Sökning: "trace metal"

Visar resultat 21 - 25 av 101 avhandlingar innehållade orden trace metal.

1. 21. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

   Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER

3. 22. Method development for the analysis of complex samples with inductively coupled plasma mass spectrometry

   Författare :Marcus Korvela; Jean Pettersson; Ulf Lindh; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ICP-MS; trace elements; complex matrix.;

   Sammanfattning : In this thesis the development of methods for handling the problems associated with analyzing trace elements in complex matrixes using inductively coupled plasma mass spectrometry is presented. Trace elements such as Cu, Fe, Se, and Zn, to name a few, do play important roles in different organisms. LÄS MER

4. 23. Mobilization of metals from mining wastes and the resuspension of contaminated sediments

   Författare :Lan Thuy Nguyen; Bo Svensson; Gunnar Jacks; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acid Rock Drainage; hydropower plant; metal contamination; mining wastes; storm-wind; resuspension; sediment; Environmental chemistry; Miljökemi;

   Sammanfattning : In some environmental situations, environmental effects caused by elevated metals resulting from past mining and smelting activities can be observed in nearby receiving water bodies several decades after mine and smelter closure. There is a growing need for managing the hazardous solid wastes such as mining wastes as well as for assessing water quality and for sustainable management of sediment quality. LÄS MER

5. 24. Speciation of copper in ashes from municipal solid waste combustion

   Författare :Henric Lassesson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; copper compounds; MSWI ash; XANES; metal speciation; EXAFS; X-Ray absorption spectroscopy;

   Sammanfattning : Copper is one of the most important trace elements in municipal solid waste (MSW) combustion. Knowledge of the speciation of copper is fundamental for the understanding of the effects of copper compounds on the combustion chemistry as well as of the environmental impact of the ash. LÄS MER

7. 25. Characterization of Impurities in Different Ferroalloys and Their Effects on the Inclusion Characteristics of Steels

   Författare :Yong Wang; Pär Jönsson; Andrey Karasev; Bart Blanpain; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferroalloys; electrolytic extraction; metal surface; non-metallic inclusions; steel cleanliness; computational thermodynamics; ferrolegering; elektrolytisk extraktion; metallyta; icke-metalliska inneslutningar; stålrenhet; beräkningstermodynamik; Materials Science and Engineering; Teknisk materialvetenskap;

   Sammanfattning :      Ferroalloys have become increasingly important due to their indispensable role in steelmaking. As the performance requirements of steel materials increase, it is necessary to have a better understanding of the impact of impurities in ferroalloys on the steel cleanliness. LÄS MER