Sökning: "sulfur"

Visar resultat 21 - 25 av 292 avhandlingar innehållade ordet sulfur.

1. 21. Catalytic Conversion of Undesired Organic Compounds to Syngas in Biomass Gasification and Pyrolysis Applications

   Författare :Pouya H. Moud; Klas Engvall; Klas J. Andersson; Roberto Lanza; Mats Ahmadi Götelid; Anker Degn Jensen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; tar reforming; biomass gasification; Ni-based catalyst; potassium; sulfur; pyrolysis gas; bio-crude conditioning; gas conditioning; Fe-based catalyst; tjärreformering; biomassaförgasning; Ni-baserad katalysator; kalium; svavel; pyrolysgas; konditionering bio-råolja; gaskonditionering; Fe-baserad katalysator; Chemical Engineering; Kemiteknik;

   Sammanfattning : Reliable energy supply is a major concern and crucial for development of the global society. To address the dependency on fossil fuel and the negative effects of this reliance on climate, there is a need for a transition to cleaner sources. An attractive solution for replacing fossil-based products is renewable substitutes produced from biomass. LÄS MER

3. 22. Fundamental studies of catalytic systems for diesel emission control

   Författare :Xavier Auvray; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NH3 SCR; NO oxidation; sulfur; hysteresis; kinetic modeling; SpaciMS; catalyst acidity; DOC; aging; Pt Al2O3;

   Sammanfattning : Due to global lean exhaust gas and new emission regulations, exhaust aftertreatment systems of diesel engines are more and more sophisticated and composed of a series of catalytic units. In the present work, two of these catalytic systems were studied with different approach. LÄS MER

4. 23. Coordination of Phosphine-Thioether Ligands to Low-valent Metal Centers

   Författare :Roger Persson; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polynuclear metal complexes; fluxional behavior; cluster; thioether; phosphine; crystal structure; sulfur; triosmium;

   Sammanfattning : The reactivity of the phosphine-thioether ligands bis(2-diphenylphosphino) ethylthio)ethane (PSSP), bis(2-(diphenylphosphino) ethyl)sulfane (PSP), PPh2CH2CH2SMe (PS), PPh2(o-C6H4SMe (PortoS), and PPh(o-C6H4SMe)2 (PSS) towards low-valent carbonyl clusters has been studied. In all structurally characterized clusters, the ligand donor atoms are terminally coordinated. LÄS MER

5. 24. New C-C coupling Reactions Enabled by Main-group Organometallics

   Författare :Kilian Colas; Abraham Mendoza; David Procter; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; C-C coupling; organometallics; aluminum; magnesium; Grignard; turbo-Hauser-bases; piperazines; sulfur; ketones; organisk kemi; Organic Chemistry;

   Sammanfattning : The carbon-carbon bond has always been at the very core of chemical research. Strategies for the creation of C−C bonds are one of the keys to the construction game that organic chemists play with the building blocks provided by Nature, with the ultimate goal of producing useful molecular structures that will serve society as medicines, materials, imaging tools, catalysts, and ligands (to mention but a few). LÄS MER

7. 25. Varved lake sediments and diagenetic processes

   Författare :Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

   Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER