Sökning: "isotopic ratio"
Visar resultat 1 - 5 av 25 avhandlingar innehållade orden isotopic ratio.
1. Numerical simulations of the isotopic composition of stratospheric water vapour and methane
Sammanfattning : The middle atmosphere is an important area of the Earth's atmosphere, but our understanding of the dynamical and chemical processes in that region is still limited. Water vapour and methane both fulfil the requirements for tracers due to their long lifetimes and have frequently been used to study dynamical processes. LÄS MER
2. On Weapons Plutonium in the Arctic Environment (Thule, Greenland)
Sammanfattning : This thesis concerns a nuclear accident that occurred in the Thule (Pituffik) area, NW Greenland in 1968, called the Thule accident. Results are based on different analytical techniques, i.e. gamma spectrometry, alpha spectrometry, ICP-MS, SEM with EDX and different sediment models, i. LÄS MER
3. Isotope Ratio and Trace Element Measurements Using Inductively Coupled Plasma – Mass Spectrometry : Method Development and Applications in Environmental Forensics
Sammanfattning : Environmental Forensics is a scientific methodology developed for identifying sources, the timing of release, and transport pathways for potentially hazardous environmental contaminants. It combines a variety of analytical methods with principles derived from disciplines such as chemistry, geology, geochemistry, hydrogeology, and statistics, with the purpose to provide objective scientific and legal conclusions on the source and/or time of a contaminant release. LÄS MER
4. Alternative methods for analysing moisture transport in buildings : Utilisation of tracer gas and natural stable isotopes
Sammanfattning : New methods, based on tracer gas measurements and isotopicanalysis can be used to evaluate the moisture properties ofbuilding materials and provide the means for forensic analysisof the origins and history of excessive water in buildings, theimmediate practical consequences of which will be the abilityto improve the moisture performance of constructions. It is shown, in theory and through measurements how thewater vapour permeability of porous building materials can witha good degree of accuracy be estimated with tracer gasmeasurements that provide an efficient alternative to the cupmethod. LÄS MER
5. Intramolecular isotope analysis reveals plant ecophysiological signals covering multiple timescales
Sammanfattning : Our societies' wellbeing relies on stable and healthy environments. However, our current lifestyles, growth-oriented economic policies and the population explosion are leading to potentially catastrophic degradation of ecosystems and progressive disruption of food chains. LÄS MER
