An assessment of the performance appraisal system applied for the junior management level at the cold chain
- Authors: Botha, Johannes Jacobus
- Date: 2007
- Subjects: Employees -- Rating of , Junior managers -- Rating of -- South Africa , Performance standards -- South Africa -- Port Elizabeth , Cold chain management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8735 , http://hdl.handle.net/10948/796 , Employees -- Rating of , Junior managers -- Rating of -- South Africa , Performance standards -- South Africa -- Port Elizabeth , Cold chain management
- Description: The study aims to identify which performance appraisal system is currently used in The Cold Chain, how this system compare with the fundamental requirements of a successful appraisal system and what requirements can be adopted to make the way in which Team Leaders are appraised more effective. An introduction into The Cold Chain, the identification of the problem and the relevance of the study is followed by a literature overview of performance management, the role of performance appraisals and the requirements for a successful performance appraisal system. Various appraisal systems, problems associated with performance appraisals and a framework for the development of an efficient system is discussed. Research conducted using a questionnaire sent to Team Leaders in The Cold Chain, delivered results which were analysed and discussed in Chapter four. In addition to biographical information, the function, effectiveness, evaluator involvement, objectives and criteria, requirements for performance appraisals, organisational alignment and evaluator faults were discussed. It was found that the current performance appraisal system in use at Mercor is a trait scale system. A trait scale method of performance appraisals does not reflect measurement against clearly defined job criteria and is difficult to legally defend. The essential elements for successful appraisal systems such as reliability, relevance, sensitivity, uncontaminated information, acceptability, practicality and legality will be present in a 360-degree approach and the implementation of such a system in Mecor was recommended.
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- Date Issued: 2007
An evaluation of the application of specific conflict management mechanisms in the South African transition to democracy, 1985-2004 : a conflict resolution perspective
- Authors: Bradshaw, Gavin John
- Date: 2007
- Subjects: Conflict management -- South Africa , Mediation -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:8160 , http://hdl.handle.net/10948/482 , Conflict management -- South Africa , Mediation -- South Africa
- Description: South Africa has always been cited as an example of protracted social conflict by the analytical conflict resolution school. Given that appellation, the conflict, in terms of the understanding of that school of thought, would not have been amenable to resolution, and yet many observers hail the South African democratic transition as a miracle of transformation. This thesis, using a detailed application of the various elements of protracted or deep-rooted social conflict, demonstrates that South Africa is indeed an example of protracted social conflict. Given the application of pre-negotiation initiatives, and the establishment of a unique National Peace Accord, negotiations were enabled, and successfully delivered a democratic election, and so far, also a sustainable democracy. The establishment of the Truth and Reconciliation Commission was the result of a realization on the part of a wide spectrum of South African leadership and conflict resolution professionals, that negotiation alone would not provide conflict resolution for South Africans, and that there was therefore an additional need to deal with the deeper issues of conflict, if the settlement were to prove sustainable. The question remains whether ours represents a successful resolution of the conflict from the theoretical perspective of the analytical conflict resolution school. A close examination of South African socio-political issues across a number of domains regarded by the analytical conflict resolution school as important, indicates that while the requirements for conflict resolution were indeed met in the South African case, their more advanced stage of resolution; conflict provention has not been satisfied. That explains the fact that many tensions, much violence and intolerance remain. South Africa’s democracy has not been infused with analytical conflict management institutions, basic human needs have not been substantially met and valued relationships remain elusive. Because protracted social conflict is cyclical, we can expect high-levels of conflict behaviour to haunt, and even threaten our fledgling democracy. It is argued here that a coherent theoretical approach to the South African conflict management process would have produced a more sustainable outcome, and we recommend the continued use and institutionalization of analytical conflict provention processes to secure the future of our country.
