Sökning: "Particle Induced X-ray Emission PIXE"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Particle Induced X-ray Emission PIXE.

1. 1. Airborne particulate matter in a Sub-Saharan Africa city: Nairobi, Kenya, and at an Equatorial high altitude site: Mount Kenya

   Författare :Samuel Mwaniki Gaita; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; X-ray Fluorescence XRF ; Particle Induced X-ray Emission PIXE ; Particulate matter pollutants; Source apportionment; sub-Saharan Africa; Deposition fractions; High- altitude; Free troposphere; Spatial distribution;

   Sammanfattning : In Sub-Saharan Africa (SSA), air quality is gravely understudied despite the existing influential factors such a rapid urbanization and population growth that negatively affect the environment. Majority of urban areas in SSA face challenges that include lack of social services, poor infrastructure development, exponential increase of second-hand vehicles and extensive use of biomass-based fuel for energy needs. LÄS MER

3. 2. Studies of Tropospheric and Stratospheric Aerosol using Ion Beam Analysis

   Författare :Giorgos Papaspiropoulos; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmosphere; Aerosols; troposphere; stratosphere; ion beam analysis; PIXE; impactors; particulate sulphur; chemical speciation; elemental analysis; thermography; Physics; Nuclear physics; Fysik; Metrology; Kärnfysik; physical instrumentation; Metrologi; fysisk instrumentering; Fysicumarkivet A:2001:Papaspiropoulos;

   Sammanfattning : Atmospheric aerosol particles are believed to have an impact on the radiative forcing of the earth's surface. The predicted results indicate a net cooling effect on the global climate, however there are few studies available to substantiate this and experimental data are needed. LÄS MER

4. 3. Chemical and Morphological Characterisation of Aerosol Particles in the Tropopause Region

   Författare :Hung Nguyen Ngoc; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CARIBIC; Physics; Singel particle analysis TEM and EFTEM; Carbon and Sulphur; Light element analysis; Aerosol sampler; Chemical Characterisation; Aerosol in the Tropopause Region; Nuclear physics; Technological sciences; Fysik; Teknik; Kärnfysik; Fysicumarkivet A:000;

   Sammanfattning : The aim of this work was to study atmospheric aerosols, focusing on the chemical composition, the morphology and the origin of the aerosol in the upper troposphere and lowermost stratosphere. An aerosol sampler was developed for this purpose. A new method for quantitative analysis of the major components of the aerosol, i.e. LÄS MER

5. 4. The Growth of External Ectomycorrhizal Mycelia in the Field in Relation to Host Nutrient Status and Local Addition of Mineral Sources

   Författare :David Hagerberg; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plant ecology; Potassium; Phosphorus; Norway spruce; Picea abies; Whole-tree harvesting; Ectomycorrhizal fungi; Wood ash fertilization; Växtekologi; Microbiology; bacteriology; virology; mycology; Mikrobiologi; bakteriologi; virologi; mykologi;

   Sammanfattning : A method based on ingrowth mesh bags was developed to study the production of EMM. These bags were made of nylon mesh with a mesh size of 50 mu-m, which allows colonisation by fungal mycelia but excludes the tree roots. LÄS MER

7. 5. Low and High Energy Ion Beams in Nanotechnology

   Författare :Thomas Winzell; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ion implantation; magnetic materials; ERDA; nanometer structures; Nuclear physics; MeV Ions; lithography; Kärnfysik; Fysicumarkivet A:2000:Winzell;

   Sammanfattning : In this thesis, two ways of fabrication of nanometer-sized semiconductor features are presented. Low Energy Ion Implantation (LEII) has been used to create shallow (sub-50 nm) and laterally small (5 m m – 200 nm) features by 10 keV As+ doping of B background doped Si. LÄS MER