https://vital.seals.ac.za/vital/access/manager/Index en-us 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:10577 Wed 12 May 2021 23:21:23 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10646 10 percent), are fine textured (>50 percent of the material passing the 0.075mm sieve) and highly plastic. These soil attributes imply low permeability, excessive water retention and high susceptibility to expansion and sliding. The vertic nature of soils at Nametsi was confirmed by the extremely high plasticity indices (averaging 33percent), while, high liquid limits at Buwabwala (53 percent) and Kitati (59 percent) qualified the soils as vertisols which are associated with landslides. The results point to the fact that soils at landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention. Therefore, the hypothesis that soils at three landslide sites are inherently ‘problem soils’ where slope failure can occur even without human intervention is accepted. Notwithstanding the fact that the study was focussed on mid-altitude slopes of Mt Elgon, the results are in tandem with investigations carried out earlier on the lower densely populated slopes, thus confirming the widespread nature of problem soils on Mt Elgon. There is an urgent need to control human population growth and restore forest cover on the heavily deforested steep slopes particularly within the National Park, and restrain communities from encroaching on the pristine slopes of Mt Elgon. This will be achieved if the politicians, Park Authorities and local communities jointly participate in the design and implementation of CFMs. Future research could focus on climate change implications of deforestation of Mt Elgon environments and quantification of carbon loss related to deforestation and soil degradation in the mountain environments.]]> Wed 12 May 2021 21:01:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10336 Wed 12 May 2021 15:44:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:26827 Thu 13 May 2021 08:53:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10603 Thu 13 May 2021 06:19:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10506 (Kw + $) −W . This result shows that the warthog’s equilibrium population density is bounded above by population thresholds, i.e., W < (Kw+$). Besides showing the occurrence under parameter space of the so-called paradox of enrichment, early indicators of chaos can also be deduced. In addition, numerical results revealed stable oscillatory behaviour and stable spirals of the species as predator fertility rate, mortality rate and prey threshold were varied. The stabilising effect of prey refuge due to variations in predator fertility and proportion of prey in the refuge was studied. Formulation and analysis of a robust mathematical model for two predators having an overlapping dietary niche were also done. The Beddington-DeAngelis functional and numerical responses which are relevant in addressing the Principle of Competitive Exclusion as species interact were incorporated in the model. The stabilizing effect of additional food in relation to the relative diffusivity D, and wave number k, was investigated. Stability, dissipativity, permanence, persistence and periodicity of the model were studied using the routine and limit cycle perturbation methods. The periodic solutions (b 1 and b 3), which influence the dispersal rate (') of the interacting species, have been shown to be controlled by the wave number. For stability, and in order to overcome predator natural mortality, the nutritional value of predator additional food has been shown to be of high quality that can enhance predator fertility gain. The threshold relationships between various ecosystem parameters and the carrying capacity of the game park for the prey species were also deduced to ensure ecosystem persistence. Besides revealing irregular periodic travelling wave behaviour due to predator interference, numerical results also show oscillatory temporal dynamics resulting from additional food supplements combined with high predation rates.]]> Thu 13 May 2021 04:45:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10544 Thu 13 May 2021 04:18:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10597 Thu 13 May 2021 00:35:38 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10647 Thu 13 May 2021 00:17:10 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:10537 580 ˚C) growth temperatures reduce the Mg incorporation. High VI/II ratios also decrease the Mg incorporation, as evidenced by the red-shift of the donor bound exciton (D°X) line. This is ascribed to a stronger premature reaction between (MeCp)2Mg and the oxidant or a preferential heterogeneous interaction between the Mg and oxygen species on the growth front. For both oxidizing agents (O2 and TBOH), the growth at 420 ˚C and a VI-II ratio of 60 on c-Al2O3 gave optimal quality layers in terms of their optical and structural quality. A comparison of films grown using TBOH and O2 gas as oxidizing agent shows no major difference in terms of Mg incorporation. The effect of annealing, the inclusion of a buffer layer and the influence of growth rate on the properties MgxZn1-xO thin films are also reported.]]> Thu 13 May 2021 00:01:15 SAST ]]>