Global ETD Search

1	Untersuchungen an Tetracalciumaluminathydrat und der Einbau von Alkylsulfonaten Stern, Edda. January 2003 (has links) (PDF) Halle, Wittenberg, Universiẗat, Diss., 2003. Calciumaluminate
2	Modelle zur Kinetik der Hydratation von Calciumaluminatzement mit Calciumsulfat aus kristallchemischer und mineralogischer sicht Götz-Neunhoeffer, Friedlinde. January 2006 (has links) Thesis (Habilitationsschrift)--Friedrich-Alexander-Universität Erlangen-Nürnberg. / Includes bibliographical references (p. 225-232).
3	Tepelně izolační lité žárovzdorné materiály / Heat insulating moulded refractory materials Novotný, Radoslav January 2016 (has links) Doctoral thesis is focused on the study, research and development of heat insulating moulded refractory materials. The replacement of shaped instead of unshaped refractories is recently and strongly industrially demanded and belongs to ongoing research topics. With the increasing demand of energy savings, the excellent insulation properties are essential. The insulating properties of castables are the result of targeted porosity formation. The porosity is coming from the controlled air intrusion into material resulted to foamed structure. The foaming process was achieved by mixing of separately prepared aqueous foam into raw castable slurry or by in situ foaming of intensively mixed castable slurry with the surfactant additive. Nevertheless, the study of foam behaviour and the influence of additives on binder hydration and setting processes (i.e. calciumaluminate cement) was substantial for successful preparation of the experimental samples. The two types of the experimental samples were prepared. The first one was based on mixing of kaolin slurry with pre-prepared aqueous foam, whereas the de-aglomeration ability of kaolin specie was utilized to water-particle film formation. In situ foaming of multicomponent system is the second one. The both processes brought some negative attributes, so the optimal properties of prepared castables were achieved by their combination.
4	Functionalization of carbon-bonded ceramic foam filters with nano-scaled materials for steel melt filtration Storti, Enrico 23 April 2018 (has links) (PDF) In order to improve the purity of steel castings, the use of special reactive coatings on carbon-bonded ceramic foam filters was explored. Carbon nanotubes were dispersed in water by means of ultrasonic treatment, using xanthan gum to stabilize the nanotubes in suspension and control the rheological behavior. The coatings were applied by cold spraying and binding was achieved during heat treatment in reducing atmosphere, thanks to an artificial pitch added to the slurry. The coated filters were successfully immersed in molten steel for different times. The thickness of the first alumina layer generated at the interface was independent of the immersion time: concentration gradients through its thickness suggested that the formation of this structure is limited by diffusion. Investigation of the steel after solidification by means of ASPEX showed that the presence of the coating influenced the size as well as the chemical composition of the remaining inclusions. Nano-coated filters had the best filtration efficiency (up to 95% for alumina inclusions after 10 s), but longer tests resulted in worse performance. In addition, coatings based on calcium aluminates in combination with carbon showed an efficiency greater than 97% for steel samples taken directly from the melt. Filtration Stahlschmelze Einschlüsse Keramikschaumfilter kohlenstoffgebundenes Aluminiumoxid CNTs Calciumaluminate Elektrospinnen Magnesiumborat Filtration Steel melt Inclusions Ceramic foam filters Carbon-bonded alumina CNTs Calcium aluminates Electrospinning Magnesium borate ddc:620 Metallschmelze Filtration Schaumkeramik Aluminiumoxide Kohlenstoff Calciumaluminate
5	Functionalization of carbon-bonded ceramic foam filters with nano-scaled materials for steel melt filtration Storti, Enrico 23 March 2018 (has links) In order to improve the purity of steel castings, the use of special reactive coatings on carbon-bonded ceramic foam filters was explored. Carbon nanotubes were dispersed in water by means of ultrasonic treatment, using xanthan gum to stabilize the nanotubes in suspension and control the rheological behavior. The coatings were applied by cold spraying and binding was achieved during heat treatment in reducing atmosphere, thanks to an artificial pitch added to the slurry. The coated filters were successfully immersed in molten steel for different times. The thickness of the first alumina layer generated at the interface was independent of the immersion time: concentration gradients through its thickness suggested that the formation of this structure is limited by diffusion. Investigation of the steel after solidification by means of ASPEX showed that the presence of the coating influenced the size as well as the chemical composition of the remaining inclusions. Nano-coated filters had the best filtration efficiency (up to 95% for alumina inclusions after 10 s), but longer tests resulted in worse performance. In addition, coatings based on calcium aluminates in combination with carbon showed an efficiency greater than 97% for steel samples taken directly from the melt. info:eu-repo/classification/ddc/620 ddc:620

1

Page generated in 0.0581 seconds