UNAM Gā-aisib Repository (University of Namibia)
Not a member yet
3204 research outputs found
Sort by
A geochemical study of gallium, germanium and indium, in sulfide mineralisation of the Kombat, Tsumeb and Khusib springs deposits, Otavi Mountain Land, Namibia
No full textA dissertation submitted in fulfillment of the requirements for the Degree of Doctor of Philosophy in Science (Geology)Carbonate-hosted base metal deposits are known to contain significant contents of critical
metals such as Ga, Ge, and In. These metals occur mainly as inclusions or incorporated
within the crystal lattice of the main sulfide minerals while they form rarely discrete
minerals. The aim of this Doctor of Philosophy (PhD) study is to determine the
geochemical characteristics of the critical raw metals that are associated with the sulfide
mineralisation of the base metal deposits of the Otavi Mountain Land, with the emphasis
on the Tsumeb, Kombat and Khusib Springs deposits. Tsumeb mine is an over the decades
exploited breccia-pipe like polymetallic deposit, hosted by Neoproterozoic dolomite and
limestones in the Otavi Group of the Damara Orogenic Belt. Exploitation took place
between 1897 and 1996, with a production of about 30 Mt of ore, yielding 1.7 Mt Cu, 2.8
Mt Pb, 0.9 Mt Zn, and 80 t Ge. Mineralisation at this deposit consists of tennantite and
sphalerite as the most abundant ore minerals, associated with galena, pyrite, bornite,
chalcocite, digenite, and minor enargite, renierite, germanite, chalcopyrite, and traces of
various arsenates. Kombat deposit, which is a stratabound, syntectonic Cu-Pb (Ag) sulfide
deposit, is hosted in the dolomite of the Hüttenberg Formation, Otavi Group. Mining of
the Kombat deposit is currently ongoing, with a total endowment of approximately 13.6
Mt, of which 12 Mt has been exploited until 2008. The ore mineralisation of the Kombat
deposit is quite variable comprising massive, disseminated, veinlet-controlled, and
brecciated mineralisation styles with abundant bornite, chalcopyrite, galena, covellite, and
chalcocite set into quartz-calcite gangue. Khusib Springs deposit is a high-grade Cu-Pb Zn deposit which is classified as a “Tsumeb-type deposit”, hosted by Neoproterozoic
dolomite, limestone and phyllites of the Maieberg Formation, Otavi Group. The main aim
of this study is to show the siting of the most important minor and trace elements in the
diverse sulfide mineral phases and to highlight the relationships between common trace
elements and critical metals within the sulfide mineral phases. Various analytical
techniques, including laser ablation inductively coupled plasma spectrometry (LA-ICP MS), electron microprobe analysis (EPMA), inductively coupled plasma mass
spectrometry (ICP-MS), and X-ray fluorescence (XRF), were employed to study the bulk
ii
geochemistry and the siting of the trace elements, for the sole purpose of answering the
above-mentioned objectives. Additionally, portable X-ray fluorescence (pXRF) technique
was utilized with the aim of evaluating the possible usability of a low-cost analytical
technique in exploration for base and critical elements in carbonate-hosted sulfide
mineralisations. The Kombat mineralization comprises three mineral assemblages (1)
bornite-chalcopyrite-covellite, (2) bornite-galena-chalcocite, and (3) bornite-chalcopyrite,
set into dolomite-quartz-calcite gangue, with chalcopyrite identified as the main carrier of
Ga, Ge, and In in this deposit. The profound micro-analysis of Tsumeb ore revealed the
presence of both Ga and Ge, associated with trace elements (Ag, As, Cd, Co, Cu, Fe, Ga,
Ge, In, Ni, Pb, Sb, Zn), in the different sulfides. The most significant carriers of Ge are
renierite (av. 8.21 wt.%) and enargite (0.78 wt.%), while Ga is mainly incorporated into
renierite (av. 0.12 wt.%) and sphalerite (av. 0.11 wt%). Trace element abundance in
sphalerite is characterized by elevated Cd, Ge, and Ga, suggestive of low formation
temperatures, which corroborates with earlier research on the formation of Tsumeb ore.
