Press cutting: 'King Kong' is most exciting show seen in years
- "R", Daily News
- Authors: "R" , Daily News
- Date: 1959-05-12
- Subjects: King Kong (Musical) -- History and critisism , Jazz -- South Africa , Musicals -- South Africa -- History and critisism , Music -- South Africa , Matshikiza, Todd, 1921-1968 -- King Kong
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/42004 , vital:25155 , MS 20 066 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
- Full Text:
- Date Issued: 1959-05-12
- Authors: "R" , Daily News
- Date: 1959-05-12
- Subjects: King Kong (Musical) -- History and critisism , Jazz -- South Africa , Musicals -- South Africa -- History and critisism , Music -- South Africa , Matshikiza, Todd, 1921-1968 -- King Kong
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/42004 , vital:25155 , MS 20 066 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017.
- Full Text:
- Date Issued: 1959-05-12
Programme of the centenary celebrations in commemoration of the arrival of the 1820 British settlers of Albany, to be held at Port Elizabeth on April 9th and at Grahamstown on April 11th 1921
- 1820 Settlers' Association of South Africa
- Authors: 1820 Settlers' Association of South Africa
- Date: 1921
- Subjects: British settlers of 1820 (South Africa) -- Celebration -- 1921 , South Africa -- History -- Frontier Wars, 1811-1878 , Eastern Cape (South Africa) -- History -- Pictorial works
- Language: English
- Type: programme , text
- Identifier: http://hdl.handle.net/10962/113427 , vital:33773 , Cory Library for Humanities Research
- Description: Programme of the centenary celebrations in commemoration of the arrival of the 1820 British settlers of Albany, to be held at Port Elizabeth on April 9th and at Grahamstown on April 11th 1921 : containing a descriptive guide to the motor route through the Eastern Province to be travelled by Major-General H R H Price Arthur of Connaught ..., Governor-General of the Union of South Africa, accompanied by H R H Princess Arthur of Connaught, at the close of the celebrations.
- Full Text:
- Date Issued: 1921
- Authors: 1820 Settlers' Association of South Africa
- Date: 1921
- Subjects: British settlers of 1820 (South Africa) -- Celebration -- 1921 , South Africa -- History -- Frontier Wars, 1811-1878 , Eastern Cape (South Africa) -- History -- Pictorial works
- Language: English
- Type: programme , text
- Identifier: http://hdl.handle.net/10962/113427 , vital:33773 , Cory Library for Humanities Research
- Description: Programme of the centenary celebrations in commemoration of the arrival of the 1820 British settlers of Albany, to be held at Port Elizabeth on April 9th and at Grahamstown on April 11th 1921 : containing a descriptive guide to the motor route through the Eastern Province to be travelled by Major-General H R H Price Arthur of Connaught ..., Governor-General of the Union of South Africa, accompanied by H R H Princess Arthur of Connaught, at the close of the celebrations.
- Full Text:
- Date Issued: 1921
But is it publishable? Mastering the MMed message
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
- Authors: A G Parrish , E S Grossman,
- Date: 202
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3353 , vital:43318 , http://www.samj.org.za/index.php/samj/article/view/13033
- Description: The research requirement for South African specialist registration offers opportunities and challenges. For some clinicians it may spark a lifelong interest in clinical investigation, while for many others it may provide a potential publication opportunity. Integrating the specific requirements of an MMed mini-dissertation with those of standard medical publications can be difficult for first-time authors and their supervisors; published guidance caters to full-length laboratory Master’s or doctoral research. We suggest that research is more likely to be publishable if it is locally relevant, has a clear clinical message and is coherently presented.
- Full Text:
- Date Issued: 202
Essential medicine selection during the COVID-19 pandemic: Enabling access in uncharted territory
- Authors: A G Parrish
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3364 , vital:43319 , http://www.samj.org.za/index.php/samj/article/view/13086
- Description: The COVID-19 pandemic requires urgent decisions regarding treatment policy in the face of rapidly evolving evidence. In response, the South African Essential Medicines List Committee established a subcommittee to systematically review and appraise emerging evidence, within very short timelines, in order to inform the National Department of Health COVID-19 treatment guidelines. To date, the subcommittee has reviewed 14 potential treatments, and made recommendations based on local context, feasibility, resource requirements and equity. Here we describe the rapid review and evidence-to-decision process, using remdesivir and dexamethasone as examples. Our experience is that conducting rapid reviews is a practical and efficient way to address medicine policy questions under pandemic conditions.
- Full Text:
- Date Issued: 2020
- Authors: A G Parrish
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/3364 , vital:43319 , http://www.samj.org.za/index.php/samj/article/view/13086
- Description: The COVID-19 pandemic requires urgent decisions regarding treatment policy in the face of rapidly evolving evidence. In response, the South African Essential Medicines List Committee established a subcommittee to systematically review and appraise emerging evidence, within very short timelines, in order to inform the National Department of Health COVID-19 treatment guidelines. To date, the subcommittee has reviewed 14 potential treatments, and made recommendations based on local context, feasibility, resource requirements and equity. Here we describe the rapid review and evidence-to-decision process, using remdesivir and dexamethasone as examples. Our experience is that conducting rapid reviews is a practical and efficient way to address medicine policy questions under pandemic conditions.
- Full Text:
- Date Issued: 2020
The androgenic and anabolic effects of pine pollen on Nile tilapia (Oreochromis niloticus)
- Authors: Abaho, Ivan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431615 , vital:72790
- Description: Access restricted. Expected release date in 2025 , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Abaho, Ivan
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431615 , vital:72790
- Description: Access restricted. Expected release date in 2025 , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Effects of an eight-week lumbar stabilization exercise programme on selected variables of patients with chronic low back pain:
- Abass, Ademola O, Alli, Abiola R, Olagbegi, Oladapo M, Christie, Candice J, Bolarinde, Olufemi S
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
- Authors: Abass, Ademola O , Alli, Abiola R , Olagbegi, Oladapo M , Christie, Candice J , Bolarinde, Olufemi S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150307 , vital:38966 , DOI: https://doi.org/10.3329/bjms.v19i3.45864
- Description: Lumbar stabilisation exercise has been shown to reduce pain and disability in patients with low back pain but information on its potential benefits in term of back muscle endurance is scarce. This study was aimed at investigating the effects of augmenting conventional physiotherapy with lumbar stabilization exercises on selected variables of patients with non-specific chronic low back pain (NSCLBP).
- Full Text:
- Date Issued: 2020
Genetic and biological characterisation of a novel Plutella xylostella granulovirus, PlxyGV-SA
- Abdulkadir, Fatima, Knox, Caroline M, Marsberg, Tamryn, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Knox, Caroline M , Marsberg, Tamryn , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417971 , vital:71498 , xlink:href="https://doi.org/10.1007/s10526-015-9666-3"
- Description: Plutella xylostella granulovirus (PlxyGV) has been isolated from insect populations in many countries and is considered a potential biopesticide for sustainable control of P. xylostella (L.) (Lepidoptera: Plutellidae). Several PlxyGV isolates have been genetically characterised, and the full genome sequence of PlxyGV-Japan is available for comparison with novel isolates. A South African PlxyGV was recently recovered from an overcrowded laboratory P. xylostella colony and identified as a genetically distinct isolate by sequencing of the granulin gene and restriction endonuclease (REN) analysis of genomic DNA. In this report, PlxyGV-SA was further characterised by PCR amplification and sequencing of egt, lef-8 and lef-9 genes, and several amino acid substitutions were observed. The PstI REN profile of PlxyGV-SA was different from that of PlxyGV-Japan in terms of band size and number, thereby confirming its novel genetic identity. Surface dose bioassays showed that PlxyGV-SA is pathogenic to neonate but not late instar larvae at the same and higher virus doses, indicating that a biopesticide should be targeted at early larval stages in the field.
