Modelling payment systems for environmental services in the Mt Elgon ecosystem of Kenya
- Authors: Kisaka, Lily
- Date: 2014
- Subjects: Ecological disturbances -- Kenya , Freshwater ecology -- Kenya , Water quality biological assessment -- Kenya , Land degradation -- Kenya , Ecosystem health -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD (Agricultural Economics)
- Identifier: vital:11206 , http://hdl.handle.net/10353/d1013123 , Ecological disturbances -- Kenya , Freshwater ecology -- Kenya , Water quality biological assessment -- Kenya , Land degradation -- Kenya , Ecosystem health -- Kenya
- Description: Unsustainable patterns of consumption by humankind have increased the rate of change in the natural ecosystems and consequently the levels of stress experienced within the environment. Access to sufficient good quality water is essential and a requirement to meet a number of the Millennium Development Goals (MDGs). However, poor land management and untenable agricultural practices have become the main drivers of the declining watershed services. Upstream farmers often have little or no incentives to take these impacts into account in their decision-making process. Therefore, without investment in ensuring proper land management, the trend in watersheds degradation will continue. Payment for Environmental Services (PES) has emerged as an incentive–based tool that is expected to motivate farmers to improve their agricultural practices. PES is set up to facilitate the process whereby the beneficiaries of environmental services pay compensation to providers of environmental services for conserving the ecosystem. This tool has received increasing attention as a means of creating incentive measures for managing the ecosystem, addressing livelihood issues for the rural poor, and providing sustainable financing for protected areas. The Government of Kenya, as part of its efforts to improve water resource management, is considering use of economic incentive. However, there is insufficient information to guide policy making in that direction. Little is known about the farmers’ preferences for management schemes that will affect land use patterns, their willingness to accept compensation and the willingness of potential buyers to pay for the services. This study evaluates the willingness to accept and the willingness to pay for environmental services with a view to assessing the viability of a PES scheme for the Kuywa Watershed in particular, as well as the Mt. Elgon Ecosystem and other areas with similar conditions. The objectives of the study are threefold (i) to examine respondents preferences for management options for the provision of environmental services in the watershed of River Kuywa of Mt. Elgon Ecosystem; (ii) to evaluate households’ willingness to pay (WTP) and willingness to accept (WTA) payment for improved environmental services from the River Kuywa watershed; and (iii) to propose viable PES approaches for the management of the natural resource of the Kuywa watershed and the Mt. Elgon ecosystem in general. Using six land management attributes relevant to the local situation, the study applied the conjoint method to evaluate farmers’ preferences for management options for the provision of environmental service and assess farmers’ willingness to pay and willingness to accept payment for environmental services. To enable assessment of viability, an analysis was done of the institutional and legal framework within which the PES scheme would operate. Data were collected using literature review and document analysis, questionnaires, focus group discussions and key informant interviews. Results indicate that poor water quality was the most acute problem, followed by deforestation. Results from the conjoint models show that the length of commitment period and land size that is 40% or more of the total land holding influence the farmers’ rating of the management scenarios. The study found that a management contract that requires use of 20% of land holding for a period of 5 years, combined with a cash incentive, harvesting partially permitted, administered by a local NGO and requiring contribution of free labour for two days had the highest likelihood of being selected. The conjoint valuation exercise also came up with a WTA by farmers upstream of KSh. 7,080/= per year. The corresponding value downstream was KSh. 43/= per month over and above their regular water bill. In terms of the institutional and regulatory framework, Kenya has a wide range of policies, laws and regulation on water and other natural resources which provide an enabling environment for PES. With the decentralized institutional setup implemented in both the water sector and the agricultural sector, the institutional setting also provides an enabling environment for PES. With a positive WTA and WTP coupled with an enabling legal and institutional environment, the study concludes that PES is a viable environmental management tool for the Kuywa water shed and similar watersheds.
- Full Text:
- Date Issued: 2014
Molecular study of mycobacterium tuberculosis complex (MTBC) DNA from Port Elizabeth
- Authors: Londiwe, Bhembe Nolwazi
- Date: 2014
- Subjects: Mycobacterium tuberculosis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11281 , http://hdl.handle.net/10353/d1016163 , Mycobacterium tuberculosis
- Description: Mycobacterium tuberculosis complex (MTBC) is a causative agent of tuberculosis (TB) in humans and animals. The burden of tuberculosis in South Africa is worsened by the concurrent epidemic of HIV. The dynamic of TB epidemics has been investigated and yet little data has been given about the Eastern Cape, particularly Port Elizabeth. The study aimed to investigate the prevalence of drug resistant MTBC and to determine the mutations causing resistance in Port Elizabeth. One hundred and ninety (190) DNA samples isolated from sputum specimen in humans suspected of having TB were amplified using the Seeplex® MTB Nested ACE detection assay. To differentiate Mycobacterium tuberculosis complex (MTBC) members for surveillance purposes a multiplex polymerase chain reaction (PCR) method was done based on genomic regions of differences such as RD1, RD1mic, RD2seal, RD4, RD9 and RD12. Target genes known to confer resistance to first and second-line drugs were amplified and the amplicons sequenced using Big Dye Terminator DNA sequencing kit v3.1 (Applied Biosystems, UK). The patient’s demographic profiles were obtained from the National Health Laboratory Service (NHLS). All hundred and ninety DNA samples tested positive for MTBC using the Seeplex® MTB Nested ACE assay. Results show a high prevalence of extensive drug resistant TB in Port Elizabeth, Eastern Cape Province. One hundred and eighty four (184) DNA isolates were used in the identification of different MTBC species. We ended up working with 184 DNA isolates because we ran out of DNA, and we could not go back to isolate DNA from the affected individuals due to the fact that some patients died, while some have been released to go to their homes. From the 184 DNA isolates 45 (24.5%) isolates were identified to be M. tuberculosis, 94 isolates (51.1%) to be M. bovis BCG and 3 isolates (1.6%) to be M. cannetti. Sequencing results show the position of mutation in each DNA isolate; however in the study we got resistance to MDR to be 100% and 42% pre-XDR while 58% was XDR. These results raise an alarm for the prevalence MDR in MTBC from Port Elizabeth. This is a serious health concern which calls for a need to strategise on the identification of extensive drug resistant TB patients from multi-drug resistant TB patients and ensure monitoring of their treatment.
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- Date Issued: 2014
Nature of occurrence and economic potential of granitic pegmatites of Mzimba district in Northern Malawi
- Authors: Salima, Jalf William Joseph
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11527 , http://hdl.handle.net/10353/d1016192
- Description: A swarm of granitic pegmatites occurs in Mzimba district from northern Kasungu to Kafukure near the western international border with Zambia. The granitic pegmatites are hosted by a mobile belt, within the Mozambiquan orogenic belt (c. 900 - 1800 Ma). They have been dated as 485 Ma. They intruded metasediments of high to medium grade metamorphic rocks of a Precambrian Basement Complex. The dominant trend of the pegmatites is NW - SE, exhibiting a cross-cutting relationship with the country rocks and their contacts with the latter are usually sharp. The six pegmatites investigated in this study are inhomogeneous, composed of a massive quartz core, an intermediate zone composed of a blocky pink K-feldspar rich sub-zone and muscovite rich sub-zone and a wall zone composed of quartz - pink K-feldspar - muscovite mineral assemblage. The Mzimba pegmatites are classified as lithium-caesium-tantalum (LCT) family of rare element granitic pegmatites as described by Černý and Ercit (2005). They belong to the beryl-columbite subtype and beryl-columbite-phosphate subtype of the rare element pegmatites. It is suggested that the pegmatites are the product of magmatic differentiation and that they form roofs of granite plutons lying deep below the current level of erosion. The six pegmatites were sampled and minerals analysed using standard analytical methods such as petrographic microscopy, X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. Mineralogy of the granitic pegmatites indicates that they are predominantly composed of perthitic K-feldspar (perthite), Na-plagioclase (albite), quartz and muscovite as main mineral phases and accessory minerals including beryl, tantalite-columbite (ferrotantalite), iron-titanium oxides (ilmeno-rutile and ilmenite), tourmaline (schorl), garnet (almandine-spessartine) and triplite. Triplite is a very rare mineral found in a few pegmatites around the world, and this is the first reported account of this mineral in the Mzimba pegmatites and probably in Malawi. These minerals are being exploited by artisanal and small scale miners. Trace elements in K-feldspar and muscovite are significant indicators for the evaluation of economic potential of pegmatites as well as for the differentiation degree and origin of the magma. The K/Rb ratio for K-feldspars ranges between 12.72 and 109.38, while for muscovites it is between 16.66 and 82.36 indicating that the pegmatites are moderately evolved. The Ta versus Cs and the Ta versus K/Cs discrimination diagram indicates that all the investigated pegmatites plot above the 20 ppm threshold suggesting that the pegmatites have potential for Ta and Nb mineralization.
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- Date Issued: 2014
Optimization of the vermidegradation of cow dung – waste paper mixtures
- Authors: Unuofin, Frank Oshioname
- Date: 2014
- Subjects: Biodegradation , Vermicomposting , Waste paper , Earthworm culture , Phosphatic fertilizers
- Language: English
- Type: Thesis , Doctoral , PhD (Soil Science)
- Identifier: vital:11966 , http://hdl.handle.net/10353/d1021276 , Biodegradation , Vermicomposting , Waste paper , Earthworm culture , Phosphatic fertilizers
- Description: Vermicomposting is an eco-friendly waste management strategy. Its successful performance necessitate that key functioning parameters like earthworm stocking density, nutrient enrichment be established for each target waste/waste mixture. One main target waste mixture in South Africa, and in the University of Fort Hare in particular is waste paper mixed with cow dung and rock phosphate (RP) for phosphorus (P) enrichment. This study was carried out to address the following specific objectives, to determine (i) the effect of Eisenia fetida stocking density on the bioconversion of cow dung waste paper mixtures enriched with rock phosphate, (ii) an optimum application rate of low grade South African Rock Phosphate and time required for efficient vermicomposting of cow dung-waste paper mixtures, and (iii) to determine if the phosphorus in RP is responsible for improved biodegradation during the vermicomposting of cow dung-waste paper mixtures. Results of this study revealed that bioconversion of cow dung waste paper mixtures enriched with RP was highly dependent on E. fetida stocking density and time. The stocking density of 12.5 g-worms kg-1 feedstock of the mixtures resulted in highest earthworm growth rate and humification of the waste mixture as reflected by a C: N ratio of < 12, polymerization index (PI) or humic acid/fulvic acid ratio of > 1.9, and a humification index of >13 for the cow dung waste paper mixtures. A germination test carried out also revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg-1 feedstock, suggesting that for maximum P release from RP enriched wastes, a high stocking density should be considered. Informed by an earlier study which demonstrated that RP improved vermidegration, a follow up study was done to determine the optimum amount of rock phosphate necessary for efficient vermidegradation of cow dung waste paper mixtures while ensuring a phosphorus rich vermicompost. The results showed that addition of RP at rates ≤ 1% P as RP efficiently enhanced the bioconversion of cow dung waste paper mixtures as reflected by low C: N ratio, high polymerization index (PI), HI and HR used as maturity indicators for matured compost. Final vermicompost products obtained at minimum amounts of RP application rates resulted highly humified vermicompost with finer morphological structure, with no inhibitory effect on the germination of tomato, carrot, and radish similar to the ones obtained at higher RP rates. The findings suggest that 1%P as RP application rate is optimum for efficient vermidegradation of cow dung waste paper mixtures. Since P or Ca happen to be the most prevalent elements in most rock phosphate used for compost enrichment, a study was carried out to determine if P or Ca in RP is predominantly responsible for the improved biodegradation of cow-dung waste paper mixture observed during vermicomposting. Phosphorus sources in form of triple superphosphate (TSP), phosphoric acid (PHA) and Ca in form of calcium chloride (CaCl2) salt were compared with rock phosphate. The results from the study indicated that TSP, a water soluble P source, resulted in greater and faster degradation of the waste mixtures than RP while the Ca source had the least effect. With TSP incorporation the compost maturity C: N ratio of 12 was reached within 28 days while RP, PHA and CaCl2 needed 42, 56 and more than 56 days, respectively. The results indicated that P was largely responsible for the enhanced bioconversion of the waste mixtures. This appeared linked to the effect of P to stimulate microbial growth as reflected by higher microbial biomass carbon levels where water soluble P sources were applied. The C: N ratios of the final vermicomposts at day 56 were 10, 11.5, 13, 14, and 23 for TSP, RP,PHA, Control (No P added) and CaCl2 treatments, respectively. Although TSP gave superior superior performance, RP may still be the preferred additive in the vermicomposting of cow dung waste paper mixtures as it is cheaper and produces mature compost in a shorter period of 8 weeks. Generally, the results of this study have shown that the vemidegradation of cow dung waste paper mixtures can be optimized through adoption of an E. fetida stocking density of 12.5g- worm kg-1 and an RP incorporation rate of 1% P as RP. However, higher rates of RPincorporation may be adopted where final vermicomposts with higher P fertilizer value are desired. Phosphorus appears to be the RP constituent responsible for its ability to enhance the vermidegradation of cow dung waste paper mixtures. Future studies should explore the effectiveness of other P-bearing minerals for their effectiveness in enhancing vemidegradation.
