@misc{Mueller, author = {M{\"u}ller, David}, title = {Optimal exercise and profit sharing of joint real investments in the energy industry}, series = {Problems and Perspectives in Management}, volume = {Vol. 11}, journal = {Problems and Perspectives in Management}, number = {3}, issn = {1727-7051}, pages = {24 -- 36}, language = {en} } @misc{MuellerStaedterRachowetal., author = {M{\"u}ller, Klaus and St{\"a}dter, Matthias and Rachow, Fabian and Hoffmannbeck, David and Schmeißer, Dieter}, title = {Sabatier-based CO2-methanation by catalytic conversion}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2609-3}, pages = {3771 -- 3778}, abstract = {The catalytic conversion of CO2is an important component for the reintegration of secondary products like CO2 or H2 into the energy supply. An example is the "power to gas'" concept with a conversion of CO2 into CH4. The CO2 is transferred into a carrier of chemical energy, with the possibility to feed the produced CH4 into the existing network of natural gas. At temperatures of around 350 °C, hydrogenation of CO2 to CH4 is possible by the Sabatier reaction CO2+4H2->CH4+H2O. One prerequisite for efficient kinetics of the Sabatier reaction is the application and optimization of catalysts. The focus of catalyst development is given to their performance under the conditions to be expected in the special application. As a part of the project Geoenergy-Research (GeoEn), we address questions related to the catalytic utilization of CO2 produced in the course of the oxyfuel combustion of lignite. In this contribution, we report on the experimental setup in laboratory scale, which enables an advanced characterization of the catalytic performance, including thermodesorption measurements at atmospheric pressure in order to determine the amount of adsorbed CO2 under real conditions. We also show data for activation energies, the catalytic performance as function of temperature and the long time stability of a commercial Ru-based catalyst.}, language = {en} } @inproceedings{MuellerHoffmannbeckKirneretal., author = {M{\"u}ller, Klaus and Hoffmannbeck, David and Kirner, Georg and St{\"a}dter, Matthias and Schmeißer, Dieter}, title = {CO2-Methanation by Catalytic Conversion}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {The utilization of CO2 as raw material is an important component of a program for CO2 reduction. A possibility is the production of methane. At a moderate temperature of around 350°C, hydrogenation of CO2 to methane is possible by the Sabatier reaction CO2 + 4H2 ->CH4 +2H2O. Prerequisite for an efficient kinetics of the Sabatier reaction is the application and optimization of catalysts. In this contribution, we present investigations of Ru and Ni catalysts on different substrates. For Ru/Al2O3 catalysts, we found stable operation without degradation within 500 hours with a conversion rate of 80\% at 350°C. For NiO/SiO2 catalysts, a conversion rate of 90\% was found for temperatures of 350-405°C. We also show the investigation of cross sensitivities against SOx and NOx, which are typical contaminations of CO2, generated by the industrial oxyfuel process. In our work the morphology (REM, AFM, specific surface), chemical composition (FTIR, XPS) and phase composition (XRD) of the catalysts are characterized. In addition, we report on thermodesorption (TDS) measurements at atmospheric pressure to determine the amount of adsorbed CO2 under real conditions. The project is funded by the German Ministry of Research and Education (BMBF-GeoEn).}, language = {en} } @misc{Mueller, author = {M{\"u}ller, David}, title = {Grid extension in German backyards: a game-theory rationale}, series = {Journal of Environmental Planning and Management}, volume = {60}, journal = {Journal of Environmental Planning and Management}, number = {3}, issn = {1360-0559}, doi = {10.1080/09640568.2016.1159952}, pages = {437 -- 461}, language = {en} } @misc{Mueller, author = {M{\"u}ller, David}, title = {… and justice for all - cost fairness in Volkswagen's product family}, series = {Journal of Applied Accounting Research}, volume = {18}, journal = {Journal of Applied Accounting Research}, number = {2}, issn = {0967-5426}, doi = {10.1108/JAAR-09-2015-0078}, pages = {261 -- 271}, language = {en} } @misc{Mueller, author = {M{\"u}ller, David}, title = {Fair allocation of cost reductions for a scale-based product family in a hierarchically structured firm}, series = {International Journal of Product Development}, volume = {22}, journal = {International Journal of Product Development}, number = {1}, issn = {1741-8178}, doi = {10.1504/IJPD.2017.10006084}, pages = {1 -- 20}, language = {en} } @incollection{Mueller, author = {M{\"u}ller, David}, title = {The Usability and Suitability of Allocation Schemes for Corporate Cost Accounting}, series = {Game Theory in Management Accounting}, booktitle = {Game Theory in Management Accounting}, editor = {M{\"u}ller, David and Trost, Ralf}, publisher = {Springer}, address = {Cham [u.a.]