Consumers' attitudes towards ready-to-eat fast-food products and their relationship with obesity in Mdantsane township in the Eastern Cape Province, South Africa
- Authors: Matyolo, Pamela
- Date: 2017
- Subjects: Obesity -- South Africa -- Eastern Cape Obesity
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9022 , vital:34183
- Description: The South African fast-food industry has experienced substantial recent growth. However, as consumers have incorporated more fast food into their daily diets, obesity has become a major problem. The aggressive marketing techniques of fast food firms coupled with the busy urban lifestyle have significant implications for dietary health habits. The study aimed at investigating consumers’ attitudes towards fast food and the relationship between fast food consumption and obesity. The field survey design of the study employed a mixed-methods approach involving the use of a semi-structured questionnaire. The study was limited to the Mdantsane Township located in the Eastern Cape Province of South Africa. A quota sample of 200 respondents (n = 200) was selected from which data were collected using a self-administered questionnaire. Descriptive results revealed that the participants had positive attitudes towards fast foods. Although they agreed that eating fast foods increased body weight, the participants mostly did not feel overweight or obese. The participants were well aware of the negative health implications of excessive fast food consumption. This knowledge generally did not deter their positive fast food attitudes, although participants expressed their desire for additional healthier fast food options in the market. Regression estimates further revealed that carbohydrate and starchy type of fast foods (𝑃 < 0.01), other sources of fast foods (𝑃 < 0.05), age group, physical appearance and meaty type of fast foods (𝑃 < 0.10) had significant influence on the frequency of fast food consumption. The results further revealed that physical appearance (𝑃 < 0.01), religion (𝑃 < 0.05), age group and supermarkets and source of fast foods (𝑃 < 0.1) had significant influence on respondents’ BMI scores. The study concludes that there exist socio-economic and institutional factors that have considerable bearing on consumers’ fast food consumption and BMI scores. The study advocates for public health policy making concerning awareness of the negative health consequences of fast food consumption targeting mostly young adult females who mainly purchase in franchises and supermarkets with a high meaty diet.
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- Date Issued: 2017
Cultural and heritage tourism trends in the Amathole District Municipality of the Eastern Cape Province, South Africa, 2004-2014
- Authors: Mboniswa, Mncedi Justice
- Date: 2017
- Subjects: Heritage tourism -- South Africa -- Eastern Cape Cultural property -- Repatriation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7897 , vital:30798
- Description: The promotion of tourism in a country, especially those with high levels of poverty is one of the strategies that can potentially improve socio-economic conditions of citizens. In South Africa, cultural and heritage tourism is seen as one of the ways in which cultural resources can be utilised to benefit marginalised communities and individuals. Such resources can also serve as source of income since both domestic and international tourists can activate industry as they are interested in learning more about other cultures and heritage. There are on-going debates, however on what constitutes cultural and heritage tourism, who it benefits and how this enterprise is located within various communities of South Africa. This research therefore aims to fill this gap through investigating cultural and heritage tourism development trends within the Amathole District Municipality (ADM) and how this development trend impacts on employment creation and improving the socio-economic conditions of citizens within this area of ADM. To realise this aim, the study looks at the availability of cultural and heritage tourism structures within the ADM and the database records on these structures. This study adopts the community benefit tourism initiatives approach to tourism development in the Amathole District Municipality of the Eastern Cape Province. This qualitative study reveals how the community benefit tourism approach encompasses rewards to local communities, in as much as it enhances sustainability of tourism initiatives. In bringing out these aspects, the study also examines efforts of the government and private sector in the up-keeping of tourism initiatives, especially for marginalised communities of South Africa.
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- Date Issued: 2017
Design, construction and performance evaluation of an agitated portable biogas digester under greenhouse-regulated temperature
- Authors: Mutungwazi Asheal
- Date: 2017
- Subjects: Sewage -- Purification -- Anaerobic treatment Green technology Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9055 , vital:34222
- Description: Biogas yield in anaerobic digesters is negatively affected by low temperatures during cold seasons and nights, temperature fluctuations and inefficient agitation. Electrical heating and underground digester installations have been used to help minimise these effects but the high cost of electrical heating, infeasibility of underground installations in some terrains, inefficient agitation and difficult maintenance continue to be major set-backs to high biogas yields. In this study a 100 ℓ, agitated, portable carbon steel digester housed within a greenhouse, whose operation temperature is automatically maintained at an optimum of 35 ± 1 oC by means of an ON/OFF electronic circuit for ventilation control through a suitably sized window and insulation offered by an air film trapped in-between a double layer of polyethylene plastic covering of the greenhouse, was designed. Cow dung from a dairy farm at the University of Fort Hare with total solids (TS), volatile solids (VS), chemical oxygen demand (COD) and ammonia nitrogen content of 162348.67 mg/ℓ, 116543.98 mg/ℓ, 37 879 mg/ℓ and 128 - 235 mg/ℓ respectively was used for the performance evaluation of the digester. Analysis of the biogas produced starting from day 6 of the 31-day retention period showed a specific biogas yield of 0.036 m3/kgVSadded and a methane yield of 55percent. The optimum pH maintained was 7.2 and the COD reduction achieved during the digestion period was 61percent. This simple, easy to construct, inexpensive yet efficient design will lead to improved biogas yields and quality and faster dissemination of the biogas technology.
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- Date Issued: 2017
Detection and antibiogram profile of members of the vibrio species in Umzimvubu, Swartkops and Buffalo rivers the Eastern Cape province, South Africa
- Authors: September, Dolly Thandeka
- Date: 2017
- Subjects: Vibrio -- South Africa -- Eastern Cape Water -- Fluoridation -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15221 , vital:40255
- Description: Freshwaterbodies are often recipients of a wide array of infectious agents yet they serve as immediate sources of water supply. Brackish and freshwater rivers support the growth of Vibrio species, which are the leading cause of diarrheal infections in the world. Their occurrence in these environments is detrimental to the health and well-being of many communities. Hence, this study aimed at assessing the occurrence and antibiogram profile of Vibrio species in Swartkops, UMzimvubu and Buffalo rivers. The rivers are important sources of freshwater supplies for some communities around the Eastern Cape Province, and water samples were collected once off from each of the sites, using standard membrane filtration method to concentrate the samples. Cultivation was carried out on Thiosulfate Citrate-Bile Salt Sucrose (TCBS) agar, were typical yellow/green colonies were enumerated as presumptive Vibrio species and expressed as CFU/100mL. Presumptive Vibrio counts ranged from 0 to 1.67 × 103 CFU/100mL, 0 to 6.42 ×102 CFU/100mL and 0 to 3.28×103 CFU/100ml in the uMzimvubu, Swartkops and Buffalo rivers respectively. Polymerase Chain Reaction was employed for molecular identification of the Vibrio isolates. Two hundred (200) presumptive Vibrio species were screened for molecular identification, and 185 isolates confirmed positive as belonging to the Vibrio genus. Antibiotic susceptibility profile of the confirmed isolates was determined using a panel of 12 commercial test antibiotics. All the confirmed Vibrio species showed 98 to 100percent multiple antibiotic resistance against all the test antibiotics from the three study sites. The most predominant phenotypic pattern of multidrug resistance displayed by the isolates was CAZ-PEN-AMP-CIP-AK-AZM-TET-CAM-CTX-STX-GEN-IPM showing 100percent resistance to all 12 antibiotics. The multiple antibiotic resistance index (MARI) on average was 1 for all the three rivers assessed. This finding suggest high possibility of antibiotic pollution and usage around the study areas, and occurrence of potentially pathogenic Vibrio species carrying antibiotic resistant genes, which is a major public and environmental health concern.
