Sökning: "vacancy"

Visar resultat 6 - 10 av 117 avhandlingar innehållade ordet vacancy.

1. 6. Thermodynamic and kinetic properties of Fe-Cr and TiC-ZrC alloys from Density Functional Theory

   Författare :Vsevolod Razumovskiy; Pavel Korzhavyi; Andrei Ruban; Malin Selleby; Sergei Dudarev; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio; first principles; point defects; vacancy clusters; alloys; steels; iron; carbides; diffusion; phase diagram; density functional theory; elastic constants; elastic properties; thermodynamic modelling;

   Sammanfattning : The complete and accurate thermodynamic and kinetic description of any systemis crucialfor understanding and predicting its properties. A particular interest is in systemsthat are used for some practical applications and have to be constantly improved usingmodification of their composition and structure. LÄS MER

3. 7. Mechanistic Approach to Corrosion of Zirconium by Water - A First Principle Study

   Författare :Mikaela Lindgren; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; zirconium; hydrogen pick-up; corrosion; oxygen vacancy; DFT;

   Sammanfattning : Zirconium and zirconium oxides are of major technological importance. There are broad applications for these materials, from fuel cell electrolyte to semiconductors and in hip-implants. In nuclear power plants, zirconium alloys are widely used as cladding material to contain the fission fuel in the reactor cores. LÄS MER

4. 8. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

   Författare :Joakim Nyman; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

   Sammanfattning : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. LÄS MER

5. 9. Mechanism-based flow stress model for Ti-6Al-4V : applicable for simulation of additive manufacturing and machining

   Författare :Bijish Babu; Lars-Erik Lindgren; Jean-Philippe Ponthot; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material modeling; Ti-6Al-4V; dislocation density; vacancy concentration; additive manufacturing; hot forming; heat treatment; Material Mechanics; Materialmekanik;

   Sammanfattning : Ti-6Al-4V has remarkable properties such as high specific mechanical properties (viz. stiffness, strength, toughness, fatigue resistance), corrosion resistance, biocompatibility etc. These properties make it attractive for applications in aerospace, chemical industry, energy production, surgical implants, etc. LÄS MER

7. 10. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

   Författare :Joakim Nyman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

   Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER