@article{Staat2000, author = {Staat, Manfred}, title = {Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material}, year = {2000}, abstract = {Limit and shakedown analysis are effective methods for assessing the load carrying capacity of a given structure. The elasto-plastic behavior of the structure subjected to loads varying in a given load domain is characterized by the shakedown load factor, defined as the maximum factor which satisfies the sufficient conditions stated in the corresponding static shakedown theorem. The finite element dicretization of the problem may lead to very large convex optimization. For the effective solution a basis reduction method has been developed that makes use of the special problem structure for perfectly plastic material. The paper proposes a modified basis reduction method for direct application to the two-surface plasticity model of bounded kinematic hardening material. The considered numerical examples show an enlargement of the load carrying capacity due to bounded hardening.}, subject = {Finite-Elemente-Methode}, language = {en} } @inproceedings{Staat2003, author = {Staat, Manfred}, title = {Design by Analysis of Pressure Components by non-linear Optimization}, year = {2003}, abstract = {This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.}, language = {en} } @article{Staat2001, author = {Staat, Manfred}, title = {LISA - a European project for FEM-based limit and shakedown analysis}, year = {2001}, abstract = {The load-carrying capacity or the safety against plastic limit states are the central questions in the design of structures and passive components in the apparatus engineering. A precise answer is most simply given by limit and shakedown analysis. These methods can be based on static and kinematic theorems for lower and upper bound analysis. Both may be formulated as optimization problems for finite element discretizations of structures. The problems of large-scale analysis and the extension towards realistic material modelling will be solved in a European research project. Limit and shakedown analyses are briefly demonstrated with illustrative examples.}, subject = {Einspielen }, language = {en} } @article{Staat2000, author = {Staat, Manfred}, title = {Direct FEM Limit and Shakedown Analysis with Uncertain Data}, year = {2000}, abstract = {The structural reliability with respect to plastic collapse or to inadaptation is formulated on the basis of the lower bound limit and shakedown theorems. A direct definition of the limit state function is achieved which permits the use of the highly effective first order reliability methods (FORM) is achieved. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. The limit state function and its gradient are obtained from a mathematical optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error, leading to highly effective and precise reliability analyses.}, subject = {Finite-Elemente-Methode}, language = {en} } @misc{Staat2006, author = {Staat, Manfred}, title = {Technische Mechanik. Vorlesungsmitschrift. Korrigierter Nachdr. der 3. Aufl.}, year = {2006}, abstract = {{\"U}berarbeitete, korrigierte und erg{\"a}nzte Version einer Vorlesungsmitschrift von Sebastian Kr{\"a}mer. 172 S. Inhaltsverzeichnis 0 Einf{\"u}hrung in die Mechanik 1 Statik starrer K{\"o}rper 2 Elastostatik (Festigkeitslehre) 3 Kinematik 4 Kinetik Literatur}, subject = {Technische Mechanik}, language = {de} } @misc{Staat2006, author = {Staat, Manfred}, title = {Engineering Mechanics. Lecture Notes. 2nd edition, translation of the 3rd corrected and extended German edition of "Technische Mechanik"}, year = {2006}, abstract = {English translation of the corrected lectures notes of Sebastian Kr{\"a}mer. Contents 0 Introduction to Mechanics 1 Statics of Rigid Bodies 2 Elastostatics (Strength of Materials) 3 Kinematics 4 Kinetics Literature}, subject = {Technische Mechanik}, language = {en} } @inproceedings{Staat2006, author = {Staat, Manfred}, title = {Problems and chances for probabilistic fracture mechanics in the analysis of steel pressure boundary reliability. - {\"U}berarb. Ausg.