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- Date Issued: 2017
Determination of physiochemical properties and metal levels in soil, water, and plant from Alice landfill site
- Authors: Maphuhla, N G
- Date: 2017
- Subjects: Heavy metals -- Environmental aspects Soil pollution Water -- Pollution
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6224 , vital:29521
- Description: The state of soil is of great significance because it is a common medium for plant growth, which provides important nutrients to plants. Water pollution is the build-up of harmful substances in water bodies to the level that results in health problems for people and animals. Heavy metal pollution (of soil, water, and plants) and their health effects on people is a persistent social issue, and several types of research have recognized health risks of residents living close to open dumpsites. Dump sites are sources of heavy metal impurity and toxicity to the surrounding environment. Analyses were done on water and soil samples for temperature, pH, Electrical conductivity (EC), Total dissolved solids (TDS), alkalinity, organic matter, organic carbon and total hardness. The pH results range from slightly acidic (6.79) to neutral soil pH (7.09), and have been recorded within the normal range from WHO. All the determined physicochemical properties in soil and water have been recorded within the normal range, except for EC in water which was found to be above the permissible limits by WHO. The heavy metals concentration was determined using the AAS technique. The results obtained shows that the dumpsite‘s soil consists of high metal concentration when compared to control site. The concentration in dumpsites ranges between 1.2783 ± 0.83 mg/kg to 26.3213 ± 6.37 mg/kg. The descending order for selected metal concentrations were in this following order Mn> Cu>Hg>Pb. The Pb and Hg mean concentration was recorded above permissible limits, while the Mn and Cu were within the normal range suggested by WHO. In both water and Acacia karroo samples the Cu was not detected. The trend of metal concentration in water sample was found to be in this order Hg> Mn > Pb> Cu, while in Acacia karroo metal concentration is Hg> Mn> Pb> Cu. The one-way ANOVA test was used to compare the mean concentration of selected metals in each sampling site. The results show that there is a statistically significant difference between the mean concentrations of selected metals; this is supported by the value of F-static and p-value (p <0.05)
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- Date Issued: 2017
Determining and analysing the emergent behaviour from context-aware devices
- Authors: Bandason, Vivian
- Date: 2017
- Subjects: Context-aware computing Mobile computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7907 , vital:30805
- Description: With the continued miniaturization of technology and the incorporation of Moore’s law, smartphones are more powerful. These mobile devices contain technologies that add other functionalities to them. Technologies such as sensors constantly provide information to the device. The constant stream of information from these sensors often leads to information overload of relevant and irrelevant information. To work towards solving this problem context-aware computing was introduced. Our major concern is that context information in context aware computing is not completely being utilized. The aggregation of context information could unlock more possibilities. This research seeks to aggregate the context of multiple devices such that, through analysis, some emergent behaviour can be observed. In this research context information from the sensors of devices is collected using an Android application and a central Server. The context information is used for pattern analysis. A pattern analysis algorithm is designed and used to observe patterns throughout the data set. It shows patterns that are similar within the dataset. In the case that the pattern observed has no similar pattern or few similar patterns this behaviour can be stated as emergent in the dataset. Further study of this emergent behaviour can be performed were a classifier can be used to give the exact activities that were being performed at that time. The research found this was possible and has many uses. One of these is in disaster prevention were the behaviour of a group of individuals may be monitored to observe any random changes such as masses running at the same time. This could be used as a first warning to natural disasters.
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- Date Issued: 2017
Development and validation of DNA barcoding for biodiversity assessment and conservation of red algae in the Algoa Bay region
- Authors: Mshiywa, Faith Masilive
- Date: 2017
- Subjects: Red algae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9011 , vital:34182
- Description: DNA barcoding is a molecular technique that uses a short DNA sequence for species identification. It harnesses global community efforts to establish large-scale public reference libraries to allow species identification. Red algae are a complex group of species and are difficult to identify on morphological grounds only. Red algae have the highest production of halogenated compounds, and are used in the medical and pharmaceutical industries. This study therefore aimed at developing DNA barcodes, universal primers and a Kenton-on-Sea red algae species list, which will aid as a baseline for red algae biodiversity and conservation research. A potential DNA barcode region was designed from the rbcL gene, because rbcL is easy to amplify, easy to sequence and it can differentiate organisms to species level. Primers were designed from multiple red algae rbcL sequences and they were evaluated using bioinformatics tools. Red algae from the Algoa Bay region were screened with these primers and a 77% PCR amplification success was obtained. The PCR products were sequenced and 96% of the amplicons were successfully sequenced and resulted in a barcode sequence length above 700bp, which could be used to identify red algae species. Twenty-six (26) red algae species from Kenton-on-Sea, near Algoa Bay, were successfully identified using the Barcode sequence amplified from a primer set developed from the rbcL gene and were uploaded on the BOLD database for public access. This barcode is, therefore, suitable for use by the South African National Biodiversity Institute or other marine researchers, to identify South African red algae species and ensure the maintenance of their biodiversity and conservation.
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- Date Issued: 2017
Development of a MPEG-7 based multimedia content description and retrieval tool for internet protocol television (IPTV)
- Authors: Ncube, Prince Daughing Ngqabutho
- Date: 2017
- Subjects: MPEG (Video coding standard) Digital television Multimedia communications
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4893 , vital:28738
- Description: Search and retrieval of multimedia content from open platforms such as the Internet and IPTV platforms has long been found to be hugely inefficient. It has been noted that a major cause of such inefficient results is the improper labeling or incomplete description of multimedia content by its creators. The lack of adequate description of video content by the proper annotation of video content with the relevant metadata leads to poor search and retrieval yields. The creation of such metadata itself is a major problem as there are various metadata description standards which users could employ. On the other hand there are tools such as FFprobe that can retrieve important features of video that can be used in searching and retrieval. The combination of such tools and metadata description standards could be the solution to the metadata problem. The Multimedia Content Description Interface (MPEG-7) is an example of a metadata description standard. It has been adopted by TISPAN for the description of IPTV multimedia content. The MPEG-7 standard is rather complex, seeing as it has over 1200 global Descriptors and Description Schemes which a user would have to know in order to implement such technology. This complexity is a nuisance when we consider the existence of multitudes of amateur video producers. These multimedia content creators have no idea how to use the MPEG-7 standard to annotate their creations with metadata. Consequently, overloading of the IPTV platform with content that has not been annotated in a standardized manner occurs, making search and retrieval of the multimedia content (videos, in this instance) inefficient. Therefore, it was imperative to try and determine whether the use of the MPEG-7 standard could be made much easier by creating a tool that is MPEG-7 enabled which will allow for the annotation of video content by any user without concerning themselves about how to use the MPEG-7 standard. In attempting to develop a tool for metadata generation, it was incumbent for us to understand the issues associated with metadata generation for users wishing to create IPTV services. An extensive literature review on IPTV standardization was carried out to determine the issues associated with metadata generation for IPTV and their proposed solutions. An experimental research approach was taken in an attempt to figure out if our proposed solution to the lack of technical expertise by users about the MPEG-7 standard could be the final solution to the metadata generation problem. We developed a Multimedia Content Description and Management System (MCDMS) prototype which enabled us to describe video content by annotating it with 16 different metadata elements and storing the descriptions in XML MPEG-7 format. Incremental development and re-use oriented development were used during the development phase of this research. The MCDMS underwent functional testing; smoke testing of the individual system components and Big Bang integration testing for the combined components. Our results indicate that the more metadata is appended to a video as description the better it is to search for and retrieve. The MCDMS hides the complexity of MPEG-7 metadata creation from the users. With the effortless creation of MPEG-7 based metadata, it becomes easier to annotate videos. Consequently, search and retrieval of video content becomes more efficient. It is important to note that the description of multimedia content remains a complex feat. Even with the metadata elements laid out for users, there still exist other issues that affect metadata creation such as polysemy and the semantic gap. However, the provision of a tool that does the MPEG-7 standardizing behind the scenes for users when they upload a video makes the description of multimedia content in a standardized manner a much easier feat to achieve.
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- Date Issued: 2017
Development of an automatic news summarizer for isiXhosa language
- Authors: Ndyalivana, Zukile
- Date: 2017
- Subjects: Text processing (Computer science) Automatic abstracting Computational linguistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7875 , vital:30783
- Description: From practice perspective, given the abundance of digital content nowadays, coming up with a technological solution that summarizes written text without losing its message, coherence and cohesion of ideas is highly essential. The technology saves time for readers as well as gives them a chance to focus on the contents that matter most. This is one of the research areas in natural language processing/ information retrieval, which the dissertation tries to contribute to. It tries to contextualize tools and technologies that are developed for other languages to automatically summarize textual Xhosa news articles. Specifically, the dissertation aims at developing a text summarizer for textual Xhosa news articles based on the extraction methods. In doing so, it examines the literature and understand the techniques and technologies used to analyse contents of a written text, transform and synthesize it, the phonology and morphology of the Xhosa language, and finally, designs, implements and test an extraction-based automatic news article for the Xhosa language. Given comprehension and relevance of the literature review, the research design, the methods and tools and technologies used to design, implement and test the pilot system. Two approaches were used to extract relevant sentences, which are, term frequency and sentence position. The Xhosa summarizer is evaluated using a test set. This study has employed both subjective and objective evaluation methods. The results of both methods are satisfactory. Keywords: Xhosa, Automatic Text Summarization, Term Frequency and Sentence Position.
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- Date Issued: 2017
Differential regulation of wheat (Triticum aestivum) callose synthases during Russian wheat aphid (diuraphis noxia)infestation
- Authors: Ngwenya, Nompilo
- Date: 2017
- Subjects: Russian wheat aphid Wheat -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8100 , vital:31522
- Description: Plant production serves as the primary food source for all living beings and is continuously being affected by many biotic and abiotic factors. Wheat, one of the most consumed cereal crops in the world and the second most cultivated crop after maize in South Africa, is continuously being affected by Russian wheat aphid (RWA) since 1978. To counteract the effect of this aphid, the first resistant wheat cultivar was developed in 1984 in South Africa containing the Dn1 resistance gene. However, the mechanism of action of the resistance is still not fully understood to date. The feeding of the RWA on the wheat induces callose deposition especially in susceptible wheat cultivars, linking the β-1.3-polysaccharide (callose) to the resistance mechanism. Callose is synthesized by callose synthases, also known as glucan synthase-like genes (GSL). Not much is known about the mechanism of action of callose synthases or how they are regulated in response to the RWA. Bioinformatics tools, such as those available at NCBI, were used to identify the wheat callose synthases genes. The proteins encoded by the identified wheat callose synthases genes, were then analyzed for conserved domain motifs using the MEME suite and InterproScan, sequence similarities using ClustaL Omega and transmembrane domains using HMMTOP and ProtCamp. These were then compared with those of the already characterized Arabidopsis callose synthase proteins in an attempt to identify the wheat callose synthase(s) that responds to aphid feeding. Further bioinformatics studies were carried out to identify the presence of biotic stress associated cis-acting regulatory elements found in the 1.5 kbp upstream region of the start codon of the Arabidopsis callose synthase genes. Eight partial wheat callose synthase sequences were identified and two of these (TaGSL2 and TaGSL22) showed high similarities to the AtGSL5, which is up-regulated in response to aphid feeding in Arabidopsis. Six of the wheat callose synthase genes were mediated to code for the functional callose synthases proteins: TaGSL3, 8, 12, 19, 22 and 23, and analyzed for conserved protein motifs. Based on the sequence similarities and conserved protein domains, TaGSL2 and TaGSL22 were found to be the most similar to AtGSL5 and most likely to respond to RWA infestation. Cis-acting regulatory element analyses confirmed the possibility of TaGSL22 being responsible for callose deposition in wheat as biotic stress associated cis-acting regulatory elements, Box W1, TC- rich element and W- box were all found in the 1.5 kbp upstream of the TaGSL22 coding region. Callose was quantified in both susceptible and resistant wheat cultivars using the aniline blue fluorescence method. When infested with RWA-SA1, the susceptible wheat cultivar (Tugela) deposited significantly higher amounts of callose, compared to the resistant wheat cultivar (Tugela DN), which deposited little, to no callose with respect to the control samples. Transcription analysis, of the TaGSL2 and TaGSL22 in RWA-SA2 infested Tugela and Tugela DN wheat cultivars, was performed using real time polymerase chain reaction (qPCR). Both TaGSL2 and TaGSL22 genes were up-regulated in Tugela and Tugela DN wheat cultivars in response to RWA-SA2 infestation, with TaGSL22 being more expressed than TaGSL2 in both cultivars, indicating that RWA-SA2 is able to overcome the resistance of Tugela DN and cause callose deposition. However, significantly higher expression of both genes was still observed in the susceptible, Tugela wheat cultivar. This study therefore confirms that callose deposition is associated with RWA-SA1 feeding, only in the susceptible wheat cultivar, Tugela and not the resistant cultivar, Tugela DN. However, during RWA-SA2 feeding, two of the eight identified callose synthases in wheat, are up-regulated in response to RWA-SA2 feeding, in both the resistant and susceptible wheat cultivars with higher levels observed in the susceptible wheat cultivar when compared to the resistant wheat cultivar. TaGSL2 and TaGSL22 are therefore implicated in the callose deposition observed in the susceptible and resistant wheat cultivars, after RWA-SA2 infestation. Further studies are required to confirm the differential regulation of the two wheat callose synthases proteins during RWA infestation and their possible role in the resistance mechanism of the resistant wheat cultivar, Tugela DN.
