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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 ...
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Thermal Stability of Residual Stresses in Differently Deep Rolled Surface Layers of Steel SAE 1045
(2021-05-07)
The stability of compressive residual stresses generated by deep rolling plays a decisive role on the fatigue behavior of specimens and components, respectively. In this regard, deep rolling at elevated temperature has proven to be very effective in stabilizing residual stresses when fatigue analysis is conducted at ambient temperature. However, since residual stresses can be affected not only by plastic deformation but also when thermal energy is provided, it is necessary to analyze the influence of temperature and ...
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Cooling rate as a process parameter in advanced roll forming to tailor microstructure,mechanical and corrosion properties of EN AW 7075 tubes
(2022-12-14)
The effects of solution heat treatment parameters and quench media as a processing tool for tailoring microstructure, mechanical and corrosion properties in roll forming of EN AW 7075 alloy were studied. The highest yield stress and ultimate tensile strength were obtained for the specimens quenched in water, while the air-cooled specimens exhibited inferior mechanical properties. Microstructural analysis of specimens showed that except water-quenched specimens, the parts cooled/quenched in oil, in direct contact with ...
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A hitchhiker’s guide: estimates of microbial biomass and microbial gene abundance in soil
(2024-03-19)
Information on microbial biomass carbon (MBC) is crucial to assess their stocks and role for plant nutrient release in soil. Next to fumigation-extraction, molecular methods are routinely used to estimate the contribution of fungi, bacteria, and archaea to the soil microbial community. However, more information on the links between these different indices would deepen the understanding of microbial processes. The current study is based on 11 datasets, which contain MBC and MBN data obtained by fumigation-extraction ...
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Gesundheit und Studienpensum von Studierenden: Ergebnisse eines Gesundheitssurveys an der Universität Kassel
(2023-04-28)
Einleitung
Über Gesundheit und Krankheit von Studierenden ist relativ wenig bekannt und die Auswirkungen auf den Studienerfolg sind kaum erforscht. Das Ziel der Studie ist, Assoziationen zwischen dem Gesundheitszustand von Studierenden und dem absolvierten Studienpensum zu analysieren.
Methoden
Es nahmen 3330 von 23.699 immatrikulierten Studierenden der Universität Kassel an der freiwilligen Befragung („computer assisted web interviews“) im März 2022 teil. Die Rücklaufquote betrug 14,1 % unter Bedingungen der ...
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Shared digital artifacts – Co-creators as beneficiaries in microlearning development
(2023-08-11)
Continuing vocational training benefits from the employees’ ability to share individual experience and expertise with their co-workers, as these assets constitute competitive advantages for companies. IT-supported systems can facilitate processes of knowledge elicitation (e. g. as part of collaborative co-creation) to ensure retainment of preferred qualitative characteristics of the resulting knowledge artifacts and provide ample opportunities to manage and configure a growing number of such artifacts in a company’s ...
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Impact of Pea necrotic yellow dwarf virus (PNYDV) on nodulation, N₂ fixation and yield in faba bean (Vicia faba, L.)
(2022-08-09)
Pea necrotic yellow dwarf virus (PNYDV) is a novel nanovirus in Europe, affecting various grain legumes. The impact of PNYDV on nodulation, symbiotic N₂ fixation and yield parameters in faba bean (Vicia faba L.) was investigated at controlled conditions in the greenhouse (2017), on-farm in natural infection foci (2018, 2019) and in a small-scale field experiment (2020). In the latter, the standard variety ‘Fuego’ was compared with the variety ‘GL Sunrise’ in early and late infections. In addition, the analogous effects ...
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Receding-Horizon Control of Constrained Switched Systems with Neural Networks as Parametric Function Approximators
(2022-11-21)
This work studies receding-horizon control of discrete-time switched linear systems subject to polytopic constraints for the continuous states and inputs. The objective is to approximate the optimal receding-horizon control strategy for cases in which the online computation is intractable due to the necessity of solving mixed-integer quadratic programs in each discrete time instant. The proposed approach builds upon an approximated optimal finite-horizon control law in closed-loop form with guaranteed constraint ...
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Relationships between feeding and microbial faeces indices in dairy cows at different milk yield levels
(2019-08-20)
A study was carried out to gain quantitative information on the diet-dependent faecal microbial biomass of dairy cows, especially on the biomass fractions of fungi, Gram-positive (G+) and Gram-negative (G-) bacteria. Groups of high-yield, low-yield and non-lactating cows were investigated at four different farms. A mean faecal microbial biomass C (MBC) concentration of 33.5 mg g-1 DM was obtained by the chloroform fumigation extraction method. This is similar to a mean microbial C concentration of 31.8 mg g-1 DM, ...
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Reliabilität und Validität des OPD-KJ-Konfliktfragebogens bei stationär behandelten Jugendlichen
(2021-06-15)
Mit dem OPD-KJ-Konfliktfragebogen (OPD-KJ-KF) können intrapsychische Konflikte gemäß der Operationalisierten Psychodynamischen Diagnostik im Kindes- und Jugendalter (OPD-KJ-2) einfach und zeitökonomisch erfasst werden. Der Fragebogen existiert in zwei Fassungen: als Selbstbeurteilungsinstrument für Jugendliche und als Fremdbeurteilungsinstrument für Therapeutinnen und Therapeuten. In einer Stichprobe stationär behandelter Jugendlicher wurden psychometrische Gütekriterien (interne Konsistenz, Konstruktvalidität, ...