UNAM Gā-aisib Repository
The UNAM Gā-aisib Repository serves as a central platform to preserve and showcase the university's scholarly output.
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Recent Submissions
Hydrogen purity assessment using laser absorption Spectroscopy
(University of Namibia, 2025) Shilongo, Rosamunde P.; Chiguvare, Zivayi
Hydrogen purity assessment is a critical concern in energy applications, especially in
fields involving hydrogen injection into natural gas pipelines and fuel cell research.
This study addresses the limitations of current hydrogen measurement techniques by
developing a novel hydrogen spectrometer (𝐻2-Spectrometer) based on direct Tunable
Diode Laser Absorption Spectroscopy (d-TDLAS). The goal is to establish a traceable
and accurate methodology for hydrogen purity and concentration measurement
without relying on calibration gases. The main objective of this research is to develop
and evaluate the performance of the 𝐻2-Spectrometer, specifically investigating its
suitability for measuring hydrogen purity and hydrogen concentration in methane
hydrogen mixtures. The study also aims to support hydrogen injection into natural gas
pipelines by providing precise hydrogen concentration measurements.
An experimental design was employed, utilizing the 𝐻2-Spectrometer to measure
hydrogen line intensity and concentration. The measurements were taken for 99.999%
pure hydrogen and hydrogen-methane gas mixtures to test the spectrometer’s accuracy
and reliability. The obtained data were compared against reference values from the
HITRAN database and the certificate from the reference gas mix to evaluate
performance. The findings revealed that the 𝐻2-Spectrometer demonstrated a
significantly lower uncertainty of 1.6% in hydrogen line intensity measurements,
compared to the 10% uncertainty reported in the HITRAN database. The measured
line intensity obtained was 3.22 × 10−26 cm/molecule, which is slightly higher than the
HITRAN value of 3.189 × 10−26 cm/molecule. In terms of hydrogen concentration, the
spectrometer achieved an average mole fraction of 0.858 with a 1% uncertainty,
closely aligning with the expected value of 0.900 as per the certificate from the
reference gas mix with a 2% uncertainty. The 𝐻2 Spectrometer proved to be highly
accurate and reliable, with potential applications in hydrogen quality control from
electrolysis, fuel cell research, process control, and environmental monitoring. Its
ability to provide traceable and precise measurements makes it a valuable tool for
hydrogen-related research, optimizing system performance and ensuring compliance
with regulatory standards
Design and performance evaluation of an oil/rock bed heat storage system for solar cooking
(University of Namibia, 2025) Naule, Cecilia N.; Chiguvare, Zivayi
This thesis presents the development and performance evaluation of a sensible thermal
energy storage system that used sunflower oil and rock pebbles as heat storage mediums.
The aim was to assess the system's performance based on charge and discharge rates,
energy storage capacity, power output, cooking efficiency, and cost-effectiveness. The
main body of the system was created with an old hot water geyser. An Arduino-based data
logger was fabricated and was used to monitor and capture temperature changes
throughout system operation periods. The data was analyzed with Python programming,
from which time-temperature graphs were drawn. The heat retention capacity was
obtained by heating the system to about 200 °C and then cooling it, with the time taken to
cool being recorded. The system took approximately 30 hours to cool from 194℃ to 60℃.
The system generated 0.028 kW of power and stored a total of 0.85 𝑘𝑊ℎ of heat energy.
The efficiency testing, which involved boiling five liters of water, yielded an average
efficiency of 78.98%. The total cost of constructing the system was: N$ 3,860, with a unit
energy cost of N$ 1.26/kJ and a unit power cost of N$ 137.86/W. The cooking test
demonstrated that the system could simultaneously cook 300 g of rice in 43 minutes and
300 g of dry beans in about 4 hours using only the stored thermal energy. The study
therefore concluded that the developed system was able to deliver a reliable and cost
effective solution for domestic use. Nonetheless, constraints including insufficient
funding for further development and a limited timescale, impeded comprehensive
investigation of the system's capabilities. Future research needs to improve the design of
the system as well as explore the possibility of using solar PV panels to heat the TES
system
Variations in the use of artificial waterholes by mammals at Okaukuejo and moringa in Etosha National Park, Namibia
(University of Namibia, 2025) Mthethwa, Nomkhuleko Vangile Helen; Mfune, John K. E.
