Online mentoring as a transformative tool for female career and business development
- Authors: Oosthuizen, Nadine
- Date: 2017
- Subjects: Mentoring in business -- South Africa Glass ceiling (Employment discrimination) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20510 , vital:29301
- Description: The under-representation of females at management level due to the glass ceiling effect has globally received considerable attention. Research found that one of the remedies for females to progress beyond the glass ceiling, was access to a mentor in senior management. Females receiving mentoring in the workplace perform at greater levels as they gain reflected power, advise and the right to use essential resources. Yet, access to mentors was recognised as a barrier to females’ professional career success, both in the corporate field and to develop their small businesses. Fortunately, the revolution in technology has led to online mentoring which combines conventional mentoring relationship approaches with new technology and provides wider access to a pool of mentors. The increasing popularity of online mentoring can be attributed to the benefits it offers stereotyped individuals and those from marginalised groups. The purpose of this study therefore was to ascertain the enabling conditions necessary for effective online mentoring in South Africa, as well as how it can be used to develop the careers of females (both corporate employees and small business entrepreneurs). The study followed a mixed method approach with a sequential exploratory design. Background literature on conventional mentoring in addition to oniline mentoring assisted in contextualising the many issues relating to conventional mentoring which also apply to online mentoring. Primary data was collected in three phases (two qualitative and one quantitative). The data collection method for phases one and two of the enquiry was interviews with the use of a semi-structured interview schedule and for phase three, a survey via an online structured questionnaire. The biographical profiles of the participants interviewed during phases one and two were presented as case studies. Based on the content analysis of the qualitative interviews with five South African mentors, six female mentees from Africa, two South African online mentoring field specialists and one United States online mentoring field specialist, three main themes were identified viz. online mentoring processes, challenges and enabling conditions. Online mentoring processes identified for effective online mentoring related to the application-, selection-, matching- and conflict resolution procedures. Mentoring challenges related to matching preferences, technology impediments, cultural fit problems, language differences, lack of mutual trust, scheduling and frequency and duration of meetings, the impersonal nature of online mentoring and specific mentee- and mentor-related challenges. Based on the content analysis, the conditions for creating an effective online mentoring environment addressed some of the challenges alluded to and could be classified as generic, mentee-specific and mentor-specific enablers. Generic online mentoring enablers are those conditions necessary for creating an effective online mentoring environment for the mentoring pair such as the ability to establish a trusting relationship, flexible meeting schedules, training offered, the expression of emotions online, having a technology infrastructure in place, clear objectives and relationship boundaries, a desirable programme- and meeting duration with adequate meetings, using multiple contact methods and following a hybrid mentoring approach. Mentor specific issues to create an effective online mentoring environment are mentors with exceptional personal qualities that are knowledgable and experienced, while mentee specific issues relate to continuous mentee commitment and that mentees should have been previously exposed to mentoring. The constant comparative data analysis provided insight into how similar or dissimilar institutions approach online mentoring process and the challenges related to the local (South African) online mentoring environment as compared to those globally. Sixty-three respondents (South African mentors both male and female and female mentees who have undergone conventional mentoring) completed the online structured questionnaire on their perceptions of the online mentoring conditions necessary for effective online mentoring. From the exploratory factor analysis results of the online survey in phase three of the study, six valid and reliable conditions necessary for online mentoring were identified namely, infrastructure readiness, demographic matching preference, mentor characteristics, the communication process, mentoring pair perceptions and mentoring pair relationship. The multiple regression analysis performed established one statistically significant relationship. The perception that the mentoring pair hold of online mentoring influence the achievements of the mentee. This study has thus identified several conditions necessary for effective online mentoring globally, as well as for South Africa. South Africa has a pool of knowledgeable mentors involved in global online mentoring progammes and they can assist with online mentoring in the South African communities in need of assistance. However, South Africa can learn from well-established global online mentoring institutions how to implement an effective online mentoring programme, but will need the necessary financial resources to do so. This study further provided evidence on how online mentoring can be utilised for the career advancement of female corporate employees and those owning small businesses. Some guidelines were provided on how to overcome the various challenges associated with online mentoring globally, and those specific to South Africa. The use of mobile technology instead of computer-mediated technology was recommended as it provides greater access to online mentoring, especially for rural communities. It is also more user-friendly for those with limited computer technology skills.
- Full Text:
- Date Issued: 2017
- Authors: Oosthuizen, Nadine
- Date: 2017
- Subjects: Mentoring in business -- South Africa Glass ceiling (Employment discrimination) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20510 , vital:29301
- Description: The under-representation of females at management level due to the glass ceiling effect has globally received considerable attention. Research found that one of the remedies for females to progress beyond the glass ceiling, was access to a mentor in senior management. Females receiving mentoring in the workplace perform at greater levels as they gain reflected power, advise and the right to use essential resources. Yet, access to mentors was recognised as a barrier to females’ professional career success, both in the corporate field and to develop their small businesses. Fortunately, the revolution in technology has led to online mentoring which combines conventional mentoring relationship approaches with new technology and provides wider access to a pool of mentors. The increasing popularity of online mentoring can be attributed to the benefits it offers stereotyped individuals and those from marginalised groups. The purpose of this study therefore was to ascertain the enabling conditions necessary for effective online mentoring in South Africa, as well as how it can be used to develop the careers of females (both corporate employees and small business entrepreneurs). The study followed a mixed method approach with a sequential exploratory design. Background literature on conventional mentoring in addition to oniline mentoring assisted in contextualising the many issues relating to conventional mentoring which also apply to online mentoring. Primary data was collected in three phases (two qualitative and one quantitative). The data collection method for phases one and two of the enquiry was interviews with the use of a semi-structured interview schedule and for phase three, a survey via an online structured questionnaire. The biographical profiles of the participants interviewed during phases one and two were presented as case studies. Based on the content analysis of the qualitative interviews with five South African mentors, six female mentees from Africa, two South African online mentoring field specialists and one United States online mentoring field specialist, three main themes were identified viz. online mentoring processes, challenges and enabling conditions. Online mentoring processes identified for effective online mentoring related to the application-, selection-, matching- and conflict resolution procedures. Mentoring challenges related to matching preferences, technology impediments, cultural fit problems, language differences, lack of mutual trust, scheduling and frequency and duration of meetings, the impersonal nature of online mentoring and specific mentee- and mentor-related challenges. Based on the content analysis, the conditions for creating an effective online mentoring environment addressed some of the challenges alluded to and could be classified as generic, mentee-specific and mentor-specific enablers. Generic online mentoring enablers are those conditions necessary for creating an effective online mentoring environment for the mentoring pair such as the ability to establish a trusting relationship, flexible meeting schedules, training offered, the expression of emotions online, having a technology infrastructure in place, clear objectives and relationship boundaries, a desirable programme- and meeting duration with adequate meetings, using multiple contact methods and following a hybrid mentoring approach. Mentor specific issues to create an effective online mentoring environment are mentors with exceptional personal qualities that are knowledgable and experienced, while mentee specific issues relate to continuous mentee commitment and that mentees should have been previously exposed to mentoring. The constant comparative data analysis provided insight into how similar or dissimilar institutions approach online mentoring process and the challenges related to the local (South African) online mentoring environment as compared to those globally. Sixty-three respondents (South African mentors both male and female and female mentees who have undergone conventional mentoring) completed the online structured questionnaire on their perceptions of the online mentoring conditions necessary for effective online mentoring. From the exploratory factor analysis results of the online survey in phase three of the study, six valid and reliable conditions necessary for online mentoring were identified namely, infrastructure readiness, demographic matching preference, mentor characteristics, the communication process, mentoring pair perceptions and mentoring pair relationship. The multiple regression analysis performed established one statistically significant relationship. The perception that the mentoring pair hold of online mentoring influence the achievements of the mentee. This study has thus identified several conditions necessary for effective online mentoring globally, as well as for South Africa. South Africa has a pool of knowledgeable mentors involved in global online mentoring progammes and they can assist with online mentoring in the South African communities in need of assistance. However, South Africa can learn from well-established global online mentoring institutions how to implement an effective online mentoring programme, but will need the necessary financial resources to do so. This study further provided evidence on how online mentoring can be utilised for the career advancement of female corporate employees and those owning small businesses. Some guidelines were provided on how to overcome the various challenges associated with online mentoring globally, and those specific to South Africa. The use of mobile technology instead of computer-mediated technology was recommended as it provides greater access to online mentoring, especially for rural communities. It is also more user-friendly for those with limited computer technology skills.
- Full Text:
- Date Issued: 2017
Optimisation of a mini horizontal axis wind turbine to increase energy yield during short duration wind variations
- Authors: Poole, Sean Nichola
- Date: 2017
- Subjects: Wind turbines -- Design and construction , Horizontal axis wind turbines -- Blades , Wind turbines -- Aerodynamics , Wind power
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7036 , vital:21196
- Description: The typical methodology for analytically designing a wind turbine blade is by means of blade element momentum (BEM) theory, whereby the aerofoil angle of attack is optimized to achieve a maximum lift-to-drag ratio. This research aims to show that an alternative optimisation methodology could yield better results, especially in gusty and turbulent wind conditions. This alternative method looks at increasing the aerofoil Reynolds number by increasing the aerofoil chord length. The increased Reynolds number generally increases the e_ectiveness of the aerofoil which would result in a higher or similar lift-to-drag ratio (even at the decreased angle of attacked require to maintain the turbine thrust coe_cient). The bene_t of this design is a atter power curve which causes the turbine to be less sensitive to uctuating winds. Also, the turbine has more torque at startup, allowing for operatation in lower wind speeds. This research is assumed to only be applicable to small wind turbines which operated in a low Reynolds number regime (<500 000), where Reynolds number manipulation is most advantageous.
- Full Text:
- Date Issued: 2017
- Authors: Poole, Sean Nichola
- Date: 2017
- Subjects: Wind turbines -- Design and construction , Horizontal axis wind turbines -- Blades , Wind turbines -- Aerodynamics , Wind power
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7036 , vital:21196
- Description: The typical methodology for analytically designing a wind turbine blade is by means of blade element momentum (BEM) theory, whereby the aerofoil angle of attack is optimized to achieve a maximum lift-to-drag ratio. This research aims to show that an alternative optimisation methodology could yield better results, especially in gusty and turbulent wind conditions. This alternative method looks at increasing the aerofoil Reynolds number by increasing the aerofoil chord length. The increased Reynolds number generally increases the e_ectiveness of the aerofoil which would result in a higher or similar lift-to-drag ratio (even at the decreased angle of attacked require to maintain the turbine thrust coe_cient). The bene_t of this design is a atter power curve which causes the turbine to be less sensitive to uctuating winds. Also, the turbine has more torque at startup, allowing for operatation in lower wind speeds. This research is assumed to only be applicable to small wind turbines which operated in a low Reynolds number regime (<500 000), where Reynolds number manipulation is most advantageous.
- Full Text:
- Date Issued: 2017
Optimization of flexible spectrum in optical transport networks
- Boiyo, Duncan Kiboi, Gamatham, Romeo
- Authors: Boiyo, Duncan Kiboi , Gamatham, Romeo
- Date: 2017
- Subjects: Digital communications Optical fiber communication , Optical communications Fiber optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14609 , vital:27803
- Description: The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from fibre-linked terminals. The eventual outcome of the high demand for broadband is strained optical and electronic devices. The backbone optical fibre transport systems and techniques such as dense wavelength division multiplexing (DWDM), higher modulation formats, coherent detection and signal amplification have increased both fibre capacity and spectrum efficiency. A major challenge to fibre capacity and spectrum efficiency is fibre-faults and optical impairments, network management, routing and wavelength assignment (RWA). In this study, DWDM and flexible spectrum techniques such as wavelength assignment and adjustment, wavelength conversion and switching, optical add and drop multiplexing (OADM) and bitrate variable transmission have been experimentally optimized in a laboratory testbed for short- and long-haul optical fibre networks. This work starts by experimentally optimising different transmitters, fibre-types and receivers suitable for implementing cost effective and energy efficient flexible spectrum networks. Vertical cavity surface-emitting lasers (VCSELs) and distributed feedback (DFB) lasers have been studied to provide up to 10 Gb/s per channel in 1310 nm and 1550 nm transmission windows. VCSELs provide wavelength assignment and adjustment. This work utilises the non-return-to-zero (NRZ) on-off keying (OOK) modulation technique and direct detection due to their cost and simplicity. By using positive intrinsic negative (PIN) photo-receivers with error-free BER sensitivity of -18±1 dBm at the acceptable 10-9-bit error rate (BER) threshold level, unamplified transmission distances between 6 km and 76 km have been demonstrated using G.652 and G.655 single mode fibres (SMFs). For the first time, an all optical VCSEL to VCSEL wavelength conversion, switching, transmission at the 1550 nm window and BER evaluation of a NRZ data signal is experimentally demonstrated. With VCSEL wavelength conversion and switching, wavelength adjustments to a spectrum width of 4.8 nm (600 GHz) can be achieved to provide alternative routes to signals when fibre-cuts and wavelength collision occurs therefore enhancing signal continuity. This work also demonstrates a technique of removing and adding a wavelength in a bundle of DWDM and flexible channels using an OADM. This has been implemented using a VCSEL and a fibre Bragg grating (FBG) providing a wavelength isolation ratio of 31.4 dB and ~0.3 𝑑𝐵 add/drop penalty of 8.5 Gb/s signal. As a result, an OADM improves spectrum efficiency by offering wavelength re-use. Optical impairments such as crosstalk, chromatic dispersion (CD) and effects of polarization mode dispersion (PMD) have been experimentally investigated and mitigated. This work showed that crosstalk penalty increased with fibre-length, bitrate, interfering signal power and reduced channel spacing and as a result, a crosstalk-penalty trade-off is required. Effects of CD on a transmitted 10 Gb/s signal were also investigated and its mitigation techniques used to increase the fibre-reach. This work uses the negative dispersion fibres to mitigate the accumulated dispersion over the distance of transmission. A 5 dB sensitivity improvement is reported for an unamplified 76 km using DFB transmitters and combination of NZDSF true-wave reduced slope (TW-RS) and submarine reduced slope (TW-SRS) with + and – dispersion coefficients respectively. We have also demonstrated up to 52 km 10 Gb/s per channel VCSEL-based transmission and reduced net dispersion. Experimental demonstration of forward Raman amplification has achieved a 4.7 dB on-off gain distributed over a 4.8 nm spectral width and a 1.7 dB improvement of receiver sensitivity in Raman-aided 10 Gb/s per wavelength VCSEL transmission. Finally, 4.25-10 Gb/s PON-based point to point (P2P) and point to multipoint (P2MP) broadcast transmission have been experimentally demonstrated. A 10 Gb/s with a 1:8 passive splitter incurred a 3.7 dB penalty for a 24.7 km fibre-link. In summary, this work has demonstrated cost effective and energy efficient potential flexible spectrum techniques for high speed signal transmission. With the optimized network parameters, flexible spectrum is therefore relevant in short-reach, metro-access and long-haul applications for national broadband networks and the Square Kilometre Array (SKA) fibre-based signal and data transmission.
