An investigation into strategies which enable South African women to break through the glass ceiling
- Authors: Peens, Maritha
- Date: 2003
- Subjects: Women executives -- South Africa , Women employees -- Promotions -- South Africa , Sex discrimination in employement -- South Africa , Sex discrimination against women -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10898 , http://hdl.handle.net/10948/135 , Women executives -- South Africa , Women employees -- Promotions -- South Africa , Sex discrimination in employement -- South Africa , Sex discrimination against women -- South Africa
- Description: The objective of this study was to identify the strategies (personal and organisational) that would enable South African women to break through the glass ceiling. A questionaire was designed based on the strategies found in a literature study on the topic and used to gather inputs from executive women in South Africa. A combination of snowball and self-selection sampling was used. The questionaire was sent to 138 potential respondents, mostly by means of electronic mail. Of the 47 completed questionairs returned, 44 could be used. These were processed and anaylsed using Microsoft Excel spreadsheets and the STATISTICA Version 6 software. In generaL, support was found for personal strategies pertaining to career management, networking (especially the relationship building activities), the reconciliation of home and work responsibilities with the emphasis on building a support system, education, business and organisational insught, skills development and increased input, but not for the assimilation of masculine attributes. Networking opportunities and education, training and development activities were regarded as the organisational strategies with the strongest impact on career progress. The literature was confirmed regarding top management support, an organisational culture conducive to women's advancement, mentorship programmes and a few career development initiatives. Although more than half of the respondents had been exposed to employment equity and affirmative action programmes, they were perceived to have only little to moderate impact on career progress. This was also the case with diversity management programmes. Flexible work arrangements, career adaptation schemes and childcare facilities and programmes were seen as having had little impact on the respondents' career advancement. Only a few of the organisational practices to support women balancing family and work responsibilities were utilised by the respondents' employers. Respondents perceived personal strategies as having greater value than organisational strategies in their progress to executive levels.
- Full Text:
- Date Issued: 2003
An investigation into strategies which enable South African women to break through the glass ceiling
- Authors: Peens, Maritha
- Date: 2003
- Subjects: Women executives -- South Africa , Women employees -- Promotions -- South Africa , Sex discrimination in employement -- South Africa , Sex discrimination against women -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10898 , http://hdl.handle.net/10948/135 , Women executives -- South Africa , Women employees -- Promotions -- South Africa , Sex discrimination in employement -- South Africa , Sex discrimination against women -- South Africa
- Description: The objective of this study was to identify the strategies (personal and organisational) that would enable South African women to break through the glass ceiling. A questionaire was designed based on the strategies found in a literature study on the topic and used to gather inputs from executive women in South Africa. A combination of snowball and self-selection sampling was used. The questionaire was sent to 138 potential respondents, mostly by means of electronic mail. Of the 47 completed questionairs returned, 44 could be used. These were processed and anaylsed using Microsoft Excel spreadsheets and the STATISTICA Version 6 software. In generaL, support was found for personal strategies pertaining to career management, networking (especially the relationship building activities), the reconciliation of home and work responsibilities with the emphasis on building a support system, education, business and organisational insught, skills development and increased input, but not for the assimilation of masculine attributes. Networking opportunities and education, training and development activities were regarded as the organisational strategies with the strongest impact on career progress. The literature was confirmed regarding top management support, an organisational culture conducive to women's advancement, mentorship programmes and a few career development initiatives. Although more than half of the respondents had been exposed to employment equity and affirmative action programmes, they were perceived to have only little to moderate impact on career progress. This was also the case with diversity management programmes. Flexible work arrangements, career adaptation schemes and childcare facilities and programmes were seen as having had little impact on the respondents' career advancement. Only a few of the organisational practices to support women balancing family and work responsibilities were utilised by the respondents' employers. Respondents perceived personal strategies as having greater value than organisational strategies in their progress to executive levels.
- Full Text:
- Date Issued: 2003
The classification of fuzzy groups of finite cyclic groups Zpn Zqm Zr and Zp1 Zp2 Zpn for distinct prime numbers p; q; r; p1; p2; ; pn and n;m 2 Z+
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
- Authors: Munywoki, Michael Mbindyo
- Date: 2018
- Subjects: Fuzzy sets Finite groups
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/17817 , vital:41295
- Description: Let G be the cyclic group Zpn _ Zqm _ Zr where p; q; r are distinct primes and n;m 2 Z+. Using the criss-cut method by Murali and Makamba, we determine in general the number of distinct fuzzy subgroups of G. This is achieved by using the maximal chains of subgroups of the respective groups, and the equivalence relation given in their research papers. For cases of m, the number of fuzzy subgroups is _rst given, from which the general pattern for G is achieved. Murali and Makamba discussed the number of fuzzy subgroups of Zpn _ Zqm using the cross-cut method. A brief revisit of the group Zpn _Zqm is done using the criss-cut method. The formulae for _nding the number of distinct fuzzy subgroups in each of the cases is given and proofs provided. Furthermore, we classify the fuzzy subgroups of the group Zp1_Zp2__ _ __Zpn for p1; p2; _ _ _ ; pn distinct primes and n 2 Z+ using the criss-cut method. An algorithm for counting the distinct fuzzy subgroups of this group is developed.
- Full Text:
- Date Issued: 2018
A contribution to the theory of prime modules
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
- Authors: Ssevviiri, David
- Date: 2013
- Subjects: Modules (Algebra) , Radical theory , Rings (Algebra)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10510 , http://hdl.handle.net/10948/d1019923
- Description: This thesis is aimed at generalizing notions of rings to modules. In par-ticular, notions of completely prime ideals, s-prime ideals, 2-primal rings and nilpotency of elements of rings are respectively generalized to completely prime submodules and classical completely prime submodules, s-prime submodules, 2-primal modules and nilpotency of elements of modules. Properties and rad-icals that arise from each of these notions are studied.
- Full Text:
- Date Issued: 2013
Prime near-ring modules and their links with the generalised group near-ring
- Authors: Juglal, Shaanraj
- Date: 2007
- Subjects: Near-rings
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10507 , http://hdl.handle.net/10948/714 , Near-rings
- Description: In view of the facts that the definition of a ring led to the definition of a near- ring, the definition of a ring module led to the definition of a near-ring module, prime rings resulted in investigations with respect to primeness in near-rings, one is naturally inclined to attempt to define the notion of a group near-ring seeing that the group ring had already been defined and investigated into by, interalia, Groenewald in [7] . However, in trying to define the group near-ring along the same lines as the group ring was defined, it was found that the resulting multiplication was, in general, not associative in the near-ring case due to the lack of one distributive property. In 1976, Meldrum [19] achieved success in defining the group near-ring. How- ever, in his definition, only distributively generated near-rings were considered and the distributive generators played a vital role in the construction. In 1989, Le Riche, Meldrum and van der Walt [17], adopted a similar approach to that which led to a successful and fruitful definition of matrix near-rings, and defined the group near-ring in a more general sense. In particular, they defined R[G], the group near-ring of a group G over a near-ring R, as a subnear-ring of M(RG), the near-ring of all mappings of the group RG into itself. More recently, Groenewald and Lee [14], further generalised the definition of R[G] to R[S : M], the generalised semigroup near-ring of a semigroup S over any faithful R-module M. Again, the natural thing to do would be to extend the results obtained for R[G] to R[S : M], and this they achieved with much success.
- Full Text:
- Date Issued: 2007
- Authors: Juglal, Shaanraj
- Date: 2007
- Subjects: Near-rings
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10507 , http://hdl.handle.net/10948/714 , Near-rings
- Description: In view of the facts that the definition of a ring led to the definition of a near- ring, the definition of a ring module led to the definition of a near-ring module, prime rings resulted in investigations with respect to primeness in near-rings, one is naturally inclined to attempt to define the notion of a group near-ring seeing that the group ring had already been defined and investigated into by, interalia, Groenewald in [7] . However, in trying to define the group near-ring along the same lines as the group ring was defined, it was found that the resulting multiplication was, in general, not associative in the near-ring case due to the lack of one distributive property. In 1976, Meldrum [19] achieved success in defining the group near-ring. How- ever, in his definition, only distributively generated near-rings were considered and the distributive generators played a vital role in the construction. In 1989, Le Riche, Meldrum and van der Walt [17], adopted a similar approach to that which led to a successful and fruitful definition of matrix near-rings, and defined the group near-ring in a more general sense. In particular, they defined R[G], the group near-ring of a group G over a near-ring R, as a subnear-ring of M(RG), the near-ring of all mappings of the group RG into itself. More recently, Groenewald and Lee [14], further generalised the definition of R[G] to R[S : M], the generalised semigroup near-ring of a semigroup S over any faithful R-module M. Again, the natural thing to do would be to extend the results obtained for R[G] to R[S : M], and this they achieved with much success.
- Full Text:
- Date Issued: 2007
Black urban employment and Coloured labour preference
- Bekker, S B, Coetzee, Johannes Hendrik
- Authors: Bekker, S B , Coetzee, Johannes Hendrik
- Date: 1980
- Subjects: Black people -- Employment -- South Africa -- Cape Town Colored people (South Africa) -- Employment -- South Africa -- Cape Town Labor supply -- South Africa -- Cape Town Health services administration -- South Africa
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2216 , vital:20266 , ISBN 0868100420
- Description: State control over the labour market usually results in the creation of different categories of labour, each having partial and unequal access to that market. In the Third World, typically, justification for control arises from an over-supply of unskilled rural labour and a small demand for such labour in the wage economy. To reduce massive urban unemployment, the state attempts to control the process of rural-urban migration by, inter alia, manipulating the labour market. ^ In South Africa, the civilised labour policy of the Pact government and the highly sophisticated system of black influx control introduced after the Second World War are two examples of such state control. In these cases, racial categories of labour, having differential access to the labour market, were created. The policy of Coloured Labour Preference is another South African example which is of particular interest since it is applied solely to one region of the Republic. Since 1962, when it was administratively coordinated for the first time, this policy has been applied in the Western Cape, a region comprising the 68 magisterial districts situated south-west of Port Elizabeth, Kimberley and the Orange River. In this region, black work-seekers' access to the labour market is severely curtailed. A series of regulations, particular to the Western Cape, are applied with the object of restricting the number of blacks resident in the region; denying blacks permanent rights of sojourn in the region; restricting the scope of employment for blacks in the region; and favouring coloured above black work-seekers throughout the region. In short, the policy aims to replace black by coloured labour and thereby aims to reduce to a minimum the number of blacks in the region. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1980
- Authors: Bekker, S B , Coetzee, Johannes Hendrik
- Date: 1980
- Subjects: Black people -- Employment -- South Africa -- Cape Town Colored people (South Africa) -- Employment -- South Africa -- Cape Town Labor supply -- South Africa -- Cape Town Health services administration -- South Africa
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2216 , vital:20266 , ISBN 0868100420
- Description: State control over the labour market usually results in the creation of different categories of labour, each having partial and unequal access to that market. In the Third World, typically, justification for control arises from an over-supply of unskilled rural labour and a small demand for such labour in the wage economy. To reduce massive urban unemployment, the state attempts to control the process of rural-urban migration by, inter alia, manipulating the labour market. ^ In South Africa, the civilised labour policy of the Pact government and the highly sophisticated system of black influx control introduced after the Second World War are two examples of such state control. In these cases, racial categories of labour, having differential access to the labour market, were created. The policy of Coloured Labour Preference is another South African example which is of particular interest since it is applied solely to one region of the Republic. Since 1962, when it was administratively coordinated for the first time, this policy has been applied in the Western Cape, a region comprising the 68 magisterial districts situated south-west of Port Elizabeth, Kimberley and the Orange River. In this region, black work-seekers' access to the labour market is severely curtailed. A series of regulations, particular to the Western Cape, are applied with the object of restricting the number of blacks resident in the region; denying blacks permanent rights of sojourn in the region; restricting the scope of employment for blacks in the region; and favouring coloured above black work-seekers throughout the region. In short, the policy aims to replace black by coloured labour and thereby aims to reduce to a minimum the number of blacks in the region. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1980
The life and work of Benjamin Tyamzashe: a contemporary Xhosa composer
- Authors: Hansen, Deirdre Doris
- Date: 1968
- Subjects: Xhosa (African people) -- Music , Hymns, Xhosa , Tyamzashe, Benjamin John Peter (1890-1978) , Composers, Black -- South Africa
- Language: English , Xhosa
- Type: Book
- Identifier: vital:550 , http://hdl.handle.net/10962/d1020214
- Description: The present paper is a digest of the thesis submitted under the same title, by Miss Deirdre Hansen for the Degree of Master of Music of Rhodes University in 1968. This work includes a large number of musical illustrations, which illuminate in detail many aspects of the works of Benjamin Tyamzashe. The section containing these has been reduced to its essentials, but what is here given should enable the reader to understand the manner in which Tyamzashe's ability as a composer has developed, and to give him his rightful place among his contemporaries. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1968
- Authors: Hansen, Deirdre Doris
- Date: 1968
- Subjects: Xhosa (African people) -- Music , Hymns, Xhosa , Tyamzashe, Benjamin John Peter (1890-1978) , Composers, Black -- South Africa
- Language: English , Xhosa
- Type: Book
- Identifier: vital:550 , http://hdl.handle.net/10962/d1020214
