@inproceedings{KernKrichel2002, author = {Kern, Alexander and Krichel, Frank}, title = {Considerations about the lightning protection system of mains independent renewable energy hybrid-systems - practical experiences}, year = {2002}, abstract = {In the paper a lightning protection design concept for renewable energy hybrid-systems without power mains connection is described. Based on a risk analysis protection measures against direct strikes and overvoltages are shown in an overview. The design concept is realized exemplarily for the hybrid-system VATALI on the Greek island Crete. VATALI, not lightning protected at that time, was a victim of a lightning strike in the year 2000 causing destructions and damages of some mechanical and electrical components with costs of approx. 60.000 €. The hardware costs for the protection measures were about 15.000 €: about 50\% of the costs are due to protection measures against direct strikes, 50\% are due to overvoltage protection.}, language = {en} } @article{Lohr2001, author = {Lohr, J{\"u}rgen}, title = {Content-Management f{\"u}r die Verteilung von Multimedia-Diensten}, year = {2001}, abstract = {In: Unterrichtsbl{\"a}tter / Deutsche Telekom AG. 54. 2001. 7. S. 410-420 (11 S. ) Angesichts der zunehmenden Globalisierung von Informationen und Informationsdiensten k{\"o}nnen Inhalte (Contents) f{\"u}r mehrere unterschiedliche Dienste genutzt und auf verschiedenen Endger{\"a}ten ausgegeben werden. Hier setzt ein Content-Management-System (CMS) an, welches sowohl f{\"u}r die Kunden als auch f{\"u}r die Anbieter der unterschiedlich distribuierten Dienste Synergien und somit Einsparpotenziale bietet. Dar{\"u}ber hinaus werden f{\"u}r die Anbieter dieser Dienste durch die allgemeine Definition von Leistungstools und die Definition von Wertsch{\"o}pfungsketten k{\"u}nftige Produktentwicklungen vereinheitlicht und optimiert werden. Mit der Entwicklung und Vertriebsfreigabe immer weiterer Informationsdienste, die von verschiedenen Dienste-Providern betrieben werden, ist der Bedarf an einer Koordinierung der Entwicklungen und Investitionen im Bereich der Content-Akquisition und des Content-Management (CM) bedeutend angestiegen. Neben Akquisition, lizenzrechtlichen Fragen und Verwaltung des im Rahmen von Diensten angebotenen Content r{\"u}cken vor allem auch Fragen der Gestaltung von Content-Management-Plattformen (CMP) immer st{\"a}rker in den Blickpunkt. Der Beitrag stellt die globalen Ergebnisse dar, die in einem Forschungs- und Entwicklungsauftrag des Zentralbereichs Innovationsmanagement der Deutschen Telekom zu diesem Thema ermittelt wurden. Es werden die Kernmodule f{\"u}r eine Content- Management-Plattform beschrieben, die die Anforderungen an die Bereitstellung vielf{\"a}ltiger Content-Angebote erf{\"u}llt. Die folgenden Themen werden behandelt: + Begriffsbestimmung, + Content- und Dienste-Portfolio, + Standard Content-Prozess, + synergetische Content-Plattform (sCP), + Modelle der sCP, + Aspekte beim Betrieb und + Nutzen eines Content-Management.}, subject = {Content Management}, language = {de} } @misc{StaatBarry2006, author = {Staat, Manfred and Barry, Steve}, title = {Continuum Mechanics with an Introduction to the Finite Element Method / Steve Barry; Manfred Staat. With extensions by Manfred Staat.}, year = {2006}, abstract = {Contents: 1 Introduction 2 One Dimensional Continuum Mechanics 3 Tensors 4 Three Dimensional Stress and Strain 5 Conservation Laws 6 Contiunuum Modelling 7 Plain Problems 8 Questions 9 Reference Information}, subject = {Technische Mechanik}, language = {en} } @article{RichterBraunsteinStaeudleetal.2021, author = {Richter, Charlotte and Braunstein, Bjoern and Staeudle, Benjamin and Attias, Julia and Suess, Alexander and Weber, Tobias and Mileva, Katya N. and Rittweger, Joern and Green, David A. and Albracht, Kirsten}, title = {Contractile behavior of the gastrocnemius medialis muscle during running in simulated hypogravity}, series = {npj Microgravity}, volume = {7}, journal = {npj Microgravity}, number = {Article number: 32}, publisher = {Springer Nature}, address = {New York}, issn = {2373-8065}, doi = {10.1038/s41526-021-00155-7}, pages = {7 Seiten}, year = {2021}, abstract = {Vigorous exercise countermeasures in microgravity can largely attenuate muscular degeneration, albeit the extent of applied loading is key for the extent of muscle wasting. Running on the International Space Station is usually performed with maximum loads of 70\% body weight (0.7 g). However, it has not been investigated how the reduced musculoskeletal loading affects muscle and series elastic element dynamics, and thereby force and power generation. Therefore, this study examined the effects of running on the vertical treadmill facility, a ground-based analog, at simulated 0.7 g on gastrocnemius medialis contractile behavior. The results reveal that fascicle-series elastic element behavior differs between simulated hypogravity and 1 g running. Whilst shorter peak series elastic element lengths at simulated 0.7 g appear to be the result of lower muscular and gravitational forces acting on it, increased fascicle lengths and decreased velocities could not be anticipated, but may inform the development of optimized running training in hypogravity. However, whether the alterations in contractile behavior precipitate musculoskeletal degeneration warrants further study.}, language = {en} } @article{AlnemerKotliarNeuhausetal.2023, author = {Alnemer, Momin Sami Mohammad and Kotliar, Konstantin and Neuhaus, Valentin and Pape, Hans-Christoph and Ciritsis, Bernhard D.}, title = {Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model}, series = {Cost Effectiveness and Resource Allocation}, journal = {Cost Effectiveness and Resource Allocation}, number = {21, Article number: 77}, publisher = {Springer Nature}, issn = {1478-7547}, doi = {10.1186/s12962-023-00482-4}, pages = {12 Seiten}, year = {2023}, abstract = {Background Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices. Methods This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare \& Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10\% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results. Results With a 10\% fracture risk reduction, model A costs between \$8,850 and \$46,940 per quality-adjusted life-year (\$/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8\% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side's prophylaxis, the patient's age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between \$11,000/QALY and \$74,000/QALY, which is below the defined willingness to pay threshold. Conclusion Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.}, language = {en} } @techreport{Drescher2024, type = {Working Paper}, author = {Drescher, Hans Paul}, title = {Critical review of the 1. Stokes' problem and consequences for mixed turbulent/laminar flow}, pages = {27 Seiten}, year = {2024}, abstract = {The "1. Stokes' problem", the "suddenly accelerated flat wall", is the oldest application of the Navier-Stokes equations. Stokes' solution of the "problem" does not comply with the mathematical theorem of Cauchy and Kowalewskaya on the "Uniqueness and Existence" of solutions of partial differential equations and violates the physical theorem of minimum entropy production/dissipation of the Thermodynamics of Irreversible Processes. The result includes very high local shear stresses and dissipation rates. That is of special interest for the theory of turbulent and mixed turbulent/laminar flow. A textbook solution of the "1. Stokes Problem" is the Couette flow, which has a constant sheer stress along a linear profile. A consequence is that the Navier-Stokes equations do not describe any S-shaped part of a turbulent profile found in any turbulent Couette experiment. The paper surveys arguments referring to that statement, concerning the history of >150 years. Contrary to this there is always a Navier-Stokes solution near the wall, observed by a linear part of the Couette profile. There a turbulent description (e.g. by the logarithmic law-of-the-wall) fails completely. That is explained by the minimum dissipation requirement together with the Couette feature τ = const. The local co-existence of a turbulent zone and a laminar zone near the wall is stable and observed also at high Reynolds-Numbers.