Sökning: "accessible surface area"
Visar resultat 16 - 20 av 47 avhandlingar innehållade orden accessible surface area.
16. Chemical characteristics of atmospheric aerosols : the influence of natural and man-made sources and sinks
Sammanfattning : In order to improve the understanding of the climatic and environmental effects of atmospheric aerosol particles, knowledge about their sources, sinks, chemical and physical characteristics as well as transportation in the atmosphere is needed. This thesis examines the water-soluble chemical characteristics of aerosol particles and precipitation and their interaction with trace gases. LÄS MER
17. Pesticide impact of intensive banana production on aquatic ecosystems in Costa Rica
Sammanfattning : A combination of chemical and biological studies demonstrated extensive surface water contamination, the occurrence of pesticides in sediments, especially near the banana plantation areas, and biological impacts. Pesticides were even found in the downstream waters of the Tortuguero conservation area, a highly diverse wetland that protects several endangered species. LÄS MER
18. Soil erosion in Tanzanian mountain areas : case studies of land degradation and recovery in relation to land use and physical land characteristics in the Uluguru and Usambara mountains, Tanzania
Sammanfattning : Thanks to favourable rainfall, soil and photosynthesis conditions, the highlands of Tanzania have a considerably higher potential for crop production than any other biogeographic region in the country. This has resulted in deforestation, high population densities, and overcultivation of the mountain slopes. LÄS MER
19. Dissolution Kinetics and Alteration Products of Micas and Epidote in Acidic Solutions at Room Temperature
Sammanfattning : The reaction kinetics of the weathering of several phyllosilicates and one sorosilicate were stud ied experimentally. The alteration products were characterised by various methods in clud ing XRD, HRTEM, SEM, FTIR, NMR and Mössbauer spectroscopy. LÄS MER
20. Studies of reactions occurring in the AUC-process : from UF₆ to sintered UO₂ pellets
Sammanfattning : This study has been carried out to investigate the influence of process parameters upon the material characteristics during the conversion of UFg to UO2 powder, and the importance of variation in these charcteristics for the final quality of the sintered pellets. The first process step is a precipitation of ammonium uranyl carbonate (AUC) from UFg, ammonia and carbon dioxide. LÄS MER
