The thermal physiology of Stenopelmus rufinasus and Neohydronomus affinis (Coleoptera: Curculionidae), two biological control agents for the invasive alien aquatic weeds, Azolla filiculoides and Pistia stratiotes in South Africa.
- Mvandaba, Sisanda F, Owen, Candice A, Hill, Martin P, Coetzee, Julie A
- Authors: Mvandaba, Sisanda F , Owen, Candice A , Hill, Martin P , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444467 , vital:74243 , https://doi.org/10.1080/09583157.2018.1525484
- Description: Water lettuce, Pistia stratiotes, and red water fern, Azolla filiculoides, are floating aquatic macrophytes that have become problematic in South Africa. Two weevils, Neohydronomus affinis and Stenopelmus rufinasus, are successful biological control agents of these two species in South Africa. The aim of this study was to investigate the thermal requirements of these two species to explain their establishment patterns in the field. Laboratory results showed that both weevils are widely tolerant to cold and warm temperatures.
- Full Text:
- Date Issued: 2019
- Authors: Mvandaba, Sisanda F , Owen, Candice A , Hill, Martin P , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444467 , vital:74243 , https://doi.org/10.1080/09583157.2018.1525484
- Description: Water lettuce, Pistia stratiotes, and red water fern, Azolla filiculoides, are floating aquatic macrophytes that have become problematic in South Africa. Two weevils, Neohydronomus affinis and Stenopelmus rufinasus, are successful biological control agents of these two species in South Africa. The aim of this study was to investigate the thermal requirements of these two species to explain their establishment patterns in the field. Laboratory results showed that both weevils are widely tolerant to cold and warm temperatures.
- Full Text:
- Date Issued: 2019
The time course changes in selected fatigue indicators in moderately trained participants
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
- Date Issued: 2019
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
- Date Issued: 2019
The Trope of the Child: Rereading Trauma, Subjectivity and Embodiment in Contemporary Child-Centred African Narratives by Ahmadou Kourouma, Chris Abani, K. Sello Duiker and Yvonne Vera
- Authors: Njovane, Thandokazi
- Date: 2019
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164557 , vital:41134 , doi:10.21504/10962/164557
- Description: Thesis (PhD)--Rhodes University, Humanities, Literary Studies in English, 2019
- Full Text:
- Date Issued: 2019
- Authors: Njovane, Thandokazi
- Date: 2019
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164557 , vital:41134 , doi:10.21504/10962/164557
- Description: Thesis (PhD)--Rhodes University, Humanities, Literary Studies in English, 2019
- Full Text:
- Date Issued: 2019
The trophic and spatial ecology of a sympatric dasyatid community at a remote Atoll, Seychelles
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
- Full Text:
- Date Issued: 2019
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
- Full Text:
- Date Issued: 2019
The tropical environment and malaria in southwestern Nigeria, 1861 – 1960
- Authors: Adetiba, Adedamola Seun
- Date: 2019
- Subjects: Diseases and history -- Africa , Diseases and history -- Nigeria , Medical anthropology -- Africa , Medical anthropology -- Nigeria , Malaria -- Social aspects -- Nigeria , Malaria -- Nigeria -- History , Nigeria -- History , Imperialism -- Health aspects , Medicine -- Colonies -- Great Britain -- History
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76564 , vital:30605
- Description: This thesis is a social history of malaria in southwestern Nigeria. It contributes to the burgeoning literature in the historiography of medicine, specifically the medicine and empire debate. Key to the issues raised in this thesis is the extent to which the limitations in colonial medical policies, most especially malaria control programmes, inspired critical and ingenious responses from African nationalists, doctors, patients, research volunteers, and indigenous medical practitioners. Challenged by a wide range of diseases and a paucity of health facilities and disease control schemes, African rural dwellers became medical pluralists in the ways they imagined and appropriated ideas of Western medicine alongside their indigenous medical practices. Beginning with a detailed historical exploration of the issues that informed the introduction of curative and preventive medicine in southwestern Nigeria, this thesis reveals the focus of colonial medicine. It exposes the one-sided nature of medical services in colonial spaces like southwestern Nigeria and the ways it shaped multifaceted responses from Africans, who were specifically side-lined till the 1950s when the rural medical service scheme was introduced. The focus of colonial medicine is drawn from relatively rich but often subjective historical evidence, such as a plethora of official reports of the department of medical and sanitary services, official correspondences within the colonial government in Lagos and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from newspaper publications and correspondences between the African public and the colonial government in Lagos. They reveal very interesting details of the ways Africans imagined, reimagined, and appropriated malaria control ideas and schemes. The central argument in this thesis is that attempts to control malaria in southwestern Nigeria till the 1950s, were shaped by a single concern to ameliorate the implications of the disease on the colonial state. It argues that this one-sided nature of malaria control programme informed the basis for medical pluralism in most rural spaces where African communities became patrons and sponsors of Western medicine and at the same time custodians of their indigenous medical practices. The series of justifications for the sustenance of these services were reinforced on the basis of the failure of the colonial state to guarantee the health needs of their colonial subjects. The aim of the thesis is to reinforce arguments that portray colonial medicine as a “tool of empire” but goes a bit further to explain the extent to which Africans related to this reality. It states quite categorically that Africans were not docile and silent, but that they acted decisively in ways that suited their varied interests and courses.
- Full Text:
- Date Issued: 2019
- Authors: Adetiba, Adedamola Seun
- Date: 2019
- Subjects: Diseases and history -- Africa , Diseases and history -- Nigeria , Medical anthropology -- Africa , Medical anthropology -- Nigeria , Malaria -- Social aspects -- Nigeria , Malaria -- Nigeria -- History , Nigeria -- History , Imperialism -- Health aspects , Medicine -- Colonies -- Great Britain -- History
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76564 , vital:30605
- Description: This thesis is a social history of malaria in southwestern Nigeria. It contributes to the burgeoning literature in the historiography of medicine, specifically the medicine and empire debate. Key to the issues raised in this thesis is the extent to which the limitations in colonial medical policies, most especially malaria control programmes, inspired critical and ingenious responses from African nationalists, doctors, patients, research volunteers, and indigenous medical practitioners. Challenged by a wide range of diseases and a paucity of health facilities and disease control schemes, African rural dwellers became medical pluralists in the ways they imagined and appropriated ideas of Western medicine alongside their indigenous medical practices. Beginning with a detailed historical exploration of the issues that informed the introduction of curative and preventive medicine in southwestern Nigeria, this thesis reveals the focus of colonial medicine. It exposes the one-sided nature of medical services in colonial spaces like southwestern Nigeria and the ways it shaped multifaceted responses from Africans, who were specifically side-lined till the 1950s when the rural medical service scheme was introduced. The focus of colonial medicine is drawn from relatively rich but often subjective historical evidence, such as a plethora of official reports of the department of medical and sanitary services, official correspondences within the colonial government in Lagos and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from newspaper publications and correspondences between the African public and the colonial government in Lagos. They reveal very interesting details of the ways Africans imagined, reimagined, and appropriated malaria control ideas and schemes. The central argument in this thesis is that attempts to control malaria in southwestern Nigeria till the 1950s, were shaped by a single concern to ameliorate the implications of the disease on the colonial state. It argues that this one-sided nature of malaria control programme informed the basis for medical pluralism in most rural spaces where African communities became patrons and sponsors of Western medicine and at the same time custodians of their indigenous medical practices. The series of justifications for the sustenance of these services were reinforced on the basis of the failure of the colonial state to guarantee the health needs of their colonial subjects. The aim of the thesis is to reinforce arguments that portray colonial medicine as a “tool of empire” but goes a bit further to explain the extent to which Africans related to this reality. It states quite categorically that Africans were not docile and silent, but that they acted decisively in ways that suited their varied interests and courses.
