Lo Ma Joini
- Matula, Yelanjani, Composer unknown, Tracey, Hugh
- Authors: Matula, Yelanjani , Composer unknown , Tracey, Hugh
- Date: 1958-03-31
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249717 , vital:51859 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT568-M20 , Research no. M2G1
- Description: A topical song about the life of the mine compound accompanied by concertina.
- Full Text: false
- Date Issued: 1958-03-31
- Authors: Matula, Yelanjani , Composer unknown , Tracey, Hugh
- Date: 1958-03-31
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249717 , vital:51859 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT568-M20 , Research no. M2G1
- Description: A topical song about the life of the mine compound accompanied by concertina.
- Full Text: false
- Date Issued: 1958-03-31
Lo Ma Joini (The Recruits)
- Yelanjani Matula, Hugh Tracey
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152644 , vital:39326 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-05
- Description: This topical song refers to the life of the mine compound with its racy side. It amused the onlookers and no one took exception to the sentiments expressed. Topical song with concertina.
- Full Text: false
- Date Issued: 1958
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152644 , vital:39326 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-05
- Description: This topical song refers to the life of the mine compound with its racy side. It amused the onlookers and no one took exception to the sentiments expressed. Topical song with concertina.
- Full Text: false
- Date Issued: 1958
Inganile Intombi Yami Nokuzula
- Yelanjani Matula, Performer not specified, Composer not specified, Tracey, Hugh
- Authors: Yelanjani Matula , Performer not specified , Composer not specified , Tracey, Hugh
- Date: 1958
- Subjects: Folk Music , Field recordings , Africa, Sub-Saharan , Africa Swaziland city not specified f-sq
- Language: swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/396669 , vital:69207 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Commercial Records, Rhodes University, Makhanda, South Africa , GM04-06-TR71-B-4
- Description: Indigenous music
- Full Text: false
- Date Issued: 1958
- Authors: Yelanjani Matula , Performer not specified , Composer not specified , Tracey, Hugh
- Date: 1958
- Subjects: Folk Music , Field recordings , Africa, Sub-Saharan , Africa Swaziland city not specified f-sq
- Language: swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/396669 , vital:69207 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Commercial Records, Rhodes University, Makhanda, South Africa , GM04-06-TR71-B-4
- Description: Indigenous music
- Full Text: false
- Date Issued: 1958
Ye muka ingwababa ifute unina
- Matula, Yelanyani, Composer unknown, Tracey, Hugh
- Authors: Matula, Yelanyani , Composer unknown , Tracey, Hugh
- Date: 1958-03-31
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249883 , vital:51878 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT571-M23 , Research no. M2H1
- Description: A topical song about a wife leaving without saying goodbye accompanied by concertina.
- Full Text: false
- Date Issued: 1958-03-31
- Authors: Matula, Yelanyani , Composer unknown , Tracey, Hugh
- Date: 1958-03-31
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249883 , vital:51878 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT571-M23 , Research no. M2H1
- Description: A topical song about a wife leaving without saying goodbye accompanied by concertina.
- Full Text: false
- Date Issued: 1958-03-31
Ye Muka Ingwababa Fute Unina (My wife is just like her mother)
- Yelanjani Matula, Hugh Tracey
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152653 , vital:39328 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-06
- Description: "When my wife left me she did not ever say goodbye to my father and mother. She was just like her mother." Topical song with concertina.
- Full Text: false
- Date Issued: 1958
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152653 , vital:39328 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-06
- Description: "When my wife left me she did not ever say goodbye to my father and mother. She was just like her mother." Topical song with concertina.
- Full Text: false
- Date Issued: 1958
Inganile Intombi Yami Nokuzula (My girl Nokuzula has left me)
- Yelanjani Matula, Hugh Tracey
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152666 , vital:39329 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-07
- Description: A phrase in this song refers to the custom of reserving a portion of an animal, the heart or chops for the younger people. So comparing this to the loss of the girl, he says, waiting in anticipation of his share of the chops, he is disappointed. Topical song with concertina.
- Full Text: false
- Date Issued: 1958
- Authors: Yelanjani Matula , Hugh Tracey
- Date: 1958
- Subjects: Folk music--Africa , Field recordings , Folk songs, Swazi , Folk music , Africa Eswatini Havelock Mine f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/152666 , vital:39329 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR071-07
- Description: A phrase in this song refers to the custom of reserving a portion of an animal, the heart or chops for the younger people. So comparing this to the loss of the girl, he says, waiting in anticipation of his share of the chops, he is disappointed. Topical song with concertina.
- Full Text: false
- Date Issued: 1958
Inganile intombi yami Nokuzula
- Matula, Yelanyani, Composer unknown, Tracey, Hugh
- Authors: Matula, Yelanyani , Composer unknown , Tracey, Hugh
- Date: 1958-04-01
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249910 , vital:51881 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT571-M23 , Research no. M2H2
- Description: A topical song about disappointment accompanied by concertina.
- Full Text: false
- Date Issued: 1958-04-01
- Authors: Matula, Yelanyani , Composer unknown , Tracey, Hugh
- Date: 1958-04-01
- Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Eswatini Havelock f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/249910 , vital:51881 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT571-M23 , Research no. M2H2
- Description: A topical song about disappointment accompanied by concertina.
- Full Text: false
- Date Issued: 1958-04-01
Lo Ma Joini
- Yelanjani Matula, Performer not specified, Composer not specified, Tracey, Hugh
- Authors: Yelanjani Matula , Performer not specified , Composer not specified , Tracey, Hugh
- Date: 1958
- Subjects: Folk Music , Field recordings , Africa, Sub-Saharan , Africa Swaziland city not specified f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/396290 , vital:69167 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Commercial Records, Rhodes University, Makhanda, South Africa , GM01-06-TR71-B1
- Description: Indigenous music
- Full Text: false
- Date Issued: 1958
- Authors: Yelanjani Matula , Performer not specified , Composer not specified , Tracey, Hugh
- Date: 1958
- Subjects: Folk Music , Field recordings , Africa, Sub-Saharan , Africa Swaziland city not specified f-sq
- Language: Swati
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/396290 , vital:69167 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Commercial Records, Rhodes University, Makhanda, South Africa , GM01-06-TR71-B1
- Description: Indigenous music
- Full Text: false
- Date Issued: 1958
Exploring perceptions on aesthetics and emotional labour experienced by women working in two different clothing retail shops in Port Elizabeth and Grahamstown
- Authors: Dalikeni, Tawonga
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/3750 , vital:20541
- Description: The retail industry is the fastest growing sector in the economy contributing trillions towards the global revenue. In a post-apartheid South African economy that is experiencing increased buying power, the clothing retail sector to be specific is consequently flourishing. However, the economy is faced by structural adjustments; an accompanying concern is how foreign direct investments and pressures of globalization impact the operation of clothing retail shops. The main focus of this thesis based on the qualitative research methodology is emotional and aesthetic labour being experienced by women working in two clothing retail shops in Port Elizabeth and Grahamstown. Empirical data shows that emotional labour is a dominant form of labour in the clothing retail shops under investigation. The women working as sales assistants are trained to exude a certain emotional aura when dealing with customers to build a relationship that will encourage the customer to purchase from the shop. Aesthetic labour on the other hand is an important public relations strategy used as sales assistants dress in a way that represents their company brand. Edgars employees dress elegantly because they focus more on formal dressing whilst Mr Price employees dress more casually because they focus on casual and relaxed fashion. Besides these external attributes, the study showed that certain aspects of the job are fairly similar. With codes of happiness and strings of dissatisfaction towards their job requirements, the women’s social lives suffer the atrocities of their long working hours and limited off-duty days.
- Full Text:
- Date Issued: 2016
- Authors: Dalikeni, Tawonga
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/3750 , vital:20541
- Description: The retail industry is the fastest growing sector in the economy contributing trillions towards the global revenue. In a post-apartheid South African economy that is experiencing increased buying power, the clothing retail sector to be specific is consequently flourishing. However, the economy is faced by structural adjustments; an accompanying concern is how foreign direct investments and pressures of globalization impact the operation of clothing retail shops. The main focus of this thesis based on the qualitative research methodology is emotional and aesthetic labour being experienced by women working in two clothing retail shops in Port Elizabeth and Grahamstown. Empirical data shows that emotional labour is a dominant form of labour in the clothing retail shops under investigation. The women working as sales assistants are trained to exude a certain emotional aura when dealing with customers to build a relationship that will encourage the customer to purchase from the shop. Aesthetic labour on the other hand is an important public relations strategy used as sales assistants dress in a way that represents their company brand. Edgars employees dress elegantly because they focus more on formal dressing whilst Mr Price employees dress more casually because they focus on casual and relaxed fashion. Besides these external attributes, the study showed that certain aspects of the job are fairly similar. With codes of happiness and strings of dissatisfaction towards their job requirements, the women’s social lives suffer the atrocities of their long working hours and limited off-duty days.
