In the present study we have used electron microscopical NADPH-diaphorase (NADPH-d) histochemistry as a visualization procedure for nitric oxide synthase (NOS) to examine patterns of activity in the subcellular distribution of NADPH-d in the rat striatal astroglia. Electron microscopical examination revealed deposition of the NADPH-d reaction product in a nuclear envelope, fragments of endoplasmic reticulum and mitochondria. Predominantly mitochondria of astrocytic “end feet” were labelled. Our ultrastructural observations promote the possibility that astroglial NADPH-d/NOS is involved in adaptation of the local blood flow in the striatal microenvironment.
The objective of this work is to gain a deeper understanding of the separation effects and particle movement during filtration of non-metallic inclusions in aluminum casting on a macroscopic level. To understand particle movement, complex simulations are performed using Flow 3D. One focus is the influence of the filter position in the casting system with regard to filtration efficiency. For this purpose, a real filter geometry is scanned with computed tomography (CT) and integrated into the simulation as an STL file. This allows the filtration processes of particles to be represented as realistically as possible. The models provide a look inside the casting system and the flow conditions before, in, and after the filter, which cannot be mapped in real casting tests. In the second part of this work, the casting models used in the simulation are replicated and cast in real casting trials. In order to gain further knowledge about filtration and particle movement, non-metallic particles are added to the melt and then separated by a filter. These particles are then detected in the filter by metallographic analysis. The numerical simulations of particle movement in an aluminum melt during filtration, give predictions in reasonable agreement with experimental measurements.