In vitro passage of ibuprofen through synthetic and biological membranes
- Authors: Purdon, Carryn Hamilton
- Date: 2001
- Subjects: Ibuprofen , Diffusion processes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3786 , http://hdl.handle.net/10962/d1003264 , Ibuprofen , Diffusion processes
- Description: Ibuprofen is a non-steroidal anti-inflammatory drug with three major types of effect: anti-inflammatory, analgesic and antipyretic. Ibuprofen may be administered in a number of different forms via the oral as well as the topical route. Published evidence suggests that topical, unlike oral, non-steroidal anti-inflammatory drugs are associated with few systemic side effects as plasma concentrations are low compared to oral therapy. In some countries it is particularly difficult to obtain human skin for in vitro experimentation and it is therefore important to have alternate biological or synthetic membranes which mimic human skin for diffusion experiments. Synthetic membranes serve as predictive models for topical drug release and in South Africa, shed snake skin is easily obtainable from the many snake parks present in the country. The FDA guidelines were considered when choosing the apparatus to be used in the comparative diffusion study on proprietary ibuprofen-containing topical preparations from three countries and the verification of the usefulness, or otherwise, of shed snake skin as a biological membrane for the assessment of the permeation of ibuprofen. Two diffusion techniques were considered appropriate for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing. One was the Franz diffusion cell, as modified by Keshary and Chien (88,169) and the other was the European Pharmacopoeia diffusion cell (187). High performance liquid chromatography was used as the analytical technique for the analysis of ibuprofen in aqueous solution using ultraviolet detection at 222 nm. The validated method was applied to the determination of the diffusion of ibuprofen from topical ibuprofen-containing formulations (gels, creams and mousse) through synthetic silicone membrane and shed snake skin biological membrane from four different species. In a study of fifteen topical ibuprofen-containing formulations (gels, creams and mousse) from three countries (South Africa, United Kingdom and France) it was found that there was a trend of products from two countries consistently exhibiting superior diffusion characteristics as well as products from the same two countries consistently exhibiting the lowest diffusion of ibuprofen. Interpretation of the results of these studies demonstrated the importance of employing a combination of statistical analyses and peak integration values when drawing conclusions regarding comparative diffusion characteristics. Shed snake skin has been described as a 'model' membrane, i.e. a membrane which shows similar permeability to human stratum corneum. The results reported here show clearly that, for ibuprofen, the four species of snake produce shed skin with completely different diffusion characteristics when all other conditions are identical. It may well be that there is one particular species of snake which produces shed skin of identical permeability to human stratum corneum, but to describe shed snake skin in general as a model membrane seems incorrect. It is therefore important that if shed snake skin is used as a membrane, the species, skin site and orientation should be reported. The European Pharmacopoeia diffusion apparatus was judged to be the better of the two diffusion techniques assessed for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing using silicone membranes and for the measurement of the amount of ibuprofen diffusing across the ventral outside orientation of shed skin during in vitro testing, whereas the Franz diffusion apparatus was judged to be better for the measurement of the amount of ibuprofen diffusing across the dorsal outside orientation of shed skin during in vitro testing. However, the choice of this diffusion apparatus must be weighed against the relatively poor reproducibility as compared with the European Pharmacopoeia diffusion apparatus.
- Full Text:
- Authors: Purdon, Carryn Hamilton
- Date: 2001
- Subjects: Ibuprofen , Diffusion processes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3786 , http://hdl.handle.net/10962/d1003264 , Ibuprofen , Diffusion processes
- Description: Ibuprofen is a non-steroidal anti-inflammatory drug with three major types of effect: anti-inflammatory, analgesic and antipyretic. Ibuprofen may be administered in a number of different forms via the oral as well as the topical route. Published evidence suggests that topical, unlike oral, non-steroidal anti-inflammatory drugs are associated with few systemic side effects as plasma concentrations are low compared to oral therapy. In some countries it is particularly difficult to obtain human skin for in vitro experimentation and it is therefore important to have alternate biological or synthetic membranes which mimic human skin for diffusion experiments. Synthetic membranes serve as predictive models for topical drug release and in South Africa, shed snake skin is easily obtainable from the many snake parks present in the country. The FDA guidelines were considered when choosing the apparatus to be used in the comparative diffusion study on proprietary ibuprofen-containing topical preparations from three countries and the verification of the usefulness, or otherwise, of shed snake skin as a biological membrane for the assessment of the permeation of ibuprofen. Two diffusion techniques were considered appropriate for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing. One was the Franz diffusion cell, as modified by Keshary and Chien (88,169) and the other was the European Pharmacopoeia diffusion cell (187). High performance liquid chromatography was used as the analytical technique for the analysis of ibuprofen in aqueous solution using ultraviolet detection at 222 nm. The validated method was applied to the determination of the diffusion of ibuprofen from topical ibuprofen-containing formulations (gels, creams and mousse) through synthetic silicone membrane and shed snake skin biological membrane from four different species. In a study of fifteen topical ibuprofen-containing formulations (gels, creams and mousse) from three countries (South Africa, United Kingdom and France) it was found that there was a trend of products from two countries consistently exhibiting superior diffusion characteristics as well as products from the same two countries consistently exhibiting the lowest diffusion of ibuprofen. Interpretation of the results of these studies demonstrated the importance of employing a combination of statistical analyses and peak integration values when drawing conclusions regarding comparative diffusion characteristics. Shed snake skin has been described as a 'model' membrane, i.e. a membrane which shows similar permeability to human stratum corneum. The results reported here show clearly that, for ibuprofen, the four species of snake produce shed skin with completely different diffusion characteristics when all other conditions are identical. It may well be that there is one particular species of snake which produces shed skin of identical permeability to human stratum corneum, but to describe shed snake skin in general as a model membrane seems incorrect. It is therefore important that if shed snake skin is used as a membrane, the species, skin site and orientation should be reported. The European Pharmacopoeia diffusion apparatus was judged to be the better of the two diffusion techniques assessed for the measurement of the amount of ibuprofen released from a topical formulation during in vitro testing using silicone membranes and for the measurement of the amount of ibuprofen diffusing across the ventral outside orientation of shed skin during in vitro testing, whereas the Franz diffusion apparatus was judged to be better for the measurement of the amount of ibuprofen diffusing across the dorsal outside orientation of shed skin during in vitro testing. However, the choice of this diffusion apparatus must be weighed against the relatively poor reproducibility as compared with the European Pharmacopoeia diffusion apparatus.
- Full Text:
Investigations to determine the long-term sustainable yield of the Karoo aquifer and the sustained availability of groundwater for small-scale irrigation projects, in Dendera area, Kwekwe District - Zimbabwe
- Authors: Njanike, Joseph Tendayi
- Date: 2001
- Subjects: Groundwater , Irrigation -- Equipement and supplies , Irrigation -- Kwekwe (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5093 , http://hdl.handle.net/10962/d1020853
- Description: In this thesis the long-term sustainable yield of the Karoo sediment aquifer unit occurring in Dendera area of Kwekwe District is investigated, with the object of providing quantitative data on the sustained availability of groundwater for small-scale irrigation projects. Archaean Basement Schists and Pre-Cambrian gneissic granites, the Basement Complex rocks, underlie the entire study area. Overlying these are Upper Karoo sediments. Aeolian Kalahari sands unconformably mantle higher interfluves, while redistributed sands occur along valleys of major rivers and streams. The Karoo sediments, which predominantly consist of loosely cemented, fine- to medium-grained sandstone alternating with red siltstone and mudstone, constitute the main aquifer. The thickness of the Karoo sediment unit ranges from 30m to 80m. The hydraulic parameters of the Karoo sediment aquifer were characterised in the field by constant discharge pumping tests and slug tests. Pumping tests indicated unconfined conditions and thus the Neuman's method of analysis has been used. Transmissivities from pumping tests are within the range 4.7 m²/d to 13.6 m²/d with an average of 8.9m²/d. The low transmissivities seem to be a major limiting factor in the exploitation of the groundwater resources. Thus the sustainable borehole yields tend to be small, mean values ranging from 33 m²/d to 253 m²/d. Specific yield could not be determined from the pumping tests due to the lack of observation boreholes. Low chemical concentrations render the water suitable for irrigation of all crops, while neither total nor any individual concentrations present health hazards to human or livestock. An average recharge value of 47.7 mm/y was inferred from water table fluctuation method. Chloride mass balance technique in the same area indicates recharge value in the order of 67.4 mm/y. Because the chloride mass balance gives a long-term mean annual recharge, the recharge figure of 67.4 mm/y was adopted for the study area. Based on the abstractable proportion of recharge, the sustainably exploitable volume of groundwater of the order of 2.68 x 10⁷ m³/y was established. This volume is more than 100 times the estimated current demand for groundwater (1.35 x 10⁵ m³/d), implying that there are large volumes of surplus water, which can be utilised for irrigation.
- Full Text:
- Authors: Njanike, Joseph Tendayi
- Date: 2001
- Subjects: Groundwater , Irrigation -- Equipement and supplies , Irrigation -- Kwekwe (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5093 , http://hdl.handle.net/10962/d1020853
- Description: In this thesis the long-term sustainable yield of the Karoo sediment aquifer unit occurring in Dendera area of Kwekwe District is investigated, with the object of providing quantitative data on the sustained availability of groundwater for small-scale irrigation projects. Archaean Basement Schists and Pre-Cambrian gneissic granites, the Basement Complex rocks, underlie the entire study area. Overlying these are Upper Karoo sediments. Aeolian Kalahari sands unconformably mantle higher interfluves, while redistributed sands occur along valleys of major rivers and streams. The Karoo sediments, which predominantly consist of loosely cemented, fine- to medium-grained sandstone alternating with red siltstone and mudstone, constitute the main aquifer. The thickness of the Karoo sediment unit ranges from 30m to 80m. The hydraulic parameters of the Karoo sediment aquifer were characterised in the field by constant discharge pumping tests and slug tests. Pumping tests indicated unconfined conditions and thus the Neuman's method of analysis has been used. Transmissivities from pumping tests are within the range 4.7 m²/d to 13.6 m²/d with an average of 8.9m²/d. The low transmissivities seem to be a major limiting factor in the exploitation of the groundwater resources. Thus the sustainable borehole yields tend to be small, mean values ranging from 33 m²/d to 253 m²/d. Specific yield could not be determined from the pumping tests due to the lack of observation boreholes. Low chemical concentrations render the water suitable for irrigation of all crops, while neither total nor any individual concentrations present health hazards to human or livestock. An average recharge value of 47.7 mm/y was inferred from water table fluctuation method. Chloride mass balance technique in the same area indicates recharge value in the order of 67.4 mm/y. Because the chloride mass balance gives a long-term mean annual recharge, the recharge figure of 67.4 mm/y was adopted for the study area. Based on the abstractable proportion of recharge, the sustainably exploitable volume of groundwater of the order of 2.68 x 10⁷ m³/y was established. This volume is more than 100 times the estimated current demand for groundwater (1.35 x 10⁵ m³/d), implying that there are large volumes of surplus water, which can be utilised for irrigation.
- Full Text:
Laboratory and occupation-simulating isokinetic and psychophysical responses of military personnel
- Authors: James, Jonathan Peter
- Date: 2001
- Subjects: Isokinetic exercise , Soldiers -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5126 , http://hdl.handle.net/10962/d1005204 , Isokinetic exercise , Soldiers -- South Africa
- Description: The present study assessed the isokinetic responses of male military personnel(N=42). The study aimed to evaluate the strength capabilities of South African infantrymen and establish benchmark data on a population not previously tested. “Work-simulation” packages have not been widely exploited and this study further aimed to approximate how effectively occupation simulating tasks could identify the capabilities of soldiers. Testing was carried out using a CYBEX 6000 isokinetic dynamometer and involved six laboratory tests (LTs) and four occupation-simulating tests (OSTs). Subjects were required to complete two testing sessions with the order of tests randomized. The LTs consisted of ankle, elbow, hip, knee, shoulder and trunk. In the OSTs, gripping, valve-tightening, wrench-turning and pulling/pushing responses were collected. Slow, medium and fast test speeds were used for each bout. Cardiac responses were measured using heart rate monitoring and perceptual measures assessed using Borg’s (1971) RPE scale. The results of the testing showed significant differences in agonist and antagonist responses at all three testing speeds, the only exception being slow speed trunk values (peak torque). Upper- to lower-extremity ratios highlighted a possible weakness in the elbow flexors group, while correlations between LTs and OSTs highlighted the specificity of strength principle, as poor relationships were observed.
- Full Text:
- Authors: James, Jonathan Peter
- Date: 2001
- Subjects: Isokinetic exercise , Soldiers -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5126 , http://hdl.handle.net/10962/d1005204 , Isokinetic exercise , Soldiers -- South Africa
- Description: The present study assessed the isokinetic responses of male military personnel(N=42). The study aimed to evaluate the strength capabilities of South African infantrymen and establish benchmark data on a population not previously tested. “Work-simulation” packages have not been widely exploited and this study further aimed to approximate how effectively occupation simulating tasks could identify the capabilities of soldiers. Testing was carried out using a CYBEX 6000 isokinetic dynamometer and involved six laboratory tests (LTs) and four occupation-simulating tests (OSTs). Subjects were required to complete two testing sessions with the order of tests randomized. The LTs consisted of ankle, elbow, hip, knee, shoulder and trunk. In the OSTs, gripping, valve-tightening, wrench-turning and pulling/pushing responses were collected. Slow, medium and fast test speeds were used for each bout. Cardiac responses were measured using heart rate monitoring and perceptual measures assessed using Borg’s (1971) RPE scale. The results of the testing showed significant differences in agonist and antagonist responses at all three testing speeds, the only exception being slow speed trunk values (peak torque). Upper- to lower-extremity ratios highlighted a possible weakness in the elbow flexors group, while correlations between LTs and OSTs highlighted the specificity of strength principle, as poor relationships were observed.
- Full Text:
Novel approaches to the synthesis of quinoline derivatives
- Authors: Klaas, Phindile Jonathan
- Date: 2001 , 2013-04-26
- Subjects: Quinoline--Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4299 , http://hdl.handle.net/10962/d1004751 , Quinoline--Synthesis
- Description: The investigation has been concerned with the application of the Baylis-Hillman methodology to the synthesis of quinoline derivatives. An extensive range of novel Baylis-Hillman products has been prepared, typically in moderate to excellent yields, by condensing 2-nitrobenzaldehyde derivatives with various vinyl ketones and acrylic esters in the presence of diazabicyclo[2.2.2]octane (DABCO). Reduction of the nitro group in the Baylis-Hillman products was effected by catalytic hydrogenation in ethanol using a 10% palladium-on-carbon catalyst to afford quinoline, quinoline-N-oxide and quinolone derivatives. In all cases, it is apparent that cyclisation involves exclusive attack of nucleophilic nitrogen at the carbonyl centre, with acrylic ester derivatives affording quinolones and vinyl ketone derivatives affording quinolines and the corresponding quinoline-N-oxides. No products arising from a conjugate addition pathway were observed. The use of stannous chloride as an alternative reagent to effect reductive cyclisation of the Baylis-Hillman products has been explored, and found to favour the formation of 1,2- dihydroquinoline derivatives, with cyclisation occurring via a conjugate addition pathway. Isolation of the products, following work-up of the stannous chloride reactions, however, presented some difficulty. All compounds were characterised by spectroscopic (NMR and IR) and, where appropriate, elemental (high-resolution MS) analysis. Interconversion of the quinoline and quinoline-N-oxide derivatives has been explored and finally achieved in quantitative yields. Reduction of 2,3-dimethylquinoline-N-oxide to the corresponding quinoline was effected using phosphorus tribromide in DMF, and the reverse transformation with meta-chloroperbenzoic acid (MCPBA) in CHCl₃. Application of these methods to mixtures of 2,3-dimethylquinoline and its N-oxide has afforded, selectively, either the quinoline derivative or the corresponding N-oxide. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Klaas, Phindile Jonathan
- Date: 2001 , 2013-04-26
- Subjects: Quinoline--Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4299 , http://hdl.handle.net/10962/d1004751 , Quinoline--Synthesis
- Description: The investigation has been concerned with the application of the Baylis-Hillman methodology to the synthesis of quinoline derivatives. An extensive range of novel Baylis-Hillman products has been prepared, typically in moderate to excellent yields, by condensing 2-nitrobenzaldehyde derivatives with various vinyl ketones and acrylic esters in the presence of diazabicyclo[2.2.2]octane (DABCO). Reduction of the nitro group in the Baylis-Hillman products was effected by catalytic hydrogenation in ethanol using a 10% palladium-on-carbon catalyst to afford quinoline, quinoline-N-oxide and quinolone derivatives. In all cases, it is apparent that cyclisation involves exclusive attack of nucleophilic nitrogen at the carbonyl centre, with acrylic ester derivatives affording quinolones and vinyl ketone derivatives affording quinolines and the corresponding quinoline-N-oxides. No products arising from a conjugate addition pathway were observed. The use of stannous chloride as an alternative reagent to effect reductive cyclisation of the Baylis-Hillman products has been explored, and found to favour the formation of 1,2- dihydroquinoline derivatives, with cyclisation occurring via a conjugate addition pathway. Isolation of the products, following work-up of the stannous chloride reactions, however, presented some difficulty. All compounds were characterised by spectroscopic (NMR and IR) and, where appropriate, elemental (high-resolution MS) analysis. Interconversion of the quinoline and quinoline-N-oxide derivatives has been explored and finally achieved in quantitative yields. Reduction of 2,3-dimethylquinoline-N-oxide to the corresponding quinoline was effected using phosphorus tribromide in DMF, and the reverse transformation with meta-chloroperbenzoic acid (MCPBA) in CHCl₃. Application of these methods to mixtures of 2,3-dimethylquinoline and its N-oxide has afforded, selectively, either the quinoline derivative or the corresponding N-oxide. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
Nurses' experience of contesting discourses in HIV/AIDS activities in the primary health care setting
- Authors: Tutani, Lumka
- Date: 2001
- Subjects: Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3074 , http://hdl.handle.net/10962/d1002583 , Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
- Description: This paper explores the experience of nurses who work both as Primary Health Care Providers and counsellors trained in the narrative model of counselling in primary health care settings. Five focus groups were conducted in both Xhosa and English. Discourse analysis was used as a method of analysing the data. Training nurses in the narrative counselling model introduced an alternative discourse, which was experienced as contradicting their usual way of working. Two dominant discourses were the “not knowing” approach, assumed by the narrative model of counselling, and the “knowing” stance, assumed by health education. The institutionalised construction of counselling by doctors and matrons, and their power versus the power of the nurse counsellors was also cited as sources of conflict. Despite the tensions, narrative model of counselling seems to be offering new positions, which may benefit people living with HIV and improve HIV/AIDS activities in the Primary Health Care (PHC) context.
- Full Text:
- Authors: Tutani, Lumka
- Date: 2001
- Subjects: Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3074 , http://hdl.handle.net/10962/d1002583 , Primary health care , AIDS (Disease) -- Nursing , AIDS (Disease) -- Patients -- Counseling of
- Description: This paper explores the experience of nurses who work both as Primary Health Care Providers and counsellors trained in the narrative model of counselling in primary health care settings. Five focus groups were conducted in both Xhosa and English. Discourse analysis was used as a method of analysing the data. Training nurses in the narrative counselling model introduced an alternative discourse, which was experienced as contradicting their usual way of working. Two dominant discourses were the “not knowing” approach, assumed by the narrative model of counselling, and the “knowing” stance, assumed by health education. The institutionalised construction of counselling by doctors and matrons, and their power versus the power of the nurse counsellors was also cited as sources of conflict. Despite the tensions, narrative model of counselling seems to be offering new positions, which may benefit people living with HIV and improve HIV/AIDS activities in the Primary Health Care (PHC) context.
