Search for dissertations about: "damage evolution"

Showing result 11 - 15 of 142 swedish dissertations containing the words damage evolution.

2. 11. Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana

   Author : Reiko Akiyama; Jon Ågren; Arjen Biere; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arabidopsis thaliana; life history evolution; flowering time; germination; phenology; plant-herbivore interactions; natural selection; tolerance to leaf damage; resistance to herbivory; Plutella xylostella; Mamestra brassicae; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Abstract : In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore. READ MORE

4. 12. Long-term rail damage evolution in railway crossings

   Author : Rostyslav Skrypnyk; Chalmers tekniska högskola; []
   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; wear; S C; plasticity; wheel-rail contact mechanics; switches crossings; FEM; metamodel; Dynamic vehicle-track interaction;

   Abstract : To accommodate the passage of wheels in intersecting traffic routes, fixed railway crossings have discontinuous rails leading to an intense load environment due to repeated wheel-rail impacts. This gives rise to high costs associated with repair and maintenance of the rails in the crossing. READ MORE

5. 13. Plant Inducible Responses to Damage: Evolution and Ecological Implications

   Author : Johannes Järemo; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; herbivory; inducible defences; compensation; Ecology; Ekologi;

   Abstract : Abstract Inducible plant responses to damage, i.e. inducible defence responses and compensatory growth responses, are theoretically examined in an evolutionary and ecological context. Inducible defences are generally considered to be beneficial under conditions of low risk of herbivory and when initial damage is moderate. READ MORE

6. 14. Pollinators, Enemies, Drought, and the Evolution of Reproductive Traits in Primula farinosa

   Author : Per Toräng; Jon Ågren; Johan Ehrlén; Rebecca Irwin; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; Alternative reproductive strategies; climate change; facilitation; floral display; flowering phenology; frequency-dependent selection; genetic diversity; life-history strategies; local adaptation; pollination; predation; Primula farinosa; reproductive effort; soil disturbance; stochastic growth rate; Ekologi;

   Abstract : In this thesis, I combined comparative and experimental approaches to examine selection on reproductive traits and population differentiation in the insect-pollinated, self-incompatible, perennial herb Primula farinosa. More specifically, I (1) determined whether the effects of floral display and interactions with pollinators and seed predators, and plant reproductive success were frequency-dependent and affected by surrounding vegetation context, (2) examined the consequences of intermittent drought years on population dynamics using numerical simulations based on demographic data collected over seven years, (3) analyzed among-population differentiation in flowering phenology and reproductive allocation, and its relationship to soil-depth at the site of origin. READ MORE

7. 15. Computational modelling of machining - Mesh objective ductile damage modelling

   Author : SENAD RAZANICA; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ductile damage; fracture modeling; Mesh dependence; machining process; visco-plastic Johnson- Cook; simulation tool; FEM;

   Abstract : AbstractTo strengthen the competitiveness the manufacturing industry strives for a continuousdevelopment of cost efficient manufacturing processes and improved product quality.These research and development issues are addressed by increasing the implementationof simulation tools based on finite element method (FEM). READ MORE