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Visar resultat 1 - 5 av 11 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Pioneer Settlement in the Mesolithic of Northern Sweden

   Författare :Anders Olofsson; Noel Broadbent; Ingela Bergman; Bo Knarrström; Umeå universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; Archaeology; Mesolithic; pioneer settlement; lithic technology; cultural context; chronology; glacio-isostatic uplift; lake-tilting; Arkeologi; Archaeology subjects; Arkeologiämnen; Archaeology; arkeologi;

   Sammanfattning : The aim of the thesis is to cast light on the earliest settlement of northern Sweden. The starting point is lithic artifacts, which have been studied from a technological as well as a more conventional typological perspective (Papers I, II, and IV). LÄS MER

3. 2. Churning losses and efficiency in gearboxes

   Författare :Martin Andersson; Ulf Olofsson; Stefan Björklund; Ulf Sellgren; Bo Alfredsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gears; efficiency; temperature; running-in; assembly; torque loss; surface roughness;

   Sammanfattning : Efficient transmissions systems are key to producing competitive motor vehicles that have a smaller environmental impact. Gears are the main components in vehicle transmissions and although they are already highly efficient, there is still room for improvement. LÄS MER

4. 3. Groundwater resources in hard rock coastal terrains : Insights into heterogeneity and spatial variability

   Författare :Robert Earon; Bo Olofsson; Okke Batelaan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Crystalline Rock; Groundwater Balance; Kinematic porosity; Groundwater Recharge; Water Security; Coastal Aquifer; Land and Water Resources Engineering; Mark- och vattenteknik;

   Sammanfattning : Challenges regarding water security in hard rock coastal regions with limited soil cover are: a seasonal absence of recharge during times of peak residency, heterogeneity and variability of the fracture network, close proximity to saline water sources and spatially inconsistent storage and extraction. In areas where it is not feasible to connect residents to municipal water systems, a better understanding of the resilience of reservoirs is needed. LÄS MER

5. 4. Water supply in hard rock coastal regions : The effect of heterogeneity and kinematic porosity

   Författare :Robert Earon; Bo Olofsson; Gerhard Barmen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Coastal aquifer; Crystalline rock; Water balance; Geographic information systems; Water supply planning;

   Sammanfattning : Water resources in hard rock terrain are difficult to characterize due to heterogeneity and anisotropy in the fracture network, low porosities and limited recharge volumes available during the summer season. Three methods were developed and evaluated in order to assist in water supply planning. LÄS MER

7. 5. Subsurface dams in water resource management : methods for assessment and location

   Författare :Imran Ali Jamali; Bo Olofsson; Stephen Foster; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Subsurface dams; Groundwater; GIS; Regolith thickness; Groundwater; Byggvetenskap; Civil and Architectural Engineering;

   Sammanfattning : Natural groundwater storage can be improved by constructing a subsurface barrier that is a subsurface dam, in order to capture the subsurface flows and raise the groundwater levels (GWLs) in the sediment layers. Subsurface dams are preferable to surface dams because of lower evaporation, higher functionality, lower cost of construction, lessened risk for contamination and the possibility of utilizing land over the dam. LÄS MER