- Full Text:
Photosensitizing properties of non-transition metal porphyrazines towards the generation of singlet oxygen
- Seotsanyana-Mokhosi, Itumeleng
- Authors: Seotsanyana-Mokhosi, Itumeleng
- Date: 2001 , 2013-05-02
- Subjects: Phthalocyanines , Photosensitization, Biological , Active oxygen -- Physiological effect , Photosensitizing compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4395 , http://hdl.handle.net/10962/d1006086 , Phthalocyanines , Photosensitization, Biological , Active oxygen -- Physiological effect , Photosensitizing compounds
- Description: Metallophthalocyanine complexes containing non-transition metals are very useful as sensitizers for photodynamic therapy, a cure for cancer that is based on visible light activation of tumour localized photo sensitizers. Excited sensitizers generate singlet oxygen as the main hyperactive species that destroy the tumour. Water soluble sensitizers are sought after for the convenience of delivery into the body. Thus, phthalocyanine (pc), tetrapyridinoporphyrazines (tppa) and tetramethyltetrapyridinoporphyrazines (tmtppa) with non-transition central metal atoms of Ge, Si, Sn and Zn were studied. First was the synthesis of these complexes, followed by their characterisation. The characterisation involved the use of ultraviolet and visible absorption spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, electrochemical properties and elemental analysis. Photochemical properties of the complexes were then investigated. Photolysis of these macrocycles showed two processes; -reduction of the dye and photobleaching, which leads to the disintegration of the conjugated chromophore structure of the dye. Photobleaching is the reductive quenching of the excited state of the sensitizers. The intensity of the quenching decreased progressively from tmtppa, tppa to pc metal complexes with photobleaching quantum yields, 6.6 x 10.5⁻¹, 1.8 x 10.5⁻¹ and 5.4 x 10⁻⁶ for Zntmtppa, Zntppa and Znpc, respectively. Efficiency of singlet oxygen sensitization is solvent dependent with very different values obtained for the same compound in different solvents, for example, 0.25 and 0.38 were observed as singlet oxygen quantum yields for Gepc complex in DMSO and DMF respectively. In DMSO the efficiency of ¹O₂ generation decrease considerably from pc to tppa and finally tmtppa. In water Getmtppa exhibits much higher singlet oxygen quantum yield, hence promising to be effective as a sensitizer for photodynamic therapy.
- Full Text:
- Authors: Seotsanyana-Mokhosi, Itumeleng
- Date: 2001 , 2013-05-02
- Subjects: Phthalocyanines , Photosensitization, Biological , Active oxygen -- Physiological effect , Photosensitizing compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4395 , http://hdl.handle.net/10962/d1006086 , Phthalocyanines , Photosensitization, Biological , Active oxygen -- Physiological effect , Photosensitizing compounds
- Description: Metallophthalocyanine complexes containing non-transition metals are very useful as sensitizers for photodynamic therapy, a cure for cancer that is based on visible light activation of tumour localized photo sensitizers. Excited sensitizers generate singlet oxygen as the main hyperactive species that destroy the tumour. Water soluble sensitizers are sought after for the convenience of delivery into the body. Thus, phthalocyanine (pc), tetrapyridinoporphyrazines (tppa) and tetramethyltetrapyridinoporphyrazines (tmtppa) with non-transition central metal atoms of Ge, Si, Sn and Zn were studied. First was the synthesis of these complexes, followed by their characterisation. The characterisation involved the use of ultraviolet and visible absorption spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, electrochemical properties and elemental analysis. Photochemical properties of the complexes were then investigated. Photolysis of these macrocycles showed two processes; -reduction of the dye and photobleaching, which leads to the disintegration of the conjugated chromophore structure of the dye. Photobleaching is the reductive quenching of the excited state of the sensitizers. The intensity of the quenching decreased progressively from tmtppa, tppa to pc metal complexes with photobleaching quantum yields, 6.6 x 10.5⁻¹, 1.8 x 10.5⁻¹ and 5.4 x 10⁻⁶ for Zntmtppa, Zntppa and Znpc, respectively. Efficiency of singlet oxygen sensitization is solvent dependent with very different values obtained for the same compound in different solvents, for example, 0.25 and 0.38 were observed as singlet oxygen quantum yields for Gepc complex in DMSO and DMF respectively. In DMSO the efficiency of ¹O₂ generation decrease considerably from pc to tppa and finally tmtppa. In water Getmtppa exhibits much higher singlet oxygen quantum yield, hence promising to be effective as a sensitizer for photodynamic therapy.
- Full Text:
Processes and products in the kimberlitic crater facies of the south lobe, Jwaneng Mine, Botswana
- Authors: Machin, Kimberley
- Date: 2001
- Subjects: Kimberlite -- Jwaneng (Botswana)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4995 , http://hdl.handle.net/10962/d1005607 , Kimberlite -- Jwaneng (Botswana)
- Description: The Pennian (~ 245 Ma) Jwaneng kimberlite, situated in southern Botswana, comprises three steep-sided pipes that coalesce approximately 100m below the present day surface to fonn a 54ha body. These pipes have been labelled the South, Centre and North Lobes. The kimberlites intruded a thick sequence of Proterozoic shales, dolomites and sandstones and a thin veneer of consolidated to poorly consolidated mudstones and siltstones of the Karoo Supergroup. Although the shapes of these pipes are comparable to other southern African pipes, they are filled predominantly with crater facies volcaniclastic kimberlite. No tuffisitic kimberlite breccia, the characteristic rock type of the diatremes of other southern African pipes, has yet been identified. The Jwaneng kimberlite thus represents an exception to the standard model for southern African kimberlites, implying that different processes need to be invoked to explain its fonnation. The present study involves a detailed volcanological and sedimentological analysis of the volcaniclastic fill of the Jwaneng South Lobe. Two principal and distinct lithofacies have been identified: the quartz-free RVK facies and the quartz-bearing QRVK facies. Both facies include fine to coarse grained, predominantly massive and subordinate chaotically bedded deposits. The volcaniclastic rocks have been classified as resedimented volcaniclastic kimberlite (RVK) , since their deposition is ascribed to mechanisms dominated by mass flow processes. Based on certain characteristics and differences between the two principal facies, and their spatial distribution within the pipe, they are interpreted as being the products of at least two separate eruption episodes. Certain characteristics (e.g. }hape, granularity~ of the juvenile· magma clasts III the volcaniclastic kimberlite suggest complete crystallisation and devolatilisation of the magma at depth prior to explosive fragmentation. A scenario in which this might have occurred, and which led to catastrophic explosive eruption and pipe excavation is proposed. Explosive eruption and associated tuff cone formation is followed by resedimentation of the material back into the pipe by mass flow processes. Mass flow processes are dominated by debris flow, with lesser grain flow, hyperconcentrated flow and subaqueous mud flow and suspension settling of muddy kimberlitic sediments. Geochemical analyses of the latter indicate a high degree of contamination and weathering, and mixing between pristine kimberlite and silicic shale/mud compositions. Failure and collapse of parts of the underlying pipe walls yielded megablocks of poorly consolidated Permian Karoo mudstone in the peripheral zone of the pipe. This source of the megablocks is supported by their bulk chemical composition. Minor phreatic/phreatomagmatic eruptions are suggested by the presence of rare accretionary and armoured lapilli within both the QRVK and RVK facies. Subsidence of the volcaniclastic pipe fill, inferred mainly from the oversteepened dips of the bedded QRVK and RVK facies, may be related to gravity-induced compaction, late-stage phreatomagmatic eruptions or eruption ofthe adjacent Centre Lobe.
- Full Text:
- Authors: Machin, Kimberley
- Date: 2001
- Subjects: Kimberlite -- Jwaneng (Botswana)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4995 , http://hdl.handle.net/10962/d1005607 , Kimberlite -- Jwaneng (Botswana)
- Description: The Pennian (~ 245 Ma) Jwaneng kimberlite, situated in southern Botswana, comprises three steep-sided pipes that coalesce approximately 100m below the present day surface to fonn a 54ha body. These pipes have been labelled the South, Centre and North Lobes. The kimberlites intruded a thick sequence of Proterozoic shales, dolomites and sandstones and a thin veneer of consolidated to poorly consolidated mudstones and siltstones of the Karoo Supergroup. Although the shapes of these pipes are comparable to other southern African pipes, they are filled predominantly with crater facies volcaniclastic kimberlite. No tuffisitic kimberlite breccia, the characteristic rock type of the diatremes of other southern African pipes, has yet been identified. The Jwaneng kimberlite thus represents an exception to the standard model for southern African kimberlites, implying that different processes need to be invoked to explain its fonnation. The present study involves a detailed volcanological and sedimentological analysis of the volcaniclastic fill of the Jwaneng South Lobe. Two principal and distinct lithofacies have been identified: the quartz-free RVK facies and the quartz-bearing QRVK facies. Both facies include fine to coarse grained, predominantly massive and subordinate chaotically bedded deposits. The volcaniclastic rocks have been classified as resedimented volcaniclastic kimberlite (RVK) , since their deposition is ascribed to mechanisms dominated by mass flow processes. Based on certain characteristics and differences between the two principal facies, and their spatial distribution within the pipe, they are interpreted as being the products of at least two separate eruption episodes. Certain characteristics (e.g. }hape, granularity~ of the juvenile· magma clasts III the volcaniclastic kimberlite suggest complete crystallisation and devolatilisation of the magma at depth prior to explosive fragmentation. A scenario in which this might have occurred, and which led to catastrophic explosive eruption and pipe excavation is proposed. Explosive eruption and associated tuff cone formation is followed by resedimentation of the material back into the pipe by mass flow processes. Mass flow processes are dominated by debris flow, with lesser grain flow, hyperconcentrated flow and subaqueous mud flow and suspension settling of muddy kimberlitic sediments. Geochemical analyses of the latter indicate a high degree of contamination and weathering, and mixing between pristine kimberlite and silicic shale/mud compositions. Failure and collapse of parts of the underlying pipe walls yielded megablocks of poorly consolidated Permian Karoo mudstone in the peripheral zone of the pipe. This source of the megablocks is supported by their bulk chemical composition. Minor phreatic/phreatomagmatic eruptions are suggested by the presence of rare accretionary and armoured lapilli within both the QRVK and RVK facies. Subsidence of the volcaniclastic pipe fill, inferred mainly from the oversteepened dips of the bedded QRVK and RVK facies, may be related to gravity-induced compaction, late-stage phreatomagmatic eruptions or eruption ofthe adjacent Centre Lobe.
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Project 1 - Student teachers' exploration of beadwork : cultural heritage as a resource for mathematical concepts
- Authors: Dabula, Nomonde Patience
- Date: 2001
- Subjects: Ethnomathematics , Beadwork -- South Africa -- Eastern Cape , Beadwork , Mathematics -- Study and teaching , Culture -- Study and teaching
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1415 , http://hdl.handle.net/10962/d1003292
- Description: This portfolio consists of three research projects that predominantly lie within the socio-cultural strand. The first project is a qualitative ethnomathematical study that links students' knowledge of mathematics to their cultural heritage. The study was conducted with a group of final year student teachers at a College of Education in Umtata, Eastern Cape. These students visited a city museum where mathematics concepts were identified from beadwork artifacts. Mathematics concepts that were identified consisted of symmetry, tessellation and number patterns. Students' views about the nature of mathematics shifted radically after their own explorations. Initially students did not perceive mathematics as relating to socio-cultural practices. But now, they have reviewed their position and see mathematics as inextricably interwoven in everyday activities and as such, a product of all cultures. They also pride themselves of their own cultural heritage to have mathematical connections. A more positive attitude towards studying mathematics in this approach was noticed. Data was collected by means of interviews, reflective journal entries and photographs. The second project is a survey with a group of practising teachers who have already implemented Curriculum 2005, and a group which is about to implement it in 2001. The study sought teachers' understanding of connections between mathematics and socio-cultural issues. The new mathematics curriculum in South Africa calls for teachers to grapple well with these issues. About a third of the articulated specific outcomes specifically relate to socio-cultural issues. If teachers' understanding of these issues is poor, implementation of the new curriculum will remain a mere dream. The findings of the survey revealed that the majority of teachers could not identify the culture related specific outcomes in the new mathematics curriculum. Complicated language used in the OBE policy documents was found to inhibit meaning to these teachers. Although, all teachers showed a positive attitude towards the inclusion of socio-cultural issues in the mathematics classroom, the implementation of these outcomes was found to be very problematic. In this survey data was collected by means of questionnaires. The third project is a literature review on the need to popularise mathematics to students in particular, and to the broader public in general. The 21 st century places great technological demands. Mathematics underpins most thinking behind technological development. The role played by mathematics in advancing other fields is largely hidden to the majority of people. There is, therefore, a need to bring forth the vital role that mathematics plays in these fields. The number of students participating in mathematics is decreasing. Mathematics, as a field, is experiencing competition from other science fields. There is a need to bring some incentives to attract more students into this field and retain those mathematicians already involved. Also important, is the need to change the negative image that the public often holds about mathematics. Many people are mathematically illiterate and do not see mathematics as an everyday activity that relates to their needs. There is, therefore, a need to change the face of mathematics.
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- Authors: Dabula, Nomonde Patience
- Date: 2001
- Subjects: Ethnomathematics , Beadwork -- South Africa -- Eastern Cape , Beadwork , Mathematics -- Study and teaching , Culture -- Study and teaching
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1415 , http://hdl.handle.net/10962/d1003292
- Description: This portfolio consists of three research projects that predominantly lie within the socio-cultural strand. The first project is a qualitative ethnomathematical study that links students' knowledge of mathematics to their cultural heritage. The study was conducted with a group of final year student teachers at a College of Education in Umtata, Eastern Cape. These students visited a city museum where mathematics concepts were identified from beadwork artifacts. Mathematics concepts that were identified consisted of symmetry, tessellation and number patterns. Students' views about the nature of mathematics shifted radically after their own explorations. Initially students did not perceive mathematics as relating to socio-cultural practices. But now, they have reviewed their position and see mathematics as inextricably interwoven in everyday activities and as such, a product of all cultures. They also pride themselves of their own cultural heritage to have mathematical connections. A more positive attitude towards studying mathematics in this approach was noticed. Data was collected by means of interviews, reflective journal entries and photographs. The second project is a survey with a group of practising teachers who have already implemented Curriculum 2005, and a group which is about to implement it in 2001. The study sought teachers' understanding of connections between mathematics and socio-cultural issues. The new mathematics curriculum in South Africa calls for teachers to grapple well with these issues. About a third of the articulated specific outcomes specifically relate to socio-cultural issues. If teachers' understanding of these issues is poor, implementation of the new curriculum will remain a mere dream. The findings of the survey revealed that the majority of teachers could not identify the culture related specific outcomes in the new mathematics curriculum. Complicated language used in the OBE policy documents was found to inhibit meaning to these teachers. Although, all teachers showed a positive attitude towards the inclusion of socio-cultural issues in the mathematics classroom, the implementation of these outcomes was found to be very problematic. In this survey data was collected by means of questionnaires. The third project is a literature review on the need to popularise mathematics to students in particular, and to the broader public in general. The 21 st century places great technological demands. Mathematics underpins most thinking behind technological development. The role played by mathematics in advancing other fields is largely hidden to the majority of people. There is, therefore, a need to bring forth the vital role that mathematics plays in these fields. The number of students participating in mathematics is decreasing. Mathematics, as a field, is experiencing competition from other science fields. There is a need to bring some incentives to attract more students into this field and retain those mathematicians already involved. Also important, is the need to change the negative image that the public often holds about mathematics. Many people are mathematically illiterate and do not see mathematics as an everyday activity that relates to their needs. There is, therefore, a need to change the face of mathematics.
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Removal of copper and nickel from solution by the non-viable biomass of the water fern Azolla filiculoides in an upscaled fixed-bed column system
- Authors: Thompson, Denis Alan
- Date: 2001
- Subjects: Copper , Nickel , Azolla , Heavy metals -- Absorption and adsorption
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3914 , http://hdl.handle.net/10962/d1003973 , Copper , Nickel , Azolla , Heavy metals -- Absorption and adsorption
- Description: The potential of non-viable Azalia filiculaides for the removal of Cu and Ni from aqueous solutions and the possibility of scaling up existing lab scale Azalia column systems was investigated. The effects of factors such as metal starting concentration, pH and two metals in solution on the removal of Ni and Cu from aqueous solution by dried and crushed Azalia biomass were studied in batch systems. Aqueous solutions of Ni with starting concentrations between 1000 and 2000J.lmolll gave the most efficient Ni removal by Azalla biomass. For Cu the optimum starting concentration for adsorption was 50J.lmol/l. The adsorption capacity of both eu and Ni increased as the starting pH of the sorption media increased. The optimum pH for Ni adsorption was found at pH 7 and for Cu, at pH 5. - Awlla biomass had a higher. maximum binding capacity (qrnax) for Cu than for Ni at pH 5. The removal of both Cu allct Ni showed little or no variation with the presence another metal in solution. Kinetic studies show that both Cu and Ni adsorbed rapidly onto the Azalia biomass. The removal of Cu and Ni from aqueous solutions using non-viable Azalia biomass was investigated in a lab scale fixed-bed column and an upscaled 4L column system. The nonviable Azalla filiculaides biomass when dried and used in a column for adsorption of Cu and Ni showed good physical stability under many different conditions. Preparation of the biomass before it could be used in the columns was very simple and did not involve any significant pretreatment steps. Prolonged exposure to UV light decreases Azalia biomass capacity for Ni and Cu adsorption. Column adsorption of Cu and Ni from aqueous solutions was successfully upscaled approximately 100 times. Relative to the lab scale column, the 4L column performed better for the uptake of Cu and Ni per gram of biomass. The larger column was also able to operate at relatively higher flow rates. The biomass showed good reusability with little change in the amount of Ni adsorbed in 10 consecutive cycles. Electron micrographs showecf little or no change in the physical structure and integrity of the Azolla biomass after exposure to mineral acids, Ni solution and high flow rates over 10 consecutive adsorption and desorption cycles. As much as 80% Ni and 70 % Cu was recovered when desorption profiles were generated using O.lMHCI as a desorption agent. The 4L column system was also tested using a highly concen~rat:~ Ni plating bath solution.(Nicrolyte 1). Only 18 % of the Ni could be removed from the expended Nicrolyte 1 pla~Jng solution after treating only 25L, indicating that Azolla biomass is more suited for removal of metals from more dilute industrial effluents.
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- Authors: Thompson, Denis Alan
- Date: 2001
- Subjects: Copper , Nickel , Azolla , Heavy metals -- Absorption and adsorption
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3914 , http://hdl.handle.net/10962/d1003973 , Copper , Nickel , Azolla , Heavy metals -- Absorption and adsorption
- Description: The potential of non-viable Azalia filiculaides for the removal of Cu and Ni from aqueous solutions and the possibility of scaling up existing lab scale Azalia column systems was investigated. The effects of factors such as metal starting concentration, pH and two metals in solution on the removal of Ni and Cu from aqueous solution by dried and crushed Azalia biomass were studied in batch systems. Aqueous solutions of Ni with starting concentrations between 1000 and 2000J.lmolll gave the most efficient Ni removal by Azalla biomass. For Cu the optimum starting concentration for adsorption was 50J.lmol/l. The adsorption capacity of both eu and Ni increased as the starting pH of the sorption media increased. The optimum pH for Ni adsorption was found at pH 7 and for Cu, at pH 5. - Awlla biomass had a higher. maximum binding capacity (qrnax) for Cu than for Ni at pH 5. The removal of both Cu allct Ni showed little or no variation with the presence another metal in solution. Kinetic studies show that both Cu and Ni adsorbed rapidly onto the Azalia biomass. The removal of Cu and Ni from aqueous solutions using non-viable Azalia biomass was investigated in a lab scale fixed-bed column and an upscaled 4L column system. The nonviable Azalla filiculaides biomass when dried and used in a column for adsorption of Cu and Ni showed good physical stability under many different conditions. Preparation of the biomass before it could be used in the columns was very simple and did not involve any significant pretreatment steps. Prolonged exposure to UV light decreases Azalia biomass capacity for Ni and Cu adsorption. Column adsorption of Cu and Ni from aqueous solutions was successfully upscaled approximately 100 times. Relative to the lab scale column, the 4L column performed better for the uptake of Cu and Ni per gram of biomass. The larger column was also able to operate at relatively higher flow rates. The biomass showed good reusability with little change in the amount of Ni adsorbed in 10 consecutive cycles. Electron micrographs showecf little or no change in the physical structure and integrity of the Azolla biomass after exposure to mineral acids, Ni solution and high flow rates over 10 consecutive adsorption and desorption cycles. As much as 80% Ni and 70 % Cu was recovered when desorption profiles were generated using O.lMHCI as a desorption agent. The 4L column system was also tested using a highly concen~rat:~ Ni plating bath solution.(Nicrolyte 1). Only 18 % of the Ni could be removed from the expended Nicrolyte 1 pla~Jng solution after treating only 25L, indicating that Azolla biomass is more suited for removal of metals from more dilute industrial effluents.
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Research portfolio
- Authors: Daphney, Robert
- Date: 2001
- Subjects: Teachers colleges -- South Africa -- Eastern Cape Competency-based education -- South Africa -- Eastern Cape Geography -- Curricula Geography -- Fieldwork -- Study and teaching Geography -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1828 , http://hdl.handle.net/10962/d1003714
- Description: This portfolio of work represents three research projects on issues related to teacher education. The research was undertaken at Dr. W.B. Rubusana College of Education over a period of three years. The first project is a situational analysis that attempts to determine whether the college is capable of meeting the challenges placed on it by the evolving South African Educational System. The key finding is that the college is not ready to embark on the changes required by the Ministry of Education chiefly because its educators and learners are seemingly not ready to embrace change. The second project is a case study that attempts to determine whether a group of 12 Senior Primary students at the college are able to interpret photographs of the local environment and as such provide evidence of their ability to be environmental educators through the medium of geography. The findings indicate that they are only able to read the photographs at a very superficial level. Their poor communication skills and their disadvantaged backgrounds seem to prevent them from achieving the level of thinking required for them to be effective environmental educators. The third project describes, analyses and evaluates a fieldwork study done with a class of Senior Primary students at the college. While the students did not achieve the necessary progression from 'look and see' to 'enquiry based' fieldwork the project was valuable in that it was an educative experience for both teacher and learner and provides evidence of the value of action research and reflective teaching.
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- Authors: Daphney, Robert
- Date: 2001
- Subjects: Teachers colleges -- South Africa -- Eastern Cape Competency-based education -- South Africa -- Eastern Cape Geography -- Curricula Geography -- Fieldwork -- Study and teaching Geography -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1828 , http://hdl.handle.net/10962/d1003714
- Description: This portfolio of work represents three research projects on issues related to teacher education. The research was undertaken at Dr. W.B. Rubusana College of Education over a period of three years. The first project is a situational analysis that attempts to determine whether the college is capable of meeting the challenges placed on it by the evolving South African Educational System. The key finding is that the college is not ready to embark on the changes required by the Ministry of Education chiefly because its educators and learners are seemingly not ready to embrace change. The second project is a case study that attempts to determine whether a group of 12 Senior Primary students at the college are able to interpret photographs of the local environment and as such provide evidence of their ability to be environmental educators through the medium of geography. The findings indicate that they are only able to read the photographs at a very superficial level. Their poor communication skills and their disadvantaged backgrounds seem to prevent them from achieving the level of thinking required for them to be effective environmental educators. The third project describes, analyses and evaluates a fieldwork study done with a class of Senior Primary students at the college. While the students did not achieve the necessary progression from 'look and see' to 'enquiry based' fieldwork the project was valuable in that it was an educative experience for both teacher and learner and provides evidence of the value of action research and reflective teaching.
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Research projects
- Authors: Adusei-Owusu, James
- Date: 2001
- Subjects: Constructivism (Education) , Review literature , College students -- Study and teaching , Teaching -- Methods , Competency based education -- Eastern Cape (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1740 , http://hdl.handle.net/10962/d1003624 , Constructivism (Education) , Review literature , College students -- Study and teaching , Teaching -- Methods , Competency based education -- Eastern Cape (South Africa)
- Description: RESEARCH PROJECTS: 1 RESEARCH PROJECT ONE: A literature review: Constructivism: An alternate approach to teaching and learning. Abstract The constructivist perspectives on learning have helped enhance science educators' understanding of how students make sense of their lived experiences. Constructivism purports to be a transformation of the traditional curriculum. As such this article starts with a brief overview of behaviorism: the scientific approach to education. The main tenets underlying constructivism, how constructivism guides educators to change their classroom practice, and the implications to science teaching have been reviewed. 2 RESEARCH PROJECT TWO (Empirical study): Being Constructive: College students' learning of work and heat as aspects of the energy concept based a constructivist approach. Abstract This study is an extension of a literature review on constructivism as an alternate teaching and learning approach discussed in research project one. It is an empirical study concerning the use of a learning module based on a constructivist approach to develop pre-service student teachers' understanding of work and heat as aspects of the energy concept. The data consisted mainly of transcripts of students' interviews, written responses to questionnaires designed in the form of a worksheet, and comments from non-participant observers and students. The results seem to suggest that a carefully designed learning module based on a constructivist teaching and learning approach may be a valuable tool in developing pre-service student teachers' understanding of work and heat. 3 RESEARCH PROJECT THREE (Empirical study): A College in transition: A case study of the readiness of a college in the Eastern Cape province to implement Outcomes-Based Education in an Education Development centre. Abstract Curriculum 2005 premised on Outcomes-Based Education is the new curriculum framework for South Africa. It signifies a paradigm shift in education from the traditional 'telling-listening' relationship between the teacher and the learner to one that emphasises leamer-centred approach to the teaching process. Teachers, though recognized as crucial to the educational transformation process in the country have also being identified as ill-equipped to meet the challenges posed by Outcomes-Based Education. This study starts with a brief overview of the South African curriculum and the main tenets underlying Outcomes-Based Education. The institutional conditions and whether the lecturers at a college in the Eastern Cape province perceive the need for a change in their classroom practice were also investigated. Bearing in mind the need for further research to validate the findings of this study, positive indicators that emerged from the study suggest the readiness of the college to implement Outcomes-Based Education at the proposed Education Development Centre.
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- Authors: Adusei-Owusu, James
- Date: 2001
- Subjects: Constructivism (Education) , Review literature , College students -- Study and teaching , Teaching -- Methods , Competency based education -- Eastern Cape (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1740 , http://hdl.handle.net/10962/d1003624 , Constructivism (Education) , Review literature , College students -- Study and teaching , Teaching -- Methods , Competency based education -- Eastern Cape (South Africa)
- Description: RESEARCH PROJECTS: 1 RESEARCH PROJECT ONE: A literature review: Constructivism: An alternate approach to teaching and learning. Abstract The constructivist perspectives on learning have helped enhance science educators' understanding of how students make sense of their lived experiences. Constructivism purports to be a transformation of the traditional curriculum. As such this article starts with a brief overview of behaviorism: the scientific approach to education. The main tenets underlying constructivism, how constructivism guides educators to change their classroom practice, and the implications to science teaching have been reviewed. 2 RESEARCH PROJECT TWO (Empirical study): Being Constructive: College students' learning of work and heat as aspects of the energy concept based a constructivist approach. Abstract This study is an extension of a literature review on constructivism as an alternate teaching and learning approach discussed in research project one. It is an empirical study concerning the use of a learning module based on a constructivist approach to develop pre-service student teachers' understanding of work and heat as aspects of the energy concept. The data consisted mainly of transcripts of students' interviews, written responses to questionnaires designed in the form of a worksheet, and comments from non-participant observers and students. The results seem to suggest that a carefully designed learning module based on a constructivist teaching and learning approach may be a valuable tool in developing pre-service student teachers' understanding of work and heat. 3 RESEARCH PROJECT THREE (Empirical study): A College in transition: A case study of the readiness of a college in the Eastern Cape province to implement Outcomes-Based Education in an Education Development centre. Abstract Curriculum 2005 premised on Outcomes-Based Education is the new curriculum framework for South Africa. It signifies a paradigm shift in education from the traditional 'telling-listening' relationship between the teacher and the learner to one that emphasises leamer-centred approach to the teaching process. Teachers, though recognized as crucial to the educational transformation process in the country have also being identified as ill-equipped to meet the challenges posed by Outcomes-Based Education. This study starts with a brief overview of the South African curriculum and the main tenets underlying Outcomes-Based Education. The institutional conditions and whether the lecturers at a college in the Eastern Cape province perceive the need for a change in their classroom practice were also investigated. Bearing in mind the need for further research to validate the findings of this study, positive indicators that emerged from the study suggest the readiness of the college to implement Outcomes-Based Education at the proposed Education Development Centre.
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Rural resettlement scheme evaluation: a case study of the Mfengu in Tsitsikamma
- Authors: Fakudze, Churchill M
- Date: 2001
- Subjects: Land settlement , Land settlement -- South Africa -- Tsitsikamma , Land settlement -- Developing countries , Land settlement -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3309 , http://hdl.handle.net/10962/d1003097 , Land settlement , Land settlement -- South Africa -- Tsitsikamma , Land settlement -- Developing countries , Land settlement -- South Africa
- Description: In 1997 South Africa came out with a policy aimed at addressing the legacy of apartheid in respect of an unequal division of land in the country. About 3.5 million people were moved from rural and urban areas between 1960 and 1980 and deposited in the reserves or areas designed for the exclusive occupation of black people. The new land policy attempts to deal with the resultant problems. The policy advocates a three-pronged approach to land reform encompassing (i) land restitution, (ii) land redistribution and (iii) land tenure reform. A number of projects have been carried out under these three aspects. This study aims to investigate and evaluate the results of a completed land restitution case. The Mfengu of Tsitsikamma was chosen as a case study because the people have moved back and are now living on their land. The Mfengu were dispossessed of their land in 1977 by the apartheid government and their land was returned in 1994. Although this case was processed outside of the land restitution legislation (Restitution of Land Rights Act, 22 of 1994), all restitution cases where people return to their original land have to deal with the problems of resettlement. From its involvement in various involuntary resettlement projects, the World Bank concluded that the new communities of resettlers should be designed as a viable settlement system equipped with infrastructure and services and integrated in the regional socio-economic context. The host communities receiving the resettlers should be assisted to overcome possible adverse social and environmental effects from the increased population density. These concerns are valid for the South African situation, and the question is, whether this resettlement encapsulates the above. The goals of the research are twofold. To evaluate the efficiency and effectiveness of the resettlement project and its sustainability. In particular focussing on the constraints to the implementation of the land policy. Research questions include the following: How was the project carried out? Is the resettlement integrated into the socio-economic and development planning of the area? How viable and sustainable is the new settlement? What are the major problems and challenges facing this area and how can they be overcome?
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- Authors: Fakudze, Churchill M
- Date: 2001
- Subjects: Land settlement , Land settlement -- South Africa -- Tsitsikamma , Land settlement -- Developing countries , Land settlement -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3309 , http://hdl.handle.net/10962/d1003097 , Land settlement , Land settlement -- South Africa -- Tsitsikamma , Land settlement -- Developing countries , Land settlement -- South Africa
- Description: In 1997 South Africa came out with a policy aimed at addressing the legacy of apartheid in respect of an unequal division of land in the country. About 3.5 million people were moved from rural and urban areas between 1960 and 1980 and deposited in the reserves or areas designed for the exclusive occupation of black people. The new land policy attempts to deal with the resultant problems. The policy advocates a three-pronged approach to land reform encompassing (i) land restitution, (ii) land redistribution and (iii) land tenure reform. A number of projects have been carried out under these three aspects. This study aims to investigate and evaluate the results of a completed land restitution case. The Mfengu of Tsitsikamma was chosen as a case study because the people have moved back and are now living on their land. The Mfengu were dispossessed of their land in 1977 by the apartheid government and their land was returned in 1994. Although this case was processed outside of the land restitution legislation (Restitution of Land Rights Act, 22 of 1994), all restitution cases where people return to their original land have to deal with the problems of resettlement. From its involvement in various involuntary resettlement projects, the World Bank concluded that the new communities of resettlers should be designed as a viable settlement system equipped with infrastructure and services and integrated in the regional socio-economic context. The host communities receiving the resettlers should be assisted to overcome possible adverse social and environmental effects from the increased population density. These concerns are valid for the South African situation, and the question is, whether this resettlement encapsulates the above. The goals of the research are twofold. To evaluate the efficiency and effectiveness of the resettlement project and its sustainability. In particular focussing on the constraints to the implementation of the land policy. Research questions include the following: How was the project carried out? Is the resettlement integrated into the socio-economic and development planning of the area? How viable and sustainable is the new settlement? What are the major problems and challenges facing this area and how can they be overcome?
