Fabrication of a photocatalytic PAN supported C-TiO2-CFA nanocomposite for use in water treatment
- Authors: Mpelane, Amkelwa
- Date: 2020
- Subjects: Photocatalysis
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/18744 , vital:42729
- Description: The goal of this study was to fabricate a visible light responsive composite of C-TiO2-CFA. The prepared nanocomposite (C-TiO2-CFA) was immobilized on poly(acrylonitrile) membrane to address the drawback of recovering the nanosized photocatalyst from water after photodegradation experiments. The C-TiO2-CFA nanocomposites were fabricated using a modified sol-gel method, while the C-TiO2-CFA/PAN membranes were prepared via the phase inversion technique. The nanocomposites were fully characterized using FTIR, XRD, SEM-EDX, TEM, DRS, and BET surface area analysis. The prepared C-TiO2-CFA/PAN membranes were evaluated in the photodegradation of methyl orange and the golden yellow dyes, as well as the photoreduction of lead and cadmium heavy metals in synthetic wastewater. UV-Visible spectroscopy was used to follow the changes in the concentration of organic dyes, while inductively coupled plasma optical emission spectroscopy was used to follow changes in the concentration of the heavy metals. FTIR analysis confirmed the presence of functional groups expected on the prepared C-TiO2- CFA/PAN membranes and EDX analysis accounted for the elements expected. The prepared membranes all exhibited an asymmetric structure as depicted by cross-sectional view study via SEM analysis. TEM and SEM analyses revealed that the prepared C-TiO2-CFA nanocomposite was roughly spherical in shape with an estimate particle size of 10.94 nm according to TEM and 11.62 nm according to XRD using Scherrer equation. The incorporation of carbon into the lattice structure of titanium dioxide resulted in a reduction in bandgap from 3.19 eV to 2.78 eV through introduction of mid-band states, allowing visible light utilization. The best nanocomposite was obtained by doping TiO2 with 4% carbon and having a C-TiO2 to CFA ratio of 4:1 respectively. The C-TiO2-CFA nanocomposite exhibits a crystalline structure with a mixture of rutile and anatase phases. The parameters investigated in the evaluation of photocatalytic performance of C-TiO2- CFA/PAN were effect of photocatalyst load on PAN membrane, initial dye concentration, pH and light source in the activation of photocatalyst. For both dyes (methyl arrange and golden yellow), it was observed that photodegradation efficiencies increased with an increase in catalyst load. In the photodegradation of MO and GY using the membrane with 1% C-TiO2- CFA, removal efficiencies of 73.3% and 59.99% were attained respectively, while the membrane with 2% C-TiO2-CFA achieved MO and GY photodegradation efficiencies of 99.8% and 99.2% respectively. Photodegradation efficiencies of MO and GY were observed to decrease with an increase in dye concentration. Low pH (3) was observed to favour the photodegradation of MO and GY azo dyes. Photodegradation efficiencies of 99.8% and 99.2% were attained where obtained at lower MO and GY initial concentration. The modified photocatalyst (C-TiO2-CFA/PAN) exhibited better photoactivity under sunlight irradiation compared to strict UV light irradiation. Evidently, the C-TiO2-CFA/PAN membranes can be 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper utilized as a sustainable and stable photocatalyst to efficiently eliminate methyl orange and golden yellow dyes. A PAN membrane with 2 wt% C-TiO2-CFA revealed enhanced cadmium and lead removal efficiencies in comparison to PAN membranes with 1 wt% and 1.5% C-TiO2-CFA. A Cd2+ removal efficiency of 95% was obtained using 2 wt% C-TiO2-CFA/PAN nanocomposite membranes. Cadmium removal efficiencies of 92.5% and 91% were obtained using the 1.5 wt% and 1 wt% C-TiO2-CFA/PAN nanocomposite membranes. A lead removal efficiency of 97% was obtained using PAN membrane with 2 wt% C-TiO2-CFA. Pb2+ removal efficiencies of 90.9% and 94.6% were obtained using the 1.5 wt% and 1 wt% C-TiO2-CFA/PAN nanocomposite membranes. The photoreduction activity was observed to decrease with an increase in cadmium and lead initial concentrations. A cadmium and lead removal efficiencies of 95% and 97% were observed at lower Cd2+ and Pb2+ initial concentrations (20 ppm), respectively. The removal efficiencies varied marginally with changes in pH values. The fouling activity of the C-TiO2 modified PAN asymmetric membranes and pure PAN was investigated by carrying out pure water filtration tests as well as bovine serum albumin (BSA) filtration tests. A bovine serum albumin rejection of 98% was obtained utilizing the 2 wt% CTiO2-CFA/PAN membrane.
- Full Text:
- Authors: Mpelane, Amkelwa
- Date: 2020
- Subjects: Photocatalysis
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/18744 , vital:42729
- Description: The goal of this study was to fabricate a visible light responsive composite of C-TiO2-CFA. The prepared nanocomposite (C-TiO2-CFA) was immobilized on poly(acrylonitrile) membrane to address the drawback of recovering the nanosized photocatalyst from water after photodegradation experiments. The C-TiO2-CFA nanocomposites were fabricated using a modified sol-gel method, while the C-TiO2-CFA/PAN membranes were prepared via the phase inversion technique. The nanocomposites were fully characterized using FTIR, XRD, SEM-EDX, TEM, DRS, and BET surface area analysis. The prepared C-TiO2-CFA/PAN membranes were evaluated in the photodegradation of methyl orange and the golden yellow dyes, as well as the photoreduction of lead and cadmium heavy metals in synthetic wastewater. UV-Visible spectroscopy was used to follow the changes in the concentration of organic dyes, while inductively coupled plasma optical emission spectroscopy was used to follow changes in the concentration of the heavy metals. FTIR analysis confirmed the presence of functional groups expected on the prepared C-TiO2- CFA/PAN membranes and EDX analysis accounted for the elements expected. The prepared membranes all exhibited an asymmetric structure as depicted by cross-sectional view study via SEM analysis. TEM and SEM analyses revealed that the prepared C-TiO2-CFA nanocomposite was roughly spherical in shape with an estimate particle size of 10.94 nm according to TEM and 11.62 nm according to XRD using Scherrer equation. The incorporation of carbon into the lattice structure of titanium dioxide resulted in a reduction in bandgap from 3.19 eV to 2.78 eV through introduction of mid-band states, allowing visible light utilization. The best nanocomposite was obtained by doping TiO2 with 4% carbon and having a C-TiO2 to CFA ratio of 4:1 respectively. The C-TiO2-CFA nanocomposite exhibits a crystalline structure with a mixture of rutile and anatase phases. The parameters investigated in the evaluation of photocatalytic performance of C-TiO2- CFA/PAN were effect of photocatalyst load on PAN membrane, initial dye concentration, pH and light source in the activation of photocatalyst. For both dyes (methyl arrange and golden yellow), it was observed that photodegradation efficiencies increased with an increase in catalyst load. In the photodegradation of MO and GY using the membrane with 1% C-TiO2- CFA, removal efficiencies of 73.3% and 59.99% were attained respectively, while the membrane with 2% C-TiO2-CFA achieved MO and GY photodegradation efficiencies of 99.8% and 99.2% respectively. Photodegradation efficiencies of MO and GY were observed to decrease with an increase in dye concentration. Low pH (3) was observed to favour the photodegradation of MO and GY azo dyes. Photodegradation efficiencies of 99.8% and 99.2% were attained where obtained at lower MO and GY initial concentration. The modified photocatalyst (C-TiO2-CFA/PAN) exhibited better photoactivity under sunlight irradiation compared to strict UV light irradiation. Evidently, the C-TiO2-CFA/PAN membranes can be 4 Final Submission of Thesis, Dissertation or Research Report/Project, Conference or Exam Paper utilized as a sustainable and stable photocatalyst to efficiently eliminate methyl orange and golden yellow dyes. A PAN membrane with 2 wt% C-TiO2-CFA revealed enhanced cadmium and lead removal efficiencies in comparison to PAN membranes with 1 wt% and 1.5% C-TiO2-CFA. A Cd2+ removal efficiency of 95% was obtained using 2 wt% C-TiO2-CFA/PAN nanocomposite membranes. Cadmium removal efficiencies of 92.5% and 91% were obtained using the 1.5 wt% and 1 wt% C-TiO2-CFA/PAN nanocomposite membranes. A lead removal efficiency of 97% was obtained using PAN membrane with 2 wt% C-TiO2-CFA. Pb2+ removal efficiencies of 90.9% and 94.6% were obtained using the 1.5 wt% and 1 wt% C-TiO2-CFA/PAN nanocomposite membranes. The photoreduction activity was observed to decrease with an increase in cadmium and lead initial concentrations. A cadmium and lead removal efficiencies of 95% and 97% were observed at lower Cd2+ and Pb2+ initial concentrations (20 ppm), respectively. The removal efficiencies varied marginally with changes in pH values. The fouling activity of the C-TiO2 modified PAN asymmetric membranes and pure PAN was investigated by carrying out pure water filtration tests as well as bovine serum albumin (BSA) filtration tests. A bovine serum albumin rejection of 98% was obtained utilizing the 2 wt% CTiO2-CFA/PAN membrane.
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Farmers' perceptions of insect pests in the Eastern Cape maize-based cropping systems and the effects of crop residue management on insect pest populations
- Authors: Kadango, Tendayi Lovemore
- Date: 2018
- Subjects: Cropping systems Crop residue management Corn -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6202 , vital:29507
- Description: Maize (Zea mays L.) is one of the most important crops in South Africa that is cultivated for food, feed and as a cash crop. Maize in the Eastern Cape is typically grown for consumption and the Province is one of the least producers owing to small landholdings, poor production conditions and pests. This study investigated: (i) the different maize cropping systems smallholder farmers practice in the Eastern Cape (EC), (ii) the major maize insect pests within the identified cropping systems, (iii) the perceptions of Eastern Cape smallholder maize farmers on the effects of insect pests, and (iv) the effects of crop residues on insect pests’ population dynamics. Four major cropping systems namely: maize sole cropping without rotations by government sponsored farmers (GCP) (94 percent), maize intercropping without rotations by independent farmers (IF) (79 percent), maize sole cropping without rotations by IF (67 percent) and maize intercropping without rotations by GCP (61 percent) were identified. The choice of a cropping system by the smallholder farmers was significantly influenced by source of sponsorship, the difference in their district localities, tenure system, availability of inputs and farming equipment, percentage of farmland farmers allocate to maize, maize varieties, farming experience, fallow operations and access to irrigation facilities. The major constraints faced by the farmers in maize production are the attack by insect pests, weeds competition, drought, the lack of fencing around the fields and destruction by mammals. The major insect pests identified were stalk borers (Busseola fusca, Chilo partellus), cutworms (Agrotis spp.), aphids (Rhopalosiphum maidis), bollworms (Helicoverpa armigera) and weevils (Sitophylus spp.). The most popular control measures employed were the use of GM maize and pesticides. Results from the field trial showed that field crickets were the major ground dwelling insect pests observed followed by bollworms and cutworms. However, there were no significant influence of residue retention on the insects’ diversity indices, richness, and evenness. Above ground insects sampling revealed the domination by four major insects namely, cutworms, maize stalk borer, bollworms, and spotted stalk borer. Residue management significantly influenced the infestation by spotted stalk borer only on maize plots. However, the general trend was that there was less infestation by the insects in plots where residues were retained than the ones with residue removed. Results from the study indicate that government sponsorship is significantly influencing the maize cropping systems of the smallholder farmers of the Eastern Cape.
