Sökning: "Sulfur species"

Visar resultat 21 - 25 av 66 avhandlingar innehållade orden Sulfur species.

1. 21. Exhaust aftertreatment under lean conditions, regenerable SOx traps and NOx reduction catalysts

   Författare :Lisa Kylhammar; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Heterogenous catalysis; Selective catalytic reduction; HC-SCR; Sulfur storage; SOx trap; Spectroscopy; Lean exhausts; NOx; Ag Al2O3; DRIFT; XPS;

   Sammanfattning : The aim of this thesis was to investigate i) potential materials for regenerable SOx traps and ii) the influence of silver distribution within Ag/Al2O3 catalysts on the selective reduction of NOx by hydrocarbons (HC-SCR). Both areas are highly relevant for present and future vehicle aftertreatment technologies for lean exhausts. LÄS MER

3. 22. Aging effects on commercial lean NOx trap catalysts

   Författare :Jesus De Abreu Goes; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aging; thermal degradation; sulfur poisoning; characterization; commercial lean NOx traps; NOx storage and reduction;

   Sammanfattning : As a countermeasure to global warming, vehicles with low carbon emissions are being investigated by promoting lean-burn engines and high combustion efficiencies. However, one limitation to the increasing use of these engines is the need to develop corresponding catalytic systems for controlling the nitrogen oxide (NOx) emissions in their lean exhaust. LÄS MER

4. 23. Application of metalation reactions for synthesis of sulfur/selenium-containing heterocyclic compounds

   Författare :Hamid Shirani; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Heterocycles; indoles; 3- arylthio indoles; thiopyranobisindoles; dibenzothiepins; 3; 3′-dithiobisindoles; alkaloids; echinosulfone A; cyclization; ortho-metalation; McMurry coupling; sulfides; sulfones and disulfides;

   Sammanfattning : This thesis deals mainly with the synthesis of various sulfur/selenium-containing heterocyclic compounds, many of which include structural features present in several biologically active molecules, with particular emphasis on compounds of synthetic importance, such as indoles, as well as other heteroaromatic species. In the first part, an efficient procedure toward synthesis of new 3-(arylthio)indoles based on reactions of aryl Grignard reagents or lithiated heteroaromatics with protected 3,3′-dithiobisindoles is described. LÄS MER

5. 24. When bioelectrochemical systems meet extremophiles, possibilities and challenges

   Författare :Gaofeng Ni; Mark Dopson; Bert Hamelers; Linnéuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acidophiles; psychrophiles; haloalkaliphiles; bioelectrochemical systems; microbial sulfur metabolism; 16S rRNA gene amplicon sequencing; metagenomics; metatranscriptomics; Mikrobiologi; Microbiology;

   Sammanfattning : Extremophiles are microorganisms live and thrive in extreme environments that are harsh and hostile to most forms of life on earth (e.g. low pH, low temperature, high pH and high salinity). They have developed strategies to obtain nutrients and conserve energy to sustain life under these adverse conditions. LÄS MER

7. 25. Catalytic Emission Abatement and Gas Separation

   Författare :Martin Petersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NOx reduction; Ozone promotion; Flow reactor studies; Propane oxidation; Molecular simulations; Sulfur dioxide promotion; Zeolite adsorption; Environmental heterogeneous catalysis; Mean-field kinetic modeling; CO oxidation;

   Sammanfattning : Air pollution is still today a major health problem. Emissions from mobile and stationary sources are regulated, but economical considerations limit the implementation of the most efficient abatement systems. To improve urban air quality, there is therefore a need to develop simple, durable and cost efficient emission control methods. LÄS MER