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Stratigraphy and geochemistry of the Makganyene formation, Transvaal supergroup, Northern Cape, South Africa
- Authors: Polteau, Stéphane
- Date: 2001
- Subjects: Geology, Stratigraphic -- South Africa -- Northern Cape , Geochemistry -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5003 , http://hdl.handle.net/10962/d1005616 , Geology, Stratigraphic -- South Africa -- Northern Cape , Geochemistry -- South Africa -- Northern Cape
- Description: The Makganyene Formation forms the base of the Postmasburg Group in the Transvaal Supergroup of the Northern Cape Province. The Makganyene Formation has diamictite as the main rock type, but siltstone, sandstone, shale, and iron-formations are also present. A glacial origin has been proposed in the past due to the presence of dropstones, faceted and striated pebbles. Typically, the Makganyene Formation contains banded iron-formations interbedded with clastic rocks (shale, siltstone, sandstone and diamictites) at the contact with the underlying iron-formations. This transitional zone is generally overlain by massive or layered diamictites which contain poorly sorted clasts (mainly chert) within a shaly matrix. Striated pebbles have been found during field work, and dropstones have been observed in diamictites and banded iron-formations during the study. The top of the Makganyene Formation contains graded cycles interbedded with diamictites and thin layers of andesitic lavas from the Ongeluk Formation. The basal contact of the Makganyene Formation with the underlying Koegas Subgroup was described as unconformable by previous workers. However field work localised in the Rooinekke area shows a broadly conformable and interbedded contact with the underlying Koegas Subgroup. As described above, banded iron-formations are interbedded with the clastic rocks of the Makganyene Formation. Moreover, boreholes from the Sishen area display the same interbedding at the base of the Makganyene Formation. This suggests that no significant time gap is present in the whole succession between the Ghaap and Postmasburg Group. The Transvaal Supergroup in the Northern Cape displays the following succession : carbonates-BIFs-diamictites/ lava-BIFs-carbonates. The Makganyene Formation is thus at the centre of a symmetrical lithologic succession. Bulk rock compositions show that the diamictites have a similar composition to banded iron-formation with regard to their major element contents. Banded iron-formations acted as a source for the diamictites with carbonates and igneous rocks representing minor components. Differences in bulk composition between the Sishen and Matsap areas emphasize that the source of the diamictite was very localised. The Chemical Index of Alteration (CIA) has been calculated, but since the source dominant rock was iron-formation, this index cannot be usefully applied to the diamictites. ACN, A-CN-K, and A-CNK-FM diagrams confer a major importance in sorting processes due to the separation between the fine and coarse diamictites. The interbedded iron-formations display little clastic contamination indicating deposition in clear water conditions. However, dropstones are present in one borehole from the Matsap area, indicating that iron-formation took place under ice cover, or at least under icebergs. Stable isotope studies show that the iron-formations, interbedded towards the base of the Makganyene Formation, have similar values to the iron-formations of the Koegas Subgroup. As a result of the above observations, new correlations are proposed in this study, relating the different Transvaal Supergroup basins located on the Kaapvaal Craton. The Pretoria Group of the Transvaal Basin has no correlative in the Griqualand West Basin, and the Postmasburg Group of the Northern Cape Basin has no lateral equivalent in the Transvaal Basin. These changes have been made to overcome problems present in the current correlations between those two basins. The Makganyene Formation correlates with the Huronian glaciations which occurred between 2.4 and 2.2 Ga ago in North America. Another Precambrian glaciation is the worldwide and well-studied Neoproterozoic glaciation (640 Ma). At each of these glaciations, major banded iron-formation deposition took place with associated deposition of sedimentary manganese in post-glacial positions. The central position of the Makganyene Formation within the Transvaal Supergroup in the Northern Cape emphasizes this glacial climatic dependence of paleoproterozoic banded iron-formation and manganese deposition. However these two Precambrian glaciations are interpreted in paleomagnetic studies as having occurred near to the equator. The controversial theory of the Snowball Earth has been proposed which proposes that the Earth was entirely frozen from pole to pole. Results from field work, sedimentology, petrography and geochemistry were integrated in a proposed depositional model of the Makganyene Formation occurring at the symmetrical centre of the lithologic succession of the Transvaal Supergroup. At the beginning of the Makganyene glaciation, a regression occurred and glacial advance took place. The diamictites are mostly interpreted as being deposited from wet-based glaciers, probably tidewater glaciers, where significant slumping and debris flows occurred. Any transgression would cause a glacial retreat by rapid calving, re-establishing the chemical sedimentation of banded iron-formations. These sea-level variations are responsible for the interbedding of these different types of rocks (clastic and chemical). The end of the Makganyene glacial event is characterised by subaerial eruptions of andesitic lava of the Ongeluk Formation bringing ashes into the basin. Banded iron-formation and associated manganese accumulations are climate-dependant. Glacial events are responsible for the build up of metallic ions such as iron and manganese in solution in deep waters. A warmer climate would induce a transgression and precipitation of these metallic ions when Eh conditions are favourable. In the Transvaal Supergroup, the climatic variations from warm to cold, and cold to warm are expressed by the lithologic succession. The warm climates are represented by carbonates. Cold climates are represented by banded iron-formations and the peak in cold climate represented by the diamictites of the Makganyene Formation. These changes in climate are gradual, which contradict the dramatic Snowball Earth event: a rapid spread of glaciated areas over low-latitudes freezing the Earth from pole-to-pole. Therefore, to explain low-latitude glaciations at sea-level, a high obliquity of the ecliptic is most likely to have occurred. This high obliquity of the ecliptic was acquired at 4.5 Ga when a giant impactor collided into the Earth to form the Moon. Above the critical value of 54° of the obliquity of the ecliptic, normal climatic zonation reverts, and glaciations will take place preferentially at low-latitudes only when favourable conditions are gathered (relative position ofthe continents and PC02 in the atmosphere).
- Full Text:
- Authors: Polteau, Stéphane
- Date: 2001
- Subjects: Geology, Stratigraphic -- South Africa -- Northern Cape , Geochemistry -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5003 , http://hdl.handle.net/10962/d1005616 , Geology, Stratigraphic -- South Africa -- Northern Cape , Geochemistry -- South Africa -- Northern Cape
- Description: The Makganyene Formation forms the base of the Postmasburg Group in the Transvaal Supergroup of the Northern Cape Province. The Makganyene Formation has diamictite as the main rock type, but siltstone, sandstone, shale, and iron-formations are also present. A glacial origin has been proposed in the past due to the presence of dropstones, faceted and striated pebbles. Typically, the Makganyene Formation contains banded iron-formations interbedded with clastic rocks (shale, siltstone, sandstone and diamictites) at the contact with the underlying iron-formations. This transitional zone is generally overlain by massive or layered diamictites which contain poorly sorted clasts (mainly chert) within a shaly matrix. Striated pebbles have been found during field work, and dropstones have been observed in diamictites and banded iron-formations during the study. The top of the Makganyene Formation contains graded cycles interbedded with diamictites and thin layers of andesitic lavas from the Ongeluk Formation. The basal contact of the Makganyene Formation with the underlying Koegas Subgroup was described as unconformable by previous workers. However field work localised in the Rooinekke area shows a broadly conformable and interbedded contact with the underlying Koegas Subgroup. As described above, banded iron-formations are interbedded with the clastic rocks of the Makganyene Formation. Moreover, boreholes from the Sishen area display the same interbedding at the base of the Makganyene Formation. This suggests that no significant time gap is present in the whole succession between the Ghaap and Postmasburg Group. The Transvaal Supergroup in the Northern Cape displays the following succession : carbonates-BIFs-diamictites/ lava-BIFs-carbonates. The Makganyene Formation is thus at the centre of a symmetrical lithologic succession. Bulk rock compositions show that the diamictites have a similar composition to banded iron-formation with regard to their major element contents. Banded iron-formations acted as a source for the diamictites with carbonates and igneous rocks representing minor components. Differences in bulk composition between the Sishen and Matsap areas emphasize that the source of the diamictite was very localised. The Chemical Index of Alteration (CIA) has been calculated, but since the source dominant rock was iron-formation, this index cannot be usefully applied to the diamictites. ACN, A-CN-K, and A-CNK-FM diagrams confer a major importance in sorting processes due to the separation between the fine and coarse diamictites. The interbedded iron-formations display little clastic contamination indicating deposition in clear water conditions. However, dropstones are present in one borehole from the Matsap area, indicating that iron-formation took place under ice cover, or at least under icebergs. Stable isotope studies show that the iron-formations, interbedded towards the base of the Makganyene Formation, have similar values to the iron-formations of the Koegas Subgroup. As a result of the above observations, new correlations are proposed in this study, relating the different Transvaal Supergroup basins located on the Kaapvaal Craton. The Pretoria Group of the Transvaal Basin has no correlative in the Griqualand West Basin, and the Postmasburg Group of the Northern Cape Basin has no lateral equivalent in the Transvaal Basin. These changes have been made to overcome problems present in the current correlations between those two basins. The Makganyene Formation correlates with the Huronian glaciations which occurred between 2.4 and 2.2 Ga ago in North America. Another Precambrian glaciation is the worldwide and well-studied Neoproterozoic glaciation (640 Ma). At each of these glaciations, major banded iron-formation deposition took place with associated deposition of sedimentary manganese in post-glacial positions. The central position of the Makganyene Formation within the Transvaal Supergroup in the Northern Cape emphasizes this glacial climatic dependence of paleoproterozoic banded iron-formation and manganese deposition. However these two Precambrian glaciations are interpreted in paleomagnetic studies as having occurred near to the equator. The controversial theory of the Snowball Earth has been proposed which proposes that the Earth was entirely frozen from pole to pole. Results from field work, sedimentology, petrography and geochemistry were integrated in a proposed depositional model of the Makganyene Formation occurring at the symmetrical centre of the lithologic succession of the Transvaal Supergroup. At the beginning of the Makganyene glaciation, a regression occurred and glacial advance took place. The diamictites are mostly interpreted as being deposited from wet-based glaciers, probably tidewater glaciers, where significant slumping and debris flows occurred. Any transgression would cause a glacial retreat by rapid calving, re-establishing the chemical sedimentation of banded iron-formations. These sea-level variations are responsible for the interbedding of these different types of rocks (clastic and chemical). The end of the Makganyene glacial event is characterised by subaerial eruptions of andesitic lava of the Ongeluk Formation bringing ashes into the basin. Banded iron-formation and associated manganese accumulations are climate-dependant. Glacial events are responsible for the build up of metallic ions such as iron and manganese in solution in deep waters. A warmer climate would induce a transgression and precipitation of these metallic ions when Eh conditions are favourable. In the Transvaal Supergroup, the climatic variations from warm to cold, and cold to warm are expressed by the lithologic succession. The warm climates are represented by carbonates. Cold climates are represented by banded iron-formations and the peak in cold climate represented by the diamictites of the Makganyene Formation. These changes in climate are gradual, which contradict the dramatic Snowball Earth event: a rapid spread of glaciated areas over low-latitudes freezing the Earth from pole-to-pole. Therefore, to explain low-latitude glaciations at sea-level, a high obliquity of the ecliptic is most likely to have occurred. This high obliquity of the ecliptic was acquired at 4.5 Ga when a giant impactor collided into the Earth to form the Moon. Above the critical value of 54° of the obliquity of the ecliptic, normal climatic zonation reverts, and glaciations will take place preferentially at low-latitudes only when favourable conditions are gathered (relative position ofthe continents and PC02 in the atmosphere).
