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Now showing items 1601-1610 of 1953
Aufsatz
On the influence of build orientation on properties of friction stir welded AleSi10Mg parts produced by selective laser melting
(2021-04-06)
Welding and joining of components processed by additive manufacturing (AM) to other AM as well as conventionally produced components is of high importance for industry as this allows to combine advantages of either technique and to produce large-scale structures, respectively. One of the key influencing factors with respect to weldability and mechanical properties of AM components was found to be the inherent microstructural anisotropy of these components. In present work, the precipitation-hardenable Al–Si10Mg was ...
Aufsatz
Effect of Grain Statistics on Micromechanical Modeling: The Example of Additively Manufactured Materials Examined by Electron Backscatter Diffraction
(2020-02-21)
Micromechanical modeling is one of the prominent numerical tools for the prediction of mechanical properties and the understanding of deformation mechanisms of metals. As input parameters, it uses data obtained from microstructure characterization techniques, among which the electron backscatter diffraction (EBSD) technique allows us to understand the nature of microstructural features, that are usually described by statistics. Because of these advantages, the EBSD dataset is widely used for synthetic microstructure ...
Aufsatz
Effect of Tool Temperature on Mechanical Properties and Microstructure of Thermo-Mechanically Processed AA6082 and AA7075 Aluminum Alloys
(2020-06-08)
The present work focuses on the effect of thermo-mechanical processing on the mechanical properties and microstructural evolution of AA6082 and AA7075 aluminum alloys using a novel forming process, i. e. integrating solution heat treatment, hot forming and tool quenching. Different tool temperatures ranging from 24 °C to 350 °C were applied to investigate their influence on mechanical strength and ductility. By using various tool temperatures, this study aims to provide insights needed for tailoring the mechanical ...
Aufsatz
Assessing segmental versus non-segmental features in the ventral nervous system of onychophorans (velvet worms)
(2017-01-03)
Background:
Due to their phylogenetic position as one of the closest arthropod relatives, studies of the organisation of the nervous system in onychophorans play a key role for understanding the evolution of body segmentation in arthropods. Previous studies revealed that, in contrast to the arthropods, segmentally repeated ganglia are not present within the onychophoran ventral nerve cords, suggesting that segmentation is either reduced or might be incomplete in the onychophoran ventral nervous system.
Results: ...
Aufsatz
Plantain mycorrhization with native consortium of arbuscular mycorrhizal fungi (AMF) induce solubilisation of metals (Fe2+ and Al3+) in soil from Azaguié (south-east of Côte d’Ivoire)
(2023-04-28)
New agroecological practices propose to manage soil fertility using soil microorganisms such as arbuscular mycorrhizal fungi (AMF). However, few studies have been conducted on the impact of plantain mycorrhization and metal (Fe²+ and Al³+) solubilisation in soil. This study evaluates the effectiveness of native AMF on plantain growth and metal leaching from soil. Trap plants (maize, sorghum and cowpea) were grown to produce various inoculums. Then, plantains were grown under controlled conditions, with six treatments ...
Aufsatz
Equilibrium K-shell excitation of highly ionized neon
(1979)
Augerelectron emission from foil-excited Ne-ions (6 to 10 MeV beam energy) has been
measured. The beam-foil time-of-flight technique has been applied to study electronic transitions of metastable states (delayed spectra) and to determine their lifetimes. To achieve a line identification for the complex structure observed in the prompt spectrum, the spectrum is separated into its isoelectronic parts by an Augerelectron-ion coincidence correlating the emitted electrons and the emitting projectiles of well defined final ...
Aufsatz
State dependent volume isotope shift analysis of the low lying states of Ba I and Ba II
(1983)
Relativistic multi-configuration Dirac-Fock wavefunctions, coupled to good angular momentum J, have been calculated for low lying states of Ba I and Ba II. The resulting electronic factors show good agreement with data derived from recent high-resolution laser spectroscopy experiments and results from a comparison of muonic and optical data.
Aufsatz
Non-relativistic and relativistic molecular calculations for the chalcogen hexafluorides: SF_6, SeF_6, TeF_6, PoF_6
(1980)
Non-relativistic Hartree-Fock-Slater and relativistic Dirac-Slater self-consistent orbital models are applied for the analysis of the electronic structure of the chalcogen hexafluorides: SF_6, SeF_6, TeF_6 and PoF_6. The molecular eigenfunctions and eigenvalues are generated using the discrete variational method (DVM) with numerical basis functions. The results obtained for SF_6 are compared with other ab initio calculations. Information about relativistic level shifts and spin-orbit splitting has been obtained by ...
Aufsatz
Predicting Flow Stress Behavior of an AA7075 Alloy Using Machine Learning Methods
(2022-09-09)
The present work focuses on the prediction of the hot deformation behavior of thermo-mechanically processed precipitation hardenable aluminum alloy AA7075. The data considered focus on a novel hot forming process at different tool temperatures ranging from 24°C to 350°C to set different cooling rates after solution heat-treatment. Isothermal uniaxial tensile tests in the temperature range of 200°C to 400°C and at strain rates ranging from 0.001 s-¹ to 0.1 s-¹ were carried out on four different material conditions. ...
Aufsatz
Effects of Aging under Stress on Mechanical Properties and Microstructure of EN AW 7075 Alloy
(2021-07-20)
In the present study, microstructural and mechanical properties of EN AW 7075 following stress-aging were assessed. For this purpose, properties of stress-aged samples were compared with values obtained for conventionally aged counterparts. It is revealed that the strength and hardness of EN AW 7075 can be increased by the presence of external stresses during aging. Precipitation kinetics were found to be accelerated. The effects of conventional and stress-aging on the microstructure were analyzed using synergetic ...