Sökning: "fine-structure constant"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden fine-structure constant.

1. 1. Measurements of High-Precision Atomic Data with Applications to Astrophysics and Cosmology

   Författare :Maria Aldenius; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atomic data; Ca; Cr; Fe; Mn; Mg; metal-poor stars; fine-structure constant; Fourier transform spectroscopy; nebulae; oscillator strengths; spectroscopy; wavelengths; Ti; Zn; Astronomy; Astronomi; Atomic and molecular physics; Atom- och molekylärfysik; rymdvetenskap; space research; cosmic chemistry; kosmisk kemi; branching fractions;

   Sammanfattning : Investigations of astrophysical spectra require accurate atomic data, such as wavelengths and transition probabilities. This thesis provides high-precision atomic data for astrophysical and cosmological applications. The measurements have been carried out using Fourier transform spectrometry on light produced in a hollow cathode light source. LÄS MER

3. 2. Microstructural properties of some oxide thin films studied by X-ray diffraction and extended X-ray absorption fine structure

   Författare :Arturas Vailionis; KTH; []
   Nyckelord :;

   Sammanfattning : The microstructure of some high-temperature superconductorrelated oxide thin films was studied by X-ray Diffraction (XRD)and Extended X-ray Absorption Fine Structure (EXAFS)techniques. A general one-dimensional kinematic x-raydiffraction model was further developed to quantitativelyanalyze the structural properties of complex layered films. LÄS MER

4. 3. Precision Improvements of Penning Trap Mass Measurements Using Highly Charged Ions : Applications to solving current problems in fundamental physics

   Författare :Tomas Fritioff; Reinhold Schuch; Jürgen Kluge; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; Atom- och molekylfysik; Physics; fysik;

   Sammanfattning : In my thesis I describe the improvements of the Penning trap mass spectrometer SMILETRAP. The objective of these improvements have been to increase the reliability and the accuracy with which an atomic mass can be measured using highly charged ions. LÄS MER

5. 4. Cation adsorption properties of substituted kraft fibres : an experimental and thermodynamic modelling study

   Författare :Ola Sundman; Lars-Olof Öhman; Per Persson; Janne Laine; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Kraft fibres; Donnan equilibria; ion exchange; acid base properties; potentiometric titrations; thermodynamic modelling; NPEs; GaAl12 7 ; EXAFS; Chemistry; Kemi;

   Sammanfattning : Acid/base and metal ion adsorption properties have been investigated for a range of chemically modified bleached Kraft fibre materials (pulps). The studies were performed via potentiometric titrations, Flame Atomic Absorbtion (and Emission) Spectroscopy, Inductively Coupled Plasma Optical Emission Spectroscopy and Extended X-ray Absorbtion Fine Structure measurements. LÄS MER

7. 5. Density functional studies of EPR and NMR parameters of paramagnetic systems

   Författare :Lyudmyla G. Telyatnyk; Olav Vahtras; Martin Kaupp; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-restricted DFT; restricted-unrestricted approach; EPR spin Hamiltonian parameters; NMR spin Hamiltonian parameters; Bioorganic chemistry; Bioorganisk kemi;

   Sammanfattning : Experimental methods based on the magnetic resonance phenomenon belong to the most widely used experimental techniques for investigations of molecular and electronic structure. The difficulty with such experiments, usually a proper interpretation of data obtained from high-resolution spectra, opens new challenges for pure theoretical methods. LÄS MER