- Description: The present paper is a digest of the thesis submitted under the same title, by Miss Deirdre Hansen for the Degree of Master of Music of Rhodes University in 1968. This work includes a large number of musical illustrations, which illuminate in detail many aspects of the works of Benjamin Tyamzashe. The section containing these has been reduced to its essentials, but what is here given should enable the reader to understand the manner in which Tyamzashe's ability as a composer has developed, and to give him his rightful place among his contemporaries. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1968
An assessment of the nutritional status of young black school children in the Albany Magisterial District, Eastern Cape
- Authors: Fincham, Robert John
- Date: 1981
- Subjects: Schools -- South Africa -- Grahamstown Africans -- Nutrition Nutrition surveys -- South Africa -- Eastern Cape Malnutrition -- South Africa -- Eastern Cape Children -- South Africa -- Nutrition
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2172 , vital:20262 , ISBN 0868100773
- Description: This working paper covers a survey conducted between 16 and 30 January 1980 of 3 171 black Sub A and Sub B pupils 8 years old or younger, at schools in both the rural and urban areas of the Albany Magisterial District, Eastern Cape. The survey, under the auspices of the Institute of Social and Economic Research (ISER), Rhodes University, was carried out as a result of a request from Dr J. D. Krynauw, Regional Director of Health Services in the Eastern Cape, to assess levels of nutrition of black children. Newspaper reports (see Appendix 1) of low levels of nutrition and high infant mortality rates among young black children in the Eastern Cape appeared to suggest a chronic nutritional situation, a situation not perceived as such by the Department of Health. A comprehensive pilot study was instituted on written request from Dr Krynauw in late October 1979. A report of the pilot study findings was presented in May 1980 to the Department of Health (Fincham, 1980). The present paper elaborates on that report and also includes analyses of data not presented before. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
- Authors: Fincham, Robert John
- Date: 1981
- Subjects: Schools -- South Africa -- Grahamstown Africans -- Nutrition Nutrition surveys -- South Africa -- Eastern Cape Malnutrition -- South Africa -- Eastern Cape Children -- South Africa -- Nutrition
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2172 , vital:20262 , ISBN 0868100773
- Description: This working paper covers a survey conducted between 16 and 30 January 1980 of 3 171 black Sub A and Sub B pupils 8 years old or younger, at schools in both the rural and urban areas of the Albany Magisterial District, Eastern Cape. The survey, under the auspices of the Institute of Social and Economic Research (ISER), Rhodes University, was carried out as a result of a request from Dr J. D. Krynauw, Regional Director of Health Services in the Eastern Cape, to assess levels of nutrition of black children. Newspaper reports (see Appendix 1) of low levels of nutrition and high infant mortality rates among young black children in the Eastern Cape appeared to suggest a chronic nutritional situation, a situation not perceived as such by the Department of Health. A comprehensive pilot study was instituted on written request from Dr Krynauw in late October 1979. A report of the pilot study findings was presented in May 1980 to the Department of Health (Fincham, 1980). The present paper elaborates on that report and also includes analyses of data not presented before. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
Who goes to parliament?
- Authors: Stultz, Newell Maynard
- Date: 1975
- Subjects: Legislators -- South Africa South Africa -- Politics and government -- 1948-1994 South Africa -- Politics and government
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2747 , vital:20322 , ISBN 0949980560
- Description: The focus here is upon the 1 169 white men and the twelve white women who were elected or nominated to the South African Parliament in Cape Town between 1910 and the conclusion of the 1970 general and Senate elections.1 Because of the integrated nature of government at the national level in South Africa, an examination of all parliamentarians concurrently produces information on all cabinet ministers during the same period, and for most if not all of the top leaders of the major political parties as well. Hence, recognizing the unitary structure of the South African regime - sometimes expressed in the principle of the 'sovereignty of Parliament' - it seems possible to designate these 1 181 persons as the formally ascendant South African political elite during the country's first six decades. Moreover, there is no reason to doubt that this number includes nearly all of the persons who exercised disproportionately great real power during these years, excepting, of course, those few non-whites who may be thought to have been politically influential at the national level. Every indication is that political life in South Africa centred on these individuals, or at least on some of them, for clearly not all were of equal political importance. Yet even the leaders within this select group, whom we shall also consider separately in detail, frequently (although not in every case) rose to prominence within the institution of Parliament, in part on the basis of their ability to influence and control its deliberations. An understanding of the backgrounds of all parliamentarians thus not only helps to describe the body itself, but may also contribute a new appreciation of the political power of the country's top leadership. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1975
- Authors: Stultz, Newell Maynard
- Date: 1975
- Subjects: Legislators -- South Africa South Africa -- Politics and government -- 1948-1994 South Africa -- Politics and government
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2747 , vital:20322 , ISBN 0949980560
- Description: The focus here is upon the 1 169 white men and the twelve white women who were elected or nominated to the South African Parliament in Cape Town between 1910 and the conclusion of the 1970 general and Senate elections.1 Because of the integrated nature of government at the national level in South Africa, an examination of all parliamentarians concurrently produces information on all cabinet ministers during the same period, and for most if not all of the top leaders of the major political parties as well. Hence, recognizing the unitary structure of the South African regime - sometimes expressed in the principle of the 'sovereignty of Parliament' - it seems possible to designate these 1 181 persons as the formally ascendant South African political elite during the country's first six decades. Moreover, there is no reason to doubt that this number includes nearly all of the persons who exercised disproportionately great real power during these years, excepting, of course, those few non-whites who may be thought to have been politically influential at the national level. Every indication is that political life in South Africa centred on these individuals, or at least on some of them, for clearly not all were of equal political importance. Yet even the leaders within this select group, whom we shall also consider separately in detail, frequently (although not in every case) rose to prominence within the institution of Parliament, in part on the basis of their ability to influence and control its deliberations. An understanding of the backgrounds of all parliamentarians thus not only helps to describe the body itself, but may also contribute a new appreciation of the political power of the country's top leadership. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1975
