Comparative studies of different ant-hypertensive treatments used for cardiovascular disease patients : a case study of public health facility in the Eastern Cape South Africa
- Abiodun, Oluwatoyin Victoria
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
- Authors: Abiodun, Oluwatoyin Victoria
- Date: 2017
- Subjects: Survival analysis (Biometry) Cardiovascular system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13205 , vital:39519
- Description: Discovery has shown that many deaths arising from cardiovascular disease often show early symptoms of high blood pressure, which makes it the leading risk factor of cardiovascular diseases. There is a distressing rate of 970 million hypertensive patients worldwide, a higher ratio of 640 million are from developing countries, if proper measures are not taken, there will be a higher growth of cardiovascular disease in adults by 2025. The focus of this study was to compare the therapeutic potentials of the anti-hypertensive therapies, drug A (amiloride + furosemide) and drug B (hydrochlorothiazide + enalapril) used in the treatment of cardiovascular disease patients for their capability to lengthen remission duration and survival time. All patients were diagnosed with a type of cardiovascular disorder, therefore patient records were followed up and blood pressure was being monitored for a period of two years. The retrospective data gotten from the public health facility was analysed using survival analysis methods. The results revealed that there was no statistical significance in the distributions of the length of remission and survival time of drug A and drug B patients. Also, in the age category, CVD patients that are 55 and above recover faster with drug A, while CVD patients below 55 shows a better survival with drug B. Then again, estimates from the gender category show a better survival in males using drug A, while the females thrive slightly better using drug B. Among all the risk factors considered in the study, only employment status showed a strong impact on survival time (remission). The findings from this study may help to formulate interventions and strategies that will increase the lifespan of cardiovascular patients and reduce early mortality due to cardiovascular diseases.
- Full Text:
- Date Issued: 2017
In vitro evaluation of antimicrobial and antioxidant activities of olea europaea subsp. africana and euryops brevipapposus used by Cala community folkloric medicine for the management of infections associated with chronic non-communicable diseases
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants , Medicinal plants , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants , Medicinal plants , Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
Incidence and molecular characterization of Hepatitis E virus from swine herds in the Eastern Cape province, South Africa
- Authors: Adelabu, Olusesan Adeyemi
- Date: 2016
- Subjects: Hepatitis -- South Africa -- Eastern Cape Virology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13966 , vital:39734
- Description: Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented and the swine HEV identified to date in different countries belongs to either genotype 3 or 4. It has been reported to cross species barrier and cause infections in humans. Hence, Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, genotypes 1 and 2 are exclusively found in human population. However, little data are available regarding the occurrence of HEV in South Africa, especially in the Eastern Cape Province. Hence, this study was designed to assess the prevalence of Hepatitis E Virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province and screened for the presence of HEV. Faecal samples were collected, using sterile swabs, from swine between the age of 2 to 6 months old, placed on ice and transported to the laboratory for further analysis. Viral RNA extraction was carried out followed by nested reverse-transcriptase polymerase chain reaction was used for amplification, after which the amplified products were examined by electrophoresis and viewed under ultraviolet illumination. The positive PCR products were sent for sequencing. Of the 160 faecal samples screened, only seven were positive (4.4percent) for HEV. The nucleotide sequence analyses revealed isolates UFT 01-03 sharing 82percent to 99percent identities with other strains with accession numbers KX896664, KX896665 and KX896666 and UMCF 01-04 with KX896667, KX896668, KX896669 and KX896670 from different regions of the world Phylogenetic analysis also showed that all seven isolates from this study clustered with both human and swine HEV from different geographical regions of the world especially with Japan Human and swine strains, Netherland swine HEV strains (AY032758, AF332620) and human HEV strain from France (JQ763611). We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.
- Full Text:
- Date Issued: 2016
- Authors: Adelabu, Olusesan Adeyemi
- Date: 2016
- Subjects: Hepatitis -- South Africa -- Eastern Cape Virology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13966 , vital:39734
- Description: Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented and the swine HEV identified to date in different countries belongs to either genotype 3 or 4. It has been reported to cross species barrier and cause infections in humans. Hence, Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, genotypes 1 and 2 are exclusively found in human population. However, little data are available regarding the occurrence of HEV in South Africa, especially in the Eastern Cape Province. Hence, this study was designed to assess the prevalence of Hepatitis E Virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province and screened for the presence of HEV. Faecal samples were collected, using sterile swabs, from swine between the age of 2 to 6 months old, placed on ice and transported to the laboratory for further analysis. Viral RNA extraction was carried out followed by nested reverse-transcriptase polymerase chain reaction was used for amplification, after which the amplified products were examined by electrophoresis and viewed under ultraviolet illumination. The positive PCR products were sent for sequencing. Of the 160 faecal samples screened, only seven were positive (4.4percent) for HEV. The nucleotide sequence analyses revealed isolates UFT 01-03 sharing 82percent to 99percent identities with other strains with accession numbers KX896664, KX896665 and KX896666 and UMCF 01-04 with KX896667, KX896668, KX896669 and KX896670 from different regions of the world Phylogenetic analysis also showed that all seven isolates from this study clustered with both human and swine HEV from different geographical regions of the world especially with Japan Human and swine strains, Netherland swine HEV strains (AY032758, AF332620) and human HEV strain from France (JQ763611). We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.
- Full Text:
- Date Issued: 2016
Risk factors associated with developing asthma and tuberculosis: a case study of a hospital, Lagos Nigeria
- Authors: Adeniji, Tolulope Olubunmi
- Date: 2015
- Subjects: Asthma -- Nigeria -- Epidemiology , Diseases -- Risk factors -- Nigeria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13216 , vital:39616
- Description: The purpose of the study is to assess risk factors associated with developing asthma and tuberculosis. Methodology: A quantitative study was conducted on 133 randomly selected tuberculosis respondents, 91 of whom were suffering from TB at the time of the study. 120 respondents were also selected randomly for asthma of which 82 were asthmatic. Data were collected by using a self-structured questionnaire. The statistical analysis was done with the statistical package for social sciences (SPSS, version 18) using the descriptive statistics and logistic regression model. Results: Findings from the study show that a large percentage of the participants for both diseases were male, and the carriers of the diseases were also mostly male. Amongst the factors assessed, smoking, a weak immune system and a history of contact with tuberculosis infected persons were factors independently associated with developing tuberculosis. In the case of asthma, family history, smoking and exposure to allergen irritants were the factors independently associated with developing the disease. Conclusion: The findings highlight the need for increasing awareness through information, education and communication to address the risk factors of tuberculosis and asthma in order to decrease the rate of outspread. Recommendations: Factors triggering asthma among humans should be avoided. Since tuberculosis can be contracted through person to person contact, proper sanitation and regular medical attention are advocated for safeguarding personal and public health.
- Full Text:
- Date Issued: 2015
- Authors: Adeniji, Tolulope Olubunmi
- Date: 2015
- Subjects: Asthma -- Nigeria -- Epidemiology , Diseases -- Risk factors -- Nigeria
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13216 , vital:39616
- Description: The purpose of the study is to assess risk factors associated with developing asthma and tuberculosis. Methodology: A quantitative study was conducted on 133 randomly selected tuberculosis respondents, 91 of whom were suffering from TB at the time of the study. 120 respondents were also selected randomly for asthma of which 82 were asthmatic. Data were collected by using a self-structured questionnaire. The statistical analysis was done with the statistical package for social sciences (SPSS, version 18) using the descriptive statistics and logistic regression model. Results: Findings from the study show that a large percentage of the participants for both diseases were male, and the carriers of the diseases were also mostly male. Amongst the factors assessed, smoking, a weak immune system and a history of contact with tuberculosis infected persons were factors independently associated with developing tuberculosis. In the case of asthma, family history, smoking and exposure to allergen irritants were the factors independently associated with developing the disease. Conclusion: The findings highlight the need for increasing awareness through information, education and communication to address the risk factors of tuberculosis and asthma in order to decrease the rate of outspread. Recommendations: Factors triggering asthma among humans should be avoided. Since tuberculosis can be contracted through person to person contact, proper sanitation and regular medical attention are advocated for safeguarding personal and public health.
- Full Text:
- Date Issued: 2015
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.
- Full Text:
- Date Issued: 2017
- 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.
