Sökning: "lenses"

Visar resultat 26 - 30 av 156 avhandlingar innehållade ordet lenses.

1. 26. Intraocular light scattering and glare testing

   Författare :Jörgen Thaung; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; light scattering; light scattering factor; glare; veling luminance; contrast sensitivity; adaptation; psychophysics; light transmission; integrating sphere; human lens; cataract; aging.;

   Sammanfattning : Aims: To analyze the parameters that are used in psychophysical glare testing and the validity of the light scattering factor (LSF). The purpose is also to investigate the light scattering properties in excised eye lenses, and to compare these properties with light transmission for different wavelengths in aging and cataractous lenses. LÄS MER

3. 27. A Stacked Prism Lens Concept for Next-Generation Hard X-Ray Telescopes

   Författare :Wujun Mi; Mats Danielsson; Peter Nillius; Ralf K. Heilmann; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; focusing X-ray telescopes; Wolter-I optics; stacked prism lens; focused UV lithography; grayscale e-beam lithography; proximity effect correction; angular resolution; effective collecting area; röntgenteleskop; Wolter-I-optik; staplade prismalinser; fokuserad UV-litografi; elektronstråle-litografi; Fysik; Physics;

   Sammanfattning : Over the past half century, the focusing X-ray telescope has played a very prominent role in X-ray astronomy at the frontier of fundamental physics. The finer angular resolution and increased effective area have enabled more and more exciting discoveries and detailed studies of the high-energy universe, including the cosmic X-ray background (CXB) radiation, black holes in active galactic nuclei (AGN), galaxy clusters, supernova remnants, and so on. LÄS MER

4. 28. Optical Studies and Applications of Single Quantum Dots

   Författare :Valéry Zwiller; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; time resolved photoluminescence; Physics; Fysik; Semiconductory physics; Halvledarfysik; Condensed matter:electronic structure; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; spektroskopi; magnetisk resonans; microphotoluminescence; microcavities; photoluminescence; quantum optics; nano-optics; photonics; low dimensional structures; quantum dots; Fysicumarkivet A:2001:Zwiller;

   Sammanfattning : The luminescence from single quantum dots has been studied. Single dot photoluminescence was studied under continuous as well as under pulsed excitation. Time-resolved studies revealed fast relaxations in quantum dots. The time resolved measurements were fitted with a set of rate equations. LÄS MER

5. 29. Influence of exposure patterns and oxidation in UVR-induced cataract

   Författare :Marcelo Ayala; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Cataract; ultraviolet radiation; lens; in vivo; rats; oxidative process; time;

   Sammanfattning : Background: Ultraviolet radiation (UVR) is one among a number of possible factors that may lead to the development of cataract. Whereas induction of cataract as the result of onetime exposure to UVR has been studied extensively, the data on lens damage resulting from repeated exposures to UVR are scarce. LÄS MER

7. 30. Cataract from ultraviolet radiation

   Författare :Stefan Löfgren; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Cataract; ultraviolet radiation; lens; rat; transmittance; pigment; age; pupil size.;

   Sammanfattning : Cataract is the major cause of low vision and blindness in the world. Epidemiological and experimental studies link cataract to (solar) ultraviolet radiation (UVR) exposure. Current safety limits of UVR exposure are based on animal experiments, but many factors are less well known in UVR cataractogenesis. LÄS MER