Resource utilization and reproduction of the hermit crab Clibanarius virescens (Crustacea: Decapoda : Anomura)
- Authors: Wait, Michelle
- Subjects: Hermit crabs -- South Africa , Hermit crabs -- South Africa -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10599 , http://hdl.handle.net/10948/1553 , Hermit crabs -- South Africa , Hermit crabs -- South Africa -- Reproduction
- Description: Clibanarius virescens (Krauss) is a common and abundant hermit crab along the East coast of South Africa. Despite this, its biology is poorly known, both in South Africa and throughout the rest of its range in the West Indo-Pacific region. This study focuses on the descriptive analysis of the shell resource used by C. virescens and of the effects of this resource on crab populations. The underlying hypothesis of the study is that biogeographically imposed gradients in the morphology of intertidal gastropod shells used by hermit crabs affect hermit crab population parameters. The gradient of potential change in the shell resource was captured by sampling at 12 localities, encompassing the range of C. virescens in South Africa. Seasonal changes in shell use, population structure and reproduction at a single locality (Cape Recife) were recorded over a period of 13 months. The breeding season of C. virescens at the southern extreme of its range extended from December to June. The population structure shows some seasonal change, but no clear trends emerge. The shell resource changed substantially in nature over the region studied. Based on shell use, localities clustered into separate southern and northern groups with a break occurring between Dwesa and Coffee Bay. Southern localities were characterised by use of Burnupena cincta, B. lagenaria and B. pubescens. Northern localities were characterised by the use of Morula granulata, M. nodosa and Peristernia forskalii. Intertidal shells used by C. virescens show fewer adaptations to predation in southern localities than shells from northern localities. Southern shells ii are relatively large, light and have wider apertures than those from northern localities which are generally smaller, heavier and have decreased aperture widths. Shell parameters affect population size-distributions as southern crabs were larger and heavier than northern crabs. C. virescens show sexual size dimorphism in which male crabs uniformly dominate the larger size classes at all localities. Differences in the sex ratio between males and females show more variable patterns. Most southern localities show no difference in the number of male and female crabs, but most northern localities show a skewed sex ratio in favour of females. Shell use and population size distributions of females affect reproductive output. Southern females produced significantly larger clutches than northern females. Reproductive output was related to crab mass and shell volume. Shell use patterns conform to the biogeographical regions in the range of the study and have a clear effect on both the population size distributions and reproductive output of Clibanarius virescens.
- Full Text:
- Authors: Wait, Michelle
- Subjects: Hermit crabs -- South Africa , Hermit crabs -- South Africa -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10599 , http://hdl.handle.net/10948/1553 , Hermit crabs -- South Africa , Hermit crabs -- South Africa -- Reproduction
- Description: Clibanarius virescens (Krauss) is a common and abundant hermit crab along the East coast of South Africa. Despite this, its biology is poorly known, both in South Africa and throughout the rest of its range in the West Indo-Pacific region. This study focuses on the descriptive analysis of the shell resource used by C. virescens and of the effects of this resource on crab populations. The underlying hypothesis of the study is that biogeographically imposed gradients in the morphology of intertidal gastropod shells used by hermit crabs affect hermit crab population parameters. The gradient of potential change in the shell resource was captured by sampling at 12 localities, encompassing the range of C. virescens in South Africa. Seasonal changes in shell use, population structure and reproduction at a single locality (Cape Recife) were recorded over a period of 13 months. The breeding season of C. virescens at the southern extreme of its range extended from December to June. The population structure shows some seasonal change, but no clear trends emerge. The shell resource changed substantially in nature over the region studied. Based on shell use, localities clustered into separate southern and northern groups with a break occurring between Dwesa and Coffee Bay. Southern localities were characterised by use of Burnupena cincta, B. lagenaria and B. pubescens. Northern localities were characterised by the use of Morula granulata, M. nodosa and Peristernia forskalii. Intertidal shells used by C. virescens show fewer adaptations to predation in southern localities than shells from northern localities. Southern shells ii are relatively large, light and have wider apertures than those from northern localities which are generally smaller, heavier and have decreased aperture widths. Shell parameters affect population size-distributions as southern crabs were larger and heavier than northern crabs. C. virescens show sexual size dimorphism in which male crabs uniformly dominate the larger size classes at all localities. Differences in the sex ratio between males and females show more variable patterns. Most southern localities show no difference in the number of male and female crabs, but most northern localities show a skewed sex ratio in favour of females. Shell use and population size distributions of females affect reproductive output. Southern females produced significantly larger clutches than northern females. Reproductive output was related to crab mass and shell volume. Shell use patterns conform to the biogeographical regions in the range of the study and have a clear effect on both the population size distributions and reproductive output of Clibanarius virescens.
- Full Text:
Self-regulation of the press in South Africa: analysis of selected cases
- Authors: Johaar, Odette
- Subjects: Press -- South Africa , Press and politics -- South Africa -- History -- 20th century , Freedom of the press -- South Africa , Newspapers , Journalism -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8423 , http://hdl.handle.net/10948/d1019752
- Description: The aim of this study is to present information to members of the South African press, academics in the field of journalism as well as individuals of the South African public who have a keen interest in printed communication in South Africa. The information presented discusses the practice of self-regulation in the South African press, through a study of the Press Council of South Africa (PCSA), the Press Ombudsman and the Press Appeals Panel that is a non-governmental organisation to regulate the press in South Africa. This study will include an analysis of the functions of the Press Ombudsman, the PCSA, the Press Appeals Panel, as well as the role of the constitution of the PSCA and the South African Press Code, which the PCSA uses as a guideline for publications that subscribe to it. Furthermore, a study into the complaints procedure and the determination of the outcome will be done in addition to the sanctions imposed on publications and journalists in breach of the Press Code as well as the acknowledgement given to individuals who have lodged a complaint to the Press Ombudsman, and the article or publication they have complained against had been in breach of the press code. In addition, this study will analyse the outcomes of selected complaints submitted to the PCSA as well as an analysis of submissions made to the PCSA task team and the Press Freedom Commission, an independent commission that was set up to research the regulations of the press. It was found that the PCSA strengthened the system of regulation with the help of the public. It is apparent that the organisation took into account many of the points raised in public submissions. Although the system is self-regulatory it is important to take note that it values and upholds the views of the public. Although though the sanctioning of wayward newspapers was not severe, it had become more defined in the amended code. A point of concern that did not improve over time is the time frame that the Press Ombudsman‟s Office took to resolve the disputes. The delays caused in some disputes were caused by loop holes in the press code and complaints procedure as well as defiant journalists. The PCSA is currently being restructured. As a society changes, the press industry needs to adapt to its needs. This means that the press code will have to constantly be developed to suit society‟s rapidly changing needs. The PCSA has attempted to meet those needs by constantly changing to ensure that the regulatory structure remains relevant.
