Sökning: "core calculations"

Visar resultat 1 - 5 av 180 avhandlingar innehållade orden core calculations.

1. 1. Structure and Dynamics of Core-Excited Species

   Författare :Oksana Travnikova; Maria Novella Piancastelli; Svante Svensson; Denis Ceolin; Pascal Lablanqui; Uppsala universitet; []
   Nyckelord :Physics; Synchrotron radiation; X-ray Photoelectron Spectroscopy XPS ; X-ray Absorption Spectroscopy XAS ; Resonant Auger Spectroscopy RAS ; Auger Electron Spectroscopy AES ; Energy-Selected Auger Electron PhotoIon COincidence ES-AEPICO ; core excitation; core ionization; linear free energy relationships LFER ; molecular-field splitting; substituent effects; nuclear dynamics; isomerization; Cl2; N2O; methane derivatives; allene; acetylacetone; Fysik;

   Sammanfattning : In this thesis we have performed core-electron spectroscopy studies of gas phase molecular systems starting with smaller diatomic, continuing with triatomic and extending our research to more complex polyatomic ones. We can subdivide the results presented here into two categories: the first one focusing on electronic fine structure and effect of the chemical bonds on molecular core-levels and the other one dealing with nuclear dynamics induced by creation of a core hole. LÄS MER

3. 2. Heavy-Core Staffanes : A Computational Study of Their Fundamental Properties of Interest for Molecular Electronics

   Författare :Niclas Sandström; Henrik Ottosson; Leif Hammarström; Bo Albinsson; Uppsala universitet; []
   Nyckelord :Organic chemistry; conjugation; polarizability; Group 14 elements; cage compounds; electronic excitations; quantum chemistry; molecular electronics; Organisk kemi;

   Sammanfattning : The basic building blocks in molecular electronics often correspond to conjugated molecules. A compound class consisting of rigid rod-like staffane molecules with the heavier Group 14 elements Si, Ge, Sn and Pb at their bridgehead positions has now been investigated. LÄS MER

4. 3. Improved PWR Core Characteristics with Thorium-containing Fuel

   Författare :Cheuk Wah Lau; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; load-following; PWR; Thorium; xenon poisoning; core calculations;

   Sammanfattning : Thorium is an element for possible use as nuclear fuel, because of the fertile property of Th-232, which could convert into U-233 after neutron capture and beta decays. However, thorium based fuels have not been successfully implemented, because of the high cost and the higher complexity compared with once-through uranium fuel. LÄS MER

5. 4. Ab initio simulations of core level spectra : Towards an atomistic understanding of the dye-sensitized solar cell

   Författare :Ida Josefsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multiconfigurational quantum chemistry; CASSCF calculations; core-level spectroscopy; x-ray photoelectron spectroscopy; x-ray absorption; resonant x-ray scattering; dye solar cells; transition metals; kemisk fysik; Chemical Physics;

   Sammanfattning : The main focus of this thesis is ab initio modeling of core level spectra with a high-level quantum chemical description both of the chemical interactions and of local atomic multiplet effects. In particular, the combination of calculations and synchrotron-based core-level spectroscopy aims at understanding the local structure of the electronic valence in transition metal complexes, and the details of the solvation mechanisms of electrolyte solutions, systems relevant for the dye-sensitized solar cell. LÄS MER

7. 5. Development and Applications of a General Coupled Thermal-hydraulic/Neutronic Model for the

   Författare :Mathias Stålek; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reactor transients; measurements; thermal-hydraulics; core calculations; coupled calculations;

   Sammanfattning : Coupled calculations are important for the simulation of nuclear power plants when there is a strongfeedback between the neutron kineticsand the thermal-hydraulics. A general coupled model of the Ringhals-3 Pressurized Water Reactor has beendeveloped for this purpose. LÄS MER