Search for dissertations about: "specimen preparation"

Showing result 1 - 5 of 20 swedish dissertations containing the words specimen preparation.

2. 1. Quantitative Electron Microscopy Studies of Metal Nanoparticle Catalysts: Nanostructure, Support Interaction and Ageing Effects

   Author : Torben Nilsson Pingel; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; CO oxidation; strain; ageing; specimen preparation; scanning electron microscopy SEM ; FIB SEM; supported nanoparticle catalyst; transmission electron microscopy TEM ; particle size distribution PSD ; platinum;

   Abstract : Heterogeneous catalysis plays a major role in modern society, for example in chemical production, sustainable energy production and emission control technologies. Metal nanoparticles (NPs) supported on oxide materials are frequent catalytic systems in this field. READ MORE

4. 2. Quantitative studies of changes in microstructure and activity during ageing of supported catalysts

   Author : Torben Pingel; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; supported nanoparticle catalyst; scanning electron microscopy SEM ; quantitative; bimetallic catalyst; ageing properties; CO oxidation; FIB SEM; specimen preparation; particle size distribution PSD ; transmission electron microscopy TEM ;

   Abstract : Catalytic converters have substantially contributed to the improvement of air quality in populated areas in the last decades by abatement of the emission of hazardous componentssuch as CO, unburned hydrocarbons and NOx. However, due to the exposure to high temperature and different components in the exhaust gas, the performance of the catalysts degrades with time. READ MORE

5. 3. Push the limitations of crystal structure determination by 3D electron diffraction : From inorganic porous materials to biomolecules

   Author : Jingjing Zhao; Xiaodong Zou; Hongyi Xu; Tim Grüne; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; electron crystallography; 3D electron diffraction; cryo-EM specimen preparation; structure determination; porous materials; biomolecules; fysikalisk kemi; Physical Chemistry;

   Abstract : Structure elucidation is fundamental to understanding the chemical and physical properties of a material. Three-dimensional electron diffraction (3D ED) has shown great power for structure determination of nanometer- or submicrometer-sized crystals that are either too small or too complex for X-ray diffraction. READ MORE

6. 4. Measuring degradation in cable insulation material under realistic operation conditions

   Author : Douglas Jutsell Nilsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : One of the challenges in laboratory investigation of degradation and ageing of HVDC cable insulation is related to securing, or in other words, imitating the real service environment of the material specimens. So far, the published data refer to experiments conducted in thermo-oxidative conditions, which is not the case during normal cable operation. READ MORE

7. 5. Determination of Weibull Parameters by Single Fibre Fragmentation for use in Modelling of Paper Tensile Properties

   Author : Carl-Henrik Ljungqvist; []
   Keywords : ;

   Abstract : The thesis presents a method for characterization of pulp fibre tensile strength. Single Fibre Fragmentation (SFF) and Weibull statistics were used. Methods for specimen preparation, sampling and analysis of fragmentation data from digital images were developed. READ MORE