- Full Text:
- Authors: Johaar, Odette
- Subjects: Press -- South Africa , Press and politics -- South Africa -- History -- 20th century , Freedom of the press -- South Africa , Newspapers , Journalism -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8423 , http://hdl.handle.net/10948/d1019752
- Description: The aim of this study is to present information to members of the South African press, academics in the field of journalism as well as individuals of the South African public who have a keen interest in printed communication in South Africa. The information presented discusses the practice of self-regulation in the South African press, through a study of the Press Council of South Africa (PCSA), the Press Ombudsman and the Press Appeals Panel that is a non-governmental organisation to regulate the press in South Africa. This study will include an analysis of the functions of the Press Ombudsman, the PCSA, the Press Appeals Panel, as well as the role of the constitution of the PSCA and the South African Press Code, which the PCSA uses as a guideline for publications that subscribe to it. Furthermore, a study into the complaints procedure and the determination of the outcome will be done in addition to the sanctions imposed on publications and journalists in breach of the Press Code as well as the acknowledgement given to individuals who have lodged a complaint to the Press Ombudsman, and the article or publication they have complained against had been in breach of the press code. In addition, this study will analyse the outcomes of selected complaints submitted to the PCSA as well as an analysis of submissions made to the PCSA task team and the Press Freedom Commission, an independent commission that was set up to research the regulations of the press. It was found that the PCSA strengthened the system of regulation with the help of the public. It is apparent that the organisation took into account many of the points raised in public submissions. Although the system is self-regulatory it is important to take note that it values and upholds the views of the public. Although though the sanctioning of wayward newspapers was not severe, it had become more defined in the amended code. A point of concern that did not improve over time is the time frame that the Press Ombudsman‟s Office took to resolve the disputes. The delays caused in some disputes were caused by loop holes in the press code and complaints procedure as well as defiant journalists. The PCSA is currently being restructured. As a society changes, the press industry needs to adapt to its needs. This means that the press code will have to constantly be developed to suit society‟s rapidly changing needs. The PCSA has attempted to meet those needs by constantly changing to ensure that the regulatory structure remains relevant.
- Full Text:
Social media reviews to investigate restaurant dinning experiences
- Authors: Van Achterbergh, Leon
- Subjects: Hospitality industry -- Social aspects , Restaurants -- Social aspects , Social media -- Economic aspects , Consumers -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9349 , http://hdl.handle.net/10948/d1021126
- Description: Restaurateurs often assume that customers' online reviews of their dining experiences are a reflection of their dining preferences. This study finds this assumption not to be true. Online written reviews do not explain diners’ preferred dining experiences. In this study post-experience reactions captured in reviews are shown to be contextually different to established dining preferences. Results show online reviews to be most important in facilitating customer dining expectations, but not influencing customers’ preferences in dining experiences. Evidence gathered during the secondary research shows that in general, social media has become the great marketing equaliser in commerce. In the dining industry, restaurants cannot solely rely on traditional media in the initial attraction and retention of dining customers. Continuous interaction between the business and customers is increasingly necessary for restaurateurs to remain competitive and in-touch with customers’ needs. This study concentrates its research area on the post-experience evaluation phase as found on review websites, like TripAdvisor. TripAdvisor has especially become a popular means to perpetuate word-of-mouth opinions of dining experiences among prospective customers. Research shows clear evidence of the importance of other's online opinions in the consumer decision-making process. The main variables of the study, namely customer experiences, restaurant dining and social media, are theoretically explored within the disciplines of service management and customer behaviour. These theories have laid a sound foundation for the subsequent research methods followed. The main purpose of the study was using social media reviews from TripAdvisor to investigate dining experiences in the restaurant industry. The outcomes desired were: firstly to advise the restaurant industry about superior customer practices, secondly emphasising the importance for industry of social media use in the dining experience, and thirdly rendering clarification on the experience perceptions of customers about factors that might lead to ‘delight’ and ‘frustration’. This research centralises the constructs of delight and frustration factors, which are typically extremely emotional dining experiences for the customer, that have the common element of surprise. Methodologically, the research required two phases: firstly, the qualitative analysis of online user-generated content by content analysis. The global sample consisted of seven international cities, which included the best, worst and average-rated TripAdvisor restaurant reviews. The content analysis produced the theoretical base for the dining perception variables used in the empirical survey. In the second phase of the study, the global surveys administered resulted in measuring the general public’s perceptions of the delight and frustration factors of dining experiences. Subsequently, the research process required various quantitative data analyses to reach substantial results with inferences. The results and interpreted findings achieved were twofold: Firstly, from the content analysis: customers regard service quality as relatively unimportant in relation to the holistic dining experience. Customers regarded food and beverage quality as crucial in the dining experience. Value for money increasingly becomes an issue as customers become more frustrated, more so than when the dining was generally experienced as pleasant. Secondly, from the empirical data: mood and aesthetics are essential, especially when diners chose between their favourite restaurants. Further results show managing the service basics for restaurants is essential; this included welcoming, professional, attentive and friendly service. Service consistency has also proven to be imperative in customers’ perceptions. Results further show that different nationalities could perceive food quality and service reliability differently. In addition, men and women could perceive food quality, mood and aesthetics, and value for money differently. This study recommends various findings to the restaurant industry: most importantly that the post-experience reviews are contextually different to customers’ dining preferences. The factor determining the reputation of a restaurant is food quality and not so much service quality. Value for money should be associated with a specific service or product feature for it to be of meaningful consequence to the restaurateur.
