Functionalized Ru(II) polypyridines and phthalocyanines: Potential dyes for dye-sensitized solar cells(DSSCs)
- Adeloye, Adewale Olufunsho https://orcid.org/0000-0003-1736-5738
- Authors: Adeloye, Adewale Olufunsho https://orcid.org/0000-0003-1736-5738
- Date: 2011-01
- Subjects: Phthalocyanines , Dye-sensitized solar cells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24343 , vital:62638
- Description: This study describes the design, synthesis, characterization and preliminary investigation of the solar-to-electrical energy conversion efficiency of ruthenium(II) functionalized polypyridine and phthalocyanine complexes with extended π-conjugation. Polypyridinyl functionalized with anthracene, 2,3-dimethylacrylic acid and 1-methoxy-1-buten-3-yne were synthesized and characterized by infrared, UV-Vis, photoluminescence, 1H and 13C NMR and elemental analysis. The functionalized polypyridine molecules were used to synthesize various ruthenium(II) homoleptic/heteroleptic and/or heteronuclear complexes and their photophysical and electrochemical properties evaluated. The preliminary results of the solar-to-electrical conversion efficiencies of some synthesized Ru(II) polypyridyl complexes were presented in chapter 5. It was found out as expected that the ruthenium(II) polypyridine complexes containing either heteronuclear polypyridine ligands or their thiocyanate analogues of the types [Ru(L1)2L2(PF6)2], [RuL1(L2)2(PF6)2] and [RuL1L2(NCS)2], showed better photophysical properties (red-shifted metal-to-ligand charge-transfer (MLCT) transitions concomitant with enhanced molar extinction coefficients), luminescence and interesting electrochemical redox properties than those containing homonuclear ligand types [Ru(L1)3(PF6)2]. The ruthenium(II) anthracenyl functionalized phthalocyanine complexes which were obtained by electrophilic aromatic substitution reactions in the peripheral positions gave good solubility properties in various organic solvents and also showed interesting near infrared absorption and electroredox characteristics. Cyclic and square wave voltammetries of these complexes revealed major redox processes and the numbers of electron(s) transfer were determined by chronocoulometry. It was established that a mono- and/or multi-electronic transfer reactions can occur in the various ruthenium(II) complexes. The photophysical properties of some complexes showed them to be better and promising candidates in the design of chemosensors, organic light emitting diodes (OLEDs) and as photosensitizers, while their redox-active natures make them potential mediators in electron-transfer for various photochemical processes. However, due to low surface concentration and/or adsorption of some tested complexes on TiO2 semiconductor nanocrystalline particle, low currents were generated and the highest solar-to-electrical conversion efficiency recorded in this study was 0.10 percent. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-01
- Authors: Adeloye, Adewale Olufunsho https://orcid.org/0000-0003-1736-5738
- Date: 2011-01
- Subjects: Phthalocyanines , Dye-sensitized solar cells
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24343 , vital:62638
- Description: This study describes the design, synthesis, characterization and preliminary investigation of the solar-to-electrical energy conversion efficiency of ruthenium(II) functionalized polypyridine and phthalocyanine complexes with extended π-conjugation. Polypyridinyl functionalized with anthracene, 2,3-dimethylacrylic acid and 1-methoxy-1-buten-3-yne were synthesized and characterized by infrared, UV-Vis, photoluminescence, 1H and 13C NMR and elemental analysis. The functionalized polypyridine molecules were used to synthesize various ruthenium(II) homoleptic/heteroleptic and/or heteronuclear complexes and their photophysical and electrochemical properties evaluated. The preliminary results of the solar-to-electrical conversion efficiencies of some synthesized Ru(II) polypyridyl complexes were presented in chapter 5. It was found out as expected that the ruthenium(II) polypyridine complexes containing either heteronuclear polypyridine ligands or their thiocyanate analogues of the types [Ru(L1)2L2(PF6)2], [RuL1(L2)2(PF6)2] and [RuL1L2(NCS)2], showed better photophysical properties (red-shifted metal-to-ligand charge-transfer (MLCT) transitions concomitant with enhanced molar extinction coefficients), luminescence and interesting electrochemical redox properties than those containing homonuclear ligand types [Ru(L1)3(PF6)2]. The ruthenium(II) anthracenyl functionalized phthalocyanine complexes which were obtained by electrophilic aromatic substitution reactions in the peripheral positions gave good solubility properties in various organic solvents and also showed interesting near infrared absorption and electroredox characteristics. Cyclic and square wave voltammetries of these complexes revealed major redox processes and the numbers of electron(s) transfer were determined by chronocoulometry. It was established that a mono- and/or multi-electronic transfer reactions can occur in the various ruthenium(II) complexes. The photophysical properties of some complexes showed them to be better and promising candidates in the design of chemosensors, organic light emitting diodes (OLEDs) and as photosensitizers, while their redox-active natures make them potential mediators in electron-transfer for various photochemical processes. However, due to low surface concentration and/or adsorption of some tested complexes on TiO2 semiconductor nanocrystalline particle, low currents were generated and the highest solar-to-electrical conversion efficiency recorded in this study was 0.10 percent. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Date Issued: 2011-01
Assessment of phytochemical constituents, antioxidant properties and cytotoxicity potentials of Leonutis leonurus and Boophone disticha extracts used in the management of Alzheimer’s disease in Hogsback, Eastern Cape, South Africa
- Authors: Tonisi, Sipho
- Date: 2019
- Subjects: Medicinal plants Alzheimer's disease
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14726 , vital:40067
- Description: In this present study, the phytochemical compounds, antioxidant activities, and cytotoxicity potentials of solvent extracts (polar solvents) of Leonotis leonurus (L. leonurus) and Boophone disitcha (B. disticha) commonly used in the management of Alzheimer’s diseases in Hogsback, in the Eastern Cape, South Africa were investigated. The phytochemical compounds were determined by standard protocols of Folin–Ciocalteu method, aluminium chloride colorimetric method as well as Mayer’s and Wagner’s method. The antioxidant capabilities were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and nitric oxide radical scavenging assays. The majority of extracts from both plant species exhibited free radical scavenging potential for oxidants they were tested against viz; DPPH, hydrogen peroxide, ABTS and nitric oxide. They further displayed good reducing potential against ferric iron. The results have shown a concentration-dependent dose of inhibition/scavenging activity (in DPPH, hydrogen peroxide, ABTS and nitric oxide assays) and reducing ability (in ferric reducing assay). However, leaf extracts of L. leonurus displayed ineffective scavenging activity against nitric oxide whereas extracts from L. leonurus flower and B. disticha bulb had higher scavenging potential against the production of nitric oxide radical. The GC-MS profiles of the plants extracts revealed the presence of numerous bioactive compounds that are known to possess excellent anti-inflammatory and most importantly antioxidant properties. Another interesting observation of GC-MS analysis data was the presence of compounds reported to inhibit Acetycholinesterase (AChE), which is a key enzyme targeted in the treatment of Alzheimers’ Disease (AD). The cytotoxicy tests for these extracts were carried out in order to assess the potentential detrimental effects on human health using Alamar Blue assay. It was noted that an increase in the extract concentration of both plant species resulted in a noticeable decline in cell population. These extracts were then declared xix to be quite toxic against HeLa (human cervix adenocarcinoma cells) cells as the cell viability in some extracts was quite low. Hence, toxicity testing of the studied plants’ extracts against normal cells is highly imperative in the future study. The results from this present study scientifically validated the use of the studied plants in folkoric medicine for the management of Alzheimer’s diseases.
- Full Text:
- Date Issued: 2019
- Authors: Tonisi, Sipho
- Date: 2019
- Subjects: Medicinal plants Alzheimer's disease
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: http://hdl.handle.net/10353/14726 , vital:40067
- Description: In this present study, the phytochemical compounds, antioxidant activities, and cytotoxicity potentials of solvent extracts (polar solvents) of Leonotis leonurus (L. leonurus) and Boophone disitcha (B. disticha) commonly used in the management of Alzheimer’s diseases in Hogsback, in the Eastern Cape, South Africa were investigated. The phytochemical compounds were determined by standard protocols of Folin–Ciocalteu method, aluminium chloride colorimetric method as well as Mayer’s and Wagner’s method. The antioxidant capabilities were assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and nitric oxide radical scavenging assays. The majority of extracts from both plant species exhibited free radical scavenging potential for oxidants they were tested against viz; DPPH, hydrogen peroxide, ABTS and nitric oxide. They further displayed good reducing potential against ferric iron. The results have shown a concentration-dependent dose of inhibition/scavenging activity (in DPPH, hydrogen peroxide, ABTS and nitric oxide assays) and reducing ability (in ferric reducing assay). However, leaf extracts of L. leonurus displayed ineffective scavenging activity against nitric oxide whereas extracts from L. leonurus flower and B. disticha bulb had higher scavenging potential against the production of nitric oxide radical. The GC-MS profiles of the plants extracts revealed the presence of numerous bioactive compounds that are known to possess excellent anti-inflammatory and most importantly antioxidant properties. Another interesting observation of GC-MS analysis data was the presence of compounds reported to inhibit Acetycholinesterase (AChE), which is a key enzyme targeted in the treatment of Alzheimers’ Disease (AD). The cytotoxicy tests for these extracts were carried out in order to assess the potentential detrimental effects on human health using Alamar Blue assay. It was noted that an increase in the extract concentration of both plant species resulted in a noticeable decline in cell population. These extracts were then declared xix to be quite toxic against HeLa (human cervix adenocarcinoma cells) cells as the cell viability in some extracts was quite low. Hence, toxicity testing of the studied plants’ extracts against normal cells is highly imperative in the future study. The results from this present study scientifically validated the use of the studied plants in folkoric medicine for the management of Alzheimer’s diseases.
- Full Text:
- Date Issued: 2019
Molecular characterization of integrons and their associated gene cassettes in multidrug-resistant enterobacteriaceae isolates from environmental sources and the exploration of antibiotic combination against some resistant strains
- Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Date: 2023
- Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27809 , vital:69942
- Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
- Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Date: 2023
- Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27809 , vital:69942
- Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023
Synthesis and characterization of titanium dioxide nanotubes on fluorine-doped tin oxide (FTO) glass substrate using electro-anodization technique
- Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Authors: Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Date: 2017-12
- Subjects: Titanium dioxide , Nanotubes , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23979 , vital:62201
- Description: One-dimensional (1-D) titanium dioxide nanotubes (TNTs) have attracted much attention as a promising alternative electrode material for dye sensitized solar cell (DSSC). As compared to the randomly packed and disordered TiO2 nanoparticles (TNPs) network with numerous particle-particle interfaces, TNTs prove to have fascinating features than make them suitable candidates in DSSCs. Well-structured TNTs arrays are of great potential among the various types of 1D TiO2 nano-materials owing to their superior electron transport properties with limited grain boundaries. Vectorial transport of photon generated electrons along the TNTs has been reported to lead to higher charge mobility which is crucial for improvement of DSSC performances. In this work, highly adhesive titanium films were deposited on functional substrates (FS) using radio frequency (RF) sputtering technique at a sputtering output power of 1kW, operating pressure of 1.5 Pa and at a deposition temperature of 200 °C to obtain a thickness of 10 μm under an inert argon atmosphere. The duration period for sputter coating 10 μm thickness of titanium film layer was 122 minutes with sputter rate for titanium target of about 82 nm per minutes. Subsequently, the RF sputtered titanium films were anodized with 0.5 wt. percent ammonium fluoride + 0.35 wt. percent deionised water and 96 wt. percent glycerol electrolyte solution at room temperature at 60 V for 72 hours. The resulting TNTs on functional substrates (TNTs-FS) were subjected to thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C for 3 hours under oxygen atmosphere. The effect of annealing temperature on the morphological, and structural properties have been scrutinized. The as prepared and thermally treated TNTs-FS were characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Confocal Raman Spectroscopy (CRS). SEM and HRTEM techniques were employed to confirm the presence of the TNTs-FS and also to study the structural-morphology of the TNTs as the annealing temperature increases. SEM revealed improvement in morphology with increase in sample annealing temperature, even at high temperatures such as 650 °C with no collapsing and sintering of the TNTs-FS occurring. SEM images revealed TNTs-FS with pore diameter sizes in the range between 85-170 nm. This is in compliance with HRTEM analysis, which revealed smooth and straight tube walls and improved surface morphology with increase in annealing temperature. In addition HRTEM images revealed pore diameter of TNTs-FS in the range between 85-165 nm. Furthermore, HRTEM revealed lattice fringes of 0.351, 0.352 and 0.353 nm between the neighbouring lattice fringes. All corresponding to (101) planes of anatase phase TNTs at different annealing temperatures (350-650 °C). The crystallographic structure of TNTs-FS was characterized by XRD measurements after thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C. The XRD pattern revealed peaks in the wide angle range of 2θ (20° < 2θ > 80°) discovered at 29.43°, 45.10°, 56.52°, 63.5°, 64.92° and 74.81° corresponding to the planes (101), (112), (200), (105), (211) and (204) crystalline structures of the anatase TNTs. The intensity of the peaks increased with increasing annealing temperature. The strong sharp peaks indicate the large quantities and higher degrees of crystallinity of anatase phase of the TNTs. CRS Large Area Scan (LAS) and Depth profiling (DP) were employed to evaluate the crystallinity and phase distribution of TNTs-FS thermally treated at different temperatures. CRS LAS in the XY direction of TNTs-FS revealed the presence of differently crystallized anatase phases of TiO2 with Raman vibrational modes of 159.38 cm-1 (Eg), 208.37 cm-1 (Eg), 399.67 cm-1 (B1g), 514.25 cm-1 (A1g) and 641.58 cm-1 (Eg) for the samples annealed at 350 °C. The effect of annealing temperature on TiO2 phase evolution was meticulously evaluated using CRS for TNTs-FS for the samples annealed at 350 °C, 450 °C, 550 °C and 650 °C. The FWHM was estimated from CRS and decreases with increasing annealing temperature resulting in increasing crystallinity. Increase in anatase FWHM and anatase peak intensity implies higher degree of crystallinity and increasing crystallite sizes were also confirmed by XRD. Growing of titanium dioxide on functional substrates one novel contribution towards the fabrication of efficient electrode materials for solar cell development. Our method of characterizing TNTs-FS from a large area scan along the surface of the samples and depth profiling along the TNTs tube walls using confocal Raman spectroscopy prove to be a pivotal step in the development of efficient photoelectrode materials of the solar devices. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017-12
- Authors: Zinya, Simcelile https://orcid.org/0000-0001-5864-0957
- Date: 2017-12
- Subjects: Titanium dioxide , Nanotubes , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23979 , vital:62201
- Description: One-dimensional (1-D) titanium dioxide nanotubes (TNTs) have attracted much attention as a promising alternative electrode material for dye sensitized solar cell (DSSC). As compared to the randomly packed and disordered TiO2 nanoparticles (TNPs) network with numerous particle-particle interfaces, TNTs prove to have fascinating features than make them suitable candidates in DSSCs. Well-structured TNTs arrays are of great potential among the various types of 1D TiO2 nano-materials owing to their superior electron transport properties with limited grain boundaries. Vectorial transport of photon generated electrons along the TNTs has been reported to lead to higher charge mobility which is crucial for improvement of DSSC performances. In this work, highly adhesive titanium films were deposited on functional substrates (FS) using radio frequency (RF) sputtering technique at a sputtering output power of 1kW, operating pressure of 1.5 Pa and at a deposition temperature of 200 °C to obtain a thickness of 10 μm under an inert argon atmosphere. The duration period for sputter coating 10 μm thickness of titanium film layer was 122 minutes with sputter rate for titanium target of about 82 nm per minutes. Subsequently, the RF sputtered titanium films were anodized with 0.5 wt. percent ammonium fluoride + 0.35 wt. percent deionised water and 96 wt. percent glycerol electrolyte solution at room temperature at 60 V for 72 hours. The resulting TNTs on functional substrates (TNTs-FS) were subjected to thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C for 3 hours under oxygen atmosphere. The effect of annealing temperature on the morphological, and structural properties have been scrutinized. The as prepared and thermally treated TNTs-FS were characterized using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Confocal Raman Spectroscopy (CRS). SEM and HRTEM techniques were employed to confirm the presence of the TNTs-FS and also to study the structural-morphology of the TNTs as the annealing temperature increases. SEM revealed improvement in morphology with increase in sample annealing temperature, even at high temperatures such as 650 °C with no collapsing and sintering of the TNTs-FS occurring. SEM images revealed TNTs-FS with pore diameter sizes in the range between 85-170 nm. This is in compliance with HRTEM analysis, which revealed smooth and straight tube walls and improved surface morphology with increase in annealing temperature. In addition HRTEM images revealed pore diameter of TNTs-FS in the range between 85-165 nm. Furthermore, HRTEM revealed lattice fringes of 0.351, 0.352 and 0.353 nm between the neighbouring lattice fringes. All corresponding to (101) planes of anatase phase TNTs at different annealing temperatures (350-650 °C). The crystallographic structure of TNTs-FS was characterized by XRD measurements after thermal treatment at 350 °C, 450 °C, 550 °C and 650 °C. The XRD pattern revealed peaks in the wide angle range of 2θ (20° < 2θ > 80°) discovered at 29.43°, 45.10°, 56.52°, 63.5°, 64.92° and 74.81° corresponding to the planes (101), (112), (200), (105), (211) and (204) crystalline structures of the anatase TNTs. The intensity of the peaks increased with increasing annealing temperature. The strong sharp peaks indicate the large quantities and higher degrees of crystallinity of anatase phase of the TNTs. CRS Large Area Scan (LAS) and Depth profiling (DP) were employed to evaluate the crystallinity and phase distribution of TNTs-FS thermally treated at different temperatures. CRS LAS in the XY direction of TNTs-FS revealed the presence of differently crystallized anatase phases of TiO2 with Raman vibrational modes of 159.38 cm-1 (Eg), 208.37 cm-1 (Eg), 399.67 cm-1 (B1g), 514.25 cm-1 (A1g) and 641.58 cm-1 (Eg) for the samples annealed at 350 °C. The effect of annealing temperature on TiO2 phase evolution was meticulously evaluated using CRS for TNTs-FS for the samples annealed at 350 °C, 450 °C, 550 °C and 650 °C. The FWHM was estimated from CRS and decreases with increasing annealing temperature resulting in increasing crystallinity. Increase in anatase FWHM and anatase peak intensity implies higher degree of crystallinity and increasing crystallite sizes were also confirmed by XRD. Growing of titanium dioxide on functional substrates one novel contribution towards the fabrication of efficient electrode materials for solar cell development. Our method of characterizing TNTs-FS from a large area scan along the surface of the samples and depth profiling along the TNTs tube walls using confocal Raman spectroscopy prove to be a pivotal step in the development of efficient photoelectrode materials of the solar devices. , Thesis (MSc) -- Faculty of Science and Agriculture, 2017
- Full Text:
- Date Issued: 2017-12
The effect of phosphorus fertilizer application on growth, biomass and nutritive value of Pigeon pea (Cajanus cajan (L.) Millsp.) varieties in Alice, South Africa
- Authors: Mpabanga, Nkosi
- Date: 2017
- Subjects: Phosphatic fertilizers Soil fertility Plants -- Effect of phosphorus on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6180 , vital:29501
- Description: Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.
- Full Text:
- Date Issued: 2017
- Authors: Mpabanga, Nkosi
- Date: 2017
- Subjects: Phosphatic fertilizers Soil fertility Plants -- Effect of phosphorus on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/6180 , vital:29501
- Description: Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.
- Full Text:
- Date Issued: 2017
Profitability and technical efficiency of small-scale organic crop farmers’ in the Eastern Cape Province of South Africa
- Eyinade, Gabriel A https://orcid.org/0000-0001-8851-7255
- Authors: Eyinade, Gabriel A https://orcid.org/0000-0001-8851-7255
- Date: 2019-08
- Subjects: Organic farming , Farms, Small
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23633 , vital:58229
- Description: Organic farming is growing gradually in South Africa. Its contribution to economic growth and poverty mitigation is notably in the pastoral areas in terms of providing adequate and affordable food for the incessantly growing population. Organic farming is also known for provision of employment and source of livelihoods for the rural populace as well as supply of raw materials to the country’s agro-allied industrial sector. For the purposes of this research, focus was only on profitability and technical efficiency because it is an essential subject in developing agriculture where resources are limited, but high population growth is very common. As a result, increased output will rely more on efficiency enhancements which will further intensify farmers’ income. As such, evaluating the extent for such efficiency enhancements within the system is a crucial prerequisite. The objective of the study was to assess the profitability and technical efficiency; and to identify socio-economic, institutional and farm characteristics that influence profitability and the technical efficiency of the small-scale organic crop farmers in the Buffalo City Metropolitan Municipality (BCMM). A purposive sampling technique was used to collect primary data from 160 small-scale organic crop farmers in BCMM. The gross margin estimation was used to estimate profitability, while multivariate Ordinary Least Square (OLS) was used to assess socio-demographic factors influencing profitability. The stochastic frontier model was used to determine the level of technical efficiency as well as the determinants of technical inefficiency of the farmers. The results of the gross margin estimation show that the small-scale organic maize (GM= R392 417.00) and cabbage (R196 489.00) farms were profitable. Similarly, the results of the OLS showed that one out of the eight variables namely, farming experience influences organic maize producers’ profitability, while factors such as gender, household size, and educational level emerged as the major significant factors influencing organic cabbage producers’ profitability. The stochastic results revealed that small-scale organic crop farmers in the study area are technically efficient at 86percent in maize production and 93percent in cabbage production respectively; and experienced unity return to scale (1.0) in maize and increasing return to scale (1.2) in cabbage. The results suggested that an increase in the use of input, would also intensify their productivity and efficiency. The results from the inefficiecncy model of the stochastic frontier further show that age and farming experience are the major determinants of organic maize producers’ technical inefficiency, while, factors such as age, years of schooling, farming experience, and household size were the significant determinants of organic cabbage producers’ technical inefficiency. To enhance the farming potential of these farmers, it is recommended that government and other several stakeholders such as researchers, entrepreneurs should invest more in organic crop farms since it is profitable and efficient in improving farmers’ livelihoods. There is also need for government to organise on-going workshops and extension training through the help of extension officers on how farmers can improve their production which will further enhance their income. , Thesis (PhD) -- Faculty of Science and Agriculture, 2019
- Full Text:
- Date Issued: 2019-08
- Authors: Eyinade, Gabriel A https://orcid.org/0000-0001-8851-7255
- Date: 2019-08
- Subjects: Organic farming , Farms, Small
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23633 , vital:58229
- Description: Organic farming is growing gradually in South Africa. Its contribution to economic growth and poverty mitigation is notably in the pastoral areas in terms of providing adequate and affordable food for the incessantly growing population. Organic farming is also known for provision of employment and source of livelihoods for the rural populace as well as supply of raw materials to the country’s agro-allied industrial sector. For the purposes of this research, focus was only on profitability and technical efficiency because it is an essential subject in developing agriculture where resources are limited, but high population growth is very common. As a result, increased output will rely more on efficiency enhancements which will further intensify farmers’ income. As such, evaluating the extent for such efficiency enhancements within the system is a crucial prerequisite. The objective of the study was to assess the profitability and technical efficiency; and to identify socio-economic, institutional and farm characteristics that influence profitability and the technical efficiency of the small-scale organic crop farmers in the Buffalo City Metropolitan Municipality (BCMM). A purposive sampling technique was used to collect primary data from 160 small-scale organic crop farmers in BCMM. The gross margin estimation was used to estimate profitability, while multivariate Ordinary Least Square (OLS) was used to assess socio-demographic factors influencing profitability. The stochastic frontier model was used to determine the level of technical efficiency as well as the determinants of technical inefficiency of the farmers. The results of the gross margin estimation show that the small-scale organic maize (GM= R392 417.00) and cabbage (R196 489.00) farms were profitable. Similarly, the results of the OLS showed that one out of the eight variables namely, farming experience influences organic maize producers’ profitability, while factors such as gender, household size, and educational level emerged as the major significant factors influencing organic cabbage producers’ profitability. The stochastic results revealed that small-scale organic crop farmers in the study area are technically efficient at 86percent in maize production and 93percent in cabbage production respectively; and experienced unity return to scale (1.0) in maize and increasing return to scale (1.2) in cabbage. The results suggested that an increase in the use of input, would also intensify their productivity and efficiency. The results from the inefficiecncy model of the stochastic frontier further show that age and farming experience are the major determinants of organic maize producers’ technical inefficiency, while, factors such as age, years of schooling, farming experience, and household size were the significant determinants of organic cabbage producers’ technical inefficiency. To enhance the farming potential of these farmers, it is recommended that government and other several stakeholders such as researchers, entrepreneurs should invest more in organic crop farms since it is profitable and efficient in improving farmers’ livelihoods. There is also need for government to organise on-going workshops and extension training through the help of extension officers on how farmers can improve their production which will further enhance their income. , Thesis (PhD) -- Faculty of Science and Agriculture, 2019
- Full Text:
- Date Issued: 2019-08
Evaluation of the utilisation of game liver and maize meal in the production of liver sausage
- Authors: Cairncross, Kelly Inga
- Date: 2020-02
- Subjects: Meat -- Preservation , Sausages
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23743 , vital:59029
- Description: The study aimed to evaluate the utilisation of game liver and maize meal as a partial fat replacer in the production of liver sausage. Mixed game livers (Blesbok, Impala and Springbok) were purchased and processed into sausages with varying levels of maize meal (6percent, 8percent, 10percent and 12percent). The liver sausages were cooked in a water bath for 2 hours to an internal temperate of 70 °C. Cooked sausages were cooled in ice water before storage at 4 °C before vacuum packed and frozen at -20 °C for 30 days. Proximate and fatty acid composition, pH, water activity, texture, lipid oxidation, and microbial content was determined on both day 0 and 30 days after frozen storage. Of the proximate composition, carbohydrate content had significant differences (P≤0.05) and increased as maize meal inclusion increased. The pH of raw game liver sausage batter differed (P≤0.05) between treatments. The pH of cooked game liver sausage differed (P≤0.05) from the raw batter. Textural parameters showed an increase (P<0.01) for both hardness and chewiness after 30 days of frozen storage. A positive correlation was found between hardness and chewiness with an increase in maize meal inclusion. TBARS values of the 12percent treatment differed (P≤0.05) from the maize meal inclusion treatments, but no differences (P>0.05) were recorded over 30 days of frozen storage. No differences (P>0.05) were recorded for the fatty acid composition between treatments. No growth was observed for microbial quality indicators nor Campylobacter spp. for all treatments. This study showed that frozen storage only had a negative effect on some textural parameters, while the inclusion of maize meal affects most physicochemical characteristics. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-02
- Authors: Cairncross, Kelly Inga
- Date: 2020-02
- Subjects: Meat -- Preservation , Sausages
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/23743 , vital:59029
- Description: The study aimed to evaluate the utilisation of game liver and maize meal as a partial fat replacer in the production of liver sausage. Mixed game livers (Blesbok, Impala and Springbok) were purchased and processed into sausages with varying levels of maize meal (6percent, 8percent, 10percent and 12percent). The liver sausages were cooked in a water bath for 2 hours to an internal temperate of 70 °C. Cooked sausages were cooled in ice water before storage at 4 °C before vacuum packed and frozen at -20 °C for 30 days. Proximate and fatty acid composition, pH, water activity, texture, lipid oxidation, and microbial content was determined on both day 0 and 30 days after frozen storage. Of the proximate composition, carbohydrate content had significant differences (P≤0.05) and increased as maize meal inclusion increased. The pH of raw game liver sausage batter differed (P≤0.05) between treatments. The pH of cooked game liver sausage differed (P≤0.05) from the raw batter. Textural parameters showed an increase (P<0.01) for both hardness and chewiness after 30 days of frozen storage. A positive correlation was found between hardness and chewiness with an increase in maize meal inclusion. TBARS values of the 12percent treatment differed (P≤0.05) from the maize meal inclusion treatments, but no differences (P>0.05) were recorded over 30 days of frozen storage. No differences (P>0.05) were recorded for the fatty acid composition between treatments. No growth was observed for microbial quality indicators nor Campylobacter spp. for all treatments. This study showed that frozen storage only had a negative effect on some textural parameters, while the inclusion of maize meal affects most physicochemical characteristics. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
- Full Text:
- Date Issued: 2020-02
Role of home gardens in enhancing food security in rural and urban areas : a case study of Nkonkobe Municipality, Eastern Cape South Africa
- Authors: Mcata, Bongiwe
- Date: 2013
- Subjects: Food security -- South Africa -- Eastern Cape Gardening -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13105 , vital:39465
- Description: In South Africa, home gardens are an important source of food and nutrition. In both urban and rural areas, home gardens have been a traditional way of providing food and offer a great potential for improving household food security and alleviating micronutrient deficiencies. In the Eastern Cape Province which is the second largest province in South Africa, and is characterized by poverty, home gardens can help enhance household food security through direct access to nutritionally-rich fresh vegetables. Home gardens are also becoming an important source of food and income, especially for poor households, in both urban and rural areas. 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 This study was carried out to investigate the role of home gardens in addressing household food security in urban and rural areas of Nkonkobe Municipality. The study also identified the factors affecting the ownership of home gardens and food security. Data was collected from 160 households from both the urban and rural areas of the Nkonkobe Municipality. These households were selected through the use of stratified random sampling. Data was collected by a questionnaire was administered through face-to-face interviews. Frequencies and means were used to describe the general characteristics of the households as well as ownership patterns of home gardens. In order to determine the factors that influence home gardens and food security among the sampled households, a binary logistic regression model was adopted. The results show that the statistically significant variables, at the 5percent level, on food security are total income and home garden ownership. Food security was measured using the dietary diversity score. Location, access to land and education significantly affect the ownership of home gardens positively. In view of the research findings, several policy proposals are suggested. These include greater investment in programmes such as Massive food projects, Siyazondla and related home garden initiatives. Household income can be improved by promoting more non-agricultural activities in order to ensure household food security.
- Full Text:
- Date Issued: 2013
- Authors: Mcata, Bongiwe
- Date: 2013
- Subjects: Food security -- South Africa -- Eastern Cape Gardening -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13105 , vital:39465
- Description: In South Africa, home gardens are an important source of food and nutrition. In both urban and rural areas, home gardens have been a traditional way of providing food and offer a great potential for improving household food security and alleviating micronutrient deficiencies. In the Eastern Cape Province which is the second largest province in South Africa, and is characterized by poverty, home gardens can help enhance household food security through direct access to nutritionally-rich fresh vegetables. Home gardens are also becoming an important source of food and income, especially for poor households, in both urban and rural areas. 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 This study was carried out to investigate the role of home gardens in addressing household food security in urban and rural areas of Nkonkobe Municipality. The study also identified the factors affecting the ownership of home gardens and food security. Data was collected from 160 households from both the urban and rural areas of the Nkonkobe Municipality. These households were selected through the use of stratified random sampling. Data was collected by a questionnaire was administered through face-to-face interviews. Frequencies and means were used to describe the general characteristics of the households as well as ownership patterns of home gardens. In order to determine the factors that influence home gardens and food security among the sampled households, a binary logistic regression model was adopted. The results show that the statistically significant variables, at the 5percent level, on food security are total income and home garden ownership. Food security was measured using the dietary diversity score. Location, access to land and education significantly affect the ownership of home gardens positively. In view of the research findings, several policy proposals are suggested. These include greater investment in programmes such as Massive food projects, Siyazondla and related home garden initiatives. Household income can be improved by promoting more non-agricultural activities in order to ensure household food security.