Reconnaissance Zn isotope data (-0.19 to 0.14‰) delineate Tsumeb ore as typical Zn-rich
massive sulfide ore, with Zn isotope values overlapping with those of the Irish MVT
deposits (-0.17 to 1.33‰), while Cu isotopes are comparable to isotopic data of hypogene
mineralisation. In Khusib Springs ore, tennantite (Fe, Zn, Ag, Sb) and chalcopyrite (Cu,
Pb, Ag) are the most important carriers of trace elements while all other sulfides are
characterized by a surprisingly low trace element content. In contrast, Khusib Springs
massive ore reveals a wealth of Ag-bearing minerals of the pearceite-polybasite mineral
group. Modern portable tools are successfully applied for the analyses of selected
elements in various fields. Portable XRF can be used as well for the analyses of selected
elements (Cu, Fe, Mn, Pb, Zn) in Kombat-type ore, while these instruments fail for the
analyses of elements like Ag, Sr, and, in particular, for the analyses of the target elements
Ga, Ge, and In. Therefore, this study gives a detailed overview about the relationship
between critical elements Ga, Ge, and In and associated elements in sulfide ores in the
carbonate-hosted base metal deposits of the Otavi Mountain Land, while showing at the
same time the limitations when access to modern analytical technologies is limite
The effect of different processing methods on the nutritional, anti-nutritional and emulsifying properties of inoculated and no-inoculated Bambara groundnut (Vigna subterranea) cultivars
No full textA thesis submitted in fulfilment of the requirements for the Master of Science in Agriculture (Food Science and Technology)Bambara groundnut (Vigna subterranea) is one of the Namibian underutilised legumes that
provides protein, carbohydrates, fats, potassium, magnesium, phosphorus, zinc and iron.
Several researchers suggest that Bradyrhizobium inoculation has the capacity to improve
nutritional composition of Bambara groundnut. This study evaluated the effects of processing
on the nutritional composition, anti-nutritional factor (ANF) and emulsifying property of
inoculated and non-inoculated cream, brown and red Bambara groundnut cultivars that were
grown in Namibia. The cultivars were roasted for 15, 30 and 45 minutes at a temperature of
140°C respectively and boiled for 30 minutes in a solution of 0.5g/100mL of sodium
bicarbonate, sodium chloride, and magnesium sulphate respectively. The beans were blended
to flours and analysed. Results indicate that each boiling salt has a unique effect on each
nutritional component. Certain nutritional composition increased with an increase in roasting
time. Bambara groundnut inoculated with Bradyrhizobium had higher protein and emulsifying
properties. Fat content of all inoculated Bambara groundnut was lower after processing. Red
Bambara groundnut had the highest fat and protein while brown and cream Bambara groundnut
had a higher crude fibre and carbohydrate. Non-inoculated Bambara groundnut had lower
minerals compared to other Bambara groundnut reported in other studies. Tannins could not
be detected in the Bambara groundnut experimented in this stud
A geochemical baseline study of giant kelp (macrocystis pyrifera) at the kelp blue farm to assess carbon sequestration potential
No full textA thesis submitted in fulfilment of the requirements for the Degree of Master of Science (Chemistry)The raised levels of carbon dioxide (CO2) in the earth’s atmosphere have contributed to global
climate change, which has adversely affected a wide range of individuals, communities, and
organizations. One of the ways to mitigate climate change is to grow a huge amount of kelp
forests that can absorb carbon dioxide from the atmosphere and sequester it in the deep ocean.
To grow these forests, the right biogeochemical conditions (temperature, nutrients, oxygen,
salinity, pH, trace metals and ions) within the ocean is vital to assess the sequestration potential
and the impacts on the ocean health. This study aimed at monitoring the biogeochemical
changes at the proposed Kelp Blue farm and surrounding areas further away from the farm.
This study also aims to create a baseline of the chemical composition of the farm and Lüderitz
areas, which has not been done before. Using the results obtained from the study, the potential
of the cultivated giant kelp to sequester CO2 will be evaluated. This study measured the
geochemical parameters using both in-situ probes and laboratory analyses at 10 different
locations in Lüderitz (both offshore and coastal): offshore (within the Kelp Blue Pilot project
farm, upstream of the farm in the Dumfudgeon rocks, downstream of the farm at Boot Bay and
further south of Lüderitz at the Halifax island) and the coastal areas which are adjacent to the
offshore study areas including at coastal site of Guano Bay which is about 17 km and the coastal
area of Grossebucht which is about 20 km south the town of Lüderitz as another control site.
