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Item Trace and heavy element distribution of the Hwange Coals in Zimbabwe(University of Namibia, 2013) Mapani, Benjamin; Finkelman, R.; Ravengai, S.The study of heavy metals in the Hwange coals enhances knowledge of both the geological evolution of the coal-bearing horizons and the climates that prevailed during their deposition, as well as indicating likely trace and heavy elements that would affect the health of the miners and the environment at large. The Main Coal Seam of the Hwange coals are bracketed by the Lower Wankie Sandstones of Carboniferous to Permian that were deposited during the Dwyka epoch and the Upper Wankie Sandstones of Permian age. The Hwange coals of Zimbabwe are inferred to have been deposited in swamps associated with fresh water lakes lying on either side of a great elevated tract of Archean and Proterozoic basement during the early Permian. Initially the lake was shallow, as observed from sedimentological data, and eventually the lake became deeper during the continuation of the Karoo period of southern Africa. The sedimentation in Zimbabwe began with the melting of the Carboniferous ice cap of the then south and central Africa. The Karoo succession in the Mid-Zambezi Valley suggests that climatic cycles of glacial to semi-glacial and finally to post-glacial nature occurred, followed by very hot, humid and arid conditions towards the end of the sedimentation period. Four sedimentary successions are reflected at Hwange, the first being fluvial-glacial beds, followed by flooding and deposition of the Lower Wankie Sandstones. At the end of this phase, there followed a general increase in flora and fauna, responsible for the formation of coal now preserved in the Main Coal Seam. Above this succession is the Lower Carbonaceous Mudstones of the Wankie succession. The unconformity of the Upper Wankie Sandstones with the Lower Mudstones marks the end of the coal-bearing horizons. Above the Upper Wankie Sandstones further flooding at a large scale occurred, which is thought to have been rapid, as no coal seams are associated with this mudstone in the whole of the Zambezi valley. A systematic study of heavy elements, ash, moisture content and arsenic, shows that during the deposition of the Hwange coals of the Main Coal Seam there were significant amounts of gallium, germanium, niobium, vanadium and chromium in the source areas, together with metals of felsic affinity such as strontium, tin and lithium. There is a systematic relationship between ash content and heavy mineral content in the coal. For coals with a high heavy metal content, their ash contents are low in some samples, whereas others demonstrate the reverse. While we can easily attribute the source of the felsic affliated elements to the basement granites, heavy metals are interpreted to have been fixed under anoxic conditions when the organic matter was being converted to coal. It is suggested that the heavy elements may have acted as catalysts in the coalification processes.Item Today, tomorrow, forever(University of Namibia, 2013) Kazembe, Lawrence N.; Neema, IsakEarly diagnosis and prompt treatment of febrile conditions is a key strategy towards control of the disease from progressing to severe or fatal stages. In this paper, we studied the timing of treatment among children with a history of diarrhoea and fever in Namibia, while simultaneously investigated socio-economic and spatial factors that influence the treatment seeking behaviour. A multinomial probit model with ordered categories was estimated, and results confirmed that there was significant spatial variation at regional level. Socio-economic factors also explain treatment seeking having controlled for spatial dependence. The spatial variation can be interpreted as representing unobserved heterogeneity not captured by the data or possible clustering inherent in nested survey data.Item Self-checking impurity method in liquids(University of Namibia, 2013) Singh, ShyamWe propose a very simple technique for the determination of impurity in liquids based on the refractive index. This technique requires two similar gratings, two similar low power lasers emitting same wavelength and a position detector. The change in refractive index of liquid determines the impurity in a liquid.Item International joint MSC Programme: University of Namibia and Humboldt University, Germany(University of Namibia, 2013) Mfune, John K.The MSc Biodiversity Management and Research Programme is a full time interdisciplinary and international postgraduate programme jointly run by the University of Namibia (Department of Biological Sciences, Faculty of Science) and Humboldt-Universitt zu Berlin, Germany. The main goal of the program is to build capacity to increase the number of postgraduate local and regional experts in the field of Biodiversity Management and Research. This program was designed to ”Build capacity to manage biodiversity and sustainable development in Namibia” as incorporated in Namibia governments ten-year strategic plan of action for sustainable development through biodiversity conservation (National Biodiversity Strategy and Action Plan, 2001-2010). During the programme, students gain in-depth knowledge of natural-spatial features and biological diversity in Southern Africa with emphasis on Namibia, understand ecosystem functioning and human-induced impacts and the economic values and importance of biodiversity. Students also acquire skills that will enable them to design and undertake research to solve practical, relevant problems to society, using scientific methods and techniques. Graduates of the programme are employable in any biodiversity conservation and related fields including but not limited to lecturing, working for the Ministry of Environment and Tourism (National Parks, Scientific Services, Tourism), ecotourism, curators of various taxa at Natural History museums, and community based organizations. Our graduates contribute to management of natural resources, conservation and sustainable use of biodiversity and also contribute to poverty reduction through use of natural resources to improve livelihoods of local people.Item Relationship between Dissolved Oxygen and the Vertical and Longitudinal Distribution of Zooplankton off the Namibian coast(Unioversity of Namibia, 2013) Julies, Elsabe M.; Kaholongo, Isak K.Zooplankton play an important role in the marine food web and are abundant on the Namibian coast, which is part of the highly productive Benguela upwelling system. In the Benguela system zooplankton populations are dominated by copepods and euphausiids. The abundance and distribution of zooplankton are affected by various environmental factors such as temperature, light intensity and dissolved oxygen (DO). This study investigated the relationship between DO and the diversity of zooplankton at different depths in the water column on the continental shelf off the Namibian coast. There was a positive correlation between DO and diversity of zooplankton offshore (Pearson’s r =0.83), while there exists a very weak positive correlation between DO and zooplankton diversity onshore (r= 0.196). Diversity of zooplankton does not differ significantly with depth at both onshore and offshore stations (Shannon’s Index H0 < 1). However, Divesity of zooplankton between offshore (H0=2.8 to 3.6) and onshore (H0=0.8 to 0.9) stations differs significanty (p = 0:0271;d f = 4) in the top 90m, but is not significantly different below 90m (p = 0:406;d f = 4). Nevertheless, the onshore stations had higher species richness compared to the offshore stations. Dissolved oxygen does not have a direct effect on the diversity of zooplankton, but an indirect effect and it is the interplay and interaction between several biological and environmental factors that affects zooplankton assemblage composition.Item On the smoothness and the totally strong properties for nearness frames(University of Namibia, 2013) Mugochi, Martin M.In this paper we briefly explore the properties of smooth and totally strong nearness frames. It turns out that there is a relationship between them, in particular, totally strong nearness frames are smooth. We also show that the category of smooth nearness frames is coproductive, and that, as is the case with that of the totally strong ones, it is closed under completions.Item On the electronic structure(University of Namibia, 2013) Archibong, Edet F.The ground and low-lying excited states of AlS2 and AlS2 have been studied using density functional theory (DFT) and coupled cluster [CCSD(T)] approximations, in conjunctions with the 6-311+G(2df) one particle basis set. AlS2 is linear with a 2Õg ground state. CCSD(T) predicts that the 2A2 state of the C2v isomer is separated from the ground state by less than 0.1 eV, while the 2Õu and 2å+ u states in D¥h symmetry are located at 0.67 eV and 1.40 eV, respectively, above the 2Õg state. The AlS2 anion possesses a 1å+ g ground state with a very similar geometry with the neutral molecule. At the CCSD(T) level, adiabatic electron detachment energies for the [AlS2(2Õg) AlS2 (1å+ g )] transition is 4.03 eV.Item Loop Space Homology of Some Homogeneous Spaces(University of Namibia, 2013) Gatsinzi, Jean-BaptisteLet X be a simply-connected compact oriented manifold of dimension m. We show that the Gerstenhaber structure of the loop space homology H (map(S1;X);Q) can be computed in terms of derivations on the minimal Sullivan model of X. The technique is applied to compute brackets in the loop space homology of homogeneous spaces.loop space homology.Item Host specificity, prevalence and intensity of infestation of fleas (Order Siphonaptera) of small mammals at selected sites in the city of Windhoek, Namibia(University of Namibia, 2013) Mfune, John K.; Kangombe, Fransiska; Eiseb, Seth J.Small mammals host diverse communities of parasites including fleas. There is considerable research interest in effects of parasites on their hosts. Host specificity, prevalence and intensity of infestation of fleas on small mammals were studied at selected sites in the city of Windhoek, Namibia from April to July 2005. Small mammals were live-trapped using Sherman traps and autopsied before collection of fleas. Fleas were processed using standard parasitological procedures and were mounted permanently onto slides using Canada balsam. Small mammal hosts and fleas were identified to species level. A total of sixty one (61) small mammals belonging to four rodent species, i.e. bushveld gerbil Gerbilliscus leucogaster, hairy-footed gerbil Gerbillurus paeba, black-tailed tree rat Thallomys nigricauda and the four-stripped mouse Rhabdomys pumilio and one insectivore, bushveld sengi Elephantulus intufi, were