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COMPREHENSIVE STUDY ON THE IMPACT OF USING AGRICULTURAL RESIDUES FOR ENHANCING BUILDING ENERGY PERFORMANCE IN NAMIBIA
No full textThis research work aimed at an understanding of the impact of using local agricultural residues to enhance building performance in Namibia. As human lifestyles improved with the emergence of high economic growth and technologies, the increasing demand for energy in Namibia as a developing country is posing a serious challenge to government and lawmakers in the allocation of funds for appropriate researches and technologies. One such appropriate kinds of research involve developing appropriate material technologies that will improve energy efficiency in the form of using agricultural residues/wastes readily available in Namibia.
Like other developing countries, the building sector accounts for approximately 40% of total energy
usage in Namibia. For that purpose, the efficient use of energy within buildings is a needed requisite to alienate against rising energy costs and contribute towards decreasing global greenhouse gas emissions. Namibia´s energy usage of buildings closely reflects these global trends and this research therefore aimed at validating its results through the construction of rigs following the design concept of the prototype of the EEBN (Energy Efficient Building in Namibia) research project at the Namibia University of Science and Technology campus that was designed, constructed and equipped through funding from EEP (Energy Efficiency Programme), in partnership between NUST and Carinthia University of Applied Sciences Austria.
Through appropriate mixed designs of well-selected locally available agricultural residues, insulating boards and bricks of standard sizes were developed, and results validated through the construction of rigs. Thermal conductivities and transmissibility of the insulating boards together with compressive strength, water absorption were also measured for bricks to measure the degree of thermal effectiveness/efficiency of a standard residential building. This is to establish how the use of affordable and readily available local materials can be used to develop high-quality and energy- efficient building materials which when used in building construction will improve the comfort level of occupants without the use of conventional heating and cooling devices.
Vary mixed percentages of residues of maize, millet, rice, and cow dung were designed to develop eleven 220cm by 110 cm by 40 cm board samples (labelled AK) from residues of maize, millet, rice, and cow dung. The samples were compacted, sun-dried for 7 days, and tested for thermal conductivity and thermal resistivity using a thermal conductivity test machine EP500e. Results from the eleven samples tested revealed that sample C (composed of 10% maize, 10% millet, 30% rice, and 40% cow dung) gives the lowest thermal conductivity (i.e.
of 54.65 mW/(m*K)) and the highest thermal resistivity (i.e. 0.6935 m2K/W), hence a very good thermal efficiency as compared with sample A (composed of 40% maize, 30% millet, 10% rice and 20% cow dung) that gave the highest thermal conductivity and lowest thermal resistivity, hence considered poor thermal efficiency. Regression analyses conducted between the best (i.e. sample C) and the worst (i.e. sample A) revealed an R2 value of 95% and 91% respectively
Test rigs were constructed and equipped with appropriate devices both inside and outside. Wide- ranging measurements were conducted, and results related to thermal behaviour of the interior at fluctuating changes in temperature at the exterior especially at extreme summer and winter periods were obtained.
The three prototype Rigs, with varying compositions, were designed and built using standard building procedures. Rig A (TAR 1) with 150 mm thick internal and external walls; made of standard bricks of 7 MPa, insulated with a compacted mixture containing 20% (wt.) Maize, 10 % (wt.) Millet, 30% (wt.) Rice and 40% (wt.),
30% (wt.) Cow dung; Rig B (Tamb2) 40% (wt.) with Maize, 30% (wt.), Millet, 10% (wt.), 20% (wt.), 20%wt. Marble dust and C (TNo3) that serve as control rig. Outside and inside temperatures of the Rigs were monitored during the warm (September 2017 - March 2018) and cold (April to August – 2018) seasons. Temperature and humidity sensors installed at critical positions in the interior of the building were connected to the symmetron data logger. Results of the three design concepts revealed that TAR 1 (Rig A) attained maximum and minimum temperatures of 24.40C and 14.80C, and humidity of 26.4% during winter and 29.60C and 19.30C during summer with an average humidity of 21.1%. Tamb2 (Rig B) recorded a maximum and minimum temperature of 31.220C and 18.70C during summer with a relative humidity of 20.3%. During winter Rig B attained an average temperature of 22.600C. Furthermore, Rig C (TN03) recorded 32.220C and 21.700C in summer and winter respectively. From the results, it can be deduced that Rig A (TAR 1) with compositions of 20% (wt.) Maize, 10 % (wt.) Millet, 30% (wt.) Rice and 40% (wt.), 30% (wt.) Cow dung; had the best performance.
Simulation on results obtained from the rigs was also done using Ansys software.
This research showed that results from both software and measured are approximately the same
Submitted in ful llment of the requirements for the degree of Master in Computer Science
No full textApplication containerisation has been introduced to mitigate the discrepancies
of the execution environment con guration and set up a complex
application goes through from development to production, including other
steps such as testing, staging, etc. Through an isolation mechanism, containers
bundle into one package (binaries plus all their dependencies) the entire
runtime environment required for an application or any of its components.
Depending on the complexity of the adopted architectural style, container
orchestration, the management and provisioning of containers, their loadbalancing,
security, scaling, and their network con guration might be needed
to smoothen the overall deployment and execution experience. In the peculiar
case of cloud-native applications, containerisation and orchestration are
even more crucial.
Application containerisation and orchestration have risen as two interrelated
technologies. However, they are handled with di erent toolset and
formalisms. This increases the complexity of deploying such applications
due to various moving parts. Moreover, for an independent team to try
out some components of an existing application, they now have to stick
to the prior deployment decisions made on their behalf. We argue that a
better approach is to describe the desired state of both containerisation and
orchestration and leave it to each team to decide on the actual tools and
infrastructure they intend to use.
In this research, we introduce velo, a unifying abstraction domainspeci
c language (DSL) for application containerisation and orchestration.
Intuitively, velo lets the user express the desired state of containerisation
and orchestration for a complex application. It has two components: (1)
an abstract speci cation language that describes the containerisation and
orchestration for a complex application; and (2) a transpiler, a source-tosource
compiler into both a container-speci c and an orchestration-speci c
environments.
In order to de ne the speci cation language, we studied various
containerisation and orchestration tools, including docker, rocket,
kubernetes, mesos marathon, docker compose and docker swarm. The
resulting concepts are centred around a virtual bag, a space within the infrastructure
where containers can be run, and a container, an isolated space
in the cluster where various processes corresponding to services will run
and access resources (CPU, network, I/O, etc.). Containers are instantiated
within a virtual bag. Each of these concepts can be further re ned and
represented in di erent ways. As well, several ne-grained descriptors are
introduced to complete the speci cation of an application containerisation
and orchestration. Furthermore, these descriptors can be provided during
speci cation time or at compilation.
The compiler in velo is implemented against the grammar de ned for
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the speci cation language. It gives the user the possibility to generate both
the container le and the orchestration description based on the same initial
speci cation. Currently, we generate a Dockerfile for the containerisation,
and kubernetes, mesos marathon and docker compose for orchestration.
Following the grammar, the compiler can also automatically detect whether
or not to prompt the user for missing descriptors.
We conducted a theoretical and practical evaluation of velo. The theoretical
evaluation focuses on the semantics of the speci cation language as
well as the correctness of its compiler. As for the practical evaluation, we
tested velo following various scenarios and discuss our ndings
A thesis submitted in partial fulfilment of the requirements for the degree of Master of Natural Resources Management at the Namibia University of Science and Technology
No full textNatural regeneration is an important component of forest dynamics, therefore the knowledge of the forest and requirements of different species are vital for proper planning of sustainable forest management. It is also important to understand how abiotic and biotic factors affect forest regeneration. This study looked at the effect of browsing, plant competition and fire on the regeneration of woody species in Onkumbula community forest in northern Namibia.
The study was divided into two experiments. Experiment 1 looked at the effect of browsing and plant competition on seedling density, seedling species richness, seedling growth and survival. Experiment 2 assessed the effects of fire on woody species regeneration density, species richness, mortality and shoot production. The study sites for Experiment 1 were set in three villages selected based on the last inventory for the community forests where high numbers of timber species were recorded. Three sites were selected; eight plots per study site were established. At each site, four subplots were fenced off to observe the effect of browsing protection on seedlings. A treatment of competition removal to observe the effect on seedlings was also applied. The effects of the treatments to seedlings were monitored between March 2018 and April 2019. In Experiment 2, ten plots were set in the burnt areas of the 2017/18 fire season and ten plots in the adjacent, not burned area and the effect of fire on woody species regeneration was observed five months after the fire.
According to the results, browsing protection did not affect seedling density (p=0.116) and species richness (p=0.445). However, browsing protection significantly improved the growth of seedlings both in height and diameter (p<0.001) but did not significantly improve seedlings survival (p=0.591). Plant competition removal did not significantly influence seedlings’ species richness (p=0.132) or growth (p=0.441 for height growth and p=0.307 for collar diameter growth). The treatment did also not influence seedling survival (p=0.838). Burned plots recorded a significantly higher number of seedlings by 31% compared to unburned plots and recorded 8 species more compared to 5 species in the no-fire treatment. Shoot production in trees and saplings increased with fire, recording average shoots of 3.9 in saplings and 4.5 in trees. Fire significantly affected sapling survival with 36% of saplings recorded dead in the fire plots compared to 2% in the unburned plots. The results of this study will help in the proper management of tree regeneration in Namibia forests by providing more insight into the extent that natural regeneration is affected by external disturbances such as herbivory, fire and plant competition
The Nelson Mandela rules: Yardstick for contemporary corrections?
No full textPresentation given at a Criminal Justice round table discussion held on 19 November 2020.The following text presents content, taken from a more extensive piece of work on the issue; the text hereafter has been prepared for the UNISA Webinar “Modern Trends in Corrections”, held at MS Teams on 19 November 2020. It must be understood as what it is, a sketch for a specific purpose. Reference made to “Slides” in the footnotes, refer to the accompanying Ppt.-slides prepared for the online presentation of the text. A more comprehensive paper is envisaged to be available by end of January 2021 only, where the slides will appear as figures, tables and so forth
Thesis presented in fulfilment of the requirement for the degree of Master of Applied Statistics to the Department of Mathematics and Statistics in the Faculty of Health and Applied Sciences.
No full textThis thesis examined household demographic factors and how they influence poverty levels in Namibia. While most previous studies have used income and expenditure to define household socio-economic status levels, this study used a three poverty dimension approach namely health, education and living standard. This is because poverty is multidimensional. The data used came from the Namibia Household Income and Expenditure Survey (NHIES) of 2009/10. Initially, the Alkire Foster method was used to select variables for modelling. To identify key determinants of poverty classification, a binary logistic regression was used. In this case, the aim was to determine whether the predictors, age of household head, gender/sex of head of house, household size, household head educational level, physical location of the household (rural or urban), main language spoken in the household and ethnicity/region were associated with poverty. To measure the structural relationship among endogenous and exogenous variables, the study used structural equation modelling (SEM).To understand the relationship between causes of poverty, the study used multilevel structural modelling which is recommended for hierarchical data.
Results show that the variables: gender, education, age, language, household size, region and location are statistically associated with poverty.
The structural equation modelling standardised solutions indicate that location (urban/rural) defines poverty significantly with a load factor of 0.54 and a residue value of 0.70. Religion and age of head of household define poverty significantly with a load factor of 0.30 each and error value of 0.91 for all the two variables. The size of the household influenced poverty significantly with a load factor of 0.22 and an error value of 0.95; while the household’s main language and gender of the head of household influenced poverty insignificantly with loads of 0.01 and -0.02 respectively.
Using the multilevel structural equation modelling, the results revealed that within level 1 and level 2 hierarch, the household head was the most influential factor of poverty.
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It can be deduced that the variables do significantly define poverty even though the error values are very high. High error values indicate that all the observed variables were difficult to measure. The latent endogenous variable, health, is influenced by poverty with a load factor of 0.44; while the latent endogenous variable education is influenced by poverty indirectly with a load factor of -0.72
Use of TanDEM-X and Sentinel Products to Derive Gully Activity Maps in Kunene Region (Namibia) Based on Automatic Iterative Random Forest Approach
No full textGullies are landforms with specific patterns of shape,topography, hydrology, vegetation, and soil characteristics. Remote sensing products (TanDEM-X, Sentinel-1, and Sentinel-2) serve as inputs into aniterative algorithm, initialized using a micro mapping simulation as training data, to map gullies in the northwestern of Namibia. A Random Forest Classifier examines pixels with similar characteristics in a pool of unlabeled data, and gully objects are detected where high densities of gully pixels are enclosed by an alpha shape. Gully objects are used in subsequent iterations following a mechanism where the algorithm uses the most reliable pixels as gully training samples. The gully class continuously grows until an optimal scenario in terms of accuracy is achieved. Results are benchmarked with manually tagged gullies (initial gully labeled
area 98%, with 60% in the gully class, Cohen Kappa >0.5, Matthews Correlation Coefficient >0.5, and receiver operating characteristic Area Under the Curve >0.89. Hence, our method outlines gullies
keeping low false-positive rates while the classification quality has a good balance for the two classes (gully/no gully). Results show the most significant gully descriptors as the high temporal radar signal coherence (22.4%) and the low temporal variability in Normalized Difference Vegetation Index (21.8%). This research builds on previous studies to face the challenge of identifying and outlining gully-affected areas with a shortage of training data using global datasets, which are then transferable to other large (semi-) arid
regions
Thesis presented in partial fulfilment of the requirements for the degree of Master of Computer Science in the Department of Computer Science at the Namibia University of Science and Technology.
No full textGlobal digitalisation has perpetuated the use of mobile devices for both personal and workrelated
activities. As such, some African organisations have been allowing their employees to
utilise their personally owned mobile devices to carry out work-related activities all in the
name of convenience, reliability, mobility, and reduced maintenance costs. The Directorate
on Corruption and Economic Offenses (DCEO), being an anti-corruption agency in Lesotho is
embracing the BYOD benefits. However, a couple of challenges have been recorded through
an interview with its employees. Yet still, the DCEO’s employees in different departments are
relishing the benefits of the Bring Your Own Device (BYOD) phenomenon as employees can
telework, access, and respond to their work emails within a pocket’s reach. These mobile
devices can work exactly as the traditional laptops and the desktops and that capability has
fuelled their predominant use.
Considering the type of sensitive information that the DCEO works with, it was interesting in
the present study to know whether the agency is maintaining its data security as the very
same perpetual utilisation of personally owned mobile devices has resulted in mobile devices
to be the number one target for hackers as well as their use by internal employees to commit
cybercrimes. Their mobility and Internet connection capabilities make them lucrative to
attacks. The use of personally owned mobile devices has also proven to be a challenge for the
IT department at the DCEO and the digital forensic investigators as there has been little
knowledge on the BYOD security; the legislative and also the law side on how to handle digital
forensic investigations of personally owned mobile devices that are used to perform workrelated
activities in the event of a breach. Thus, the study aimed to design a real-time forensic
investigation framework that could assist the DCEO with proper deployment, management
of BYOD adoption, and real-time digital forensics investigation of data leakage through
personally owned mobile devices.
The study followed a mixed-method research approach where a single case study was
conducted and this was complemented with an experiment. This pragmatic study enabled
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the researcher to gather primary data using interviews, questionnaires, and experimentation.
Thematic data analyses were used to make meaning of the interview and survey data, and
the case site results demonstrated a lack of information security awareness, training, and
education; lack of a Bring your Own Device policy; lack of infrastructure, and lack IT security
governance. The results revealed that android mobile devices are the most used by DCEO
employees for work-related activities. The experimentation was then conducted on android
mobile devices to ascertain the existence of data leakage. The results revealed the challenges
of using personally owned android mobile devices to access corporate data and other
resources. The findings were validated using literature and thus informed the design of the
Real-Time BYOD Digital Forensic Investigation Framework. A comparative evaluation was
used to evaluate the relevancy and usability of the framework. To confirm its relevancy,
usability and suitability expert reviews were employed against set metrics which assisted in
redefining the framework components and structure, thus enhancing the framework’s ability
to attaining the research objectives. The proposed Real-Time BYOD Digital Forensic
Investigation Framework guides BYOD enabled organisations to investigate malicious
activities committed through personally owned mobile devices. An implementation guide
was also developed. This study adds to the understanding of how to securely adopt BYOD
phenomena within the working environments as well as how to account for breaches that
are committed through employees’ devices through organisational policies enforcement.
Furthermore, the study can aid some organisations in Lesotho and other similar
environments that have adopted BYOD with proper management and some understanding
of how to perform internal digital forensic investigations in cases where sensitive
organisational data might be leaking through their personally owned mobile devices
Master thesis dissertation Submitted in fulfilment of the requirements for the degree master of computer science in the Department of computer science at the Namibia University Science and technology.
No full textSchool dropouts have been a concern in Namibia, especially among San learners. Thus this research focused on developing a mobile counselling platform for Grade seven (7) primary school learners in Donkerbos village. The aim of the application is to build resilience in primary school San learners for them to withstand adversity by bouncing back. This is to reduce San learners’ high dropout rates in Namibian schools. The study looked into the area of an individual’s life where resilience could be developed more. The study focused on the challenges learners normally face in order to support them in those areas for them to be more positive and develop a strong sense of purpose and meaning in their own lives. There are factors that can enhance resilience in an individual. Factors such as environmental, family, social, cultural, community and personal characteristics can have an impact in an individual’s life (Herrman, Stewart, Diaz-Granados, Berger, Jackson, & Yuen, 2011). The study used a qualitative methodology for data collection for the sampling within the San community to explore and understand the contributing dropout and success factors.
For data collection, video recorded interviews were conducted with successful Windhoek based San youth and audio recordings with dropout Donkerbos village based San youth.
The primary school San learners also shared their current challenges through a rich picture method which is some form of a narrative. Snowball sampling technique was used to choose the participants for the research study. The mobile counselling platform was developed based on data extracted from narratives of successful, dropout San youths’ school life stories as well as current issues identified by primary school San learners using rich pictures. The collected success and failure stories by the San youth as well as the current issues by the school learners were co-curated for inclusion in the mobile counselling platform. A common tool for qualitative research, namely thematic analysis was used to analyse the data collected to extract themes. Coding was done on the data set for understanding and to interpret their meanings. The themes were then categorised into key themes namely financial, social, emotional, personal, family and education after coding was done. The key themes were then reviewed and examined to gain an understanding of participants’ challenges.
Furthermore, the research explored technologies currently being used elsewhere to provide counselling services. Findings demonstrate that online counselling on the web or mobile platforms
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exist and is still increasingly growing. However, most of these online counselling services are rather generic, meaning that they will not be fit in all situations and cultural backgrounds.
Findings from the collected data were used as a guide to develop the mobile counselling platform. The platform was prototyped and evaluated with the successful, dropout San youth and primary school San learners for refinement. Feedback from evaluations shows that the youth and learners like the application, however, they would like to see audio and video recordings as well to make it more interesting and emotionally engaging
Thesis submitted in fulfilment of the requirements for the degree of Master of Informatics At the Namibia University of Science and Technology.
No full textThe use of mobile phones in everyday life has increased dramatically in recent years, making mobile phones a very integral part of our lifestyle. Namibia is amongst 105 countries with more cellular subscriptions than inhabitants.
The increased ownership of smart phones and the affordability of mobile data packages offered more ways for banks to make even more services available such as, customer-to-customer direct payment services. Banks have rolled out this service under various names such as eWallet, Blue-Wallet and Easy-Wallet. This means that, consumers no longer have to walk around with a wallet full of cards or cash as their cell phones offer access to their banks, and convenience of banking everywhere. Despite the potential benefits to consumers, especially those without bank accounts, the adoption rate among consumers was limited.
The aim of this research was to investigate the factors that are influencing consumer adoption of the eWallet service in Namibia and provide insights on how to redesign the eWallet service for increased adoption. The research methods included a semi structured questionnaire and interviews. The findings of the research indicates that, factors such as effective communication, system availability and reliability, transaction speed, usefulness, cost, system response, security and trust, convenience and accuracy of transaction influencing consumer adoption of eWallet services. A redesign of the eWallet service based on the findings and design heuristics were proposed
Livelihood needs for Namibia’s urban future’: A seminar series with John Mendelsohn
No full textThis Document Note presents the discussions that took place during three seminars with John Mendelsohn on the issue of livelihood needs for
Namibia’s urban future. The first seminar focused on the topic of “‘Traditional’ and ‘modern’ forms of capital and security: value production and circulation” and took place along with the final presentations of the first year of the master in architecture at NUST; the second focused on the issue of “Land as capital and foundation: opportunities and limitations of empowerment of the poor”, and included a visit to the land developed
by the Dibasen Homeless Committee of Katutura; and the final one focused on “The question of ‘the informal’: engaging with the ‘formal’ economic and labour outlook in Namibia” and took place at Oshetu Market, including input from the market managers.
This document describes the main points of the seminars, the discussions, and notes on the accompanying activities. The event took place in the context of the Urban Forum, which is a platform for multi-stakeholder engagement on issues of urbanisation in Namibia, Southern Africa and beyond