Effects of a resistance training intervention on the physical fitness of youth in a rural soccer development programme
- Authors: Greyling, Jacob Johannes
- Date: 2020
- Subjects: Physical fitness--Soccer
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/50795 , vital:42701
- Description: Background: Soccer is the most popular sport worldwide with an estimated 270 million people involved in the sport. Soccer is a fast-paced contact team sport that requires physical capabilities such as speed, agility, strength, power, aerobic and anaerobic fitness in addition to technical proficiency. Most goals are preceded by a linear sprint, jump or change of direction which is why the ability to perform fast powerful movements is important. Research has indicated that resistance training performed in combination with high intensity speed and plyometric training, improves athletic performance of soccer players. Aims and Objectives: This study investigated the effects of a resistance training intervention on the physical fitness of youth in a rural soccer development programme in Addo in the Eastern Cape province of South Africa. Methodology: This study employed a quantitative approach in the form of a quasi-experimental design with an experimental and control group. The sample was conveniently selected based on availability of players and on them meeting specific inclusion criteria. Local soccer clubs in the Nomathamsanqa township - an impoverished area in Addo, which forms part of the Addo Soccer Development Programme (ASDP) - were invited to participate in the study. The final sample for this study consisted of 12 participants. A 10-week soccer-based resistance training intervention, addressing the components of physical fitness with specific emphasis on resistance training, was implemented after completion of the baseline testing. The intervention was designed to be suitable for a rural setting. Results: Within group comparisons revealed significant improvements in the experimental group for power (p = 0.028), speed (p = 0.028) and overall performance (grouped physical fitness measures) (p = 0.018) whereas the control group improved significantly in speed (p = 0.043) and regressed significantly in cardiovascular endurance (p = 0.043). Between group comparisons revealed significant differences for overall performance improvement in the experimental group (p = 0.006) and a reduction in cardiovascular endurance in the control group (p = 0.028). The main finding of this study is therefore this: that the individual parameters did not show consistent improvement when viewed in isolation, however that the intervention had a positive effect on overall performance when all the physical fitness measures were computed as a collective result. Conclusion: The results of the study indicate that the intervention had a positive effect on overall performance however more research is required on soccer in rural and disadvantaged settings of South Africa to develop a convincing model for supplementary training other than conventional soccer practice to improve performance and to overcome the unique challenges faced in a rural setting.
- Full Text: false
- Date Issued: 2020
- Authors: Greyling, Jacob Johannes
- Date: 2020
- Subjects: Physical fitness--Soccer
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/50795 , vital:42701
- Description: Background: Soccer is the most popular sport worldwide with an estimated 270 million people involved in the sport. Soccer is a fast-paced contact team sport that requires physical capabilities such as speed, agility, strength, power, aerobic and anaerobic fitness in addition to technical proficiency. Most goals are preceded by a linear sprint, jump or change of direction which is why the ability to perform fast powerful movements is important. Research has indicated that resistance training performed in combination with high intensity speed and plyometric training, improves athletic performance of soccer players. Aims and Objectives: This study investigated the effects of a resistance training intervention on the physical fitness of youth in a rural soccer development programme in Addo in the Eastern Cape province of South Africa. Methodology: This study employed a quantitative approach in the form of a quasi-experimental design with an experimental and control group. The sample was conveniently selected based on availability of players and on them meeting specific inclusion criteria. Local soccer clubs in the Nomathamsanqa township - an impoverished area in Addo, which forms part of the Addo Soccer Development Programme (ASDP) - were invited to participate in the study. The final sample for this study consisted of 12 participants. A 10-week soccer-based resistance training intervention, addressing the components of physical fitness with specific emphasis on resistance training, was implemented after completion of the baseline testing. The intervention was designed to be suitable for a rural setting. Results: Within group comparisons revealed significant improvements in the experimental group for power (p = 0.028), speed (p = 0.028) and overall performance (grouped physical fitness measures) (p = 0.018) whereas the control group improved significantly in speed (p = 0.043) and regressed significantly in cardiovascular endurance (p = 0.043). Between group comparisons revealed significant differences for overall performance improvement in the experimental group (p = 0.006) and a reduction in cardiovascular endurance in the control group (p = 0.028). The main finding of this study is therefore this: that the individual parameters did not show consistent improvement when viewed in isolation, however that the intervention had a positive effect on overall performance when all the physical fitness measures were computed as a collective result. Conclusion: The results of the study indicate that the intervention had a positive effect on overall performance however more research is required on soccer in rural and disadvantaged settings of South Africa to develop a convincing model for supplementary training other than conventional soccer practice to improve performance and to overcome the unique challenges faced in a rural setting.
- Full Text: false
- Date Issued: 2020
Effects of an eight-week lumbar stabilization exercise programme on selected variables of patients with chronic low back pain:
- Abass, Ademola O, Alli, Abiola R, Olagbegi, Oladapo M, Christie, Candice J, Bolarinde, Olufemi S
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
Effects of economic growth on greenhouse emissions
- Mkunyana, Asebenzile Priscilla
- Authors: Mkunyana, Asebenzile Priscilla
- Date: 2020
- Subjects: Greenhouse gases -- Environmental aspects -- Africa , Climate change mitigation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/50404 , vital:42162
- Description: This study employs the panel cointegration and Pooled Mean Group technique to examine the effects of economic growth on greenhouse emissions using the panel data from the period of 1970 to 2014 for five Southern African Development Community group of countries. The increase in the combustion of burning fossil fuels has become the global threat in environmental quality. The Environmental Kuznets Curve hypothesis postulates that at the primary stages of industrial economies there is more extracting of natural resources and more agricultural activities taking place as a result the waste generation and resource depletion accelerate. However, as the economic development improves more, the curve reaches a threshold where it starts to decline due to the increase in economic growth and the change to information-based industries. Based on the empirical evidence, the variables of this study were found to be stationary at first difference and integrated of I(0) and I(1) using Im, Pesaran & Shin W-stat, Fisher ADF, and Levin, Lin & Chu panel unit root test. The existing long-run relationship between the variables were found in both the Pedroni and Kao cointegration test and were significant at 5% in finding the relationship between the variables. The Pooled Mean Group demonstrated mixed results in the study’s regressions, monotonic relationship was found between carbon dioxide and economic growth. The strong existence relationship between economic growth and energy consumption was found to be significant at the 1% level. These results are in line with the EKC hypothesis, which assumes that as the income level increases the society will start to be environmentally friendly and the technology advancement will decrease the emission of pollutants. In addition, in finding the causal relationship between variables, the researcher used the Granger causality test, with the results from this test revealing a unidirectional and bidirectional relationship between all the chosen variables. These results are important for policy makers.
