Sökning: "extinction dynamics"

Hittade 5 uppsatser innehållade orden extinction dynamics.

  1. 1. Visibility in Smoke With Different Extinction Coefficients

    Master-uppsats, Lunds universitet/Avdelningen för Brandteknik

    Författare :Lea Elhokayem; [2022]
    Nyckelord :Visibility; smoke; exit sign; extinction coefficient; visibility constant; evacuation; Technology and Engineering;

    Sammanfattning : Visibility in smoke has since the 1970s gained some attention, mostly after Tadahisa Jin ran the experiments which helped him develop todays widely used visibility equation. By showing that visibility can be assumed to be inversely proportional to the extinction coefficient by a visibility constant (equal to 8 for light emitting sign and 3 for light reflecting), Jin opened up new doors for researchers who were testing out his theory by going around experimenting in different ways and also by showing that there is way for more research to be done. LÄS MER

  2. 2. Effects of population size, density and local environment on the population dynamics of the fragrant orchid (Gymnadenia conopsea)

    Master-uppsats, Uppsala universitet/Institutionen för biologisk grundutbildning

    Författare :Kasper Kupka; [2021]
    Nyckelord :Demography; Gymnadenia conopsea; local habitat; matrix models; orchids; population density; population size; stochastic growth rate; soil organic matter; quasi-extinction probability;

    Sammanfattning : A wide majority of orchid populations are decreasing due to habitat fragmentation and to changes in land management. Population size, density and habitat quality are factors that are expected to be positively related to the viability and future growth of a population. LÄS MER

  3. 3. Nutrient distribution by mammalian herbivores in Hluhluwe-Imfolozi Park (South Africa)

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

    Författare :Laura van Veenhuisen; [2018]
    Nyckelord :megaherbivores; nutrient distribution; stoichiometry; South Africa; Hluhluwe–Imfolozi Park; African savannah; herbivores; wildlife ecology; dung;

    Sammanfattning : African megaherbivores are ecosystem engineers, which are under threat of extinction caused by, among others, poaching and climate change. Their current rates of loss means that there’s a need to better analyse their impact on the environment, in order to predict the consequences of losing this group. LÄS MER

  4. 4. Optimal Fishery Modelling Population Dynamics with Optimal Harvest Strategies

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Mats Barkman; [2016]
    Nyckelord :;

    Sammanfattning : Determining sustainable harvest strategies are of interest in order to avoid overexploitation of ecosystems. In this report the dynamics of sh populations a ected by shery is studied. The aim is to nd an optimal catch policy under which shery shall be performed in order to obtain maximum catch without the sh population facing extinction. LÄS MER

  5. 5. Computational Simulations of Evolutionary Dynamics: The Fate of Deleterious Alleles

    Master-uppsats, Lunds universitet/Examensarbeten i bioinformatik

    Författare :Simon Cesarini; [2014]
    Nyckelord :Biology and Life Sciences;

    Sammanfattning : When a severe deleterious mutation appears in a population, it is expected to disappear through negative selection within a few generations. However, the variance of this number is significantly large to allow some deleterious mutations to exist for several generations. LÄS MER