- Full Text:
Talking about teams within a team building context: a discourse analytic study
- Authors: Chapman-Blair, Sharon
- Date: 2001
- Subjects: Discourse analysis , Teams in the workplace
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2947 , http://hdl.handle.net/10962/d1002456 , Discourse analysis , Teams in the workplace
- Description: This research initiative responds to some of the issues raised by theoretical challenges leveled at Industrial Psychology (postmodernism), and practical challenges in the workplace (the use of teams) by investigating notions of what a team is via the postmodern methodology of discourse analysis. The research explores “team talk” – repertoires of speech employed by individuals to construct particular versions of “the team” for specific effects, of importance given emphasis placed on shared understanding, expectations and goals in a “team”. A Rhodes University Industrial Psychology Honours class required to work as a team (having participated in a team building exercise), as well as their lecturers who facilitated the team building process were interviewed to obtain “talk” to analyse. This uncovered a multiplicity of meaning, namely four ways of speaking about (constructing) the team. These repertoires are explored in terms of how they are constructed, how they differ across context and speakers, how they interrelate and what they function to achieve. The educational team repertoire constructs academic hierarchy, justifies individualism, positions members as experts and maintains distance from interpersonal processes. The machine repertoire divides work and interpersonal issues, regulates productivity and constructs team roles (defining individual activity and “team fit”), but is inflexible to change. The family repertoire voices emotive aspects to maintain cohesion via conformity, leaderlessness, group identity and shared achievement, but cannot accommodate conflict or workpersonal boundaries. The psychologised team repertoire constructs the team primarily as a therapeutic entity legitimately creating individual identities (and expertise) and facilitating personal growth, but this flounders when support in the “team” fails. Given that each repertoire has a different emphasis (reflective learning versus work processes versus building relationships versus personal growth), there are slippages / clashes between repertoires. This postmodern look at “the team” thus assists in recognizing and problematising these multiple meanings and identifying practical implications.
- Full Text:
- Authors: Chapman-Blair, Sharon
- Date: 2001
- Subjects: Discourse analysis , Teams in the workplace
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2947 , http://hdl.handle.net/10962/d1002456 , Discourse analysis , Teams in the workplace
- Description: This research initiative responds to some of the issues raised by theoretical challenges leveled at Industrial Psychology (postmodernism), and practical challenges in the workplace (the use of teams) by investigating notions of what a team is via the postmodern methodology of discourse analysis. The research explores “team talk” – repertoires of speech employed by individuals to construct particular versions of “the team” for specific effects, of importance given emphasis placed on shared understanding, expectations and goals in a “team”. A Rhodes University Industrial Psychology Honours class required to work as a team (having participated in a team building exercise), as well as their lecturers who facilitated the team building process were interviewed to obtain “talk” to analyse. This uncovered a multiplicity of meaning, namely four ways of speaking about (constructing) the team. These repertoires are explored in terms of how they are constructed, how they differ across context and speakers, how they interrelate and what they function to achieve. The educational team repertoire constructs academic hierarchy, justifies individualism, positions members as experts and maintains distance from interpersonal processes. The machine repertoire divides work and interpersonal issues, regulates productivity and constructs team roles (defining individual activity and “team fit”), but is inflexible to change. The family repertoire voices emotive aspects to maintain cohesion via conformity, leaderlessness, group identity and shared achievement, but cannot accommodate conflict or workpersonal boundaries. The psychologised team repertoire constructs the team primarily as a therapeutic entity legitimately creating individual identities (and expertise) and facilitating personal growth, but this flounders when support in the “team” fails. Given that each repertoire has a different emphasis (reflective learning versus work processes versus building relationships versus personal growth), there are slippages / clashes between repertoires. This postmodern look at “the team” thus assists in recognizing and problematising these multiple meanings and identifying practical implications.
- Full Text:
The changing knowledge and expectations of public health nurses in a HIV/AIDS training programme for managers
- Authors: Harry, Karuna
- Date: 2001
- Subjects: HIV infections , HIV infections -- Nursing , HIV-positive persons -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2986 , http://hdl.handle.net/10962/d1002495 , HIV infections , HIV infections -- Nursing , HIV-positive persons -- Counseling of
- Description: This research project examined the changing expectations and knowledge of Managers in the Department of Health who attended the Sexual Health Counselling Project offered by Rhodes University, East London, South Africa. These managers came from contexts in which the hierarchical medical model is firmly entrenched. The Sexual Health Counselling Project, drawing on theoretical principles from Narrative and other theories,presented a challenge to the standard management practices used by the managers. It also challenged how they dealt with clients. This research explored changes in expectations and knowledge prior to and during a two- week training course that the managers attended. A personal awareness and shift in knowledge occurred for many managers who examined their current practices. Some managers, who were firmly entrenched in the hierarchical model,found it difficult to change their ways of working.
- Full Text:
- Authors: Harry, Karuna
- Date: 2001
- Subjects: HIV infections , HIV infections -- Nursing , HIV-positive persons -- Counseling of
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2986 , http://hdl.handle.net/10962/d1002495 , HIV infections , HIV infections -- Nursing , HIV-positive persons -- Counseling of
- Description: This research project examined the changing expectations and knowledge of Managers in the Department of Health who attended the Sexual Health Counselling Project offered by Rhodes University, East London, South Africa. These managers came from contexts in which the hierarchical medical model is firmly entrenched. The Sexual Health Counselling Project, drawing on theoretical principles from Narrative and other theories,presented a challenge to the standard management practices used by the managers. It also challenged how they dealt with clients. This research explored changes in expectations and knowledge prior to and during a two- week training course that the managers attended. A personal awareness and shift in knowledge occurred for many managers who examined their current practices. Some managers, who were firmly entrenched in the hierarchical model,found it difficult to change their ways of working.
- Full Text:
The construction of 'farm killings' in the Eastern Province Herald: an ideological analysis of the Herald's farm killings' disclosure, August 1998
- Authors: Jacobs, Luzuko
- Date: 2001
- Subjects: Farm killings -- South Africa -- Eastern Cape Murder -- South Africa -- Eastern Cape Eastern Province Herald (Newspaper)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3436 , http://hdl.handle.net/10962/d1002890
- Description: This study examines the ideological inflection of the ‘farm killings’ discourse in the Eastern Province Herald articles published in August 1998. ‘Farm killings’ is a media frame which was applied to a spate of killings of people on the country’s farms since 1994. Heightened and sustained media attention on the ‘farm killings’ has lifted the phenomenon from the other ‘run-of-the-mill’ murder crimes, and located it firmly as a matter of public concern and a subject of a broad political and economic debate. In this study I investigate the media coverage of the ‘farm killings’ within the context of these debates. The cultural studies approach to the study of the media provides a fruitful theoretical framework within which this study is located. The ideological examination of the articles is done using the critical linguistics method - a brand of reflexive, interpretative style of analysis which enables a sustained examination of media texts within their social, cultural and historical context. This study’s conclusions pose a challenge to the ‘Fourth Estate’ role often claimed for the media. In particular, it denies that the Herald objectively, fairly and truthfully reflected the experience on the farms during the period of this study. Its main finding is that the newspaper instead, constructed a particular understanding of the killings characterised by subtle racism, bias and partiality.
- Full Text:
- Authors: Jacobs, Luzuko
- Date: 2001
- Subjects: Farm killings -- South Africa -- Eastern Cape Murder -- South Africa -- Eastern Cape Eastern Province Herald (Newspaper)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3436 , http://hdl.handle.net/10962/d1002890
- Description: This study examines the ideological inflection of the ‘farm killings’ discourse in the Eastern Province Herald articles published in August 1998. ‘Farm killings’ is a media frame which was applied to a spate of killings of people on the country’s farms since 1994. Heightened and sustained media attention on the ‘farm killings’ has lifted the phenomenon from the other ‘run-of-the-mill’ murder crimes, and located it firmly as a matter of public concern and a subject of a broad political and economic debate. In this study I investigate the media coverage of the ‘farm killings’ within the context of these debates. The cultural studies approach to the study of the media provides a fruitful theoretical framework within which this study is located. The ideological examination of the articles is done using the critical linguistics method - a brand of reflexive, interpretative style of analysis which enables a sustained examination of media texts within their social, cultural and historical context. This study’s conclusions pose a challenge to the ‘Fourth Estate’ role often claimed for the media. In particular, it denies that the Herald objectively, fairly and truthfully reflected the experience on the farms during the period of this study. Its main finding is that the newspaper instead, constructed a particular understanding of the killings characterised by subtle racism, bias and partiality.