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- Date Issued: 2007
A model for adaptive multimodal mobile notification
- Authors: Brander, William
- Date: 2007
- Subjects: Mobile computing , Context-aware computing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10473 , http://hdl.handle.net/10948/699 , Mobile computing , Context-aware computing
- Description: Information is useless unless it is used whilst still applicable. Having a system that notifies the user of important messages using the most appropriate medium and device will benefit users that rely on time critical information. There are several existing systems and models for mobile notification as well as for adaptive mobile notification using context awareness. Current models and systems are typically designed for a specific set of mobile devices, modes and services. Communication however, can take place in many different modes, across many different devices and may originate from many different sources. The aim of this research was to develop a model for adaptive mobile notification using context awareness. An extensive literature study was performed into existing models for adaptive mobile notification systems using context awareness. The literature study identified several potential models but no way to evaluate and compare the models. A set of requirements to evaluate these models was developed and the models were evaluated against these criteria. The model satisfying the most requirements was adapted so as to satisfy the remaining criteria. The proposed model is extensible in terms of the modes, devices and notification sources supported. The proposed model determines the importance of a message, the appropriate device and mode (or modes) of communication based on the user‘s context, and alerts the user of the message using these modes. A prototype was developed as a proof-of-concept of the proposed model and evaluated by conducting an extensive field study. The field study highlighted the fact that most users did not choose the most suitable mode for the context during their initial subscription to the service. The field study also showed that more research needs to be done on an appropriate filtering mechanism for notifications. Users found that the notifications became intrusive and less useful the longer they used them.
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- Date Issued: 2007
Wi-Fi as a last mile access technology and The Tragedy of the Commons
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
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- Date Issued: 2007
The initial grounding of rational numbers : an investigation
- Authors: Brown, Bruce John Lindsay
- Date: 2007
- Subjects: Number theory Numbers, Rational -- Study and teaching (Elementary) Numeracy -- Study and teaching (Elementary) Mathematics -- Study and teaching (Elementary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1904 , http://hdl.handle.net/10962/d1006351
- Description: This small scale exploratory research project investigated the grounding of rational number concepts in informal, everyday life situations. A qualitative approach was taken to allow for the identification and then in depth investigation, of issues of importance for such a grounding of rational number understanding. The methodology followed could be seen as a combination of grounded theory and developmental research. And the data was generated through in-depth and clinical interviews structured around a number of grounded tasks related to rational numbers. The research comprised three cycles of interviews that were transcribed and then analysed in detail, interspersed with periods of reading and reflection. The pilot cycle involved a single grade three teacher, the second cycle involved 2 grade three teachers and the third cycle involved 2 grade three children. The research identified a number of different perspectives that were all important for the development of a fundamental intuitive understanding that could be considered personally meaningful to the individual concerned and relevant to the development of rational number concepts. Firstly in order to motivate and engage the child on a personal level the grounding situation needed to be seen as personally significant by the child. Secondly, coordinating operations provided a means of developing a fundamental intuitive understanding, through coordination with affording structures of the situation that are relevant to rational numbers. Finally, goal directed actions that are deliberately structured to achieve explicit goals in a situation are important for the development of more explicit concepts and skills fundamental for rational number understanding. Different explicit structures give rise to different interpretations of rational numbers in grounding situations. In addition to these perspectives, it became evident that building and learning representations was important for developing a more particularly mathematical understanding, based on the fundamental understanding derived from the child's grounded experience. The conclusion drawn in this research as a result of this complexity, is that to achieve a comprehensive and meaningful grounding, children's learning of rational numbers will not follow a simple linear trajectory. Rather this process forms a web of learning, threading coordinating operations for intuitive development, interpretations for explicit grounding and representations to develop more formal mathematical conceptions.
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- Date Issued: 2007
Determination of the botanical composition of black rhinoceros (Diceros bicornis) dung using the rbcL gene as a molecular marker, and analysis of antioxidant and phenolic content of its browse
- Authors: Bulani, Siyavuya Ishmael
- Date: 2007 , 2013-06-25
- Subjects: Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4070 , http://hdl.handle.net/10962/d1006468 , Black rhinoceros -- Food , Black rhinoceros -- South Africa -- Eastern Cape , Browse (Animal food) -- Analysis -- South Africa -- Eastern Cape , Plant ecology -- South Africa -- Eastern Cape , Genetic markers , Black rhinoceros -- Manure -- Analysis , Phenols , Antioxidants
- Description: The black rhinoceros remains one of the world's extremely endangered species despite a variety of policies to protect it. The black rhinoceros population at the Great Fish River Reserve (GFRR) in the Eastern Cape in South Africa has increased steadily since their re-introduction in 1986. This megaherbivore is a browser, with a diet obtained largely from the short and medium succulent thicket of the GFRR. Knowledge of the preferential diet of the black rhinoceros on the reserve is an important factor for the effective management of the land and the herbivores that compete for its resources. The dietary preferences of the black rhinoceros at the reserve have been established using backtracking methods. In this study the rbcL gene was used to establish an rbcL gene database of the plants from the GFRR and determine the botanical composition of the black rhinoceros dung from the GFRR. Due to the limited number of rbcL gene plant sequences from the GFRR deposited in the GenBank database, 18 plant species from the GFRR were sequenced. Sequence analyses between the partial rbcL gene sequences generated were able to distinguish between plants down to species level. Plant species from the family Euphorbiaceae and Fabaceae showed sequence variation at intra-specific level compared to those of Tiliaceae which were more conserved. The generated rbcL gene sequences from seasonal dung samples were compared to the rbcL gene sequenced from 18 plant species obtained from the GFRR and those from the GenBank database. A wide range of plant species were identified from the dung samples. There were no major differences in botanical composition between the dung samples, except that Grewia spp. were found to dominate in almost all seasons. The results obtained on the free radical scavenging activity of the extracts against 2,2-Diphenyl-l-picrylhydrazyl (DPPH) increased in the order of methanol > ethyl acetate > chloroform. The DPPH free radical scavenging activity of the methanol plant extracts increased in the order Brachylaena elliptica > Plumbago auriculata > Grewia robusta > Azima tetracantha. Methanol extracts on the TLC plate sprayed with Fe³⁺-2,4,6-Tri-2-pyridyl-s-triazine (TPTZ) showed that the compounds present in the extracts react differently to ferric ion, with most compounds unable to reduce ferric ion. Furthermore the methanol extracts were able to exhibit reduction potentials vs. Ag/AgCl at low concentrations. The compounds in the extracts were shown to be phenolic acids and flavonoid glycosides.
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- Date Issued: 2007
A drug utilisation review of Isotretinoin in the management of acne
- Authors: Burger, Solé
- Date: 2007
- Subjects: Acne -- Treatment , Isotretinoin
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:10147 , http://hdl.handle.net/10948/673 , Acne -- Treatment , Isotretinoin
- Description: Acne is a common, chronic disorder that affects many adolescents. The most effective acne medication is systemic isotretinoin. It provides a permanent cure for many patients, but has various side effects. A South African Acne Treatment Guideline was introduced in 2005. Adherence to this guideline could lead to safer, more effective acne management. The primary aim of this study was to investigate the appropriateness of medications prescribed in the treatment of acne in South Africa, and to evaluate the safety and efficacy of systemic isotretinoin utilised by patients in the Nelson Mandela Metropole (NMM). A drug utilisation study (including 18 803 South African acne patients’ chronic prescription data between 2000 and 2005) and a patient questionnaire survey (including information from 57 patients in the NMM who used systemic isotretinoin) were conducted. Basic descriptive and interferential statistics were calculated. The drug utilisation study revealed that systemic antibiotics were the acne treatment prescribed to most (43.3 percent) patients, followed by 42.1 percent of patients on systemic isotretinoin, 33.2 percent on hormonal therapy and 18.9 percent on topical therapy. Topical retinoids were underused. The questionnaire survey indicated a lack of compliance by prescribers with guideline recommendations regarding the prescription (and accompanying counselling and monitoring) of isotretinoin. Incorrect cumulative doses were frequently prescribed, and a lack of proper implementation of pregnancy prevention measures was evident. The majority of isotretinoin patients reported a high efficacy of isotretinoin in clearing their acne.
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- Date Issued: 2007
An investigation into the challenges affecting the effective implementation of the Public Finance Management Act, 1999 (Act 1 of 1999 as amended by Act 29 of 1999) int the Eastern Cape Province with specific reference to the Provincial Department of Public Works
- Authors: Buso, Luthando Gilbert
- Date: 2007
- Subjects: Finance, Public -- South Africa -- Eastern Cape , Financial management , Public administration -- Africa, Southern , Local government -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:8252 , http://hdl.handle.net/10948/483 , http://hdl.handle.net/10948/d1011903 , Finance, Public -- South Africa -- Eastern Cape , Financial management , Public administration -- Africa, Southern , Local government -- South Africa -- Eastern Cape
- Description: The objective of the study was to investigate challenges affecting the effective implementation of the Public Finance Management Act, 1999 (Act No. 1 of 1999 as amended by Act No. 29 of 1999) in the Eastern Cape Province with specific reference to the Provincial Department of Public Works. The research study has been conducted in such a manner that the reason to send a team of experts by the DPSA on approval by the President to come to the Eastern Cape and assist the ailing administrations of four departments is determined. The four departments that had a problem were: 1. Department of Roads and Public Works 2. Department of Health 3. Department of Education and 4. Department of Social Development The roads function of the Department of Roads and Public Works was later transferred to the Department of Transport and the Department of Roads and Public Works changed the name to Department of Public Works in September 2004. The team that was sent to the Eastern Cape together with the Director-General of the Province and the Superintendent-General of the Provincial Treasury formed up the IMT. The objective was to introduce turnaround strategies that would enable the four departments to effectively and efficiently implement the PFMA to the best interest of the South African Government. The PFMA is part of the broader strategy on improving public financial management in the public sector in the Republic of South Africa. It prescribes measures to ensure responsibility, accountability and transparency in national and provincial departments. Qualified Auditor-General’s reports for the previous financial years compelled the President in 2002 to establish Interim Management Team (IMT) in the Eastern Cape, comprising of experts from national government, to assist the ailing administration in four provincial departments, including the Department of Roads and Public Works. Questionnaires to employees, Auditor-General, Provincial Director-General, Superintendent-General of Provincial Treasury and as well as to the Accounting Officer of the Department of Public Works, were designed and issued out for completion. Interviews were also conducted to some of the employees. The assumption is that the majority of employees do not understand policies and procedures of the department and they displayed this by remaining neutral in questions asked and disagreed with some of the statements. During the interview process, the majority emphasised their protest against over usage of consultants by the department. Preference given to candidates from outside the department when senior posts are advertised instead of looking for excellently performing candidates from the internal ranks of serving employees, has been outlined as one of the elements contributing to low moral and low productivity in the workplace. Over usage of consultants and a big number of employees who disagreed with statements and remained neutral signify incapacity of the management to perfectly implement the PFMA for sound public financial management in the department. It has been established that regular risk assessments are not conducted, poor organisational structure with many posts that are not filled, no Anti-Corruption Unit to implement Public Service Anti-Corruption Strategy and, no clear managerial lines of accountability due to poor planning, ineffective internal controls and procedures, all render the department incapable of becoming one of the best provincial departments that get unqualified audit report from the Auditor-General. The findings provide clear indication that drastic transformation of the department into an institution that can perfectly implement the PFMA is necessary. The implication is that mismanagement of financial resources and fraud and corruption defeat service delivery objectives. Strategic objectives of the department are not achieved. The Eastern Cape Provincial Departments are obliged to align their strategic plans to the Provincial Growth and Development Plan (2004 – 2014). Therefore the implication is that, poor performance by the Department of Public Works impacts negatively to this provincial objective. Lack of effective control systems has negative implications on the administration of the department and renders it vulnerable to fraud and corruption.
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- Date Issued: 2007
The cost of credit in the micro-finance industry in South Africa
- Authors: Campbell, Jonathan
- Date: 2007
- Subjects: Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3667 , http://hdl.handle.net/10962/d1003182 , Contracts -- South Africa , Credit -- Law and legislation -- South Africa , Microfinance -- South Africa , Usury laws -- South Africa
- Description: This thesis analyses the cost of credit in the micro-finance industry in South Africa. The study situates micro-lending agreements within the law of contract, beginning with an examination of contractual fairness in terms of the common law: the fundamental principle of freedom of contract that underpins the common law of contract; the principle that agreements contrary to public policy should not be enforced; and the impetus given by constitutional values that inform public policy. In regard to moneylending transactions, common law usury law will be explained. The study then goes on to trace the origins and rapid growth of the micro-finance industry which was made possible by its exemption in 1992 from the Usury Act 73 of 1968. The upshot of this development was that registered micro-lenders have for nearly 14 years charged excessive interest rates, and continue to do so. The dire socio-economic impact of these high interest rates on individual consumers and lowincome communities is then demonstrated: how borrowers of small loans soon become over-indebted; the loss of billions of rands every year to low-income communities in the form of interest on micro-loans. The study then shifts to the legislative response to the need for consumer protection in regard to consumer credit. The extensive credit law review process is explained, resulting ultimately in the National Credit Act 34 of 2005, which allows the Minister to prescribe limits on interest rates and fees in all sectors of the consumer credit market. The prescribed limits on the cost of credit in the micro-finance sector are thoroughly explained and analysed, with particular reference to the implications of each element of the credit costing structure, and the combined impact of the total cost of credit on different types and sizes of loans. The envisaged maximum interest and fees will markedly alter the positions of micro-lenders and consumers, and receive careful analysis. The study closes with a summary of findings in the thesis, which includes suggested amendments to the National Credit Regulations and a review of possible legal challenges to the high cost of credit on smaller loans.
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- Date Issued: 2007
The comparison of in vitro release methods for the evaluation of oxytocin release from Pluronic® F127 parenteral formulations
- Authors: Chaibva, Faith A , Walker, Roderick B
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6351 , http://hdl.handle.net/10962/d1006033
- Description: The objective of these studies was to develop a discriminatory in vitro release test for assessing formulation factors that may affect oxytocin (OT) release during formulation development studies of a Pluronic® F127 OT in situ gel-forming parenteral dosage form. An appropriate release assessment method should be able to discriminate between the performance of different formulation compositions (1, 2), and this was the primary criterion used for selection of an appropriate test procedure during the test method development process. ANOVA and the difference (f1) and similarity (f2)factors were used to evaluate the discriminatory behavior of different test methods that were investigated in these studies. The in vitro release tests that were investigated included the use of USP Apparatus 1, 2, and 3; a dialysis bag in USP Apparatus 2; and a membrane-less diffusion method. It was concluded that the use of USP Apparatus 3 was best able to discriminate between OT release for the different formulations tested. USP Apparatus 3 was thus considered the most suitable in vitro release test apparatus for studying formulation factors affecting OT release during the development of a parenteral dosage form prepared using Pluronic® F127.
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- Date Issued: 2007
Development and assessment of an oxytocin parenteral dosage form prepared using pluronic ® F127
- Authors: Chaibva, Faith Anesu
- Date: 2007
- Subjects: Oxytocin -- Therapeutic use , Drugs -- Dosage forms , Pregnancy -- Complications -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3747 , http://hdl.handle.net/10962/d1003225 , Oxytocin -- Therapeutic use , Drugs -- Dosage forms , Pregnancy -- Complications -- Management
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- Date Issued: 2007
Evaluation of the safety and efficacy of topical mometasone furoate formulations
- Authors: Chamboko, Bernadett Vongayi
- Date: 2007
- Subjects: Adrenocortical hormones -- Physiological effect , Drugs -- Testing , Dermatopharmacology , High performance liquid chromatography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3748 , http://hdl.handle.net/10962/d1003226 , Adrenocortical hormones -- Physiological effect , Drugs -- Testing , Dermatopharmacology , High performance liquid chromatography
- Description: The human skin blanching assay (HSBA) is a well-researched and validated method for the bioequivalence assessment of topical corticosteroids. Traditionally, visual assessment of skin blanching has been used. Such testing methods are not conducive for interlaboratory comparisons. Regulatory bodies prefer less subjective methods of analysis. The FDA released guidelines on the assessment of bioequivalence for topical corticosteroids that recommends the use of a chromameter as a reliable method to measure skin blanching although the use of visual assessment with acceptable validation is also provided for. However, the FDA does not elucidate on the manipulation and handling of the chromameter during skin blanching measurements. The purpose of this project was several fold, which included investigations to standardize the manipulation and handling of a chromameter. In particular, measures to avoid skin whitening resulting from the effects of pressure on the skin during chromameter use were investigated. Other methods of analysis should surpass or at least be comparable to the HSBA if such methods are to be used for the assessment of topical corticosteroids. Microdialysis is a relatively new technique for assessing the rate at which drug penetrates the skin. The advantage of using this method is that there are fewer restrictions for selection of an appropriate study population unlike those required for the HSBA where one has to be both a ‘responder’ and a ‘detector’ for their results to be used in data analysis. Microdialysis was investigated by initially conducting experiments in which microdialysis probes were embedded into topical formulations containing mometasone furoate (MF) and the initial results revealed that relatively low drug was released from the formulations. These results indicated that should microdialysis be applied to measure the in vivo release of MF from such topical formulations following application to the skin, even lower concentrations of MF would likely result in the dialysate, necessitating the need for ultra-high sensitive methods of analysis. Typically, the availability of an appropriate analytical technique such as liquid chromatography coupled with mass spectrometry (LCMS) would be a pre-requisite for such in vivo studies. However, only high-pressure liquid chromatography (HPLC) and other less sensitive equipment was available in the laboratories. The study objectives were therefore focussed on in vitro assessment of the release of MF from topical formulations using microdialysis and Franz cells. In addition, the in vivo release of MF was also studied using the HSBA. Data obtained from the microdialysis experiments were compared with the data obtained from the Franz cell diffusion studies in order to provide information on the pharmaceutical availability of MF from the various topical MF dosage forms. Subsequently, pharmaceutical equivalence was investigated from the comparative pharmaceutical availability data using statistical analysis. An additional objective was to attempt to correlate in vitro with in vivo data (IVIVC) to establish a model that could be used to assess safety and efficacy of generic topical drug products. The in vivo data obtained from the HSBA were processed according to the FDA requirements and these pharmacodynamic data were subsequently compared with the microdialysis and Franz cell results. In summary the objectives of this project were: 1. To develop a system to improve the reproducibility of the use of a Minolta® chromameter and compare this with the standard/normal manipulation and handling of such instruments. 2. To develop and validate an HPLC method for the analysis of MF for use with in vitro diffusion studies using microdialysis and Franz cells. 3. To conduct a comparative HSBA on proprietary MF topical creams from two different countries in accordance with the FDA guidance. 4. To assess the pharmaceutical equivalence of topical formulations containing MF using Franz diffusion cells and in vitro microdialysis. 5. To compare the in vivo data obtained from the HSBA with those obtained in vitro using microdialysis and Franz cells.
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- Date Issued: 2007
Improving certain high performance properties of natural fibres
- Authors: Chapple, Stephen Anthony
- Date: 2007
- Subjects: Textile chemistry , Fireproofing of fabrics
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10451 , http://hdl.handle.net/10948/815 , Textile chemistry , Fireproofing of fabrics
- Description: Cotton possesses many characteristics that make it desirable to the consumer, and this has resulted in its usage in a broad range of products. Cotton, however, is a flammable material that is easily ignited and rapidly consumed. The flame retardant treatment of cotton is, therefore, an important textile process that has received wide attention over many years. There are a number of commercial flame retardant treatments available for cotton, the most common being phosphate-based. These treatments, however, often have drawbacks or have a negative impact on the desirable properties of the fibre and the challenge still exists for designing better flame retardant products and systems that are durable and have limited impact on fibre properties. The study considers the application of the sol-gel as a coating on fabric that was pre-treated with a phosphate-based flame retardant or as a means for applying a phosphate-based flame retardant. Both treatment methods were found to be suitable for imparting flame resistance to the fabric. The effect of various phosphate-based flame retardants on flammability and fabric properties such as colour, handle and strength was investigated and it was shown that a diammonium phosphate and urea combination gave the best flame resistance. In this regard, a flame resistance was achieved with a lower amount of phosphorous than was used in similar conventional treatments. The durability of the coating to rinsing with water and soaping with a detergent was also investigated. It was found that the flame resistance was lost after rinsing or soaping but the prevention of afterglow combustion was retained. It was shown that the preparatory treatment of the fabric influenced the sol-gel coating process and the flammability of the fabric. Mercerisation and bleaching of the fabric increased the “wet pick-up” during the coating process and improved the flame resistance. The influence of various factors was also investigated in further detail. The ratio of the sol-gel components, the delay after coating prior to drying (hang time) and the curing time were investigated using an experimental design. The curing time and the ratio of components in the sol-gel were shown to have the greatest influence on fabric properties and fabric flammability. It was shown that there is a trade-off between the desired high level of fabric flame resistance and preserving the inherent properties of the fabric such as colour, handle and strength.
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- Date Issued: 2007
Load stress; carrier strain: implications for military and receational backpacking
- Authors: Charteris, J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6754 , http://hdl.handle.net/10962/d1009456
- Description: This paper reviews a growing literature on the stress of backpacking, particularly in military situations. Conceptual issues are raised and the implications for recreational backpackers are addressed. Under moderate to fairly heavy loading the energy cost, per kg total load carried, per hour, relates almost linearly to walking speed. Empirical data from studies in this unit are presented as benchmark indicators for use by recreational backpackers.
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- Date Issued: 2007
Novel gallium (III) phthalocyanine derivatives–Synthesis, photophysics and photochemistry
- Authors: Chauke, Vongani , Ogunsipe, Abimbola , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283118 , vital:55912 , xlink:href="https://doi.org/10.1016/j.poly.2007.01.016"
- Description: The syntheses of gallium(III) chloride phthalocyanine {(Cl)GaPc}, octaphenoxyphthalocyaninato gallium(III) chloride {(Cl)GaOPPc} and octakis(4-tert-butylphenoxy)phthalocyaninato gallium(III) chloride {(Cl)GaOTBPPc}; as well as their photophysical and photochemical parameters are hereby presented. Fluorescence quantum yields do not vary much among the three metallophthalocyanines (MPcs); therefore it was concluded that the effect of the substituents is not significant amongst (Cl)GaPc, (Cl)GaOPPc and (Cl)GaOTBPPc. Solvents effects, however, had an effect on the results. Triplet quantum yields were found to be lower in DMSO than in DMF and toluene. The rate constants for fluorescence, intersystem crossing and internal conversion as well as fluorescence and triplet lifetimes are reported. We have also reported photodegradation and singlet oxygen quantum yields. There was no clear correlation between the later parameters. It was, however, established that the three MPcs were stable.
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- Date Issued: 2007
Photochemistry, photophysics and nonlinear optical parameters of phenoxy and tert-butylphenoxy substituted indium (III) phthalocyanines
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268823 , vital:54235 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
- Full Text:
- Date Issued: 2007
Photochemistry, photophysics and nonlinear optical parameters of phenoxy and tert-butylphenoxy substituted indium (III) phthalocyanines
- Authors: Chauke, Vongani , Durmus, Mahmut , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/268787 , vital:54232 , xlink:href="https://doi.org/10.1016/j.jphotochem.2007.05.022"
- Description: This work hereby presents the syntheses, photochemistry and photophysics of octaphenoxy ((Cl)InOPPc) and octakis(4-tert-butylphenoxy)chloroindium ((Cl)InOTBPPc) phthalocyanines. Calculated nonlinear parameters of these complexes are compared with those of the corresponding GaPc derivatives and tetrasubstituted GaPc and InPc complexes. Fluorescence quantum yields do not vary much between (Cl)InOPPc and (Cl)InOTBPPc complexes in different solvents. High quantum yields of triplet state (ΦT ranging from 0.70 to 0.91 in dimethysulphoxide, DMSO) and singlet oxygen generation (ΦΔ, ranging from 0.61 to 0.79 in DMSO) were obtained. Short triplet lifetimes 50–60 μs were obtained in DMSO). The optical limiting threshold intensity (Ilim) for the InPc derivatives were calculated and compared with those of corresponding tetrasubstituted InPc and GaPc complexes. The latter were found to be better optical limiters.
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- Date Issued: 2007
Spermiogenesis in three species of cicadas (Hemiptera: Cicadidae)
- Authors: Chawanji, A S , Hodgson, Alan N , Villet, Martin H , Sanborn, Allen F , Phillips, Polly K F
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6865 , http://hdl.handle.net/10962/d1011207
- Description: Spermiogenesis in three species of cicadas representing one cicadettine (Monomatapa matoposa Boulard) and two cicadines (Diceroprocta biconica [Walker] and Kongota punctigera [Walker]) was investigated by light and electron microscopy. Although spermiogenesis was occurring in the testis of adult males of all species, earlier spermiogenic stages were observed in D. biconica only. While spermiogenesis was similar to that described for other insects, some differences were noted. For example granular material did not assemble around the centriole to form a centriolar adjunct but did accumulate in the cytoplasm of early spermatids adjacent to a region of the nuclear membrane where nuclear pores were aggregated. In late spermatids this material accumulated anterior to the mitochondrial derivatives in a developing postero-lateral nuclear groove. While this material has been named the ‘centriolar adjunct’ by previous authors, its formation away from the centriole raises questions about its true identity. Second, during acrosome maturation an ante-acrosomal region of cytoplasm develops. Although present in later spermatids, this region is lost in spermatozoa. Interspecific variations in chromatin condensation patterns and the number of microtubule layers encircling the spermatid nucleus during spermiogenesis were noted.
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- Date Issued: 2007
Spermiogenesis, sperm ultrastructure and reproductive tract morphology in cicadas implications for systematic relationships
- Authors: Chawanji, Abraham Simbarashe
- Date: 2007
- Subjects: Cicadas Cicadas -- Reproduction Spermiogenesis in animals
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5770 , http://hdl.handle.net/10962/d1005458
- Description: Sperm structure in five species of cicadine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis, P. hirtipennis and Pycna semiclara) and five species of cicadettine cicadas (Melampsalta leucoptera, Quintilia walkeri, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) was investigated by light and electron microscopy. In addition, spermiogenesis in cicadas was described; the information was derived from two cicadettines (Diceroprocta biconica and M. matoposa) and three cicadines (Kongota punctigera, P. capensis and P. semiclara). Mature spermatozoa of all species investigated are elongate and filiform, consisting of three distinct regions: the head (acrosome and nucleus), mid-piece and tail. All species produce more than one discrete length of nucleated, motile sperm, a form of sperm polymorphism termed polymegaly. Polymegaly is expressed in three ways; sperm have uni-, bi- or trimodal nucleus and tail lengths. Besides the differences in length, there are also notable differences in the size of nuclei. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming spermatodesmata. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with a tubular substructure and a subacrosomal space. The anterior of the nucleus intrudes into the posterior section of the subacrosomal space. Anteriorly the acrosome is laterally flattened; posteriorly it extends as two tubular processes on either side of the nucleus that gradually decrease in diameter. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the putative centriolar adjunct which does not form in close proximity to the centriole and hence may not be a true centriolar adjunct. The lamellate disposition of the centriolar adjunct material within the sperm-midpiece of cicadettine cicadas is distinct, and separates these cicadas from their cicadine counterparts in which the centriolar adjunct material is non-lamellate. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. Except for size the architecture of short and long spermatozoa is generally similar in all species. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely related. Only long nuclei were observed in the fertilized eggs of A. zuluensis indicating that sperm with long nuclei might be favoured for fertilization. Spermiogenesis involves: (a) development of the acrosome from a proacrosomal granule; (b) development of the nucleus, characterized by elongation and streamlining with a simultaneous condensation of chromatin; (c) development of the axoneme from the centriole; (d) amalgamation of individual small mitochondria to form elongated mitochondrial derivatives in which cristae are arranged into regularly spaced lamellae; and (f) elimination of cytoplasm. The presence of a manchette, a transient microtubular organelle, which surrounds the acrosome, nucleus and mitochondrial derivatives, is a characteristic feature of spermiogenesis. The gross morphology of the reproductive tract in both male and female cicadas exhibits an organization similar to that in most oviparous insects. The non-functional spermatheca is the only exceptional feature in the female reproductive tract. Its role has been taken over by the common oviduct which, subsequently, has become modified into a swollen, differentiated structure with a dual role of receiving oocytes from the paired ovaries and storage of spermatozoa. Testis mass varies between cicada species; this variation might be linked to the intensity of sperm competition which has been found to be positively correlated with relative investment in spermatogenesis. Based on the preliminary findings of this study, K. punctigera, with its larger testis relative to body size, would be the ideal candidate to show the greatest levels of sperm competition. Accessory glands in both male and female A. zuluensis, D. biconica, P. hirtipennis and O. quadraticollis are very long; this character might be of phylogenetic significance. Despite being notoriously refractory spermiocladistics is potentially valuable in systematic and phylogenic studies of cicadas, especially at the subfamily level.
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- Date Issued: 2007
Child sex tourism in South African law
- Authors: Chetty, Kasturi
- Date: 2007
- Subjects: Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10276 , http://hdl.handle.net/10948/485 , Child sexual abuse -- South Africa , Sex tourism -- Law and legislation -- South Africa , Sex crimes -- South Africa , Child prostitution -- South Africa
- Description: Child sex tourism is tourism organised with the primary purpose of facilitating a commercial sexual relationship with a child. It involves a segment of the local child sex industry that is directly connected to both an international and domestic tourist market. The increase of tourism has brought with it complications in that tourism is being used as a means for sex tourists to initiate contact with children. Aside from child sex tourists who are paedophiles, there are those who engage in the opportunistic exploitation of children while travelling on business or for other reasons. There are a number of social and economic factors leading to child sex tourism and the effect is that child victims are exposed to immediate harm, irreversible damage and even death. As South Africa's tourism industry expands into one of the country’s top earners of foreign currency, it is unfortunate to note that its child sex tourist trade is also on the increase. Reports show that sex tours are as easily organised as wine route tours in Cape Town. Commercial sexual exploitation of children is prevalent in South Africa and has become more organised in recent years. A comprehensive response to the problem is essential to ensure that South Africa does not become a “safe haven” for child sex tourists. Effective laws at home and the extraterritorial application of these laws to prosecute South African nationals for crimes committed abroad are imperative. Significant steps are being taken both nationally and internationally to target child sex tourism. South Africa has ratified several international instruments on children’s rights, trafficking in persons, child labour, and discrimination against women and young girls, all of which relate to child sex tourism. In doing so, South Africa has made an international commitment to uphold the provisions of these instruments and give effect to them. South Africa is therefore under an international obligation to create the necessary structures and apply mechanisms and resources to combat child sex tourism.
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- Date Issued: 2007