Photophysical studies of Zinc phthalocyanine-silica nanoparticles conjugates
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
Aspects of fuzzy spaces with special reference to cardinality, dimension, and order-homomorphisms
- Authors: Lubczonok, Pawel
- Date: 1992
- Subjects: Fuzzy sets Topological spaces
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5399 , http://hdl.handle.net/10962/d1005213
- Description: Aspects of fuzzy vector spaces and fuzzy groups are investigated, including linear independence, basis, dimension, group order, finitely generated groups and cyclic groups. It was necessary to consider cardinality of fuzzy sets and related issues, which included a question of ways in which to define functions between fuzzy sets. Among the results proved, are the additivity property of dimension for fuzzy vector spaces, Lagrange's Theorem for fuzzy groups ( the existing version of this theorem does not take fuzziness into account at all), a compactness property of finitely generated fuzzy groups and an extension of an earlier result on the order-homomorphisms. An open question is posed with regard to the existence of a basis for an arbitrary fuzzy vector space.
- Full Text:
- Date Issued: 1992
- Authors: Lubczonok, Pawel
- Date: 1992
- Subjects: Fuzzy sets Topological spaces
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5399 , http://hdl.handle.net/10962/d1005213
- Description: Aspects of fuzzy vector spaces and fuzzy groups are investigated, including linear independence, basis, dimension, group order, finitely generated groups and cyclic groups. It was necessary to consider cardinality of fuzzy sets and related issues, which included a question of ways in which to define functions between fuzzy sets. Among the results proved, are the additivity property of dimension for fuzzy vector spaces, Lagrange's Theorem for fuzzy groups ( the existing version of this theorem does not take fuzziness into account at all), a compactness property of finitely generated fuzzy groups and an extension of an earlier result on the order-homomorphisms. An open question is posed with regard to the existence of a basis for an arbitrary fuzzy vector space.
- Full Text:
- Date Issued: 1992
Synthesis and electrocatalytic properties of polymerizable metallophthalocyanines
- Authors: Obirai, Joseph Chinye
- Date: 2005
- Subjects: Phthalocyanines Electrochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4447 , http://hdl.handle.net/10962/d1007733
- Description: The syntheses, spectral and electrochemical characterization of new family electropolymerizable pyrrole, thiophene and mercaptopyrimidin substituted metallophthalocyanine (MPc) complexes are described. Tetraamino substituted chromium and manganese phthalocyanine complexes were also synthesized and characterized. The spectral and electrochemical results are comparable to literature reports. The complexes formed stable films when deposited on electrode surfaces. The MPc films were formed by electropolymerization, drop-dry method and self-assembling. Nickel hydroxide-like electrodes were formed by electrotransformation of nickel-tetra-4- (pyrrol-1-yl)phenoxy phthalocyanine polymer films to the corresponding PcNi-O-NiPc modified electrodes in alkaline solution. The thiophene, mercaptopyrimidine functionalized MPcs and amino group containing complexes formed good self-assembled monolayers (SAMs) on gold electrode. The electrode modification processes were reproducible. The conductivities of the electrode were dependent on the surface concentrations of the complexes as a function of electropolymerization scan numbers. The electrodes showed good catalytic responses toward L-cysteine, nitrite, nitric oxide (NO), glycine, phenol and its derivative and oxygen. The results also suggest that the presence of thio groups on the ring substituents lowers the oxidation potential of Lcysteine more compared to literature values. The stability of the amperometric responses toward the various analytes is used to diagnose the applicability of the materials for electroanalytical purposes. The limits of detection for L-cysteine, nitrite, NO and glycine were in the range of ~10⁻⁷ to 10⁻⁵ mol dm⁻³.
- Full Text:
- Date Issued: 2005
- Authors: Obirai, Joseph Chinye
- Date: 2005
- Subjects: Phthalocyanines Electrochemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4447 , http://hdl.handle.net/10962/d1007733
- Description: The syntheses, spectral and electrochemical characterization of new family electropolymerizable pyrrole, thiophene and mercaptopyrimidin substituted metallophthalocyanine (MPc) complexes are described. Tetraamino substituted chromium and manganese phthalocyanine complexes were also synthesized and characterized. The spectral and electrochemical results are comparable to literature reports. The complexes formed stable films when deposited on electrode surfaces. The MPc films were formed by electropolymerization, drop-dry method and self-assembling. Nickel hydroxide-like electrodes were formed by electrotransformation of nickel-tetra-4- (pyrrol-1-yl)phenoxy phthalocyanine polymer films to the corresponding PcNi-O-NiPc modified electrodes in alkaline solution. The thiophene, mercaptopyrimidine functionalized MPcs and amino group containing complexes formed good self-assembled monolayers (SAMs) on gold electrode. The electrode modification processes were reproducible. The conductivities of the electrode were dependent on the surface concentrations of the complexes as a function of electropolymerization scan numbers. The electrodes showed good catalytic responses toward L-cysteine, nitrite, nitric oxide (NO), glycine, phenol and its derivative and oxygen. The results also suggest that the presence of thio groups on the ring substituents lowers the oxidation potential of Lcysteine more compared to literature values. The stability of the amperometric responses toward the various analytes is used to diagnose the applicability of the materials for electroanalytical purposes. The limits of detection for L-cysteine, nitrite, NO and glycine were in the range of ~10⁻⁷ to 10⁻⁵ mol dm⁻³.
- Full Text:
- Date Issued: 2005
The detection of glyphosate and glyphosate-based herbicides in water, using nanotechnology
- De Almeida, Louise Kashiyavala Sophia
- Authors: De Almeida, Louise Kashiyavala Sophia
- Date: 2015
- Subjects: Water -- Glyphosate content , Aquatic herbicides -- South Africa , Aquatic herbicides -- Physiological effect , Nanotechnology , Invasive plants -- South Africa , Genetic toxicology , Thiazoles , Tetrazolium , Immunotoxicology , Colorimetry , Nanofibers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4163 , http://hdl.handle.net/10962/d1019755
- Description: Glyphosate (N-phosphonomethylglycine) is an organophosphate compound which was developed by the Monsanto Company in 1971 and is the active ingredient found in several herbicide formulations. The use of glyphosate-based herbicides in South Africa for the control of alien invasive plants and weeds is well established, extensive and currently unregulated, which vastly increases the likelihood of glyphosate contamination in environmental water systems. Although the use of glyphosate-based herbicides is required for economic enhancement in industries such as agriculture, the presence of this compound in natural water systems presents a potential risk to human health. Glyphosate and glyphosate formulations were previously considered safe, however their toxicity has become a major focal point of research over recent years. The lack of monitoring protocols for pesticides in South Africa is primarily due to limited financial capacity and the lack of analytical techniques.
- Full Text:
- Date Issued: 2015
- Authors: De Almeida, Louise Kashiyavala Sophia
- Date: 2015
- Subjects: Water -- Glyphosate content , Aquatic herbicides -- South Africa , Aquatic herbicides -- Physiological effect , Nanotechnology , Invasive plants -- South Africa , Genetic toxicology , Thiazoles , Tetrazolium , Immunotoxicology , Colorimetry , Nanofibers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4163 , http://hdl.handle.net/10962/d1019755
- Description: Glyphosate (N-phosphonomethylglycine) is an organophosphate compound which was developed by the Monsanto Company in 1971 and is the active ingredient found in several herbicide formulations. The use of glyphosate-based herbicides in South Africa for the control of alien invasive plants and weeds is well established, extensive and currently unregulated, which vastly increases the likelihood of glyphosate contamination in environmental water systems. Although the use of glyphosate-based herbicides is required for economic enhancement in industries such as agriculture, the presence of this compound in natural water systems presents a potential risk to human health. Glyphosate and glyphosate formulations were previously considered safe, however their toxicity has become a major focal point of research over recent years. The lack of monitoring protocols for pesticides in South Africa is primarily due to limited financial capacity and the lack of analytical techniques.
- Full Text:
- Date Issued: 2015
Nonlinear optical studies of phthalocyanines and their conjugates with nanomaterials
- Authors: Sanusi, Sikiru Olukayode
- Date: 2015
- Subjects: Phthalocyanines , Nonlinear optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4545 , http://hdl.handle.net/10962/d1017925
- Description: A number of metallophthalocyanines (MPcs) and metal-free phthalocyanines (H₂Pcs) have been synthesized and characterized using various characterization tools such as ¹H-NMR, TOF mass spectrometry, FT-IR, UV-visible spectrophotometry and CHNS elemental analysis. Some of the MPcs were covalently linked to nanomaterials such as silica nanoparticles (SiNPs), single-walled carbon nanotubes (SWCNTs), magnetite nanoparticles (MNPs) and quantum dots (QDs), or embedded in polymer thin-films using poly(methyl methacrylate) (PMMA) and poly(acrylic acid) (PAA) as the polymer sources. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), thermogravimetry analysis and X-ray diffractometry. The nonlinear optical (NLO) properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. In general, most of the investigated MPcs showed good optical limiting behaviors, except for a few, like the non-peripherally-substituted 2-pyridyloxy phthalocyanines, which showed inhibited NLO response as a result of the ring-strain effects. The absence of a metal center was found to greatly reduce the inherent high nonlinearities expected of some of the phthalocyanine complexes. The octaphenoxy derivatives (61a – 61e) were found to exhibit reverse saturable absorption (RSA) that depends on the singlet-singlet transitions, hence making them less reliable optical limiters. The optical limiting properties of the MPcs were improved in the presence of nanomaterials such as the QDs, MNPs and SWCNTs, with MPc-QDs showing the best optical limiting behavior of the three. SiNPs have no significant effect on the optical limiting behavior of the MPcs. The optical limiting properties of the MPcs were greatly enhanced in the presence of PMMA or PAA polymers. The PAA polymer showed better optical limiting behavior compared to PMMA
- Full Text:
- Date Issued: 2015
- Authors: Sanusi, Sikiru Olukayode
- Date: 2015
- Subjects: Phthalocyanines , Nonlinear optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4545 , http://hdl.handle.net/10962/d1017925
- Description: A number of metallophthalocyanines (MPcs) and metal-free phthalocyanines (H₂Pcs) have been synthesized and characterized using various characterization tools such as ¹H-NMR, TOF mass spectrometry, FT-IR, UV-visible spectrophotometry and CHNS elemental analysis. Some of the MPcs were covalently linked to nanomaterials such as silica nanoparticles (SiNPs), single-walled carbon nanotubes (SWCNTs), magnetite nanoparticles (MNPs) and quantum dots (QDs), or embedded in polymer thin-films using poly(methyl methacrylate) (PMMA) and poly(acrylic acid) (PAA) as the polymer sources. The phthalocyanine-nanomaterial composites (Pc-NMCs) were characterized with FT-IR, UV-visible spectrophotometry, transmission electron microscopy (TEM), thermogravimetry analysis and X-ray diffractometry. The nonlinear optical (NLO) properties (using the open-aperture Z-scan technique) of the MPcs and the Pc-NMCs were investigated. In general, most of the investigated MPcs showed good optical limiting behaviors, except for a few, like the non-peripherally-substituted 2-pyridyloxy phthalocyanines, which showed inhibited NLO response as a result of the ring-strain effects. The absence of a metal center was found to greatly reduce the inherent high nonlinearities expected of some of the phthalocyanine complexes. The octaphenoxy derivatives (61a – 61e) were found to exhibit reverse saturable absorption (RSA) that depends on the singlet-singlet transitions, hence making them less reliable optical limiters. The optical limiting properties of the MPcs were improved in the presence of nanomaterials such as the QDs, MNPs and SWCNTs, with MPc-QDs showing the best optical limiting behavior of the three. SiNPs have no significant effect on the optical limiting behavior of the MPcs. The optical limiting properties of the MPcs were greatly enhanced in the presence of PMMA or PAA polymers. The PAA polymer showed better optical limiting behavior compared to PMMA
- Full Text:
- Date Issued: 2015
The environmental imagination in Arthur Nortje’s poetry
- Authors: Kaze, Douglas Eric
- Date: 2018
- Subjects: Nortje, Arthur, 1942-1970 -- Criticism and interpretation , Ecology in literature , Race awareness in literature , South African poetry (English) -- History and criticism , Nature in literature , Transversal postcolonial environmental criticism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58024 , vital:27033
- Description: This thesis seeks to contribute to the conversations in the humanities about the treatment of the physical environment in the context of a global ecological fragility and increased scholarly interest in the poetry of Arthur Nortje, a South African poet who wrote in the 1960s. While previous studies on Nortje concentrate on the political, psychic and technical aspects of his poetry, this study particularly explores the representations of the environment in Nortje’s poetic imagination. Writing in the dark period of apartheid in South Africa’s history, Nortje’s poetry articulates a strong interest in the physical environment against the backdrop of official racialization of space and his personal nomadic life and exile. The poetry abounds with constant intersections of nature and culture (industrialism, urbanity and the quotidian), a sense of place and a deep sense of dislocation. The poems, therefore, present a platform from which to reevaluate conventional ecocritical ideas about nature, place-attachment and environmental consciousness. Drawing mainly on Felix Guattari’s ideas of three ecologies and transversality along with other theories, I conduct the study through what I call a transversal postcolonial environmental criticism, which considers the ecological value of the kind of assemblages that Nortje’s works represent. The first chapter focuses on conceptualizing a postcolonial approach to the environment based on Guattari’s concept of transversality to lay the theoretical foundation for the whole work. The second chapter analyses Nortje’s poetic imagination of place and displacement through his treatment of the private-public tension and the motif of exile. While the third chapter examines Nortje’s depiction of nature as both an everyday and urban phenomenon, the fourth chapter turns to his direct treatment of environmental crises handled through his imagination of the Canadian urban spaces, exile memory of apartheid geography, war and ecocide and the human body as a subject of environmental degradation. The fifth chapter, which is the conclusion, takes a brief look at the implication of Nortje’s complex treatment of the environment on postcolonial environmentalism.