- Full Text:
- Date Issued: 2013
Integrating legacy applications into service oriented architecture middleware
- Makamba, Makaziwe https://orcid.org/0000-0001-6998-4480
- Authors: Makamba, Makaziwe https://orcid.org/0000-0001-6998-4480
- Date: 2012-12
- Subjects: Service-oriented architecture (Computer science) , Computer architecture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24294 , vital:62599
- Description: Information and Communication Technology (ICT) is a dynamic approach that is widely recognized as an innovative and powerful tool for socio-economic development, it is a key catalyst for the emergence of knowledge economy. ICT have been used to develop applications, promote transparency and efficiency in multiple services such e-Learning, e-Government, e-Health and e-Judiciary especially for Marginalized Rural Areas (MRAs). The ICT approach is designed to bridge the digital divide. This approach has been widely deployed in many programs and it has led to the development of a new field which is Information and Communication Technology for Development (ICT4D). Within the context of ICT4D there are arrays of e-services that have been deployed to improve the impoverished communities. Some of these applications have failed to bring the changes that were designed to bring in the community due to the use of old architectures. There is therefore a need to develop a system that will integrate legacy applications into contemporary architectures. To solve the problem of the legacy applications we have developed TeleWeaver Service Oriented Architecture (SOA) middleware into which we integrate an e-Commerce and e-Learning applications into SOA middleware. For this integration system there are specific technologies that were used to integrate legacy applications into SOA middleware: RESTful web services using the slim API, SOAP via Nu-SOAP technologies were used to integrate these legacy applications. Specific methodologies were used to achieve the objectives of this research. The literature review, brainstorming, interviews and development of the system are some of the methods that were used to achieve the objectives of this study. The research methodology is mainly through experiments and to study TeleWeaver SOA middleware architecture. Interviews were conducted to analyze and understand the community needs, since the application discussed in this thesis is tested and implemented for a rural community. The community is called Dwesa, and falls under the ICT project within the Siyakhula Living Lab (SLL). A basic prototyping and Unified Modeling Language (UML) was created to design the system. This thesis presents the design and implementation of a system that integrates legacy applications into an SOA middleware that brings flexibility and effectiveness to these ICT e-services. The research focuses on integrating legacy applications into Service Oriented Architecture (SOA) middleware. It seeks to bring flexibility to e-services that are developed for MRAs. The use of SOA architecture that supports re-usability and interoperability of application provides effectiveness to the e-services. The novelty of the system is in its flexibility, usability and sustainability. SOA is an approach that provides a separation between the interface of the service and its underlying implementation. One of the achievements of the integration project is its ability to connect to SOA middleware. This increases the effectiveness of these e-services. The usability and performance evaluations are conducted to test and evaluate the system within the SLL on the TeleWeaver platform. , Thesis (MSc) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012-12
- Authors: Makamba, Makaziwe https://orcid.org/0000-0001-6998-4480
- Date: 2012-12
- Subjects: Service-oriented architecture (Computer science) , Computer architecture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24294 , vital:62599
- Description: Information and Communication Technology (ICT) is a dynamic approach that is widely recognized as an innovative and powerful tool for socio-economic development, it is a key catalyst for the emergence of knowledge economy. ICT have been used to develop applications, promote transparency and efficiency in multiple services such e-Learning, e-Government, e-Health and e-Judiciary especially for Marginalized Rural Areas (MRAs). The ICT approach is designed to bridge the digital divide. This approach has been widely deployed in many programs and it has led to the development of a new field which is Information and Communication Technology for Development (ICT4D). Within the context of ICT4D there are arrays of e-services that have been deployed to improve the impoverished communities. Some of these applications have failed to bring the changes that were designed to bring in the community due to the use of old architectures. There is therefore a need to develop a system that will integrate legacy applications into contemporary architectures. To solve the problem of the legacy applications we have developed TeleWeaver Service Oriented Architecture (SOA) middleware into which we integrate an e-Commerce and e-Learning applications into SOA middleware. For this integration system there are specific technologies that were used to integrate legacy applications into SOA middleware: RESTful web services using the slim API, SOAP via Nu-SOAP technologies were used to integrate these legacy applications. Specific methodologies were used to achieve the objectives of this research. The literature review, brainstorming, interviews and development of the system are some of the methods that were used to achieve the objectives of this study. The research methodology is mainly through experiments and to study TeleWeaver SOA middleware architecture. Interviews were conducted to analyze and understand the community needs, since the application discussed in this thesis is tested and implemented for a rural community. The community is called Dwesa, and falls under the ICT project within the Siyakhula Living Lab (SLL). A basic prototyping and Unified Modeling Language (UML) was created to design the system. This thesis presents the design and implementation of a system that integrates legacy applications into an SOA middleware that brings flexibility and effectiveness to these ICT e-services. The research focuses on integrating legacy applications into Service Oriented Architecture (SOA) middleware. It seeks to bring flexibility to e-services that are developed for MRAs. The use of SOA architecture that supports re-usability and interoperability of application provides effectiveness to the e-services. The novelty of the system is in its flexibility, usability and sustainability. SOA is an approach that provides a separation between the interface of the service and its underlying implementation. One of the achievements of the integration project is its ability to connect to SOA middleware. This increases the effectiveness of these e-services. The usability and performance evaluations are conducted to test and evaluate the system within the SLL on the TeleWeaver platform. , Thesis (MSc) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012-12
Understanding the links between smallholder farmers and retailers of meat and vegetables in Mthatha, Mqanduli, Port St Johns and Tsolo, Eastern Cape, South Africa
- Authors: Qaula, Nyaniso
- Date: 2020
- Subjects: Farms, Small
- Language: English
- Type: Thesis , Masters , M Agric
- Identifier: http://hdl.handle.net/10353/18823 , vital:42811
- Description: It is commonly accepted that one of the challenges faced by smallholder farmers is lack of ‘access to markets’. This is especially so against the backdrop of the supermarket revolution, which is widely understood to give advantage to large-scale farmers at the expense of smallholder farmers. Given that supermarkets are now well established even within South Africa’s former homelands, it would seem that even smallholders based in these areas are at a disadvantage. The purpose of this study is to delve deeply into the market access of smallholder farmers, and to do so specifically across a large area of the former Transkei where supermarkets are well established and where there are also a range of other types of retailers. The study seeks to understand the links between smallholder farmers and diverse kinds of food retailers of meat and vegetables in and around the towns of Mthatha, Mqanduli, Port St Johns and Tsolo in the Eastern Cape Province, South Africa. For each of these sites, the study estimates the share of purchased fresh vegetables and meat that ultimately originates from smallholder farmers within the former Transkei, as opposed to large-scale farmers further afield. The findings suggest that smallholder farmers account for about 24% to 40% of fresh vegetables, and 3% to 13% of meat. The difference between vegetables and meat seems to relate to the fact that smallholder farmers account for a reasonably large share of the fresh vegetables sold by at least some supermarkets, whereas smallholder livestock farmers are largely unable to sell to abattoirs, whether because of the standards imposed by these abattoirs (including the one in Mthatha), or because of the cost of transport. The differences between sites appear to be a function of several factors, including differential market size and resource endowments. The study further sought to identify the advantages and disadvantages that the different types of retailers experience in procuring from smallholder farmers, and also identify the advantages and disadvantages that smallholder farmers experience in supplying different types of retailers. The advantage of working with smallholder farmers is that smallholder farmers can even deliver on Sundays, unlike other suppliers that refuse to work during weekends. The disadvantage is that smallholder farmers are not producing consistently therefore it is hard to rely on smallholder farmers for supply of produce. The advantage that smallholder farmers experience in supplying different types of retailers is that they get their cash right away after delivering the produce. The challenge that smallholder farmers experience when supplying food retailers is that some of the supermarkets will see the sample and order large quantity, however on the day of delivery they will complain and say it is not the good quality so the farmers must reduce the selling price. The study suggests the strategy that could be used by farmers to access the market, which is to enhance knowledge of market skills and negotiation skills.
- Full Text:
- Date Issued: 2020
- Authors: Qaula, Nyaniso
- Date: 2020
- Subjects: Farms, Small
- Language: English
- Type: Thesis , Masters , M Agric
- Identifier: http://hdl.handle.net/10353/18823 , vital:42811
- Description: It is commonly accepted that one of the challenges faced by smallholder farmers is lack of ‘access to markets’. This is especially so against the backdrop of the supermarket revolution, which is widely understood to give advantage to large-scale farmers at the expense of smallholder farmers. Given that supermarkets are now well established even within South Africa’s former homelands, it would seem that even smallholders based in these areas are at a disadvantage. The purpose of this study is to delve deeply into the market access of smallholder farmers, and to do so specifically across a large area of the former Transkei where supermarkets are well established and where there are also a range of other types of retailers. The study seeks to understand the links between smallholder farmers and diverse kinds of food retailers of meat and vegetables in and around the towns of Mthatha, Mqanduli, Port St Johns and Tsolo in the Eastern Cape Province, South Africa. For each of these sites, the study estimates the share of purchased fresh vegetables and meat that ultimately originates from smallholder farmers within the former Transkei, as opposed to large-scale farmers further afield. The findings suggest that smallholder farmers account for about 24% to 40% of fresh vegetables, and 3% to 13% of meat. The difference between vegetables and meat seems to relate to the fact that smallholder farmers account for a reasonably large share of the fresh vegetables sold by at least some supermarkets, whereas smallholder livestock farmers are largely unable to sell to abattoirs, whether because of the standards imposed by these abattoirs (including the one in Mthatha), or because of the cost of transport. The differences between sites appear to be a function of several factors, including differential market size and resource endowments. The study further sought to identify the advantages and disadvantages that the different types of retailers experience in procuring from smallholder farmers, and also identify the advantages and disadvantages that smallholder farmers experience in supplying different types of retailers. The advantage of working with smallholder farmers is that smallholder farmers can even deliver on Sundays, unlike other suppliers that refuse to work during weekends. The disadvantage is that smallholder farmers are not producing consistently therefore it is hard to rely on smallholder farmers for supply of produce. The advantage that smallholder farmers experience in supplying different types of retailers is that they get their cash right away after delivering the produce. The challenge that smallholder farmers experience when supplying food retailers is that some of the supermarkets will see the sample and order large quantity, however on the day of delivery they will complain and say it is not the good quality so the farmers must reduce the selling price. The study suggests the strategy that could be used by farmers to access the market, which is to enhance knowledge of market skills and negotiation skills.
