Acacia dealbata invasion and clearing in Upper Tsitsana communal areas of South Africa: human perceptions and ecological impacts
- Authors: Coka, Nwabisa
- Date: 2024-04-04
- Subjects: Restoration ecology South Africa Eastern Cape , Acacia dealbata , Invasive plants South Africa Eastern Cape , Working for Water Programme , Invasive plants Control South Africa Eastern Cape
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434876 , vital:73113
- Description: The number of invasive alien plants in South Africa and globally continue to increase mostly due to increased human movement and climate change. It is estimated that approximately 10 000 hectares of South Africa’s terrestrial land is invaded by invasive alien species. Recent studies have reported that invasion by invasive alien plants cost South Africa billions of Rands every year through loss of water and ecosystem services. Although much has been done to understanding invasion trends, patterns, and processes in South Africa, little is knowns regarding human benefits linked to alien plant invasion as well as human perceptions regarding management interventions, particularly clearing by the national Working for Water programme. This thesis took a socio-ecological approach to assess (i) local people perceptions and knowledge of Acacia dealbata invasion and clearing, and (ii) extent of grazing grass diversity and composition recovery following A. dealbata clearing. To answer the above-mentioned objectives, both qualitative (face-to-face interviews) and quantitative (vegetation surveys) methods were used in grasslands located in upper Tsitsana catchment, South Africa. Results from the 165 interviews conducted in six villages show that most villagers are aware of A. dealbata in the area, but do not know that it is an invasive alien plant. Respondents accrue several benefits from the plant that include firewood (98% across all villages), construction pools (34% across all villages), and shade (3% across all villages). Respondents identified several costs associated with A. dealbata invasion, such as roots damage to houses (37% across all villages), hindering growth of crops (15% across all villages), and takes up yard space (29% across all villages). Most of the villages ranked the effects of A. dealbata on grazing as highly severe. Villages indicated that the Working for Water clearing programme presents them with socio-economic benefits such as employment and money. Some villagers noted that the clearing of A. dealbata in the area restores grazing grass (62% across all villages) and water (32% across all villages). Based on these interview survey results, the study concludes that A. dealbata has both costs and benefits that support local people’s livelihoods; therefore, its management should consider views for local users. Grass surveys conducted in 1 m2 quadrats that were replicated 15 times across four paired A. dealbata cleared and grassland sites showed that the removal of A. dealbata facilitates the recovery of native grasses. Of the 14 different grazable grass species that were identified across all quadrats only one (Bulbostylis sp.) is not palatable to livestock. Although grass cover was significantly (p < 0.05) higher in the grasslands than the cleared patches, grass richness was significantly (p < 0.05) higher in the cleared patches an indication that recovery of different grasses is taking place. Based on these vegetation survey results; the study concludes that recovery of grazing grasses after A. dealbata clearing four years ago is following a positive trajectory as the cleared sites are looking like the grassland sites. Overall, the study recommends that management of A. dealbata in Tsitsana landscape requires a socio-ecological approach to understand user benefits whilst at the same time developing measure to control the plant. The study has provided evidence that A. dealbata clearing facilitates passive restoration of grazing grass and local villages are aware of these restoration benefits. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
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- Date Issued: 2024-04-04
Influence of argon ion implantation on the thermoluminescence properties of aluminium oxide
- Authors: Khabo, Bokang
- Date: 2022-04-06
- Subjects: Aluminum oxide , Thermoluminescence , Ion implantation , Kinetic analysis , Oxygen vacancies , Argon , Irradiation
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/234220 , vital:50173
- Description: The influence of argon ion implantation on the thermoluminescence properties (TL) of aluminium oxide (alumina) was investigated. Aluminium oxide (Al2O3) samples were implanted with 80 keV Ar ions. An unimplanted sample and samples implanted at fluences of 1×1014, 5×1014, 1×1015, 5×1015, 1×1016 Ar+/cm2 were irradiated at a dose of 40 Gy and heated at a rate of 1°C/s using a Risø reader model TL/OSL-DA-20 equipped with a Hoya U-340 filter. The thermoluminescence glow curves showed five distinct peaks with main peaks at 178°C, 188°C, 176°C, 208°C, 216°C and 204°C for the unimplanted sample as well as implanted samples. The peak positions of the samples were independent of the irradiation dose suggesting that the samples were characterised by first order kinetics. This was also confirmed by the TM-TSTOP analysis. It was observed that the TL intensity decreases with fluence of implantation. This observation suggests that the concentration of electron traps responsible for thermoluminescence decreases with ion implantation. The decrease in electron concentration might be due to the formation of non-radiative transition bands or the creation of defect clusters and extended defects following the ion implantation and ion fluence increases. The stopping and range of atoms in matter (SRIM) program was used to correlate the TL response of Al2O3 with defects under ion implantation. Subsequent to ion implantation, it was found that the number of oxygen vacancies which are related to electron traps are higher than the number of aluminium vacancies. Kinetic analysis was carried out using the initial rise, Chens peak shape, various heating rate, the whole glow curve, glow curve fitting and the isothermal decay methods. The activation energy was found to be around 0.8 eV and the frequency factor to be of the order 108 𝑠−1 regardless of the implantation fluence. This means that argon ion implantation did not affect the nature of electron traps. The dosimetric features of samples were also investigated at doses in the range of 40 – 200 Gy. Samples generally showed a superlinear response at doses less than 140 Gy and sublinear response at doses higher than 160 Gy. , Thesis (MSc) -- Faculty of Science, Physics and Electronics, 2022
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- Date Issued: 2022-04-06
Impact of a manufacturing execution system on production lead-times at a pharmaceutical company
- Authors: Kemp, Lizet
- Date: 2021-04
- Subjects: Pharmaceutical industry , Computer integrated manufacturing systems
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51253 , vital:43238
- Description: Despite the development in computerised systems and in planning and manufacturing programmes since 1950, Pharma-X* still record their manufacturing processes manually, using a paper batch record, (Manufacturing Batch Records (MBR) or Batch Manufacturing Records (MBR)) and equipment logbooks. There can be up to five logbooks and an equipment control label for each type of equipment used at each process step, which must be completed manually before manufacturing can commence. This paper-based system is a laborious practice, as excessive time is spent completing manual entries into the MBRs and logbooks. Lean thinking, a popular manufacturing improvement philosophy, would describe any such activity as non-value adding and therefore waste (Melton, 2005). Pharma-X started implementing a manufacturing execution system (MES) in June 2018 to automate the manual entries of the manufacturing process. Once the MES is completely implemented, it will allow pharmacists the opportunity to review the manufacturing batch in real-time and to conduct investigations when an error occurs. MES will also allow the operators to complete logbooks with a single scan of equipment, as well as decrease manual entries into the MBR. This study was a quantitative research study comparing data of the past state (Pharma-X pre-MES) with data of a current state (Pharma-X post-MES implementation) to assess the impact of the implementation of a manufacturing execution system and lean manufacturing on a pharmaceutical company. A meaningful reduction in manufacturing lead time and reduction in time wastage were proven but further study and data documentation are recommended. , Thesis (M Pharm) -- Faculty of Health Sciences, 2021
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- Date Issued: 2021-04
Impact of automation technologies on employment
- Authors: Dukashe, Loyiso
- Date: 2021-04
- Subjects: Automation , Automation -- Economic aspects , Employees -- Technological innovations
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/51335 , vital:43265
- Description: Throughout history, the introduction of automated technologies has an impact on on human labour. The current wave of technological advancement has expanded the scope of automation raising a concern about the future relevance of human labour. Hence, this study investigated possible futures on the effect of automation technologies on employment. The study adopted a desktop research approach using secondary sources employing future studies methodologies. The study identified a need to transform employment, educational systems and social policy to proactively respond to future effects of automation technologies towards employment. , Thesis (MBA) -- Faculty of Business and Economic Sciences, Business Administration, 2021
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- Date Issued: 2021-04
Evaluation of surface functionalized electrospun polyacrylonitrile nanofibers for heavy metal ions removal from synthetic wastewater
- Authors: Maqinana, Siphosethu Sesethu
- Date: 2020-12
- Subjects: Nanofibers , Nanostructured materials
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20871 , vital:46680
- Description: Heavy metal ions are elements that are discharged into water streams from municipal or industrial waste. In abundance, they can be threating to the environment and human health. Amongst other several convention methods, adsorption has been proven to be the most effective method in the removal of heavy metal ions from wastewater. The aim of this research was to fabricate electrospun polyacrylonitrile (PAN) nanofibers and modify their surface to improve the adsorption efficiency for Chromium and Cadmium metal ions from synthetic wastewater. Electrospun nanofibers PAN nanofibers were fabricated via electrospinning process though careful monitoring of its parameters and modified via two-step process: hydrolysis with sodium hydroxide (NaOH), hydrochloric acid (HCl) and ethylenediamine (EDA). The morphologies, functional groups, thermal stability, chemical composition and crystallinities or amorphous structures of the nanofibers were characterised by Scanning electron microscopy (SEM), Fourier-Transform Infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD), respectively. The experiments were conducted in batch tests to analyse the effect to pH, contact time and initial concentration of the solution. Ultraviolet-Visible spectroscopy (UV-Vis) was used to analyse the concentration of metal ions. The adsorption equilibrium was reached after 120 min with a maximum adsorption capacity of 301.1 mg/g for Cd(II) ions and 195.02 mg/g for Cr(VI) ions. The adsorption capacity increased with increasing pH and initial concentration of the solution. The adsorption capacity of Cd(II) and Cr(VI) ions was higher at pH 8 and 10, respectively. The equilibrium data was best described using Freundlich isotherm with a maximum adsorption capacity for Cd(II) ions than Cr(VI) ions. Pseudo-second order kinetic model best fitted both heavy metal ions with R2 value of 0.99 for Cr(VI) ions and 0.67 for Cd(II) ions. Heavy metal ions were desorbed from the nanofibers after one regeneration cycle with an equilibrium concentration of 4.83 mg/L for Cr(VI) ions and 43.06 mg/L for Cd(II) ions. , Thesis (MSc) (Chemistry) -- University of Fort Hare, 2021
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- Date Issued: 2020-12
An assessment of professional development for public service employees: a case study of the Eastern Cape office of the premier
- Authors: Nzoyi, Lindokuhle
- Date: 2020-04
- Subjects: Performance--Management (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/55118 , vital:49121
- Description: Professional development in the public service sector has attracted increased interest of researchers over the years. It has been tipped to bolster the quality of public services, which is often frowned upon, especially in the developing world. Thus, this study was carried out with the aim of establishing the perceptions of managers at the Office of the Premier (OTP) regarding the need for a comprehensive framework to enhance service delivery. The study adopted a qualitative case study approach that was based on the use of semi-structured interviews as the primary data collection method. Public officials who work in the OTP were interviewed to determine the challenges encountered by the government department in an effort to improve their performance management. The findings of the study revealed that the OTP has various developmental and training programmes in place to equip its officials to enhance their skills, competences and Knowledge which includes the Leadership programmes and Change Management that aims at linking management and employees to improve performance of the organisation. The findings showed that there is a need for a learning organisation within the OTP, as stipulated in the Senge model. The OTP also needs to conduct regular staff training, which is of paramount importance for improving competence and performance in the delivery of services. The study concluded by proposing the need to establish a learning environment that will provide opportunities for employees to be capacitated with relevant skills development programmes. , Thesis (MPA) -- Faculty of Humanities, School of Governmental and Social Sciences, 2020
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- Date Issued: 2020-04
Self-reports on the effectiveness of psychotherapy with therapists-in-training: an 18-month follow-up study at a psychology training clinic
- Authors: Angus, Catherine Clare
- Date: 1993
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193069 , vital:45295
- Description: The purpose of this study is to ascertain whether the clients who make use of the services of the Psychology Clinic at Rhodes University perceive the masters students being trained at the Clinic as providing adequate psychotherapy. Using a sample of 18 clients, who underwent psychotherapy at the Rhodes Psychology Clinic during 1990, a follow-up study was conducted to ascertain the perceived success of that psychotherapy. Those variables most pertinent to the outcome of psychotherapy are examined. The study uses both qualitative and quantitative methodology and shows that, overall, 89% of the clients who participated in this study perceived the psychotherapy at the Rhodes Psychology Clinic to be satisfactory. The study also highlights those factors which were perceived to be negative in the psychotherapeutic equation and it is hoped that the findings can be beneficial in planning more efficient services for the Clinic in the future. , Thesis (MA) -- Faculty of Humanities, Psychology, 1993
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- Date Issued: 1993