Local government budgetary reforms reconsidered: the case of Amatole District Municipality, province of the Eastern Cape
- Authors: Hanabe, Lulamile Donacious
- Date: 2017
- Subjects: Municipal budgets -- South Africa -- Eastern Cape Municipal finance -- South Africa -- Eastern Cape , Local budgets -- Political aspects -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape Public administration -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/15093 , vital:28122
- Description: This research critically analysed the role, if any, that is played by the budgetary reforms in enhancing basic service delivery, with specific reference to the case of Amathole District Municipality. The main objectives of this study were to investigate and evaluate the causes of possible challenges encountered by the ADM in the implementation of local government budgetary reforms; to assess and determine the role played by budgetary reforms in promoting basic service delivery by the Amathole District Municipality; to analyse the extent to which budgetary reforms are used in the preparation of the municipal budget and the IDP; and to evaluate the level of ADM institutional capacity in delivering basic services to communities in terms of the municipality’s capital budget and financial plan. The study is premised on the fact that there is no guaranteed service delivery without a sound financial management and planning. In this study, it is acknowledged that municipalities in South Africa are struggling to implement the local government budgetary reforms; and as such, South African municipalities could succeed in rendering effective and efficient public services, provided the matters of governance are adhered to, as well as financial governance in particular. This research is solely based on the assumption that the Amathole District Municipality’s budgets and budget process, like other municipalities in South Africa, are done for the sake of compliance with the requirements of National Treasury and the MFMA – with less emphasis being placed on enhanced basic service delivery to communities. The study proposed to provide a brief literature review on the basic service delivery, with reference to the South African context, as well as a theoretical overview on the evolution of developmental local government budgetary reforms. The empirical survey and research methodology employed in the study are described, followed by the operationalization of the survey questionnaire used for gathering the field data. The research findings of the empirical survey are then statistically analysed, using statistical procedures. The qualitative data analysis involved thematic content analysis, being interpreted and reported on. The triangulation-research methodology was employed with the emphasis being on the quantitative and qualitative methodologies. The sample comprised councillors, officials and ward committee members. Questionnaires, with open and closed-ended questions, were employed for the councillors and the officials. Focus-group interviews were conducted with the ward committee members from the respective local municipalities.The findings strongly suggest that, the introduction of the budgetary reforms indeed resulted in a shift by municipalities from their core mandate – that is service delivery – to a more legislative-compliant mode of practice. Recommendations flowing from, inter alia, the results of the empirical study, are presented to improve financial governance and service delivery in the Amathole District Municipality, as well as in other municipalities in South Africa. If adopted, these recommendations should enable the Amathole District Municipality, as a development agent, to fulfil its developmental mandate, thereby addressing the matters of financial governance and service delivery.
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- Date Issued: 2017
L’etude comparative des elements merveilleux dans trois epopees africaines: Soundjata ou I’epopee mandingue, Emperor Shaka The Great: a Zulu Epic et Nsongo’a Lianja: I’epopee nationale des Nkundo
- Authors: Nkaongami, Josue Bosange
- Date: 2017
- Language: French , English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/5590 , vital:20944
- Description: This thesis is a comparative study in Francophone literature which analyses the supernatural factors in three African epics, namely the Sundiata or Mandingo Epic from West Africa by Djibril Tasmir Niane (1960), Emperor Shaka The Great : A Zulu Epic from Southern Africa by Mazisi Kunene (1979), and Nsongo’a Lianja : the National Epic of Nkundo People from Central Africa by Edmond Boelaert (1949). The study analyses similarities and differences between the supernatural figures in these epics and their respective societies using contextual and socio-critical theories. In this thesis it is demonstrated that the presence of supernatural forces is a sine qua non condition for the existence of the epic in the sense that : “the essential mark of the heroic personality in many African folk epics is its reliance on supernatural resources” (Okpewho 1979 : 119). This study shows that in Africa, supernatural forces play vital roles in the society and therefore dominate the African oral epic traditions. Furthermore, the study is significant in the sense that it tries to describe the worldview, especially the religious and cultural beliefs of the particular society or group that produces the epic. The thesis is made up of six chapters. In the first chapter, I outline the study’s subject matter, its aims and objectives, its significance, its assumptions and methodology. In the second chapter, I examine the impact of supernatural devices on the lives of the epic heroes Sundiata, Shaka, and Lianja, the predictions and divinations about their births, childhoods, exiles or epic journeys, their ascension to the throne as well as their genealogies and deaths. Such analysis allows one to identify the supernatural factors surrounding each stage of the life of the heroes, and to understand further the importance of supernatural forces in the communities and institutions where the heroes exercise their powers. In the third chapter, I discuss the typology of the supernatural forces in the heroic epics Sundiata, Shaka and Lianja, using Greimas’s theory of actants. I divide the characters into protagonists, accessories and opponents. In the fourth chapter, I examine the sources of the supernatural forces prevailing on Sundiata, Shaka, and Lianja. The chapter shows how supernatural agents act on the epic heroes and how these supernatural beings make or mar them in the course of the narratives. In the fifth chapter, I investigate the supernatural factors acting on the heroes’ opponents, and in chapter six, I examine the supernatural forces and heroism of the women in the three epics. In the conclusion, I demonstrate that this analysis of supernatural factors enables us not only to appreciate their place and function in the three African epics under study, but also opens a window onto the culture of the Mandingo, Zulu, and Mongo People’s : their activities, beliefs, taboos and the rules which organise their respective societies. , This thesis is presented in two parts: French and English.
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- Date Issued: 2017
Management of endotracheal tube cuff pressure in mechanically ventilated adult patients in intensive care units in Malawi
- Authors: Mpasa, Ferestas
- Date: 2017
- Subjects: Intensive care nursing -- Malawi Respiratory intensive care -- Malawi , Patient monitoring -- Malawi
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/19673 , vital:28930
- Description: Patients who are critically ill get often admitted to intensive care units (ICUs). The majority of these patients require support with their breathing and are thus connected to a mechanical ventilator. One aspect to consider in the mechanically ventilated patient is endotracheal tube cuff pressure (ETT) management. The management of ETT cuff pressure entails that nurses working in ICUs have the responsibility of ensuring that ETT cuff pressure is kept within normal range of 20-30 cmH20 for the safety of the patients in order to avoid complication of over and under inflation. Poor management of ETT cuff pressure places the mechanically ventilated patients under risk of tracheal injury. Tracheal injury may also be caused by over or under inflation of the ETT cuff. Over inflation of the ETT cuff can lead to the occlusion of capillaries lining the trachea at the cuff site, tracheal stenosis, and can also lead to the death of mucus membranes around the area, just to mention a few. On the other hand, under inflation of the ETT cuff, can lead to air leaks as well as aspiration of gastric contents into the tracheal tree. Therefore, in order to maintain ETT cuff pressure within normal ranges, evidence-based guidelines related to the management of ETT cuff pressure should be used. However, in Malawi the management of endotracheal tube cuff pressure in mechanically ventilated adult patients by nurses in ICUs is not well explored and it is not clear whether this practice is based on evidence-based guidelines. Furthermore, strategies on how to implement evidence-based guidelines in the ICU might not be known and poorly defined because of the complexity of the context. The study is therefore aimed at implementing and evaluating the effect of an evidence-based guideline on the management of ETT cuff pressure in mechanically ventilated adult patients by nurses in ICUs in Malawi using active (printed educational materials and monitoring visits) and passive (printed educational materials only) implementation strategies. The research study used a quantitative approach with multi-designs. Four phases were used in order to achieve the four objectives that were set. Phase one was the pre-test and used a survey design, two was the expert panel review of the evidence-based guideline, three was the implementation of the reviewed evidence-based guideline using a randomised controlled trial design and phase four was the post-test which used a survey design. The RCT included 25 participants from the control and 27 from the intervention group. Each group had three ICUs of which one in each group was from a private hospital and the other were government. Data collection in phases one and four was by a hand delivered pre-and post-questionnaire. In phase two the expert panel members with experience in critical care used the AGREE II Instrument to review the evidence-based guideline that was implemented. In order to gather data during the monitoring visits, the researcher recorded field notes. The applications that were developed by the University statistician consultant using visual basic applications in excel were used to analyse data. Two different implementation strategies were used to implement the evidence-based guideline. The control group used passive implementation strategy which was printed educational materials thus the evidence-based guideline and algorithm. The intervention group used both active and passive implementation strategies which was the printed educational materials thus the evidence-based guideline and algorithm plus monitoring visits by the researcher. In order to establish the effect of the implemented evidence-based guideline on the nursing care practice for the management of endotracheal tube cuff pressure an evaluative posttest survey was conducted in phase four of the research study. The results revealed that the majority of participants had gaps in both groups regarding nursing care practice for the management of endotracheal tube cuff pressure for the mechanically ventilated adult patients in the pretest but improved in the posttest. In the control group 52% had very low knowledge score, 16% had low score, 28% average, and 4% high score while in the category of very high score there was nobody. However, in the posttest those in the very low score were only 44% while the percentage in the low score remained 16%. There was an improvement in the average scores in the posttest such that only 44% were in this category. There was no one in the high and very high score in the pretest. On the other hand, in the intervention group, 78% had a very low score, 9% low score, and 13% were in the category of average score, while in the high and very high score category there was zero percent in the pretest. However, there was also an improvement in the posttest such that only 44% a very low knowledge score. But 19% had a low score, there were 37% in the average category and no one was in the high and very high score. Statistical analysis revealed that the results were not significantly different between and within groups. Improvements were observed in the two groups regarding the scientific knowledge scores for the nursing care practices in the posttest. Upon qualitative analysis of the data from the open-ended question, two main themes emerged thus the need for documentation of endotracheal tube cuff and the process of implementation the evidence-based guidelines. Sub themes such as lack of documentation; no part of routine care and monitoring not done at all were identified under the main theme of the need for documentation of ETT cuff pressure. The Guideline itself need to be clear; implementation strategies; follow up; incentives; supervision; incentives; time factor; resources or equipment required for successful implementation; nurses buy-in critical for the implementation; training detrimental to EBP implementation; nurses attitude crucial to implementation of EBGs and knowledge of nurses for guideline essential for the implementation were the sub themes identified under the main theme of the process of implementing the evidence-based guideline. All appropriate ethical considerations such as principles of autonomy and self-determination, confidentiality and anonymity, voluntary participation, right to receive treatment, informed consent, were adhered to throughout the research study. The research study was unique in nature because it was the first of its kind in Malawi and it contributed to the awareness of the recommended practice for management of endotracheal tube cuff pressure in the ICUs in the country by implementing an evidence-based guideline. The unique contribution of the study is that it is a challenge to implement evidence-based guideline in poor and resource constraint countries like Malawi.
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- Date Issued: 2017
Mineral governance and human development : the case of Western Ghana
- Authors: Danso, Felix
- Date: 2017
- Subjects: Mines and mineral resources -- Ghana Mining law -- Ghana Mineral industries -- Ghana
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8725 , vital:33472
- Description: This thesis focuses on mineral governance and how it can contribute to ameliorating human development challenges in Ghana. The study adopted the human centered mineral resource governance approach to assess the mineral governance structure in Ghana and identified that, the current system is a colonial legacy and does not promote human development in Ghana. The study, whilst recognizing the legacies of colonialism, argues that in order for mineral resources to be managed responsibly to promote human development, there should be a paradigm shift to focus on how mineral resources are governed. As a result, the study, relying on the human centered development approach investigates how mineral resources can be governed to promote development in Ghana, with specific focus on the mineral wealth Western Region of the country. Due to the finite nature of mineral resources, the human centered development approach argues that revenues from mineral resources should be invested in human capacity building and medical care delivery. Further, the mining sector should be integrated with other non-mining sectors of the economy to create jobs and provide alternative livelihoods which will go a long way to assist in the general expansion and growth of the country‟s economy. Although this thesis is a case study of mineral governance in Ghana, it can serve as a springboard to appreciate the role mineral governance can play in promoting people centered development in other sub – Saharan mineral wealth countries.
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- Date Issued: 2017
Monetary and fiscal policy effects on unemployment and inflation in Uganda
- Authors: Sebuliba, Nantumbwe Aminah
- Date: 2017
- Subjects: Monetary policy -- Uganda Fiscal policy -- Uganda
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14904 , vital:27899
- Description: Over the recent past, Uganda has experienced disproportionate volatility in inflation alongside rapid growth of unemployment. Whilst inflation has been curtailed to single digit figures since the economic crisis of the 1970s, nevertheless, in the recent past, inflation volatility and unemployment have constrained Uganda’s growth outlook. Like many various developing countries, Uganda has interacted monetary and fiscal policy frameworks as macroeconomic tools to spur productive growth. Most developing countries like Uganda continue to grapple with the challenges of jobless growth which is largely attributed to unstable inflationary pressures as well as low investment which further eggravated rapid expansion in unemployment levels. Government policy efforts have recently been greatly inhibited by rising youth unemployment rates in the country, this has greatly affected Uganda’s growth dynamics. Whilst developed countries have successfully used monetary and fiscal policy frameworks in their pursuit to macroeconomic stability, due to their complex structural economic dynamics, low income countries face challenges in implementing both monetary and fiscal policy to stabilize their economies. Central banks across all countries strive for low and predictable inflation as key in fostering economic growth. The debate over the applicability between monetary and fiscal policy frameworks in the pursuit of enhanced growth continues among policy analysts. The general observation especially in low income countries pertains to the use and effective coordination of monetary and fiscal policy in efforts to stabilize these economies. Despite numerous public expenditure reforms implemented and decline in poverty levels in Uganda, unemployment continued to rise over the past decade consequently inhibiting the country’s growth prospects which has ultimately undermined the econoimy’s capacity to external shocks. Keynes and the monetarists ignited the contentious debate over the superiority between monetary and fiscal policy frameworks which has transformed macroeconomic policy application. A conducive private sector environment as well as large expansions of infrastructure are key fundamental aspects of the development strategy in developing countries, they enhance growth in per capita income. Whilst the monetary authority emphasizes price stability when formulating policies, the fiscal authority pursues its objectives accommodative of the underlying circumstances in the economy. This study aimed to establish an econometric model to predict the impact of monetary and fiscal policy on unemployment and inflation in Uganda using annual time series data for the period 1980 to 2013. The study sought to investigate the influence of monetary and fiscal policy variables on the Ugandan economy in relation to unemployment and inflation. The analysis in the study is based on a twofold oriented objective. The first objective was to investigate monetary and fiscal policy dynamics in Uganda in relation to unemployment. The second objective examined the conduct of monetary and fiscal policy framework on inflation in Uganda. The study analysis begins with a review of literature on the various monetarists and Keynesian theories in relation to the underlying monetary and fiscal policy frameworks. Considering the analysis was a twofold objective, two empirical models linked to unemployment and inflation as well as their relative determinants are specified. The Empirical literature review examined in the study is based on various monetary and fiscal policy theories as well as empirical works by Keynesians, classical economists and the Friedman views. The time series data used were obtained from published sources of the World Bank and IMF, the Uganda Bureau of Statistics (UBOS), Ministry of Finance, Planning and Economic Development (MoFPED) statistical reports and annual statistical drafts from the Uganda Revenue Authority (URA) and Bank of Uganda (BOU). To empirically investigate the influence of monetary and fiscal policy variables on unemployment and inflation in Uganda, considering the use of two dependent variables i. e unemployment and inflation, hence, two estimation techniques were applied in the study namely; the Modified Ordinary Least Squares that comprise of FMOLS and DOLS and the Autoregressive Distributed Lag (ARDL) approach. The estimation analysis in the study contains two main parts which are spread over two chapters. The first part of the analysis deals with the effects of fiscal and monetary policy on unemployment. The estimation techniques applied in the study included the Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS) applied to a Vector Autoregressive (VAR) model. The analysis regressed monetary and fiscal policy aggregates on unemployment in a twofold objective. The first sub section regressed fiscal policy aggregates on unemployment using; total government expenditure, total government revenue, tax revenue and trade openness on unemployment using both FMOLS and DOLS techniques. The second sub-section regressed monetary policy on unemployment using; interest rates, money supply, real effective exchange rates and inflation being regressed against unemployment. To test for presence of unit root among the variables of the sample period of 1980 to 2013, the study employed three approaches; i.e. the Augmented Dickey Fuller (ADF) test, Phillips-Perron (PP) test and Kwiatkowski–Phillips–Schmidt–Shin (KPSS) test. Included in this analysis is the test for structural breaks to further determine stationarity in the data series. The results revealed the presence of structural breaks. Structural breaks tend to inhibit stationarity among the variables at levels. However, when presence of structural breaks is taken into consideration, it simplifies empirical estimation analysis under review. The Johansen Cointegration approach was further applied to establish existence of a stable long-run relationship between monetary policy and fiscal policy as well as their respective variables included in the model in relation to unemployment, this further entailed estimation of FMOLS and DOLS in the model estimation analysis. The results from the above analysys show a negative and statistically significant relationship between total government expenditure (LGOVTEXP) and unemployment (LUNEMPLOYMENT). However, tax revenue, trade openness as well structural reforms which denotes the (SB) coefficient all show a positive and significant relationship with unemployment. Additionally, total government revenue (LGOVTREV) shows a negative relationship with unemployment although statistically insignificant. The DOLS results in this analysis all show statistically insignificant results between all the variables and unemployment. The second subsection using DOLS, analysed the impact of monetary policy on unemployment, revealed a negative and significant relation between interest rates, real exchange rates and structural reforms (SB) with unemployment. Money supply indicates a negative but statistically insignificant relationship with unemployment. However, inflation has a positive and statistically significant relationship with unemployment. The normality tests conducted indicate normal distribution of the residuals. Similiraly, the AR inverse roots show stability of the models estimated whilst the multi-collinearity and Wald tests all showed unbiased estimation results. Having analysed the effects of fiscal and monetary policy on unemployment the interest was to further test the impact of fiscal and monetary policy on inflation. This part constitutes two sub-sections. The ARDL approach ws used to analyse the influence of fiscal policy on inflation. The results reveal a negative and statistically significant relationship between inflation (DLINF) and total government expenditure (DLGOVTEXP) both lagged twice. Similiraly, total government revenue (DLGOVTREV) and tax revenue (DLTAXREV) both lagged once indicate a negative and statistically significant relationship with inflation. However, unemployment lagged three times indicates a negative and statistically insignificant relationship with inflation whilst trade openness lagged three times has a positive and satatistically significant relationship with inflation. The Granger causality test results revealed among all the fiscal policy aggregates used, only inflation Granger causes total government revenue. The second part on the effects of fiscal and monetary policy on inflation used monetary variables; interest rates (DLINT), money supply (DLMS) and real exchange rates (DLREER). The ARDL results revealed all coefficients to have positive signs. Inflation and real exchange rates lagged five and four times respectively have a positive and significant relationship with the dependent variable of inflation. However, interest rate and money supply lagged five and three times respectively show a positive and statistically insignificant relationship with inflation. The estimated model showed no evidence of presence of serial correlation through numerous diagnostic tests performed. These include; heteroscedasticity, residual normality and misspecification tests as well as the Cusum stability tests. Under the analysis of monetary policy dynamics on inflation, the Granger causality test revealed that inflation Granger causes interest rates. Similiraly, real exchange rate Granger causes inflation. The ARDL results in this sub-section suggest that inflation regressed against its own lagged values is statistically significant in explaining variations on inflation. Further, interest rates, money supply and real exchange rates significantly explain variations in inflation during the period under review. The results from the above analysis suggest that firstly, the fiscal authority in Uganda should formulate dynamic as well as robust fiscal reforms that can effeficiently be coordinated with sound monetary policy reforms. This ought to stimulate meaningful economic growth in the economy which would further enhance employment growth. Secondly, policy authorities should implement macroeconomic policies which harmonise public spending whilst at the same keep inflation subdued. In this regard, inflation targeting policies should be strengthened. Thirdly, the macroeconomic policy framework in Uganda should be coordinated with strong employment targeting policies in an effort to broaden labour market dynamics.
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- Date Issued: 2017
Ngomso 'special school': contestations of morality and education in the Eastern Cape
- Authors: Pattenden, Oliver
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65200 , vital:28704
- Description: Expected release date-May 2019
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- Date Issued: 2017
Nonlinear optical behavior of lanthanide phthalocyanines and their conjugates with a selection of nanomaterials
- Authors: Sekhosana, Kutloano Edward
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4580 , vital:20695
- Description: This thesis presents novel asymmetrical and symmetrical lanthanide phthalocyanines (Pcs) characterized using a number techniques including proton nuclear magnetic resonance, electron spin resonance, time correlated single photon counting, FTIR spectrometry, MALDI-TOF mass spectrometry, UV-Vis spectrometry, Raman spectroscopy and CHNS elemental analysis. The design of theses lanthanide Pcs takes the form of mononuclear, binuclear, trinuclear, bis- and tris(phthalocyanines). Nanomaterials such as zinc oxide nanoparticles (ZnO NPs), multi-walled carbon nanotubes (MWCNTs) and graphene oxide nanosheets (GONS) (oxidized and reduced) were employed for covalent linkage to mono- and binuclear phthalocyanines as conjugates. Transmission electron microscopy was used to characterize ZnO NPs, MWCNTs and GONS alone and when linked to lanthanide Pcs. Lanthanide Pcs alone and when linked to ZnO NPs, MWCNTs and GONS where embedded in polymers such as poly (methyl methacrylate) (PMMA), poly (bisphenol A carbonate) (PBC) and poly (acrylic acid) (PAA) for thin film preparation. The thickness of the thin films was determined by utilization of the knife edge attachment of the A Bruker D8 Discover X-ray diffraction (XRD). Optical limiting properties of lanthanide Pcs alone and as conjugates in solution and when incorporated into polymers were determined by employing a Z-scan technique. It emerged that low symmetry lanthanide Pcs (19, 20 and 21), the blue forms of bis(phthalocyanines) (only in solution; 24 and 28) as well as tris(phthalocyanines) (30 and 31) exhibit low limiting threshold (Ilim) values in solution and thin films (particularly PBC and PAA). The low limiting threshold values make these lanthanide Pcs reliable optical limiters.
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- Date Issued: 2017
Nonlinear optical responses of phthalocyanines in the presence of nanomaterials or when embedded in polymeric materials
- Authors: Bankole, Owolabi Mutolib
- Date: 2017
- Subjects: Phthalocyanines , Phthalocyanines -- Optical properties , Alkynes , Triazoles , Nonlinear optics , Photochemistry , Complex compounds , Amines , Mercaptopyridine
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/45794 , vital:25548
- Description: This work describes the synthesis, photophysical and nonlinear optical characterizations of alkynyl Pcs (1, 2, 3, 8 and 9), 1,2,3-triazole ZnPc (4), mercaptopyridine Pcs (5, 6 and 7) and amino Pcs (10 and 11). Complexes 1, 2, 4, 7, 8, 9 and 11 were newly synthesized and characterized using techniques including 1H-NMR, MALDI-TOF, UV-visible spectrophotometry, FTIR and elemental analysis. The results of the characterizations were in good agreement with their molecular structures, and confirmed the purity of the new molecules. Complex 10 was covalently linked to pristine graphene (GQDs), nitrogen- doped (NGQDs), and sulfur-nitrogen co-doped (SNGQDs) graphene quantum dots; gold nanoparticles (AuNPs); poly(acrylic acid) (PAA); Fe3O4@Ag core-shell and Fe3O4- Ag hybrid nanoparticles via covalent bonding. Complex 11 was linked to Agx Auy alloy nanoparticles via NH2-Au and/or Au-S bonding, 2 and 3 were linked to gold nanoparticles (AuNPs) via clicked reactions. Evidence of successful conjugation of 2, 3, 10 and 11 to nanomaterials was revealed within the UV-vis, EDS, TEM, XRD and XPS spectra. Optical limiting (OL) responses of the samples were evaluated using open aperture Z-scan technique at 532 nm and 10 ns radiation in solution or when embedded in polymer mixtures. The analyses of the Z-scan data for the studied samples did fit to a two-photon absorption mechanism (2PA), but the Pcs and Pc-nanomaterial or polymer composites also possess the multi-photon absorption mechanisms aided by the triplet-triplet population to have reverse saturable absorption (RSA) occur. Phthalocyanines doped in polymer matrices showed larger nonlinear absorption coefficients (ßeff), third-order susceptibility (Im [x(3)]) and second-order hyperpolarizability (y), with an accompanying low intensity threshold (Ium) than in solution. Aggregation in DMSO negatively affected NLO behaviour of Pcs (8 as a case study) at low laser power, and improved at relatively higher laser power. Heavy atom-substituted Pcs (6) enhanced NLO and OL properties than lighter atoms such as 5 and 7. Direct relationship between enhanced photophysical properties and nonlinear effects favoured by excited triplet absorption of the 2, 3, 10 and 11 in presence of nanomaterials was established. Major factor responsible for the enhanced nonlinearities of 10 in the presence of NGQDs and SNGQDs were fully described and attributed to the surface defects caused by the presence of heteroatoms such as nitrogen and sulfur. The studies showed that phthalocyanines-nanomaterial composites were useful in applications such as optical switching, pulse compressor and laser pulse narrowing.
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- Date Issued: 2017
Nontsizi Mgqwetho’s the nation’s bounty: a prophetic voice towards an African literary theory
- Authors: Nxasana, Thulani
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4547 , vital:20687
- Description: This thesis seeks to examine the ways in which Africans and African scholarship in particular have relied on the West to lead the way in scientific inquiry, theory and ways of approaching literary texts thus the stunting effects of this in the growth and development of uniquely African literary scholarship and theorising. In his seminal work, Decolonising the Mind, Wa Thiong’o (1987a) stresses that “...how we view ourselves, our environment even, is very much dependent on where we stand in relationship to imperialism in its colonial and neocolonial stages; that if we are to do anything about our individual and collective being today, then we have to coldly and consciously look at what imperialism has been doing to us and to our view of ourselves in the universe” (Wa Thiong’o, 1987a, p.88). Although most African countries obtained their liberation decades ago, seemingly western cultural imperialism still dominates and plagues the African psyche; hence they largely look to the West and ways of the West for established and emergent theoretical conceptions. This thesis aims to interrogate popular western literary theories unquestioningly used to analyse African works, particularly feminism and post-colonial theory; furthermore, to show crucial factors not taken into account such as the evolving power dynamics in African societies, the role of the “sacred” or spirituality which often forms and informs the dynamics of the text, and lastly, based on the poetry of Nontsizi Mgqwetho, to advocate for the need for an African literary theory and put forward the essential tenets of such a theory. The poetry of Xhosa poet, Nontsizi Mgqwetho, is used to analyse the complexities and dynamics of African literary production written in African languages; her poetry is written in isiXhosa to a Xhosa audience, a far cry from the assumption that African literary texts are concerned with writing to the “centre” as post-colonial theorists claim. Her work explicitly provides Africans with an approach to overcome territorial and cultural imperialism; she sees within the African psyche and traditional values empowering modes of resistance against any type of domination and through her poetry illustrates meaningful ways that Africans can critically engage with and examine the positives and negatives of cultural exchange and or assimilation, and the effects thereof while at the same time remaining proudly Africa.
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- Date Issued: 2017
Online mentoring as a transformative tool for female career and business development
- Authors: Oosthuizen, Nadine
- Date: 2017
- Subjects: Mentoring in business -- South Africa Glass ceiling (Employment discrimination) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20510 , vital:29301
- Description: The under-representation of females at management level due to the glass ceiling effect has globally received considerable attention. Research found that one of the remedies for females to progress beyond the glass ceiling, was access to a mentor in senior management. Females receiving mentoring in the workplace perform at greater levels as they gain reflected power, advise and the right to use essential resources. Yet, access to mentors was recognised as a barrier to females’ professional career success, both in the corporate field and to develop their small businesses. Fortunately, the revolution in technology has led to online mentoring which combines conventional mentoring relationship approaches with new technology and provides wider access to a pool of mentors. The increasing popularity of online mentoring can be attributed to the benefits it offers stereotyped individuals and those from marginalised groups. The purpose of this study therefore was to ascertain the enabling conditions necessary for effective online mentoring in South Africa, as well as how it can be used to develop the careers of females (both corporate employees and small business entrepreneurs). The study followed a mixed method approach with a sequential exploratory design. Background literature on conventional mentoring in addition to oniline mentoring assisted in contextualising the many issues relating to conventional mentoring which also apply to online mentoring. Primary data was collected in three phases (two qualitative and one quantitative). The data collection method for phases one and two of the enquiry was interviews with the use of a semi-structured interview schedule and for phase three, a survey via an online structured questionnaire. The biographical profiles of the participants interviewed during phases one and two were presented as case studies. Based on the content analysis of the qualitative interviews with five South African mentors, six female mentees from Africa, two South African online mentoring field specialists and one United States online mentoring field specialist, three main themes were identified viz. online mentoring processes, challenges and enabling conditions. Online mentoring processes identified for effective online mentoring related to the application-, selection-, matching- and conflict resolution procedures. Mentoring challenges related to matching preferences, technology impediments, cultural fit problems, language differences, lack of mutual trust, scheduling and frequency and duration of meetings, the impersonal nature of online mentoring and specific mentee- and mentor-related challenges. Based on the content analysis, the conditions for creating an effective online mentoring environment addressed some of the challenges alluded to and could be classified as generic, mentee-specific and mentor-specific enablers. Generic online mentoring enablers are those conditions necessary for creating an effective online mentoring environment for the mentoring pair such as the ability to establish a trusting relationship, flexible meeting schedules, training offered, the expression of emotions online, having a technology infrastructure in place, clear objectives and relationship boundaries, a desirable programme- and meeting duration with adequate meetings, using multiple contact methods and following a hybrid mentoring approach. Mentor specific issues to create an effective online mentoring environment are mentors with exceptional personal qualities that are knowledgable and experienced, while mentee specific issues relate to continuous mentee commitment and that mentees should have been previously exposed to mentoring. The constant comparative data analysis provided insight into how similar or dissimilar institutions approach online mentoring process and the challenges related to the local (South African) online mentoring environment as compared to those globally. Sixty-three respondents (South African mentors both male and female and female mentees who have undergone conventional mentoring) completed the online structured questionnaire on their perceptions of the online mentoring conditions necessary for effective online mentoring. From the exploratory factor analysis results of the online survey in phase three of the study, six valid and reliable conditions necessary for online mentoring were identified namely, infrastructure readiness, demographic matching preference, mentor characteristics, the communication process, mentoring pair perceptions and mentoring pair relationship. The multiple regression analysis performed established one statistically significant relationship. The perception that the mentoring pair hold of online mentoring influence the achievements of the mentee. This study has thus identified several conditions necessary for effective online mentoring globally, as well as for South Africa. South Africa has a pool of knowledgeable mentors involved in global online mentoring progammes and they can assist with online mentoring in the South African communities in need of assistance. However, South Africa can learn from well-established global online mentoring institutions how to implement an effective online mentoring programme, but will need the necessary financial resources to do so. This study further provided evidence on how online mentoring can be utilised for the career advancement of female corporate employees and those owning small businesses. Some guidelines were provided on how to overcome the various challenges associated with online mentoring globally, and those specific to South Africa. The use of mobile technology instead of computer-mediated technology was recommended as it provides greater access to online mentoring, especially for rural communities. It is also more user-friendly for those with limited computer technology skills.
- Full Text:
- Date Issued: 2017
Optimisation of a mini horizontal axis wind turbine to increase energy yield during short duration wind variations
- Authors: Poole, Sean Nichola
- Date: 2017
- Subjects: Wind turbines -- Design and construction , Horizontal axis wind turbines -- Blades , Wind turbines -- Aerodynamics , Wind power
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/7036 , vital:21196
- Description: The typical methodology for analytically designing a wind turbine blade is by means of blade element momentum (BEM) theory, whereby the aerofoil angle of attack is optimized to achieve a maximum lift-to-drag ratio. This research aims to show that an alternative optimisation methodology could yield better results, especially in gusty and turbulent wind conditions. This alternative method looks at increasing the aerofoil Reynolds number by increasing the aerofoil chord length. The increased Reynolds number generally increases the e_ectiveness of the aerofoil which would result in a higher or similar lift-to-drag ratio (even at the decreased angle of attacked require to maintain the turbine thrust coe_cient). The bene_t of this design is a atter power curve which causes the turbine to be less sensitive to uctuating winds. Also, the turbine has more torque at startup, allowing for operatation in lower wind speeds. This research is assumed to only be applicable to small wind turbines which operated in a low Reynolds number regime (<500 000), where Reynolds number manipulation is most advantageous.
- Full Text:
- Date Issued: 2017
Optimization of flexible spectrum in optical transport networks
- Authors: Boiyo, Duncan Kiboi , Gamatham, Romeo
- Date: 2017
- Subjects: Digital communications Optical fiber communication , Optical communications Fiber optics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14609 , vital:27803
- Description: The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from fibre-linked terminals. The eventual outcome of the high demand for broadband is strained optical and electronic devices. The backbone optical fibre transport systems and techniques such as dense wavelength division multiplexing (DWDM), higher modulation formats, coherent detection and signal amplification have increased both fibre capacity and spectrum efficiency. A major challenge to fibre capacity and spectrum efficiency is fibre-faults and optical impairments, network management, routing and wavelength assignment (RWA). In this study, DWDM and flexible spectrum techniques such as wavelength assignment and adjustment, wavelength conversion and switching, optical add and drop multiplexing (OADM) and bitrate variable transmission have been experimentally optimized in a laboratory testbed for short- and long-haul optical fibre networks. This work starts by experimentally optimising different transmitters, fibre-types and receivers suitable for implementing cost effective and energy efficient flexible spectrum networks. Vertical cavity surface-emitting lasers (VCSELs) and distributed feedback (DFB) lasers have been studied to provide up to 10 Gb/s per channel in 1310 nm and 1550 nm transmission windows. VCSELs provide wavelength assignment and adjustment. This work utilises the non-return-to-zero (NRZ) on-off keying (OOK) modulation technique and direct detection due to their cost and simplicity. By using positive intrinsic negative (PIN) photo-receivers with error-free BER sensitivity of -18±1 dBm at the acceptable 10-9-bit error rate (BER) threshold level, unamplified transmission distances between 6 km and 76 km have been demonstrated using G.652 and G.655 single mode fibres (SMFs). For the first time, an all optical VCSEL to VCSEL wavelength conversion, switching, transmission at the 1550 nm window and BER evaluation of a NRZ data signal is experimentally demonstrated. With VCSEL wavelength conversion and switching, wavelength adjustments to a spectrum width of 4.8 nm (600 GHz) can be achieved to provide alternative routes to signals when fibre-cuts and wavelength collision occurs therefore enhancing signal continuity. This work also demonstrates a technique of removing and adding a wavelength in a bundle of DWDM and flexible channels using an OADM. This has been implemented using a VCSEL and a fibre Bragg grating (FBG) providing a wavelength isolation ratio of 31.4 dB and ~0.3 𝑑𝐵 add/drop penalty of 8.5 Gb/s signal. As a result, an OADM improves spectrum efficiency by offering wavelength re-use. Optical impairments such as crosstalk, chromatic dispersion (CD) and effects of polarization mode dispersion (PMD) have been experimentally investigated and mitigated. This work showed that crosstalk penalty increased with fibre-length, bitrate, interfering signal power and reduced channel spacing and as a result, a crosstalk-penalty trade-off is required. Effects of CD on a transmitted 10 Gb/s signal were also investigated and its mitigation techniques used to increase the fibre-reach. This work uses the negative dispersion fibres to mitigate the accumulated dispersion over the distance of transmission. A 5 dB sensitivity improvement is reported for an unamplified 76 km using DFB transmitters and combination of NZDSF true-wave reduced slope (TW-RS) and submarine reduced slope (TW-SRS) with + and – dispersion coefficients respectively. We have also demonstrated up to 52 km 10 Gb/s per channel VCSEL-based transmission and reduced net dispersion. Experimental demonstration of forward Raman amplification has achieved a 4.7 dB on-off gain distributed over a 4.8 nm spectral width and a 1.7 dB improvement of receiver sensitivity in Raman-aided 10 Gb/s per wavelength VCSEL transmission. Finally, 4.25-10 Gb/s PON-based point to point (P2P) and point to multipoint (P2MP) broadcast transmission have been experimentally demonstrated. A 10 Gb/s with a 1:8 passive splitter incurred a 3.7 dB penalty for a 24.7 km fibre-link. In summary, this work has demonstrated cost effective and energy efficient potential flexible spectrum techniques for high speed signal transmission. With the optimized network parameters, flexible spectrum is therefore relevant in short-reach, metro-access and long-haul applications for national broadband networks and the Square Kilometre Array (SKA) fibre-based signal and data transmission.
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- Date Issued: 2017
Performance of magnetic nanocomposites for the removal of some selected contaminants from aqueous solution
- Authors: Ojemaye, Mike Onyewelehi
- Date: 2017
- Subjects: Nanocomposites (Materials)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8746 , vital:33508
- Description: In this thesis, the performances of magnetic nanoparticles based materials were assessed for the removal or reduction of heavy metals in aqueous solutions. The successful synthesis of a novel adsorbent, azomethine functionalized magnetic nanoparticles (MNP-Maph) by covalent bonding between the amine group (-NH2) of amine functionalized magnetic nanoparticles (MNP-NH2) and carboxylic group (-COOH) of 4-{[(E)-phenylmethylidene]amino}benzoic acid (Maph-COOH) was achieved. This adsorbent was examined for the removal of di and trivalent ions (Cu2+, Zn2+, As3+, Pb2+ and Hg2+) from aqueous solutions. Also, magnetic photocatalyst with silica interlayer (NiFe2O4-SiO2-TiO2) was synthesized and employed for the reduction of Cr(VI) in aqueous solution. The photocatalytic reduction efficiency of this material was compared with that of magnetic titanium dioxide (NiFe2O4-TiO2) photocatalyst and titanium dioxide (TiO2) to ascertain the material with the best photocatalytic efficiency and ease of separation. All synthesized materials were characterized by using XRD, FT-IR, TEM, SEM, TGA and VSM before application. For the adsorption processes, the effects of pH, contact time, adsorbent dose and temperature were examined to ascertain the experimental condition necessary for the optimal removal of metal ions from solution. The data obtained from all experiments were fitted into four kinetic models; pseudo-first order, pseudo-second order, elovich and intra particle diffusion models to determine the mechanism involved in the adsorption of these di and trivalent ions while two isotherm models were employed in the adorption processes; these include: Langmuir and Freudlich models. Also, for the photocatalytic experiment, the effects of pH, contact time and photocatalyst dose were investigated to determine the experimental conditions necessary for the optimal reduction of Cr(VI) in aqueous solution. MNP-Maph showed excellent removal capacities of 34.08, 35.83, 50.08, 58.24 and 59.24 mg g-1 for Cu2+, Zn2+, As3+, Pb2+ and Hg2+ respectively compared to data previously reported in literature. This is as a result of the high affinity of azomethine group towards metal ions which tremendously enhanced removal of metal ions by adsorption. The incorporation of azomethine to magnetic nanoparticles improved the affinity towards metal ions removal forming strong electrostatic interaction between the adsorbent active sites and adsorbates. Also, the utilization of NiFe2O4-SiO2-TiO4, NiFe2O4-TiO2 and TiO2 for the reduction of Cr(VI) in aqueous solution showed a good photocatalytic performance with NiFe2O4-SiO2-TiO2 showing to be better in terms of both photocatalytic reduction and magnetic separation. TiO2 was observed to have 96.7percent reduction efficiency within 240 min while NiFe2O4-SiO2-TiO2 has 96.5percent reduction efficiency within 300 min and NiFe2O4-TiO2 gave 60percent reduction efficiency within 300 min of UV irradiation. This magnetic photocatalyst composite (NiFe2O4-SiO2-TiO2) gives the advantage of avoiding the problem of separation often encountered with most photocatalyst materials including TiO2 by allowing separation with the aid of a magnetic field. The adsorption processes were all described by pseudo-second order and Langmuir isotherm models while the photocatalytic process was described by Langmuir-Hinshelwood (L-H) kinetic model. Furthermore, thermodynamic experiment studied for the adsorption processes showed that all metal ion adsorption except Hg2+ by MNP-Maph were endothermic in nature, rapid and spontaneous indicating the feasibility of the sorbent material for the removal of metal ions from aqueous solutions. Also, regenerability study conducted to determine the reusability of sorbent material after seven cycles showed the potential to reuse sorbent material seven times or more. The reusability of the sorbent material was observed to show a percentage of an average of 78percent using 50:50 mixture of 0.1 mol dm-3 HNO3 and HCl for all adsorption processes. For the photocatalytic experiment, regenerability using 0.1 mol dm-3 for 1 h was observed to be very impressive after 3 runs for all synthesized photocatalytic materials. This thereby implies that the removal of metal ions by these materials will not in any way introduce secondary pollutants into the environment. Rather, it will avert the production of secondary pollutants. Also, the use of simple conventional chemicals for the regeneration of synthesized materials showed that regeneration in this study is cost effective as regeneration has been known to cost about three quarter of the total operation and maintenance of an adsorption or photocatalytic process. Application of MNP-Maph to real wastewater sampled from five different wastewater treatment plants in Eastern Cape Province for the removal of Cu2+, Zn2+ and As3+ showed that removal efficiencies of approximately 80 percent were achieved for all three metal ions upon adsorption by MNP-Maph. These therefore show that the introduction of metal loving ligand such as Maph-COOH improved the efficiency of MNP towards the removal of heavy metal ions from aqueous solution. Also, silica positively influenced the performance of magnetic titanium dioxide towards Cr(VI) reduction and separation from aqueous solution. This study therefore showed that these materials should be considered for future applications in the area of water/wastewater decontamination.
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- Date Issued: 2017
Pharmacological evaluation of phragmanthera capitata (sprengel) balle, loranthaceae :a parasiticmistletoe growing on rubber trees
- Authors: Ohikhena, Franklin Uangbaoje
- Date: 2017
- Subjects: Hevea Hevea -- Diseases and pests Rubber
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8899 , vital:33937
- Description: Rubber tree (Hevea brasiliensis Muell.) is the world’s major source of natural rubber and a major non-oil, agricultural export commodity in the producing countries in Africa. However, it is highly susceptible to specific mistletoes of the Loranthaceae family. Phragmanthera capitate (Sprengel) Balle is the major mistletoe parasitizing the rubber tree plantations in Africa and hence, alongside with other mistletoes, has attracted indiscriminate destruction from plantation owners. Indiscriminate destruction of plants could be as a result of ignorance of the importance or benefit(s) of the plants and this could lead to their extinction if not checked. Hence, there is the need for scientific documentation of plants and their uses because, from the pharmacological perception, the destruction of a plant could result in the permanent loss of a potential drug. Therefore, this study was aimed at documenting and evaluating the pharmacological potentials of P. capitata collected from rubber tree. Fresh leaves were gently rinsed with water and dried. Dried leaves were pulverised and kept at 4oC when not in use. Pulverised leaves were extracted with acetone, methanol, ethanol and water and concentrated to give the respective solvent crude extracts used in most of the assays. From the extraction, Methanol had the highest yield of 21.5percent, water had 10.8percent and acetone was 6.87percent while ethanol had the lowest yield of 4.3percent. Standard spectrophotometry assays on the extracts were used to quantify some major phytochemicals of pharmacological interest and also to determine the antioxidant potentials of the sample. The result revealed high amounts of phenols (175.53 ± 0.32 mg GAE/g to 218.62 ± 3.38 mg GAE/g), flavonoids (197.06 ± 3.80 mg QE/mg to 679.82 ± 6.26 mg QE/g) and proanthocyanidins (128.83 ± 1.69 mg CE/g to 645.68 ± 6.35 mg CE/g) with the acetone extract having the highest amount of the phytochemicals while the aqueous extract had the least. The results of the antioxidant assays revealed that the sample had high radical scavenging potentials with comparable inhibitory concentrations to standard antioxidant drugs. The proximate and mineral analysis on the pulverised sample showed that it is rich in carbohydrate with a composition of 57.73 ± 0.33 g/100 g. Protein, fat and fibre compositions were 12.50 ± 0.50 g/100 g, 3.34 ± 0.18 g/100 g and 11.66 ± 0.54 g/100g. The total energy composition was 310.97 ± 2.30 Kcal/100 g. The mineral composition revealed high potassium level of 1047.83 ± 34 mg/100g. Calcium (6.22.58 ± 0.01 mg/100g), magnesium (361.15 ± 0.01 mg/100 g) and phosphorous (115.40 ± 0.01 mg/100 g) were also present in appreciable amounts. The toxicity of the four extracts was assayed using brine shrimp. The LC50 in all the solvent extracts was greater than 1 mg/mL which according to Meyer’s index and other indexes signify “no toxicity” for crude plant extracts. Antimicrobial activity of the extracts was done using the minimal inhibitory concentration (MIC) assay against 10 bacteria (Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus pyogenes, Vibrio cholera, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli) and 4 fungi (Trichophyton mucoides, Trichophyton tonsurans, Candida albicans and Aspergillus niger) of human pathogenic strains. The MIC of the antibacterial assay ranged from 1.25 mg/mL to 5 mg/mL for the organic extracts while no activity was observed in the aqueous extract at the highest concentration tested. However, the aqueous extract had a great inhibitory activity on all four of the tested fungi with a MIC of ≤ 0.3125 mg/mL to 1.25 mg/mL while only two fungi (Trichophyton Tonsurans and Aspergillus niger) were susceptible to the organic extracts. The MIC of the TB causative pathogen, Mycobacterium tuberculosis (H37Rv) strain ranged from 25 μg/mL (acetone and aqueous extracts) to 50 μg/mL in the ethanol extract while it was > 50 μg/mL (highest concentration tested) in the methanol extract. This study revealed that the sample has the potential in phytotherapy against oxidative stresses (inflammations) caused by free radicals. It could also be a useful herb in combating diseases caused by pathogenic organisms. The high anti-Mycobacterium tuberculosis activity observed in this study suggests it could be a plant with high promise in the fight against tuberculosis. The toxicity evaluation signifies it is safe for further plant-based pharmaceutical explorations. This study also validated some reported ethnopharmacological uses of this plant and call for its protection from indiscriminate destruction in rubber plantations and other crop gardens/plantations in the world.
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- Date Issued: 2017
Pharmacological investigations of Kedrostis africana (L.) Cogn. and Vernonia mespilifolia Less. used in folk medicine in the Eastern Cape, South Africa
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
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- Date Issued: 2017
Physical organic studies of substituted norbornyl systems: aspects of mechanisms and chirality
- Authors: Singh, Alicia
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50558 , vital:25999
- Description: Fenchone and camphor are essential natural products that are available optically pure and contribute to the chiral pool in asymmetric synthesis. Further, they are both derivatives of norbornane, a structure that undergoes a remarkable diversity of rearrangements in acidic conditions. This work explores two aspects of the camphor/fenchone derived systems. Firstly an attempt to clarify rearrangement mechanisms on a camphor system successfully via deuterium labelling and unsuccessfully via derivatization of fenchone (with rearrangement) to produce other 13C-labelled camphor substitutions, has resulted in confirmation of a theoretically proposed, highly concerted Wagner-Meerwein, 6,2 - hydride shift, Wagner-Meerwein rearrangement in competition with an associated 2,3-methide shift. Kinetics and activation parameters for many steps have been resolved in this rearrangement of the deuterium labelled camphor-derived tosylate system to two pairs of isotopomers. Further, the kinetics and formation of an unexpected pair of dimers encountered during the scheme for 13C labelling are investigated in detail. These dimers (forming during the initial stages of the synthetic scheme) are unusual in that they are not expected rotamers of each other, but diastereomers resulting from chirality of a sulfur atom in a sulfite moiety. A feasible mechanism of formation that matches the kinetics has been proposed in this unexpectedly complex system, and thermodynamic parameters have been determined. The second aspect of substituted norbornyl systems pertains to their chirality, and the influence of this chirality on reaction mixtures, with an aim to identify novel chiral micellar catalysts for use in heterogeneous reaction mixtures. Headway has been made towards the synthesis of the appropriate surfactants to be used in the construction of these micelles, but extensive molecular dynamics simulations have illustrated the feasibility of forming the stable chiral micelles in a dual-solvent system, and detail precisely the influence of chirality on surrounding media. These studies add important physical organic data as well as show the immense possibilities pertaining to substituted norbornane systems.
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- Date Issued: 2017
Poverty, Food insecurity and livelihood diversification among households in Eastern Cape province, South Africa
- Authors: Megbowon, Ebenezer Toyin
- Date: 2017
- Subjects: Food supply -- South Africa -- Eastern Cape Poverty -- South Africa -- Eastern Cape Households -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/13086 , vital:39464
- Description: Livelihood diversification have been thought to be a rural issue where agriculture is the main source of income, however in an era of dwindling global and national economic situations, livelihood diversification have been seen to be prominent among urban dwellers as well although literatures have focused more on rural households. There is also a growing evidence in literature showing that livelihood diversification is indispensable for improving household welfare. This study adopts the sustainable livelihood framework to investigate the pattern and determinants of livelihood diversification (number of income sources) and the welfare (poverty and food insecurity) effect of livelihood diversification on household in the Eastern Cape Province of South Africa. Indicators of poverty and food security were computed using Multidimensional Poverty Index (MPI) and FANTA’s Household Dietary Diversity Scores (HDDS). The study relied on data obtained from the Nation-wide annual General household Survey carried out in 2014 having 3033 households sampled from the Eastern Cape Province of South Africa. Data were analyzed using descriptive statistics, Poisson regression, Tobit regression and logistic regression models. The result of the Multidimensional Poverty Index headcount revealed that while majority (71.28 percent) of the households are not multidimensionaly poor, 20.51 percent, 6.89 percent and 1.32 percent are vulnerable to multidimensional poverty, multidimensionaly poor and severely multidimensionaly poor respectively. The study also revealed that while there is a significant differences between multidimensional poverty status in the both rural and urban area, there is no much differences when considering the gender of the household head. This indicates that poverty is still a rural phenomenon in the Province. Furthermore, the largest contributor (dimension and indicators) to household multidimensional poverty in the Province is standard of living dimension and specific indicator are the fuels use for cooking, water and space heating, toilet system, dwelling and asset accumulation are the most areas of highest deprivation. The household dietary diversity score show that household have a diverse diet with a mean score of 6.9; however the diversity is skewed toward food groups that do not give expected nutritional diets for a healthy and an economically active life. In General pulse diet and vegetables (spinach and wild green leaves) are least consumed in the province. Consumption of fruit is shown to be less consumed in the rural area as compared to the urban area. Descriptive analysis of livelihood diversification among households in the province revealed that majority of households are not diversified. Poisson regression estimate produced a good fit shown by the statistical insignificance of the deviance good of fit (p=1.09). Age of household head, population group of the head, education attainment of the head, engagement in agriculture, recipient of remittance and number of economic active member of the household) were found to be statistically significant (p<0.01) and were found to influence the probability of a household diversifying their livelihood base in the study area. The result of the Tobit regression on effect of livelihood diversification and other household socio-economic characteristics on household poverty suggest livelihood diversification has no statistically significant effect on the probability of being poor in the study area. Other variables found to influence poverty are, household head’s gender (male), age, education, employment status, access to electricity, engagement in agriculture, salary earning, economic active size of household and asset score) were found to be significantly (p<0.01) to influencing multidimensional poverty of the poor households. The result of the logistic regression indicates that livelihood diversification has no significant effect on the probability of a household being poor. Gender of head, age of household head, education attainment of the head, access to electricity, engagement in agriculture, recipients of pension, number of economic active and living in urban area were also found to be statistically significant in influencing household food insecurity in the province. The findings illustrates that livelihood diversification may not be relevant for household welfare in the case of South Africa. However promoting livelihood diversification remain imperative for household welfare in the South Africa in the long-run. It further illustrate that gender of head, education, access to electricity, home agriculture are imperative for the improvement of household welfare. Hence the study recommends policy relating to conditional granting of cash grant support, intensification of rural development programmes, education affordable and accessible at all level and support home stead or subsistence agriculture.
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- Date Issued: 2017
Pre-service teachers’ concerns on teaching practicum: a mixed methods case study from Zimbabwe
- Authors: Chitumwa, Chemunondirwa Christopher
- Date: 2017
- Subjects: Practicums -- Zimbabwe Teachers -- Training of -- Zimbabwe , Teaching -- Zimbabwe -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/14840 , vital:27879
- Description: The purpose of this study was to identify and examine pre-service teachers’ concerns relating to their teaching practicum in Zimbabwe and to suggest strategies that could be used to support them in a digitalised era. This study was necessitated by the desire to understand the concerns that pre-service teachers experience during teaching practicum in a fast changing world and in a depressing, unstable socio-politico-economic environment. The study employed a meta-conceptual approach comprising constructivist and social cognitive epistemology as its theoretical framework. A concurrent mixed methods research design was utilised to address the research questions. Both quantitative and qualitative methods were used to design the study, collect, and analyse data. Thirty participants comprising of 24 pre-service teachers and six college supervisors were purposively selected for the qualitative study from United College of Education in Zimbabwe. Qualitative data was collected by means of interviews and analysed through a thematic analysis. For the quantitative phase, 300 pre-service teachers were chosen through stratified random sampling from the same institution and were asked to complete a questionnaire. One hundred and ninety-three questionnaires were returned and usable, giving a return rate of 64%. Data from the survey were analysed using descriptive and inferential statistics. Findings from the study revealed that pre-service teachers experience diverse concerns during teaching practicum that included classroom management, teacher knowledge, socio-economic factors, workload, interpersonal relationships and assessment anxiety. Findings from the quantitative phase revealed some differences in the levels of concerns among the year groups. A general downward trend in the levels of concerns was detected except for teacher beliefs concerns that remained constant. Findings from the qualitative phase of the study revealed that the concerns that pre-service teachers experienced during teaching practicum had negative impact on their classroom practice. Most of the student teachers had devised some coping strategies to deal with their concerns and they were satisfied with the quality of support from mentors and peers, but not that from their supervisors. In an increasingly globalised world, the researcher felt that teaching practicum related concerns could be minimised by exploiting the benefits of digitalised knowledge and communities of learning.
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- Date Issued: 2017
Production systems, profitability and participation in the mainstream markets by smallholder broiler chicken farmers of Maseru district in Lesotho
- Authors: Mphahama, Litsoanelo Evodiah
- Date: 2017
- Subjects: Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8678 , vital:33423
- Description: Growth in global demand for broiler chicken meat has become tremendous, hence; as one segment of poultry, broiler chicken production has a privilege to highly contribute to nations’ nutritional demands because of the shorter productive age, with only 42 days needed to reach a marketable weight with a high rate of productivity. In fact; in developing countries the importance of broiler chickens to the national economy cannot be overemphasized, as it has become a popular industry especially for the smallholder farmers that have great contribution to the economies of their countries. However, it is difficult to see a bright future for smallholder broiler chicken farmers in this rapidly changing industry structure. A major concern is that this group of farmers faces severe constraints and challenges to taking advantage of mainstream market opportunities; a situation that would impede the success of the sector leading the farmers to exit the business. The aim of this study was to investigate factors challenging small-holder broiler chicken profitability and the choice of market channels used by these famers. The study was conducted in the Maseru district in Lesotho. Using availability sampling; 220 smallholder broiler chicken farming households were purposively selected. Data were obtained from secondary sources and by an administration of questionnaires from January until March 2016. Excel, XLSTAT and SPSS were used for analyzing the data. The descriptive findings of this study were applied to the biographical characteristics of the smallholder broiler chicken farmers. Ages, household size, marital status, occupation, source of credit and broiler chicken production system were determined using SPSS through graphs, mean and percentages. Findings from determining broiler chicken profitability revealed that a mean gross margin of M607.74 in the rural areas and M665.13 from the urban areas were obtained. The results indicated broiler chicken feeds and day old chicks as major operational costs in broiler chicken rearing. This study also explored factors that influence broiler chicken profitability on smallholder farmers. The results suggest that cost starter feeds, cost finisher feeds, transport cost and cost dox/doc negatively affected broiler chicken profits while a number of sold chicken and chicken price had a positive influence. The empirical results from the Binary option of market participation revealed that three variables (number of years in broiler chicken business, access to transport, and access to extension) and one variable (stock size) in rural and urban households respectively had positive signs, thereby, implying an increase in participation in the formal markets. On the other hand two variables; access to information and household size in rural and urban households respectively had negative associations, thus implying that an increase in any of these variables may be associated with a decrease in the formal market participation level. The study therefore, concludes that number of sold chicken and chicken price positively affect broiler chicken profitability however; household size have negative effect on the level of formal market participation among urban households. Therefore, it is recommended that smallholder broiler chicken farmers increase their stocking volumes and get amalgamated into cooperatives in order to be able to access formal markets; hence increased broiler chicken profits.
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- Date Issued: 2017
Psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria
- Authors: Aderibigbe, John Kolawole
- Date: 2017
- Subjects: Psychology, Industrial Emotional intelligence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8642 , vital:33250
- Description: The study investigated psychological capital and emotional intelligence as moderators of the relationship between occupational stress and organisational citizenship behaviour among graduate employees in Nigeria, using the explanatory cross-sectional (survey) research design and three sampling techniques (The Two-stage Cluster Sampling Method, The Convenience Sampling Method and The Purposive Sampling Technique) to sample 1532 male and female graduate employees in Nigeria. A structured validated questionnaire was used to collect data from the respondents. Six hypotheses were stated and tested in the study towards propounding a model, using Pearson Correlation Analysis, Multiple Regression Analysis and Structural Equation Modelling. The results show that there is a weak positive relationship between occupational stress and organisational citizenship behaviour, r = 0.070, p<0.01; there is a significant positive relationship between psychological capital and organisational citizenship behaviour, r = 0.588, p<0.01; there is a significant positive relationship between emotional intelligence and organisational citizenship behaviour, r = 0.473, p<0.01; psychological capital is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 8.514; R2= 0.011; p <.05; emotional intelligence is a significant moderator of the relationship between occupational stress and organisational citizenship behaviour, F (2,1529) = 5.945; R2= 0.008; p <.05; psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour, F (1,1530) = 221.240; R2= 0.186; p <.05; psychological capital has a direct and significant positive effect on organisational citizenship behaviour, R= 0.657, p<.001; emotional intelligence has a direct and significant positive effect on organisational citizenship behaviour, R= 0.183, p<.001; psychological capital has a direct and significant positive effect on occupational stress, R= 0.100, p<.001; emotional intelligence has a direct and significant positive effect on psychological capital, R= 0.547, p<.001. Based on the results, the study concludes that psychological capital and emotional intelligence are significant joint moderators of the relationship between occupational stress and organisational citizenship behaviour. The proposed model was, therefore, empirically confirmed. The researcher recommends that the empirical model of effective management of occupational stress and organisational citizenship behaviour, which has been propounded in the study, should be adopted and applied by teachers, lecturers, seminar facilitators, workshop trainers, supervisors and managers during their coaching or training sessions.
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- Date Issued: 2017