- Full Text:
- Date Issued: 2017
- Authors: Boiyo, Duncan Kiboi , Gamatham, Romeo
- Date: 2017
- Subjects: Digital communications Optical fiber communication , Optical communications Fiber optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14609 , vital:27803
- Description: The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from fibre-linked terminals. The eventual outcome of the high demand for broadband is strained optical and electronic devices. The backbone optical fibre transport systems and techniques such as dense wavelength division multiplexing (DWDM), higher modulation formats, coherent detection and signal amplification have increased both fibre capacity and spectrum efficiency. A major challenge to fibre capacity and spectrum efficiency is fibre-faults and optical impairments, network management, routing and wavelength assignment (RWA). In this study, DWDM and flexible spectrum techniques such as wavelength assignment and adjustment, wavelength conversion and switching, optical add and drop multiplexing (OADM) and bitrate variable transmission have been experimentally optimized in a laboratory testbed for short- and long-haul optical fibre networks. This work starts by experimentally optimising different transmitters, fibre-types and receivers suitable for implementing cost effective and energy efficient flexible spectrum networks. Vertical cavity surface-emitting lasers (VCSELs) and distributed feedback (DFB) lasers have been studied to provide up to 10 Gb/s per channel in 1310 nm and 1550 nm transmission windows. VCSELs provide wavelength assignment and adjustment. This work utilises the non-return-to-zero (NRZ) on-off keying (OOK) modulation technique and direct detection due to their cost and simplicity. By using positive intrinsic negative (PIN) photo-receivers with error-free BER sensitivity of -18±1 dBm at the acceptable 10-9-bit error rate (BER) threshold level, unamplified transmission distances between 6 km and 76 km have been demonstrated using G.652 and G.655 single mode fibres (SMFs). For the first time, an all optical VCSEL to VCSEL wavelength conversion, switching, transmission at the 1550 nm window and BER evaluation of a NRZ data signal is experimentally demonstrated. With VCSEL wavelength conversion and switching, wavelength adjustments to a spectrum width of 4.8 nm (600 GHz) can be achieved to provide alternative routes to signals when fibre-cuts and wavelength collision occurs therefore enhancing signal continuity. This work also demonstrates a technique of removing and adding a wavelength in a bundle of DWDM and flexible channels using an OADM. This has been implemented using a VCSEL and a fibre Bragg grating (FBG) providing a wavelength isolation ratio of 31.4 dB and ~0.3 𝑑𝐵 add/drop penalty of 8.5 Gb/s signal. As a result, an OADM improves spectrum efficiency by offering wavelength re-use. Optical impairments such as crosstalk, chromatic dispersion (CD) and effects of polarization mode dispersion (PMD) have been experimentally investigated and mitigated. This work showed that crosstalk penalty increased with fibre-length, bitrate, interfering signal power and reduced channel spacing and as a result, a crosstalk-penalty trade-off is required. Effects of CD on a transmitted 10 Gb/s signal were also investigated and its mitigation techniques used to increase the fibre-reach. This work uses the negative dispersion fibres to mitigate the accumulated dispersion over the distance of transmission. A 5 dB sensitivity improvement is reported for an unamplified 76 km using DFB transmitters and combination of NZDSF true-wave reduced slope (TW-RS) and submarine reduced slope (TW-SRS) with + and – dispersion coefficients respectively. We have also demonstrated up to 52 km 10 Gb/s per channel VCSEL-based transmission and reduced net dispersion. Experimental demonstration of forward Raman amplification has achieved a 4.7 dB on-off gain distributed over a 4.8 nm spectral width and a 1.7 dB improvement of receiver sensitivity in Raman-aided 10 Gb/s per wavelength VCSEL transmission. Finally, 4.25-10 Gb/s PON-based point to point (P2P) and point to multipoint (P2MP) broadcast transmission have been experimentally demonstrated. A 10 Gb/s with a 1:8 passive splitter incurred a 3.7 dB penalty for a 24.7 km fibre-link. In summary, this work has demonstrated cost effective and energy efficient potential flexible spectrum techniques for high speed signal transmission. With the optimized network parameters, flexible spectrum is therefore relevant in short-reach, metro-access and long-haul applications for national broadband networks and the Square Kilometre Array (SKA) fibre-based signal and data transmission.
- Full Text:
- Date Issued: 2017
Perceptions regarding the impact of ubuntu and servant leadership on employee engagement in the workplace
- Authors: Muller, Roger Joseph
- Date: 2017
- Subjects: Leadership Management -- South Africa , Management -- Africa -- Philosophy Employees -- Attitudes Organizational effectiveness -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/19409 , vital:28868
- Description: South Africa have some of the lowest employee engagement scores in the world. Leadership is a key determinant of employee engagement, but existing leadership theories and practices are often ineffective in more humanistic and collectivistic cultures like South Africa. To this end, Ubuntu and servant leadership is posited to positively influence organisational performance by increasing employee engagement. The primary objective of this study is to investigate perceptions regarding the impact of Ubuntu and servant leadership on employee engagement in private organisations of the Eastern Cape. A quantitative research design was utilised and yielded 428 usable questionnaires through nonprobability sampling. The empirical results revealed that the spirit of solidarity dimension of Ubuntu leadership influenced significantly and positively. Furthermore, it was found that survival and spirit of solidarity had a significant and positive influence on organisational performance as measured through the balanced scorecard (BSC). Servant leadership positively and significantly influenced employee engagement and organisational performance. In addition, it was found that employee engagement mediates the relationship between servant leadership and organizational performance. This study has made several significant empirical and theoretical contributions, and can be classified as one of the pioneering attempts to gather empirical evidence on how Ubuntu manifests in the workplace. The high convergent validity of the dimensions of Ubuntu leadership and comparisons to Servant leadership established in this study, provides some proof of its novel contribution towards leadership theory. A highly reliable and valid measuring instrument was developed to evaluate Ubuntu from a leadership perspective. This is a major empirical contribution as, at the time, there were no reliable scales available in South Africa to measure Ubuntu leadership.
- Full Text:
- Date Issued: 2017
- Authors: Muller, Roger Joseph
- Date: 2017
- Subjects: Leadership Management -- South Africa , Management -- Africa -- Philosophy Employees -- Attitudes Organizational effectiveness -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/19409 , vital:28868
- Description: South Africa have some of the lowest employee engagement scores in the world. Leadership is a key determinant of employee engagement, but existing leadership theories and practices are often ineffective in more humanistic and collectivistic cultures like South Africa. To this end, Ubuntu and servant leadership is posited to positively influence organisational performance by increasing employee engagement. The primary objective of this study is to investigate perceptions regarding the impact of Ubuntu and servant leadership on employee engagement in private organisations of the Eastern Cape. A quantitative research design was utilised and yielded 428 usable questionnaires through nonprobability sampling. The empirical results revealed that the spirit of solidarity dimension of Ubuntu leadership influenced significantly and positively. Furthermore, it was found that survival and spirit of solidarity had a significant and positive influence on organisational performance as measured through the balanced scorecard (BSC). Servant leadership positively and significantly influenced employee engagement and organisational performance. In addition, it was found that employee engagement mediates the relationship between servant leadership and organizational performance. This study has made several significant empirical and theoretical contributions, and can be classified as one of the pioneering attempts to gather empirical evidence on how Ubuntu manifests in the workplace. The high convergent validity of the dimensions of Ubuntu leadership and comparisons to Servant leadership established in this study, provides some proof of its novel contribution towards leadership theory. A highly reliable and valid measuring instrument was developed to evaluate Ubuntu from a leadership perspective. This is a major empirical contribution as, at the time, there were no reliable scales available in South Africa to measure Ubuntu leadership.
- Full Text:
- Date Issued: 2017
Performance of magnetic nanocomposites for the removal of some selected contaminants from aqueous solution
- Authors: Ojemaye, Mike Onyewelehi
- Date: 2017
- Subjects: Nanocomposites (Materials)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8746 , vital:33508
- Description: In this thesis, the performances of magnetic nanoparticles based materials were assessed for the removal or reduction of heavy metals in aqueous solutions. The successful synthesis of a novel adsorbent, azomethine functionalized magnetic nanoparticles (MNP-Maph) by covalent bonding between the amine group (-NH2) of amine functionalized magnetic nanoparticles (MNP-NH2) and carboxylic group (-COOH) of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) was achieved. This adsorbent was examined for the removal of di and trivalent ions (Cu2+, Zn2+, As3+, Pb2+ and Hg2+) from aqueous solutions. Also, magnetic photocatalyst with silica interlayer (NiFe2O4-SiO2-TiO2) was synthesized and employed for the reduction of Cr(VI) in aqueous solution. The photocatalytic reduction efficiency of this material was compared with that of magnetic titanium dioxide (NiFe2O4-TiO2) photocatalyst and titanium dioxide (TiO2) to ascertain the material with the best photocatalytic efficiency and ease of separation. All synthesized materials were characterized by using XRD, FT-IR, TEM, SEM, TGA and VSM before application. For the adsorption processes, the effects of pH, contact time, adsorbent dose and temperature were examined to ascertain the experimental condition necessary for the optimal removal of metal ions from solution. The data obtained from all experiments were fitted into four kinetic models; pseudo-first order, pseudo-second order, elovich and intra particle diffusion models to determine the mechanism involved in the adsorption of these di and trivalent ions while two isotherm models were employed in the adorption processes; these include: Langmuir and Freudlich models. Also, for the photocatalytic experiment, the effects of pH, contact time and photocatalyst dose were investigated to determine the experimental conditions necessary for the optimal reduction of Cr(VI) in aqueous solution. MNP-Maph showed excellent removal capacities of 34.08, 35.83, 50.08, 58.24 and 59.24 mg g-1 for Cu2+, Zn2+, As3+, Pb2+ and Hg2+ respectively compared to data previously reported in literature. This is as a result of the high affinity of azomethine group towards metal ions which tremendously enhanced removal of metal ions by adsorption. The incorporation of azomethine to magnetic nanoparticles improved the affinity towards metal ions removal forming strong electrostatic interaction between the adsorbent active sites and adsorbates. Also, the utilization of NiFe2O4-SiO2-TiO4, NiFe2O4-TiO2 and TiO2 for the reduction of Cr(VI) in aqueous solution showed a good photocatalytic performance with NiFe2O4-SiO2-TiO2 showing to be better in terms of both photocatalytic reduction and magnetic separation. TiO2 was observed to have 96.7percent reduction efficiency within 240 min while NiFe2O4-SiO2-TiO2 has 96.5percent reduction efficiency within 300 min and NiFe2O4-TiO2 gave 60percent reduction efficiency within 300 min of UV irradiation. This magnetic photocatalyst composite (NiFe2O4-SiO2-TiO2) gives the advantage of avoiding the problem of separation often encountered with most photocatalyst materials including TiO2 by allowing separation with the aid of a magnetic field. The adsorption processes were all described by pseudo-second order and Langmuir isotherm models while the photocatalytic process was described by Langmuir-Hinshelwood (L-H) kinetic model. Furthermore, thermodynamic experiment studied for the adsorption processes showed that all metal ion adsorption except Hg2+ by MNP-Maph were endothermic in nature, rapid and spontaneous indicating the feasibility of the sorbent material for the removal of metal ions from aqueous solutions. Also, regenerability study conducted to determine the reusability of sorbent material after seven cycles showed the potential to reuse sorbent material seven times or more. The reusability of the sorbent material was observed to show a percentage of an average of 78percent using 50:50 mixture of 0.1 mol dm-3 HNO3 and HCl for all adsorption processes. For the photocatalytic experiment, regenerability using 0.1 mol dm-3 for 1 h was observed to be very impressive after 3 runs for all synthesized photocatalytic materials. This thereby implies that the removal of metal ions by these materials will not in any way introduce secondary pollutants into the environment. Rather, it will avert the production of secondary pollutants. Also, the use of simple conventional chemicals for the regeneration of synthesized materials showed that regeneration in this study is cost effective as regeneration has been known to cost about three quarter of the total operation and maintenance of an adsorption or photocatalytic process. Application of MNP-Maph to real wastewater sampled from five different wastewater treatment plants in Eastern Cape Province for the removal of Cu2+, Zn2+ and As3+ showed that removal efficiencies of approximately 80 percent were achieved for all three metal ions upon adsorption by MNP-Maph. These therefore show that the introduction of metal loving ligand such as Maph-COOH improved the efficiency of MNP towards the removal of heavy metal ions from aqueous solution. Also, silica positively influenced the performance of magnetic titanium dioxide towards Cr(VI) reduction and separation from aqueous solution. This study therefore showed that these materials should be considered for future applications in the area of water/wastewater decontamination.
