Search for dissertations about: "manganese oxides"

Showing result 1 - 5 of 45 swedish dissertations containing the words manganese oxides.

2. 1. Possibilities and Challenges of Using Combined Manganese Oxides as Oxygen Carriers

   Author : Malin Hanning; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbon capture; combined oxides; manganese oxides; oxygen carriers; manganese ores; chemical-looping combustion;

   Abstract : One alternative proposed to reduce greenhouse gas emissions is carbon capture and storage, where the carbon dioxide emitted from large point sources is captured, compressed and stored in underground geological formations. Many of the largest point sources of carbon dioxide are power plants and industries fuelled by fossil fuels or biomass. READ MORE

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

   Author : Elin M. Westin; John Ågren; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

   Author : Urban Öjteg; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

   Abstract : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). READ MORE

6. 4. Cold lap formation in Gas Metal Arc Welding of steel : An experimental study of micro-lack of fusion defects

   Author : Peigang Li; Lars-Erik Svensson; Norbert Enzinger; Högskolan Väst; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tandem GMAW; old laps; lack of fusion; Spatter; Overlap; Overflow; Manganese; Silicon; Oxides; Temperature; Manufacturing and materials engineering; Produktions- och materialteknik;

   Abstract : Cold laps are defined as micro-lack of fusion defects at the weld toe more or less parallel to the surface of the parent plate. These defects are known to negatively influence the fatigue properties of weldments. Previous studies suggest that cold lap formation can not be avoided completely in Gas Metal Arc Welding (GMAW). READ MORE

7. 5. Experimental Study on Cold Lap Formation in Tandem Gas Metal Arc Welding

   Author : Peigang Li; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; oxides; imperfection; spatter; silicon; lack of fusion; overflow; temperature energy; overlap; cold lap; manganese; tandem GMAW;

   Abstract : Tandem gas metal arc welding (GMAW) is a high productivity welding process which is appliedin many industries. However, a type of imperfection, known as cold lap, was revealed thatmostly accompanies the tandem GMAW process. READ MORE