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- Date Issued: 2017
Effects of loading time and lairage duration on pig behaviour, sex and lairage time on pork physio-chemical characteristics
- Authors: Ntlatywa, Bongiswa
- Date: 2017
- Subjects: Pork -- Quality Meat -- Quality Loading and unloading
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12270 , vital:39225
- Description: The objectives of the study were to determine the effect of loading time, transportation unloading and lairage period, their subsequent effect on responses behaviour and the effect of sex and lairage period on the meat quality of cross breeds reared in commercial farm. The first part of the study assessed the behaviour of pigs during loading at the farm, offloading and in the lairages. A total of 900 pigs from 5 trips (180 per trip) were monitored on behaviour from farm to slaughter plant. The pigs were transported to a commercial abattoir which is 120 km distance, travelling for 2 hours from the farm. The results revealed that time spent in loading pigs was more than when offloading pigs. The frequency of slipping or falling-off in pigs was high (18percent) than voluntary movement (8percent) during loading times (χ2 >0.05) that when off-loading. A significant difference was determined on the avoidance (χ2=0.03), mounting behaviour (χ2 =0.01) and vocal sound (χ2 =0.02) during loading time on each observation day. Furthermore there was no significant difference determined on the time and day of observation in the lairages. These results also reveal that the avoidance behaviour was the highest (47percent) while fighting (34percent) and vocalizing were the least compared to other behaviour during the first 30 minutes after arrival at the abattoir. Moreover, the lying behaviour was found to have highest frequency (15percent) on day 6 compared to other sampling days. These results reveal that time of loading pigs had an influence on pigs’ behaviour before slaughter and consequently that affected physiological features and meat quality. The second section of the study assessed sex and the different lairage time effects on the pork quality attributes. A total of fifty four pigs, 22 weeks old of different sex (26 boars x 28 gilts) reared on a commercial farm and transported to the abattoir on the same day was used in this study. At the abattoir, pigs were grouped according to lairage periods of 17 hours (Group1; 13 gilts and 14 boars) and 36 hours (Group 2; 15 gilts and 12 boars). Results showed no significant difference on the sex of pigs (P >0.05) and meat pH. However, lairage time influenced the thawing loss (P= 0.02) of meat and also the interactions of sex by lairage had a significant difference (P= 0.04) on meat tenderness. There was a positive significant correlation found between sex and meat attributes values were high in boars (r= 0.61) than in gilts (r = 0.49). A negative correlation between a*and WBSF on lairage group1 (r= -0.52) was determined while on group 2 there was a positive correlation between a* and b* (r=0.49). This study suggest that a proper timing on farm feed withdrawal in combination with a sufficient lairage at the slaughter plant may result in better carcass and meat quality traits. Communication among producers and abattoirs is critical when planning the fasting and lairage times in order to elude carcass and technological pork quality complications. To conclude, there is influence caused by time of loading in stressing pigs before transportation and slaughter as aggressive behaviour showed and also lairage time affected meat quality.
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- Date Issued: 2017
Estimating maize grain yield from crop growth stages using remote sensing and GIS in the Free State Province, South Africa
- Authors: Mditshwa, Sithembele
- Date: 2017
- Subjects: Crop yields Crops -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6016 , vital:29481
- Description: Early yield prediction of a maize crop is important for planning and policy decisions. Many countries, including South Africa use the conventional techniques of data collection for maize crop monitoring and yield estimation which are based on ground-based visits and reports. These methods are subjective, very costly and time consuming. Empirical models have been developed using weather data. These are also associated with a number of problems due to the limited spatial distribution of weather stations. Efforts are being made to improve the accuracy and timeliness of yield prediction methods. With the launching of satellites, satellite data are being used for maize crop monitoring and yield prediction. Many studies have revealed that there is a correlation between remotely sensed data (vegetation indices) and crop yields. The satellite based approaches are less expensive, save time, data acquisition covers large areas and can be used to estimate maize grain yields before harvest. This study applied Landsat 8 satellite based vegetation indices, Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Moisture Stress Index (MSI) to predict maize crop yield. These vegetation indices were derived at different growth stages. The investigation was carried out in the Kopanong Local Municipality of the Free State Province, South Africa. Ground-based data (actual harvested maize yields) was collected from Department of Agriculture, Forestry and Fisheries (DAFF). Satellite images were acquired from Geoterra Image (Pty) Ltd and weather data was from the South African Weather Service (SAWS). Multilinear regression approaches were used to relate yields to the remotely sensed indices and meteorological data was used during the development of yield estimation models. The results showed that there are significant correlations between remotely sensed vegetation indices and maize grain yield; up to 63 percent maize yield was predicted from vegetation indices. The study also revealed that NDVI and SAVI are better yield predictors at reproductive growth stages of maize and MSI is a better index to estimate maize yield at both vegetative and reproductive growth stages. The results obtained in this study indicated that maize grain yields can be estimated using satellite indices at different maize growth stages.
