Antidiabetic and toxicological properties of Dianthus thunbergii (Caryophyllaceae) roots and Hypoxis argentea (Hypoxidaceae) corms
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
- Authors: Akinrinde, Akinleye Stephen
- Date: 2017
- Subjects: Medicinal plants--South Africa--Eastern Cape Traditional medicine--South Africa--Eastern Cape Diabetics--Alternative treatment--South Africa
- Language: English
- Type: Thesis , Doctoral , Biochemistry
- Identifier: http://hdl.handle.net/10353/16036 , vital:40606
- Description: Diabetes mellitus is a chronic metabolic disorder primarily characterized by elevated blood glucose levels. Its rapidly increasing prevalence as a major non-communicable disease is now a growing concern for both developed and developing countries. The development of safe, cost-effective and pharmacologically-effective medications continues to a major challenge of antidiabetic management. Since most conventional antidiabetic drugs are costly and present with numerous adverse effects, alternatives are increasingly being sought from natural sources, most notably medicinal plants, as viable approaches to tackling the scourge of this disease. In the Eastern Cape Province of South Africa, the roots of Dianthus thunbergii and corms of Hypoxis argentea are frequently used traditionally for the treatment of diabetes mellitus, although no scientific evidence exists to validate their effectiveness for diabetes management. The studies conducted in the resent research were, therefore, aimed at investigating the antidiabetic and toxicological properties of these plants, in an attempt to providing data towards validating their use in traditional management of diabetes mellitus. Aqueous and ethanol extracts of the underground parts of D. thunbergii and H. argentea were initially subjected to analysis of their phytochemical composition, relative to standard compounds, and the nature of their in-vitro antioxidant activities using standard spectrophotometric methods. The potentials of these extracts for cytotoxicity and/or cell proliferation were evaluated using MTT assay in HepG2 cells and Crystal violet assay in INS-1 cells. These activities were further examined in INS-1 cells using live cell fluorescence imaging techniques. To evaluate the antidiabetic properties of the extracts, they were screened for their inhibitory effects on the activities of different enzymes including α-amylase, α-glucosidase, porcine pancreatic lipase, Dipeptidyl peptidase IV (DPP-IV), collagenase and the drug metabolizing enzyme, CYP3A4, while also assessing their effects on protein glycation using in- vitro visible and fluorescence spectrophotometric approaches. Cell culture procedures were carried out to evaluate the effects of the extracts on glucose utilization in HepG2 cells and L6 myotubes; nitric oxide production in RAW 264.7 macrophages; glucose metabolism in INS-1 cells, as well as triglyceride accumulation in 3T3-L1 pre-adipocytes. Furthermore, identification of compounds present in the aqueous and ethanol extracts was carried out by Liquid chromatography- Mass spectrometry (LC-MS), while volatile oils extracted from fresh and dried parts of the two plants by hydrodistillation were also analyzed by Gas chromatography-Mass spectrometry (GC-MS). The ethanol extracts of both D. thunbergii and H. argentea contained higher amounts of total phenols, flavonoids, tannins, proanthocyanidins and alkaloids, when compared with the aqueous extracts. This finding was in direct correlation with the antioxidant activities of the extracts, with the ethanol extracts of both plants demonstrating stronger scavenging activities against hydrogen peroxide, nitric oxide, ABTS and DPPH radicals, while also exhibiting higher ferric reducing antioxidant potentials, when compared with the aqueous extracts, and in some cases, the standard antioxidants, Vitamin C, butylated hydroxytoluene and rutin. The aqueous extracts of D. thunbergii exhibited the highest toxicity in HepG2 cells with IC50 < 50 μg/ml, while also producing a concentration-dependent reduction in the viability of INS-1 cells up to 41.81percent at 50 μg/ml. Both extracts of H. argentea, however, did not produce any significant toxicity in these cells. Fluorescence imaging of live INS-1 cells using Hoechst and propidium iodide staining revealed stimulation of cell proliferation by H. argentea, while the cytotoxicity of D. thunbergii was further confirmed. H. argentea caused stimulation of glucose uptake in HepG2 cells up to 119.58 percent at 100 μg/ml and as much as 116.96 percent in L6 myotubes at 50 μg/ml, without showing toxicity to these cells. D. thunbergii produced 18.39 percent increase in L6 glucose uptake above untreated control; although its effect on HepG2 glucose uptake was irrelevant as significant toxicity was produced in these cells. H. argentea produced a concentration-dependent reduction in nitric oxide production in RAW macrophages, although not as effectively as the positive control, aminoguanidine. Again, the toxicity of D. thunbergii to this cell line precludes the relevance of nitric oxide inhibition as an antidiabetic mechanism for this plant. D. thunbergii produced a concentration-dependent increase in 3T3-L1 triglyceride accumulation, as measured by Oil red O staining, compared to untreated cells, while H. argentea exerted no significant alterations in pre- adipocyte differentiation. Generally, the two plants produced weak inhibition of the activities of the various enzymes measured, suggesting that this mechanism may not play a major role in the activities of these plants as possible antidiabetic agents. GC-MS analysis revealed major differences in the volatile oil composition between fresh and dried plant parts for both plants. Most notably, total terpenoid content of D. thunbergii oils reduced significantly from 77.17 percent in the fresh root oil to 47.58 percent in the dried root oil. Total terpenoid content was much lower in H. argentea oils, but similarly reduced from 10.58 percent in the fresh corm oil to 4.00 percent in the dried corm oil. LC-MS analysis enabled the tentative identification of compounds including phenolic glycosides, flavonoids, alkaloids, terpenoids saponins and sapogenins, many of which have been reported in literature to exert bioactivities relevant to the ones elucidated in the present study. Overall, H. argentea exhibited antidiabetic properties that may be mediated by its stimulation of glucose uptake in HepG2 and L6 cells; stimulation of proliferation in INS-1 cells; lack of stimulation of 3T3-L1 triglyceride accumulation and a tendency to reduce nitric oxide production in RAW macrophages. These activities suggest that H. argentea has promise for further investigations as an antidiabetic agent. On the contrary, D. thunbergii exhibited significant toxicity to HepG2 cells, INS-1 cells and RAW macrophages. Its cytotoxicity at the concentrations investigated in the present studies raises significant concerns about any potential antidiabetic applications for this plant.
- Full Text:
- Date Issued: 2017
Assessment of the antibacterial properties of n-Hexane extract of Cocos Nucifera and its interactions with some conventional antibiotics
- Authors: Akinyele, Taiwo Adesola
- Date: 2011
- Subjects: Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11245 , http://hdl.handle.net/10353/416 , Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Description: Cocos nucifera belong to the family Aracaceae (palm Family). The English name is coconut and it is used extensively as medicinal remedies against infections such as urinary tract infections, gastro intestinal infections, skin and wound infections. The in vitro antibacterial (including anti-listerial and anti-vibrio) properties as well as the evaluation of the combination potentials of the plant extract with six front-line antibiotics were evaluated in this study using standard procedures. The in vitro anti-listerial properties of the crude aqueous and n-Hexane extract of the husk of Cocos nucifera were carried out against 37 Listeria isolates. Twenty-nine of the test organisms were susceptible to the aqueous extract while thirty were susceptible to the n-Hexane extract both at the screening concentration of 25 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.6 - 5.0 mg/ml. For the aqueous extract, average log reduction in viable cell count ranged between 0.32 Log10 and 4.8 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 2.4 Log10 and 6.2 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. The time-kill characteristics of the two extracts suggest that at higher concentration (2 × MIC) and longer duration of interaction (8 hr), more bacteria were killed. In vitro anti-vibrio and antibacterial properties experiment revealed that of all the 45 vibrio and 25 bacteria strains that was tested, 37 were susceptible to the aqueous extract and 38 to the n-Hexane extract, while 17 were susceptible to the aqueous extract and 21 to the n-Hexane extract. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.3 - 5.0 mg/ml. viii The time kill studies revealed that for the aqueous extract, average log reduction in viable cell count in time kill assay ranged between 0.12 Log10 and 4.2 Log10 CFU/ml after 8 hr interaction at 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 0.56 Log10 and 6.4 Log10 CFU/ml after 8 hr interaction in 1 × MIC and 2 × MIC. In the test for the combination interactions, the checkerboard method revealed synergy of 67% and indifferent of 33%, while the time kill assay detected synergy in 72% and indifferent in 28% of the combinations tested. The synergy detected was not specific to any of the antibiotics or the Gram reaction of the bacteria, and no antagonism was detected. We conclude that the aqueous and n-Hexane extract of the husk of C. nucifera contains potential broad spectrum antibiotics resistance modulating compounds that could be relevant in the treatment of infections caused by these pathogens. In addition, the husk which is being discarded as agro waste will opens up a vista of opportunities for utilization for therapeutic purposes
- Full Text:
- Date Issued: 2011
- Authors: Akinyele, Taiwo Adesola
- Date: 2011
- Subjects: Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11245 , http://hdl.handle.net/10353/416 , Coconut palm , Microbial sensitivity tests , Gram-negative bacterial infections , Vibrio infections , Antibiotics , Hexane , Extracts
- Description: Cocos nucifera belong to the family Aracaceae (palm Family). The English name is coconut and it is used extensively as medicinal remedies against infections such as urinary tract infections, gastro intestinal infections, skin and wound infections. The in vitro antibacterial (including anti-listerial and anti-vibrio) properties as well as the evaluation of the combination potentials of the plant extract with six front-line antibiotics were evaluated in this study using standard procedures. The in vitro anti-listerial properties of the crude aqueous and n-Hexane extract of the husk of Cocos nucifera were carried out against 37 Listeria isolates. Twenty-nine of the test organisms were susceptible to the aqueous extract while thirty were susceptible to the n-Hexane extract both at the screening concentration of 25 mg/ml. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.6 - 5.0 mg/ml. For the aqueous extract, average log reduction in viable cell count ranged between 0.32 Log10 and 4.8 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 2.4 Log10 and 6.2 Log10 CFU/ml after 8 hours interaction in 1 × MIC and 2 × MIC. The time-kill characteristics of the two extracts suggest that at higher concentration (2 × MIC) and longer duration of interaction (8 hr), more bacteria were killed. In vitro anti-vibrio and antibacterial properties experiment revealed that of all the 45 vibrio and 25 bacteria strains that was tested, 37 were susceptible to the aqueous extract and 38 to the n-Hexane extract, while 17 were susceptible to the aqueous extract and 21 to the n-Hexane extract. Minimum Inhibitory Concentration (MIC) values for all the susceptible bacteria ranged between 0.3 - 5.0 mg/ml. viii The time kill studies revealed that for the aqueous extract, average log reduction in viable cell count in time kill assay ranged between 0.12 Log10 and 4.2 Log10 CFU/ml after 8 hr interaction at 1 × MIC and 2 × MIC. For the n-Hexane extract, the log reduction ranged between 0.56 Log10 and 6.4 Log10 CFU/ml after 8 hr interaction in 1 × MIC and 2 × MIC. In the test for the combination interactions, the checkerboard method revealed synergy of 67% and indifferent of 33%, while the time kill assay detected synergy in 72% and indifferent in 28% of the combinations tested. The synergy detected was not specific to any of the antibiotics or the Gram reaction of the bacteria, and no antagonism was detected. We conclude that the aqueous and n-Hexane extract of the husk of C. nucifera contains potential broad spectrum antibiotics resistance modulating compounds that could be relevant in the treatment of infections caused by these pathogens. In addition, the husk which is being discarded as agro waste will opens up a vista of opportunities for utilization for therapeutic purposes
- Full Text:
- Date Issued: 2011
Barriers to public participation in developmental projects : a Nigerian community perspective (case study of the Gbaran-Ubie oil and gas project)
- Authors: Akoh, Emmanuel Inalegwu
- Date: 2013
- Subjects: Gbaran-Ubie oil and gas project -- Public opinion Community development -- Nigeria Economic development -- Nigeria -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:715 , http://hdl.handle.net/10962/d1001869
- Description: This research paper is broken up into three sections, namely an evaluation report, a literature review and research methodology. The evaluation report section is the assessment of the current state of change readiness within the Eskom Contact Centre’s based upon what the literature on change readiness prescribes. The timing of the change readiness assessment is just prior to significant organisational change. The organisational change that was about to be initiated by the organisation was initiated from the boardroom of the most senior echelons of the organisation, and was directed in a top down approach, being a strategic organisational change. The change is deemed to be critical to the organisation being able to meet its long term strategic and sustainability objectives. A critical examination of the literature explored the meaning of change readiness, the importance of it and explained the consequences for organisations that commit to transformational agendas without being ready. Key concepts such as such resistance to change and organisational inertia are described and differentiated from change readiness. The ADKAR change model and its change readiness assessment instrument were used due to the organisations preference for the model. The ADKAR model formed the framework for the analyses of the data, the discussion of the results and the recommendations to the organisation. The research conducted was quantitative in nature; a questionnaire was distributed to the employees of the seven Eskom Contact centre sites around the country through an email. A slightly modified version of the ADKAR change readiness questionnaire was sent via email with an on-line questionnaire link on it; and questions on individual readiness for change were used to assess the level of readiness of the employees. Most of the descriptive and inferential statistics were analysed with the use of Excel (version, 2010), with Factor Analysis being done in Statistica. The results of the research showed that: [iii] - The factors as proposed by the ADKAR change readiness assessment questionnaire (i.e. Awareness, Desire, Knowledge, Ability and Reinforcement) are not different enough to be considered as independent factors for this data set. Based on factor analysis, the factors were subsequently amended from five to three, namely Readiness, Opportunity Realisation and Uncertainty. - The Contact Centre employees were somewhat ready for change. - The Contact Centres needed to focus on all amended ADKAR factors in order to improve the readiness of the department. - The readiness levels in response to the roll out were more or less uniform. The study shows that given Eskom’s preference for the ADKAR model, future research within Eskom should therefore be conducted more circumspectly with respect to ascertaining the validity of the ADKAR factors. The study also makes mention that future work and/or research will need to be conducted, specifically on the readiness of the organisation itself, in order to improve the probability of transformational success. The ADKAR assessment is a people focused assessment and therefore focuses only on the readiness of the individual. Factors such as the adequacy of the current state of resources within the organisation, which incorporate aspects such as infrastructure, technology and staffing, will also need to be assessed to make a more holistic statement of change readiness. A concise review of the literature is incorporated into the Evaluation Report of Section 1 to underpin the study. In Section 2 a more extensive review of the literature is presented. Similarly, the design of the research is discussed in more detail in Section 3 to both describe and justify the appropriateness of the research methodology, and to give a detailed account of the way in which the research was carried out.
- Full Text:
- Date Issued: 2013
- Authors: Akoh, Emmanuel Inalegwu
- Date: 2013
- Subjects: Gbaran-Ubie oil and gas project -- Public opinion Community development -- Nigeria Economic development -- Nigeria -- Environmental aspects
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:715 , http://hdl.handle.net/10962/d1001869
- Description: This research paper is broken up into three sections, namely an evaluation report, a literature review and research methodology. The evaluation report section is the assessment of the current state of change readiness within the Eskom Contact Centre’s based upon what the literature on change readiness prescribes. The timing of the change readiness assessment is just prior to significant organisational change. The organisational change that was about to be initiated by the organisation was initiated from the boardroom of the most senior echelons of the organisation, and was directed in a top down approach, being a strategic organisational change. The change is deemed to be critical to the organisation being able to meet its long term strategic and sustainability objectives. A critical examination of the literature explored the meaning of change readiness, the importance of it and explained the consequences for organisations that commit to transformational agendas without being ready. Key concepts such as such resistance to change and organisational inertia are described and differentiated from change readiness. The ADKAR change model and its change readiness assessment instrument were used due to the organisations preference for the model. The ADKAR model formed the framework for the analyses of the data, the discussion of the results and the recommendations to the organisation. The research conducted was quantitative in nature; a questionnaire was distributed to the employees of the seven Eskom Contact centre sites around the country through an email. A slightly modified version of the ADKAR change readiness questionnaire was sent via email with an on-line questionnaire link on it; and questions on individual readiness for change were used to assess the level of readiness of the employees. Most of the descriptive and inferential statistics were analysed with the use of Excel (version, 2010), with Factor Analysis being done in Statistica. The results of the research showed that: [iii] - The factors as proposed by the ADKAR change readiness assessment questionnaire (i.e. Awareness, Desire, Knowledge, Ability and Reinforcement) are not different enough to be considered as independent factors for this data set. Based on factor analysis, the factors were subsequently amended from five to three, namely Readiness, Opportunity Realisation and Uncertainty. - The Contact Centre employees were somewhat ready for change. - The Contact Centres needed to focus on all amended ADKAR factors in order to improve the readiness of the department. - The readiness levels in response to the roll out were more or less uniform. The study shows that given Eskom’s preference for the ADKAR model, future research within Eskom should therefore be conducted more circumspectly with respect to ascertaining the validity of the ADKAR factors. The study also makes mention that future work and/or research will need to be conducted, specifically on the readiness of the organisation itself, in order to improve the probability of transformational success. The ADKAR assessment is a people focused assessment and therefore focuses only on the readiness of the individual. Factors such as the adequacy of the current state of resources within the organisation, which incorporate aspects such as infrastructure, technology and staffing, will also need to be assessed to make a more holistic statement of change readiness. A concise review of the literature is incorporated into the Evaluation Report of Section 1 to underpin the study. In Section 2 a more extensive review of the literature is presented. Similarly, the design of the research is discussed in more detail in Section 3 to both describe and justify the appropriateness of the research methodology, and to give a detailed account of the way in which the research was carried out.
- Full Text:
- Date Issued: 2013
Widows' experiences of spousal mourning among AmaXhosa: an interpretative phenomenological study
- Authors: Akol, Grace
- Date: 2011
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Psych)
- Identifier: vital:11609 , http://hdl.handle.net/10353/523 , Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Description: This study was conducted on the mourning rituals of the AmaXhosa widows of the Eastern Cape Province of South Africa. The study focused on the descriptive presentation of the experiences of the AmaXhosa widows in the Buffalo City municipality of the Province. The study sought to establish the widows’ perceptions regarding the mourning rituals and to interpret their experiences within the context of contemporary cultural, religious, gender and socio-political influences. The experiences among the widows interviewed were found to have a similar context but their perceptions about the mourning rituals were different between the widows younger than 40 years and those older than 50 years. Widows from urban and rural areas of East London, Mdantsane Township and from within a 60 kilometre radius of East London were interviewed. Purposive random sampling was used to identify an equal number of either urban or rural voluntary participants for the study. Structured interviews were held with widows ranging in age from 29 to 91 years. An interpretative phenomenological analysis of the recorded discussions was conducted. The experiences of the AmaXhosa widows during the conduct of the mourning rituals are described. The key findings of the study indicated that most of the widows felt they had to go through the mourning rituals mainly to show respect for their departed husbands and so that the dignity of the family and clan was maintained. The mourning rituals seemed mostly to have negative implications for the widows such as a lack of family and financial support and being treated as social outcasts; however the rituals also seemed to help the women adjust to their new status as widows. Although the mourning rituals were embedded in the socio-cultural tradition generally followed by the AmaXhosa, religious beliefs also influenced some of the traditions by introducing changes in the way some widows conducted the mourning rituals. For example, some religions advocated for shorter periods of mourning than usual as well as wearing different types of mourning clothes from the usual black or purple dress. Overall the perceptions of the older widows aged above 50 years revealed that they had no reservations about performing the mourning rituals and quite readily and unquestioningly accepted the customs. The younger widows aged below 40 years on the other hand felt that the mourning rituals were biased against women and did not serve a useful purpose and even proposed changes to the manner in which the mourning rituals are conducted particularly the shortening of the mourning period from 12 to 6 months or less. However, they seemed to recognize the role played by the mourning ritual in lessening and possibly healing the pain and sorrow caused by their bereavement.
- Full Text:
- Date Issued: 2011
- Authors: Akol, Grace
- Date: 2011
- Subjects: Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , M Soc Sc (Psych)
- Identifier: vital:11609 , http://hdl.handle.net/10353/523 , Widowhood -- South Africa -- Eastern Cape , Widows -- South Africa -- Eastern Cape , Xhosa (African people) -- Funeral customs and rites , Xhosa (African people) -- Psychology , Bereavement -- Psychological aspects , Mourning customs -- South Africa -- Eastern Cape , Death -- Social aspects -- South Africa -- Eastern Cape
- Description: This study was conducted on the mourning rituals of the AmaXhosa widows of the Eastern Cape Province of South Africa. The study focused on the descriptive presentation of the experiences of the AmaXhosa widows in the Buffalo City municipality of the Province. The study sought to establish the widows’ perceptions regarding the mourning rituals and to interpret their experiences within the context of contemporary cultural, religious, gender and socio-political influences. The experiences among the widows interviewed were found to have a similar context but their perceptions about the mourning rituals were different between the widows younger than 40 years and those older than 50 years. Widows from urban and rural areas of East London, Mdantsane Township and from within a 60 kilometre radius of East London were interviewed. Purposive random sampling was used to identify an equal number of either urban or rural voluntary participants for the study. Structured interviews were held with widows ranging in age from 29 to 91 years. An interpretative phenomenological analysis of the recorded discussions was conducted. The experiences of the AmaXhosa widows during the conduct of the mourning rituals are described. The key findings of the study indicated that most of the widows felt they had to go through the mourning rituals mainly to show respect for their departed husbands and so that the dignity of the family and clan was maintained. The mourning rituals seemed mostly to have negative implications for the widows such as a lack of family and financial support and being treated as social outcasts; however the rituals also seemed to help the women adjust to their new status as widows. Although the mourning rituals were embedded in the socio-cultural tradition generally followed by the AmaXhosa, religious beliefs also influenced some of the traditions by introducing changes in the way some widows conducted the mourning rituals. For example, some religions advocated for shorter periods of mourning than usual as well as wearing different types of mourning clothes from the usual black or purple dress. Overall the perceptions of the older widows aged above 50 years revealed that they had no reservations about performing the mourning rituals and quite readily and unquestioningly accepted the customs. The younger widows aged below 40 years on the other hand felt that the mourning rituals were biased against women and did not serve a useful purpose and even proposed changes to the manner in which the mourning rituals are conducted particularly the shortening of the mourning period from 12 to 6 months or less. However, they seemed to recognize the role played by the mourning ritual in lessening and possibly healing the pain and sorrow caused by their bereavement.
- Full Text:
- Date Issued: 2011
The design of a boarding school for displaced children near Graaff-Reinet
- Authors: Akom, Chelcie Jade
- Date: 2017
- Subjects: School buildings -- South Africa -- Eastern Cape , School buildings -- Specifications -- South Africa -- Eastern Cape Architecture -- Designs and plans Graaff-Reinet (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/17888 , vital:28479
- Description: The treatise developed from a preoccupation with regards to the theories rooted around the human need for a sense of embeddedness in a specific place. This need lies deep within the human heart, as humans have a psychological and phenomenological need for a sense of comfort and security. The preoccupation lead to the notions pertaining to place to place making. The treatise acknowledges that certain places have the ability to evoke certain moods in human beings as a result of their extension and character, and when a place possesses a certain character it becomes meaningful to man. In order for man to fulfill his need to dwell amid the earth and sky, he has to orientate himself and identify with the natural place in which he is located.
- Full Text:
- Date Issued: 2017
- Authors: Akom, Chelcie Jade
- Date: 2017
- Subjects: School buildings -- South Africa -- Eastern Cape , School buildings -- Specifications -- South Africa -- Eastern Cape Architecture -- Designs and plans Graaff-Reinet (South Africa)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/17888 , vital:28479
- Description: The treatise developed from a preoccupation with regards to the theories rooted around the human need for a sense of embeddedness in a specific place. This need lies deep within the human heart, as humans have a psychological and phenomenological need for a sense of comfort and security. The preoccupation lead to the notions pertaining to place to place making. The treatise acknowledges that certain places have the ability to evoke certain moods in human beings as a result of their extension and character, and when a place possesses a certain character it becomes meaningful to man. In order for man to fulfill his need to dwell amid the earth and sky, he has to orientate himself and identify with the natural place in which he is located.
- Full Text:
- Date Issued: 2017
The taxability of rewards from suppliers
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016
Valuing preferences for freshwater inflows into selected Western and Southern Cape estuaries
- Authors: Akoto, William
- Date: 2009
- Subjects: Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8992 , http://hdl.handle.net/10948/915 , Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Description: An estuary is the last stage of a river. It is where the river meets the sea. Estuaries are one of the most significant features of the South African coastline. In recent years, South Africa has witnessed an increase in the demand for freshwater for both industrial and domestic purposes. At the same time, there has been a gradual deterioration of river systems and their catchments. To add to this, there has been a gradual reduction in the amount of recorded rainfall, which is the primary source of freshwater for rivers. This has resulted in decreased freshwater inflow into estuaries, a situation which poses a serious threat to the biological functioning of these estuaries and the services rendered to its recreational users. A deterioration of estuary services reduces the yield for subsistence households and their appeal for recration. This study uses the contingent valuation method as its primary methodology to elicit users' willingness-to-pay to reduce the negative impacts of reduced freshwater inflow into selected western and southern Cape estuaries. Eight estuaries were selected for this study; the Breede, Duiwenhoks, Great Berg, Kleinemond West, Mhlathuze, Swartvlei and Olifants estuaries. The contingent valuation (CV) method is widely used for studies of this nature because of its ability to capture active, passive and non-use values. The CV method involves directly asking people how much they would be willing to pay for specific environmental services. In this case, users were asked what they would be willing to pay to sustain freshwater inflows into selected estuaries in order to prevent the negative impacts of reduced inflows. The travel cost method (TCM) was uesed to generate an alternative comparative set of values for the purposes of convergence testing. This is because convergence testing is highly desirable as a validity test for CV estimates.
- Full Text:
- Date Issued: 2009
- Authors: Akoto, William
- Date: 2009
- Subjects: Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:8992 , http://hdl.handle.net/10948/915 , Estuarine ecology -- South Africa , Freshwater ecology -- South Africa , Estuaries -- South Africa
- Description: An estuary is the last stage of a river. It is where the river meets the sea. Estuaries are one of the most significant features of the South African coastline. In recent years, South Africa has witnessed an increase in the demand for freshwater for both industrial and domestic purposes. At the same time, there has been a gradual deterioration of river systems and their catchments. To add to this, there has been a gradual reduction in the amount of recorded rainfall, which is the primary source of freshwater for rivers. This has resulted in decreased freshwater inflow into estuaries, a situation which poses a serious threat to the biological functioning of these estuaries and the services rendered to its recreational users. A deterioration of estuary services reduces the yield for subsistence households and their appeal for recration. This study uses the contingent valuation method as its primary methodology to elicit users' willingness-to-pay to reduce the negative impacts of reduced freshwater inflow into selected western and southern Cape estuaries. Eight estuaries were selected for this study; the Breede, Duiwenhoks, Great Berg, Kleinemond West, Mhlathuze, Swartvlei and Olifants estuaries. The contingent valuation (CV) method is widely used for studies of this nature because of its ability to capture active, passive and non-use values. The CV method involves directly asking people how much they would be willing to pay for specific environmental services. In this case, users were asked what they would be willing to pay to sustain freshwater inflows into selected estuaries in order to prevent the negative impacts of reduced inflows. The travel cost method (TCM) was uesed to generate an alternative comparative set of values for the purposes of convergence testing. This is because convergence testing is highly desirable as a validity test for CV estimates.
- Full Text:
- Date Issued: 2009
A pilot wide-field VLBI survey of the GOODS-North field
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
- Authors: Akoto-Danso, Alexander
- Date: 2019
- Subjects: Radio astronomy , Very long baseline interferometry , Radio interometers , Imaging systems in astronomy , Hubble Space Telescope (Spacecraft) -- Observations
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72296 , vital:30027
- Description: Very Long Baseline Interferometry (VLBI) has significant advantages in disentangling active galactic nuclei (AGN) from star formation, particularly at intermediate to high-redshift due to its high angular resolution and insensitivity to dust. Surveys using VLBI arrays are only just becoming practical over wide areas with numerous developments and innovations (such as multi-phase centre techniques) in observation and data analysis techniques. However, fully automated pipelines for VLBI data analysis are based on old software packages and are unable to incorporate new calibration and imaging algorithms. In this work, the researcher developed a pipeline for VLBI data analysis which integrates a recent wide-field imaging algorithm, RFI excision, and a purpose-built source finding algorithm specifically developed for the 64kx64k wide-field VLBI images. The researcher used this novel pipeline to process 6% (~ 9 arcmin2 of the total 160 arcmin2) of the data from the CANDELS GOODS- North extragalactic field at 1.6 GHz. The milli-arcsec scale images have an average rms of a ~ 10 uJy/beam. Forty four (44) candidate sources were detected, most of which are at sub-mJy flux densities, having brightness temperatures and luminosities of >5x105 K and >6x1021 W Hz-1 respectively. This work demonstrates that automated post-processing pipelines for wide-field, uniform sensitivity VLBI surveys are feasible and indeed made more efficient with new software, wide-field imaging algorithms and more purpose-built source- finders. This broadens the discovery space for future wide-field surveys with upcoming arrays such as the African VLBI Network (AVN), MeerKAT and the Square Kilometre Array (SKA).
- Full Text:
- Date Issued: 2019
Quantification of the cross-sectoral impacts of waterweeds and their control in Ghana
- Authors: Akpabey, Felix Jerry
- Date: 2012
- Subjects: Water hyacinth -- Control -- Environmental aspects -- Ghana Alien plants -- Research -- Ghana Introduced organisms Economic development -- Social aspects -- Research -- Ghana
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5748 , http://hdl.handle.net/10962/d1005435
- Description: The Akosombo Dam on the Volta River in Ghana was built in 1963 to provide cheap energy to fuel industry and to accelerate the economic growth of the country. It provides hydroelectric power, enhanced fishing and water transportation upstream, and improved opportunities for irrigated farming, especially in the lower reaches, and their attendant economic multiplier effects. A few years after the construction of this major dam, a rapid expansion of industrialization took place in Ghana. This brought about an exponential increase in demand for more electrical power. This led to the construction of a smaller dam at Akuse, downstream of the Akosomho Dam in 1981 and the formation of a headpond at Kpong. The impoundment of the river at the two sites (Akosombo and Kpong) caused an alteration in the existing ecological and biophysical processes in the river basin, including a slowing of the flow of the river, upstream and downstream. Changes in the natural processes, such as a reduction in the flow of the river and an increase in nutrient status of the water, resulted in an invasion of aquatic weeds, increasing the density of aquatic snails (intermediate hosts of schistosomiasis), silting and closure of the estuary, as well as other more subtle effects. The invasion of the river's main course and the dams by aquatic plants led to a corresponding reduction of navigable water both upstream and downstream. The aim of this thesis was to quantify the impact and control of waterweeds, especially water hyacinth, Eichhornia crassipes (Mart) Solms-Laubach (Pontederiaceae), in Ghana. A floral survey on the Kpong Headpond recorded 49 emergent, 12 free floating and I submerged aquatic plant species, many of which were indigenous, but the exotic or introduced water hyacinth was recorded at most of the sampling sites, and was the most abundant and had the biggest impact on the utilization of the water resource. Mats of water hyacinth served as substrates for other, indigenous species to grow out into the main channel of the headpond, including the intake point of the Kpong head works of the Ghana Water Company Limited (GWCL) and landing sites for boats. These mats resulted in a reduction of the fish (fin and shell) harvest, reducing the annual production to far below demand. Water hyacinth was also shown to have severe health implications. A survey of the Ministry of Health records showed that the prevalence of both urinary and intestinal schistosomiasis had risen significantly over time as the abundance of waterweeds, most notably water hyacinth, increased, and ranged between 70% and 75% but up to 100% in some lakeside communities. Based on the work done by an NGO on board the medical boat ("Onipa Nua "), losses in terms of money due to the effect on health of the aquatic weed infestations on the Volta River in 2006 amounted to US$ 620,000. Economic losses due to invasive alien aquatic weeds were also calculated on the Oti River Arm of Lake Volta. It was estimated that about US$2.3 million per annum would be lost to the Volta Lake Transport Company and individual boat transport operators if this section of the river were 100% covered by aquatic weeds (water hyacinth and Salvinia molesta D.S. Mitchell (Salviniaceae)). It was also estimated that US$327,038 was spent annually in monitoring and managing the weeds in the Oti River. Control interventions for aquatic weeds have been implemented in river systems in Ghana. The biological control agents Neochetina bruchi Hustache (Coleoptera, Curculionidae) and Neochetina eichhorniae Warner (Coleoptera, Curculionidae) have been used on water hyacinth infestations in the Oti River Arm of Lake Volta, the Tano River and the Lagoon complex in the south-western part of the country. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) has been used to control salvinia, and Neohydronomous affinis Hustache (Coleoptera: Curculionidae) to control water lettuce, Pistia stratiotes Lilmaeus (Araceae) in the Tano River and Lagoon complex. Although these projects have been regarded as successful, they have relied on research from elsewhere in the world and no postrelease quantification has been conducted. In evaluating the impact of the biological control agents Neochetina bruchi and Neochetina eichhorniae weevils on water hyacinth infestations in the Tano River, fresh adult feeding scars were recorded as well as the numbers of adult weevils on each water hyacinth plant sampled at six sites. Despite being released in 1994, weevil numbers and resultant damage to plants in the Tano Lagoon was low in comparison to other regions of the world where these agents have been used. The main reason for this is that this lagoon floods seasonally, washing weevil-infested plants out to sea. Water hyacinth then re-infests the lagoon from seed and the weevil populations are low. To resolve this situation, two courses of action are proposed. The first is to mass rear the weevils along the shore of the lagoon and release them when the first seedlings recruit. The second proposal is that additional agents that have shorter lifecycies and are more mobile than the weevils should be released. To this end, the water hyacinth mirid, Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae) was imported from South Africa and released onto the Tano Lagoon in 2009. Retrospective laboratory host specificity trials were conducted on Neachetina eichharniae and Neachetina bruchi weevils 15 years after their release into Ghana to see if any variation in their host ranges had occurred. Considerable damage was inflicted on the E. crassipes leaves by the Neachetina weevils, while little feeding damage was recorded on both Heteranthera callifalia Kunth. (Pontederiaceae) and Eichharnia natans (P.Beauv.) Solms (Pontederiaceae). All the weevils introduced on H callifalia and E. natans died after the first week. This study served to confirm the host specificity and thereby the safety of these agents. Invasive alien aquatic macrophytes have negative impacts on the environment and economy of Ghana. The control of these weeds is essential to socioeconomic development and improved human health standards in riparian communities. Biological control offers a safe and sustainable control option, but requires diligent implementation. However, aquatic weed invasion is more typically a result of the anthropogenically induced eutrophication of water bodies, and this is the main issue that has to be addressed.
- Full Text:
- Date Issued: 2012
- Authors: Akpabey, Felix Jerry
- Date: 2012
- Subjects: Water hyacinth -- Control -- Environmental aspects -- Ghana Alien plants -- Research -- Ghana Introduced organisms Economic development -- Social aspects -- Research -- Ghana
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5748 , http://hdl.handle.net/10962/d1005435
- Description: The Akosombo Dam on the Volta River in Ghana was built in 1963 to provide cheap energy to fuel industry and to accelerate the economic growth of the country. It provides hydroelectric power, enhanced fishing and water transportation upstream, and improved opportunities for irrigated farming, especially in the lower reaches, and their attendant economic multiplier effects. A few years after the construction of this major dam, a rapid expansion of industrialization took place in Ghana. This brought about an exponential increase in demand for more electrical power. This led to the construction of a smaller dam at Akuse, downstream of the Akosomho Dam in 1981 and the formation of a headpond at Kpong. The impoundment of the river at the two sites (Akosombo and Kpong) caused an alteration in the existing ecological and biophysical processes in the river basin, including a slowing of the flow of the river, upstream and downstream. Changes in the natural processes, such as a reduction in the flow of the river and an increase in nutrient status of the water, resulted in an invasion of aquatic weeds, increasing the density of aquatic snails (intermediate hosts of schistosomiasis), silting and closure of the estuary, as well as other more subtle effects. The invasion of the river's main course and the dams by aquatic plants led to a corresponding reduction of navigable water both upstream and downstream. The aim of this thesis was to quantify the impact and control of waterweeds, especially water hyacinth, Eichhornia crassipes (Mart) Solms-Laubach (Pontederiaceae), in Ghana. A floral survey on the Kpong Headpond recorded 49 emergent, 12 free floating and I submerged aquatic plant species, many of which were indigenous, but the exotic or introduced water hyacinth was recorded at most of the sampling sites, and was the most abundant and had the biggest impact on the utilization of the water resource. Mats of water hyacinth served as substrates for other, indigenous species to grow out into the main channel of the headpond, including the intake point of the Kpong head works of the Ghana Water Company Limited (GWCL) and landing sites for boats. These mats resulted in a reduction of the fish (fin and shell) harvest, reducing the annual production to far below demand. Water hyacinth was also shown to have severe health implications. A survey of the Ministry of Health records showed that the prevalence of both urinary and intestinal schistosomiasis had risen significantly over time as the abundance of waterweeds, most notably water hyacinth, increased, and ranged between 70% and 75% but up to 100% in some lakeside communities. Based on the work done by an NGO on board the medical boat ("Onipa Nua "), losses in terms of money due to the effect on health of the aquatic weed infestations on the Volta River in 2006 amounted to US$ 620,000. Economic losses due to invasive alien aquatic weeds were also calculated on the Oti River Arm of Lake Volta. It was estimated that about US$2.3 million per annum would be lost to the Volta Lake Transport Company and individual boat transport operators if this section of the river were 100% covered by aquatic weeds (water hyacinth and Salvinia molesta D.S. Mitchell (Salviniaceae)). It was also estimated that US$327,038 was spent annually in monitoring and managing the weeds in the Oti River. Control interventions for aquatic weeds have been implemented in river systems in Ghana. The biological control agents Neochetina bruchi Hustache (Coleoptera, Curculionidae) and Neochetina eichhorniae Warner (Coleoptera, Curculionidae) have been used on water hyacinth infestations in the Oti River Arm of Lake Volta, the Tano River and the Lagoon complex in the south-western part of the country. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) has been used to control salvinia, and Neohydronomous affinis Hustache (Coleoptera: Curculionidae) to control water lettuce, Pistia stratiotes Lilmaeus (Araceae) in the Tano River and Lagoon complex. Although these projects have been regarded as successful, they have relied on research from elsewhere in the world and no postrelease quantification has been conducted. In evaluating the impact of the biological control agents Neochetina bruchi and Neochetina eichhorniae weevils on water hyacinth infestations in the Tano River, fresh adult feeding scars were recorded as well as the numbers of adult weevils on each water hyacinth plant sampled at six sites. Despite being released in 1994, weevil numbers and resultant damage to plants in the Tano Lagoon was low in comparison to other regions of the world where these agents have been used. The main reason for this is that this lagoon floods seasonally, washing weevil-infested plants out to sea. Water hyacinth then re-infests the lagoon from seed and the weevil populations are low. To resolve this situation, two courses of action are proposed. The first is to mass rear the weevils along the shore of the lagoon and release them when the first seedlings recruit. The second proposal is that additional agents that have shorter lifecycies and are more mobile than the weevils should be released. To this end, the water hyacinth mirid, Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae) was imported from South Africa and released onto the Tano Lagoon in 2009. Retrospective laboratory host specificity trials were conducted on Neachetina eichharniae and Neachetina bruchi weevils 15 years after their release into Ghana to see if any variation in their host ranges had occurred. Considerable damage was inflicted on the E. crassipes leaves by the Neachetina weevils, while little feeding damage was recorded on both Heteranthera callifalia Kunth. (Pontederiaceae) and Eichharnia natans (P.Beauv.) Solms (Pontederiaceae). All the weevils introduced on H callifalia and E. natans died after the first week. This study served to confirm the host specificity and thereby the safety of these agents. Invasive alien aquatic macrophytes have negative impacts on the environment and economy of Ghana. The control of these weeds is essential to socioeconomic development and improved human health standards in riparian communities. Biological control offers a safe and sustainable control option, but requires diligent implementation. However, aquatic weed invasion is more typically a result of the anthropogenically induced eutrophication of water bodies, and this is the main issue that has to be addressed.
- Full Text:
- Date Issued: 2012
The Grameen Bank model of microcredit and its relevance for South Africa
- Authors: Akpan, Iniobong Wilson
- Date: 2005
- Subjects: Grameen Bank , Microfinance -- South Africa , Microfinance -- Bangladesh , Credit -- Management , Risk management , Poor -- Finance, Personal , South Africa -- Economic conditions , Bangladesh -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:980 , http://hdl.handle.net/10962/d1002714 , Grameen Bank , Microfinance -- South Africa , Microfinance -- Bangladesh , Credit -- Management , Risk management , Poor -- Finance, Personal , South Africa -- Economic conditions , Bangladesh -- Economic conditions
- Description: Among the reasons for financial exclusion is the fact that the poor, being largely illiterate and unemployed, are traditionally perceived as ‘bad credit risks’. This is the dominant perception of the poor in the formal credit markets – a perception that also exists in the microcredit sector. In other words, while information asymmetry is a recognized problem in lender-borrower relationships, lenders consider the problem particularly severe when they contemplate doing business with the poor. A contrasting paradigm, such as the one adopted by Grameen Bank of Bangladesh, views the poor as possessing economic potentials that have not been tapped – that is, as ‘good credit risks’. Grameen Bank’s microcredit features appear to have successfully mitigated the problems of information asymmetry and, to a large extent, made it possible for the poor to access microenterprise credit. Using the Grameen Bank model as a benchmark, this study examined the lending features of private sector microlenders in South Africa and those of KhulaStart (credit) scheme. The aim was to identify how the lending features affect microenterprise credit access. Primary data were obtained through interviews, while relevant secondary data were also used in the study. A key finding of the study was that while the Khulastart scheme was, like Grameencredit, targeted at the poor, the method of its delivery appeared diluted or unduly influenced by the conventional (private sector) paradigm that pre-classifies people as ‘good’ or ‘bad’ credit risks. As a result, the scheme was not robust enough to support microenterprise credit access. This has consequences for job-creation and poverty reduction. Based on the findings, the study maintains that a realistic broadening of microenterprise credit access will not occur unless there is a fundamental paradigm shift in microcredit practices, and unless measures designed to mitigate information asymmetries are sensitive to the historical, economic and sociocultural realities of the South African poor.
- Full Text:
- Date Issued: 2005
- Authors: Akpan, Iniobong Wilson
- Date: 2005
- Subjects: Grameen Bank , Microfinance -- South Africa , Microfinance -- Bangladesh , Credit -- Management , Risk management , Poor -- Finance, Personal , South Africa -- Economic conditions , Bangladesh -- Economic conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:980 , http://hdl.handle.net/10962/d1002714 , Grameen Bank , Microfinance -- South Africa , Microfinance -- Bangladesh , Credit -- Management , Risk management , Poor -- Finance, Personal , South Africa -- Economic conditions , Bangladesh -- Economic conditions
- Description: Among the reasons for financial exclusion is the fact that the poor, being largely illiterate and unemployed, are traditionally perceived as ‘bad credit risks’. This is the dominant perception of the poor in the formal credit markets – a perception that also exists in the microcredit sector. In other words, while information asymmetry is a recognized problem in lender-borrower relationships, lenders consider the problem particularly severe when they contemplate doing business with the poor. A contrasting paradigm, such as the one adopted by Grameen Bank of Bangladesh, views the poor as possessing economic potentials that have not been tapped – that is, as ‘good credit risks’. Grameen Bank’s microcredit features appear to have successfully mitigated the problems of information asymmetry and, to a large extent, made it possible for the poor to access microenterprise credit. Using the Grameen Bank model as a benchmark, this study examined the lending features of private sector microlenders in South Africa and those of KhulaStart (credit) scheme. The aim was to identify how the lending features affect microenterprise credit access. Primary data were obtained through interviews, while relevant secondary data were also used in the study. A key finding of the study was that while the Khulastart scheme was, like Grameencredit, targeted at the poor, the method of its delivery appeared diluted or unduly influenced by the conventional (private sector) paradigm that pre-classifies people as ‘good’ or ‘bad’ credit risks. As a result, the scheme was not robust enough to support microenterprise credit access. This has consequences for job-creation and poverty reduction. Based on the findings, the study maintains that a realistic broadening of microenterprise credit access will not occur unless there is a fundamental paradigm shift in microcredit practices, and unless measures designed to mitigate information asymmetries are sensitive to the historical, economic and sociocultural realities of the South African poor.
- Full Text:
- Date Issued: 2005
Financial literacy training in the small, medium and microenterprises sector : effect on business growth in the Eastern Cape, South Africa
- Authors: Akpan, Iniobong Wilson
- Date: 2016
- Subjects: Economics Small business Business enterprises -- Finance
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: http://hdl.handle.net/10353/13608 , vital:39684
- Description: The centrality of financial literacy to business performance is increasingly becoming established in the literature, with several studies attributing business failures, especially in the small, medium and microenterprises (SMME) sector, to the failure of entrepreneurs to acquire needed levels of formal financial training. This emphasis represents a paradigm shift: small business failures were conventionally blamed on lack of access to capital, infrastructural deficits, lack of markets for SMME goods and services, regulatory constraints, and crime. In South Africa, and elsewhere in the developing world, this new orthodoxy has spurned new policy interventions aimed at improving the financial literacy levels in the SMME sector. Such is the drive to entrench formal literacy provisioning in the SMME sector that some microcredit providers now bundle financial management training into their SMME loan packages. However, there is a dearth of empirical studies that demonstrate, in any conclusive way, the effect of financial literacy training on small business growth and sustainability. The question, therefore, about whether formal financial literacy training actually leads to significant improvements in turnover levels and growth appears to be answered more as advocacy rather than on the basis of empirical evidence. It is against the backdrop of these arguments that the thesis adopted a quasi experimental design to study the business performance of a sample of SMME entrepreneurs who had received financial literacy training (the “treatment group”) at least two years before the study’s commencement and those who had had no financial literacy training at all (the “control group”). The objective was to determine whether any differences in business growth could be attributed to exposure to formal financial management training or the lack thereof. A survey was conducted with 40 respondents from each of the two groups (n = 80). The survey was triangulated with in-depth interviews of a randomly selected sample 10 of SMME operators from each of the two groups. The interviews sought to uncover the entrepreneurs’ narratives regarding the sources and salience of financial literacy in the sector. The study was conducted among SMME operators in Port Elizabeth, East London and Mthatha – the Eastern Cape’s major centres of commerce and industry. Data estimation was conducted using the Difference In Difference (DID) estimation model to determine whether financial literacy training has had any effect on the turnover of training recipients’ businesses (the treatment group) over that of non-training recipients (the control group). Also, the DID coefficient was used as a growth rate indicator to determine whether growth has occurred in training recipients’ businesses over non-training recipients businesses as a result of having received financial literacy training. The Propensity Score Matching (PSM) was used to estimate the average treatment effect (ATE) and the average treatment effect on the treated (ATET). Quantile DID correlations with covariates were also run to reveal the relationship between turnover (a growth variable) and the covariates as possible influencers of firm performance. The key findings of the study were that based on the specific financial variables tested, some basic financial management knowledge existed among members of the two groups of SMME operators, but there was very minimal application of the knowledge in the day-to-day running of the business. Operators utilise both formal financial literacy training and informal knowledge sources in the operation of their businesses. The study also found that in comparison, the difference in turnover between the treatment and control group at follow-up period was significant at a P value of 0.000. This gave rise to an overall DID P value of 0.000 in the estimation. However, the significance was in favour of control group businesses as the business of respondents in the “control group” (with no financial literacy training) performed better than that of respondents in the “treatment group” (who had received financial literacy training). Finally, the study found that financial literacy training had no effect on the growth of businesses in the short term as the growth rate of turnover of the treatment group was lower than that of the control group and the difference between the two rates was significant at a P value of 0.025. Also, compared to itself, the change in turnover levels of the treatment group was not significant in the pre- and post-training periods as revealed by the PSM ATET estimation result. Minimal changes in turnover of the treatment group was not significant at a P value of 0.124. The study concludes from these findings that while financial literacy remains a salient factor in business, scholarship about the real significance of financial literacy training on small business performance in the short term stands on a relatively shaky empirical foundation, especially when viewed against the background that many SMME entrepreneurs also rely on informal knowledge sources to make everyday business decisions. The study thus highlights the imperative of ensuring that knowledge-related interventions in the SMME sector draws on both formal and informal sources of knowledge.
- Full Text:
- Date Issued: 2016
- Authors: Akpan, Iniobong Wilson
- Date: 2016
- Subjects: Economics Small business Business enterprises -- Finance
- Language: English
- Type: Thesis , Doctoral , DCom
- Identifier: http://hdl.handle.net/10353/13608 , vital:39684
- Description: The centrality of financial literacy to business performance is increasingly becoming established in the literature, with several studies attributing business failures, especially in the small, medium and microenterprises (SMME) sector, to the failure of entrepreneurs to acquire needed levels of formal financial training. This emphasis represents a paradigm shift: small business failures were conventionally blamed on lack of access to capital, infrastructural deficits, lack of markets for SMME goods and services, regulatory constraints, and crime. In South Africa, and elsewhere in the developing world, this new orthodoxy has spurned new policy interventions aimed at improving the financial literacy levels in the SMME sector. Such is the drive to entrench formal literacy provisioning in the SMME sector that some microcredit providers now bundle financial management training into their SMME loan packages. However, there is a dearth of empirical studies that demonstrate, in any conclusive way, the effect of financial literacy training on small business growth and sustainability. The question, therefore, about whether formal financial literacy training actually leads to significant improvements in turnover levels and growth appears to be answered more as advocacy rather than on the basis of empirical evidence. It is against the backdrop of these arguments that the thesis adopted a quasi experimental design to study the business performance of a sample of SMME entrepreneurs who had received financial literacy training (the “treatment group”) at least two years before the study’s commencement and those who had had no financial literacy training at all (the “control group”). The objective was to determine whether any differences in business growth could be attributed to exposure to formal financial management training or the lack thereof. A survey was conducted with 40 respondents from each of the two groups (n = 80). The survey was triangulated with in-depth interviews of a randomly selected sample 10 of SMME operators from each of the two groups. The interviews sought to uncover the entrepreneurs’ narratives regarding the sources and salience of financial literacy in the sector. The study was conducted among SMME operators in Port Elizabeth, East London and Mthatha – the Eastern Cape’s major centres of commerce and industry. Data estimation was conducted using the Difference In Difference (DID) estimation model to determine whether financial literacy training has had any effect on the turnover of training recipients’ businesses (the treatment group) over that of non-training recipients (the control group). Also, the DID coefficient was used as a growth rate indicator to determine whether growth has occurred in training recipients’ businesses over non-training recipients businesses as a result of having received financial literacy training. The Propensity Score Matching (PSM) was used to estimate the average treatment effect (ATE) and the average treatment effect on the treated (ATET). Quantile DID correlations with covariates were also run to reveal the relationship between turnover (a growth variable) and the covariates as possible influencers of firm performance. The key findings of the study were that based on the specific financial variables tested, some basic financial management knowledge existed among members of the two groups of SMME operators, but there was very minimal application of the knowledge in the day-to-day running of the business. Operators utilise both formal financial literacy training and informal knowledge sources in the operation of their businesses. The study also found that in comparison, the difference in turnover between the treatment and control group at follow-up period was significant at a P value of 0.000. This gave rise to an overall DID P value of 0.000 in the estimation. However, the significance was in favour of control group businesses as the business of respondents in the “control group” (with no financial literacy training) performed better than that of respondents in the “treatment group” (who had received financial literacy training). Finally, the study found that financial literacy training had no effect on the growth of businesses in the short term as the growth rate of turnover of the treatment group was lower than that of the control group and the difference between the two rates was significant at a P value of 0.025. Also, compared to itself, the change in turnover levels of the treatment group was not significant in the pre- and post-training periods as revealed by the PSM ATET estimation result. Minimal changes in turnover of the treatment group was not significant at a P value of 0.124. The study concludes from these findings that while financial literacy remains a salient factor in business, scholarship about the real significance of financial literacy training on small business performance in the short term stands on a relatively shaky empirical foundation, especially when viewed against the background that many SMME entrepreneurs also rely on informal knowledge sources to make everyday business decisions. The study thus highlights the imperative of ensuring that knowledge-related interventions in the SMME sector draws on both formal and informal sources of knowledge.
- Full Text:
- Date Issued: 2016
Between the 'sectional' and the 'national' : oil, grassroots discontent and civic discourse in Nigeria
- Authors: Akpan, Wilson Ndarake
- Date: 2006
- Subjects: Petroleum industry and trade -- Nigeria Revenue -- Nigeria Nigeria -- Social conditions Nigeria -- Economic conditions Niger River Delta (Nigeria) -- Environmental conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3294 , http://hdl.handle.net/10962/d1003082
- Description: This thesis examines the social character of petroleum-related grassroots struggles in Nigeria’s oil-producing region. It does this against the background of the dominant scholarly narratives that portray the struggles as: a) a disguised pursuit of an ethnic/sectional agenda, b) a 'minority rights' project, and c) a minority province’s protest against 'selective' environmental 'victimisation' by the majority ethnic nationalities. While the dominant scholarly analyses of the struggles are based on the activities of the better known activist organisations operating in the oil region, this thesis focuses primarily on the everyday 'grammar' of discontent and lived worlds of ordinary people vis-à-vis upstream petroleum operations and petroleum resource utilisation. The aim has been to gain an understanding of the forces driving community struggles in the oil region and their wider societal significance. Examined alongside the narratives of ordinary people are the legal/institutional framework for upstream petroleum operations and the operational practices of the oil-producing companies. Using primary data obtained through ethnography, focus group discussions, in-depth interviews and visual sociology, as well as relevant secondary data, the researcher constructs a discourse matrix, showing how grassroots narratives in selected oilproducing communities intersect with contemporary civic discourses in the wider Nigerian context. The thesis highlights the theoretical and policy difficulties that arise when the social basis of petroleum-related grassroots struggles and ordinary people’s narratives are explained using an essentialist idiom. It reveals, above all, the conditions under which so-called 'locale-specific' struggles in a multi-ethnic, oil-rich African country can become a campaign for the emancipation of ordinary people in the wider society. This research extends the existing knowledge on citizen mobilisation, extractive capitalism, transnational corporate behaviour, and Nigeria’s contemporary development predicament. It sheds light on some of the processes through which ordinary people are forcing upon the state a change agenda that could drive the country along a more socially sensitive development and democratisation trajectory.
- Full Text:
- Date Issued: 2006
- Authors: Akpan, Wilson Ndarake
- Date: 2006
- Subjects: Petroleum industry and trade -- Nigeria Revenue -- Nigeria Nigeria -- Social conditions Nigeria -- Economic conditions Niger River Delta (Nigeria) -- Environmental conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3294 , http://hdl.handle.net/10962/d1003082
- Description: This thesis examines the social character of petroleum-related grassroots struggles in Nigeria’s oil-producing region. It does this against the background of the dominant scholarly narratives that portray the struggles as: a) a disguised pursuit of an ethnic/sectional agenda, b) a 'minority rights' project, and c) a minority province’s protest against 'selective' environmental 'victimisation' by the majority ethnic nationalities. While the dominant scholarly analyses of the struggles are based on the activities of the better known activist organisations operating in the oil region, this thesis focuses primarily on the everyday 'grammar' of discontent and lived worlds of ordinary people vis-à-vis upstream petroleum operations and petroleum resource utilisation. The aim has been to gain an understanding of the forces driving community struggles in the oil region and their wider societal significance. Examined alongside the narratives of ordinary people are the legal/institutional framework for upstream petroleum operations and the operational practices of the oil-producing companies. Using primary data obtained through ethnography, focus group discussions, in-depth interviews and visual sociology, as well as relevant secondary data, the researcher constructs a discourse matrix, showing how grassroots narratives in selected oilproducing communities intersect with contemporary civic discourses in the wider Nigerian context. The thesis highlights the theoretical and policy difficulties that arise when the social basis of petroleum-related grassroots struggles and ordinary people’s narratives are explained using an essentialist idiom. It reveals, above all, the conditions under which so-called 'locale-specific' struggles in a multi-ethnic, oil-rich African country can become a campaign for the emancipation of ordinary people in the wider society. This research extends the existing knowledge on citizen mobilisation, extractive capitalism, transnational corporate behaviour, and Nigeria’s contemporary development predicament. It sheds light on some of the processes through which ordinary people are forcing upon the state a change agenda that could drive the country along a more socially sensitive development and democratisation trajectory.
- Full Text:
- Date Issued: 2006
Identity, culture, architecture & the design of a Chinese cultural school in Morningside, Kabega, Port Elizabeth, South Africa
- Authors: Akpokiniovo, Oghenetejiri
- Date: 2018
- Subjects: Architecture, Chinese -- South Africa -- Port Elizabeth , Interior architecture School buildings -- Design and construction
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/42727 , vital:36685
- Description: This treatise is born out of preoccupation with Identity, Culture and Architecture. Through the study of the fragility of the South-African Chinese community: their double heritage, their quest for a sense of place and permanence with the establishment of Chinese Schools that maintain the Chinese culture. It begins with identifying their almost unstable and fragmented nature of movement, their struggle to find a ‘place’ in Port Elizabeth, especially after the establishment of the Group Areas Act of 1960 and their fight against apartheid and discrimination. It becomes clear that migration, racial segregation, confusion, forced removals, and displacement have been their legacy in South Africa. The purpose of this document is to investigate the symbolic nature of architecture, and how it can be used as a tangible medium to bring about an affirmation of identity, and create a sense of place for the future; giving credence to the celebration of culture and social interaction. Through the use of literature reviews, informal interviews, desktop research, analysis, precedent studies and other qualitative studies; there will be an understanding of the community in terms of how they came about settling in South Africa; their migratory patterns due to forced removals and the current status of the community in terms of cultural revolution; understanding the cultural issues the community face; in the establishment of a centralised symbolic precinct that allows for the celebration and promotion of culture. Through the design of the Chinese Cultural School, it will be demonstrated that in order to create a sense of place for the Chinese community, aiding in integration and restoration; one will need to engage in the argument of the vitality of authentic architecture, the vernacular language of a particular culture, and the subjectivity of identity especially in a context outside of its homeland.
- Full Text:
- Date Issued: 2018
- Authors: Akpokiniovo, Oghenetejiri
- Date: 2018
- Subjects: Architecture, Chinese -- South Africa -- Port Elizabeth , Interior architecture School buildings -- Design and construction
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/42727 , vital:36685
- Description: This treatise is born out of preoccupation with Identity, Culture and Architecture. Through the study of the fragility of the South-African Chinese community: their double heritage, their quest for a sense of place and permanence with the establishment of Chinese Schools that maintain the Chinese culture. It begins with identifying their almost unstable and fragmented nature of movement, their struggle to find a ‘place’ in Port Elizabeth, especially after the establishment of the Group Areas Act of 1960 and their fight against apartheid and discrimination. It becomes clear that migration, racial segregation, confusion, forced removals, and displacement have been their legacy in South Africa. The purpose of this document is to investigate the symbolic nature of architecture, and how it can be used as a tangible medium to bring about an affirmation of identity, and create a sense of place for the future; giving credence to the celebration of culture and social interaction. Through the use of literature reviews, informal interviews, desktop research, analysis, precedent studies and other qualitative studies; there will be an understanding of the community in terms of how they came about settling in South Africa; their migratory patterns due to forced removals and the current status of the community in terms of cultural revolution; understanding the cultural issues the community face; in the establishment of a centralised symbolic precinct that allows for the celebration and promotion of culture. Through the design of the Chinese Cultural School, it will be demonstrated that in order to create a sense of place for the Chinese community, aiding in integration and restoration; one will need to engage in the argument of the vitality of authentic architecture, the vernacular language of a particular culture, and the subjectivity of identity especially in a context outside of its homeland.
- Full Text:
- Date Issued: 2018
Factors influencing consumer decision-making process in the private health institutions
- Authors: Akponah, Voke Blessing
- Date: 2015
- Subjects: Consumer behavior Decision making , Public-private sector cooperation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/50033 , vital:41993
- Description: The development that has taken place in the health care sector includes all factors that have brought changes in the consumer decision-making process regarding the private health institutions. In Nigeria, the development is evident in the delivery of the health care services. This indicates that the private health institutions deliver quality health care service by using efficient and quality medical equipment. However, there is a growing awareness among clients to perform an extensive search before the purchase of health care service and the increased expectation from health care quality by clients and their family. The change in consumer behaviour has caused a shift in the consumer decision-making process due to the availability of several sources of information and various health institutions they can choose from. The purpose of this study is to investigate the factors that influence the consumer decision-making process that can enhance customer satisfaction and reduce cognitive dissonance. In this study the behaviour of consumers is related to how they make decisions along several stages before they make a purchase and in a health care setting the decision-making process refers to the process that clients pass through in making choices on alternative health institutions. The quantitative research method was adopted in this study in describing, analysing and interpreting data. A structured questionnaire was employed to collect primary data from 450 respondents in Lagos state, Nigeria. The primary data was statistically analysed using five stages, namely, exploratory factor analysis, Cronbach‟s alpha reliability testing, descriptive statistics, multiple regression analysis, and Pearson correlation analysis. The empirical results of this study indicates that service encounter experience, personal income and support sources are significantly related to the decision-making process. The decision-making process also has significant positive relationship with both customer satisfaction and cognitive dissonance. This indicates that influential factors that have been identified through the empirical results enlighten researchers and the private health institutions on issues that influence the clients‟ decisions to utilise private health institutions. The well-being and satisfaction of clients will be enhanced if the private health institutions can craft effective strategies that will enable clients to gain easy access and utilise health care services. This study emphasised that access to and utilisation of health care services in the private health institutions can be granted to clients through personal income and support sources from family members and private health institutions. Futhermore, health insurance coverage is an effective way that will help clients overcome the financial constraints and restricted access to and utilisation of private health institutions. The study further reveals that the well-being and satisfaction of clients will be enhanced if private health institutions improve access to quality health care. Failure to improve the overall quality and performances of the health care services in the private health institutions can lead to clients‟ cognitive dissonance. Both private and public health institutions should play a major role in providing the necessary facilities that can assist the clients in their decision-making process regarding their health care needs. This will enable the health care institutions‟ staff to understand what clients value and need and, therefore, how well to satisfy them and reduce cognitive dissonance. Easy access and utilisation of the private health institutions as well as satisfaction in quality health care delivery will create better health outcomes for the workforce and citizens of a country and this will improve economic development.
- Full Text:
- Date Issued: 2015
- Authors: Akponah, Voke Blessing
- Date: 2015
- Subjects: Consumer behavior Decision making , Public-private sector cooperation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/50033 , vital:41993
- Description: The development that has taken place in the health care sector includes all factors that have brought changes in the consumer decision-making process regarding the private health institutions. In Nigeria, the development is evident in the delivery of the health care services. This indicates that the private health institutions deliver quality health care service by using efficient and quality medical equipment. However, there is a growing awareness among clients to perform an extensive search before the purchase of health care service and the increased expectation from health care quality by clients and their family. The change in consumer behaviour has caused a shift in the consumer decision-making process due to the availability of several sources of information and various health institutions they can choose from. The purpose of this study is to investigate the factors that influence the consumer decision-making process that can enhance customer satisfaction and reduce cognitive dissonance. In this study the behaviour of consumers is related to how they make decisions along several stages before they make a purchase and in a health care setting the decision-making process refers to the process that clients pass through in making choices on alternative health institutions. The quantitative research method was adopted in this study in describing, analysing and interpreting data. A structured questionnaire was employed to collect primary data from 450 respondents in Lagos state, Nigeria. The primary data was statistically analysed using five stages, namely, exploratory factor analysis, Cronbach‟s alpha reliability testing, descriptive statistics, multiple regression analysis, and Pearson correlation analysis. The empirical results of this study indicates that service encounter experience, personal income and support sources are significantly related to the decision-making process. The decision-making process also has significant positive relationship with both customer satisfaction and cognitive dissonance. This indicates that influential factors that have been identified through the empirical results enlighten researchers and the private health institutions on issues that influence the clients‟ decisions to utilise private health institutions. The well-being and satisfaction of clients will be enhanced if the private health institutions can craft effective strategies that will enable clients to gain easy access and utilise health care services. This study emphasised that access to and utilisation of health care services in the private health institutions can be granted to clients through personal income and support sources from family members and private health institutions. Futhermore, health insurance coverage is an effective way that will help clients overcome the financial constraints and restricted access to and utilisation of private health institutions. The study further reveals that the well-being and satisfaction of clients will be enhanced if private health institutions improve access to quality health care. Failure to improve the overall quality and performances of the health care services in the private health institutions can lead to clients‟ cognitive dissonance. Both private and public health institutions should play a major role in providing the necessary facilities that can assist the clients in their decision-making process regarding their health care needs. This will enable the health care institutions‟ staff to understand what clients value and need and, therefore, how well to satisfy them and reduce cognitive dissonance. Easy access and utilisation of the private health institutions as well as satisfaction in quality health care delivery will create better health outcomes for the workforce and citizens of a country and this will improve economic development.
- Full Text:
- Date Issued: 2015
The adoption of employee share ownership plans (ESOPs) in Nigeria
- Authors: Akponah, Voke Blessing
- Date: 2017
- Subjects: Employee ownership -- Nigeria , Profit-sharing -- Nigeria Management -- Employee participation -- Nigeria Nigeria -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13834 , vital:27312
- Description: This study investigated the factors that influence the adoption of ESOPs in Nigeria. Furthermore, the study investigated the influence of the adoption of ESOPs on organisational performance, employee retention and employee commitment. The study results reveal that trade union responsiveness, reforms, awareness of employee benefits and taxation implication positively influence the adoption of ESOPs based on transparency. The results in this study further reveal that trade union responsiveness, takeovers, reforms, awareness of employee benefits and taxation implication effectively influence the adoption of ESOPs based on two-way communication. In addition, the study results reveal that trade union responsiveness, takeovers, reforms, awareness of employee benefits and trust positively influence the adoption of ESOPs based on empowerment. The study further reveals that adoption of ESOPs based on transparency, two-way communication and empowerment leads to organisational performance, employee retention and employee commitment. This study, being the first of its kind in Nigeria, filled the gap that existed in the Nigerian literature in respect of the awareness and adoption of ESOPs. This study provides literature and theoretical model that can be used as a foundation by organisations and the government to start up the adoption of ESOPs. This study showed that ESOPs is beneficial to boost the economy, enhance desired organisational outcomes (organisational performance, employee retention and employee commitment) and meet the financial and retirement needs of employees. However, for organisations and employees to enjoy the full benefits of ESOPs, underlying forces such as, trade union responsiveness, takeovers, reforms, awareness of employee benefits, trusts and taxation implication must be taken into account. Furthermore, the adoption, implementation and operations of ESOPs will be successful management, trade union leaders and employees utilise strategies such as, transparency, two-way communication and empowerment.
- Full Text:
- Date Issued: 2017
- Authors: Akponah, Voke Blessing
- Date: 2017
- Subjects: Employee ownership -- Nigeria , Profit-sharing -- Nigeria Management -- Employee participation -- Nigeria Nigeria -- Economic aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/13834 , vital:27312
- Description: This study investigated the factors that influence the adoption of ESOPs in Nigeria. Furthermore, the study investigated the influence of the adoption of ESOPs on organisational performance, employee retention and employee commitment. The study results reveal that trade union responsiveness, reforms, awareness of employee benefits and taxation implication positively influence the adoption of ESOPs based on transparency. The results in this study further reveal that trade union responsiveness, takeovers, reforms, awareness of employee benefits and taxation implication effectively influence the adoption of ESOPs based on two-way communication. In addition, the study results reveal that trade union responsiveness, takeovers, reforms, awareness of employee benefits and trust positively influence the adoption of ESOPs based on empowerment. The study further reveals that adoption of ESOPs based on transparency, two-way communication and empowerment leads to organisational performance, employee retention and employee commitment. This study, being the first of its kind in Nigeria, filled the gap that existed in the Nigerian literature in respect of the awareness and adoption of ESOPs. This study provides literature and theoretical model that can be used as a foundation by organisations and the government to start up the adoption of ESOPs. This study showed that ESOPs is beneficial to boost the economy, enhance desired organisational outcomes (organisational performance, employee retention and employee commitment) and meet the financial and retirement needs of employees. However, for organisations and employees to enjoy the full benefits of ESOPs, underlying forces such as, trade union responsiveness, takeovers, reforms, awareness of employee benefits, trusts and taxation implication must be taken into account. Furthermore, the adoption, implementation and operations of ESOPs will be successful management, trade union leaders and employees utilise strategies such as, transparency, two-way communication and empowerment.
- Full Text:
- Date Issued: 2017
Evaluating late payment-induced waste in South Africa through lean construction principles
- Authors: Akuffo-Ntow, Eric Ayesu
- Date: 2016
- Subjects: Construction industry -- South Africa -- Finance , Lean manufacturing -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/8867 , vital:26437
- Description: Central to the sustainable and competitive growth of the South African construction industry is a predictable cash flow through on time payment by clients to contractors. However, chronic late payments, a recurring problem in the industry, especially in the public sector, is bringing untold hardship to contractors by derailing their competitiveness and also eroding the trust among the supply chain partners to the extent that some firms end up closing business in the industry. The situation is viewed from the lean construction perspective as an obstacle that is preventing the accrual of the required value to project parties in the construction industry. This research addresses the causes of late payments to contractors and the role of the quantity surveyor (QS) in terms of influencing early payment from a lean construction perspective. A mixed method approach was used for compiling the primary data for the study. Sequentially, one hundred and two (102) quantitative and twelve (12) interview questionnaires were administered to selected contractors and construction professionals working predominantly on public sector projects. The findings revealed that the approval process for evaluation and certification by the client- appointed agent and intermediary institutions is taking longer than contractually allowed, with parties independently undertaking their evaluation prior to the certification date. This is found to be adverse to achieving consensus on the values of the works for authorisation. Other significant barriers are the lack of funds to authorise payment, random auditor general’s documentation changes, lack of administrators’ system integration and capacity to handle cyclical payment processing. Also, contractors have been found to be in default of timeously submitting complete claim documents. It is therefore recommended that the client agents should partner with the contractor in regular design and documentation reviews, arranging the payment process and should also meet jointly to prepare monthly evaluations. In addition, contractors should be mentored from the onset of the project regarding all the necessary documentation and supporting documents that will be required by the client to ensure that payment approvals are not delayed. The payment authori-sation agent’s capacity should be enhanced through training and improved powers as a singular point of control to perform efficiently and their systems and processes should be integrated to ensure that all parties are implementing the same protocols.
- Full Text:
- Date Issued: 2016
- Authors: Akuffo-Ntow, Eric Ayesu
- Date: 2016
- Subjects: Construction industry -- South Africa -- Finance , Lean manufacturing -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/8867 , vital:26437
- Description: Central to the sustainable and competitive growth of the South African construction industry is a predictable cash flow through on time payment by clients to contractors. However, chronic late payments, a recurring problem in the industry, especially in the public sector, is bringing untold hardship to contractors by derailing their competitiveness and also eroding the trust among the supply chain partners to the extent that some firms end up closing business in the industry. The situation is viewed from the lean construction perspective as an obstacle that is preventing the accrual of the required value to project parties in the construction industry. This research addresses the causes of late payments to contractors and the role of the quantity surveyor (QS) in terms of influencing early payment from a lean construction perspective. A mixed method approach was used for compiling the primary data for the study. Sequentially, one hundred and two (102) quantitative and twelve (12) interview questionnaires were administered to selected contractors and construction professionals working predominantly on public sector projects. The findings revealed that the approval process for evaluation and certification by the client- appointed agent and intermediary institutions is taking longer than contractually allowed, with parties independently undertaking their evaluation prior to the certification date. This is found to be adverse to achieving consensus on the values of the works for authorisation. Other significant barriers are the lack of funds to authorise payment, random auditor general’s documentation changes, lack of administrators’ system integration and capacity to handle cyclical payment processing. Also, contractors have been found to be in default of timeously submitting complete claim documents. It is therefore recommended that the client agents should partner with the contractor in regular design and documentation reviews, arranging the payment process and should also meet jointly to prepare monthly evaluations. In addition, contractors should be mentored from the onset of the project regarding all the necessary documentation and supporting documents that will be required by the client to ensure that payment approvals are not delayed. The payment authori-sation agent’s capacity should be enhanced through training and improved powers as a singular point of control to perform efficiently and their systems and processes should be integrated to ensure that all parties are implementing the same protocols.
- Full Text:
- Date Issued: 2016
The challenges facing non-governmental organisations in transforming conflict through capacity-building in Nothern Uganda
- Authors: Akurut, Catherine
- Date: 2011
- Subjects: Conflict management -- Uganda , Peace-building -- Uganda
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8189 , http://hdl.handle.net/10948/1412 , Conflict management -- Uganda , Peace-building -- Uganda
- Description: Capacity-building is an essential component of post-conflict reconstruction (PCR) and peace-building in the aftermath of violent conflict. Civilians, mainly women and children are driven or abducted from their homes during violent conflict and suffer various abuses and atrocities. Many spend the duration of the conflict as refugees in Internally Displaced People (IDP) camps in neighbouring countries. Violent conflict impinges on their psychological well-being and socio-economic development making their re-integration into their former communities extremely complex and challenging. In the case of Northern Uganda, the conflict lasted for over two decades. However, since the ―Cessation of Hostilities Agreement‖ of 2006, the peace-building process has been particularly evident here. Numerous stakeholders have been involved in the capacity-building processes in Northern Uganda, and one such organisation is the Friends of Orphans (FRO) in Pader district, Northern Uganda. The purpose of this research study is to explore the challenges facing the FRO in transforming conflict and building sustainable peace through capacity-building in Pader district. The study explores the programmes the organisation implements and investigates how these programmes are relevant for the transformation of conflict. Apart from reviewing the literature, the researcher conducted semi-structured interviews and used participant observation. The employees of the FRO – all of whom are involved with capacity-building in these communities – participated in these interviews in their capacities as social workers, teachers, administrators and field workers. The beneficiaries of these programmes include former child soldiers, abductees, child mothers, land mine survivors and orphans. Lessons learned by the FRO, as well as the researcher‘s recommendations, are discussed in the study in order to assist the future work of the organisation and other stakeholders who have devoted their efforts to the recovery of areas emerging from conflict.
- Full Text:
- Date Issued: 2011
- Authors: Akurut, Catherine
- Date: 2011
- Subjects: Conflict management -- Uganda , Peace-building -- Uganda
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8189 , http://hdl.handle.net/10948/1412 , Conflict management -- Uganda , Peace-building -- Uganda
- Description: Capacity-building is an essential component of post-conflict reconstruction (PCR) and peace-building in the aftermath of violent conflict. Civilians, mainly women and children are driven or abducted from their homes during violent conflict and suffer various abuses and atrocities. Many spend the duration of the conflict as refugees in Internally Displaced People (IDP) camps in neighbouring countries. Violent conflict impinges on their psychological well-being and socio-economic development making their re-integration into their former communities extremely complex and challenging. In the case of Northern Uganda, the conflict lasted for over two decades. However, since the ―Cessation of Hostilities Agreement‖ of 2006, the peace-building process has been particularly evident here. Numerous stakeholders have been involved in the capacity-building processes in Northern Uganda, and one such organisation is the Friends of Orphans (FRO) in Pader district, Northern Uganda. The purpose of this research study is to explore the challenges facing the FRO in transforming conflict and building sustainable peace through capacity-building in Pader district. The study explores the programmes the organisation implements and investigates how these programmes are relevant for the transformation of conflict. Apart from reviewing the literature, the researcher conducted semi-structured interviews and used participant observation. The employees of the FRO – all of whom are involved with capacity-building in these communities – participated in these interviews in their capacities as social workers, teachers, administrators and field workers. The beneficiaries of these programmes include former child soldiers, abductees, child mothers, land mine survivors and orphans. Lessons learned by the FRO, as well as the researcher‘s recommendations, are discussed in the study in order to assist the future work of the organisation and other stakeholders who have devoted their efforts to the recovery of areas emerging from conflict.
- Full Text:
- Date Issued: 2011
Conflict related sexual violence against males:recognition by and responses of humanitarian organizations in Africa
- Authors: Akurut, Catherine
- Date: 2020
- Subjects: Male rape victims -- Africa , Gender in conflict management --Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46648 , vital:39605
- Description: The study investigated the knowledge, attitudes, and experiences of humanitarian service providers concerning the recognition of and response to the phenomenon of male victims of conflict-related sexual violence against males. Sources of literature in respect to the awareness, understanding, and recognition of conflict-related sexual violence against males were explored. Perceptions about the recognition of male victims were discovered. Response strategies available to male victims were explored through the experiences of humanitarian organisation representatives, including, inter alia, programme managers, gender-based violence advisers, protection officers and activists. Mechanisms to augment any existing practices to allow for the care of and support for male victims were examined. A qualitative research approach was used to explore the topic of this study. Data was collected using semi-structured interview questions that were developed. And document review was also used as the second means of data collection. The research participants were recruited using purposive sampling, which was complemented by snowballing until data saturation. Triangulation was used by combining the two data collection methods to avoid relying on one source. A narrative literature review was aimed to obtain further information about the phenomenon of conflict-related sexual violence against males.
- Full Text:
- Date Issued: 2020
- Authors: Akurut, Catherine
- Date: 2020
- Subjects: Male rape victims -- Africa , Gender in conflict management --Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/46648 , vital:39605
- Description: The study investigated the knowledge, attitudes, and experiences of humanitarian service providers concerning the recognition of and response to the phenomenon of male victims of conflict-related sexual violence against males. Sources of literature in respect to the awareness, understanding, and recognition of conflict-related sexual violence against males were explored. Perceptions about the recognition of male victims were discovered. Response strategies available to male victims were explored through the experiences of humanitarian organisation representatives, including, inter alia, programme managers, gender-based violence advisers, protection officers and activists. Mechanisms to augment any existing practices to allow for the care of and support for male victims were examined. A qualitative research approach was used to explore the topic of this study. Data was collected using semi-structured interview questions that were developed. And document review was also used as the second means of data collection. The research participants were recruited using purposive sampling, which was complemented by snowballing until data saturation. Triangulation was used by combining the two data collection methods to avoid relying on one source. A narrative literature review was aimed to obtain further information about the phenomenon of conflict-related sexual violence against males.
- Full Text:
- Date Issued: 2020
An evaluation of the interdisciplinary nature of environmental education in colleges of education in Bophuthatswana
- Authors: Akwa, Joseph Yeboah
- Date: 1994
- Subjects: Environmental education -- South Africa -- Bophuthatswana Environmental education -- Curricula -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1526 , http://hdl.handle.net/10962/d1003408
- Description: This study was aimed at evaluating the interdisciplinary nature of environmental education within the colleges of education in Bophuthatswana. Data collection was based on semi-structured interviews with college lecturers and, to a lesser extent, on observations during a workshop with environmental educators from Bophuthatswana. Knowledge was gained about college related factors which influence the varying extent to which environmental education is being implemented within the colleges of education. Lecturers' understanding of the interdisciplinary nature of environmental education and related concepts was explored. Insights were also gained into problems of implementation which included lecturers' limited understanding of the concept of interdisciplinarity, structural ambiguities, limited training and experience, and a lack of clarity in both local and international literature on environmental education concepts and terms. Specifically the study sought to illuminate the dichotomy between theory and practice, the conflict between the dominant curriculum paradigm and the new emerging paradigm, and tensions between the interdisciplinary nature of environmental education and subject-based disciplines, which lead to problems of implementation. The study could make an important contribution to the current curriculum debate on environmental education in South Africa by illuminating the dichotomy between the theory and the practice of environmental education, and the problems involved in translating interdisciplinary approaches into workable classroom practices within discipline based curriculum structures.
- Full Text:
- Date Issued: 1994
- Authors: Akwa, Joseph Yeboah
- Date: 1994
- Subjects: Environmental education -- South Africa -- Bophuthatswana Environmental education -- Curricula -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1526 , http://hdl.handle.net/10962/d1003408
- Description: This study was aimed at evaluating the interdisciplinary nature of environmental education within the colleges of education in Bophuthatswana. Data collection was based on semi-structured interviews with college lecturers and, to a lesser extent, on observations during a workshop with environmental educators from Bophuthatswana. Knowledge was gained about college related factors which influence the varying extent to which environmental education is being implemented within the colleges of education. Lecturers' understanding of the interdisciplinary nature of environmental education and related concepts was explored. Insights were also gained into problems of implementation which included lecturers' limited understanding of the concept of interdisciplinarity, structural ambiguities, limited training and experience, and a lack of clarity in both local and international literature on environmental education concepts and terms. Specifically the study sought to illuminate the dichotomy between theory and practice, the conflict between the dominant curriculum paradigm and the new emerging paradigm, and tensions between the interdisciplinary nature of environmental education and subject-based disciplines, which lead to problems of implementation. The study could make an important contribution to the current curriculum debate on environmental education in South Africa by illuminating the dichotomy between the theory and the practice of environmental education, and the problems involved in translating interdisciplinary approaches into workable classroom practices within discipline based curriculum structures.
- Full Text:
- Date Issued: 1994
Scalable chemistry involving diazonium salts
- Authors: Akwi, Faith Mary
- Date: 2016
- Subjects: Azo compounds -- Synthesis , Chemical processes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6909 , vital:21162
- Description: Herein an alternative approach aimed at reducing the cost of numbering up technique as a scale up strategy for chemical processes from the laboratory bench top to the industry is explored. The effect of increasing channel size on the reaction conversion of the synthesis of azo compounds is investigated. This was achieved via a systematic investigative understanding of the synthesis in microreactors where a proof of concept study was performed to determine the optimum reaction parameters in azo coupling reactions involving couplers with aminated or hydroxylated groups in Little Things Factory-MS microreactors (Channel diameter: 1.0 mm) It was found that at slightly alkaline conditions (pH 8.55) and at a temperature of 25 °C, excellent conversions were attained in the azo coupling reaction of the diazonium salt solution of 2,4-dimethylaniline to 2-naphthol. On the other hand, the azo coupling reaction of the diazonium salt solution of p-nitroaniline to diphenylamine was found to thrive at a pH of 5.71 and at a temperature of 25 °C. Using, these optimized reaction parameters, the in-situ and reactive quench of diazonium salts in LTF-MS microreactors was investigated where it was found that at a flow rate of 0.2 ml/min, 0.03 ml/min and 0.07 ml/min of diazotizable amine & HCl, sodium nitrite and coupler solutions respectively, a conversion of 98% is achieved in approximately 2.4 minutes. A library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic aromatic systems. The scaled up synthesis of these compounds in a homemade PTFE tubing (ID 1.5 mm) reactor system was thereafter investigated and comparable conversions were observed. Capitalizing on the benefits of a large surface area and the short molecular diffusion distances observed in microreactors, in-situ phase transfer catalyzed azo coupling reaction of diphenylamine to p-nitroaniline was also explored. In this investigation a rapid and easy optimization protocol that yielded a 99%, 22% and 33% conversion of diphenylamine, carbazole and triphenylamine respectively in approximately 2.4 minutes using Chemtrix microreactors was established. On increasing the microreactor channel internal diameter in the scaled up synthesis approach, it was found that a 0.5 mm increase in channel internal diameter does result in lower reaction conversions.
- Full Text:
- Date Issued: 2016
- Authors: Akwi, Faith Mary
- Date: 2016
- Subjects: Azo compounds -- Synthesis , Chemical processes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/6909 , vital:21162
- Description: Herein an alternative approach aimed at reducing the cost of numbering up technique as a scale up strategy for chemical processes from the laboratory bench top to the industry is explored. The effect of increasing channel size on the reaction conversion of the synthesis of azo compounds is investigated. This was achieved via a systematic investigative understanding of the synthesis in microreactors where a proof of concept study was performed to determine the optimum reaction parameters in azo coupling reactions involving couplers with aminated or hydroxylated groups in Little Things Factory-MS microreactors (Channel diameter: 1.0 mm) It was found that at slightly alkaline conditions (pH 8.55) and at a temperature of 25 °C, excellent conversions were attained in the azo coupling reaction of the diazonium salt solution of 2,4-dimethylaniline to 2-naphthol. On the other hand, the azo coupling reaction of the diazonium salt solution of p-nitroaniline to diphenylamine was found to thrive at a pH of 5.71 and at a temperature of 25 °C. Using, these optimized reaction parameters, the in-situ and reactive quench of diazonium salts in LTF-MS microreactors was investigated where it was found that at a flow rate of 0.2 ml/min, 0.03 ml/min and 0.07 ml/min of diazotizable amine & HCl, sodium nitrite and coupler solutions respectively, a conversion of 98% is achieved in approximately 2.4 minutes. A library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic aromatic systems. The scaled up synthesis of these compounds in a homemade PTFE tubing (ID 1.5 mm) reactor system was thereafter investigated and comparable conversions were observed. Capitalizing on the benefits of a large surface area and the short molecular diffusion distances observed in microreactors, in-situ phase transfer catalyzed azo coupling reaction of diphenylamine to p-nitroaniline was also explored. In this investigation a rapid and easy optimization protocol that yielded a 99%, 22% and 33% conversion of diphenylamine, carbazole and triphenylamine respectively in approximately 2.4 minutes using Chemtrix microreactors was established. On increasing the microreactor channel internal diameter in the scaled up synthesis approach, it was found that a 0.5 mm increase in channel internal diameter does result in lower reaction conversions.
- Full Text:
- Date Issued: 2016