Sökning: "trace gas"
Visar resultat 1 - 5 av 70 avhandlingar innehållade orden trace gas.
1. Mid-infrared photonic devices for on-chip optical gas sensing
Sammanfattning : Gas detection is crucial in a wide range of fields and applications, such as safety and process control in the industry, atmospheric sciences, and breath diagnostics. Optical gas sensing offers some key advantages, compared to other sensing methods such as electrochemical and semiconductor sensing: high specificity, fast response, and minimal drift. LÄS MER
2. Synthesis gas from black liquor : trace components and methanol synthesis
Sammanfattning : The common European Energy and Climate policy states that in 2020 the share of biofuels for inland transports should be 10 %. Such a stipulation calls for a commercially sustainable biofuel production. LÄS MER
3. Carbon trace gas dynamics in subarctic lakes
Sammanfattning : Northern lakes are important sources of greenhouse gases carbon dioxide and methane to the atmosphere. Emissions are expected to increase as the climate continues to warm. Even so, lake carbon budgets are currently poorly constrained. This is in part because of a limited understanding of the processes that govern the flux. LÄS MER
4. Trace metals in the atmosphere : the wet deposition of trace metals : the selenium cycle
Sammanfattning : Cd, Cu, Fe, Mn, Pb and Zn concentrations in wet deposition have been monitored in Sweden since the autumn of 1983. Concentrations of these elements are highest in southern Sweden and decrease northward. Examination of enrichment factors, relative to crustal material, indicate that the major source of Cd, Cu, Pb and Zn is anthropogenic emissions. LÄS MER
5. Improved methods for enrichment of organic ultra trace components for analysis by gas chromatography
Sammanfattning : This thesis describes some new methods for analysis oforganic trace components from air and water by gaschromatography. The work is particularly focused on thedevelopment of new technologies for analyte enrichment, usingsorbent-based concepts. Short lengths of open tubular columnswere examined for their potential use as denuders. LÄS MER