Application of reverse-flow micellar electrokinetic chromatography for the simultaneous determination of flavonols and terpene trilactones in Ginkgo biloba dosage forms
- Dubber, Mary-Jean, Kanfer, Isadore
- Authors: Dubber, Mary-Jean , Kanfer, Isadore
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6357 , http://hdl.handle.net/10962/d1006049
- Description:
A reverse-flow micellar electrokinetic chromatographic (RF-MEKC) method was developed for the simultaneous qualitative determination of 10 components consisting of the flavonol glycosides, rutin and quercitrin, the flavonol aglycones, isorhamnetin, kaempferol and quercetin, the terpene trilactones, ginkgolides A, B, C and J and the sesquiterpene, bilobalide. This method was used to fingerprint Ginkgo biloba solid oral dosage forms and validated for the quantitation of the marker compounds, rutin and quercetin in some commercial products. In addition to the usual variables, the influence of some essential background electrolyte (BGE) components such as sodium dodecyl sulphate (SDS) and
-cyclodextrin concentrations were investigated. A polyimide fused-silica square capillary column (75 μm I.D. × 360 μm O.D.) with a total length of 60.0 cm and effective length of 45.0 cm was used for the separation. The final BGE consisted of 20 mM phosphoric acid, 40 mM SDS and 12 mM -cyclodextrin (pH 2.2) using reverse polarity with a voltage of −17.5 kV. Samples were injected electrokinetically at −5 kV for 3 s for the qualitative analysis and hydrodynamically at 20 mbar for 0.6 s for the quantitative assay. The total run time was 22 min and the limits of detection were 3.13 μg/ml and 1.88 μg/ml for rutin and quercetin, respectively. Fingerprint profiles of the solid oral dosage forms and the results of the quantitative analysis indicated that there were major discrepancies in the marker content between products and illustrates the value of this method for use as a procedure to assess product quality of commercially available Ginkgo biloba products. - Full Text:
- Date Issued: 2006
- Authors: Dubber, Mary-Jean , Kanfer, Isadore
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6357 , http://hdl.handle.net/10962/d1006049
- Description:
A reverse-flow micellar electrokinetic chromatographic (RF-MEKC) method was developed for the simultaneous qualitative determination of 10 components consisting of the flavonol glycosides, rutin and quercitrin, the flavonol aglycones, isorhamnetin, kaempferol and quercetin, the terpene trilactones, ginkgolides A, B, C and J and the sesquiterpene, bilobalide. This method was used to fingerprint Ginkgo biloba solid oral dosage forms and validated for the quantitation of the marker compounds, rutin and quercetin in some commercial products. In addition to the usual variables, the influence of some essential background electrolyte (BGE) components such as sodium dodecyl sulphate (SDS) and
-cyclodextrin concentrations were investigated. A polyimide fused-silica square capillary column (75 μm I.D. × 360 μm O.D.) with a total length of 60.0 cm and effective length of 45.0 cm was used for the separation. The final BGE consisted of 20 mM phosphoric acid, 40 mM SDS and 12 mM -cyclodextrin (pH 2.2) using reverse polarity with a voltage of −17.5 kV. Samples were injected electrokinetically at −5 kV for 3 s for the qualitative analysis and hydrodynamically at 20 mbar for 0.6 s for the quantitative assay. The total run time was 22 min and the limits of detection were 3.13 μg/ml and 1.88 μg/ml for rutin and quercetin, respectively. Fingerprint profiles of the solid oral dosage forms and the results of the quantitative analysis indicated that there were major discrepancies in the marker content between products and illustrates the value of this method for use as a procedure to assess product quality of commercially available Ginkgo biloba products. - Full Text:
- Date Issued: 2006
Composition portfolio
- Authors: Webb, Cassidy Frank
- Date: 2006
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2659 , http://hdl.handle.net/10962/d1003729
- Description: Introduction: This portfolio consists of musical ideas which I have had for some time now. I have attempted to capture these ideas throughout the portfolio, starting with the smaller works (Brumes et Pluies) and building up to the larger works (James Tiberius, The tide). Brumes et Pluies is minimalistic in style. The interlocking of the two pianos plays an important role in the texture of the piece. The rhythms are repetitive throughout, with only slight variations. Kalahari is more idiomatic, rhythmical and has a main theme which recurs throughout the piece. Melodic fragments are used, sometimes with slight variations. This piece was inspired by the Kalahari desert, with its abundance of life. I enjoy the string quartet because of the homogeneity of sound on the one hand, and the diversity possible by using different techniques and effects on the other. James Tiberius is a work for chamber orchestra. Motifs in the music resemble certain animals. The rhythm is unstable, as is the harmony. There are many melodic fragments throughout. The texture is thin in certain areas (at the beginning) and dense in others (the waltz). The harmony is sometimes unconventional. The Tide was written in response to a memory of a drowning incident I experienced when I was a child. This orchestral piece is strong in form. The opening, for example, is tense and slightly atonal in harmony. The pomposo section tends to utilise most of the orchestra, so the texture is a lot denser here and the harmony is more conventional. I try not to use traditional forms in my composition. Rather, I prefer to compose by re-using and re-introducing ideas as I proceed.
- Full Text:
- Date Issued: 2006
- Authors: Webb, Cassidy Frank
- Date: 2006
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2659 , http://hdl.handle.net/10962/d1003729
- Description: Introduction: This portfolio consists of musical ideas which I have had for some time now. I have attempted to capture these ideas throughout the portfolio, starting with the smaller works (Brumes et Pluies) and building up to the larger works (James Tiberius, The tide). Brumes et Pluies is minimalistic in style. The interlocking of the two pianos plays an important role in the texture of the piece. The rhythms are repetitive throughout, with only slight variations. Kalahari is more idiomatic, rhythmical and has a main theme which recurs throughout the piece. Melodic fragments are used, sometimes with slight variations. This piece was inspired by the Kalahari desert, with its abundance of life. I enjoy the string quartet because of the homogeneity of sound on the one hand, and the diversity possible by using different techniques and effects on the other. James Tiberius is a work for chamber orchestra. Motifs in the music resemble certain animals. The rhythm is unstable, as is the harmony. There are many melodic fragments throughout. The texture is thin in certain areas (at the beginning) and dense in others (the waltz). The harmony is sometimes unconventional. The Tide was written in response to a memory of a drowning incident I experienced when I was a child. This orchestral piece is strong in form. The opening, for example, is tense and slightly atonal in harmony. The pomposo section tends to utilise most of the orchestra, so the texture is a lot denser here and the harmony is more conventional. I try not to use traditional forms in my composition. Rather, I prefer to compose by re-using and re-introducing ideas as I proceed.
- Full Text:
- Date Issued: 2006
Invariant optimal control on the three-dimensional semi-Euclidean group: control affine and quadratic Hamilton-Poisson systems
- Authors: Barrett, Dennis Ian
- Date: 2014
- Subjects: Automorphisms , Symmetry (Mathematics) , Lyapunov stability , Geometry, Riemannian , Geometry, Affine , Elliptic functions
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64805 , vital:28605
- Description: In this thesis we consider invariant control systems and Hamilton-Poisson systems on the three dimensional semi-Euclidean group SE(1,1). We first classify the left-invariant control affine systems (under detached feedback equivalence). We provide a complete list of normal forms, as well as classifying conditions. As a corollary to this classification, we derive controllability criteria for control affine systems on SE(1,1). Secondly, we consider quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space se(1,1)*. These systems are classified up to an affine isomorphism. Six normal forms are identified for the homogeneous case, whereas sixteen representatives (including several infinite families) are obtained for the inhomogeneous systems. Thereafter we consider the stability and integration of the normal forms obtained. For all homogeneous systems, and a subclass of inhomogeneous systems, we perform a complete stability analysis and derive explicit expressions for all integral curves. (The extremal controls of a large class of optimal control problems on SE(1,1) are linearly related to these integral curves.) Lastly, we discuss the Riemannian and sub-Riemannian problems. The (left-invariant) Riemannian and sub-Riemannian structures on SE(1,1) are classified, up to isometric group automorphisms and scaling. Explicit expressions for the geodesics of the normalised structures are found.
- Full Text:
- Date Issued: 2014
- Authors: Barrett, Dennis Ian
- Date: 2014
- Subjects: Automorphisms , Symmetry (Mathematics) , Lyapunov stability , Geometry, Riemannian , Geometry, Affine , Elliptic functions
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64805 , vital:28605
- Description: In this thesis we consider invariant control systems and Hamilton-Poisson systems on the three dimensional semi-Euclidean group SE(1,1). We first classify the left-invariant control affine systems (under detached feedback equivalence). We provide a complete list of normal forms, as well as classifying conditions. As a corollary to this classification, we derive controllability criteria for control affine systems on SE(1,1). Secondly, we consider quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space se(1,1)*. These systems are classified up to an affine isomorphism. Six normal forms are identified for the homogeneous case, whereas sixteen representatives (including several infinite families) are obtained for the inhomogeneous systems. Thereafter we consider the stability and integration of the normal forms obtained. For all homogeneous systems, and a subclass of inhomogeneous systems, we perform a complete stability analysis and derive explicit expressions for all integral curves. (The extremal controls of a large class of optimal control problems on SE(1,1) are linearly related to these integral curves.) Lastly, we discuss the Riemannian and sub-Riemannian problems. The (left-invariant) Riemannian and sub-Riemannian structures on SE(1,1) are classified, up to isometric group automorphisms and scaling. Explicit expressions for the geodesics of the normalised structures are found.
- Full Text:
- Date Issued: 2014
Maputo declaration on the textiles, clothing and leather industries
- Authors: Worker representatives
- Date: 1999?
- Subjects: Clothing trade , Textile industry , Leather industry and trade , Complaints (Civil procedure)
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/76004 , vital:30491
- Description: The massive job losses and factory closures in the clothing, textiles and leather industries in almost all countries in the region. The low wages that continue in our industries, resulting in a low and, in many instances, declining standard of living of workers. The crisis which face unemployed workers who have no income, no social security net, and no immediate prospect of a job. It is a fundamental responsibility of governments in the region to work with trade unions and employers in order to develop appropriate policies to secure a future for the industries and to improve the conditions of workers.
- Full Text:
- Date Issued: 1999?
- Authors: Worker representatives
- Date: 1999?
- Subjects: Clothing trade , Textile industry , Leather industry and trade , Complaints (Civil procedure)
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/76004 , vital:30491
- Description: The massive job losses and factory closures in the clothing, textiles and leather industries in almost all countries in the region. The low wages that continue in our industries, resulting in a low and, in many instances, declining standard of living of workers. The crisis which face unemployed workers who have no income, no social security net, and no immediate prospect of a job. It is a fundamental responsibility of governments in the region to work with trade unions and employers in order to develop appropriate policies to secure a future for the industries and to improve the conditions of workers.
- Full Text:
- Date Issued: 1999?
A socio-economic survey of the Amatola Basin: interim report
- Bekker, S B, de Wet, Christopher J, Manona, Cecil W
- Authors: Bekker, S B , de Wet, Christopher J , Manona, Cecil W
- Date: 1981
- Subjects: Ciskei (South Africa) -- Rural conditions Agriculture -- South Africa -- Ciskei Middledrift (South Africa) Fingo (African people) Hlubi (African people) Agriculture -- South Africa -- Ciskei Amatola River Watershed (South Africa) -- Economic conditions Amatola River Watershed (South Africa) -- Social conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2282 , vital:20272 , ISBN 0868100730
- Description: Early in 1981, Professor S. Bekker of Rhodes University was invited to attend a meeting of the Amatola Basin Steering Committee of the Agricultural and Rural Development Research Institute (ARDRI) at the University of Fort Hare. At this meeting, Professor Bekker was invited to undertake a socio-economic survey of the Amatola Basin. The Board of the Institute of Social and Economic Research at Rhodes University gave Professor Bekker permission in February 1981 to undertake the research project on condition that it was conducted in the fashion this Institute usually requires. It was subsequently agreed that the survey, known as 'Amatola Basin VII: Socio-economic survey', was to establish the basic demographic, kinship, consumption and employment patterns of the residents of the Amatola Basin. Practices and traditions related to dry land agriculture would also be identified , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
- Authors: Bekker, S B , de Wet, Christopher J , Manona, Cecil W
- Date: 1981
- Subjects: Ciskei (South Africa) -- Rural conditions Agriculture -- South Africa -- Ciskei Middledrift (South Africa) Fingo (African people) Hlubi (African people) Agriculture -- South Africa -- Ciskei Amatola River Watershed (South Africa) -- Economic conditions Amatola River Watershed (South Africa) -- Social conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2282 , vital:20272 , ISBN 0868100730
- Description: Early in 1981, Professor S. Bekker of Rhodes University was invited to attend a meeting of the Amatola Basin Steering Committee of the Agricultural and Rural Development Research Institute (ARDRI) at the University of Fort Hare. At this meeting, Professor Bekker was invited to undertake a socio-economic survey of the Amatola Basin. The Board of the Institute of Social and Economic Research at Rhodes University gave Professor Bekker permission in February 1981 to undertake the research project on condition that it was conducted in the fashion this Institute usually requires. It was subsequently agreed that the survey, known as 'Amatola Basin VII: Socio-economic survey', was to establish the basic demographic, kinship, consumption and employment patterns of the residents of the Amatola Basin. Practices and traditions related to dry land agriculture would also be identified , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1981
A reconciliation study of different resource estimation methods and drill hole spacing as applied to the Langer Heinrich calcrete-hosted uranium deposit, Namibia
- Authors: Baufeldt, Sven
- Date: 2018
- Subjects: Uranium -- Namibia , Calcretes -- Namibia , Carnotite -- Namibia , Uranium mines and mining -- Namibia , Uranium ores -- Geology -- Namibia , Langer-Heinrich Uranium mine
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62527 , vital:28203
- Description: The Langer Heinrich calcrete hosted uranium deposit is situated approximately 90 km to east of the coastal town of Swakopmund in Namibia. It is run by an Australian owned company, Paladin Energy Limited, along with China National Nuclear Corporation (CNNC) who maintain 25% of the shares. Production commenced in 2007 and has been ongoing. Carnotite is the primary and only ore mineral, and the nature of mineralisation within the Langer Heinrich palaeo channel dictates westward-directed continuous open pit mining. Smaller-scale 1micro pits target near-surface, high-grade, lenses toward the east. The high variability in uranium grade over relatively short distances complicates the grade estimation process. This combined with a low uranium price, and a study aimed at optimising of mine production is one of the key drivers for the research presented in this thesis. The efficacy of four resource estimation techniques, commonly used in the mining industry, are investigated by application to variable exploration, infill drilling and grade-control drill pattern spacing. The drill spacing includes regular grids of 50 m x 50 m, 25 m x 25 m and 12,5 m x 12,5 m exploration data. Also included is grade control drill data, drilled on a 4 m x 4 m spacing. The current selective mining unit (SMU) is 4mE x 4mN x 3mRl which is an indication of the minimum dimension whereby the loading equipment can separate ore from waste. The two datasets are processed by four estimation techniques: Inverse Distance Weighting (IDW, squared and cubed), Ordinary Kriging (OK), Multiple Indicator Kriging (MIK) and Conditional Simulation (CS). The two datasets consisted of real-time mining data from pit G1 (micro-pit) in the eastern parts of the mining licence, and pit H1 (continuous larger open pit) in the western area of the palaeo channel. The reconciliation project aims to provide results suitable for devising optimised mining strategies, particularly in future targets where drill spacing can perhaps be improved to provide suitable data with a greater cost saving strategy. Along with the optimal drill spacing or combination thereof, a preferred estimation technique can be suggested and recommended for future operations that involve mining of surficial calcrete-hosted uranium deposits. Results of this study show that 12,5 m x 12,5 m drill spacing provided estimation accuracies similar to that of the narrow 4 m x 4 m grade control spacing (blast hole drilling spacing). The 12,5 m x 12,5m spacing has potential for accurate grade estimations during mining, and could be supplemented by infill downhole radiometric logging on a 4 m x 4 m spacing when 1 Micro pit: Small pits within palaeo channel usually targeted for their near surface high-grade ore necessary. In general, Multiple Indicator Kriging (MIK) provided the most accurate and robust estimations on the wider spaced exploration data and conditional simulation (CS) proved more efficient on the narrow grade control data. These results correspond with current exploration practices for surficial uranium deposits world-wide. Deposit type, therefore complexity and hence SMU sizes play a pivotal role in drill hole planning and estimation accuracies.
- Full Text:
- Date Issued: 2018
- Authors: Baufeldt, Sven
- Date: 2018
- Subjects: Uranium -- Namibia , Calcretes -- Namibia , Carnotite -- Namibia , Uranium mines and mining -- Namibia , Uranium ores -- Geology -- Namibia , Langer-Heinrich Uranium mine
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/62527 , vital:28203
- Description: The Langer Heinrich calcrete hosted uranium deposit is situated approximately 90 km to east of the coastal town of Swakopmund in Namibia. It is run by an Australian owned company, Paladin Energy Limited, along with China National Nuclear Corporation (CNNC) who maintain 25% of the shares. Production commenced in 2007 and has been ongoing. Carnotite is the primary and only ore mineral, and the nature of mineralisation within the Langer Heinrich palaeo channel dictates westward-directed continuous open pit mining. Smaller-scale 1micro pits target near-surface, high-grade, lenses toward the east. The high variability in uranium grade over relatively short distances complicates the grade estimation process. This combined with a low uranium price, and a study aimed at optimising of mine production is one of the key drivers for the research presented in this thesis. The efficacy of four resource estimation techniques, commonly used in the mining industry, are investigated by application to variable exploration, infill drilling and grade-control drill pattern spacing. The drill spacing includes regular grids of 50 m x 50 m, 25 m x 25 m and 12,5 m x 12,5 m exploration data. Also included is grade control drill data, drilled on a 4 m x 4 m spacing. The current selective mining unit (SMU) is 4mE x 4mN x 3mRl which is an indication of the minimum dimension whereby the loading equipment can separate ore from waste. The two datasets are processed by four estimation techniques: Inverse Distance Weighting (IDW, squared and cubed), Ordinary Kriging (OK), Multiple Indicator Kriging (MIK) and Conditional Simulation (CS). The two datasets consisted of real-time mining data from pit G1 (micro-pit) in the eastern parts of the mining licence, and pit H1 (continuous larger open pit) in the western area of the palaeo channel. The reconciliation project aims to provide results suitable for devising optimised mining strategies, particularly in future targets where drill spacing can perhaps be improved to provide suitable data with a greater cost saving strategy. Along with the optimal drill spacing or combination thereof, a preferred estimation technique can be suggested and recommended for future operations that involve mining of surficial calcrete-hosted uranium deposits. Results of this study show that 12,5 m x 12,5 m drill spacing provided estimation accuracies similar to that of the narrow 4 m x 4 m grade control spacing (blast hole drilling spacing). The 12,5 m x 12,5m spacing has potential for accurate grade estimations during mining, and could be supplemented by infill downhole radiometric logging on a 4 m x 4 m spacing when 1 Micro pit: Small pits within palaeo channel usually targeted for their near surface high-grade ore necessary. In general, Multiple Indicator Kriging (MIK) provided the most accurate and robust estimations on the wider spaced exploration data and conditional simulation (CS) proved more efficient on the narrow grade control data. These results correspond with current exploration practices for surficial uranium deposits world-wide. Deposit type, therefore complexity and hence SMU sizes play a pivotal role in drill hole planning and estimation accuracies.
- Full Text:
- Date Issued: 2018
From frontier to midlands: a history of the Graaff-Reinet district, 1786-1910
- Authors: Smith, Kenneth Wyndham
- Date: 1976
- Subjects: Graaff-Reinet (South Africa) -- History
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2656 , vital:20313 , ISBN 0949980730
- Description: The study of local history in South Africa is still in its infancy and has not been accorded the same recognition as elsewhere. There is no convenient manual to guide the would-be local historian of the Cape. There are few models that provide an insight into the main problems encountered by the local historian of a Cape community. In such local histories as exist, attention has been focussed predominantly on the foundation and physical growth of towns, the naming of streets, the establishment of schools and hospitals. Many of these accounts were written for publicity purposes or to commemorate the founding of towns. Although there is no history of the Dutch Reformed Church in Graaff-Reinet, the history of local congregations of the Dutch Reformed Church has generally been well covered in the form of Gedenkboeke and other studies. These frequently have a particular relevance as many towns such as Burgersdorp and Colesberg were founded as a result of the initiative of the church. Preface. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1976
- Authors: Smith, Kenneth Wyndham
- Date: 1976
- Subjects: Graaff-Reinet (South Africa) -- History
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2656 , vital:20313 , ISBN 0949980730
- Description: The study of local history in South Africa is still in its infancy and has not been accorded the same recognition as elsewhere. There is no convenient manual to guide the would-be local historian of the Cape. There are few models that provide an insight into the main problems encountered by the local historian of a Cape community. In such local histories as exist, attention has been focussed predominantly on the foundation and physical growth of towns, the naming of streets, the establishment of schools and hospitals. Many of these accounts were written for publicity purposes or to commemorate the founding of towns. Although there is no history of the Dutch Reformed Church in Graaff-Reinet, the history of local congregations of the Dutch Reformed Church has generally been well covered in the form of Gedenkboeke and other studies. These frequently have a particular relevance as many towns such as Burgersdorp and Colesberg were founded as a result of the initiative of the church. Preface. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1976
Fishes of the family Apogonidae of the Western Indian Ocean and the Red Sea
- Smith, J.L.B. (James Leonard Brierley), 1897-1968
- Authors: Smith, J.L.B. (James Leonard Brierley), 1897-1968
- Date: 1961
- Subjects: Cardinalfishes , Fishes -- Classification , Fishes -- Indian Ocean , Fishes -- Red Sea
- Language: English
- Type: Text
- Identifier: vital:14985 , http://hdl.handle.net/10962/d1018952 , Ichthyological Bulletin; No. 22
- Description: Fishes of the family Apogonidae of the Western Indian Ocean and the Red Sea. Small and relatively feeble as most of these fishes are many cover an astonishing range. Some are found over truly vast areas of the Indo-Pacific, ranging from Southern Africa to the mid-Pacific. As a result, workers on even mid-Pacific Apogonidae need to give heed to the fauna of the Red Sea and of the Western Indian Ocean, from where, as in the case of the Parrot fishes, many early types were described. Failure to do this has caused species from the Pacific described as new, later to be proved identical with those long known from the Red Sea or the Indian Ocean. , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1961
- Authors: Smith, J.L.B. (James Leonard Brierley), 1897-1968
- Date: 1961
- Subjects: Cardinalfishes , Fishes -- Classification , Fishes -- Indian Ocean , Fishes -- Red Sea
- Language: English
- Type: Text
- Identifier: vital:14985 , http://hdl.handle.net/10962/d1018952 , Ichthyological Bulletin; No. 22
- Description: Fishes of the family Apogonidae of the Western Indian Ocean and the Red Sea. Small and relatively feeble as most of these fishes are many cover an astonishing range. Some are found over truly vast areas of the Indo-Pacific, ranging from Southern Africa to the mid-Pacific. As a result, workers on even mid-Pacific Apogonidae need to give heed to the fauna of the Red Sea and of the Western Indian Ocean, from where, as in the case of the Parrot fishes, many early types were described. Failure to do this has caused species from the Pacific described as new, later to be proved identical with those long known from the Red Sea or the Indian Ocean. , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1961
Tetra 4-(propargyloxy)phenoxy phthalocyanines: synthesis, spectroscopic, nonlinear optical and electrocatalytic properties
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mwanza, Daniel
- Date: 2017
- Subjects: Phthalocyanines , Nonlinear optics , Electrocatalysis , Spectrum analysis , Thermogravimetry , Phthalocyanines Spectra
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/65144 , vital:28695
- Description: This study presents the synthesis, spectroscopic, photophysical and theoretical characterisation of metal-free (H2TPrOPhOPc), cobalt (CoTPrOPhOPc) and manganese (MnTPrOPhOPc) tetra 4-(4-propargyloxy) phenoxy phthalocyanines. Thermal analysis using thermogravimetric analysis (TGA) confirmed the excellent thermal stability of synthesized tetra 4-(4- propargyloxy) phenoxy phthalocyanines. The metal complexes, CoTPrOPhOPc and MnTPrOPhOPc, exhibited better thermal stability when compared to H2TPrOPhOPc. The residual percentage weight remaining was approximately 70% for CoTPrOPhOPc and MnTPrOPhOPc and 45% for H2TPrOPhOPc after 600°C, clearly confirming the stability of the metal complexes. The MTPrOPhOPcs (where M = H2, Co and Mn) complexes exhibited excellent nonlinear optical properties with strong reverse saturable absorption (RSA), especially when 560 nm excitation laser was used. Their nonlinear optical properties followed this trend: H2TPrOPhOPc > CoTPrOPhOPc > MnTPrOPhOPc. According to the trend observed, the H2TPrOPhOPc was an excellent nonlinear optical limiter when compared to the CoTPrOPhOPc and MnTPrOPhOPc. All the investigated complexes exhibited optical limiting properties comparable to the phthalocyanine complexes reported in the literature. The MTPrOPhOPc complexes were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. For the electrocatalytic studies, the synthesized complexes were immobilized onto gold electrode surfaces pre-functionalized with phenylazide (Au-PAz) monolayer. Copper (I) catalyzed alkynyl-azide cycloaddition reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs modified gold surfaces (Au-PAz-MTPrOPhOPc) exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and surface characterisation of the functionalised gold electrode surfaces confirmed the presence of the MTPrOPhOPcs and their electroanalysis was excellent towards electrocatalytic reduction of H2O2, with the limit of detection (LoD) and limit of quantification (LoQ) in the ^M range. The electrocatalytic reduction peaks for H2O2 were observed at -0.37 V for Au-PAz-MnTPrOPhOPc and -0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-MnTPrOPhOPc and Au- PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution. , Thesis (MSc) -- Faculty of Science, Chemistry, 2017
- Full Text:
- Date Issued: 2017
A multi-threading software countermeasure to mitigate side channel analysis in the time domain
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
SADTU existing job grading
- SADTU
- Authors: SADTU
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/117997 , vital:34582
- Description: NEGATIVE ASPECTS OF EXISTING JOB GRADING. Staff members do not have a stable basic salary. The basic salary fluctuate in relation to changes within the package such as medical aid , housing and car allowance. Financial Institutions base their credit assessment on the gross salary and not on the total package since other benefits do not form part of the cash received in the bank on pay day. This system encourage staff members to be able to cancel medical aid contributions and other allowances since one in return receives an increased basic salary at the end an increased cash in the bank . Blue collar employees are not benefiting from such salary structuring . Most of these employees have bigger families which adds more dependants at the end . These are staff members who earn low income . With this category of employees you find staff members who are frequently ill or offsick due to improper diet and poor living conditions or lack of proper medical treatment. Good heath is a basic need . Employers should have such salary systems which should encourage staff members to have medical aids in order to have employees who are in a good state of health . This should be the resposibility of the employer to encourage its staff members to be in a position of participating in medical scheme for a better output of the organisation and have a healthier society and a growing economy .
- Full Text:
- Authors: SADTU
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/117997 , vital:34582
- Description: NEGATIVE ASPECTS OF EXISTING JOB GRADING. Staff members do not have a stable basic salary. The basic salary fluctuate in relation to changes within the package such as medical aid , housing and car allowance. Financial Institutions base their credit assessment on the gross salary and not on the total package since other benefits do not form part of the cash received in the bank on pay day. This system encourage staff members to be able to cancel medical aid contributions and other allowances since one in return receives an increased basic salary at the end an increased cash in the bank . Blue collar employees are not benefiting from such salary structuring . Most of these employees have bigger families which adds more dependants at the end . These are staff members who earn low income . With this category of employees you find staff members who are frequently ill or offsick due to improper diet and poor living conditions or lack of proper medical treatment. Good heath is a basic need . Employers should have such salary systems which should encourage staff members to have medical aids in order to have employees who are in a good state of health . This should be the resposibility of the employer to encourage its staff members to be in a position of participating in medical scheme for a better output of the organisation and have a healthier society and a growing economy .
- Full Text:
Constitutional frameworks and democratization in Africa since independence
- Authors: Neirynck, Karim
- Date: 2000
- Subjects: Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2816 , http://hdl.handle.net/10962/d1003026 , Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Description: The subject of this thesis is international studies, specifically a study of constitutional frameworks in Africa in the second half of the 20th century, focussing on a statistical correlation between constitutional frameworks, party systems, electoral systems and the Index of Democracy. The struggle to consolidate new democracies - especially those in Eastern Europe, Latin America and Asia - has given rise to a wide-ranging debate about the hard choices concerning democratic political institutions and political markets. According to Stepan and Skach " this literature has produced provocative hypotheses about the effects of institutions on democracy" (Stepan and Skach, 1993 : 1). It forms part of the' new institutionalism I literature in comparative politics that'holds as a premise that political democracy depends not only on economic and social conditions but also on the design of political institutions (Koelble, 1995 : 231-243). " One fundamental political-institutional question that has only received serious scholarly attention concerns the impact of different constitutional frameworks on democratic consolidation. Although the topic has been increasingly debated and discussed, little systematic cross-regional evidence [especially for our field of research: Africa] has been brought to bear on it " (Stepan and Skach, 1993 : 1-2). So far, only the book"on regime transitions in Africa written by Bratton and Van De Walle seeks to fill this empirical gap (Bratton and Van De Walle, 1997, preface xiii). In this thesis, we paid particular attention to the dichotomy between (pure) parliamentarism and (pure) presidentialism. Each type has fundamental characteristics, and for the purposes of classification these characteristics are necessary and sufficient. It was not our purpose to weigh the benefits and drawbacks of parliamentarism and presidentialism. Our intention was to report and analyse different sources of data, and we based our case exclusively on statistic correlatiohs between regime type and the record of democratic success and failure. We collected a data set about constitutional frameworks (matrix1), democracy indices (matrix2), party systems (matrix3) and election systems (matrix4). The basis for matrix 1 was the constitutions of the African countries (over time) and relevant literature. The basis for matrix 2 was the annual Freedom House ratings made by Raymond D. Gastil and others. The basis for matrix 3 and 4 was relevant literature. Once these matrices had been composed, we compared them and calculated statistic correlations. This long-dyration model allowed us to estimate whether African constitutional frameworks, party systems and electoral systems exhibit positive or negative correlation with the index of democracy.
- Full Text:
- Date Issued: 2000
- Authors: Neirynck, Karim
- Date: 2000
- Subjects: Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2816 , http://hdl.handle.net/10962/d1003026 , Democracy -- Africa , Constitutions -- Africa , Africa -- Politics and government -- 1960-
- Description: The subject of this thesis is international studies, specifically a study of constitutional frameworks in Africa in the second half of the 20th century, focussing on a statistical correlation between constitutional frameworks, party systems, electoral systems and the Index of Democracy. The struggle to consolidate new democracies - especially those in Eastern Europe, Latin America and Asia - has given rise to a wide-ranging debate about the hard choices concerning democratic political institutions and political markets. According to Stepan and Skach " this literature has produced provocative hypotheses about the effects of institutions on democracy" (Stepan and Skach, 1993 : 1). It forms part of the' new institutionalism I literature in comparative politics that'holds as a premise that political democracy depends not only on economic and social conditions but also on the design of political institutions (Koelble, 1995 : 231-243). " One fundamental political-institutional question that has only received serious scholarly attention concerns the impact of different constitutional frameworks on democratic consolidation. Although the topic has been increasingly debated and discussed, little systematic cross-regional evidence [especially for our field of research: Africa] has been brought to bear on it " (Stepan and Skach, 1993 : 1-2). So far, only the book"on regime transitions in Africa written by Bratton and Van De Walle seeks to fill this empirical gap (Bratton and Van De Walle, 1997, preface xiii). In this thesis, we paid particular attention to the dichotomy between (pure) parliamentarism and (pure) presidentialism. Each type has fundamental characteristics, and for the purposes of classification these characteristics are necessary and sufficient. It was not our purpose to weigh the benefits and drawbacks of parliamentarism and presidentialism. Our intention was to report and analyse different sources of data, and we based our case exclusively on statistic correlatiohs between regime type and the record of democratic success and failure. We collected a data set about constitutional frameworks (matrix1), democracy indices (matrix2), party systems (matrix3) and election systems (matrix4). The basis for matrix 1 was the constitutions of the African countries (over time) and relevant literature. The basis for matrix 2 was the annual Freedom House ratings made by Raymond D. Gastil and others. The basis for matrix 3 and 4 was relevant literature. Once these matrices had been composed, we compared them and calculated statistic correlations. This long-dyration model allowed us to estimate whether African constitutional frameworks, party systems and electoral systems exhibit positive or negative correlation with the index of democracy.
- Full Text:
- Date Issued: 2000