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Rezension: Jutta Ströter-Bender, Larissa Eickermann, Susanne Völker (Hg. / Eds.) Die Kinder- und Jugendzeichnungen der Brüder Grimm und ihrer Familie: "Ein Fenster in die Vergangenheit" / The Children's and Youth Drawings of the Brothers Grimm and Family: "A Window into the Past". KONTEXT Kunst - Vermittlung - Kulturelle Bildung, Band 38. Baden-Baden: Tectum Verlag, 2023 (352 S.), ISBN (Print) 978-3-8288-4904-4, ISBN (ePDF) 978-3-8288-5032-3, ISSN 1868-6060
No full textDer Sammelband präsentiert und analysiert bisher unerforschte Kinder- und Jugendzeichnungen von Jacob und Wilhelm Grimm sowie deren Familie. Diese Skizzen, Zeichnungen und Aquarelle bieten nicht nur einen einzigartigen Blick auf das familiäre Leben und die Kreativität der weltberühmten Märchensammler und Sprachwissenschaftler im 19.Jahrhundert, sondern spiegeln auch die zeitgenössische Kinder- und Jugendkultur. Der Bildkatalog im Anhang ermöglicht Leser*innen, die Originale systematisch zu erkunden und in den bildlichen Kosmos der Grimms einzutauchen. Die zweisprachige Ausgabe – deutsch und englisch – unterstreicht den internationalen Anspruch über das nationale Kulturerbe hinaus und betont die Bedeutung dieser Werke im Kontext des Weltdokumentenerbes
Development and comparison of bare soil moisture retrieval methods for compact polarimetric data
No full textRetrieval of soil moisture is crucial for weather and climate change predictions as well as in decision-making for agriculture management practices. Several theoretical, semi-empirical, empirical, and machine learning-based scattering models have been developed for simulating fully polarimetric (FP) synthetic aperture radar (SAR) data. The potential of SAR compact polarimetry (CP) for soil moisture retrieval over bare agriculture fields is still an active area of research. In this study, we develop new CP backscattering models for soil moisture retrieval under bare soil conditions. First, we apply empirical relationships between FP and CP to formulate an empirical CP-advanced integral equation model (AIEM). In addition, we propose two adapted theoretical models CP-AIEM and CP-improved IEM (CP-I2EM) using the direct analytical relationship between FP and CP. We also propose two empirical models CP-Dubois and CP-Oh by recalibrating Dubois and Oh models using CP observations and in situ data. To compare the soil moisture retrieval performance of developed CP-backscattering models with that of a standard machine learning approach, the random forest (RF) technique is utilized. The six adapted and developed algorithms are tested using the C-band CP data of Canada’s RADARSAT constellation mission (RCM). In situ soil moisture, roughness, and texture measurements were collected from bare agriculture fields of Lennoxville and Montérégie, Quebec, Canada, for calibration and validation of models. Results show that the RF model provides accurate estimates (error: RMSE = 0.04 m3/m3, correlation: r = 0.8 and inversion rate: (IR) = 100%) while requiring extensive training. CP-Oh and CP-Dubois models perform adequately (RMSE = 0.08 m3/m3, r > 0.7 and IR > 60%) having limited applicability range. In the end, CP-AIEM offers the best choice including reasonable accuracy (RMSE = 0.07 m3/m3, r = 0.6, and IR = 64%), wider applicability range and transferability without requiring calibration
Coins as proxy for urban development: rethinking Augusta Vindelicum via digital geonumismatics
No full textCoins constitute an exceptional source of archaeological, chronological, and historical information. In this paper, we explore the potential of Geographic Information Systems (GIS) for analyzing a selection of over 4000 Roman coins unearthed within the city of Augsburg (Germany). By integrating the numismatic database built by the local Stadtarchäologie in the existing AugustaGIS developed in cooperation with the University of Augsburg, we were able to visualize the density and distribution of the coins, offering new hints to interpret the urban development of the city. In particular, we present two case studies to showcase the relevance of the approach, the first related to the formative phase of the settlement in early Imperial times, and the second devoted to better understanding the extension of the city during the Late Roman period (4th to early 5th century AD)
Wohnen in der Warteschleife: eine qualitative Analyse der Konflikte von Familien in Wohnungsnot auf dem Augsburger Wohnungsmarkt
No full textIn dieser Masterarbeit werden Konflikte von Familien in Wohnungsnot auf dem Augsburger Wohnungsmarkt untersucht. Grundlage der Untersuchung sind sieben problemzentrierte Interviews mit betroffenen Elternteilen, die inhaltsanalytisch ausgewertet wurden. Dabei wurden sechs zentrale Konflikterfahrungen deutlich: fehlende Rückmeldungen und mangelhafte Kommunikation, nicht nachvollziehbare Absagen, Diskriminierung und Stigmatisierung, die Wahrnehmung einer ungerechten Bevorzugung von Migrant:innen, eine finanzielle Priorisierung unter Ausklammerung sozialer Faktoren sowie Druck und mangelndes Verständnis. Diese Konflikterfahrungen sind mit erheblichen emotionalen Belastungen verbunden und werden von den Interviewpartner:innen als dauerhaftes Gefühl von Unsicherheit und Instabilität beschrieben. Unter Bezugnahme auf die Desintegrationstheorie lassen sich drei zentrale Ansätze zur Bearbeitung dieser Konflikte ableiten. Dazu zählt ein integratives Wohnraummodell, die Einrichtung einer wohnungsmarktspezifischen Konfliktmediationsstelle sowie die Etablierung eines dialogischen Austauschformats. Die Arbeit leistet somit einen ersten Einblick in die Konflikte von Familien in Wohnungsnot im Kontext eines spezifischen urbanen Wohnungsmarktes