- Full Text:
- Date Issued: 2020
An Updated Catalogue and Review of Afrotherian (Afroplacentalia) Mammals in the Amathole Museum Collection, Eastern Cape Province, South Africa
- Authors: Mahala, Buyiswa
- Date: 2021-03
- Subjects: Mammals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20741 , vital:46513
- Description: The Mammalogy Collection of the Amathole Museum is one of the most comprehensive mammal collections in Africa, with a specialisation in southern African fauna. It was accumulated over almost 100 years, in some instances from areas that no longer support sustainable populations of wildlife. The collection, therefore, is irreplaceable. A museum collection is only as good as its accessibility to students and researchers for it to perform its functions as a biodiversity archive. Accessibility, in turn, depends on up-to-date taxonomy and classification; good curation practices; public awareness of the collection; and electronic access to the details of the collection’s composition. The higher-level taxonomy of the Class Mammalia has undergone extensive changes since the adoption of molecular systematic techniques. Phylogenetic reconstructions based on large DNA sequence databases consistently group placental mammals into four superorders: Laurasiatheria (carnivores, bats, ungulates, whales); Euarchontoglires, a super-clade that includes primates (apes, monkeys and allies), rodents (mouse, rat and guinea pig), lagomorphs, (rabbit and hares), dermopterans (flying lemurs or colugos) and scandentians (tree shrew); Xenarthra (armadillos, anteaters, sloths), and Afrotheria (elephants, sea cows, tenrecs, aardvarks, sengis, golden moles, hyraxes). New relationships have been recognised that have required the erection of new taxonomic groups. Most of the Amathole Museum mammal collection was assembled and accessioned long before this new system was devised, and I undertook this project to begin the re-organisation of the collection according to the new information. I conducted and audit and inventory of all specimens of Afrotheria, or the mammals of African origin, housed in the Amathole Museum collection. I photographed the specimens and corrected and updated their taxonomic details. As we now live in an age of digital information, natural history collections need to be available online to extend public access. Specimen details were entered into Excel files, and their localities were mapped. This kind of information has the possibility of transforming biological curricula to include more authentic and inquiry-driven educational experiences. My future goals are to acquire Malagasy tenrecs for the Amathole Afrotheria collection, and to investigate the taxonomic validity of the Amathole hyrax collection, as many specimens were found with confusing and out-of-date classifications. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
- Authors: Mahala, Buyiswa
- Date: 2021-03
- Subjects: Mammals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20741 , vital:46513
- Description: The Mammalogy Collection of the Amathole Museum is one of the most comprehensive mammal collections in Africa, with a specialisation in southern African fauna. It was accumulated over almost 100 years, in some instances from areas that no longer support sustainable populations of wildlife. The collection, therefore, is irreplaceable. A museum collection is only as good as its accessibility to students and researchers for it to perform its functions as a biodiversity archive. Accessibility, in turn, depends on up-to-date taxonomy and classification; good curation practices; public awareness of the collection; and electronic access to the details of the collection’s composition. The higher-level taxonomy of the Class Mammalia has undergone extensive changes since the adoption of molecular systematic techniques. Phylogenetic reconstructions based on large DNA sequence databases consistently group placental mammals into four superorders: Laurasiatheria (carnivores, bats, ungulates, whales); Euarchontoglires, a super-clade that includes primates (apes, monkeys and allies), rodents (mouse, rat and guinea pig), lagomorphs, (rabbit and hares), dermopterans (flying lemurs or colugos) and scandentians (tree shrew); Xenarthra (armadillos, anteaters, sloths), and Afrotheria (elephants, sea cows, tenrecs, aardvarks, sengis, golden moles, hyraxes). New relationships have been recognised that have required the erection of new taxonomic groups. Most of the Amathole Museum mammal collection was assembled and accessioned long before this new system was devised, and I undertook this project to begin the re-organisation of the collection according to the new information. I conducted and audit and inventory of all specimens of Afrotheria, or the mammals of African origin, housed in the Amathole Museum collection. I photographed the specimens and corrected and updated their taxonomic details. As we now live in an age of digital information, natural history collections need to be available online to extend public access. Specimen details were entered into Excel files, and their localities were mapped. This kind of information has the possibility of transforming biological curricula to include more authentic and inquiry-driven educational experiences. My future goals are to acquire Malagasy tenrecs for the Amathole Afrotheria collection, and to investigate the taxonomic validity of the Amathole hyrax collection, as many specimens were found with confusing and out-of-date classifications. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
Nutritional quality of sausage made with edible meat waste and the perception of consumers on offal product in Eastern Cape Province, South Africa
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
- Authors: Oluwasegun, Babatunde Alao
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/19021 , vital:40094
- Description: Meat processing at the abattoir provides meat by product and waste while, the major part of the muscle which constitutes a third is edible. The edible by products (EBP) of meat have a notable position in our day-to-day life and are used in diverse forms. However, the quality of offal meat may differ according to intrinsic and extrinsic attributes that may occasionally be shaped by the attitude of consumers towards the products. Therefore, the first objective of this thesis focused on features that might influence consumer preferences and their perception of offal meat. A total of 202 consumers from three Municipalities in Amathole District were randomly sampled using exponential nondiscriminative snowball sampling. Data were gathered through a structured questionnaire containing open ended and closed ended questions. The study showed that consumers were more influenced by the freshness, price and availability of the product and these factors are used to determine the purchase outlet. Differences were observed in the offal meat consumption between the age groups. Age groups 25-34 (29.7%) and 35-44 (27.4%) showed the highest offal meat consumption, while the decline was observed in age groups of 55-64 (11.9%), 65- 74 (5.9%) and 75-85 (0.01%) respectively. The most preferred purchase point for offal meat in this study was in butcheries. However, it was observed that the factors influencing offal consumption in Amathole District were similar to meat consumption except that, offals were mainly purchased at butcher shops. The second objective in this study was to determine the sensory characteristics and consumer acceptance of sausages with 10% fat, 30% edible meat waste and 50% edible meat waste. Sensory descriptive attributes such as appearance, texture, colour, taste, flavour and overall acceptance of the sausage were evaluated by sensory panel (n = 60). The sensory panel comprised of students from undergraduates, post-graduates, post-doctoral fellows and lecturers at the University of Fort Hare. The findings of the study indicated that 50% replacement of xiii edible meat waste was similar to the commercial 10% fat with regard to several sensory attributes and pooled liking. Therefore, the utilization of the edible meat waste in production of sausages has the potential to increase profitability in meat industry and minimise meat waste in the industry. However, the cooking method that was more acceptable to consumers in this study was using the microwave as compared to oven-grilling. Furthermore, the effects of different cooking methods (microwave and oven-grilling) on proximate and mineral composition of the formulated sausages were determined. However, the cooking process appeared to have a significant effect on most of the minerals in the sausage. The cooking methods had a significant effect at P <0.01 on the nutrients composition of the formulated sausage. It was observed that the nutritional values of the sausage was better preserved after the cooking process due to higher mean values obtained after cooking. The mean values for calcium (173.1, 221.76, 231.29), potassium (444.57, 158.58, 156.67), magnesium (84.43, 257.97, 127.27), zinc (52.94, 35.27, 27.13), copper (8.8, 7.07, 4.44), manganese (8.74, 0.65, 0.08), sodium (589.42, 604.45, 529.79) and iron (63.3, 85.38, 74.81) in cooked. And the mean values for calcium (286.18, 132.18, 114.79), potassium (206.64, 113.83, 207.81), magnesium (189.89, 33.97, 48.11), zinc (61.05, 28.09, 26.44), copper (2.92, 2.73, 3.89), manganese (1.42, 0.11, 0.35), sodium (566.47, 530.79, 527.35) and iron (77.56, 58.68, 45.42) in uncooked sausage varied greatly among the treatments. Although, the disparities in the mineral content may be attributed to the different edible meat waste from different parts of the cattle which are either from feedlot or pastured based. In regard to the results obtained from proximate and mineral composition, microwave cooking method was found to be the best cooking technique for healthy eating. Finally, the effect of frying with two different oils (sunflower oil and olive oil) on the fatty acid composition of sausage made with edible meat waste was examined. The results revealed that beef sausage containing 70% edible meat wastes and 30% beef (T1) had a higher fat content xiv (25.7%±0.83%) than other treatments. On the other hand, beef sausage fortified with 10% fat and 90% beef (T3) had the lowest fat content but highest FFDM (55.85±0.57%) and moisture content (69.15±0.62) than other treatments. Despite the increase in omega-3: omega-6 fatty acid ratio in the sausage treatments after cooking, the mean value of omega-3: omega-6 fatty acid ratio was greater than 1:5 (0.2) which is within the FAO/WHO recommended range. The omega-3: omega-6 association is well-known for its importance in the diet because it is a key factor for balanced eicosanoid production in the living organism. The significant reduction in saturated fatty acids after cooking showed that there could also be a positive influence on the human health if consumed. Therefore, it may be concluded from the findings of the study that sausage made with edible meat waste as fat replacer is safe for human consumption.
- Full Text:
- Date Issued: 2019
Effect of Moringa oleifera leaf meal on growth performance, faecal ammonia emissions, carcass characteristics and the quality of meat from broiler chickens
- Authors: Mxunyelwa, Avela,
- Date: 2016
- Subjects: Moringa oleifera Meat -- Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15034 , vital:40154
- Description: The objective of the study was to determine growth performance, faecal ammonia gas emission, carcass characteristics and physico-chemical meat traits from broilers fed one of the four dietary treatments, containing 0percent, 1percent, 3percent or 5percent Moringa oleifera leaf meal (MOLM) (T1, T2, T3, and T4, respectively). Dietary treatments were formulated to be isonitrogenous and isocaloric for a starter (0-14 days), grower (15-21days) and finisher (22-35 days). A total of 160 day old Cobb 500 broiler chickens, initially weighing an average of 45g were randomly allocated to each of the dietary treatments, each with four replicates, in 16 pens. Feed and water were offered ad libitum. Feed intakes (FI), average daily gain (ADG), body weight gain (BWG) and feed conversion efficiency (FCE) were measured weekly. At the end of the feeding trial, the feed was withdrawn from the birds for 12 hours with water available ad libitum and the birds were slaughtered using standard abattoir procedures. The breast muscle of each carcass was sampled for meat quality analysis. Organ and carcass weights differences were measured. Birds fed with T1 had the highest FI. Birds fed with T4 had the best FCE at day 14, 21 and 35. At day 7 and 35, there were no significant differences in FCE in all the treatments. At 0 to 35 days, faecal ammonia emission decreased (P<0.05) as MOLM concentration and age of birds increased. Moringa fed broilers had the highest body weights in all the periods despite the incorporation level in the diet. The results showed that inclusion of MOLM had a significant effect (P<0.05) on the heart, neck, and head weights but had no significant effect on liver, gizzard, intestine and feet. Broilers fed with T1 had heavier heart, neck and head weights compared to MOLM fed broilers. In terms of carcass traits, MOLM had a significant effect (P<0.05) on wings and thighs but had no significant effect (P>0.05) on breast and drumsticks. Moringa oleifera leaf meal had a significant effect on carcass weights, control diet had heavier weights (1185g ± 28.96) compared to chickens fed with MOLM diets (1121g±28.96, 1070g ± 28.96, 1030g± 28.96). Broilers fed with MOLM had higher values of lightness (L*) and (b*) values (P<0.05) at 45 minutes and 24 hours and no difference was observed in redness (a*) at 45 minutes and 24 hours. The L* values dropped at 24 hours for all the treatments and MOLM fed broilers had the lowest values (46.59 ± 0.76,46 ± 0.76,49 ± 0.76) compared to the control diet (50 ± 0.76). The pH levels were comparable after 24 hours; T2 had the highest pH values (5.95 ± 0.024) compared to other treatments (5.90 ± 0.024, 5.75 ± 0.024, 5.73 ± 0.024). The results of this study demonstrated that even though the FI was reduced in MOLM fed broilers, they efficiently consumed and used nutrients, as a result MOLM fed birds had higher weights and low ammonia concentration throughout the experiment, which may improve the house environment without affecting the quality of meat.
- Full Text:
- Date Issued: 2016
- Authors: Mxunyelwa, Avela,
- Date: 2016
- Subjects: Moringa oleifera Meat -- Quality Broilers (Chickens)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15034 , vital:40154
- Description: The objective of the study was to determine growth performance, faecal ammonia gas emission, carcass characteristics and physico-chemical meat traits from broilers fed one of the four dietary treatments, containing 0percent, 1percent, 3percent or 5percent Moringa oleifera leaf meal (MOLM) (T1, T2, T3, and T4, respectively). Dietary treatments were formulated to be isonitrogenous and isocaloric for a starter (0-14 days), grower (15-21days) and finisher (22-35 days). A total of 160 day old Cobb 500 broiler chickens, initially weighing an average of 45g were randomly allocated to each of the dietary treatments, each with four replicates, in 16 pens. Feed and water were offered ad libitum. Feed intakes (FI), average daily gain (ADG), body weight gain (BWG) and feed conversion efficiency (FCE) were measured weekly. At the end of the feeding trial, the feed was withdrawn from the birds for 12 hours with water available ad libitum and the birds were slaughtered using standard abattoir procedures. The breast muscle of each carcass was sampled for meat quality analysis. Organ and carcass weights differences were measured. Birds fed with T1 had the highest FI. Birds fed with T4 had the best FCE at day 14, 21 and 35. At day 7 and 35, there were no significant differences in FCE in all the treatments. At 0 to 35 days, faecal ammonia emission decreased (P<0.05) as MOLM concentration and age of birds increased. Moringa fed broilers had the highest body weights in all the periods despite the incorporation level in the diet. The results showed that inclusion of MOLM had a significant effect (P<0.05) on the heart, neck, and head weights but had no significant effect on liver, gizzard, intestine and feet. Broilers fed with T1 had heavier heart, neck and head weights compared to MOLM fed broilers. In terms of carcass traits, MOLM had a significant effect (P<0.05) on wings and thighs but had no significant effect (P>0.05) on breast and drumsticks. Moringa oleifera leaf meal had a significant effect on carcass weights, control diet had heavier weights (1185g ± 28.96) compared to chickens fed with MOLM diets (1121g±28.96, 1070g ± 28.96, 1030g± 28.96). Broilers fed with MOLM had higher values of lightness (L*) and (b*) values (P<0.05) at 45 minutes and 24 hours and no difference was observed in redness (a*) at 45 minutes and 24 hours. The L* values dropped at 24 hours for all the treatments and MOLM fed broilers had the lowest values (46.59 ± 0.76,46 ± 0.76,49 ± 0.76) compared to the control diet (50 ± 0.76). The pH levels were comparable after 24 hours; T2 had the highest pH values (5.95 ± 0.024) compared to other treatments (5.90 ± 0.024, 5.75 ± 0.024, 5.73 ± 0.024). The results of this study demonstrated that even though the FI was reduced in MOLM fed broilers, they efficiently consumed and used nutrients, as a result MOLM fed birds had higher weights and low ammonia concentration throughout the experiment, which may improve the house environment without affecting the quality of meat.
- Full Text:
- Date Issued: 2016
The use of earth observation multi-sensor systems to monitor and model Pastures: a case of Savannah Grasslands in Hluvukani Village, Bushbuckridge Local Municipality, Mpumalanga Province, South Africa
- Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
Genetically modified (GM) maize cultivation by smallholders in the Eastern Cape Province of South Africa: Effects on target and non-target organisms and adoption challenges
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
- Authors: Kotey, Daniel Ashie
- Date: 2017
- Subjects: Farms, Small -- South Africa -- Eastern Cape Genetically modified foods -- South Africa -- Eastern Cape Corn -- Biotechnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5161 , vital:29092
- Description: The use of genetically modified (GM) maize technology is subject to compliance with stewardship requirements and the adoption of specific management practices that promote the long-term effectiveness and environmental sustainability of the technology. For smallholders to comply with these requirements and adopt the desired management practices to ultimately benefit from the technology, they require information that creates awareness of the value of these requirements. To determine what information farmers receive about GM maize and how this information is disseminated to farmers, face to face interviews were conducted with 81 extension personnel and 210 smallhoder GM maize farmers in the Eastern Cape Province of South Africa. The effect of Bt maize introduction and management practices in smallholder maize agroecosystems in the Eastern Cape on Bt maize target [Busseola fusca (Fuller) (Lepidoptera: Noctuidae)] and non-target insect pests [Agrotis segetum (Denis & Schiffermüller) (Lepidoptera: Noctuidae), Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)] and a snail species, [Cornu aspersum (Müller) (Gastropoda: Helicidae)] was determined through laboratory, field and cage experiments. The effect of smallhoder farmers‟ GM maize cultivation practices on the profitability of GM maize technology was also determined through on-farm trials in different localities of the Eastern Cape identified as hot-spots for stem borer and weed infestation. Results of surveys indicated that extension personnel had a low level of awareness of GM maize technology stewardship requirements. GM maize technology was also largely disseminated to smallholder farmers through non-participatory approaches and print media sourced from GM seed companies. Although farmers had a high level of contact with extension services, they lacked access to information about GM maize technology. Smallholder farmers‟ level of awareness about GM maize and compliance with the requirement for the planting of non-Bt maize refuge areas adjacent to Bt maize was also very low. While Bt maize event (MON810) commonly cultivated by smallholder farmers in the Eastern Cape Province had a variable effect on A. segetum under laboratory conditions, it had no effect on the incidence of plants damaged by A. segetum and C. aspersum under field conditions. The incidence of H. armigera damage on Bt maize plants was however significantly affected by Bt maize. Populations of B. fusca collected from smallholder maize fields in the province were observed to be still highly susceptible to Bt maize. Results of on-farm evaluation of the profitability of GM maize revealed that stem borer pressure, growing conditions, input supplies and market access affect the productivity and profitability of GM maize cultivation. Challenges within the extension and advisory services of the Eastern Cape which can militate against smallholder farmers‟ ability to benefit from GM maize technology and sustain the long-term efficacy of the technology were identified during this study. Given these challenges and the fact that the cultivation of GM maize may not be profitable under typical smallholder maize cultivation conditions and management practices, dissemination approaches that provide farmers the opportunity to evaluate GM maize technology alongside alternate technologies under their conditions, may prove beneficial.
- Full Text:
- Date Issued: 2017
Characterization of various garden grass species for energy conversion in a down draft biomass gasifier
- Authors: Mkosi, Lungisa
- Date: 2016
- Subjects: Biomass energy Greenhouse gases Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5817 , vital:29399
- Description: Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
- Full Text:
- Date Issued: 2016
- Authors: Mkosi, Lungisa
- Date: 2016
- Subjects: Biomass energy Greenhouse gases Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5817 , vital:29399
- Description: Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
- Full Text:
- Date Issued: 2016
Statistical analysis and modelling of malaria relapse risk factors using Cox Proportional Hazards model approach : a case study of material data collected from Democratic Republic of Congo
- Authors: Mutambayi, Ruffin Mpiana
- Date: 2017
- Subjects: Malaria -- Congo (Democratic Republic) -- Mathematical models Statistics -- Congo (Democratic Republic) -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15001 , vital:40110
- Description: The field of survival analysis has experienced tremendous growth during the latter half of the 20th century. The objective of this study was to model the relapsing time of uncomplicated falciparum malaria using biographical, sanitation, environmental and preventive information as covariate risk factors. The methodological developments of survival analysis that have had the most profound impact are the Kaplan-Meier method for estimating the survival function, the log-rank test for comparing the equality of two or more survival distributions, and the Cox proportional hazards (PH) model for examining the covariate effects on the hazard function. This thesis presents basic concepts, nonparametric methods (the Kaplan-Meier method and the log-rank test), semi parametric methods (the Cox PH model, and Cox model with time-dependent covariates) and parametric methods (Parametric PH model and the AFT model) for analysing survival data. An improved method was applied to randomized uncomplicated falciparum malaria patients to investigate the risk factors related to the relapsing time in RD Congo. Firstly, the Cox PH model , inf 1 0 ( ) ( )exp 1.91613 0.49633 0.81466 dump spr t X h h t X X X where is the instantaneous risk of experiencing the event at time , without the influence of any covariate was found to better fit the data, as confirmed by the results of the global test that present reasonable and significant results: (Likelihood Ratio: 18.2264 with p-value < 0.0004; Score: 17.6569 with p-value < 0.0005 and Wald: 19.3975 with p<0.0002). Hence from the model above, it can be noticed that ‘dumping site’ (p-value <0.0106; 95percent HR C.I: 1.545, 29.451), ‘spray used’ (p-value < 0. 0.0220; 95percent C.I: 0.391, 0.915), and ‘information related to source of malaria’ (p-value < 0. 0.0012; 95percent C.I: 1.380, 3.725), have a significant impact on the relapsing time of the patients under investigation. It should be noted that many 0() h tt other important covariates such as “usage of mosquito nets” were excluded because of the non-proportionality of the hazards. Secondly, the improvement concept was applied to the Cox model as proposed, and the improved model was as follows: h h t t X t X t X t X t X t X t X t r dump_inf1 spr_inf1 Where h0 (t) is the instantaneous risk of experiencing the event at time t , without the influence of any covariate. The model was found to better fit the data than the standard model — as confirmed by the results from the convergence criterion comparison, where the AIC value of the improved model (754.460) was lower than that of the standard model (767.428). Moreover, the improved model was found to be adequate as the results from the global null hypothesis were significant: (Likelihood Ratio: p-value is 0.0001; Score: p-value is 0.0001; Wald: p-value is 0.0001) and the goodness-of-fit test was confirmed by the plotting of Coxresiduals where the 45 degrees’ line confirmed the results. In conclusion, it was found that the covariates ‘pit’ (p-value is 0.0009; 95percent HR C.I: 11.4133, 1.243e+04), ‘tdwel_spr’ (pvalue = 0.0257; 95percent HR C.I: 1.0016, 1.030e+00), ‘tdwel_inf1 (p-value = 0.0122; 95percent HR C.I: 0.9691, 9.964e-01), ‘maint_dump’ (p-value is 0.0005; 95percent HR C.I: 1.0239, 1.087e+00),‘maint_pit’ (p-value is 0.0007; 95percent HR C.I: 0.9179, 9.774e-01), ‘dump_spr’ (p-value is 0.0027; 95percent HR C.I: 0.9308, 9.853e-01), ‘dump_inf1’ (p-value <0.0001; 95percent HR C.I: 0.9849, 9.947e-01) and ‘spr_inf1’ (p-value is 0.0005; 95percent HR C.I: 1.0119, 1.043e+00) affected the time to relapse from uncomplicated falciparum malaria.
- Full Text:
- Date Issued: 2017
- Authors: Mutambayi, Ruffin Mpiana
- Date: 2017
- Subjects: Malaria -- Congo (Democratic Republic) -- Mathematical models Statistics -- Congo (Democratic Republic) -- Econometric models
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15001 , vital:40110
- Description: The field of survival analysis has experienced tremendous growth during the latter half of the 20th century. The objective of this study was to model the relapsing time of uncomplicated falciparum malaria using biographical, sanitation, environmental and preventive information as covariate risk factors. The methodological developments of survival analysis that have had the most profound impact are the Kaplan-Meier method for estimating the survival function, the log-rank test for comparing the equality of two or more survival distributions, and the Cox proportional hazards (PH) model for examining the covariate effects on the hazard function. This thesis presents basic concepts, nonparametric methods (the Kaplan-Meier method and the log-rank test), semi parametric methods (the Cox PH model, and Cox model with time-dependent covariates) and parametric methods (Parametric PH model and the AFT model) for analysing survival data. An improved method was applied to randomized uncomplicated falciparum malaria patients to investigate the risk factors related to the relapsing time in RD Congo. Firstly, the Cox PH model , inf 1 0 ( ) ( )exp 1.91613 0.49633 0.81466 dump spr t X h h t X X X where is the instantaneous risk of experiencing the event at time , without the influence of any covariate was found to better fit the data, as confirmed by the results of the global test that present reasonable and significant results: (Likelihood Ratio: 18.2264 with p-value < 0.0004; Score: 17.6569 with p-value < 0.0005 and Wald: 19.3975 with p<0.0002). Hence from the model above, it can be noticed that ‘dumping site’ (p-value <0.0106; 95percent HR C.I: 1.545, 29.451), ‘spray used’ (p-value < 0. 0.0220; 95percent C.I: 0.391, 0.915), and ‘information related to source of malaria’ (p-value < 0. 0.0012; 95percent C.I: 1.380, 3.725), have a significant impact on the relapsing time of the patients under investigation. It should be noted that many 0() h tt other important covariates such as “usage of mosquito nets” were excluded because of the non-proportionality of the hazards. Secondly, the improvement concept was applied to the Cox model as proposed, and the improved model was as follows: h h t t X t X t X t X t X t X t X t r dump_inf1 spr_inf1 Where h0 (t) is the instantaneous risk of experiencing the event at time t , without the influence of any covariate. The model was found to better fit the data than the standard model — as confirmed by the results from the convergence criterion comparison, where the AIC value of the improved model (754.460) was lower than that of the standard model (767.428). Moreover, the improved model was found to be adequate as the results from the global null hypothesis were significant: (Likelihood Ratio: p-value is 0.0001; Score: p-value is 0.0001; Wald: p-value is 0.0001) and the goodness-of-fit test was confirmed by the plotting of Coxresiduals where the 45 degrees’ line confirmed the results. In conclusion, it was found that the covariates ‘pit’ (p-value is 0.0009; 95percent HR C.I: 11.4133, 1.243e+04), ‘tdwel_spr’ (pvalue = 0.0257; 95percent HR C.I: 1.0016, 1.030e+00), ‘tdwel_inf1 (p-value = 0.0122; 95percent HR C.I: 0.9691, 9.964e-01), ‘maint_dump’ (p-value is 0.0005; 95percent HR C.I: 1.0239, 1.087e+00),‘maint_pit’ (p-value is 0.0007; 95percent HR C.I: 0.9179, 9.774e-01), ‘dump_spr’ (p-value is 0.0027; 95percent HR C.I: 0.9308, 9.853e-01), ‘dump_inf1’ (p-value <0.0001; 95percent HR C.I: 0.9849, 9.947e-01) and ‘spr_inf1’ (p-value is 0.0005; 95percent HR C.I: 1.0119, 1.043e+00) affected the time to relapse from uncomplicated falciparum malaria.
- Full Text:
- Date Issued: 2017
Evaluation of functionalized silver and silica nanoparticles for the removal of deoxyribonucleic acid conveying antibiotics resistance genes from water
- Authors: Ezeuko, Adaora Stella
- Date: 2022
- Subjects: DNA , Silica , Water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27765 , vital:69414
- Description: Antibiotic resistance genes ARGs are recognized as a serious public health emergency linked to extensive use of antibiotics by humans and animals as a prophylactic agent that treats and prevents infections. The occurrence of high concentrations being identified in wastewater treatment plants, rivers, etc is due to untreated effluents being discharged from households, hospitals, agriculture, and pharmaceutical industries. The application of adequate treatment techniques and material for the removal of bacteria DNA conveying ARGs from the effluents before their release to the environment cannot be overemphasized. Adsorption techniques seem to be effective due to their easy design, operation, and ability to regenerate adsorbents for use without producing toxic by-products. This concept was employed for the removal of bacteria DNA conveying ARGs from simulated aqueous solution, effluents from hospital, river and WWTPs using silver and silica metallic nanoparticles. This thesis investigated the effectiveness of metallic nanoparticles containing silver AgNPs and mesoporous silica nanoparticles MSNPs as well as magnetite Fe3O4 functionalized with 4 4hydroxyphenyl 2 262-terpyridine onto their surface, for the removal of bacteria DNA conveying antibiotic resistance genes from water samples from hospitals, river, and wastewater treatment plants WWTPs. Silver nanoparticles AgNPs of different molar concentrations 0.1M, 0.5M and 1.0 M and mesoporous silica nanoparticles MSNPs adsorbents were successfully synthesized in their original states and surface functionalization achieved by incorporating magnetite Fe3O4 and 4 4 hydroxyphenyl 2 2 6 2 terpyridine on the silver AgNPs Fe3O4 and silica MSNPs TPPY surfaces respectively. Their effectiveness as adsorbent for the removal of bacteria DNA conveying ARGs from aqueous solutions and real water/wastewater samples were investigated. The DNA uptake by the as-synthesized AgNPs and MSNPs were compared to the functionalized AgNPs Fe3O4 and MSNPsTPPY by determining the adsorbents with the highest removal efficiencies. All as synthesized and functionalized adsorbents were characterized by SEM, EDX, FTIR, XRD, UV spectroscopy and PZC before the removal process. The extraction of genomic DNA from antibiotic-resistant Enterococcus faecium and Vibrio parahaemolyticus was successfully achieved via the boiling method. Antibiotic susceptibility test was conducted using the disk diffusion method before the commencement of genomic DNA extraction. Molecular characterization via gel electrophoresis confirmed the presence of resistance genes at different base pairs. Adsorption batch experiment were investigated, and the best optimum parameters were evaluated through the influence of pH, contact time, initial DNA concentration, adsorbent dose, and competitive ions for each sorption process. The rate determining step were determined by fitting kinetic models such as Natarajan and Khalaf first order, pseudo first order, pseudo second order, Elovich model to experimental data. Also, the adsorption mechanisms determining adsorption equilibrium were investigated by fitting Freundlich, Langmuir and Sips model into the experimental data. The application of AgNPsFe3O4 nanocomposite and MSNPsTPPY for the removal of bacteria DNA demonstrated much enhancement for DNA uptake than the as-synthesized AgNPs and MSNPs materials. The incorporation of magnetite and 4 4hydroxyphenyl 2 2 6 2-terpyridine onto AgNPs and MSNPs significantly enhanced the binding affinity towards the removal the bacteria DNA via strong electrostatic attraction between the active sites on the adsorbent and the negative DNA molecules. Finally, high adsorption capacities were recorded with AgNPsFe3O4 nanocomposite and MSNPsTPPY compared to AgNPs and MSNPs with chaotropic salts. The kinetic adsorption models were mostly best fitted by the pseudo-second order and Elovich models while the adsorption equilibrium was best described by Langmuir and Sips isotherm models. MSNPs with different chaotropic salts, AgNPsFe3O4 nanocomposite and MSNPsTPPY also proved its effectiveness in DNA removal not only in the simulated aqueous solution but in three different real life water samples obtained from Cofimvaba hospital, Ndevana river and Uitenhage WWTPs. High adsorption efficiencies above 90 percent were achieved during the removal of DNA in all the three real water samples. Therefore, application of these adsorbents for the removal of bacteria DNA conveying ARGs may be a promising option that would tackle the consequences of consuming ARGs infected water globally. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
- Authors: Ezeuko, Adaora Stella
- Date: 2022
- Subjects: DNA , Silica , Water
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27765 , vital:69414
- Description: Antibiotic resistance genes ARGs are recognized as a serious public health emergency linked to extensive use of antibiotics by humans and animals as a prophylactic agent that treats and prevents infections. The occurrence of high concentrations being identified in wastewater treatment plants, rivers, etc is due to untreated effluents being discharged from households, hospitals, agriculture, and pharmaceutical industries. The application of adequate treatment techniques and material for the removal of bacteria DNA conveying ARGs from the effluents before their release to the environment cannot be overemphasized. Adsorption techniques seem to be effective due to their easy design, operation, and ability to regenerate adsorbents for use without producing toxic by-products. This concept was employed for the removal of bacteria DNA conveying ARGs from simulated aqueous solution, effluents from hospital, river and WWTPs using silver and silica metallic nanoparticles. This thesis investigated the effectiveness of metallic nanoparticles containing silver AgNPs and mesoporous silica nanoparticles MSNPs as well as magnetite Fe3O4 functionalized with 4 4hydroxyphenyl 2 262-terpyridine onto their surface, for the removal of bacteria DNA conveying antibiotic resistance genes from water samples from hospitals, river, and wastewater treatment plants WWTPs. Silver nanoparticles AgNPs of different molar concentrations 0.1M, 0.5M and 1.0 M and mesoporous silica nanoparticles MSNPs adsorbents were successfully synthesized in their original states and surface functionalization achieved by incorporating magnetite Fe3O4 and 4 4 hydroxyphenyl 2 2 6 2 terpyridine on the silver AgNPs Fe3O4 and silica MSNPs TPPY surfaces respectively. Their effectiveness as adsorbent for the removal of bacteria DNA conveying ARGs from aqueous solutions and real water/wastewater samples were investigated. The DNA uptake by the as-synthesized AgNPs and MSNPs were compared to the functionalized AgNPs Fe3O4 and MSNPsTPPY by determining the adsorbents with the highest removal efficiencies. All as synthesized and functionalized adsorbents were characterized by SEM, EDX, FTIR, XRD, UV spectroscopy and PZC before the removal process. The extraction of genomic DNA from antibiotic-resistant Enterococcus faecium and Vibrio parahaemolyticus was successfully achieved via the boiling method. Antibiotic susceptibility test was conducted using the disk diffusion method before the commencement of genomic DNA extraction. Molecular characterization via gel electrophoresis confirmed the presence of resistance genes at different base pairs. Adsorption batch experiment were investigated, and the best optimum parameters were evaluated through the influence of pH, contact time, initial DNA concentration, adsorbent dose, and competitive ions for each sorption process. The rate determining step were determined by fitting kinetic models such as Natarajan and Khalaf first order, pseudo first order, pseudo second order, Elovich model to experimental data. Also, the adsorption mechanisms determining adsorption equilibrium were investigated by fitting Freundlich, Langmuir and Sips model into the experimental data. The application of AgNPsFe3O4 nanocomposite and MSNPsTPPY for the removal of bacteria DNA demonstrated much enhancement for DNA uptake than the as-synthesized AgNPs and MSNPs materials. The incorporation of magnetite and 4 4hydroxyphenyl 2 2 6 2-terpyridine onto AgNPs and MSNPs significantly enhanced the binding affinity towards the removal the bacteria DNA via strong electrostatic attraction between the active sites on the adsorbent and the negative DNA molecules. Finally, high adsorption capacities were recorded with AgNPsFe3O4 nanocomposite and MSNPsTPPY compared to AgNPs and MSNPs with chaotropic salts. The kinetic adsorption models were mostly best fitted by the pseudo-second order and Elovich models while the adsorption equilibrium was best described by Langmuir and Sips isotherm models. MSNPs with different chaotropic salts, AgNPsFe3O4 nanocomposite and MSNPsTPPY also proved its effectiveness in DNA removal not only in the simulated aqueous solution but in three different real life water samples obtained from Cofimvaba hospital, Ndevana river and Uitenhage WWTPs. High adsorption efficiencies above 90 percent were achieved during the removal of DNA in all the three real water samples. Therefore, application of these adsorbents for the removal of bacteria DNA conveying ARGs may be a promising option that would tackle the consequences of consuming ARGs infected water globally. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022
Geological and geophysical investigations of the reservoir rock properties of the Gamtoos Basin in the Eastern Cape Province of South Africa
- Authors: Mokoele, Salmina Phuthi
- Date: 2017
- Subjects: Petroleum reserves -- Mechanical properties Petroleum reserves -- South Africa -- Eastern Cape Geophysics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7863 , vital:30779
- Description: Geological and geophysical studies of the Gamtoos Basin were carried out by using the research methods of stratigraphic analysis, petrographic analysis, sedimentary facies analysis, and geophysical studies. The orientation of the Gamtoos Basin onshore is controlled by the Gamtoos Fault which cuts through the lithologies of the Cape Supergroup on the eastern edge of the basin. Magnetic data and depth slices show the presence of the Cape Supergroup basement on the south east corner of the onshore Kirkwood Formation which is further sitting on the Gamtoos Group basement from the Neoproterozoic extending up to 8860 m in depth. Most previously compiled stratigraphic profiles of the Uitanhage Group revealed the presence of reddish massive conglomerate units from the Enon Formation and massive reddish to greenish alternating units of sandstones, siltstones and mudstones from the Kirkwood Formation. The results obtained from this research also revealed the presence of reddish to whitish massive alternating units of sandstones, mudstones and siltstones from the upper Enon Formation overlaying the reddish massive conglomeritic layers while the alternating reddish to greenish units of sandstones, siltstones and mudstones from the Kirkwood Formation are overlaid by massive reddish to greyish conglomeritic layers. Thirteen types of lithofacies and five types of biofacies were accounted for across the Gamtoos Basin from core logs, field observations and petrographic analysis. The same type of reddish to greyish massive conglomerate facies interbedded with subordinate sandstone lenses were observed on both the Enon (Lower most part) and the Kirkwood (top most part) Formations. Similar reddish to whitish sandstone facies were also observed in both formations except some of the units from the Kirkwood Formation revealed the presence of a lot of sedimentary structures such as laminations, thin beds, tabular cross beds, trough cross beds, convolute structures, load casts and even secondary structures like calcite veins and honey comb structures. Mudstone deposits are divided into reddish laminated facies and whitish massive facies. The whitish mudstone facies of the Enon Formation comprise caliche indicating the process of leaching while the reddish facies contain mudcracks indicating the process of desiccation. The Kirkwood Formation comprises reddish laminated mudstone facies and whitish massive mudstones. Petrographic studies revealed the presence of quartz arenites, lithic arenites, quartz wacke, lithic wacke, pelletic wacke, siltstones and mudstones. The mineral compositions were monocrystalline and polycrystalline quartz, plagioclase, K-feldspar and lithic fragments as the main framework grains. Muscovite and glauconite were identified as accessory minerals along with heavy minerals of hematite spotted on a few occasions. The matrix was composed of clay (mainly kaolinite and smectite), bentonite, illite-sericite and fine quartz silts. Microscope petrography revealed that organic matters occurred in 4 occurrences, i.e. as organic intraclasts, kerogen pellets, organic carbon laminae or stringers, and diagenetic crack-filling organic carbon (asphalt). Density determinations onshore have revealed an average wet density of 2.439 g/cm3 for the Enon Formation sandstones and 2.589 g/cm3 for the Kirkwood Formation sandstones. The average rock density for Borehole Ha-B2 is 2.67 g/cm3 whereas Borehole Ha-G1 rocks show an average density of 2.64 g/cm3. Geophysical data from the offshore boreholes has indicated an increase in the following parameters with depth: bulk density, porosity and geothermal gradient. Data from borehole logs resulted in a linear relationship between bulk density and depth although some boreholes were represented by more than one linear segment in one graph still showing gradual increase of bulk density with depth. The basin was deposited in terrestrial environments (braided fluvial fans and meandering rivers) and marine environments (beach, shallow and deep marine).
- Full Text:
- Date Issued: 2017
- Authors: Mokoele, Salmina Phuthi
- Date: 2017
- Subjects: Petroleum reserves -- Mechanical properties Petroleum reserves -- South Africa -- Eastern Cape Geophysics -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/7863 , vital:30779
- Description: Geological and geophysical studies of the Gamtoos Basin were carried out by using the research methods of stratigraphic analysis, petrographic analysis, sedimentary facies analysis, and geophysical studies. The orientation of the Gamtoos Basin onshore is controlled by the Gamtoos Fault which cuts through the lithologies of the Cape Supergroup on the eastern edge of the basin. Magnetic data and depth slices show the presence of the Cape Supergroup basement on the south east corner of the onshore Kirkwood Formation which is further sitting on the Gamtoos Group basement from the Neoproterozoic extending up to 8860 m in depth. Most previously compiled stratigraphic profiles of the Uitanhage Group revealed the presence of reddish massive conglomerate units from the Enon Formation and massive reddish to greenish alternating units of sandstones, siltstones and mudstones from the Kirkwood Formation. The results obtained from this research also revealed the presence of reddish to whitish massive alternating units of sandstones, mudstones and siltstones from the upper Enon Formation overlaying the reddish massive conglomeritic layers while the alternating reddish to greenish units of sandstones, siltstones and mudstones from the Kirkwood Formation are overlaid by massive reddish to greyish conglomeritic layers. Thirteen types of lithofacies and five types of biofacies were accounted for across the Gamtoos Basin from core logs, field observations and petrographic analysis. The same type of reddish to greyish massive conglomerate facies interbedded with subordinate sandstone lenses were observed on both the Enon (Lower most part) and the Kirkwood (top most part) Formations. Similar reddish to whitish sandstone facies were also observed in both formations except some of the units from the Kirkwood Formation revealed the presence of a lot of sedimentary structures such as laminations, thin beds, tabular cross beds, trough cross beds, convolute structures, load casts and even secondary structures like calcite veins and honey comb structures. Mudstone deposits are divided into reddish laminated facies and whitish massive facies. The whitish mudstone facies of the Enon Formation comprise caliche indicating the process of leaching while the reddish facies contain mudcracks indicating the process of desiccation. The Kirkwood Formation comprises reddish laminated mudstone facies and whitish massive mudstones. Petrographic studies revealed the presence of quartz arenites, lithic arenites, quartz wacke, lithic wacke, pelletic wacke, siltstones and mudstones. The mineral compositions were monocrystalline and polycrystalline quartz, plagioclase, K-feldspar and lithic fragments as the main framework grains. Muscovite and glauconite were identified as accessory minerals along with heavy minerals of hematite spotted on a few occasions. The matrix was composed of clay (mainly kaolinite and smectite), bentonite, illite-sericite and fine quartz silts. Microscope petrography revealed that organic matters occurred in 4 occurrences, i.e. as organic intraclasts, kerogen pellets, organic carbon laminae or stringers, and diagenetic crack-filling organic carbon (asphalt). Density determinations onshore have revealed an average wet density of 2.439 g/cm3 for the Enon Formation sandstones and 2.589 g/cm3 for the Kirkwood Formation sandstones. The average rock density for Borehole Ha-B2 is 2.67 g/cm3 whereas Borehole Ha-G1 rocks show an average density of 2.64 g/cm3. Geophysical data from the offshore boreholes has indicated an increase in the following parameters with depth: bulk density, porosity and geothermal gradient. Data from borehole logs resulted in a linear relationship between bulk density and depth although some boreholes were represented by more than one linear segment in one graph still showing gradual increase of bulk density with depth. The basin was deposited in terrestrial environments (braided fluvial fans and meandering rivers) and marine environments (beach, shallow and deep marine).
- Full Text:
- Date Issued: 2017
The effectiveness of public participation in the environmental politics of hydraulic fracturing : the case of the Great Karoo
- Kalipa-Mini, Nomampondomise Cynthia
- Authors: Kalipa-Mini, Nomampondomise Cynthia
- Date: 2018
- Subjects: Hydraulic fracturing Hydraulic fracturing -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Environmental Studies
- Identifier: http://hdl.handle.net/10353/10779 , vital:35760
- Description: Shale gas has become a part of the world’s energy mix. South Africa (SA) is facing huge energy problems and job creation challenges whilst the Karoo region has large amounts of shale gas reserves. It is against this background that the South African government is considering fracking, showing interest by lifting fracking ban and repeatedly calling it a game changer. This generated debates among environmentalists, farmer groups, capitalists, politicians, researchers and community groups, as they voiced their views regarding fracking. The debates influenced the study to focus on public participation regarding the Karoo fracking initiative, with particular emphasis on the marginalised persons. The aim was to examine the effectiveness of public participation in the environmental politics of fracking in the Great Karoo region in Eastern Cape Province. The study adopted a qualitative case study approach through document analysis, questionnaires given to the interested and affected parties, relevant government department, local municipality and non-governmental organisations as well as focus group discussions with 35 participants from marginalised groupings. It was grounded on the Integrated Environmental Management (IEM) paradigm using the outcomes-based framework in the thematic analysis of the collected data. The results showed little evidence of social learning among the marginalised persons when the collected data was benchmarked against the chosen pillars of the IEM paradigm within the outcomes-based approach. These results convey that effective and developmental public participation should be empowering, informing and educating rather than merely serving documentary purposes.
- Full Text:
- Date Issued: 2018
- Authors: Kalipa-Mini, Nomampondomise Cynthia
- Date: 2018
- Subjects: Hydraulic fracturing Hydraulic fracturing -- Environmental aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , Environmental Studies
- Identifier: http://hdl.handle.net/10353/10779 , vital:35760
- Description: Shale gas has become a part of the world’s energy mix. South Africa (SA) is facing huge energy problems and job creation challenges whilst the Karoo region has large amounts of shale gas reserves. It is against this background that the South African government is considering fracking, showing interest by lifting fracking ban and repeatedly calling it a game changer. This generated debates among environmentalists, farmer groups, capitalists, politicians, researchers and community groups, as they voiced their views regarding fracking. The debates influenced the study to focus on public participation regarding the Karoo fracking initiative, with particular emphasis on the marginalised persons. The aim was to examine the effectiveness of public participation in the environmental politics of fracking in the Great Karoo region in Eastern Cape Province. The study adopted a qualitative case study approach through document analysis, questionnaires given to the interested and affected parties, relevant government department, local municipality and non-governmental organisations as well as focus group discussions with 35 participants from marginalised groupings. It was grounded on the Integrated Environmental Management (IEM) paradigm using the outcomes-based framework in the thematic analysis of the collected data. The results showed little evidence of social learning among the marginalised persons when the collected data was benchmarked against the chosen pillars of the IEM paradigm within the outcomes-based approach. These results convey that effective and developmental public participation should be empowering, informing and educating rather than merely serving documentary purposes.
- Full Text:
- Date Issued: 2018