Search for dissertations about: "Dissolved silica"

Showing result 1 - 5 of 28 swedish dissertations containing the words Dissolved silica.

  2. 1. Silicon cycling in the Baltic Sea : Trends and budget of dissolved silica

    Author : Liana Papush; Åsa Danielsson; Lars Rahm; Petra Tallberg; Linköpings universitet; []
    Keywords : Dissolved silica; trends; nutrient; nutrient ratios; diatoms; Redfield; limitation; eutrophication; riverine load; budget; fluxes; accumulation; retention; optimisation; Baltic Sea; Löst kisel; trender; näringsämne; näringsämnens kvoter; kiselalger; Redfield; tillväxtbegränsning; övergödning; flodtillförsel; budget; flöden; ackumulering; retention; optimering; Östersjön; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. READ MORE

  4. 2. Diatom-rich sediment formation in lakes

    Author : Petra Zahajská; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Silicon; silica; diatom; biogenic silica; lake; sediment; stable Si isotopes; Ge Si; Yellowstone; Northern Sweden;

    Abstract : Unicellular photosynthetic golden algae called diatoms are one of the most abundant silicifying organisms. Diatoms take up silicon and build their frustules, in the form of biogenic silica (BSi), which have high preservation potential, and thus are found in sediments. READ MORE

  5. 3. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

    Author : Anders Tengberg; Göteborgs universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

    Abstract : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). READ MORE

  6. 4. Microstructure and liquid mass transport control in nanocomposite materials

    Author : Christoffer Abrahamsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; magnetic alignment; permeability; colloidal gels; microgels; bond water; clay; flow; microstructure; nanocomposites; poly N-isopropylacrylamide ; porous materials; liquid mass transport; diffusion; diffusion NMR; particle aggregation; phase behavior; silica;

    Abstract : Some of the biggest problems currently facing the world are closely tied to unsolved technological challenges in the material sciences. Many materials have a porous microstructure that controls their overall properties. READ MORE

  7. 5. The Co-Structure Directing Agent (CSDA) Approach to Mesoporous Silica Formation – Exploring the Assembly Characteristics

    Author : Ruiyu Lin; Fysikalisk kemi; []
    Keywords : mesoporous silica materials; co-structure directing agent; surfactants; mesostructures; scattering; NMR; TEM;

    Abstract : We investigate the formation mechanism responsible for two specific systems of mesoporous silicas formed with the so-called co-structure directing agent (CSDA) route. The synthesis relies on the interactions between silica source (tetraethylorthosilicate, TEOS), surfactants and CSDA. READ MORE