The presence of artificial waterholes can alter local mammal biodiversity. Research on the
impact of artificial waterholes on local mammal biodiversity and studies on the nocturnal
patterns of water usage are limited in Namibia. In this study, large mammals that visited
Okaukuejo and Moringa artificial waterholes in Etosha National Park were studied in the
cool dry season in July 2022 to determine and compare their species richness, patterns of
waterhole usage, duration of stay, and behaviors displayed at the waterholes. A total of 14
large mammal species were recorded at both waterholes. Species richness was
significantly higher at Okaukuejo than at Moringa waterhole, with cape fox (Vulpes
chama), blue wildebeest (Connochaetes taurinus), giraffe (Giraffa camelopardalis) and
warthog (Phacochoerus africanus) sighted at either Moringa or Okaukuejo waterhole.
Zebras (Equus quagga) and springboks (Antidorcas marsupialis) had the highest
abundance at both waterholes and visited at all sampling sessions (03h00- 06h00, 07h00
10h00, 12h00-15h00, 17h00-20h00 and 22h00-01h00). This indicates more water
dependence than other species and may be influenced by the diet and home ranges of these
species. There was a temporal differentiation in the use of the waterholes; mammals
mostly visited between 12h00-15h00 and least between 03h00-06h00. Low overlap in
waterhole visitation times was observed between predators and potential prey, possibly
due to predation risk. The duration of mammal stay was significantly higher at Okaukuejo
than at Moringa for elephants (Loxodonta africana), springboks, and spotted hyenas
(Crocuta crocuta). Duration of mammal stay was significantly higher between 22h00
01h00 at Okaukuejo, and significantly lower between 03h00-06h00 at Moringa than other
sampling sessions. Black rhinos, elephants and giraffes stayed significantly longer at
Okaukuejo, while black rhinos and elephants stayed significantly longer at Moringa,
compared to other species. Vigilance and aggression were the most frequently observed
behaviors among 13 behavior types recorded, possibly driven by the need for water,
predation risk and competition for water. Behaviors occurred at a higher frequency at
Okaukuejo waterhole due to higher species richness and abundance. This study provides
valuable insights on the activity patterns of mammals around artificial waterholes.
Repeated and seasonal observations, incorporating water quality tests at waterholes are
recommended for year-round assessment of mammal waterhole use and for explaining
variations in visitations, species distribution and behaviors of mammals at waterholes
Vegetative and reproductive biomass allocation responses of herbaceous plant species to induced drought in a semi–arid highland savanna, central, Namibia
(University of Namibia, 2024) Nashini, Martha E.; Kwembeya, Ezekiel
Namibia's arid conditions renders its vegetation vulnerable to changes in precipitation,
affecting plant growth and biomass allocation. Recurring droughts, intensified by climate
change lead to alterations in biomass allocation. Thus resulting in the reduction of
medicinal products, livestock fodder, and food sources while disrupting nutrient cycles.
This study investigated herbaceous drought responses in biomass allocation and the
influence of environmental variables on these patterns, aiming to inform ecosystem
management to conserve Namibia's biodiversity. Twenty fixed rainout shelters (4 m x 4
m) were used at Neudamm Agricultural Farm to simulate drought conditions with four
treatments (0%, 20%, 40%, and 80% rainfall reduction), each replicated five times.
Environmental parameters, including temperature (measured with a mercury
thermometer), soil moisture content and chlorophyll content (using a SPAD-502 Plus
Chlorophyll meter) were recorded before biomass harvesting. Biomass was collected from
0.5 m x 0.5 m quadrants, with aboveground biomass clipped at ground level and
belowground biomass obtained through soil excavation. The Generalized Linear Models
indicate that drought treatments are significant predictors of reproductive biomass
allocation (χ²(3) = 13.114, p < 0.004), while temperature significantly influences
vegetative biomass allocation (χ²(1) = 17.103, p < 0.004). The Friedman test results show
a significant difference in chlorophyll content across drought treatments (χ² = 18.456, df
= 1, p < 0.001), with Aptosimum lineare and Ocimum americanum exhibiting the highest
chlorophyll levels under treatment 60 highlighting the resilience of these species in arid
savannas. These findings underscore the significant impact of drought on biomass
allocation and the need for targeted interventions to mitigate its effects on plant growth
and development
A comparative study on the fish species composition, diversity and catch rates among the fisheries reserves on the Zambezi and Kwando rivers, Zambezi region
(University of Namibia, 2025) Namitaa, Tukelo Lavinia; Mfune, John K. E.
