Clays derived from the Lower Dwyka Shales, occurring in the vicinity of Grahamstown
- Authors: Blignaut, J J G
- Date: 1928
- Subjects: Clay -- South Africa -- Grahamstown Clay -- Economic aspects -- South Africa -- Grahamstown Geology -- South Africa -- Grahamstown Mineralogy -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4935 , http://hdl.handle.net/10962/d1005547
- Description: The Lower Dwyka Shales in South Africa oocur south of latitude 32⁰; resting conformably upon the Witteberg quartzites, which extend as coastal mountain rangee along the length of the South Coast. The shales, being less resistant to weathering than the quartzites below, and the Dwyka Tillite immediately above, are consequently found in valleys between these two formations. In one of these valleys Grahamstown is situated; where the Lower Dwyka Shales have been eroded by the various rivulets forming the eource of the Blaauwkrantz River. A geological map of the country round Grahamstown was prepared in eome detail, showing all the various rock formations occurring in the area, the full extent of the Lower Dwyka Shales being mapped with the Dwyka Tillite and the Witteberg Quartzite along its margins. The map includes an area of about six miles by three, with the Cathedral spire occupying an approximately central position, and is prepared on a scale of 5.65 inches to one mile. Traversing was done by means of prismatic compass and pacing.
- Full Text:
- Date Issued: 1928
- Authors: Blignaut, J J G
- Date: 1928
- Subjects: Clay -- South Africa -- Grahamstown Clay -- Economic aspects -- South Africa -- Grahamstown Geology -- South Africa -- Grahamstown Mineralogy -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4935 , http://hdl.handle.net/10962/d1005547
- Description: The Lower Dwyka Shales in South Africa oocur south of latitude 32⁰; resting conformably upon the Witteberg quartzites, which extend as coastal mountain rangee along the length of the South Coast. The shales, being less resistant to weathering than the quartzites below, and the Dwyka Tillite immediately above, are consequently found in valleys between these two formations. In one of these valleys Grahamstown is situated; where the Lower Dwyka Shales have been eroded by the various rivulets forming the eource of the Blaauwkrantz River. A geological map of the country round Grahamstown was prepared in eome detail, showing all the various rock formations occurring in the area, the full extent of the Lower Dwyka Shales being mapped with the Dwyka Tillite and the Witteberg Quartzite along its margins. The map includes an area of about six miles by three, with the Cathedral spire occupying an approximately central position, and is prepared on a scale of 5.65 inches to one mile. Traversing was done by means of prismatic compass and pacing.
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- Date Issued: 1928
A linear model for valuating preferences of freshwater inflows into forty selected estuaries along the South African coastline
- Authors: Smith, Melnick Jurgen
- Subjects: Estuaries -- South Africa -- Eastern Cape , Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10581 , http://hdl.handle.net/10948/d1020916
- Description: According to the National Water Act of 1998, an estuary is an enclosed body of water that is either periodically or permanently open to the ocean. Within an estuary, the seawater is diluted to a measurable degree, creating a unique aquatic environment for animals and plants. Estuaries are environmental and economic assets to the population. The health status of our local estuaries, however, is being compromized due to a steady decrease in the freshwater inflow and supply. Tides and climatic conditions do have an impact upon the dynamics of an estuary, but these factors remain relatively constant throughout each year. The freshwater inflow and supply, however, are highly variable and are directly influenced by human involvement. Upstream abstraction for industrial and domestic use, for example, could lead to mouth closure where the ocean meets the river. The National Water Act of 1998 was established to address the lack of research and predominant mismanagement of freshwater inflow into South Africa’s estuaries (Allanson and Baird, 1999). To ensure proper water resource management, different water allocation costs and benefits need to be compared and analyzed to secure an optimum solution (Mlangeni, 2007). Like many environmental services yielded to man, estuary services are not traded in any markets. Alternative markets are thus sought to allow the estimation of the values of such services. Among the available valuation techniques are the Contingent Valuation Method (CVM), Travel Cost Method (TCM) and Hedonic Pricing Method (HPM). The involved benefits of water allocations are predicted in this study by use of the CVM which elicits respondents’ willingness to pay (WTP) towards predetermined changes in freshwater inflow into estuaries. The CVM was applied throughout the Water Research Commission’s (WRC) Project K5/1413 from 2000 to 2008 (Hosking, 2010). Each individual study employed specialized surveys which ideally created a close correspondence between the answers provided by respondents to the supposed scenarios and their voluntary exchanges in markets should money actually have been handled (Mlangeni, 2007). Much criticism has been directed towards the CVM, but careful use and application of the method has been shown to produce significant and satisfactory results (Hosking, 2010). The primary aim of this study was to collectively analyze the collated data provided by the WRC and compare the results with the findings of previous studies. Each variable was analyzed separately in order to reveal any discrepancies between the respective findings. A supplementary objective of this study was to add to the body of knowledge pertaining to South Africa’s estuaries and guide management in the distribution of freshwater towards proficient levels (Du Preez and Hosking, 2010). The associated change in the cumulative consumer surplus with an increased freshwater supply into forty selected estuaries was therefore investigated. The subsequent benefits due to a superior freshwater supply are therefore reflected (Du Preez and Hosking, 2010). The data gathered by each of the individual researchers throughout their studies (supported by the WRC) were combined to form a single dataset including all recorded information supplied by the corresponding respondents. As the investigation progressed, improvements were made upon the questionnaires posed to the considered estuary populations. Consequently, some of the data in the combined dataset were “missing”, since previous studies did not include certain questions, while later studies omitted others. Data imputation was employed to create an imputed dataset, enabling the modeling of the public’s WTP through regression techniques. A linear model was utilized in this study, also incorporating interaction between the predictor variables. The double-log functional form was implemented to estimate the public’s WTP. The population’s total willingness to pay (TWTP) was further estimated by aggregation. A summary of the respective results is displayed in in Table 1.
- Full Text:
- Authors: Smith, Melnick Jurgen
- Subjects: Estuaries -- South Africa -- Eastern Cape , Mathematical statistics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10581 , http://hdl.handle.net/10948/d1020916
- Description: According to the National Water Act of 1998, an estuary is an enclosed body of water that is either periodically or permanently open to the ocean. Within an estuary, the seawater is diluted to a measurable degree, creating a unique aquatic environment for animals and plants. Estuaries are environmental and economic assets to the population. The health status of our local estuaries, however, is being compromized due to a steady decrease in the freshwater inflow and supply. Tides and climatic conditions do have an impact upon the dynamics of an estuary, but these factors remain relatively constant throughout each year. The freshwater inflow and supply, however, are highly variable and are directly influenced by human involvement. Upstream abstraction for industrial and domestic use, for example, could lead to mouth closure where the ocean meets the river. The National Water Act of 1998 was established to address the lack of research and predominant mismanagement of freshwater inflow into South Africa’s estuaries (Allanson and Baird, 1999). To ensure proper water resource management, different water allocation costs and benefits need to be compared and analyzed to secure an optimum solution (Mlangeni, 2007). Like many environmental services yielded to man, estuary services are not traded in any markets. Alternative markets are thus sought to allow the estimation of the values of such services. Among the available valuation techniques are the Contingent Valuation Method (CVM), Travel Cost Method (TCM) and Hedonic Pricing Method (HPM). The involved benefits of water allocations are predicted in this study by use of the CVM which elicits respondents’ willingness to pay (WTP) towards predetermined changes in freshwater inflow into estuaries. The CVM was applied throughout the Water Research Commission’s (WRC) Project K5/1413 from 2000 to 2008 (Hosking, 2010). Each individual study employed specialized surveys which ideally created a close correspondence between the answers provided by respondents to the supposed scenarios and their voluntary exchanges in markets should money actually have been handled (Mlangeni, 2007). Much criticism has been directed towards the CVM, but careful use and application of the method has been shown to produce significant and satisfactory results (Hosking, 2010). The primary aim of this study was to collectively analyze the collated data provided by the WRC and compare the results with the findings of previous studies. Each variable was analyzed separately in order to reveal any discrepancies between the respective findings. A supplementary objective of this study was to add to the body of knowledge pertaining to South Africa’s estuaries and guide management in the distribution of freshwater towards proficient levels (Du Preez and Hosking, 2010). The associated change in the cumulative consumer surplus with an increased freshwater supply into forty selected estuaries was therefore investigated. The subsequent benefits due to a superior freshwater supply are therefore reflected (Du Preez and Hosking, 2010). The data gathered by each of the individual researchers throughout their studies (supported by the WRC) were combined to form a single dataset including all recorded information supplied by the corresponding respondents. As the investigation progressed, improvements were made upon the questionnaires posed to the considered estuary populations. Consequently, some of the data in the combined dataset were “missing”, since previous studies did not include certain questions, while later studies omitted others. Data imputation was employed to create an imputed dataset, enabling the modeling of the public’s WTP through regression techniques. A linear model was utilized in this study, also incorporating interaction between the predictor variables. The double-log functional form was implemented to estimate the public’s WTP. The population’s total willingness to pay (TWTP) was further estimated by aggregation. A summary of the respective results is displayed in in Table 1.