}, isbn = {978-3-319-61602-5}, doi = {10.1007/978-3-319-61603-2_19}, pages = {401 -- 427}, language = {en} } @misc{DornischSchradeXuetal., author = {Dornisch, Wolfgang and Schrade, David and Xu, Bai-Xiang and Keip, Marc-Andr{\´e} and M{\"u}ller, Ralf}, title = {Coupled phase field simulations of ferroelectric and ferromagnetic layers in multiferroic heterostructures}, series = {Archive of Applied Mechanics}, volume = {89}, journal = {Archive of Applied Mechanics}, number = {6}, issn = {0939-1533}, doi = {10.1007/s00419-018-1480-9}, pages = {1031 -- 1056}, abstract = {The combination of materials with either pronounced ferroelectric or ferromagnetic effect characterizes multiferroic heterostructures, whereby the different materials can be arranged in layers, columns or inclusions. The magnetization can be controlled by the application of electrical fields through a purely mechanical coupling at the interfaces between the different materials. Thus, a magneto-electric coupling effect is obtained. Within a continuum mechanics formulation, a phase field is used to describe the polarization and the magnetization in the ferroelectric and ferromagnetic layers, respectively. The coupling between polarization/magnetization and strains within the layers, in combination with the mechanical coupling at the sharp layer interfaces, yields the magneto-electric coupling within the heterostructure. The continuum formulations for both layers are discretized in order to make the differential equations amenable to a numerical solution with the finite element method. A state-of-the-art approach is used for the ferroelectric layer. The material behavior of the ferromagnetic layer is described by a continuum formulation from the literature, which is discretized using a newly proposed approach for the consistent interpolation of the magnetization vector. Four numerical examples are presented which show the applicability of the newly proposed approach for the ferromagnetic layer as well as the possibility to simulate magneto-electric coupling in multiferroic heterostructures.}, language = {en} } @misc{DornischSchradeXuetal., author = {Dornisch, Wolfgang and Schrade, David and Xu, Bai-Xiang and M{\"u}ller, Ralf}, title = {Coupling of phase field models for ferroelectric and ferromagnetic layers in multiferroic heterostructures}, series = {VII International Conference on Coupled Problems in Science and Engineering (Coupled Problems 2017)}, journal = {VII International Conference on Coupled Problems in Science and Engineering (Coupled Problems 2017)}, publisher = {CIMNE}, address = {Barcelona}, pages = {1}, abstract = {Heterostructures of ferroelectric and ferromagnetic layers are commonly used to obtain electromagnetic effects. The elastic coupling between the layers is widely acknowledged as the main mechanism responsible for the electro-magneto interaction. Within this contribution we study the coupling of ferroelectric and ferromagnetic layers with well-defined interfaces. The intention is to simulate the switching of the magnetization with the help of electric fields, which has been studied experimentally in [1]. Each layer is simulated by using mechanically coupled phase field modeling, whereby the approaches presented in [2] and [3] will be used. The strains in each layer depend on the direction of the polarization/magnetization. A mismatch of these strains will be compensated by local deformations at the interface as the coupling results from the coherent deformation at the interface. This leads to the possibility to alter the magnetization direction by changing the electric polarization and vice verse. Numerical simulations will illustrate the evolution of the ferroic microstructures with a focus on the strain coupling and the resulting interactions between layers.}, language = {en} } @misc{DornischSchradeWolfetal., author = {Dornisch, Wolfgang and Schrade, David and Wolf, Jana and M{\"u}ller, Ralf}, title = {Numerical methods for the modeling of the magnetization vector in multiferroic heterostructures}, series = {Proceedings in Applied Mathematics and Mechanics, Special Issue: 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), Weimar 2017)}, volume = {17}, journal = {Proceedings in Applied Mathematics and Mechanics, Special Issue: 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), Weimar 2017)}, number = {1}, publisher = {WILEY-VCH Verlag GmbH \& Co. KGaA}, address = {Weinheim}, issn = {1617-7061}, doi = {10.1002/pamm.201710221}, pages = {503 -- 504}, abstract = {Multiferroic heterostructures are commonly used to obtain electro-magnetic coupling effects. Thereby, the ferroelectric layer is used to control the magnetization in the ferromagnetic layer. The coupling between the layers is obtained by the mechanical coupling between the layers, which have well-defined interfaces. Within this contribution we use phase field models to define the polarization and magnetization in the ferroelectric and ferromagnetic layers, respectively. A coupling between polarization/magnetization and strains in each layer in combination with coherent deformations at the interface yields an electromagnetic coupling within the entire heterostructure. Numerical formulations for the interpolation of the polarization vector are well-defined in the literature. However, the establishment of a consistent numerical formulation for the ferromagnetic layer, where the length of the magnetization vector has to be constant, remains a difficult task. We propose a new numerical approach for the consistent treatment of the ferromagnetic layer and provide numerical simulations which illustrate the electromagnetic coupling effect.