- Full Text:
- Date Issued: 2020
- Authors: Mkunyana, Asebenzile Priscilla
- Date: 2020
- Subjects: Greenhouse gases -- Environmental aspects -- Africa , Climate change mitigation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/50404 , vital:42162
- Description: This study employs the panel cointegration and Pooled Mean Group technique to examine the effects of economic growth on greenhouse emissions using the panel data from the period of 1970 to 2014 for five Southern African Development Community group of countries. The increase in the combustion of burning fossil fuels has become the global threat in environmental quality. The Environmental Kuznets Curve hypothesis postulates that at the primary stages of industrial economies there is more extracting of natural resources and more agricultural activities taking place as a result the waste generation and resource depletion accelerate. However, as the economic development improves more, the curve reaches a threshold where it starts to decline due to the increase in economic growth and the change to information-based industries. Based on the empirical evidence, the variables of this study were found to be stationary at first difference and integrated of I(0) and I(1) using Im, Pesaran & Shin W-stat, Fisher ADF, and Levin, Lin & Chu panel unit root test. The existing long-run relationship between the variables were found in both the Pedroni and Kao cointegration test and were significant at 5% in finding the relationship between the variables. The Pooled Mean Group demonstrated mixed results in the study’s regressions, monotonic relationship was found between carbon dioxide and economic growth. The strong existence relationship between economic growth and energy consumption was found to be significant at the 1% level. These results are in line with the EKC hypothesis, which assumes that as the income level increases the society will start to be environmentally friendly and the technology advancement will decrease the emission of pollutants. In addition, in finding the causal relationship between variables, the researcher used the Granger causality test, with the results from this test revealing a unidirectional and bidirectional relationship between all the chosen variables. These results are important for policy makers.
- Full Text:
- Date Issued: 2020
Effects of high-intensity speed training on the speed reserve of university middle-distance and field sport athletes
- Authors: Thomas, Emma Jayne
- Date: 2020
- Subjects: Athletes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46346 , vital:39599
- Description: Context: Despite the multiple differences between athletic events and sports, they all share the sporadic bouts of moderate to extreme intensities and all require some contribution from an integrated bioenergetic system to allow for optimal performance. Although D’ is often considered as an ‘anaerobic work capacity’, such a definition is over-simplistic and its precise composition is nebulous, especially given the mixed findings of the experimental evidence. Clearly, further research is needed to provide a more complete understanding of the D’ parameter, as well as the speed reserve(range of speeds exceeding critical speed) especially within high-intensity exercise. Purpose (Aim): The aim of this study is to determine whether a short term high-intensity speed training intervention within the severe intensity domain effects speed reserve in athletic and non-athletic individuals considered moderately trained.Methods: A quantitative research design was used. Participantscompletedbaseline testing (pre-test), after which they were assigned into two groups. Both groups received a HIIT training program, with group 1 (G140%) receiving a program based on intensity prescription (work bouts performed at 140% of CS)and group 2 (G90-s) receiving a program based on time intervals (work bouts performed for 90-s). HIIT sessions were performed twice-weekly for a total of 6-weeks. A post-test assessment was then conducted by both groups to determine whether any changes have accrued in any of the physiological variables in question. Participants of the study met a specific criterion(18 –30 years of age, residing in Nelson Mandela Bay, and met the minimum fitness requirements). Results: No significant between-group differences were evident prior to and following cessation of the HIIT intervention. Findings that can be highlighted holistically include improvements in CS(G140%: M = 0.62 m.s-1; G90-s: M = 0.46 m.s-1)and 𝑉̇𝑂2𝑚𝑎𝑥 (G140%: +3.81 ml.kg-1.min-1; G90-s: +5.19 ml.kg-1.min-1)and a decrease in fatigue index (G140%: M = -6.75%; G90-s: M = -4.38%) and D’(G140%: M = -56.34 m; G90-s: M = -18.36 m).Normative data were generated for athletic and non-athletic participants using the standard nine (Stanine) categorization to facilitate interpretation and recommendations of key parameters for coaches and clinicians. Moreover, a deterministic model was also generated which revealed novel interactions and the strength of the relationship between variables-potentially opening new and innovative areas of future research. Conclusions: The interval durations and speeds utilised in the present study were insufficient to stimulate an increase in D’. To elicit an increase of D’, one would have to decrease the duration of the intervals performed(i.e. < 90-sec), while increasing speed at which the intervals performed at some speed greater than 140% of CS, but below MSS. Further research is needed to understand the physiological underpinning of the D’ parameter both in isolation and in conjunction with CS. It is clear that D’ is influenced by parameters such as MSS, 𝜏d and FI%; therefore, these sub-parameters should be explored further as potentiators for moderating the D’ parameter.
- Full Text:
- Date Issued: 2020
- Authors: Thomas, Emma Jayne
- Date: 2020
- Subjects: Athletes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/46346 , vital:39599
- Description: Context: Despite the multiple differences between athletic events and sports, they all share the sporadic bouts of moderate to extreme intensities and all require some contribution from an integrated bioenergetic system to allow for optimal performance. Although D’ is often considered as an ‘anaerobic work capacity’, such a definition is over-simplistic and its precise composition is nebulous, especially given the mixed findings of the experimental evidence. Clearly, further research is needed to provide a more complete understanding of the D’ parameter, as well as the speed reserve(range of speeds exceeding critical speed) especially within high-intensity exercise. Purpose (Aim): The aim of this study is to determine whether a short term high-intensity speed training intervention within the severe intensity domain effects speed reserve in athletic and non-athletic individuals considered moderately trained.Methods: A quantitative research design was used. Participantscompletedbaseline testing (pre-test), after which they were assigned into two groups. Both groups received a HIIT training program, with group 1 (G140%) receiving a program based on intensity prescription (work bouts performed at 140% of CS)and group 2 (G90-s) receiving a program based on time intervals (work bouts performed for 90-s). HIIT sessions were performed twice-weekly for a total of 6-weeks. A post-test assessment was then conducted by both groups to determine whether any changes have accrued in any of the physiological variables in question. Participants of the study met a specific criterion(18 –30 years of age, residing in Nelson Mandela Bay, and met the minimum fitness requirements). Results: No significant between-group differences were evident prior to and following cessation of the HIIT intervention. Findings that can be highlighted holistically include improvements in CS(G140%: M = 0.62 m.s-1; G90-s: M = 0.46 m.s-1)and 𝑉̇𝑂2𝑚𝑎𝑥 (G140%: +3.81 ml.kg-1.min-1; G90-s: +5.19 ml.kg-1.min-1)and a decrease in fatigue index (G140%: M = -6.75%; G90-s: M = -4.38%) and D’(G140%: M = -56.34 m; G90-s: M = -18.36 m).Normative data were generated for athletic and non-athletic participants using the standard nine (Stanine) categorization to facilitate interpretation and recommendations of key parameters for coaches and clinicians. Moreover, a deterministic model was also generated which revealed novel interactions and the strength of the relationship between variables-potentially opening new and innovative areas of future research. Conclusions: The interval durations and speeds utilised in the present study were insufficient to stimulate an increase in D’. To elicit an increase of D’, one would have to decrease the duration of the intervals performed(i.e. < 90-sec), while increasing speed at which the intervals performed at some speed greater than 140% of CS, but below MSS. Further research is needed to understand the physiological underpinning of the D’ parameter both in isolation and in conjunction with CS. It is clear that D’ is influenced by parameters such as MSS, 𝜏d and FI%; therefore, these sub-parameters should be explored further as potentiators for moderating the D’ parameter.
- Full Text:
- Date Issued: 2020
Efficacy of the rind physiological disorder oleocellosis control measures in lemon fruit (Citrus limon) under shade netting
- Authors: Njili, Zamazima
- Date: 2020
- Subjects: Citrus fruits--Storage--Diseases and injuries , Citrus--Diseases and pests Citrus fruit industry Citrus products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49237 , vital:41613
- Description: Lemon growers aim to produce fruit with no blemishes on the rind. Fruit without blemishes is regarded as high value fruit required for the export market. Leakage of phytotoxic oil from the rind tissues damages them and results in the development of oleocellosis symptoms. Four experiments were conducted to investigate methods of avoiding and controlling the development of oleocellosis during harvest and post-harvest handling. The first experiment indicated that the rind oil release pressure (RORP) test is the method most effective at predicting oleocellosis incidents. The experiment also suggested that fruit not exposed to the sun are the most susceptible to oleocellosis due to low temperatures that cause high turgidity. Oleocellosis results when turgid fruit is mishandled. A cultivar experiment was carried out to ascertain the lemon cultivar most susceptible to oleocellosis. The results show that the Limoneira cultivar is the most susceptible to oleocellosis and 2PH seedless is the least susceptible cultivar when compared to other lemon cultivars such as Lisbon, Eureka and Genoa. When the use of shade netting was tested to determine its effect on oleocellosis severity, it was found that using shade netting did not have an effect. Fruit grown under shade netting had the same colour and average diameter as fruit grown in an open orchard. In the same experiment, mature fruit were shown to be more susceptible to oleocellosis than immature fruit. The final part of the project investigated harvesting and post-harvest practices to determine those that cause oleocellosis the most. It was found that fruit after degreening had greater oleocellosis due to exposure to moisture conditions and rough handling. Another practice that results in oleocellosis occurs before waxing when the fruit was roughly transferred from the bins into the packline. The third oleocellosis inducing practice was moving fruit along the conveyor belt while it is turgid. Improvement of handling procedures to reduce oleocellosis can increase export volume and result in higher value of fruit per carton.
- Full Text:
- Date Issued: 2020
- Authors: Njili, Zamazima
- Date: 2020
- Subjects: Citrus fruits--Storage--Diseases and injuries , Citrus--Diseases and pests Citrus fruit industry Citrus products
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/49237 , vital:41613
- Description: Lemon growers aim to produce fruit with no blemishes on the rind. Fruit without blemishes is regarded as high value fruit required for the export market. Leakage of phytotoxic oil from the rind tissues damages them and results in the development of oleocellosis symptoms. Four experiments were conducted to investigate methods of avoiding and controlling the development of oleocellosis during harvest and post-harvest handling. The first experiment indicated that the rind oil release pressure (RORP) test is the method most effective at predicting oleocellosis incidents. The experiment also suggested that fruit not exposed to the sun are the most susceptible to oleocellosis due to low temperatures that cause high turgidity. Oleocellosis results when turgid fruit is mishandled. A cultivar experiment was carried out to ascertain the lemon cultivar most susceptible to oleocellosis. The results show that the Limoneira cultivar is the most susceptible to oleocellosis and 2PH seedless is the least susceptible cultivar when compared to other lemon cultivars such as Lisbon, Eureka and Genoa. When the use of shade netting was tested to determine its effect on oleocellosis severity, it was found that using shade netting did not have an effect. Fruit grown under shade netting had the same colour and average diameter as fruit grown in an open orchard. In the same experiment, mature fruit were shown to be more susceptible to oleocellosis than immature fruit. The final part of the project investigated harvesting and post-harvest practices to determine those that cause oleocellosis the most. It was found that fruit after degreening had greater oleocellosis due to exposure to moisture conditions and rough handling. Another practice that results in oleocellosis occurs before waxing when the fruit was roughly transferred from the bins into the packline. The third oleocellosis inducing practice was moving fruit along the conveyor belt while it is turgid. Improvement of handling procedures to reduce oleocellosis can increase export volume and result in higher value of fruit per carton.
- Full Text:
- Date Issued: 2020
Efficient market hypothesis : testing weak-form efficiency on the Johannesburg stock exchange
- Authors: Eaton, Bradley Hayes
- Date: 2020
- Subjects: Efficient market theory
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/47895 , vital:40396
- Description: Understanding financial markets is paramount in acknowledging the flow of domestic and foreign funds over time. In this study, net market capitalisation price and simple return characteristics were investigated for the period from January 2009 to December 2017. An empirical, statistical approach was used to explore the possibility that, since the 2008 financial crisis, forward-looking, aggregate market and financial-oriented equity indices have conformed to the Efficient Market Hypothesis. Accordingly, monthly observations were made to ensure long-run traits were identified and scrutinised. Such revelations are important for portfolio diversification, risk, and expected return potentials with respect to South African equity markets. Based on the study, it was found that random walks were evident in both the price and return time-series as a result of significant stochastic price action, supported by evidence suggesting non-normality of price and return distributions. Unit root and stationarity modelling confirmed such traits. However, significant trending behaviours were evident in the auto-correlation figures with regards to prices, despite mean-reverting and stochastic influences. Therefore, it was concluded from the results of the study that the respective time-series were weak-form efficient. The empirical component was supplemented by a comprehensive investigation into the market determinants of financial market inefficiencies, including partial correlations, contagion effects, momentum, financial bubbles, and liquidity issues. Secondary objectives of the study included identifying the roles of security exchanges and the effect of international linkages, as a result of globalisation, on the financial markets. Increased macro-economic and systems integration has led to positive and negative connotations for business cycles. Spill-over effects into global equity markets are evident as can be seen through the co-integration of leading world exchanges, both in the developed and emerging market spheres. Fundamental to this study was the sensitivity of South African equity markets to recessionary pressures, as analysed through the efficiency of aggregated equity indices.
- Full Text:
- Date Issued: 2020
- Authors: Eaton, Bradley Hayes
- Date: 2020
- Subjects: Efficient market theory
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/47895 , vital:40396
- Description: Understanding financial markets is paramount in acknowledging the flow of domestic and foreign funds over time. In this study, net market capitalisation price and simple return characteristics were investigated for the period from January 2009 to December 2017. An empirical, statistical approach was used to explore the possibility that, since the 2008 financial crisis, forward-looking, aggregate market and financial-oriented equity indices have conformed to the Efficient Market Hypothesis. Accordingly, monthly observations were made to ensure long-run traits were identified and scrutinised. Such revelations are important for portfolio diversification, risk, and expected return potentials with respect to South African equity markets. Based on the study, it was found that random walks were evident in both the price and return time-series as a result of significant stochastic price action, supported by evidence suggesting non-normality of price and return distributions. Unit root and stationarity modelling confirmed such traits. However, significant trending behaviours were evident in the auto-correlation figures with regards to prices, despite mean-reverting and stochastic influences. Therefore, it was concluded from the results of the study that the respective time-series were weak-form efficient. The empirical component was supplemented by a comprehensive investigation into the market determinants of financial market inefficiencies, including partial correlations, contagion effects, momentum, financial bubbles, and liquidity issues. Secondary objectives of the study included identifying the roles of security exchanges and the effect of international linkages, as a result of globalisation, on the financial markets. Increased macro-economic and systems integration has led to positive and negative connotations for business cycles. Spill-over effects into global equity markets are evident as can be seen through the co-integration of leading world exchanges, both in the developed and emerging market spheres. Fundamental to this study was the sensitivity of South African equity markets to recessionary pressures, as analysed through the efficiency of aggregated equity indices.
- Full Text:
- Date Issued: 2020
Either way you die: a collection of short stories
- Authors: Sithole, Sipho
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145081 , vital:38406
- Description: Part A: Thesis (Creative Work); Part B: Portfolio.
- Full Text:
- Date Issued: 2020
- Authors: Sithole, Sipho
- Date: 2020
- Subjects: South African fiction (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/145081 , vital:38406
- Description: Part A: Thesis (Creative Work); Part B: Portfolio.
- Full Text:
- Date Issued: 2020
Electricity use behaviour in a high-income neighbourhood in Johannesburg, South Africa:
- Williams, Stephanie P, Thondhlana, Gladman, Kua, Harn W
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
- Authors: Williams, Stephanie P , Thondhlana, Gladman , Kua, Harn W
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149725 , vital:38878 , https://doi.org/10.3390/su12114571
- Description: Worldwide, households’ consumption of electricity contributes to a substantial proportion of total national energy demand. Thus, the residential sector is a major entity in efforts to define and achieve global sustainability goals. Understanding electricity use behaviour and factors underlying behaviour is critical for designing behaviour change interventions, particularly in contexts characterised by fast-growing economies, burgeoning number of high-income households, and consumption growth. However, relative to developed economies, very little is known on this subject in South Africa. Using structured questionnaires, this study examines electricity use behaviour among high-income households in Johannesburg, South Africa.
- Full Text:
- Date Issued: 2020
Electrodeposited Benzothiazole Phthalocyanines for Corrosion Inhibition of Aluminium in Acidic Medium
- Nnaji, Nnaemeka, Nwaji, Njemuwa, Nyokong, Tebello
- Authors: Nnaji, Nnaemeka , Nwaji, Njemuwa , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186112 , vital:44464 , xlink:href="https://doi.org/10.1155/2020/8892559"
- Description: Tetrakis[(benzo[d]thiazol-2-yl-thio) phthalocyaninato] gallium(III)chloride (1) and tetrakis[(benzo[d]thiazol-2ylphenoxy) phthalocyaninato] gallium(III)chloride (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. The aim of this study was to compare the corrosion resistance of electrodeposited metallated phthalocyanines. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy (EIS), and polarization confirmed the aluminium corrosion inhibition potentials of complexes 1 and 2. EIS and polarization techniques showed that complex 2 performed better than complex 1, with values from EIS measurements of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution. The importance of electrodeposition in industries and a dearth of research on the use of electrodeposited metallated phthalocyanines necessitated this study, and results show that coatings formed by electrodeposition of 1 and 2 onto aluminium reduced its susceptibility to corrosion attack.
- Full Text:
- Date Issued: 2020
- Authors: Nnaji, Nnaemeka , Nwaji, Njemuwa , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186112 , vital:44464 , xlink:href="https://doi.org/10.1155/2020/8892559"
- Description: Tetrakis[(benzo[d]thiazol-2-yl-thio) phthalocyaninato] gallium(III)chloride (1) and tetrakis[(benzo[d]thiazol-2ylphenoxy) phthalocyaninato] gallium(III)chloride (2) were successfully electrodeposited onto aluminium for corrosion retardation in 1.0 M hydrochloric acid solution. The aim of this study was to compare the corrosion resistance of electrodeposited metallated phthalocyanines. Scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy (EIS), and polarization confirmed the aluminium corrosion inhibition potentials of complexes 1 and 2. EIS and polarization techniques showed that complex 2 performed better than complex 1, with values from EIS measurements of 82% for 1 and 86% for 2 in 1.0 M hydrochloric acid solution. The importance of electrodeposition in industries and a dearth of research on the use of electrodeposited metallated phthalocyanines necessitated this study, and results show that coatings formed by electrodeposition of 1 and 2 onto aluminium reduced its susceptibility to corrosion attack.
- Full Text:
- Date Issued: 2020
Electronic and nonlinear optical properties of 2-(((5-aminonaphthalen-1-yl) imino) methyl) phenol
- Ojo, Nathanael D, Krause, Rui W M, Obi-Egbedi, Nelson O
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193397 , vital:45328 , xlink:href="https://doi.org/10.1016/j.molliq.2020.114157"
- Description: In this study, solvent dependence of electronic and nonlinear optical properties of a new Schiff base, 2-(((5-aminonaphthalen-1-yl)imino)methyl) phenol (DANOHB), has been investigated. Electronic and optical properties of the Schiff base studied using Uv-visible absorption and fluorescence spectroscopic techniques in solution show that the Schiff base exhibits fluorescence with a quantum yield of 0.21 and a Stokes shift of 39 nm. Quantum chemical calculations were performed on the Schiff base at time-dependent density functional level of theory using Becke-3-Lee-Yang-Parr method with 6-311++G(d,p) basis set. Solvent dependence of the excited state energies (EE), energy gap (ΔE), first-order (β) and second-order (γ) hyperpolarizabilities were studied in gas, cyclohexane and ethanol. The medium perturbed the energy levels which implies that the reactivity, activity and stability of the system are solvent sensitive. The γ is more than thirty times higher than urea (standard NLO material) and this property is further enhanced in less polar medium. Small ΔE and large hyperpolarizabilities obtained for this system suggest its good potential in photonics and nonlinear optical devices.
- Full Text:
- Date Issued: 2020
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193397 , vital:45328 , xlink:href="https://doi.org/10.1016/j.molliq.2020.114157"
- Description: In this study, solvent dependence of electronic and nonlinear optical properties of a new Schiff base, 2-(((5-aminonaphthalen-1-yl)imino)methyl) phenol (DANOHB), has been investigated. Electronic and optical properties of the Schiff base studied using Uv-visible absorption and fluorescence spectroscopic techniques in solution show that the Schiff base exhibits fluorescence with a quantum yield of 0.21 and a Stokes shift of 39 nm. Quantum chemical calculations were performed on the Schiff base at time-dependent density functional level of theory using Becke-3-Lee-Yang-Parr method with 6-311++G(d,p) basis set. Solvent dependence of the excited state energies (EE), energy gap (ΔE), first-order (β) and second-order (γ) hyperpolarizabilities were studied in gas, cyclohexane and ethanol. The medium perturbed the energy levels which implies that the reactivity, activity and stability of the system are solvent sensitive. The γ is more than thirty times higher than urea (standard NLO material) and this property is further enhanced in less polar medium. Small ΔE and large hyperpolarizabilities obtained for this system suggest its good potential in photonics and nonlinear optical devices.
- Full Text:
- Date Issued: 2020
Electronic and nonlinear optical properties of 3-(((2-substituted-4-nitrophenyl) imino) methyl) phenol
- Ojo, Nathanael D, Krause, Rui W M, Obi-Egbedi, Nelson O
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193408 , vital:45329 , xlink:href="https://doi.org/10.1016/j.comptc.2020.113050"
- Description: This work entails the study of electronic and nonlinear optical (NLO) properties of two synthesized Schiff bases namely 3-(((2-methyl-4-nitrophenyl)imino)methyl)phenol (MMP) and 3-(((2,4-dinitrophenyl)imino)methyl)phenol (DMP). Electronic absorption properties studied using UV–Visible spectrophotometry in ethanol reveal low-energy absorption indicating a low band gap. Time-dependent density functional calculations on their excited state properties with ωB97X-D/6-311++G(d,p) method show comparable transition energies and intensities with the experimental results. Energy gaps (ΔE) and NLO properties were evaluated from the frontier orbitals and hyperpolarizabilities (βtot and γ) in gas, cyclohexane and ethanol. Low ΔE obtained shows the potentials of the systems as organic semiconductor with remarkable band gap stabilization in ethanol. Higher βtot and γ than urea imply that the Schiff bases possess potentials for NLO applications. The solvatochromic shift in transition energies and perturbation of electronic properties reveal the solvent dependence of the electronic and optical properties of MMP and DMP due to solute-solvent interactions.
- Full Text:
- Date Issued: 2020
- Authors: Ojo, Nathanael D , Krause, Rui W M , Obi-Egbedi, Nelson O
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193408 , vital:45329 , xlink:href="https://doi.org/10.1016/j.comptc.2020.113050"
- Description: This work entails the study of electronic and nonlinear optical (NLO) properties of two synthesized Schiff bases namely 3-(((2-methyl-4-nitrophenyl)imino)methyl)phenol (MMP) and 3-(((2,4-dinitrophenyl)imino)methyl)phenol (DMP). Electronic absorption properties studied using UV–Visible spectrophotometry in ethanol reveal low-energy absorption indicating a low band gap. Time-dependent density functional calculations on their excited state properties with ωB97X-D/6-311++G(d,p) method show comparable transition energies and intensities with the experimental results. Energy gaps (ΔE) and NLO properties were evaluated from the frontier orbitals and hyperpolarizabilities (βtot and γ) in gas, cyclohexane and ethanol. Low ΔE obtained shows the potentials of the systems as organic semiconductor with remarkable band gap stabilization in ethanol. Higher βtot and γ than urea imply that the Schiff bases possess potentials for NLO applications. The solvatochromic shift in transition energies and perturbation of electronic properties reveal the solvent dependence of the electronic and optical properties of MMP and DMP due to solute-solvent interactions.
- Full Text:
- Date Issued: 2020
Elucidation of the effect of cannabinoids on ER stress to determine their molecular mechanism of action in breast cancer cells
- Authors: De la Harpe, Amy
- Date: 2020
- Subjects: Endoplasmic reticulum -- Pathophysiology , Breast -- Cancer -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48213 , vital:40525
- Description: Endoplasmic reticulum (ER) stress is defined as an imbalance between the ER’s protein-folding load and folding capacity. ER stress is induced by various physiological conditions and subsequently triggers the activation of the unfolded protein response (UPR) to re-establish homeostasis and promote cell survival. However, under severe or chronic stress, apoptosis is induced. Normal cells generally do not experience ER stress; however, stressful conditions in the tumour micro-environment facilitates chronic ER stress and UPR activation, which plays a pivotal role in tumour survival. Exacerbation of pre-existing ER stress can trigger cancer cell death, with a minimal effect on normal cells. Currently, no high-throughput method exists to detect and quantify ER stress in cell lines. This study showed that Thioflavin T, a fluorescent dye that binds to misfolded protein aggregates, can be used for the high-throughput detection of ER stress, and provides several advantages over currently used methods. Current literature suggests that cannabinoid treatment may induce cancer cell death via ER stress, however little is known about the mechanism of induction. This study proposed a mechanism that occurs via the influx of Ca2+ via the vanilloid receptor 1 (TRPV1), and subsequent ROS production, which affects protein folding. ER stress was induced using various cannabinoids and measured using Thioflavin T and western blot analysis. The effect of cannabinoid treatment on ROS production and the intracellular Ca2+ concentration was measured. Cannabidiol (CBD) was the most potent ER stress inducer, significantly increasing Ca2+ and ROS accumulation; however, the level of accumulated Ca2+ across cell lines varied, which may be due to the differences in the TRPV1 expression and localization. Concomitant treatment of CBD with an antioxidant significantly increased cell viability and decreased ER stress induction in the MCF7 cell line. Concomitant treatment with a TRPV1 antagonist increased viability in this cell line. In conclusion, the results suggested that CBD may induce ER stress via Ca2+ influx through the TRPV1 receptor, thereby elevating intracellular ROS levels and disrupting protein folding.
- Full Text:
- Date Issued: 2020
- Authors: De la Harpe, Amy
- Date: 2020
- Subjects: Endoplasmic reticulum -- Pathophysiology , Breast -- Cancer -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/48213 , vital:40525
- Description: Endoplasmic reticulum (ER) stress is defined as an imbalance between the ER’s protein-folding load and folding capacity. ER stress is induced by various physiological conditions and subsequently triggers the activation of the unfolded protein response (UPR) to re-establish homeostasis and promote cell survival. However, under severe or chronic stress, apoptosis is induced. Normal cells generally do not experience ER stress; however, stressful conditions in the tumour micro-environment facilitates chronic ER stress and UPR activation, which plays a pivotal role in tumour survival. Exacerbation of pre-existing ER stress can trigger cancer cell death, with a minimal effect on normal cells. Currently, no high-throughput method exists to detect and quantify ER stress in cell lines. This study showed that Thioflavin T, a fluorescent dye that binds to misfolded protein aggregates, can be used for the high-throughput detection of ER stress, and provides several advantages over currently used methods. Current literature suggests that cannabinoid treatment may induce cancer cell death via ER stress, however little is known about the mechanism of induction. This study proposed a mechanism that occurs via the influx of Ca2+ via the vanilloid receptor 1 (TRPV1), and subsequent ROS production, which affects protein folding. ER stress was induced using various cannabinoids and measured using Thioflavin T and western blot analysis. The effect of cannabinoid treatment on ROS production and the intracellular Ca2+ concentration was measured. Cannabidiol (CBD) was the most potent ER stress inducer, significantly increasing Ca2+ and ROS accumulation; however, the level of accumulated Ca2+ across cell lines varied, which may be due to the differences in the TRPV1 expression and localization. Concomitant treatment of CBD with an antioxidant significantly increased cell viability and decreased ER stress induction in the MCF7 cell line. Concomitant treatment with a TRPV1 antagonist increased viability in this cell line. In conclusion, the results suggested that CBD may induce ER stress via Ca2+ influx through the TRPV1 receptor, thereby elevating intracellular ROS levels and disrupting protein folding.
- Full Text:
- Date Issued: 2020
Employee retention as a strategy for the sustainability of rehabilitation services within the Nelson Mandela Bay Health District
- Authors: Campbell, Teneille Dawn
- Date: 2020
- Subjects: Employee retention--South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47530 , vital:40124
- Description: Health care facilities in the South African public sector have, over time, become notorious for poor service delivery, peppered with issues of poor governance, weak administration capabilities, and ailing working conditions. Often, the consequence hereof is a loss of good talent to both the private sector and health sectors abroad, all the while placing more strain on institutional service delivery capabilities. To achieve the United Nation’s Sustainable Development Goal (SDG) of Universal Health Coverage (UHC) by 2030, the strengthening of health systems is critical. The purpose of this study is therefore to offer supportable solutions to improve and maintain a sustainable rehabilitation service in the Nelson Mandela Metro through successful retention of staff. The aim of this study then is to investigate the influence that Human Resources (HR) processes, working conditions and leadership have had on retention of staff. A review of the available literature was conducted on possible factors that contribute to the problem and the solutions thereof. The study population included all staff that worked in rehabilitation service departments in the public health institutions in the Nelson Mandela Metro, namely; physiotherapy, occupational therapy, speech therapy and audiology. The sample constituted n=51 respondents. Data was collected via a questionnaire as the selected measurement tool. The data was analysed using the statistical data analysis software system, TIBCO Statistica (version 13), and selected methods for quantitative data. The results of the study showed that only HR processes were significantly and positively (r = 0.67, p < 0.05) related to retention. It means that satisfying the HR needs of this population is most likely to retain their employ and improve and maintain rehabilitation service delivery in the selected metro. Descriptive statistics of all the variables were also calculated and reported on. Lastly, the managerial implications of the study findings were reported on.
- Full Text:
- Date Issued: 2020
- Authors: Campbell, Teneille Dawn
- Date: 2020
- Subjects: Employee retention--South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/47530 , vital:40124
- Description: Health care facilities in the South African public sector have, over time, become notorious for poor service delivery, peppered with issues of poor governance, weak administration capabilities, and ailing working conditions. Often, the consequence hereof is a loss of good talent to both the private sector and health sectors abroad, all the while placing more strain on institutional service delivery capabilities. To achieve the United Nation’s Sustainable Development Goal (SDG) of Universal Health Coverage (UHC) by 2030, the strengthening of health systems is critical. The purpose of this study is therefore to offer supportable solutions to improve and maintain a sustainable rehabilitation service in the Nelson Mandela Metro through successful retention of staff. The aim of this study then is to investigate the influence that Human Resources (HR) processes, working conditions and leadership have had on retention of staff. A review of the available literature was conducted on possible factors that contribute to the problem and the solutions thereof. The study population included all staff that worked in rehabilitation service departments in the public health institutions in the Nelson Mandela Metro, namely; physiotherapy, occupational therapy, speech therapy and audiology. The sample constituted n=51 respondents. Data was collected via a questionnaire as the selected measurement tool. The data was analysed using the statistical data analysis software system, TIBCO Statistica (version 13), and selected methods for quantitative data. The results of the study showed that only HR processes were significantly and positively (r = 0.67, p < 0.05) related to retention. It means that satisfying the HR needs of this population is most likely to retain their employ and improve and maintain rehabilitation service delivery in the selected metro. Descriptive statistics of all the variables were also calculated and reported on. Lastly, the managerial implications of the study findings were reported on.
- Full Text:
- Date Issued: 2020
Enabling violence: the ethics of writing and reading rape in South Africa
- Authors: Lloyd, Dylan Reumen
- Date: 2020
- Subjects: Rape -- South Africa , Rape -- Fiction , Rape in literature , Rape in literature -- South Africa , Psychic trauma in literature , Post-traumatic stress disorder in literature , Dystopias in literature , Coetzee, J. M., 1940- Disgrace , South African fiction (English) -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/166173 , vital:41335
- Description: This thesis is concerned with describing the stakes of reading, writing and criticising fictional depictions of rape in a country plagued by high levels of sexual violence. I consider the capacity of rape representations to cause harm to women and rape survivors, and worsen the various injuries suffered by survivors as a direct or indirect consequence of rape. The possibility of such harm prompts me to examine the role and responsibilities of readers and critics in facilitating or preventing such harm. I further discuss the potential strategies of harm prevention that readers of novelistic portrayals of rape might adopt as well as the positive outcomes that such reading strategies make possible, and which might balance out the risks that accompany them. My description of the potential harm of rape representations combines postmodern critical feminist analysis with Miranda Fricker’s work on epistemic justice and Judith Herman’s work on trauma in order to illustrate the way that these representations shape our conception of rape in a manner that affects everything from how it is enacted to our treatment of survivors to the possibility of their recovery from posttraumatic stress disorder. In order to situate my analysis in the context of South African literature and to explore the notion of responsibility in relation to the writing of scenes of rape, I utilise a close reading of J.M. Coetzee’s Disgrace. Furthermore, I discuss the utility and limits of the critical feminist strategy of using a normative critical approach to rape representations in order to prevent harm. Ultimately, I argue that the use of such a strategy, along with the development of a purpose-honed adaptive critical style, is essential to the fulfilment of our responsibilities as readers and to the prevention of further suffering.
- Full Text:
- Date Issued: 2020
- Authors: Lloyd, Dylan Reumen
- Date: 2020
- Subjects: Rape -- South Africa , Rape -- Fiction , Rape in literature , Rape in literature -- South Africa , Psychic trauma in literature , Post-traumatic stress disorder in literature , Dystopias in literature , Coetzee, J. M., 1940- Disgrace , South African fiction (English) -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/166173 , vital:41335
- Description: This thesis is concerned with describing the stakes of reading, writing and criticising fictional depictions of rape in a country plagued by high levels of sexual violence. I consider the capacity of rape representations to cause harm to women and rape survivors, and worsen the various injuries suffered by survivors as a direct or indirect consequence of rape. The possibility of such harm prompts me to examine the role and responsibilities of readers and critics in facilitating or preventing such harm. I further discuss the potential strategies of harm prevention that readers of novelistic portrayals of rape might adopt as well as the positive outcomes that such reading strategies make possible, and which might balance out the risks that accompany them. My description of the potential harm of rape representations combines postmodern critical feminist analysis with Miranda Fricker’s work on epistemic justice and Judith Herman’s work on trauma in order to illustrate the way that these representations shape our conception of rape in a manner that affects everything from how it is enacted to our treatment of survivors to the possibility of their recovery from posttraumatic stress disorder. In order to situate my analysis in the context of South African literature and to explore the notion of responsibility in relation to the writing of scenes of rape, I utilise a close reading of J.M. Coetzee’s Disgrace. Furthermore, I discuss the utility and limits of the critical feminist strategy of using a normative critical approach to rape representations in order to prevent harm. Ultimately, I argue that the use of such a strategy, along with the development of a purpose-honed adaptive critical style, is essential to the fulfilment of our responsibilities as readers and to the prevention of further suffering.
- Full Text:
- Date Issued: 2020
Enactment of hands-on practical activities through using easily accessible resources in a Grade 10 Physical Science classroom
- Authors: Ndevahoma, Martha Kashike
- Date: 2020
- Subjects: Physical science -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/110229 , vital:33251
- Description: The Namibian National Subject Policy Guide for Physical Science Grade 8-12 (MoE, 2010) indicates that science teachers should be creative and innovative in producing their own teaching and learning support materials that are linked to practice. Practical activities play a major role in the learning of science. Due to the lack of science laboratory equipment, however, minimal practical activities are done in some schools especially under-resourced disadvantaged schools. It is against this background that this case study investigated the possibilities and challenges associated with the use of easily accessible resources to carry out hands-on practical activities. Underpinned by an interpretive paradigm, this study used a mixed-method approach by generating both quantitative and qualitative data. It was carried out in the Otjozondjupa region in Namibia at Wato Secondary School (pseudonym). It was conducted with a Grade 10 Physical Science class consisting of 30 learners. To generate data, questionnaires, focus group interviews, lesson observations, stimulated recall interviews, as well as learners’ journal reflections were used. Conceptions, dispositions, interest and sense-making were used as conceptual lenses while Vygotsky’s social constructivism was the theoretical framework that informed this study. Quantitative data were analysed using the conceptual lenses and were subsequently presented in tables and graphs. That is, a deductive approach to analysis was used. On the other hand, a thematic approach was used to analyse the qualitative data. That is, qualitative data were inductively analysed to come up with sub-themes and themes. The findings from this study revealed significant shifts in learners’ conceptions, dispositions and interest towards science after the use of easily accessible resources to do hands-on practical activities. Similarly, learners’ sense-making of science concepts improved. This study thus recommends that science teachers should, where possible, make use of easily accessible resources to carry out hands-on practical activities during their science lessons. During such hands-on practicals, however, emphasis should be on the development of scientific concepts.
