Ausbildung von Rettungspersonal: Worin und wozu?

Zusammenfassung: Für viele an und für sich akzeptierte Interventionen in der Notfallmedizin fehlt die wissenschaftliche Evidenz. Das erschwert zwangsläufig die Ausbildungsinhalte des eingesetzten Personals. Rettungssanitäter werden in der Schweiz in allen lebensrettenden Basismaßnahmen ausgebildet, können aber in delegierter Kompetenz auch gewisse ärztliche Interventionen ausführen. Für Notärzte gilt, dass nur erfahrene und gut ausgebildete Kliniker im Rahmen eines strukturierten Weiterbildungsprogramms, respektive nach dessen Abschluss zum Einsatz kommen sollen, was dann aufgrund ihrer Entscheidungskompetenz und Teamleitungsfunktion auch in ethischen Spannungsfeldern vorteilhaft is

Structural-thermal FE simulation of vibration and heat generation of cracked steel plates due to ultrasound excitation used for vibrothermography

A major drawback of ultrasound excited thermography applied to metal components manifests in the pronounced frequency dependence of crack detectability. In order to investigate the crack face interaction by which it is constituted whether a certain crack can be detected or not structural-thermal Finite Element simulations of a massive steel plate are conducted using ANSYS/LS-DYNA considering the physical roughness of the crack faces. The achieved numerical results are in a good agreement with experimental data of a performed ultrasonic sweep thermography (UST)

DeMoN: Depth and Motion Network for Learning Monocular Stereo

In this paper we formulate structure from motion as a learning problem. We train a convolutional network end-to-end to compute depth and camera motion from successive, unconstrained image pairs. The architecture is composed of multiple stacked encoder-decoder networks, the core part being an iterative network that is able to improve its own predictions. The network estimates not only depth and motion, but additionally surface normals, optical flow between the images and confidence of the matching. A crucial component of the approach is a training loss based on spatial relative differences. Compared to traditional two-frame structure from motion methods, results are more accurate and more robust. In contrast to the popular depth-from-single-image networks, DeMoN learns the concept of matching and, thus, better generalizes to structures not seen during training.Comment: Camera ready version for CVPR 2017. Supplementary material included. Project page: http://lmb.informatik.uni-freiburg.de/people/ummenhof/depthmotionnet

Calibration of High-Frequency Mechanical Impact Simulation Based on Drop Tests

A series of drop tests was implemented in the present study in order to allow the reproduction of a single impact identical to the high frequency mechanical impact (HFMI) under monitored conditions in the laboratory. Therewith, characterization of the investigated material’s mechanical behavior by explicitly considering possible irregularities concerning the present deformation modes would be enabled. Main goal was the determination of the investigated material’s dynamic yield stress for various strain rates inside the spectrum of interest, so that the Cowper–Symonds viscous material model would be calibrated for the subsequent HFMI simulation. The values of the dynamic yield stress extracted by the present drop tests show good agreement with other experimental methods regarding the investigated material S355. The introduction of the calibrated material behavior on the present drop tests in the finite element (FE) analysis of HFMI led to reduced preciseness though, in comparison with the FE analysis, which considered high strain rate tensile tests found in literature. A series of conclusions was drawn from both the experimental and numerical investigations, confirming most of the initial expectations. Further work is proposed, in order to clarify an incompatibility met during the numerical investigations

Extreme weather and climate events with ecological relevance : a review

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Philosophical Transactions of the Royal Society of London.Series B, Biological Sciences, 372 (2017): 2016.0135, doi: 10.1098/rstb.2016.0135.Robust evidence exists that certain extreme weather and climate events, especially daily temperature and precipitation extremes, have changed in regard to intensity and frequency over recent decades. These changes have been linked to human-induced climate change, while the degree to which climate change impacts an individual extreme climate event (ECE) is more difficult to quantify. Rapid progress in event attribution has recently been made through improved understanding of observed and simulated climate variability, methods for event attribution and advances in numerical modelling. Attribution for extreme temperature events is stronger compared with other event types, notably those related to the hydrological cycle. Recent advances in the understanding of ECEs, both in observations and their representation in state-of-the-art climate models, open new opportunities for assessing their effect on human and natural systems. Improved spatial resolution in global climate models and advances in statistical and dynamical downscaling now provide climatic information at appropriate spatial and temporal scales. Together with the continued development of Earth System Models that simulate biogeochemical cycles and interactions with the biosphere at increasing complexity, these make it possible to develop a mechanistic understanding of how ECEs affect biological processes, ecosystem functioning and adaptation capabilities. Limitations in the observational network, both for physical climate system parameters and even more so for long-term ecological monitoring, have hampered progress in understanding bio-physical interactions across a range of scales. New opportunities for assessing how ECEs modulate ecosystem structure and functioning arise from better scientific understanding of ECEs coupled with technological advances in observing systems and instrumentation.Portions of this study were supported by the Regional and Global Climate Modeling Program (RGCM) of the U.S. Department of Energy's Office of Biological & Environmental Research (BER) Cooperative Agreement #DE-FC02-97ER62402, and the National Science Foundation

A pseudothermal approach for simulating the residual stress field caused by shot blasting

Industrial practice often prescribes cleaning of steel surfaces prior to welding with shot blasting. Shot blasted components have been considered free of residual stresses. Hence, recent studies show that these residual stresses from mechanical surface treatments are not negligible. A simulation of the surface treatments and their mechanical effect in full scale though, is not possible under modern computational capabilities. Instead, a straightforward, pseudothermal approach is proposed and tested in the present study, in order to introduce an initial residual stress field from shot blasting by application of thermal strains. This engineering concept is applied for validation reasons on a small-scale specimen, where a measured profile of residual stresses from shot blasting is simulated with preciseness. Subsequently a component with dimensions of real weldments is modelled, so that simplifications reducing the computational time to acceptable levels can be derived

Influence of welding parameters on the welding residual stresses

FE simulation of welds from austenitic steel was carried out in the current paper. Two different multi-pass welds were modelled. Measurements of welding residual stresses, which were found in literature, were applied for the validation of the results. The validated models were then used as basis for sensitivity analysis. The influence of differentiating the welding speed, the heat input of the weld heat source, intermediate cooling between consecutive weld-passes and welding sequence on the welding residual stresses was investigated