}, year = {2006}, abstract = {In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in J{\"u}lich, 21-24 November 1994. - Vienna , 1996. - Seite: 43 - 55 IAEA-TECDOC-920 Abstract: It is shown that the difficulty for probabilistic fracture mechanics (PFM) is the general problem of the high reliability of a small population. There is no way around the problem as yet. Therefore what PFM can contribute to the reliability of steel pressure boundaries is demon­strated with the example of a typical reactor pressure vessel and critically discussed. Although no method is distinguishable that could give exact failure probabilities, PFM has several addi­tional chances. Upper limits for failure probability may be obtained together with trends for design and operating conditions. Further, PFM can identify the most sensitive parameters, improved control of which would increase reliability. Thus PFM should play a vital role in the analysis of steel pressure boundaries despite all shortcomings.}, subject = {Bruchmechanik}, language = {en} } @article{Staat2021, author = {Staat, Manfred}, title = {An extension strain type Mohr-Coulomb criterion}, series = {Rock mechanics and rock engineering}, volume = {54}, journal = {Rock mechanics and rock engineering}, number = {12}, publisher = {Springer Nature}, address = {Cham}, issn = {1434-453X}, doi = {10.1007/s00603-021-02608-7}, pages = {6207 -- 6233}, year = {2021}, abstract = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.}, language = {en} } @inproceedings{SrivastavaSinghDhandetal.2006, author = {Srivastava, Alok and Singh, Virendra and Dhand, Chetna and Kaur, Manindar and Singh, Tejvir and Witte, Katrin and Scherer, Ulrich W.}, title = {Study of swift heavy ion modified conduction polymer composites for application as gas sensor}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1345}, year = {2006}, abstract = {A polyaniline-based conducting composite was prepared by oxidative polymerisation of aniline in a polyvinylchloride (PVC) matrix. The coherent free standing thin films of the composite were prepared by a solution casting method. The polyvinyl chloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluence ranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammonia gas than the unirradiated composite. The response time of the irradiated composites was observed to be comparably shorter. We report for the first time the application of swift heavy ion modified insulating polymer conducting polymer (IPCP) composites for sensing of ammonia gas.}, subject = {Biosensor}, language = {en} } @masterthesis{Spomer2021, type = {Bachelor Thesis}, author = {Spomer, Ruth}, title = {Zoologisches Forschungsmuseum Alexander K{\"o}nig : Entwicklung eines neuen Erscheinungsbildes}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {139 Seiten}, year = {2021}, abstract = {Artenvielfalt erforschen und erkl{\"a}ren - So lautet der Leitsatz des Bonner Forschungsmuseums. Durch inszenierte Lebensr{\"a}ume sowie beeindruckende sammlungsbasierte Ausstellungen werden komplexe biologische Ph{\"a}nomene erkl{\"a}rt und die Biodiversit{\"a}tsforschung f{\"u}r ein breites Publikum zug{\"a}nglich gemacht. Dabei wird das {\"u}bergeordnete Ziel verfolgt, das Interesse der Allgemeinheit an zoologischer Wissenschaft zu wecken. Das neue Erscheinungsbild schafft Wiedererkennbarkeit und positioniert das Museum als wissenschaftliche Institution. Dabei stellt die Verkn{\"u}pfung des Forschungsaspektes und der Artenvielfalt die Basis der Gestaltung dar und kommuniziert die wesentlichen Inhalte. Zudem sorgt ein medien{\"u}bergreifendes Ordnungssystem f{\"u}r eine bessere {\"U}bersicht und erleichtert den Zugang zu komplexen Inhalten. So erh{\"a}lt das Museum eine spannendere, attraktivere Wirkung nach Außen und eine bessere Orientierung im Inneren.