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- Date Issued: 2014
Perceived academic support of student nurses at a public nursing college in the Eastern Cape Province
- Authors: Sineke, Nqatyiswa
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11917 , http://hdl.handle.net/10353/d1016158
- Description: Academic support is critical in promoting success among student nurses. Support for student learning is a key element in optimizing student learning experiences, in any learning environment, and its importance has been widely discussed. Student academic support is closely related to motivation for learning, and helping students achieve their learning goals and objectives. Student nurses continue to struggle during their training, to the point of failing a year or being excluded from the course, in spite of the academic support provided through classroom facilitation, and remedial teaching provided by academic staff. They frequently complain that the course is difficult, the workload is heavy, and they are unable to integrate theory with practice. As a result they are too stressed, throughout their training. The purpose of this study is to explore and describe the perceptions of student nurses about the academic support provided to them at a public nursing college in the Eastern Cape Province. This study was guided by the Caring Curriculum Model, based on Watson‟s Theory of Caring. The core of this theory is the implementation of ten carative factors to promote health and equilibrium. Caring was endorsed as a core value in nursing education and practice, by the National League of Nursing and the American Association of Colleges of Nursing, while the centrality of a caring-healing relationship was recognized as a basis for all health professional education by the Pew Health Professions Commission. A quantitative approach, using a descriptive and explanatory design, was used to determine the perceptions of student nurses on the academic support they received from the public nursing college. Participants were selected by a simple random sampling method. A total of 189 student nurses, who registered for the 4-year diploma programme at the East London Campus of the Lilitha College of Nursing, participated in the study. Self-report data was collected by means of the Academic Support questionnaire, using a Likert scale which addressed both the performance and importance of academic support. Data were analysed using Statistical Analysis Systems version 9.3, using mean tables and graphical data analysis. The findings revealed high performance ratings for aspects relating to academic advising and teaching-learning process, indicating that there is satisfaction among students on these service attributes. Poor performance ratings were identified, relative to campus support services, indicating that student nurses were not happy with the availability and accessibility of library resources, and computer and internet services. Student nurses, at the college under study, were also not happy with aspects of service excellence relating to campus-based health care facilities, and personal student counselling services. The study identified a gap between the perceived performance and the importance of academic support at the nursing college, as the general performance was rated lower than the importance of academic support. The findings suggest the necessity for improved library facilities and resources, healthcare and counselling services and the establishment of student support programmes, to build the capacity of students and to enhance their chances of success.
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- Date Issued: 2014
Perceptions of rural consumers on behaviour and beef quality of cattle slaughtered for traditional ceremonies in the Eastern Cape of South Africa
- Authors: Soga, Sizwe William
- Date: 2014
- Subjects: Meat -- Quality , Consumers' preferences , Consumers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11833 , http://hdl.handle.net/10353/d1019812 , Meat -- Quality , Consumers' preferences , Consumers -- South Africa -- Eastern Cape
- Description: The objective of the study was to determine perceptions of the consumers on how they judged behaviour and beef quality of cattle slaughtered for traditional ceremonies in the Eastern Cape Province of South Africa. A survey was conducted where a sample of 200 consumers were randomly selected and interviewed. Fifty non-descript cattle were slaughtered during traditional ceremonies and two hundred and twenty four (224) cattle were slaughtered at 3 through-put abattoirs (high, medium and low). Meat quality attributes were determined from the cattle slaughtered for traditional ceremonies and from cattle slaughtered at the abattoirs. Data for questionnaires was summarized as frequencies for each ceremony and statistical differences were analysed using chi square test (X2). The effect of Age, breed and sex on beef pH, colour, meat tenderness, temperature and cooking loss of cattle slaughtered during traditional ceremonies, at low, medium and high throughput abattoirs were analyzed using General Linear Model (PROG GLM) of SAS (2003). There was a significant age effect (P < 0.05) on beef tenderness and cooking loss of cattle slaughtered for traditional ceremonies. Age of cattle that have milk teeth to 1 year and age of 6 years to 8 years had an effect on the beef tenderness (25.55 ± 8.05) and cooking loss (48.00 ± 4.26) of cattle slaughtered for traditional ceremonies in Table 4.1. There was no significant sex effect on beef tenderness and cooking loss of cattle slaughtered for traditional ceremonies. Non-descript and Angus cattle slaughtered at low throughput abattoir had an effect on the colour of the beef in Table 4.2. The lightness (27.49 ± 2.53) and yellowness (21.16 ± 0.79) of the beef shows that there was a significant breed effect on cattle that are slaughtered at Low throughput abattoir, however redness of the meat was not affected by breed after slaughter. Cattle that are slaughtered at high throughput abattoir between ages of 6 to 8 years and also cattle that are more than 8 years in Table 4.4 had an effect on cooking loss (p < 0.05). Age between 6 to 8 years had an effect on the beef tenderness from cattle that are slaughtered at medium throughput abattoir. It was concluded that the meat tenderness of the young cattle with milk teeth slaughtered for traditional ceremonies was affected. On the other hand the meat tenderness and cooking loss of beef from the cattle slaughtered from low, medium and high throughput abattoir were affected by sex and breed mostly.
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- Date Issued: 2014
Perinatal experiences of pregnant undergraduate students of a higher education institution in the Eastern Cape
- Authors: Simandla, Linda
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11913 , http://hdl.handle.net/10353/d1016125
- Description: Unplanned pregnancies among students are increasing annually. There are cases of students giving birth by themselves in the rooms within higher education institution residences unsupervised. Unsupervised births put the students at health risk as birth can complicate or even lead to death. The purpose of this study was to explore the perinatal experiences of undergraduate students whilst a pregnant student. In this study the researcher used a qualitative phenomenological approach within interpretive realism. The study was exploratory focusing on the need to understand how students experience perinatal care. Population for this study comprised of undergraduate students that had been pregnant within their undergraduate program which normally takes three to four years and were staying in the higher education institution residence at the time of pregnancy. A snowball sample was used. Data was collected from participants using unstructured in-depth interviews. For the study a total of 9 students were interviewed. Data was collected in English and Xhosa depending on preference. During pilot interviews the researcher established that the participants had difficulty in expressing themselves in English and used slang in spite of being registered for a degree. The interviews were conducted by the researcher and the data tape recorded. Permission to conduct a study at the higher education institution was sought from the Vice- chancellor, the Dean of Students and Research Ethics Committee To ensure trustworthiness of the study credibility, transferability, dependability and confirmability were adhered to. Four themes with several sub-themes emerged which were: Dynamics on awareness about existence of pregnancy. Support system for female students pertaining to reproductive health. Encountered psychosocial experiences. Coping strategies used by pregnant students. Excerpts were used to support the interpretation of perinatal experiences of the undergraduate students. Recommendations to the management of the higher education institution are to develop guidelines that ensure implementation of the pregnancy policy.
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- Date Issued: 2014
Preparation and characterisation of nanocomposites of biomass and montmorillonite clay for use as biofuels
- Authors: Nyamutswa, Lavern Tendayi
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: vital:11345 , http://hdl.handle.net/10353/d1019779
- Description: The aim of the study was to prepare composites of clay and biomass which burn longer than unmodified biomass. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified forms of the clay with sawdust. The three forms of clay used for the formation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. The solution blending method was used to make the nanocomposites. FT-IR and XRD analysis showed that organic surfactant increases the interlayer space of the clay since it is bulkier than the inorganic cations that are naturally present in the interlayer space of montmorillonite. The combination of clay and sawdust resulted in the formation of exfoliated nanocomposites as shown by the absence of peaks in the low 2 theta angle in the x-ray diffraction data of the nanocomposite. The nanocomposite which was made from sawdust and 1% organically modified clay showed the best results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.
