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High-resolution geological, petrological and geochemical investigation of the mid mid-lower c. 3.3 Ga Kromberg type type-section, Barberton greenstone belt, South Africa Africa

  • Authors: Ndlela, Sibusisiwe
  • Date: 2021
  • Subjects: Petrology -- Eswatini and South Africa -- Barberton Greenstone Belt , Geology -- Eswatini and South Africa -- Barberton Greenstone Belt , Geochemistry -- Eswatini and South Africa -- Barberton Greenstone Belt , Onverwacht Group (South Africa) , Barberton Greenstone Belt (Eswatini and South Africa) , Groups (Stratigraph) -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/172241 , vital:42179
  • Description: The geology of the SE limb of the Kromberg type-section, its origin and its evolution has remained controversial for more than five decades since its discovery by Viljoen and Viljoen (1969). Different lithostratigraphy and geodynamic models have been proposed that were centred around two end-member models, a continuous layer-cake stratigraphy model (Viljoen and Viljoen, 1969c, Lowe et al., 1999) or a tectono-stratigraphic model (de Wit et al., 2011, Furnes et al., 2012). Additionally, the Kromberg type-section mafic-ultramafic sequence represents a relatively thin, dismembered sequence compared to other formations or ‘complexes’ in the Onverwacht Group. Previous geology workers relied on the field interpretations for the construction of the geological architecture of the Kromberg type-section; but no petrographic analyses were conducted for accurate, integrated geological characterization of different rock compositions. To address controversies centred around the Kromberg type-section geology and geodynamic setting, this study is aimed at testing previously proposed stratigraphic and geodynamic models by integrating high-resolution geological mapping, petrography, mineral chemistry and whole-rock geochemistry to verify rock characterization. The aim is to accurately reconstruct the volcano-sedimentary architecture of the Kromberg type-section and to compare this to the results of previous fieldwork. Moreover, the manner in which the Kromberg sequence may relate to current Archean geodynamic models is evaluated, and a new model explaining the origin and evolution of the Kromberg type sequence is proposed. The integration of high-resolution field mapping, petrography and geochemistry has allowed for a high precision study and that has resulted in the construction of a new geological architecture for the SE limb of the Kromberg type-section. The stratigraphic thickness of the SE limb of the Kromberg sequence comprises dominant c. 80% volcanic rocks and minor c. 15% intrusive rocks, intercalated by 7 volcano-sedimentary chert horizons (c. 5%). Four main rock types (groups) are present in the Kromberg type-section with two sub-types of komatiitic basalts (the Badplaas-type and Geluk-types), Fe-rich tholeiitic basalt, cumulate peridotite, and a metadunite. Although the Kromberg type-section records sub-greenschist to lower greenschist facies, more than 50% of the rock samples classify as altered with parts of the stratigraphy recording extensive chloritization and severe ocean-floor silicification. Geochemical data revealed an enrichment in SiO2, K2O, Ba, Rb and variation in HREE for highly silicified samples whereas, chloritized samples are enriched in FeO and have concave upward LREE patterns. Partially chloritized tholeiites and komatiitic basalts have overlapping SiO2 signatures, relatively flat REE patterns and a small negative Nb anomaly in the primitive mantle-normalized spider diagrams. This thesis provides the first Lu-Hf isotope data on whole rock samples from the Kromberg type-section. The εHf values at t=3.33 Ga range between -0.62 to +4.18 and Hf model ages range between 3.43 - 4.27 Ga. The rock compositions are compared to the geochemistry of other greenstone belt rocks, which are considered to provide insight onto the geodynamic setting under which the Kromberg mafic-ultramafic sequence formed. The rock compositions reveal plume-related processes where a primitive mantle melt interacts with recycled mafic crust or mafic lower crust of older units of the Onverwacht Group. Only a small Nb anomaly is found in some samples and the data plots outside the subduction zone (forearc and back-arc) field. Rare-Earth element profiles are flat and not consistent with a subduction zone signature, as proposed in previous studies. Rifting of an oceanic floor in a juvenile basin is proposed for the formation of the Kromberg type-section rocks, prior to being tectonically accreted during regional transpressional deformation at c. 3.23 Ga.
  • Full Text:
  • Date Issued: 2021

Preparation, characterization and optimization of carbamazepine based pellets prepared by extrusion-spheronization technique

An investigation of the influence of knowledge-production and learning processes on complex practices in a community-driven citizen science initiative: A nature conservation case study

  • Authors: Alexander, Jaclyn
  • Date: 2020
  • Subjects: Science -- Citizen participation , Western Leopard Toad Conservation Committee , Environmental education , Frogs -- South Africa
  • Language: English
  • Type: text , Thesis , Masters , MEd
  • Identifier: http://hdl.handle.net/10962/138173 , vital:37603
  • Description: Community-driven citizen science initiatives have become an increasingly popular tool for combating social-ecological challenges that arise within communities. Scientific protocols have been designed to strengthen and support the accuracy and reliability of data collection and information sharing; however, little is understood of the dynamic social processes that reinforce and co-ordinate such community-driven action. This qualitative case study was undertaken to identify and understand complex organisational, political and socio-cultural processes (in particular knowledge-production and learning processes) that have guided, sustained and informed complex practices in a community driven citizen science initiative. The study aimed to inform the development of a social protocol that might be transferable to other citizen science contexts. The study drew on the theory of ‘Landscapes of Practice’, which highlights how multiple communities of practice overlap, interrelate, share knowledge and cross boundaries to create potential learning across a landscape. Additionally, ideas and typologies in recent citizen science literature offered perspective on the community-driven citizen science practices. This qualitative case study focused on the bounded case of the Western Leopard Toad Conservation Committee. Specific data generation tools (interviews, observations, document analysis and diagrams) were used from multiple perspectives over time to provide rigor and depth to the data. The study demonstrated how multiple ‘nexes of practice’ co-engaged in collective knowledge creation practices, which helped to enhance ‘knowledgeability’ across the landscape. This coordinated effort, however, was sporadic and inconsistent. Recommendations are made for the development of social protocols that could assist collaborators in citizen science initiatives to scrutinise and rethink their practices and to examine both their successes and shortfalls towards their shared interest.
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  • Date Issued: 2020

The determination of whether a Unified Communication System can be effective in supporting informal communication and collaboration in virtual teams

  • Authors: Hill, Kyle
  • Date: 2020
  • Subjects: Telecommuting , Virtual work teams , Telecommunication systems , Computer networks
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/146343 , vital:38517
  • Description: The overall objective of the research is to determine whether a Unified Communication System intervention can be effective in supporting informal communication and collaboration in virtual teams. In so doing, this research is aimed at developing a current framework of critical success factors for facilitating informal collaboration and communication. As teams have evolved to the point where there is no longer a need for team members to be co-located, with a greater importance now being placed on how they collaborate, this framework will also highlight how it can support virtual teams due to the huge potential advantage they can provide to the organisation. A virtual communication and collaboration system will be selected based on the outputs of the current framework and interactions which occur through the system will be observed to provide quantitative and qualitative results. In conclusion, the research will suggest recommendations for the successful implementation of informal communication and collaboration technologies within the organisation. The research will also indicate to a limited degree, the impact of the implementation of these technologies, and the outcome for the organisation, whether positive or negative. Whilst conducting the research, it became apparent that while the UCS was capable of performing the processes and functions required, the individuals and teams engaging with the technology did not always make use of the full scope of the technology provided. Regardless, a UCS was observed to provide direct benefits to an organisation in increasing communication and collaboration in the organisation. These increases can be observed in both the physical and virtual sense. However, the converse is true for generating social capital which lead to the observation that there are a smaller number of interactions happening in the smaller teams, but these are of higher value when compared to the larger teams of this study. It is also clear that the larger a team becomes, the more the trend is to focus on adopting new technologies to make their roles more efficient. This adoption is not however translated into outputs such as social capital but is translated into stronger networks and the formation of new networks. It is also clear that most negative factors around the UCS are related to the respondent’s hardware rather than the solution itself. Cost reductions because of virtuality will also be observed and using the Developed Framework as a blue print, an organisation should be able to observe direct benefits for an organisation by being able to confirm the thesis of this research in that having a UCS intervention is effective in supporting informal communication and collaboration in virtual teams.
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  • Date Issued: 2020

Non-government organizations’ adoption of knowledge management systems to enhance service delivery of projects in Grahamstown in the Makana region of the Eastern Cape Province, South Africa

  • Authors: Sherif, Nabiha Mohammed
  • Date: 2018
  • Subjects: Knowledge management , Organizational learning , Non-governmental organizations South Africa Makhanda , Human services South Africa Makhanda
  • Language: English
  • Type: text , Thesis , Masters , MCom
  • Identifier: http://hdl.handle.net/10962/61723 , vital:28052
  • Description: The object of this research is to enhance the performance of non-government organizations in the Makana region of the Eastern Cape Province of South Africa by the use of knowledge management practices and principles. Non-government organizations face several service delivery challenges that affect their performance. Knowledge management assists in enhancing performance by means of organizational learning. However, the adoption of knowledge management systems has been limited to the profit-making sector. This study includes an evaluation of the contributing factors influencing the adoption of knowledge management and the extent to which non-government organizations use knowledge management to promote organizational learning. An interpretivist, qualitative case study approach was used on five non-government organizations cases from the Makana region of the Eastern Cape Province of South Africa. A suitability profile sampling method was developed to select the non-government organization cases. The participants in the research include non-government organizations’ managers, employees and volunteers. Literature was explored to gain a better understanding of the research area. The research was initiated by an open-ended questionnaire to gather data from the participants, followed by a focus group to enrich the interpretation of the findings. The research proposes a framework to facilitate the adoption of knowledge management systems in non-government organizations. The findings of the research are intended to enhance the performance of non-government organizations projects by means of the use of knowledge management systems.
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  • Date Issued: 2018

Development and implementation of health promotion activities for the prevention of adolescent pregnancies

  • Authors: Chemuru, Nomsa Rutendo
  • Date: 2017
  • Subjects: Teenage pregnancy -- South Africa -- Makhanda , Teenage pregnancy -- Prevention -- South Africa -- Makhanda
  • Language: English
  • Type: Thesis , Masters , MPharm
  • Identifier: http://hdl.handle.net/10962/5115 , vital:20776
  • Description: Of the eight Millennium Development Goals (MDGs) established in 2000 by the World Health Organisation, Millennium Development Goals 5 aimed at improving maternal health by addressing the high maternal mortality rate and increasing universal access to reproductive health by 2015.Adolescent pregnancy contributes to maternal, perinatal and infant mortality and also worsens the empowerment of young girls by negatively affecting their physical, educational, social, and economic development.This is a pressing public health concern in South Africa. The reduction of adolescent pregnancy is vital for achieving the sustainable human, health social and economic development of society at large. Culturally sensitive interventions to prevent adolescent pregnancies not only integrate the communities' norms, values, practices and behavioural patterns into the intervention's design and implementation but also the historical, social and economic contexts in which they exist. Progress has been made on the research on health promotion and education in South Africa; however communities are often not consulted on the design and conduct of health promotion research projects.The aim of the study was to develop and implement culturally sensitive and appropriate health promotion activities for the prevention of adolescent pregnancy in Grahamstown, Glenmore and Ndwayana communities in the Eastern Cape, South Africa.Two community based organisations and community care workers associated with them participated in this Community Based Participatory Research using the PEN-3 cultural model. The first phase of this study involved semi-structured interviews carried out with 14 community care workers to identify factors and consequences of adolescent pregnancies in their respective communities. The audio-recorded interviews were transcribed and coded using NVivo® 2010 software. The PEN 3 cultural model was adopted in the studyto address the socio-cultural factors contributing to adolescent pregnancy in the communities. The second phase involved a series of interactive workshops with CCWs for a participatory development of the facilitator's manual. Responses from CCWs informed the design of this study's intervention strategies. A facilitator's manual was developed to implement health promotion intervention, leading to the third phase of this study. The guided implementationof the health promotion intervention for the prevention of adolescent pregnancy was carried out over a period of 14 months and evaluated in the final phase of the study. The facilitator's manual was modified based on feedback fromCCWs, on possible improvements and cultural appropriateness. Readability testing guided the final modification of the manual. According to the community care workers, there were a number of adolescents who fell pregnant in their communities each year. The CCWs identified the influence of family members, friends and other stakeholders as contributory factors to adolescent pregnancy. They identified the lack of parental support in informing and educating adolescents about sexual health. Adolescents themselves lacked the maturity to recognise the risks and consequences of adolescent pregnancy. The negative perceptions of contraception in the community were discouraging contraceptive use amongst the adolescents. However, the results showed that enablers such as home and school visits done by the community care workers can be utilised to prevent adolescent pregnancy. Other factors included lack of health promotion materials and activities with information about preventing of adolescent pregnancy, and if available, the material is in English, that the adolescents may not comprehend. Socio-economic factors such as poverty, the Child Support Grant, cross generational relationships and coerced sex further contributed to adolescent pregnancy in the communities.CCWs identified the need for a more comprehensive health promotion intervention to prevent of adolescent pregnancy. A facilitator's manual addressing the prevention of adolescent pregnancy was developed and modified through a series participatory workshops with the community care workers.The facilitator's manual was used by CCWs to conducthealth promotion activities encouraging the prevention of adolescent pregnancies within the community's clinics, schools and during home visits. Community based participatory research methods and the PEN-3cultural model were used to develop this culturally sensitive and community specific adolescent pregnancy intervention for and by the CCWs. The participatory development of the facilitator's manual and the regular interactive workshops with the CCWs were strengthened by embedding this project into the development programs of the two non-governmental organisations contributing to sustainable development programs for women and children.
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  • Date Issued: 2017

Governance and management of urban trees and green spaces in South Africa: ensuring benefits to local people and the environment

  • Authors: Chishaleshale, Mwale
  • Date: 2013
  • Subjects: Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4739 , http://hdl.handle.net/10962/d1006035 , Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
  • Description: In the face of rapid urbanization and global climate change, urban trees and green spaces (UTGS) can contribute to the welfare of people and the urban environment. Urban trees and green spaces can assist to address urbanization challenges related to environmental degradation. While functions of UTGS have been well documented in the developed world, they have not yet received full attention in much of sub-Saharan Africa. Consequently, UTGS are under threat from urban development and fragmentation. Notably, the problems associated with UTGS also fall into the governance realm and indications are that poor governance and management of UTGS can negatively influence the potential benefits of UTGS to local people and the environment. This formed a basis for this research. The main objective of the study was to determine the current governance and management approaches to UTGS in South Africa. Through document search and review, the study determined the governance institutions influencing UTGS at national level and at provincial level (in the Limpopo and Eastern Cape Provinces). Face-to-face and online survey methods were used to determine the extent to which 28 local municipalities had adopted planned, systematic and integrated management of UTGS. The snowball approach was used to determine the key actors involved in UTGS activities and interviews were conducted to establish the roles and capabilities of these actors. A total of 540 household interviews were conducted to determine the institutional factors influencing local peoples’ ability to access, plant and use UTGS. The findings of the study showed that UTGS have not been adequately covered in existing governance institutions and practice at national and provincial levels. Local government municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7.1 % of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32.1 % had tree policies; 28.6 % had tree bylaws; 21.4 % had tree planting schedules; 10.7 % had tree maintenance schedules and only 3.6 % had tree inspection schedules. Key actors involved in UTGS activities differed among levels of government. The actors included national and provincial government departments, local government municipalities, Non-Governmental Organizations, private sector companies and local volunteers. Most of the actors, however, either planted trees or provided tree seedlings to municipalities and the local people. Tenure security was a key institutional factor affecting peoples’ ability to plant, use or even remove trees from their residential plots. The same applied to trees in the streets and public parks. Whereas most respondents did not require permission to plant (79.8 %) or remove (75 %) trees on their residential plots, a majority of them required permission to plant and remove trees from streets (over 70 %) and public parks (over 80 %). However, with regard to planting and removing urban trees in public open spaces, 54% of the respondents indicated that permission was not required suggesting a lack of clarity among local residents on the issue. Overall, the findings of this study indicate that there is no political recognition and support for UTGS at almost all levels of government. This has resulted in the lack of incorporation of UTGS in urban planning and development and has caused UTGS to receive limited funding to permit planned and systematic management. Given the current rates of urbanization and urban development, the lowly prioritised UTGS are vulnerable to exploitation. To conserve UTGS and promote their potential contribution to local people and the environment, UTGS must be recognized and placed on political and development agendas. There is a need to develop national guidelines for UTGS management, assess the extent of the urban forest resource in local municipalities, clearly define the roles and capabilities of different actors, integrate UTGS in the urban planning and development system, and most of all seek to involve the local people in overall management and governance of UTGS.
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  • Date Issued: 2013

Clustering algorithms and their effect on edge preservation in image compression

  • Authors: Ndebele, Nothando Elizabeth
  • Date: 2009
  • Subjects: Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5576 , http://hdl.handle.net/10962/d1008210 , Image compression , Vector analysis , Cluster analysis , Cluster anaylsis -- Data processing , Algorithms
  • Description: Image compression aims to reduce the amount of data that is stored or transmitted for images. One technique that may be used to this end is vector quantization. Vectors may be used to represent images. Vector quantization reduces the number of vectors required for an image by representing a cluster of similar vectors by one typical vector that is part of a set of vectors referred to as the code book. For compression, for each image vector, only the closest codebook vector is stored or transmitted. For reconstruction, the image vectors are again replaced by the the closest codebook vectors. Hence vector quantization is a lossy compression technique and the quality of the reconstructed image depends strongly on the quality of the codebook. The design of the codebook is therefore an important part of the process. In this thesis we examine three clustering algorithms which can be used for codebook design in image compression: c-means (CM), fuzzy c-means (FCM) and learning vector quantization (LVQ). We give a description of these algorithms and their application to codebook design. Edges are an important part of the visual information contained in an image. It is essential therefore to use codebooks which allow an accurate representation of the edges. One of the shortcomings of using vector quantization is poor edge representation. We therefore carry out experiments using these algorithms to compare their edge preserving qualities. We also investigate the combination of these algorithms with classified vector quantization (CVQ) and the replication method (RM). Both these methods have been suggested as methods for improving edge representation. We use a cross validation approach to estimate the mean squared error to measure the performance of each of the algorithms and the edge preserving methods. The results reflect that the edges are less accurately represented than the non - edge areas when using CM, FCM and LVQ. The advantage of using CVQ is that the time taken for code book design is reduced particularly for CM and FCM. RM is found to be effective where the codebook is trained using a set that has larger proportions of edges than the test set.
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  • Date Issued: 2009

The impact of load and frequency on the biomechanical, physiological and perceptual responses to dynamic pushing

  • Authors: Cripwell, Adam Michael
  • Date: 2007
  • Subjects: Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5144 , http://hdl.handle.net/10962/d1008183 , Work -- Physiological aspects , Psychophysiology , Human engineering , Biomechanics
  • Description: The objective of the present research was to establish the biomechanical, physiological and perceptual responses of male operators to dynamic pushing tasks. The pushing tasks were performed using an industrial pallet jack with varying load/frequency combinations, in a controlled laboratory environment. Thirty healthy male subjects comprised the sample. Experimental procedures were conducted utilising the Chatillon ™ Dynamometer to measure force output in the initial, sustained and ending phases. The K4b2 Ergospirometer was used to assess physiological responses (heart rate and oxygen consumption [V02])' Nine recorded forces and nine experimental conditions formed the basis of this study, with subjects required to push three loads (200kg, 350kg, 500kg) at three frequencies (1120 sec, 1/40 sec, 1/60 sec) at a speed of 3.6km.h-1 over 14 metres on a co-efficient of friction controlled walkway for six minutes. Gait analysis, along with perceptions of exertion (,Central ' and 'Local' RPE) were collected during the third and sixth minutes of each condition . Body discomfort and contribution were identified upon completion of each condition. The results demonstrated that load and frequency interacted to influence responses within each domain. Increasing loads required increased force output during each stage of the push, which had a concomitant effect on physiological and perceptual responses. Significant differences arose between the initial, sustained and ending forces for each load, showing the direct relationship between load and force exertion. The combination of heaviest load/quickest frequency required the greatest physiological output, exceeding recommended guidelines for heart rate, V02 and energy expenditure responses. Intermediate combinations required moderate and acceptable energy cost. Linear relationships were established between heart rate and oxygen consumption , as well as between load and V02 , thus providing industrial practitioners an opportunity to evaluate task demands in situ. The combination of high forces and elevated physiological responses increased the subjective rating of the condition. The results emphasise the need to holistically consider all contributing factors in a dynamic pushing task. Dynamic pushing tasks place biomechanical, physiological and perceptual demands on the human operator, which must be minimised in order to ensure that this form of manual materials handling becomes sustainable in the long term.
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  • Date Issued: 2007

A phenomenological study of psychotherapy: a client explicates his experience

  • Authors: Frank, Anthony Ernest
  • Date: 1982
  • Subjects: Psychotherapy -- Research , Insight in psychotherapy , Psychotherapy -- Case studies , Psychotherapy patients
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3128 , http://hdl.handle.net/10962/d1006344 , Psychotherapy -- Research , Insight in psychotherapy , Psychotherapy -- Case studies , Psychotherapy patients
  • Description: From Introduction: This thesis involves a detailed explication of my experience as a client in psychotherapy. Being in therapy has brought about extremely important ·changes in my life and continues to do so. Being involved · in the field of· psychology as a student and therapist-to-be, the experience of therapy has also been a valuable source of a greater understanding of the process itself. The various facets of the importance of my experience of psychotherapy will become clear in my explication. It is a fact that experience, which is an essential aspect of our humanness, has been sadly neglected in psychological research. It is surely psychology's task to explore all aspects of humanity, and this neglect of experience has only fairly recently been questioned. Its reasons have been psychology's bias towards the natural sciences whose methods are not suitable for the study of experience. The tremendous achievements of the natural sciences caused psychology to adopt this slant, as Sigmund Koch (19.69) puts it, "The stipulation that psychology be adequate · to science outweighed the commitment that it be adequate to man". (p 65).
  • Full Text:
  • Date Issued: 1982
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