@article{StedingSchneider2021, author = {Steding, Svenja and Schneider, Wilfried}, title = {Prognose des Schadstoffaustrags aus mehrphasigen DNAPL-Pools mittels semi-analytischem Berechnungsmodell}, series = {Grundwasser : Zeitschrift der Fachsektion Hydrogeologie in der Deutschen Gesellschaft f{\"u}r Geowissenschaften (FH-DGG)}, volume = {26}, journal = {Grundwasser : Zeitschrift der Fachsektion Hydrogeologie in der Deutschen Gesellschaft f{\"u}r Geowissenschaften (FH-DGG)}, number = {3}, publisher = {Springer}, address = {Berlin ; Heidelberg}, issn = {1430-483X}, doi = {10.1007/s00767-021-00490-2}, pages = {241 -- 253}, year = {2021}, abstract = {Multicomponent DNAPL pools are among the most common reasons for groundwater contamination and represent highly persistent source areas. Although several studies have already shown that their constituents influence each other's solubility, existing models neglect these interactions. For this reason, a semi-analytical model has been developed, considering the pool composition as temporally variable. Based on Raoult's law, the molar fraction, the effective solubility and finally the mass discharge due to advection, dispersion and diffusion of each component are determined. The results significantly differ from studies on single-phase pools. It is shown that mass discharges can both increase and decrease over time and that the longevity of DNAPL pools as well as the time until threshold values are fullfilled will be significantly underestimated if Raoult's law is neglected. Additionally, a sensitivity analysis reveals that poorly soluble minor components must not be neglected, whereas highly soluble ones can.}, language = {de} } @article{SerranoMunozMishurovaThiedeetal.2020, author = {Serrano-Munoz, Itziar and Mishurova, Tatiana and Thiede, Tobias and Sprengel, Maximilian and Kromm, Arne and Nadammal, Naresh and Nolze, Gert and Saliwan-Neumann, Romeo and Evans, Alexander and Bruno, Giovanni}, title = {The residual stress in as-built laser powder bed fusion IN718 alloy as a consequence of the scanning strategy induced microstructure}, series = {Scientific reports}, volume = {10}, journal = {Scientific reports}, number = {1}, publisher = {Macmillan Publishers Limited, part of Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-020-71112-9}, pages = {15}, year = {2020}, abstract = {The effect of two types of scanning strategies on the grain structure and build-up of Residual Stress (RS) has been investigated in an as-built IN718 alloy produced by Laser Powder Bed Fusion (LPBF). The RS state has been investigated by X-ray diffraction techniques. The microstructural characterization was performed principally by Electron Backscatter Diffraction (EBSD), where the application of a post-measurement refinement technique enables small misorientations (< 2 degrees) to be resolved. Kernel average misorientation (KAM) distributions indicate that preferably oriented columnar grains contain higher levels of misorientation, when compared to elongated grains with lower texture. The KAM distributions combined with X-ray diffraction stress maps infer that the increased misorientation is induced via plastic deformation driven by the thermal stresses, acting to self-relieve stress. The possibility of obtaining lower RS states in the build direction as a consequence of the influence of the microstructure should be considered when envisaging scanning strategies aimed at the mitigation of RS.}, language = {en} }