- Full Text:
- Date Issued: 2020
- Authors: Ndevahoma, Martha Kashike
- Date: 2020
- Subjects: Physical science -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/110229 , vital:33251
- Description: The Namibian National Subject Policy Guide for Physical Science Grade 8-12 (MoE, 2010) indicates that science teachers should be creative and innovative in producing their own teaching and learning support materials that are linked to practice. Practical activities play a major role in the learning of science. Due to the lack of science laboratory equipment, however, minimal practical activities are done in some schools especially under-resourced disadvantaged schools. It is against this background that this case study investigated the possibilities and challenges associated with the use of easily accessible resources to carry out hands-on practical activities. Underpinned by an interpretive paradigm, this study used a mixed-method approach by generating both quantitative and qualitative data. It was carried out in the Otjozondjupa region in Namibia at Wato Secondary School (pseudonym). It was conducted with a Grade 10 Physical Science class consisting of 30 learners. To generate data, questionnaires, focus group interviews, lesson observations, stimulated recall interviews, as well as learners’ journal reflections were used. Conceptions, dispositions, interest and sense-making were used as conceptual lenses while Vygotsky’s social constructivism was the theoretical framework that informed this study. Quantitative data were analysed using the conceptual lenses and were subsequently presented in tables and graphs. That is, a deductive approach to analysis was used. On the other hand, a thematic approach was used to analyse the qualitative data. That is, qualitative data were inductively analysed to come up with sub-themes and themes. The findings from this study revealed significant shifts in learners’ conceptions, dispositions and interest towards science after the use of easily accessible resources to do hands-on practical activities. Similarly, learners’ sense-making of science concepts improved. This study thus recommends that science teachers should, where possible, make use of easily accessible resources to carry out hands-on practical activities during their science lessons. During such hands-on practicals, however, emphasis should be on the development of scientific concepts.
- Full Text:
- Date Issued: 2020
Encapsulation and physicochemical evaluation of efavirenz in liposomes
- Okafor, Nnamdi Ikemefuna, Nkanga, Christian I, Walker, Roderick B, Noundou, Xavier S, Krause, Rui W M
- Authors: Okafor, Nnamdi Ikemefuna , Nkanga, Christian I , Walker, Roderick B , Noundou, Xavier S , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183414 , vital:43988 , xlink:href="https://doi.org/10.1007/s40005-019-00458-8"
- Description: Antiretroviral therapy remains the most efective means of managing the human immune defciency virus/acquired immune defciency syndrome (HIV/AIDS). Application of therapeutics has been hampered by factors including poor bioavailability of most anti-retroviral compounds (ARV), side efects and an alarming emergence of drug resistant strains of the virus. Recent developments and use of drug delivery systems (DDS) has shown potential for improving the pharmacological profle of ARV. Amongst these complex DDS, liposomes have been explored for delivery of ARV. In this study, we have aimed at exploring efcient encapsulation of efavirenz (EFV), a potent ARV using diferent mass ratios of crude soybean lecithin and cholesterol. The EFV-loaded liposomes (EFL) were prepared using thin flm hydration and evaluated for particle size, zeta potential (ZP), encapsulation efciency (EE%), morphology and drug release studies. Diferential scanning calorimetry (DSC), X-ray difraction (XRD), energy dispersity spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy were used for comprehensive physicochemical characterization of EFL. EFL exhibited high encapsulation (99%) in 1:1 crude lecithin to cholesterol mass ratio. The average particle size and Zeta Potential of EFL were found to be 411.10±7.40 nm and −53.5.3±0.06 mV, respectively. EFL showed a relatively controlled EFV release behaviour that was similar to the dissolution profle of un-encapsulated EFV. This suggests that EFL represents a promising vehicle for efective EFV delivery while providing the advantages of a nano-scaled delivery system
- Full Text:
- Date Issued: 2020
- Authors: Okafor, Nnamdi Ikemefuna , Nkanga, Christian I , Walker, Roderick B , Noundou, Xavier S , Krause, Rui W M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183414 , vital:43988 , xlink:href="https://doi.org/10.1007/s40005-019-00458-8"
- Description: Antiretroviral therapy remains the most efective means of managing the human immune defciency virus/acquired immune defciency syndrome (HIV/AIDS). Application of therapeutics has been hampered by factors including poor bioavailability of most anti-retroviral compounds (ARV), side efects and an alarming emergence of drug resistant strains of the virus. Recent developments and use of drug delivery systems (DDS) has shown potential for improving the pharmacological profle of ARV. Amongst these complex DDS, liposomes have been explored for delivery of ARV. In this study, we have aimed at exploring efcient encapsulation of efavirenz (EFV), a potent ARV using diferent mass ratios of crude soybean lecithin and cholesterol. The EFV-loaded liposomes (EFL) were prepared using thin flm hydration and evaluated for particle size, zeta potential (ZP), encapsulation efciency (EE%), morphology and drug release studies. Diferential scanning calorimetry (DSC), X-ray difraction (XRD), energy dispersity spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy were used for comprehensive physicochemical characterization of EFL. EFL exhibited high encapsulation (99%) in 1:1 crude lecithin to cholesterol mass ratio. The average particle size and Zeta Potential of EFL were found to be 411.10±7.40 nm and −53.5.3±0.06 mV, respectively. EFL showed a relatively controlled EFV release behaviour that was similar to the dissolution profle of un-encapsulated EFV. This suggests that EFL represents a promising vehicle for efective EFV delivery while providing the advantages of a nano-scaled delivery system
- Full Text:
- Date Issued: 2020
Energy management as an element of a financial efficiency strategy : a case of the City Tshwane
- Authors: Maubane, Lekgatla Donald
- Date: 2020
- Subjects: Industries -- Energy conservation -- South Africa -- City of Tshwane Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , MSBE
- Identifier: http://hdl.handle.net/10948/49507 , vital:41727
- Description: The costs of operating buildings and facilities which the City of Tshwane utilises for conducting business have substantially increased due to the cost of electricity more than quadrupling in the past decade in South Africa, worsening the already constrained budgets. Research has shown that implementation of successful and sustainable energy management of built environment assets is effective in reducing costs due to resulting reduction in energy consumption and is therefore fitting to include it as an element of a financial efficiency strategy in organisations. This study aims to investigate how the City of Tshwane utilises energy management of its built environment assets to support financial efficiency and to make recommendations where necessary. Building on existing literature on energy management, it asks: How does the City of Tshwane utilise energy management of its built environment assets to support financial efficiency? In this context, energy management is defined as the continuous process of managing behavioural, organisational and technical change to improve an organisation’s energy performance. An instrument suitable for collecting qualitative data was constructed based on theories found in the reviewed literature. Interview participants were purposively sampled from departments which have direct influence on the energy management chain in the city. Relevant documents provided by the city were also reviewed to support triangulation of data. An analysis of data demonstrated that the city utilises energy management of its built environment assets to support financial efficiency. The results also indicated that there are several deficiencies in the manner in which the city currently manages energy. On this basis, it is recommended that the city installs meters for all energy consuming built environment assets; abandons the practice of accounting for energy costs as part of overheads and adopt the practice of direct costs accounting; and implements measures to review relevant strategy documents at planned intervals in order to ensure their continuing suitability.