- Full Text:
- Date Issued: 2019
The use of filter-feeding fish (Clarias gariepinus and Oreochromis mossambicus) to remove microalgae from brewery effluent treatment ponds
- Authors: Nombembe, Lwazi
- Date: 2019
- Subjects: Clarias gariepinus -- Food , Mozambique tilapia -- Food , Water -- Purification -- South Africa , Algae -- Biotechnology -- South Africa , Microalgae -- Biotechnology-- South Africa , Brewery waste -- South Africa , Fish culture -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95745 , vital:31194
- Description: The removal of microalgae from high rate algal ponds (HRAP) in waste-water treatment systems remains a constraint to their use in effluent treatment systems. Conventional algae harvesting methods often have high energy demands, take up lots of space, are expensive to operate or are time consuming. The aim of the study was to determine if fish such as Clarias gariepinus and Oreochromis mossambicus, could be used to remove microalgae from waste-water treatment ponds (in the absence/presence of a flocculent in the former and in the absence or presence of pH moderation in the latter), and to investigate the subsequent influence of algae concentration on several water quality parameters. The age of Clarias gariepinus (3-12 months) had a positive relationship with the distance between gill rakers (98.27 to 163.34 μm; y=90.576+4.823*x: R²=0.549; F(1,18)=21.867; p<0.001) and these data suggested that these fish might be efficient at removing algae from HRAP effluent. However, this was not the case, even with flocculent application (but this result might have been confounded by very high pH readings, at which flocculation is less likely to occur). Oreochromis mossambicus removed some of this algae, but the pH was too high for tilapia culture. It was not possible to moderate the increase in pH by keeping tanks in the dark and thus preventing photosynthesis; but pH fluctuation in HRAP effluent could be moderated using CO2 sparging in an attempt to make the environment more hospitable for tilapia (the average pH that was moderated with CO2 was 8.43±0.06, whereas the unmoderated average was 10.65±0.06). However, pH moderation using CO2 sparging did not increase the rate at which algae were removed by O. mossambicus; rather, it compromised O2 concentration which dropped to 4.17±1.26 mg/l after five hours of CO2 sparging, whereas it increased to 20.50±1.41 mg/l in treatments with unadjusted pH over the same period. Fish can be used to remove algae from treated effluent, and Oreochromis mossambicus remains a recommended species. Future work needs to investigate moderating fluctuations in pH and O2 concentration to further facilitate this method of algae removal.
- Full Text:
- Date Issued: 2019
- Authors: Nombembe, Lwazi
- Date: 2019
- Subjects: Clarias gariepinus -- Food , Mozambique tilapia -- Food , Water -- Purification -- South Africa , Algae -- Biotechnology -- South Africa , Microalgae -- Biotechnology-- South Africa , Brewery waste -- South Africa , Fish culture -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95745 , vital:31194
- Description: The removal of microalgae from high rate algal ponds (HRAP) in waste-water treatment systems remains a constraint to their use in effluent treatment systems. Conventional algae harvesting methods often have high energy demands, take up lots of space, are expensive to operate or are time consuming. The aim of the study was to determine if fish such as Clarias gariepinus and Oreochromis mossambicus, could be used to remove microalgae from waste-water treatment ponds (in the absence/presence of a flocculent in the former and in the absence or presence of pH moderation in the latter), and to investigate the subsequent influence of algae concentration on several water quality parameters. The age of Clarias gariepinus (3-12 months) had a positive relationship with the distance between gill rakers (98.27 to 163.34 μm; y=90.576+4.823*x: R²=0.549; F(1,18)=21.867; p<0.001) and these data suggested that these fish might be efficient at removing algae from HRAP effluent. However, this was not the case, even with flocculent application (but this result might have been confounded by very high pH readings, at which flocculation is less likely to occur). Oreochromis mossambicus removed some of this algae, but the pH was too high for tilapia culture. It was not possible to moderate the increase in pH by keeping tanks in the dark and thus preventing photosynthesis; but pH fluctuation in HRAP effluent could be moderated using CO2 sparging in an attempt to make the environment more hospitable for tilapia (the average pH that was moderated with CO2 was 8.43±0.06, whereas the unmoderated average was 10.65±0.06). However, pH moderation using CO2 sparging did not increase the rate at which algae were removed by O. mossambicus; rather, it compromised O2 concentration which dropped to 4.17±1.26 mg/l after five hours of CO2 sparging, whereas it increased to 20.50±1.41 mg/l in treatments with unadjusted pH over the same period. Fish can be used to remove algae from treated effluent, and Oreochromis mossambicus remains a recommended species. Future work needs to investigate moderating fluctuations in pH and O2 concentration to further facilitate this method of algae removal.
- Full Text:
- Date Issued: 2019
The use of image processing to determine cell defects in polycrystalline solar modules
- Authors: Banda, Peter
- Date: 2019
- Subjects: Polycrystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36573 , vital:33996
- Description: This research aims to use image processingtodetermine cell defects in polycrystalline solar modules. Image processing is a process of enhancing images for differentapplications. One domain that seems to not yet utilise the use of image processing, is photovoltaics. An increased use of fossil fuels is damaging the earth and a call to protect the earth has resulted in the emergence of pollutant-free technologies such as polycrystalline photovoltaic (PV) cells, which are connected to make up solar modules. However, defects often affect the performance of PV cells and consequently solar modules. Electroluminescence (EL) images are used to examine polycrystalline solar (PV) modules to determine if the modules are defective. The main research question that this research addressed is“How can an image processing technique be used to effectively identify defective polycrystalline PV cells from EL images of such cells?“. The experimental research methodology was used to address the main research question. The initial investigation into the problem revealed that certain sectors within industry, as well as the Physics Department at Nelson Mandela University(NMU), do not currently utiliseimage processing when examining EL images of solar modules. The current process is a tedious, manual process whereby solar modules are manually inspected. An analysis of the current processes enabled the identification of ways in which to automatically examine EL images of solar modules. An analysis of literatureprovided a better understanding of the different techniques that are used to examine solar modules, and it was identified how image processing can be applied to EL images. Further analysis of literatureprovided a better understanding of image processing and how image classification experiments using Deep Learning (DL) as an image processing technique can be used to address the main research question. The outcome of the experiments conducted in this research weredifferentadaptive models(LeNet, MobileNet, Xception)that can classify EL images of PV cellsaccording to known standardsused by the Physics Department at NMU. The known standards yielded four classes; normal, uncritical, critical and very critical, which were used for the classification of EL images of PV cells. The adaptive models were evaluated to obtain the precision, recall and F1–scoreof the models.The precession, recall, and F1–score were required to determine how effective the models were in identifying defective PV cells from EL images.The results indicated that an image processing technique canbe used to identify defective polycrystalline PV cells from EL images of such cells. However, further research needs to be conducted to improve the effectiveness of the adaptive models.
