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Showing result 1 - 5 of 41 swedish dissertations matching the above criteria.

2. 1. Interaction of CO and methane with platinum, Low-temperature oxidation and sensor response mechanisms

   Author : Elin Becker; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CO; Low-temperature activity; XAS; In situ spectroscopy; Environmental catalysis; Support material; Periodic operation; XANES; Chemical sensors;

   Abstract : The aim of this thesis project was to increase the understanding of the mechanisms for low-temperature oxidation of carbon monoxide and methane over supported platinum catalysts. In situ spectroscopic methods together with mass spectrometry were used to study the catalysts during both steady state and transient conditions. READ MORE

4. 2. Strontium Titanate-based Anodes for Solid Oxide Fuel Cells

   Author : Peter Blennow Tullmar; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; supraconductors; magnetic and optical properties; electrical; Condensed matter:electronic structure; fasjämvikt; egenskaper termiska och mekaniska ; kristallografi; phase equilibria; Kondenserade materiens egenskaper:struktur; Condensed matter:stucture; thermal and mechanical properties; crystallography; infiltration; surfactant; ceria; Gd-doped ceria; redox stability; SOFC; ceramic anode; XRD; XANES; electrochemical impedance spectroscopy; defect chemistry; Nb-doped SrTiO3; electron microscopy; egenskaper elektriska; magnetiska och optiska ; supraledare; magnetisk resonans; spektroskopi; Inorganic chemistry; Oorganisk kemi; Electrochemistry; Elektrokemi; Energy research; Energiforskning; Composite materials; Kompositmaterial; Ceramic materials and powders; Keramiska material och pulver;

   Abstract : The purpose for this work has been to develop new robust fuel electrodes for solid oxide fuel cells (SOFC). The aim was to find suitable ceramic materials or composites with promising properties for the use as SOFC anodes. READ MORE

5. 3. Structure and Properties Investigations of the La2Co1+z(Ti1-xMgx)1-zO6 Perovskite System

   Author : Samrand Shafeie; Gunnar Svensson; Mari-Ann Einarsrud; Mats Johnsson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; solid oxide fuel cell; SOFC; LaCoO3; cobaltates; cobalt oxide; perovskite; XANES; XRD; Neutron powder diffraction; thermal expansion; electronic conductivity; magnetism; citrate; electron diffraction; synthesis; phase diagram; spin state; fast fas oxid bränslecell; LaCoO3; koboltoxid; perovskit; XANES; XRD; neutron diffraktion; elektron diffraktion; termisk expansion; elektrisk ledningsförmåga; magnetism; citrat; SOFC; syntes; fasdiagram; spin tillstånd; Solid state chemistry; Fasta tillståndets kemi; Materials chemistry; Materialkemi; Structural Chemistry; strukturkemi; Materials Chemistry; materialkemi;

   Abstract : Perovskite based materials have great potentials for various energy applications and the search for new materials for uses in SOFCs has largely been concentrated to this class of compounds. In this search, we have studied perovskite phases in the system La2Co1+z(Ti1-xMgx)1-zO6, with 0  x 0.9 and z = 0.0, 0. READ MORE

6. 4. Properties in New Complex Perovskite-Related Materials, a Matter of Composition and Structure

   Author : Samrand Shafeie; Gunnar Svensson; Jekabs Grins; John T. S. Irvine; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Perovskite; XANES; XRPD; NPD; TEC; TEM; SEM; TGA; SAED; HREM; thermal expansion; Seebeck coefficient; electronic conductivity; SOFC materials; magnetic susceptibility; Perovskit; XANES; XRPD; NPD; TEC; TEM; SEM; TGA; SAED; HREM; termisk expansion; Seebeck koefficient; elektrisk ledningsförmåga; SOFC material; magnetiska egenskaper; Materials Chemistry; materialkemi;

   Abstract : This PhD thesis presents investigations of perovskite-related compounds in systems of interest for applications in components in solid oxide fuel cells. The compound compositions derive from substitutions in the parent compounds LaCoO3, LaCrO3 and SrFeO3. READ MORE

7. 5. The Bentonite Barrier - Swelling Properties, Redox Chemistry and Mineral Evolution

   Author : Daniel Svensson; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; montmorillonite; bentonite; smectite; freezing; thawing; hydration; intercalation; four-water-layer; ethylene glycol; X-ray diffraction; time-resolved; spatial-resolution; XANES; Fe; redox; iron; ABM; TBT; Äspö;

   Abstract : Bentonite is planned for use as a buffer material in high-level radioactive waste repositories, where safety assessment is performed for very long periods (100-1000 ka). This thesis focuses on the swelling of smectites in liquid water, and analysis of bentonite from field experiments at Äspö Hard Rock Laboratory, Sweden. READ MORE