- Full Text:
- Date Issued: 2015
- Authors: Abdulkadir, Fatima , Knox, Caroline M , Marsberg, Tamryn , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417971 , vital:71498 , xlink:href="https://doi.org/10.1007/s10526-015-9666-3"
- Description: Plutella xylostella granulovirus (PlxyGV) has been isolated from insect populations in many countries and is considered a potential biopesticide for sustainable control of P. xylostella (L.) (Lepidoptera: Plutellidae). Several PlxyGV isolates have been genetically characterised, and the full genome sequence of PlxyGV-Japan is available for comparison with novel isolates. A South African PlxyGV was recently recovered from an overcrowded laboratory P. xylostella colony and identified as a genetically distinct isolate by sequencing of the granulin gene and restriction endonuclease (REN) analysis of genomic DNA. In this report, PlxyGV-SA was further characterised by PCR amplification and sequencing of egt, lef-8 and lef-9 genes, and several amino acid substitutions were observed. The PstI REN profile of PlxyGV-SA was different from that of PlxyGV-Japan in terms of band size and number, thereby confirming its novel genetic identity. Surface dose bioassays showed that PlxyGV-SA is pathogenic to neonate but not late instar larvae at the same and higher virus doses, indicating that a biopesticide should be targeted at early larval stages in the field.
- Full Text:
- Date Issued: 2015
Morphological and genetic characterization of a South African Plutella xylostella granulovirus (plxy GV) isolate
- Abdulkadir, Fatima, Marsberg, Tamryn, Knox, Caroline M, Hill, Martin P, Moore, Sean D
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
- Authors: Abdulkadir, Fatima , Marsberg, Tamryn , Knox, Caroline M , Hill, Martin P , Moore, Sean D
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406117 , vital:70240 , xlink:href="https://hdl.handle.net/10520/EJC132828"
- Description: Plutella xylostella (L.) (Lepidoptera: Plutellidae), also known as diamondback moth, is a destructive insect pest of cruciferous crops (Talekar and Shelton 1993; Shelton 2004). The pest occurs wherever its host plants are cultivated and the global annual cost of damage and control is estimated to be US$4-5 billion (Zalucki et al. 2012). The extensive use of synthetic pesticides for control combined with the high fecundity of P. xylostella has resulted in the pest developing resistance to nearly all classes of insecticides (Grzywacz et al. 2009). Moreover, these chemicals have negative environmental implications and may affect non-target species, some of which are natural enemies of the pest.
- Full Text:
- Date Issued: 2013
Optical surface quality and molecular dynamics modelling of ultra-high precision optical silicon machining
- Authors: Abdulkadir, Lukman Niyi
- Date: 2019-04
- Subjects: Engineering design -- Data processing , Manufacturing processes -- Data processing , Mechatronics
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/66552 , vital:75601
- Description: Hard and brittle materials, such as silicon, silicon carbide etc., are widely used in aerospace, integrated circuit, and other fields due to their excellent physical and chemical properties. However, these materials display poor machinability owing to hardness, brittleness, non-linearity in machining process and complexities in selecting suitable machining parameters and tool geometry. These leads to low quality lenses due to subsurface damage and surface micro-crack. Additionally, it is experimentally very difficult to observe all nanoscale physical phenomena due to in-process measurement problems, inaccessible contact area of tool and workpiece, and the difficulty of surface analysis. With the use of molecular dynamics (MD) which is a comprehensive nanoscale modelling technique, proper selection of process parameters, tool geometry and online monitoring techniques, production of freeform optics is possible through Ultra-high precision diamond turning (UHPDT). Though, depending on view point, machinability in UHPDT may be in terms of tool wear rate, hardness, chip morphology, surface roughness, and other benchmarks. These situations have called for more insights, which on the long run will help to achieve high precision manufacturing with predictability, repeatability, productivity and high infrared (IR) optical quality. In this thesis, UHPDT of monocrystalline silicon at atomistic scale was conducted to investigate combined effects of edge radius, feed rate, cutting speed, depth of cut, rake and clearance angles hitherto not done so far. Using appropriate potential functions with the MD algorithm, comprehensive analysis of thermal effects, diamond tool wear, phase change, cutting forces and machining stresses (normal, shear, hydrostatic and von Mises) were carried out. Dislocation extraction algorithm (DXA) and radial distribution function (RDF) were used to evaluate dislocation nucleation, variations in bond lengths, microstructural transformation and represents structural changes in histogram form. Selected parameters for optical quality surface roughness were afterwards compared and optimized through response surface methodology (RSM) based on Box Behnken (BBD) and Taguchi L9 methods. The results indicated that, silicon atoms in the chip formation zone undergo high pressure phase transformation (HPPT) at high hydrostatic pressure and temperature.Silicon microstructure transformed from four-coordinated diamond cubic structure (Si- I) to unstable six-coordinated body-centered tetragonal structure (β-silicon) which then transformed to amorphous silicon atoms (a-Si) through amorphization. These resulted in plastic deformation and defects in the machining zone causing subsurface damage. Stress analysis indicated that the compressive stress in the machining zone (i.e. amorphous region) suppressed crack formation contributing to continuous plastic flow which is responsible for silicon ductile-mode cutting. Furthermore, formation of silicon carbide which constituted diamond wear was observed to be by sp3 - sp2 diamond carbon atom disorder and tribochemistry. The tribochemistry occurred through both multiphase and solid-state single-phase reaction between diamond tool and silicon workpiece at cutting temperatures above and below 959 K. Both the experimental findings and the simulation results reveal that, at edge radius less than uncut chip thickness, tool wear was more of rake wear than flank wear. Tool wear and kinetic friction reduced as the edge radius approached the uncut chip thickness while forces, stresses and SCE increased. When machining silicon at differentratio, silicon stress state, SCE, SSD, forces (reduced with increase in clearance angle), shear plane, chip velocity and chip ratio increased as edge radius and rake angle increased, while, kinetic friction, chip length and thickness reduced. The crystal lattice of the machined surfaces and subsurface deformed layer depth increased with increase in edge radius, feed and rake angle. Amongst all tested and analysed parameters, feed rate had the highest influence on surface quality while depth of cut showed the least. Acoustic emission was also monitored during machining and its results statistically analysed. The trends of the monitored acoustic emissions showed its capability to adequately represent and predict surface roughness results. Based on the developed simulation model a novel method for quantitative assessment of tool wear was proposed. The proposed model can be used to compare tool wear using graphitization and tribochemistry to decide the path and mode of the diamond tool wear. Finally, based on the experiment results and predictive model, a novel combination and hierarchical arrangement of the considered factors capable of suppressing tool wear and improve attainable machined surface roughness when turning hard-to-machine materials was proposed. , Thesis (D.Phil) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2019
- Full Text:
- Date Issued: 2019-04
- Authors: Abdulkadir, Lukman Niyi
- Date: 2019-04
- Subjects: Engineering design -- Data processing , Manufacturing processes -- Data processing , Mechatronics
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/66552 , vital:75601
- Description: Hard and brittle materials, such as silicon, silicon carbide etc., are widely used in aerospace, integrated circuit, and other fields due to their excellent physical and chemical properties. However, these materials display poor machinability owing to hardness, brittleness, non-linearity in machining process and complexities in selecting suitable machining parameters and tool geometry. These leads to low quality lenses due to subsurface damage and surface micro-crack. Additionally, it is experimentally very difficult to observe all nanoscale physical phenomena due to in-process measurement problems, inaccessible contact area of tool and workpiece, and the difficulty of surface analysis. With the use of molecular dynamics (MD) which is a comprehensive nanoscale modelling technique, proper selection of process parameters, tool geometry and online monitoring techniques, production of freeform optics is possible through Ultra-high precision diamond turning (UHPDT). Though, depending on view point, machinability in UHPDT may be in terms of tool wear rate, hardness, chip morphology, surface roughness, and other benchmarks. These situations have called for more insights, which on the long run will help to achieve high precision manufacturing with predictability, repeatability, productivity and high infrared (IR) optical quality. In this thesis, UHPDT of monocrystalline silicon at atomistic scale was conducted to investigate combined effects of edge radius, feed rate, cutting speed, depth of cut, rake and clearance angles hitherto not done so far. Using appropriate potential functions with the MD algorithm, comprehensive analysis of thermal effects, diamond tool wear, phase change, cutting forces and machining stresses (normal, shear, hydrostatic and von Mises) were carried out. Dislocation extraction algorithm (DXA) and radial distribution function (RDF) were used to evaluate dislocation nucleation, variations in bond lengths, microstructural transformation and represents structural changes in histogram form. Selected parameters for optical quality surface roughness were afterwards compared and optimized through response surface methodology (RSM) based on Box Behnken (BBD) and Taguchi L9 methods. The results indicated that, silicon atoms in the chip formation zone undergo high pressure phase transformation (HPPT) at high hydrostatic pressure and temperature.Silicon microstructure transformed from four-coordinated diamond cubic structure (Si- I) to unstable six-coordinated body-centered tetragonal structure (β-silicon) which then transformed to amorphous silicon atoms (a-Si) through amorphization. These resulted in plastic deformation and defects in the machining zone causing subsurface damage. Stress analysis indicated that the compressive stress in the machining zone (i.e. amorphous region) suppressed crack formation contributing to continuous plastic flow which is responsible for silicon ductile-mode cutting. Furthermore, formation of silicon carbide which constituted diamond wear was observed to be by sp3 - sp2 diamond carbon atom disorder and tribochemistry. The tribochemistry occurred through both multiphase and solid-state single-phase reaction between diamond tool and silicon workpiece at cutting temperatures above and below 959 K. Both the experimental findings and the simulation results reveal that, at edge radius less than uncut chip thickness, tool wear was more of rake wear than flank wear. Tool wear and kinetic friction reduced as the edge radius approached the uncut chip thickness while forces, stresses and SCE increased. When machining silicon at differentratio, silicon stress state, SCE, SSD, forces (reduced with increase in clearance angle), shear plane, chip velocity and chip ratio increased as edge radius and rake angle increased, while, kinetic friction, chip length and thickness reduced. The crystal lattice of the machined surfaces and subsurface deformed layer depth increased with increase in edge radius, feed and rake angle. Amongst all tested and analysed parameters, feed rate had the highest influence on surface quality while depth of cut showed the least. Acoustic emission was also monitored during machining and its results statistically analysed. The trends of the monitored acoustic emissions showed its capability to adequately represent and predict surface roughness results. Based on the developed simulation model a novel method for quantitative assessment of tool wear was proposed. The proposed model can be used to compare tool wear using graphitization and tribochemistry to decide the path and mode of the diamond tool wear. Finally, based on the experiment results and predictive model, a novel combination and hierarchical arrangement of the considered factors capable of suppressing tool wear and improve attainable machined surface roughness when turning hard-to-machine materials was proposed. , Thesis (D.Phil) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2019
- Full Text:
- Date Issued: 2019-04
Optical surface quality and molecular dynamics modelling of ultra-high precision optical silicon machining
- Authors: Abdulkadir, Lukman Niyi
- Date: 2019-04
- Subjects: Lasers -- Industrial applications , Manufacturing processes , Materials science
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/66551 , vital:75600
- Description: Hard and brittle materials, such as silicon, silicon carbide etc., are widely used in aerospace, integrated circuit, and other fields due to their excellent physical and chemical properties. However, these materials display poor machinability owing to hardness, brittleness, non-linearity in machining process and complexities in selecting suitable machining parameters and tool geometry. These leads to low quality lenses due to subsurface damage and surface micro-crack. Additionally, it is experimentally very difficult to observe all nanoscale physical phenomena due to in-process measurement problems, inaccessible contact area of tool and workpiece, and the difficulty of surface analysis. With the use of molecular dynamics (MD) which is a comprehensive nanoscale modelling technique, proper selection of process parameters, tool geometry and online monitoring techniques, production of freeform optics is possible through Ultra-high precision diamond turning (UHPDT). Though, depending on view point, machinability in UHPDT may be in terms of tool wear rate, hardness, chip morphology, surface roughness, and other benchmarks. These situations have called for more insights, which on the long run will help to achieve high precision manufacturing with predictability, repeatability, productivity and high infrared (IR) optical quality. In this thesis, UHPDT of monocrystalline silicon at atomistic scale was conducted to investigate combined effects of edge radius, feed rate, cutting speed, depth of cut, rake and clearance angles hitherto not done so far. Using appropriate potential functions with the MD algorithm, comprehensive analysis of thermal effects, diamond tool wear, phase change, cutting forces and machining stresses (normal, shear, hydrostatic and von Mises) were carried out. Dislocation extraction algorithm (DXA) and radial distribution function (RDF) were used to evaluate dislocation nucleation, variations in bond lengths, microstructural transformation and represents structural changes in histogram form. Selected parameters for optical quality surface roughness were afterwards compared and optimized through response surface methodology (RSM) based on Box Behnken (BBD) and Taguchi L9 methods. The results indicated that, silicon atoms in the chip formation zone undergo high pressure phase transformation (HPPT) at high hydrostatic pressure and temperature Silicon microstructure transformed from four-coordinated diamond cubic structure (Si-I) to unstable six-coordinated body-centered tetragonal structure (β-silicon) which then transformed to amorphous silicon atoms (a-Si) through amorphization. These resulted in plastic deformation and defects in the machining zone causing subsurface damage. Stress analysis indicated that the compressive stress in the machining zone (i.e.amorphous region) suppressed crack formation contributing to continuous plastic flow which is responsible for silicon ductile-mode cutting. Furthermore, formation of silicon carbide which constituted diamond wear was observed to be by sp3 - sp2 diamond carbon atom disorder and tribochemistry. The tribochemistry occurred through both multiphase and solid-state single-phase reaction between diamond tool and silicon workpiece at cutting temperatures above and below 959 K. Both the experimental findings and the simulation results reveal that, at edge radius less than uncut chip thickness, tool wear was more of rake wear than flank wear. Tool wear and kinetic friction reduced as the edge radius approached the uncut chip thickness while forces, stresses and SCE increased. When machining silicon at different ratio, silicon stress state, SCE, SSD, forces (reduced with increase in clearance angle), shear plane, chip velocity and chip ratio increased as edge radius and rake angle increased, while, kinetic friction, chip length and thickness reduced. The crystal lattice of the machined surfaces and subsurface deformed layer depth increased with increase in edge radius, feed and rake angle. Amongst all tested and analysed parameters, feed rate had the highest influence on surface quality while depth of cut showed the least. Acoustic emission was also monitored during machining and its results statistically analysed. The trends of the monitored acoustic emissions showed its capability to adequately represent and predict surface roughness results. Based on the developed simulation model a novel method for quantitative assessment of tool wear was proposed. The proposed model can be used to compare tool wear using graphitization and tribochemistry to decide the path and mode of the diamond tool wear. Finally, based on the experiment results and predictive model, a novel combination and hierarchical arrangement of the considered factors capable of suppressing tool wear and improve attainable machined surface roughness when turning hard-to-machine materials was proposed. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2019
- Full Text:
- Date Issued: 2019-04
- Authors: Abdulkadir, Lukman Niyi
- Date: 2019-04
- Subjects: Lasers -- Industrial applications , Manufacturing processes , Materials science
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/66551 , vital:75600
- Description: Hard and brittle materials, such as silicon, silicon carbide etc., are widely used in aerospace, integrated circuit, and other fields due to their excellent physical and chemical properties. However, these materials display poor machinability owing to hardness, brittleness, non-linearity in machining process and complexities in selecting suitable machining parameters and tool geometry. These leads to low quality lenses due to subsurface damage and surface micro-crack. Additionally, it is experimentally very difficult to observe all nanoscale physical phenomena due to in-process measurement problems, inaccessible contact area of tool and workpiece, and the difficulty of surface analysis. With the use of molecular dynamics (MD) which is a comprehensive nanoscale modelling technique, proper selection of process parameters, tool geometry and online monitoring techniques, production of freeform optics is possible through Ultra-high precision diamond turning (UHPDT). Though, depending on view point, machinability in UHPDT may be in terms of tool wear rate, hardness, chip morphology, surface roughness, and other benchmarks. These situations have called for more insights, which on the long run will help to achieve high precision manufacturing with predictability, repeatability, productivity and high infrared (IR) optical quality. In this thesis, UHPDT of monocrystalline silicon at atomistic scale was conducted to investigate combined effects of edge radius, feed rate, cutting speed, depth of cut, rake and clearance angles hitherto not done so far. Using appropriate potential functions with the MD algorithm, comprehensive analysis of thermal effects, diamond tool wear, phase change, cutting forces and machining stresses (normal, shear, hydrostatic and von Mises) were carried out. Dislocation extraction algorithm (DXA) and radial distribution function (RDF) were used to evaluate dislocation nucleation, variations in bond lengths, microstructural transformation and represents structural changes in histogram form. Selected parameters for optical quality surface roughness were afterwards compared and optimized through response surface methodology (RSM) based on Box Behnken (BBD) and Taguchi L9 methods. The results indicated that, silicon atoms in the chip formation zone undergo high pressure phase transformation (HPPT) at high hydrostatic pressure and temperature Silicon microstructure transformed from four-coordinated diamond cubic structure (Si-I) to unstable six-coordinated body-centered tetragonal structure (β-silicon) which then transformed to amorphous silicon atoms (a-Si) through amorphization. These resulted in plastic deformation and defects in the machining zone causing subsurface damage. Stress analysis indicated that the compressive stress in the machining zone (i.e.amorphous region) suppressed crack formation contributing to continuous plastic flow which is responsible for silicon ductile-mode cutting. Furthermore, formation of silicon carbide which constituted diamond wear was observed to be by sp3 - sp2 diamond carbon atom disorder and tribochemistry. The tribochemistry occurred through both multiphase and solid-state single-phase reaction between diamond tool and silicon workpiece at cutting temperatures above and below 959 K. Both the experimental findings and the simulation results reveal that, at edge radius less than uncut chip thickness, tool wear was more of rake wear than flank wear. Tool wear and kinetic friction reduced as the edge radius approached the uncut chip thickness while forces, stresses and SCE increased. When machining silicon at different ratio, silicon stress state, SCE, SSD, forces (reduced with increase in clearance angle), shear plane, chip velocity and chip ratio increased as edge radius and rake angle increased, while, kinetic friction, chip length and thickness reduced. The crystal lattice of the machined surfaces and subsurface deformed layer depth increased with increase in edge radius, feed and rake angle. Amongst all tested and analysed parameters, feed rate had the highest influence on surface quality while depth of cut showed the least. Acoustic emission was also monitored during machining and its results statistically analysed. The trends of the monitored acoustic emissions showed its capability to adequately represent and predict surface roughness results. Based on the developed simulation model a novel method for quantitative assessment of tool wear was proposed. The proposed model can be used to compare tool wear using graphitization and tribochemistry to decide the path and mode of the diamond tool wear. Finally, based on the experiment results and predictive model, a novel combination and hierarchical arrangement of the considered factors capable of suppressing tool wear and improve attainable machined surface roughness when turning hard-to-machine materials was proposed. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2019
- Full Text:
- Date Issued: 2019-04
Pyridone substituted phthalocyanines: Photophysico-chemical properties and TD-DFT calculations
- Abdurrahmanoğlu, Şaziye, Canlica, Mevlüde, Mack, John, Nyokong, Tebello
- Authors: Abdurrahmanoğlu, Şaziye , Canlica, Mevlüde , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188216 , vital:44735 , xlink:href="https://doi.org/10.1142/S1088424617500730"
- Description: 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile has been used to prepare a novel Zn(II) phthalocyanines with four peripheral pyridone substituents. The compound has been characterized by UV-visible absorption, FT-IR and 11H-NMR spectroscopy, elemental analysis and MALDI-TOF mass spectroscopy. The fluorescence, triplet quantum and singlet oxygen quantum yields have been determined and TD-DFT calculations have been used to identify trends in the electronic structure.
- Full Text:
- Date Issued: 2018
- Authors: Abdurrahmanoğlu, Şaziye , Canlica, Mevlüde , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188216 , vital:44735 , xlink:href="https://doi.org/10.1142/S1088424617500730"
- Description: 4-(6-methyl-3-nitro-2-oxo-1,2-dihydropyridin-4-yloxy)phthalonitrile has been used to prepare a novel Zn(II) phthalocyanines with four peripheral pyridone substituents. The compound has been characterized by UV-visible absorption, FT-IR and 11H-NMR spectroscopy, elemental analysis and MALDI-TOF mass spectroscopy. The fluorescence, triplet quantum and singlet oxygen quantum yields have been determined and TD-DFT calculations have been used to identify trends in the electronic structure.
- Full Text:
- Date Issued: 2018
Conjuring our beings: Stacey Gillian Abe and Immy Mali in conversational partnership
- Abe, Stacey Gillian, Mali, Immy
- Authors: Abe, Stacey Gillian , Mali, Immy
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145963 , vital:38482 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00457
- Description: The series of Conversational Partnerships began in 2017 in African Arts vol. 50, no. 2, with a conversation between two artists: Eria Nsubuga SANE from Uganda and Sikhumbuzo Makandula from South Africa. The format of a “conversational partnership” (Rubin and Rubin 2012: 7) emphasizes the cocreation of meaning by the interviewer and interviewee as coauthors. This enables a move away from the art history format of the interviewer (usually a writer) assuming the role of the sole author and the interviewee (often an artist) having no status as an author despite the fact that her or his practice-led creation of knowledge is foundational to the content of the interview. Stacey Gillian Abe and Immy Mali participated in a joint artists' residency as part of the RAW program at Rhodes University in South Africa from November to December 2017. During this time, they engaged with each other's practice-led work, and they created this conversational partnership at a writing breakaway in the Eastern Cape.
- Full Text:
- Date Issued: 2019
- Authors: Abe, Stacey Gillian , Mali, Immy
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145963 , vital:38482 , https://0-doi.org.wam.seals.ac.za/10.1162/afar_a_00457
- Description: The series of Conversational Partnerships began in 2017 in African Arts vol. 50, no. 2, with a conversation between two artists: Eria Nsubuga SANE from Uganda and Sikhumbuzo Makandula from South Africa. The format of a “conversational partnership” (Rubin and Rubin 2012: 7) emphasizes the cocreation of meaning by the interviewer and interviewee as coauthors. This enables a move away from the art history format of the interviewer (usually a writer) assuming the role of the sole author and the interviewee (often an artist) having no status as an author despite the fact that her or his practice-led creation of knowledge is foundational to the content of the interview. Stacey Gillian Abe and Immy Mali participated in a joint artists' residency as part of the RAW program at Rhodes University in South Africa from November to December 2017. During this time, they engaged with each other's practice-led work, and they created this conversational partnership at a writing breakaway in the Eastern Cape.
- Full Text:
- Date Issued: 2019
An analytical study of narrative techniques in Giono's Regain
- Authors: Abel, Hermione
- Date: 1986
- Subjects: French fiction , Novels , Criticism , Symbolism , Regain , Giono, Jean, 1895-1970 -- Criticism and interpretation
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3561 , http://hdl.handle.net/10962/d1002008
- Description: The dominant theme in Regain is that of death leading to rebirth. This dissertation attempts to explore Giono's narrative techniques within this context. No single chapter will be devoted to a specific technique; instead, the various devices used by the author are discussed as they emerge from the structure of the chapters. Justifying the field of study as defined in the "Introduction", the following three chapters outline the passage of life from death to eventual rebirth. With acknowledgement to Frank Kermode, who writes: "A concord of past, present and future three dreams which, as Augustine said, cross in our minds, as in the present of things past, the present of things present, and the present of things future" ¹, the first three chapters bear his terminology for their headings. Chapter One, "The Present of Things Past", deals with Mameche's loss of her husband and son. Chapter Two, "The Present of Things Present", focuses upon Mameche' s realization of Gaubert's departure, and the decision that she must do something to save the dying village of Aubignane. Chapter Three, "The Present of Things Future", sees Mameche setting out in search of a wife for Panturle, and succeeding. This brings to an end Part One of the novel. Interwoven throughout the chapters are paradigms from Greek mythology, rich in universal symbolism, and the author's belief in man's ability to fuse himself with his surroundings. The conclusion summarizes the findings of this study, attempting to show how an analysis of Giono's narrative technique provides an insight into such a novel as Regain. ¹The Sense of an Ending (London: Oxford University Press, 1966), rpt., 1970, p. 50.
- Full Text:
- Date Issued: 1986
- Authors: Abel, Hermione
- Date: 1986
- Subjects: French fiction , Novels , Criticism , Symbolism , Regain , Giono, Jean, 1895-1970 -- Criticism and interpretation
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3561 , http://hdl.handle.net/10962/d1002008
- Description: The dominant theme in Regain is that of death leading to rebirth. This dissertation attempts to explore Giono's narrative techniques within this context. No single chapter will be devoted to a specific technique; instead, the various devices used by the author are discussed as they emerge from the structure of the chapters. Justifying the field of study as defined in the "Introduction", the following three chapters outline the passage of life from death to eventual rebirth. With acknowledgement to Frank Kermode, who writes: "A concord of past, present and future three dreams which, as Augustine said, cross in our minds, as in the present of things past, the present of things present, and the present of things future" ¹, the first three chapters bear his terminology for their headings. Chapter One, "The Present of Things Past", deals with Mameche's loss of her husband and son. Chapter Two, "The Present of Things Present", focuses upon Mameche' s realization of Gaubert's departure, and the decision that she must do something to save the dying village of Aubignane. Chapter Three, "The Present of Things Future", sees Mameche setting out in search of a wife for Panturle, and succeeding. This brings to an end Part One of the novel. Interwoven throughout the chapters are paradigms from Greek mythology, rich in universal symbolism, and the author's belief in man's ability to fuse himself with his surroundings. The conclusion summarizes the findings of this study, attempting to show how an analysis of Giono's narrative technique provides an insight into such a novel as Regain. ¹The Sense of an Ending (London: Oxford University Press, 1966), rpt., 1970, p. 50.
- Full Text:
- Date Issued: 1986
In vitro investigation of the anti-hyperglycemic and chemical composition of Heteromorpha arborescens (Spreng.) Cham leaf extracts used in the management of diabetes mellitus
- Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Authors: Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Date: 2021-09
- Subjects: Diabetes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22798 , vital:52760
- Description: Diabetes mellitus is currently a major threat all over the world. It is a chronic disorder characterized by elevated blood glucose levels and disturbance in carbohydrate, fat and protein metabolism which often times leads to several complications such as, atherosclerosis, diabetic nephropathy, retinopathy and neuropathy. Due to the side effects associated with synthetic oral hypoglycemic drugs, herbal remedies have become the alternative in the management of diabetes mellitus. Heteromorpha arborescens is one of the many plants used as herbal remedies for the management of diabetes mellitus in South Africa. In addition, the roots, barks and leaves are used in other parts of Southern Africa for the treatment of mental problems, asthma, cough, dysentery and tuberculosis. The roots are fed to malnourished children in Botswana and Swaziland. However, despite the high medicinal importance, there is little or no scientificinformation to prove this claim. Therefore, the basis of this study is to determine the chemical composition as well as perform and invitro investigation of the antihyperglycemic potential of H. arborescens leaf extracts to provide information that could validate the ethno-medicinal claims for the use of this plant in the management of diabetes mellitus. Phytochemical contents and antioxidant activity of the leaf extracts were determined. Phytochemical analysis of the acetone, ethanol, aqueous and blanched extracts of H. arborescens leaves indicated that the total phenol content of the extracts ranged between 15.10 mg GAE/g- 42.50 mg QAE/g, proanthocyanidin, 459-8402.1 mg QE/g and the flavonoid content, 109.24- 235.79 mg QE/g. In addition, alkaloids (7.65percent) and saponin (25.33percent) were present in significantamounts. Based on the IC50 values, the ethanol extract exhibited the highest total antioxidant activity (0.0125 mg/mL) with highest inhibition against DPPH and ABTS radicals (0.06 and 0.049 mg/mL respectively). Relatively high antioxidant activity may be attributed to the polyphenolic contents which possess hypoglycemic potentials. Minimum Inhibitory Concentrations (MIC) of H. arborescens leaf extracts against Bacillus pumilus, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebselia pneumoniae was also determined and results indicated considerable antibacterial activity in the acetone, ethanol and blanched extracts with MIC values ranging from 1.563-12.5 mg/mL; however, the aqueous extract was inactive against all the bacteria strains. The antibacterial activity of the leaf extracts could be advantageous against diabetic related infections. The cytotoxicity, anti-obesity and antidiabetic potentials of blanched, aqueous and ethanol extracts of Heteromorpha arborescens (Spreng.) Cham leaves were also investigated. The results revealed that both ethanol and aqueous extracts indicated considerable inhibition against α-glucosidase (IC50 of 627.29 ± 4.33 μg/mL and 576.46 ± 3.21 μg/mL respectively) while the blanched extract showed weak α- glucosidase inhibition (IC50; 855.38 ± 4.29 μg/mL). The aqueous extract showed the best α- amylase inhibition (IC50; 583.74 ± 5.87 μg/mL) among the assessed extracts. However, weak α- amylase inhibition was observed in the ethanol (IC50; 724.60 ± 4.33 μg/mL) and blanched extracts (IC50; 791.63 ± 3.76 μg/mL) of H. arborescens leaves. Some level of glucose utilization in both C3A and L6 cells was also observed for the aqueous and ethanol extracts which may be attributed to the relatively lower toxicity levels present in them, however, glucose utilization was very weak for the blanched extract, which may be due to higher level of cytotoxicity it possessed. Relatively weak lipase inhibition was observed for the ethanol (IC50; 699.3 ± 1.33 μg/mL), aqueous (IC50; 811.52 ± 3.52 μg/mL) and blanched extract (IC50; 1152.7 ± 4.61 μg/mL) as compared to orlistat (IC50; 56.88 ± 0.11 μg/mL). However, there was no reasonable reduction in lipid accumulation observed in all the extract treated cells. The results obtained suggest that H.arborescens leaf extracts can serve as a potential tool for the development of new strategies for the treatment of diabetes and obesity. However, further analysis is required to ascertain its anti- obesity potential. Also, caution should be taken in the use of the plant at high concentrations in order to ensure safety and efficacy. Analyses were also carried out to determine the nutritional and antinutritional constituents of the plant for possible inclusion in the diet of diabetic patients. Proximate analysis revealed the presence of 8.5 percent total ash, 4.92 percent crude fat, 8.41 percent moisture, 15.74 percent crude protein, 21.48 percent crude fiber, 40.95 percent carbohydrates and 271.04 kcal/100g energy value. Mineral analysis showed that H. arborescens leaves are very rich in K, Ca, and Fe. Considerable amounts of Mg, Mn, Na, P, Cu and Zn were also present. Vitamin analysis showed that the plant has a high content of vitamins A, C and E. The anti-nutrients evaluated were phytate, oxalate, saponin, and alkaloids, all of which were below toxic levels except for saponin which was observed in moderately high level. This study revealed that H. arborescens leaves are a good source of nutrients and mineral elements, (with low anti-nutrient content) that are highly beneficial to human health especially in diabetic individuals, therefore, encouraging its possible inclusion as a vegetable. Essential oil composition of fresh Heteromorphaarborescens leaves were also determined by Solvent-Free-Microwave-Extraction (SFME) and Hydrodistillation (HD) methods and the compositions of both mehods were compared in terms of their chemical compositions, yield, CO2 emission and energy consumption. Solvent Free Microwave extraction method indicated higher oil yield of 0.7 mL/200 g (0.35 percent) as compared to 0.59 mL/200 g (0.295 percent), lower energy consumption and CO2 emission as compared to the hydrodistillation method. In conclusion, H. arborescens leaves indicated considerable potential efficacy in the management for diabetes mellitus and may require further structural elucidation and characterization in order to identify the bioactive constituents. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
- Authors: Abifarin, Taiwo Oluwafunmilola https://orcid.org/00000003-4994-4638
- Date: 2021-09
- Subjects: Diabetes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22798 , vital:52760
- Description: Diabetes mellitus is currently a major threat all over the world. It is a chronic disorder characterized by elevated blood glucose levels and disturbance in carbohydrate, fat and protein metabolism which often times leads to several complications such as, atherosclerosis, diabetic nephropathy, retinopathy and neuropathy. Due to the side effects associated with synthetic oral hypoglycemic drugs, herbal remedies have become the alternative in the management of diabetes mellitus. Heteromorpha arborescens is one of the many plants used as herbal remedies for the management of diabetes mellitus in South Africa. In addition, the roots, barks and leaves are used in other parts of Southern Africa for the treatment of mental problems, asthma, cough, dysentery and tuberculosis. The roots are fed to malnourished children in Botswana and Swaziland. However, despite the high medicinal importance, there is little or no scientificinformation to prove this claim. Therefore, the basis of this study is to determine the chemical composition as well as perform and invitro investigation of the antihyperglycemic potential of H. arborescens leaf extracts to provide information that could validate the ethno-medicinal claims for the use of this plant in the management of diabetes mellitus. Phytochemical contents and antioxidant activity of the leaf extracts were determined. Phytochemical analysis of the acetone, ethanol, aqueous and blanched extracts of H. arborescens leaves indicated that the total phenol content of the extracts ranged between 15.10 mg GAE/g- 42.50 mg QAE/g, proanthocyanidin, 459-8402.1 mg QE/g and the flavonoid content, 109.24- 235.79 mg QE/g. In addition, alkaloids (7.65percent) and saponin (25.33percent) were present in significantamounts. Based on the IC50 values, the ethanol extract exhibited the highest total antioxidant activity (0.0125 mg/mL) with highest inhibition against DPPH and ABTS radicals (0.06 and 0.049 mg/mL respectively). Relatively high antioxidant activity may be attributed to the polyphenolic contents which possess hypoglycemic potentials. Minimum Inhibitory Concentrations (MIC) of H. arborescens leaf extracts against Bacillus pumilus, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli and Klebselia pneumoniae was also determined and results indicated considerable antibacterial activity in the acetone, ethanol and blanched extracts with MIC values ranging from 1.563-12.5 mg/mL; however, the aqueous extract was inactive against all the bacteria strains. The antibacterial activity of the leaf extracts could be advantageous against diabetic related infections. The cytotoxicity, anti-obesity and antidiabetic potentials of blanched, aqueous and ethanol extracts of Heteromorpha arborescens (Spreng.) Cham leaves were also investigated. The results revealed that both ethanol and aqueous extracts indicated considerable inhibition against α-glucosidase (IC50 of 627.29 ± 4.33 μg/mL and 576.46 ± 3.21 μg/mL respectively) while the blanched extract showed weak α- glucosidase inhibition (IC50; 855.38 ± 4.29 μg/mL). The aqueous extract showed the best α- amylase inhibition (IC50; 583.74 ± 5.87 μg/mL) among the assessed extracts. However, weak α- amylase inhibition was observed in the ethanol (IC50; 724.60 ± 4.33 μg/mL) and blanched extracts (IC50; 791.63 ± 3.76 μg/mL) of H. arborescens leaves. Some level of glucose utilization in both C3A and L6 cells was also observed for the aqueous and ethanol extracts which may be attributed to the relatively lower toxicity levels present in them, however, glucose utilization was very weak for the blanched extract, which may be due to higher level of cytotoxicity it possessed. Relatively weak lipase inhibition was observed for the ethanol (IC50; 699.3 ± 1.33 μg/mL), aqueous (IC50; 811.52 ± 3.52 μg/mL) and blanched extract (IC50; 1152.7 ± 4.61 μg/mL) as compared to orlistat (IC50; 56.88 ± 0.11 μg/mL). However, there was no reasonable reduction in lipid accumulation observed in all the extract treated cells. The results obtained suggest that H.arborescens leaf extracts can serve as a potential tool for the development of new strategies for the treatment of diabetes and obesity. However, further analysis is required to ascertain its anti- obesity potential. Also, caution should be taken in the use of the plant at high concentrations in order to ensure safety and efficacy. Analyses were also carried out to determine the nutritional and antinutritional constituents of the plant for possible inclusion in the diet of diabetic patients. Proximate analysis revealed the presence of 8.5 percent total ash, 4.92 percent crude fat, 8.41 percent moisture, 15.74 percent crude protein, 21.48 percent crude fiber, 40.95 percent carbohydrates and 271.04 kcal/100g energy value. Mineral analysis showed that H. arborescens leaves are very rich in K, Ca, and Fe. Considerable amounts of Mg, Mn, Na, P, Cu and Zn were also present. Vitamin analysis showed that the plant has a high content of vitamins A, C and E. The anti-nutrients evaluated were phytate, oxalate, saponin, and alkaloids, all of which were below toxic levels except for saponin which was observed in moderately high level. This study revealed that H. arborescens leaves are a good source of nutrients and mineral elements, (with low anti-nutrient content) that are highly beneficial to human health especially in diabetic individuals, therefore, encouraging its possible inclusion as a vegetable. Essential oil composition of fresh Heteromorphaarborescens leaves were also determined by Solvent-Free-Microwave-Extraction (SFME) and Hydrodistillation (HD) methods and the compositions of both mehods were compared in terms of their chemical compositions, yield, CO2 emission and energy consumption. Solvent Free Microwave extraction method indicated higher oil yield of 0.7 mL/200 g (0.35 percent) as compared to 0.59 mL/200 g (0.295 percent), lower energy consumption and CO2 emission as compared to the hydrodistillation method. In conclusion, H. arborescens leaves indicated considerable potential efficacy in the management for diabetes mellitus and may require further structural elucidation and characterization in order to identify the bioactive constituents. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-09
International legal protection of women's reproductive rights: a comparative analysis of abortion laws and policies in four jurisdictions-Nigeria, Ghana, South Africa and U.S.A.
- Authors: Abiodun, Adeleke Funminiyi
- Date: 2010-10
- Subjects: Abortion -- Law and legislation , Reproductive right
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25839 , vital:64491
- Description: The subject matter of abortion law is extremely broad and multi-disciplinary. While naturally having its basis in criminal and constitutional law of individual states, the global development of abortion discourse has been influenced by the need to protect the reproductive rights of women as a sub-set of international human rights laws; thereby advocating not only the decriminalisation of abortion but also, that individual State should take affirmative actions in promoting abortion as a right for every woman. However, that induced abortion is a punishable criminal act or a “protectable” woman’s reproductive right remains controversial due to the plethora of perspectives, beliefs and reservations held by different groups of people which are multi-dimensional and contradictory. This thesis therefore attempts a comparative study of abortion laws and policies in four jurisdictions: Nigeria and Ghana, operating criminalised abortion laws, South Africa and United States which operate liberalised/permissive abortion laws and policies. The study basically examines the legal status and reproductive rights of women to legal and safe abortion within the existing legal framework of national laws of the four selected jurisdictions vis-à-vis the legal protection offered by various international instruments on human rights. While we show that strict and restrictive abortion laws, and also, failure of States to create conditions for safe abortion constitute infractions of the reproductive rights of women, we submit further that over-liberalisation of abortion laws and policies could also amount to infringement of the basic rights of other people, thus there is need to ensure a legal and acceptable balance. The study finally acknowledges the role of international human rights laws in the protection of women’s right to legal and safe abortion but asserts that there can be no universally acceptable morality to which the whole world could subsume in term of women’s right to abortion due to the interplay of socio-cultural, religious, and moral affiliations of the people in different communities. , Thesis (LLD) -- Faculty of Law, 2010
- Full Text:
- Date Issued: 2010-10
- Authors: Abiodun, Adeleke Funminiyi
- Date: 2010-10
- Subjects: Abortion -- Law and legislation , Reproductive right
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/25839 , vital:64491
- Description: The subject matter of abortion law is extremely broad and multi-disciplinary. While naturally having its basis in criminal and constitutional law of individual states, the global development of abortion discourse has been influenced by the need to protect the reproductive rights of women as a sub-set of international human rights laws; thereby advocating not only the decriminalisation of abortion but also, that individual State should take affirmative actions in promoting abortion as a right for every woman. However, that induced abortion is a punishable criminal act or a “protectable” woman’s reproductive right remains controversial due to the plethora of perspectives, beliefs and reservations held by different groups of people which are multi-dimensional and contradictory. This thesis therefore attempts a comparative study of abortion laws and policies in four jurisdictions: Nigeria and Ghana, operating criminalised abortion laws, South Africa and United States which operate liberalised/permissive abortion laws and policies. The study basically examines the legal status and reproductive rights of women to legal and safe abortion within the existing legal framework of national laws of the four selected jurisdictions vis-à-vis the legal protection offered by various international instruments on human rights. While we show that strict and restrictive abortion laws, and also, failure of States to create conditions for safe abortion constitute infractions of the reproductive rights of women, we submit further that over-liberalisation of abortion laws and policies could also amount to infringement of the basic rights of other people, thus there is need to ensure a legal and acceptable balance. The study finally acknowledges the role of international human rights laws in the protection of women’s right to legal and safe abortion but asserts that there can be no universally acceptable morality to which the whole world could subsume in term of women’s right to abortion due to the interplay of socio-cultural, religious, and moral affiliations of the people in different communities. , Thesis (LLD) -- Faculty of Law, 2010
- Full Text:
- Date Issued: 2010-10
Perceptions of social media as a tool for research: a study of postgraduate students, University of Fort Hare, Alice campus
- Authors: Abolanle, Ogunnubi Adeyemi
- Date: 2014-10
- Subjects: University of Fort Hare , Media literacy , Internet research
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26381 , vital:65299
- Description: The study aimed at examining the perceptions of social media as a tool for research among postgraduate students at the University of Fort Hare, Alice campus. Data were collected using a quantitative research approach by administering structured questionnaires to 310 postgraduate students under the cluster sampling across different faculties and departments, and analysed by SPSS Statistical software and Chi-square test. 264 questionnaires were returned for analysis and these respondents maintained that they utilized social media platforms for their academic research. The findings further revealed that social media has to a large extent improved students‟ research activities as they frequently seek practical knowledge for demonstration and tutorship. Furthermore, the respondents regard social media as a good platform for research topics in audio and video formats, scholarly articles, journals and books. This study concluded that since students explore the social media platforms and search engines for various reasons, academic research inclusive, it therefore becomes imperative to create more links within the social media for students to explore books, scholarly journals and articles necessary for research and academic purposes. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2014
- Full Text:
- Date Issued: 2014-10
- Authors: Abolanle, Ogunnubi Adeyemi
- Date: 2014-10
- Subjects: University of Fort Hare , Media literacy , Internet research
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26381 , vital:65299
- Description: The study aimed at examining the perceptions of social media as a tool for research among postgraduate students at the University of Fort Hare, Alice campus. Data were collected using a quantitative research approach by administering structured questionnaires to 310 postgraduate students under the cluster sampling across different faculties and departments, and analysed by SPSS Statistical software and Chi-square test. 264 questionnaires were returned for analysis and these respondents maintained that they utilized social media platforms for their academic research. The findings further revealed that social media has to a large extent improved students‟ research activities as they frequently seek practical knowledge for demonstration and tutorship. Furthermore, the respondents regard social media as a good platform for research topics in audio and video formats, scholarly articles, journals and books. This study concluded that since students explore the social media platforms and search engines for various reasons, academic research inclusive, it therefore becomes imperative to create more links within the social media for students to explore books, scholarly journals and articles necessary for research and academic purposes. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2014
- Full Text:
- Date Issued: 2014-10
Ultra-high precision manufacturing
- Authors: Abou-El-Hossein, Khaled
- Subjects: Machining , Diamond turning , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20878 , vital:29410
- Description: One of the engineering areas focusing on the research and development of highvalue components and manufacturing technologies is precision engineering. Precision engineering represents a variety of engineering and science disciplines ranging from areas such as mechanical, electronics and industrial engineering to chemistry, physics, optics and materials science. This paper aims at familiarising the reader with the recent advances in ultra-high precision manufacturing technologies and their applications for the production of various critical components employed in different sectors of the industry. In this paper, the principles of ultra-high precision manufacturing will be discussed followed by examples of its use in various industrial applications. The status of ultra-high precision manufacturing in terms of current research issues and future trends will be discussed. In addition, research activities and projects in the area of precision manufacturing that are currently conducted at the NMMU will be also highlighted. Finally, the author looks forward to presenting herewith comprehensive information that could be useful to the reader and easy to understand by the bigger NMMU’s community.
- Full Text:
- Authors: Abou-El-Hossein, Khaled
- Subjects: Machining , Diamond turning , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20878 , vital:29410
- Description: One of the engineering areas focusing on the research and development of highvalue components and manufacturing technologies is precision engineering. Precision engineering represents a variety of engineering and science disciplines ranging from areas such as mechanical, electronics and industrial engineering to chemistry, physics, optics and materials science. This paper aims at familiarising the reader with the recent advances in ultra-high precision manufacturing technologies and their applications for the production of various critical components employed in different sectors of the industry. In this paper, the principles of ultra-high precision manufacturing will be discussed followed by examples of its use in various industrial applications. The status of ultra-high precision manufacturing in terms of current research issues and future trends will be discussed. In addition, research activities and projects in the area of precision manufacturing that are currently conducted at the NMMU will be also highlighted. Finally, the author looks forward to presenting herewith comprehensive information that could be useful to the reader and easy to understand by the bigger NMMU’s community.