This study also collected sediment samples at these offshore sites including further north of
Walvis Bay at the different latitudinal transects. The sediments were analysed for trace metals
by using a portable XRF and for carbon content by LOI (Loss on Ignition) method. Another
geochemical analysis done was the titrimetric method to CO2 determination of seawater by
using NaOH as a titrant the end points were determined. The concentrations of nutrients
(phosphates and nitrites) in seawater samples were determined by adding them to a 10 mL
cuvette, which had been zeroed first. A specific nutrient reagent was then introduced, and using
ii
prescribed sample preparation techniques, a spectrophotometer was employed to measure the
concentrations of the nutrients in µg/L and mg/L. The geochemical parameters changed in
relation to the seasonality and geographical positioning. In a season when the upwelling system
was strong, the concentration of nutrients, acidity and the value of the pH, salinity, other
geochemical parameters increased more, compared to other seasons and the further southern
sampling sites resembled to that of the Southern Benguela Upwelling System (SBUS). Higher
concentrations of phosphates (614 µg/L) were found in areas close to the islands. This is due
to the presence of guanos. These remarkable long duration geochemical measuring results
shows that the cultivated kelp can co-exist with other natural existing kelp beds in this
ecosystem, and they can thrive more predominantly in season of great influx of nutrients during
the season of strong winds. With a dynamic Benguela upwelling eastern boundary, these kelp
forests have an enormous potential to grow more and will function as carbon absorber and
eventually sequester more carbon when cultivated at larger scale. To quantify the carbon
sequestration potential of these giant kelps, there are other areas to be investigated such as
developing a sediment carbon baseline using isotopic analyses, lipid biomarkers, identifying
sediment hotspots where the kelp will be deposited, developing a carbon dioxide removal
model and geochemical dispersion models. All these other areas will be developed from the
baseline being developed by this study. This study recommends that a continuous and rigorous
monitoring of the water and sediment geochemical changes be done as the kelp forest grows
and as the scale of operation expand
Sustainable bioeconomy for next-generation industrial ecology
No full textThe sustainable bioeconomy is becoming an increasingly important aspect of industrial ecology as we seek to reduce our dependence on finite resources and shift toward more sustainable production and consumption practices. In this chapter, we explore the principles of sustainable bioeconomy and their application in next-generation industrial ecology. We discuss the use of bio-based feedstocks in industrial processes, sustainable manufacturing processes, circular economy and industrial symbiosis, and the importance of social and environmental responsibility in the bioeconomy. Finally, we examine the future directions of sustainable bioeconomy, including technological advancements, policy and regulatory frameworks, and collaboration and partnership
Exploring time-travel in children’s literature: The case study of when you dance with the crocodile by Erna Muller and crusade in jeans by Thea Beckman
No full textA thesis submitted in full fulfilment of the requirements for the degree of master of arts in english studiesThis thesis provides a comparative analysis of the novels When you Dance with
the Crocodile (2012) by Erna Muller and Crusade in Jeans (1973) by Thea
Beckman. The two novels were purposefully selected because they primarily
characterise children or young people as protagonists. Additionally, the novels
were selected because of the recurring themes of historical time travel. The major
objectives of the study were to analyse the presentation of historical time travel
elements in the selected novels and to explore the different methods of time travel
used in both novels. This was done through the theory of narratology and
mythology. The study then employed a qualitative desktop analysis, and data was
analysed using a thematic content analysis, which was systemised into different
themes to ease the data analysis and presentation process. The study observed that
although the themes in both novels are similar, each novel presents the themes in a
unique manner. In Crusade in Jeans (1973), it was found that historical time travel
embarked on by the protagonists was a result of a scientific experiment with the
hope of providing results and answers to scientific questions pertaining to time
travel beyond human comprehension. On the other hand, historical time travel in
When you Dance with the Crocodile (2012), accidentally happens with the main
characters not knowing they would be going back in time, but just playing a
computer game, and this consequently provides an opportunity for a nuanced
scientific discovery from video game experiments. Among the themes that
emerged in the study are child endangerment, credulity in religion and tradition,
and magic and heresy. Further research recommendations are to employ a
rhetorical theory analysis to futuristic time travel in children’s literary narrative
Integrating traditional health care practice into primary health care services: From the perceptions of nurses and medical officers in Windhoek District, Khomas region
No full textA Thesis submitted in partial fulfillment of the requirements for the degree of Master of Public HealthThis research explored the perceptions of nurses and medical officers in Windhoek
District, Khomas Region, on the relevance of integrating traditional health care practice
into primary health care services. The study aimed to understand the role of traditional
health care practice on the healthcare system and the potential advantages and
disadvantages associated with its integration.