}, language = {en} } @misc{SchmidtAmmarDornischetal., author = {Schmidt, Simon David and Ammar, Kais and Dornisch, Wolfgang and Forest, Samuel and M{\"u}ller, Ralf}, title = {Phase field model for the martensitic transformation: comparison of the Voigt/Taylor and Khachaturyan approach}, series = {Continuum Mechanics and Thermodynamics}, volume = {33}, journal = {Continuum Mechanics and Thermodynamics}, number = {5}, issn = {0935-1175}, doi = {10.1007/s00161-021-01007-1}, pages = {2075 -- 2094}, language = {en} } @misc{Mueller, author = {M{\"u}ller, David}, title = {A reply to Ponte et al. (2016) supply chain collaboration: some comments on the Nucleolus of the beer game}, series = {Journal of Industrial Engineering and Management}, volume = {11}, journal = {Journal of Industrial Engineering and Management}, number = {3}, issn = {2013-8423}, doi = {10.3926/jiem.2430}, pages = {528 -- 534}, language = {en} } @misc{HannanSeidlitzHartungetal., author = {Hannan, Azmin Nasrin and Seidlitz, Holger and Hartung, David and Kuke, Felix and Ambrosio, Marcello and M{\"u}ller, Marco}, title = {Sustainability and Circular Economy in Carbon Fiber-Reinforced Plastics}, series = {Materials Circular Economy}, volume = {6}, journal = {Materials Circular Economy}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2524-8146}, doi = {10.1007/s42824-024-00111-2}, pages = {11}, abstract = {Carbon fiber-reinforced plastic (CFRP) components are known for their exceptional resilience and ultra-lightweight nature, making them the preferred choice for applications requiring high mechanical loads with minimal weight. However, the intricate and anisotropic structure of CFRP components poses challenges, resulting in expensive repairs and testing. This complexity also leads to increased waste generation. Yet, innovative recycling processes offer a solution by reintegrating carbon components into a closed material cycle, promoting sustainability and circular economy principles. This work focuses on recycled CFs (rCFs) obtained through a continuous recycling method for CFRP primary recyclate from composite pressure vessel. Furthermore, re-purposing of the separated matrix material for secondary energy sources makes the process, a 100\% recycling route. This closed-loop approach addresses conventional pyrolysis challenges and contributes to more efficient utilization of CFRP waste components. rCF and recycled polyethylene terephthalate (rPET) polymers were compounded through an extrusion process. Test specimens were then fabricated according to standard test norms to evaluate the resulting tensile and bending properties. The tensile and flexural modulus of the rCF-rPET obtained are 6.80 and 4.99 GPa, respectively. The need for enhancing the quality of rCF is apparent. Suggestive and potential implications and the marketability of rCF-rPET compounds are also discussed.}, language = {en} } @misc{MuellerPisch, author = {M{\"u}ller, David and Pisch, Marcus Franz Konrad}, title = {An improper solution to the flood cost sharing problem}, series = {Economic Letters}, volume = {238}, journal = {Economic Letters}, issn = {0165-1765}, doi = {10.1016/j.econlet.2024.111706}, pages = {1 -- 3}, abstract = {A model for sharing the costs of flood damage has recently been proposed in this journal (Abraham and Ramachandran, 2020). The suggested model is correct from a mathematical point of view, but unfortunately lacks economic coherence.}, language = {en} } @misc{PischMueller, author = {Pisch, Marcus Franz Konrad and M{\"u}ller, David}, title = {How cooperative are games in river sharing models?}, series = {Water}, volume = {17}, journal = {Water}, number = {15}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w17152252}, pages = {1 -- 28}, abstract = {There is a long tradition of studying river sharing problems. A central question frequently examined and addressed is how common benefits or costs can be distributed fairly. In this context, axiomatic approaches of cooperative game theory often use contradictory principles of international water law, which are strictly rejected in practice. That leads to the question: Are these methods suitable for a real-world application? First, we conduct a systematic literature review based on the PRISMA approach to categorise the river sharing problems. We identified several articles describing a variety of methods and real-world applications, highlighting interdisciplinary interest. Second, we evaluate the identified axiomatic literature related to TU games with regard to their suitability for real-world applications. We exclude those "standalone" methods that exclusively follow extreme principles and/or do not describe cooperative behaviour. This is essential for a fair distribution. Third, we propose to use the traditional game-theoretical approach of airport games in the context of river protection measures to ensure a better economic interpretation and to enforce future cooperation in the joint implementation of protective measures.}, language = {en} }