- Full Text:
- Date Issued: 2020
- Authors: Maubane, Lekgatla Donald
- Date: 2020
- Subjects: Industries -- Energy conservation -- South Africa -- City of Tshwane Metropolitan Municipality
- Language: English
- Type: Thesis , Masters , MSBE
- Identifier: http://hdl.handle.net/10948/49507 , vital:41727
- Description: The costs of operating buildings and facilities which the City of Tshwane utilises for conducting business have substantially increased due to the cost of electricity more than quadrupling in the past decade in South Africa, worsening the already constrained budgets. Research has shown that implementation of successful and sustainable energy management of built environment assets is effective in reducing costs due to resulting reduction in energy consumption and is therefore fitting to include it as an element of a financial efficiency strategy in organisations. This study aims to investigate how the City of Tshwane utilises energy management of its built environment assets to support financial efficiency and to make recommendations where necessary. Building on existing literature on energy management, it asks: How does the City of Tshwane utilise energy management of its built environment assets to support financial efficiency? In this context, energy management is defined as the continuous process of managing behavioural, organisational and technical change to improve an organisation’s energy performance. An instrument suitable for collecting qualitative data was constructed based on theories found in the reviewed literature. Interview participants were purposively sampled from departments which have direct influence on the energy management chain in the city. Relevant documents provided by the city were also reviewed to support triangulation of data. An analysis of data demonstrated that the city utilises energy management of its built environment assets to support financial efficiency. The results also indicated that there are several deficiencies in the manner in which the city currently manages energy. On this basis, it is recommended that the city installs meters for all energy consuming built environment assets; abandons the practice of accounting for energy costs as part of overheads and adopt the practice of direct costs accounting; and implements measures to review relevant strategy documents at planned intervals in order to ensure their continuing suitability.
- Full Text:
- Date Issued: 2020
Enhanced Light-Driven Antimicrobial Activity of Cationic Poly (oxanorbornene) s by Phthalocyanine Incorporation into Polymer as Pendants
- Ahmetali, Erem, Sen, Pinar, Süer, N Ceren, Aksu, Burak, Nyokong, Tebello, Eren, Tarik, Sener, Kasim M
- Authors: Ahmetali, Erem , Sen, Pinar , Süer, N Ceren , Aksu, Burak , Nyokong, Tebello , Eren, Tarik , Sener, Kasim M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185976 , vital:44453 , xlink:href=" https://doi.org/10.1002/macp.202000386"
- Description: Amphiphilic poly(oxanorbornene)s are promising synthetic polymers that mimic the structural properties and antimicrobial functions of naturally occurring antimicrobial peptides. Here, poly(oxanorbornene)s bearing pendant zinc(II) phthalocyanine and triphenyl(ethyl) phosphonium functionalities are synthesized by ring-opening metathesis polymerization (ROMP). Fluorescence, singlet oxygen and triplet quantum yields of polymers are measured in dimethyl sulfoxide and aqueous medium. The singlet oxygen quantum yields of copolymers with the highest triphenyl and triethyl phosphonium content are found to be 0.29 and 0.41, respectively. Then, antimicrobial activities of polymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are investigated under both dark and light conditions. Synergistic effect of zinc(II) phthalocyanine and phosphonium-containing poly(oxanorbornene) is observed that the conjugate possessing the most triphenyl phosphonium side chains has the highest activity under light against both gram-positive and gram-negative bacterial strains after 80 min irradiation, reducing the survival of E. coli or S. aureus by 99.9999%. Hemolytic concentrations of the copolymers are found between 8 and 512 µg mL−1. Scanning electron microscopy (SEM) proves that the bacteria membrane deforms after contacting with the biocidal polymer.
- Full Text:
- Date Issued: 2020
- Authors: Ahmetali, Erem , Sen, Pinar , Süer, N Ceren , Aksu, Burak , Nyokong, Tebello , Eren, Tarik , Sener, Kasim M
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185976 , vital:44453 , xlink:href=" https://doi.org/10.1002/macp.202000386"
- Description: Amphiphilic poly(oxanorbornene)s are promising synthetic polymers that mimic the structural properties and antimicrobial functions of naturally occurring antimicrobial peptides. Here, poly(oxanorbornene)s bearing pendant zinc(II) phthalocyanine and triphenyl(ethyl) phosphonium functionalities are synthesized by ring-opening metathesis polymerization (ROMP). Fluorescence, singlet oxygen and triplet quantum yields of polymers are measured in dimethyl sulfoxide and aqueous medium. The singlet oxygen quantum yields of copolymers with the highest triphenyl and triethyl phosphonium content are found to be 0.29 and 0.41, respectively. Then, antimicrobial activities of polymers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are investigated under both dark and light conditions. Synergistic effect of zinc(II) phthalocyanine and phosphonium-containing poly(oxanorbornene) is observed that the conjugate possessing the most triphenyl phosphonium side chains has the highest activity under light against both gram-positive and gram-negative bacterial strains after 80 min irradiation, reducing the survival of E. coli or S. aureus by 99.9999%. Hemolytic concentrations of the copolymers are found between 8 and 512 µg mL−1. Scanning electron microscopy (SEM) proves that the bacteria membrane deforms after contacting with the biocidal polymer.
- Full Text:
- Date Issued: 2020
Enhanced photodynamic antimicrobial activity of surface modified SiNPs doped with zinc (II) phthalocyanines: The effect of antimicrobial ampicillin and extra charges from a sultone
- Magadla, Aviwe, Nyokong, Tebello
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186034 , vital:44457 , xlink:href="https://doi.org/10.1016/j.pdpdt.2020.101996"
- Description: 1-(2-Methoxyethyl) piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186034 , vital:44457 , xlink:href="https://doi.org/10.1016/j.pdpdt.2020.101996"
- Description: 1-(2-Methoxyethyl) piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020
Enhanced photodynamic antimicrobial activity of surface modified SiNPs doped with zinc (II) phthalocyanines: the effect of antimicrobial ampicillin and extra charges from a sultone
- Magadla, Aviwe, Nyokong, Tebello
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160511 , vital:40452 , https://doi.org/10.1016/j.pdpdt.2020.101996
- Description: 1-(2-Methoxyethyl)piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020
- Authors: Magadla, Aviwe , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160511 , vital:40452 , https://doi.org/10.1016/j.pdpdt.2020.101996
- Description: 1-(2-Methoxyethyl)piperidine sustituted Zn phthalocyanine complex (2) is synthesised and quartenised (3). These complexes are loaded into silica nanoparticles (SiNPs) that are futher surface modified with ampicillin and 1.3-propanesultone. The photophysical and photochemical properties of the complexes and their doped conjugates were investigated in dimethylsulfoxide. The cationic complex (3) is used for photodynamic antimicrobial activity. Log reduction values of above 9 are obtained towards the photoiactivation of Staphyloccocus aureus.
- Full Text:
- Date Issued: 2020