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- Date Issued: 2014
Prevalence and pathogenicity of vibrios in treated final effluents of selected wastewater treatment plants in the Amathole District Municipality of Eastern Cape Province of South Africa
- Authors: Badela, Andiswa Unathi
- Date: 2014
- Subjects: Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11284 , http://hdl.handle.net/10353/d1019774 , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis
- Description: Waterborne diarrhoeal infections continue to be a major health setback in developing countries, especially in rural areas which lack adequate supply of portable water and sanitation facilities. Globally, waterborne diarrhoeal infections occur with an estimated mortality rate of 10–25 million deaths per year, 95% of which are children under the age of 5 years. The Vibrio species is one of the major groups of enteric pathogens that are responsible for diarrhoeal infections. Many strains of these bacterial species continue to cause epidemics of diarrhoea throughout the world. In this study, the prevalence of Vibrio pathogens in wastewater final effluents was assessed. Wastewater final effluent and discharge point samples were collected monthly between September 2012 and August 2013. All samples were collected aseptically using sterile 1 L Nalgene bottles containing 0.5 ml of sterile sodium thiosulphate solution and transported on ice to the laboratory for analyses within 6 h of collection. The membrane filtration method was used for enumeration of presumptive Vibrio densities on thiosulfate citrate bile salt (TCBS) agar plates. Polymerase chain reaction (PCR) was then used to confirm the identities of the presumptive Vibrio species using the species-specific primers. The confirmed isolates were further subjected to molecular characterization to confirm their respective pathotypes. Presumptive Vibrio densities varied from 0 to 2.11 × 102 cfu/100 ml. Out of 300 confirmed Vibrio isolates; 13.3% (40/300) were Vibrio fluvialis, 22% (66/300) were confirmed to be Vibrio parahaemolyticus, and 24.7% (74/300) proved to be Vibrio vulnificus, and 40% (120/300) were other Vibrio species which were not assessed for in this study. The strains of Vibrio fluvialis were found to exhibit 100% resistance to Polymixin and Tetracycline. However, Gentamicin was active against all the three Vibrio species selected for the purpose of this research. The recovery of Vibrio species in the discharged effluents throughout the sampling period even in adequately disinfected effluents is not acceptable considering the fact that Vibrio is a pathogenic bacterium. The findings of this study underline the need for constant monitoring of the microbiological qualities of discharged effluents and might also be suggestive for a review of the disinfection methods used at the treatment works.
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- Date Issued: 2014
Prevalence of pathogenic Escherichia coli strains in the final effluents of four wastewater treatment plants in the Eastern Cape Province of South Africa
- Authors: Seti, Nozuko Zukiswa
- Date: 2014
- Subjects: Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11286 , http://hdl.handle.net/10353/d1019808 , Escherichia coli -- South Africa -- Eastern Cape , Bacterial diseases -- Pathogenesis , Sewage -- Purification -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Whole effluent toxicity testing -- South Africa -- Eastern Cape
- Description: Water is an essential need that stimulates health and well being. Increase in population size and urbanization negatively affect water resources due to high demands of effluent outputs. Wastewater is an important reservoir for Escherichia coli and can present significant acute toxicity if released into receiving water sources without being adequately treated. E. coli is used as indicator organism for the detection of faecal contamination. These strains have been considered to be one of the primary causes of diarrhoeal infections worldwide. The present study was conducted between September 2012 and June 2013 to assess the prevalence of pathogenic E. coli strains in the final effluents of four wastewater treatment plants in Chris Hani and Buffalo City Municipalities in the Eastern Cape Province of South Africa. Standard membrane filtration technique was used for bacteriological analysis and molecular based technique was used for identification of E. coli pathotypes. The results were recorded in colony forming units/100 ml. Faecal coliforms ranged between 0-9.6×10³ CFU/100 ml for the wwtp-Q and E. coli densities ranged between 0-8.4×10³ CFU/100ml. Faecal coliforms ranged between 4×10²-9.7×10³ CFU/100 ml for wwtp-M and E. coli densities ranged between 1.2×10¹-8.4×10³ CFU/100 ml. The wwtp-E showed to have bacterial counts of faecal coliforms ranging between 4.0×10³-8.2×10³ CFU/100 ml and E. coli densities ranging between 3.5×10¹-7.1×10³ CFU/100 ml. The WWTP-K in this study was only assessed for the presence of E. coli. Faecal coliforms were assessed by the other members of the group. This plant showed to have E. coli densities ranging between 0-7.5×10²CFU/100 ml. A total of 200 presumptive E. coli isolates were subjected to screening by conventional PCR in which (29%) of the wwtp-M isolates were positively identified as E. coli, (16%) of the wwtp-K, (22%) of the wwtp-Q and (34%) of the wwtp-E isolates were positively confirmed as E. coli. A total of 100 randomly selected E. coli isolates were characterised into different pathotypes. (16%) of positive isolates were detected as EPEC and 11% were detected as UPEC strains. There was no detection for the ETEC strains. Antibiotic susceptibility patterns of E. coli strains showed high levels of resistance to Penicillin G, Erythromycin, Tetracycline and Sulfamethoxazole. High levels of Susceptibility were observed in antibiotics such as Chloramphenicol, Amoxicillin and Tetracycline. The results of this study reveal that the plants were above the recommended Standard limit of zero CFU/100 ml for effluents meant to be discharge into receiving water sources. This study reveals inadequacy of the plants studied to produce effluents of acceptable quality.
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- Date Issued: 2014
Professional nurses’ perceptions on quality patient care in one of the Eastern Cape state hospitals
- Authors: Somahela, Khanyisa Judith
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11353 , http://hdl.handle.net/10353/d1021141
- Description: The focus of this study was to explore the perceptions of professional nurses in the quality of care rendered by nurses in the public hospitals. Nursing is a challenging, demanding, and yet fulfilling profession, whose goal is to provide quality care to individuals, families and communities. However, there are inconsistencies regarding the quality of care rendered by nurses in the public hospitals. The media and the public portray nurses as providing poor quality care in the health care facilities. Conversely, the nurses view that they are doing their best, considering the challenging circumstances under which they work in public institutions.The study followed a qualitative approach and an exploratory descriptive design. A purposive sample of 13 professional nurses participated in the study. The sample size was not pre-determined. Data were collected until data saturation, when the interviews yielded no new information. The study was conducted in a state hospital in the Eastern Cape, using an interview guide. Responses were recorded using a tape recorder. No incentives were given to participants. Data were collected and analysed following the Tesch’s method. Prior to conducting the study, the researcher obtained ethical clearance from the University of Fort Hare research ethics committee. The perceptions of the professional nurses who participated in this study were inconsistent. The majority pointed out that the quality of patient care was deteriorating which means the patient care is poor. whereas some participants indicated that the quality of patient care was still the same; it had not changed or deteriorated, The contributing factors to the poor quality patient care were indicated as; shortage of staff, shortage of resources such as equipment, inadequate empowerment of staff, insufficient training of students, staff arriving late for duties, lack of passion their work, skipping and missing of routines, support service that was not working hand in hand with the nursing staff, increased hospitalization of patients and the Eastern cape Department of Health failing to remunerate the nurses as promised.
