextro, Walter and Six, Klaus}}, issn = {{0043-1648}}, journal = {{ZEVrail}}, pages = {{127--135}}, title = {{{Einfluss von Oberflächenrauheit, fluiden Zwischenschichten und Kontakttemperaturen auf den Kraftschluss zwischen Rad und Schiene}}}, volume = {{134}}, year = {{2010}}, } @article{4210, abstract = {{In this paper we demonstrate a strain-driven GaN interlayer method to reduce dislocation densities in GaN grown on (111) oriented silicon by metal organic vapour phase epitaxy (MOVPE). In order to achieve crack-free GaN layers of reasonable thicknesses and dislocation densities it is crucial to integrate both dislocation reduction and strain management layers. In contrast to techniques like FACELO or nanoELO we show the in situ formation of GaN islands directly on the AlN nucleation layer without the need to deposit a SiO2 or SiNx mask. A graded AlGaN layer for strain management can be grown on top of this dislocation reducing 3D GaN inter-layer in order to achieve crack-free GaN layers grown on top of the AlGaN strain management layer. Furthermore, an additional SiNx layer for subsequent dislocation reduction can also be incorporated into the structure and is shown to efficiently reduce the dislocation density down to the low 10^9 cm^2. The structural properties of the 3D GaN island buffer layer and overgrown samples are studied by means of SEM, cross-sectional, and plan view TEM. Cathodoluminiscence in an SEM is employed to correlate the dislocation microstructure as observed by plan view TEM with luminescent properties.}}, author = {{Häberlen, Maik and Zhu, Dandan and McAleese, Clifford and Zhu, Tongtong and Kappers, Menno J. and Humphreys, Colin J.}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, number = {{7}}, pages = {{1753--1756}}, publisher = {{Wiley}}, title = {{{Dislocation reduction in GaN grown on Si(111) using a strain-driven 3D GaN interlayer}}}, doi = {{10.1002/pssb.200983537}}, volume = {{247}}, year = {{2010}}, } @article{13170, author = {{Gorenflo, Dieter and Baumhögger, Elmar and Windmann, Thorsten and Herres, Gerhard}}, issn = {{0140-7007}}, journal = {{International Journal of Refrigeration}}, pages = {{1251--1263}}, title = {{{Nucleate pool boiling, film boiling and single-phase free convection at pressures up to the critical state. Part II: Circumferential variation of the wall superheat for a horizontal 25mm copper cylinder}}}, doi = {{10.1016/j.ijrefrig.2010.08.004}}, year = {{2010}}, } @article{13171, author = {{Gorenflo, Dieter and Baumhögger, Elmar and Windmann, Thorsten and Herres, Gerhard}}, issn = {{0140-7007}}, journal = {{International Journal of Refrigeration}}, pages = {{1229--1250}}, title = {{{Nucleate pool boiling, film boiling and single-phase free convection at pressures up to the critical state. Part I: Integral heat transfer for horizontal copper cylinders}}}, doi = {{10.1016/j.ijrefrig.2010.07.015}}, year = {{2010}}, } @inproceedings{22050, abstract = {{Generative production techniques have the advantage of manufacturing parts via an additive process without needing a forming tool. One of these additive manufacturing technologies is “Fused Deposition Modeling” (FDM). From a 3D-CAD data set, components and assemblies are manufactured out of thermoplastic material in only a few working steps. Native software automatically slices the data, calculates the support structures, and creates toolpaths. The parts then are built up layer by layer by means of an additive process. An extrusion head deposits the molten thermoplastic filament to create each layer. This technology began as a process for creating prototype parts; recently it has found new utility in the production of manufacturing tools and as a manufacturing process for end-use parts. In order to be used as a part for serial production, the components must possess the required mechanical properties. To this end, not only is the chosen material relevant, but a correct process control is also necessary. An interesting material for the aircraft and automotive industry is the material PEI with the trade name Ultem*9085. This material should typically be used on FDM-machines for the manufacturing of end products. The aim of the research is to determine the present mechanical data based on the process control, as well as reproducibility from job to job. In this work the influence of the orientation and the structure of the manufactured parts based on the mechanical data are analyzed. Sample parts are generated with the given parameters of the native software based upon the CAD data. First, specimens were analyzed concerning their geometry and configuration. The dimensions and weight were measured. The mechanical tests conducted were the tensile and compression tests.}}, author = {{Bagsik, A. and Schöppner, Volker and Klemp, E.}}, booktitle = {{Proceedings of International Conference Polymeric Materials}}, isbn = {{978-3-868-29282-4}}, title = {{{FDM Part Quality Manufactured with ULTEM 9085}}}, doi = {{https://docplayer.net/255735-Fdm-part-quality-manufactured-with-ultem-9085.html}}, year = {{2010}}, } @inbook{34948, author = {{Süßmann, Johannes}}, booktitle = {{Freiheit und Unfreiheit. Mittelalterliche und frühneuzeitliche Facetten eines zeitlosen Problems}}, editor = {{Andermann, Kurt and Zeilinger, Gabriel}}, isbn = {{978-3-928471-87-9}}, pages = {{153–169}}, publisher = {{bibliotheca academica}}, title = {{{›Deutsche Freiheit‹ in der Frühen Neuzeit. Privileg oder Grundrecht?}}}, volume = {{7}}, year = {{2010}}, } @inproceedings{35273, author = {{Magyar, Balázs and Horák, P}}, booktitle = {{VDI-Berichte 2108}}, isbn = {{978-3-18-092108-2}}, pages = {{225--236}}, publisher = {{VDI Verlag GmbH}}, title = {{{Numerical and Experimental Analysis of TEHD Lubrication of ZK Type Worm Gear Drives}}}, year = {{2010}}, } @inproceedings{35274, author = {{Magyar, Balázs and Horák, P}}, isbn = {{978-963-313-007-0}}, pages = {{502--509}}, title = {{{Investigation of the Lubrication of ZI Type Worm Gear Drives}}}, year = {{2010}}, } @article{35280, author = {{Magyar, Balázs and Horák, P and Sauer, B and Fábián, Cs}}, issn = {{0016-8572}}, journal = {{GÉP}}, number = {{9-10}}, pages = {{51--54}}, title = {{{Experimentelle Untersuchung der Zahnreibungszahl von Schneckengetrieben mit der Flankenform K}}}, volume = {{LXI}}, year = {{2010}}, } @inbook{48675, author = {{Hartung, Olaf}}, booktitle = {{Sprache und Geschichte}}, editor = {{Handro, Saskia and Schönemann, Bernd}}, isbn = {{978-3-643-10662-9}}, pages = {{61--77}}, publisher = {{LIT Verlag}}, title = {{{Geschichte schreiben und lernen. Eine empirische Studie}}}, volume = {{21}}, year = {{2010}}, } @inbook{49974, author = {{Autsch, Sabiene}}, booktitle = {{Polke für Alle! Zugänge zu den künstlerischen Arbeiten und Strategien von Sigmar Polke und seiner Kunst [= Studentisches Projekt im Rahmen einer "Didaktik der Kunstgeschichte" an der Universität Paderborn]}}, editor = {{Autsch, Sabiene}}, pages = {{5--10}}, title = {{{Sigmar Polke, Do, 9-11 S. 2.110.}}}, year = {{2010}}, }