Sökning: "Dissolved organic nitrogen"
Visar resultat 16 - 20 av 40 avhandlingar innehållade orden Dissolved organic nitrogen.
16. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron
Sammanfattning : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. LÄS MER
17. Molecular detection of abundance and activity of marine, symbiotic, N2-fixing cyanobacteria
Sammanfattning : Marine primary productivity in large parts of the oceans is supported by nitrogen fixers (diazotrophs). Richelia, a genus of multiple closely related species of heterocystous filamentous cyanobacterial diazotrophs, are often found in symbioses with a few genera of diatoms. Several Richelia species: R. euintracellularis, R. LÄS MER
18. Nutrient and Organic Matter Dynamics in Beech Forest Floors, in Relation to the Presence of Ground Flora
Sammanfattning : The objective of this thesis was to quantify differences between adjacent patches with and without ground flora of Deschampsia flexuosa L. Trin or Anemone nemorosa L. in two acid European beech (Fagus sylvatica L.) forest floors in south-west of Sweden. LÄS MER
19. Insights into the Molecular Mechanisms of Litter Decomposition and Assimilation of Nitrogen by Ectomycorrhizal Fungi
Sammanfattning : Ectomycorrhizae is the dominant type of mycorrhiza found in association with tree roots in boreal and northern temperate forests. In this symbiosis, the fungal partner derives energy from photosynthates provided by the host trees and in return delivers soil-derived nutrients such as nitrogen (N). LÄS MER
20. Hydrothermal alteration of organic matter at spreading centers
Sammanfattning : Alteration of organic matter, mainly amino acids, at sub-seafloor hydrothermal conditions has been investigated by performing laboratory experiments and by studying deep-sea sediments from hydrothermally active areas on the northern Juan de Fuca Ridge, northeast Pacific Ocean.Quaternary sediments from Middle Valley and the eastern flank of the Juan de Fuca Ridge recovered during the Ocean Drilling Program Legs 139 and 168 have been analyzed for total hydrolyzable amino acid concentrations, individual amino acid abundances and stereochemistry in order to evaluate the effects of hydrothermal stress on the decomposition of sedimentary amino acids. LÄS MER