ABSTRACT This thesis explores the relationships between commercial data and those obtained from research surveys in an attempt to broaden the database available for management, and to cover seasonal and inter-annual changes in density estimates of Cape hake (Merluccius capensis). It also attempts to explain hake variability of in terms of environmental indices based on satellite remote sensing, carefully chosen to reflect underlying oceanographic processes. The influence of various factors on...
Abstract Fires are often used as a management tool in both game reserves and rangelands to manipulate food availability for grazing animals. After fires, large areas of the landscape are quickly covered with nutritious new regrowth, which grazers move into and utilise as a food resource. The effect of this change in animal grazing patterns on the grass communities is not yet well understood. Certain grass communities depend on heavy, continuous grazing for their persistence: they are out-comp...
ABSTRACT Unsteady heat and mass transfers are important transport phenomena that are found in many engineering and industrial applications. In such systems, the variations in the fluid flow result in variations in the heat flux for fluid-solid temperature difference. In this study, analytical and theoretical investigations of some non-linear problems arising from unsteady heat and mass transfer through porous media are considered. Analytical models are developed. These are non-linear mathem...
The primary focus of this thesis was to investigate the movement patterns of the South African West Coast rock lobster, Jasus lalandii, using a diverse range of techniques. These were (1) an examination of long-term data from an ongoing tag-recapture program, (2) observations on rock lobsters in a mesocosm aquarium, (3) surveys that monitored the seasonal fluxes in activities and abundance of rock lobsters in the field, (4) video recordings of movement behaviour in small aquaria and (5) acous...
ABSTRACT This thesis is divided into 2 parts. The first part (Chapters 1-5) concentrates on unravelling the . Precambrian geological history of the high-grade poly-metamorphic and poly-deformed basement of southernmost India, using field geology and U-Pb geochronology. Because Peninsular India occupied a central position in Gondwana, this work bears on reconstruction models of central Gondwana between circa 600 Ma and 200 :f,a. The second part of the thesis (Chapter 6) tests the use of organ...
ABSTRACT The synthesis, characterization, spectroscopic and biological evaluation of 2-benzoylpyridine-s-methyldithiocarbazate (HL1 ) and di-2-pyradylketone-s-methyldithiocarbazate (HL2 ) with selected metal ions of copper (II), zinc (II), cadmium (II), nickel (II), iron (II) and cobalt (II). The ligands, HL1 and HL2 were synthesized by an acid catalyzed condensation reaction of s-methyldithiocarbazate with 2-benzoylpyradine and di-2-pyradylketone respectively. The reaction of metal salts wi...
ABSTRA.CT The studies in this thesis recognise the key role of fire as a factor which has shaped the life-histories of plants in fire-prone mediterranean shrublands. Fire regimes are not simply products of the abiotic elements of climate and ignition sources. The biotic component makes a significant contribution because community structure and processes like litter fall determine fuel loads, and fuel distribution, and will determine properties such as fire recurrence intervals and shapes and ...
Abstract By utilizing some basic analytical techniques, the authors establish some new Gamma function inequalities occurring in the study of Probability Theory.
ABSTRACT BACKGROUND: Developing countries including Namibia are experiencing a rapid increase in non-communicable diseases. Blood pressure is estimated to instigate round about 60 percent of deaths around the world, of which 80 percent occur in developing countries.
ABSTRACT Pearl millet is a staple food and fodder crop of marginal areas of sub-Saharan Africa, South Asia and the Americas. Although pearl millet is stable food for 70 % of Namibian population, its productivity is very low (low yield, susceptible to diseases/insect and prolonged reproductive cycle) and has a limited genetic diversity. For the purpose of widening gene diversity, developing high yielding and drought resistant pearl millet, the Kangara and Okashana 2 were mutated using Colbalt...
ABSTRACT Refractive index is an important optical parameter that exhibits the optical properties of materials. Single-Diffraction Method (SDM) and Abbe’s Refractometer Method (ARM) have been used for the measurements of refractive indices of twelve water samples collected from different surface water sources in Namibia. SDM employs a diffraction grating, rectangular glass cell and Ne-He laser emitting a monochromatic light of 632.5 nm. Refractive indices of water samples were measured with...
Abstract Malaria is a major health concern in Sub Saharan Africa and there are few effective treatment options. Namibia has diverse flora with potent antimalarial phytochemicals and high ethnomedicinal plants uses. This study investigated the phytochemical and in vitro antiplasmodial activity of ten ethnomedicinal plants namely: Baikea plurijuga, Cyphostemma spp, Guibourtia coleosperma, Mundulea sericea, Neptunia oleracea, Diospyros mespiliformis, Acrotome inflata, Oxygonum dregeanum, Ziziph...
ABSTRACT Type 2 diabetes is a global problem that can be controlled by a diet that consists of carbohydrates with substantial amounts of slowly digestible starch amongst others. Pearl millet (Pennisetum glaucum (L) R. Br.) is an underutilised cereal crop that in recent times, raised interest due to its health benefits. The low starch hydrolysis rate of pearl millet is particularly of interest in type 2 diabetes modulation. To contribute to the value-addition and food diversification using pe...
Abstract. In this paper, we present the (p,q)-analogues of some inequalities concerning the digamma function. Our results generalize some earlier results.
ABSTRACT Bush encroachment, characterized by increase in woody plants in ecosystems, is one of the manifestations of environmental degradation that is prevalent in many parts of Namibia. The present study was conducted in Ben Hur area in the Omaheke Region, about 60 km South-East of Gobabis with the objectives of comparing family diversity, abundance and composition of ground dwelling invertebrates in habitats that are at different levels of bush encroachment and determining their seasonal v...