- Full Text:
- Authors: Van Achterbergh, Leon
- Subjects: Hospitality industry -- Social aspects , Restaurants -- Social aspects , Social media -- Economic aspects , Consumers -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9349 , http://hdl.handle.net/10948/d1021126
- Description: Restaurateurs often assume that customers' online reviews of their dining experiences are a reflection of their dining preferences. This study finds this assumption not to be true. Online written reviews do not explain diners’ preferred dining experiences. In this study post-experience reactions captured in reviews are shown to be contextually different to established dining preferences. Results show online reviews to be most important in facilitating customer dining expectations, but not influencing customers’ preferences in dining experiences. Evidence gathered during the secondary research shows that in general, social media has become the great marketing equaliser in commerce. In the dining industry, restaurants cannot solely rely on traditional media in the initial attraction and retention of dining customers. Continuous interaction between the business and customers is increasingly necessary for restaurateurs to remain competitive and in-touch with customers’ needs. This study concentrates its research area on the post-experience evaluation phase as found on review websites, like TripAdvisor. TripAdvisor has especially become a popular means to perpetuate word-of-mouth opinions of dining experiences among prospective customers. Research shows clear evidence of the importance of other's online opinions in the consumer decision-making process. The main variables of the study, namely customer experiences, restaurant dining and social media, are theoretically explored within the disciplines of service management and customer behaviour. These theories have laid a sound foundation for the subsequent research methods followed. The main purpose of the study was using social media reviews from TripAdvisor to investigate dining experiences in the restaurant industry. The outcomes desired were: firstly to advise the restaurant industry about superior customer practices, secondly emphasising the importance for industry of social media use in the dining experience, and thirdly rendering clarification on the experience perceptions of customers about factors that might lead to ‘delight’ and ‘frustration’. This research centralises the constructs of delight and frustration factors, which are typically extremely emotional dining experiences for the customer, that have the common element of surprise. Methodologically, the research required two phases: firstly, the qualitative analysis of online user-generated content by content analysis. The global sample consisted of seven international cities, which included the best, worst and average-rated TripAdvisor restaurant reviews. The content analysis produced the theoretical base for the dining perception variables used in the empirical survey. In the second phase of the study, the global surveys administered resulted in measuring the general public’s perceptions of the delight and frustration factors of dining experiences. Subsequently, the research process required various quantitative data analyses to reach substantial results with inferences. The results and interpreted findings achieved were twofold: Firstly, from the content analysis: customers regard service quality as relatively unimportant in relation to the holistic dining experience. Customers regarded food and beverage quality as crucial in the dining experience. Value for money increasingly becomes an issue as customers become more frustrated, more so than when the dining was generally experienced as pleasant. Secondly, from the empirical data: mood and aesthetics are essential, especially when diners chose between their favourite restaurants. Further results show managing the service basics for restaurants is essential; this included welcoming, professional, attentive and friendly service. Service consistency has also proven to be imperative in customers’ perceptions. Results further show that different nationalities could perceive food quality and service reliability differently. In addition, men and women could perceive food quality, mood and aesthetics, and value for money differently. This study recommends various findings to the restaurant industry: most importantly that the post-experience reviews are contextually different to customers’ dining preferences. The factor determining the reputation of a restaurant is food quality and not so much service quality. Value for money should be associated with a specific service or product feature for it to be of meaningful consequence to the restaurateur.
