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An overview of the ORACLES (Observations of Aerosols above Clouds and their interactions) project: aerosol–cloud–radiation interactions in the southeast Atlantic basin
No full textSouthern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA EVS-2 (Earth Venture Suborbital-2) investigation with three intensive observation periods designed to study key atmospheric processes that determine the climate impacts of these aerosols. During the Southern Hemisphere winter and spring (June–October), aerosol particles reaching 3–5 km in altitude are transported westward over the southeast Atlantic, where they interact with one of the largest subtropical stratocumulus (Sc) cloud decks in the world. The representation of these interactions in climate models remains highly uncertain in part due to a scarcity of observational constraints on aerosol and cloud properties, as well as due to the parameterized treatment of physical processes. Three ORACLES deployments by the NASA P-3 aircraft in September 2016, August 2017, and October 2018 (totaling ∼350 science flight hours), augmented by the deployment of the NASA ER-2 aircraft for remote sensing in September 2016 (totaling ∼100 science flight hours), were intended to help fill this observational gap. ORACLES focuses on three fundamental science themes centered on the climate effects of African BB aerosols: (a) direct aerosol radiative effects, (b) effects of aerosol absorption on atmospheric circulation and clouds, and (c) aerosol–cloud microphysical interactions. This paper summarizes the ORACLES science objectives, describes the project implementation, provides an overview of the flights and measurements in each deployment, and highlights the integrative modeling efforts from cloud to global scales to address science objectives. Significant new findings on the vertical structure of BB aerosol physical and chemical properties, chemical aging, cloud condensation nuclei, rain and precipitation statistics, and aerosol indirect effects are emphasized, but their detailed descriptions are the subject of separate publications. The main purpose of this paper is to familiarize the broader scientific community with the ORACLES project and the dataset it produced
Investigating the potential of Moringa Oleifera for agribusiness development and rural youths’ self-employment in the Livingstone rural areas
No full textMoringa oleifera is a nutritious vegetable tree with a variety of potential uses as almost every part of the tree can be used. Moringa oleifera is very useful as an alley crop in the agro-forestry industry. It is useful not only for human beings but also for animals and also in various industrial applications. Besides Moringa oleifera being processed into medicine, it contains acetone which can be prepared into herbal formulation which is an effective anti-malaria bio agent. Moringa oleifera has the potential to be a source of new drugs. This study was conducted in Livingstone district of the southern province of Zambia. The main objective of the study was to examine the factors that determine the use of Moringa oleifera for agribusiness development and rural youths’ self-employment around the Livingstone rural area in Zambia. Purposive sampling was used to select the respondents that grow Moringa oleifera and who are youths aged 18-34 years in two villages, namely, Musokotwane and Mukuni. Descriptive analysis of the data was done where frequencies and percentages illustrated the different aspects of data. Quantitative data obtained were summarised and presented in graphs, pie charts and tables. Regression analysis using a binary Probit model was conducted to specifically identify the youths’ socio-economic attributes, their perceptions, challenges, aspirations, and the opportunities of Moringa oleifera for agribusiness development and rural youths’ self-employment around Livingstone rural areas of Zambia. Results from the study revealed that the majority of the respondents (28 percent) fell within the range of less than 18 years of age and they were single (71 percent). The results also showed that the majority of respondents were aware of the Moringa oleifera plant and its uses (30.3 percent) and they used it for medicine, while 0.3 percent used the plant for income generation through the sale of its products. The perception statements on the benefits of Moringa oleifera indicated that the respondents rated it to be favourable. The results showed that there was no statistically significant relationship between the sex of the respondents and the growing of Moringa oleifera, at five percent level of significance, with 45 percent males and 55 percent females in the sample. There was also no statistically significant difference in the growing of Moringa oleifera by family size. The study further revealed that youths were aware of the plant and could identify the plant physically and by name. The findings of the study provide information on the challenges and opportunities that the youths are facing as they venture into agribusiness in the study area. The results show that 18 percent of the youth have challenges in accessing land while 45 percent lacked finance, 24 percent mentioned high costs of agricultural machinery and 8 percent cited illiteracy among the youths. These challenges contribute to the small numbers of youths participating in agribusiness. Therefore, if policy makers would consider polices that increase access to land, finance, agricultural machinery and address illiteracy among the youths, the production and use of Moringa oleifera would increase. The study findings are significant to policy makers and donors as they provide information to direct funding towards supporting and designing policies that are beneficial for youths involved in agribusiness
DESIGNING A CONTINUOUS QUALITY IMPROVEMENT FRAMEWORK FOR IMPROVING ELECTROWINNING CURRENT EFFICIENCY
No full textIn general, the electrowinning process consumes substantial electrical energy. Considering the ever-increasing unit cost of electrical power there is a need to improve current efficiency so that electrical energy is utilised efficiently. In light of the research/knowledge gap identified, this research aims to design a continuous quality improvement framework for improving electrowinning current efficiency. The objectives of this research are as follow: (i) To explore factors that influence current efficiency; (ii) To evaluate the factor that has the most significant effect on current efficiency, by applying statistical process control; and finally (iii) To design a continuous quality improvement framework for improving electrowinning current efficiency, by applying statistical process control. The scope of work for this research focused on applying statistical process control on an online industrial copper electrowinning process instead of doing laboratory experiments. In this case, a sequential mixed research methodology was applied and Minitab statistical software package was utilized for analysing data by creating control charts. The factors that influence current efficiency were explored and the main factors are as follow: metallurgical short-circuits, impurities, electrode condition, electrode alignment, contacts condition, electrolyte temperature, reagent addition, electrolyte acid concentration, current density, rectifier current, electrode insulators, cathode nodules, electrolyte copper content, and electrolyte flow rate. After analysing constructed control charts and implementing an out of control action plan, it was concluded that metallurgical short-circuits (hotspots) have the most significant effect on current efficiency than all the other factors. Bringing hotspots under statistical control resulted in improved current efficiency by 5.40 % which is equivalent to approximately 74 MT of 99.999 % pure grade A copper cathode production over a period of 1.5 months. Finally, a continuous quality improvement framework for improving electrowinning current efficiency was designed. This was done by considering the following: Anderson Darlington normality test, non-normal data transformation (using Johnson and Box-Cox transformation), constructing control charts, and then analysing control charts which include Pearson correlation analysis, out of control points alignment analysis, root cause analysis, process capability analysis, and implementing an out of control action plan
Thesis submitted in fulfilment of the requirements for the degree of Master of Natural Resources Management at the Namibia University of Science and Technology
No full textLike many other fossorial rodents, gerbils are known to modulate their environments by changing the soil characteristics and conditions via their activities such as ground bioturbation, foraging, defecating and urinating. They play an important ecological engineering role because they can affect water hydraulic conductivity and water holding capacity, mineralization rates, thus plant-available-nutrients and moisture stored in the soil profile. If the bioturbation activities of gerbils affect water availability in the hyper arid environment, gerbils may create patches of favourable micro-sites for vegetation establishment and growth, and thus also affect the structure and function of the vegetation community at the landscape scale. The main objective of this study was to test whether the gerbil species are significantly improving the growth of vegetation through their burrowing activities on the Husab gravel plains in central Namib. In this way I wanted to verify whether they play a functional ecological engineering role in the ecosystem. Firstly, the study mapped out the spatial distribution and density of vegetation patches with and without burrows on the Husab gravel plains of the central Namib and then selected specific areas for in-depth experimental study. The focus was on the effects of gerbils’ burrowing activities by comparing soil nutrients and moisture, and vegetation characteristics between contrasting sites (active burrow patches, inactive burrow patches, no-burrow vegetation patches and their control sites) on the Husab gravel plains. This study revealed that: (1) the spatial distribution and density of vegetation patches with and without burrows is not uniform and that the gerbils mostly prefer the grassy plain over other habitats. (2) The spatial distribution of density of their burrow patches can be explained by soil substrates such as surface cover and hardness. (3) Gerbils through their burrowing activities increase the hydraulic conductivity and soil’s fertility-related variables together with the vegetation cover, abundance and biomass.Thus, it can be concluded that gerbils significantly improve primary productivity through changing the conditions and characteristics of the soil on their burrow patches and this may have a knock-on effect on other organisms at the landscape level. Thus, gerbils may be considered to be essential ecological engineers in the central Namib
Thesis submitted in partial fulfillment of the requirements for the degree of Master of Natural Resource Management at the Namibia University of Science and Technology
No full textWithin the last twenty years, Namibia has become a leading model of biodiversity conservation, largely due to its Community-Based Natural Resource Management (CBNRM) model and its allocation of large areas of land towards biodiversity conservation. The CBNRM model is largely based on the rights of communal conservancies to benefit from the wildlife that is present on their land; one such right is to receive meat and revenue from trophy hunting. However, the marketability of desirable trophy animals is dependent on the consistent presence of larger trophy individuals within wildlife populations. The global trophy hunting industry is highly competitive, with larger trophies in each species being sought by premium paying hunters. Over-hunting in specific populations, however, may lead to an unsustainable trophy operation. A negative trophy measurement trend over time may be indicative of overhunting since the preferred trophy genetic trait is selectively removed from the gene-pool by hunters. Three commonly hunted trophy species of Namibia’s north-eastern landscape, namely, buffalo (Syncerus caffer), roan (Hippotragus equinus), and sable (Hippotragus niger), along with the common nationally hunted species, kudu (Tragelaphus strepsiceros), were selected in this study to determine the effects of hunting upon the trophy measurements between 2011 and 2015. The buffalo and roan measurements showed signs of non-significant positive growth trends. The sable trophy measurements show a non-significant negative growth trend, and the kudu trophy measurements showed a significant negative growth trend across Namibia over the 5 years. Though the study provided some insight into the trophy measurement trends for each land-use type (communal conservancies, national parks, and private farms), the distribution of the animals hunted, and the numbers of animals hunted, there are still many variables that could be factored into determining the influence on trophy measurement trends (e.g. game count numbers, rainfall, drought, migration, hunter’s experience, trophy market, predation, fire patterns, rabies, etc.). Namibia can still prove its sustainability if it also makes age-related scoring as a methodology for trophy scoring, and the creation and management of a web-based database to capture the essential details of hunted animals could assist with eliminating data entry errors and with the standardizing of a Namibian approach to redefining trophy qualit
The pedagogic relevance of Namibian literature in English at secondary and tertiary levels: A terminal research report submitted to the Institutional Research and Publication Committee (IRPC), NUST
No full textA terminal research report submitted to the Institutional Research and Publication
Committee (IRPC), NUSTThis study examined the pedagogic relevance of post-independent Namibian literature assessing the texts selected for tertiary and high school studies and evaluating course delivery methodologies. The study engaged chiefly the Namibian literature course facilitators of the two universities in Windhoek and collected the views of high school teachers and students in different regions of Namibia. The study also engaged the current University MA candidates in language departments through questionnaires. Through in-depth interviews, the research also sensitised educators, curriculum designers at NIED and high school learners to the significance of studying and reading Namibian literature in English. Significantly, the project advocated persuasively the inclusion of many more Namibian literary texts in the English curriculum at all levels of the Namibian education system. Visiting a total of 23 high schools and 2 public universities, the team collected 69 questionnaires, conducted 31 interviews with high school teachers and 32 with learners during 2018 and 2019. The views of 5 university lecturers and 2 language experts at NIED were also included in this report. A review of the latest (2018) Namibian high school curriculum (Grade 9-12) shows us that only two Namibian literary texts: Sifiso Nyathis’ God of Women and a poem about Hendrik Witbooi were included in the new ESL syllabus along with other European canonical poems, plays and novels. The research team did not discover a single Namibian short story, novel or an autobiography as part of the high school ESL syllabus. The research team expected that in order to inculcate a reading and writing culture in Namibia, Namibian children’s literature in English should have been introduced at the lower level, too. The Namibian high school ESL syllabus has given more focus on the descriptive, functional and communicative grammar tasks, essay writing exercises and short piece composition activities. The imaginative writing and creative thinking part of language teaching has almost been disused. On the contrary, at the tertiary level, it can be conspicuously observed that there exists a tremendous growth of research niche areas in the Namibian texts at UNAM and NUST. The research team documented the diversity of genres studied by the postgraduate Namibian students of language and literature departments of UNAM and NUST. Respondents who completed questionnaires and engaged in interviews and Focus Group Discussions (FGD’s) recommended that literature in the Namibian high schools be taught to enhance the linguistic capabilities, overall personalities, the literary competencies of high school learners and inculcate the diverse Namibian cultures, values and traditions. This research has recommended a wide range of text selection strategies and listed several Namibian literary texts which can be studied either by the university or high school learners of English as subjects or research niche areas.IRPC Funded (2018 -2019
Multiculturalism and communication in the HE classroom context: A Namibian case study
No full textArticle published in an Open Access journalThis study was conducted at the Namibia University of Science and Technology
(NUST) to investigate the challenges of intercultural communication between lecturers
and first year students in the Faculty of Human Sciences, Windhoek, Namibia. The
study followed a mixed methods research design. A total of 40 respondents formed
the study inclusive of lecturers, local and foreign students following a simple random
sampling method. The researchers selected 40 respondents who could speak different
languages and belong to diverse cultures. Out of the 40 respondents, 10 lecturers who
dealt with first year students were selected to be part of the study. A total of 11 foreign
respondents were included in the study and the other 19 were local Namibian
students. Cultural and linguistic diversities were the main selection criteria. Primary
data was collected through questionnaires and in-depth interviews. It was found out
that the main barriers to intercultural communication amongst students and lecturers
were the use of English as a medium of communication, anxiety and fear, generalizations
including prejudice, poor listening skills (noise: distractions such as cell phone
use and unclear messages), physical separation – the space between lecturers and students
during classes, lack of knowledge of others’ cultural background, ignorance, and
lack of knowledge of others linguistic background. Therefore, it was recommended
that English with intercultural communication content should be offered to all firstyear
students in the Faculty regardless of the programme. On the other hand, since
NUST offers language classes for foreigners and beginners, students who struggle
with English as a medium of instruction and communication are advised to enrol for
extra language classes to help them to effectively communicate with lecturers and fellow
classmates. It was further recommended that to enhance the competence of students
and teachers in intercultural communication and interlanguage pragmatics, lecturers
and students should expand the existing knowledge to enable them embrace
cultural diversity
Designing of an Equalization Process for Improving the Performance of the Gammams Water Care Works, Windhoek, Namibia
No full textThis thesis examines and presents a first stage assessment of the potential improvement of waste-water treatment plant performance by including an equalization process as part of the treatment train of the Gammams Water Care works in Windhoek, Namibia. The treatment plant’s operational objective of achieving compliant final effluent quality on a consistent basis is hampered by influent hydraulic and pollutant load daily diurnal pattern variations oppose to a near uniform condition experienced. These non-uniform hydraulic and pollutant loading conditions impose a negative impact on achieving overall optimal treatment plant performance.
During the study, daily variations in hydraulic and pollutant loading at the Gammams Water Care Works were established and a representative day of a typical week identified for the equalization process attenuation capacity design in order to minimize both flow and pollutant load diurnal pattern variations. Furthermore, a comparative analysis of equalised and unequalised treatment scenarios on overall plant performance was done by applying both numerical and graphical analysis methodologies aided by the STOAT computer software simulation model. This study uniquely made a comparative analysis of the current Gammams Water Care Works treatment train (which currently operates without an equalization step) using the STOAT model, considering both unequalised and equalised process equalization scenarios.
The graphical or Ripple method and a numerical time-step method were employed for equalization process attenuation capacity determination. The numerical time-step method together with STOAT modelling steady state simulations were employed for this 1st approximation step analyses, for initial comparison and impact assessment as well as for identifying the road map for further future detailed extended-time simulation purposes.
The study found that the plant typically experiences diurnal daily influent hydraulic and pollutant load variations similar to other plants receiving mainly domestic wastewater in the early morning hours and between midday and early evenings. For STOAT modelling purposes, current plant influent and subsequent unit process outflows along the treatment train were sampled and selected pollutant concentrations were determined over 4-hour intervals for the representative dry weather weekday mentioned before. The STOAT model calibration was limited to the actual Gammams plant treatment train, unit process sizes and operational criteria employed. Bio-chemical process kinetic algorithms inherent to the STOAT model was not changed due to the software limitations of use and not being allowed. The analysis done of unequalised and equalised scenarios was thereof of a comparative nature
A thesis submitted in fulfilment of the requirements for the degree of master of science in applied mathematics of the namibia university of science.
No full textIt seems that during the last decades, no research was done which is related to the Steinitz
exchange theorem. However, the generalised Steinitz exchange theorem has been investigated
in books and articles . The generalized Steinitz exchange theorem is not a theorem of linear
algebra but for reaching generalization of the Steinitz exchange theorem which has applications
for example in eld theory, in the theory of abelian groups and in module theory.
The objective of this study was to prove the Steinitz exchange theorem of linear algebra for
arbitrary vector spaces over arbitrary division rings. Nearly all books on linear algebra which
have the Steinitz exchange theorem explicitly state and prove this theorem only for nitely
generated vector spaces. Only one exception can be found. In another source, the Steinitz
exchange theorem is proved under the additional assumption, that the linearly independent
subset is nite.
In this study the exchange theorem of Steinitz is proved in full generality with the means of
linear algebra. The statement of the theorem of Steinitz is a statement of the following type:
under certain conditions there exists a set with certain properties.The question when this set is
uniquely determined could be completely solved. In addition, an application of the theorem of
Steinitz is presented. This is the classical application which was given already by Gra mann:
Any two bases of a vector space are equipotent.
The rst chapter is about the basic concepts of the study. The second chapter reviews the
relevant literature and outlines the methodology used in the study. The literature review is
mainly about the generalized theorem of Steinitz, but also include the versions of the Steinitz
exchange theorem found in books of linear algebra. The third chapter presents the results of
the study with proofs. The study is concluded in the last chapter with proposals for further
study
Submitted in fulfillment of the requirements for the degree Master of Informatics In the Department of Informatics at the NAMIBIA UNIVERSITY OF SCIENCE AND TECHNOLOGY.
No full textUnmanaged stress negatively impacts the health of students and it has a tendency of leading to mental health disorders. Hence, the alarming statistics on stress - induced conditions in Namibia calls for concern. Unmanaged stress can potentially lead to depression. Unsurprisingly, depression is one of the major contributors to suicide in Namibia. Namibia ranks the 4th highest country in Africa on suicide rates within the age group of 18-28 years. This represents a significant percentage of the vulnerable population susceptible to suicide in the country. Mobile health (mHealth) applications have achieved remarkable success in the healthcare domain. The use of mHealth applications to manage chronic illnesses has gained popularity with patients especially as mobile phones become ubiquitous. Mobile apps for stress management are readily available and can be easily downloaded online for individual use. Most of these mHealth applications are free and they work either online or offline. However there is limited use of mHealth applications for stress management among Namibian students despite the availability of mHealth applications for stress management that can help improve the handling of stress conditions. Persuasive technology is the use of computers to change people’s behaviour. Persuasive technologies have the potential of improving health behaviour as shown in the literature. Unfortunately, there is limited study to show persuasive strategies included in some of the available mHealth applications for stress management, especially for the Namibian context. There is a need to investigate persuasive strategies that will motivate NUST students to use mHealth applications to initiate health behavioural change. This study planned to develop persuasive strategies that would facilitate the use of mHealth applications for stress management among NUST students. This was done by identifying persuasive elements in existing academic literature and qualitative research methodology was used to investigate suitable persuasive strategies required to motivate the use of mHealth apps for stress management among NUST students. Design Science Research strategy was applied in the study and NUST was the case considered in the evaluation of the developed guidelines. The first phase of the research was systematic literature scoping to identify elements of persuasive strategies in existing literature and persuasive elements in mobile apps for stress management. The review identified 21 persuasive strategies in the thirty-one (31) studies evaluated. The second phase included student interviews, which were developed with selected lists of context relevant elements of persuasive strategies to see which of them applied to NUST students. The outcome of the interviews was a list of elements of persuasive strategies found to facilitate the use of mHealth apps for stress management by the students and draft guidelines developed. Content analysis was used to analyse the data gathered from the interviews. The final phase involved interviews with mental health professionals and mHealth apps developers to review and validate the identified elements of persuasive strategies and guidelines identified; for their efficacy and suitability for mHealth apps for stress management among NUST students. The findings revealed 24 persuasive elements. Personalization, Tunnelling, Mindfulness, Self-tracking, Social Influence and Reminders were among the preferred persuasive strategies for mHealth apps for stress management. Scarcity, Liking, Leaderboard and Environment were not favoured. Engaging elements of persuasive strategies of the end users can improve the use of mHealth apps for stress management. It is anticipated that the findings of this study will be incorporated into existing and future mHealth apps for stress management especially for students by developers