The Zambezi and Kwando Rivers in northeastern Namibia support vital floodplain
fisheries that provide food, income, and seasonal employment for many local
communities. However, increasing pressure from overfishing, habitat degradation,
and climate change has highlighted the need to establish fisheries reserves to
promote sustainable resource use. This baseline study evaluated fish assemblages,
specifically species composition, diversity, and catch per unit effort (CPUE); across
five fisheries reserves located along the Zambezi River (Sitwela, Kabweza, and
Makangala) and the Kwando River (Luhingi and Qhuqhumupa). Gillnet surveys
using both experimental and monofilament gillnets were conducted between 13
November and 13 December 2021. A total of 3,360 individual fish, representing 32
species, were captured. On the Zambezi River, Makangala had the highest species
richness with 24 species, followed by Sitwela with 21 species, and Kabweza with 20.
On the Kwando River, Luhingi recorded 17 species, while Qhuqhumupa had 12.
There was no statistically significant difference in species diversity among the
reserves (H(4)=8.268, p=0.082). However, overall CPUE (by weight) varied
significantly between sites (H(4)=46.621, p<0.001), with Luhingi showing the highest
CPUE (0.704±0.78 kg/set) and Kabweza the lowest (0.209±0.14 kg/set). Significant
differences in individual CPUE were observed for two commercially important
species: Clarias gariepinus(H(4)=26.783, p<0.001) and Clarias ngamensis
(H(4)=17.967, p=0.001), while no significant variation was found for Serranochromis
macrocephalus (H(3)=0.260, p=0.967). Similarly, mean fish sizes for C. gariepinus
(H(4)= 25.850, p<0.001) and C. ngamensis (H(4)=14.660, p=0.005) differed
significantly across sites, whereas no difference was noted for S. macrocephalus
(H(3)=0.779, p=0.885). Regression analysis showed that temperature had no effect on
fish catch rates. However, reserve size explained 14% of the variation in catch rates.
These spatial differences in catch rates for key commercial species may be
influenced by factors such as the degree of protection, age, and size of the reserves.
In particular, higher CPUEs in the Kwando River reserves may be attributed to
stronger protection measures and longstanding conservation awareness compared to
the more recently established reserves along the Zambezi River. These findings
underscore the need for tailored, site-specific management strategies to ensure the
sustainability of fish populations across all five newly established fisheries reserves
in the region
Comparing the effects of two types of Mulches on soil properties and the performance of selected woody species on a degraded land in Kunene region, Namibia
(University of Namibia, 2025) Ndatipo, Simon K.; Nesongano, Wellencia
Land degradation in arid and semi-arid regions has put tremendous pressure on
rangelands, reducing their ability to provide important ecosystem services and
sufficient forage for livestock. Given the increasing pressures on rangelands, it is of
utmost importance to find ways to restore degraded rangelands. Incorporating
mulching treatments into ecological restoration plans could aid in establishing diverse
and resilient plant communities and enhance the long-term success of restoration
projects. The present study sought to determine the effects of two types of mulching
materials (leaf litter and straw) on the soil's temperature, moisture content, and pH as
well as the cumulative stem length, seedling survival, and leaf chlorophyll content of
the selected species (Faidherbia albida, Catophractes alexandri, Vachellia erioloba,
and Senegalia galpinii) during three watering periods (once-daily, twice-weekly and
once-weekly). A 5 x 5 block grid was used with treatments (control, 5cm leaf litter,
10cm leaf litter, 5cm straw, and 10cm straw) assigned randomly and within each
treatment the species were assigned randomly to holes. Mulching significantly reduced
soil temperatures and retained soil moisture content but did not influence soil pH
during the course of the study. Amongst the various treatment combinations tested,
both 10 cm mulch depths (straw and leaf litter) appeared to be the most effective in
terms of optimizing soil conditions, seedling growth, and survival for Senegalia
galpinii, Catophractes alexandri, and Faidherbia albida. During the twice-weekly
watering period, Vachellia erioloba seedlings grew much better in the control blocks
than in the two 5 cm mulch depths (leaf litter and straw), but their seedling survival
rate was unaffected by mulching throughout the study period, indicating that mulching
had no positive effect. These findings could be attributed to the fact that Vachellia
erioloba is a phreatophyte, which means that it can excess groundwater in water
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stressed environments (possibly very early on) and that mulching has a lower impact
on its survival and growth, making the shallow effect of mulching on it less noticeable.
