Sökning: "Nitrogen oxide"

Visar resultat 21 - 25 av 185 avhandlingar innehållade orden Nitrogen oxide.

1. 21. Passivation of Austenitic Stainless Steel

   Författare :Lena Wegrelius; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stainless steel; chloride; molybdenum; passivation; hydrochloric acid; nitrogen; ESCA; dissolution;

   Sammanfattning : The objective of this thesis is to study the corrosion resistance and passivation of high alloyed austenitic stainless steels exposed to hydrochloric acid. The introductory section gives a background to the subject; electrochemical measurements and surface analysis by the ESCA-technique (Electron Spectroscopy for Chemical Analysis). LÄS MER

3. 22. Welds in the lean duplex stainless steel LDX 2101 : effect of microstructure and weld oxides on corrosion properties

   Författare :Elin M. Westin; John Ågren; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; weld metal; HAZ; nitrogen; manganese; austenite formation; phase balance; precipitates; pitting resistance; heat input; solidification; element loss; evaporation; deposition; weld oxides; discoloration; mechanical properties; thermo-mechanical simulation; Geeble; GTA; laser; LOM; SEM; EDS; TEM; Leco; EPMA; ferroxyl test; XPS; post weld cleaning; pickling; Materials science; Teknisk materialvetenskap;

   Sammanfattning : Duplex stainless steels are a very attractive alternative to austenitic grades due to their higher strength and good corrosion performance. The austenitic grades can often be welded autogenously, while the duplex grades normally require addition of filler metal. LÄS MER

4. 23. Manganese Combined Oxides as Oxygen Carriers for Chemical-Looping Combustion

   Författare :Malin Hanning; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbon capture; combined oxide; manganese oxide; chemical-looping;

   Sammanfattning : The global emissions of greenhouse gases are increasing and the development of mitigation measures is becoming more important. One of the alternatives proposed is carbon capture and storage, where the carbon dioxide emitted from large point sources is captured, compressed and stored in underground storage sites. LÄS MER

5. 24. Graphite oxides for preparation of graphene related materials : structure, chemical modification and hydrogen storage properties

   Författare :Alexey Klechikov; Alexandr Talyzin; Tamás Szabó; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Graphite oxide; graphene oxide; hydrogen storage; nanomaterials; adsorption; surface area; pore volume; Materials Science; materialvetenskap;

   Sammanfattning : Carbon materials have been studied for hydrogen storage for decades, but they showed too low capacity at ambient temperature compared to target values for practical applications. This thesis includes two parts. First one is fundamental study of graphite oxides (GO) structure and properties. LÄS MER

7. 25. Oxidation of terpenes in indoor environments : A study of influencing factors

   Författare :Linda Pommer; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; Monoterpene; Ozone O3 ; Nitrogen dioxide NO2 ; Nitrogen oxide NO ; Relative humidity RH ; Modelling; Scrubber; Experimental design; Interaction; Volatile organic compounds VOC ; Sick buildings syndrome SBS ; Principal component analysis PCA ; Indoor air; Ventilation; Tenax TA; Sodium sulphite; Miljökemi; Environmental chemistry; Miljökemi; analytisk kemi; Analytical Chemistry;

   Sammanfattning : In this thesis the oxidation of monoterpenes by O3 and NO2 and factors that influenced the oxidation were studied. In the environment both ozone (O3) and nitrogen dioxide (NO2) are present as oxidising gases, which causes sampling artefacts when using Tenax TA as an adsorbent to sample organic compounds in the air. LÄS MER