- Full Text:
The development and assessment of both a separate, once-daily modified release matrix formulation of metoprolol tartrate and a combination formulation with hydrochlorothiazide
- Authors: Arjun, Jessica
- Date: 2001
- Subjects: Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3742 , http://hdl.handle.net/10962/d1003220 , Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Description: The use of controlled release dosage forms has increased significantly in recent years as they result in increased patient compliance and higher therapeutic efficiency. This research focused on the development of a once daily dosage form that could be used for the treatment of hypertension. Both a separate sustained release dosage of metoprolol tartrate and a combination dosage form that included both an immediate release hydrochlorothiazide and a sustained release metoprolol component, were developed and evaluated. A matrix tablet, consisting of an ethylcellulose ranulation of metoprolol tartrate compressed into a hydrophilic hydroxypropyl methylcellulose polymer matrix, effectively sustained metoprolol release over a 22-hour experimental period. A multiparticulate combination dosage form that consisted of six coated mini matrix tablets of metoprolol and a powder blend of hydrochlorothiazide packed into a gelatin capsule, displayed zero order release kinetics for metoprolol release over 22 hours (r2=0.9946). The release of hydrochlorothiazide was found to be comparable to that of a commercially available product tested. Differential Scanning Calorimetry was used to identify possible incompatibilities between MPTA and excipients initially, and long term stability testing was used to assess to behaviour of the dosage form. Dissolution testing of the dosage forms was performed using USP Apparatus III, which was found to be more discriminating between the batches assessed. Dissolution curves were evaluated for similarity and difference using f1 and f2 fit factors. Samples were analyzed using a high performance liquid chromatographic method that was developed and validated for the simultaneous determination of the compounds of interest. Various factors influencing drug release from the developed dosage forms were assessed and recommendations for further optimization of the formulation are made. Factors evaluated included the quantity of granulating fluid, matrix polymer content, drug load and process variables, including drying time and compression force. The influence of various coating levels on drug release was assessed and none of the levels assessed were found to adequately retarded drug release over a 22-hour period. Combinations of tablets coated to different levels allowed for the successful development of a sustained release metoprolol component, which could be included into the combination dosage form.
- Full Text:
- Authors: Arjun, Jessica
- Date: 2001
- Subjects: Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3742 , http://hdl.handle.net/10962/d1003220 , Metoprolol -- Controlled release , Chlorothiazide -- Controlled release , Diuretics , Hypertension -- Treatment
- Description: The use of controlled release dosage forms has increased significantly in recent years as they result in increased patient compliance and higher therapeutic efficiency. This research focused on the development of a once daily dosage form that could be used for the treatment of hypertension. Both a separate sustained release dosage of metoprolol tartrate and a combination dosage form that included both an immediate release hydrochlorothiazide and a sustained release metoprolol component, were developed and evaluated. A matrix tablet, consisting of an ethylcellulose ranulation of metoprolol tartrate compressed into a hydrophilic hydroxypropyl methylcellulose polymer matrix, effectively sustained metoprolol release over a 22-hour experimental period. A multiparticulate combination dosage form that consisted of six coated mini matrix tablets of metoprolol and a powder blend of hydrochlorothiazide packed into a gelatin capsule, displayed zero order release kinetics for metoprolol release over 22 hours (r2=0.9946). The release of hydrochlorothiazide was found to be comparable to that of a commercially available product tested. Differential Scanning Calorimetry was used to identify possible incompatibilities between MPTA and excipients initially, and long term stability testing was used to assess to behaviour of the dosage form. Dissolution testing of the dosage forms was performed using USP Apparatus III, which was found to be more discriminating between the batches assessed. Dissolution curves were evaluated for similarity and difference using f1 and f2 fit factors. Samples were analyzed using a high performance liquid chromatographic method that was developed and validated for the simultaneous determination of the compounds of interest. Various factors influencing drug release from the developed dosage forms were assessed and recommendations for further optimization of the formulation are made. Factors evaluated included the quantity of granulating fluid, matrix polymer content, drug load and process variables, including drying time and compression force. The influence of various coating levels on drug release was assessed and none of the levels assessed were found to adequately retarded drug release over a 22-hour period. Combinations of tablets coated to different levels allowed for the successful development of a sustained release metoprolol component, which could be included into the combination dosage form.
- Full Text:
The development of a scale to measure sexual orientation and an examination of its psychometric properties
- Authors: Heath, Lance Julien
- Date: 2001
- Subjects: Sexual orientation , Sexual orientation -- Research -- Psychological aspects , Psychometrics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3145 , http://hdl.handle.net/10962/d1007408 , Sexual orientation , Sexual orientation -- Research -- Psychological aspects , Psychometrics
- Description: The purpose of the study was to develop a scale to measure sexual orientation and to examine its psychometric properties. Previous scales were critically examined and compared and the need for a scale which simultaneously measures same and opposite sex responsiveness independently, and accounts for dynamic changes over time, while testing a number of overt and covert dimensions of sexual orientations, was established. A 48-item scale was designed to tap self-reported intensity and frequency of Emotional Attachment, Sexual Fantasy, Sexual Attraction and Sexual Contact towards males and females in the Past, Present and Future. An initial study was conducted with 13 undergraduate university students of both genders, representing a variety of sexual orientations and nationalities, and qualitative feedback was obtained and utilized to make appropriate adjustments and refinements to the scale. The scale was then administered to 133 Rhodes University undergraduate psychology students to obtain quantitative data with regard to its internal structure. The scale was found to have a good internal consistency reliability Cronbach alpha coefficient of 0.8106. Existing sub-scales had lower alpha coefficients. Factor analysis, a form of construct validation, was performed and four factors emerged. These had very good internal consistency reliability alpha coefficients: Sexual Responsiveness to Females (0.9894), Sexual Responsiveness to Males (0.9741), Emotional Attachment to Females (0.8403) and Emotional Attachment to Males (0.8372). These factors were further statistically analysed to ascertain how they relate to one another and to the demographics of gender, age, relational status and sexual orientation identity. Future research will need to assess other forms of reliability and validity and focus on larger and more varied samples.
- Full Text:
- Authors: Heath, Lance Julien
- Date: 2001
- Subjects: Sexual orientation , Sexual orientation -- Research -- Psychological aspects , Psychometrics
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3145 , http://hdl.handle.net/10962/d1007408 , Sexual orientation , Sexual orientation -- Research -- Psychological aspects , Psychometrics
- Description: The purpose of the study was to develop a scale to measure sexual orientation and to examine its psychometric properties. Previous scales were critically examined and compared and the need for a scale which simultaneously measures same and opposite sex responsiveness independently, and accounts for dynamic changes over time, while testing a number of overt and covert dimensions of sexual orientations, was established. A 48-item scale was designed to tap self-reported intensity and frequency of Emotional Attachment, Sexual Fantasy, Sexual Attraction and Sexual Contact towards males and females in the Past, Present and Future. An initial study was conducted with 13 undergraduate university students of both genders, representing a variety of sexual orientations and nationalities, and qualitative feedback was obtained and utilized to make appropriate adjustments and refinements to the scale. The scale was then administered to 133 Rhodes University undergraduate psychology students to obtain quantitative data with regard to its internal structure. The scale was found to have a good internal consistency reliability Cronbach alpha coefficient of 0.8106. Existing sub-scales had lower alpha coefficients. Factor analysis, a form of construct validation, was performed and four factors emerged. These had very good internal consistency reliability alpha coefficients: Sexual Responsiveness to Females (0.9894), Sexual Responsiveness to Males (0.9741), Emotional Attachment to Females (0.8403) and Emotional Attachment to Males (0.8372). These factors were further statistically analysed to ascertain how they relate to one another and to the demographics of gender, age, relational status and sexual orientation identity. Future research will need to assess other forms of reliability and validity and focus on larger and more varied samples.
- Full Text:
The development of the common fraction concept in grade three learners
- Authors: Fraser, Claire Anne
- Date: 2001
- Subjects: Mathematics -- Study and teaching (Elementary) Mathematics Problems, exercises, etc Fractions -- Study and teaching (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1497 , http://hdl.handle.net/10962/d1003379
- Description: Over a period of nine months in 1999, a longitudinal teaching intervention was undertaken with Grade 3 learners in the Fort Beaufort district, Eastern Cape. Working in the interpretive paradigm, the intervention focussed on: - the development of the common fraction concept, - the relevance of the hierarchy of Murray and Olivier’s Four Levels of Development in common fractions and - whether learners’ informal knowledge could be utilised in developing this concept. Using the Problem-centred approach to teaching mathematics, problems set in reallife contexts were used as vehicles for learning. Learners were required to discuss, reflect and make sense of the mathematics they were doing. Participant observation, completed worksheets and unstructured interviews with learners, formed the primary method of data collection. Learners’ work was analysed and classified according to the method used and manner in which the solution was notated. Results showed that learners were able to achieve a significant degree of success in developing a stable common fraction concept. Learners were afforded opportunities to construct their own ideas and to develop a deeper understanding of the concept. Many methods used were based on their informal knowledge of sharing. Learners made sense of realistic problems using drawings, and invented their own procedures. Apart from Level One, Phase Three, all Murray and Olivier’s Levels of Development could be identified during the research. This study will provide educators with valuable information on how learners solve mathematical problems involving fractions and how informal knowledge can be used as a foundation on which to build.
- Full Text:
- Authors: Fraser, Claire Anne
- Date: 2001
- Subjects: Mathematics -- Study and teaching (Elementary) Mathematics Problems, exercises, etc Fractions -- Study and teaching (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1497 , http://hdl.handle.net/10962/d1003379
- Description: Over a period of nine months in 1999, a longitudinal teaching intervention was undertaken with Grade 3 learners in the Fort Beaufort district, Eastern Cape. Working in the interpretive paradigm, the intervention focussed on: - the development of the common fraction concept, - the relevance of the hierarchy of Murray and Olivier’s Four Levels of Development in common fractions and - whether learners’ informal knowledge could be utilised in developing this concept. Using the Problem-centred approach to teaching mathematics, problems set in reallife contexts were used as vehicles for learning. Learners were required to discuss, reflect and make sense of the mathematics they were doing. Participant observation, completed worksheets and unstructured interviews with learners, formed the primary method of data collection. Learners’ work was analysed and classified according to the method used and manner in which the solution was notated. Results showed that learners were able to achieve a significant degree of success in developing a stable common fraction concept. Learners were afforded opportunities to construct their own ideas and to develop a deeper understanding of the concept. Many methods used were based on their informal knowledge of sharing. Learners made sense of realistic problems using drawings, and invented their own procedures. Apart from Level One, Phase Three, all Murray and Olivier’s Levels of Development could be identified during the research. This study will provide educators with valuable information on how learners solve mathematical problems involving fractions and how informal knowledge can be used as a foundation on which to build.
- Full Text:
The effects of level and quality of education on a South African sample of English and African first language speakers, for WAIS-III digit symbol-incidental learning
- Donnelly, Martin Joseph Rhodes
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text:
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text: