Sökning: "ultraviolet UV"

Visar resultat 21 - 25 av 109 avhandlingar innehållade orden ultraviolet UV.

1. 21. Modification of flavonoid content and photosynthesis by ultraviolet-B radiation. Atrazine-tolerant and -sensitive ultivars of Brassica napus

   Författare :Louise Olsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; recovery; quercetin; photosynthesis; photoinhibition; photoacoustics; leaf anatomy; kaempferol; flavonoid; D1 protein; fluorescence; cold stress; carbon dioxide; atrazine tolerance; Brassica napus; UV-B; Physiological biophysics; Växtfysiologi;

   Sammanfattning : Levels of ultraviolet-B (UV-B, 280-320 nm) radiation reaching the Earth´s surface increase due to stratospheric ozone depletion. In this thesis the effect of enhanced UV-B radiation was studied on the atrazine-tolerant mutant Stallion, susceptible to photoinhibition, and the atrazine-sensitive cultivar Paroll of Brassica napus (oilseed rape). LÄS MER

3. 22. Role of cadmium and ultraviolet-B radiation in plants, Influence on photosynthesis and element content in two species of Brassicaceae

   Författare :Helene Larsson Jönsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; UV-B; plant nutrients; photosynthesis; oxygen evolution; chlorophyll fluorescence; Cd uptake; cadmium; Arabidopsis thaliana; Brassica napus; Plant biochemistry; Växtbiokemi; Botany; Botanik;

   Sammanfattning : Plants are exposed to many different stress factors during their lifetime, often more than one factor at a time, which highlights the importance of research regarding interaction among stress factors. Cadmium and ultraviolet-B radiation (UV-B, 280-315 nm) are two potential stress factors in the environment, which have gained increased interest due to atmospheric pollution. LÄS MER

4. 23. Optical properties and degradation of deep ultraviolet AIGaN-based light-emitting diodes

   Författare :Andrea Pinos; Saulius Marcinkevicius; Andreas Hangleiter; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AIGaN; deep-UV LEDs; polarization fields; screening; exciton binding energy; alloy fluctuations; near-field microscopy; carrier dynamics; LED aging; Optics; Optik;

   Sammanfattning : .... LÄS MER

5. 24. The molecular mechanisms behind perception and signal transduction of UV-B irradiation in Arabidopsis thaliana

   Författare :Irina Kalbina; Åke Strid; Lars-Gunnar Franzén; Örebro universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Action spectroscopy; Arabidopsis; gene expression; reverse genetics; signal transduction; UV-B irradiation.; Biochemistry; Biokemi; Biochemistry; Biokemi;

   Sammanfattning : Elevation of UV-B radiation (280-315 nm), occurring as a result of depletion of the stratospheric ozone, causes a number of physiological and biochemical changes in plants. Damage to the photosynthetic apparatus (including the bleaching of the pigments which trap the sun's energy), to the processes of cell division and growth regulation, and to the composition and replication of genetic material are just some of these changes. LÄS MER

7. 25. 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