- Full Text:
Speaking out : Africa orality and post-colonial preoccupations in selected examples of contemporary performance poetry
- Authors: Mnensa, Mabel Thandeka
- Subjects: Oral interpretation of poetry , Poetry slams , Oral tradition -- Africa , Folk literature -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8455 , http://hdl.handle.net/10948/1193 , Oral interpretation of poetry , Poetry slams , Oral tradition -- Africa , Folk literature -- Africa
- Description: Contemporary performance poetry is a democratic art form that elicits dialogue and is a catalyst for social change. Yet it is an art form that is still not well understood: it is accused of unconsciously mimicking hip-hop and being a watered-down, lesser version of "real" poetry. However once its power is harnessed it may be a powerful art form that can be used to address social ills and act as a medium for memory work. The themes that are prevalent in contemporary performance poetry illustrate society‘s preoccupations. Different South African and American poets from a wide range of socio-economic, national, generational and racial backgrounds are examined to explore the collective preoccupations that keep emerging in the poetry, issues pertaining to race and class, gender, and to the politics of the past and its effect on the present. There is a long debate around the influences of contemporary performance poetry, which is negotiated in Chapter One. Though Gil Scott-Heron‘s "The Revolution will not be Televised" is identified as being a major influence, Saul Williams‘s "Black Stacey" challenges some of the arguments made by Scott-Heron. Lesego Rampolokeng lays the foundation for South African performance poetry by criticising the new black elite in the country in "Riding the Victim Train". Chapter Two examines how the poets challenge the status quo in their work. Sarah Jones‘s "Blood" illustrates how the new black middle class in America is complicit in keeping poor people on the margins, while Kgafela oa Magogodi levels his criticism against state sanctioned poets in South Africa. Mxolisi Nyezwa‘s "The Man is Gone" illustrates that the new class based hierarchal system in South Africa is potentially harsher than the apartheid one that was based on race. Chapter Three focuses on gender issues that are prevalent in South Africa. Tumi Molekane‘s "Yvonne" illustrates the danger that is embedded in the hetero-normative narrative while oa Magogodi‘s "Samson and deli(e)lah" and Sam‘s "Eve" explore how this narrative is unjustly informed by misinterpretations of the Bible. History and the impact of the past on the present is the focus of Chapter Four. "76" by Molekane illustrates how the apartheid legacy still affects many in South Africa, while Andrea Gibson‘s "Eli" explores the devastating effects of America‘s war efforts in Iraq. Dennis Brutus highlights the cathartic attributes of poetry that is community-driven in "So Neat They Were" and "Mumia". The chapter ends with an exploration of how the form of izibongo is used by Chris Thurman in "Holy City (A Jozi Praise-Poem)". The last poem illustrates how the past informs the present and suggests that despite the bleakness of the past, there is hope for South Africa because of its rich cultural heritage.
- Full Text:
- Authors: Mnensa, Mabel Thandeka
- Subjects: Oral interpretation of poetry , Poetry slams , Oral tradition -- Africa , Folk literature -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8455 , http://hdl.handle.net/10948/1193 , Oral interpretation of poetry , Poetry slams , Oral tradition -- Africa , Folk literature -- Africa
- Description: Contemporary performance poetry is a democratic art form that elicits dialogue and is a catalyst for social change. Yet it is an art form that is still not well understood: it is accused of unconsciously mimicking hip-hop and being a watered-down, lesser version of "real" poetry. However once its power is harnessed it may be a powerful art form that can be used to address social ills and act as a medium for memory work. The themes that are prevalent in contemporary performance poetry illustrate society‘s preoccupations. Different South African and American poets from a wide range of socio-economic, national, generational and racial backgrounds are examined to explore the collective preoccupations that keep emerging in the poetry, issues pertaining to race and class, gender, and to the politics of the past and its effect on the present. There is a long debate around the influences of contemporary performance poetry, which is negotiated in Chapter One. Though Gil Scott-Heron‘s "The Revolution will not be Televised" is identified as being a major influence, Saul Williams‘s "Black Stacey" challenges some of the arguments made by Scott-Heron. Lesego Rampolokeng lays the foundation for South African performance poetry by criticising the new black elite in the country in "Riding the Victim Train". Chapter Two examines how the poets challenge the status quo in their work. Sarah Jones‘s "Blood" illustrates how the new black middle class in America is complicit in keeping poor people on the margins, while Kgafela oa Magogodi levels his criticism against state sanctioned poets in South Africa. Mxolisi Nyezwa‘s "The Man is Gone" illustrates that the new class based hierarchal system in South Africa is potentially harsher than the apartheid one that was based on race. Chapter Three focuses on gender issues that are prevalent in South Africa. Tumi Molekane‘s "Yvonne" illustrates the danger that is embedded in the hetero-normative narrative while oa Magogodi‘s "Samson and deli(e)lah" and Sam‘s "Eve" explore how this narrative is unjustly informed by misinterpretations of the Bible. History and the impact of the past on the present is the focus of Chapter Four. "76" by Molekane illustrates how the apartheid legacy still affects many in South Africa, while Andrea Gibson‘s "Eli" explores the devastating effects of America‘s war efforts in Iraq. Dennis Brutus highlights the cathartic attributes of poetry that is community-driven in "So Neat They Were" and "Mumia". The chapter ends with an exploration of how the form of izibongo is used by Chris Thurman in "Holy City (A Jozi Praise-Poem)". The last poem illustrates how the past informs the present and suggests that despite the bleakness of the past, there is hope for South Africa because of its rich cultural heritage.
- Full Text:
Substantive fairness in dismissals for operational requirements cases
- Authors: Camagu, Asanda Pumeza
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Labor discipline -- Law and legislation -- South Africa , Unfair labor practices -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10214 , http://hdl.handle.net/10948/d1008114 , Employees -- Dismissal of -- Law and legislation -- South Africa , Labor discipline -- Law and legislation -- South Africa , Unfair labor practices -- South Africa
- Description: Part II of the International Labour Organisation Convention 158 recognises operational requirements of an organisation as a ground for dismissal. Section 213 of the Labour Relations Act describes operational requirements reasons as requirements based on the economic, technological, structural or related needs of an employer. The employer‟s needs in case of operational requirement dismissal must be separated from the other reasons for dismissal, such as misconduct and incapacity. Operational requirements dismissals are governed by section 189 of the LRA. The LRA draws a distinction between small and large scale dismissals and regulates them separately. Section 189 control small scale dismissals, while section 189A pertains to large scale dismissals For substantive fairness of a dismissal for operational requirements, the employer must prove that the said reason is one based on operational requirements of the business. The employer must be able to prove that the reason for the dismissal falls within the statutory definition of operational requirements. Employers are not allowed to use retrenchment to dismiss employees who they believe to have performed unsatisfactorily. This means that employers are not entitled to retrench for ulterior reasons, than those of operational requirements.The Labour Court has held that an employer may not under any situation retrench an employee on a fixed-term contract if the termination takes place before the contract of the employee ends, unless the contract of employment makes provision for termination at an earlier date. Retrenchment in this situation will amount to a breach of contract. Another point of interest in dismissals for operational requirements is that the Labour Relations Act states that it is not unlawful to dismiss a striking employee for reasons based on the employer‟s operational requirements. In relation to the selection criteria to be used during these dismissals, the Labour Relations Act again states that if an agreement cannot be reached between the consulting parties, then the employer must use criteria that are fair and objective.
- Full Text:
- Authors: Camagu, Asanda Pumeza
- Subjects: Employees -- Dismissal of -- Law and legislation -- South Africa , Labor discipline -- Law and legislation -- South Africa , Unfair labor practices -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10214 , http://hdl.handle.net/10948/d1008114 , Employees -- Dismissal of -- Law and legislation -- South Africa , Labor discipline -- Law and legislation -- South Africa , Unfair labor practices -- South Africa
- Description: Part II of the International Labour Organisation Convention 158 recognises operational requirements of an organisation as a ground for dismissal. Section 213 of the Labour Relations Act describes operational requirements reasons as requirements based on the economic, technological, structural or related needs of an employer. The employer‟s needs in case of operational requirement dismissal must be separated from the other reasons for dismissal, such as misconduct and incapacity. Operational requirements dismissals are governed by section 189 of the LRA. The LRA draws a distinction between small and large scale dismissals and regulates them separately. Section 189 control small scale dismissals, while section 189A pertains to large scale dismissals For substantive fairness of a dismissal for operational requirements, the employer must prove that the said reason is one based on operational requirements of the business. The employer must be able to prove that the reason for the dismissal falls within the statutory definition of operational requirements. Employers are not allowed to use retrenchment to dismiss employees who they believe to have performed unsatisfactorily. This means that employers are not entitled to retrench for ulterior reasons, than those of operational requirements.The Labour Court has held that an employer may not under any situation retrench an employee on a fixed-term contract if the termination takes place before the contract of the employee ends, unless the contract of employment makes provision for termination at an earlier date. Retrenchment in this situation will amount to a breach of contract. Another point of interest in dismissals for operational requirements is that the Labour Relations Act states that it is not unlawful to dismiss a striking employee for reasons based on the employer‟s operational requirements. In relation to the selection criteria to be used during these dismissals, the Labour Relations Act again states that if an agreement cannot be reached between the consulting parties, then the employer must use criteria that are fair and objective.
- Full Text:
Sustainable construction (development) in the city of Cape Town
- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
- Full Text:
- Authors: Mgudlwa, Nosiyabonga Portia
- Subjects: Construction industry -- South Africa -- Cape Town , Biodiversity -- South Africa -- Cape Town , Sustainable development -- South Africa -- Cape Town
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9700 , http://hdl.handle.net/10948/d1015042
- Description: Considering the challenges faced by the City of Cape Town such as loss of biodiversity, limited supply of energy and unsustainable land use, it is argued that it is imperative for the construction industry to promote sustainable development. The objective of the research was to understand the contributions of the construction industry to over exploitation of resources such as biodiversity, energy and land. Secondly, the study considers initiatives to be undertaken by the construction industry to enhance the environment so as to promote sustainable development. The research mixed methods was used as the form of collecting required data. The collection of data comprised of the design and administration of open-ended and closed-ended questionnaires among a non-random selected population of building contractor, public works officials and practising Architectural firms within the City of Cape Town. The data obtained from open-ended questionnaire on building contractors and public works officials was analysed qualitatively and data from the closed-ended questionnaires through practising Architectural firms was analysed quantitatively. Research results showed that biodiversity in the City of Cape Town is under threat. Passive design has a significant role in protecting the biodiversity and should be encouraged by the construction industry and the City of Cape Town. The City of Cape Town should strongly enforce polices that support the conservation of biodiversity. This will have a positive impact through encouraging the construction industry to adhere to these polices. The City of Cape Town is faced with energy shortage. The construction industry needs to reduce its energy usage as a dominant energy user. This will be achieved through energy efficient designs and retrofitting the existing buildings. The City of Cape Town has a responsibility to promote sustainable land use. Land prices are highly priced in the City of Cape Town as a result the poor cannot enter the market without external assistance. The construction industry has a role to encourage sustainable land use in the city.
- Full Text:
The experiences and coping resources of retirees in a vehicle manufacturing company
- Authors: Cain, Bridgette
- