Sökning: "existence"

Visar resultat 36 - 40 av 1917 avhandlingar innehållade ordet existence.

  1. 36. On Lorentz Invariance, Regularity and Global Existence for Kinetic Equations

    Författare :Håkan Andreasson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : [A1] Regularity of the gain term and strong L1 convergence to equilibrium for the relativistic Boltzmann equation. The main purpose of the paper is to show that the gain term of the relativistic collision operator is regularizing. This is a generalization of P.L. LÄS MER

  3. 37. Existence theorems for noncoercive incremental contact problems with Coulomb friction

    Författare :Andreas Rietz; Lars-Erik Andersson; Jaroslav Haslinger; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Coulomb friction; noncoercive; normal compliance; mollification; MATEMATIK; MATHEMATICS; MATEMATIK;

    Sammanfattning : Friction is a phenomenon which is present in most mechanical devices and frequently encountered in everyday life. In particular, understanding of this phenomenon is important in the modelling of contact between an elastic object and an obstacle. LÄS MER

  4. 38. Effects of seed size and habitat on recruitment patterns in grassland and forest plants

    Författare :Karin Lönnberg; Ove Eriksson; Per Milberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Seed size; seedling establishment; seedling survival; recruitment; seed removal; co-existence; game-theory; Plant Ecology; växtekologi;

    Sammanfattning : A trade-off between seed size and seed number is central in seed ecology, and has been suggested to be related to a trade-off between competition and colonization, as well as to a trade-off between stress tolerance and fecundity. Large seeds endure hazards during establishment, such as shading, drought, litter coverage and competition from other plants, better than do small seeds, due to a larger amount of stored resources in the seed. LÄS MER

  5. 39. Natural and Sexual Selection in a Natural Hybrid Zone of Ficedula Flycatchers

    Författare :Nina Svedin; Anna Qvarnström; Lars Gustafsson; Ian Owens; Uppsala universitet; []
    Nyckelord :Biology; postzygotic isolation; prezygotic isolation; asymmetrical isolation; sexual signals; hybrid fitness; co-existence; Biologi;

    Sammanfattning : Speciation can be viewed as the formation of reproductive barriers between different populations. This thesis investigates patterns of natural and sexual selection shaping reproductive barriers between two hybridizing flycatchers (i.e. collared – and pied flycatchers). LÄS MER

  7. 40. How the sensory ecology of the bumblebee affects their functional traits

    Författare :Vun Wen Jie; Emily Baird; Mikael Carlsson; Martin How; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Bumblebee; functional morphological traits; intraspecific differences; allometry; DRA; micro-CT; co-existence; Functional Zoomorphology; funktionell zoomorfologi;

    Sammanfattning : Morphological traits are important for trait-based ecological studies as they allow for the prediction of biodiversity across the biosphere. Currently, the predictive power of trait-based ecology is not often applied to terrestrial arthropods, even though they provide us with important agricultural, ecological, and cultural value. LÄS MER