TY - JOUR A1 - Sterner, Michael A1 - Hofrichter, Andreas A1 - Meisinger, Alexander A1 - Bauer, Franz A1 - Pinkwart, Karsten A1 - Maletzko, Annabelle A1 - Dittmar, Felix A1 - Cremers, Carsten T1 - 19 Import options for green hydrogen and derivatives - An overview of efficiencies and technology readiness levels JF - International Journal of Hydrogen Energy N2 - The import of hydrogen and derivatives forms part of many national strategies and is fundamental to achieving climate protection targets. This paper provides an overview and technical comparison of import pathways for hydrogen and derivatives in terms of efficiency, technological maturity and development and construction times with a focus on the period up to 2030. The import of hydrogen via pipeline has the highest system efficiency at 57-67 % and the highest technological maturity with a technology readiness level (TRL) of 8-9. The import of ammonia and methanol via ship and of SNG via pipeline shows efficiencies in the range of 39-64 % and a technological maturity of TRL 7 to 9 when using point sources. Liquid hydrogen, LOHC and Fischer-Tropsch products have the lowest efficiency and TRL in comparison. The use of direct air capture (DAC) reduces efficiency and TRL considerably. Reconversion of the derivatives to hydrogen is also associated with high losses and is not achievable for all technologies on an industrial scale up to 2030. In the short to medium term, import routes for derivatives that can utilise existing infrastructures and mature technologies are the most promising for imports. In the long term, the most promising option is hydrogen via pipelines. KW - Hydrogen KW - Derivatives KW - Power-to-X KW - Efficiency KW - TRL KW - Construction time KW - Technical assessment KW - Import KW - Hydrogen strategy KW - Energy system modelling Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-77756 SN - 0360-3199 N1 - Corresponding author der OTH Regensburg: Michael Sterner VL - 90 SP - 1112 EP - 1127 PB - Elsevier ER - TY - JOUR A1 - Raths, Max A1 - Bauer, Lukas A1 - Kuettner, Andreas A1 - Fischer, Samuel A1 - Laumer, Tobias T1 - Gradual error detection technique for non-destructive assessment of density and tensile strength in fused filament fabrication processes JF - The International Journal of Advanced Manufacturing Technology N2 - Fused filament fabrication (FFF) is a widely used additive manufacturing process for producing functional components and prototypes. The FFF process involves depositing melted material layer-by-layer to build up 3D physical parts. The quality of the final product depends on several factors, including the component density and tensile strength, which are typically determined through destructive testing methods. X-ray microtomography (XCT) can be used to investigate the pore sizes and distribution. These approaches are time-consuming, costly, and wasteful, making it unsuitable for high-volume manufacturing. In this paper, a new method for non-destructive determination of component density and estimation of the tensile strength in FFF processes is proposed. This method involves the use of gradual error detection by sensors and convolutional neural networks. To validate this approach, a series of experiments has been conducted. Component density and tensile strength of the printed specimens with varying extrusion factor were measured using traditional destructive testing methods and XCT. The cumulative error detection method was used to predict the same properties without destroying the specimens. The predicted values were then compared with the measured values, and it was observed that the method accurately predicted the component density and tensile strength of the tested parts. This approach has several advantages over traditional destructive testing methods. The method is faster, cheaper, and more environmentally friendly since it does not require the destruction of the product. Moreover, it facilitates the testing of each individual part instead of assuming the same properties for components from one series. Additionally, it can provide real-time feedback on the quality of the product during the manufacturing process, allowing for adjustments to be made as needed. The advancement of this approach points toward a future trend in non-destructive testing methodologies, potentially revolutionizing quality assurance processes not only for consumer goods but various industries such as electronics or automotive industry. Moreover, its broader applications extend beyond FFF to encompass other additive manufacturing techniques such as selective laser sintering (SLS), or electron beam melting (EBM). A comparison between the old