- Full Text:
- Date Issued: 2017
- Authors: Ojemaye, Mike Onyewelehi
- Date: 2017
- Subjects: Nanocomposites (Materials)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8746 , vital:33508
- Description: In this thesis, the performances of magnetic nanoparticles based materials were assessed for the removal or reduction of heavy metals in aqueous solutions. The successful synthesis of a novel adsorbent, azomethine functionalized magnetic nanoparticles (MNP-Maph) by covalent bonding between the amine group (-NH2) of amine functionalized magnetic nanoparticles (MNP-NH2) and carboxylic group (-COOH) of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) was achieved. This adsorbent was examined for the removal of di and trivalent ions (Cu2+, Zn2+, As3+, Pb2+ and Hg2+) from aqueous solutions. Also, magnetic photocatalyst with silica interlayer (NiFe2O4-SiO2-TiO2) was synthesized and employed for the reduction of Cr(VI) in aqueous solution. The photocatalytic reduction efficiency of this material was compared with that of magnetic titanium dioxide (NiFe2O4-TiO2) photocatalyst and titanium dioxide (TiO2) to ascertain the material with the best photocatalytic efficiency and ease of separation. All synthesized materials were characterized by using XRD, FT-IR, TEM, SEM, TGA and VSM before application. For the adsorption processes, the effects of pH, contact time, adsorbent dose and temperature were examined to ascertain the experimental condition necessary for the optimal removal of metal ions from solution. The data obtained from all experiments were fitted into four kinetic models; pseudo-first order, pseudo-second order, elovich and intra particle diffusion models to determine the mechanism involved in the adsorption of these di and trivalent ions while two isotherm models were employed in the adorption processes; these include: Langmuir and Freudlich models. Also, for the photocatalytic experiment, the effects of pH, contact time and photocatalyst dose were investigated to determine the experimental conditions necessary for the optimal reduction of Cr(VI) in aqueous solution. MNP-Maph showed excellent removal capacities of 34.08, 35.83, 50.08, 58.24 and 59.24 mg g-1 for Cu2+, Zn2+, As3+, Pb2+ and Hg2+ respectively compared to data previously reported in literature. This is as a result of the high affinity of azomethine group towards metal ions which tremendously enhanced removal of metal ions by adsorption. The incorporation of azomethine to magnetic nanoparticles improved the affinity towards metal ions removal forming strong electrostatic interaction between the adsorbent active sites and adsorbates. Also, the utilization of NiFe2O4-SiO2-TiO4, NiFe2O4-TiO2 and TiO2 for the reduction of Cr(VI) in aqueous solution showed a good photocatalytic performance with NiFe2O4-SiO2-TiO2 showing to be better in terms of both photocatalytic reduction and magnetic separation. TiO2 was observed to have 96.7percent reduction efficiency within 240 min while NiFe2O4-SiO2-TiO2 has 96.5percent reduction efficiency within 300 min and NiFe2O4-TiO2 gave 60percent reduction efficiency within 300 min of UV irradiation. This magnetic photocatalyst composite (NiFe2O4-SiO2-TiO2) gives the advantage of avoiding the problem of separation often encountered with most photocatalyst materials including TiO2 by allowing separation with the aid of a magnetic field. The adsorption processes were all described by pseudo-second order and Langmuir isotherm models while the photocatalytic process was described by Langmuir-Hinshelwood (L-H) kinetic model. Furthermore, thermodynamic experiment studied for the adsorption processes showed that all metal ion adsorption except Hg2+ by MNP-Maph were endothermic in nature, rapid and spontaneous indicating the feasibility of the sorbent material for the removal of metal ions from aqueous solutions. Also, regenerability study conducted to determine the reusability of sorbent material after seven cycles showed the potential to reuse sorbent material seven times or more. The reusability of the sorbent material was observed to show a percentage of an average of 78percent using 50:50 mixture of 0.1 mol dm-3 HNO3 and HCl for all adsorption processes. For the photocatalytic experiment, regenerability using 0.1 mol dm-3 for 1 h was observed to be very impressive after 3 runs for all synthesized photocatalytic materials. This thereby implies that the removal of metal ions by these materials will not in any way introduce secondary pollutants into the environment. Rather, it will avert the production of secondary pollutants. Also, the use of simple conventional chemicals for the regeneration of synthesized materials showed that regeneration in this study is cost effective as regeneration has been known to cost about three quarter of the total operation and maintenance of an adsorption or photocatalytic process. Application of MNP-Maph to real wastewater sampled from five different wastewater treatment plants in Eastern Cape Province for the removal of Cu2+, Zn2+ and As3+ showed that removal efficiencies of approximately 80 percent were achieved for all three metal ions upon adsorption by MNP-Maph. These therefore show that the introduction of metal loving ligand such as Maph-COOH improved the efficiency of MNP towards the removal of heavy metal ions from aqueous solution. Also, silica positively influenced the performance of magnetic titanium dioxide towards Cr(VI) reduction and separation from aqueous solution. This study therefore showed that these materials should be considered for future applications in the area of water/wastewater decontamination.
- Full Text:
- Date Issued: 2017
Pharmacological evaluation of phragmanthera capitata (sprengel) balle, loranthaceae :a parasiticmistletoe growing on rubber trees
- Ohikhena, Franklin Uangbaoje
- Authors: Ohikhena, Franklin Uangbaoje
- Date: 2017
- Subjects: Hevea Hevea -- Diseases and pests Rubber
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8899 , vital:33937
- Description: Rubber tree (Hevea brasiliensis Muell.) is the world’s major source of natural rubber and a major non-oil, agricultural export commodity in the producing countries in Africa. However, it is highly susceptible to specific mistletoes of the Loranthaceae family. Phragmanthera capitate (Sprengel) Balle is the major mistletoe parasitizing the rubber tree plantations in Africa and hence, alongside with other mistletoes, has attracted indiscriminate destruction from plantation owners. Indiscriminate destruction of plants could be as a result of ignorance of the importance or benefit(s) of the plants and this could lead to their extinction if not checked. Hence, there is the need for scientific documentation of plants and their uses because, from the pharmacological perception, the destruction of a plant could result in the permanent loss of a potential drug. Therefore, this study was aimed at documenting and evaluating the pharmacological potentials of P. capitata collected from rubber tree. Fresh leaves were gently rinsed with water and dried. Dried leaves were pulverised and kept at 4oC when not in use. Pulverised leaves were extracted with acetone, methanol, ethanol and water and concentrated to give the respective solvent crude extracts used in most of the assays. From the extraction, Methanol had the highest yield of 21.5percent, water had 10.8percent and acetone was 6.87percent while ethanol had the lowest yield of 4.3percent. Standard spectrophotometry assays on the extracts were used to quantify some major phytochemicals of pharmacological interest and also to determine the antioxidant potentials of the sample. The result revealed high amounts of phenols (175.53 ± 0.32 mg GAE/g to 218.62 ± 3.38 mg GAE/g), flavonoids (197.06 ± 3.80 mg QE/mg to 679.82 ± 6.26 mg QE/g) and proanthocyanidins (128.83 ± 1.69 mg CE/g to 645.68 ± 6.35 mg CE/g) with the acetone extract having the highest amount of the phytochemicals while the aqueous extract had the least. The results of the antioxidant assays revealed that the sample had high radical scavenging potentials with comparable inhibitory concentrations to standard antioxidant drugs. The proximate and mineral analysis on the pulverised sample showed that it is rich in carbohydrate with a composition of 57.73 ± 0.33 g/100 g. Protein, fat and fibre compositions were 12.50 ± 0.50 g/100 g, 3.34 ± 0.18 g/100 g and 11.66 ± 0.54 g/100g. The total energy composition was 310.97 ± 2.30 Kcal/100 g. The mineral composition revealed high potassium level of 1047.83 ± 34 mg/100g. Calcium (6.22.58 ± 0.01 mg/100g), magnesium (361.15 ± 0.01 mg/100 g) and phosphorous (115.40 ± 0.01 mg/100 g) were also present in appreciable amounts. The toxicity of the four extracts was assayed using brine shrimp. The LC50 in all the solvent extracts was greater than 1 mg/mL which according to Meyer’s index and other indexes signify “no toxicity” for crude plant extracts. Antimicrobial activity of the extracts was done using the minimal inhibitory concentration (MIC) assay against 10 bacteria (Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus pyogenes, Vibrio cholera, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli) and 4 fungi (Trichophyton mucoides, Trichophyton tonsurans, Candida albicans and Aspergillus niger) of human pathogenic strains. The MIC of the antibacterial assay ranged from 1.25 mg/mL to 5 mg/mL for the organic extracts while no activity was observed in the aqueous extract at the highest concentration tested. However, the aqueous extract had a great inhibitory activity on all four of the tested fungi with a MIC of ≤ 0.3125 mg/mL to 1.25 mg/mL while only two fungi (Trichophyton Tonsurans and Aspergillus niger) were susceptible to the organic extracts. The MIC of the TB causative pathogen, Mycobacterium tuberculosis (H37Rv) strain ranged from 25 μg/mL (acetone and aqueous extracts) to 50 μg/mL in the ethanol extract while it was > 50 μg/mL (highest concentration tested) in the methanol extract. This study revealed that the sample has the potential in phytotherapy against oxidative stresses (inflammations) caused by free radicals. It could also be a useful herb in combating diseases caused by pathogenic organisms. The high anti-Mycobacterium tuberculosis activity observed in this study suggests it could be a plant with high promise in the fight against tuberculosis. The toxicity evaluation signifies it is safe for further plant-based pharmaceutical explorations. This study also validated some reported ethnopharmacological uses of this plant and call for its protection from indiscriminate destruction in rubber plantations and other crop gardens/plantations in the world.
- Full Text:
- Date Issued: 2017
- Authors: Ohikhena, Franklin Uangbaoje
- Date: 2017
- Subjects: Hevea Hevea -- Diseases and pests Rubber
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8899 , vital:33937
- Description: Rubber tree (Hevea brasiliensis Muell.) is the world’s major source of natural rubber and a major non-oil, agricultural export commodity in the producing countries in Africa. However, it is highly susceptible to specific mistletoes of the Loranthaceae family. Phragmanthera capitate (Sprengel) Balle is the major mistletoe parasitizing the rubber tree plantations in Africa and hence, alongside with other mistletoes, has attracted indiscriminate destruction from plantation owners. Indiscriminate destruction of plants could be as a result of ignorance of the importance or benefit(s) of the plants and this could lead to their extinction if not checked. Hence, there is the need for scientific documentation of plants and their uses because, from the pharmacological perception, the destruction of a plant could result in the permanent loss of a potential drug. Therefore, this study was aimed at documenting and evaluating the pharmacological potentials of P. capitata collected from rubber tree. Fresh leaves were gently rinsed with water and dried. Dried leaves were pulverised and kept at 4oC when not in use. Pulverised leaves were extracted with acetone, methanol, ethanol and water and concentrated to give the respective solvent crude extracts used in most of the assays. From the extraction, Methanol had the highest yield of 21.5percent, water had 10.8percent and acetone was 6.87percent while ethanol had the lowest yield of 4.3percent. Standard spectrophotometry assays on the extracts were used to quantify some major phytochemicals of pharmacological interest and also to determine the antioxidant potentials of the sample. The result revealed high amounts of phenols (175.53 ± 0.32 mg GAE/g to 218.62 ± 3.38 mg GAE/g), flavonoids (197.06 ± 3.80 mg QE/mg to 679.82 ± 6.26 mg QE/g) and proanthocyanidins (128.83 ± 1.69 mg CE/g to 645.68 ± 6.35 mg CE/g) with the acetone extract having the highest amount of the phytochemicals while the aqueous extract had the least. The results of the antioxidant assays revealed that the sample had high radical scavenging potentials with comparable inhibitory concentrations to standard antioxidant drugs. The proximate and mineral analysis on the pulverised sample showed that it is rich in carbohydrate with a composition of 57.73 ± 0.33 g/100 g. Protein, fat and fibre compositions were 12.50 ± 0.50 g/100 g, 3.34 ± 0.18 g/100 g and 11.66 ± 0.54 g/100g. The total energy composition was 310.97 ± 2.30 Kcal/100 g. The mineral composition revealed high potassium level of 1047.83 ± 34 mg/100g. Calcium (6.22.58 ± 0.01 mg/100g), magnesium (361.15 ± 0.01 mg/100 g) and phosphorous (115.40 ± 0.01 mg/100 g) were also present in appreciable amounts. The toxicity of the four extracts was assayed using brine shrimp. The LC50 in all the solvent extracts was greater than 1 mg/mL which according to Meyer’s index and other indexes signify “no toxicity” for crude plant extracts. Antimicrobial activity of the extracts was done using the minimal inhibitory concentration (MIC) assay against 10 bacteria (Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus pyogenes, Vibrio cholera, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli) and 4 fungi (Trichophyton mucoides, Trichophyton tonsurans, Candida albicans and Aspergillus niger) of human pathogenic strains. The MIC of the antibacterial assay ranged from 1.25 mg/mL to 5 mg/mL for the organic extracts while no activity was observed in the aqueous extract at the highest concentration tested. However, the aqueous extract had a great inhibitory activity on all four of the tested fungi with a MIC of ≤ 0.3125 mg/mL to 1.25 mg/mL while only two fungi (Trichophyton Tonsurans and Aspergillus niger) were susceptible to the organic extracts. The MIC of the TB causative pathogen, Mycobacterium tuberculosis (H37Rv) strain ranged from 25 μg/mL (acetone and aqueous extracts) to 50 μg/mL in the ethanol extract while it was > 50 μg/mL (highest concentration tested) in the methanol extract. This study revealed that the sample has the potential in phytotherapy against oxidative stresses (inflammations) caused by free radicals. It could also be a useful herb in combating diseases caused by pathogenic organisms. The high anti-Mycobacterium tuberculosis activity observed in this study suggests it could be a plant with high promise in the fight against tuberculosis. The toxicity evaluation signifies it is safe for further plant-based pharmaceutical explorations. This study also validated some reported ethnopharmacological uses of this plant and call for its protection from indiscriminate destruction in rubber plantations and other crop gardens/plantations in the world.
- Full Text:
- Date Issued: 2017
Pharmacological investigations of Kedrostis africana (L.) Cogn. and Vernonia mespilifolia Less. used in folk medicine in the Eastern Cape, South Africa
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
- Full Text:
- Date Issued: 2017
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
- Full Text:
- Date Issued: 2017
Physical organic studies of substituted norbornyl systems: aspects of mechanisms and chirality
- Authors: Singh, Alicia
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50558 , vital:25999
- Description: Fenchone and camphor are essential natural products that are available optically pure and contribute to the chiral pool in asymmetric synthesis. Further, they are both derivatives of norbornane, a structure that undergoes a remarkable diversity of rearrangements in acidic conditions. This work explores two aspects of the camphor/fenchone derived systems. Firstly an attempt to clarify rearrangement mechanisms on a camphor system successfully via deuterium labelling and unsuccessfully via derivatization of fenchone (with rearrangement) to produce other 13C-labelled camphor substitutions, has resulted in confirmation of a theoretically proposed, highly concerted Wagner-Meerwein, 6,2 - hydride shift, Wagner-Meerwein rearrangement in competition with an associated 2,3-methide shift. Kinetics and activation parameters for many steps have been resolved in this rearrangement of the deuterium labelled camphor-derived tosylate system to two pairs of isotopomers. Further, the kinetics and formation of an unexpected pair of dimers encountered during the scheme for 13C labelling are investigated in detail. These dimers (forming during the initial stages of the synthetic scheme) are unusual in that they are not expected rotamers of each other, but diastereomers resulting from chirality of a sulfur atom in a sulfite moiety. A feasible mechanism of formation that matches the kinetics has been proposed in this unexpectedly complex system, and thermodynamic parameters have been determined. The second aspect of substituted norbornyl systems pertains to their chirality, and the influence of this chirality on reaction mixtures, with an aim to identify novel chiral micellar catalysts for use in heterogeneous reaction mixtures. Headway has been made towards the synthesis of the appropriate surfactants to be used in the construction of these micelles, but extensive molecular dynamics simulations have illustrated the feasibility of forming the stable chiral micelles in a dual-solvent system, and detail precisely the influence of chirality on surrounding media. These studies add important physical organic data as well as show the immense possibilities pertaining to substituted norbornane systems.
- Full Text:
- Date Issued: 2017
- Authors: Singh, Alicia
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50558 , vital:25999
- Description: Fenchone and camphor are essential natural products that are available optically pure and contribute to the chiral pool in asymmetric synthesis. Further, they are both derivatives of norbornane, a structure that undergoes a remarkable diversity of rearrangements in acidic conditions. This work explores two aspects of the camphor/fenchone derived systems. Firstly an attempt to clarify rearrangement mechanisms on a camphor system successfully via deuterium labelling and unsuccessfully via derivatization of fenchone (with rearrangement) to produce other 13C-labelled camphor substitutions, has resulted in confirmation of a theoretically proposed, highly concerted Wagner-Meerwein, 6,2 - hydride shift, Wagner-Meerwein rearrangement in competition with an associated 2,3-methide shift. Kinetics and activation parameters for many steps have been resolved in this rearrangement of the deuterium labelled camphor-derived tosylate system to two pairs of isotopomers. Further, the kinetics and formation of an unexpected pair of dimers encountered during the scheme for 13C labelling are investigated in detail. These dimers (forming during the initial stages of the synthetic scheme) are unusual in that they are not expected rotamers of each other, but diastereomers resulting from chirality of a sulfur atom in a sulfite moiety. A feasible mechanism of formation that matches the kinetics has been proposed in this unexpectedly complex system, and thermodynamic parameters have been determined. The second aspect of substituted norbornyl systems pertains to their chirality, and the influence of this chirality on reaction mixtures, with an aim to identify novel chiral micellar catalysts for use in heterogeneous reaction mixtures. Headway has been made towards the synthesis of the appropriate surfactants to be used in the construction of these micelles, but extensive molecular dynamics simulations have illustrated the feasibility of forming the stable chiral micelles in a dual-solvent system, and detail precisely the influence of chirality on surrounding media. These studies add important physical organic data as well as show the immense possibilities pertaining to substituted norbornane systems.
- Full Text:
- Date Issued: 2017
Potential use of Islamic finance among Muslims in Port Elizabeth
- Authors: Ismail, Badroen
- Date: 2017
- Subjects: Finance -- Religious aspects Banks and banking -- Religious aspects -- Islam , Consumer behavior -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17526 , vital:28374
- Description: The resurgence of Islam across the globe combined with the resilience that Islamic financial assets have shown against the onslaught of the current financial crisis, make Islamic finance an attractive alternative financial system. Over the past decade, the Islamic finance sector have shown double digit growth rates beyond the traditional areas of the Gulf Cooperation Council (GCC) regions of Asia as well as other parts of the Middle-East and North Africa (MENA) regions. Research suggests that the future of Islamic finance in Africa depends on business opportunities in South Africa, Kenya, Nigeria and Senegal. The South African government, in conjunction with the national finance authorities, have made their intention clear to position the country as the Islamic finance hub for the rest of the African continent. Despite various marketing campaigns over the past decade to convince the public that Islamic banking and finance is for everyone, non-Muslims generally view Islamic banking as being for Muslims alone. Scepticism towards Islamic finance has resulted in a mere 15 per cent of the estimated 1.5 million South African Muslims currently making use of the sector’s banking and retail instruments. This lack of interest is impacting negatively on the country’s aspirations to establish itself as the gateway of Islamic finance to the rest of Africa. Generally, people’s attitudes toward utilising Islamic finance are regarded as a key obstacle to the development of the Islamic banking and finance system in Muslim minority countries. A Kuwait Finance House research report (2012) highlighted a lack of awareness and knowledge of Islamic finance products and services as key factors stifling the growth of the Islamic finance sector in South Africa. In this context, it was deemed necessary to analyse how knowledge, awareness, expectations, beliefs, perceptions and ancillary external factors impact on potential users’ attitude and decision to adopt or reject Islamic finance.By means of adapting Fishbein’s (2000; 2008) Integrative Model of Behavioural Prediction, a universally-acceptable behavioural-change model, this research explains in a holistic manner how cognitive, affective and environmental measures impact on a Port Elizabethan Muslim’s attitude and eventual decision to accept (or reject) Islamic finance. This study has found that knowledge was the most important variable influencing attitude and intention to use (or reject) Islamic finance. Consequently, this thesis proposed that Islamic institutions should focus their efforts on promoting knowledge and awareness of their products among the South African Muslim and non- Muslim population. As the global Shari’ah finance industry continues its positive growth trajectory, it is imperative that Islamic finance stakeholders in South Africa ensure that they exploit the benefits derived from online learning platforms and assist, by means of cross-border collaborations, more students to have greater access to Islamic finance courses. Furthermore, universities and training institutions are encouraged to offer courses and qualifications in Islamic finance to close the talent gap that currently exist in this particular field of study.
- Full Text:
- Date Issued: 2017
- Authors: Ismail, Badroen
- Date: 2017
- Subjects: Finance -- Religious aspects Banks and banking -- Religious aspects -- Islam , Consumer behavior -- Religious aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/17526 , vital:28374
- Description: The resurgence of Islam across the globe combined with the resilience that Islamic financial assets have shown against the onslaught of the current financial crisis, make Islamic finance an attractive alternative financial system. Over the past decade, the Islamic finance sector have shown double digit growth rates beyond the traditional areas of the Gulf Cooperation Council (GCC) regions of Asia as well as other parts of the Middle-East and North Africa (MENA) regions. Research suggests that the future of Islamic finance in Africa depends on business opportunities in South Africa, Kenya, Nigeria and Senegal. The South African government, in conjunction with the national finance authorities, have made their intention clear to position the country as the Islamic finance hub for the rest of the African continent. Despite various marketing campaigns over the past decade to convince the public that Islamic banking and finance is for everyone, non-Muslims generally view Islamic banking as being for Muslims alone. Scepticism towards Islamic finance has resulted in a mere 15 per cent of the estimated 1.5 million South African Muslims currently making use of the sector’s banking and retail instruments. This lack of interest is impacting negatively on the country’s aspirations to establish itself as the gateway of Islamic finance to the rest of Africa. Generally, people’s attitudes toward utilising Islamic finance are regarded as a key obstacle to the development of the Islamic banking and finance system in Muslim minority countries. A Kuwait Finance House research report (2012) highlighted a lack of awareness and knowledge of Islamic finance products and services as key factors stifling the growth of the Islamic finance sector in South Africa. In this context, it was deemed necessary to analyse how knowledge, awareness, expectations, beliefs, perceptions and ancillary external factors impact on potential users’ attitude and decision to adopt or reject Islamic finance.By means of adapting Fishbein’s (2000; 2008) Integrative Model of Behavioural Prediction, a universally-acceptable behavioural-change model, this research explains in a holistic manner how cognitive, affective and environmental measures impact on a Port Elizabethan Muslim’s attitude and eventual decision to accept (or reject) Islamic finance. This study has found that knowledge was the most important variable influencing attitude and intention to use (or reject) Islamic finance. Consequently, this thesis proposed that Islamic institutions should focus their efforts on promoting knowledge and awareness of their products among the South African Muslim and non- Muslim population. As the global Shari’ah finance industry continues its positive growth trajectory, it is imperative that Islamic finance stakeholders in South Africa ensure that they exploit the benefits derived from online learning platforms and assist, by means of cross-border collaborations, more students to have greater access to Islamic finance courses. Furthermore, universities and training institutions are encouraged to offer courses and qualifications in Islamic finance to close the talent gap that currently exist in this particular field of study.
- Full Text:
- Date Issued: 2017
Poverty, Food insecurity and livelihood diversification among households in Eastern Cape province, South Africa
- Authors: Megbowon, Ebenezer Toyin
- Date: 2017
- Subjects: Food supply -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13086 , vital:39464
- Description: Livelihood diversification have been thought to be a rural issue where agriculture is the main source of income, however in an era of dwindling global and national economic situations, livelihood diversification have been seen to be prominent among urban dwellers as well although literatures have focused more on rural households. There is also a growing evidence in literature showing that livelihood diversification is indispensable for improving household welfare. This study adopts the sustainable livelihood framework to investigate the pattern and determinants of livelihood diversification (number of income sources) and the welfare (poverty and food insecurity) effect of livelihood diversification on household in the Eastern Cape Province of South Africa. Indicators of poverty and food security were computed using Multidimensional Poverty Index (MPI) and FANTA’s Household Dietary Diversity Scores (HDDS). The study relied on data obtained from the Nation-wide annual General household Survey carried out in 2014 having 3033 households sampled from the Eastern Cape Province of South Africa. Data were analyzed using descriptive statistics, Poisson regression, Tobit regression and logistic regression models. The result of the Multidimensional Poverty Index headcount revealed that while majority (71.28 percent) of the households are not multidimensionaly poor, 20.51 percent, 6.89 percent and 1.32 percent are vulnerable to multidimensional poverty, multidimensionaly poor and severely multidimensionaly poor respectively. The study also revealed that while there is a significant differences between multidimensional poverty status in the both rural and urban area, there is no much differences when considering the gender of the household head. This indicates that poverty is still a rural phenomenon in the Province. Furthermore, the largest contributor (dimension and indicators) to household multidimensional poverty in the Province is standard of living dimension and specific indicator are the fuels use for cooking, water and space heating, toilet system, dwelling and asset accumulation are the most areas of highest deprivation. The household dietary diversity score show that household have a diverse diet with a mean score of 6.9; however the diversity is skewed toward food groups that do not give expected nutritional diets for a healthy and an economically active life. In General pulse diet and vegetables (spinach and wild green leaves) are least consumed in the province. Consumption of fruit is shown to be less consumed in the rural area as compared to the urban area. Descriptive analysis of livelihood diversification among households in the province revealed that majority of households are not diversified. Poisson regression estimate produced a good fit shown by the statistical insignificance of the deviance good of fit (p=1.09). Age of household head, population group of the head, education attainment of the head, engagement in agriculture, recipient of remittance and number of economic active member of the household) were found to be statistically significant (p<0.01) and were found to influence the probability of a household diversifying their livelihood base in the study area. The result of the Tobit regression on effect of livelihood diversification and other household socio-economic characteristics on household poverty suggest livelihood diversification has no statistically significant effect on the probability of being poor in the study area. Other variables found to influence poverty are, household head’s gender (male), age, education, employment status, access to electricity, engagement in agriculture, salary earning, economic active size of household and asset score) were found to be significantly (p<0.01) to influencing multidimensional poverty of the poor households. The result of the logistic regression indicates that livelihood diversification has no significant effect on the probability of a household being poor. Gender of head, age of household head, education attainment of the head, access to electricity, engagement in agriculture, recipients of pension, number of economic active and living in urban area were also found to be statistically significant in influencing household food insecurity in the province. The findings illustrates that livelihood diversification may not be relevant for household welfare in the case of South Africa. However promoting livelihood diversification remain imperative for household welfare in the South Africa in the long-run. It further illustrate that gender of head, education, access to electricity, home agriculture are imperative for the improvement of household welfare. Hence the study recommends policy relating to conditional granting of cash grant support, intensification of rural development programmes, education affordable and accessible at all level and support home stead or subsistence agriculture.
