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Namibian Museum for Architecture: preserving and archiving architectural heritage
No full textThis dissertation stems from the love and appreciation of things that tells a story of time and makes us reflect on our impermanence as the individual self. Personally; the vast open horizons that are infrequently defined by mountainous sprouts that draws one in, added with the rhythmic silhouettes of the mountains as dusk sets as a backdrop to seemingly infinite flat plains; reminds us of just how majestic this land is. The ghost towns of the Namib Desert, washed away by the passing waves of sand dunes contrasted by the indigenous villages still animated by intricate dance rituals and social gatherings. In the Namibian context these are the contexts that invokes a sense of nostalgia and mortality which humble us in our approach to life. This dissertation attempts to create awareness of our unique environments that we often find ourselves in and that there is merit in preserving such places and elements for both our future generations and people from other regions to experience and learn from. In reference to this; this dissertation proposes the preservation of only a fraction of that which is valuable in Namibia; its vernacular, and German-colonial architecture which have a considerable influence on the identity of the country as a whole. The establishment of a museum and research centre in Windhoek, Namibia will primarily focus on the restoration and documentation of both indigenous vernacular and colonial architecture as a preservation mechanism and to create awareness of this tangible heritage as it makes up an integral part of the identity of culturally diverse Namibia
Elemental assessment and extraction of the waste rock tailings from a Free State goldmine
No full textMining activities normally produce large quantities of different waste products after the separation and isolation of the economically valuable elements present in the mineral ores. The mine waste dumps do not only tarnish the natural environment, but also have the capacity to liberate potentially harmful elements which contaminate local natural resources such as water and air. However, the same waste may also be a source of economically valuable elements which have been mined simultaneously with other valuable elements (then target elements), but were not of any economic importance during the previous mining activities. The aim of this study was to determine the elemental composition of gold mine waste material in the Free State. The possible separation and isolation of some of the more valuable elements in waste material also formed a part of the study. Samples were collected from various dump sites near Welkom in the Free State. Flux-fusion decomposition was extensively employed in the dissolution of the solid samples and the elemental contents of these samples were determined, using the inductively coupled plasma optical emission spectrometer (ICP-OES) for elemental content. The water samples were also analysed with the same instrument. The ICP-OES was used throughout the study in order to monitor and evaluate the success of numerous separation techniques which were carried out to recover some of the valuable elements. Waste dumps in the Welkom/Virginia are in the Northern Free State were selected for this study. Waste rock sampling was carried out at six dump sites, where five samples were randomly collected at various points in order to include waste with different particle-sizes and surfaces colours. The sub-samples were milled and equal masses of those taken from one site were combined and homogenised manually. Tailings were collected at three dumps from different layers. Mine water samples were also collected at two sites in ditches surrounding the tailings.
Decomposition by flux-fusion was carried out with different fluxes, some of which did not dissolve the waste rock completely. Lithium tetraborate (Li2B4O7) was used for the waste rock samples and the resulting melts were dissolved with H3PO4. The tailings were also decomposed with Li2B4O7 and the melts were dissolved with HNO3. Water samples were acidified immediately after collection and those that were collected with sediments were filtered. All the samples were analysed by means of ICP-OES.
The waste rock generally contained, Cr, Mn, Zr, Pt, Th, with significantly high concentrations of Al, S, Ti and Fe. The tailings generally comprised Ti, Cr, Mn and high concentrations of Fe and S. The EDS spectrum indicated the presence of a very high concentration of Al. Many more elements with various degrees of economic importance were found in the water samples collected in the vicinity of the tailings dams. Elements identified in these water samples with stream bed sediments included P, S, Ti, Cr, Mn, Fe, Co, Cu, As, Cd, Pt, Hg, Pb, Th and U.
Electro-winning was carried out to recover copper selectively from mine wastewater, using electrolysis apparatus with platinum gauze electrodes, resulting in a copper recovery of 81.13% and a Ti recovery of 106.27%. In another part of the study, oxine, in the presence of NH4OH, was used in the selective precipitation of copper in an acetic acid matrix. The analysis of the dissolved precipitate in HNO3 revealed the presence of Fe, Co and S in the precipitate. The recoveries of 56.89% Cu, 5.51% S, 89.27% Fe and 54.66% Co were obtained.