- Full Text:
- Date Issued: 2019
- Authors: Banda, Peter
- Date: 2019
- Subjects: Polycrystals
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/36573 , vital:33996
- Description: This research aims to use image processingtodetermine cell defects in polycrystalline solar modules. Image processing is a process of enhancing images for differentapplications. One domain that seems to not yet utilise the use of image processing, is photovoltaics. An increased use of fossil fuels is damaging the earth and a call to protect the earth has resulted in the emergence of pollutant-free technologies such as polycrystalline photovoltaic (PV) cells, which are connected to make up solar modules. However, defects often affect the performance of PV cells and consequently solar modules. Electroluminescence (EL) images are used to examine polycrystalline solar (PV) modules to determine if the modules are defective. The main research question that this research addressed is“How can an image processing technique be used to effectively identify defective polycrystalline PV cells from EL images of such cells?“. The experimental research methodology was used to address the main research question. The initial investigation into the problem revealed that certain sectors within industry, as well as the Physics Department at Nelson Mandela University(NMU), do not currently utiliseimage processing when examining EL images of solar modules. The current process is a tedious, manual process whereby solar modules are manually inspected. An analysis of the current processes enabled the identification of ways in which to automatically examine EL images of solar modules. An analysis of literatureprovided a better understanding of the different techniques that are used to examine solar modules, and it was identified how image processing can be applied to EL images. Further analysis of literatureprovided a better understanding of image processing and how image classification experiments using Deep Learning (DL) as an image processing technique can be used to address the main research question. The outcome of the experiments conducted in this research weredifferentadaptive models(LeNet, MobileNet, Xception)that can classify EL images of PV cellsaccording to known standardsused by the Physics Department at NMU. The known standards yielded four classes; normal, uncritical, critical and very critical, which were used for the classification of EL images of PV cells. The adaptive models were evaluated to obtain the precision, recall and F1–scoreof the models.The precession, recall, and F1–score were required to determine how effective the models were in identifying defective PV cells from EL images.The results indicated that an image processing technique canbe used to identify defective polycrystalline PV cells from EL images of such cells. However, further research needs to be conducted to improve the effectiveness of the adaptive models.
- Full Text:
- Date Issued: 2019
The use of insecticides and cultural control for the management of soil-borne pests during plantation establishment
- Authors: Siwela, Evidence Miyelani
- Date: 2019
- Subjects: Insecticides , Plant diseases Pests -- Control Pesticides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43446 , vital:36882
- Description: Over the past decades, the productivity of South African forestry plantations has been negatively impacted by abiotic (fire, hail, wind, frost, drought etc.) and biotic factors (pests and diseases). The biotic component of insect pests and pathogens cause significant loss to the forestry industry and this affects the productivity, financial viability and long-term sustainability of plantations. Common establishment insect pests and diseases in South Africa include the pine bark beetle (Hylastes angustatus), cutworms (Agrotis spp), white grubs (Scarabaeidae larvae), rhizina root rot (Rhizina undulata), fusarium pitch canker (Fusarium circinatum), and pine dieback (Diplodia pinea). Soil-borne pests, mainly white grubs and cutworms can contribute to high seedling mortality following the re-establishment of eucalypts and wattle. Synthetic insecticides used for their control include alpha-cypermethrin, deltamethrin, and imidacloprid. However, all these insecticides are considered highly hazardous to the environment and/or human health and can no longer be considered for use in South African plantations. A need has therefore arisen to find and screen alternative products (synthetic and/or natural), that are not only environmentally safe for use, but also effective for the control of soil-borne pests during plantation establishment. In addition, these products can then be combined with other control mechanisms (such as cultural and biological control) to form an integrated pest management strategy. To address the above, a series of research trials were implemented with the outcomes discussed below. Two trials were implemented in KwaZulu-Natal (Demagtenberg) and Mpumalanga (Klipkraal) to determine if seedling size in combination with, or without an insecticide would result in improved survival of Pinus Patula. The main factors tested were Root Plug Volume (36 cm3 versus 103 cm3), Seedling Age (Standard [smaller] versus Older [larger]), and Pesticide application (untreated versus treated). Seedling quality was assessed in terms of Shoot:Root ratio, optimum Height (Ht in cm), and root collar diameter (Rcd in mm) before planting, with tree growth variates measured at planting, and then at regular intervals. The final measurements were taken at 7 years and 2 months for Demagtenberg and 5 years and 1 month for Klipkraal. For both trials, the Root Growth Potential (RGP) and total Plant Quality Index (PQI) indicated that Root Plug Volume 36 cm3 and Seedling Age (SA)_Standard (smaller) had a better Sturdiness ratio and Shoot:Root ratio compared to that of Root Plug Volume 103 cm3 and Seedling Age (SA)_Older (larger), with these benefits translated into improved field performance. The diameter at breast height (Dbh), Basal area (BA), Stocking and Volume indicated that SA_Standard and Root Plug Volume 36 cm3 resulted in better survival and growth than that of SA_Older (larger) seedlings and Root Plug Volume 103 cm3. The application of a Pesticide resulted in improved survival and growth at Klipkraal, but not at Demagtenberg. This indicated the presence of soil-borne pests at this site. In addition, the interaction between Pesticide application and SA_Standard resulted in a significantly larger BA than all other treatments only at Klipkraal, which indicates that both improved seedling quality and pesticides contributed to improved performance. One trial was established to Eucalyptus dunnii William Dunn at Umvoti North to investigate the effectiveness of the synthetic insecticides (deltamethrin, clothianidin, imidacloprid, imidacloprid + fertilizer, imidacloprid + clothianidin + fertilizer) and two natural products (azadirachtin and potassium silicate) for the control of soil-borne pests following planting. Groundline diameter (Gld), Height (Ht) and survival were assessed over a six-month period. Despite the selection of a site known to have a high incidence of soil-borne pests, few soil-borne pest were detected on the site for the trial duration, with no treatment differences observed for any of the tree growth variates. Significant differences were observed for foliar discolouration (possible phytotoxicity), however, these results were inconclusive as majority of the affected treatments (those that survived) showed full recovery. Three-month results from 12 eucalypt trials in KwaZulu-Natal, South Africa were compared to determine the benefits (including costs) of insecticides for the control of soil-borne pests. The 12 trials were selected to represent different physiographic regions, mainly within the warm temperate regions where white grubs and cutworms are likely to occur. Data for the trials were obtained from previous management research (published documents) and included six where mortality was the only variate assessed, with the Ht and Gld also assessed in the remaining six trials. There was a ≥ 2.5% increase in survival in seven of the 12 trials through the use of insecticides relative to the control, although only four of these seven were statistically significant. Of the 12 trials, the use of insecticides resulted in > 90% survival compared to the control at Mistley (93 versus 83%), Bloemendal (96 versus 62%) and Enon (burn) (96 versus 89%). At Garfield, Vulindlela, and Baynesfield, survival in both the treated and untreated treatments was below 90%, whereas both the treated and untreated treatments were above 90% at Rustig, Greenhill, Enon (slash), Umvoti, Dargle and Umvoti North. This data indicates that where soil-borne pests are present, the application of an insecticide is beneficial. Due to the costs associated with insecticide application, the challenge will be to determine which are high-risk sites that require treatment with an insecticide. Results from these trials indicate that on sites where soil-borne pests are present (and active), the application of insecticides is beneficial. However, even if present, the level of impact is less obvious, and possibly influenced by life cycle stage, site management and climate. The testing of alternative and less highly hazardous insecticides indicated the potential future use of insecticides in terms of limited seedling phytotoxicity (some of the products tested). To understand more fully the extent of their efficacy, these products would need to be re-tested again on sites where soil-borne pests are active. Optimum establishment practices, together with the planting of quality seedlings and application of an approved insecticide, will all contribute to improved survival and growth. Perhaps the biggest challenge will be the determination of soil pest activity, such that the application of pesticides can be limited to those sites where control is necessary..