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- Authors: Kadango, Tendayi Lovemore
- Date: 2018
- Subjects: Cropping systems Crop residue management Corn -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6202 , vital:29507
- Description: Maize (Zea mays L.) is one of the most important crops in South Africa that is cultivated for food, feed and as a cash crop. Maize in the Eastern Cape is typically grown for consumption and the Province is one of the least producers owing to small landholdings, poor production conditions and pests. This study investigated: (i) the different maize cropping systems smallholder farmers practice in the Eastern Cape (EC), (ii) the major maize insect pests within the identified cropping systems, (iii) the perceptions of Eastern Cape smallholder maize farmers on the effects of insect pests, and (iv) the effects of crop residues on insect pests’ population dynamics. Four major cropping systems namely: maize sole cropping without rotations by government sponsored farmers (GCP) (94 percent), maize intercropping without rotations by independent farmers (IF) (79 percent), maize sole cropping without rotations by IF (67 percent) and maize intercropping without rotations by GCP (61 percent) were identified. The choice of a cropping system by the smallholder farmers was significantly influenced by source of sponsorship, the difference in their district localities, tenure system, availability of inputs and farming equipment, percentage of farmland farmers allocate to maize, maize varieties, farming experience, fallow operations and access to irrigation facilities. The major constraints faced by the farmers in maize production are the attack by insect pests, weeds competition, drought, the lack of fencing around the fields and destruction by mammals. The major insect pests identified were stalk borers (Busseola fusca, Chilo partellus), cutworms (Agrotis spp.), aphids (Rhopalosiphum maidis), bollworms (Helicoverpa armigera) and weevils (Sitophylus spp.). The most popular control measures employed were the use of GM maize and pesticides. Results from the field trial showed that field crickets were the major ground dwelling insect pests observed followed by bollworms and cutworms. However, there were no significant influence of residue retention on the insects’ diversity indices, richness, and evenness. Above ground insects sampling revealed the domination by four major insects namely, cutworms, maize stalk borer, bollworms, and spotted stalk borer. Residue management significantly influenced the infestation by spotted stalk borer only on maize plots. However, the general trend was that there was less infestation by the insects in plots where residues were retained than the ones with residue removed. Results from the study indicate that government sponsorship is significantly influencing the maize cropping systems of the smallholder farmers of the Eastern Cape.
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Exploring the contributions of youth development programme as a poverty eradication strategy: The case study of the National Youth Development Agency in Ezibeleni Township; Queenstown
- Authors: Vazi, Thembelani
- Date: 2017
- Subjects: Youth development -- South Africa -- Eastern Cape Youth -- Political activity -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Social Work
- Identifier: http://hdl.handle.net/10353/6502 , vital:30137
- Description: Youth development programmes in South Africa stirs a lot of debates on whether youth development programmes reach all the young people of South Africa even the rural youth. The youth involved in these programmes argue that even though these youth development programmes were created for all the young people of South Africa, some of them do not get the opportunity to be part of such programmes and they are not getting the proper skills that they need in order to create employment opportunities for themselves. Therefore, this study is aimed at exploring the contributions of the youth development programme as a poverty eradication strategy. The data in the study was collected qualitatively through interviews in which the youth, Social Workers, the ward Councillors and NYDA officials were interviewed. The total sample size in the study was 26 participants. The study established that the lack of youth skills is one of the causes of youth unemployment and poverty. Generally, the quality of these youth development programmes are not up to standard for assisting young people, most importantly these youth programmes lack resources. The study revealed that, even though the youth programmes are available, they do not cater for all the young people of Ezibeleni Township and they do not alleviate poverty for all the youth of Ezibeleni Township. Furthermore, those that are part of these youth programmes further complain about the lack of skills within the staff employed in these youth development programmes.
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- Authors: Vazi, Thembelani
- Date: 2017
- Subjects: Youth development -- South Africa -- Eastern Cape Youth -- Political activity -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Social Work
- Identifier: http://hdl.handle.net/10353/6502 , vital:30137
- Description: Youth development programmes in South Africa stirs a lot of debates on whether youth development programmes reach all the young people of South Africa even the rural youth. The youth involved in these programmes argue that even though these youth development programmes were created for all the young people of South Africa, some of them do not get the opportunity to be part of such programmes and they are not getting the proper skills that they need in order to create employment opportunities for themselves. Therefore, this study is aimed at exploring the contributions of the youth development programme as a poverty eradication strategy. The data in the study was collected qualitatively through interviews in which the youth, Social Workers, the ward Councillors and NYDA officials were interviewed. The total sample size in the study was 26 participants. The study established that the lack of youth skills is one of the causes of youth unemployment and poverty. Generally, the quality of these youth development programmes are not up to standard for assisting young people, most importantly these youth programmes lack resources. The study revealed that, even though the youth programmes are available, they do not cater for all the young people of Ezibeleni Township and they do not alleviate poverty for all the youth of Ezibeleni Township. Furthermore, those that are part of these youth programmes further complain about the lack of skills within the staff employed in these youth development programmes.