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- Date Issued: 2014
Quality indices of the final effluents of two sub-urban-based wastewater treatment plants in Amathole District Municipality in the Eastern Cape Province of South Africa
- Authors: Gcilitshana, Onele
- Date: 2014
- Subjects: Whole effluent toxicity testing -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape , Effluent quality -- Testing , Viruses -- South Africa -- Eastern Cape , Water reuse -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11288 , http://hdl.handle.net/10353/d1019816 , Whole effluent toxicity testing -- South Africa -- Eastern Cape , Sewage disposal plants -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape , Effluent quality -- Testing , Viruses -- South Africa -- Eastern Cape , Water reuse -- South Africa -- Eastern Cape
- Description: Worldwide, water reuse is promoted as an alternative for water scarcity, however, wastewater effluents have been reported as possible contaminants to surface water. The failure of some wastewater treatment processes to completely remove organic matter and some pathogenic microorganisms allows them to initiate infections. This manifests more in communities where surface water is used directly for drinking. To assess water quality, bacteria alone cannot be used as it may be absent in virus-contaminated water. This study was carried out to assess the quality of two wastewater treatment plant effluents from the Eastern Cape Province of South Africa. Physicochemical parameters and microbiological parameters like faecal coliforms, adenovirus, rotavirus, hepatitis A virus, norovirus and enterovirus were evaluated over a projected period of one year. Physicochemical parameters were measured on site using multiparameters, faecal coliforms enumerated using culture-based methods and viruses are detected using both conventional and real-time PCR. Physicochemical parameters like electrical conductivity, turbidity, free chlorine and phosphates were incompliant with the standards set by the Department of Water affairs for effluents to be discharged. Faecal coliform counts were nil for one plant (WWTP-R) where they correlated inversely (P < 0.01) with the high free chlorine. For WWTP-K, faecal coliforms were detected in 27% of samples in the range of 9.9 × 101 to 6.4× 104 CFU/100ml. From the five viruses assessed, three viruses were detected with Rotavirus being the most abundant (0-2034176 genome copies/L) followed by Adenovirus (0–275 genome copies/L) then Hepatitis A virus (0–71 genome copies/L) in the WWTP-K while none of the viruses was detected in WWTP-R. Species B, species C and Adv41 serotypes were detected from the May 2013 and June 2013 samples where almost all parameters were incompliant in the plant. The detection of these viruses in supposedly treated effluents is suggestive of these being the sources of contamination to surface water and therefore renders surface waters unsafe for direct use and to aquatic life. Although real-time PCR is more sensitive and reliable in detection of viruses, use of cell-culture techniques in this study would have been more efficient in confirming the infectivity of the viruses detected, hence the recommendation of these techniques in future projects of this nature.
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- Date Issued: 2014
Resting site ecology and microhabitat use of the Mozambique thicket rat (Grammomys cometes) in a riverine Combretum forest
- Authors: Gebe, Zimkhitha
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11794 , http://hdl.handle.net/10353/d1019768
- Description: Very little is known about the resting and spatial ecology of the Mozambique thicket rat, Grammomys cometes, a rodent species distributed in two disjoint populations in South Africa and Mozambique. The present study focused on determining the characteristics and usage patterns of resting sites, as well as the microhabitat use and selection of this species during its activity period. Broadly, I predicted that resting ecology and space use would be affected by environmental, climatic, social and sexual factors. I also hypothesized that predatory risk could affect thicket rat behaviour. Field work took place in the Great Fish River Reserve complex (Eastern Cape Province, South Africa), in a stretch of riverine Combretum forest (length × breadth: ca. 500 × 100 m) located in the western section of the conservation area. Overall, 38 different rats (22 males and 16 females) were trapped and radio-tracked for varying periods between July 2011 and November 2012. Individual rats used a mean of 2.54 1.89 different resting sites (range: 1–9) during each tracking session and resting-site fidelity averaged 85 17%. Overall, 27% of the 131 resting sites identified were artificial wooden nestboxes, 45% were inside branches, 21% were inside trunks, 3% were located on the ground, 2% in bushes, 1% inside dead logs, with one uncertain location (1%). Cape bushwillows Combretum caffrum were the predominant trees (60.32%) used for the resting sites, probably due to their abundance in the forest, and their propension to rot from the inside and provide natural cavities. The mean height of resting sites used by thicket rats was 217 119 cm, and the mean circumference of branches and trunks was 79 35 cm, with no seasonal and sexual variation. In contrast, males exhibited an overall lower percentage usage of individual resting sites than females, probably due to their increased movements during the long mating season. Percentage usage was significantly higher during the cold season, likely for thermoregulatory seasons. Nearly 50% of the resting sites were shared with an average ( SD) of 3.20 1.25 individuals (range: 2–6). However, simultaneous use of resting sites only took place in about 8% of locations. Sharing involved 2–3 males in 90% of the cases. It is suggested that females are solitary but not territorial, while at least some males are more social or tolerant towards each other, and have overlapping ‘home ranges’. These observations could be indicative of a promiscuous mating system. v Microhabitat use and selection were determined by conducting a 5-day trapping session during each season between June 2011 and May 2012. A grid of 96 stations (16 rows 6 lines) was set at the study site, with pairs of traps per station placed at 10-m intervals, at different heights and on different types of vegetative stands. Several variables describing microhabitat structure were recorded seasonally at each station. Thicket rats (38 individuals captured 91 times) were captured mostly at night, with an overall trapping success of 2.16 0.27% over the year. The average height at which rats were trapped (140 65 cm) was significantly higher than the height of traps set in the field (99 ± 75 cm). A large proportion of traps (31.3%) where rats were caught were placed on Combretum caffrum trees, and majoritarily on trunks (46%), tree canopy (19%) and woody lace (19%). Bonferroni Z tests indicated that thicket rats actively avoided trap stations with less than 50% canopy cover as well as areas that had arboreal connections in less than 50% of the directions. Rats also significantly avoided traps that were set in bushes and on the ground, irrespective of whether these were situated in open terrain or surrounded by some vegetation. Generalized Linear Models confirmed that two main predictors (Cover >150 cm and height) had a significant positive effect on the use of traps and on the numbers of visits to, and different animals caught at, trapping stations. All other variables, including connectivity with the surrounding vegetation, tree species, vegetation type and position in which the traps were placed, and tree trunk/branch circumference at trap height, did not have any significant effects. This study confirms that thicket rats are essentially nocturnal, arboreal and prefer dense canopy cover, possibly because this decreases predation risk at the microhabitat level.
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- Date Issued: 2014
Risk preferences of smallholder irrigation farmers in the former Ciskei homelands of the Eastern Cape Province, South Africa
- Authors: Itumeleng, Mathlo
- Date: 2014
- Subjects: Risk-return relationships -- South Africa -- Eastern Cape , Crops -- Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11214 , http://hdl.handle.net/10353/d1016206 , Risk-return relationships -- South Africa -- Eastern Cape , Crops -- Irrigation -- South Africa -- Eastern Cape , Irrigation farming -- South Africa -- Eastern Cape
- Description: Although several studies have investigated on commercial farmers’ risk preferences, there is still lack of information on the risk attitudes and risk preferences of smallholder farmers in South Africa. Risks associated with the adoption of new agricultural technology need to be explored in order to address the transition from homestead food gardening to smallholder irrigated farming. This study seeks to understand risk perception of smallholder irrigation farmers by linking constraints to commercialisation, adoption of new agricultural technologies and risk preferences of smallholder farmers in the former Ciskei Homelands of the Eastern Cape. A total of 101 respondents were surveyed, consisting of 38 smallholder farmers and 63 homestead food gardeners in the Eastern Cape. Questionnaires were used to record household activities, socio-economic and institutional data as well as household demographics through personal interviews. The probit results indicated that older farmers are less risk averse thus more willing to take risk. The risk analysis indicates that farmers who are employed elsewhere are more willing to take risk as income is playing a major role in risk preferences. The results also prove that factors such as tenure system and years in farming have a major influence on farmers’ decision to take risk and adopt new agricultural technology. According to the multi-logit model the major factors influencing technology adoption and risk taking are household size, water rate and type of irrigation system used by the farmers. This study provides useful practical insights for policy makers, farm advisers and researchers in the design of effective and efficient policies, programmes and projects which can affect the adoption of technology, increase smallholder farmers capacity to manage risk and drive growth in the food market.
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- Date Issued: 2014
Rural households livelihood strategies in communities around the Fort Hare and Middle Drift rural dairy projects in Eastern Cape Province South Africa
- Authors: Mukotami, Samuel
- Date: 2014
- Subjects: Households -- Economic aspects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11228 , http://hdl.handle.net/10353/d1021132 , Households -- Economic aspects -- South Africa -- Eastern Cape , Sustainable development -- South Africa -- Eastern Cape , Dairy farming -- South Africa -- Eastern Cape
- Description: In this study, rural households livelihood strategies in communities around Fort Hare and Middle Drift dairy projects in the Nkonkobe Municipality are explored from a household perspective. Rural communities around Fort Hare and Middle Drift dairy projects in Eastern Cape, South Africa are found choosing a multiple of livelihood portfolios that are linked to dairy project activities to increase food, generate income, and safeguard against risks and shocks. The dairy projects in rural areas can reduced the problem of shrinking livelihood options in rural areas were most of the households are relying on government grants which has characterised the rural areas with long queues during month ends. The main objectives of this study are, to assess whether the rural dairy projects set goals are being achieved; to identify dominant livelihood strategies of households living around dairy projects in Eastern Cape Province, South Africa and to identify determinant factors influencing rural households around dairy projects to choose certain livelihood strategies that improve their welfare. The study analysed socio-economic survey data that had been collected from households in six rural villages in Nkonkobe Municipality surrounding the Fort Hare and Middle drift dairy projects. The stratified and random sampling method was used. The descriptive analysis comparing the livelihood portfolios’ in the six rural villages around Fort hare and Middle Drift dairy projects has revealed that there is an increasingly important role of the non-farm economy in the area (income from activities not linked to farming) as compared to farming, non-labour (income from remittances and government grants) and non-farm activities that are combined with farming (non-farm and farming activities). The multinomial logistic regression model revealed, with respect to the household variables, social-economic and institutional related variables as some of the barriers faced by poor households in rural areas sharing boundaries with rural dairy projects to enter into various livelihood strategies. Results from this study outlined that rural communities around dairy projects do not rely much on one livelihood pathway but they link multiple strategies together to improve their standard of living. The study, therefore, conclude that rural dairy projects with activities that are complementing with rural livelihood pathways available can be trusted as a reliable and sustainable livelihood source to reduce poverty in communities which share boundaries with rural dairy projects.
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- Date Issued: 2014
Socio-economic contribution of community food gardens to the livelihoods of rural households in Lepelle-Nkumpi local municipality of Limpopo province, South Africa
- Authors: Malahlela, Nkele Dorcus
- Date: 2014
- Subjects: Community development -- South Africa -- Limpopo , Rural development -- South Africa -- Limpopo , Food security -- South Africa -- Limpopo , Food crops -- South Africa -- Limpopo
- Language: English
- Type: Thesis , Masters , MSc Agric (Agricultural Economics)
- Identifier: vital:11238 , http://hdl.handle.net/10353/d1021330 , Community development -- South Africa -- Limpopo , Rural development -- South Africa -- Limpopo , Food security -- South Africa -- Limpopo , Food crops -- South Africa -- Limpopo
- Description: Community food gardens are regarded as a means through which rural households can improve their livelihoods. This study explores the contribution of community food gardens (CFG) to livelihoods in the Lepelle-Nkumpi local municipality in the Limpopo province. The objectives of this study are, firstly to explore the reason behind CFG participation and the reasons behind the participating possibility. Secondly, the study seeks to identify the socio-economic factors influencing the participation of households in CFG and lastly to determine the influence of CFG and other socio-economic variables on household food security status (HFSS). Descriptive statistical analysis was used to describe the socio-economic characteristics and the reasons behind CFG participation and the reasons behind the participating possibility. The binary logistic regression model was used to analyse the determinants of household participation in community food gardens as well as the contribution of CFG to HFSS on Statistical Package for Social Science (SPSS) software version 21. Through a structured questionnaire, data was collected from a sample of 180 households which was obtained using multistage sampling. Descriptive results on the characteristics of sampled households revealed that there are high levels of food security in the area with 70% being food secure of which around 42.2% are CFG participants and 30% are food insecure. Furthermore the descriptive statistical analysis indicated that participation of households in CFG is mainly to obtain a source of food among the CFG participants and to generate income amongst the non-participants. On the basis of descriptive analysis, this study concludes that source of food and income generation respectively are the main reasons behind CFG participation and the possibilities of becoming a participant. Therefore the study accepts the research hypothesis stating that “There are social and economic reasons behind household participation and the possibilities of participating in CFG”. Binary results for the determinants of CFG participation revealed that socio-economic variables such as household size, farm income, household monthly income, land size, household perception, marital status, agricultural training and homestead gardening significantly influence household decisions to participate in CFG. This is an implication that socio-economic variables tested in this study are significantly influential to the household decision to participate in CFG, leading to the acceptance of the first hypothesis which states that “Socioeconomic factors determine the community food garden ownership or participation”. The results of the contribution made by CFG to HFSS showed that socioeconomic variables such as gender, age, household size, farm income, educational level, household monthly income, marital status, information access, formal employment status and CFG involvement significantly affect household food security status in the study area. The result indicates a positive contribution to HFSS and implies that socio-economic variables tested in this study have a significant influence on HFSS, leading to the acceptance of the second hypothesis which states that “Community food gardens have a positive effect on food security status of household in Lepelle-Nkumpi Local Municipality Limpopo province.” Therefore it is relevant to concluded that in the area of Lepelle-Nkumpi local municipality, social economic factors plays a vital role in the participation of households in CFG as well as improving the state household food security status.