destructive testing methods and this innovative non-destructive approach underscores the possible fundamental change toward more efficient and sustainable manufacturing practices. This approach has the potential to significantly reduce the time and cost associated with traditional destructive testing methods while ensuring the quality of FFF-manufactured products. KW - Error detection KW - Additive manufacturing KW - Fused filament fabrication KW - Artificial neural network KW - Image processing KW - Porosity Y1 - 2024 U6 - https://doi.org/10.1007/s00170-024-13280-w SN - 1433-3015 SN - 0268-3768 N1 - Open Access funding enabled and organized by Projekt DEAL. IS - 131 SP - 4149 EP - 4163 PB - Springer CY - London ER - TY - JOUR A1 - Dehnhardt, Markus A1 - Palm, Christoph A1 - Vieten, Andrea A1 - Bauer, Andreas A1 - Pietrzyk, Uwe T1 - Quantifying the A1AR distribution in peritumoral zones around experimental F98 and C6 rat brain tumours JF - Journal of Neuro-Oncology N2 - Quantification of growth in experimental F98 and C6 rat brain tumours was performed on 51 rat brains, 17 of which have been further assessed by 3D tumour reconstruction. Brains were cryosliced and radio-labelled with a ligand of the peripheral type benzodiazepine-receptor (pBR), 3H-Pk11195 [(1-(2-chlorophenyl)-N-methyl-N-(1-methyl-propylene)-3-isoquinoline-carboxamide)] by receptor autoradiography. Manually segmented and automatically registered tumours have been 3D-reconstructed for volumetric comparison on the basis of 3H-Pk11195-based tumour recognition. Furthermore automatically computed areas of −300 μm inner (marginal) zone as well as 300 μm and 600 μm outer tumour space were quantified. These three different regions were transferred onto other adjacent slices that had been labelled by receptor autoradiography with the A1 Adenosine receptor (A1AR)-ligand 3H-CPFPX (3H-8-cyclopentyl-3-(3-fluorpropyl)-1-propylxanthine) for quantitative assessment of A1AR in the three different tumour zones. Hence, a method is described for quantifying various receptor protein systems in the tumour as well as in the marginal invasive zones around experimentally implanted rat brain tumours and their representation in the tumour microenvironment as well as in 3D space. Furthermore, a tool for automatically reading out radio-labelled rat brain slices from auto radiographic films was developed, reconstructed into a consistent 3D-tumour model and the zones around the tumour were visualized. A1AR expression was found to depend upon the tumour volume in C6 animals, but is independent on the time of tumour development. In F98 animals, a significant increase in A1AR receptor protein was found in the Peritumoural zone as a function of time of tumour development and tumour volume. KW - 3D reconstruction KW - A1 adenosine receptor KW - GBM KW - Kmeans algorithm KW - Brain tumour KW - Receptor autoradiography KW - Hirntumor KW - Dreidimensionale Bildverarbeitung KW - Adenosinrezeptor Y1 - 2007 U6 - https://doi.org/10.1007/s11060-007-9391-6 VL - 85 SP - 49 EP - 63 ER - TY - JOUR A1 - Palm, Christoph A1 - Dehnhardt, Markus A1 - Vieten, Andrea A1 - Pietrzyk, Uwe A1 - Bauer, Andreas A1 - Zilles, Karl T1 - 3D rat brain tumors JF - Naunyn-Schmiedebergs Archives of Pharmacology Y1 - 2005 VL - 371 IS - R103 ER - TY - JOUR A1 - Heberl, Michael A1 - Hofrichter, Andreas A1 - Rank, Daniel A1 - Bauer, Franz A1 - Sterner, Michael T1 - Influence of plant dimensioning and location on the ecology of PEM electrolysis JF - International Journal of Hydrogen Energy N2 - PV and wind systems with PEM electrolysis offer great potential for producing hydrogen with low emissions. Our research has identified the ecologically optimal size of PEM in relation to fixed PV/wind capacities. We calculate efficiencies and production volumes for PEM with 240 capacity and site variations. We analyse the global warming potential of all systems and draw conclusions about the optimal system design. The lowest GWP is achieved at the site with the highest full load hours with 1.32 kg CO2-eq/kg H2 (Wind, 28 MW electrolysis) and 4.24 kg CO2-eq/kg H2 (PV, 23 MW electrolysis). We have identified a clear trend: increasing PV/wind full load hours leads to higher ideal PEM capacities. However, there is a significant discrepancy between the ideal economic and ecological capacity. Furthermore, higher electrolysis capacities can achieve lower emissions as they increasingly operate at a more efficient partial load. KW - Electrolysis KW - Life cycle analysis KW - Global warming potential KW - Plant design KW - Renewable energy Y1 - 2025 U6 - https://doi.org/10.1016/j.ijhydene.2025.151039 SN - 0360-3199 VL - 167 PB - Elsevier ER -