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Needs assessment in the development of a problem-based learning for paediatric nurse specialist programme at the University of Fort Hare Eastern Cape
- Authors: Melitafa, Nomntu
- Date: 2017
- Subjects: Nursing assessment Problem-based learning Nursing -- Study and teaching
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10353/8921 , vital:33966
- Description: The study seeks to assess the need for developing a post graduate child nursing science programme with a problem based learning approach at the University of Fort Hare East London Campus. The aim is to the aim of the study was to conduct a needs assessment in preparation for development of a PBL curriculum so as to produce reflective PNSs. Literature exposed the high mortality rates of children and the competency gaps of trained PNSs. A descriptive quantitative design was used to guide the study. The data were collected by means of self-administered survey questionnaires which constituted closed and open ended questions to yield both quantitative and qualitative data. Data were obtained based on demographic information, performance and importance of the PNS activities, competences of PNSs as well as the prevalence of child health problems at the rural, semi-urban and urban hospitals in the ECP. The purposive sampling technique was used to select participants. The sample size was 70 and 38 participants responded. Quantitative and qualitative data were obtained. Quantitative data were analyzed through use of the Statistical Programme for Social Science software (SPSS) Version 9.0.1 and qualitative data were analyzed manually. Quantitative results were presented with pie graphs, tables and frequencies. Four themes emerged, revealing factors prohibiting the service delivery of PNSs, special training needs of PNSs, prevalent health problems in children and personal interventions. The results showed that in essence there is a need to develop the envisaged Problem Based Learning (PBL) curriculum.
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- Authors: Melitafa, Nomntu
- Date: 2017
- Subjects: Nursing assessment Problem-based learning Nursing -- Study and teaching
- Language: English
- Type: Thesis , Masters , MCur
- Identifier: http://hdl.handle.net/10353/8921 , vital:33966
- Description: The study seeks to assess the need for developing a post graduate child nursing science programme with a problem based learning approach at the University of Fort Hare East London Campus. The aim is to the aim of the study was to conduct a needs assessment in preparation for development of a PBL curriculum so as to produce reflective PNSs. Literature exposed the high mortality rates of children and the competency gaps of trained PNSs. A descriptive quantitative design was used to guide the study. The data were collected by means of self-administered survey questionnaires which constituted closed and open ended questions to yield both quantitative and qualitative data. Data were obtained based on demographic information, performance and importance of the PNS activities, competences of PNSs as well as the prevalence of child health problems at the rural, semi-urban and urban hospitals in the ECP. The purposive sampling technique was used to select participants. The sample size was 70 and 38 participants responded. Quantitative and qualitative data were obtained. Quantitative data were analyzed through use of the Statistical Programme for Social Science software (SPSS) Version 9.0.1 and qualitative data were analyzed manually. Quantitative results were presented with pie graphs, tables and frequencies. Four themes emerged, revealing factors prohibiting the service delivery of PNSs, special training needs of PNSs, prevalent health problems in children and personal interventions. The results showed that in essence there is a need to develop the envisaged Problem Based Learning (PBL) curriculum.
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Template-assisted sol-gel synthesis of carbon doped titanium dioxide nanotubes and their characterization
- Authors: Takata, Nwabisa
- Date: 2017
- Subjects: Nanotechnology Titanium dioxide Nanostructures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13194 , vital:39473
- Description: This study reveals the effects of doping on the morphological, structural and optical properties of titanium dioxide (TiO2) nanotubes (TNTs), synthesized by sol-gel template-assisted sol-gel technique. The nanotubes (TNTs) were prepared in anodic alumina membranes (AAM) with a pore diameter range of 110-210 nm by using titanium tetra butoxide as a sol-gel precursor and oxalic acid dihydrate as a dopant source. The synthesized nanotubes were evaluated using scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), confocal Raman spectroscopy (CRS) and photoluminescence spectroscopy (PL). SEM analysis has revealed the presence of closely-packed TNTs, with a modal external tube diameters of 150, 170, 210,190 and 210 nm for the un-doped TNTs, 9 mM carbon doped-TNTs (C-TNTs), 27 mM C-TNTs, 45 mM C-TNTs and 75 mM C-TNTs respectively. The diameters are consistent with the AAM diameter range. EDX spectra revealed the presence of Ti peaks at 0.45 and 4.9 keV corresponding to Kα1 and Kβ1 emission lines respectively. Oxygen exhibits a signal at 0.5 keV corresponding to Kα1 emission line. The occurrence of these peaks in the EDX spectra endorses the existence of Ti and O atoms in the prepared titanium dioxide nanotubes. FTIR spectroscopy has revealed the presence of vibration modes at 580-660 cm-1 indicating the presence of Ti-O bonds and additional vibration modes at 2324 cm-1 resulting from C-O stretching in the C-TNTs. The XRD analysis has revealed the presence of a mixed anatase-brookite phase with diffraction peaks at 2θ angles of 25.49⁰, 38.11⁰, 40.60º, 48.14⁰, 54.58⁰, 63.00⁰, 70.11⁰ and 75.66⁰. Additionally, XRD analysis has revealed elongation of lattice parameter “c” from 9.143 to 9.830 Å with carbon concentration increase. Lattice expansion indicates the possibility of carbon substituting oxygen sites. Raman large area scan has revealed the presence of rutile, brookite and anatase for the undoped samples. On doping the rutile phase of TiO2 has shown to be suppressed by the presence of carbon atoms such that the doped samples consist of brookite and anatase phases only. The Eg1 mode of anatase of the undoped TNTs at 153. 78 cm-1 was red shifted by Δ9.78 cm-1 relative to the bulk anatase TiO2. This was attributed to decrease in particle size, presence of brookite and phonon confinement. Upon doping, the 9 mM C-TNTs, 27 mM TNTs and 75 mM TNTs have shown a red shift of Δ0. 09 cm-1, Δ1. 39 cm-1 and 1.81 cm-1 respectively, suggesting the incorporation of carbon in the TiO2 matrix. CRS depth profiling in the XZ direction has also validated the presence of a mixed anatase-brookite phase at Raman active modes 153.19 cm-1, 208.87 cm-1, 404.55 cm-1, 523.26 cm-1 and 648.55 cm-1. Photoluminescence spectra of carbon doped TiO2 showed two emission peaks at 398 nm attributed to annihilation of excitons while the broad peak at 400-460 nm was attributed to the presence of oxygen vacancies. The peak intensity of the 45 mM C-TNTs has shown a lower PL intensity suggesting that efficiency of charge separation was higher and recombination rate was lower than other carbon containing samples.
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- Authors: Takata, Nwabisa
- Date: 2017
- Subjects: Nanotechnology Titanium dioxide Nanostructures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13194 , vital:39473
- Description: This study reveals the effects of doping on the morphological, structural and optical properties of titanium dioxide (TiO2) nanotubes (TNTs), synthesized by sol-gel template-assisted sol-gel technique. The nanotubes (TNTs) were prepared in anodic alumina membranes (AAM) with a pore diameter range of 110-210 nm by using titanium tetra butoxide as a sol-gel precursor and oxalic acid dihydrate as a dopant source. The synthesized nanotubes were evaluated using scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), confocal Raman spectroscopy (CRS) and photoluminescence spectroscopy (PL). SEM analysis has revealed the presence of closely-packed TNTs, with a modal external tube diameters of 150, 170, 210,190 and 210 nm for the un-doped TNTs, 9 mM carbon doped-TNTs (C-TNTs), 27 mM C-TNTs, 45 mM C-TNTs and 75 mM C-TNTs respectively. The diameters are consistent with the AAM diameter range. EDX spectra revealed the presence of Ti peaks at 0.45 and 4.9 keV corresponding to Kα1 and Kβ1 emission lines respectively. Oxygen exhibits a signal at 0.5 keV corresponding to Kα1 emission line. The occurrence of these peaks in the EDX spectra endorses the existence of Ti and O atoms in the prepared titanium dioxide nanotubes. FTIR spectroscopy has revealed the presence of vibration modes at 580-660 cm-1 indicating the presence of Ti-O bonds and additional vibration modes at 2324 cm-1 resulting from C-O stretching in the C-TNTs. The XRD analysis has revealed the presence of a mixed anatase-brookite phase with diffraction peaks at 2θ angles of 25.49⁰, 38.11⁰, 40.60º, 48.14⁰, 54.58⁰, 63.00⁰, 70.11⁰ and 75.66⁰. Additionally, XRD analysis has revealed elongation of lattice parameter “c” from 9.143 to 9.830 Å with carbon concentration increase. Lattice expansion indicates the possibility of carbon substituting oxygen sites. Raman large area scan has revealed the presence of rutile, brookite and anatase for the undoped samples. On doping the rutile phase of TiO2 has shown to be suppressed by the presence of carbon atoms such that the doped samples consist of brookite and anatase phases only. The Eg1 mode of anatase of the undoped TNTs at 153. 78 cm-1 was red shifted by Δ9.78 cm-1 relative to the bulk anatase TiO2. This was attributed to decrease in particle size, presence of brookite and phonon confinement. Upon doping, the 9 mM C-TNTs, 27 mM TNTs and 75 mM TNTs have shown a red shift of Δ0. 09 cm-1, Δ1. 39 cm-1 and 1.81 cm-1 respectively, suggesting the incorporation of carbon in the TiO2 matrix. CRS depth profiling in the XZ direction has also validated the presence of a mixed anatase-brookite phase at Raman active modes 153.19 cm-1, 208.87 cm-1, 404.55 cm-1, 523.26 cm-1 and 648.55 cm-1. Photoluminescence spectra of carbon doped TiO2 showed two emission peaks at 398 nm attributed to annihilation of excitons while the broad peak at 400-460 nm was attributed to the presence of oxygen vacancies. The peak intensity of the 45 mM C-TNTs has shown a lower PL intensity suggesting that efficiency of charge separation was higher and recombination rate was lower than other carbon containing samples.
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The WTO agreement on technical barriers to trade : a critical appraisal of its implementation within the Southern African Development Community
- Authors: Chimeri, Vongai
- Date: 2017
- Subjects: Tariff -- Law and legislation Non-tariff trade barriers -- Law and legislation Foreign trade regulation
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/2855 , vital:28108
- Description: The World Trade Organisation Agreement on Technical Barriers to Trade (TBT Agreement) was crafted with the aim of ensuring that technical regulations, standards and conformity assessment procedure do not constitute unnecessary obstacles to international trade. Southern African Development Community (SADC) countries have since ratified this Agreement and took a step further to incorporate its principles into the Technical Barriers to Trade Annex to the SADC Protocol on Trade. Despite this effort, SADC countries are still grappling with implementing the TBT Agreement in their domestic frameworks. Consequently, technical barriers to trade have become impediments to both regional and international trade. It is in this context that this study aims to examine the implementation of the TBT Agreement within the SADC. The study answers the question what are the challenges facing SADC Member states to fully implement the TBT Agreement? The study demonstrates that SADC Member face challenges which include of lack adequate resources, technical expertise and enforcement mechanisms to effectively implement the TBT Agreement. In the finality, the study recommends SADC Member states to deepen regional integration in order to collaborate on matters relating to technical barriers to trade within the region. Member states should also share information and learn from the experiences of other countries on how to effectively implement the TBT Agreement. Further, government officials should be educated on trade-friendly regulations that do not compromise on the principles of the TBT Agreement. To this end, regulatory impact assessments should be established in order to assess the trade effects of both new and old regulations. Effective enforcement mechanisms should also be introduced in order to coerce Member states to comply with their regional obligations. By effecting these recommendations, SADC states have the opportunity to eradicate technical barriers to trade thereby increasing both regional and international trade.
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- Authors: Chimeri, Vongai
- Date: 2017
- Subjects: Tariff -- Law and legislation Non-tariff trade barriers -- Law and legislation Foreign trade regulation
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10353/2855 , vital:28108
- Description: The World Trade Organisation Agreement on Technical Barriers to Trade (TBT Agreement) was crafted with the aim of ensuring that technical regulations, standards and conformity assessment procedure do not constitute unnecessary obstacles to international trade. Southern African Development Community (SADC) countries have since ratified this Agreement and took a step further to incorporate its principles into the Technical Barriers to Trade Annex to the SADC Protocol on Trade. Despite this effort, SADC countries are still grappling with implementing the TBT Agreement in their domestic frameworks. Consequently, technical barriers to trade have become impediments to both regional and international trade. It is in this context that this study aims to examine the implementation of the TBT Agreement within the SADC. The study answers the question what are the challenges facing SADC Member states to fully implement the TBT Agreement? The study demonstrates that SADC Member face challenges which include of lack adequate resources, technical expertise and enforcement mechanisms to effectively implement the TBT Agreement. In the finality, the study recommends SADC Member states to deepen regional integration in order to collaborate on matters relating to technical barriers to trade within the region. Member states should also share information and learn from the experiences of other countries on how to effectively implement the TBT Agreement. Further, government officials should be educated on trade-friendly regulations that do not compromise on the principles of the TBT Agreement. To this end, regulatory impact assessments should be established in order to assess the trade effects of both new and old regulations. Effective enforcement mechanisms should also be introduced in order to coerce Member states to comply with their regional obligations. By effecting these recommendations, SADC states have the opportunity to eradicate technical barriers to trade thereby increasing both regional and international trade.
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Evaluation of physiochemical qualities and heavy metal levels of the final effluents of some wastewater treatment facilities in the Eastern Cape Province of South Africa
- Authors: Kulati, Thanduxolo Cullinan
- Date: 2016
- Subjects: Water -- Purification Sewage -- Purification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1547 , vital:27417
- Description: Water is the most abundant substance in nature and vital for life activities. The major water sources for use are surface water bodies such as rivers and lakes, and underground aquifers and pore spaces down the water table (Ring, 2003). Water derived from these sources is not necessarily pure since it contains dissolved inorganic and organic substances, living organisms (viruses, bacteria, etc). For these reasons, water intended for domestic uses should be free from toxic substances and microorganisms that are of health significance (WHO, 2005). The availability and quality of water always have played an important role in determining the quality of life. Water quality is closely linked to water use and to the state of economic development (Chennakrishnan et al., 2008). Ground and surface waters can be contaminated by several sources. In urban areas, the careless disposal of industrial effluents and other wastes may contribute greatly to the poor quality of water (Mathuthu et al., 1997). In most developing countries, most areas are located on the watersheds which are the end points of effluents discharged from various industries (Oberholster and Ashton, 2008). South Africa, as a developing country, is experiencing rapid demographic changes due to urbanization, industrialization and population growth. The country has also been identified as being water-scarce, which can lead to a challenge of meeting the increasing water demand due to industrialization and urbanization. Such population growth increase may result in an increase in wastewater output, especially around urban areas.
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- Authors: Kulati, Thanduxolo Cullinan
- Date: 2016
- Subjects: Water -- Purification Sewage -- Purification
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/1547 , vital:27417
- Description: Water is the most abundant substance in nature and vital for life activities. The major water sources for use are surface water bodies such as rivers and lakes, and underground aquifers and pore spaces down the water table (Ring, 2003). Water derived from these sources is not necessarily pure since it contains dissolved inorganic and organic substances, living organisms (viruses, bacteria, etc). For these reasons, water intended for domestic uses should be free from toxic substances and microorganisms that are of health significance (WHO, 2005). The availability and quality of water always have played an important role in determining the quality of life. Water quality is closely linked to water use and to the state of economic development (Chennakrishnan et al., 2008). Ground and surface waters can be contaminated by several sources. In urban areas, the careless disposal of industrial effluents and other wastes may contribute greatly to the poor quality of water (Mathuthu et al., 1997). In most developing countries, most areas are located on the watersheds which are the end points of effluents discharged from various industries (Oberholster and Ashton, 2008). South Africa, as a developing country, is experiencing rapid demographic changes due to urbanization, industrialization and population growth. The country has also been identified as being water-scarce, which can lead to a challenge of meeting the increasing water demand due to industrialization and urbanization. Such population growth increase may result in an increase in wastewater output, especially around urban areas.
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A comparative analysis of the phonological acquisition of consonants in the speech of pre-school age isiXhosa and English-speaking children in selected schools in the East London area
- Authors: Myoli, Ndileka
- Date: 2014
- Language: English
- Type: Thesis , Masters , MA (African Languages)
- Identifier: vital:11151 , http://hdl.handle.net/10353/d1015437
- Description: The problems of reading and incomprehension found in South African schools are often linked to children‟s differences of phonological acquisition rates and the articulation of consonants. This is according to the report of the Impact Study of the System Method for Reading Success study (SMRS) of 2009. This problem has always been associated with the racial inequalities that have previously ruled the South African education system. An understanding of the existence of the differences in children‟s articulation of consonants between the English-speaking and the isiXhosa-speaking children may lead to further understanding of the causes of such differences and the application of strategies that are aimed at remedying that situation. While many studies have been conducted in the area of language acquisition, this study found it necessary to contribute further to this debate. This study investigated the different rates of consonant articulation between pre-school-going Englishspeaking and isiXhosa-speaking children of 2-6 years of age. The main aim was to establish which of these two cohorts have early phonological acquisition of consonants and, therefore, master their articulation and why. 26 children from the two pre-schools within the East London directorate weren sampled, 13 consisting of females and males from each of the two pre-primary schools. This study used informal interviews and case study as the means of data collection as well as a case study as its investigation strategy. Children‟s speech utterances were recorded in order to analyse and compare with respect to order of acquisition, types of errors as well as the ages at which consonants were acquired. This study ensured a high degree of validity as well as giving due consideration to ethical matters in order to ensure the reliability of the results. The problems of reading and incomprehension found in South African schools are often linked to children‟s differences of phonological acquisition rates and the articulation of consonants. This is according to the report of the Impact Study of the System Method for Reading Success study (SMRS) of 2009. This problem has always been associated with the racial inequalities that have previously ruled the South African education system. An understanding of the existence of the differences in children‟s articulation of consonants between the English-speaking and the isiXhosa-speaking children may lead to further understanding of the causes of such differences and the application of strategies that are aimed at remedying that situation. While many studies have been conducted in the area of language acquisition, this study found it necessary to contribute further to this debate. This study investigated the different rates of consonant articulation between pre-school-going Englishspeaking and isiXhosa-speaking children of 2-6 years of age. The main aim was to establish which of these two cohorts have early phonological acquisition of consonants and, therefore, master their articulation and why. 26 children from the two pre-schools within the East London directorate weren sampled, 13 consisting of females and males from each of the two pre-primary schools. This study used informal interviews and case study as the means of data collection as well as a case study as its investigation strategy. Children‟s speech utterances were recorded in order to analyse and compare with respect to order of acquisition, types of errors as well as the ages at which consonants were acquired. This study ensured a high degree of validity as well as giving due consideration to ethical matters in order to ensure the reliability of the results. The study found that isiXhosa speaking children have earlier consonant acquisition than English-speaking children do. While that is the case, the study also found that English-speaking children‟s rates of phonological acquisition accelerated from the age of 4 years to the age of 6 years much more than the isiXhosa-speaking children of the same age could do. The implications of these results to education stakeholders, particularly the teachers and other related professionals who deal with children with articulation disorders on a daily basis, will create an understanding as well as an awareness of the existence of such problems. Policies formulated will have to take the existence of articulation disorders into consideration. The distribution of resources relevant to the needs of children will include and cater for children with such disorders. Further research is recommended to investigate more around this area of study to a point where solutions for the existing differences of articulation of consonants for one group of children over another are realised.The study found that isiXhosa speaking children have earlier consonant acquisition than English-speaking children do. While that is the case, the study also found that English-speaking children‟s rates of phonological acquisition accelerated from the age of 4 years to the age of 6 years much more than the isiXhosa-speaking children of the same age could do. The implications of these results to education stakeholders, particularly the teachers and other related professionals who deal with children with articulation disorders on a daily basis, will create an understanding as well as an awareness of the existence of such problems. Policies formulated will have to take the existence of articulation disorders into consideration. The distribution of resources relevant to the needs of children will include and cater for children with such disorders. Further research is recommended to investigate more around this area of study to a point where solutions for the existing differences of articulation of consonants for one group of children over another are realised.
- Full Text:
- Authors: Myoli, Ndileka
- Date: 2014
- Language: English
- Type: Thesis , Masters , MA (African Languages)
- Identifier: vital:11151 , http://hdl.handle.net/10353/d1015437
- Description: The problems of reading and incomprehension found in South African schools are often linked to children‟s differences of phonological acquisition rates and the articulation of consonants. This is according to the report of the Impact Study of the System Method for Reading Success study (SMRS) of 2009. This problem has always been associated with the racial inequalities that have previously ruled the South African education system. An understanding of the existence of the differences in children‟s articulation of consonants between the English-speaking and the isiXhosa-speaking children may lead to further understanding of the causes of such differences and the application of strategies that are aimed at remedying that situation. While many studies have been conducted in the area of language acquisition, this study found it necessary to contribute further to this debate. This study investigated the different rates of consonant articulation between pre-school-going Englishspeaking and isiXhosa-speaking children of 2-6 years of age. The main aim was to establish which of these two cohorts have early phonological acquisition of consonants and, therefore, master their articulation and why. 26 children from the two pre-schools within the East London directorate weren sampled, 13 consisting of females and males from each of the two pre-primary schools. This study used informal interviews and case study as the means of data collection as well as a case study as its investigation strategy. Children‟s speech utterances were recorded in order to analyse and compare with respect to order of acquisition, types of errors as well as the ages at which consonants were acquired. This study ensured a high degree of validity as well as giving due consideration to ethical matters in order to ensure the reliability of the results. The problems of reading and incomprehension found in South African schools are often linked to children‟s differences of phonological acquisition rates and the articulation of consonants. This is according to the report of the Impact Study of the System Method for Reading Success study (SMRS) of 2009. This problem has always been associated with the racial inequalities that have previously ruled the South African education system. An understanding of the existence of the differences in children‟s articulation of consonants between the English-speaking and the isiXhosa-speaking children may lead to further understanding of the causes of such differences and the application of strategies that are aimed at remedying that situation. While many studies have been conducted in the area of language acquisition, this study found it necessary to contribute further to this debate. This study investigated the different rates of consonant articulation between pre-school-going Englishspeaking and isiXhosa-speaking children of 2-6 years of age. The main aim was to establish which of these two cohorts have early phonological acquisition of consonants and, therefore, master their articulation and why. 26 children from the two pre-schools within the East London directorate weren sampled, 13 consisting of females and males from each of the two pre-primary schools. This study used informal interviews and case study as the means of data collection as well as a case study as its investigation strategy. Children‟s speech utterances were recorded in order to analyse and compare with respect to order of acquisition, types of errors as well as the ages at which consonants were acquired. This study ensured a high degree of validity as well as giving due consideration to ethical matters in order to ensure the reliability of the results. The study found that isiXhosa speaking children have earlier consonant acquisition than English-speaking children do. While that is the case, the study also found that English-speaking children‟s rates of phonological acquisition accelerated from the age of 4 years to the age of 6 years much more than the isiXhosa-speaking children of the same age could do. The implications of these results to education stakeholders, particularly the teachers and other related professionals who deal with children with articulation disorders on a daily basis, will create an understanding as well as an awareness of the existence of such problems. Policies formulated will have to take the existence of articulation disorders into consideration. The distribution of resources relevant to the needs of children will include and cater for children with such disorders. Further research is recommended to investigate more around this area of study to a point where solutions for the existing differences of articulation of consonants for one group of children over another are realised.The study found that isiXhosa speaking children have earlier consonant acquisition than English-speaking children do. While that is the case, the study also found that English-speaking children‟s rates of phonological acquisition accelerated from the age of 4 years to the age of 6 years much more than the isiXhosa-speaking children of the same age could do. The implications of these results to education stakeholders, particularly the teachers and other related professionals who deal with children with articulation disorders on a daily basis, will create an understanding as well as an awareness of the existence of such problems. Policies formulated will have to take the existence of articulation disorders into consideration. The distribution of resources relevant to the needs of children will include and cater for children with such disorders. Further research is recommended to investigate more around this area of study to a point where solutions for the existing differences of articulation of consonants for one group of children over another are realised.
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Appraisal of community-based childcare practices in rural Malawi: the case of Malili traditional authority area, Lilongwe District
- Authors: Alufandika, Dina
- Date: 2012
- Subjects: Tribal government -- Malawi , Child welfare -- Malawi , Child development -- Malawi , Child care services -- Malawi , Community development -- Malawi , Rural development -- Malawi , Malawi -- Social policy , Lilongwe (Malawi)
- Language: English
- Type: Thesis , Masters , M Soc Sc (Rural Development)
- Identifier: vital:11945 , http://hdl.handle.net/10353/d1005968 , Tribal government -- Malawi , Child welfare -- Malawi , Child development -- Malawi , Child care services -- Malawi , Community development -- Malawi , Rural development -- Malawi , Malawi -- Social policy , Lilongwe (Malawi)
- Description: The government of Malawi established the community based childcare (CBCC) programme with the aim of addressing early childhood problems and achieve national development in the long run. The CBCC programme, as one of the approaches to early childhood development (ECD), is guided by the national early childhood development policy. It promotes some practices that somehow deviate from the traditional childcare ways that communities have always known. Experience has shown that programmes that have elements of conflict with commonly held beliefs are bound to meet with resistance in society. The study employed a mini survey, focus group discussion, observation and document review to understand how the CBCC childcare practices in Malili intersect with commonly held beliefs about childcare as well as how they reflect on the national ECD policy. The study also focused on understanding the perceptions of community members on the CBCC programme. The study revealed that while some aspects of CBCC delivery conform to commonly held beliefs about childcare in the area under study, others diverge from such beliefs. Such convergence and divergence appear to be in line with the propositions of transformalist globalisation theory- one of the perspectives adopted for the study. The study also found that care practices at CBCC are not a true reflection of the national ECD policy as community members’ perceptions, poor community participation, poverty and lack of caregiver training in ECD contribute towards poor quality of care in CBCC, contrary to what is defined in the national ECD policy. The study also found that while both CBCC caregivers and sampled community members perceived the quality of care at the centers as poor, caregivers had a more positive perception towards the CBCC than community members. The study indicated that CBCC are centres of desperation for low economic status communities. Findings from the research have revealed that cultural values and commonly held beliefs, and exposure to new knowledge through globalisation play a role in determining childcare practices as well as perceptions towards them. In this sense the study has indicated that meanings that communities attach to development interventions influence their actions and perceptions towards it.
- Full Text:
- Authors: Alufandika, Dina
- Date: 2012
- Subjects: Tribal government -- Malawi , Child welfare -- Malawi , Child development -- Malawi , Child care services -- Malawi , Community development -- Malawi , Rural development -- Malawi , Malawi -- Social policy , Lilongwe (Malawi)
- Language: English
- Type: Thesis , Masters , M Soc Sc (Rural Development)
- Identifier: vital:11945 , http://hdl.handle.net/10353/d1005968 , Tribal government -- Malawi , Child welfare -- Malawi , Child development -- Malawi , Child care services -- Malawi , Community development -- Malawi , Rural development -- Malawi , Malawi -- Social policy , Lilongwe (Malawi)
- Description: The government of Malawi established the community based childcare (CBCC) programme with the aim of addressing early childhood problems and achieve national development in the long run. The CBCC programme, as one of the approaches to early childhood development (ECD), is guided by the national early childhood development policy. It promotes some practices that somehow deviate from the traditional childcare ways that communities have always known. Experience has shown that programmes that have elements of conflict with commonly held beliefs are bound to meet with resistance in society. The study employed a mini survey, focus group discussion, observation and document review to understand how the CBCC childcare practices in Malili intersect with commonly held beliefs about childcare as well as how they reflect on the national ECD policy. The study also focused on understanding the perceptions of community members on the CBCC programme. The study revealed that while some aspects of CBCC delivery conform to commonly held beliefs about childcare in the area under study, others diverge from such beliefs. Such convergence and divergence appear to be in line with the propositions of transformalist globalisation theory- one of the perspectives adopted for the study. The study also found that care practices at CBCC are not a true reflection of the national ECD policy as community members’ perceptions, poor community participation, poverty and lack of caregiver training in ECD contribute towards poor quality of care in CBCC, contrary to what is defined in the national ECD policy. The study also found that while both CBCC caregivers and sampled community members perceived the quality of care at the centers as poor, caregivers had a more positive perception towards the CBCC than community members. The study indicated that CBCC are centres of desperation for low economic status communities. Findings from the research have revealed that cultural values and commonly held beliefs, and exposure to new knowledge through globalisation play a role in determining childcare practices as well as perceptions towards them. In this sense the study has indicated that meanings that communities attach to development interventions influence their actions and perceptions towards it.
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