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Aim: Intraosseous (IO)-access plays an alternative route during resuscitation. Our study in preterm and term stillborns was performed to find alternative IO puncture sites beside the recommended proximal tibia. Methods:The cadavers used were legal donations. 20 stillborns (mean: 29.2weeks, IQR 27.1À39.6) were investigated. Spectral-CT were analysed to calculate the diameter and circumferences of: i) proximal humerus ii) distal femur iii) proximal tibia iv) diaphyseal tibial. Contrast medium was applied under video documentation to investigate the drainage into the vascular system.Results: In term newborns, diameter of the cortex of the proximal humeral head is 12.1 AE 1.8 mm, distal end of the femur 11.9 AE 3.4 mm and the proximal tibial bone 12.0 AE 2.4 mm with cross-sectional diameter of 113.5 AE 19.7 mm 2 , 120.6 AE 28.2 mm 2 and 111.6 AE 29.5 mm 2 , respectively. Regarding the preterm groups, there is a strong age-related growth in diameter and cross -sectional size. The diaphyseal area is the smallest in all measured bones with an age-dependent increase and is about half of that of metaphyseal diameters (proximal and distal) and about one third of that of metaphyseal cross sectional areas. The proximal femoral head region has the largest diameter of all measured bones with an egg-shaped formation with an extensive joint capsula. All investigated metaphyseal areas lack a clearly enclosed bone marrow cavity. Infusion of contrast medium into the distal femoral end and the proximal humerus head demonstrate the drainage of contrast medium into the central venous system within seconds. Conclusion:Proximal humeral head and distal femoral end might be alternative IO areas which may lead to further IO puncture sites in neonates.

A sustainable, interconnected, and smart energy network in which hydrogen plays a major role cannot be dismissed as a utopia anymore. There are vast international and industrial ambitions to reach the envisioned system transformation, and the decarbonization of the mobility sector is a central pillar comprising a huge economic share. Solid oxide fuel cells (SOFCs) are one of the most promising technologies in the brigade of clean energy devices and have potentially wide applicability for transportation, due to their high efficiencies and impurity tolerance. To uncover future pathways to boost the cell's performance, we propose a detailed multiscale modeling methodology to evaluate the direct impact of cell materials and morphologies on commercial-scale system performance. After acquiring intrinsic electrokinetics decoupled from mass and charge transport of different anode and cathode materials via a half-cell model, a full cell model is employed to identify the most promising electrode combination. Subsequently, a scale-up to the system level is performed by coupling a 3-D kW-stack model to the balance of plant components while focusing on morphological optimization of the membrane electrode assembly (MEA). On optimally tailoring the MEA, model results demonstrate that an advanced cell design comprising a Ni fiber-CGO matrix structured anode and a LSCF-infiltrated CGO cathode could reach a stack power density of 1.85 kW L −1 and a net system efficiency of 52.2% for operation at <700 °C, with manageable stack temperature gradients of <14 K cm −1 . The modeloptimized power density is substantially higher than those of commercial stacks and surpasses industrial targets for SOFC-based range extenders. Thus, with further cell and stack development targeting the performance limiting processes elucidated in the paper, commercial SOFCs could, alongside range extenders, also act as prime movers in larger scale transport applications such as trucks, trains, and ships.

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Reversible solid oxide cells (rSOCs) are highly efficient devices, which allow either the generation of electric power or the storage of energy via fuel production. In this paper, the characteristics of the mode switch are investigated by applying a dynamic 3D stack model. The responses of temperature, current density, and species mole fractions regarding a switch from storage (SOEC) to generation mode (SOFC) are examined in detail. Additionally, the impact of using excess air and continuous voltage variations to limit temperature gradients and fluctuations during the mode switch are analyzed.

The temporarily fluctuating power supply produced by renewable energy sources (RES) forces the integration of energy storage technologies in our energy network at a massive scale, in order to make future scenarios of a sector-coupling and distributed clean energy supply feasible. Power-to-Methane (PtM) chemical storage concepts are very attractive in this regard, since the production of synthetic CH4 has the advantages of a high-energy density carrier that is easily transportable within the existing pipeline infrastructure and that is a feedstock for various applications in the form of compressed or liquefied natural gas (CNG/LNG). However, in all these scenarios, the levelized cost of the synthetic fuel is a major obstacle due the relatively inefficient conversion chain, i.e. energy losses associated with the fuel production plus consumption. Thermal integration of high-temperature (HT) steam electrolysis based on solid oxide electrolysis cells (SOECs) with the exothermic catalytic methanation is a very promising concept to boost the system’s efficiency by making use of the intrinsically favored thermodynamics and kinetics of HT-electrolysis for H2 generation. On stack level, electrical efficiencies (based on the lower heating value (LHV)) of 96% and specific energy consumptions of 3.3 kWh per Nm3 of H2 were reported for HT-steam electrolysis [1], whilst net system PtM efficiencies of ~80% could be demonstrated in a pilot project [2]. Still, there exists the fundamental question on how to optimize the cell design and the operating conditions in terms of balancing area-specific power density, efficiency, degradation rates, and costs, i.e., how to use this synergy optimally in a future real-world application. Here, we use a detailed multi-physics and multi-scale SOEC simulation tool alongside initial and long-term experiments performed on commercial electrolyte- (ESC) and anode-supported cells (ASCs) to make further strikes towards this question. Firstly, a planar single cell model coupling 1D+1D gas transport and spatially-resolved charge transfer across the electrode thickness is calibrated based on polarization curves recorded at different temperatures (600-900 °C) and inlet compositions (80-95% H2O, balance H2). By accounting for realistic microstructural cell data acquired from Scanning Electron Microscopy (SEM), a nearly quantitative accordance with the experimental data could be achieved. Subsequently, by incorporating a 2D heat transport model, adiabatic simulations are performed to identify optimal operation conditions in a parametric study, which are used as a basis for the long-term degradation experiments. It is demonstrated how the selection of the cell design affects the selection of optimal operation points, and how the creation of reactant starvation zones within the cell can severely impact the electrical efficiency. A scale-up to the stack level is performed afterwards by applying a 3D stack model [3], which considers heat loss to the surroundings across a thermal insulation layer. This enables to realize system-oriented simulations with conditions experienced by the stack that are close to the real-world application. In this way, the implications of scaling-up on (i) the SOEC performance depending on the cell design, and (ii) the selection of optimal operation conditions from an electrolyzer point-of-view in the context of PtM are illustrated on the basis of industrially-scaled stacks. Acknowledgements Financial support by the federal ministry for economic affairs and energy (Bundesministerium für Wirtschaft und Energie, BMWi) under Grant Numbers 03EIV041D and 03EIV041E in the “MethFuel” group of the collaborative research project “MethQuest” is gratefully acknowledged. References [1] sunfire GmbH, Gasanstaltstraße 2, 01237 Dresden, Germany. [2] M. Gruber, P. Weinbrecht, L. Biffar, S. Harth, D. Trimis, J. Brabandt, O. Posdziech and R. Blumentritt, Fuel Process. Technol., 181, 61 (2018). [3] A. Banerjee, Y. Wang, J. Diercks and O. Deutschmann, Appl. Energy, 230, 996 (2018).

Solid oxide fuel cells (SOFCs) have the potential to run on ammonia without the need for any pre-reforming and therefore enable effective energy conversion of ammonia to power. In this work, an ammonia based SOFC-Gas turbine (GT) system concept is proposed and assessed for the mobility sector. The model integrates a three-dimensional multiscale SOFC stack simulation based on a validated Ni-GDC/GDC/SSC button cell model with balance-of-plant component modeling. This work discusses the thermodynamics of SOFC operation and system concepts to utilize ammonia in a hybrid system for a kW-scale transportation application. System indicators and performance metrics such as efficiency, electrochemical utilization and turbine inlet temperature are evaluated and optimized. The proposed hybrid system is computationally predicted to reach efficiencies of up to 60% for pressurized operation.