UNAM Gā-aisib Repository
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Recent Submissions
Leadership competencies for teacher professional development: perspectives of Namibian principals, heads of departments and teachers
(Perspectives in Education, 2023) So-Oabeb, Josef; du Plessis, Andre
Using a blend of functional, distributed, and instructional
leadership theories as a theoretical lens, this article presents the
perspectives of Namibian principals, heads of departments (HODs)
and teachers on the various leadership competencies that are
required in their role of enabling school leaders to support their
teachers’ professional development. The study was approached
from a pragmatist perspective employing a mixed-methods
methodology. The sequential explanatory design employed
combined quantitative and qualitative data obtained from school
principals, HODs and teachers. Analysis entailed the generation
of descriptive statistics using SPSS and open coding of qualitative
data to generate themes. It was found that school leaders
require multiple competencies, such as accountability, effective
communication, good interpersonal relations, subject-matter
competencies, administrative competencies, digital competencies
and listening skills to be able to support their teachers’ professional
development efforts. This study provides insights into how school
leadership competencies enable principals’ and HODs to support
teacher professional development within a Namibian context. The
study also provides a new knowledge base for Namibian policy
makers, political office bearers and administrators to avail human
and financial resources to capacitate school leaders with muchneeded
competencies to be able support teachers’ professional
development through training.
Strategies that leadership employ to support teacher professional development in Namibia
(2024) So-Oabeb, Josef; du Plessis, Andre; Masenge, Andries
Background: Namibian education is faced with a concern of poor-quality teaching and
learning. One way of seeking to address this is through the professional development of
teachers. Therefore, this study examined strategies used by school leaders to support teachers
for improved subject knowledge and pedagogy.
Aim: The study aims to provide a fresh repository of information tailored for policymakers,
political leaders and administrators to avail resources to capacitate and support school
leaders towards innovative and creative strategies geared towards teachers’ professional
development.
Setting: This article provides insights into the various strategies employed by principals and
heads of departments (HODs) to support teacher professional development in the Namibian
context.
Methods: This was a mixed-method study in which quantitative findings were used to guide
the development of questions used during interviews. During the quantitative phase of the
study, data were obtained from nine principals, 32 HODs and 62 teachers, while 23
participants comprising school principals, HOD and teachers participated in the qualitative
phase of the study.
Results: The findings revealed that Namibian principals and heads of departments use
multiple strategies employed by the leadership to support their teachers’ professional
development efforts.
Conclusion: Namibian principals and heads of departments play a significant role in
supporting teachers’ professional development and hence have established various strategies
for improved subject knowledge and pedagogy.
Contribution: The study contributes to a body of knowledge on school leadership and teacher
professional development by unveiling the current practices and relationships between school
leaders and their teachers’ professional development in Namibia.
Assessment and characterization of human bacterial Diarrheapathogens in street-vended ready-to-eat meats in Havana informal settlement, Namibia
(University of Namibia, 2024) Ndjabayondume, Hilma N.; Misihairabgwi, Jane
The study aimed to evaluate and characterize human diarrhea pathogens
potentially present in street-vended ready-to-eat meats sold in Havana,
Windhoek. A total of fifty (50) samples, including fresh beef, dried beef
(biltong/droëwors), polony, sausages, fish, and chicken, were assessed for
the prevalence of diarrhea pathogens (Salmonella, Shigella, Escherichia
coli, and Staphylococcus aureus). Selective media and biochemical
confirmation tests were used for the assessment of bacterial pathogens, and
a multiplex Polymerase Chain Reaction system (Seeplex®Diarrhea-B1/B2
Ace detection kit) was employed for the detection and characterization of
additional diarrhea pathogens (Vibrio spp, Campylobacter spp,
Clostridioides difficile toxin B, E. coli O157:H7, Clostridium. perfringens,
Yersinia enterocolitica, Verocytotoxin-producing E. coli, and Aeromonas
spp). Results showed positive findings for aerobic plate count (80%), E. coli
(46%), S.aureus (36%), Shigella (46%), and Salmonella (24%). Mean
microbial counts were 5.15±0.32 log cfu/g for aerobic plate counts,
3.22±0.30 log cfu/g for E. coli, 3.27±0.54 log cfu/g for S.aureus, and
3.80±0.57 log cfu/g for Shigella. Unsatisfactory levels were recorded in
18% ofthe samples for aerobic plate count, E. coli (46%), S.aureus (12%),
Shigella (46%), and Salmonella(24%). From the Seeplex system, additional
enteric pathogens were detected, including Campylobacter spp., C. difficile
toxin B, E. coli O157:H7, and O157, C. perfringens, and Y. enterocolitica.
Vibrio spp was present in 2% of the Russian sausage meat sample. With the
B2 system, C. perfringens was detected in 38% of samples, E. coli
O157:H7 in 32%, E. coli O157 in 20%, and Y. enterocolitica in 14%.
ii
Significant differences (P < 0.05) were observed between dried beef
(biltong/droëwors) and fresh beef, chicken, and fish samples for aerobic
plate count, with dried beef samples recording higher APC. No significant
differences were observed between samples for E. coli, S. aureus, and
Shigella
Influence of enclosure geometries and internal installations on the explosion pressure of hydrogen-air mixtures
(University of Namibia, 2025) Uunona, Ndamononghenda N.; Chiguvare, Zivayi
The use of green hydrogen gas as a clean energy carrier solution is gaining global
momentum and Namibia is on track to being one of the major producers of green
hydrogen. The growing emphasis on green hydrogen has elevated the importance of safety
in its value chain. This thesis investigates the influence of enclosure geometries and
internal installations on the explosion pressure of hydrogen-air mixtures within
flameproof enclosures. The aim of this work is to investigate two critical aspects: the
impact that different flameproof enclosure geometries have on the explosion pressure, and
the role that internal installations play in exacerbating or mitigating the phenomenon of
pressure piling.
Experimental tests were conducted in the metrological laboratories of Physikalisch
Technische Bundesanstalt, an Institute in the Federal Republic of Germany in compliance
with the international standards, such as IEC 60079-1, in order to adhere to the safety
guidelines which are vital for preserving structural integrity during hydrogen explosions.
These experiments were conducted using specific enclosure geometries – spherical,
cylindrical and multi-chambered enclosures. Different orifice sizes and welded internal
installations were used to replicate the real-world industrial conditions of pressure piling.
The results demonstrated that enclosures with complex geometric design and internal
installations were more susceptible to pressure piling effects due to localised pressure
compression and uneven pressure distribution. Additionally, this work highlighted the
importance of the proper design of the enclosure, emphasizing the need for optimized
internal configurations to minimize risks.
The findings from these experiments contribute to enhancing and improving the design of
flameproof enclosures, potentially informing future regulatory updates, promoting safer
practices in hydrogen production plants, and ultimately, bridging the existing knowledge
gaps in hydrogen explosion protection
Challenges faced by Namibian school principals and heads of departments in the professional development of school teachers
(Namibia Educational Reform Forum Journal, 2024) So-Oabeb, Josef; du Plessis, André
School leadership members play an important role in influencing teacher practices through teacher professional development. However, school leaders often face challenges in their efforts to successfully develop teachers professionally. Therefore, the purpose of this article was to present the challenges faced by the Namibian principals and heads of departments in their quest to support their teachers’ professional development for improved subject knowledge and pedagogy. The findings presented in this article were obtained during the qualitative phase of a mixed method study conducted in the Otjiwarongo’s education circuit of the Otjozondjupa region in Namibia. Semi-structured interviews were conducted with 14 participants comprising school principals and heads of departments. The findings revealed that Namibian principals and heads of departments faced challenges such as inadequate resources; lack of or insufficient time; multiple responsibilities; resistance from teachers; lack of or poor governmental support; and poor subject knowledge and pedagogies. To address the challenges of inadequate resources and poor governmental support, it is recommended that the Ministry of Education, Arts and Culture increases funding and logistical support for professional development programs. To combat the issue of insufficient time and multiple responsibilities, it is recommended that schools should integrate dedicated professional development periods into the regular school schedule. This would ensure that teachers had consistent and focused time for professional growth, minimizing conflicts with their teaching and administrative duties.
Viability of substitution of electricity with biogas for thermal uses at Neudamm campus of the University of Namibia
(University of Namibia, 2025) Tomas, Pineas Panduleni; Chiguvare, Zivayi
The growing demand for sustainable and affordable energy solutions in rural areas has
led to increased interest in biogas technology, particularly in developing regions. This
thesis presents the design and evaluation of a low-cost biogas digester for the
Neudamm Campus of the University of Namibia. The study adresses the campus's
energy cost and the underutilisation of livestock manure as a renewable energy
resource.
A 100 L digester, constructed from locally available materials, was fed with a cow
manure-water slurry and operated over a 60-day period. Key operational parameters
included an estimated 30-day hydraulic retention time, with pressure monitored three
times daily in the first week, twice daily from Days 8–21, and once daily thereafter..
The digester achieved an average daily biogas yield of 0.95 L, equivalent to 7.61 MJ
(2.11 kWh). Based on manure availability at Neudamm (22.2 tonnes/day), the system
could theoretically produce 318.76 L/day of biogas. This represents a payback period
of 2.5 years and an estimated 594% return on investment over a 10-year lifespan.
The gas produced was sufficient to substitute part of the campus’s electricity demand
for cooking and water heating, demonstrating both economic and environmental
benefits, including reduced greenhouse gas emissions and nutrient-rich slurry for
fertilizer.
The study acknowledges limitations such as short monitoring duration, reliance on
pressure as the sole gas measurement, and minor leakage issues.
ii
Despite these constraints, the study demonstrates the feasibility of low-cost, small
scale digesters in Namibia and provides a replicable model for rural settings. The
findings contribute to renewable energy knowledge in Southern Africa and highlight
practical opportunities for integrating biogas into campus and farm operations
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