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Now showing items 181-190 of 192
Aufsatz
Spatial and Temporal Dynamics of Urban Wetlands in an Indian Megacity over the Past 50 Years
(2020-02-17)
Asian megacities have attracted much scientific attention in the context of global urbanization, but few quantitative studies analyze wetland transformation in the rural–urban interface. With its rampant growth and transformation from a tree-lined “Garden City” to a busy megalopolis with often-blocked highways and large built-up areas, Bengaluru (Karnataka, S-India) is a good example for assessing how urbanization has led to the acute degradation of wetlands. We therefore investigated long-term land cover and wetland ...
Aufsatz
Co-Creation durch Peers im digitalen Lernen – Wie Plattformen und Chatbots die Partizipation bei der Lernmaterialerstellung begleiten können
(2020-07-07)
Die Arbeit in Industrieunternehmen verändert sich auf Grund der Digitalisierung grundlegend. Entwicklungen in der Automatisierungstechnik können in naher Zukunft einen Teil der Arbeit von Arbeitnehmenden ersetzen. Dadurch wird es notwendig sein, sich auf die sich schnell wechselnden Qualifikationsanforderungen aus diesem Digitalisierungsprozess einzustellen. Hierzu gehört einerseits die schnelle Reaktionsfähigkeit auf die fortlaufenden Veränderungen, die in Unternehmen stattfinden, beispielsweise die Einbettung neuer ...
Aufsatz
Probabilistic upscaling and aggregation of wind power forecasts
(2020-03-16)
Background
Wind power forecasts of the expected wind feed-in for the next hours or days are necessary to integrate the generated volatile wind energy into power systems. Most forecasting models predict in some sense the best value, but they ignore the other possible outcomes which may arise because of forecasting uncertainties. Probabilistic forecasts, on the other hand, also predict a distribution of possible outcomes with their respective probabilities that specific power values will occur and therefore have higher ...
Aufsatz
Bacterivorous Nematodes Correlate with Soil Fertility and Improved Crop Production in an Organic Minimum Tillage System
(2020-08-19)
Reduced nutrient mineralization rates under minimum tillage are usually compensated by mineral fertilizer application. These, however, cannot be applied in organic farming systems. We hypothesized that an organic minimum tillage system based on frequent cover cropping and application of dead mulch would improve soil fertility and compensate for the potential negative effects of minimum tillage. Two long-term field experiments were set up in 2010 and 2011 to compare plowing versus minimum tillage including the application ...
Aufsatz
Integrated reporting of environmental, social, and governance and financial data: Does the market value integrated reports?
(2020-01-09)
The concept of reporting nonfinancial information within the annual report, so‐called Integrated Reporting (IR) is a rising topic in reporting practice. Supporters claim that IR provides a better view regarding the value creation of a firm.
This study investigates the value relevance of IR and the influence of certain characteristics such as assurance. Thus, this paper contributes to the existing literature by examining the actual advantages for firms when adopting an IR approach.
The Ohlson model is applied for ...
Aufsatz
Dynamic Tensile Deformation of High Strength Aluminum Alloys Processed Following Novel Thermomechanical Treatment Strategies
(2020-05-14)
Herein, the effects of a very recently introduced novel thermomechanical process route on the microstructural evolution and dynamic tensile deformation behavior of two different precipitation hardenable aluminum alloys, i.e., AA6082 and AA7075, are studied. The investigated materials are hot formed and quenched in differently tempered tools to reveal the influence of cooling rate. Microstructure analysis is conducted to study the influences of different cooling strategies on the microstructure evolution and prevailing ...
Aufsatz
Effect of Compositional Variation Induced by EBM Processing on Deformation Behavior and Phase Stability of Austenitic Cr-Mn-Ni TRIP Steel
(2020-01-24)
Electron beam melting (EBM) is an established powder bed-based additive manufacturing process for the fabrication of complex-shaped metallic components. For metastable austenitic Cr-Mn-Ni TRIP steel, the formation of a homogeneous fine-grained microstructure and outstanding damage tolerance have been reported. However, depending on the process parameters, a certain fraction of Mn evaporates. This can have a significant impact on deformation mechanisms as well as kinetics, as was previously shown for as-cast material. ...
Aufsatz
On the Impact of Texture and Grain Size on the Pseudoelastic Properties of Polycrystalline Fe–Ni–Co–Al–Ti Alloy
(2020-05-08)
The effects of thermomechanical treatments on crystallographic texture and grain size evolution and their impact on the pseudoelastic properties in Fe41–Ni28–Co17–Al11.5–Ti2.5 (at.%) were studied in the present paper. The results show that cold rolling leads to brass-type texture in this alloy, which is typical for low stacking fault energy materials. Thermal treatments up to 1300 °C were conducted and it is shown that the presence of β-phase helps to control grain growth. After the dissolution of the secondary phase ...
Aufsatz
On the Influence of Surface Hardening Treatments on Microstructure Evolution and Residual Stress in Microalloyed Medium Carbon Steel
(2020-06-09)
Tailoring surface properties is a key to superior performance of components subjected to fatigue loadings in application. Process–microstructure–property relationships have to be established to allow for optimization of techniques employed for surface treatments such as deep rolling and induction hardening. Although both techniques are employed widely in industrial application, studies examining microstructure evolution and residual stress states for a single material in a comparative manner are missing. Amongst ...
Aufsatz
On the Influence of Microstructure on the Corrosion Behavior of Fe–Mn–Al–Ni Shape Memory Alloy in 5.0 wt% NaCl Solution
(2020-10-03)
Herein the corrosion behavior of Fe–Mn–Al–Ni shape memory alloys characterized by different microstructures in a 5.0 wt% NaCl solution is investigated. Open circuit potential and potentiodynamic polarisation tests are conducted. Generally, Fe–Mn–Al–Ni shows corrosion properties being similar to pure iron. However, the polarization curves of single crystals indicate the presence of an unstable passive system. The corrosion damage is analyzed by means of optical microscopy and electron microscopy. It is revealed that ...