- Full Text:
- Date Issued: 2018
- Authors: Kaze, Douglas Eric
- Date: 2018
- Subjects: Nortje, Arthur, 1942-1970 -- Criticism and interpretation , Ecology in literature , Race awareness in literature , South African poetry (English) -- History and criticism , Nature in literature , Transversal postcolonial environmental criticism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/58024 , vital:27033
- Description: This thesis seeks to contribute to the conversations in the humanities about the treatment of the physical environment in the context of a global ecological fragility and increased scholarly interest in the poetry of Arthur Nortje, a South African poet who wrote in the 1960s. While previous studies on Nortje concentrate on the political, psychic and technical aspects of his poetry, this study particularly explores the representations of the environment in Nortje’s poetic imagination. Writing in the dark period of apartheid in South Africa’s history, Nortje’s poetry articulates a strong interest in the physical environment against the backdrop of official racialization of space and his personal nomadic life and exile. The poetry abounds with constant intersections of nature and culture (industrialism, urbanity and the quotidian), a sense of place and a deep sense of dislocation. The poems, therefore, present a platform from which to reevaluate conventional ecocritical ideas about nature, place-attachment and environmental consciousness. Drawing mainly on Felix Guattari’s ideas of three ecologies and transversality along with other theories, I conduct the study through what I call a transversal postcolonial environmental criticism, which considers the ecological value of the kind of assemblages that Nortje’s works represent. The first chapter focuses on conceptualizing a postcolonial approach to the environment based on Guattari’s concept of transversality to lay the theoretical foundation for the whole work. The second chapter analyses Nortje’s poetic imagination of place and displacement through his treatment of the private-public tension and the motif of exile. While the third chapter examines Nortje’s depiction of nature as both an everyday and urban phenomenon, the fourth chapter turns to his direct treatment of environmental crises handled through his imagination of the Canadian urban spaces, exile memory of apartheid geography, war and ecocide and the human body as a subject of environmental degradation. The fifth chapter, which is the conclusion, takes a brief look at the implication of Nortje’s complex treatment of the environment on postcolonial environmentalism.
- Full Text:
- Date Issued: 2018
Rainfall variability in Southern Africa, its influences on streamflow variations and its relationships with climatic variations
- Authors: Valimba, Patrick
- Date: 2005
- Subjects: Rain and rainfall -- Africa, Southern Climatic changes -- Africa, Southern Streamflow -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6030 , http://hdl.handle.net/10962/d1006159
- Description: Hydrological variability involving rainfall and streamflows in southern Africa have been often studied separately or have used cumulative rainfall and streamflow indices. The main objective of this study was to investigate spatio-temporal variations of rainfall, their influences on streamflows and their relationships with climatic variations with emphasis on indices that characterise the hydrological extremes, floods and droughts. It was found that 60-70% of the time when it rains, daily rainfalls are below their long-term averages and daily amounts below 10 mm are the most frequent in southern Africa. Spatially, climatologies of rainfall sub-divided the southern African subcontinent into the dry western/southwestern part and the “humid” eastern and northern part. The daily amounts below 20 mm contribute significantly to annual rainfall amounts in the dry part while all types of daily rainfall exceeding 1 mm have comparable contributions in the humid part. The climatologies indicated the highest likelihood of experiencing intense daily events during the core of the wet seasons with the highest frequencies in central Mozambique and the southern highlands of Tanzania. Interannual variations of rainfall indicated that significant changes had occurred between the late-1940s and early-1980s, particularly in the 1970s. The changes in rainfall were more evident in the number of daily rainfall events than in rainfall amounts, led generally to increasing early summer and decreased late summer rainfall. It was also found that intra-seasonal dry day sequences were an important parameter in the definition of a rainy season’s onset and end in southern Africa apart from rainfall amounts. Interannual variations of the rainy season characteristics (onset, end, duration) followed the variations of rainfall amounts and number of events. The duration of the rainy season was affected by the onset (Tanzania), onset or end (tropical southern Africa - southwestern highlands of Tanzania, Zambia, northern Zimbabwe and central Mozambique) and end (the remaing part of southern Africa). Flow duration curves (FDCs) identified three types of rivers (ephemeral, seasonal and perennial) in southern Africa with ephemeral rivers found mainly in the dry western part of the region. Seasonal streamflow patterns followed those of rainfall while interannual streamflow variations indicated significant changes of mean flows with little evidences of high and low flow regime changes except in Namibia and some parts of northern Zimbabwe. It was, however, not possible to provide strong links between the identified changes in streamflows and those in rainfall. Regarding the influences of climate variability on hydrological variability in southern Africa, rainfall variations in southern Africa were found to be influenced strongly by ENSO and SST in the tropical Indian ocean and moderately by SST in the south Madagascar basin. The influence of ENSO was consistent for all types of daily rainfall and peaks for the light and moderate (< 20 mm) events in the southern part and for the intense events in the northern part. SST in the tropical Indian ocean influence the light and moderate events while SST close to the region influence the heavy events. However, the relationships experienced significant changes in the mid-1950s and in the 1970s. The former changes led to improved associations while the latter deteriorated or reversed the relationships. The influences of climatic variables on streamflows and rainy season characteristics were inferred from the rainfall-streamflow and rainfall-climatic variables relationships.
- Full Text:
- Date Issued: 2005
- Authors: Valimba, Patrick
- Date: 2005
- Subjects: Rain and rainfall -- Africa, Southern Climatic changes -- Africa, Southern Streamflow -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6030 , http://hdl.handle.net/10962/d1006159
- Description: Hydrological variability involving rainfall and streamflows in southern Africa have been often studied separately or have used cumulative rainfall and streamflow indices. The main objective of this study was to investigate spatio-temporal variations of rainfall, their influences on streamflows and their relationships with climatic variations with emphasis on indices that characterise the hydrological extremes, floods and droughts. It was found that 60-70% of the time when it rains, daily rainfalls are below their long-term averages and daily amounts below 10 mm are the most frequent in southern Africa. Spatially, climatologies of rainfall sub-divided the southern African subcontinent into the dry western/southwestern part and the “humid” eastern and northern part. The daily amounts below 20 mm contribute significantly to annual rainfall amounts in the dry part while all types of daily rainfall exceeding 1 mm have comparable contributions in the humid part. The climatologies indicated the highest likelihood of experiencing intense daily events during the core of the wet seasons with the highest frequencies in central Mozambique and the southern highlands of Tanzania. Interannual variations of rainfall indicated that significant changes had occurred between the late-1940s and early-1980s, particularly in the 1970s. The changes in rainfall were more evident in the number of daily rainfall events than in rainfall amounts, led generally to increasing early summer and decreased late summer rainfall. It was also found that intra-seasonal dry day sequences were an important parameter in the definition of a rainy season’s onset and end in southern Africa apart from rainfall amounts. Interannual variations of the rainy season characteristics (onset, end, duration) followed the variations of rainfall amounts and number of events. The duration of the rainy season was affected by the onset (Tanzania), onset or end (tropical southern Africa - southwestern highlands of Tanzania, Zambia, northern Zimbabwe and central Mozambique) and end (the remaing part of southern Africa). Flow duration curves (FDCs) identified three types of rivers (ephemeral, seasonal and perennial) in southern Africa with ephemeral rivers found mainly in the dry western part of the region. Seasonal streamflow patterns followed those of rainfall while interannual streamflow variations indicated significant changes of mean flows with little evidences of high and low flow regime changes except in Namibia and some parts of northern Zimbabwe. It was, however, not possible to provide strong links between the identified changes in streamflows and those in rainfall. Regarding the influences of climate variability on hydrological variability in southern Africa, rainfall variations in southern Africa were found to be influenced strongly by ENSO and SST in the tropical Indian ocean and moderately by SST in the south Madagascar basin. The influence of ENSO was consistent for all types of daily rainfall and peaks for the light and moderate (< 20 mm) events in the southern part and for the intense events in the northern part. SST in the tropical Indian ocean influence the light and moderate events while SST close to the region influence the heavy events. However, the relationships experienced significant changes in the mid-1950s and in the 1970s. The former changes led to improved associations while the latter deteriorated or reversed the relationships. The influences of climatic variables on streamflows and rainy season characteristics were inferred from the rainfall-streamflow and rainfall-climatic variables relationships.
- Full Text:
- Date Issued: 2005
Measurements of the solubilities of some silver halides in water by electrical methods
- Authors: Malan, George McPherson
- Date: 1955
- Subjects: Silver halides -- Solubility , Silver halides -- Analysis , Conductometric analysis , Potentiometry , Silver halides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4515 , http://hdl.handle.net/10962/d1013502
- Description: [Introduction, p. 3] The solubilities of the silver halides cannot be determined by the conventional methods of analytical chemistry because they are too sparingly soluble (of the order 1 x 10⁻⁵ to 1 x 10⁻⁶ g . equiv./1. at 25°C.) However, electrical, and to a lesser extent optical methods, are admirably suited because of their greater sensitivity. The conductometric and potentiometric methods are the two most important electrical techniques for the measurement of the solubilities of sparingly soluble salts, and are the ones employed in this research. There are large discrepancies between the published values for the solubility of silver chloride. Results obtained by the conductometric and potentiometric methods disagree. In addition, figures quoted by independent authors using the same method differ by as much as 15%.
