Search

To ensure high qualification standards in medical institutions, a questionnaire has been developed to evaluate the postgraduate medical education in Switzerland. This article describes the development and longitudinal analysis of a questionnaire using eight scales to assess the quality of postgraduate medical education. The questionnaire has been administered to all residents every year since 2003. In 2020, 8,745 residents returned the questionnaire, resulting in a response rate of 70%. In addition, a survey is conducted annually among the directors of medical institutions. We present results of the directors’ survey and the resident evaluation from 2020, as well as longitudinal data over 16 years. The mean values of the eight scales remained stable or increased slightly over the years. The decision-making culture scale is generally rated best by the residents, while the evidence-based medicine scale is rated as the least good. The most important drivers of residents’ satisfaction with a training site are the work environment and leadership culture scales. The directors perceive the evaluation to be fair and useful. The questionnaire represents a reliable and useful tool for the quality control in postgraduate medical training. It provides yearly feedback to the directors regarding how the residents perceive their training giving insights for improvments.

Porous, nanostructured particles ensure the wetting of electrolyte up to the particle core and shortened diffusion paths, which is relevant not only for lithium-ion batteries but also for postlithium systems like sodium-ion batteries. The porous structure leads to a high C-rate capability. However, compared to conventional compact NCM, porous NCM shows a reduced adhesion force but no or only slight negative influence on C-rate capability by binder migration at higher drying rates. Herein, a multilayer concept is used to increase the adhesion force with equal or better electrochemical performance compared to single-layer electrodes. Compact particles of high volumetric energy density and porous particles with high C-rate capability are combined in a simultaneously coated multilayer electrode. Multilayers with compact NCM toward the current collector and porous NCM with reduced binder content toward the separator side show an about 16-times higher adhesion force at lower drying rate and an about ten-times higher adhesion force at increased drying rate compared to electrodes produced of porous NCM only. The specific discharge capacity of the multilayers is increased by 88% at the lower and 67% at the higher drying rate for a discharge rate of 3C compared to a single layer with compact NCM.

TRiSK-type numerical schemes are widely used in both atmospheric and oceanic dynamical cores, due to their discrete analogues of important properties such as energy conservation and steady geostrophic modes. In this work, we show that these numerical methods are best understood as a discrete exterior calculus (DEC) scheme applied to a Hamiltonian formulation of the rotating shallow water equations based on split exterior calculus. This comprehensive description of the differential geometric underpinnings of TRiSK-type schemes completes the one started in \cite{Thuburn2012,Eldred2017}, and provides a new understanding of certain operators in TRiSK-type schemes as discrete wedge products and topological pairings from split exterior calculus. All known TRiSK-type schemes in the literature are shown to fit inside this general framework, by identifying the (implicit) choices made for various DEC operators by the different schemes. In doing so, unexplored choices and combinations are identified that might offer the possibility of fixing known issues with TRiSK-type schemes such as operator accuracy and Hollingsworth instability., 40 pages, 3 figures

Magnesium–Sulfur batteries are one of most appealing options among the post-lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high overpotentials, low sulfur utilization, and poor Coulombic efficiency. Herein, a functional Mo$_{6}$S$_{8}$ modified separator is designed to effectively address these issues. Both the experimental results and density functional theory calculations show that the electrochemically active Mo6S8 layer has a superior adsorption capability of polysulfides and simultaneously acts as a mediator to accelerate the polysulfide conversion kinetics. Remarkably, the magnesium–sulfur cell assembled with the functional separator delivers a high specific energy density (942.9 mA h g$^{-1}$ in the 1st cycle) and can be cycled at 0.2 C for 200 cycles with a Coulombic efficiency of 96%. This work demonstrates a new design concept toward high-performance metal–sulfur batteries.

Magnesium–Sulfur batteries are one of most appealing options among the post-lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high overpotentials, low sulfur utilization, and poor Coulombic efficiency. Herein, a functional Mo6S8 modified separator is designed to effectively address these issues. Both the experimental results and density functional theory calculations show that the electrochemically active Mo6S8 layer has a superior adsorption capability of polysulfides and simultaneously acts as a mediator to accelerate the polysulfide conversion kinetics. Remarkably, the magnesium–sulfur cell assembled with the functional separator delivers a high specific energy density (942.9 mA h g−1 in the 1st cycle) and can be cycled at 0.2 C for 200 cycles with a Coulombic efficiency of 96%. This work demonstrates a new design concept toward high-performance metal–sulfur batteries.

Unser M��nster / Die Informationsschrift des M��nsterbauvereins Breisach e.V., Nr. 58 (2021): Unser M��nster: Thron der Glocken

Unser Münster / Die Informationsschrift des Münsterbauvereins Breisach e.V., Nr. 57 (2020): Unser Münster: 30 Jahre Unser Münster

International audience; We propose to follow a recent stochastic quasi-geostrophic model [4] derived from a decomposition of the flow into a resolved component and a time-uncorrelated uncertainty. One important characteristic of this random model is that it conserves the total energy along each realization. Such a stochastic principle has been tested for the numerical simulation of the wind-driven circulation in a shallow ocean basin. The numerical assement shows that the proposed random model can well capture on a coarse mesh the correct four-gyre time-averaged circulation structure, as predicted by a direct numerical simulation at a much finer resolution.

We introduce locally conservative, structure-preserving split finite element (FE) discretizations of a y-independent (slice) model of the covariant rotating shallow water equations. Studying this y-independent model case provides insight towards developing schemes for the full 2D rotating shallow equations and more sophisticated models. These split schemes are derived using the split Hamiltonian FE method, which is an extension of the split FE framework of Bauer and Behrens (2018) . The splitting introduces two chains of compatible FE spaces such that the differential operators hold strongly. This leads to a separation of the set of equations into topological prognostic and metric-dependent closure equations. Consequently, the structure preservation is related to the topological equations, namely the conservation of the Hamiltonian (i.e. energy) follows from the antisymmetry of the Poisson bracket and the conservation of mass, potential vorticity and potential enstrophy from the bracket's Casimirs. These structure-preserving properties are not affected by the metric closure equations that, in turn, carry metric information and are therefore responsible for the schemes' accuracy, stability, convergence and discrete dispersion properties. We verify the clear separation of structure preservation and numerical properties analytically and show numerical examples of geophysical relevance for a low order single mesh implementation.

We introduce variational integrators for soundproof approximations of the Euler equations on irregular triangular C-grids. In particular we provide explicit vector-matrix formulations and the solving algorithm for the previously derived discrete covariant equations of Boussinesq, anelastic, and pseudo-incompressible models of [4]. The derivation of these variational integrators is based on a discrete version of the Euler-Poincaré variational method, hence it provides structure-preserving discretizations that preserve Kelvin's circulation theorem and provide excellent long term energy behavior for arbitrary triangular C-grids. We verify the structure-preserving nature of these schemes for various scenarios of geophysical relevance: the hydrostatic adjustment process, the Kelvin-Helmholtz instability, and the cold and warm bubble test cases.

International audience

International audience

Unser Münster / Die Informationsschrift des Münsterbauvereins Breisach e.V., Nr. 55 (2018): Unser Münster: Glockenguss am Stadtpatrozinium

Unser Münster / Die Informationsschrift des Münsterbauvereins Breisach e.V., Nr. 54 (2017): Unser Münster: Meisterliche Altäre

We introduce a new finite element (FE) discretization framework applicable for covariant split equations. The introduction of additional differential forms (DF) that form pairs with the original ones permits the splitting of the equations into topological momentum and continuity equations and metric-dependent closure equations that apply the Hodge-star operator. Our discretization framework conserves this geometrical structure and provides for all DFs proper FE spaces such that the differential operators hold in strong form. We introduce lowest possible order discretizations of the split 1D wave equations, in which the discrete momentum and continuity equations follow by trivial projections onto piecewise constant FE spaces, omitting partial integrations. Approximating the Hodge-star by nontrivial Galerkin projections (GP), the two discrete metric equations follow by projections onto either the piecewise constant (GP0) or piecewise linear (GP1) space. Our framework gives us three schemes with significantly different behavior. The split scheme using twice GP1 is unstable and shares the dispersion relation with the P1-P1 FE scheme that approximates both variables by piecewise linear spaces (P1). The split schemes that apply a mixture of GP1 and GP0 share the dispersion relation with the stable P1-P0 FE scheme that applies piecewise linear and piecewise constant (P0) spaces. However, the split schemes exhibit second order convergence for both quantities of interest. For the split scheme applying twice GP0, we are not aware of a corresponding standard formulation to compare with. Though it does not provide a satisfactory approximation of the dispersion relation as short waves are propagated much too fast, the discovery of the new scheme illustrates the potential of our discretization framework as a toolbox to study and find FE schemes by new combinations of FE spaces., Comment: 30 pages, 9 figures

