Sökning: "Christofer Leygraf"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Christofer Leygraf.

1. 1. High temperature corrosion in a biomass-fired power boiler : Reducing furnace wall corrosion in a waste wood-fired power plant with advanced steam data

   Författare :Yousef Alipour; Pamela Henderson; Peter Szalalos; Christofer Leygraf; Jan Froitzheim; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High temperature corrosion; Waterwalls; Power plant corrosion; NOx reducing enviroments; Biomass; Waste wood; Thermodynamic calculation modelling; corrosion-resistance alloy; Furnace wall corrosion; Högtemperaturekorrosion; Eldstadsväggar; kraftverks korrosion; låg Nox mijöer; biomassa; returträ; Termodynamisk modellering; korrosionsbeständighet legering; eldstadskorrosion;

   Sammanfattning : The use of waste (or recycled) wood as a fuel in heat and power stations is becoming more widespread in Sweden (and Europe), because it is CO2 neutral with a lower cost than forest fuel. However, it is a heterogeneous fuel with a high amount of chlorine, alkali and heavy metals which causes more corrosion than fossil fuels or forest fuel. LÄS MER

3. 2. Radiation induced corrosion of copper

   Författare :Åsa Björkbacka; Mats Jonsson; Christofer Leygraf; Mehran Mostafavi; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Corrosion; oxidation; copper; copper oxide; gamma radiation; radiolysis; hydrogen peroxide; hydroxyl radical; Kemi; Chemistry;

   Sammanfattning : The process of radiation induced corrosion of copper is not well understood. The most obvious situation where the knowledge of this process is crucial is in a deep repository for high level spent nuclear fuel where the fuel will be sealed inside copper canisters. LÄS MER

4. 3. The role of particles on initial atmospheric corrosion of copper and zinc : lateral distribution, secondary spreading and CO2-/SO2-influence

   Författare :Zhuo Yuan Chen; Christofer Leygraf; Jan-Erik Svensson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric corrosion; copper; zinc; NaCl particles; NH4 2SO4; Materials chemistry; Materialkemi;

   Sammanfattning : The role of sodium chloride (NaCl) particles and ammonium sulfate ((NH4)2SO4) particles on the initial atmospheric corrosion of copper and zinc was investigated under in situ and ex situ conditions using microgravimetry, FTIR spectroscopy, ion chromatography, scanning electron microscopy with x-ray microanalysis and the scanning Kelvin probe. For the first time, in situ infrared spectra were collected on a micron level during particle induced atmospheric corrosion using a recently developed experimental set-up for in situ FTIR microspectroscopy. LÄS MER

5. 4. Micro-galvanic effects and corrosion inhibition of copper-zinc alloys

   Författare :Mattias Forslund; Jinshan Pan; Christofer Leygraf; Per Claesson; Jin Ying; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Copper; zinc; brass; octadecanethiol; IR Spectroscopy; AFM; atmospheric corrosion; aqueous corrosion; corrosion inhibition; Koppar; zink; mässing; oktadekantiol; IR-reflektions absorptionsspektroskopi; AFM; atmosfärisk korrosion; vattenaktig korrosion; korrosionsinhibering.; Chemical Engineering; Kemiteknik; Kemi; Chemistry;

   Sammanfattning :    With the advancement and accessibility of local probing techniques that can operate at the submicron scale it has become possible to analyse the local corrosion properties of industrially important metallic materials and relate these properties to microstructure characteristics of the same materials. In this doctoral study the focus has been on copper-zinc samples, both as industrial brass alloys and as micro-patterned copper-zinc samples. LÄS MER

7. 5. Quantitative in situ analysis of initial atmospheric corrosion of copper induced by carboxylic acids

   Författare :Harveth Gil; Christofer Leygraf; Mark Rutland; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atmospheric corrosion; carboxylic acids; copper; in situ; IRAS; QCM; coulometric reduction.; Chemistry; Kemi;

   Sammanfattning : The interaction of carboxylic acids with copper is a phenomenon found both outdoors and, more commonly, indoors. The influence on copper of some carboxylic acids (formic, acetic, propionic, and butyric) have so far been studied at concentrations levels at least three or four orders of magnitude higher than actual indoor conditions (< 20 ppb, volume parts per billion), and with only limited emphasis on any mechanistic approach. LÄS MER