- Full Text:
- Date Issued: 2016
The influence of vandalism in schools on learner's academic performance
- Authors: Esau, Vernon Garth
- Date: 2007
- Subjects: School vandalism -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9534 , http://hdl.handle.net/10948/691 , School vandalism -- South Africa -- Port Elizabeth
- Description: School vandalism is a serious problem in South Africa, particularly, as it places a heavy burden on education budgets. It could also cause learning to collapse, since it infringes on the right of learners to be taught in clean, well kept school buildings, and to develop their full potential. It is generally accepted that cared for school facilities, adequate furniture and equipment, as well as clean ablution facilities, are conducive to a healthy learning environment. The aim of this research was to determine whether vandalism at schools in Nelson Mandela Metropole (NMM) has an influence on learners’ scholastic achievement. Against the background of the literature review, this investigation endeavours to report on the nature and extent of vandalism at a sample of South African schools, as well as preventative measures that be introduced to combat such vandalism. The research comprised of a study of relevant literature, followed by a qualitative research design. The literature study covered aspects regarding the nature, extent and consequences of vandalism at schools. The sample group consisted of learners, teachers and parents from four secondary schools in the western region of the Uitenhage District. The respondents completed questionnaires regarding their viewpoints on the role that the school, the parents, the community, the police and the media could play in curbing acts of vandalism at schools. The respective principals and some members of staff were also interviewed. The research revealed that both teachers and learners were of the opinion that preventative measures need to be put in place to combat the scourge of vandalism at schools. However, such programmes should be implemented in collaboration with the community, the parents, the South African Police Services and the media. In conclusion some recommendations were made to combat the scourge of vandalism at schools and these may be of value to all schools in South Africa that experience similar problems.
- Full Text:
- Date Issued: 2007
- Authors: Esau, Vernon Garth
- Date: 2007
- Subjects: School vandalism -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:9534 , http://hdl.handle.net/10948/691 , School vandalism -- South Africa -- Port Elizabeth
- Description: School vandalism is a serious problem in South Africa, particularly, as it places a heavy burden on education budgets. It could also cause learning to collapse, since it infringes on the right of learners to be taught in clean, well kept school buildings, and to develop their full potential. It is generally accepted that cared for school facilities, adequate furniture and equipment, as well as clean ablution facilities, are conducive to a healthy learning environment. The aim of this research was to determine whether vandalism at schools in Nelson Mandela Metropole (NMM) has an influence on learners’ scholastic achievement. Against the background of the literature review, this investigation endeavours to report on the nature and extent of vandalism at a sample of South African schools, as well as preventative measures that be introduced to combat such vandalism. The research comprised of a study of relevant literature, followed by a qualitative research design. The literature study covered aspects regarding the nature, extent and consequences of vandalism at schools. The sample group consisted of learners, teachers and parents from four secondary schools in the western region of the Uitenhage District. The respondents completed questionnaires regarding their viewpoints on the role that the school, the parents, the community, the police and the media could play in curbing acts of vandalism at schools. The respective principals and some members of staff were also interviewed. The research revealed that both teachers and learners were of the opinion that preventative measures need to be put in place to combat the scourge of vandalism at schools. However, such programmes should be implemented in collaboration with the community, the parents, the South African Police Services and the media. In conclusion some recommendations were made to combat the scourge of vandalism at schools and these may be of value to all schools in South Africa that experience similar problems.
- Full Text:
- Date Issued: 2007
The effect of Acacia karroo tree density on grass species composition, forage yield and quality in different rainfall regimes in the Eastern Cape, South Africa
- Authors: De Ridder, Cornelius Henry
- Date: 2016
- Subjects: Grasses -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2858 , vital:20357
- Description: It is widely believed that Acacia karroo Hayne trees compete with and negatively affect the production of grasses in their immediate surroundings. This perception formed as a result of observations by farmers of their veld as well as some research. The complexity of plant interactions in different conditions required that research be done to better explain the extent of grass and tree interactions. In response to this need, the effect of a range of Acacia karroo densities on grass production was tested in areas of differing rainfall. Results emphasize the complexity of such plant interactions but highlight rainfall as influencing the effect of tree density on grass production and grass quality. Study sites were chosen with significant differences in tree density and rainfall and this was found to be concomitant with significant differences in grass yield and crude protein (p < 0.001). Grass yield (mass produced) was negatively correlated with tree density (p < 0.001) and was affected by rainfall. High tree density reduced grass yield at the lower rainfall sites, but a reduction in yield was only recorded during dry conditions in the higher rainfall areas. By contrast, the crude protein content of grasses was positively correlated to tree density (p < 0.001). However, as with yield, rainfall played an important part in the strength of the correlation. Soil properties such as temperature (-) (p = 0.011), phosphorus content (+) (p = 0.006), calcium concentration (+) (p = 0.005), acid saturation (-) (p = 0.018), and soil pH (+) (p = 0.008) were also significantly correlated to tree density. Tree density enriched the soil, subsequently benefitting grass quality. The study sites investigated, had different plant communities and environmental conditions with Cradock, Kubusi Drift and Kei Mouth having unique communities and conditions while Adelaide and Cathcart could not be separated in either. Cradock was the driest site and the vegetation was dominated by both grasses and karroid shrubs, differing in pattern and process from the other sites. The Kubusi Drift site had high tree densities, to the extent that the trees altered the grass species composition. The effects of rainfall on grass yield and quality exceeded that of community composition differences.