- Full Text:
- Date Issued: 2017
Characterization of Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) in selected recreational marine waters and beach sand in the Eastern Cape Province, South Africa
- Authors: Ankabi, Olufemi Emmanuel
- Date: 2017
- Subjects: Marine microbiology -- South Africa -- Eastern Cape Staphylococcus aureus infections -- South Africa -- Eastern Cape Pathogenic microorganisms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4992 , vital:28915
- Description: Staphylococcus aureus is a Gram-positive bacterium predominantly found on human skin and in nasal passages with 20 to 40 percent of the population carrying this organism. Although S. aureus is an unspectacular, non-motile coccoid bacterium, it is a perilous human pathogen associated with both nosocomial and community-acquired infections and it is increasingly becoming virulent and resistant to most antibiotics. It is responsible for several infections such as osteomyelitis, toxin-mediated diseases and bacteraemia, with severe infections arising from strains harbouring antibiotic resistance genes together with virulence genes. S. aureus has been largely confined to hospitals and long-term care facilities, but it is now emerging in the community in places such as recreational beach waters, and occurring in healthy individuals with no associated risk factors. This organism has been reported to be released by swimmers in beaches, suggesting that recreational waters are a potential source of community-acquired S. aureus infections. It is possibly the pathogen of greatest concern due to its intrinsic virulence, its capacity to cause various life-threatening infections, and its ability to adapt to varying environmental conditions. This study was aimed at characterizing S. aureus and methicillin-resistant S. aureus (MRSA) in Port Elizabeth, Port Alfred, Kenton-on-sea and East London beaches of the Eastern Cape Province of South Africa. This was done by investigating the occurrence, antibiotic susceptibilities, antibiotic-resistant genes and virulence genes profiles of S. aureus in the selected beaches. To achieve this aim, 249 beach sand and water samples were obtained from the beaches during the period of April 2015 to April 2016. Physico-chemical parameters of beach water was investigated on site using a multi-parameter ion specific meter during sample collection. Samples were filtered and inoculated on m-Endo agar, m-FC agar and bile aesculin azide agar for total and faecal coliform as well as Enterococci respectively. For isolation of S. aureus and MRSA, samples were cultured on Mannitol salt agar and Staph 24 agar. S. aureus was identified using morphological, Gram staining and molecular (PCR) methods. The isolates were further characterized by determining their antimicrobial resistance profiles, antibiotic resistant genes (mecA, rpoB, blaZ, ermB and tetK genes) and detection of virulent genes encoding intracellular adhesion (icaA), enterotoxin (seaA) and cytolytic toxins (PVL). The majority of study sites passed the directives of physico-chemical standards levels set by WHO during the study period. A total of 143 presumptive isolates were obtained of which 30 (30 percent) were confirmed as S. aureus with 22 (73.3 percent) of these confirmed isolates from marine water and 8 (26.7 percent) from marine sand. Upon culturing on MRSA 2 agar, 15 (50 percent) of isolates showed phonotypic resistance to methicillin. Based on Antimicrobial susceptibility tests, (22/30) 73.3 percent of the isolates showed phonotypic resistance to oxacillin. Out of the 30 isolates, 16 (53.3 percent) were mecA positive and were considered methicillin-resistant S. aureus. S. aureus showed high susceptibility to gentamycin, cefoxithin, levofloxacin, ciprofloxacin, imipenem, and chloramphenicol. A large proportion (36.67 percent to 96.7 percent) of the S. aureus isolates was resistant to penicillin G, ampicillin, oxacillin, tetracycline, clindamycin, rifampicin, vancomycin, sulfamethoxazole-Trimethoprim and erythromycin. Multiple antibiotic resistance (MAR) phenotypes were generated from 7 S. aureus isolates showing resistance to three or more antibiotics. The mecA, rpoB, blaZ, ermB and tetM genes coding for methicillin, rifampicin, βeta-lactam, erythromycin and tetracycline antibiotics resistance was detected in 5 (22.7 percent), 11 (45.8 percent), 16 (55.2 percent), 15 (71.4 percent) and 8 (72.7 percent) respectively. The PVL, icaA and seaA genes coding for virulent determinants were detected in 50, 20 and 13.3 percent of the confirmed isolates respectively. Physico-chemical and faecal indicator bacteria results obtained from this study can assist municipal authorities in developing appropriate management strategies for beaches in the study area. The findings of this study showed that the investigated beaches were contaminated with toxigenic and multi-drug resistant S. aureus strains. This emphasizes the need for the implementation of better control measures to reduce the occurrence of antibiotic resistant S. aureus and of virulent S. aureus strains in recreational waters. In our study it was established that the potential of recreational waters to be reservoirs of S. aureus should not be taken for granted, and it is important that beach goers be educated about this organism as well as other related pathogens that could affect human health, especially immuno-compromised individuals. The community should be educated on antibiotic stewardship and the detrimental effects of antibiotics abuse.
- Full Text:
- Date Issued: 2017
- Authors: Ankabi, Olufemi Emmanuel
- Date: 2017
- Subjects: Marine microbiology -- South Africa -- Eastern Cape Staphylococcus aureus infections -- South Africa -- Eastern Cape Pathogenic microorganisms
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4992 , vital:28915
- Description: Staphylococcus aureus is a Gram-positive bacterium predominantly found on human skin and in nasal passages with 20 to 40 percent of the population carrying this organism. Although S. aureus is an unspectacular, non-motile coccoid bacterium, it is a perilous human pathogen associated with both nosocomial and community-acquired infections and it is increasingly becoming virulent and resistant to most antibiotics. It is responsible for several infections such as osteomyelitis, toxin-mediated diseases and bacteraemia, with severe infections arising from strains harbouring antibiotic resistance genes together with virulence genes. S. aureus has been largely confined to hospitals and long-term care facilities, but it is now emerging in the community in places such as recreational beach waters, and occurring in healthy individuals with no associated risk factors. This organism has been reported to be released by swimmers in beaches, suggesting that recreational waters are a potential source of community-acquired S. aureus infections. It is possibly the pathogen of greatest concern due to its intrinsic virulence, its capacity to cause various life-threatening infections, and its ability to adapt to varying environmental conditions. This study was aimed at characterizing S. aureus and methicillin-resistant S. aureus (MRSA) in Port Elizabeth, Port Alfred, Kenton-on-sea and East London beaches of the Eastern Cape Province of South Africa. This was done by investigating the occurrence, antibiotic susceptibilities, antibiotic-resistant genes and virulence genes profiles of S. aureus in the selected beaches. To achieve this aim, 249 beach sand and water samples were obtained from the beaches during the period of April 2015 to April 2016. Physico-chemical parameters of beach water was investigated on site using a multi-parameter ion specific meter during sample collection. Samples were filtered and inoculated on m-Endo agar, m-FC agar and bile aesculin azide agar for total and faecal coliform as well as Enterococci respectively. For isolation of S. aureus and MRSA, samples were cultured on Mannitol salt agar and Staph 24 agar. S. aureus was identified using morphological, Gram staining and molecular (PCR) methods. The isolates were further characterized by determining their antimicrobial resistance profiles, antibiotic resistant genes (mecA, rpoB, blaZ, ermB and tetK genes) and detection of virulent genes encoding intracellular adhesion (icaA), enterotoxin (seaA) and cytolytic toxins (PVL). The majority of study sites passed the directives of physico-chemical standards levels set by WHO during the study period. A total of 143 presumptive isolates were obtained of which 30 (30 percent) were confirmed as S. aureus with 22 (73.3 percent) of these confirmed isolates from marine water and 8 (26.7 percent) from marine sand. Upon culturing on MRSA 2 agar, 15 (50 percent) of isolates showed phonotypic resistance to methicillin. Based on Antimicrobial susceptibility tests, (22/30) 73.3 percent of the isolates showed phonotypic resistance to oxacillin. Out of the 30 isolates, 16 (53.3 percent) were mecA positive and were considered methicillin-resistant S. aureus. S. aureus showed high susceptibility to gentamycin, cefoxithin, levofloxacin, ciprofloxacin, imipenem, and chloramphenicol. A large proportion (36.67 percent to 96.7 percent) of the S. aureus isolates was resistant to penicillin G, ampicillin, oxacillin, tetracycline, clindamycin, rifampicin, vancomycin, sulfamethoxazole-Trimethoprim and erythromycin. Multiple antibiotic resistance (MAR) phenotypes were generated from 7 S. aureus isolates showing resistance to three or more antibiotics. The mecA, rpoB, blaZ, ermB and tetM genes coding for methicillin, rifampicin, βeta-lactam, erythromycin and tetracycline antibiotics resistance was detected in 5 (22.7 percent), 11 (45.8 percent), 16 (55.2 percent), 15 (71.4 percent) and 8 (72.7 percent) respectively. The PVL, icaA and seaA genes coding for virulent determinants were detected in 50, 20 and 13.3 percent of the confirmed isolates respectively. Physico-chemical and faecal indicator bacteria results obtained from this study can assist municipal authorities in developing appropriate management strategies for beaches in the study area. The findings of this study showed that the investigated beaches were contaminated with toxigenic and multi-drug resistant S. aureus strains. This emphasizes the need for the implementation of better control measures to reduce the occurrence of antibiotic resistant S. aureus and of virulent S. aureus strains in recreational waters. In our study it was established that the potential of recreational waters to be reservoirs of S. aureus should not be taken for granted, and it is important that beach goers be educated about this organism as well as other related pathogens that could affect human health, especially immuno-compromised individuals. The community should be educated on antibiotic stewardship and the detrimental effects of antibiotics abuse.
- Full Text:
- Date Issued: 2017
The impact of the farmer field school approach on small-scale vegetable farmers' knowledge, agency and production in Alice, Eastern Cape
- Authors: Apleni, Asanda
- Date: 2017
- Subjects: Agricultural extension work -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8187 , vital:31873
- Description: This study investigates the impact of the Farmer Field School approach on the knowledge, agency and production of small-scale farmers. Farmer Field Schools were devised in the 1980s by the Food and Agriculture Organization as a form of adult education in agriculture. It is a group-based approach in which a facilitator meets with farmers on a regular basis and sets in motion a process by which farmers ‘learn how to learn’, both from themselves and from one another. However, it remains an open question whether the Farmer Field School approach could be a solution to South Africa’s abiding problem of weak agricultural extension. Early in 2015, the University of Fort Hare and the Nkonkobe Farmers’ Association initiated a number of study groups in the Alice area, based largely on Farmer Field School principles. The main objective of the study was to assess the impact of the Farmer Field School approach on small-scale farmers’ knowledge, agency and production, focusing on home gardeners. The study was conducted in the Raymond Mhlaba Local Municipality in Alice of the Eastern Cape Province of South Africa. The research consisted of a survey of all the study group participants involved with home gardens, including some who joined the groups in 2015 but left in 2016. Both cross-sectional and longitudinal designs were used. Findings from this study have shown how participation in the study groups modelled on the FFS approach can improve the knowledge and skills of home gardeners, while also enabling them to produce significantly larger quantities of vegetables, and even a marketable surplus, albeit from a small base. In order to make more people to join, more incentives should be made available. Such incentives should be made available only to “kick start” the FFS study groups and take heed in prevention of dependence.
- Full Text:
- Date Issued: 2017
- Authors: Apleni, Asanda
- Date: 2017
- Subjects: Agricultural extension work -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8187 , vital:31873
- Description: This study investigates the impact of the Farmer Field School approach on the knowledge, agency and production of small-scale farmers. Farmer Field Schools were devised in the 1980s by the Food and Agriculture Organization as a form of adult education in agriculture. It is a group-based approach in which a facilitator meets with farmers on a regular basis and sets in motion a process by which farmers ‘learn how to learn’, both from themselves and from one another. However, it remains an open question whether the Farmer Field School approach could be a solution to South Africa’s abiding problem of weak agricultural extension. Early in 2015, the University of Fort Hare and the Nkonkobe Farmers’ Association initiated a number of study groups in the Alice area, based largely on Farmer Field School principles. The main objective of the study was to assess the impact of the Farmer Field School approach on small-scale farmers’ knowledge, agency and production, focusing on home gardeners. The study was conducted in the Raymond Mhlaba Local Municipality in Alice of the Eastern Cape Province of South Africa. The research consisted of a survey of all the study group participants involved with home gardens, including some who joined the groups in 2015 but left in 2016. Both cross-sectional and longitudinal designs were used. Findings from this study have shown how participation in the study groups modelled on the FFS approach can improve the knowledge and skills of home gardeners, while also enabling them to produce significantly larger quantities of vegetables, and even a marketable surplus, albeit from a small base. In order to make more people to join, more incentives should be made available. Such incentives should be made available only to “kick start” the FFS study groups and take heed in prevention of dependence.
- Full Text:
- Date Issued: 2017
The classsification of fuzzy subgroups of some finite Abelian p-groups of rank 3
- Authors: Appiah, Isaac Kwadwo
- Date: 2016
- Subjects: Fuzzy sets Abelian groups Finite groups
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2468 , vital:27845
- Description: An important trend in fuzzy group theory in recent years has been the notion of classification of fuzzy subgroups using a suitable equivalence relation. In this dissertation, we have successfully used the natural equivalence relation defined by Murali and Makamba in [81] and a natural fuzzy isomorphism to classify fuzzy subgroups of some finite abelian p-groups of rank three of the form Zpn + Zp + Zp for any fixed prime integer p and any positive integer n. This was achieved through the usage of a suitable technique of enumerating distinct fuzzy subgroups and non-isomorphic fuzzy subgroups of G. We commence by giving a brief discussion on the theory of fuzzy sets and fuzzy subgroups from the perspective of group theory through to the theory of sets, leading us to establish a linkage among these theories. We have also shown in this dissertation that the converse of theorem 3.1 proposed by Das in [24] is incorrect by giving a counter example and restate the theorem. We have then reviewed and enriched the study conducted by Ngcibi in [94] by characterising the non-isomorphic fuzzy subgroups in that study. We have also developed a formula to compute the crisp subgroups of the under-studied group and provide its proof. Furthermore, we have compared the equivalence relation under which the classification problem is based with various versions of equivalence studied in the literature. We managed to use this counting technique to obtain explicit formulae for the number of maximal chains, distinct fuzzy subgroups, non-isomorphic maximal chains and non-isomorphic fuzzy subgroups of these groups and their proofs are provided.
- Full Text:
- Date Issued: 2016
- Authors: Appiah, Isaac Kwadwo
- Date: 2016
- Subjects: Fuzzy sets Abelian groups Finite groups
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2468 , vital:27845
- Description: An important trend in fuzzy group theory in recent years has been the notion of classification of fuzzy subgroups using a suitable equivalence relation. In this dissertation, we have successfully used the natural equivalence relation defined by Murali and Makamba in [81] and a natural fuzzy isomorphism to classify fuzzy subgroups of some finite abelian p-groups of rank three of the form Zpn + Zp + Zp for any fixed prime integer p and any positive integer n. This was achieved through the usage of a suitable technique of enumerating distinct fuzzy subgroups and non-isomorphic fuzzy subgroups of G. We commence by giving a brief discussion on the theory of fuzzy sets and fuzzy subgroups from the perspective of group theory through to the theory of sets, leading us to establish a linkage among these theories. We have also shown in this dissertation that the converse of theorem 3.1 proposed by Das in [24] is incorrect by giving a counter example and restate the theorem. We have then reviewed and enriched the study conducted by Ngcibi in [94] by characterising the non-isomorphic fuzzy subgroups in that study. We have also developed a formula to compute the crisp subgroups of the under-studied group and provide its proof. Furthermore, we have compared the equivalence relation under which the classification problem is based with various versions of equivalence studied in the literature. We managed to use this counting technique to obtain explicit formulae for the number of maximal chains, distinct fuzzy subgroups, non-isomorphic maximal chains and non-isomorphic fuzzy subgroups of these groups and their proofs are provided.
- Full Text:
- Date Issued: 2016
Group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa
- Authors: Arwari, Margaret Kwamboka
- Date: 2017
- Subjects: Farmers -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8144 , vital:31535
- Description: In South Africa, the organisation of farmers into groups has been a basic tenet for numerous, small and dispersed small-scale farmers to make their voices heard, address challenges and access support services from the government and other development agencies. However, the literature shows that the South African government promotes inappropriate forms of farmer collective action, i.e. collective production. The government seems to lack knowledge on what forms of collective action to implement and support. It is also noted in the literature that in South Africa, the majority of farmers do not participate in farmer organisations. There is limited research on the determinants of membership in farmer organisations, especially in terms of the role of ‘human agency’. Human agency is a concept which is interrelated with the concept of ‘empowerme nt’, whereby a person with strong agency is someone who is an agent of positive change. Therefore, the study sought to address these gaps. The broad objective of this study was to explore the phenomenon of group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa. The study used the mixed method approach where an exploratory design was employed. A mult istage sampling technique was used which employed random, purposive and convenience sampling techniques. Quantitative and qualitative data were collected from 245 farmers using semistructured questionnaires and detailed qualitative data were elicited from 16 farmer organisat ions using interview guides. For the quantitative research, a cross-sectional survey design was employed. After discarded unusable observations, data from 228 farmers were analysed using a combination of descriptive statistics, simple inferential statistics, and econometric analysis. For the qualitative data obtained, thematic analysis was used in line with the study objectives. The study findings show that farmers undertake collective action through farmer organisations. These farmer organisations were categorised into two types, i.e. farmer cooperatives and farmer associations. However, low membership in these farmer organisations is noted and this was attributed to the following: (1) low farmer awareness of the existence of farmer organisations, (2) challenges faced by the organisations that contribute to their ineffectiveness and thus low membership, (3) the prevalence of negative perceptions of farmer organisations due to confusion as to their role, (4) the government’s farmer support approach which compels or encourages farmers to form groups. The results also showed that the following are determinants of participation in farmer organisations: farmer’s age, level of education, human agency, whether a farmer has off-farm income sources, whether a farmer is involved in government supported projects, whether a farmer accesses extension information, the number of visits from extension officers received by a farmer, and the number of adults in a household contributing family labour. The study findings also show that the farmers in farmer organisations have higher human agency compared to those not in farmer organisations. According to the study results, farmer groups offer a number of benefits. For one, farmer organisations are avenues for farmers’ voices to be heard, they lobby government for better access to support services such as credit, input supply, information, and training. In addition, farmers who belong to organisations experience the benefits of collective marketing. Despite the aforementioned benefits of farmer organisations, group challenges are observed. For example, farmer organisations face declining membership, the free rider problem and conflicts between members, have a problem of ineffective, old members and lack of commitment of some group members. It was therefore recommended that there is a need for concerted effort by the government, development agencies, non-governmental organisations, farmers, and farmer organisations to ensure the success of farmer organisations in promoting small-scale agriculture.
- Full Text:
- Date Issued: 2017
- Authors: Arwari, Margaret Kwamboka
- Date: 2017
- Subjects: Farmers -- South Africa -- Eastern Cape Farms, Small -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8144 , vital:31535
- Description: In South Africa, the organisation of farmers into groups has been a basic tenet for numerous, small and dispersed small-scale farmers to make their voices heard, address challenges and access support services from the government and other development agencies. However, the literature shows that the South African government promotes inappropriate forms of farmer collective action, i.e. collective production. The government seems to lack knowledge on what forms of collective action to implement and support. It is also noted in the literature that in South Africa, the majority of farmers do not participate in farmer organisations. There is limited research on the determinants of membership in farmer organisations, especially in terms of the role of ‘human agency’. Human agency is a concept which is interrelated with the concept of ‘empowerme nt’, whereby a person with strong agency is someone who is an agent of positive change. Therefore, the study sought to address these gaps. The broad objective of this study was to explore the phenomenon of group membership and collective action among small-scale farmers in Nkonkobe Local Municipality, Eastern Cape Province, South Africa. The study used the mixed method approach where an exploratory design was employed. A mult istage sampling technique was used which employed random, purposive and convenience sampling techniques. Quantitative and qualitative data were collected from 245 farmers using semistructured questionnaires and detailed qualitative data were elicited from 16 farmer organisat ions using interview guides. For the quantitative research, a cross-sectional survey design was employed. After discarded unusable observations, data from 228 farmers were analysed using a combination of descriptive statistics, simple inferential statistics, and econometric analysis. For the qualitative data obtained, thematic analysis was used in line with the study objectives. The study findings show that farmers undertake collective action through farmer organisations. These farmer organisations were categorised into two types, i.e. farmer cooperatives and farmer associations. However, low membership in these farmer organisations is noted and this was attributed to the following: (1) low farmer awareness of the existence of farmer organisations, (2) challenges faced by the organisations that contribute to their ineffectiveness and thus low membership, (3) the prevalence of negative perceptions of farmer organisations due to confusion as to their role, (4) the government’s farmer support approach which compels or encourages farmers to form groups. The results also showed that the following are determinants of participation in farmer organisations: farmer’s age, level of education, human agency, whether a farmer has off-farm income sources, whether a farmer is involved in government supported projects, whether a farmer accesses extension information, the number of visits from extension officers received by a farmer, and the number of adults in a household contributing family labour. The study findings also show that the farmers in farmer organisations have higher human agency compared to those not in farmer organisations. According to the study results, farmer groups offer a number of benefits. For one, farmer organisations are avenues for farmers’ voices to be heard, they lobby government for better access to support services such as credit, input supply, information, and training. In addition, farmers who belong to organisations experience the benefits of collective marketing. Despite the aforementioned benefits of farmer organisations, group challenges are observed. For example, farmer organisations face declining membership, the free rider problem and conflicts between members, have a problem of ineffective, old members and lack of commitment of some group members. It was therefore recommended that there is a need for concerted effort by the government, development agencies, non-governmental organisations, farmers, and farmer organisations to ensure the success of farmer organisations in promoting small-scale agriculture.
- Full Text:
- Date Issued: 2017
Multi-temporal assessment of spatial changes in vegetation distribution in the Swartkops estuary, Port Elizabeth, Eastern Cape, South Africa
- Authors: Atyosi, Yonwaba
- Date: 2017
- Subjects: Climatic changes -- South Africa -- Eastern Cape Environmental impact analysis Estuaries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13762 , vital:39710
- Description: Over the last decade, image classification has been widely used as a change detection method and provides detailed information for detecting and monitoring changes in land use and land cover (LULC). The main objective of this study was to reconstruct long-term changes in the spatial distribution of different vegetation types in the Swartkops Estuary from 1983 to 2013. The Swartkops Estuary is ecologically important for its wide range of vegetation types that are habitat to estuarine and riverine organisms. Four Landsat images for the years 1984 (Thematic Mapper), 1993 (Thematic Mapper), 2003(Enhanced Thematic Mapper +) and 2013 (Operational Land Imager) were used with the aid of aerial photographs that were used as an ancillary data source. The research methodology comprised of supervised classification, classification accuracy assessment and image differencing. Supervised classification was performed and results of the image classification process for the four time periods were compared to derive information on changes that occurred over the 29-year study period. Images were classified into the following classes: Estuarine water, Salt works, Zostera capensis, Spartina maritima, Terrestrial vegetation, Salt marsh, Swartkops thicket, Built-up areas, Bare areas, and Beach sand, using the Maximum likelihood classifier on Erdas IMAGINE 2014 Software. The significance of the image classification was tested using linear trend regression analysis. Image differencing was performed using 1984 and 2013 Landsat images to reconstruct overall changes in vegetation distribution of the Swartkops Estuary. Results of this investigation revealed significant changes in all land cover types, 24 ha increase from 1984 to 2013 in Zostera capensis as well as Spartina maritima, salt marshes increased by 14 ha between 1984 and 2013, terrestrial vegetation declined by 18 ha between 1984 and 2013. There was a stable increase in estuarine water from 1984 to 2013 by a total area of 29 ha. Water increased by 14 ha between 1984 and 1993, 11 ha increase between 1993 and 2003. However, there was a decline in estuarine water in the period between 2003 and 2013.This decline is associated with the increase in submerged macrophytes like Zostera capensis which utilise open water habitat. The dominant salt marsh species Limonium peregrinum, Sarcoconia pillansii and Spartina maritima occurred in the intertidal, supratidal and floodplain areas where the water table was the shallowest, with the soil moisture being the highest. These results indicate that Remote Sensing and GIS can be effectively used to detect and monitor changes in estuarine biodiversity and habitat in South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Atyosi, Yonwaba
- Date: 2017
- Subjects: Climatic changes -- South Africa -- Eastern Cape Environmental impact analysis Estuaries -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13762 , vital:39710
- Description: Over the last decade, image classification has been widely used as a change detection method and provides detailed information for detecting and monitoring changes in land use and land cover (LULC). The main objective of this study was to reconstruct long-term changes in the spatial distribution of different vegetation types in the Swartkops Estuary from 1983 to 2013. The Swartkops Estuary is ecologically important for its wide range of vegetation types that are habitat to estuarine and riverine organisms. Four Landsat images for the years 1984 (Thematic Mapper), 1993 (Thematic Mapper), 2003(Enhanced Thematic Mapper +) and 2013 (Operational Land Imager) were used with the aid of aerial photographs that were used as an ancillary data source. The research methodology comprised of supervised classification, classification accuracy assessment and image differencing. Supervised classification was performed and results of the image classification process for the four time periods were compared to derive information on changes that occurred over the 29-year study period. Images were classified into the following classes: Estuarine water, Salt works, Zostera capensis, Spartina maritima, Terrestrial vegetation, Salt marsh, Swartkops thicket, Built-up areas, Bare areas, and Beach sand, using the Maximum likelihood classifier on Erdas IMAGINE 2014 Software. The significance of the image classification was tested using linear trend regression analysis. Image differencing was performed using 1984 and 2013 Landsat images to reconstruct overall changes in vegetation distribution of the Swartkops Estuary. Results of this investigation revealed significant changes in all land cover types, 24 ha increase from 1984 to 2013 in Zostera capensis as well as Spartina maritima, salt marshes increased by 14 ha between 1984 and 2013, terrestrial vegetation declined by 18 ha between 1984 and 2013. There was a stable increase in estuarine water from 1984 to 2013 by a total area of 29 ha. Water increased by 14 ha between 1984 and 1993, 11 ha increase between 1993 and 2003. However, there was a decline in estuarine water in the period between 2003 and 2013.This decline is associated with the increase in submerged macrophytes like Zostera capensis which utilise open water habitat. The dominant salt marsh species Limonium peregrinum, Sarcoconia pillansii and Spartina maritima occurred in the intertidal, supratidal and floodplain areas where the water table was the shallowest, with the soil moisture being the highest. These results indicate that Remote Sensing and GIS can be effectively used to detect and monitor changes in estuarine biodiversity and habitat in South Africa.
- Full Text:
- Date Issued: 2017
Analyses of the simple harmonic oscillator and its variations
- Authors: Bambiso, Noludwe Patience
- Date: 2017
- Subjects: Harmonic analysis Vibration -- Mathematical models Oscillations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8132 , vital:31530
- Description: Vibratory motion is fundamental to all natural phenomena. It occurs everywhere in nature, from fundamental particles to the complexity of the life of the smallest cell, to the properties of the cosmos. Its frequency ranges from those of gammarays down the spectrum of X-rays, microwave, optical and radio waves. These are common concepts in everyday life, but their origin and nature are seldom comprehended. In this thesis we look at the mathematical fundamentals and how to apply them. We start with fundamental concepts and extend them to more complicated systems. We consider methods of analysis and applications. In Chapter 2 we consider simple harmonic oscillators and their mathematical analyses and in Chapter 3 we look at applications. Chapter 4 discusses the general form of simple harmonic motion, i.e. damped and forced harmonic motion. We consider simple coupled systems and their analysis. In Chapter 5 we introduce the method of complex functions and its application to complicated compound systems. Chapter 6 introduces a novel application, that of how SHM can be used as a model for advanced effects, or acausality. Chapter 7 presents a summary and conclusion.
- Full Text:
- Date Issued: 2017
- Authors: Bambiso, Noludwe Patience
- Date: 2017
- Subjects: Harmonic analysis Vibration -- Mathematical models Oscillations
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/8132 , vital:31530
- Description: Vibratory motion is fundamental to all natural phenomena. It occurs everywhere in nature, from fundamental particles to the complexity of the life of the smallest cell, to the properties of the cosmos. Its frequency ranges from those of gammarays down the spectrum of X-rays, microwave, optical and radio waves. These are common concepts in everyday life, but their origin and nature are seldom comprehended. In this thesis we look at the mathematical fundamentals and how to apply them. We start with fundamental concepts and extend them to more complicated systems. We consider methods of analysis and applications. In Chapter 2 we consider simple harmonic oscillators and their mathematical analyses and in Chapter 3 we look at applications. Chapter 4 discusses the general form of simple harmonic motion, i.e. damped and forced harmonic motion. We consider simple coupled systems and their analysis. In Chapter 5 we introduce the method of complex functions and its application to complicated compound systems. Chapter 6 introduces a novel application, that of how SHM can be used as a model for advanced effects, or acausality. Chapter 7 presents a summary and conclusion.
- Full Text:
- Date Issued: 2017
An analysis on the use of web-based ontology to support ubiquitous learning in South African secondary schools
- Bamigboye, Oluwatosin Omotoyosi
- Authors: Bamigboye, Oluwatosin Omotoyosi
- Date: 2018
- Subjects: Internet in education World Wide Web Ontology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12859 , vital:39385
- Description: There is certainly a need to upgrade our educational system and this can be done through technology-enhanced learning. Technology-enhanced learning can be achieved by developing a web-based ontology e-learning platform, which allows learning to take place ubiquitously. In achieving this task, this research is focusing on analyzing the use of web-based ontology to support the design and implementation of a ubiquitous learning system in South Africa. The implemented web-based ontology e-learning system was deployed and tested. The system testing was done on two variables (Information retrieval and Scalability) of localhost and client system, with the following testing metrics: time is taken for information retrieval, request time to process the request, transfer rate, time localhost receives request, time to respond, roundtrip time for request and network usage. The metrics testing was achieved using apache benchmarking console and gnuplot application to generate the data captured and performance graph, while Wireshark was also used to test/analyze round trip time and network usage through the deployed system. The results of the findings in this study show that the relationship between student and learning content becomes explicit when using ontology technology in searching, organizing, gathering and development content. Results obtained from information retrieval show that the transfer rate of information on localhost for 100 request @ current level of 5 is 37169.89kb/s, while on the client’s system, the transfer rate was 48494.36kb/s which was due to multiple request on the client’s side. Results obtained on scalability shows the round trip time which was (time to respond-time to request). The longest roundtrip was 8 seconds as a result of network being congested with multiple packets request from various sources trying to access the localhost at the same time while the fastest was 1 seconds. The implications of this results show that web-based ontology e-learning system has a positive input to teaching and learning processes in schools for content retrieval and network usage. The system furthermore shows the relationship adopted by learners and teachers, and also the match needs that arise in between. The contribution of this study adds to the existing discoveries on the use of web-based and knowledge-based ontology.
- Full Text:
- Date Issued: 2018
- Authors: Bamigboye, Oluwatosin Omotoyosi
- Date: 2018
- Subjects: Internet in education World Wide Web Ontology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/12859 , vital:39385
- Description: There is certainly a need to upgrade our educational system and this can be done through technology-enhanced learning. Technology-enhanced learning can be achieved by developing a web-based ontology e-learning platform, which allows learning to take place ubiquitously. In achieving this task, this research is focusing on analyzing the use of web-based ontology to support the design and implementation of a ubiquitous learning system in South Africa. The implemented web-based ontology e-learning system was deployed and tested. The system testing was done on two variables (Information retrieval and Scalability) of localhost and client system, with the following testing metrics: time is taken for information retrieval, request time to process the request, transfer rate, time localhost receives request, time to respond, roundtrip time for request and network usage. The metrics testing was achieved using apache benchmarking console and gnuplot application to generate the data captured and performance graph, while Wireshark was also used to test/analyze round trip time and network usage through the deployed system. The results of the findings in this study show that the relationship between student and learning content becomes explicit when using ontology technology in searching, organizing, gathering and development content. Results obtained from information retrieval show that the transfer rate of information on localhost for 100 request @ current level of 5 is 37169.89kb/s, while on the client’s system, the transfer rate was 48494.36kb/s which was due to multiple request on the client’s side. Results obtained on scalability shows the round trip time which was (time to respond-time to request). The longest roundtrip was 8 seconds as a result of network being congested with multiple packets request from various sources trying to access the localhost at the same time while the fastest was 1 seconds. The implications of this results show that web-based ontology e-learning system has a positive input to teaching and learning processes in schools for content retrieval and network usage. The system furthermore shows the relationship adopted by learners and teachers, and also the match needs that arise in between. The contribution of this study adds to the existing discoveries on the use of web-based and knowledge-based ontology.
- Full Text:
- Date Issued: 2018
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.
- Full Text:
- Date Issued: 2017
- 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.
- Full Text:
- Date Issued: 2017
Thermodynamic and electrical performance monitoring of a domestic split-type air conditioner and development of a simulation based R22 permanent replacement
- Authors: Bantan, Mafor Glory
- Date: 2017
- Subjects: Air conditioning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4857 , vital:28537
- Description: The difficulty that exists in accurately monitoring the performance of air conditioners has made performance prediction an arduous task. Nevertheless, the performance still needs to be monitored and predicted as it helps solve a lot of problems resulting from this technology like effect of the technology on the grid, energy consumption, water utilisation and GHGs emission. With the introduction of regression modelling as a means of system monitoring and prediction some years ago, the accuracy was still a call for concern. It is worth realising that increasing the number of predictors will enhance this method’s accuracy. As such, this document intends to increase the accuracy of this method’s monitoring and predicting ability by increasing the number of predictors to cut across system thermal, environmental and human behavioural variation. These predictors experimentally gotten are used to build an environ-behavioural model that monitors the coefficient of performance and energy consumption of a domestic split-type air conditioner with higher accuracy. Refrigerants have undergone evolution in the past decades in a bid to come up with a refrigerant that has zero ODP, lower – than – R22 GWP and much better than R22 thermodynamic performance. No pure refrigerant has been found to possess these qualities as such mixtures or blends are the best shot at the moment. R410A could stand the test of time to be the long term R22 replacement but for the fact that besides R410A’s higher GWP than that of R22, the former’s system performance is lower than that of the latter’s due to the lower thermodynamic performance of the former. This means the search continues. In this document, a combination of carefully chosen refrigerant components are carefully blended to come up with a simulation based R22 long term replacement, which will be referred to in this document as BTEP.
- Full Text:
- Date Issued: 2017
- Authors: Bantan, Mafor Glory
- Date: 2017
- Subjects: Air conditioning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4857 , vital:28537
- Description: The difficulty that exists in accurately monitoring the performance of air conditioners has made performance prediction an arduous task. Nevertheless, the performance still needs to be monitored and predicted as it helps solve a lot of problems resulting from this technology like effect of the technology on the grid, energy consumption, water utilisation and GHGs emission. With the introduction of regression modelling as a means of system monitoring and prediction some years ago, the accuracy was still a call for concern. It is worth realising that increasing the number of predictors will enhance this method’s accuracy. As such, this document intends to increase the accuracy of this method’s monitoring and predicting ability by increasing the number of predictors to cut across system thermal, environmental and human behavioural variation. These predictors experimentally gotten are used to build an environ-behavioural model that monitors the coefficient of performance and energy consumption of a domestic split-type air conditioner with higher accuracy. Refrigerants have undergone evolution in the past decades in a bid to come up with a refrigerant that has zero ODP, lower – than – R22 GWP and much better than R22 thermodynamic performance. No pure refrigerant has been found to possess these qualities as such mixtures or blends are the best shot at the moment. R410A could stand the test of time to be the long term R22 replacement but for the fact that besides R410A’s higher GWP than that of R22, the former’s system performance is lower than that of the latter’s due to the lower thermodynamic performance of the former. This means the search continues. In this document, a combination of carefully chosen refrigerant components are carefully blended to come up with a simulation based R22 long term replacement, which will be referred to in this document as BTEP.
- Full Text:
- Date Issued: 2017
Synthesis and characterization of MXS (M = Mo & V) and carbon supported MXS nanocomposites as Pt-free counter electrodes for electrode for DSSC application
- Authors: Bede, Asanda
- Date: 2020
- Subjects: Voltammetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18599 , vital:42612
- Description: It has been reported that the morphology, crystalline phase composition and electrochemical properties of counter electrode materials such MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials was of considerable importance because it governs the efficiency of many photon assisted chemical and physical reactions in dye sensitized solar cells (DSSCs). The efficiency of DSSCs with composite counter electrode materials is reliant on the stability of the photochemistry reactions which can be optimized by appropriate doping levels of the composite materials. Moreover, the microstructure such as surface area, distribution of the MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials, and the stability of the electrostatic bonds between the MxS (Mo, V) with the carbon support also play a significant role in the performance of the DSSCs. This work evaluates the effect of different mole ratios of the MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials on the morphological, structural and electrochemical properties of the composite materials. MoS2 nanoflakes nanostructures have been synthesized by hydrothermal technique using sodium orthovanadate (Na2MoO4) as precursor. In this work Carbon supported MoS2 NFs have been prepared by physically/chemically mixing different mole ratios of MoS2 NFs with multi-walled carbon nanotubes (MWCNTs) and polyvinylidene in N-methyl-2-pyrrolidinone. The morphological, structural and electrochemical properties of the composite counter electrode materials have been investigated using SEM, XRD FTIR, TEM, RS and CV. SEM analysis has revealed the presence of large MoS2 nanoflakes (NFs) as synthesized. SEM analysis has also revealed significant change in the surface morphology of carbon supported MoS2 composite nanostructures with the change in the mole ratio of the MoS2 NFs and carbon support multi-walled carbon nanotubes. Structural analysis through HRTEM analysis revealed a d-spacing of 0.65 nm with a corresponding (002) lattice plane belonging to a trigonal crystalline phase of MoS2. Also, HRTEM analysis has revealed d-spacing of 0.291 nm corresponding to 002 plane of MWCNTs. Raman spectroscopy has revealed Characteristic Raman vibration frequencies and symmetries at 264.6 cm-1(Eg), 354.2 cm-1 (Ag ) belonging trigonal phase of MoS2 (1T-MoS2). FTIR analysis has revealed a narrow peak at 457.6 cm-1 due Mo-S vibration bond. This observation confirms the success of synthesis of MoS2 nanostructures. Cyclic voltammetry (CV), charge-discharge (CD) and electrochemical impedance spectroscopy (EIS) measurements have revealed that the ratio 6:3:1 have shown to be optimum ratio due to its large reduction rate compared to pristine MoS2 NFs and other carbon supported MoS2 NFs. Calculated Rreduction for the carbon supported MoS2 NFs is the order 3:6:1>1:8:1>6:3:1>8:1:1 indicating the trend of ratio 3:6:1 appeared to have higher reduction rate than the rest of the material and it had far less ΔEpp than the rest of other ratios. All CV curves for both pristine MoS2 NFs and carbon supported MoS2 NFs confirmed a distinct Faradic characteristic. The VS2 nanosheets (NSs) and carbon supported VS2 NSs were also effectively synthesized via hydrothermal method. The SEM micrographs for VS2 NSs and carbon supported VS2 NSs samples reveals level increased. Furthermore, SEM-EDX analysis have confirmed the presence of V and S as well as C and O on carbon supported VS2 nanocomposites, and it clearly shown a gradually blending as the ratios increases. The structural studies through XRD analysis have revealed peaks at 2θ angles of 15.4◦, 28.2◦, 34.2◦, 36.2◦, 43.3◦,48.3◦, 54.4◦, 57.7◦ and 66.2◦ which correspond to the lattice planes (001), (002), (100), (011), (102), (003), (110), (103) and (201) belonging to hexagonal VS2 (H-VS2) crystalline phase as per JCPDS card 36-1139. The HRTEM have revealed that the VS2 NSs have an edge to edge length of ~ 0.294 – 1.248 µm. Also, HRTEM micrographs of VS2 NSs have revealed interplanar d spacing of 0.571 nm belonging to the (001) lattice plane of hexagonal VS2 (H-VS2) structure. FTIR analysis have shown a peak at 558 cm-1 attributed to V-S which is evident that sulfur has bonded with the metal (V) and is in agreement with EDS. CV, CD and EIS measurements have shown that the ratio 1:8:1 is more superior to VS2 NSs and other carbon supported VS2 NSs. Based on Rreduction for the carbon supported nanosheets VS2 nanosheets are ordered as 1:8:1>3:6:1>6:3:1>8:1:1. Carbon supported VS2 NSs of the mole ratio 1:8:1 showed a small resistance of 0.32 Ω. This is further evidence that the carbon supported VS2 NSs of the mole ratio 1:8:1 in addition to revealing excellent catalytic behaviour is also more chemically stable and has good conductivity properties._________
- Full Text:
- Date Issued: 2020
- Authors: Bede, Asanda
- Date: 2020
- Subjects: Voltammetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/18599 , vital:42612
- Description: It has been reported that the morphology, crystalline phase composition and electrochemical properties of counter electrode materials such MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials was of considerable importance because it governs the efficiency of many photon assisted chemical and physical reactions in dye sensitized solar cells (DSSCs). The efficiency of DSSCs with composite counter electrode materials is reliant on the stability of the photochemistry reactions which can be optimized by appropriate doping levels of the composite materials. Moreover, the microstructure such as surface area, distribution of the MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials, and the stability of the electrostatic bonds between the MxS (Mo, V) with the carbon support also play a significant role in the performance of the DSSCs. This work evaluates the effect of different mole ratios of the MxS (Mo, V) and carbon supported MxS (Mo, V) composite nanomaterials on the morphological, structural and electrochemical properties of the composite materials. MoS2 nanoflakes nanostructures have been synthesized by hydrothermal technique using sodium orthovanadate (Na2MoO4) as precursor. In this work Carbon supported MoS2 NFs have been prepared by physically/chemically mixing different mole ratios of MoS2 NFs with multi-walled carbon nanotubes (MWCNTs) and polyvinylidene in N-methyl-2-pyrrolidinone. The morphological, structural and electrochemical properties of the composite counter electrode materials have been investigated using SEM, XRD FTIR, TEM, RS and CV. SEM analysis has revealed the presence of large MoS2 nanoflakes (NFs) as synthesized. SEM analysis has also revealed significant change in the surface morphology of carbon supported MoS2 composite nanostructures with the change in the mole ratio of the MoS2 NFs and carbon support multi-walled carbon nanotubes. Structural analysis through HRTEM analysis revealed a d-spacing of 0.65 nm with a corresponding (002) lattice plane belonging to a trigonal crystalline phase of MoS2. Also, HRTEM analysis has revealed d-spacing of 0.291 nm corresponding to 002 plane of MWCNTs. Raman spectroscopy has revealed Characteristic Raman vibration frequencies and symmetries at 264.6 cm-1(Eg), 354.2 cm-1 (Ag ) belonging trigonal phase of MoS2 (1T-MoS2). FTIR analysis has revealed a narrow peak at 457.6 cm-1 due Mo-S vibration bond. This observation confirms the success of synthesis of MoS2 nanostructures. Cyclic voltammetry (CV), charge-discharge (CD) and electrochemical impedance spectroscopy (EIS) measurements have revealed that the ratio 6:3:1 have shown to be optimum ratio due to its large reduction rate compared to pristine MoS2 NFs and other carbon supported MoS2 NFs. Calculated Rreduction for the carbon supported MoS2 NFs is the order 3:6:1>1:8:1>6:3:1>8:1:1 indicating the trend of ratio 3:6:1 appeared to have higher reduction rate than the rest of the material and it had far less ΔEpp than the rest of other ratios. All CV curves for both pristine MoS2 NFs and carbon supported MoS2 NFs confirmed a distinct Faradic characteristic. The VS2 nanosheets (NSs) and carbon supported VS2 NSs were also effectively synthesized via hydrothermal method. The SEM micrographs for VS2 NSs and carbon supported VS2 NSs samples reveals level increased. Furthermore, SEM-EDX analysis have confirmed the presence of V and S as well as C and O on carbon supported VS2 nanocomposites, and it clearly shown a gradually blending as the ratios increases. The structural studies through XRD analysis have revealed peaks at 2θ angles of 15.4◦, 28.2◦, 34.2◦, 36.2◦, 43.3◦,48.3◦, 54.4◦, 57.7◦ and 66.2◦ which correspond to the lattice planes (001), (002), (100), (011), (102), (003), (110), (103) and (201) belonging to hexagonal VS2 (H-VS2) crystalline phase as per JCPDS card 36-1139. The HRTEM have revealed that the VS2 NSs have an edge to edge length of ~ 0.294 – 1.248 µm. Also, HRTEM micrographs of VS2 NSs have revealed interplanar d spacing of 0.571 nm belonging to the (001) lattice plane of hexagonal VS2 (H-VS2) structure. FTIR analysis have shown a peak at 558 cm-1 attributed to V-S which is evident that sulfur has bonded with the metal (V) and is in agreement with EDS. CV, CD and EIS measurements have shown that the ratio 1:8:1 is more superior to VS2 NSs and other carbon supported VS2 NSs. Based on Rreduction for the carbon supported nanosheets VS2 nanosheets are ordered as 1:8:1>3:6:1>6:3:1>8:1:1. Carbon supported VS2 NSs of the mole ratio 1:8:1 showed a small resistance of 0.32 Ω. This is further evidence that the carbon supported VS2 NSs of the mole ratio 1:8:1 in addition to revealing excellent catalytic behaviour is also more chemically stable and has good conductivity properties._________
- Full Text:
- Date Issued: 2020
The contribution of small-scale fisheries to rural livelihoods and food security : evidence from Hamburg, Eastern Cape Province, South Africa
- Authors: Budaza, Nwabisa
- Date: 2018
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Fishery management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10338 , vital:35396
- Description: Small-scale fisheries are known to provide food and income to millions of people around the world, but their role and existence is often ignored in development planning. The growing human demand for animal protein has become one of the foremost world challenges for which aquatic organisms have a significant role to play. In South Africa, small-scale fisheries have been recognized since the end of Apartheid, but the extent of the contribution of the sector to rural livelihoods and food security is not well understood. Using data drawn from a sample of 80 fishers in the coastal community of Hamburg, Eastern Cape, this dissertation presents an assessment of the contribution of small-scale fisheries to rural livelihoods, income and food security. The primary data were collected from the fishers using a structured questionnaire and non-probability sampling. The data were analysed with the assistance of descriptive techniques and a few simply statistical tests. The results of the study indicate that fishers in Hamburg catch a wide range of fish, which include wild kob, octopus, spotted grunter, white/black mussel cracker and white steenbras. Fishers in the study area are not solely dependent on small-scale fisheries for their livelihoods, income and food security, but generally supplement their welfare payments with fishing in order to sustain their livelihoods. About 78percent of the surveyed fishers depend on government grants, including old age grants, child support grants and social care grant. In terms of employment, 15percent of the surveyed fishers are casually employed, while 6percent are formally employed on a contract basis. Although they are not only dependent on fishing, nevertheless fishing is an important source of livelihood, income and food security. About 37percent of the fishers harvest marine resources for home consumption, while 7percent harvest solely for income, and 56percent harvest for both home consumption and income. Income generated from fisheries is approximately R935 per month and is used to buy food, electricity, fishing equipment and other household needs. The findings from this research underline the need for interventions such as coordinated institutions, improved infrastructure, improved monitoring and enforcement systems, as well as improved access to permit/fishing rights for sustainable use of marine resources.
- Full Text:
- Date Issued: 2018
- Authors: Budaza, Nwabisa
- Date: 2018
- Subjects: Small-scale fisheries -- South Africa -- Eastern Cape Food supply -- South Africa -- Eastern Cape Fishery management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10338 , vital:35396
- Description: Small-scale fisheries are known to provide food and income to millions of people around the world, but their role and existence is often ignored in development planning. The growing human demand for animal protein has become one of the foremost world challenges for which aquatic organisms have a significant role to play. In South Africa, small-scale fisheries have been recognized since the end of Apartheid, but the extent of the contribution of the sector to rural livelihoods and food security is not well understood. Using data drawn from a sample of 80 fishers in the coastal community of Hamburg, Eastern Cape, this dissertation presents an assessment of the contribution of small-scale fisheries to rural livelihoods, income and food security. The primary data were collected from the fishers using a structured questionnaire and non-probability sampling. The data were analysed with the assistance of descriptive techniques and a few simply statistical tests. The results of the study indicate that fishers in Hamburg catch a wide range of fish, which include wild kob, octopus, spotted grunter, white/black mussel cracker and white steenbras. Fishers in the study area are not solely dependent on small-scale fisheries for their livelihoods, income and food security, but generally supplement their welfare payments with fishing in order to sustain their livelihoods. About 78percent of the surveyed fishers depend on government grants, including old age grants, child support grants and social care grant. In terms of employment, 15percent of the surveyed fishers are casually employed, while 6percent are formally employed on a contract basis. Although they are not only dependent on fishing, nevertheless fishing is an important source of livelihood, income and food security. About 37percent of the fishers harvest marine resources for home consumption, while 7percent harvest solely for income, and 56percent harvest for both home consumption and income. Income generated from fisheries is approximately R935 per month and is used to buy food, electricity, fishing equipment and other household needs. The findings from this research underline the need for interventions such as coordinated institutions, improved infrastructure, improved monitoring and enforcement systems, as well as improved access to permit/fishing rights for sustainable use of marine resources.
- Full Text:
- Date Issued: 2018
Performance evaluation of an off-grid building integrated photovoltaic system in Alice, Eastern Cape province, South Africa
- Authors: Buma, Carine Lethem
- Date: 2018
- Subjects: Building-integrated photovoltaic systems Buildings -- Energy conservation Performance -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13227 , vital:39623
- Description: The constant increase in the global demand for energy and the current crisis on global warming and climate change has prompted a dying quest for clean, sustainable and reliable sources of energy. Amongst numerous renewable energy technologies, harnessing energy from the sun is the most viable way of guaranteeing a clean and sustainable supply of energy. Also, photovoltaic energy is one of the ways of using energy from the sun, where sunlight is converted to electricity using photovoltaic panels. Furthermore, the integration of photovoltaic modules into buildings is one of the most elegant innovations of this technology, as it plays the dual role of supplying energy to the building as well as protecting the building from outdoor weather conditions. Moreover, operating off the grid offers the possibility of energy access to locations far off from the grid and individuals willing to gain some degree of energy independence. Evaluating the performance of existing off grid and/or building integrated photovoltaic systems is the key to guaranteeing sustainable development and advancement in the technology. Thus, the aim of this work was to evaluate the performance of an off-grid building integrated photovoltaic system that was installed at the Fort Hare Institute of Technology. This entailed performing an in-depth characterisation of the solar resource at this location, evaluating the performance of the modules under outdoor weather conditions and also evaluating the performance of the balance of system (BOS) components. The system was monitored for a period of nine months (between February and October 2017). A data acquisition system was designed for measuring and recording both electrical system parameters and meteorological parameters affecting the performance of the system. These meteorological parameters include; solar irradiance, ambient temperature, cell temperature, relative humidity, wind speed and direction. A detailed characterisation of the solar resource at this location was carried out. It was observed that the solar declination angle varied from -23.5o on the summer solstice to 23.5o on the winter solstice. Also, the solar altitude angle (at solar noon) which is a complementary angle to the zenith angle varied from 33.7o in June to 80.65o in December. During the summer months, longer day lengths were experienced because the sun traversed the sky over a longer time, rising south of east and setting south of west. Whereas, in the winter months, the path length of the sun was shorter, with the sun rising north of east and setting north of west, hence, shorter day lengths. The solar radiation incident on a 25o north facing solar collector was found to be in three components; beam, diffuse and reflected. The beam component was higher in summer whereas the diffuse component was higher in winter due to an increase in the air mass ratio. However, the total daily average radiation was highest in January (7.12 peak sun hours) and least in June (3.04 peak sun hours). Finally, a comparison between the calculated and measured values of solar radiation showed just a 1.1percent difference over the year with disparities being in the individual months.m The influence of outdoor weather conditions on the performance of the system was also evaluated. Operating temperatures were noticed to have a great impact on the output voltage and power of the PV array. Significant correlations existed between various meteorological parameters. Also, a multiple linear regression model was developed to ascertain the dependence of module temperature on solar irradiance, ambient temperature, relative humidity, wind speed and wind direction. The coefficient of determination for the model was 0.928, showing a strong relationship between cell temperature and the chosen predictors. Also, the six thermocouples installed at various locations of the PV array revealed variations in the operating temperatures of the modules. The modules on the east side of the array recorded relatively lower temperatures because of the ceiling that had been removed beneath one of the modules on this side of the array, which permitted the free flow of air. Furthermore, I-V measurements conducted on various strings of the array revealed so many steps (hotspots), indicative of module (or cell) mismatch on almost all the cell strings.
- Full Text:
- Date Issued: 2018
- Authors: Buma, Carine Lethem
- Date: 2018
- Subjects: Building-integrated photovoltaic systems Buildings -- Energy conservation Performance -- Evaluation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13227 , vital:39623
- Description: The constant increase in the global demand for energy and the current crisis on global warming and climate change has prompted a dying quest for clean, sustainable and reliable sources of energy. Amongst numerous renewable energy technologies, harnessing energy from the sun is the most viable way of guaranteeing a clean and sustainable supply of energy. Also, photovoltaic energy is one of the ways of using energy from the sun, where sunlight is converted to electricity using photovoltaic panels. Furthermore, the integration of photovoltaic modules into buildings is one of the most elegant innovations of this technology, as it plays the dual role of supplying energy to the building as well as protecting the building from outdoor weather conditions. Moreover, operating off the grid offers the possibility of energy access to locations far off from the grid and individuals willing to gain some degree of energy independence. Evaluating the performance of existing off grid and/or building integrated photovoltaic systems is the key to guaranteeing sustainable development and advancement in the technology. Thus, the aim of this work was to evaluate the performance of an off-grid building integrated photovoltaic system that was installed at the Fort Hare Institute of Technology. This entailed performing an in-depth characterisation of the solar resource at this location, evaluating the performance of the modules under outdoor weather conditions and also evaluating the performance of the balance of system (BOS) components. The system was monitored for a period of nine months (between February and October 2017). A data acquisition system was designed for measuring and recording both electrical system parameters and meteorological parameters affecting the performance of the system. These meteorological parameters include; solar irradiance, ambient temperature, cell temperature, relative humidity, wind speed and direction. A detailed characterisation of the solar resource at this location was carried out. It was observed that the solar declination angle varied from -23.5o on the summer solstice to 23.5o on the winter solstice. Also, the solar altitude angle (at solar noon) which is a complementary angle to the zenith angle varied from 33.7o in June to 80.65o in December. During the summer months, longer day lengths were experienced because the sun traversed the sky over a longer time, rising south of east and setting south of west. Whereas, in the winter months, the path length of the sun was shorter, with the sun rising north of east and setting north of west, hence, shorter day lengths. The solar radiation incident on a 25o north facing solar collector was found to be in three components; beam, diffuse and reflected. The beam component was higher in summer whereas the diffuse component was higher in winter due to an increase in the air mass ratio. However, the total daily average radiation was highest in January (7.12 peak sun hours) and least in June (3.04 peak sun hours). Finally, a comparison between the calculated and measured values of solar radiation showed just a 1.1percent difference over the year with disparities being in the individual months.m The influence of outdoor weather conditions on the performance of the system was also evaluated. Operating temperatures were noticed to have a great impact on the output voltage and power of the PV array. Significant correlations existed between various meteorological parameters. Also, a multiple linear regression model was developed to ascertain the dependence of module temperature on solar irradiance, ambient temperature, relative humidity, wind speed and wind direction. The coefficient of determination for the model was 0.928, showing a strong relationship between cell temperature and the chosen predictors. Also, the six thermocouples installed at various locations of the PV array revealed variations in the operating temperatures of the modules. The modules on the east side of the array recorded relatively lower temperatures because of the ceiling that had been removed beneath one of the modules on this side of the array, which permitted the free flow of air. Furthermore, I-V measurements conducted on various strings of the array revealed so many steps (hotspots), indicative of module (or cell) mismatch on almost all the cell strings.
- Full Text:
- Date Issued: 2018
Stratigraphy and sedimentology of the Msikaba formation in KwaZulu Natal South Coast, South Africa
- Authors: Busakwe, Nolukholo Sinovuyo
- Date: 2015
- Subjects: Geology, Stratigraphic Sedimentology -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2501 , vital:27877
- Description: The Msikaba Formation is a Late Devonian fluvial and marine succession which outcrops from Hibberdene to Port Edward along the south coast of KwaZulu-Natal Province, South Africa. The Formation is composed of brownish conglomerate at the bottom and white-greyish quartz arenite sequence in the middle and mixed quartz-arenite with feldspathic sandstone in the upper sequence. Previous studies put more emphasis on the correlation of Msikaba Formation with the Natal Group and Cape Supergroup, whereas this study revised the stratigraphy, and also put new insight on the petrography, sedimentary facies, depositional environments and diagenesis of the Formation. The total stratigraphic section attains a thickness of 184 m at Margate area and 186 m at Port Edward area. The stratigraphy of Msikaba Formation is well exposed on the outcrops along the KwaZulu-Natal coastline. The stratigraphy is subdivided into 4 new members along Margate to Shelly beach section; namely Manaba Member, Uvongo Member, Mhlangeni Member and Shelly Beach Member from bottom upward. Twelve sedimentary facies were identified and the sedimentary facies were integrated into 4 facies association: Facies association 1 (Gmm+Sm) represents braided fluvial deposits, Facies association 2 (Gcm+St+Sp+Sl+Shb) represents tidal channel and tidal flat deposit, Facies association 3 (St+Sp+Sr+Sl) is result of shallow marine deposit and Facies association 4 (Sp+Sl+St+Sm) is a mixed marine and fluvial deposit. Each facies association represents a specific stratigraphic unit and were deposited in a specific sedimentary environment. Grain size analysis was conducted on seventeen thin sections and 500 grains were counted from each thin section. The sandstone grain size parameters of mean, sorting, skewness and kurtosis fell under the average of 0.75, 0.78, 0.4 and 1.2φ respectively. The results show that most of the grain size are coarse to medium grained throughout the study areas and sorting of the sandstones are moderate to poorly sorted. The cumulative frequency diagrams and bivariate plots show positive skewness and negative kurtosis, which indicate a high hydrodynamic environment. Modal composition analysis and petrography studies show that detrital components of the Msikaba Formation are dominated by monocrystalline quartz, feldspar (mostly K-feldspar) and lithic fragments of igneous and metamorphic rocks. The sandstones could be classified as quartz arenite, sub-arkosic sandstone and feldspathic litharenite; and the provenance analysis indicates that the sandstones were derived from craton interior, recycled or quartzose recycled sources which may derived from weathering and erosion of igneous and metamorphic rocks. Diagenetic processes of the Msikaba Formation have been passed through early, mid- and late diagenetic stages. Cementation, mineral conversion and compaction affect early diagenetic stage; authigenic minerals, quartz and feldspar overgrowth are presented in mid-diagenetic stage, whereas recrystallization, replacement, deformation and dissolution have been strongly affected late diagenetic stage. Microscopy, XRD and SEM-EDX studies have identified five types of cements including smectite clay, kaolinite, hematite, quartz and feldspar cements. Quartz cement, pore-filling and pore-lining clay are the major type of cements in the Msikaba Formation. Based on the lithology, sedimentary structure and facies variations, the Manaba Member was most probably deposited in a braided fluvial environment, the Uvongo Member was deposited in a tidal channel environment, the Mhlangeni Member was formed in shallow marine storm-influenced environment, whereas the Shelly Beach Member was represented mixed marine and fluvial environment. The sequence stratigraphy of Msikaba Formation constitutes a transgressive sequence from Manaba Member to Uvongo Member, whereas it ended as a regressive sequence from Mhlangeni Member to Shelly beach Member. The Msikaba Formation shows major differences with the Natal Group and Table Mountain Group (Cape Supergroup) in the lithology, stratigraphic sequence, sedimentary structures, facies system, palaeocurrent styles, fossil contents and depositional environments, which demonstrate that they are not the equivalent stratigraphic unit. Therefore, the Msikaba Formation is a separate, younger stratigraphic unit, and cannot correlate with the Natal Group and Table Mountain Group as suggested by previous researchers.
- Full Text:
- Date Issued: 2015
- Authors: Busakwe, Nolukholo Sinovuyo
- Date: 2015
- Subjects: Geology, Stratigraphic Sedimentology -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2501 , vital:27877
- Description: The Msikaba Formation is a Late Devonian fluvial and marine succession which outcrops from Hibberdene to Port Edward along the south coast of KwaZulu-Natal Province, South Africa. The Formation is composed of brownish conglomerate at the bottom and white-greyish quartz arenite sequence in the middle and mixed quartz-arenite with feldspathic sandstone in the upper sequence. Previous studies put more emphasis on the correlation of Msikaba Formation with the Natal Group and Cape Supergroup, whereas this study revised the stratigraphy, and also put new insight on the petrography, sedimentary facies, depositional environments and diagenesis of the Formation. The total stratigraphic section attains a thickness of 184 m at Margate area and 186 m at Port Edward area. The stratigraphy of Msikaba Formation is well exposed on the outcrops along the KwaZulu-Natal coastline. The stratigraphy is subdivided into 4 new members along Margate to Shelly beach section; namely Manaba Member, Uvongo Member, Mhlangeni Member and Shelly Beach Member from bottom upward. Twelve sedimentary facies were identified and the sedimentary facies were integrated into 4 facies association: Facies association 1 (Gmm+Sm) represents braided fluvial deposits, Facies association 2 (Gcm+St+Sp+Sl+Shb) represents tidal channel and tidal flat deposit, Facies association 3 (St+Sp+Sr+Sl) is result of shallow marine deposit and Facies association 4 (Sp+Sl+St+Sm) is a mixed marine and fluvial deposit. Each facies association represents a specific stratigraphic unit and were deposited in a specific sedimentary environment. Grain size analysis was conducted on seventeen thin sections and 500 grains were counted from each thin section. The sandstone grain size parameters of mean, sorting, skewness and kurtosis fell under the average of 0.75, 0.78, 0.4 and 1.2φ respectively. The results show that most of the grain size are coarse to medium grained throughout the study areas and sorting of the sandstones are moderate to poorly sorted. The cumulative frequency diagrams and bivariate plots show positive skewness and negative kurtosis, which indicate a high hydrodynamic environment. Modal composition analysis and petrography studies show that detrital components of the Msikaba Formation are dominated by monocrystalline quartz, feldspar (mostly K-feldspar) and lithic fragments of igneous and metamorphic rocks. The sandstones could be classified as quartz arenite, sub-arkosic sandstone and feldspathic litharenite; and the provenance analysis indicates that the sandstones were derived from craton interior, recycled or quartzose recycled sources which may derived from weathering and erosion of igneous and metamorphic rocks. Diagenetic processes of the Msikaba Formation have been passed through early, mid- and late diagenetic stages. Cementation, mineral conversion and compaction affect early diagenetic stage; authigenic minerals, quartz and feldspar overgrowth are presented in mid-diagenetic stage, whereas recrystallization, replacement, deformation and dissolution have been strongly affected late diagenetic stage. Microscopy, XRD and SEM-EDX studies have identified five types of cements including smectite clay, kaolinite, hematite, quartz and feldspar cements. Quartz cement, pore-filling and pore-lining clay are the major type of cements in the Msikaba Formation. Based on the lithology, sedimentary structure and facies variations, the Manaba Member was most probably deposited in a braided fluvial environment, the Uvongo Member was deposited in a tidal channel environment, the Mhlangeni Member was formed in shallow marine storm-influenced environment, whereas the Shelly Beach Member was represented mixed marine and fluvial environment. The sequence stratigraphy of Msikaba Formation constitutes a transgressive sequence from Manaba Member to Uvongo Member, whereas it ended as a regressive sequence from Mhlangeni Member to Shelly beach Member. The Msikaba Formation shows major differences with the Natal Group and Table Mountain Group (Cape Supergroup) in the lithology, stratigraphic sequence, sedimentary structures, facies system, palaeocurrent styles, fossil contents and depositional environments, which demonstrate that they are not the equivalent stratigraphic unit. Therefore, the Msikaba Formation is a separate, younger stratigraphic unit, and cannot correlate with the Natal Group and Table Mountain Group as suggested by previous researchers.
- Full Text:
- Date Issued: 2015
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.
- Full Text:
- Date Issued: 2017
- 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.
- Full Text:
- Date Issued: 2017
Image processing and data analysis tools of a remote sensing-based euthrophication monitoring system
- Authors: Chamunorwa, Brighton
- Date: 2018
- Subjects: Eutrophication Image processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10210 , vital:35376
- Description: Numerous surface water bodies in South Africa face serious challenges of eutrophication despite several initiatives from government to solve the problem. Government efforts have not been successful particularly because of three issues: 1) insufficient and inconsistent water quality data and 2) the costly nature of collecting this data. Third, the limited uptake of remote sensing based technologies in water quality management due to lack of skills, as well as the lengthy and complex procedures involved in retrieving water quality parameters. This thesis aims to explore the possibilities of using satellite data and simple software for mapping and collecting water quality data. The broad goal was to determine the function of software dedicated to meet the requirements of a remote sensing-based eutrophication-monitoring system. Two specific goal were set in this study: 1. To extract software requirements from available eutrophication management documentation. This was necessary to determine the functions of the dedicated software that matches the legislative requirements and 2. To determine a design capable of handling spatial and temporal requirement of a remote sensing based eutrophication-monitoring system. The study applied Goal Based Requirement Analysis Model [GBRAM] model to extract goals from the National Eutrophication Monitoring Programme [NEMP] implementation plan document and recent publication on remote sensing of water quality monitoring conducted in South Africa. Afterwards, the study used object-oriented concepts to model suitable data objects and processes to implement spatial-temporal requirements of a remote sensing-based eutrophication-monitoring system. Based on the study findings the following are essential functions of a remote sensing based eutrophication-monitoring system. A graphical user interface that allows the user to set up a monitoring programming. Automated image processing procedures. Data assessment methods used to generate eutrophication status information. Numerous display options for viewing data in several perfectives.
- Full Text:
- Date Issued: 2018
Image processing and data analysis tools of a remote sensing-based euthrophication monitoring system
- Authors: Chamunorwa, Brighton
- Date: 2018
- Subjects: Eutrophication Image processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/10210 , vital:35376
- Description: Numerous surface water bodies in South Africa face serious challenges of eutrophication despite several initiatives from government to solve the problem. Government efforts have not been successful particularly because of three issues: 1) insufficient and inconsistent water quality data and 2) the costly nature of collecting this data. Third, the limited uptake of remote sensing based technologies in water quality management due to lack of skills, as well as the lengthy and complex procedures involved in retrieving water quality parameters. This thesis aims to explore the possibilities of using satellite data and simple software for mapping and collecting water quality data. The broad goal was to determine the function of software dedicated to meet the requirements of a remote sensing-based eutrophication-monitoring system. Two specific goal were set in this study: 1. To extract software requirements from available eutrophication management documentation. This was necessary to determine the functions of the dedicated software that matches the legislative requirements and 2. To determine a design capable of handling spatial and temporal requirement of a remote sensing based eutrophication-monitoring system. The study applied Goal Based Requirement Analysis Model [GBRAM] model to extract goals from the National Eutrophication Monitoring Programme [NEMP] implementation plan document and recent publication on remote sensing of water quality monitoring conducted in South Africa. Afterwards, the study used object-oriented concepts to model suitable data objects and processes to implement spatial-temporal requirements of a remote sensing-based eutrophication-monitoring system. Based on the study findings the following are essential functions of a remote sensing based eutrophication-monitoring system. A graphical user interface that allows the user to set up a monitoring programming. Automated image processing procedures. Data assessment methods used to generate eutrophication status information. Numerous display options for viewing data in several perfectives.
- Full Text:
- Date Issued: 2018