Mulching had no effect on the leaf chlorophyll content of Senegalia galpinii,
Catophractes alexandri, or Faidherbia albida but significantly increased chlorophyll
content of Vachellia erioloba at both straw mulching depths, suggesting a positive
species-specific response in V. erioloba’s photosynthetic rate towards mulching with
straw. This study concludes that using leaf litter or straw mulch at 10 cm depths can
improve soil conditions for plant growth and help restore degraded regions, and that
some of the plant responses to the different mulching treatment combination may be
species specific
An assessment of the efficacy of decentralisation on public health service delivery: A case study of the Omaheke region
(University of Namibia, 2025) Hikuama, Hilde V.; Lwendo, Brian
This study assesses the impact of decentralisation on healthcare service delivery in the
Omaheke Region, Namibia. The study employed a qualitative approach, incorporating
data from a targeted sample of 30 participants out of a population of 406. Data
collection was conducted through semi-structured interviews, which allowed
participants to share their experiences and perceptions regarding the accessibility,
resource challenges, and engagement within the decentralised healthcare framework.
The findings indicate that decentralisation has made healthcare services more
accessible, especially in rural areas, due to the introduction of community health
workers and outreach programs. Participants noted that healthcare services are now
more reachable, which has reduced travel times for many residents and increased
engagement in preventive care. However, resource inconsistencies, particularly
medication shortages and insufficient staffing, emerged as significant challenges,
affecting the quality and reliability of services in the decentralised system. These
resource issues were commonly reported, underscoring the need for more consistent
supply chains and improved staffing levels to ensure effective healthcare delivery.
The study further found that decentralisation has empowered communities by
fostering greater engagement and local involvement in healthcare processes,
enhancing accountability and making services more responsive to local needs. Based
on these findings, the study recommends strengthening supply chains for essential
medical resources to mitigate shortages and implementing staffing improvements to
address service gaps. Additionally, investing in healthcare infrastructure by building
more clinics in underserved areas is advised to improve accessibility
Effect of a multi-modal approach on developing number sense in Grade 8 learners in Ncamagoro circuit, Kavango West region
(University of Namibia, 2025) Moses, Kahuli; Miranda, Helena
Persistent poor performance in Mathematics among learners in rural Namibian schools,
particularly in the Ncamagoro Circuit of the Kavango West Region, has been relatively
attributed to the use of traditional teaching methods that fail to support number sense
development. This study investigated the effects of a multimodal approach on the
development of number sense in Grade 8 learners. It was guided by two research
questions: “1. What are the effects of a multimodal approach on the development of
number sense in Grade 8 learners? 2. How does the multimodal approach affect Grade 8
learners’ retention of numerical concepts?" While previous studies in Namibia have
examined number sense in the early phase, senior grades and among pre-service teachers,
limited research has focused on junior secondary learners, particularly Grade 8, using
experimental designs. The purpose of this study was to determine whether a multimodal
approach, incorporating visual, auditory, and kinaesthetic modes, could offer a more
effective alternative to traditional methods. A quasi-experimental design was used,
involving a total population sample of 60 learners from two schools, with one group
receiving multimodal instruction and the other taught using traditional approaches. To
determine the learner’s entry level of number sense before the intervention, a pre-test was
given to both groups. A post-test that contained identical content as the pre-test was then
administered to both groups again to measure the effects of the instructional approach
after intervention. Quantitative data collected through pre-tests, post-tests, and follow-up
assessments were analysed using t-tests and one-way repeated measures ANOVA. The
experimental group performed better than the control group at every assessment point,
according to the results, suggesting that the multimodal approach greatly enhanced both
number sense development and long-term retention. This indicates that the multimodal
approach effectively strengthened learners’ understanding and retention of number
concepts. The findings suggest that multimodal teaching has significant ability to improve
Mathematics learning outcomes in under-resourced, rural educational settings such as that
of the two schools in the Ncamagoro circuit, Kavango West Region
The effect of Ethnomathematics-based teaching approach on Grade 3 learners’ performance in numeracy concepts: A case study in the Zambezi region, Namibia
(University of Namibia, 2025) Muswalali, Karen F.; February, Pamela
The main purpose of this study was to explore the effect of an Ethnomathematics-based
teaching approach on Grade 3 learners’ performance in numeracy concepts. The study was
guided by the following research objectives: 1). To investigate the effects of the
Ethnomathematics-based teaching approach on Grades 3 learners’ academic performance in
numeracy concepts in a selected lower primary school in the Zambezi Region. 2. To establish
the perceptions and challenges of Grade 3 teachers in using the Ethnomathematics-based
teaching approach to teach numeracy concepts in selected lower primary schools in the
Zambezi Region. Furthermore, the following null hypothesis was tested: H0: There is no
significant difference between the performances of Grade 3 learners taught using the
Ethnomathematics-based teaching approach and the lecture method respectively. The study
employed the mixed-methods research design, in which a sample of 40 Grade 3 learners was
selected using stratified random sampling from one Junior Primary school for the experiment.