Methods: The population of this study consisted of nurses and medical officers stationed
in Primary Health Care Facilities in Windhoek District, Khomas Region. A total of thirty eight (38) participants comprised of; twenty-nine (29) nurses and nine (9) Medical
Officers took part in this study, who were selected using purposive heterogeneous
sampling method. An ethnographic research design was used to collect data through
interviews and focus group discussions. Data analysis was guided by the direct content
analysis framework from Roger’s Diffusion of Innovation (DOI) theory on adoption
processes for a new innovation, namely: compatibility, relative advantage, trial ability,
observability, and complexity. These criteria were applied to the adoption of traditional
health care services as a new/innovative idea for incorporation into the modern health care
system (PHC services).
Results: The findings from this study revealed the importance of embracing and
respecting traditional healthcare practices and professionalizing them. Integration,
collaboration, and regulation were seen as essential elements for enhancing healthcare
services and meeting the diverse healthcare needs of the population. Additionally, the
findings emphasized the need for regulatory frameworks to ensure the safety and
effectiveness of traditional healthcare services and echoed the significance of
interdisciplinary dialogue and cooperation.
Conclusion: It is recommended that policymakers and healthcare authorities consider
developing clear regulatory frameworks, create comprehensive, holistic regulatory
guidelines, and standards for the integration of traditional health practices into the primary
healthcare system, with a special focus on patient safety, efficacy, cultural sensitivity, and
the preservation of Namibia’s diverse ethnic traditional knowledge and healing practice
The impact of COVID-19 on the livelihood of informal sector workers: A case study of street vendors in Eenhana Town, Ohangwena region, Namibia
No full textA thesis submitted in partial fulfilment of the requirements for Degree of Masters of Arts in Development studiesThe global impact of the COVID-19 pandemic has been extensive and has resulted in
significant negative consequences, particularly impacting individuals employed in the informal
sector. Among the most susceptible groups are street vendors, who face increased vulnerability
due to their limited skills and resources for coping with such crises. This research aimed to
investigate the effects of COVID-19 on the informal sector in Eenhana Town, Ohangwena
Region, Namibia. A quantitative research approach was used, and descriptive statistics on
income before, during, and after COVID-19, frequency table, and crosstabulations were used
to present the research results. A sample of 133 respondents of street vendors were targeted
using a stratified sampling method. Data was gathered using a quantitative survey
questionnaire. The data collected through the questionnaires was subjected to statistical data
analysis techniques utilising version 23 of the Statistical Package for Social Science (SPSS)
software. Many informal sector workers had livelihood losses, with high rates of job and
income losses amongst street vendors. The Namibian government has implemented support
programmes, but few are aware of them, thus indicating a lack of cohesion between the
government and the sector. The research found that it is important to increase the involvement
of informal workers in decision-making processes to promote a sustainable recovery and
protect against potential crise
Learner support experiences of learners with learning difficulties at a resource school in Windhoek
No full textA thesis submitted in partial fulfilment of the requirements for the Degree of Master of Education in Inclusive EducationThis study aimed to explore the learner support experiences of learners with learning
difficulties at a Resource school in Windhoek, Namibia. The study was informed by
Vygotsky's Social cultural-historical theory of development, specifically the Zone of
proximal development. The researcher employed a phenomenological research design
to explore the participants’ experiences of learning support from their point of view.
The sample was conveniently drawn, and participants’ views were explored through
semi-structured interviews and focus group discussions. Participants’ responses were
analysed using thematic analysis. The findings revealed that learners receive different
types of learning support delivered through individualised learning instructions and
cooperative learning. Furthermore, findings showed that teachers provide a conducive
environment for learning, and they employ various learning strategies to accommodate
all learners with their various learning styles, such as visual, auditory and kinaesthetic.