Tunable electrochemical hydrogen evolution reaction employing surface acoustic waves
No full textElectrolysis of water is an attractive hydrogen generation method. As the most efficient catalyst for this reaction is platinum (Pt), what makes this approach expensive, many studies focus on enhancing the hydrogen producing efficiency of other inexpensive catalysts. In this study, an Au electrode and Au supported Pt/TiO2 electrode without UV illumination were chosen as the catalyst for electrochemical hydrogen evolution reaction (HER) in acidic solution, and a Rayleigh-type surface acoustic wave (SAW) was used to promote the HER. Our results demonstrate that under the influence of SAW, both electrodes exhibit better HER activity with a higher current in the polarization curves from cyclic voltammetry. Analyzing the Tafel slope and the exchange current density with and without the effect of SAW suggests the enhancement of the HER activity especially at low overpotentials up to 100 mV. The effect strength increases with increasing power of the radio frequency (RF) signal. Various control experiments indicate that this is mainly induced by a microstreaming effect caused by the mechanical vibration of the SAW, while an off-resonance RF signal with a comparable electric field only reaches about 16.5 % of the increase of the current density at medium overpotentials. Thus, SAW-induced acoustic streaming is shown as tunable method to boost hydrogen production especially in the low and medium range of overpotential with promising potential for broader application in electrocatalysis and photocatalysis
Higher-order discontinuous Galerkin splitting schemes for fluids with variable viscosity
No full textThis article investigates matrix-free higher-order discontinuous Galerkin discretizations of the Navier–Stokes equations for incompressible flows with variable viscosity. The viscosity field may be prescribed analytically or governed by a rheological law, as often found in biomedical or industrial applications. The DG discretization of the adapted second-order viscous terms is carried out via the symmetric interior penalty Galerkin method, obviating auxiliary variables. Based on this spatial discretization, we compare several linearized variants of saddle point block systems and projection-based splitting time integration schemes in terms of their computational performance. Compared to the velocity-pressure block-system for the former, the splitting scheme allows solving a sequence of simple problems such as mass, convection-diffusion and Poisson equations. We investigate under which conditions the improved temporal stability of fully implicit schemes and resulting expensive nonlinear solves outperform the splitting schemes and linearized variants that are stable under hyperbolic time step restrictions. The key aspects of this work are i) a higher-order DG discretization for incompressible flows with variable viscosity, ii) accelerated nonlinear solver variants and suitable linearizations adopting a matrix-free
-multigrid solver, and iii) a detailed comparison of the monolithic and projection-based solvers in terms of their (non-)linear solver performance.
The presented schemes are evaluated in a series of numerical examples verifying their spatial and temporal accuracy, and the preconditioner performance under increasing viscosity contrasts, while their efficiency is showcased in the backward-facing step benchmark
LCA‐based evaluation of greenhouse gas reduction potentials of carbon/carbon wheel brakes for medium‐haul aircraft
No full textAir transport is expected to substantially grow in the next decades, presenting a significant challenge for the aviation industry to reconcile this growth with the need to mitigate climate change by reducing greenhouse gas (GHG) emissions. A viable strategy for diminishing aviation emissions involves reducing aircraft fuel consumption, which can inter alia be achieved by incorporating lightweight ceramic matrix composites (CMC) into aircraft components. However, this is offset by an energy-intensive production of CMC, and there remains limited understanding of the environmental impacts associated with this group of materials. This study aims to assess the potential of carbon/carbon (C/C) wheel brakes to reduce large passenger aircraft emissions. Employing a cradle-to-grave approach, a life cycle assessment based on ISO standards was conducted. The findings indicate that, although the production of a C/C wheel brake incurs a markedly greater carbon footprint than its metallic counterpart, the lightweight and durability aspect of C/C significantly contribute to decreased GHG emissions over the entire service life of an aircraft across all evaluated scenarios. Furthermore, the results emphasize the importance of component durability and improved manufacturing process control in enhancing emission savings, ultimately guiding stakeholders toward informed decisions regarding the use of CMC for sustainable aircraft design