Search for dissertations about: "Magnesium oxides"

Showing result 1 - 5 of 14 swedish dissertations containing the words Magnesium oxides.

2. 1. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

   Author : Urban Öjteg; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

   Abstract : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). READ MORE

4. 2. Atomistic modelling of functional solid oxides for industrial applications : Density Functional Theory, hybrid functional and GW-based studies

   Author : Cecilia Århammar; Rajeev Ahuja; Steven Louie; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; density functional theory; oxides; GW; Condensed matter physics; Kondenserade materiens fysik; Magnetism; Magnetism; Defects and diffusion; Defekter och diffusion;

   Abstract : In this Thesis a set of functional solid oxides for industrial applications have been addressed by first principles and thermodynamical modelling. More specificially, measurable quantities such as Gibbs free energy, geometry and electronic structure have been calculated and compared when possible with experimental data. READ MORE

5. 3. Combined Molecular Dynamics and Embedded-Cluster Calculations in Metal Oxide Surface Chemistry

   Author : Björn Herschend; Kersti Hermansson; Micael Baudin; Joachim Sauer; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Inorganic chemistry; embedded-cluster; ab initio; molecular dynamics; metal oxide; ceria; magnesium oxide; adsorption; surface defect; Oorganisk kemi; Inorganic chemistry; Oorganisk kemi;

   Abstract : The development and improvement of the functionality of metal oxides in heterogeneous catalysis and other surface chemical processes can greatly benefit from an atomic-level understanding of the surface chemistry. Atomistic calculations such as quantum mechanical (QM) calculations and molecular dynamics (MD) simulations can provide highly detailed information about the atomic and electronic structure, and constitute valuable complements to experimental surface science techniques. READ MORE

6. 4. Interactions between iron oxides and the additives olivine, quartzite and calcite in magnetite pellets

   Author : Pär Semberg; Abdel-Hady Abdel-Hady El-Geassy; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Process Metallurgy; Processmetallurgi;

   Abstract : In the present study, magnetite pellets with the additives olivine, calcite and quartzite were isothermally reduced in a tubular furnace to study the interaction between iron oxides and the additives. Exaggerated amounts of additives were used in order to enable analyses of phases that do not otherwise occur in sufficient amounts for X-ray diffraction and EDS-analyses. READ MORE

7. 5. Interactions between iron oxides and the additives quartzite, calcite and olivine in magnetite-based pellets

   Author : Pär Semberg; Lawrence Hooey; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Process Metallurgy; Processmetallurgi;

   Abstract : In the present study, magnetite pellets with large amounts of the additives olivine, calcite and quartzite were isothermally reduced in a tubular furnace to study the interaction between iron oxides and the additives. A first attempt at using exaggerated amounts of additives was made in order to enable analyses of phases that do not otherwise occur in sufficient amounts for Xray diffraction and EDS-analyses. READ MORE