Vest, A. . (2022). Planetarium Talks: Extra dimensions and microscopic black holes.
Abstract
Although Einstein’s general theory of relativity precisely describes the properties of gravity, it is not clear why gravity is so much weaker than the other fundamental forces of nature. The weakness of gravity could be explained, however, by speculative theories that predict spatial dimensions in addition to the three dimensions we experience in our everyday live. One spectacular way of revealing these extra dimensions would be through the formation of microscopic black holes, which, if there are extra dimensions, might be produced at the Large Hadron Collider. Microscopic black holes would be harmless, but their discovery would revolutionize our physical world picture.
Witte, F. ., Hofmann, M. ., Meier, J. ., Tuschy, I. ., & Tsatsaronis, G. . (2022). Generic and Open-Source Exergy Analysis - Extending the Simulation Framework TESPy. Energies, 15. http://doi.org/10.3390/en15114087
Abstract
Exergy-based methods support the identification of thermodynamic inefficiencies and the discovery of optimization potentials in thermal engineering applications. Although a large variety of simulation software is available in this field, most do not offer an integrated solution for exergy analysis. While there are commercial products on the market with such capabilities, their access for research and educational purposes is limited. The presented open-source software offers an integrated and fully automated exergy analysis tool for thermal conversion processes. In a first step, physical exergy is implemented, and the tool is then applied to three different example plants to highlight its capabilities and validate the implementation: A solar thermal power plant, a supercritical CO2 power cycle, and an air refrigeration cycle. The respective models and the results of the analyses are presented briefly. By providing the results in modern data structures, they are easily accessible and postprocessible. Future work will include chemical exergy to enable analyses of applications with conversion of matter. Additionally, the implementation of the exergoeconomic analysis and optimization is envisaged.
Neumann, T. ., Widrat, A. ., & Fichter, K. . (2022). Finanzierungs- & Förderangebote für Ecopreneure. Gründerplattform. Abgerufen von https://cdn.kettufy.io/gp.kettufy.io/documents/gruenderplattform.de/Material-3_Broschuere-FinanzierungFoerderungangebote.pdf
Irshad, M. ., Börstler, J. ., & Petersen, K. . (2022). Supporting refactoring of BDD specifications—An empirical study. Information and Software Technology, 141, 106717.
Lübben, R. ., & Misfeld, N. . (2022). Exploring the Measurement Lab Open Dataset for Internet Performance Evaluation: The German Internet Landscape. Electronics, 11. http://doi.org/10.3390/electronics11010162
Abstract
The Measurement Lab (MLab) provides a large and open collection of Internet performance measurements. We make use of it to look at the state of the German Internet by a structured analysis, in which we carve out expressive results from the dataset to identify busy hours and days, the impact of server locations and congestion control protocols, and compare Internet service providers. Moreover, we examine the impact of the COVID-19 lockdown in Germany. We observe that only parts of the Internet show a performance degradation at the beginning of the lockdown and that a large impact in performance depends on the network the servers are located in. Furthermore, the evolution of congestion control algorithms is reflected by performance improvements. For our analysis, we focus on the busy hours. From the end-user perspective, this time is of most interest to identify if the network can support challenging services such as video streaming or cloud gaming at these intervals.
Chateaureynaud, M.-A. ., & John, P. . (Hrsg.). (2022). LSP Teacher Training Summer School . The TRAILs project. Champs Didactiques Plurilingues : données pour des politiques stratégiques (Bd. 13, S. 280). Brüssel (Belgien): Peter Lang. http://doi.org/10.3726/b20096
Abstract
This book is the result of research carried out in partnership with seven European universities as part of an Erasmus+ project on training teachers of Language for Specifi c Purpose (LSP) in higher education. All university partners, i.e. Bordeaux (France), Zagreb (Croatia), Jade (Germany), Cádiz (Spain), Adam Mickiewicz (Poland), Ljubljana (Slovenia), Arcola Research (UK), and Bergamo (Italy) carried out surveys and developed a detailed report showing that in Europe there is very little training for this type of teaching, and that teachers generally need to be trained in the specifi cities of the language fi eld they are going to teach. Medical or maritime English, legal Spanish, French for tourism, etc. require both an expert domain
knowledge and a grounding in language teaching. Several testimonies highlight this situation and show the lack of career development prospects for LSP teachers at European universities.