- Full Text:
- Date Issued: 1955
- Authors: Malan, George McPherson
- Date: 1955
- Subjects: Silver halides -- Solubility , Silver halides -- Analysis , Conductometric analysis , Potentiometry , Silver halides
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4515 , http://hdl.handle.net/10962/d1013502
- Description: [Introduction, p. 3] The solubilities of the silver halides cannot be determined by the conventional methods of analytical chemistry because they are too sparingly soluble (of the order 1 x 10⁻⁵ to 1 x 10⁻⁶ g . equiv./1. at 25°C.) However, electrical, and to a lesser extent optical methods, are admirably suited because of their greater sensitivity. The conductometric and potentiometric methods are the two most important electrical techniques for the measurement of the solubilities of sparingly soluble salts, and are the ones employed in this research. There are large discrepancies between the published values for the solubility of silver chloride. Results obtained by the conductometric and potentiometric methods disagree. In addition, figures quoted by independent authors using the same method differ by as much as 15%.
- Full Text:
- Date Issued: 1955
Versions of confinement: Melville's bodies and the psychology of conquest
- Authors: Goddard, Kevin Graham
- Date: 2003
- Subjects: Melville, Herman, 1819-1891 -- Criticism and interpretation Human body in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2216 , http://hdl.handle.net/10962/d1002259
- Description: This thesis explores aspects of Melville’s presentation of both the whale and the human bodies in Moby-Dick and human bodies in other important novels. It argues that Melville uses his presentation of bodies to explore some of the versions of confinement those bodies experience, and by doing so, analyses the psychology which subtends that confinement. Throughout Melville’s works bodies are confined, both within literal spatial limits and by the psychology which creates and/or accepts these spatial limits. The thesis argues that perhaps the most important version of bodily confinement Melville addresses is the impulse to conquer bodies, both that of the other and one’s own. It adopts a largely psychoanalytic approach to interpreting bodies and their impulse to conquer, so that the body is seen to figure both in its actions and its external appearance the operations of the inner psyche. The figure of the body is equally prevalent in Melville’s exploration of nationalist conquest, where, as with Manifest Destiny and antebellum expansionism, the psychological and physical lack experienced by characters can be read as motivating factors in the ideology of conquest. A final important strand of the thesis is its argument in favour of a gradual shift in Melville’s interpretation of the value and possibility of genuine communion between human beings and between humans and the whale. One may read Typee as an attempt by Melville to explore the possibility of a this-worldly utopia in which human beings can return to a version of primitive interconnectedness. This exploration may be seen to be extended in Moby-Dick, particularly in Ishmael’s attempts to find communion with others and in some moments of encounter with the whales. The thesis uses phenomenology as a theory to interpret what Melville is trying to suggest in these moments of encounter. However, it argues, finally, that such encounter, or ‘intersubjectivity’ is eventually jettisoned, especially in the works after Moby-Dick. By the end of Melville’s life and work, any hope of an intersubjective utopia he may have harboured as a younger man have been removed in favour of a refusal actually to assert any final ‘truth’ about social, political or even religious experience. Billy Budd, his last body, is hanged, and his final word is silence.
- Full Text:
- Date Issued: 2003
- Authors: Goddard, Kevin Graham
- Date: 2003
- Subjects: Melville, Herman, 1819-1891 -- Criticism and interpretation Human body in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2216 , http://hdl.handle.net/10962/d1002259
- Description: This thesis explores aspects of Melville’s presentation of both the whale and the human bodies in Moby-Dick and human bodies in other important novels. It argues that Melville uses his presentation of bodies to explore some of the versions of confinement those bodies experience, and by doing so, analyses the psychology which subtends that confinement. Throughout Melville’s works bodies are confined, both within literal spatial limits and by the psychology which creates and/or accepts these spatial limits. The thesis argues that perhaps the most important version of bodily confinement Melville addresses is the impulse to conquer bodies, both that of the other and one’s own. It adopts a largely psychoanalytic approach to interpreting bodies and their impulse to conquer, so that the body is seen to figure both in its actions and its external appearance the operations of the inner psyche. The figure of the body is equally prevalent in Melville’s exploration of nationalist conquest, where, as with Manifest Destiny and antebellum expansionism, the psychological and physical lack experienced by characters can be read as motivating factors in the ideology of conquest. A final important strand of the thesis is its argument in favour of a gradual shift in Melville’s interpretation of the value and possibility of genuine communion between human beings and between humans and the whale. One may read Typee as an attempt by Melville to explore the possibility of a this-worldly utopia in which human beings can return to a version of primitive interconnectedness. This exploration may be seen to be extended in Moby-Dick, particularly in Ishmael’s attempts to find communion with others and in some moments of encounter with the whales. The thesis uses phenomenology as a theory to interpret what Melville is trying to suggest in these moments of encounter. However, it argues, finally, that such encounter, or ‘intersubjectivity’ is eventually jettisoned, especially in the works after Moby-Dick. By the end of Melville’s life and work, any hope of an intersubjective utopia he may have harboured as a younger man have been removed in favour of a refusal actually to assert any final ‘truth’ about social, political or even religious experience. Billy Budd, his last body, is hanged, and his final word is silence.
- Full Text:
- Date Issued: 2003
Biopharmaceutics of phenylpropanolamine
- Authors: Dowse, Roslind
- Date: 1984
- Subjects: Biopharmaceutics Pharmacokinetics Phenylpropanolamine Pharmacology High performance liquid chromatography
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3818 , http://hdl.handle.net/10962/d1004915
- Description: Phenylpropanolamine (PPA), a sympathomimetic amine, has been widely used over the past 40 years as a decongestant and, in much larger dosages, as an appetite suppressant. Considerable interest has recently been shown in this drug due to its increasing popularity as an over-the-counter anorectic agent. Much controversy exists concerning the unfavourable side-effects of PPA resulting from the higher doses required for appetite suppression and the potential of this drug for abuse. A literature search revealed a paucity of information concerning the determination of PPA in biological fluids and, most noticeably, on the pharmacokinetics of this drug. An original method for determining PPA in serum and urine using high performance liquid chromatography (HPLC) which has increased sensitivity over other published HPLC methods is presented here. The simplicity of the extraction from biological fluids and subsequent determination by HPLC, enables concentrations of PPA to be monitored after a single dose of the drug. This method is therefore readily applicable to bioavailability and pharmacokinetic studies. The dissolution profiles of 4 sustained-release formulations of PPA were determined in a modified USP rotating paddle apparatus and the samples analysed using HPLC. A mathematical equation was applied to these data which are expressed in terms of dissolution parameters. Oral test dosage forms and solutions of PPA were investigated in bioavailability trials using the developed HPLC method to analyse the urine and serum samples. Linear one body compartment kinetics were assumed and the WagnerNelson method used to transform in vivo serum data to absorption plots which were then fitted to the well known Weibull equation. In order to more appropriately characterize the kinetic processes of absorption, distribution and elimination, a more complex model was utilized which involved numerical integration of a series of differential equations. The data were fitted to these models using nonlinear regression techniques. The pharmacokinetics of PPA are shown to exhibit some evidence of nonlinearity. The absorption of the drug appears to be di scontinuous and PPA seems to favour a two body compartment model.
- Full Text:
- Date Issued: 1984
- Authors: Dowse, Roslind
- Date: 1984
- Subjects: Biopharmaceutics Pharmacokinetics Phenylpropanolamine Pharmacology High performance liquid chromatography
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3818 , http://hdl.handle.net/10962/d1004915
- Description: Phenylpropanolamine (PPA), a sympathomimetic amine, has been widely used over the past 40 years as a decongestant and, in much larger dosages, as an appetite suppressant. Considerable interest has recently been shown in this drug due to its increasing popularity as an over-the-counter anorectic agent. Much controversy exists concerning the unfavourable side-effects of PPA resulting from the higher doses required for appetite suppression and the potential of this drug for abuse. A literature search revealed a paucity of information concerning the determination of PPA in biological fluids and, most noticeably, on the pharmacokinetics of this drug. An original method for determining PPA in serum and urine using high performance liquid chromatography (HPLC) which has increased sensitivity over other published HPLC methods is presented here. The simplicity of the extraction from biological fluids and subsequent determination by HPLC, enables concentrations of PPA to be monitored after a single dose of the drug. This method is therefore readily applicable to bioavailability and pharmacokinetic studies. The dissolution profiles of 4 sustained-release formulations of PPA were determined in a modified USP rotating paddle apparatus and the samples analysed using HPLC. A mathematical equation was applied to these data which are expressed in terms of dissolution parameters. Oral test dosage forms and solutions of PPA were investigated in bioavailability trials using the developed HPLC method to analyse the urine and serum samples. Linear one body compartment kinetics were assumed and the WagnerNelson method used to transform in vivo serum data to absorption plots which were then fitted to the well known Weibull equation. In order to more appropriately characterize the kinetic processes of absorption, distribution and elimination, a more complex model was utilized which involved numerical integration of a series of differential equations. The data were fitted to these models using nonlinear regression techniques. The pharmacokinetics of PPA are shown to exhibit some evidence of nonlinearity. The absorption of the drug appears to be di scontinuous and PPA seems to favour a two body compartment model.
- Full Text:
- Date Issued: 1984
Policy and practice : an activity systems' analysis of a further diploma in education (technology)
- Thomen, Eva Christine Salzmann
- Authors: Thomen, Eva Christine Salzmann
- Date: 2002
- Subjects: Action theory Teachers -- Training of -- South Africa Technology -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1854 , http://hdl.handle.net/10962/d1004525
- Description: This research examines, within the interpretive paradigm, how emerging educational policy in an in-service educator education programme, namely, a Further Diploma in Education (Technology), is implemented and practiced by educators in the classroom. Technology is a new learning area in the South African curriculum that aims to develop learners' technological skills and promote the practical application of Science and Mathematics. Technology is seen as a way of developing a productive workforce that can design, realise and evaluate technological problems in a global economy. Engestrom's version of Activity Theory was used as the conceptual framework. Activity Theory focuses on 'activity' as a unit of analysis that captures the individual in context. This research focuses on the lecturers' and the students' actions in the programme, and the educators' and the learners' actions in the classroom. The research design was an eclectic case study consisting of two embedded cases within a single larger case namely, in-service educator education. Multiple single cases were selected within the two embedded cases. Trustworthiness and authenticity were addressed through the triangulation of data using mUltiple sources and methods of data collection. Data were analysed and interpreted in a hermeneutic-like process that emerged through gradual induction over time. The findings of the research suggest that the in-service educator education programme did not promote the effective implementation of educational policy. Major challenges to the effective implementation of educational policy include: the formulation and implementation of an INSET programme during rapid educational policy change, the under-preparedness and language difficulties of the participating educators that constrained policy implementation in the INSET programme and the classroom, the role of organisational rules in shaping the activities in the INSET programme and the classroom, and the broader community'S contribution to resource constraints in the classroom. This research suggests that the participating educators are not likely to be major change agents in the transformation of education in South Africa. This concurs with other research findings that suggest that educator education is a weak intervention incapable of overcoming the shortcomings of the educators' own personal schooling or the impact of work experience.