We introduce a new finite element (FE) discretization framework applicable for covariant split equations. The introduction of additional differential forms (DF) that form pairs with the original ones permits the splitting of the equations into topological momentum and continuity equations and metric-dependent closure equations that apply the Hodge-star operator. Our discretization framework conserves this geometrical structure and provides for all DFs proper FE spaces such that the differential operators hold in strong form. We introduce lowest possible order discretizations of the split 1D wave equations, in which the discrete momentum and continuity equations follow by trivial projections onto piecewise constant FE spaces, omitting partial integrations. Approximating the Hodge-star by nontrivial Galerkin projections (GP), the two discrete metric equations follow by projections onto either the piecewise constant (GP0) or piecewise linear (GP1) space. Our framework gives us three schemes with significantly different behavior. The split scheme using twice GP1 is unstable and shares the dispersion relation with the P1-P1 FE scheme that approximates both variables by piecewise linear spaces (P1). The split schemes that apply a mixture of GP1 and GP0 share the dispersion relation with the stable P1-P0 FE scheme that applies piecewise linear and piecewise constant (P0) spaces. However, the split schemes exhibit second order convergence for both quantities of interest. For the split scheme applying twice GP0, we are not aware of a corresponding standard formulation to compare with. Though it does not provide a satisfactory approximation of the dispersion relation as short waves are propagated much too fast, the discovery of the new scheme illustrates the potential of our discretization framework as a toolbox to study and find FE schemes by new combinations of FE spaces., 30 pages, 9 figures

Unser Münster / Die Informationsschrift des Münsterbauvereins Breisach e.V., Nr. 53 (2016): Unser Münster: Sankt Stephan

250 Jahre Johann Wolfgang von Goethe Symposium Goethe-Wirkung und Gegenwart, ゲーテ生誕２０５周年記念シンポジウム 現代におけるゲーテの影響

The invention relates to a device for die cutting a stack consisting of sheet-type materials, in particular labels. According to said method, a movement of a stack to be cut in relation to a hollow cylindrical die-cutter blade causes the stack to be pushed into said die-cutter blade. This type of device comprises a frame (16), with clamping elements (17) mounted therein for fixing the die-cutter blade (18), said elements being displaced and fixed in relation to the frame (16), in addition to an adjusting element (70, 72) mounted in the frame (16) for the flush alignment, using at least one alignment edge of said adjusting element (70, 72), with a section of a cutting edge (69) of the die-cutter blade (18), prior to the fixation of the positioned clamping elements (17). A die-cutter device of this type enables the die-cutter blade to be preset in order to achieve an optimum positioning of the latter in relation to the stack to be cut.

The compatible finite element method has recently gained an increased interest in numerical weather prediction, as it allows for higher order discretisations and more general meshes, thus avoiding the parallel computing issues associated with grid poles. Further, it can be seen as a finite element extension of the Arakawa finite difference C grid. A dynamical core based on it is currently in development at the UK Met Office, due to replace the current finite difference latitude longitude grid discretisation. In this thesis, we focus on compatible finite element discretisations that are energy conserving, which is an important property in particular for climate simulations. This is achieved using a Hamiltonian framework, where energy conservation is expressed via the antisymmetry of a Poisson bracket that underlies the governing equations. In order to achieve an improved field development, we newly incorporate into the Poisson bracket Discontinuous Galerkin upwind and Streamline Upwind Petrov Galerkin stabilisation methods for the thermal, density related, and vorticity field equations. The energy conserving property is validated by coupling the upwind-stabilised spatial discretisations to an energy conserving time discretisation. Further, the discretisations are demonstrated to lead to an improved field development with respect to stability for the 2D and 3D dry compressible Euler, rotating shallow water, and thermal rotating shallow water equations. Open Access

Im Rahmen dieser Arbeit wurden experimentelle Untersuchungen an pneumatisch geförderten Schüttgutpfropfen durchgeführt. Dazu wurde ein Messsensor entwickelt, der es ermöglicht, die an einem pneumatisch geförderten Schüttgutpfropfen auftretenden Spannungen an der Förderrohrwand sowie den Druckverlust des durchströmenden Fördergases gleichzeitig zu detektieren ohne dabei den eigentlichen Fördervorgang zu beeinflussen. Es zeigt sich, dass die Förderstabilität maßgeblich durch den Porositätsgradienten entlang des Pfropfens beeinflusst wird. Die Ergebnisse wurden mit theoretischen Modellen aus der Literatur verglichen. Alle bisherigen Ansätze zur Erklärung der an einem Schüttgutpfropfen auftretenden Spannungen konnten nicht bestätigt werden, da die inhomogen fluidisierten Pfropfen insbesondere eine Wandschubspannung aufweisen. Berechnungen basierend auf Einzelpartikelstößen zeigen eine sehr gute Übereinstimmung der Wandschubspannung eines pneumatisch geförderten Schüttgutpfropfens mit den experimentellen Ergebnissen. In the context of this study experimental investigations on pneumatically conveyed plugs are carried out. Therefore a measuring method is developed to detect wall shear stress, normal stress and pressure drop of plugs at the same time. The results show, that plug stability is mainly influenced by the porosity gradient of the plug itself. The experimental results are compared with different theoretical plug models from literature. These approaches to explain and to determine wall shear stress, normal stress and pressure drop of a plug during pneumatic conveying cannot be confirmed. The reason therefore is the occurring wall shear stress of the inhomogeneous fluidised plugs. Theoretical calculations of the wall shear stress of pneumatically conveyed plugs based on single particle wall impacts are verified by the experimental results.