Sökning: "vibrational analysis"

Visar resultat 1 - 5 av 77 avhandlingar innehållade orden vibrational analysis.

  1. 1. Calculated Potential Energy Surfaces and Vibrational Analysis

    Författare :Niclas Forsberg; Beräkningskemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Benzene; HCO; NEMO; Imaginary Level Shift; Double Harmonic Approximation; Potential Energy Surface; CASPT2; Franck-Condon Factors; CASSCF; p-Benzosemiquinone; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Sammanfattning : The focus of this thesis is on the calculation of potential energy surfaces and on the study of vibrational properties. For example: - We have developed a new method for calculation of Franck-Condon factors. - We have calculated full energy surfaces of the ground (X2A’) the excited (B2A’) states of the formyl radical. LÄS MER

  3. 2. Vibrational and Structural Characterisation in Two Perovskite Challenges: A Density Functional Theory Study

    Författare :Erik Jedvik Granhed; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phonon; chemical expansion; materials modelling; oxyhydride; polaron; vibrational analysis; BaTiO3; BaZrO3; anti-ferrodistortive; density functional theory;

    Sammanfattning : The modelling of perovskites using density functional theory (DFT) can sometimes be a challenge with many different states very close in energy. In particular, the tilting of the inscribed octahedron, as well as the formation of electron polarons, leads to states with energy differences in the meV range. LÄS MER

  4. 3. Computer simulations of condensed phases with icosahedral local order

    Författare :Sergei Simdyankin; Paul Madden; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; simple liquids; glasses; liquid-glass transition; Frank-Kasper phase; molecular dynamics; phonon dispersion; normal-mode analysis; wavelet analysis; numerisk analys; Numerical Analysis;

    Sammanfattning : Understanding the fundamental aspects, and the formation mechanisms of glasses remains an outstanding unsolved problem of condensed-matter physics.Glass-formation in simple atomic systems is generally associated with the icosahedral local order. LÄS MER

  5. 4. Laser-Based Combustion and Trace-element Analysis

    Författare :Yvonne Malmsten; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser-induced fluorescence; graphite furnace; trace element analysis; LEI; laser-enhanced ionisation; LIF; meta-stable; flow-tagging; NO; OH; counter-flow diffusion flame;

    Sammanfattning : Laser spectroscopy has been utilised as a tool for combustion diagnostics and sensitive trace-element analysis. In the field of combustion analysis, a characterisation of a CH4/N2 - O2/N2 counter-flow diffusion flame has been performed using Laser-Induced Fluorescence (LIF). LÄS MER

  7. 5. Local structure and dynamics of proton and hydride-ion conducting perovskite type oxides

    Författare :Laura Mazzei; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; hydrogen; local coordination; vibrational dynamics; neutron scattering; vibrational spectroscopy; thin films; Perovskite oxides;

    Sammanfattning : Proton and hydride-ion conducting oxides show potential for application in several technological devices, such as solid oxide fuel cells and batteries. However, fundamental properties pertaining to the local structure and conduction mechanisms in these materials are unclear. LÄS MER