- Full Text:
- Date Issued: 2017
- Authors: Megbowon, Ebenezer Toyin
- Date: 2017
- Subjects: Food supply -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13086 , vital:39464
- Description: Livelihood diversification have been thought to be a rural issue where agriculture is the main source of income, however in an era of dwindling global and national economic situations, livelihood diversification have been seen to be prominent among urban dwellers as well although literatures have focused more on rural households. There is also a growing evidence in literature showing that livelihood diversification is indispensable for improving household welfare. This study adopts the sustainable livelihood framework to investigate the pattern and determinants of livelihood diversification (number of income sources) and the welfare (poverty and food insecurity) effect of livelihood diversification on household in the Eastern Cape Province of South Africa. Indicators of poverty and food security were computed using Multidimensional Poverty Index (MPI) and FANTA’s Household Dietary Diversity Scores (HDDS). The study relied on data obtained from the Nation-wide annual General household Survey carried out in 2014 having 3033 households sampled from the Eastern Cape Province of South Africa. Data were analyzed using descriptive statistics, Poisson regression, Tobit regression and logistic regression models. The result of the Multidimensional Poverty Index headcount revealed that while majority (71.28 percent) of the households are not multidimensionaly poor, 20.51 percent, 6.89 percent and 1.32 percent are vulnerable to multidimensional poverty, multidimensionaly poor and severely multidimensionaly poor respectively. The study also revealed that while there is a significant differences between multidimensional poverty status in the both rural and urban area, there is no much differences when considering the gender of the household head. This indicates that poverty is still a rural phenomenon in the Province. Furthermore, the largest contributor (dimension and indicators) to household multidimensional poverty in the Province is standard of living dimension and specific indicator are the fuels use for cooking, water and space heating, toilet system, dwelling and asset accumulation are the most areas of highest deprivation. The household dietary diversity score show that household have a diverse diet with a mean score of 6.9; however the diversity is skewed toward food groups that do not give expected nutritional diets for a healthy and an economically active life. In General pulse diet and vegetables (spinach and wild green leaves) are least consumed in the province. Consumption of fruit is shown to be less consumed in the rural area as compared to the urban area. Descriptive analysis of livelihood diversification among households in the province revealed that majority of households are not diversified. Poisson regression estimate produced a good fit shown by the statistical insignificance of the deviance good of fit (p=1.09). Age of household head, population group of the head, education attainment of the head, engagement in agriculture, recipient of remittance and number of economic active member of the household) were found to be statistically significant (p<0.01) and were found to influence the probability of a household diversifying their livelihood base in the study area. The result of the Tobit regression on effect of livelihood diversification and other household socio-economic characteristics on household poverty suggest livelihood diversification has no statistically significant effect on the probability of being poor in the study area. Other variables found to influence poverty are, household head’s gender (male), age, education, employment status, access to electricity, engagement in agriculture, salary earning, economic active size of household and asset score) were found to be significantly (p<0.01) to influencing multidimensional poverty of the poor households. The result of the logistic regression indicates that livelihood diversification has no significant effect on the probability of a household being poor. Gender of head, age of household head, education attainment of the head, access to electricity, engagement in agriculture, recipients of pension, number of economic active and living in urban area were also found to be statistically significant in influencing household food insecurity in the province. The findings illustrates that livelihood diversification may not be relevant for household welfare in the case of South Africa. However promoting livelihood diversification remain imperative for household welfare in the South Africa in the long-run. It further illustrate that gender of head, education, access to electricity, home agriculture are imperative for the improvement of household welfare. Hence the study recommends policy relating to conditional granting of cash grant support, intensification of rural development programmes, education affordable and accessible at all level and support home stead or subsistence agriculture.
- Full Text:
- Date Issued: 2017
Pre-service teachers’ concerns on teaching practicum: a mixed methods case study from Zimbabwe
- Chitumwa, Chemunondirwa Christopher
- Authors: Chitumwa, Chemunondirwa Christopher
- Date: 2017
- Subjects: Practicums -- Zimbabwe Teachers -- Training of -- Zimbabwe , Teaching -- Zimbabwe -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14840 , vital:27879
- Description: The purpose of this study was to identify and examine pre-service teachers’ concerns relating to their teaching practicum in Zimbabwe and to suggest strategies that could be used to support them in a digitalised era. This study was necessitated by the desire to understand the concerns that pre-service teachers experience during teaching practicum in a fast changing world and in a depressing, unstable socio-politico-economic environment. The study employed a meta-conceptual approach comprising constructivist and social cognitive epistemology as its theoretical framework. A concurrent mixed methods research design was utilised to address the research questions. Both quantitative and qualitative methods were used to design the study, collect, and analyse data. Thirty participants comprising of 24 pre-service teachers and six college supervisors were purposively selected for the qualitative study from United College of Education in Zimbabwe. Qualitative data was collected by means of interviews and analysed through a thematic analysis. For the quantitative phase, 300 pre-service teachers were chosen through stratified random sampling from the same institution and were asked to complete a questionnaire. One hundred and ninety-three questionnaires were returned and usable, giving a return rate of 64%. Data from the survey were analysed using descriptive and inferential statistics. Findings from the study revealed that pre-service teachers experience diverse concerns during teaching practicum that included classroom management, teacher knowledge, socio-economic factors, workload, interpersonal relationships and assessment anxiety. Findings from the quantitative phase revealed some differences in the levels of concerns among the year groups. A general downward trend in the levels of concerns was detected except for teacher beliefs concerns that remained constant. Findings from the qualitative phase of the study revealed that the concerns that pre-service teachers experienced during teaching practicum had negative impact on their classroom practice. Most of the student teachers had devised some coping strategies to deal with their concerns and they were satisfied with the quality of support from mentors and peers, but not that from their supervisors. In an increasingly globalised world, the researcher felt that teaching practicum related concerns could be minimised by exploiting the benefits of digitalised knowledge and communities of learning.
- Full Text:
- Date Issued: 2017
- Authors: Chitumwa, Chemunondirwa Christopher
- Date: 2017
- Subjects: Practicums -- Zimbabwe Teachers -- Training of -- Zimbabwe , Teaching -- Zimbabwe -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14840 , vital:27879
- Description: The purpose of this study was to identify and examine pre-service teachers’ concerns relating to their teaching practicum in Zimbabwe and to suggest strategies that could be used to support them in a digitalised era. This study was necessitated by the desire to understand the concerns that pre-service teachers experience during teaching practicum in a fast changing world and in a depressing, unstable socio-politico-economic environment. The study employed a meta-conceptual approach comprising constructivist and social cognitive epistemology as its theoretical framework. A concurrent mixed methods research design was utilised to address the research questions. Both quantitative and qualitative methods were used to design the study, collect, and analyse data. Thirty participants comprising of 24 pre-service teachers and six college supervisors were purposively selected for the qualitative study from United College of Education in Zimbabwe. Qualitative data was collected by means of interviews and analysed through a thematic analysis. For the quantitative phase, 300 pre-service teachers were chosen through stratified random sampling from the same institution and were asked to complete a questionnaire. One hundred and ninety-three questionnaires were returned and usable, giving a return rate of 64%. Data from the survey were analysed using descriptive and inferential statistics. Findings from the study revealed that pre-service teachers experience diverse concerns during teaching practicum that included classroom management, teacher knowledge, socio-economic factors, workload, interpersonal relationships and assessment anxiety. Findings from the quantitative phase revealed some differences in the levels of concerns among the year groups. A general downward trend in the levels of concerns was detected except for teacher beliefs concerns that remained constant. Findings from the qualitative phase of the study revealed that the concerns that pre-service teachers experienced during teaching practicum had negative impact on their classroom practice. Most of the student teachers had devised some coping strategies to deal with their concerns and they were satisfied with the quality of support from mentors and peers, but not that from their supervisors. In an increasingly globalised world, the researcher felt that teaching practicum related concerns could be minimised by exploiting the benefits of digitalised knowledge and communities of learning.
- Full Text:
- Date Issued: 2017
Production systems, profitability and participation in the mainstream markets by smallholder broiler chicken farmers of Maseru district in Lesotho
- Mphahama, Litsoanelo Evodiah
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
- Full Text:
- Date Issued: 2017
Psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria
- Authors: Aderibigbe, John Kolawole
- Date: 2017
- Subjects: Psychology, Industrial Emotional intelligence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8642 , vital:33250
- Description: The study investigated psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria, using the explanatory cross-sectional (survey) research design and three sampling techniques (The Two-stage Cluster Sampling Method, The Convenience Sampling Method and The Purposive Sampling Technique) to sample 1532 male and female graduate employees in Nigeria. A structured validated questionnaire was used to collect data from the respondents. Six hypotheses were stated and tested in the study towards propounding a model, using Pearson Correlation Analysis, Multiple Regression Analysis and Structural Equation Modelling. The results show that there is a weak positive relationship between occupational stress and organisational citizenship behaviour, r = 0.070, p<0.01; there is a significant positive relationship between psychological capital and organisational citizenship behaviour, r = 0.588, p<0.01; there is a significant positive relationship between emotional intelligence and organisational citizenship behaviour, r = 0.473, p<0.01; psychological capital is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 8.514; R2= 0.011; p <.05; emotional intelligence is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 5.945; R2= 0.008; p <.05; psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour, F (1,1530) = 221.240; R2= 0.186; p <.05; psychological capital has a direct and significant positive effect on organisational citizenship behaviour, R= 0.657, p<.001; emotional intelligence has a direct and significant positive effect on organisational citizenship behaviour, R= 0.183, p<.001; psychological capital has a direct and significant positive effect on occupational stress, R= 0.100, p<.001; emotional intelligence has a direct and significant positive effect on psychological capital, R= 0.547, p<.001. Based on the results, the study concludes that psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour. The proposed model was, therefore, empirically confirmed. The researcher recommends that the empirical model of effective management of occupational stress and organisational citizenship behaviour, which has been propounded in the study, should be adopted and applied by teachers, lecturers, seminar facilitators, workshop trainers, supervisors and managers during their coaching or training sessions.
- Full Text:
- Date Issued: 2017
- Authors: Aderibigbe, John Kolawole
- Date: 2017
- Subjects: Psychology, Industrial Emotional intelligence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8642 , vital:33250
- Description: The study investigated psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria, using the explanatory cross-sectional (survey) research design and three sampling techniques (The Two-stage Cluster Sampling Method, The Convenience Sampling Method and The Purposive Sampling Technique) to sample 1532 male and female graduate employees in Nigeria. A structured validated questionnaire was used to collect data from the respondents. Six hypotheses were stated and tested in the study towards propounding a model, using Pearson Correlation Analysis, Multiple Regression Analysis and Structural Equation Modelling. The results show that there is a weak positive relationship between occupational stress and organisational citizenship behaviour, r = 0.070, p<0.01; there is a significant positive relationship between psychological capital and organisational citizenship behaviour, r = 0.588, p<0.01; there is a significant positive relationship between emotional intelligence and organisational citizenship behaviour, r = 0.473, p<0.01; psychological capital is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 8.514; R2= 0.011; p <.05; emotional intelligence is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 5.945; R2= 0.008; p <.05; psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour, F (1,1530) = 221.240; R2= 0.186; p <.05; psychological capital has a direct and significant positive effect on organisational citizenship behaviour, R= 0.657, p<.001; emotional intelligence has a direct and significant positive effect on organisational citizenship behaviour, R= 0.183, p<.001; psychological capital has a direct and significant positive effect on occupational stress, R= 0.100, p<.001; emotional intelligence has a direct and significant positive effect on psychological capital, R= 0.547, p<.001. Based on the results, the study concludes that psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour. The proposed model was, therefore, empirically confirmed. The researcher recommends that the empirical model of effective management of occupational stress and organisational citizenship behaviour, which has been propounded in the study, should be adopted and applied by teachers, lecturers, seminar facilitators, workshop trainers, supervisors and managers during their coaching or training sessions.
- Full Text:
- Date Issued: 2017
Psychological well-being of institutionalised and non-institutionalised isiXhosa and English ethnic speaking elderly south African residing within the Buffalo City area
- Authors: Ntozini, Anathi
- Date: 2017
- Subjects: Self-actualization (Psychology) in old age Older people -- Institutional care -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/6368 , vital:29593
- Description: Background: International research has clearly indicated that the world’s population is ageing: almost all countries in the world are experiencing a significant growth in the proportion of older persons in their population. This is also true for developing countries such as South Africa that are beginning to show signs and symptoms of an ageing population. Among Southern African Development Communities (SADC), South Africa has the highest number of ‘senior citizens’. Population reports indicate that the population of old people rose from paltry 2.8 million in 1996 to more than 4 million in 2011 and this is expected to skyrocket to seven million by 2030. In spite of the increasing number of senior citizens in socio-structural landscapes in South Africa, there is still lack of adequate, workable and effective policy frameworks for the wellbeing of the elderly. There is also paucity of psychological data of the elderly, especially along racial divides to determine whether the after-effects of apartheid still hold sway or not in post-apartheid South Africa. This study was conceived to investigate the psychological well-being of the elderly in Buffalo City, Eastern Cape, South Africa between two racial-ethnic elderly groups. The specific objectives of the study were to explore the relationship between the socio-demographic characteristics and psychological well-being of the black (Xhosa) and white (English) elderly in Buffalo City, South Africa and second, to validate the relationship between psychological well-being and physical activity, loneliness, spirituality/religiosity as well as ageism among the sampled population. The set-point theory, selective optimisation compensation theory (SOCT) as well as the continuity theory were employed to guide the conduct of the study. Method: Psychological measuring instruments were deployed to collect data for the study from a total of 301 elderly respondents in retirement and private individual homes (191 isiXhosa and 110 English speaking elderly). Both simple random sampling (SRS) and purposive sampling procedures were used to select the respondents. The measuring instruments included the Ryff Scales of Psychological Well-being (RSPWB), Physical Activity Scale for the Elderly (PASE), Assessment of Spiritual and Religious Sentiments Scale (ASPIRES), University of California at Los Angeles (UCLA) Loneliness Scale, the Palmore Ageism Survey scale and a biographical questionnaire. Data was analysed using MANOVA, One-way variance analysis and regression coefficient. The racial differences logically influenced the selection of the respondents for the study. Results: The study revealed a significant statistical relationship between physical activity (PA) and psychological well-being of the elderly, regardless of the sociodemographic variables. PA showed a significant relationship with psychological wellbeing of the elderly. The study also discovered that loneliness correlates significantly with all four of the psychological well-being scales. It shows that the higher the levels of loneliness experienced by the elderly, socio-demographic variables controlled, the lower the levels of psychological well-being in terms of autonomy, environmental mastery, purpose in life, and self-acceptance. However, with the exception of the relationship between loneliness and purpose in life, ethnic affiliation moderates autonomy, environmental mastery and self-acceptance. English elderly constantly experienced higher levels of autonomy than the isiXhosa elderly do with an increase in loneliness. The study also found a positive relationship between ageism and psychological well- being. However, with low levels of ageism, the English elderly, in comparison with the isiXhosa elderly, is likely to show higher levels of autonomy. In addition, a significant statistical relationship between ageism and environmental mastery and purpose in life was found among the isiXhosa elderly. Although, with an increase in ageism, there is a slight increase in autonomy in both groups, the English elderly throughout showed higher levels of autonomy than the isiXhosa elderly showed. The study found a positive relationship between religiosity/spirituality and psychological well-being of the elderly. However, race could moderate the relationship between prayer fulfillment and psychological well-being at all four levels (autonomy, environmental mastery, purpose in life, and self-acceptance). With an increase in prayer fulfillment, the autonomy of the English elderly increases fairly quickly, while the autonomy of the isiXhosa elderly decreases slightly. Comparatively, the study found that isiXhosa elderly reported lower levels of psychological well-being than the English elderly. Conclusion/Recommendation: The study concludes that there is the need to develop a solid national data bases on needs and use of services, and process of ageing in order to access research data to assist planning, dissemination, delivery and evaluation of effective service delivery for the elderly population in South Africa, especially along racial divides.
- Full Text:
- Date Issued: 2017
- Authors: Ntozini, Anathi
- Date: 2017
- Subjects: Self-actualization (Psychology) in old age Older people -- Institutional care -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/6368 , vital:29593
- Description: Background: International research has clearly indicated that the world’s population is ageing: almost all countries in the world are experiencing a significant growth in the proportion of older persons in their population. This is also true for developing countries such as South Africa that are beginning to show signs and symptoms of an ageing population. Among Southern African Development Communities (SADC), South Africa has the highest number of ‘senior citizens’. Population reports indicate that the population of old people rose from paltry 2.8 million in 1996 to more than 4 million in 2011 and this is expected to skyrocket to seven million by 2030. In spite of the increasing number of senior citizens in socio-structural landscapes in South Africa, there is still lack of adequate, workable and effective policy frameworks for the wellbeing of the elderly. There is also paucity of psychological data of the elderly, especially along racial divides to determine whether the after-effects of apartheid still hold sway or not in post-apartheid South Africa. This study was conceived to investigate the psychological well-being of the elderly in Buffalo City, Eastern Cape, South Africa between two racial-ethnic elderly groups. The specific objectives of the study were to explore the relationship between the socio-demographic characteristics and psychological well-being of the black (Xhosa) and white (English) elderly in Buffalo City, South Africa and second, to validate the relationship between psychological well-being and physical activity, loneliness, spirituality/religiosity as well as ageism among the sampled population. The set-point theory, selective optimisation compensation theory (SOCT) as well as the continuity theory were employed to guide the conduct of the study. Method: Psychological measuring instruments were deployed to collect data for the study from a total of 301 elderly respondents in retirement and private individual homes (191 isiXhosa and 110 English speaking elderly). Both simple random sampling (SRS) and purposive sampling procedures were used to select the respondents. The measuring instruments included the Ryff Scales of Psychological Well-being (RSPWB), Physical Activity Scale for the Elderly (PASE), Assessment of Spiritual and Religious Sentiments Scale (ASPIRES), University of California at Los Angeles (UCLA) Loneliness Scale, the Palmore Ageism Survey scale and a biographical questionnaire. Data was analysed using MANOVA, One-way variance analysis and regression coefficient. The racial differences logically influenced the selection of the respondents for the study. Results: The study revealed a significant statistical relationship between physical activity (PA) and psychological well-being of the elderly, regardless of the sociodemographic variables. PA showed a significant relationship with psychological wellbeing of the elderly. The study also discovered that loneliness correlates significantly with all four of the psychological well-being scales. It shows that the higher the levels of loneliness experienced by the elderly, socio-demographic variables controlled, the lower the levels of psychological well-being in terms of autonomy, environmental mastery, purpose in life, and self-acceptance. However, with the exception of the relationship between loneliness and purpose in life, ethnic affiliation moderates autonomy, environmental mastery and self-acceptance. English elderly constantly experienced higher levels of autonomy than the isiXhosa elderly do with an increase in loneliness. The study also found a positive relationship between ageism and psychological well- being. However, with low levels of ageism, the English elderly, in comparison with the isiXhosa elderly, is likely to show higher levels of autonomy. In addition, a significant statistical relationship between ageism and environmental mastery and purpose in life was found among the isiXhosa elderly. Although, with an increase in ageism, there is a slight increase in autonomy in both groups, the English elderly throughout showed higher levels of autonomy than the isiXhosa elderly showed. The study found a positive relationship between religiosity/spirituality and psychological well-being of the elderly. However, race could moderate the relationship between prayer fulfillment and psychological well-being at all four levels (autonomy, environmental mastery, purpose in life, and self-acceptance). With an increase in prayer fulfillment, the autonomy of the English elderly increases fairly quickly, while the autonomy of the isiXhosa elderly decreases slightly. Comparatively, the study found that isiXhosa elderly reported lower levels of psychological well-being than the English elderly. Conclusion/Recommendation: The study concludes that there is the need to develop a solid national data bases on needs and use of services, and process of ageing in order to access research data to assist planning, dissemination, delivery and evaluation of effective service delivery for the elderly population in South Africa, especially along racial divides.
- Full Text:
- Date Issued: 2017
Psychosocial effects of court verdicts on children as rape victims : a case study of Queenstown area, Eastern Cape, South Africa
- Lupuwana, Vuyokazi Phumza Pearl
- Authors: Lupuwana, Vuyokazi Phumza Pearl
- Date: 2017
- Subjects: Rape victims -- South Africa -- Eastern Cape Rape victims -- Services for -- South Africa -- Eastern Cape Victims of crimes -- Legal status, laws, etc
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9821 , vital:35015
- Description: The motivation for this study originated from the problem of children who are being neglected after they have given evidence in the court of law. The researcher also noticed that when children were giving evidence, some were still showing signs of trauma and were crying throughout the proceedings. The researcher became aware that most of the children were never referred to social service professionals for counselling and after care services. The goal of the research was to explore the psycho-social effects of court verdicts on children as rape victims. The aim of the study was to determine the effects, challenges, emotional development and consequences, experience and reactions of rape and sexually assaulted child victims after the court verdict has been adjudicated. This was a case study of the Queenstown Area, Eastern Cape, South Africa. The purpose was to identify gaps as there are minimal services rendered to rape victims after the court verdict has been adjudicated in the South African context so as to formulate strategies that can be framed in order to work effectively with the victims and their immediate families. In order to reach the research goal, the following objectives were presented: To examine the after-effects of rape to children as victims of rape. To investigate the challenges the victims of rape are facing in their communities. To investigate the impact of giving evidence in the court of law by children who are victims of rape. To examine the after-effects of court verdicts on children who are victims of rape. To establish the kind of support provided to children by social networks after they have given evidence in the court of law. To investigate the kind of support provided by social service as well as legal professionals to children as victims of rape. In order to meet the objectives of the study, interviews were conducted to 30 victims of rape (both boys and girls) and data were analyzed according to the qualitative data – analysis procedures. The researcher also conducted literature review on core concepts (such as victims, rape and the legal perspectives of rape) pertaining to the topic under study in order to refer the findings of the study to literature. The researcher utilized the grounded theory research design. The research domain where the interviews took place was at the Queenstown Area under the Department of Justice and Constitutional Development magistrate jurisdiction (McBride, Lesseyton, Mlungisi Township, Komani Township, Molteno, Sterkstroom Dordrecht and Indwe). In this study, 30 Xhosa speaking children of different ages, gender, educational standards, socio-economic backgrounds as well as those who suffered different types of rape, as defined by the Sexual Related Matters Act 32 of 2007; they were all interviewed through use of a semi-structured interview schedule. The respondents were selected with the help of the Department of Justice and Constitutional development as well as South African Police Services (SAPS) based on their suitability to provide information rich data. The interviews were audio-taped and transcribed verbatim. The data were analyzed according to the grounded theory analysis procedures. The following conclusions regarding the study were made: There is lack of implementation of Children’s Rights by professionals working with victims of rape. Children were never informed about the sentences imposed to the offenders. Focus group (professionals) participants acknowledged the fact that there is no compensation given to victims in a South African court of Law. Registering the offender is not benefitting the victim as the offender is sometimes appealing the judgement and sentencing. There are no adequate services rendered by social services professionals to rape victims, especially children. In most cases, they were never referred to any professionals for services following the rape incident. There are no aftercare services for children after giving evidence in the court of law. Children as victims of rape as well as their immediate families must be continuously referred to specialist to get therapeutic services. There is lack of forensic professionals working with children as victims of rape in Eastern Cape. Children as victims of rape are secondary victimized by relatives of the perpetrators after the sentence has been adjudicated. When there is no support provided by family members, victims are more likely to drop out of school. Members of the community lack information on the concept rape, and knowledge that everybody in South Africa can be raped.
- Full Text:
- Date Issued: 2017
- Authors: Lupuwana, Vuyokazi Phumza Pearl
- Date: 2017
- Subjects: Rape victims -- South Africa -- Eastern Cape Rape victims -- Services for -- South Africa -- Eastern Cape Victims of crimes -- Legal status, laws, etc
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9821 , vital:35015
- Description: The motivation for this study originated from the problem of children who are being neglected after they have given evidence in the court of law. The researcher also noticed that when children were giving evidence, some were still showing signs of trauma and were crying throughout the proceedings. The researcher became aware that most of the children were never referred to social service professionals for counselling and after care services. The goal of the research was to explore the psycho-social effects of court verdicts on children as rape victims. The aim of the study was to determine the effects, challenges, emotional development and consequences, experience and reactions of rape and sexually assaulted child victims after the court verdict has been adjudicated. This was a case study of the Queenstown Area, Eastern Cape, South Africa. The purpose was to identify gaps as there are minimal services rendered to rape victims after the court verdict has been adjudicated in the South African context so as to formulate strategies that can be framed in order to work effectively with the victims and their immediate families. In order to reach the research goal, the following objectives were presented: To examine the after-effects of rape to children as victims of rape. To investigate the challenges the victims of rape are facing in their communities. To investigate the impact of giving evidence in the court of law by children who are victims of rape. To examine the after-effects of court verdicts on children who are victims of rape. To establish the kind of support provided to children by social networks after they have given evidence in the court of law. To investigate the kind of support provided by social service as well as legal professionals to children as victims of rape. In order to meet the objectives of the study, interviews were conducted to 30 victims of rape (both boys and girls) and data were analyzed according to the qualitative data – analysis procedures. The researcher also conducted literature review on core concepts (such as victims, rape and the legal perspectives of rape) pertaining to the topic under study in order to refer the findings of the study to literature. The researcher utilized the grounded theory research design. The research domain where the interviews took place was at the Queenstown Area under the Department of Justice and Constitutional Development magistrate jurisdiction (McBride, Lesseyton, Mlungisi Township, Komani Township, Molteno, Sterkstroom Dordrecht and Indwe). In this study, 30 Xhosa speaking children of different ages, gender, educational standards, socio-economic backgrounds as well as those who suffered different types of rape, as defined by the Sexual Related Matters Act 32 of 2007; they were all interviewed through use of a semi-structured interview schedule. The respondents were selected with the help of the Department of Justice and Constitutional development as well as South African Police Services (SAPS) based on their suitability to provide information rich data. The interviews were audio-taped and transcribed verbatim. The data were analyzed according to the grounded theory analysis procedures. The following conclusions regarding the study were made: There is lack of implementation of Children’s Rights by professionals working with victims of rape. Children were never informed about the sentences imposed to the offenders. Focus group (professionals) participants acknowledged the fact that there is no compensation given to victims in a South African court of Law. Registering the offender is not benefitting the victim as the offender is sometimes appealing the judgement and sentencing. There are no adequate services rendered by social services professionals to rape victims, especially children. In most cases, they were never referred to any professionals for services following the rape incident. There are no aftercare services for children after giving evidence in the court of law. Children as victims of rape as well as their immediate families must be continuously referred to specialist to get therapeutic services. There is lack of forensic professionals working with children as victims of rape in Eastern Cape. Children as victims of rape are secondary victimized by relatives of the perpetrators after the sentence has been adjudicated. When there is no support provided by family members, victims are more likely to drop out of school. Members of the community lack information on the concept rape, and knowledge that everybody in South Africa can be raped.
- Full Text:
- Date Issued: 2017
Public procurement reforms in Ghana: impact on the growth of the local construction industry
- Authors: Amoah, Christopher
- Date: 2017
- Subjects: Government purchasing -- Ghana Construction industry -- Ghana
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15862 , vital:28285
- Description: Public procurement reform has become a modern phenomenon where various countries are reforming their procurement systems either to make the systems more efficient, transparent, achieve value for money, reduce or eliminate corrupt activities, to meet the requirements of donor countries or to make the system meet the international standards. Some countries also use public procurement reform as a policy tool to address socio-economic issues including the promotion of local sectors and disadvantaged groups. Ghana has not remained stagnant in this regard but has followed suit in reforming its procurement systems to address the weaknesses of the past procurement practices. However, the effectiveness of these reforms in promoting the local construction firms has not been investigated. This research therefore, investigated how the various procurement reforms instituted by the government of Ghana have impacted on the growth of the Ghanaian construction sector. A comprehensive review of the related literature revealed that there is a relationship between public procurement reforms and the growth of the local sectors as various governments in the past have managed to use their procurements levers as policy tools to address the imbalances in the socio-economic development of their citizens. A phenomenological (qualitative) research approach was adopted for this study. Accra, the capital of Ghana was chosen based on its strategic position and also because of massive construction activities currently taking place in the city. Again, many construction firms are also registered and operating in this city. The research instrument used is the interview guide made of both tick box and open ended questions. Other sources of data included archival records such as contracts awarded, the current public procurement regulations, and manuals. It was concluded after the analysis of the findings that, even though public procurement reforms have brought about improved procurement practices, the reforms have failed to have a positive impact on the growth of the local construction industry. The implication is that, the construction industry in Ghana is still dominated by foreign firms executing major government projects to the detriment of the local construction firms thereby stifling their growth. The findings also revealed that local contractors only executive minor works devoid of complexities and mainly engaged as subcontractors by foreign firms on major government projects. The findings also revealed that government has so far not instituted any radical protective laws in the procurement systems to protect the local construction firms. The research has produced a tender evaluation template with protective mechanisms such as awarding points to bidders during the tender evaluation process. The research has also produced tender evaluation formulas for calculating points for bidders and how the successful bidder is arrived at. The study provides recommendations to all stakeholders in the Ghanaian construction industry and proposes that the evaluation criteria produced by this study be used in the public procurement system to help grow the indigenous construction industry.
- Full Text:
- Date Issued: 2017
- Authors: Amoah, Christopher
- Date: 2017
- Subjects: Government purchasing -- Ghana Construction industry -- Ghana
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15862 , vital:28285
- Description: Public procurement reform has become a modern phenomenon where various countries are reforming their procurement systems either to make the systems more efficient, transparent, achieve value for money, reduce or eliminate corrupt activities, to meet the requirements of donor countries or to make the system meet the international standards. Some countries also use public procurement reform as a policy tool to address socio-economic issues including the promotion of local sectors and disadvantaged groups. Ghana has not remained stagnant in this regard but has followed suit in reforming its procurement systems to address the weaknesses of the past procurement practices. However, the effectiveness of these reforms in promoting the local construction firms has not been investigated. This research therefore, investigated how the various procurement reforms instituted by the government of Ghana have impacted on the growth of the Ghanaian construction sector. A comprehensive review of the related literature revealed that there is a relationship between public procurement reforms and the growth of the local sectors as various governments in the past have managed to use their procurements levers as policy tools to address the imbalances in the socio-economic development of their citizens. A phenomenological (qualitative) research approach was adopted for this study. Accra, the capital of Ghana was chosen based on its strategic position and also because of massive construction activities currently taking place in the city. Again, many construction firms are also registered and operating in this city. The research instrument used is the interview guide made of both tick box and open ended questions. Other sources of data included archival records such as contracts awarded, the current public procurement regulations, and manuals. It was concluded after the analysis of the findings that, even though public procurement reforms have brought about improved procurement practices, the reforms have failed to have a positive impact on the growth of the local construction industry. The implication is that, the construction industry in Ghana is still dominated by foreign firms executing major government projects to the detriment of the local construction firms thereby stifling their growth. The findings also revealed that local contractors only executive minor works devoid of complexities and mainly engaged as subcontractors by foreign firms on major government projects. The findings also revealed that government has so far not instituted any radical protective laws in the procurement systems to protect the local construction firms. The research has produced a tender evaluation template with protective mechanisms such as awarding points to bidders during the tender evaluation process. The research has also produced tender evaluation formulas for calculating points for bidders and how the successful bidder is arrived at. The study provides recommendations to all stakeholders in the Ghanaian construction industry and proposes that the evaluation criteria produced by this study be used in the public procurement system to help grow the indigenous construction industry.
- Full Text:
- Date Issued: 2017
Pursuing socio-economic rights in post-apartheid South Africa : a case study of the Buffalo City metropolitan municipality, Eastern Cape province
- Authors: Makapela, Sicelo Leonard
- Date: 2017
- Subjects: Civil rights -- South Africa -- Eastern Cape Human rights -- South Africa -- Eastern Cape Social justice -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12881 , vital:39387
- Description: The overall aim of this research was to investigate the extent to which a wide range of socio-economic rights such as housing, education, healthcare, water, sanitation, electricity, food security, social security and the right to work are enjoyed in the Buffalo City Metropolitan Municipality in the Eastern Cape Province. South Africa has nine provinces and the Eastern Cape is considered as one of the poorest with high levels of the triad of poverty, inequality and unemployment. The study used a rights-based approach (RBA) which examines the quality of human life from a rights perspective. Survey questionnaires were distributed to a sample of 500 respondents who were selected through a cluster random sample and six in-depth interviews were further conducted with government officials who were selected through purposive sampling. The study was guided by four main objectives and the first sought to explore citizens’ perceptions of the intersection between service delivery protests and socio-economic rights. The findings revealed that the majority of the survey respondents had no sense of the intersection between service delivery and socio-economic rights. Many did not know anything about the South African Constitution and could not relate to its content. Most critically, the majority did not know the socio-economic rights enshrined in the Constitution. The majority was more comfortable with the phrase service delivery over socio-economic rights and this was so because the former was the most commonly used by the politicians, the media and community leaders. In short, the majority of respondents had a poor understanding of the Constitution and socio-economic rights. On the contrary, the in-depth interview participants showed an excellent knowledge of the Constitution and its socio-economic rights content and saw a strong intersection between service delivery protests and socio-economic rights. Both the questionnaire respondents and the in-depth interview participants regarded employment as the most import demand that the government should address urgently. The second objective sought to describe the extent to which the government has fulfilled various rights. Caution was needed in interpreting this objective. While the majority of the questionnaire respondents had rated the government’s efforts negatively in many socio-economic rights, however, further probing revealed that the government had done well. The questionnaire respondents continued to rate the government negatively even in instances where they indicated that the government had done well. Thus, the findings revealed mixed results that the government had done pretty well in some, not so well in others and very bad in some cases. The in-depth interview participants, on the contrary, were all positive about the government’s fulfilment of various socio-economic rights and rated it favourably. The findings, therefore, dismiss the views shared by the majority of the questionnaire respondents that the government had fulfilled various socio-economic rights to a smaller extent and equally challenge the idea that the government was highly successful in all its efforts to fulfil various socio-economic rights. The evidence shows that the government was successful in some and not so in others. Third, the study revealed a number of factors affecting the enjoyment of socio-economic rights in the Buffalo City Metropolitan Municipality including lack of democracy, lack of human rights knowledge, poor performance by Ward Councillors etc. Finally, the study identified a number of challenges which inhibited the enjoyment of socio-economic rights and these included corruption, crime, lack of participation by the poor in decision-making, alienation of the masses, but the most single serious threat identified by both the questionnaire respondents and in-depth interview participants was the rampant corruption. Most disturbingly, the respondents did not know what to do, how or where to go to claim their rights. This was revealed by the majority who pointed out that they have never approached the government, Constitutional Court or any court and don’t talk to their Ward Councillors about socio-economic rights. Moreover, they have never used the rights language during service delivery protests. All these point to the significant lack of knowledge about rights despite being familiar with the phrase (amalungel’ethu), a Xhosa expression for our rights. Thus, the questionnaire respondents were simply passive citizens and were not doing enough to pursue their socio-economic rights. Since corruption has been indicated as a major challenge affecting the enjoyment socio-economic rights, it is therefore recommended that alternative institutions should play a critical role not only in exposing corruption but the state should prosecute those found guilty of corruption especially on issues that affect the enjoyment of socio-economic rights. It is also recommended that there should be a dialogue between community representatives and the citizens to talk about socio-economic rights during community meetings. The study further, recommends that human rights education should be incorporated in school curricula, especially in secondary and tertiary institutions. Finally, it is recommended that the development of a comprehensive tool for monitoring and evaluating socio-economic rights should be put in place. At present, no such tool exists.
- Full Text:
- Date Issued: 2017
- Authors: Makapela, Sicelo Leonard
- Date: 2017
- Subjects: Civil rights -- South Africa -- Eastern Cape Human rights -- South Africa -- Eastern Cape Social justice -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12881 , vital:39387
- Description: The overall aim of this research was to investigate the extent to which a wide range of socio-economic rights such as housing, education, healthcare, water, sanitation, electricity, food security, social security and the right to work are enjoyed in the Buffalo City Metropolitan Municipality in the Eastern Cape Province. South Africa has nine provinces and the Eastern Cape is considered as one of the poorest with high levels of the triad of poverty, inequality and unemployment. The study used a rights-based approach (RBA) which examines the quality of human life from a rights perspective. Survey questionnaires were distributed to a sample of 500 respondents who were selected through a cluster random sample and six in-depth interviews were further conducted with government officials who were selected through purposive sampling. The study was guided by four main objectives and the first sought to explore citizens’ perceptions of the intersection between service delivery protests and socio-economic rights. The findings revealed that the majority of the survey respondents had no sense of the intersection between service delivery and socio-economic rights. Many did not know anything about the South African Constitution and could not relate to its content. Most critically, the majority did not know the socio-economic rights enshrined in the Constitution. The majority was more comfortable with the phrase service delivery over socio-economic rights and this was so because the former was the most commonly used by the politicians, the media and community leaders. In short, the majority of respondents had a poor understanding of the Constitution and socio-economic rights. On the contrary, the in-depth interview participants showed an excellent knowledge of the Constitution and its socio-economic rights content and saw a strong intersection between service delivery protests and socio-economic rights. Both the questionnaire respondents and the in-depth interview participants regarded employment as the most import demand that the government should address urgently. The second objective sought to describe the extent to which the government has fulfilled various rights. Caution was needed in interpreting this objective. While the majority of the questionnaire respondents had rated the government’s efforts negatively in many socio-economic rights, however, further probing revealed that the government had done well. The questionnaire respondents continued to rate the government negatively even in instances where they indicated that the government had done well. Thus, the findings revealed mixed results that the government had done pretty well in some, not so well in others and very bad in some cases. The in-depth interview participants, on the contrary, were all positive about the government’s fulfilment of various socio-economic rights and rated it favourably. The findings, therefore, dismiss the views shared by the majority of the questionnaire respondents that the government had fulfilled various socio-economic rights to a smaller extent and equally challenge the idea that the government was highly successful in all its efforts to fulfil various socio-economic rights. The evidence shows that the government was successful in some and not so in others. Third, the study revealed a number of factors affecting the enjoyment of socio-economic rights in the Buffalo City Metropolitan Municipality including lack of democracy, lack of human rights knowledge, poor performance by Ward Councillors etc. Finally, the study identified a number of challenges which inhibited the enjoyment of socio-economic rights and these included corruption, crime, lack of participation by the poor in decision-making, alienation of the masses, but the most single serious threat identified by both the questionnaire respondents and in-depth interview participants was the rampant corruption. Most disturbingly, the respondents did not know what to do, how or where to go to claim their rights. This was revealed by the majority who pointed out that they have never approached the government, Constitutional Court or any court and don’t talk to their Ward Councillors about socio-economic rights. Moreover, they have never used the rights language during service delivery protests. All these point to the significant lack of knowledge about rights despite being familiar with the phrase (amalungel’ethu), a Xhosa expression for our rights. Thus, the questionnaire respondents were simply passive citizens and were not doing enough to pursue their socio-economic rights. Since corruption has been indicated as a major challenge affecting the enjoyment socio-economic rights, it is therefore recommended that alternative institutions should play a critical role not only in exposing corruption but the state should prosecute those found guilty of corruption especially on issues that affect the enjoyment of socio-economic rights. It is also recommended that there should be a dialogue between community representatives and the citizens to talk about socio-economic rights during community meetings. The study further, recommends that human rights education should be incorporated in school curricula, especially in secondary and tertiary institutions. Finally, it is recommended that the development of a comprehensive tool for monitoring and evaluating socio-economic rights should be put in place. At present, no such tool exists.
- Full Text:
- Date Issued: 2017
Pushing the bounds of possibility: South African academics narrate their experiences of having agency to effect transformation
- Authors: Idahosa, Grace Ese-Osa
- Date: 2017
- Subjects: Education, Higher -- South Africa , Education, Higher -- Social aspects -- South Africa , Educational change -- South Africa , Higher education and state -- South Africa , Rhodes University
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/5845 , vital:20981
- Description: Over 20 years after the first democratic elections, the institutional cultures and structures of many South African universities remain un-transformed; they are embedded with racist and sexist discourses and attitudes that allow for the marginalisation and exclusion of students and staff (Department of Education 2008; Soudien 2010; van Wyk and Alexander 2010; Akoojee and Nkomo 2007; Hemson and Singh 2010). In order to effect change, research has noted the importance of leadership and staff involvement in the transformation process (Van-Der Westhuizen 2006; Portnoi 2009; Niemann 2010; Viljoen and Rothmann 2002). These studies argue that both leaders and staff members must be interested, and actively involved in, the transformation process. This suggests that the extent to which leaders and individual staff members have agency to effect transformatory practices determines the success of transformation policies. But what motivates this interest in transformation? While a number of studies have focused on the imperative to transform, few studies have focused on the role of individual agency in the transformation process. After all the world and in some ways structural properties are given to us and at the same time ‘actively constituted by us’ (van Manen 1997, XI). Drawing on interviews with academic staff members at one university in South Africa, this study uses a hermeneutic phenomenological approach to understand the nature of having agency to enable transformation drawing on the experiences of academic staff members. In the context of studies on the agency- structure divide and the need for a structural and cultural change in universities in South Africa, the project aimed to find out how transformation happens, when it does happen. I was interested in how individual agents are able to use their agency to ensure transformation amid limiting and rigid structures and cultures in the university. Given the fact that structures are only revealed in human action, the individual experience of transformation at once gives insight into the dominant structures, the social context and how their capacity to act was deployed to enable a change in such structures - at least in their own experience and understanding. This may help our understanding of transformation and what is needed to effect the transformation of deeply embedded apartheid legacies in university structures and cultures. This study aimed to reveal moments at which individuals embedded in what have been identified as rigid structures and cultures perceive themselves as having had the agency to interrupt and transform them despite their rigid nature. The study was interested in what characterises these moments and what individual and institutional contexts make them more or less possible/likely.
- Full Text:
- Date Issued: 2017
- Authors: Idahosa, Grace Ese-Osa
- Date: 2017
- Subjects: Education, Higher -- South Africa , Education, Higher -- Social aspects -- South Africa , Educational change -- South Africa , Higher education and state -- South Africa , Rhodes University
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/5845 , vital:20981
- Description: Over 20 years after the first democratic elections, the institutional cultures and structures of many South African universities remain un-transformed; they are embedded with racist and sexist discourses and attitudes that allow for the marginalisation and exclusion of students and staff (Department of Education 2008; Soudien 2010; van Wyk and Alexander 2010; Akoojee and Nkomo 2007; Hemson and Singh 2010). In order to effect change, research has noted the importance of leadership and staff involvement in the transformation process (Van-Der Westhuizen 2006; Portnoi 2009; Niemann 2010; Viljoen and Rothmann 2002). These studies argue that both leaders and staff members must be interested, and actively involved in, the transformation process. This suggests that the extent to which leaders and individual staff members have agency to effect transformatory practices determines the success of transformation policies. But what motivates this interest in transformation? While a number of studies have focused on the imperative to transform, few studies have focused on the role of individual agency in the transformation process. After all the world and in some ways structural properties are given to us and at the same time ‘actively constituted by us’ (van Manen 1997, XI). Drawing on interviews with academic staff members at one university in South Africa, this study uses a hermeneutic phenomenological approach to understand the nature of having agency to enable transformation drawing on the experiences of academic staff members. In the context of studies on the agency- structure divide and the need for a structural and cultural change in universities in South Africa, the project aimed to find out how transformation happens, when it does happen. I was interested in how individual agents are able to use their agency to ensure transformation amid limiting and rigid structures and cultures in the university. Given the fact that structures are only revealed in human action, the individual experience of transformation at once gives insight into the dominant structures, the social context and how their capacity to act was deployed to enable a change in such structures - at least in their own experience and understanding. This may help our understanding of transformation and what is needed to effect the transformation of deeply embedded apartheid legacies in university structures and cultures. This study aimed to reveal moments at which individuals embedded in what have been identified as rigid structures and cultures perceive themselves as having had the agency to interrupt and transform them despite their rigid nature. The study was interested in what characterises these moments and what individual and institutional contexts make them more or less possible/likely.
- Full Text:
- Date Issued: 2017
Reform-based approaches in the learning and teaching for conceptual understanding of calculus for diploma studies at south african university
- Authors: Coetzee, Johanna
- Date: 2017
- Subjects: Calculus Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4959 , vital:28878
- Description: This research tested whether Reform-Based Approaches (RBAs) in the learning and teaching of calculus could lead to improved conceptual understanding. The study adopted positivistic paradigm, quantitative approach and pre- and post-test in a quasi-experimental design. The theoretical framework was Constructivism. The interventions were grounded on learner-centred RBAs including Interactive Engagement (IE), Peer Discussion (PD) and Good Questions (GQ). The experimental group comprised 119 volunteering students from a population of 461 registered for Mathematics as a service subject for the National Diploma (ND) in science or engineering at a South African university. Those not in the experimental group were taught through teacher-centred traditional approaches which have been the norm. However, only 71 out of those in the traditionally taught cohort volunteered to write both Pre- and Post-tests. As such, the total number of subjects in the study was 190, i.e., 119 from the Reform-Based cohort and 71 from the Traditional cohort. The instrument, the Calculus Concept Inventory for Technicians (CCIT), consisted of 19 questions on functions, differentiation and integration. Based on a pilot test, the instrument was improved. The Reform-Based cohort did not receive any participation reward and test scores did not contribute to promotion scores. The students wrote Pre-tests in the second week after commencement of lectures and Post-tests during the last week of lectures. The data were analysed using various statistical tools, tests and measures such as Chi-squares, Student t-tests, Pearson’s Product Moment correlation, Cronbach alpha, KR-20, the Difficulty Index, and Item Discrimination Point Biserial Index (PBI). The raw gain and normalised gains were also employed in data analyses. The main finding of this study was that RBA made a significant impact on the conceptual understanding of calculus of the experimental group. The gain achieved by the experimental group was in a low range and corresponded to the low use of IE (25% of contact time). A combination of RBA with Traditional teaching is recommended. Also, RBA will be most successfully introduced if supplemented and complemented through supportive environments.
- Full Text:
- Date Issued: 2017
- Authors: Coetzee, Johanna
- Date: 2017
- Subjects: Calculus Mathematics -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4959 , vital:28878
- Description: This research tested whether Reform-Based Approaches (RBAs) in the learning and teaching of calculus could lead to improved conceptual understanding. The study adopted positivistic paradigm, quantitative approach and pre- and post-test in a quasi-experimental design. The theoretical framework was Constructivism. The interventions were grounded on learner-centred RBAs including Interactive Engagement (IE), Peer Discussion (PD) and Good Questions (GQ). The experimental group comprised 119 volunteering students from a population of 461 registered for Mathematics as a service subject for the National Diploma (ND) in science or engineering at a South African university. Those not in the experimental group were taught through teacher-centred traditional approaches which have been the norm. However, only 71 out of those in the traditionally taught cohort volunteered to write both Pre- and Post-tests. As such, the total number of subjects in the study was 190, i.e., 119 from the Reform-Based cohort and 71 from the Traditional cohort. The instrument, the Calculus Concept Inventory for Technicians (CCIT), consisted of 19 questions on functions, differentiation and integration. Based on a pilot test, the instrument was improved. The Reform-Based cohort did not receive any participation reward and test scores did not contribute to promotion scores. The students wrote Pre-tests in the second week after commencement of lectures and Post-tests during the last week of lectures. The data were analysed using various statistical tools, tests and measures such as Chi-squares, Student t-tests, Pearson’s Product Moment correlation, Cronbach alpha, KR-20, the Difficulty Index, and Item Discrimination Point Biserial Index (PBI). The raw gain and normalised gains were also employed in data analyses. The main finding of this study was that RBA made a significant impact on the conceptual understanding of calculus of the experimental group. The gain achieved by the experimental group was in a low range and corresponded to the low use of IE (25% of contact time). A combination of RBA with Traditional teaching is recommended. Also, RBA will be most successfully introduced if supplemented and complemented through supportive environments.
- Full Text:
- Date Issued: 2017
Removal rate of endocrine disruptors (phthalates and phenolic compounds) in effluents of selected wastewater treatment plants operated under different treatment technologies in the Eastern Cape, South Africa
- Authors: Salaudeen, Taofeek Gbenga
- Date: 2017
- Subjects: Water -- Purification Phenols
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8552 , vital:33113
- Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
- Full Text:
- Date Issued: 2017
- Authors: Salaudeen, Taofeek Gbenga
- Date: 2017
- Subjects: Water -- Purification Phenols
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8552 , vital:33113
- Description: The presence of phthalate esters (PAEs) and certain phenolic compounds widely known as endocrine disruptors in environmental waters such as treated wastewaters constitutes health hazard to human and aquatic lives. Unfortunately, wastewater treatment plants (WWTPs) only partially remove these synthetic chemical compounds from wastewater. In order to forestall the health challenge faced by rural dwellers, which rely on surface water for their daily needs, the present study embarked on investigating these endocrine disruptors in Municipal wastewater in the Amathole and Buffalo Districts in the Eastern Cape, South Africa and their removal rate by different WWTP technologies. One WWTP each from Adelaide, Alice, Bedford, Berlin and Seymour, using activated sludge (AS), trickling filter (TF), and oxidation pond (OP) technology were randomly selected. Some physicochemical parameters of these wastewaters were determined on-site using standard methods and the extraction method for endocrine disrupting chemicals (EDCs) in water was validated using solid phase extraction (SPE). Extracts were analysed using gas chromatography-mass spectrometer (GC-MS). Nine phenolic compounds; phenol (PH), 2-chlorophenol (2-CP), 2,4-dimethylphenol (2,4-DMP), 2,4-dichlorophenol (2,4-DCP), 4-chloro-3-methylphenol (4-C-3MP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP) and six priority PAEs namely; dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethyl hexyl) phthalate (DEHP), and di-n-octyl phthalate (DOP) were the investigated EDCs. PAEs were extracted from dried sludge samples in an ultrasonic bath using dichloromethane. Some physicochemical parameters of the wastewater assessed revealed that treatment processes of AS, TF, and OP reduced turbidity, total suspended solids (TSS), total dissolved solids (TDS), and electrical conductivity (EC) while dissolved oxygen (DO) was increased. There was no significant influence on temperature and pH across the sampling points. Except for turbidity, the quality of effluent released mostly falls within South Africa standard limits for domestic and recreational water. The nine phenolic compounds were detected across the sampling points for all the WWTPs at different frequencies. The prominent phenolic compounds were 2-NP, 4-C-3MP, PCP, and 2,4-DMP with concentrations ranging from 3.3 (2,4-DMP) – 83.0 μgL-1 (4-C-3MP) in the influents. However, their concentrations in the effluents and receiving water bodies were below tolerable limits of 5 μgL-1 set by the US Environmental Protection Agency (USEPA) and the European Union (EU) for domestic use. The removal capacities of the WWTPs varied between 33 and 96 percent. The six PAEs were detected in all water samples from all the WWTPs. DBP was the most abundant compound in all the sampling points and sometimes DEHP in some receiving waters. The maximum detection for DBP in influent, effluent, downstream and sludge were 2,488 μgL-1 (Alice), 26.47 μgL-1 (Adelaide), 115.3 μgL-1 (Seymour) and 1,249 μg/g dw (Alice), respectively. DEHP was the highest detected PAE in the upstream 17.53 μgL-1 (Seymour). There was a notable reduction of all PAEs in the final effluent with a removal efficiency which varied as much as 61.9 – 99.5 percent except for AS in Seymour which operated a single tank system (27.3 - 93.7 percent). Removal mechanisms continued more on adsorption on settling particles and sludge than biodegradation as this study found a high positive correlation between TSS, turbidity and PAEs removal. The concentrations of PAEs detected in the receiving waters were above 1.3 and 3μgL-1 limit standard set by the EU and USEPA, respectively for DEHP in surface water. Similarly, the average concentrations of DBP, BBP, DEHP and DOP which vary as much as 25.97 (BBP) – 1249 μg/g d.w (DBP) in sludge samples were above EU legislation of 100 μg/g d.w. for agricultural use. AS technology, showed a better performance in the removal of PAEs (77 – 99 percent), followed by TF (76 – 98 percent) and OP (61 – 98 percent). In conclusion, the PAE concentration in the WWTP effluents impacted negatively on the receiving water bodies and sewage sludge unlike the phenolic compounds that were notably reduced below the acceptable limits. Perhaps, due to the meagre amounts of the phenolic compounds that was detected entering the WWTPs. In order to avert the potential health risk to aquatic organisms’ and rural dwellers, it is exigent that constituted authorities gather more information on micro-pollutants in the environment as a basis for regulations on the use of these dangerous chemicals in industries.
- Full Text:
- Date Issued: 2017