}, language = {en} } @article{Staat2001, author = {Staat, Manfred}, title = {Cyclic plastic deformation tests to verify FEM-based shakedown analyses}, year = {2001}, abstract = {Fatigue analyses are conducted with the aim of verifying that thermal ratcheting is limited. To this end it is important to make a clear distintion between the shakedown range and the ratcheting range (continuing deformation). As part of an EU-supported research project, experiments were carried out using a 4-bar model. The experiment comprised a water-cooled internal tube, and three insulated heatable outer test bars. The system was subjected to alternating axial forces, superimposed with alternating temperatures at the outer bars. The test parameters were partly selected on the basis of previous shakedown analyses. During the test, temperatures and strains were measured as a function of time. The loads and the resulting stresses were confirmed on an ongoing basis during performance of the test, and after it. Different material models were applied for this incremental elasto-plastic analysis using the ANSYS program. The results of the simulation are used to verify the FEM-based shakedown analysis.}, subject = {Materialerm{\"u}dung}, language = {en} } @masterthesis{Wojcieszak2022, type = {Bachelor Thesis}, author = {Wojcieszak, Marc David}, title = {Da Capo - The Town of Music}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {43 Seiten}, year = {2022}, abstract = {In dem Film geht es um die Musikstadt "Da Capo", in der jedes Genre sein eigenes Viertel hat. Unser Protagonist wurde im falschen Viertel geboren und muss sich nun heraus musizieren.}, language = {de} } @masterthesis{Heslenfeld2021, type = {Bachelor Thesis}, author = {Heslenfeld, Nina Malou}, title = {Das Auge h{\"o}rt mit: Ein animiertes Bilderbuch begleitend zum H{\"o}rbuch "Der Goldene Kompass"}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {99 Seiten}, year = {2021}, abstract = {Audio-Inhalte wie H{\"o}rb{\"u}cher erfreuen sich gerade seit vergangenem Jahr immer gr{\"o}ßerer Beliebtheit. Oft werden nebenbei jedoch andere T{\"a}tigkeiten verrichtet und dem H{\"o}rbuch wird weniger Aufmerksamkeit geschenkt, als es beim Lesen des entsprechenden Buches der Fall w{\"a}re. »Das Auge h{\"o}rt mit« beinhaltet ein Konzept, welches den Fokus wieder auf das H{\"o}rbuch und die Erz{\"a}hlung lenkt. Innerhalb der Arbeit wurde dazu ein audiovisuelles Erlebnis f{\"u}r Nutzende geschaffen, das einen spannenden Ausgleich zum Alltag bietet. Am Beispiel des H{\"o}rbuchs „Der Goldene Kompass" von Philip Pullman ist ein digitales Bilderbuch entstanden, wobei zu ausgew{\"a}hlten Szenen passende Illustrationen erstellt wurden. Diese wurden als eine Art Diashow unter das H{\"o}rbuch gelegt. Untermalt von Animationen und Kamerabewegungen wird so das Vorstellungsverm{\"o}gen angeregt, um g{\"a}nzlich in die Geschichte eintauchen zu k{\"o}nnen.}, language = {de} } @masterthesis{Bruegging2023, type = {Bachelor Thesis}, author = {Br{\"u}gging, Justus Wilhelm}, title = {Das Keramikmuseum KERAMION : Entwicklung eines neuen Erscheinungsbildes}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {121 Seiten}, year = {2023}, abstract = {Das KERAMION beherbergt ein breites Sortiment an historischen Keramikst{\"u}cken wie auch modernen k{\"u}nstlerischen Keramikarbeiten. Bei der neuen Konzeptionierung des Museums wurde eine Verbindung der historischen Sammlung und der modernen Kunst geschaffen, als Visualisierung daf{\"u}r steht die eigens f{\"u}r das Museum erstellte Schrift. In dieser Schrift wird eine historische, schwungvolle Kurrentschrift aus dem 16. Jahrhundert mit einer modernen kantigen Serifenschrift verbunden. Daraus entsteht eine Schrift, die die Breite der Keramik widerspiegelt und von Steingut bis Porzellan alle Facetten aufgreift. Gepaart wird die einzigartige Schrift mit einem auf das Zentrum ausgerichteten Layoutprinzip, bei dem 3D Scans der Exponate in den Fokus r{\"u}cken. Somit k{\"o}nnen die Besucher*innen auch von zu Hause einen Vorgeschmack auf die einzigartigen Materialien und Keramiktechniken bekommen.}, language = {de} }