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Now showing items 21-30 of 229
Aufsatz
Effect of Crystallographic Orientation and Grain Boundaries on Martensitic Transformation and Superelastic Response of Oligocrystalline Fe–Mn–Al–Ni Shape Memory Alloys
(2021-07-26)
In situ tensile tests employing digital image correlation were conducted to study the martensitic transformation of oligocrystalline Fe–Mn–Al–Ni shape memory alloys in depth. The influence of different grain orientations, i.e., near-〈001〉 and near-〈101〉, as well as the influence of different grain boundary misorientations are in focus of the present work. The results reveal that the reversibility of the martensite strongly depends on the type of martensitic evolving, i.e., twinned or detwinned. Furthermore, it is ...
Aufsatz
Drought stress triggers differential survival and functional trait responses in the establishment of Arnica montana seedlings
(2021-07-15)
- The establishment and survival of seedlings are critical stages in the life cycle of plants and therefore usually well timed to humid and favourable conditions. Climate projections suggest that the threatened mountain grassland species Arnica montana may be increasingly exposed to drought stress. However, studies that focus on the species’ early development are missing. We evaluated impacts of drought-induced stress on A. montana seedlings in their early establishment phase and identified traits that could cause ...
Aufsatz
Extension of Gap Bridgeability and Prevention of Oxide Lines in the Welding Seam through Application of Tools with Multi-Welding Pins
(2021-07-30)
Friction stir welding has become important in many areas of production and is increasingly used for joining aluminum components. For long welding seams, conventional tools with only one welding pin reach their technical limitations due to low gap bridgeability. When welding aluminum, the stirred in surface layers, such as oxides, lead to a decrease in static and dynamic strength since linear accumulations are formed in the welding seam. The aim of the present study is to increase the gap bridgeability using tools ...
Aufsatz
Photon–electron coincidence experiments at synchrotron radiation facilities with arbitrary bunch modes
(2021-04-21)
We report the adaptation of an electron–photon coincidence detection scheme to the multibunch hybrid mode of the synchrotron radiation source BESSY II (Helmholtz-Zentrum Berlin). Single-event-based data acquisition and evaluation, combined with the use of relative detection times between the coincident particles, enable the acquisition of proper coincidence signals from a quasi-continuous excitation pattern. The background signal produced by accidental coincidences in the time difference representation is modeled ...
Aufsatz
On the appearance of horseshoe chaos in a nonlinear hysteretic systems with negative stiffness
(2021-09-16)
The problem of inhibition of horseshoe chaos in a nonlinear hysteretic systems using negative stiffness is investigated in this paper. The Bouc–Wen model is used to describe the force produced by both the purely hysteretic and linear elastic springs. The analytical investigation of the Hamiltonian shows that the appearance of separatrix in the system is directly related to the parameters of the hysteretic forces. This means that the transverse intersection between the perturbed and unperturbed separatrix can be ...
Aufsatz
Stakeholder Influence on Sustainable Supply Chain Management: A Case Study of a German Apparel Frontrunner
(2021-10-12)
Although interest in green and sustainable supply chains has been growing for over a decade in the academic discourse, the textile industry still embraces numerous examples of non-sustainable behavior (i.e., environmental damage, poor working conditions, or modern slavery). While there is a general agreement that stakeholder pressure can lead to more sustainable SCs, a lot remains for a more differentiated stakeholder perspective in sustainable supply chain management (SSCM). Thus, this study aims for theory elaboration ...
Aufsatz
Self-referencing circular dichroism ion yield measurements for improved statistics using femtosecond laser pulses
(2021-03-10)
The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source ...
Aufsatz
Sensitivity of Convection-Permitting Regional Climate Simulations to Changes in Land Cover Input Data: Role of Land Surface Characteristics for Temperature and Climate Extremes
(2021-10-14)
Characterization of climate uncertainties due to different land cover maps in regional climate models is essential for adaptation strategies. The spatiotemporal heterogeneity in surface characteristics is considered to play a key role in terrestrial surface processes. Here, we quantified the sensitivity of model results to changes in land cover input data (GlobCover 2009, GLC 2000, CCI, and ECOCLIMAP) in the regional climate model (RCM) COSMO-CLM (v5.0_clm16). We investigated land cover changes due to the retrieval ...
Aufsatz
Technological Frames in the Digital Age: Theory, Measurement Instrument, and Future Research Areas
(2021-05-21)
Digital technologies fuel technological change that generates substantial uncertainty and complexity. Corporate actors rely on their technological frames to cope with these challenges. Technological frames determine how actors interpret, assess, and shape a technology’s development, usage, and trajectory. However, the research fails to provide insights into the microfoundations that can explain the consequences of heterogeneity in technological frames. We argue that this research gap is due to a lack of a proper ...
Aufsatz
Animal Welfare Consequences of Organic Boar Fattening and Occurrence of Boar Taint on Five Commercial Farms
(2021-10-10)
Simple Summary
The usual castration of male fattening pigs is under discussion, especially in organic farming, because of the negative effects on the pig’s welfare and integrity. Nevertheless, it is feared that boars show more aggressive and mounting behaviours, resulting in stress, painful injuries and lameness, and that their meat has an unpleasant odour/taste (called “boar taint”). Therefore, it was examined to which extent these concerns come true under commercial organic conditions. Additionally, influences ...