Manganese was recovered selectively by ion exchange chromatography using the Dowex 66 free base anion exchange resin and 0.5 M orthophosphoric acid for elution. This resulted in the Mn recovery of 77(7)%. Adsorption of Pt onto activated carbon was attempted, at an elevated temperature. This procedure was not regarded as effective as since only 17% Pt was adsorbed, while many other elements were also adsorbed, leading to lack of selectivity. The use of banana peel as sorbent for Th was also attempted. The sorbent was prepared by rinsing, drying and crushing banana peels, for use as possible sorbent. Analysis of the filtrate revealed adsorption of various elements, the adsorption percentage of Th being 61.37%. These results indicated lack of selectivity within the method. Desorption of the elements from the loaded banana peel sorbent with H2SO4 resulted in 28.08% Th recovery, while larger recoveries were obtained for Cd, Hg and Mn.
From this study, it is clear that mine waste dump sites may be a valuable source of economically valuable elements. Moreover, very modest hydrometallurgical methods may be used in the isolation and recovery of these elements, thus making mine waste sites valuable alternative elemental sources with economic value
The effect of different sodium reduction strategies on the chemical, microbial and sensory quality of a traditional South African sausage
No full textDue to recent regulations that were passed by the South African Government limiting the sodium content of various processed food products of which Boerewors is one, the food industry now has to abide by new specified sodium levels. These regulations were implemented in an attempt to improve public health. Sodium chloride is one of the primary additives used in Boerewors production due to different functional and preservative properties it exhibits. Sodium does however, have an adverse effect on health when consumed in large quantities.
Subsequently, a survey was done representative of the commercially available Boerewors in Bloemfontein, South Africa, in order to establish what the current sodium levels are in Boerewors, to what extent the products deviate from the current and upcoming Na limit and whether reformulation is necessary. It was found that around 60% of product labels did not include information on sodium included in the products. Most products did comply with current sodium limits and some of the products even complied with the next sodium limit for 2019.
The second part of this study looked into the implications of these sodium reductions on the overall quality and stability of Boerewors products. The treatments were formulated according to current and upcoming regulations for sodium content. The effects of current inclusion limits and also of only reduced sodium content were tested alone and also in combination with KCl and K-lactate replacers, respectively. This was done in order to establish what the implication of the regulations are, if it is sustainable, whether selected replacers can help maintain quality and stability and whether or not products will need reformulation.
From the study on the effect of reduced sodium content and addition of different replacers it was found that the aw, pH and moisture content was not significantly affected and there are no links to deviation independent parameters such as microbial stability. The results obtained from microbial and oxidative stability evaluation as well as from sensory analyses proved to be positive. Even though the replacers did not significantly help with improving microbial and lipid oxidative stability, all the treatments were stable over the shelf-life period with all the microbial values being within limits and no detection of rancidity. The addition of replacers could not be detected sensorily by consumers and in comparison with only the addition of NaCl, they also did not prefer one product over the other. Reduced levels of NaCl and also the addition of replacers maintained overall quality and stability. The treatment that contained KCl showed to help reduce cooking and total losses. In terms of the colour parameters tested, in general, all the formulations experienced decreases in lightness, redness, yellowness, and colour brightness while colour purity increased. The oxidative effect of high NaCl on meat product colour was confirmed, the addition of lactate as replacer did to some extent affect the meat product colour positively.