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An investigation into the localization of peptide-gold nanoparticles in an in vitro and in vivo colorectal cancer model
- Authors: Cairncross, Lynn
- Subjects: Colon (Anatomy) -- Cancer -- Treatment , Cancer -- Early detection
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10351 , http://hdl.handle.net/10948/d1020921
- Description: Background: Colorectal cancer is the third most common cancer and cause of related deaths worldwide. Early colorectal cancer diagnosis is vital in reducing incidence and mortality. There is a need for the development of non-invasive screening tools for enhancing the detection of the disease. Cancer specific peptides are useful cancer targeting agents that can be used to specifically improve early detection strategies. Several cancer targeting peptides have been identified. Previous work investigated the specific binding of three of these peptides (p.C, p.L and p.14) conjugated to quantum dots and were found to bind to colorectal cancer cell lines (HT-29 and Caco-2). However, their uptake, localization and biodistribution in an in vitro and in vivo colorectal cancer model have not been determined. This is essential in gaining an understanding for future diagnostic or therapeutic based applications. Primary Aim: The aim of this study was investigate the localization of three selected peptides p.C, p.L and p.14 conjugated to gold nanoparticles in an in vitro and in vivo colorectal cancer model using HRTEM. Methodology: The AuNP/peptide conjugates were characterized by HRTEM and DLS. For in vitro studies; HT-29, Caco-2 and C3A cells were exposed to the AuNP-p.C, AuNP-p.L and AuNP-p.14, collected and processed for HRTEM to assess targeting and localization. For in vivo studies; the establishment of a colorectal cancer model using the AOM/DSS model 1 and 2 was conducted. Wistar rats were assigned to 6 groups, five experimental and 1 control group. Group 1 received AOM/DSS method 1 and was treated with AuNP-p.L. Group 2 and 3 received AOM/DSS method 2 and were treated with AuNP-p.C and AuNP-p.14. Group 4 and 5 remained healthy and treated with AuNP-p.C and AuNP-p.14. Group 6 remained healthy receiving no nanoparticle treatment. After treatment, rats were sacrificed and tissue was processed for HRTEM. Tissue chosen for HRTEM analysis included: Group 1 (inflamed colon, rectum, pancreatic and kidney), Group 4 (kidney) and Group 5 (liver). Results: results obtained from nanoparticle characterization suggested that nanoparticles were conjugated to their respective peptides and were stable in dispersion. For in vitro studies, results suggested no AuNP targeting and localization in HT-29 cell lines. For in vivo studies, no colorectal cancer tumours were induced. TEM micrographs did not indicate the presence of nanoparticles in colon, rectum, pancreatic, kidney and liver tissue. However, AuNPs were found in the kidney tissue (group 4). Conclusion: Although the overall objectives were not met, this study provided insight into TEM cell preparation and optimization for future nanoparticle cell interaction research. This study also demonstrated the absence of AuNPs in healthy tissue and the presence of AuNPs in healthy kidney tissue through renal clearance, a favourable quality for diagnostic or therapeutic applications.
- Full Text:
- Authors: Cairncross, Lynn
- Subjects: Colon (Anatomy) -- Cancer -- Treatment , Cancer -- Early detection
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10351 , http://hdl.handle.net/10948/d1020921
- Description: Background: Colorectal cancer is the third most common cancer and cause of related deaths worldwide. Early colorectal cancer diagnosis is vital in reducing incidence and mortality. There is a need for the development of non-invasive screening tools for enhancing the detection of the disease. Cancer specific peptides are useful cancer targeting agents that can be used to specifically improve early detection strategies. Several cancer targeting peptides have been identified. Previous work investigated the specific binding of three of these peptides (p.C, p.L and p.14) conjugated to quantum dots and were found to bind to colorectal cancer cell lines (HT-29 and Caco-2). However, their uptake, localization and biodistribution in an in vitro and in vivo colorectal cancer model have not been determined. This is essential in gaining an understanding for future diagnostic or therapeutic based applications. Primary Aim: The aim of this study was investigate the localization of three selected peptides p.C, p.L and p.14 conjugated to gold nanoparticles in an in vitro and in vivo colorectal cancer model using HRTEM. Methodology: The AuNP/peptide conjugates were characterized by HRTEM and DLS. For in vitro studies; HT-29, Caco-2 and C3A cells were exposed to the AuNP-p.C, AuNP-p.L and AuNP-p.14, collected and processed for HRTEM to assess targeting and localization. For in vivo studies; the establishment of a colorectal cancer model using the AOM/DSS model 1 and 2 was conducted. Wistar rats were assigned to 6 groups, five experimental and 1 control group. Group 1 received AOM/DSS method 1 and was treated with AuNP-p.L. Group 2 and 3 received AOM/DSS method 2 and were treated with AuNP-p.C and AuNP-p.14. Group 4 and 5 remained healthy and treated with AuNP-p.C and AuNP-p.14. Group 6 remained healthy receiving no nanoparticle treatment. After treatment, rats were sacrificed and tissue was processed for HRTEM. Tissue chosen for HRTEM analysis included: Group 1 (inflamed colon, rectum, pancreatic and kidney), Group 4 (kidney) and Group 5 (liver). Results: results obtained from nanoparticle characterization suggested that nanoparticles were conjugated to their respective peptides and were stable in dispersion. For in vitro studies, results suggested no AuNP targeting and localization in HT-29 cell lines. For in vivo studies, no colorectal cancer tumours were induced. TEM micrographs did not indicate the presence of nanoparticles in colon, rectum, pancreatic, kidney and liver tissue. However, AuNPs were found in the kidney tissue (group 4). Conclusion: Although the overall objectives were not met, this study provided insight into TEM cell preparation and optimization for future nanoparticle cell interaction research. This study also demonstrated the absence of AuNPs in healthy tissue and the presence of AuNPs in healthy kidney tissue through renal clearance, a favourable quality for diagnostic or therapeutic applications.
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Sustainable construction (development) in the city of Cape Town
- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
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- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
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