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- Date Issued: 2017
Evaluation of groundwater potential using neotectonics and geophysics in the context of post Karoo tectonic framework around Fort Beaufort and Smithfield, Eastern Cape, South Africa
- Authors: Ndlovu, Nkosilathi
- Date: 2017
- Subjects: Neotectonics -- South Africa -- Eastern Cape Groundwater -- South Africa -- Eastern Cape Geophysical surveys -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12687 , vital:39299
- Description: Geological and geophysical methods were used to investigate the Karoo area extending from longitudes 25.50 E to 27.50 E and latitudes 300 S to 330 S in South Africa, particularly Fort Beaufort, Aliwal North, Venterstad and Smithfield. The geology of the area is dominated by the upper Beaufort Group (Adelaide Subgroup) with an extensive network of dolerite sills and dykes that intruded the sedimentary sequence. A relationship between neotectonics, post-Karoo tectonics, groundwater and lithology was investigated to locate suitable groundwater potential sites. Apart from studying the role of neotectonics and the post Karoo tectonics, this research aims at generating groundwater targets to alleviate water shortages mainly for farming and livestock, and prove that neotectonics is still active. Methodologies adopted for obtaining these results included a comprehensive literature review, thin section analysis, scanning electron microscopy, geophysical investigation (magnetic, gravity, and vertical electrical sounding), and the application of Geographical Information Systems (GIS) and remote sensing. Twenty samples were collected at various locations within the study area and were analyzed using the petrographic microscope while others were analyzed with the Scanning Electron Microscopic (SEM) combined with an Energy dispersive x-ray spectrometry. The results show that the rocks are fractured, porous and have variable mineralogy (presence of heavy minerals) within the rocks. The use of Geographical Information Systems (GIS) and remote sensing in geological surveys, especially hydrogeology, has gained momentum over the past few years. This research is no exception as ArcMap software was used to create a map of seismic epicentres of the Eastern Cape Province. From the map it can be observed that seismicity still occurs and thus leading to the notion of neotectonics being active. Lineaments were also automatically extracted using the ENVI 5.1 and Geomatica 2013 software. Lineaments are zones of weakness in the subsurface of the Earth and are very important in locating groundwater potential sites. Geophysical techniques are essential and highly accurate for groundwater studies. Gravity and magnetic techniques were applied on data which was supplied as grids. Analysis using Geosoft Oasis 8.3 revealed extensive lineaments and ring like patterns and these were inferred to be dolerite intrusions (sills and dykes). The morphology of the intrusions help in identifying possible groundwater potential zones and thus they should be investigated. Vertical electrical sounding (VES) technique using the Schlumberger array was carried out at three sites (Fort Beaufort fracture which is possibly related to Quaternary surface uplift of the Amatole-Swaziland axis, splay of the Fort Beaufort fracture and at a site which showed high groundwater potential) to explore subsurface layering. IP2win (lite), 1-D modelling software was used to model the apparent resistivity data to obtain the geoelectric parameters of the subsurface (thickness and resistivity). The VES results are consistent with fractured rocks that aid groundwater movement. The VES data for the three sites was further modelled by the RES2DINV software and this shows low resistivity values associated with loose, water saturated top sandy soil and higher resistivity values associated with sedimentary sequences and dolerite. Moreover, potential sites for citing wells are predicted to be between 79.5 and 128 m on the profile. Further neotectonic studies need to be done, especially on the quaternary sediments as they would have more neotectonic evidence. The use of geophysical techniques for groundwater search need to be intensified, with more emphasis being put to the sedimentary sequences bordered by dolerite intrusions and fractured zones.
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- Date Issued: 2017
Evaluation of some pseudomonas species isolated from Hogsback forest reserve for the production of antibacterial compounds
- Authors: Mkono, Yonela Pelokazi
- Date: 2017
- Subjects: Bacteriology -- South Africa -- Eastern Cape Pseudomonas
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5961 , vital:29458
- Description: Pseudomonas species are Gram-negative bacteria most abundant in soil and water bodies, with the capacity to thrive in varied environments. They are largely associated with resistant pathogenic bacteria linked to human and plant diseases. Species such as Pseudomonas aeruginosa have been particularly targeted as case studies due to the extremity to which they pose a threat to human health. With more focus directed at using these species for biocontrol and bioremediation purposes, their role in bioactive compound production may be equally important. As the crisis on antimicrobial resistance still persists, the need for effective antimicrobial compounds is ever more urgent and solutions may possibly still be dormant in bacterial species whose potential has not been fully investigated. On a bid to source out potential antimicrobial compound producers, soil samples were collected from Hogback forest reserve in the province of the Eastern Cape, South Africa. For bacterial screening, M1 and R2A agar were used and the cultures grown at 37˚C for a period of seven days. After the presumed Pseudomonas species were identified, antimicrobial production was determined by submerged fermentation method using nutrient broth as media of choice. Active isolates were further studied to determine the optimum conditions which best facilitate for antimicrobial compound production, with parameters such as temperature (25˚C – 40˚C) and pH (4 – 9) considered. The role plasmids play in antimicrobial compound production was also investigated. Each isolate was grown in fermentation media containing Sodium dodecyl sulphate and Ethedium Bromide, at varying concentrations, to facilitate for plasmid curing. With each sample, distinct colonies were identified with varying pigmentations most dominant being a cream colour. The identity of the isolated strains was achieved through sequencing of 16S rDNA. Phylogenetic analysis showed that isolate A16 had 80 percent homology with Pseudomonas plecoglossicida strain P4 and share a close ancestor with isolates Y52 and Y81, also isolate Y89 showed a 90 percent homology with Pseudomonas sp. Co-11a. With the exception of isolate A16, the isolates which were active against Gram-negative bacteria lost activity as the screening processes continued. When looking at temperature variations, isolates Y81 and A16 were highly active with maximum activity observed at 35˚C while Y89 performed best at 25˚C and Y52 showed constant activity across all studied temperatures. The plasmids in all isolates were found to be 48.5 kb in size with the exception of isolate Y89 which was 20 kb. The plasmids were cured at concentrations of (1 mg/ml; 5 mg/ml; 7 mg/ml; 10 mg/ml; 11 mg/ml) SDS and (125 μg/ml; 6.5 μg/ml; 5μg/ml) EtBr. The curing process also showed changes in both the antimicrobial activity of the isolates as well as their physical characteristics. The isolates are the first reported Pseudomonas species from Hogsback forest reserve with the ability to produce antimicrobial compounds which are active against Gram-positive and Gram-negative bacteria. These mesophilic bacteria also show that plasmids do not pay any role in the production of antimicrobial compounds and that the biosynthesis genes are highly likely to be chromosomal borne meaning that the production cannot be linked to horizontal transfer of genes. Therefore, these isolated Pseudomonas species provide a potential reservoir of antimicrobial compounds which may play an important role in the antimicrobial resistance phenomenon.
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- Date Issued: 2017
Evaluation of the physicochemical qualities and heavy metal regimes of the final effluents of some wastewater treatment facilties in Berlin, Alice and Bedford communities in the Eastern Cape, South Africa
- Authors: Agoro, Mojeed Adedoyin
- Date: 2017
- Subjects: Water -- Purification -- South Africa -- Eastern Cape Sewage -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5003 , vital:28924
- Description: Wastewater treatment facilities have been identified as potential source of surface water pollution worldwide. In this study, the physicochemical qualities and heavy metal (including Zinc, Cadmium, Iron, Lead and Copper) concentrations in the final effluents, as well as the reduction efficiencies of three municipal wastewater plants in the Eastern Cape, South Africa were evaluated from September 2015 to February 2016 using standard methods. Wastewater effluent and sludge samples were collected from the selected plants on monthly basis over a period of six months from September 2015 to February 2016. Standard analytical method (Atomic absorption spectroscopy [AAS]) was used to assess the concentration levels of heavy metals. The physicochemical parameters assessed include pH, Temperature, Total Dissolved Solid, Turbidity, Biochemical Oxygen Demand, Chemical Oxygen Demand, Alkalinity, Dissolved Oxygen, Free chlorine, Chloride, Sulphate, Phosphate, Ammonium and Electrical Conductivity. The results of the evaluation showed that temperature ranges from 19 to 36 °C, Electrical Conductivity from 60-1095 mS/m, Alkalinity from 2.6-20.9 mg/L, Nitrate from 0.24-26.5 mg/L, Nitrite from 0.01-90 mg/L, Phosphate from 0.02-5.12 mg/L, Ammonium from 0.06-112 mg/L, Sulphate from 3-72 mg/L, Chloride from 3.25-224 mg/L, Chemical Oxygen Demand from 17-394 mg/L and Turbidity from 1.96-715 NTU. Free chlorine concentrations and dissolved oxygen were within the recommended limits for most part of the sampling period and ranged between 0.17-0.48 mg/L and 0.19-21.9 mg/L respectively. The pH, Phosphate, Sulphate and Free chlorine were within acceptable limits while Electrical Conductivity, Temperature, Total Dissolved Solid, Turbidity, Chemical Oxygen Demand, Chloride, Ammonium, Nitrate and Nitrite were not within specified limits. The reduction efficiencies observed generally ranged between 43.9 and 100 percent at all sampling points while zinc and lead were not detected throughout the sampling period. Cadmium showed low reduction rate ranging from 0 to 11.7 percent, while the rate of Copper reduction ranged from 0 to25 percent in January and February 2016. Zinc, lead and cadmium were generally not detected in the sludge samples except in January and February which could be due to the prevailing atmospheric conditions during the sampling period. Cu and Fe were detected through the sampling months of the study. We conclude that these municipal sewage plants are sources of pollution to their receiving watersheds and threats to public and environmental health.
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- Date Issued: 2017
Evaluation of the socio-economic performance of smallholder irrigation schemes in Idutywa Village of the Eastern Cape Province
- Authors: Jiba, Phiwe
- Date: 2017
- Subjects: Irrigation farming -- Economic aspects Farms, Small -- South Africa -- Eastern Cape Agricultural development projects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4705 , vital:28497
- Description: South Africa and other African countries are faced with high levels of food insecurity and poverty levels as a result of slow growth of the macro economy and weak or sluggish rural development. Irrigation scheme development is seen as an important strategy to address the challenges faced by households in rural areas and restores growth and enhanced livelihoods. While the international experience shows that Irrigation schemes are potentially transformative of poor communities and have been operational for many years now, there is no marked improvement in living conditions of rural households in terms of livelihoods and income. This raises the question as to whether or not the schemes are viable from a socio-economic perspective and whether or not there are reasons for concern and revision of the policy framework for smallholder irrigation schemes. As a result of that, the broad objective of the study was to evaluate the contribution of smallholder irrigation schemes to household income and food security of rural households in Idutywa village of the Eastern Cape Province in South Africa. Specifically, this research investigated the major factors that influence their performance, impact of irrigation farming on rural livelihood and household food security as well as identifying the possible opportunities of production that would improve their performance. The study was carried out in Idutywa villages of the Eastern Cape Province in South Africa and employed survey data obtained from 107 households. The study employed a cross-sectional research design and the study employed stratified random sampling. The study made use of descriptive and inferential statistics to estimate the central tendency and dispersion as well as testing the hypothesis that there is a difference in the contribution between irrigators and non-irrigators using STATA and SPSS. Probit regression model was used to estimate factors that influenced the performance of smallholder irrigation schemes. The descriptive statistics employed included means, percentages and frequencies on the socio-economic characteristics of households in the study areas. The results show that females were dominant with a representation of 66.7 percent. The majority of households were aged and the mean age was 65 years. High level of illiteracy in the project area was revealed by the data. The average number of years, households spent in school was between 6 years to 10 years in school. Farming was found to be the major agricultural economic activity. Sixty-three (63 percent) were full time farmers. The results further show that household size ranges between 1 to 5 persons. The households were shown to be mostly dependent on social grant with household income hovering around R 1 000. The results from propensity score matching revealed that irrigation exerts a positive impact on household income. This provides sufficient evidence that irrigation schemes do make a contribution to rural livelihoods through their effect on household income and food security. This implies that government should continue investing in irrigation schemes as part of a strategy to grow the rural economy and improve rural livelihoods. This is in line with the Agricultural Policy Action Plan (APAP) and National Development Plan (NDP) of South Africa. Probit analysis suggests that age of the households, household size and market were some of the key determinants that positively influenced households’ decision to participate in smallholder irrigation schemes while access to credit had significant but negative effect on households’ decision to participate in smallholder irrigation schemes. Based on the findings highlighted above, it is recommended that addressing such barriers may create enabling conditions that would encourage households to access and participate more effectively in smallholder irrigation schemes.
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- Date Issued: 2017
Exploring the attitudes of selected community members on the interplay between incidences of poverty and the escalation of HIV/AIDS in Cofimvaba, Eastern Cape Province, South Africa
- Authors: Mrashula, Zodidi
- Date: 2017
- Subjects: AIDS (Disease) -- South Africa -- Eastern Cape AIDS (Disease) -- Economic aspects Poverty -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7941 , vital:30987
- Description: Cofimvaba has had a noticeable increase of people who got infected with HIV/AIDS and is one of the poorest of the poor in the Eastern Cape. Hence, the researcher became interested to investigate the interplay between incidences of poverty and the prevalence of HIV/AIDS. The reasons for the continued increase of HIV infection in Cofimvaba were investigated. The study used a qualitative approach, was descriptive and explorative and specifically used a case study as a specific research design. The study investigated 32 participants, nine of whom were infected and diagnosed to be seropositive between the years 2012, and 2014; six community members; twelve from the volunteer care givers who were members from the support group. The study also investigated a number of key informants who included a traditional leader, a care giver, a nurse, a social worker and a community development practitioner. The study used a non-probability sampling methodology, but specifically purposive sampling technique. On data collection, the study triangulated both in-depth interviews and focus group discussions. The findings of the study revealed that people who are infected with HIV/AIDS are unemployed, illiterate and suffer from poverty. The study also found that poor people are more vulnerable to HIV/AIDS infections. The study findings were as follows: There is a lack knowledge about HIV/AIDS that leads to lack of prevention. It has been discovered that there is a high level of poverty and HIV/AIDS in Cofimvaba. High level of unemployment is a contributing factor of poverty and high level of HIV/AIDS in Cofimvaba. Level of unprotected sex as driver of HIV/AIDS has also been identified. There is an inextricable relationship poverty and prevalence of HIV/AIDS. Unreliability of the food parcel on people who are HIV positive leads to poverty. The study findings were also as: Caregivers breaching the ethos and principle of confidentiality leads to people not to to HIV/disclose their HIV/AIDS status. Migration driving vulnerability to HIV/AIDS. It has been insisted that transactional sex drives to HIV/AIDS. Low HIV/AIDS education makes people to be vulnerable to HIVAIDS., The fear of testing makes people unaware of their HIV/AIDS status. Also the excessive alcohol intake as a driver to HIV/AIDS vulnerability. It has also been noted that only women responded to the study and there was a high rate of death revealed on account of HIV/AIDS in Cofimvaba. The researcher has also made the following recommendations to the study: obligatory psychol-social support programs for PLWHA, extension and replication of community based organisation, collaboration between different stakeholders in the HIV/AIDS domain. Widen the horizon of training education and HIV/AIDS awareness campaigns and availability of counselling, job opportunity, social grants and food parcels.
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- Date Issued: 2017
Farm level cost-benefit analysis of conservation agriculture for maize smallholder farners in Okhahlamba Municipality in Kwa-Zulu Natal Province, South Africa
- Authors: Tafa, Sanelise
- Date: 2017
- Subjects: Agriculture -- South Africa -- Cost effectiveness Agricultural conservation -- South Africa -- Kwa-Zulu Natal Land use -- Economic aspects -- South Africa , Sustainable agriculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2809 , vital:28094
- Description: Land degradation is a serious problem that many poor communities face and this worsens their vulnerability and therefore, poses a threat to food security, as it reduces yield, forces farmers to use more inputs, and disproportionately affect the smallholder farmers in remote communities that also suffer diverse infrastructure disadvantages. In response to that, the international development agencies, donors, and Non-Governmental Organizations (NGOs), especially faith-based organizations have turned towards sustainable farming approaches. Much attention has been paid to a combination of sustainable farming measures which are packaged under the “Conservation Agriculture” (CA) banner. The previous work in the KZN Province and elsewhere has demonstrated that CA has the potential to improve the soil structure, thereby reversing the effect of soil degradation. Consequently, many of the farmers in the areas in which these demonstrations have been conducted appreciate the ecological and economic value of adopting CA. However, the on-farm financial benefits of adopting a CA specific tillage practice are not as well known or thought to be as pronounced. By means of integrating field survey, reviewed literature, and econometric analysis, this study assessed the farm level cost-benefit analysis of conservation agriculture for smallholder maize farmers in OLM, specifically in one demonstration village of Bergville town. The analysis is based on the case study of the NGO’s work in which they had selected a community and participating households who received assistance in a number of ways such as maize seed, soil preparation, and CA planters. To analyse the farm level cost-benefit analysis, descriptive, linear regression, gross margin (GM) and appraisal indicators such as Net Present Value (NPV), Benefit Cost Ratio (BCR) and Internal Rate of Return (IRR) were used. The descriptive analysis, used to analyse the factors affecting the extent of adoption of CA revealed that socio-economic characteristics have the influence on the level to which a farmer responds to incentives. Linear regression model used in this study showed that years in farming, involvement in joint farmer’s group, and use of cover crops have the significant effect on the extent of adoption of CA. Moreover, the calculated gross margins of the two tillage systems were different, revealing higher Gross Margins for CA plots than for conventional plots. The major cause of the difference was found to be differences in the variable costs. When using appraisal indicators (NPV, BCR, and IRR) the study projected a 10-year period at 8% and 10.5% discount rates. The study also revealed positive NPVs for both CA and conventional agriculture. The positive sign implies that there are positive pay-offs for investing in both trial and control plots. However, trial plots have larger NPVs compared to control plots, meaning that there are less additional returns for investing in control plots compared to trial plots. Results also reveal that with 10.5% discount rate, the NPVs are lower than with 8% discount rate, showing that lower discount rates are consistent with higher performance over the long term. This therefore means that at lower discount rate, it is more viable to produce maize using CA than using conventional tillage system. In the case of BRC presented in the study, it was revealed that at both low and high discount rates, the trial plots were more viable than the control plots. Finally, the IRR presented in the study reveal that the trial plots would be able to pay their way much faster than the control plots. Overall, the study found that there are incentives to adoption of CA compared to conventional farming. The message from the different results arising from the use of different discount rates is that farmers should receive assistance at low cost of capital in order for their operations to be viable and this works out well over the long term as shown by the 10-year period projections.