- Full Text:
- Date Issued: 2016
- Authors: De Ridder, Cornelius Henry
- Date: 2016
- Subjects: Grasses -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/2858 , vital:20357
- Description: It is widely believed that Acacia karroo Hayne trees compete with and negatively affect the production of grasses in their immediate surroundings. This perception formed as a result of observations by farmers of their veld as well as some research. The complexity of plant interactions in different conditions required that research be done to better explain the extent of grass and tree interactions. In response to this need, the effect of a range of Acacia karroo densities on grass production was tested in areas of differing rainfall. Results emphasize the complexity of such plant interactions but highlight rainfall as influencing the effect of tree density on grass production and grass quality. Study sites were chosen with significant differences in tree density and rainfall and this was found to be concomitant with significant differences in grass yield and crude protein (p < 0.001). Grass yield (mass produced) was negatively correlated with tree density (p < 0.001) and was affected by rainfall. High tree density reduced grass yield at the lower rainfall sites, but a reduction in yield was only recorded during dry conditions in the higher rainfall areas. By contrast, the crude protein content of grasses was positively correlated to tree density (p < 0.001). However, as with yield, rainfall played an important part in the strength of the correlation. Soil properties such as temperature (-) (p = 0.011), phosphorus content (+) (p = 0.006), calcium concentration (+) (p = 0.005), acid saturation (-) (p = 0.018), and soil pH (+) (p = 0.008) were also significantly correlated to tree density. Tree density enriched the soil, subsequently benefitting grass quality. The study sites investigated, had different plant communities and environmental conditions with Cradock, Kubusi Drift and Kei Mouth having unique communities and conditions while Adelaide and Cathcart could not be separated in either. Cradock was the driest site and the vegetation was dominated by both grasses and karroid shrubs, differing in pattern and process from the other sites. The Kubusi Drift site had high tree densities, to the extent that the trees altered the grass species composition. The effects of rainfall on grass yield and quality exceeded that of community composition differences.
- Full Text:
- Date Issued: 2016
Laser welding of thin-walled stainless steel tubing
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019
- Authors: Mabveka, Greystone Graham
- Date: 2019
- Subjects: Laser welding , Welding Mechanical engineering
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/40690 , vital:36223
- Description: Longitudinal butt welds in the motor industry are increasingly being made by laser welding. One of the materials being welded is thin walled type 441 stainless steel tubing. The welding process parameters should however be optimised to give a weld that possesses acceptable properties. In this research, a Yb:YAG laser machine was used to weld a 1.2mm thick tubing. Laser power and welding speed were varied to achieve an optimum weld whose properties compare well with the parent metal. The two parameters were combined such that the heat input was in the range of 7.5 to 25kJ/m. The welds were characterised by the microstructure from the weld, intergranular attack and mechanical properties. It has been shown by microstructure study that grains originated from ‘weld metal/base metal’ interface and elongated towards the weld centreline. A defined line ran through the interface through the thickness of the plate. Smaller grains were noted around the interface in some welds. Susceptibility to intergranular attack tests showed random ditching in the weld metal microstructure which indicated that the weldments produced were acceptable. Mechanical tests of all welds showed a slight increase in micro-hardness in the weld metal. While the base metal had a micro-hardness range of 160 –199HV0.1, it increased to 187 – 242HV0.1 in the fusion zone. An ANOVA regression of tensile test results predicted an expected maximum of 471MPa to occur when a 1000W power is used at a welding speed of 0.06m/s. Fracture morphology of tensile test samples showed that all failures were by overload. This showed that the weld metal still exhibited similar ductility properties with the base metal.
- Full Text:
- Date Issued: 2019
Synthesis of modified zinc oxide nanoparticles using pneumatic spray pyrolysis for solar cell application
- Authors: Ntozakhe, Luyolo
- Date: 2017
- Subjects: Zinc oxide -- Synthesis Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5862 , vital:29408
- Description: In this work, the pneumatic spray pyrolysis was used to synthesize un-doped and carbon doped zinc oxide (ZnO) nanoparticles. The zinc acetate, tetrabutylammonium bromide and ethanol were used as starting materials for the desired ZnO nanoparticles and the prepared samples were annealed at 400 oC in the furnace. The as synthesized un-doped and carbon doped ZnO NPs were evaluated using X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive x-ray spectroscopy (EDX), High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and Ultraviolet-visible spectroscopy (UV-Vis). XRD analysis of the synthesized NPs revealed peaks at 31.90°, 34.50°, 36.34°, 47.73°, 56.88°, 63.04°, 68.20°, and 77.33° belonging to the hexagonal Wurtzite ZnO crystal structure. The incorporation of C species into ZnO lattice was cross examined by monitoring the peak positions of the (100), (002) and (001) planes. These three main peaks of C-ZnO NPs show a peak shift to higher 2θ values which indicates substitutional carbon doping in ZnO NPs. SEM analysis has revealed that the as synthesized NPs have spherical shape and the morphology of the NPs change as the concentration of carbon increases. The EDX spectra of both un-doped and doped ZnO nanoparticles have revealed prominent peaks at 0.51 keV, 1.01 keV, 1.49 keV, 8.87 keV and 9.86 keV. Peaks at, X-ray energies of 0.51 keV and 1.01 keV respectively represent the emissions from the K-shell of oxygen and L-shell of zinc. The L-shell emission at 1.01 keV is considered as convolution of Zn 2p3/2 and Zn 2p1/2 photoelectron energies. The occurrence of these peaks in the EDX endorses the existence of Zn and O atoms in the PSP prepared samples. HRTEM analysis has revealed NPs size modal range from 6.65-14.21 nm for the PSP synthesized samples which is in mutual agreement with the XRD data calculated values. More over the selected area diffraction images displaying the fact that only the diffraction planes of (101), (002) and (100) are responsible for the diffraction pattern belonging to Wurtzite ZnO. RS analysis has revealed that the un-doped ZnO and doped ZnO samples have characteristic Raman vibration modes at 325 cm-1, and 434 cm-1 belonging to Wurtzite ZnO structure. Moreover, the prominent peak at 434 cm-1 which is the characteristic peak of E2(2) (high) mode of the Wurtzite ZnO and the E2(2) (high) has been red shifted by 4 cm-1, as compared to that found in the bulk ZnO. Additionally, the effect of carbon doping through Raman spectroscopy peak shifts of the E2(2) (high) mode, A1(LO) mode and multi-phonon has also been considered and discussed in detail. UV-Vis diffuse reflectance spectroscopy has revealed a red shift of the absorption edge with increase in C doping. Finally, the effect of nano-crystallite size and gradual prominence of C into ZnO lattice due to increase in C doping concentration in the PSP prepared nanoparticles was meticulously elaborated through Raman Spectroscopy analysis.
- Full Text:
- Date Issued: 2017
- Authors: Ntozakhe, Luyolo
- Date: 2017
- Subjects: Zinc oxide -- Synthesis Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/5862 , vital:29408
- Description: In this work, the pneumatic spray pyrolysis was used to synthesize un-doped and carbon doped zinc oxide (ZnO) nanoparticles. The zinc acetate, tetrabutylammonium bromide and ethanol were used as starting materials for the desired ZnO nanoparticles and the prepared samples were annealed at 400 oC in the furnace. The as synthesized un-doped and carbon doped ZnO NPs were evaluated using X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive x-ray spectroscopy (EDX), High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy (RS) and Ultraviolet-visible spectroscopy (UV-Vis). XRD analysis of the synthesized NPs revealed peaks at 31.90°, 34.50°, 36.34°, 47.73°, 56.88°, 63.04°, 68.20°, and 77.33° belonging to the hexagonal Wurtzite ZnO crystal structure. The incorporation of C species into ZnO lattice was cross examined by monitoring the peak positions of the (100), (002) and (001) planes. These three main peaks of C-ZnO NPs show a peak shift to higher 2θ values which indicates substitutional carbon doping in ZnO NPs. SEM analysis has revealed that the as synthesized NPs have spherical shape and the morphology of the NPs change as the concentration of carbon increases. The EDX spectra of both un-doped and doped ZnO nanoparticles have revealed prominent peaks at 0.51 keV, 1.01 keV, 1.49 keV, 8.87 keV and 9.86 keV. Peaks at, X-ray energies of 0.51 keV and 1.01 keV respectively represent the emissions from the K-shell of oxygen and L-shell of zinc. The L-shell emission at 1.01 keV is considered as convolution of Zn 2p3/2 and Zn 2p1/2 photoelectron energies. The occurrence of these peaks in the EDX endorses the existence of Zn and O atoms in the PSP prepared samples. HRTEM analysis has revealed NPs size modal range from 6.65-14.21 nm for the PSP synthesized samples which is in mutual agreement with the XRD data calculated values. More over the selected area diffraction images displaying the fact that only the diffraction planes of (101), (002) and (100) are responsible for the diffraction pattern belonging to Wurtzite ZnO. RS analysis has revealed that the un-doped ZnO and doped ZnO samples have characteristic Raman vibration modes at 325 cm-1, and 434 cm-1 belonging to Wurtzite ZnO structure. Moreover, the prominent peak at 434 cm-1 which is the characteristic peak of E2(2) (high) mode of the Wurtzite ZnO and the E2(2) (high) has been red shifted by 4 cm-1, as compared to that found in the bulk ZnO. Additionally, the effect of carbon doping through Raman spectroscopy peak shifts of the E2(2) (high) mode, A1(LO) mode and multi-phonon has also been considered and discussed in detail. UV-Vis diffuse reflectance spectroscopy has revealed a red shift of the absorption edge with increase in C doping. Finally, the effect of nano-crystallite size and gradual prominence of C into ZnO lattice due to increase in C doping concentration in the PSP prepared nanoparticles was meticulously elaborated through Raman Spectroscopy analysis.
- Full Text:
- Date Issued: 2017
The refining of calcium using a sulfate reducing bacterial system
- Authors: Horne, Kerry Allison
- Date: 2001
- Subjects: Calcium carbonate -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3915 , http://hdl.handle.net/10962/d1003974 , Calcium carbonate -- Synthesis
- Description: White lime is used in many industries in South Africa but is not produced locally and must be imported. Many technologies have been suggested for the large-scale manufacture of calcium carbonate but these are not necessarily suitable for application in South Africa. This study investigated a chemical preparation of calcium carbonate combined with biological purification Calcium containing materials from the Pretoria Portland Cement, Lime Division factory at Lime Acres in the Northern Cape were studied as the starting materials for the manufacture. Investigation showed that they contained various impurities, including iron and manganese compounds which were largely responsible for the brown-grey colour of the lime products. Complete dissolution of calcium hydroxide, the purest of the potential starting materials, and subsequent hydroxide precipitation was not successful in removing all iron and manganese. Precipitation with sulfide ions was successfill, decreasing levels of metals to below the detection limit of atomic absorption spectrophotometry. Studies of all potential starting materials revealed that the levels of impurities in the starting material did not have a large effect on levels of impurities in the calcium carbonate produced. It was therefore possible to convert the residual calcium oxide or hydroxide in waste lime dusts to white calcium carbonate, a marketable prciduct Recycling of the water and starting material used in the process served to increase, rather than decrease, the purity of the calcium carbonate product. This allows for water conservation as water is not consumed in the process but merely utilised. When waste lime dust was used as the starting material, sulfate was found in the product. While still a white lime, the calcium carbonate was not chemically pure. Sulfate removal was therefore investigated and the use of sulfate-reducing bacteria was studied as a novel application. A mixed sulfate-reducing bacterial population was isolated and found to be hIghly active at sulfate concentrations between 0.2 and 2 ~~~. They were capable of autotrophic growth and could reduce sulfate in solutions with elevated pH and in calcium carbonate suspensions, although they did not grow readily in these media. A process was designed for the production of bulk quantities of calcium carbonate making use of the facilities and materials available at Lime Acres. This was tested using a small scale bench-top reactor series, with favourable results. The process would allow automatic, continuous production of large quantities of white lime using waste lime dust. Provision was also made for manufacture of smaller quantities of pure calcium carbonate using sulfate-reducing bacteria to remove the sulfate impurity.
- Full Text:
- Date Issued: 2001
- Authors: Horne, Kerry Allison
- Date: 2001
- Subjects: Calcium carbonate -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3915 , http://hdl.handle.net/10962/d1003974 , Calcium carbonate -- Synthesis
- Description: White lime is used in many industries in South Africa but is not produced locally and must be imported. Many technologies have been suggested for the large-scale manufacture of calcium carbonate but these are not necessarily suitable for application in South Africa. This study investigated a chemical preparation of calcium carbonate combined with biological purification Calcium containing materials from the Pretoria Portland Cement, Lime Division factory at Lime Acres in the Northern Cape were studied as the starting materials for the manufacture. Investigation showed that they contained various impurities, including iron and manganese compounds which were largely responsible for the brown-grey colour of the lime products. Complete dissolution of calcium hydroxide, the purest of the potential starting materials, and subsequent hydroxide precipitation was not successful in removing all iron and manganese. Precipitation with sulfide ions was successfill, decreasing levels of metals to below the detection limit of atomic absorption spectrophotometry. Studies of all potential starting materials revealed that the levels of impurities in the starting material did not have a large effect on levels of impurities in the calcium carbonate produced. It was therefore possible to convert the residual calcium oxide or hydroxide in waste lime dusts to white calcium carbonate, a marketable prciduct Recycling of the water and starting material used in the process served to increase, rather than decrease, the purity of the calcium carbonate product. This allows for water conservation as water is not consumed in the process but merely utilised. When waste lime dust was used as the starting material, sulfate was found in the product. While still a white lime, the calcium carbonate was not chemically pure. Sulfate removal was therefore investigated and the use of sulfate-reducing bacteria was studied as a novel application. A mixed sulfate-reducing bacterial population was isolated and found to be hIghly active at sulfate concentrations between 0.2 and 2 ~~~. They were capable of autotrophic growth and could reduce sulfate in solutions with elevated pH and in calcium carbonate suspensions, although they did not grow readily in these media. A process was designed for the production of bulk quantities of calcium carbonate making use of the facilities and materials available at Lime Acres. This was tested using a small scale bench-top reactor series, with favourable results. The process would allow automatic, continuous production of large quantities of white lime using waste lime dust. Provision was also made for manufacture of smaller quantities of pure calcium carbonate using sulfate-reducing bacteria to remove the sulfate impurity.
- Full Text:
- Date Issued: 2001
Rhodeo, Vol. 22, No. 16
- Date: 1968-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14590 , http://hdl.handle.net/10962/d1019462
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-22
- Date: 1968-08-22
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14590 , http://hdl.handle.net/10962/d1019462
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-22
The use of earth observation multi-sensor systems to monitor and model Pastures: a case of Savannah Grasslands in Hluvukani Village, Bushbuckridge Local Municipality, Mpumalanga Province, South Africa
- Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
An historical study of channel change in the Bell river, north eastern Cape
- Authors: Dollar, E S J
- Date: 1993
- Subjects: River channels -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Bell river
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4837 , http://hdl.handle.net/10962/d1005513 , River channels -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Bell river
- Description: Channel instability has occurred in the Bell river, north eastern Cape, in the form of meander cutoffs, incipient meander cutoffs, channel straightening and general channel instability. Recent cutoffs occurred in 1974 and 1988. The study examines the spatial and temporal controls of channel form and pattern in the Bell river in order to assess the causes of channel instability. From the 17 km surveyed stretch, it was found that the main spatial controls of channel form were riparian vegetation density and channel bed material. Discharge as estimated in the field was not the main controlling variable of channel form. Two distinct groups of stream beds were identified from the survey; an upper gravel-bed stream and a lower sand-bed stream. These sites displayed distinct form ratios, channel gradients and bed material characteristics. The incidences of major channel instability were identified as being the transitional zone between the two reaches. Examination of temporal controls of channel form included climatic trend analysis and catchment sediment production analysis. Rainfall analysis indicated that no long term progressive trends in the annual or seasonal data existed. Distinct wet and dry cycles occur with peaks every 16 to 19 years. Wet cycles are the result of an increase in the frequency of daily events rather than in the magnitude of events. Flow record analysis demonstrated the relationship between regional discharge and upper catchment rainfall. Coincidence of peak flows and channel straightening were also noted. Soil erosion surveys showed that erosion had increased in the catchment and that accelerated erosion were probably the result of overstocking and poor veld management. It was concluded that channel changes in the Bell river are possibly the result of anthropogenic influence in catchment and channel processes. Increased sediment production to the channel resulted in channel aggradation with attendant instability. The plantation of riparian vegetation led to perimeter stability in the short term at flows less than bankfull discharge, but served to reduce cross-sectional area in the long term, thereby increasing the potential for flooding, meander cutoffs and channel change
- Full Text:
- Date Issued: 1993
- Authors: Dollar, E S J
- Date: 1993
- Subjects: River channels -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Bell river
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4837 , http://hdl.handle.net/10962/d1005513 , River channels -- South Africa -- Eastern Cape , Sedimentation and deposition -- South Africa -- Eastern Cape , Bell river
- Description: Channel instability has occurred in the Bell river, north eastern Cape, in the form of meander cutoffs, incipient meander cutoffs, channel straightening and general channel instability. Recent cutoffs occurred in 1974 and 1988. The study examines the spatial and temporal controls of channel form and pattern in the Bell river in order to assess the causes of channel instability. From the 17 km surveyed stretch, it was found that the main spatial controls of channel form were riparian vegetation density and channel bed material. Discharge as estimated in the field was not the main controlling variable of channel form. Two distinct groups of stream beds were identified from the survey; an upper gravel-bed stream and a lower sand-bed stream. These sites displayed distinct form ratios, channel gradients and bed material characteristics. The incidences of major channel instability were identified as being the transitional zone between the two reaches. Examination of temporal controls of channel form included climatic trend analysis and catchment sediment production analysis. Rainfall analysis indicated that no long term progressive trends in the annual or seasonal data existed. Distinct wet and dry cycles occur with peaks every 16 to 19 years. Wet cycles are the result of an increase in the frequency of daily events rather than in the magnitude of events. Flow record analysis demonstrated the relationship between regional discharge and upper catchment rainfall. Coincidence of peak flows and channel straightening were also noted. Soil erosion surveys showed that erosion had increased in the catchment and that accelerated erosion were probably the result of overstocking and poor veld management. It was concluded that channel changes in the Bell river are possibly the result of anthropogenic influence in catchment and channel processes. Increased sediment production to the channel resulted in channel aggradation with attendant instability. The plantation of riparian vegetation led to perimeter stability in the short term at flows less than bankfull discharge, but served to reduce cross-sectional area in the long term, thereby increasing the potential for flooding, meander cutoffs and channel change
- Full Text:
- Date Issued: 1993
Isolation, purification and partial characterisation of cancer procoagulant from placental amnion-chorion membranes and its role in angiogenesis inflammation and metastasis
- Authors: Krause, Jason
- Date: 2014
- Subjects: Coagulation , Amnion , Chorion , Metastasis , Inflammation , Neovascularization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10350 , http://hdl.handle.net/10948/d1020897
- Description: Cancer procoagulant (EC 3.4.22.26) is an enzyme that is derived from tumour and foetal tissue, but not normal tissue. It is a direct activator of factor X and has been isolated from amnion-chorion membranes as well as from extracts and cells from human melanoma. The presence of cancer procoagulant has been associated with the malignant phenotype, as well as having a particularly high activity in metastatic cells. Cancer procoagulant activity is elevated in the serum of early stage breast cancer patients and decreased to normal in the advanced stages of the disease. In this study, cancer procoagulant was successfully isolated from amnion-chorion membranes and purified to homogeneity. The molecular weight of cancer procoagulant was determined using SDS-PAGE and was found to be 68 kDa. Cancer procoagulant was delipidated and it was shown that its activity was increased by the presence of lipids in a dose-dependent manner. Recovery of cancer procoagulant after delipidation is poor, consequently, a larger mass of sample is required to obtain sufficient amounts of delipidated material for N-terminal amino acid analysis. The optimum pH of cancer procoagulant was determined to be pH 8 and its optimal temperature was found to be 50°C. Novel synthetic substrates were designed to assay for cancer procoagulant activity. Currently, 2 potential candidates have been identified, namely, PQVR-AMC and AVSQSKP-AMC. Cancer procoagulant-induced expression of cytokines is differently modulated in the less aggressive MCF-7 cell line as compared to the metastatic and more aggressive MDA-MB-231 cell line. There are marked similarities in the inflammatory response produced by cancer procoagulant in hTERT-HDLEC and MDA-MB-231 cells, which are both associated with migratory capacity. Furthermore, cancer procoagulant-induced PDGF-β expression in hTERT-HDLEC and MDA-MB-231 cells could point to involvement of cancer procoagulant in wound healing and metastatic spread, respectively. Cancer procoagulant induced the motility of MDA-MB-231, MCF-7 and hTERT- cells in vitro in a time- and dose-dependent manner. Together, these results suggest that cancer procoagulant plays a role in the migration of breast cancer cells as well as the migration of endothelial cells.
- Full Text:
- Date Issued: 2014
- Authors: Krause, Jason
- Date: 2014
- Subjects: Coagulation , Amnion , Chorion , Metastasis , Inflammation , Neovascularization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10350 , http://hdl.handle.net/10948/d1020897
- Description: Cancer procoagulant (EC 3.4.22.26) is an enzyme that is derived from tumour and foetal tissue, but not normal tissue. It is a direct activator of factor X and has been isolated from amnion-chorion membranes as well as from extracts and cells from human melanoma. The presence of cancer procoagulant has been associated with the malignant phenotype, as well as having a particularly high activity in metastatic cells. Cancer procoagulant activity is elevated in the serum of early stage breast cancer patients and decreased to normal in the advanced stages of the disease. In this study, cancer procoagulant was successfully isolated from amnion-chorion membranes and purified to homogeneity. The molecular weight of cancer procoagulant was determined using SDS-PAGE and was found to be 68 kDa. Cancer procoagulant was delipidated and it was shown that its activity was increased by the presence of lipids in a dose-dependent manner. Recovery of cancer procoagulant after delipidation is poor, consequently, a larger mass of sample is required to obtain sufficient amounts of delipidated material for N-terminal amino acid analysis. The optimum pH of cancer procoagulant was determined to be pH 8 and its optimal temperature was found to be 50°C. Novel synthetic substrates were designed to assay for cancer procoagulant activity. Currently, 2 potential candidates have been identified, namely, PQVR-AMC and AVSQSKP-AMC. Cancer procoagulant-induced expression of cytokines is differently modulated in the less aggressive MCF-7 cell line as compared to the metastatic and more aggressive MDA-MB-231 cell line. There are marked similarities in the inflammatory response produced by cancer procoagulant in hTERT-HDLEC and MDA-MB-231 cells, which are both associated with migratory capacity. Furthermore, cancer procoagulant-induced PDGF-β expression in hTERT-HDLEC and MDA-MB-231 cells could point to involvement of cancer procoagulant in wound healing and metastatic spread, respectively. Cancer procoagulant induced the motility of MDA-MB-231, MCF-7 and hTERT- cells in vitro in a time- and dose-dependent manner. Together, these results suggest that cancer procoagulant plays a role in the migration of breast cancer cells as well as the migration of endothelial cells.
- Full Text:
- Date Issued: 2014
Rhodeo, Vol. 22, No. 17
- Date: 1968-08-29
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14591 , http://hdl.handle.net/10962/d1019463
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-29
- Date: 1968-08-29
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14591 , http://hdl.handle.net/10962/d1019463
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1968-08-29
Rhodeo, Vol. 22, No. 8
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14583 , http://hdl.handle.net/10962/d1019455
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14583 , http://hdl.handle.net/10962/d1019455
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text: