@misc{Mueller, author = {M{\"u}ller, David}, title = {L{\"o}sung von NIMBY-Problemen beim Ausbau des deutschen Stromnetzes}, series = {Zeitschrift f{\"u}r {\"o}ffentliche und gemeinwirtschaftliche Unternehmen}, volume = {39}, journal = {Zeitschrift f{\"u}r {\"o}ffentliche und gemeinwirtschaftliche Unternehmen}, number = {3}, issn = {0344-9777}, pages = {248 -- 269}, language = {de} } @incollection{SagradovMueller, author = {Sagradov, Olga and M{\"u}ller, David}, title = {Verbesserung der Prognosequalit{\"a}t im Personalcontrolling}, series = {Controlling \& Innovation 2022, Gesundheitswesen}, booktitle = {Controlling \& Innovation 2022, Gesundheitswesen}, editor = {K{\"u}mpel, Thomas and Schlenkrich, Kay and Heupel, Thomas}, publisher = {Springer Gabler}, address = {Wiesbaden}, isbn = {978-3-658-36483-0}, issn = {2625-7114}, doi = {10.1007/978-3-658-36484-7}, pages = {95}, abstract = {F{\"u}r das langfristige Bestehen eines Unternehmens ist es notwendig, schnell und gezielt auf st{\"a}ndige Umweltver{\"a}nderungen zu reagieren. Die Reaktionsgeschwindigkeit auf zuk{\"u}nftige Ver{\"a}nderungen h{\"a}ngt von der F{\"a}higkeit des Unternehmens ab, m{\"o}gliche Szenarien f{\"u}r die Entwicklung der internen sowie externen Umgebung vorherzusagen. Die Controlling-Abteilungen, welche regul{\"a}r kurz-, mittel- und langfristige Prognosen vorbereiten m{\"u}ssen, erhalten heutzutage neue M{\"o}glichkeiten in der Auswahl der Forecast-Instrumentarien. Die Regressionsmodelle sowie Predictive Analytics und vor allem Machine Learning stellen keine neuen Analysemethoden dar, jedoch finden sie eher selten Anwendung in Controlling und Planung der Unternehmen. Einer der m{\"o}glichen Anwendungsbereiche der fortgeschrittenen Analytics im Unternehmenscontrolling stellt die Krankheitsanalyse bzw. -vorhersage dar. Mit dem Ausfall der Arbeitskr{\"a}fte sind abh{\"a}ngig von der Unternehmenst{\"a}tigkeit hohe Kosten verbunden. Steigende Aufmerksamkeit zum Thema Gesundheitsmanagement in Unternehmen fordert ebenso die Erstellung aussagekr{\"a}ftiger Analytics, um die entsprechenden Maßnahmen strategisch zu planen. Anhand von Daten eines ostdeutschen Großunternehmens beantworten die Autoren die Frage, wie sich die Prognosequalit{\"a}t des Krankheitsstandes mittels Regressionsmodellen und Predictive Analytics verbessern l{\"a}sst. Abschließend sind aus dem Beitrag der Nutzen und die Herausforderungen der Anwendung von fortgeschrittenen Prognosemethoden im Personalcontrolling zu entnehmen.}, language = {de} } @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} } @book{Mueller, author = {M{\"u}ller, David}, title = {Investitionsrechnung und Investitionscontrolling}, edition = {2. Auflage}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-662-57608-3}, doi = {10.1007/978-3-662-57609-0}, pages = {695}, abstract = {Investitionen als eine wesentliche Grundlage unternehmerischer T{\"a}tigkeit sind durch komplexe Entscheidungsprozesse gekennzeichnet. Zentrale Aufgabe des Investitionscontrollings ist deshalb die Unterst{\"u}tzung der Planung, Realisierung und Umsetzung dieser Entscheidungen. Damit diese Aufgabe bestm{\"o}glich erf{\"u}llt werden kann, wurde die vorliegende Auflage neu strukturiert. Die Eigenschaften des Investitionsprozesses und des Investitionscontrollings werden in den ersten beiden Kapiteln vorgestellt. Im Anschluss daran werden die Grundlagen der Entscheidungstheorie dargelegt. Diese werden {\"u}blicherweise als Einzelentscheidungen betrachtet, jedoch sind Investitionsentscheidungen in den seltensten F{\"a}llen Individualentscheidungen. In der Regel sind mehrere Mitarbeiter und Abteilungen in die Entscheidungsprozesse eingebunden. Es liegt nahe, neben den Individualentscheidungen auch kollektive Entscheidungen zu ber{\"u}cksichtigen. Aus diesem Grund werden Theorie und Praxis kollektiver Entscheidungen in einem eigenst{\"a}ndigen Kapitel beleuchtet. Neben der Entscheidungstheorie bildet die Investitionstheorie das klassische Fundament zur Unterst{\"u}tzung von Investitionsentscheidungen. Die grundlegenden Verfahren f{\"u}r Situationen unter Sicherheit werden ebenso vorgestellt wie die Verfahren f{\"u}r Entscheidungen unter Unsicherheit. Eine ganze Reihe von Investitionen wird nicht durch einen einzelnen Akteur (z.B. Unternehmen, Kostenstelle, Gemeinde) sondern als Gemeinschaftsinvestitionen durch mehrere Akteure realisiert. Die kooperative Spieltheorie ist in der Lage, f{\"u}r eine gerechte Nutzenaufteilung zu sorgen. Deshalb ist diesem Bereich ein umfangreiches Kapitel mit vielen Anwendungsbeispielen gewidmet.}, language = {de} } @incollection{Mueller, author = {M{\"u}ller, David}, title = {Analyse der Improvisation als Probleml{\"o}sungsalternative in KMU}, series = {Controlling f{\"u}r kleine und mittlere Unternehmen}, booktitle = {Controlling f{\"u}r kleine und mittlere Unternehmen}, editor = {M{\"u}ller, David}, edition = {2. Auflage}, publisher = {De Gruyter-Oldenbourg}, address = {M{\"u}nchen}, isbn = {978-3-11-051487-2}, doi = {10.1515/9783110517163-016}, pages = {393 -- 427}, language = {de} } @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{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{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{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} }