- Full Text:
- Date Issued: 2019
- Authors: Siwela, Evidence Miyelani
- Date: 2019
- Subjects: Insecticides , Plant diseases Pests -- Control Pesticides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43446 , vital:36882
- Description: Over the past decades, the productivity of South African forestry plantations has been negatively impacted by abiotic (fire, hail, wind, frost, drought etc.) and biotic factors (pests and diseases). The biotic component of insect pests and pathogens cause significant loss to the forestry industry and this affects the productivity, financial viability and long-term sustainability of plantations. Common establishment insect pests and diseases in South Africa include the pine bark beetle (Hylastes angustatus), cutworms (Agrotis spp), white grubs (Scarabaeidae larvae), rhizina root rot (Rhizina undulata), fusarium pitch canker (Fusarium circinatum), and pine dieback (Diplodia pinea). Soil-borne pests, mainly white grubs and cutworms can contribute to high seedling mortality following the re-establishment of eucalypts and wattle. Synthetic insecticides used for their control include alpha-cypermethrin, deltamethrin, and imidacloprid. However, all these insecticides are considered highly hazardous to the environment and/or human health and can no longer be considered for use in South African plantations. A need has therefore arisen to find and screen alternative products (synthetic and/or natural), that are not only environmentally safe for use, but also effective for the control of soil-borne pests during plantation establishment. In addition, these products can then be combined with other control mechanisms (such as cultural and biological control) to form an integrated pest management strategy. To address the above, a series of research trials were implemented with the outcomes discussed below. Two trials were implemented in KwaZulu-Natal (Demagtenberg) and Mpumalanga (Klipkraal) to determine if seedling size in combination with, or without an insecticide would result in improved survival of Pinus Patula. The main factors tested were Root Plug Volume (36 cm3 versus 103 cm3), Seedling Age (Standard [smaller] versus Older [larger]), and Pesticide application (untreated versus treated). Seedling quality was assessed in terms of Shoot:Root ratio, optimum Height (Ht in cm), and root collar diameter (Rcd in mm) before planting, with tree growth variates measured at planting, and then at regular intervals. The final measurements were taken at 7 years and 2 months for Demagtenberg and 5 years and 1 month for Klipkraal. For both trials, the Root Growth Potential (RGP) and total Plant Quality Index (PQI) indicated that Root Plug Volume 36 cm3 and Seedling Age (SA)_Standard (smaller) had a better Sturdiness ratio and Shoot:Root ratio compared to that of Root Plug Volume 103 cm3 and Seedling Age (SA)_Older (larger), with these benefits translated into improved field performance. The diameter at breast height (Dbh), Basal area (BA), Stocking and Volume indicated that SA_Standard and Root Plug Volume 36 cm3 resulted in better survival and growth than that of SA_Older (larger) seedlings and Root Plug Volume 103 cm3. The application of a Pesticide resulted in improved survival and growth at Klipkraal, but not at Demagtenberg. This indicated the presence of soil-borne pests at this site. In addition, the interaction between Pesticide application and SA_Standard resulted in a significantly larger BA than all other treatments only at Klipkraal, which indicates that both improved seedling quality and pesticides contributed to improved performance. One trial was established to Eucalyptus dunnii William Dunn at Umvoti North to investigate the effectiveness of the synthetic insecticides (deltamethrin, clothianidin, imidacloprid, imidacloprid + fertilizer, imidacloprid + clothianidin + fertilizer) and two natural products (azadirachtin and potassium silicate) for the control of soil-borne pests following planting. Groundline diameter (Gld), Height (Ht) and survival were assessed over a six-month period. Despite the selection of a site known to have a high incidence of soil-borne pests, few soil-borne pest were detected on the site for the trial duration, with no treatment differences observed for any of the tree growth variates. Significant differences were observed for foliar discolouration (possible phytotoxicity), however, these results were inconclusive as majority of the affected treatments (those that survived) showed full recovery. Three-month results from 12 eucalypt trials in KwaZulu-Natal, South Africa were compared to determine the benefits (including costs) of insecticides for the control of soil-borne pests. The 12 trials were selected to represent different physiographic regions, mainly within the warm temperate regions where white grubs and cutworms are likely to occur. Data for the trials were obtained from previous management research (published documents) and included six where mortality was the only variate assessed, with the Ht and Gld also assessed in the remaining six trials. There was a ≥ 2.5% increase in survival in seven of the 12 trials through the use of insecticides relative to the control, although only four of these seven were statistically significant. Of the 12 trials, the use of insecticides resulted in > 90% survival compared to the control at Mistley (93 versus 83%), Bloemendal (96 versus 62%) and Enon (burn) (96 versus 89%). At Garfield, Vulindlela, and Baynesfield, survival in both the treated and untreated treatments was below 90%, whereas both the treated and untreated treatments were above 90% at Rustig, Greenhill, Enon (slash), Umvoti, Dargle and Umvoti North. This data indicates that where soil-borne pests are present, the application of an insecticide is beneficial. Due to the costs associated with insecticide application, the challenge will be to determine which are high-risk sites that require treatment with an insecticide. Results from these trials indicate that on sites where soil-borne pests are present (and active), the application of insecticides is beneficial. However, even if present, the level of impact is less obvious, and possibly influenced by life cycle stage, site management and climate. The testing of alternative and less highly hazardous insecticides indicated the potential future use of insecticides in terms of limited seedling phytotoxicity (some of the products tested). To understand more fully the extent of their efficacy, these products would need to be re-tested again on sites where soil-borne pests are active. Optimum establishment practices, together with the planting of quality seedlings and application of an approved insecticide, will all contribute to improved survival and growth. Perhaps the biggest challenge will be the determination of soil pest activity, such that the application of pesticides can be limited to those sites where control is necessary..
