29 research outputs found
Virtual microscope interface to high resolution histological images
The Hypertext atlas of Dermatopathology, the Atlas of Fetal and Neonatal Pathology and Hypertext atlas of Pathology (this one in Czech only) are available at . These atlases offer many clinical, macroscopic and microscopic images, together with short introductory texts. Most of the images are annotated and arrows pointing to the important parts of the image can be activated
Helium permeation through mixed matrix membranes based on polyimides and silicalite-1
Mixed matrix membranes based on modified polyimides and silicalite-1 were prepared and studied. The novel preparation approach consists in improvement of the interfacial adhesion by employment of the coupling agent 3-aminopropyltriethoxysilane in such a way which leads to forming of chemical bonds between polyimide and silicalite-1. Firstly polyimide chains were endcapped by this agent
which subsequently enabled their reaction with groups naturally present on silicalite-1 surface. Membranes with silicalite-1 content up to 60 wt. % were prepared and characterized by SEM, light microscopy and permeation of gases, prevailingly of He. The accessibility of sililicalite-1 pores prior to embedding and after embedding into polymeric matrices was studied by an iodine indicator technique. The permeability of membranes for gases was measured using a semi-open permeation apparatus with a small volume. Helium permeability depended on filler content and increased monotonously with the increasing content of filler. There were, however, significant deviations of the permeability dependences on filler content from shapes predicted by Bruggeman’s model. The qualitative explanation of the data disagreement with the model was proposed based on a stratification of mixed matrix membranes found by SEM
Obrazová analýza řezů pórovitého materiálu
Two methods of image analysis of cross-sections through two-phase porous media are compared. Linear filtering uses the recursive (IIR) Gaussian filter with the same vertical and horizontal blur radii. The images are also treated by removing small clusters of pixels in the void and solid phases. After linear filtering and before removing small clusters, the grey-level threshold is determined in order to partition all grey pixels into pore and solid pixels. Linear filtering reduces the specific surface very efficiently creating ``smooth'' pore walls and leaves small clusters of pixels in the images. Removing preserves ``rough'' pore walls and removes simultaneously small clusters from both the phases
Zpracování snímků výbrusů za účelem 3d rekonstrukce pórovitých materiálů
The technique of electron microscopy in SEM/BSE work modes was compared for the purpose of porosity estimation of some porous materials such as potential membrane supports on the basis of a-alumina. To prepare casts, an individual samples were impregnated by epoxide resin AralditO under high vacuum. Every cast was cut, grinded and polished to achieve its smooth face for observation by means of electron microscopy
3D Microstructure Modeling of Porous Metal Filters
The contribution presents a modified method of stochastic reconstruction of two porous stainless-steel filters. The description of their microstructures was based on a combination of the two-point probability function for the void phase and the lineal-path functions for the void and solid phases. The method of stochastic reconstruction based on simulated annealing was capable of reproducing good connectivity of both phases, which was confirmed by calculating descriptors of the local porosity theory. Theoretical values of permeability were compared with their experimental counterparts measured by means of quasi-stationary permeation of four inert gases