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Exploring targeted metagenomics and untargeted metabolomics for characterising aquaponics bacterial ecology and phytochemistry
- Authors: Abraham, Benjamin Melakail
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192453 , vital:45227
- Description: Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Abraham, Benjamin Melakail
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192453 , vital:45227
- Description: Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
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- Date Issued: 2021-10-29
An exploration into an ESD-based teaching strategy to improve the critical thinking and problem-solving skills amongst development studies students at Nelson Mandela University
- Authors: Abrahams, Andre John
- Date: 2021-04
- Subjects: Sustainable development -- Study and teaching , Universities and colleges -- South Africa , Critical thinking
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50906 , vital:43149
- Description: In recent years, Education for Sustainable Development (ESD) has been a significant focus for research pertaining to teacher education and transformative approaches to teaching and learning. However, there has been less specific focus on the implementation of ESD in the context of higher education. This study, therefore, explored the use of an ESD-based teaching and learning approach in an undergraduate Development Studies programme. The focus was on developing a teaching approach that was informed by the principles of ESD and which could assist Development Studies lecturers in creating a more transformative, student-centred environment. This study was a qualitative undertaking, conducted at the Nelson Mandela University’s (NMU) Development Studies undergraduate programme. The ESD-based approach was implemented by two participating lecturers who utilised the approach across four undergraduate classes. Qualitative data were generated through a systematic literature analysis (SLA), exploratory interviews, student exercises and assessments, focus group discussions, and reflective journal entries. The gathered data were then analysed using a framework analysis rubric adapted from the theoretical framework utilised in the study. In addition, the data were coded using the six coding techniques promoted by Saldaña (2013). The findings suggest that the ESD-based approach developed in the study could effectively contribute towards promoting ESD in the Development Studies programme. The findings also suggest that, when properly implemented, the ESD-based approach could assist lecturers in creating a more transformative learning environment where students have greater control over their learning experience. In addition, this study found that students in the selected Development Studies undergraduate programme could benefit from continued exposure to the teaching methods and techniques adopted in the approach. The implementation of the approach also uncovered some of the inhibiting factors that may prevent an ESD-based approach being mainstreamed into the context of higher education. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Development Studies, 2021
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- Date Issued: 2021-04
- Authors: Abrahams, Andre John
- Date: 2021-04
- Subjects: Sustainable development -- Study and teaching , Universities and colleges -- South Africa , Critical thinking
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50906 , vital:43149
- Description: In recent years, Education for Sustainable Development (ESD) has been a significant focus for research pertaining to teacher education and transformative approaches to teaching and learning. However, there has been less specific focus on the implementation of ESD in the context of higher education. This study, therefore, explored the use of an ESD-based teaching and learning approach in an undergraduate Development Studies programme. The focus was on developing a teaching approach that was informed by the principles of ESD and which could assist Development Studies lecturers in creating a more transformative, student-centred environment. This study was a qualitative undertaking, conducted at the Nelson Mandela University’s (NMU) Development Studies undergraduate programme. The ESD-based approach was implemented by two participating lecturers who utilised the approach across four undergraduate classes. Qualitative data were generated through a systematic literature analysis (SLA), exploratory interviews, student exercises and assessments, focus group discussions, and reflective journal entries. The gathered data were then analysed using a framework analysis rubric adapted from the theoretical framework utilised in the study. In addition, the data were coded using the six coding techniques promoted by Saldaña (2013). The findings suggest that the ESD-based approach developed in the study could effectively contribute towards promoting ESD in the Development Studies programme. The findings also suggest that, when properly implemented, the ESD-based approach could assist lecturers in creating a more transformative learning environment where students have greater control over their learning experience. In addition, this study found that students in the selected Development Studies undergraduate programme could benefit from continued exposure to the teaching methods and techniques adopted in the approach. The implementation of the approach also uncovered some of the inhibiting factors that may prevent an ESD-based approach being mainstreamed into the context of higher education. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Development Studies, 2021
- Full Text:
- Date Issued: 2021-04
An exploration into an ESD-based teaching strategy to improve the critical thinking and problem-solving skills amongst development studies students at Nelson Mandela University
- Authors: Abrahams, André John
- Date: 2021-04
- Subjects: Problem solving -- Study and teaching , Divergent thinking -- Study and teaching , Sustainable development -- Study and teaching , Environmental education
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50907 , vital:43148
- Description: In recent years, Education for Sustainable Development (ESD) has been a significant focus for research pertaining to teacher education and transformative approaches to teaching and learning. However, there has been less specific focus on the implementation of ESD in the context of higher education. This study, therefore, explored the use of an ESD-based teaching and learning approach in an undergraduate Development Studies programme. The focus was on developing a teaching approach that was informed by the principles of ESD and which could assist Development Studies lecturers in creating a more transformative, student-centred environment. This study was a qualitative undertaking, conducted at the Nelson Mandela University’s (NMU) Development Studies undergraduate programme. The ESD-based approach was implemented by two participating lecturers who utilised the approach across four undergraduate classes. Qualitative data were generated through a systematic literature analysis (SLA), exploratory interviews, student exercises and assessments, focus group discussions, and reflective journal entries. The gathered data were then analysed using a framework analysis rubric adapted from the theoretical framework utilised in the study. In addition, the data were coded using the six coding techniques promoted by Saldaña (2013). The findings suggest that the ESD-based approach developed in the study could effectively contribute towards promoting ESD in the Development Studies programme. The findings also suggest that, when properly implemented, the ESD-based approach could assist lecturers in creating a more transformative learning environment where students have greater control over their learning experience. In addition, this study found that students in the selected Development Studies undergraduate programme could benefit from continued exposure to the teaching methods and techniques adopted in the approach. The implementation of the approach also uncovered some of the inhibiting factors that may prevent an ESD-based approach being mainstreamed into the context of higher education. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Development Studies, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Abrahams, André John
- Date: 2021-04
- Subjects: Problem solving -- Study and teaching , Divergent thinking -- Study and teaching , Sustainable development -- Study and teaching , Environmental education
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/50907 , vital:43148
- Description: In recent years, Education for Sustainable Development (ESD) has been a significant focus for research pertaining to teacher education and transformative approaches to teaching and learning. However, there has been less specific focus on the implementation of ESD in the context of higher education. This study, therefore, explored the use of an ESD-based teaching and learning approach in an undergraduate Development Studies programme. The focus was on developing a teaching approach that was informed by the principles of ESD and which could assist Development Studies lecturers in creating a more transformative, student-centred environment. This study was a qualitative undertaking, conducted at the Nelson Mandela University’s (NMU) Development Studies undergraduate programme. The ESD-based approach was implemented by two participating lecturers who utilised the approach across four undergraduate classes. Qualitative data were generated through a systematic literature analysis (SLA), exploratory interviews, student exercises and assessments, focus group discussions, and reflective journal entries. The gathered data were then analysed using a framework analysis rubric adapted from the theoretical framework utilised in the study. In addition, the data were coded using the six coding techniques promoted by Saldaña (2013). The findings suggest that the ESD-based approach developed in the study could effectively contribute towards promoting ESD in the Development Studies programme. The findings also suggest that, when properly implemented, the ESD-based approach could assist lecturers in creating a more transformative learning environment where students have greater control over their learning experience. In addition, this study found that students in the selected Development Studies undergraduate programme could benefit from continued exposure to the teaching methods and techniques adopted in the approach. The implementation of the approach also uncovered some of the inhibiting factors that may prevent an ESD-based approach being mainstreamed into the context of higher education. , Thesis (DPhil) -- Faculty of Business and Economic Sciences, Development Studies, 2021
- Full Text:
- Date Issued: 2021-04