- Full Text:
- Date Issued: 2019
The use of liquid petroleum gas (LPG) as an alternative automotive fuel in South Africa towards 2030
- Authors: Ognianov, Nadine
- Date: 2019
- Subjects: Automobiles -- Motors -- Exhaust gas -- Economic aspects -- South Africa , Automobiles -- Motors -- Exhaust gas -- Environmental aspects -- South Africa , Automobiles -- Fuel consumption -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/42979 , vital:36716
- Description: South Africa is considered to be the economic power house of Africa, yet still lags behind when implementing energy efficient solutions. This can be attributed to bureaucracy and red tape. South Africa is the smallest importer and user of liquefied petroleum gas in Africa. Algeria is the biggest importer and consumer on a domestic scale. The use of liquid petroleum gas as an automotive fuel is not a new concept, either on this continent or the rest of the world. Vehicles have been driving on autogas for many decades and have seen various technological changes and improvements along the way. The latest autogas technology has been tried, tested and improved to be in line with Euro 5 standards. The purpose of the paper is to highlight all the benefits to motorists and to encourage the adoption of liquid petroleum gas (Autogas) as an automotive fuel. The literature review highlights the financial and environmental benefits, as well as identifying the barriers to adoption as well as the critical success factors for adopting autogas as a transport fuel. This resulted in the identification of six independent variables, namely cost, environmental impact, government legislation, infrastructure, public demand and product availability. These variables were then used to construct a conceptual framework to test the perceived outcome, which was the dependant variable.
- Full Text:
- Date Issued: 2019
The use of liquid petroleum gas (LPG) as an alternative automotive fuel in South Africa towards 2030
- Authors: Ognianov, Nadine
- Date: 2019
- Subjects: Automobiles -- Motors -- Exhaust gas -- Economic aspects -- South Africa , Automobiles -- Motors -- Exhaust gas -- Environmental aspects -- South Africa , Automobiles -- Fuel consumption -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/42979 , vital:36716
- Description: South Africa is considered to be the economic power house of Africa, yet still lags behind when implementing energy efficient solutions. This can be attributed to bureaucracy and red tape. South Africa is the smallest importer and user of liquefied petroleum gas in Africa. Algeria is the biggest importer and consumer on a domestic scale. The use of liquid petroleum gas as an automotive fuel is not a new concept, either on this continent or the rest of the world. Vehicles have been driving on autogas for many decades and have seen various technological changes and improvements along the way. The latest autogas technology has been tried, tested and improved to be in line with Euro 5 standards. The purpose of the paper is to highlight all the benefits to motorists and to encourage the adoption of liquid petroleum gas (Autogas) as an automotive fuel. The literature review highlights the financial and environmental benefits, as well as identifying the barriers to adoption as well as the critical success factors for adopting autogas as a transport fuel. This resulted in the identification of six independent variables, namely cost, environmental impact, government legislation, infrastructure, public demand and product availability. These variables were then used to construct a conceptual framework to test the perceived outcome, which was the dependant variable.
- Full Text:
- Date Issued: 2019
The use of the performance management system as management tool to accelerate service delivery in municipalities, case study Amathole District Municipality Eastern Cape
- Authors: Nako, Mkhululi
- Date: 2019
- Subjects: Performance -- Management Public administration Local government
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/13824 , vital:39715
- Description: In the recent years have been several public protests in our communities which was a result of slow pace in the provision of services by the municipalities in the district which has led to the use of the performance management system in order to accelerate the service delivery. The study focused on the usage of the system like performance management to accelerate service delivery in Amatole District Municipality (ADM) in the Eastern Cape Province. There is limited research regarding the usage of the system like performance management to accelerate service delivery in Amatole District Municipality. Mixed research methodology was used. The sample (n=10) comprised of individual involved in performance management systems. Data was collected through the questionnaire method and both qualitative and quantitative methods were used for data analysis. The study results show that while the performance management systems are being practiced at the municipality it is not done effectively and efficiently. In addition, not all municipal employees had the necessary knowledge and expertise to implement PMS. It can also be noted that every respondent in the study agreed that performance management systems do accelerate service delivery if done efficiently. The study recommends that local government should not only focus on their plans on dealing with backlogs but also on the rapid development taking place and the performance management system framework should cater for individual performance.
- Full Text:
- Date Issued: 2019
- Authors: Nako, Mkhululi
- Date: 2019
- Subjects: Performance -- Management Public administration Local government
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/13824 , vital:39715
- Description: In the recent years have been several public protests in our communities which was a result of slow pace in the provision of services by the municipalities in the district which has led to the use of the performance management system in order to accelerate the service delivery. The study focused on the usage of the system like performance management to accelerate service delivery in Amatole District Municipality (ADM) in the Eastern Cape Province. There is limited research regarding the usage of the system like performance management to accelerate service delivery in Amatole District Municipality. Mixed research methodology was used. The sample (n=10) comprised of individual involved in performance management systems. Data was collected through the questionnaire method and both qualitative and quantitative methods were used for data analysis. The study results show that while the performance management systems are being practiced at the municipality it is not done effectively and efficiently. In addition, not all municipal employees had the necessary knowledge and expertise to implement PMS. It can also be noted that every respondent in the study agreed that performance management systems do accelerate service delivery if done efficiently. The study recommends that local government should not only focus on their plans on dealing with backlogs but also on the rapid development taking place and the performance management system framework should cater for individual performance.
- Full Text:
- Date Issued: 2019
The use of turnitin in the higher education sector: Decoding the myth
- Mphahlele, Amanda, McKenna, Sioux
- Authors: Mphahlele, Amanda , McKenna, Sioux
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124229 , vital:35578 , https://doi.org/10.1080/02602938.2019.1573971
- Description: Plagiarism needs to be addressed to maintain academic standards and to safeguard the integrity of the academic project. With the evolving digital world, conventional methods of addressing plagiarism are gradually being dismissed in favour of new technologies. Unfortunately, there is a general misunderstanding about what such technologies do. This paper was written from a PhD study, and looks at how such misunderstandings emerge across the higher education sector of one country. Institutional policies and other documents related to plagiarism were analysed from public universities across South Africa, and this was then augmented with interviews with members of institutional plagiarism committees. The results of the study revealed that technology is a key facet in these universities’ attempts to reduce the incidents of plagiarism, and that Turnitin is the most favored text-matching tool. However, the software is misunderstood to be predominantly a plagiarism detection tool for policing purposes, ignoring its educational potential for student development. The implication is that, if Turnitin is primarily used as a policing tool, students are not only denied access to nuanced pedagogical interventions that might develop their academic writing, but its misuse could also change students’ behavior in undesirable ways.
- Full Text:
- Date Issued: 2019
- Authors: Mphahlele, Amanda , McKenna, Sioux
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124229 , vital:35578 , https://doi.org/10.1080/02602938.2019.1573971
- Description: Plagiarism needs to be addressed to maintain academic standards and to safeguard the integrity of the academic project. With the evolving digital world, conventional methods of addressing plagiarism are gradually being dismissed in favour of new technologies. Unfortunately, there is a general misunderstanding about what such technologies do. This paper was written from a PhD study, and looks at how such misunderstandings emerge across the higher education sector of one country. Institutional policies and other documents related to plagiarism were analysed from public universities across South Africa, and this was then augmented with interviews with members of institutional plagiarism committees. The results of the study revealed that technology is a key facet in these universities’ attempts to reduce the incidents of plagiarism, and that Turnitin is the most favored text-matching tool. However, the software is misunderstood to be predominantly a plagiarism detection tool for policing purposes, ignoring its educational potential for student development. The implication is that, if Turnitin is primarily used as a policing tool, students are not only denied access to nuanced pedagogical interventions that might develop their academic writing, but its misuse could also change students’ behavior in undesirable ways.
- Full Text:
- Date Issued: 2019
The utility of facilities management in alleviating poor service delivery at Polokwane department of public works
- Sipungela, Nosipho Agreenett
- Authors: Sipungela, Nosipho Agreenett
- Date: 2019
- Subjects: Facility management , Public works -- South Africa Government productivity -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43457 , vital:36888
- Description: This study dealt with improving service delivery in the National Department of Public Works (NDPW) Polokwane Regional Office through facilities management (FM). It posits that FM can be usefully employed as an instrument to achieve integration of design, construction and FM. It argues that since FM encompasses the essential components of maintenance, refurbishment, reconfiguration and rehabilitation of accommodation it can be usefully utilised to ensure sustainability of government assets. An online data collection method was used to collect raw data from the selected sample. The sample population consisted of assistant directors, control works managers, works managers and administration officers within the FM of Polokwane regional office of the National Department of Public Works.The results show that performance management is not aligned to set service delivery standards and organisational objectives. Monitoring during the implementation of a project is sub- optimal and therefore does not ensure that services are rendered to the satisfaction of the client department. Moreover, there is no establised Management Information Systems (MIS) to keep records of information pertaining to infrastructure; conditional assessments; maintenance; the measurement of the quality of project output; the effectiveness of FM and the procurement policy; and the availability of skills and resources to execute the duties. The set hypotheses were tested by means of evaluation of data collected. The research finally presents a number of professional opinions and recommendations that could be considered to improve service delivery within the FM unit.
- Full Text:
- Date Issued: 2019
- Authors: Sipungela, Nosipho Agreenett
- Date: 2019
- Subjects: Facility management , Public works -- South Africa Government productivity -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/43457 , vital:36888
- Description: This study dealt with improving service delivery in the National Department of Public Works (NDPW) Polokwane Regional Office through facilities management (FM). It posits that FM can be usefully employed as an instrument to achieve integration of design, construction and FM. It argues that since FM encompasses the essential components of maintenance, refurbishment, reconfiguration and rehabilitation of accommodation it can be usefully utilised to ensure sustainability of government assets. An online data collection method was used to collect raw data from the selected sample. The sample population consisted of assistant directors, control works managers, works managers and administration officers within the FM of Polokwane regional office of the National Department of Public Works.The results show that performance management is not aligned to set service delivery standards and organisational objectives. Monitoring during the implementation of a project is sub- optimal and therefore does not ensure that services are rendered to the satisfaction of the client department. Moreover, there is no establised Management Information Systems (MIS) to keep records of information pertaining to infrastructure; conditional assessments; maintenance; the measurement of the quality of project output; the effectiveness of FM and the procurement policy; and the availability of skills and resources to execute the duties. The set hypotheses were tested by means of evaluation of data collected. The research finally presents a number of professional opinions and recommendations that could be considered to improve service delivery within the FM unit.
- Full Text:
- Date Issued: 2019
The Zulu girl and other poems
- Authors: Ngidi, Sandile Brian
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92748 , vital:30744
- Description: My thesis is a collection of English poems that converse with Mazisi Kunene’s literary corpus. I draw from both Kunene’s early works, which followed the pioneering work of the Zulu poet BW Vilakazi, and his socio‐political later work, which is at once Pan African in scope and intent yet deeply rooted in a Zulu socio‐linguistic milieu. Like Kunene, I aim to create a poetics of exile by working between languages, writing in Zulu and then translating into English to express my alienation in South Africa and what it means to be exiled from language and culture and speak a foreign language with your mother tongue. Here, I also take influence from the rich, evocative imagery in Palestinian poet Mahmoud Darwish's poetry of exile and the quest for a lost homeland, as well as Brazilian poet Adela Prado’s wit and direct speech. I also engage popular contemporary forms of expression and use poetry to question some themes in the popular music genre maskandi, especially its rhetoric on identity, class and gender politics.
- Full Text:
- Date Issued: 2019
- Authors: Ngidi, Sandile Brian
- Date: 2019
- Subjects: Xhosa poetry
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92748 , vital:30744
- Description: My thesis is a collection of English poems that converse with Mazisi Kunene’s literary corpus. I draw from both Kunene’s early works, which followed the pioneering work of the Zulu poet BW Vilakazi, and his socio‐political later work, which is at once Pan African in scope and intent yet deeply rooted in a Zulu socio‐linguistic milieu. Like Kunene, I aim to create a poetics of exile by working between languages, writing in Zulu and then translating into English to express my alienation in South Africa and what it means to be exiled from language and culture and speak a foreign language with your mother tongue. Here, I also take influence from the rich, evocative imagery in Palestinian poet Mahmoud Darwish's poetry of exile and the quest for a lost homeland, as well as Brazilian poet Adela Prado’s wit and direct speech. I also engage popular contemporary forms of expression and use poetry to question some themes in the popular music genre maskandi, especially its rhetoric on identity, class and gender politics.
- Full Text:
- Date Issued: 2019
Therefore I am
- Authors: Núñez-Lagos, Andres
- Date: 2019
- Subjects: South African fiction (English)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92737 , vital:30743
- Full Text:
- Date Issued: 2019
- Authors: Núñez-Lagos, Andres
- Date: 2019
- Subjects: South African fiction (English)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92737 , vital:30743
- Full Text:
- Date Issued: 2019
Thermal plasticity and microevolution enhance establishment success and persistence of a water hyacinth biological control agent
- Griffith, Tamzin C, Paterson, Iain D, Owen, Candice A, Coetzee, Julie A
- Authors: Griffith, Tamzin C , Paterson, Iain D , Owen, Candice A , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424866 , vital:72190 , xlink:href="https://doi.org/10.1111/eea.12814"
- Description: Aspects of the thermal physiology of the water hyacinth biological control agent Eccritotarsus catarinensis Carvalho (Hemiptera: Miridae) have been extensively investigated over the past 20 years to understand and improve post-release establishment in the field. Thermal physiology studies predicted that the agent would not establish at a number of cold sites in South Africa, where it has nonetheless subsequently established and thrived. Recently, studies have begun to incorporate the plastic nature of insect thermal physiology into models of agent establishment. This study determined whether season and locality influenced the thermal physiology of two field populations of E. catarinensis, one collected from the hottest site where the agent has established in South Africa, and one from the coldest site. The thermal physiology of E. catarinensis was significantly influenced by season and site, demonstrating a degree of phenotypic plasticity, and that some post-release local adaptation to climatic conditions has occurred through microevolution. We then determined whether cold acclimation under laboratory conditions was possible. Successfully cold-acclimated E. catarinensis had a significantly lower critical thermal minimum (CTmin) compared to the field cold-acclimated population. This suggests that cold acclimation of agents could be conducted in the laboratory before future releases to improve their cold tolerance, thereby increasing their chance of establishment at cold sites and allowing further adaptation to colder climates to occur in the field. Although the thermal tolerance of E. catarinensis is limited by local adaptations to climatic conditions in the native range, the plastic nature of the insect's thermal physiology has allowed it to survive in the very different climatic conditions of the introduced range, and there has been some adaptive change to the insect's thermal tolerance since establishment. This study highlights the importance of plasticity and microevolutionary processes in the success of biological control agents under the novel climatic conditions in the introduced range.
