Sökning: "Zirconium"

Visar resultat 21 - 25 av 79 avhandlingar innehållade ordet Zirconium.

1. 21. Studies of Electrocatalytic Reactions of NADH at Mediator Modified Electrodes and of H2O2 at Peroxidase Modified Electrodes

   Författare :Florentina Munteanu; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electrochemistry; Elektrokemi; kinetic studies; silica gel; titanium phoshate; zirconium phosphate; NADH; redox mediator; phenolic compounds; hydrogen peroxide; electron transfer; graphite and carbon paste electrodes; peroxidase; biosensor;

   Sammanfattning : This thesis addresses: (1) studies of direct and mediated electron transfer and kinetics of peroxidases on electrodes and the development of amperometric peroxidase-based biosenors, (2) electrochemical and kinetic studies of NADH oxidation at mediator modified electrodes. The direct and mediated electron transfer of horseradish and tobacco peroxidase were investigated on graphite electrodes by using wall-jet electrode methodology. LÄS MER

3. 22. CVD and ALD of Group IV- and V-Oxides for Dielectric Applications

   Författare :Katarina Forsgren; Steven George; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; CVD; ALD; Dielectric constant; Tantalum oxide; Ta2O5; Zirconium oxide; ZrO2; Hafnium oxide; HfO2; QCM; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Due to the constantly decreasing dimensions of electronic devices, the conventional dielectric material in transistors and capacitors, SiO2, has to be replaced by a material with higher dielectric constant. Some of the most promising candidates are tantalum oxide,Ta2O5, zirconium oxide, ZrO2 and hafnium oxide, HfO2. LÄS MER

4. 23. Study on the Mechanisms for Corrosion and Hydriding of Zircaloy

   Författare :Magnus Oskarsson; KTH; []
   Nyckelord :Zircaloy; Zirconium alloys; Oxidation; Oxide layer; Pre-Transition; Hydriding; Pre-Hydrided; Hydrides; Lithium Hydroxide LiOH ; Lithiated water; Dissolution; Cross sectional TEM;

   Sammanfattning : This thesis is focused on the mechanisms for corrosion andhydriding of Zircaloy. Special attention is paid tomicrostructural characterisation by cross sectionaltransmission electron microscopy of the oxide layer formed. LÄS MER

5. 24. Atom probe tomography of Zircaloy-2 exposed to boiling water reactor operation

   Författare :Johan Eriksson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nuclear fuel claddings; Zirconium alloys; Boiling water reactor; Clustering; Atom probe tomography; Radiation effects; Zircaloy-2; Dislocation loops;

   Sammanfattning : Zirconium alloys are used as cladding tubes for the fuel in nuclear reactors. In boiling water reactors (BWRs), the alloy Zircaloy-2, which contains the alloying elements Sn, Fe, Cr, Ni, and O, is commonly used. LÄS MER

7. 25. Evolution of microstructure and nanoscale chemistry of Zircaloy-2-type alloys during nuclear reactor operation

   Författare :Johan Eriksson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Zircaloy-2; Nuclear fuel cladding; Atom probe tomography; Zirconium alloys; Clustering; Dislocation loops; Radiation effects; Boiling water reactor;

   Sammanfattning : Zirconium alloys are used as fuel cladding tubes in nuclear reactors. During reactor operation, these alloys are degraded by corrosion, hydrogen pickup (HPU), and radiation-induced growth, processes influenced by the alloying elements. LÄS MER