Sökning: "Bjørn Wallgren"

Hittade 3 uppsatser innehållade orden Bjørn Wallgren.

  1. 1. Influence of ANS Triboconditioning on friction and fatigue in rolling contact configurations

    Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/Institutionen för teknikvetenskap och matematik

    Författare :Björn Hedmark; Per Wallgren; [2019]
    Nyckelord :Tribology; friction; fatigue; micropitting; surface engineering; twin-disc; triboconditioning; LTU;

    Sammanfattning : The automotive industry is constantly being challenged by customers and authorities to enhance the efficiency of the internal combustion engine (ICE) in order to achieve improved fuel consumption and reduced emissions. There are several interfaces within the design of an ICE that causes frictional losses, one of them is the valvetrain. LÄS MER

  3. 2. The role of predation in mass mortality of wood Lemmings (Myopus schisticolor)

    Master-uppsats, SLU/Dept. of Wildlife, Fish and Environmental Studies

    Författare :Björn Wallgren; [2019]
    Nyckelord :wood lemming; Myopus schisticolor; outbreak; predation; predator; mass mortality;

    Sammanfattning : The wood lemming (Myopus schisticolor) is known for its skewed sex-ratio and unpredictable population outbreaks followed by mass mortality. Both mammalian and avian predators include the wood lemming in their diet, but the role of predation in the population dynamics and mass mortality of wood lemmings is unclear. LÄS MER

  4. 3. Jätteuttrar och deras beteende när de tilldelas musslor i hägn

    Kandidat-uppsats, SLU/Dept. of Animal Environment and Health

    Författare :Björn Wallgren; [2014]
    Nyckelord :jätteutter; berikning; verktygsanvändning;

    Sammanfattning : The giant otter (Pteronura brasiliensis) is listed as an endangered species and scientific litterature concerning its biology and behaviour is scarce. The current study observed a group of three giant otters in a Swedish zoo. First the otters normal behaviour was recorded. LÄS MER