Sökning: "Atom- och molekylärfysik"

Visar resultat 6 - 10 av 45 avhandlingar innehållade orden Atom- och molekylärfysik.

1. 6. Methods, Instrumentation and Mechanisms for Optical Characterization of Tissue and Treatment of Malignant Tumours

   Författare :Sara Pålsson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; temperature; perfusion; PDT; photodynamic therapy; mechanisms; tissue characterization; instrumentation; optical biopsy; fluorescence spectroscopy; spectroscopy techniques; Raman spectroscopy; interstitial photodynamic therapy; photodynamic threshold dose; Atomic and molecular physics; Atom- och molekylärfysik;

   Sammanfattning : In this thesis, different optical methods utilising visible light for characterization of tissue have been developed and evaluated. The feasibility of many of these methods has been demonstrated in the laboratory or in animal experiments. LÄS MER

3. 7. Spectroscopic techniques for photodynamic therapy dosimetry

   Författare :Ann Johansson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; diffuse light spectroscopy; photodynamic therapy; biomedical optics; Atom- och molekylärfysik;

   Sammanfattning : Photodynamic therapy (PDT) as a cancer treatment modality relies on the simultaneous presence of three components; light, photosensitiser and oxygen. Once excited by the light, the photosensitiser can interact with oxygen, leading to the formation of toxic oxygen species. LÄS MER

4. 8. Attosecond Optical and Electronic Wave Packets

   Författare :Per Johnsson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; optik; acoustics; optics; Electromagnetism; Ionization Dynamics; Electron Wave Packet Interferometry; Electron Wave Packet Control; Pulse Characterization; High-Order Harmonics; Attosecond Pulse Trains; Atom- och molekylärfysik; Atomic and molecular physics; akustik; Elektromagnetism;

   Sammanfattning : When a low-frequency laser pulse is focused to a high intensity in a gas, the electric field of the laser may become comparable to, or even exceed, the electric field between the electrons and the nucleus in the atom. Under such conditions, through a process known as high-order harmonic generation, bursts of extreme ultraviolet radiation may be emitted, with durations in the attosecond domain (1 as = 10^{-18} s), which is the time-scale of electronic processes. LÄS MER

5. 9. Biomedical and atmospheric applications of optical spectroscopy in scattering media

   Författare :Johannes Swartling; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Turbid media; Tissue optics; Tissue optical properties; Multiple scattering; Radiative transfer; Diffusion equation; Monte Carlo method; Time-resolved spectroscopy; Atomic and molecular physics; Integrating spheres; Atom- och molekylärfysik; Fysicumarkivet A:2002:Swartling;

   Sammanfattning : Spectroscopic analysis of scattering media is difficult because the effective path length of the light is non-trivial to predict when photons are scattered many times. The main area of research for such conditions is biological tissues, which scatter light because of variations of the refractive index on the cellular level. LÄS MER

7. 10. Lidar Techniques for Environmental Monitoring

   Författare :Rasmus Grönlund; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; remote laser-induced breakdown spectroscopy; laser-induced fluorescence; differential absorption lidar; fluorescence lidar; Atom- och molekylärfysik;

   Sammanfattning : Atoms and molecules absorb and emit light at certain, welldefined wavelengths, and this forms the basis of spectroscopy. The wavelengths are given by the discrete energy levels of the atoms/molecules. LÄS MER