- Full Text:
- Date Issued: 2002
- Authors: Thomen, Eva Christine Salzmann
- Date: 2002
- Subjects: Action theory Teachers -- Training of -- South Africa Technology -- Study and teaching -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1854 , http://hdl.handle.net/10962/d1004525
- Description: This research examines, within the interpretive paradigm, how emerging educational policy in an in-service educator education programme, namely, a Further Diploma in Education (Technology), is implemented and practiced by educators in the classroom. Technology is a new learning area in the South African curriculum that aims to develop learners' technological skills and promote the practical application of Science and Mathematics. Technology is seen as a way of developing a productive workforce that can design, realise and evaluate technological problems in a global economy. Engestrom's version of Activity Theory was used as the conceptual framework. Activity Theory focuses on 'activity' as a unit of analysis that captures the individual in context. This research focuses on the lecturers' and the students' actions in the programme, and the educators' and the learners' actions in the classroom. The research design was an eclectic case study consisting of two embedded cases within a single larger case namely, in-service educator education. Multiple single cases were selected within the two embedded cases. Trustworthiness and authenticity were addressed through the triangulation of data using mUltiple sources and methods of data collection. Data were analysed and interpreted in a hermeneutic-like process that emerged through gradual induction over time. The findings of the research suggest that the in-service educator education programme did not promote the effective implementation of educational policy. Major challenges to the effective implementation of educational policy include: the formulation and implementation of an INSET programme during rapid educational policy change, the under-preparedness and language difficulties of the participating educators that constrained policy implementation in the INSET programme and the classroom, the role of organisational rules in shaping the activities in the INSET programme and the classroom, and the broader community'S contribution to resource constraints in the classroom. This research suggests that the participating educators are not likely to be major change agents in the transformation of education in South Africa. This concurs with other research findings that suggest that educator education is a weak intervention incapable of overcoming the shortcomings of the educators' own personal schooling or the impact of work experience.
- Full Text:
- Date Issued: 2002
Verdrängung und verleugnung der wirklichkeit als erzählproblem im werk Hans Erich Nossacks
- Krueger, Gustav Adolf Ludwig Werner
- Authors: Krueger, Gustav Adolf Ludwig Werner
- Date: 1982
- Subjects: Nossack, Hans Erich, 1901-1977 -- Criticism and interpretation Authors, German -- 20th century -- History and criticism German fiction -- 20th century German literature -- History and criticism
- Language: German
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3612 , http://hdl.handle.net/10962/d1005627
- Description: From introduction: Wenn ich mir neben anderen sozial-psychologischen Theorien· auch die Theorie Freuds zunutze mache, so geschieht das nicht nur um der Textgerechtheit und der Nachprüfbarkeit willen, sondern auch aufgrund der überlegung, daß der Nossacksche Held, als "bürgerlicher Held"⁵²) , in mehr oder minderem Maße krank- und wahnhafte Züge haben wird, denn seine Bürgerlichkeit ist schon beim ersten, auffassenden Lesen der Texte kaum rnehr zu bezweifeln. Sein verstockter Individualismus ist hingegen, um noch einmal Adorno anzuführen, auch wieder nicht rückhaltlos verwerflich, ist dieser doch, "sowohl Produkt desDrucks", wie "das Kraftzentrum, das ihm widersteht".⁵³)
- Full Text:
- Date Issued: 1982
- Authors: Krueger, Gustav Adolf Ludwig Werner
- Date: 1982
- Subjects: Nossack, Hans Erich, 1901-1977 -- Criticism and interpretation Authors, German -- 20th century -- History and criticism German fiction -- 20th century German literature -- History and criticism
- Language: German
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3612 , http://hdl.handle.net/10962/d1005627
- Description: From introduction: Wenn ich mir neben anderen sozial-psychologischen Theorien· auch die Theorie Freuds zunutze mache, so geschieht das nicht nur um der Textgerechtheit und der Nachprüfbarkeit willen, sondern auch aufgrund der überlegung, daß der Nossacksche Held, als "bürgerlicher Held"⁵²) , in mehr oder minderem Maße krank- und wahnhafte Züge haben wird, denn seine Bürgerlichkeit ist schon beim ersten, auffassenden Lesen der Texte kaum rnehr zu bezweifeln. Sein verstockter Individualismus ist hingegen, um noch einmal Adorno anzuführen, auch wieder nicht rückhaltlos verwerflich, ist dieser doch, "sowohl Produkt desDrucks", wie "das Kraftzentrum, das ihm widersteht".⁵³)
- Full Text:
- Date Issued: 1982
A mineralogical investigation of co-existing iron-titanium oxides from various igneous rocks with special reference to some South African titaniferous iron ores
- Authors: Reynolds, Ivan Melvin
- Date: 1979
- Subjects: Igneous rocks Mineralogy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4926 , http://hdl.handle.net/10962/d1004589
- Description: Part I consists of a detailied review of the available literature on the Fe- Ti oxides and their solid solution relationships. Particular attention is glven to the microstructures exhibited by these oxides and the hypotheses put forward to explain them. These data are synthesised and models are presented in which the microstructural developments in titaniferous magnetites amd ilmenites are explained in terms of current ideas on the influence of oxygen fugacity, exsolution mechanisms and crystal chemistry. These models have direct application to the microintergrowths observed in the naturally occurring Fe-Ti oxides from a wide range of igneous rocks. The available data on the minor and trace element chemistry of the Fe-Ti oxides are reviewed with particular reference to their variation in these minerals from different host rocks. The behaviour of the Fe-Ti oxides during secondary oxidation is discussed with particular reference to the oxidation of titaniferous magnetite and the weathering of ilmenite. The results of a mineralogical investigation into the co-existing Fe-Ti oxides from a range of igneous rocks including kimberlites, gabbros, dolerites, diabases, syenites, granophyres, granites and pegmatites are presented in Part 2 together with data on the ilmenites present in certain Eastern Cape beach sands. The kimberlite ilmenites are chemically distinct and can be readily distinguished on the basis of their relatively high MgO, Fe₂0₃ and Cr₂O₃ contents. They can also be distinguished from ilmenites from other igneous rocks on the basis of unit cell dimensions, d-spacings, reflectivities and micro-indentation hardness. The ilmenites from a wide range of basic to granitic igneous rocks exhibit a limited compositional range in which the MnO content appears to increase with increasing Si0₂ content. Relatively insensitive indirectly determined parameters such as unit cell dimensions, reflectivities and micro-indentation hardnesses cannot be used to distinguish between the ilmenites from the different rock types in these classes. The titaniferous magnetites exhibit progressively decreasing Ti0₂ contents from a maximum in the basic igneous rocks to a minimum in the granitic types. The titaniferous magnetite typically exhibits varying degrees of deuteric alteration, while the microstructures developed can be interpreted 1n terms of the models presented in Part 1. Part 3 represents an extension of Part 2 and deals with a mineralogical investigation of the titaniferous iron ores in five South African basic intrusions. The Bushveld and Kaffirskraal ores consist of multi-phase titaniferous magnetite grains containing crystallographically oriented ilmenite, ulvospinel and pleonaste microintergrowths. Minor coarser-grained ilmenite is also present. The Usushwana ores are texturally similar but contain abundant lamellar ilmenite in place of the ulvospinel. The primary features are well preserved in the unmetamorphosed Bushveld and Kaffirskraal ores. The Usushwana ores have been slightly metamorphosed resulting in the extensive replacement of the titaniferous magnetites by sphene and chlorite aggregates. The ores from these three complexes cannot be beneficiated by conventional ore-dressing techniques and require direct metallurgical treatment for the recovery of Fe, Ti0₂ and V₂O₅. The metamorphosed Mambula and Rooiwater ores have been recrystallised to a varying degrees and consist of multi-phase titaniferous magnetite grains containing modified ilmenite and pleonaste microintergrowths. These modified microstructures differ from those encountered in titaniferous magnetites from unmetnmorphosed basic rocks and their degree of modification can be related to the degree of met amorphism. Variable amounts of coarse granular ilmenite are also present and their development is related to the metamorphic grade and degree of recrystallisation. These ores can be partially beneficiated to yield ilmenite- and lower-Ti0₂ magnetite concentrates in which V₂O₅ contents of the magnetic fractions are higher than those of the original ores. The Trompsburg ores differ from those of the other complexes in that they are Mg-rich and are characterised by the presence of abundant olivine. The titaniferous magnetites typically exhibit well-defined ulvospinel cloth textures and are often surrounded by small amounts of graphite. They show evidence of a variety of extensive late-stage alteration features. The ores from the five investigated complexes are compared with similar ores from the Bushveld Complex. The ores from each complex can be readily distinguished on the basis of their chemical compositions and textural relationships. These features can be related to their crystallisation his tories and, in some cases, to post-crystallisation processes. The microstructural evolution of the ores from each complex is interpreted in terms of the models developed in Part I.
- Full Text:
- Date Issued: 1979
- Authors: Reynolds, Ivan Melvin
- Date: 1979
- Subjects: Igneous rocks Mineralogy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4926 , http://hdl.handle.net/10962/d1004589
- Description: Part I consists of a detailied review of the available literature on the Fe- Ti oxides and their solid solution relationships. Particular attention is glven to the microstructures exhibited by these oxides and the hypotheses put forward to explain them. These data are synthesised and models are presented in which the microstructural developments in titaniferous magnetites amd ilmenites are explained in terms of current ideas on the influence of oxygen fugacity, exsolution mechanisms and crystal chemistry. These models have direct application to the microintergrowths observed in the naturally occurring Fe-Ti oxides from a wide range of igneous rocks. The available data on the minor and trace element chemistry of the Fe-Ti oxides are reviewed with particular reference to their variation in these minerals from different host rocks. The behaviour of the Fe-Ti oxides during secondary oxidation is discussed with particular reference to the oxidation of titaniferous magnetite and the weathering of ilmenite. The results of a mineralogical investigation into the co-existing Fe-Ti oxides from a range of igneous rocks including kimberlites, gabbros, dolerites, diabases, syenites, granophyres, granites and pegmatites are presented in Part 2 together with data on the ilmenites present in certain Eastern Cape beach sands. The kimberlite ilmenites are chemically distinct and can be readily distinguished on the basis of their relatively high MgO, Fe₂0₃ and Cr₂O₃ contents. They can also be distinguished from ilmenites from other igneous rocks on the basis of unit cell dimensions, d-spacings, reflectivities and micro-indentation hardness. The ilmenites from a wide range of basic to granitic igneous rocks exhibit a limited compositional range in which the MnO content appears to increase with increasing Si0₂ content. Relatively insensitive indirectly determined parameters such as unit cell dimensions, reflectivities and micro-indentation hardnesses cannot be used to distinguish between the ilmenites from the different rock types in these classes. The titaniferous magnetites exhibit progressively decreasing Ti0₂ contents from a maximum in the basic igneous rocks to a minimum in the granitic types. The titaniferous magnetite typically exhibits varying degrees of deuteric alteration, while the microstructures developed can be interpreted 1n terms of the models presented in Part 1. Part 3 represents an extension of Part 2 and deals with a mineralogical investigation of the titaniferous iron ores in five South African basic intrusions. The Bushveld and Kaffirskraal ores consist of multi-phase titaniferous magnetite grains containing crystallographically oriented ilmenite, ulvospinel and pleonaste microintergrowths. Minor coarser-grained ilmenite is also present. The Usushwana ores are texturally similar but contain abundant lamellar ilmenite in place of the ulvospinel. The primary features are well preserved in the unmetamorphosed Bushveld and Kaffirskraal ores. The Usushwana ores have been slightly metamorphosed resulting in the extensive replacement of the titaniferous magnetites by sphene and chlorite aggregates. The ores from these three complexes cannot be beneficiated by conventional ore-dressing techniques and require direct metallurgical treatment for the recovery of Fe, Ti0₂ and V₂O₅. The metamorphosed Mambula and Rooiwater ores have been recrystallised to a varying degrees and consist of multi-phase titaniferous magnetite grains containing modified ilmenite and pleonaste microintergrowths. These modified microstructures differ from those encountered in titaniferous magnetites from unmetnmorphosed basic rocks and their degree of modification can be related to the degree of met amorphism. Variable amounts of coarse granular ilmenite are also present and their development is related to the metamorphic grade and degree of recrystallisation. These ores can be partially beneficiated to yield ilmenite- and lower-Ti0₂ magnetite concentrates in which V₂O₅ contents of the magnetic fractions are higher than those of the original ores. The Trompsburg ores differ from those of the other complexes in that they are Mg-rich and are characterised by the presence of abundant olivine. The titaniferous magnetites typically exhibit well-defined ulvospinel cloth textures and are often surrounded by small amounts of graphite. They show evidence of a variety of extensive late-stage alteration features. The ores from the five investigated complexes are compared with similar ores from the Bushveld Complex. The ores from each complex can be readily distinguished on the basis of their chemical compositions and textural relationships. These features can be related to their crystallisation his tories and, in some cases, to post-crystallisation processes. The microstructural evolution of the ores from each complex is interpreted in terms of the models developed in Part I.
- Full Text:
- Date Issued: 1979
Waste management knowledge, its production, recontextualisation and circulation in Expanded Public Works Programme (EPWP) training programmes
- Authors: Giqwa, Nomfundiso Louisa
- Date: 2018
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , South Africa. Expanded Public Works Programme , Refuse and refuse disposal -- Employees -- Training of -- South Africa -- Eastern Cape , South Africa. Department of Environmental Affairs , Knowledge, Theory of , Knowledge, Sociology of
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63729 , vital:28478
- Description: This study set out to investigate the structuring, recontextualisation and circulation of waste management knowledge in the South African environmental Expanded Public Works Programme (EPWP) Waste Management Projects. In this thesis these projects also referred to as the Working on Waste (WoW) programme or focus area within the Environmental Protection and Infrastructure Programme (EPIP) hosted by the National Department of Environmental Affairs. Expanded Public Work Programmes are a strategy used by governments to address unemployment and in South Africa; the programmes also seek to address a need for skills development. In this study, the focus is on EPWP waste management knowledge, training programmes and activities only. With waste management knowledge as the core interest, the focus of the investigation was on knowledge circulation of waste management via informal (participation in the project) and formal training of workers at Level 2 National Qualifications Framework (NQF). The study started by firstly investigating what waste management knowledge is produced in the Field of Production via scientific research and policy. It then studied how this waste management knowledge is recontextualised into qualifications and skills programmes designed in the official recontextualising field and learning materials and training programmes designed and offered in the professional recontextualising field. The study also focused on the knowledge of workers and their experience of training in the EPWP workplaces, with an emphasis on rural workplaces. This is where the Department of Environmental Affairs (DEA) is placing emphasis on training for job creation, empowerment and skills development, and it is also where a number of EPWP Working on Waste programmes are being implemented. The aim was also to develop an understanding of how knowledge circulates amongst learners in training sessions and in workplaces. To do this, I drew on Bernstein’s theory of the pedagogical device which provides theoretical lenses and a language of description to explain how knowledge is recontextualised from the field of production to the field of reproduction. To investigate the structuring of this knowledge by official and pedagogical recontextualisers, I drew on the work of Maton, who offers a Legitimation Code Theory to explain the principles structuring knowledge, of which I used specialisation and semantics (two of his suite of knowledge structuring principles) for analysis. The questions that guided the study throughout were: 1. What is the structure of legitimate knowledge and knowers in waste management? 2. What are the underlying principles underpinning knowledge and knowers in waste management? 3. How is the knowledge recontextualised in waste management training qualifications, documents and manuals for worker training at NQF Level 2? 4. How is the knowledge reproduced and evaluated in the waste management EPWP training activities (formal) and workplaces (informal)? 5. How does waste management knowledge circulate amongst the workers in the EPWP training activities and workplaces? For this study I used the case study method, focusing only on one field or DEA EPWP focus area (waste management) and one programme (EPWP Working on Waste), looking in more depth at two cases (two similar types of projects) within the EPWP Working on Waste programme, though they are situated in different areas and though I could only carry through observations of actual workplace training in one of the two sites due to contextual circumstances. The first project was situated in the Amathole District Municipality while the second one was situated in the Chris Hani District Municipality, both of which are in the rural towns of the former Transkei region in the Eastern Cape, South Africa. This area has been at the forefront in accessing funding for these projects due to the level of poverty surrounding these towns and the inability of the local government sphere to deliver on its mandate in the region. Data was collected through document analysis, questionnaires, interviews and observations. Documents analysed were research documents produced by researchers at the level of production as well as legal frameworks guiding waste management processes in this country. Qualifications and Unit Standards at Level 2, as well as training materials designed by providers were analysed. Training in one of the projects was observed and workers in both sites were interviewed twice. The main finding of the study is that waste management knowledge is characterised by interdisciplinarity and a strong epistemic relation which emphasises procedural and technical forms of knowledge. The study found that the knowledge constructed in the field, as well as the policies, qualifications and training programmes are all consequently characterised by a strong epistemic code (ER+) and a weak social relations code (SR-). The study also identified a ‘code clash’ with the knowledge of workers in rural towns whose knowledge and experience of waste management was found to reflect a strong social relation (SR+) and weak epistemic code (ER-), a pattern which was traced back to a similar code in waste management knowledge at home and school (i.e. workers’ prior knowledge and learning experiences). This created difficulties for the trainers who sought to use strategies of descending from the abstract to the concrete in various ‘descending’ semantic waves that tended to move from high levels of semantic density (SD+) to lower levels of semantic density (SD-) as the training provider sought to contextualise a range of concepts. This was the main strategy identified for mediating waste management knowledge reflecting a dominant pattern of SD+/SG- to SD-/SG+ (with SG meaning semantic gravity). This shows that the trainer seldom started mediating concepts from the basis of workers’ prior knowledge and experience and observations showed little responsiveness from workers resulting from this strategy. Despite this, the study found that workers did develop an improved understanding of specialised waste management knowledge over time, especially through observing and doing more complex tasks in the workplace. The study offers a model for addressing the pedagogical difficulty identified around the code clash, and suggests that further attention needs to be given to ‘ascending’ from the concrete to the abstract in pedagogical practices. The study also pointed to the need for a more inclusive knowledge framework for waste management training, especially in the field of recontextualisation (both the official and pedagogical recontextualisation fields) to extend possibilities for workers to learn more about economic potential and access routes into more sustainable jobs. It identifies the need for a more systemic approach to waste management in rural towns and municipalities, improved compliance and also proposes that better waste management practices are modelled to avoid performative contradictions between the knowledge promoted in the field of production and the official and pedagogical recontextualising fields and the field of reproduction, where workers are learning this knowledge via a mix of accredited training and exposure to participation in waste management practices. This study contributes to new knowledge in that it offers an epistemically grounded and theorised pedagogical process model for Level 2 Waste Management Training (in the EPWP programmes, but potentially also more broadly) that accords with the need for a strong epistemic relation code (ER+) embodied in the need for learning scientific and technical waste management knowledge and procedures. It also addresses workers’ needs for greater epistemic access and participation in knowledge building and application of waste management knowledge in praxis as per the purpose of the EPW training programmes, thereby potentially opening up more sustainable learning pathways for them out of poverty through the EPWP training opportunities. The study has pointed to key areas for further research, including further research on the proposed model, further research into Level 2 pedagogical practices and further research into the foundations of waste management learning in schools. Most of the workers who were participating in the training in the EPWP programmes were educated at above Level 2 before participating in the projects, yet their knowledge and experience of waste management was mostly based on everyday knowledge, pointing to an absence of adequate waste management education in schools in rural contexts in South Africa. The study has also made various recommendations for improving waste management education and training at Level 2 in EPWP programmes in rural areas in particular (but potentially also more widely), notably the need to develop a more inclusive knowledge framework that includes historical and economic knowledge more explicitly at all levels of the recontextualisation process; improved pedagogical and assessment practices that take better account of learners knowledge and experiences in knowledge building processes; and giving attention to structural and systemic approaches to waste management in rural areas to avoid performative contradictions that arise between the knowledge being promoted in the field of production and the field of reproduction and the actual context of waste management.
- Full Text:
- Date Issued: 2018
- Authors: Giqwa, Nomfundiso Louisa
- Date: 2018
- Subjects: Refuse and refuse disposal -- South Africa -- Eastern Cape , South Africa. Expanded Public Works Programme , Refuse and refuse disposal -- Employees -- Training of -- South Africa -- Eastern Cape , South Africa. Department of Environmental Affairs , Knowledge, Theory of , Knowledge, Sociology of
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/63729 , vital:28478
- Description: This study set out to investigate the structuring, recontextualisation and circulation of waste management knowledge in the South African environmental Expanded Public Works Programme (EPWP) Waste Management Projects. In this thesis these projects also referred to as the Working on Waste (WoW) programme or focus area within the Environmental Protection and Infrastructure Programme (EPIP) hosted by the National Department of Environmental Affairs. Expanded Public Work Programmes are a strategy used by governments to address unemployment and in South Africa; the programmes also seek to address a need for skills development. In this study, the focus is on EPWP waste management knowledge, training programmes and activities only. With waste management knowledge as the core interest, the focus of the investigation was on knowledge circulation of waste management via informal (participation in the project) and formal training of workers at Level 2 National Qualifications Framework (NQF). The study started by firstly investigating what waste management knowledge is produced in the Field of Production via scientific research and policy. It then studied how this waste management knowledge is recontextualised into qualifications and skills programmes designed in the official recontextualising field and learning materials and training programmes designed and offered in the professional recontextualising field. The study also focused on the knowledge of workers and their experience of training in the EPWP workplaces, with an emphasis on rural workplaces. This is where the Department of Environmental Affairs (DEA) is placing emphasis on training for job creation, empowerment and skills development, and it is also where a number of EPWP Working on Waste programmes are being implemented. The aim was also to develop an understanding of how knowledge circulates amongst learners in training sessions and in workplaces. To do this, I drew on Bernstein’s theory of the pedagogical device which provides theoretical lenses and a language of description to explain how knowledge is recontextualised from the field of production to the field of reproduction. To investigate the structuring of this knowledge by official and pedagogical recontextualisers, I drew on the work of Maton, who offers a Legitimation Code Theory to explain the principles structuring knowledge, of which I used specialisation and semantics (two of his suite of knowledge structuring principles) for analysis. The questions that guided the study throughout were: 1. What is the structure of legitimate knowledge and knowers in waste management? 2. What are the underlying principles underpinning knowledge and knowers in waste management? 3. How is the knowledge recontextualised in waste management training qualifications, documents and manuals for worker training at NQF Level 2? 4. How is the knowledge reproduced and evaluated in the waste management EPWP training activities (formal) and workplaces (informal)? 5. How does waste management knowledge circulate amongst the workers in the EPWP training activities and workplaces? For this study I used the case study method, focusing only on one field or DEA EPWP focus area (waste management) and one programme (EPWP Working on Waste), looking in more depth at two cases (two similar types of projects) within the EPWP Working on Waste programme, though they are situated in different areas and though I could only carry through observations of actual workplace training in one of the two sites due to contextual circumstances. The first project was situated in the Amathole District Municipality while the second one was situated in the Chris Hani District Municipality, both of which are in the rural towns of the former Transkei region in the Eastern Cape, South Africa. This area has been at the forefront in accessing funding for these projects due to the level of poverty surrounding these towns and the inability of the local government sphere to deliver on its mandate in the region. Data was collected through document analysis, questionnaires, interviews and observations. Documents analysed were research documents produced by researchers at the level of production as well as legal frameworks guiding waste management processes in this country. Qualifications and Unit Standards at Level 2, as well as training materials designed by providers were analysed. Training in one of the projects was observed and workers in both sites were interviewed twice. The main finding of the study is that waste management knowledge is characterised by interdisciplinarity and a strong epistemic relation which emphasises procedural and technical forms of knowledge. The study found that the knowledge constructed in the field, as well as the policies, qualifications and training programmes are all consequently characterised by a strong epistemic code (ER+) and a weak social relations code (SR-). The study also identified a ‘code clash’ with the knowledge of workers in rural towns whose knowledge and experience of waste management was found to reflect a strong social relation (SR+) and weak epistemic code (ER-), a pattern which was traced back to a similar code in waste management knowledge at home and school (i.e. workers’ prior knowledge and learning experiences). This created difficulties for the trainers who sought to use strategies of descending from the abstract to the concrete in various ‘descending’ semantic waves that tended to move from high levels of semantic density (SD+) to lower levels of semantic density (SD-) as the training provider sought to contextualise a range of concepts. This was the main strategy identified for mediating waste management knowledge reflecting a dominant pattern of SD+/SG- to SD-/SG+ (with SG meaning semantic gravity). This shows that the trainer seldom started mediating concepts from the basis of workers’ prior knowledge and experience and observations showed little responsiveness from workers resulting from this strategy. Despite this, the study found that workers did develop an improved understanding of specialised waste management knowledge over time, especially through observing and doing more complex tasks in the workplace. The study offers a model for addressing the pedagogical difficulty identified around the code clash, and suggests that further attention needs to be given to ‘ascending’ from the concrete to the abstract in pedagogical practices. The study also pointed to the need for a more inclusive knowledge framework for waste management training, especially in the field of recontextualisation (both the official and pedagogical recontextualisation fields) to extend possibilities for workers to learn more about economic potential and access routes into more sustainable jobs. It identifies the need for a more systemic approach to waste management in rural towns and municipalities, improved compliance and also proposes that better waste management practices are modelled to avoid performative contradictions between the knowledge promoted in the field of production and the official and pedagogical recontextualising fields and the field of reproduction, where workers are learning this knowledge via a mix of accredited training and exposure to participation in waste management practices. This study contributes to new knowledge in that it offers an epistemically grounded and theorised pedagogical process model for Level 2 Waste Management Training (in the EPWP programmes, but potentially also more broadly) that accords with the need for a strong epistemic relation code (ER+) embodied in the need for learning scientific and technical waste management knowledge and procedures. It also addresses workers’ needs for greater epistemic access and participation in knowledge building and application of waste management knowledge in praxis as per the purpose of the EPW training programmes, thereby potentially opening up more sustainable learning pathways for them out of poverty through the EPWP training opportunities. The study has pointed to key areas for further research, including further research on the proposed model, further research into Level 2 pedagogical practices and further research into the foundations of waste management learning in schools. Most of the workers who were participating in the training in the EPWP programmes were educated at above Level 2 before participating in the projects, yet their knowledge and experience of waste management was mostly based on everyday knowledge, pointing to an absence of adequate waste management education in schools in rural contexts in South Africa. The study has also made various recommendations for improving waste management education and training at Level 2 in EPWP programmes in rural areas in particular (but potentially also more widely), notably the need to develop a more inclusive knowledge framework that includes historical and economic knowledge more explicitly at all levels of the recontextualisation process; improved pedagogical and assessment practices that take better account of learners knowledge and experiences in knowledge building processes; and giving attention to structural and systemic approaches to waste management in rural areas to avoid performative contradictions that arise between the knowledge being promoted in the field of production and the field of reproduction and the actual context of waste management.
- Full Text:
- Date Issued: 2018
Contributions to the ecology of the anomuran mud prawn Upogebia africana (Ortmann)
- Authors: Hill, Burke J
- Date: 1967
- Subjects: Decapoda , Shrimps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5888 , http://hdl.handle.net/10962/d1013341
- Description: Estuarine ecology in South Africa has progressed in two distinct stages. The first of these was a necessary descriptive phase which documented the general distribution of estuarine animals and recorded the physical conditions within estuaries . This phase has been carried out by the Zoology Department of the University of Cape Town which has made a series of ecological surveys of southern African estuaries. These surveys have provided a vast amount of valuable information which was utilised by Day (1964.) to state some general conclusions about estuarine faunas. The most important of these conclusions is that most of the estuarine fauna is really a quiet water fauna which also occurs in sheltered non-estuarine water. The information gained in this first stage is necessarily general and it can only indicate overall trends or reveal major features of distribution. Further estuary surveys are not justified unless they deal with unique conditions. It is at this point that the second phase of estuarine ecology becomes necessary. This phase involves a detailed investigation of individual species or particular problems. The present investigation falls into this second stage of estuarine ecology and was designed to extend our knowledge of the anomuran mud prawn Upogebia africana (Ortmann). The general estuarine surveys have shown that U. africana is a common inhabitant of many estuaries and sheltered bays along the southern African coast from Langebaan on the West coast to Inhambane on the East coast. However these surveys only revealed and could not explain anomalies in its distribution such as its apparent absence from closed estuaries and from estuaries in the tropics. In addition it was not even certain whether this abundant and widespread animal should really be considered a valid species distinct from a common West Coast prawn Upogebia capensis (Krauss). It was felt that a study of an estuarine species should be based upon a sound knowledge of its distribution, population structure and habitat. Knowledge of the habitat must be gained by studies in the field to establish which facets of the environment are of importance to the species. It was decided on the basis of field observations that temperature and salinity are of prime importance: in limiting the distribution of U. africana and a detailed laboratory study was therefore made of the tolerance of U. africana to these two physical factors. The results of laboratory experiments together with field observations were finally used to interpret the ecology of the species. Most of present day knowledge of crustacean ecology has been gained from a study of European and North American animals and information about southern hemisphere species has lagged behind. It is hoped that the present study will contribute to a wider understanding of Crustacea and that it will lead to further more advanced research on South African marine and estuarine animals
- Full Text:
- Date Issued: 1967
- Authors: Hill, Burke J
- Date: 1967
- Subjects: Decapoda , Shrimps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5888 , http://hdl.handle.net/10962/d1013341
- Description: Estuarine ecology in South Africa has progressed in two distinct stages. The first of these was a necessary descriptive phase which documented the general distribution of estuarine animals and recorded the physical conditions within estuaries . This phase has been carried out by the Zoology Department of the University of Cape Town which has made a series of ecological surveys of southern African estuaries. These surveys have provided a vast amount of valuable information which was utilised by Day (1964.) to state some general conclusions about estuarine faunas. The most important of these conclusions is that most of the estuarine fauna is really a quiet water fauna which also occurs in sheltered non-estuarine water. The information gained in this first stage is necessarily general and it can only indicate overall trends or reveal major features of distribution. Further estuary surveys are not justified unless they deal with unique conditions. It is at this point that the second phase of estuarine ecology becomes necessary. This phase involves a detailed investigation of individual species or particular problems. The present investigation falls into this second stage of estuarine ecology and was designed to extend our knowledge of the anomuran mud prawn Upogebia africana (Ortmann). The general estuarine surveys have shown that U. africana is a common inhabitant of many estuaries and sheltered bays along the southern African coast from Langebaan on the West coast to Inhambane on the East coast. However these surveys only revealed and could not explain anomalies in its distribution such as its apparent absence from closed estuaries and from estuaries in the tropics. In addition it was not even certain whether this abundant and widespread animal should really be considered a valid species distinct from a common West Coast prawn Upogebia capensis (Krauss). It was felt that a study of an estuarine species should be based upon a sound knowledge of its distribution, population structure and habitat. Knowledge of the habitat must be gained by studies in the field to establish which facets of the environment are of importance to the species. It was decided on the basis of field observations that temperature and salinity are of prime importance: in limiting the distribution of U. africana and a detailed laboratory study was therefore made of the tolerance of U. africana to these two physical factors. The results of laboratory experiments together with field observations were finally used to interpret the ecology of the species. Most of present day knowledge of crustacean ecology has been gained from a study of European and North American animals and information about southern hemisphere species has lagged behind. It is hoped that the present study will contribute to a wider understanding of Crustacea and that it will lead to further more advanced research on South African marine and estuarine animals
- Full Text:
- Date Issued: 1967
Demobilisation and the civilian reintegration of women ex-combatants in post-apartheid South Africa: the aftermath of transnational guerrilla girls, combative mothers and in- betweeners in the shadows of a late twentieth-century war
- Authors: Magadla, Siphokazi
- Date: 2017
- Subjects: South Africa. National Defence Force , Umkhonto we Sizwe (South Africa) -- Demobilization , Azanian People's Liberation Army -- Demobilization , Amabutho Self-Defence Unit -- Demobilization , South Africa. Army -- Women , Women soldiers -- South Africa , Government, Resistance to -- South Africa -- History , Women veterans -- South Africa -- History , Women veterans -- South Africa -- Interviews
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/41775 , vital:25133
- Description: This study examines the state assisted demobilisation and civilian reintegration of women excombatants in post-apartheid South Africa. The study is based on life history interviews conducted with 36 women who fought for Umkhonto we Sizwe (MK), Azanian People’s Liberation Army (APLA) and Amabutho Self-Defence Unit. There is agreement across the literature that the armed struggle against apartheid falls within the category of guerilla warfare, fought in multiple terrains, that blur conventional distinctions of civilian and combatant, homefront and battlefront, as well as the domestic and transnational. Located within feminist International Relations theory, the study argues that the formal process that led to the integration of statutory and non-statutory forces to form the South African National Defence Force, which facilitated the demobilisation process, was framed in ways that did not reflect the unconventional nature of the armed struggle against apartheid. The few women who participated in this process were the transnationally trained combatants of MK and APLA. The majority of women who participated in the multiple and overlapping sites of the domestic and international apartheid battlefront were left out of this process. It is argued that women’s roles in the armed struggle were shaped by various factors, such as age, space and period of struggle. Three categories, guerilla girls, combative mothers and the in-betweeners, are introduced in order to demonstrate the different spaces from within which women fought, and the methods they used, all of which were central to the success of the People’s War strategy. In this regard, the venerated transnationally trained woman combatant, like their male counterpart, is argued to be an exception, as the majority of women were thrust into the armed struggle without military training. Furthermore, it is argued that conservative feminist readings of black women’s relationship with nationalism in the anti-apartheid struggle have misrecognised and undermined women’s combatant contributions, by inscribing their forms of resistance as maternal, and outside the war effort. The study shows that the majority of women combatants have transitioned to civilian life without formal state recognition and assistance. The erasure of women’s role as combatants also means that they are excluded from the current legislative framework facilitated by the Department of Military Veterans to support the welfare of former combatants. As such, the study builds on Jacklyn Cock’s (1991) pioneering study on war and gender in South Africa; it is the first study that exclusively focuses on women ex-combatants’ experiences in postapartheid South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Magadla, Siphokazi
- Date: 2017
- Subjects: South Africa. National Defence Force , Umkhonto we Sizwe (South Africa) -- Demobilization , Azanian People's Liberation Army -- Demobilization , Amabutho Self-Defence Unit -- Demobilization , South Africa. Army -- Women , Women soldiers -- South Africa , Government, Resistance to -- South Africa -- History , Women veterans -- South Africa -- History , Women veterans -- South Africa -- Interviews
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/41775 , vital:25133
- Description: This study examines the state assisted demobilisation and civilian reintegration of women excombatants in post-apartheid South Africa. The study is based on life history interviews conducted with 36 women who fought for Umkhonto we Sizwe (MK), Azanian People’s Liberation Army (APLA) and Amabutho Self-Defence Unit. There is agreement across the literature that the armed struggle against apartheid falls within the category of guerilla warfare, fought in multiple terrains, that blur conventional distinctions of civilian and combatant, homefront and battlefront, as well as the domestic and transnational. Located within feminist International Relations theory, the study argues that the formal process that led to the integration of statutory and non-statutory forces to form the South African National Defence Force, which facilitated the demobilisation process, was framed in ways that did not reflect the unconventional nature of the armed struggle against apartheid. The few women who participated in this process were the transnationally trained combatants of MK and APLA. The majority of women who participated in the multiple and overlapping sites of the domestic and international apartheid battlefront were left out of this process. It is argued that women’s roles in the armed struggle were shaped by various factors, such as age, space and period of struggle. Three categories, guerilla girls, combative mothers and the in-betweeners, are introduced in order to demonstrate the different spaces from within which women fought, and the methods they used, all of which were central to the success of the People’s War strategy. In this regard, the venerated transnationally trained woman combatant, like their male counterpart, is argued to be an exception, as the majority of women were thrust into the armed struggle without military training. Furthermore, it is argued that conservative feminist readings of black women’s relationship with nationalism in the anti-apartheid struggle have misrecognised and undermined women’s combatant contributions, by inscribing their forms of resistance as maternal, and outside the war effort. The study shows that the majority of women combatants have transitioned to civilian life without formal state recognition and assistance. The erasure of women’s role as combatants also means that they are excluded from the current legislative framework facilitated by the Department of Military Veterans to support the welfare of former combatants. As such, the study builds on Jacklyn Cock’s (1991) pioneering study on war and gender in South Africa; it is the first study that exclusively focuses on women ex-combatants’ experiences in postapartheid South Africa.
- Full Text:
- Date Issued: 2017
Development of a hydraulic sub-model as part of a desktop environmental flow assessment method
- Authors: Desai, Ahmed Yacoob
- Date: 2012
- Subjects: Hydrologic models -- Research -- South Africa Hydraulic engineering -- South Africa Rivers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6041 , http://hdl.handle.net/10962/d1006200
- Description: Countries around the world have been developing ecological policies to protect their water resources and minimise the impacts of development on their river systems. The concept of ‘minimum flows’ was initially established as a solution but it did not provide sufficient protection as all elements of a flow regime were found to be important for the protection of the river ecosystem. “Environmental flows” were developed to determine these flow regimes to maintain a river in some defined ecological condition. Rapid, initial estimates of the quantity component of environmental flows may be determined using the Desktop Reserve Model in South Africa. However, the Desktop Reserve Model is dependent upon the characteristics of the reference natural hydrology used. The advancements in hydraulic and ecological relationships from the past decade have prompted the development of a Revised Desktop Reserve Model (RDRM) that would incorporate these relationships. The research in this thesis presents the development of the hydraulic sub-model for the RDRM. The hydraulic sub-model was designed to produce a realistic representation of the hydraulic conditions using hydraulic parameters/characteristics from readily available information for any part of South Africa. Hydraulic data from past EWR studies were used to estimate the hydraulic parameters. These estimated hydraulic parameters were used to develop hydraulic estimation relationships and these relationships were developed based on a combination of regression and rule-based procedures. The estimation relationships were incorporated into the hydraulic sub-model of the integrated RDRM and assessments of the hydraulic outputs and EWR results were undertaken to assess the ‘applicability’ of the hydraulic sub-model. The hydraulic sub-model was assessed to be at a stage where it can satisfactorily be incorporated in the RDRM and that it is adequately robust in many situations. Recommendations for future work include the refinement of estimation of the channel forming discharge or the use of spatial imagery to check the maximum channel width estimation. It is also proposed that a future version of the hydraulic sub-model could include flow regime change impacts on channel geomorphology and sedimentology so that flow management scenarios can be more effectively assessed.
- Full Text:
- Date Issued: 2012
- Authors: Desai, Ahmed Yacoob
- Date: 2012
- Subjects: Hydrologic models -- Research -- South Africa Hydraulic engineering -- South Africa Rivers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6041 , http://hdl.handle.net/10962/d1006200
- Description: Countries around the world have been developing ecological policies to protect their water resources and minimise the impacts of development on their river systems. The concept of ‘minimum flows’ was initially established as a solution but it did not provide sufficient protection as all elements of a flow regime were found to be important for the protection of the river ecosystem. “Environmental flows” were developed to determine these flow regimes to maintain a river in some defined ecological condition. Rapid, initial estimates of the quantity component of environmental flows may be determined using the Desktop Reserve Model in South Africa. However, the Desktop Reserve Model is dependent upon the characteristics of the reference natural hydrology used. The advancements in hydraulic and ecological relationships from the past decade have prompted the development of a Revised Desktop Reserve Model (RDRM) that would incorporate these relationships. The research in this thesis presents the development of the hydraulic sub-model for the RDRM. The hydraulic sub-model was designed to produce a realistic representation of the hydraulic conditions using hydraulic parameters/characteristics from readily available information for any part of South Africa. Hydraulic data from past EWR studies were used to estimate the hydraulic parameters. These estimated hydraulic parameters were used to develop hydraulic estimation relationships and these relationships were developed based on a combination of regression and rule-based procedures. The estimation relationships were incorporated into the hydraulic sub-model of the integrated RDRM and assessments of the hydraulic outputs and EWR results were undertaken to assess the ‘applicability’ of the hydraulic sub-model. The hydraulic sub-model was assessed to be at a stage where it can satisfactorily be incorporated in the RDRM and that it is adequately robust in many situations. Recommendations for future work include the refinement of estimation of the channel forming discharge or the use of spatial imagery to check the maximum channel width estimation. It is also proposed that a future version of the hydraulic sub-model could include flow regime change impacts on channel geomorphology and sedimentology so that flow management scenarios can be more effectively assessed.
- Full Text:
- Date Issued: 2012
Apartheid South Africa's foreign relations with African states, 1961-1994
- Authors: Pfister, Roger
- Date: 2004
- Subjects: Apartheid -- South Africa -- History -- 20th century Government, Resistance to -- South Africa Democracy -- South Africa South Africa -- Politics and government -- 20th century South Africa -- History -- 1961-1994 South Africa -- Foreign relations -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2863 , http://hdl.handle.net/10962/d1007632
- Description: This thesis examines South Africa's foreign relations, viewed from a South African perspective, with the black African countries beyond southern Africa from 1961 to 1994. These relations were determined by the conflict between Pretoria's apartheid ideology on the one hand, and African continental rejection of South Africa's race discrimination policies and its exclusion from the community of African states on the other. The documentary material used primarily stems from the Department of Foreign Affairs archive in Pretoria, supplemented by research conducted in other archives. Furthermore, we conducted interviews and correspondence, and consulted the relevant primary and secondary literature. Given the main source of information, we chose to make this work a case study in Diplomatic History. In consequence, and constituting the core of the study, Chapters 3 to 6 explore the interaction between South Africa and the black African states in a chronological order. At the same time, we draw on the analytical concepts from the academic disciplines of Political Science and its derivative, International Relations, to comprehend developments more fully. We discuss the significance of the approaches from these two disciplines in both the Introduction and Chapter 2. In particular, we emphasise that this study is about Pretoria's foreign policy, involving state and non-state actors, and we suggest that the unequal status between South Africa and the other African states constitutes an inherent factor in the relationship between them. The Conclusion examines the role of the state and non-state actors in determining Pretoria's foreign relations and the relevance of the structural imbalance between South Africa and the black African states in this context.
- Full Text:
- Date Issued: 2004
- Authors: Pfister, Roger
- Date: 2004
- Subjects: Apartheid -- South Africa -- History -- 20th century Government, Resistance to -- South Africa Democracy -- South Africa South Africa -- Politics and government -- 20th century South Africa -- History -- 1961-1994 South Africa -- Foreign relations -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2863 , http://hdl.handle.net/10962/d1007632
- Description: This thesis examines South Africa's foreign relations, viewed from a South African perspective, with the black African countries beyond southern Africa from 1961 to 1994. These relations were determined by the conflict between Pretoria's apartheid ideology on the one hand, and African continental rejection of South Africa's race discrimination policies and its exclusion from the community of African states on the other. The documentary material used primarily stems from the Department of Foreign Affairs archive in Pretoria, supplemented by research conducted in other archives. Furthermore, we conducted interviews and correspondence, and consulted the relevant primary and secondary literature. Given the main source of information, we chose to make this work a case study in Diplomatic History. In consequence, and constituting the core of the study, Chapters 3 to 6 explore the interaction between South Africa and the black African states in a chronological order. At the same time, we draw on the analytical concepts from the academic disciplines of Political Science and its derivative, International Relations, to comprehend developments more fully. We discuss the significance of the approaches from these two disciplines in both the Introduction and Chapter 2. In particular, we emphasise that this study is about Pretoria's foreign policy, involving state and non-state actors, and we suggest that the unequal status between South Africa and the other African states constitutes an inherent factor in the relationship between them. The Conclusion examines the role of the state and non-state actors in determining Pretoria's foreign relations and the relevance of the structural imbalance between South Africa and the black African states in this context.
- Full Text:
- Date Issued: 2004
A knowledge-oriented, context-sensitive architectural framework for service deployment in marginalized rural communities
- Authors: Thinyane, Mamello P
- Date: 2009
- Subjects: Information technology Expert systems (Computer science) Software architecture User interfaces (Computer systems) Ethnoscience Social networks Rural development Technical assistance -- Developing countries Information networks -- Developing countries
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4599 , http://hdl.handle.net/10962/d1004843
- Description: The notion of a global knowledge society is somewhat of a misnomer due to the fact that large portions of the global community are not participants in this global knowledge society which is driven, shaped by and socio-technically biased towards a small fraction of the global population. Information and Communication Technology (ICT) is culture-sensitive and this is a dynamic that is largely ignored in the majority of ICT for Development (ICT4D) interventions, leading to the technological determinism flaw and ultimately a failure of the undertaken projects. The deployment of ICT solutions, in particular in the context of ICT4D, must be informed by the cultural and socio-technical profile of the deployment environments and solutions themselves must be developed with a focus towards context-sensitivity and ethnocentricity. In this thesis, we investigate the viability of a software architectural framework for the development of ICT solutions that are context-sensitive and ethnocentric1, and so aligned with the cultural and social dynamics within the environment of deployment. The conceptual framework, named PIASK, defines five tiers (presentation, interaction, access, social networking, and knowledge base) which allow for: behavioural completeness of the layer components; a modular and functionally decoupled architecture; and the flexibility to situate and contextualize the developed applications along the dimensions of the User Interface (UI), interaction modalities, usage metaphors, underlying Indigenous Knowledge (IK), and access protocols. We have developed a proof-of-concept service platform, called KnowNet, based on the PIASK architecture. KnowNet is built around the knowledge base layer, which consists of domain ontologies that encapsulate the knowledge in the platform, with an intrinsic flexibility to access secondary knowledge repositories. The domain ontologies constructed (as examples) are for the provisioning of eServices to support societal activities (e.g. commerce, health, agriculture, medicine) within a rural and marginalized area of Dwesa, in the Eastern Cape province of South Africa. The social networking layer allows for situating the platform within the local social systems. Heterogeneity of user profiles and multiplicity of end-user devices are handled through the access and the presentation components, and the service logic is implemented by the interaction components. This services platform validates the PIASK architecture for end-to-end provisioning of multi-modal, heterogeneous, ontology-based services. The development of KnowNet was informed on one hand by the latest trends within service architectures, semantic web technologies and social applications, and on the other hand by the context consideration based on the profile (IK systems dynamics, infrastructure, usability requirements) of the Dwesa community. The realization of the service platform is based on the JADE Multi-Agent System (MAS), and this shows the applicability and adequacy of MAS’s for service deployment in a rural context, at the same time providing key advantages such as platform fault-tolerance, robustness and flexibility. While the context of conceptualization of PIASK and the implementation of KnowNet is that of rurality and of ICT4D, the applicability of the architecture extends to other similarly heterogeneous and context-sensitive domains. KnowNet has been validated for functional and technical adequacy, and we have also undertaken an initial prevalidation for social context sensitivity. We observe that the five tier PIASK architecture provides an adequate framework for developing context-sensitive and ethnocentric software: by functionally separating and making explicit the social networking and access tier components, while still maintaining the traditional separation of presentation, business logic and data components.
- Full Text:
- Date Issued: 2009
- Authors: Thinyane, Mamello P
- Date: 2009
- Subjects: Information technology Expert systems (Computer science) Software architecture User interfaces (Computer systems) Ethnoscience Social networks Rural development Technical assistance -- Developing countries Information networks -- Developing countries
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4599 , http://hdl.handle.net/10962/d1004843
- Description: The notion of a global knowledge society is somewhat of a misnomer due to the fact that large portions of the global community are not participants in this global knowledge society which is driven, shaped by and socio-technically biased towards a small fraction of the global population. Information and Communication Technology (ICT) is culture-sensitive and this is a dynamic that is largely ignored in the majority of ICT for Development (ICT4D) interventions, leading to the technological determinism flaw and ultimately a failure of the undertaken projects. The deployment of ICT solutions, in particular in the context of ICT4D, must be informed by the cultural and socio-technical profile of the deployment environments and solutions themselves must be developed with a focus towards context-sensitivity and ethnocentricity. In this thesis, we investigate the viability of a software architectural framework for the development of ICT solutions that are context-sensitive and ethnocentric1, and so aligned with the cultural and social dynamics within the environment of deployment. The conceptual framework, named PIASK, defines five tiers (presentation, interaction, access, social networking, and knowledge base) which allow for: behavioural completeness of the layer components; a modular and functionally decoupled architecture; and the flexibility to situate and contextualize the developed applications along the dimensions of the User Interface (UI), interaction modalities, usage metaphors, underlying Indigenous Knowledge (IK), and access protocols. We have developed a proof-of-concept service platform, called KnowNet, based on the PIASK architecture. KnowNet is built around the knowledge base layer, which consists of domain ontologies that encapsulate the knowledge in the platform, with an intrinsic flexibility to access secondary knowledge repositories. The domain ontologies constructed (as examples) are for the provisioning of eServices to support societal activities (e.g. commerce, health, agriculture, medicine) within a rural and marginalized area of Dwesa, in the Eastern Cape province of South Africa. The social networking layer allows for situating the platform within the local social systems. Heterogeneity of user profiles and multiplicity of end-user devices are handled through the access and the presentation components, and the service logic is implemented by the interaction components. This services platform validates the PIASK architecture for end-to-end provisioning of multi-modal, heterogeneous, ontology-based services. The development of KnowNet was informed on one hand by the latest trends within service architectures, semantic web technologies and social applications, and on the other hand by the context consideration based on the profile (IK systems dynamics, infrastructure, usability requirements) of the Dwesa community. The realization of the service platform is based on the JADE Multi-Agent System (MAS), and this shows the applicability and adequacy of MAS’s for service deployment in a rural context, at the same time providing key advantages such as platform fault-tolerance, robustness and flexibility. While the context of conceptualization of PIASK and the implementation of KnowNet is that of rurality and of ICT4D, the applicability of the architecture extends to other similarly heterogeneous and context-sensitive domains. KnowNet has been validated for functional and technical adequacy, and we have also undertaken an initial prevalidation for social context sensitivity. We observe that the five tier PIASK architecture provides an adequate framework for developing context-sensitive and ethnocentric software: by functionally separating and making explicit the social networking and access tier components, while still maintaining the traditional separation of presentation, business logic and data components.
- Full Text:
- Date Issued: 2009
Development of integrated biological processing for the biodesalination of sulphate- and metal-rich wastewaters
- Authors: Boshoff, Genevieve Ann
- Date: 1999
- Subjects: Sewage -- Purification -- Biological treatment Sulfates Mineral industries -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3899 , http://hdl.handle.net/10962/d1003958
- Description: The substantial pollution threat to the South African environment from acid mine drainage (AMD) effluents has been well documented. Due to the juvenile nature of acidity in these flows, any remediation strategies implemented will need to function effectively and at low cost for long periods of time. The widespread use of sulphate reducing biological systems for the treatment of such effluents, and in particular large volume flows, has been limited. The supply of inexpensive electron donor and carbon sources, as well as appropriate reactor designs capable of handling large volume flows, have been identified as among the principal factors limiting development of this technology. The broad aim of the research programme reported here was to undertake an evaluation of the feasibility of an algal-bacterial integrated ponding system for the treatment of AMD, and the waste stabilisation pond (WSP) as an appropriate reactor design for this application. The study attempted to demonstrate the feasibility of individual unit operations in a proposed process train using complex organic carbon serving as the electron donor source for the sulphate reducing bacteria (SRB). Studies were undertaken as laboratory and pilot-scale investigations. Tannery effluent was shown to be a functional carbon source for biological sulphate reduction, with effective removal of sulphate and organics being recorded. In turn, the use of biological sulphate reduction for the treatment of tannery effluent was demonstrated. Algal biomass was shown in laboratory studies to function as an effective carbon source for biological sulphate reduction. It is known that micro-algae produce large quantities of photosynthate which is released to the growth medium under conditions of physiological stress. The potential for the use of photosynthate production in high rate algal ponding systems and its manipulation and use as a sustainable carbon source for sulphate reduction was investigated. Growth of a mixed culture of Dunaliella under conditions of light, temperature and salinity stress demonstrated production of large quantities of organic carbon. However, growth was inhibited at high temperatures. An elevation of salinity levels led to a decrease in growth of Dunaliella, but to increased organic carbon production. Spirulina spp., on the other hand, grew well at higher temperatures but showed the highest organic carbon production, and release to the medium, under low light conditions. These results led to a proposed process for the integration of algal ponding into an integrated system for the treatment of AMD. The algal biomass may be fed into the anaerobic digester as a carbon source, or it may be passed into a High Rate Algal Pond (HRAP) where it is stressed to enhance the organic carbon content. This can then be fed into the anaerobic digester as a carbon source. The impact of high levels of sulphide in the water feeding to the algal growth compartment was investigated. Spirulina spp. isolated from a tannery waste stabilisation pond was shown to be a sulphidophilic strain of cyanobacterium, capable of being adapted to high concentrations of sulphide. Dunaliella salina on the other hand was less tolerant. These results demonstrated the practical use of algal biomass providing an oxygen-rich cap for odour control on the surface of the facultative pond as well for the secondary treatment of sulphide-rich overflow to the High Rate Algal Pond. The ability of micro-algae to elevate the pH of their surrounding environment was evaluated as a functional precipitant and neutralisation reagent for acidic metal containing wastewater. Spirulina spp. was shown to perform effectively. D. salina was less functional in this environment. Anacystis spp. was effective in elevating the pH of a defined medium as well as a zinc-rich effluent. These results indicated the practicality of a neutralising function for algal ponds in the treatment of AMD. Metal removal in the system was found to be a combined function of sulphide precipitation, removal by binding to micro-algal biomass and extracellular polymeric substances. The feasibility of waste stabilisation ponding technology use for the treatment of large volume AMD effluents was provisionally demonstrated. It was shown that complex carbon sources would be used as efficient electron donors for sulphate reduction. The integration of algal ponding into the system provides for the generation of a sustainable carbon source, odour control with the recycling of oxygen-rich water onto the top of the facultative pond, secondary treatment of the anaerobic digester overflow, and the neutralisation of the incoming acidic effluents and removal of heavy metals. Integration of the individual unit operations, the feasibility of which has been provisionally demonstrated in this study, into a continuous process train is being investigated in follow-upstudies.
- Full Text:
- Date Issued: 1999
- Authors: Boshoff, Genevieve Ann
- Date: 1999
- Subjects: Sewage -- Purification -- Biological treatment Sulfates Mineral industries -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3899 , http://hdl.handle.net/10962/d1003958
- Description: The substantial pollution threat to the South African environment from acid mine drainage (AMD) effluents has been well documented. Due to the juvenile nature of acidity in these flows, any remediation strategies implemented will need to function effectively and at low cost for long periods of time. The widespread use of sulphate reducing biological systems for the treatment of such effluents, and in particular large volume flows, has been limited. The supply of inexpensive electron donor and carbon sources, as well as appropriate reactor designs capable of handling large volume flows, have been identified as among the principal factors limiting development of this technology. The broad aim of the research programme reported here was to undertake an evaluation of the feasibility of an algal-bacterial integrated ponding system for the treatment of AMD, and the waste stabilisation pond (WSP) as an appropriate reactor design for this application. The study attempted to demonstrate the feasibility of individual unit operations in a proposed process train using complex organic carbon serving as the electron donor source for the sulphate reducing bacteria (SRB). Studies were undertaken as laboratory and pilot-scale investigations. Tannery effluent was shown to be a functional carbon source for biological sulphate reduction, with effective removal of sulphate and organics being recorded. In turn, the use of biological sulphate reduction for the treatment of tannery effluent was demonstrated. Algal biomass was shown in laboratory studies to function as an effective carbon source for biological sulphate reduction. It is known that micro-algae produce large quantities of photosynthate which is released to the growth medium under conditions of physiological stress. The potential for the use of photosynthate production in high rate algal ponding systems and its manipulation and use as a sustainable carbon source for sulphate reduction was investigated. Growth of a mixed culture of Dunaliella under conditions of light, temperature and salinity stress demonstrated production of large quantities of organic carbon. However, growth was inhibited at high temperatures. An elevation of salinity levels led to a decrease in growth of Dunaliella, but to increased organic carbon production. Spirulina spp., on the other hand, grew well at higher temperatures but showed the highest organic carbon production, and release to the medium, under low light conditions. These results led to a proposed process for the integration of algal ponding into an integrated system for the treatment of AMD. The algal biomass may be fed into the anaerobic digester as a carbon source, or it may be passed into a High Rate Algal Pond (HRAP) where it is stressed to enhance the organic carbon content. This can then be fed into the anaerobic digester as a carbon source. The impact of high levels of sulphide in the water feeding to the algal growth compartment was investigated. Spirulina spp. isolated from a tannery waste stabilisation pond was shown to be a sulphidophilic strain of cyanobacterium, capable of being adapted to high concentrations of sulphide. Dunaliella salina on the other hand was less tolerant. These results demonstrated the practical use of algal biomass providing an oxygen-rich cap for odour control on the surface of the facultative pond as well for the secondary treatment of sulphide-rich overflow to the High Rate Algal Pond. The ability of micro-algae to elevate the pH of their surrounding environment was evaluated as a functional precipitant and neutralisation reagent for acidic metal containing wastewater. Spirulina spp. was shown to perform effectively. D. salina was less functional in this environment. Anacystis spp. was effective in elevating the pH of a defined medium as well as a zinc-rich effluent. These results indicated the practicality of a neutralising function for algal ponds in the treatment of AMD. Metal removal in the system was found to be a combined function of sulphide precipitation, removal by binding to micro-algal biomass and extracellular polymeric substances. The feasibility of waste stabilisation ponding technology use for the treatment of large volume AMD effluents was provisionally demonstrated. It was shown that complex carbon sources would be used as efficient electron donors for sulphate reduction. The integration of algal ponding into the system provides for the generation of a sustainable carbon source, odour control with the recycling of oxygen-rich water onto the top of the facultative pond, secondary treatment of the anaerobic digester overflow, and the neutralisation of the incoming acidic effluents and removal of heavy metals. Integration of the individual unit operations, the feasibility of which has been provisionally demonstrated in this study, into a continuous process train is being investigated in follow-upstudies.
- Full Text:
- Date Issued: 1999