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- Date Issued: 2014
Socio-economic importance, health and welfare aspects of donkeys (Equus asinus) used for carting in a peri-urban area of South Africa
- Authors: Marufu, Madure
- Date: 2014
- Subjects: Donkeys -- South Africa , Animal welfare , Donkeys -- Handling , Donkeys -- Health
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11832 , http://hdl.handle.net/10353/d1019781 , Donkeys -- South Africa , Animal welfare , Donkeys -- Handling , Donkeys -- Health
- Description: The broad objective of the study was to determine the socio-economic importance, health and welfare aspects of donkeys used for carting in a peri-urban area. A survey was conducted among 71 donkey owners in Joza, a peri-urban area near Grahamstown in the Eastern Cape Province (ECP) of South Africa to investigate their perceptions on socio-economic importance, health and welfare aspects of donkeys used for transport. Two hundred and seventy-one donkeys used for carting were assessed through direct observation of health and behaviour parameters to determine their welfare status. Results revealed that donkeys are indeed of immense value to people, being used daily (54.93%) for income generation activities and at least once per month (7.08%) for domestic chores. Most of the respondents (32%) earned R 600.00 per week while 11% earned at least R 200.00 per week from carting using donkeys. Donkeys were used for carting of goods (90.14%) more than for manure (16.9%). Gender and age of owners significantly (P < 0.05) influence perceptions on source of income while education level influenced their perceptions on carting firewood, goods and water. Results on management practices and health problems encountered by working donkeys showed that most of the owners managed their animals poorly. Most donkeys were being beaten (74.65%) during work, made to travel long distances (43.66%), worked long hours (52.11%) without adequate water (59.10%) and feed supplements (83.10%). Wounds (95.97%), coughing (75.65%) and lameness (64.79%) were some of the health problems encountered by donkeys. Significant relationships (P ˂ 0.05) were observed between owners’ perceptions on management practices and health problems encountered by donkeys. Among the observed animals, 61% were thin and mostly apathetic (26.2%) than medium and fat animals. Responses to observer approaches were significantly associated with sex and body condition score (BCS), with stallions in good body condition being more aggressive. Donkeys having a BCS of 3-5 avoided chin contact either by kicking out or moving away. Results further showed that most of the donkeys were suffering from external injuries, with the hindquarters (39.85%), shoulder (32.10%) and spine (21.77%) being the mostly affected areas. The prevalence of wounds on tail-base, belly, flank and neck were seen in less than 13% of the animals. The prevalence of wounds was influenced by age and BCS of the animals. Young donkeys with good BCS were less affected than old donkeys. Lameness, poor coat condition, external parasites, abnormal mucous membrane and dental problems were observed in less than 30% of the animals. It was concluded that donkeys play a pivotal role economically and socially to the livelihoods of people in a peri-urban area (Joza) in terms of income generation and transportation. However, these animals are experiencing multiple health and welfare problems. Therefore, more access to veterinary services, training on donkey use and management, health and welfare promotion programs are of paramount importance in solving the problem of poor health and welfare in donkeys.
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- Date Issued: 2014
Stratigraphy and sedimentology of the Mzamba formation in the Eastern Cape, South Africa
- Authors: Susela, Zamampondo
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11529 , http://hdl.handle.net/10353/d1019807
- Description: This research project is aimed at providing new information to the stratigraphy, sedimentology, palaeontology and diagenesis of the Mzamba Formation. The study area is located at the south of Port Edward, Eastern Cape. The methodologies employed in this study include field geological investigation and sampling, stratigraphic measurement and logging, thin-section microscope study, powder samples of XRD analysis, and SEM-EDX analysis of rock textures and mineral compositions. The stratigraphy of the Mzamba Formation can be divided into three newly established members, i.e. the Lower Conglomerate Member, Middle Silt/Mudstone-Shell Bed Member and Upper Mudstone-Shell Bed Member with a total thickness of 31.26m in an inland borehole and 30.05m in the field measurement. The Lower Conglomerate Member is 2.65m thick and consists of pebbly conglomerate with coarse sandstone, shell fragments and silicified wood trunks, representing shallow marine nearshore deposits. The Middle Silt/Mudstone and Shell Bed Member is 9.5 m thick and consists of black mudstone and fine-grained siltstone alternated with medium grained pecten beds, which was deposited in a storm influenced deeper marine environment. The Upper Mudstone-Shell Bed Member is 17.9m thick and is made up of fine-mudstones with articulated pecten layers which were deposited in a deep and quiet marine environment. Petrology studies showed that the Mzamba Formation consists of mixed sediments of carbonate and siliciclastic rocks. Siliciclastic rocks include pebbly conglomerates, medium to coarse sandstones and fine-grained mudstones, whereas carbonate rocks include packstone, wackstone and grainstone (pecten beds). The formation shows cyclical pattern of a series fining-upward cyclicities, changing from bottom conglomerate to sandstone, then upward repeated series of cyclotherms from pecten bed to mudstone. Mineralogy of the Mzamba Formation consists of terrigenous minerals of quartz, orthoclase, plagioclase, muscovite and various igneous and metamorphic rock-lithics, clay minerals of smectite, illite and sericite, and carbonate minerals of calcite and dolomite; with minor diagenetic minerals of pyrite, glauconite, hematite, gypsum, albite and organic maceral of vitrinite. Heavy minerals of garnet, zircon and rutile are minor minerals in the strata, which were detrital in origin. Mzamba Formation is a fossiliferous sequence, and contains both fauna and flora fossils in the strata. The pecten beds host well-preserved bivalve, gastropod, brachiopoda, ammonite, and echinoderm; whereas trace fossils of coprolites, burrows and tracks, as well as plant fossils of silicified wood trunks were also found in the formation. Some new fossil species were collected and studied, which include Bivalve: Pteriaceae, Pinnacea and Ostreacea; Gastropod: Cerithiacea and Mesogastopoda; Echinoderm: Echinocystoidea and Crinoidea. The benthonic species predominate in the lower part in the succession, whilst the planktonic species are abundant in the upper part of the sequence, which points to increase in water depths of the depositional environment. Based on lithology, sedimentary structures, and stratum architecture, seven different facies have been distinguished. Facies A (Flat bedded pebbly conglomerate), Facie B (Cross-bedded coarse calcareous sandstone facies), Facies C (Burrowed sandstone facies), Facies D (Shell-fragmental fine-grained calcareous sandstone facies), Facies E (Horizontal bedded calcareous mudstone facies), Facies F (Calcareous patch reef), Facies G (Wash out reef facies). Wash out reef facies is rich in algae, bivalve shells, broken oysters, coral fragments and small pebbles. Four types of cements were found in the Mzamba Formation, including calcite, smectite, illite and quartz. Calcite cement can be further classified into two types, micrite calcite cement and sparite calcite cement. The clay cement consists of smectite and illite and mainly occurs as matrix. The isopachous rim calcite and bright isopachous rim of silica cements indicate diagenesis in a marine phreatic zone. Authigenic minerals which formed in early diagenetic stage include quartz, plagioclase, glauconite and organic maceral of vitrinite. Three stages of diagenesis have been recognised in the sequence, i.e. syndiagenesis, early and late diagenesis. Glauconite pellets and worm faecal pellets were formed in syndiagenetic stage; cementation and authigenic minerals were formed in early diagenetic stage; whereas clay mineral conversion of smectite to illite, quartz overgrowth, bioclast recrystallization and calcite replacement took place during late diagenetic stage. The pebbly conglomerate at the bottom of the Mzamba Formation represents high energy deposits in a shallow marine environment; the grain-size gradually becomes finer in the middle succession and finest mudstone facies at the top of the succession, which represents deep marine deposits. Meanwhile, benthonic fossils are dominant in the bottom succession while plankton fossils are more abundant in the top succession. These features indicate that the Mzamba Formation constitutes a perfect transgression sequence, and the depositional environments started from shallow marine near shore environment, and gradually shifted to a deep marine quiet water environment.
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- Date Issued: 2014
Stratigraphy, sedimentary facies and diagenesis of the ECCA group, Karoo supergroup in the Eastern Cape, South Africa
- Authors: Nyathi, Nonhlanhla
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11528 , http://hdl.handle.net/10353/d1019776
- Description: This is a MSc research project, and is aimed at the new insight on the stratigraphy, sedimentary facies, diagenesis and depositional environments of the Ecca Group, Karoo Supergroup in the Eastern Cape Province. Methodologies used in this research include field investigation, stratigraphic logging, thin-section microscope study, X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. The stratigraphy of the Ecca Group is divided into five formations, namely the Prince Albert Formation, Whitehill Formation, Collingham Formation, Rippon Formation and the Fort Brown Formation from bottom upward. Based on the field investigation and laboratory correlation, the Prince Albert, Whitehill, Collingham, and Fort Brown Formations can each be subdivided into two new members, i.e. lower member and upper member; whereas three new members have been proposed for the Rippon Formation, i.e. lower, middle and upper members. The Ecca Group sediments were accumulated in various depositional environments, from bottom of deep marine environment, passed through the middle of deltaic environment, and ended in a lacustrine environment. The Prince Albert Formation, Whitehill Formation and the Collingham Formation were all deposited in a deep marine basin, whilst the Rippon Formation was laid down in a deltaic environment. As the climate gradually became warmer and drier, the top Fort Brown Formation was lastly deposited in a lacustrine environment. The stratigraphic succession of the Ecca Group constitutes a perfect regression sequence, indicating that the marine water gradually retreated and the sea-level gradually dropped. The rocks in the Ecca Group are mainly terrigenous sandstone and mudstone with some coarse grain-sized siliciclastic rock of conglomerate. The sandstones are dominated by feldspathic graywackes with minor quartz-wackes, and there are no arenites in the Ecca Group. Whereas the mudstones are dominated by grayish mudrocks and black shales, purer claystone was found in the turbidite facies of the Collingham Formation, which probably has economic significance for the future since the reserve is quite large. Optical microscope, XRD and SEM analyses demonstrated that the minerals in the Ecca Group include detrital minerals of quartz, orthoclase, microcline, plagioclase, biotite, muscovite; and clay minerals (smectite, kaolinite, illite and sericite). These minerals constitute the rock framework grains and cements whereas; the authigenic minerals of calcite and hematite were formed during diagenesis. Accessory minerals such as rutile and zircon are the heavy minerals present in the strata, and occur only in a small amount. Based on the lithologies, sedimentary structures and sequence stacking patterns, ten sedimentary facies have been recognised, namely 1) Grayish laminated and thin bedded shale facies, 2) Grayish laminated shale and intercalated chert facies, 3) Grayish rhythmite facies (all the three facies above were deposited in deep marine water); 4) Flat and lenticular bedded graywacke facies, 5) Grayish alternating mudstone and sandstone facies, 6) Dark organic rich mudstone facies, 7) Fossil bearing mudstone facies, 8) Laminated and thin bedded black mudstone with lenticular siltstone facies, 9) Interbedded grayish sandstone and mudstone facies (above Facies 4-9 were deposited in deltaic environment and appeared in the Rippon Formation); and 10) Varved rhythmic mudstone facies, which occurs only in the Fort Brown Formation and represents lacustrine sediments. Four types of cements have been identified in the rocks of the Ecca Group, including quartz, smectite, calcite and feldspar cements. The first three cement types are the major cement types, whilst the feldspar cement is minor and occurs only locally. Recrystallisation in Ecca sediments includes quartz, feldspar, clay mineral recrystallisation and conversion from smectite and kaolinite to illite and then to sericite. Replacement involves calcite replacing quartz, feldspar and clay matrix; accompanied by albitization, i.e. albite replacing other feldspar minerals in a deep burial environment. Dissolution in the Ecca Group involved calcite and kaolinite dissolving and leaching, which created more pore-space and increased porosity. The sediments of the Ecca Group went through three stages of digenesis, namely the early stage, the late stage and the up lift stage which led the rocks being exposed on the Earth’s surface and being weathered. In each stage, some minerals became unstable, then replaced by a more stable mineral suitable for the new diagenetic environment. Precipitation of cements and formation of authigenic minerals mostly occurred in the early diagenetic stage, which led the soft sediments becoming a hard rock; whilst recrystallisation, replacement, and dissolution took place mostly in the later diageneti
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- Date Issued: 2014
Structural, optical and electrical characterization of nano-sized c-tio2 quamtum dots synthesized by spray pyrolysis
- Authors: Taziwa, Raymond Tichaona
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11342 , http://hdl.handle.net/10353/d1016089
- Description: In the 21st century, scientific communities face challenges and opportunities concerning future development, where innovations must be a key driver over the past, evolution of African societies were based on incomplete models, only taking into account economical growth and not paying attention to environmental deterioration as a consequence of anthropogenic activity and environmental pollution. We have to learn from our past mistakes in order not to repeat them. Education and research of today as the embryonic stages of the development models of tomorrow should be directed toward a sustainable mentality. In this sense, solar energy technologies have emerged as key instruments for minimizing environmental impact as well as reducing economic cost in the field of renewable energies. Titanium dioxide is a fascinating low cost material exhibiting unique properties of stability and photo catalytic activities, leading to clean technologies in water purification and energy conversion of sunlight. However, conventional techniques (high temperature, high vacuum, high pressures) of processing titanium dioxide are a technological limitation due to excessive energy consumption. This poses a handicap for practical applications in areas such as preparation of hybrid organic/Titanium dioxide materials or devices on thermo flexible substrates such as plastic material. It is for this reason that the investigation presented in this Ph.D thesis deals with the development of spray pyrolysis techniques for preparation of carbon doped titanium dioxide nano powders for solar cell applications. This thesis is therefore structured as follows: Chapter 1 gives a general overview of the work done in this thesis. This work relies greatly on the excellent structural optical and electrical properties of TiO2 thin films, as well as its chemical resistance and insulating properties. A summary of the physical, optical, electrical and chemical properties reported in the literature, with an emphasis on those relevant to solar cell fabrication, is presented in Chapter 2. Chapter 3 gives a concise literature review on models governing droplet formation in ultrasonic spray pyrolysis (USP) techniques, the limitations of these models have been exposed and a new relation model for estimating the final particle size given a set of initial reaction conditions has been proposed. The presently derived model is quite advantageous in that it does not require the investigator to look up values of surface tension and density for every precursor solution. Chapter 4 presents in detail the designed and constructed spray pyrolysis system capable of realizing desired nano structures for photovoltaic applications. The first system employed an ultrasonic atomization spray nozzle in order to create an aerosol of the TiO2 precursor. The reasons for choosing ultrasonic spray deposition (USP) and the TiO2 precursors, titanium iso propoxide and titanium tetra butoxide are discussed. Chapter 5 outlines experimental methodologies used in synthesis and characterization of the materials used in this study. Chapter 5 further provides experimental methodologies used in fabrication of a new type of photo electrochemical solar cells (PECs). Chapter 6 reveals the opto-electrical results of PECs solar cells fabricated. There are numerous properties that are affected by the size but emphasis will be placed on nano-size and confinement effects. Chapter 7 presents a confirmation of the phonon confinement effects in C-TiO2 QDs for the first time. In addition Chapter 7 also presents a new phonon confinement model. Chapter 8 reveals the optical, structural and electronic properties of C-TiO2 QDs synthesized by USP and PSP techniques. In addition the electrical properties of C-TiO2 QDs PEC solar cells devices are reported in Chapter 8. Concluding remarks, with potential future research projects are presented in Chapter 9. Through these 9 chapters, all research questions have been answered satisfactorily and all objectives met. Most of the work contained in this thesis has been subjected to external reviews through publication of these peer reviewed articles.
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- Date Issued: 2014