Search for dissertations about: "maintenance of variation"

Showing result 6 - 10 of 139 swedish dissertations containing the words maintenance of variation.

2. 6. Friction in threaded fasteners : Influence of materials and tooling

   Author : Mayank Kumar; Sergei Glavatskih; Erik Persson; Ellen Bergseth; Ian Sherrington; Robert Wood; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Friction; Coating; Surface topography; Tightening speed; Additive manufacturing; Tightening condition; Assembly tool; Material; Friktion; Ytbehandling; Yttopografi; Åtdragningshastighet; Additiv tillverkning; Åtdragningsförhållanden; Monteringsverktyg; Material; Machine Design; Maskinkonstruktion;

   Abstract : Threaded fasteners represent the most common type of machine element, with a unique function that facilitates ease of assembly and disassembly. This ease of disassembly allows machine parts to be reused, refurbished, and recycled. READ MORE

4. 7. The ecological significance of cleistogamy

   Author : Henrik Berg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; bet-hedging; chasmogamous; enviromnental variation; fitness; outcrossing; progeny; selling; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; ekologisk botanik; Ecological Botany;

   Abstract : Various aspects of cleistogamy, a reproductive system combining selfing in closed (cleistogamous) flowers and potential outcrossing in open (chasmogamous) flowers, were investigated in four perennial species. The main purpose was to shed some light on the adaptive value of having a dual reproductive strategy, and to test some hypotheses on the maintenance of xenogamy. READ MORE

5. 8. Enhancing the industrial use of process capability studies

   Author : Mats Deleryd; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kvalitetsteknik; Quality Technology and Management;

   Abstract : The overall aim of this thesis is focused on how the industrial use of process capability studies can be improved. This aim is achieved by using two different approaches. As a first approach the gap between the theoretical frontier and practitioners use of process capability studies is identified, quantified, and explained. READ MORE

6. 9. Evolutionary Ecology of Floral Traits in Fragrant Orchids

   Author : Elodie Chapurlat; Nina Sletvold; Jon Ågren; Magne Friberg; Kathleen Kay; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; agents of selection; diurnal and nocturnal pollination; divergent selection; field experiment; floral evolution; floral scent; Gymnadenia conopsea; Gymnadenia densiflora; Orchidaceae; phenotypic selection; pollinator-mediated selection; spatial variation; scent rhythm;

   Abstract : Why are flowers so diverse? Much of floral evolution is thought to be driven by pollinator-mediated selection. However, the connection between macroevolutionary patterns of floral diversity and microevolutionary processes remains poorly understood. In this thesis, I have used the fragrant orchids Gymnadenia conopsea s.s. READ MORE

7. 10. Local Adaptation, Countergradient Variation and Ecological Genetics of Life-history Traits in Rana Temporaria

   Author : Ane Timenes Laugen; Wolf Blanckenhorn; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; amphibians; Bergmanns rule; body size clines; countergradient variation; developmental rate; FST; temperature; QST; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; populationsbiologi; Population Biology;

   Abstract : The main aim of this work was to identify local adaptation processes in amphibian populations, thereby improving the general understanding of genetics and mechanisms behind the evolution and maintenance of biological diversity. Phenotypic and genetic variation in life-history traits was studied within and between populations common frog (Rana temporaria) populations along a 1600 km transect from southern Sweden to northern Finland. READ MORE