The 40 learners were divided into two groups: the Experimental group and the Control group,
each made up of 20 participants. The Experimental group was taught using the
Ethnomathematics-based teaching approach while the Control group was taught using the
conventional lecture approach. Both groups were given common pre- and post-tests to assess
their performances both before and after the treatment. In addition, 30 Grade 3 teachers were
purposively selected to complete questionnaires while a subsample of 8 teachers participated
in the follow-up one-on-one interview to share their perceptions and challenges of using the
Ethnomathematics-based teaching approach. The findings of the study revealed that the
Experimental group recorded approximate mean scores of 54% in the pre-test and 79% in the
post-test while the Control group recorded 46% and 50% in the pre-and post-tests respectively.
The result of the t-test analysis between paired sample means of the Control and Experimental
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groups’ post-tests was statistically significant (p < 0.05). This suggests that the
Ethnomathematics-based teaching approach improves the Grade 3 learners’ performance in
numeracy concepts. The Grade 3 teachers’ perceptions of the Ethnomathematics-based
teaching approach revealed that the majority of the participants have no knowledge of the
Ethnomathematics-based teaching approach. However, the participants perceived that
Mathematics can be related to culture. A few participants stated that they sometimes use the
Ethnomathematics-based approach and that learners comprehend numeracy concepts better
when they are linked to real-life situations. Finally, the study also revealed that the non
inclusion of the Ethnomathematics-based approach in the Grade 3 Mathematics syllabus, lack
of time, and lack of specialized training on the usage of Ethnomathematics-based approach
constitute the major challenges that Grade 3 teachers face in incorporating Ethnomathematics
based approach in the teaching of numeracy concepts in the study area. Nonetheless,
considering that the Ethnomathematics-based teaching approach significantly improved Grade
3 learners’ performance in this study, it is important to carry out wider studies on the prospect
of using this teaching approach to improve Grade 3 learners’ performance in numeracy
concepts. Furthermore, the Ministry of Education, Acts and Culture should include an
Ethnomathematics-based teaching approach in the Grade 3 Mathematics curriculum and
capacitate the teachers to be able to incorporate it in teaching numeracy concepts
An analysis of students’ and lecturers’ experiences of learning and teaching mathematics education online: A case of the University of Namibia, Khomasdal campus
(University of Namibia, 2025) Theofilus, Hilda Inamumvulwa; Neshila, F. K.
This study analysed the online learning and teaching experiences of Mathematics
Education modules from the perspective of both students and lecturers at the
University of Namibia, Khomasdal Campus. The study adopted the concepts of the
Technology Acceptance Model (TAM) and the Unified Theory of Acceptance and Use
of Technology (UTAUT) to construct the conceptual framework. The conceptual
framework was used to understand students’ and lecturers’ viewpoints on embracing
technology during the online learning and teaching of Mathematics Education.
Equally, the study adopted a qualitative case study design. Participants of this study
comprised two undergraduate Mathematics Education course lecturers, ten third-year
students, and eight fourth-year students studying towards a Bachelor of Education with
Mathematics Education as one of their majors, who were taught online in 2021. The
participants were purposively and conveniently selected as information-rich sources.
Data was collected using semi-structured, face-to-face interviews, which were
thematically analysed. The findings of the study revealed that students and lecturers
had positive and negative experiences while learning and teaching Mathematics
Education online. The positive experiences include flexibility and convenience in
terms of time and place, access to resources, personalised learning, and responsibility
and accountability for one’s learning. The negative experiences include a lack of
technological tools; internet connection issues; issues with the learning management
system (LMS); insufficient internet data bundles; psychological challenges; lack of
support from lecturers; academic dishonesty, and unconducive home environments for
learning. Based on the findings, this study recommends that UNAM upgrades the LMS
server so as to accommodate all lecturers teaching online simultaneously. In addition,
the university should provide continuous professional development for lecturers and
train both students and lecturers on learning and teaching online Further, the study
recommends that UNAM provides both students and lecturers with appropriate
technological devices, unlimited data bundles, and space for students to attend online
classes. Finally, the study recommended that lecturers should record lessons, create
online breakout rooms for student collaborations, and high schools should introduce a
compulsory digital literacy subject