Sökning: "Sulphur"

Visar resultat 1 - 5 av 220 avhandlingar innehållade ordet Sulphur.

  1. 1. Vegetation changes on Swedish mires Effects of raised temperature and increased nitrogen and sulphur influx

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Urban Gunnarsson; Uppsala universitet.; [2000]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Acidification; growth; long-term studies; mires; nitrogen; species richness; Sphagnum; succession; sulphur; temperature; Utvecklingsbiologi; NATURAL SCIENCES Biology Organism biology Developmental biology; NATURVETENSKAP Biologi Organismbiologi Utvecklingsbiologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Since the start of the industrialisation, the deposition of nitrogen and sulphur and the atmospheric concentrations of greenhouse gases have increased. The main objectives of this study were to find how these changes in climate and deposition can change the vegetation of mire ecosystems and the growth of Sphagnumspecies. LÄS MER

  2. 2. Reducing Alkali Chloride-Induced High Temperature Corrosion by Sulphur Containing Additives – A Combined Laboratory and Field Study

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Sofia Karlsson; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sulphur; Stainless Steels; Additives; Biomass; Waste; High Temperature Corrosion; Alkali Chlorides; Co-combustion;

    Sammanfattning : In order to achieve a more sustainable society renewable fuels such as biomass and waste are attractive alternatives to fossil fuels for power production. However, fireside corrosion is a serious concern in boilers combusting biomass or waste. The high corrosion rates are often linked to large amounts of alkali chlorides in the flue gas. LÄS MER

  3. 3. Experimental Studies of NOx Catalysts; Storage, Reduction and Sulphur Deactivation

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Annika Amberntsson; [2002]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; barium oxide; NOx storage; platinum; rhodium; sulphur poisoning; NOx reduction;

    Sammanfattning : The aim of this thesis work was to investigate how different gaseous compounds, present in an automotive exhaust from lean-tuned combustion, interact with so-called NOx storage catalysts containing Al2O3 as a support, BaO as the NOx storage compound and noble metals to provide oxidation and reduction functions. The investigations included model sample preparations, flow reactor studies with various gas mixtures and spectroscopic experiments (FTIR and XPS). LÄS MER

  4. 4. Molecular Alligator Clips: A Study of Metal-Molecule Contacts for Molecular Electronics

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Anton Grigoriev; [2004]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nonequilibrium Green s functions; single crystal surfaces; nanostructures; chemisorption; selenium; low index single crystal surface; density functional calculations; organic molecules; sulphur; nonequilibrium electron transport; gold;

    Sammanfattning : In this thesis we present a computational study of the elementary building blocks for molecular electronics, interconnected electronic devices with critical dimensions below 5 nm. Building electronic circuits on that scale requires stable connection between the various parts of the device and to the macroscopic metal electrodes, needed for power supply, support and integration with conventional electronics. LÄS MER

  5. 5. Investigations of Chlorine-Induced High Temperature Corrosion of Steels

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Nicklas Folkeson; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sulphur; alkali; chlorine; field exposures; HCl-induced corrosion; high temperature corrosion; deposits.; chloride-induced corrosion; waste; 310S; HCl;

    Sammanfattning : The high corrosivity of the fireside environment in waste and biomass fired boilers is commonly attributed to the presence of chlorine-containing compounds. Chlorine-induced high temperature corrosion is not well understood, however. LÄS MER