The members of the Erasmus+ TRAILs project have therefore been interested in the specifi c needs of LSP teachers and have been able to update the information through several types of surveys. The competences
of LSP teachers were thus identifi ed. Based on this precise inventory, they are proposing to draw up a complete training programme.
A pedagogical approach has been developed: resources, lesson preparation, course design, innovative pedagogical approaches are presented. The research presented in this book goes well beyond the TRAILs project and questions the training of specialised language teachers. More generally, it highlights the need to provide effective training and professional development for LSP teachers and offers a contribution to overcoming the shortcomings of LSP teacher education.
Chen, C. ., Witte, F. ., Tuschy, I. ., Kolditz, O. ., & Shao, H. . (2022). Parametric optimization and comparative study of an organic Rankine cycle power plant for two-phase geothermal sources. Energy, 123910. http://doi.org/https://doi.org/10.1016/j.energy.2022.123910
Abstract
For two-phase geothermal sources, Organic Rankine Cycle (ORC) based binary plant is often applied for power production. In this work, a network topology is designed with the open-source Thermal Engineering Systems in Python (TESPy) software to simulate the stationary operation of the ORC plant. With this topology, the performance of six different working fluids are compared. From the thermodynamic perspective, the gross and net power output are optimized respectively. Results show that R600 has the highest gross power output of 17.55 MW, while R245fa has the highest net power output of 12.93 MW. However, the turbine inlet temperatures for these two working fluids need to be designed at the upper theoretical limit. R245ca and R601a require the heat exchange rates of internal heat exchanger to be larger than 1.51 MW and 0.99 MW to satisfy the re-injection temperature limit, which are smaller than the R600 (6.7 MW) and R245fa (6.0 MW) cases. Besides, the working fluid with lower critical state is preferred for a geothermal source with smaller steam fraction to establish a stable ORC plant. The workflow for the ORC design and optimization in this work is generic, and can be further applied to thermo-economic investigation.
Branlard, E. ., & Geisler, J. . (2022). A symbolic framework to obtain mid-fidelity models of flexible multibody systems with application to horizontal-axis wind turbines. Wind Energy Science, 7, 2351–2371. http://doi.org/10.5194/wes-7-2351-2022
Abstract
The article presents a symbolic framework (also called computer algebra program) that is used to obtain, in symbolic mathematical form, the linear and nonlinear equations of motion of a mid-fidelity multibody system including rigid and flexible bodies. Our approach is based on Kane's method and a nonlinear shape function representation for flexible bodies. The shape function approach does not represent the state of the art for flexible multibody dynamics but is an effective trade-off to obtain mid-fidelity models with few degrees of freedom, taking advantage of the separation of space and time. The method yields compact symbolic equations of motion with implicit account of the constraints. The general and automatic framework facilitates the creation and manipulation of models with various levels of complexity by adding or removing degrees of freedom. The symbolic treatment allows for analytical gradients and linearized equations of motion. The linear and nonlinear equations can be exported to Python code or dedicated software. There are multiple applications, such as time domain simulation, stability analyses, frequency domain analyses, advanced controller design, state observers, and digital twins. In this article, we describe the method we used to systematically generate the equations of motion of multibody systems and present the implementation of the framework using the Python package SymPy. We apply the framework to generate illustrative land-based and offshore wind turbine models. We compare our results with OpenFAST simulations and discuss the advantages and limitations of the method. The Python implementation is provided as an open-source project.