@masterthesis{Ferraioli2023, type = {Bachelor Thesis}, author = {Ferraioli, Luigi}, title = {Validierung einer Simulationsumgebung f{\"u}r Umfeldsensorik von Schienenfahrzeugen}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {49 Seiten}, year = {2023}, abstract = {Diese Bachelorarbeit befasst sich mit der digitalen Nachbildung eines Testgel{\"a}ndes sowie eines Schienenfahrzeugs in der Simulationsumgebung Gazebo. Der Schwerpunkt liegt auf der pr{\"a}zisen Abbildung der Umfeldsensorik anhand eines realen Schienenfahrzeuges. Ziel ist die Erzeugung {\"a}quivalenter Messdaten der Simulationsumgebung und des realen Schienenfahrzeuges unter gleichen Einsatzbedingungen. Dazu werden unterschiedliche Verfahren eingesetzt, um die Parameter der einzelnen Sensorik so zu konfigurieren, dass die Messergebnisse mit den Messdaten der realen Sensorik konvergieren. Die Ergebnisse der Messdaten zeigen, dass obwohl die Simulationsumgebung einige physikalische Materialeigenschaften nicht ber{\"u}cksichtigt, eine pr{\"a}zise Abbildung der Sensorik und geometrischen Strukturen des Testgel{\"a}ndes m{\"o}glich ist. Dar{\"u}ber hinaus erm{\"o}glicht die Kombination von Gazebo und ROS2 Integrationstests und die Entwicklung von Softwareanwendungen sowohl in der Simulation als auch auf dem realen Schienenfahrzeug. Eine realit{\"a}tsnahe und reproduzierbare Auswertung der Sensormessdaten der Simulationsumgebung f{\"u}r Schienenfahrzeuge ist somit realisierbar.}, language = {de} } @book{Tuennemann2023, author = {T{\"u}nnemann, Thomas}, title = {Formine 2023 : Concezione II}, publisher = {FH Aachen, Fachbereich Architektur}, address = {Aachen}, isbn = {978-3-9811003-2-7}, publisher = {Fachhochschule Aachen}, pages = {112 Seiten}, year = {2023}, abstract = {Der diesj{\"a}hrige Workshop steht im Zeichen der r{\"a}umlichen Konzeption. Das Erfahren und Definieren des engsten, ganz eigenen Betrachtungsraums, bis hin zur weitl{\"a}ufigen {\"o}ffentlichen Umgebung des Ortes ist hierbei der erste Schritt. Hierzu stehen alle konzeptionellen Werkzeuge - von der Entwicklung vereinzelter Skizzenabfolgen, bis hin zur Collage - in den ersten Tagen des Workshops zur Verf{\"u}gung. All diese {\"U}berlegungen, Konzepte und Entw{\"u}rfe werden in eine Plastik {\"u}berf{\"u}hrt.}, language = {de} } @incollection{Dreschers2023, author = {Dreschers, Martin}, title = {\S25 Arbeitsrechtliche Probleme im Rahmen der Betriebsfortf{\"u}hrung}, series = {Betriebsfortf{\"u}hrung in Restrukturierung und Insolvenz}, booktitle = {Betriebsfortf{\"u}hrung in Restrukturierung und Insolvenz}, editor = {M{\"o}nning, Rolf-Dieter}, publisher = {RWS Verlag}, address = {K{\"o}ln}, isbn = {978-3-8145-2012-4 (print)}, doi = {https://doi.org/10.15375/9783814558882-028}, pages = {947 -- 988}, year = {2023}, language = {de} } @incollection{Dreschers2023, author = {Dreschers, Martin}, title = {\S18 Grenz{\"u}berschreitende Eigenverwaltung}, series = {HRI II - Handbuch Restrukturierung in der Insolvenz}, booktitle = {HRI II - Handbuch Restrukturierung in der Insolvenz}, editor = {K{\"u}bler, Bruno M. and Bork, Reinhard and Pr{\"u}tting, Hanns}, publisher = {RWS Verlag}, address = {K{\"o}ln}, isbn = {978-3-8145-2010-0 (print)}, doi = {10.15375/9783814558714-028}, pages = {524 -- 556}, year = {2023}, language = {de} } @inproceedings{MaurerMiskiwAcostaetal.2023, author = {Maurer, Florian and Miskiw, Kim K. and Acosta, Rebeca Ramirez and Harder, Nick and Sander, Volker and Lehnhoff, Sebastian}, title = {Market abstraction of energy markets and policies - application in an agent-based modeling toolbox}, series = {EI.A 2023: Energy Informatics}, booktitle = {EI.A 2023: Energy Informatics}, editor = {Jorgensen, Bo Norregaard and Pereira da Silva, Luiz Carlos and Ma, Zheng}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-48651-7 (Print)}, doi = {10.1007/978-3-031-48652-4_10}, pages = {139 -- 157}, year = {2023}, abstract = {In light of emerging challenges in energy systems, markets are prone to changing dynamics and market design. Simulation models are commonly used to understand the changing dynamics of future electricity markets. However, existing market models were often created with specific use cases in mind, which limits their flexibility and usability. This can impose challenges for using a single model to compare different market designs. This paper introduces a new method of defining market designs for energy market simulations. The proposed concept makes it easy to incorporate different market designs into electricity market models by using relevant parameters derived from analyzing existing simulation tools, morphological categorization and ontologies. These parameters are then used to derive a market abstraction and integrate it into an agent-based simulation framework, allowing for a unified analysis of diverse market designs. Furthermore, we showcase the usability of integrating new types of long-term contracts and over-the-counter trading. To validate this approach, two case studies are demonstrated: a pay-as-clear market and a pay-as-bid long-term market. These examples demonstrate the capabilities of the proposed framework.}, language = {en} } @incollection{DuffnerUibelPetersonetal.2023, author = {Duffner, Markus and Uibel, Thomas and Peterson, Leif Arne and Moorkamp, Wilfried}, title = {Cross Layers Light - Ein ressourceneffizientes und recyclebares Holz-Wandsystem}, series = {Bauphysik Kalender 2023: Nachhaltigkeit}, booktitle = {Bauphysik Kalender 2023: Nachhaltigkeit}, editor = {Fouad, Nabil A.}, publisher = {Ernst \& Sohn}, address = {Berlin}, isbn = {9783433033890 (Print)}, doi = {10.1002/9783433611289.ch13}, pages = {483 -- 501}, year = {2023}, abstract = {Ein neues tragendes, lagenweise aufgebautes Holzbau-Wandsystem und seine {\"o}konomische und statische Entwicklung werden vorgestellt. Randbedingungen wie Nachhaltigkeit, Ressourceneffizienz und eine beanspruchungsadaptive Konstruktionsweise sind f{\"u}r diese innovative Bauteilentwicklung von zentraler Bedeutung. Eine wesentliche Herausforderung ist die Herstellung der Verbindung der Lagen untereinander zu einem bauphysikalisch und statisch leistungsf{\"a}higen Wandsystem. Die Tragf{\"a}higkeit und Steifigkeit verschiedener Verbindungsvarianten wurden ebenso wie die Eigenschaften der Wandelemente analytisch, numerisch und experimentell untersucht.}, language = {de} } @incollection{MoorkampPetersonUibel2023, author = {Moorkamp, Wilfried and Peterson, Leif Arne and Uibel, Thomas}, title = {Standardholzbr{\"u}cken f{\"u}r kommunale Geh- und Radwege}, series = {Strukturen, Formen und Prinzipien : Festschrift zum 60. Geburtstag von Univ.-Prof. Dr.-Ing. Martin Trautz}, booktitle = {Strukturen, Formen und Prinzipien : Festschrift zum 60. Geburtstag von Univ.-Prof. Dr.-Ing. Martin Trautz}, editor = {Wehren, Cedric}, publisher = {RWTH Aachen}, address = {Aachen}, isbn = {978-3-95886-500-6}, pages = {140 -- 165}, year = {2023}, language = {de} } @book{UibelPeterson2023, author = {Uibel, Thomas and Peterson, Leif Arne}, title = {Tagungsband Aachener Holzbautagung 2023}, editor = {Uibel, Thomas and Peterson, Leif Arne}, publisher = {FH Aachen}, address = {Aachen}, issn = {2197-4489}, year = {2023}, language = {de} } @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} } @article{KuchlerGuenthnerRibeiroetal.2023, author = {Kuchler, Timon and G{\"u}nthner, Roman and Ribeiro, Andrea and Hausinger, Renate and Streese, Lukas and W{\"o}hnl, Anna and Kesseler, Veronika and Negele, Johanna and Assali, Tarek and Carbajo-Lozoya, Javier and Lech, Maciej and Adorjan, Kristina and Stubbe, Hans Christian and Hanssen, Henner and Kotliar, Konstantin and Haller, Berhard and Heemann, Uwe and Schmaderer, Christoph}, title = {Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation}, volume = {26}, publisher = {Springer Nature}, address = {Dordrecht}, doi = {10.1007/s10456-023-09885-6}, pages = {547 -- 563}, year = {2023}, abstract = {Background Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians. Methods In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204). Measurements and main results PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42\% ± 1.77\% vs. 4.64\% ± 2.59\%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5-190.2] vs. 189.1 [179.4-197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8-0.9] vs. 0.88 [0.8-0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = - 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters. Conclusion Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.}, language = {en} } @article{FayyaziSardarThomasetal.2023, author = {Fayyazi, Mojgan and Sardar, Paramjotsingh and Thomas, Sumit Infent and Daghigh, Roonak and Jamali, Ali and Esch, Thomas and Kemper, Hans and Langari, Reza and Khayyam, Hamid}, title = {Artificial intelligence/machine learning in energy management systems, control, and optimization of hydrogen fuel cell vehicles}, volume = {15}, number = {6}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/su15065249}, pages = {38}, year = {2023}, abstract = {Environmental emissions, global warming, and energy-related concerns have accelerated the advancements in conventional vehicles that primarily use internal combustion engines. Among the existing technologies, hydrogen fuel cell electric vehicles and fuel cell hybrid electric vehicles may have minimal contributions to greenhouse gas emissions and thus are the prime choices for environmental concerns. However, energy management in fuel cell electric vehicles and fuel cell hybrid electric vehicles is a major challenge. Appropriate control strategies should be used for effective energy management in these vehicles. On the other hand, there has been significant progress in artificial intelligence, machine learning, and designing data-driven intelligent controllers. These techniques have found much attention within the community, and state-of-the-art energy management technologies have been developed based on them. This manuscript reviews the application of machine learning and intelligent controllers for prediction, control, energy management, and vehicle to everything (V2X) in hydrogen fuel cell vehicles. The effectiveness of data-driven control and optimization systems are investigated to evolve, classify, and compare, and future trends and directions for sustainability are discussed.}, language = {en} } @article{FissabreRottke2023, author = {Fissabre, Anke and Rottke, Evelin}, title = {Das Quelle-Fertighaus : Einklang von Maß, Konstruktion und Entwurf}, series = {architectura}, volume = {51}, journal = {architectura}, number = {1}, editor = {Bergdoll, Barry and Schwarting, Andreas and Tragbar, Klaus}, publisher = {Deutscher Kunstverlag (DKV)}, address = {Berlin}, issn = {2569-1554}, doi = {10.1515/atc-2021-1005}, pages = {57 -- 78}, year = {2023}, abstract = {The steel prefabricated family house ›Quelle-Fertighaus‹ designed and constructed by the German company Quelle, is an innovative modular system commercialised in 1962. All aspects of the Quelle-Fertighaus are planned on the principle of minimal effort for maximal flexibility. The clever design of the ground plan based on a 4 m × 7 m module offers the flexibility for either one to three additional modules. The steel construction is innovative and unique, consisting of load-bearing portal frames acting as braces. The house design is furthermore characterised by a simple metrical grid layout and the practical placement of the foundation and basement, which allowed the very cost-effective production and the lowest price for a prefabricated family house in Germany during the postwar era. Nowadays its portal-frame-construction offers an interesting approach for its renovation and transformation according to present building demands.}, language = {de} } @article{LaarmannThomaMischetal.2023, author = {Laarmann, Lukas and Thoma, Andreas and Misch, Philipp and R{\"o}th, Thilo and Braun, Carsten and Watkins, Simon and Fard, Mohammad}, title = {Automotive safety approach for future eVTOL vehicles}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer Nature}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-023-00655-0}, pages = {11 Seiten}, year = {2023}, abstract = {The eVTOL industry is a rapidly growing mass market expected to start in 2024. eVTOL compete, caused by their predicted missions, with ground-based transportation modes, including mainly passenger cars. Therefore, the automotive and classical aircraft design process is reviewed and compared to highlight advantages for eVTOL development. A special focus is on ergonomic comfort and safety. The need for further investigation of eVTOL's crashworthiness is outlined by, first, specifying the relevance of passive safety via accident statistics and customer perception analysis; second, comparing the current state of regulation and certification; and third, discussing the advantages of integral safety and applying the automotive safety approach for eVTOL development. Integral safety links active and passive safety, while the automotive safety approach means implementing standardized mandatory full-vehicle crash tests for future eVTOL. Subsequently, possible crash impact conditions are analyzed, and three full-vehicle crash load cases are presented.}, language = {en} } @article{BoehnischBraunMuscarelloetal.2023, author = {B{\"o}hnisch, Nils and Braun, Carsten and Muscarello, Vincenzo and Marzocca, Pier}, title = {A sensitivity study on aeroelastic instabilities of slender wings with a large propeller}, series = {AIAA SCITECH 2023 Forum}, journal = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2023-1893}, pages = {1 -- 14}, year = {2023}, abstract = {Next-generation aircraft designs often incorporate multiple large propellers attached along the wingspan. These highly flexible dynamic systems can exhibit uncommon aeroelastic instabilities, which should be carefully investigated to ensure safe operation. The interaction between the propeller and the wing is of particular importance. It is known that whirl flutter is stabilized by wing motion and wing aerodynamics. This paper investigates the effect of a propeller onto wing flutter as a function of span position and mounting stiffness between the propeller and wing. The analysis of a comparison between a tractor and pusher configuration has shown that the coupled system is more stable than the standalone wing for propeller positions near the wing tip for both configurations. The wing fluttermechanism is mostly affected by the mass of the propeller and the resulting change in eigenfrequencies of the wing. For very weak mounting stiffnesses, whirl flutter occurs, which was shown to be stabilized compared to a standalone propeller due to wing motion. On the other hand, the pusher configuration is, as to be expected, the more critical configuration due to the attached mass behind the elastic axis.}, language = {de} } @inproceedings{ThomaStiemerBraunetal.2023, author = {Thoma, Andreas and Stiemer, Luc and Braun, Carsten and Fisher, Alex and Gardi, Alessandro G.}, title = {Potential of hybrid neural network local path planner for small UAV in urban environments}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2023-2359}, pages = {13 Seiten}, year = {2023}, abstract = {This work proposes a hybrid algorithm combining an Artificial Neural Network (ANN) with a conventional local path planner to navigate UAVs efficiently in various unknown urban environments. The proposed method of a Hybrid Artificial Neural Network Avoidance System is called HANNAS. The ANN analyses a video stream and classifies the current environment. This information about the current Environment is used to set several control parameters of a conventional local path planner, the 3DVFH*. The local path planner then plans the path toward a specific goal point based on distance data from a depth camera. We trained and tested a state-of-the-art image segmentation algorithm, PP-LiteSeg. The proposed HANNAS method reaches a failure probability of 17\%, which is less than half the failure probability of the baseline and around half the failure probability of an improved, bio-inspired version of the 3DVFH*. The proposed HANNAS method does not show any disadvantages regarding flight time or flight distance.}, language = {en} } @inproceedings{VladovaUllrichSultanowetal.2023, author = {Vladova, Gergana and Ullrich, Andr{\´e} and Sultanow, Eldar and Tobolla, Marinho and Sebrak, Sebastian and Czarnecki, Christian and Brockmann, Carsten}, title = {Visual analytics for knowledge management}, series = {INFORMATIK 2023 - Designing Futures: Zuk{\"u}nfte gestalten}, booktitle = {INFORMATIK 2023 - Designing Futures: Zuk{\"u}nfte gestalten}, publisher = {GI - Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-731-9}, issn = {1617-5468}, doi = {10.18420/inf2023_187}, pages = {1851 -- 1870}, year = {2023}, abstract = {The management of knowledge in organizations considers both established long-term processes and cooperation in agile project teams. Since knowledge can be both tacit and explicit, its transfer from the individual to the organizational knowledge base poses a challenge in organizations. This challenge increases when the fluctuation of knowledge carriers is exceptionally high. Especially in large projects in which external consultants are involved, there is a risk that critical, company-relevant knowledge generated in the project will leave the company with the external knowledge carrier and thus be lost. In this paper, we show the advantages of an early warning system for knowledge management to avoid this loss. In particular, the potential of visual analytics in the context of knowledge management systems is presented and discussed. We present a project for the development of a business-critical software system and discuss the first implementations and results.}, language = {en} } @incollection{SchultLosseCzarneckietal.2023, author = {Schult, Prince Garcia and Losse, Ann-Kathrin and Czarnecki, Christian and Sultanow, Eldar}, title = {Proposing a Framework to address the Sustainable Development Goals}, series = {EnviroInfo 2023}, booktitle = {EnviroInfo 2023}, publisher = {GI - Gesellschaft f{\"u}r Informatik}, address = {Bonn}, isbn = {978-3-88579-736-4}, issn = {1617-5468}, doi = {10.18420/env2023-022}, pages = {243 -- 249}, year = {2023}, abstract = {Reducing poverty, protecting the planet, and improving life on earth for everyone are the essential goals of the "2030 Agenda for Sustainable Development"committed by the United Nations (UN). Achieving those goals will require technological innovation as well as their implementation in almost all areas of our business and day-to-day life. This paper proposes a high-level framework that collects and structures different uses cases addressing the goals defined by the UN. Hence, it contributes to the discussion by proposing technical innovations that can be used to achieve those goals. As an example, the goal "Climate Action{\"i}s discussed in detail by describing use cases related to tackling biodiversity loss in order to conservate ecosystems.}, language = {en} } @book{Czarnecki2023, author = {Czarnecki, Christian}, title = {Angewandte Forschung in der Wirtschaftsinformatik 2023 : Tagungsband zur 36. AKWI-Jahrestagung}, editor = {Czarnecki, Christian and L{\"u}bbe, Alexander and Meister, Vera G. and M{\"u}ller, Christian and Steglich, Mike and Walther, Mathias}, organization = {Arbeitskreis Wirtschaftsinformatik an Hochschulen f{\"u}r Angewandte Wissenschaften im deutschsprachigen Raum (AKWI)}, doi = {10.15771/1794}, pages = {214 Seiten}, year = {2023}, abstract = {Beitr{\"a}ge der Fachtagung „Angewandte Forschung in der Wirtschaftsinformatik - Zukunft gestalten" im Rahmen der 36. Jahrestagung des Arbeitskreises Wirtschaftsinformatik an Hochschulen f{\"u}r Angewandte Wissenschaften (AKWI) vom 11. bis 13.09.2023 an der Technischen Hochschule Wildau}, language = {de} } @article{MuesgenanntKoersMcNeilRadchenkoetal.2023, author = {Mues genannt Koers, Lucas and McNeil, S. W. and Radchenko, V. and Paulßen, Elisabeth and Hoehr, Cornelia}, title = {Production of Co-58m in a siphon-style liquid target on a medical cyclotron}, volume = {195}, number = {Art. 110734}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0969-8043}, doi = {10.1016/j.apradiso.2023.110734}, year = {2023}, abstract = {We present the production of 58mCo on a small, 13 MeV medical cyclotron utilizing a siphon style liquid target system. Different concentrated iron(III)-nitrate solutions of natural isotopic distribution were irradiated at varying initial pressures and subsequently separated by solid phase extraction chromatography. The radio cobalt (58m/gCo and 56Co) was successfully produced with saturation activities of (0.35 ± 0.03) MBq μA-1 for 58mCo with a separation recovery of (75 ± 2) \% of cobalt after one separation step utilizing LN-resin.}, language = {en} } @article{MuesgenanntKoersPrevostPaulssenetal.2023, author = {Mues genannt Koers, Lucas and Prevost, David and Paulßen, Elisabeth and Hoehr, Cornelia}, title = {Density reduction effects on the production of [11C]CO2 in Nb-body targets on a medical cyclotron}, volume = {199}, number = {Art. 110911}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.apradiso.2023.110911}, year = {2023}, abstract = {Medical isotope production of 11C is commonly performed in gaseous targets. The power deposition of the proton beam during the irradiation decreases the target density due to thermodynamic mixing and can cause an increase of penetration depth and divergence of the proton beam. In order to investigate the difference how the target-body length influences the operation conditions and the production yield, a 12 cm and a 22 cm Nb-target body containing N2/O2 gas were irradiated using a 13 MeV proton cyclotron. It was found that the density reduction has a large influence on the pressure rise during irradiation and the achievable radioactive yield. The saturation activity of [11C]CO2 for the long target (0.083 Ci/μA) is about 10\% higher than in the short target geometry (0.075 Ci/μA).}, language = {en} }