Search for dissertations about: "Trace recovery"

Showing result 21 - 25 of 31 swedish dissertations containing the words Trace recovery.

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

   Author : Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 22. Miniaturized, Membrane-Based and Environmentally Green Sample Preparation Systems: Applications for Biological and Environmental Aqueous Samples

   Author : Thaer Barri; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Analytisk kemi; Analytical chemistry; Free concentration; Exhustive extraction; Microporous membrane liquid-liqid extraction; Miniaturization; Supported liquid membrane extraction; Environmental chemistry; Miljökemi;

   Abstract : Contemporary advancements in miniaturization of analytical systems have advantageously fostered development, automation, and hyphenation of a variety of sample preparation techniques. Among several downscaled extraction designs, porous synthetic polymeric membranes (such as flat sheet (FS) or hollow fiber (HF)) have been utilized for membrane-based extraction, separating two aqueous phases (as in supported liquid membrane (SLM) extraction or one aqueous phase and another organic phase (as in microporous membrane liquid-liquid extraction (MMLLE)). READ MORE

5. 23. Chemical Properties of FBC Ashes

   Author : Britt-Marie Steenari; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; straw ash; environmental impact of ash handling; sintering; deposits; fouling; wood ash recycling; FBC; ash leaching; ash chemistry; PFBC; forest fertiliser; ash hydration reactions; fuel additives; wood ash characteristics; CaS; ash melting; plant nutrient recycling;

   Abstract : In this thesis several aspects of ash chemistry are discussed. An issue of primary concern for boiler operators is the formation of ash deposits. New biomass fuels are introduced, many of which have unfavourable ash melting behaviour due to high levels of alkali metal species and chlorine. READ MORE

6. 24. Assessment of Raw Materials in Stainless Steelmaking-Their Energy Consumption and Greenhouse Gas Emission

   Author : Wei Wenjing; Anders Tilliander; Peter Samuelsson; Pär Jönsson; Ye Guozhu; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; static process model; mass and energy balance; molybdenum; nickel; phosphorus; stainless steel; life cycle assessment; GHG emission; energy consumption; statisk procesmodell; mass- och energibalans; molybden; nickel; fosfor; rostfritt stål; livscykelanalys; växthusgasutsläpp; energiförbrukning; Metallurgical process science; Metallurgisk processvetenskap;

   Abstract : In stainless steelmaking, around 68% of the total greenhouse gas emissions come from the processing of raw materials. Thus, it is important for steelmakers to make efforts together with their raw material suppliers to implement low-carbon initiatives. To facilitate such initiatives, assessment of raw materials will provide guidance. READ MORE

7. 25. An in-situ ATR-FTIR Spectroscopy Study of Adsorption in MFI Zeolites : A step towards effective upgrading of biofuels

   Author : Lindsay Ohlin; Niklas Hedin; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Technology; Kemisk teknologi;

   Abstract : Global warming is believed to be caused by the extensive emission of greenhouse gases, for example carbon dioxide, into the atmosphere by combustion of fossil fuels, such as coal, oil and natural gas. To reduce the emission of carbon dioxide and hence avoid global warming, alternative fuels derived from renewable resources are desired. READ MORE