The overall conclusions made after taking all the findings from results obtained into consideration, are firstly that product labels do not indicate necessary dietary information regardless of set out requirements through legislation and that there is still a large margin for improvement in providing consumers with information to help them understand legislation better and consequently to make healthier choices when buying products. Secondly, the next mandatory sodium inclusion limit in 2019 will not have a negative effect on the chemical or microbial stability of Boerewors products. And lastly, that because there were no major differences between the treatments with different NaCl levels and added replacers, the best option would be to only add NaCl at the indicated legislative level simply because it is more cost effective and consumers might feel more at ease when there are no extra added additives.Meat Industry Trust (MIT)National Research Foundation (NRF
School mathematics performance: a longitudinal case study
No full textIn South African schooling, two sectors exist in which 75% of schools achieve significantly lower than the upper 25% of schools, resulting in a bimodal education system. However, the level of mathematics performance of South African learners from schools of all quintiles is far below international standards. There is a dearth of longitudinal studies investigating mathematics performance and it appears as though none have been done on South African learner performance in mathematics from Grade 1 to 12. The aim of this study was to investigate the mathematics performance from Grade 1 to 12 of boys attending a South African ex-Model C, single-gender school. A two-pronged approach was used. Firstly, the mathematics performance of learners who took Mathematics up to Grade 12 was compared to that of those who opted for Grade 12 Mathematical Literacy instead. Secondly, the effectiveness of mathematics performance in lower grades in predicting that in subsequent grades was investigated. In order to do so, the promotion marks of learners in eight consecutive cohorts (Grades 1 to 12) at the same school were used. Archived data were retrieved from SA-SAMS and the school’s hardcopies of learners’ results. Learners matriculating at the school in either Mathematics or Mathematical Literacy were separated into a Mathematics-set (M-set) (n=302) or a Mathematical Literacy set (ML-set) (n=160) respectively. The “Proc Mixed” procedure was used to analyse the data. The Mixed Model for Repeated Measures (MMRM) with an unstructured covariance matrix for repeated measures within learners was fitted, using Restricted Maximum Likelihood (REML), fitting fixed effects of cohort, grade and grade within a cohort. Regression analysis was performed to establish correlations and thus the precision with which current grade marks predict future grade marks. Ryan and Deci’s Self-Determination Theory and Piaget’s Cognitive Theory were useful in providing possible explanations for the results. The mathematics performance of the two sets from Grade 1 to 7 followed a similar trend, but on average, the M-set performed 10% better than the ML-set. Mathematics performance was stable in the Foundation Phase. While national results generally reflect a decrease in marks from Grade 3 to 4, the learners in the current study showed an increase in mean marks. There was a decline in mean marks in Grade 6, which had the weakest correlations with those in other grades than any other grades with one another. The highest mean mark for Mathematics (across all grades) was in Grade 7. The steepest decline in mean marks was from Grade 7 to 9; however, the ML-set experienced a much greater decline, causing the gap between the two sets to widen to 22%. The implications arising from these results are numerous. For instance, the ML-set achieved mean marks that were below those of the M-set. The set that started out lower in Grade 1 ended lower in Grade 7. This underscores the importance of learners starting formal education in the strongest position possible as this trajectory is generally maintained throughout their schooling. Contrary to national averages, the mean marks increased from Grade 3 to 4. The learners’ minimum of four years’ exposure to English, as the LOLT, prior to Grade 4 could account for this. The decline in mean marks from Grade 7 to 9 coincides with other simultaneously occurring factors, namely puberty, the transition to high school and the introduction of more abstract concepts such as algebra. Learners in the Senior Phase face many difficulties and adjustments. It is in the interest of the learners’ education that they are supported and guided, especially during these changes
Breed effects and non additive genetic variation in indigenous and commercial sheep in an extensive environment
No full textThe first part of the study compared a commercial, the Dorper as an arguably adapted commercial breed to the Namaqua Afrikaner as an unselected, indigenous, far-tail breed. The Dorper conclusively outperformed the Namaqua Afrikaner with reference to live weight and growth traits. On the other hand, Namaqua Afrikaner lambs were superior to Dorpers for an adaptive trait like total tick count. Lamb survival was unaffected by breed. When meat traits were considered, it was evident that Dorper lambs outperformed their Namaqua Afrikaner contemporaries for important attributes associated with size and meat yield, namely carcass weight and dressing percentage. Dorper carcasses also attained better grades and were more tender according to instrumental measurements (Warner Brazler equipment). Dorper lambs were fatter than Namaqua Afrikaner lambs, as derived from the backfat thickness at the 13th rib and the rump. While leaner meat would be preferred by health-conscious consumers, it is important to note that, under the conditions of the study, Dorper carcasses were more likely to be in the preferred grades.
In the second part of the study, Dorpers were evaluated against the SA Mutton Merino (SAMM; the most numerous dual-purpose breed in South Africa), as well as the reciprocal cross between the two breeds. No conclusive breed differences were found for weight traits, lamb survival, tick counts or meat traits. However, there was a suggestion that lamb survival of Dorpers was higher than that of their SAMM contemporaries (P = 0.08), but significance could not be demonstrated. Crossbred progeny outperformed the midparent value by 6.3% for weaning weight.
The corresponding study on meat traits was constrained by low numbers. However, it was evident that the observed heterosis for weaning weight was also present a later growth stage. Direct heterosis estimates amounted to 7.7% for slaughter weight and 7.1% for carcass weight. These estimates were consistent with the literature for the expected level of heterosis for early growth when assessed in fairly divergent sheep breeds. This outcome once again reiterated that crossbreeding may have a definite role to play at the commercial level in the South African sheep industry. Further studies on the comparison of indigenous genetic resources with commercial breeds, as well as crossbreeding studies with the variety of available breeds were recommended.Lesotho National Manpower Development secretariat (NMDS
Physical activity and lifestyle habits of female undergraduate students
No full textIntroduction: There is an extensive body of empirical evidence which demonstrates health benefits of physical activity. PA is associated with lower mortality rates for female students. Young female adults attending universities gain increased control over their lifestyles, however don’t necessarily develop positive behaviours like regular PA.
Aims: To determine PA levels and lifestyle habits of female undergraduate students.Three objectives were set out for this research: (1) To identify PA levels of the female undergraduate students at the University of the Free State campus using a validated self-reported measure instrument; and (2) To establish the lifestyle profile and body composition of undergraduate female students attending this Tertiary Institution and (3) to determine the impact of ethnicity on PA levels, lifestyle habits and body composition of undergraduate female students attending a tertiary institution.
Methods: A quantitative approach, using a one-time non-randomized cross-sectional study approach was used. Ethical clearance was obtained and participants completed the Belloc and Breslow’s lifestyle questionnaire and IPAQ questionnaire. Anthropometric testing was then conducted on the participants.
Results: The PA levels of the students was determined with a total of 68% participating in PA. There was an increase in the participation in PA from first year (62.3%) to third year (79.4%). This increase was also evident in the mean MET minutes/week from first year through to third year. The majority of the students were considered to be moderately healthy. There were however no statistically significant associations in PA and lifestyle habits between ethnicity and year groups.
Conclusion: An increase in the PA frequency as well as the mean MET minutes/week from first year to third year was found. The ethnic groups on the other hand didn’t show significant differences among their lifestyle habits, PA levels and body composition This proved that students improved to high levels of PA and are aware of the health benefits
Vein size and demographics: is there a correlation?
No full textPeripheral arterial occlusive disease has a high prevalence worldwide, as well as in our population, and contributes to an immense burden of morbidity and mortality. Due to the systemic nature of especially atherosclerotic vascular disease, most patients also have cardiovascular and cerebrovascular involvement at the time of presentation, adding to the huge impact on the patient and the economy. Lower limb amputation is associated with a 50% 5-year mortality rate, thus peripheral arterial disease itself is also responsible for considerable mortality rates. Attempting to re-establish perfusion to an ischaemic limb is crucial in saving the limb and the life of the patient. Options for revascularisation of patients with limb-threatening ischaemia include open and endovascular approaches, each with its own indications and shortcomings. In the case of open infra-inguinal bypass grafting, the great saphenous vein is the preferred conduit used to replace the diseased segment. It has been proven to perform superiorly to synthetic grafts with respect to long-term patency, adequate length, and swift harvesting. This vein is also used in other autogenous bypass procedures, including coronary bypass graft surgery and arterio-venous fistula grafts for access in renal replacement therapy. Occlusion of the graft, or graft-failure, is one of the dreaded complications of any bypass procedure, and can be divided into primary or secondary failure, according to the time from procedure to the establishment of the diagnosis. Both scenarios are detrimental to the salvage rate of the limb, and can also indirectly contribute to the demise of the patient. Many factors have been associated with primary graft failure, particularly the size of the conduit graft, which was the main focus of our study. Our primary aim was to determine the average great saphenous vein size in our study population, and our secondary aim was to demonstrate a relationship between vein size and demographic variables like race, age and gender. The study was a cross-sectional retrospective study, using data over 10 years from January 2006 to December 2015. All patients underwent vein mapping with ultrasound pre-operatively prior to a lower limb bypass procedure in Universitas Academic Hospital, and the demographics of these patients were then analysed. A total of 811 patients were included and the meteorological season was used as a surrogate indication of the average temperature in the vascular suite to account for the influence of ambient temperature on vaso-action and vein size. The average size of the great saphenous vein in our study population was found to be 4.08 mm. After analysis, it was found that black patients had smaller veins than white patients (p < 0.0001) and men had smaller veins than women (p = 0.0217). Vein measurements were smaller during summer months, and there was no significant difference between vein sizes in different age groups. Owing to the existing risk of small conduit size for graft failure, vein size plays an important role in the choice of procedure used to revascularize limbs in patients with critical ischaemia, whether acute or chronic. The results from our study may assist in improving selection of patients suitable for open surgery based on demographic parameters, thus decreasing poor outcomes of revascularisation procedures and decreasing complications associated with graft failure
Maternal knowledge, attitude and practices with regard to postnatal care services in a Free State rural hospital
No full textMothers and newborn are vulnerable to illness during the postnatal period. In Africa, half of the mortalities during the postnatal period occur during the first week after delivery, and most of these deaths are preventable. To overcome this burden of disease South Africa implemented the guidelines for maternity care to encourage mothers and newborns to attend to their clinic within three to six days. Unfortunately, the utilisation of these services in South Africa, but more especially, Ladybrand is neglected and the maternal- and neonatal mortality and morbidity rate remains high. A study to assess the maternal knowledge, attitude and practices with regard to postnatal care services in a Free State rural hospital, was thought to be the best strategy to identify the barriers that ultimately prevent the mothers from utilising these services. The aim of the study were to describe the maternal knowledge, attitudes and practices (KAP) with regard to postnatal care services in a Free State rural hospital. Considering the nature of KAP studies, a quantitative, descriptive, cross-sectional design was used to address the domain investigated. The research question addressed was what are the maternal knowledge, attitude and practice with regard to postnatal care services in a Free State rural hospital? The theory of planned behaviour together with knowledge, attitude and practices were used as guidelines to design a structured questionnaire as data collection tool. Ethics approval was obtained from the Health Science Research Ethics Committee, University of the Free State, and the three principles of the Belmont report were continuously implemented throughout the course of the study. The questionnaire was piloted on a sample of four respondents who gave birth in Senorita Nhlabathi hospital. The pilot study was implemented before the actual data collection to identify any unforeseen problems that may affect the validity and reliability of the study. No problems were identified during the pilot study and the data was included in the main study. The data collection took place in the maternity ward at Senorita Nhlabathi hospital, and included a sample of 110 respondents who delivered babies during July to October 2017. One hundred and ten questionnaires were completed and almost all of the respondents were Sesotho speaking women with a mean education level of grade 11. The respondents had a mean age of 28 years, with the youngest participant 18 years and the oldest 47 years of age. The majority (79.1%) of the respondents were unemployed and living in an informal type of dwelling (76.4%). More than half of the respondents (57.7%) lived less than two kilometres from the nearest clinic and all of the respondents had access to primary healthcare services. With regard to the results pertaining the theory of planned behaviour and knowledge attitude and practice, the knowledge of the respondents were found inadequate with an average between 50-70% (behavioural beliefs, normative beliefs, subjective norms, control beliefs and perceived behaviour control). The attitude of mothers towards postnatal care services was found to be negative (44.6%, n=49). The worst performing statements with regard to attitude included long waiting times at the clinic (73.6%) and the respondents showed signs of postpartum depression during their previous pregnancies (74.6%).
The practice (intention, 93.6%; actual behaviour control, 81.8%; and behaviour, 82.7%) performed overwhelmingly well, although the statement that underperformed in all three sections was related to the utilisation of postnatal care services. Poor maternal knowledge, attitude and practice were found with regard to postnatal care services in a Free State rural hospital. The awareness and attitude of the mothers towards postnatal care services should be addressed through health education throughout the antetnatal care period and before discharge from the hospital, and thereby decreasing the maternal and newborn morbidity and mortality
New methodology for the biomimetic synthesis of Flavan-3,4-diols and derivatives
No full textAbstract not availablePET Labs (Pty) Lt
Reinventing the social scientist and humanist in era of big data : a perspective from South African scholars
No full textFirst editionAbstract not availableUniversity of the Free StatePublished versio