Sökning: "reactive tracers"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden reactive tracers.

1. 1. Effect of Hyporheic Exchange on Conservative and Reactive Solute Transport in Streams : Model Assessments Based on Tracer Tests

   Författare :Karin Jonsson; Anders Wörman; Bernhard H. Schmid; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; conservative; hyporheic exchange; model; reactive; retention; solute; sorption kinetics; stream transport; temporal moments; tracer experiment; Geovetenskap; Earth sciences; Geovetenskap; Sedimentology; sedimentologi;

   Sammanfattning : Understanding of the processes affecting solute transport in flowing water is important for the possibility to predict the evolution with time of polluted stream systems. This thesis presents tracer experiment methodology and model developments for solute transport in streams, with special focus on retention processes and their effect on solute stream transport. LÄS MER

3. 2. Contaminant transport in non-uniform streams and streambeds

   Författare :Jonas K. Forsman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Sub-surface transient storage; reactive tracers; analytical solutions; Geovetenskap; Earth sciences; Geovetenskap; Sedimentology; sedimentologi;

   Sammanfattning : The interplay between hydraulic and chemical processes in streams and adjacent storage zones, e.g. streambed sediments, is of crucial importance for the large-scale transport of released contaminants. This thesis presents a methodology for tracer experiments and the development of mechanistic transport models. LÄS MER

4. 3. Development of 18F- and 68Ga-Labelled Tracers : Design Perspectives and the Search for Faster Synthesis

   Författare :Elisabeth Blom; Bengt Långström; Oleksiy Itsenko; Irina Velikyan; Farhad Karimi; Frank Rösch; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PET; nucleophilic 18F-fluorination; perfluoro; F-SPE; molecular design; 68Ga; chelators; DOTA; NOTA; microwave; halogen exchange; harmine; biotin; RGD; VEGF; CRP; Chemistry; Kemi; Organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis deals with the design of 18F- and 68Ga-labelled positron emission tomography (PET) tracers and the development of technologies that enable faster and simpler preparation with high specific radioactivity. Techniques like microwave heating and reducing the concentrations of the precursor were investigated with this perspective. LÄS MER

5. 4. Catecholaminergic neurotransmission in heart and brain : development of tracers for positron emission tomography

   Författare :Claus Oliver Langer; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :PET; Radioligand; Catecholamine; Norepinephrine; Dopamine; Heart; Brain; Metaraminol; Dopamine D2 Receptor;

   Sammanfattning : The catecholamines norepinephrine and its biosynthetic precursor dopamine are two principal neurotransmitters in the human central nervous system (CNS). Moreover, norepinephrine is a major transmitter substance in the peripheral, autonomic nervous system. LÄS MER

7. 5. 231Pa, 230Th and 232Th as tracers of deep water circulation and particle transport : Insights from the Mediterranean Sea and the Arctic Ocean

   Författare :Sandra Gdaniec; Carl Magnus Mörth; Matthieu Roy-Barman; Per Andersson; Laura Robinson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; protactinium; thorium; Mediterranean Sea; Arctic Ocean; scavenging; marine particles; boundary scavenging; particle transport; geotraces; Marine Geology; maringeologi;

   Sammanfattning : The naturally occurring U and Th-series radionuclides have shown to have a considerable importance for the understanding of biogeochemical processes on Earth and in the ocean. In this thesis, the isotopes 230-thorium (230Th), 232-thorium (232Th) and 231-protactinium (231Pa) are used as tracers of the transport and scavenging of marine particles and water circulation. LÄS MER