}, language = {de} } @inproceedings{SpannhakeSchulzHelwigetal.2006, author = {Spannhake, Jan and Schulz, Olaf and Helwig, Andreas and Krenkow, Angelika and M{\"u}ller, Gerhard and Doll, Theodor}, title = {High-temperature MEMS heater platforms: long-term performance of metal and semiconductor heater materials}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1513}, year = {2006}, abstract = {Micromachined thermal heater platforms offer low electrical power consumption and high modulation speed, i.e. properties which are advantageous for realizing nondispersive infrared (NDIR) gas- and liquid monitoring systems. In this paper, we report on investigations on silicon-on-insulator (SOI) based infrared (IR) emitter devices heated by employing different kinds of metallic and semiconductor heater materials. Our results clearly reveal the superior high-temperature performance of semiconductor over metallic heater materials. Long-term stable emitter operation in the vicinity of 1300 K could be attained using heavily antimony-doped tin dioxide (SnO2:Sb) heater elements.}, subject = {Biosensor}, language = {en} } @article{SildatkeKarwanniKraftetal.2023, author = {Sildatke, Michael and Karwanni, Hendrik and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {A distributed microservice architecture pattern for the automated generation of information extraction pipelines}, series = {SN Computer Science}, journal = {SN Computer Science}, number = {4, Article number: 833}, publisher = {Springer Singapore}, address = {Singapore}, issn = {2661-8907}, doi = {10.1007/s42979-023-02256-4}, pages = {19 Seiten}, year = {2023}, abstract = {Companies often build their businesses based on product information and therefore try to automate the process of information extraction (IE). Since the information source is usually heterogeneous and non-standardized, classic extract, transform, load techniques reach their limits. Hence, companies must implement the newest findings from research to tackle the challenges of process automation. They require a flexible and robust system that is extendable and ensures the optimal processing of the different document types. This paper provides a distributed microservice architecture pattern that enables the automated generation of IE pipelines. Since their optimal design is individual for each input document, the system ensures the ad-hoc generation of pipelines depending on specific document characteristics at runtime. Furthermore, it introduces the automated quality determination of each available pipeline and controls the integration of new microservices based on their impact on the business value. The introduced system enables fast prototyping of the newest approaches from research and supports companies in automating their IE processes. Based on the automated quality determination, it ensures that the generated pipelines always meet defined business requirements when they come into productive use.}, language = {en} } @techreport{SiegertBongaertsWagneretal.2022, author = {Siegert, Petra and Bongaerts, Johannes and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Selmer, Thorsten}, title = {Abschlussbericht zum Projekt zur {\"U}berwachung biotechnologischer Prozesse mittels Diacetyl-/Acetoin-Biosensor und Evaluierung von Acetoin-Reduktasen zur Verwendung in Biotransformationen}, address = {Aachen}, organization = {FH Aachen}, pages = {16 Seiten}, year = {2022}, language = {de} } @book{Siebel1996, author = {Siebel, Lothar}, title = {Bauteile sicher beurteilen: W{\"a}rme, Feuchte, Schall. Erkennen der Einfl{\"u}sse, einfaches Absch{\"a}tzen und Bewerten in Planung und Ausf{\"u}hrung. 1. {\"u}berarb. Nachdruck}, isbn = {3-930860-30-9}, publisher = {Fachhochschule Aachen}, year = {1996}, abstract = {Siebel, Lothar: Bauteile sicher beurteilen: W{\"a}rme, Feuchte, Schall. Erkennen der Einfl{\"u}sse, einfaches Absch{\"a}tzen und Bewerten in Planung und Ausf{\"u}hrung. 1. {\"u}berarb. Nachdruck / Lothar Siebel. Aachen: LBB 1996. 95 S. : Ill., graph. Darst. (Landesinstitut f{\"u}r Bauwesen und Angewandte Bauschadensforschung NRW : 2 ; 19) ISBN 3-930860-30-9}, subject = {Bauschaden}, language = {de} } @masterthesis{Shafaghi2023, type = {Bachelor Thesis}, author = {Shafaghi, Shiva}, title = {Zan, Zendegi, Azadi}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {66 Seiten}, year = {2023}, abstract = {Das Projekt „Zan, Zendegi, Azadi" (Frau, Leben, Freiheit) setzt sich mit der aktuellen Situation im Iran auseinander. Bereits nach der Macht{\"u}bernahme der islamischen Republik im Jahr 1979 wird die iranische Bev{\"o}lkerung durch das brutale Regime unterdr{\"u}ckt und zum Schweigen gezwungen. Dieser Druck hat sich lange aufgestaut und nun gibt es seit Jahren in gr{\"o}ßeren Abst{\"a}nden Proteste gegen die Regierung. Der gewaltsame Tod der kurdischen Iranerin Mahsā J{\^i}na Amīnī in Polizeigewahrsam am 16.09.2022 hat eine beispiellose Welle des Protests in allen Landesteilen Irans ausgel{\"o}st. Ihr Protest wird von Frauen angef{\"u}hrt und hat sich in eine beeindruckende Welle des Widerstands und der Rebellion entwickelt. Die unterschiedlichen Medien in diesem Projekt wie Dokumentarfotografie, Illustration, Projektion und Texte geben Betrachter:innen einen Eindruck der unmittelbaren Wirkung der revolution{\"a}ren Ereignisse und der Reaktion des totalit{\"a}ren Regimes auf die Betroffenen.}, language = {de} } @book{SeptZillingerWiechertetal.2023, author = {Sept, Marcel and Zillinger, Christina and Wiechert, Johanna and Thelen, Marius}, title = {Aachener Online-Schriften Wirtschaft und Recht. Band 6. 01/2023}, editor = {Kroll-Ludwigs, Kathrin and Bassen-Metz, Yasmine and Bernecker, Andreas and Eggert, Mathias and Fritz, Thomas and Golland, Alexander and H{\"o}hne, Tim and Tran, Duc Hung and Vogt, J{\"u}rgen}, publisher = {FH Aachen / Fachbereich Wirtschaftswissenschaften}, address = {Aachen}, publisher = {Fachhochschule Aachen}, pages = {265 Seiten}, year = {2023}, abstract = {Inhaltsverzeichnis - Bachelorarbeiten 1. Zukunft der Rente - Kann eine Erwerbst{\"a}tigenversicherung das demografische Problem nachhaltig l{\"o}sen? - Marcel Sept | Seite 4-73 2. Die versammlungsgebundenen Aktion{\"a}rsrechte in der neuen virtuellen Hauptversammlung - eine Bewertung aus Unternehmer- und Aktion{\"a}rssicht - Christina Zillinger | Seite 74-130 3. Praxisleitfaden f{\"u}r den Arbeitgeber zum gesetzlichen Sonderk{\"u}ndigungsschutz - Was muss der Arbeitgeber tun, um durch Gesetz besonders gesch{\"u}tzten Arbeitnehmern k{\"u}ndigen zu k{\"o}nnen? - Johanna Wiechert | Seite 131-195 4. Die Steuerverg{\"u}nstigung bei Umstrukturierungen im Konzern nach \S 6a GrEStG im Lichte der aktuellen Rechtsprechung - Marius Thelen | Seite 196-265}, language = {de} } @article{SeifarthSchehlLinderetal.2011, author = {Seifarth, Volker and Schehl, D. and Linder, Peter and Gossmann, Matthias and Digel, Ilya and Artmann, Gerhard and Porst, Dariusz and Preiß, C. and Kayser, Peter and Pack, O. and Temiz Artmann, Ayseg{\"u}l}, title = {Ureplace: development of a bioreactor for in vitro culturing of cell seeded tubular vessels on collagen scaffolds}, year = {2011}, abstract = {The demand of replacements for inoperable organs exceeds the amount of available organ transplants. Therefore, tissue engineering developed as a multidisciplinary field of research for autologous in-vitro organs. Such three