- Full Text:
- Date Issued: 2019
- Authors: Griffith, Tamzin C , Paterson, Iain D , Owen, Candice A , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424866 , vital:72190 , xlink:href="https://doi.org/10.1111/eea.12814"
- Description: Aspects of the thermal physiology of the water hyacinth biological control agent Eccritotarsus catarinensis Carvalho (Hemiptera: Miridae) have been extensively investigated over the past 20 years to understand and improve post-release establishment in the field. Thermal physiology studies predicted that the agent would not establish at a number of cold sites in South Africa, where it has nonetheless subsequently established and thrived. Recently, studies have begun to incorporate the plastic nature of insect thermal physiology into models of agent establishment. This study determined whether season and locality influenced the thermal physiology of two field populations of E. catarinensis, one collected from the hottest site where the agent has established in South Africa, and one from the coldest site. The thermal physiology of E. catarinensis was significantly influenced by season and site, demonstrating a degree of phenotypic plasticity, and that some post-release local adaptation to climatic conditions has occurred through microevolution. We then determined whether cold acclimation under laboratory conditions was possible. Successfully cold-acclimated E. catarinensis had a significantly lower critical thermal minimum (CTmin) compared to the field cold-acclimated population. This suggests that cold acclimation of agents could be conducted in the laboratory before future releases to improve their cold tolerance, thereby increasing their chance of establishment at cold sites and allowing further adaptation to colder climates to occur in the field. Although the thermal tolerance of E. catarinensis is limited by local adaptations to climatic conditions in the native range, the plastic nature of the insect's thermal physiology has allowed it to survive in the very different climatic conditions of the introduced range, and there has been some adaptive change to the insect's thermal tolerance since establishment. This study highlights the importance of plasticity and microevolutionary processes in the success of biological control agents under the novel climatic conditions in the introduced range.
- Full Text:
- Date Issued: 2019
Thermally and optically stimulated luminescence of natural red and blue corundum (Al2O3)
- Kalita, Jitumani M, Thomas, Sunil, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Thomas, Sunil , Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/105177 , vital:32472 , https://doi.org/10.1016/j.jlumin.2018.09.058
- Description: We report the thermoluminescence (TL) and optically stimulated luminescence (OSL) of natural corundum (Al2O3) of two varieties; one red and the other blue. X-ray fluorescence spectroscopy of the samples show that the concentration of Al2O3 in the red corundum is 43.05% and 46.87% in the blue corundum. TL measurements carried out on un-annealed samples and samples annealed at 700 °C, 900 °C and 1200 °C show that the TL sensitivity increases with annealing. The sensitivity of the red corundum reaches a maximum after annealing at 900 °C whereas that of the blue corundum increases with annealing up to the maximum annealing temperature of 1200 °C used in this study. Both samples have a complex glow curve between 30 °C and 500 °C. The composite nature of the glow curves is deduced to be due to a continuum in the trap distribution in the crystal. The activation energy of the traps vary between 0.70 eV and 1.15 eV. The dose response of the red corundum under TL is linear within 100‒1000 Gy whereas that of the blue corundum is superlinear for the same dose range. The TL of both samples is reproducible but the signal fades with time between irradiation and measurement. Both samples produce OSL under 470 nm blue light stimulation. The dose response of the OSL is superlinear within 100‒1000 Gy. It is found that the samples also produce thermally-assisted OSL (TA-OSL) at elevated temperature. The TA-OSL intensity of the red corundum increases with dose up to 400 Gy and saturates thereafter. On the other hand, the intensity of the blue corundum increases consistently with dose from 100 Gy to 1000 Gy.
- Full Text: false
- Date Issued: 2019
- Authors: Kalita, Jitumani M , Thomas, Sunil , Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/105177 , vital:32472 , https://doi.org/10.1016/j.jlumin.2018.09.058
- Description: We report the thermoluminescence (TL) and optically stimulated luminescence (OSL) of natural corundum (Al2O3) of two varieties; one red and the other blue. X-ray fluorescence spectroscopy of the samples show that the concentration of Al2O3 in the red corundum is 43.05% and 46.87% in the blue corundum. TL measurements carried out on un-annealed samples and samples annealed at 700 °C, 900 °C and 1200 °C show that the TL sensitivity increases with annealing. The sensitivity of the red corundum reaches a maximum after annealing at 900 °C whereas that of the blue corundum increases with annealing up to the maximum annealing temperature of 1200 °C used in this study. Both samples have a complex glow curve between 30 °C and 500 °C. The composite nature of the glow curves is deduced to be due to a continuum in the trap distribution in the crystal. The activation energy of the traps vary between 0.70 eV and 1.15 eV. The dose response of the red corundum under TL is linear within 100‒1000 Gy whereas that of the blue corundum is superlinear for the same dose range. The TL of both samples is reproducible but the signal fades with time between irradiation and measurement. Both samples produce OSL under 470 nm blue light stimulation. The dose response of the OSL is superlinear within 100‒1000 Gy. It is found that the samples also produce thermally-assisted OSL (TA-OSL) at elevated temperature. The TA-OSL intensity of the red corundum increases with dose up to 400 Gy and saturates thereafter. On the other hand, the intensity of the blue corundum increases consistently with dose from 100 Gy to 1000 Gy.
- Full Text: false
- Date Issued: 2019
Think Piece. Situating Education for Sustainable Development in southern African philosophy and contexts of social-ecological change to enhance curriculum relevance and the common good
- Pesanayi, Tichaona V, O'Donoghue, Rob B, Shava, Soul
- Authors: Pesanayi, Tichaona V , O'Donoghue, Rob B , Shava, Soul
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/388105 , vital:68307 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/187217"
- Description: The study opens with a brief review of how education in colonial southern Africa was steered by a succession of externally framed abstractions that have been implemented within the prevailing hegemony of western modernisation that dominated and marginalised indigenous cultures. It probes how, within an expanding functionalist framework, Education for Sustainable Development (ESD) has been similarly constituted as a proposition for implementation. Here the supposition is that implementing ESD as an intervention will transform education into an inclusive and collaborative pedagogy that will shape competences for participants to transform society towards a sustainable future. In an effort to explore the possibility of making a break from a succession of education imperatives functioning as ‘salvation narratives’ to put things right in Africa, the study explores ESD from a more situated and emergent vantage point within African landscapes, philosophy and cultural practices. This requires a shift from a view of ESD as a perspective to be brought in and enacted to foster change, to ESD as a situated engagement in education as a process where relevance is deliberated and brought out in quality education with high order skills. This perspective exemplifies working with a more fully situated framing of deliberative social learning for the common good. It is explored here to contemplate how socio-cultural processes of deliberative ethics and co-engaged reflexive processes of learning-led change might emerge. Here, also, using a capabilities approach might provide useful starting points for ESD as an expansive process of transformative social learning.
- Full Text:
- Date Issued: 2019
- Authors: Pesanayi, Tichaona V , O'Donoghue, Rob B , Shava, Soul
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/388105 , vital:68307 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/187217"
- Description: The study opens with a brief review of how education in colonial southern Africa was steered by a succession of externally framed abstractions that have been implemented within the prevailing hegemony of western modernisation that dominated and marginalised indigenous cultures. It probes how, within an expanding functionalist framework, Education for Sustainable Development (ESD) has been similarly constituted as a proposition for implementation. Here the supposition is that implementing ESD as an intervention will transform education into an inclusive and collaborative pedagogy that will shape competences for participants to transform society towards a sustainable future. In an effort to explore the possibility of making a break from a succession of education imperatives functioning as ‘salvation narratives’ to put things right in Africa, the study explores ESD from a more situated and emergent vantage point within African landscapes, philosophy and cultural practices. This requires a shift from a view of ESD as a perspective to be brought in and enacted to foster change, to ESD as a situated engagement in education as a process where relevance is deliberated and brought out in quality education with high order skills. This perspective exemplifies working with a more fully situated framing of deliberative social learning for the common good. It is explored here to contemplate how socio-cultural processes of deliberative ethics and co-engaged reflexive processes of learning-led change might emerge. Here, also, using a capabilities approach might provide useful starting points for ESD as an expansive process of transformative social learning.
- Full Text:
- Date Issued: 2019
Three Generations of Healers
- Dlamini, Paul C, Pullanikkatil, Deepa
- Authors: Dlamini, Paul C , Pullanikkatil, Deepa
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433627 , vital:72988 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_
- Description: For eons, traditional medicine was the dominant medical system for millions of people in Africa. It plays an important role in health care for the majority of rural folk in Africa, who often do not have access to modern medicine. The high cost of modern health care systems has prompted the integration of traditional African medicine into the continent’s national health care systems. In Swaziland, a small kingdom located in Southern Africa, 85% of the people rely on traditional medicine for their primary health care. For Swazis, traditional medicine is anchored in their cultural and religious beliefs. In traditional African medicine, it is believed that illness is caused through spiritual or social imbalance and diagnosis is reached through spiritual means.
- Full Text:
- Date Issued: 2019
- Authors: Dlamini, Paul C , Pullanikkatil, Deepa
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433627 , vital:72988 , ISBN 978-3-319-75580-9 , https://link.springer.com/chapter/10.1007/978-3-319-75580-9_
- Description: For eons, traditional medicine was the dominant medical system for millions of people in Africa. It plays an important role in health care for the majority of rural folk in Africa, who often do not have access to modern medicine. The high cost of modern health care systems has prompted the integration of traditional African medicine into the continent’s national health care systems. In Swaziland, a small kingdom located in Southern Africa, 85% of the people rely on traditional medicine for their primary health care. For Swazis, traditional medicine is anchored in their cultural and religious beliefs. In traditional African medicine, it is believed that illness is caused through spiritual or social imbalance and diagnosis is reached through spiritual means.
- Full Text:
- Date Issued: 2019
Time motion analyses of one-day international and twenty/20 matches and the development of a simulated batting protocol specifically designed for female cricket players
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
- Date Issued: 2019
- Authors: Munro, Catherine
- Date: 2019
- Subjects: Women cricket players , Cricket -- Batting , Cricket -- Coaching , Cricket -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76342 , vital:30550
- Description: Background: Accurate and reliable in-game data is fundamental when designing effective batting training. A simulated batting protocol that could aid research and training has not been specifically designed for female cricketers because of a distinct lack of empirical in-game data for the women’s version of the game. Objective: The purpose of this study was to quantify the motion demands and run-breakdown of a century and T20 half-century for women’s cricket matches to establish a simulated batting protocol specifically designed for female batters. Method: Time-motion analyses of four one-day international and six T20 innings were conducted on international cricket matches played around the world between 2012 and 2017. The innings was divided into the bowling and batting innings. The ODI innings that met the criterion of 100 runs scored and T20 innings with scores above 50 runs were used in the run breakdown, which included scores from the top 10 countries ranked by the ICC. The time-motion analyses and century breakdown were utilised in the establishment of a simulated batting protocol. The simulated batting protocol for female batters was created/developed by utilising the method designed by Houghton et al., (2011), who developed the BATEX© protocol. Results: The time-motion analyses indicated that the mean duration of an ODI innings was 169 minutes. An over lasted 2.45 minutes, with 24.86 seconds between each delivery and 55 seconds between each over. When the bowling side changed to a new bowler, it was 1.12 minutes between overs. The mean score for the first power play in an ODI was 41 runs with 1.38 wickets being taken. The mean score during the second power play was 28 runs with 0.714 wickets being taken. The T20 bowling innings lasted 75.50 minutes, with an over lasting 2.52 minutes with 25.58 seconds between deliveries. The mean score in the T20 batting innings was 122 runs. During the power play, which lasted 24.35 minutes, 37 runs were scored with 1.45 wickets being taken. The simulated batting innings was then designed as four stages lasting the duration of a typical women’s century. Each stage was based on theoretical phases of play that may occur during a batting innings. Conclusion: The study indicated that the women’s game has different movement requirements compared to the men’s game in both the ODI and T20 formats. Further, the demands differ depending on the country that is playing. A training and research protocol specifically designed for female batters is an important outcome.
- Full Text:
- Date Issued: 2019
Time-resolved luminescence: progress in development of theory and analytical methods
- Authors: Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/105403 , vital:32509 , https://doi.org/10.1142/9781786345790_0007
- Description: Time-resolved optical stimulation is an important method for measurement of optically stimulated luminescence. The aim of time-resolved optical stimulation is to separate the stimulation and emission of luminescence in time. The luminescence is stimulated from a sample using a short light pulse of constant intensity. The ensuing luminescence can be monitored either during stimulation in the presence of scattered stimulating light, or after the light-pulse. The time-resolved luminescence spectrum produced in this way can be resolved into components, each with a distinct lifetime. The lifetimes are linked to physical processes of luminescence. Time-resolved optical stimulation has thus been used to study dynamics of luminescence in various materials, particularly ones of interest in dosimetry such as quartz, feldspar, α-Al2O3:C and BeO. This chapter will review the theory of time-resolved luminescence, look at the instrumentation involved and discuss advances in analytical methods of time-resolved luminescence spectra.
- Full Text: false
- Date Issued: 2019
- Authors: Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/105403 , vital:32509 , https://doi.org/10.1142/9781786345790_0007
- Description: Time-resolved optical stimulation is an important method for measurement of optically stimulated luminescence. The aim of time-resolved optical stimulation is to separate the stimulation and emission of luminescence in time. The luminescence is stimulated from a sample using a short light pulse of constant intensity. The ensuing luminescence can be monitored either during stimulation in the presence of scattered stimulating light, or after the light-pulse. The time-resolved luminescence spectrum produced in this way can be resolved into components, each with a distinct lifetime. The lifetimes are linked to physical processes of luminescence. Time-resolved optical stimulation has thus been used to study dynamics of luminescence in various materials, particularly ones of interest in dosimetry such as quartz, feldspar, α-Al2O3:C and BeO. This chapter will review the theory of time-resolved luminescence, look at the instrumentation involved and discuss advances in analytical methods of time-resolved luminescence spectra.
- Full Text: false
- Date Issued: 2019