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- Date Issued: 2017
Forage production, nutritive value and intake rates by goats of pigeon pea (Cajanus cajan (L.) forages grown in the subtropical region of South Africa
- Authors: Buthelezi, Lindokuhle Sizwe
- Date: 2017
- Subjects: Forage Pigeon pea Forage plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7852 , vital:30773
- Description: Different growth stages and drying methods were used to assess forage production, nutritive value and intake of leaves from three Cajanus cajan varieties (ICEAP 00557, ICEAP 01514 and CIMMYT 100/01). In the 2016/17 growing season, three complete randomized block designs (CRBD’s) were conducted. Regrowth parameters were measured during both the both vegetative and flowering stages. The plots were harvested at the flowering stage. Biomass yields were measured at the flowering stage. The harvested leaves were then dried under the two different drying methods. The methods used were shade- and oven-drying at 60 oC. This was used to determine dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL) and total non-structural carbohydrates (TNC) for the C. cajan varieties. Minerals Ca, Mg, K, Na, K/(Ca+Mg), P and Zn, Cu, Mn and Fe and phytochemicals condensed tannins, phenolic compounds and saponins were also analyzed. The intake rates and in vitro and in sacco ruminal degradabilities were also determined. The survival percentage was significantly different (P<0.05) only across the means of varieties. There was no significant difference (P>0.05) in the number of shoots per plant, stems per shoot and coppice stems produced by the three C. cajan varieties at vegetative and flowering stage. There was a significant difference (P<0.05) in the heights of plants recorded by the varieties only at flowering stage. The yields of fresh biomass in C. cajan was significantly different (P<0.05) across all the varieties harvested in 2016. In all the varieties there was a significant difference (P<0.05) in dry matter yield in both seasons of 2016 and 2017. The effect of browse varieties and drying methods showed a significant effect (P<0.05) on DM, CP, fat, NDIN, ADIN and hemicellulose content of varieties. There was little impact by varieties and drying methods (P<0.05) on ash, NDF, ADF, ADL, TNC and cellulose content of varieties. Varieties and drying method had no effect (P>0.05) on Ca, Mg and K except for Na and P. There was no effect caused by varieties and drying methods (P>0.05) on Zn and Mn with Cu and Fe being the exceptions. Oven drying showed an overall reduction in the tannin concentration on leaves while there was an increase in saponins. The different varieties had no effect (P>0.05) on the IIR, 0.0275±0.0089, 0.0275±0.0077 and 0.0409±0.0109 for Cv1, Cv2 and Cv3, respectively. The day of the trial and browse variety had an effect (P<0.05) on bite rate. However, the day of trial had no significant effect (P>0.05) on both bite size and the instantaneous intake rate. Individual goat had a significant effect (P<0.05) on bite rate. There was a significant difference (P<0.05) in the in vitro and in sacco rapidly degradable fractions (a) of all the three varieties but the drying method had no effect (P>0.05). The slowly degradable fraction (b) and degradation rate constant (c) of all varieties was not significantly different (P>0.05) on both drying methods during IV DaisyII procedure. However, b and c, in all the varieties was significantly different (P<0.05) in both drying methods during the in sacco procedure. There was no significant difference (P>0.05) in the mean potentially degradable fraction (a+b) across all C. cajan varieties during IV DaisyII procedure, however a+c of all varieties was significantly different (P<0.05) in both the drying methods during the in sacco procedure. The effective in vitro and in sacco degradability of the varieties was significantly different (P<0.05) with a rumen outflow rate of 2, 5 and 8 percent per hour. The shade-dried varieties had a higher (P<0.05) ED than the oven-dried materials during IV DaisyII and the in sacco procedures. It was concluded that the decline in yield of C. cajan during the study is a reflection of poor survival, the insufficient regeneration from seed, nutrient depletion over time and the extended dry seasons. Therefore, shade drying is commended method of drying forages.
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- Date Issued: 2017
Geological and geophysical investigations of the reservoir rock properties of the Gamtoos Basin in the Eastern Cape Province of South Africa
- Authors: Mokoele, Salmina Phuthi
- Date: 2017
- Subjects: Petroleum reserves -- Mechanical properties Petroleum reserves -- South Africa -- Eastern Cape Geophysics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7863 , vital:30779
- Description: Geological and geophysical studies of the Gamtoos Basin were carried out by using the research methods of stratigraphic analysis, petrographic analysis, sedimentary facies analysis, and geophysical studies. The orientation of the Gamtoos Basin onshore is controlled by the Gamtoos Fault which cuts through the lithologies of the Cape Supergroup on the eastern edge of the basin. Magnetic data and depth slices show the presence of the Cape Supergroup basement on the south east corner of the onshore Kirkwood Formation which is further sitting on the Gamtoos Group basement from the Neoproterozoic extending up to 8860 m in depth. Most previously compiled stratigraphic profiles of the Uitanhage Group revealed the presence of reddish massive conglomerate units from the Enon Formation and massive reddish to greenish alternating units of sandstones, siltstones and mudstones from the Kirkwood Formation. The results obtained from this research also revealed the presence of reddish to whitish massive alternating units of sandstones, mudstones and siltstones from the upper Enon Formation overlaying the reddish massive conglomeritic layers while the alternating reddish to greenish units of sandstones, siltstones and mudstones from the Kirkwood Formation are overlaid by massive reddish to greyish conglomeritic layers. Thirteen types of lithofacies and five types of biofacies were accounted for across the Gamtoos Basin from core logs, field observations and petrographic analysis. The same type of reddish to greyish massive conglomerate facies interbedded with subordinate sandstone lenses were observed on both the Enon (Lower most part) and the Kirkwood (top most part) Formations. Similar reddish to whitish sandstone facies were also observed in both formations except some of the units from the Kirkwood Formation revealed the presence of a lot of sedimentary structures such as laminations, thin beds, tabular cross beds, trough cross beds, convolute structures, load casts and even secondary structures like calcite veins and honey comb structures. Mudstone deposits are divided into reddish laminated facies and whitish massive facies. The whitish mudstone facies of the Enon Formation comprise caliche indicating the process of leaching while the reddish facies contain mudcracks indicating the process of desiccation. The Kirkwood Formation comprises reddish laminated mudstone facies and whitish massive mudstones. Petrographic studies revealed the presence of quartz arenites, lithic arenites, quartz wacke, lithic wacke, pelletic wacke, siltstones and mudstones. The mineral compositions were monocrystalline and polycrystalline quartz, plagioclase, K-feldspar and lithic fragments as the main framework grains. Muscovite and glauconite were identified as accessory minerals along with heavy minerals of hematite spotted on a few occasions. The matrix was composed of clay (mainly kaolinite and smectite), bentonite, illite-sericite and fine quartz silts. Microscope petrography revealed that organic matters occurred in 4 occurrences, i.e. as organic intraclasts, kerogen pellets, organic carbon laminae or stringers, and diagenetic crack-filling organic carbon (asphalt). Density determinations onshore have revealed an average wet density of 2.439 g/cm3 for the Enon Formation sandstones and 2.589 g/cm3 for the Kirkwood Formation sandstones. The average rock density for Borehole Ha-B2 is 2.67 g/cm3 whereas Borehole Ha-G1 rocks show an average density of 2.64 g/cm3. Geophysical data from the offshore boreholes has indicated an increase in the following parameters with depth: bulk density, porosity and geothermal gradient. Data from borehole logs resulted in a linear relationship between bulk density and depth although some boreholes were represented by more than one linear segment in one graph still showing gradual increase of bulk density with depth. The basin was deposited in terrestrial environments (braided fluvial fans and meandering rivers) and marine environments (beach, shallow and deep marine).
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- Date Issued: 2017