dimensional tissue constructs request the application of a bioreactor. The UREPLACE bioreactor is used to grow cells on tubular collagen scaffolds OPTIMAIX Sponge 1 with a maximal length of 7 cm, in order to culture in vitro an adequate ureter replacement. With a rotating unit, (urothelial) cells can be placed homogeneously on the inner scaffold surface. Furthermore, a stimulation is combined with this bioreactor resulting in an orientation of muscle cells. These culturing methods request a precise control of several parameters and actuators. A combination of a LabBox and the suitable software LabVision is used to set and conduct parameters like rotation angles, velocities, pressures and other important cell culture values. The bioreactor was tested waterproof successfully. Furthermore, the temperature controlling was adjusted to 37 °C and the CO2 - concentration regulated to 5 \%. Additionally, the pH step responses of several substances showed a perfect functioning of the designed flow chamber. All used software was tested and remained stable for several days.}, subject = {Tissue Engineering}, language = {en} } @masterthesis{Sehl2022, type = {Bachelor Thesis}, author = {Sehl, Kristina}, title = {Adapt or die : Heimische W{\"a}lder im Wandel durch Mensch und Zeit}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {316 Seiten}, year = {2022}, abstract = {Wo einst fast l{\"u}ckenlos Laubw{\"a}lder wuchsen, steht heute nur noch ein Drittel der urspr{\"u}nglichen Waldfl{\"a}che. Echte Urw{\"a}lder gibt es hier schon lange nicht mehr: Die Rede ist vom deutschen Wald. Unsere Welt ist im Wandel. Auch in unseren heimischen W{\"a}ldern lassen sich die Einfl{\"u}sse von Mensch und Klimawandel auf die Biodiversit{\"a}t beobachten. Die illustrierte Publikation „Adapt or die" l{\"a}dt mit mehr als 80 großformatigen Artenportraits, Habitat-Kartierungen und gestalteten Themenklappenseiten zur Auseinandersetzung mit dem Wandel unserer heimischen W{\"a}lder ein. Dabei sensibilisiert sie f{\"u}r einen bewussteren Umgang mit Umwelt und Natur. Erweiterungen durch Augmented Reality bieten vereinzelt neben dem Printprodukt aktualisierbare Prognosen, digital und ressourcenschonend. Das komplexe {\"O}kosystem des Waldes reagiert empfindlich auf Ver{\"a}nderungen: Wer sich nicht anpassen kann, wird verschwinden.}, language = {de} } @inproceedings{SedlacekGesslerSchleseretal.2003, author = {Sedlacek, G. and Geßler, A. and Schleser, Markus and Mund, F. and V{\"o}lling, B.}, title = {Verbindungen vorgefertigter Textilbetonbauteile}, series = {Textile reinforced structures : proceedings of the 2nd Colloquium on Textile Reinforced Structures (CTRS2), Dresden, Germany, 29.9. - 1.10.2003}, booktitle = {Textile reinforced structures : proceedings of the 2nd Colloquium on Textile Reinforced Structures (CTRS2), Dresden, Germany, 29.9. - 1.10.2003}, publisher = {Techn. Univ.}, address = {Dresden}, organization = {Colloquium on Textile Reinforced Structures <2, 2003, Dresden>}, isbn = {3-86005-386-8}, pages = {481 -- 493}, year = {2003}, language = {en} } @article{SchuellerRuhlDinstuehlerSengeretal.2022, author = {Sch{\"u}ller-Ruhl, Aaron and Dinst{\"u}hler, Leonard and Senger, Thorsten and Bergfeld, Stefan and Ingenhag, Christian and Fleischhaker, Robert}, title = {Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications}, series = {Applied Physics B}, volume = {128}, journal = {Applied Physics B}, number = {Article number: 208}, editor = {Mackenzie, Jacob}, publisher = {Springer}, address = {Berlin}, issn = {1432-0649 (Online)}, doi = {10.1007/s00340-022-07928-2}, pages = {1 -- 11}, year = {2022}, abstract = {We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg-Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10-3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements.}, language = {en} }