Although learners receive learning support to ease the learning difficulties they
experience, the findings of the study reveal that learners are finding it difficult to
develop long-term mechanisms that will help them cope with learning independently.
The study recommends that teachers teaching at resource schools should collaborate
with professionals and paraprofessionals to share expertise and resources that can be
utilised in the classroom to maximise learning for learners with learning difficulties.
The study further recommends that the Ministry of Education, Arts and Culture should
provide resource schools with the necessary learning devices and financial resources
to provide and promote effective teaching and learning environments for learners with
learning difficultie
Percieved perceptions of registered nurses on task-shifting of male circumcision in public health facilities in the Khomas region of Namibia
No full textA thesis submitted in fulfilment of the requirements for the degree of Master’s in Nursing ScienceTask-shifting in the context of Voluntary Medical Male Circumcision (VMMC) refers to
enabling well-trained clinical personnel who are not Medical doctors to perform all steps
of the male circumcision procedure. Since 2009, over 200 000 Voluntary Medical Male
Circumcision surgical procedures have been performed throughout Namibia. This
performance has been achieved against a backdrop of scarce human resources thus
various options have been explored such as task-shifting to increase access to safe
VMMC. Since the introduction of male circumcision task-shifting in the Khomas region, little is known about the perceived perceptions of nurses regarding male circumcision
task-shifting. Therefore, the purpose of this study was to explore and describe the
perceived perceptions of registered nurses on task-shifting of male circumcision in
public health facilities in the Khomas Region of Namibia. A qualitative, explorative, descriptive and contextual design was conducted, using individual in-depth interviews to
gather data from 14 registered nurses in Katutura Health Centre, of the Khomas region. Data analysis was done using Tesch’s method. The results showed that registered nurses
have good and positive perceived perceptions of task-shifting of male circumcision. The
study revealed that through task-shifting, nurses are now equipped with special skills, and knowledge that was not part of their scope of practice initially. The study also
revealed that because of male circumcision task-shifting, there is limited backlog for
patients in need of circumcision services. Recommendations based on this study’s
findings include: that the Ministry of Health should provide continuous training and
refresher training for the nurses so they gain more skills and knowledge and improve
where they can, for continuous provision of exceptional services to the client
Climate-growth relationships of Argyrosomus spp. found along the Namibian coast
No full textA thesis submitted in fulfilment of the requirements for the degree of master of science (Fisheries and Aquatic sciences)Understanding how fish growth responds to changing environments is critical for
monitoring and predicting the impacts of climate change on fish populations. The
ocean warming hotspot in the northern part of the northern Benguela provides an
excellent opportunity to examine the responses of fishes to rapid environmental
change. This research focused on the congeneric Argyrosomus inodorus and
Argyrosomus coronus as these are commercially and recreationally important fishery
species in Namibia. Standard otolith age determination techniques were used to
determine if the age and growth of A. inodorus had changed from the 1990s to 2019.
The results showed that there was a significant difference (Likelihood-ratio chi square test, χ
2 = 33.36, df = 4, p < 0.001) for the historical (1994-1996) and
contemporary (2018-2019) period, thus indicating that A. inodorus stock used to grow
older and faster in the historical period when compared to the contemporary. Kruskal Wallis test showed that there was a significant difference between A. inodorus and A.
coronus lengths at age 4 (H (1) = 8.264, p = 0.004 < 0.05). The linear mixed-effects
models fitted to the A. inodorus otolith biochronology indicated that a best linear
unbiased predictor (BLUP) of growth was significantly positively correlated (r =
0.580, n = 25, p < 0.05) with mean SSTs (July, year of formation) and significantly
negatively correlated (r = -0.473, n = 25, p < 0.05) with mean spring-summer SSTs
(October y-1 to December y-1) in the area 20-24◦S, 12-14◦E. Thus, faster annual
growth was observed during cooler periods (above 15℃) and slower growth was
noted when exposed to warmer temperatures >17℃. These findings suggest that
changes in A. inodorus growth was associated with a change in temperature and that
its growth and productivity will be negatively affected with the increasing frequency
of extreme climate events and ocean warmin