Sökning: "Water cycle"
Visar resultat 1 - 5 av 317 avhandlingar innehållade orden Water cycle.
1. Time-resolved Structural and Mechanistic Studies of Water Oxidation in Photosystem II : water here, water there, water everywhere
Sammanfattning : Oxygenic photosynthesis is undisputedly one of the most important chemical processes for human life on earth as it not only fills the atmosphere with the oxygen that we need to breathe, but also sustains the accumulation of biomass, which is not only used as nourishment but is also present in almost every aspect of our lives as building material, textiles in clothes and furniture, or even as living decorations to name a few.The photosynthetic water-splitting mechanism is catalyzed by a water:plastoquinone oxido-reductase by the name of photosystem II (PSII), which is embedded in the thylakoid membranes of plants, algae and cyanobacteria. LÄS MER
2. Global and continental perspectives on the sustainability of future agricultural water management
Sammanfattning : Ensuring water and food security in the Anthropocene requires an understanding of combined climate change patterns and land and water management options from local to global scale. In many regions, irrigation from river and groundwater sources is being used at unsustainable rates and climate change will further threaten those water sources. LÄS MER
3. Heat and water flows in freezing and thawing soils : numerical modelling, laboratory and field observations
Sammanfattning : A laboratory study of infiltration rates into frozen and unfrozen fine sand, including temperature effects of both soil and infiltration water, is reported. The average infiltration rate varied from about 10.6 mm/min for unfrozen conditions, to about 1-2 mm/min for frozen conditions. LÄS MER
Sammanfattning : The world demand for electrical power increasescontinuously, requiring efficient and low-cost methods forpower generation. This thesis investigates two advanced powercycles with mixtures as the working fluid: the Kalina cycle,alternatively called the ammonia-water cycle, and theevaporative gas turbine cycle. LÄS MER
Sammanfattning : Evapotranspiration is the second largest quantity in the water cycle and an important indicator for climate changes. Accurate estimations and better understanding of evapotranspiration are required in hydrologic studies and water resources modelling under stationary and changing climate conditions. LÄS MER