captured. One hundred and thirty six (136) fleas belonging to eight species, i.e. Xenopsylla brasiliensis, Xenopsylla cheopis, Xenopsylla hirsuta, Xenopsylla trispinis, Dinopsyllus ellobius, Dinopsyllus zuluensis, Epirimia aganipes and Listropsylla aricinae were collected from infested hosts. Dinopsyllus ellobius and X. trispinis and L. aricinae were host specific, being collected only from G. leucogaster and G. paeba, respectively. No fleas were collected from E. intifi and R. pumilio. The prevalence of fleas ranged from zero in E. entufi and R. pumilio through 50 % in T. nigricauda, 55.1% in G. leucogaster to 61.1% in G. paeba. High species richness of fleas was recorded in G. leucogaster (seven out of eight flea species) and in G. paeba (six out of eight flea species). The overall prevalence of fleas was higher in male (54.3%) than in female (34.6%) hosts. There was no association between the body mass of small mammal hosts and the intensity of flea infestation. The intensity of infestation of fleas did not vary significantly by host species and sex of hosts.Item Educational Emulation of a Soft Handoff Teaching Model (EESH-TM)(University of Namibia, 2013) Mbale, JamesonThe use of fixed Base and Mobile Stations offer a set of challenges dealing with the movement of a Mobile Station away from one Base Station toward a second Base Station. In this situation, the signal strength decreases as the distance of the mobile position increases (following an inverse-square law) from the first station; while an increase in signal strength is experienced as the distance decreases from the second one. Gradually the signal from the former is lost. This is a difficult problem in wireless technology, not only to picture but also to solve. This problem which is prominent in mobile and wireless applications is called ”Soft Handoff”, the solution of which applies the concept of ”make-before-break”, which postulates the smooth and gradual transition of signals from the previous Base Station to the next one without causing a sharp break or interruption of the signal. Such a hypothetically smooth and soft hand over signal mechanism is very difficult for students to understand especially those who have had little or no experience with telecommunication equipment, with the analysis of wireless circuits or with hands-on experience with the technology. This became evident when the topic was initially covered in a Telecommunications course at University of Namibia. It was within this context that the Educational Emulation of Soft Handoff Teaching Model (EESH-TM) was designed and developed to model the mechanism of Soft Handoff. The EESH-TM is comprised of: two Base Stations, two Cells, a Mobile Station, and two interacting signals. This teaching model clearly demonstrated, step-by-step, various scenarios with a mobile unit moving between two Base Stations clearly illustrating how Soft Handoff works. Hence, the utilization of this teaching tool presented inexperienced students with an opportunity to observe and understand how signal hand off works in a wireless network. The success of the model was demonstrated by higher examination scores and greater student interest in the topic.Item Science: An all encompassing field(University of Namibia, 2013) Kazembe, Lawrence N.; Archibong, Edet F.; Chimwamurombe, Percy M.; Singh, Shyam; Chinsembu, Kazhila C.What unites science, as Sir David Cox mentioned, is not the subject matter we all work in, but the methodology and the thought process that help solve the problems that arise [1]. Put differently, it is the replicability of its methods, the validity of its findings and reliability of its instruments and techniques. The diversity in science now emphasizes that not a single subject matter will work alone in isolation - especially if you are working in applied sciences, but has to learn from others. Even so, contemporary applied sciences have extended this collaboration to the social sciences [2]. For instance, in implementation science they have learnt to involve social sciences to inform human behaviour if scaling-up of interventions is to be a success.Item Distribution of Gamma-Emitting Radionuclides in the Soils of the Neudamm Campus of the University of Namibia, Windhoek, Namibia(University of Namibia, 2013) Oyedele, JamesThe concentrations of naturally occurring radionuclides 40K, 232Th and 238U in soil samples taken from the Neudamm campus of the University of Namibia, Windhoek, Namibia have been determined and used to calculate a mean annual effective dose for the campus. The concentrations were measured using a sensitive gamma-ray spectroscopic system consisting of a high purity germanium detector and associated equipment. 40K was found to have the highest specific concentration varying between 229.1 13.5 Bq kg1 and 499.0 16.5 Bq kg1 with a mean value of 364.5 79.3 Bq kg1 while the concentration of 232Th varies between 10.4 2.8 Bq kg1 and 38.5 3.8 Bq kg1 with a mean value of 28.0 9.2 Bq kg1 and the concentration of 238U varies between 11.7 1.3 Bq kg1 and 24.7 2.1 Bq kg1 with a mean value of 18.5 4.8 Bq kg1. The value of 0.05 0.01 mSv y1 obtained for the mean annual effective dose is well below the limit of 1 mSv y1 recommended for the public by the International Commission on Radiological Protection. This result indicates that radiation hazard is negligible on the campus.