Aspects of renormalisation in some quantum field theories
- Authors: Roy, Alan A
- Date: 1998
- Subjects: Quantum field theory , Renormalization group
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5400 , http://hdl.handle.net/10962/d1005214 , Quantum field theory , Renormalization group
- Description: Renormalisation is an important aspect of Quantum Field Theory. It is used to create physically meaningful theories and some major developments took place in the 1970's and onwards. We consider Renormalisation in its application to the theories of ψ⁴ , Quantum Electrodynamics, Quantum Chromodynamics and the Background Field Method. Feynman diagrams are used to illustrate many of the concepts.
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- Authors: Roy, Alan A
- Date: 1998
- Subjects: Quantum field theory , Renormalization group
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5400 , http://hdl.handle.net/10962/d1005214 , Quantum field theory , Renormalization group
- Description: Renormalisation is an important aspect of Quantum Field Theory. It is used to create physically meaningful theories and some major developments took place in the 1970's and onwards. We consider Renormalisation in its application to the theories of ψ⁴ , Quantum Electrodynamics, Quantum Chromodynamics and the Background Field Method. Feynman diagrams are used to illustrate many of the concepts.
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Biology and management of the Cape gurnard, Chelidonichthys capensis (Order Scorpaeniformes, Family Triglidae) in South Africa
- Authors: McPhail, Amanda Sue
- Date: 1998
- Subjects: Scorpaeniformes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5236 , http://hdl.handle.net/10962/d1005079 , Scorpaeniformes
- Description: The South African demersal trawl fishery, as with most trawl-directed fisheries worldwide, has a substantial bycatch component. With increasing commercial emphasis being placed on retained bycatch, an urgent need has arisen to investigate these species. In the past the bycatch component has received little research or management attention. Members of the gurnard family Triglidae make up up to 2.4 % of the South African hake-directed demersal catch and are thus considered an important bycatch species. The catch history and biology, including population structure, reproduction, feeding, age, growth and mortality, of the Cape gurnard, Chelidonichthys capensis, sampled from the Agulhas Bank, South Africa, were thus investigated. Males (mean TL = 366mm) were significantly smaller than females (mean TL = 411mm). The sex ratio was close to parity, males being more dominant in commercial trawls and less dominant in research trawls. Gonad maturation and gonadosomatic indices showed this species to have an extended spawning period with peaks in reproductive activity during September, January and April. First approximations of size at 50 % maturity were similar for females (349mm TL) and males (348mm TL) but differed significantly in terms of age (3.6 years and 4.6 years respectively). Otolith growth marks were validated as annuli using marginal zone analysis. The maximum age estimated was 16 years for a female of 675mm TL and recruitment to the commercial fishery was estimated as taking place in the fifth year of growth for both males and females. Gut content analysis showed C. capensis to be an opportunistic feeder preying preferentially on the benthic crustaceans Goneplax angulata and Mursia cristimanus. Landings from the commercial linefishery were insignificant whilst those for the commercial trawl fishery ranged from 500 tonnes to 3250 tonnes between 1984 to 1995, and indicated that this species forms an important component of the South African trawl fishery bycatch. A first approximation of fishing mortality (0.36 year⁻¹) for the inshore commercial trawl fishery was higher than that of natural mortality (0.25 year⁻¹) suggesting some fishing pressure on this species on the Agulhas Bank. However this fishing mortality value was significantly less than that for F₀·₁ (4.78 year⁻¹) that was estimated using a yield-per-recruit model.
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- Authors: McPhail, Amanda Sue
- Date: 1998
- Subjects: Scorpaeniformes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5236 , http://hdl.handle.net/10962/d1005079 , Scorpaeniformes
- Description: The South African demersal trawl fishery, as with most trawl-directed fisheries worldwide, has a substantial bycatch component. With increasing commercial emphasis being placed on retained bycatch, an urgent need has arisen to investigate these species. In the past the bycatch component has received little research or management attention. Members of the gurnard family Triglidae make up up to 2.4 % of the South African hake-directed demersal catch and are thus considered an important bycatch species. The catch history and biology, including population structure, reproduction, feeding, age, growth and mortality, of the Cape gurnard, Chelidonichthys capensis, sampled from the Agulhas Bank, South Africa, were thus investigated. Males (mean TL = 366mm) were significantly smaller than females (mean TL = 411mm). The sex ratio was close to parity, males being more dominant in commercial trawls and less dominant in research trawls. Gonad maturation and gonadosomatic indices showed this species to have an extended spawning period with peaks in reproductive activity during September, January and April. First approximations of size at 50 % maturity were similar for females (349mm TL) and males (348mm TL) but differed significantly in terms of age (3.6 years and 4.6 years respectively). Otolith growth marks were validated as annuli using marginal zone analysis. The maximum age estimated was 16 years for a female of 675mm TL and recruitment to the commercial fishery was estimated as taking place in the fifth year of growth for both males and females. Gut content analysis showed C. capensis to be an opportunistic feeder preying preferentially on the benthic crustaceans Goneplax angulata and Mursia cristimanus. Landings from the commercial linefishery were insignificant whilst those for the commercial trawl fishery ranged from 500 tonnes to 3250 tonnes between 1984 to 1995, and indicated that this species forms an important component of the South African trawl fishery bycatch. A first approximation of fishing mortality (0.36 year⁻¹) for the inshore commercial trawl fishery was higher than that of natural mortality (0.25 year⁻¹) suggesting some fishing pressure on this species on the Agulhas Bank. However this fishing mortality value was significantly less than that for F₀·₁ (4.78 year⁻¹) that was estimated using a yield-per-recruit model.
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English communication in the hospitality industry: the employees' perspective
- Authors: Hobson, Josephine Mary
- Date: 1998
- Subjects: Hospitality industry -- Employees -- Training of -- South Africa , English language -- Study and teaching -- South Africa -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2992 , http://hdl.handle.net/10962/d1002501 , Hospitality industry -- Employees -- Training of -- South Africa , English language -- Study and teaching -- South Africa -- Foreign speakers
- Description: The purpose of this research project was to explore the English communicative competency of management and supervisory level employees within the South Mrican hospitality industry. The Pro lit English Written Assessment, a competency-based assessment tool, was used to establish a relatively objective measure of the English communicative competency of nineteen managers and supervisors. Thereafter thirteen of these respondents were interviewed to determine their perceptions of their English communicative competency and the impact thereof on their work situation, as well as their perceptions of their learning needs and recommendations for intervention. The researcher selected a multi-method approach to the investigation and sought both quantitative and qualitative data. The assessment revealed that the English reading and writing ability of the respondents is distinctly lower than their recorded education level and inadequate in relation to the tasks they are expected to perform at work. The interviews indicated that the respondents are not aware of their lack of English communicative competency or the implications thereof. However, the respondents expressed important insights into the factors that should be taken into account when planning an educational intervention III an organization. These included the need to incorporate English second language learning principles, to treat the learner as an individual, to involve the learner in the decision-making process, to consider the practical concerns of the learner and to ensure that the programme content is appropriate. Recommendations for human resource practices and research in the hospitality industry are presented.
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- Authors: Hobson, Josephine Mary
- Date: 1998
- Subjects: Hospitality industry -- Employees -- Training of -- South Africa , English language -- Study and teaching -- South Africa -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2992 , http://hdl.handle.net/10962/d1002501 , Hospitality industry -- Employees -- Training of -- South Africa , English language -- Study and teaching -- South Africa -- Foreign speakers
- Description: The purpose of this research project was to explore the English communicative competency of management and supervisory level employees within the South Mrican hospitality industry. The Pro lit English Written Assessment, a competency-based assessment tool, was used to establish a relatively objective measure of the English communicative competency of nineteen managers and supervisors. Thereafter thirteen of these respondents were interviewed to determine their perceptions of their English communicative competency and the impact thereof on their work situation, as well as their perceptions of their learning needs and recommendations for intervention. The researcher selected a multi-method approach to the investigation and sought both quantitative and qualitative data. The assessment revealed that the English reading and writing ability of the respondents is distinctly lower than their recorded education level and inadequate in relation to the tasks they are expected to perform at work. The interviews indicated that the respondents are not aware of their lack of English communicative competency or the implications thereof. However, the respondents expressed important insights into the factors that should be taken into account when planning an educational intervention III an organization. These included the need to incorporate English second language learning principles, to treat the learner as an individual, to involve the learner in the decision-making process, to consider the practical concerns of the learner and to ensure that the programme content is appropriate. Recommendations for human resource practices and research in the hospitality industry are presented.
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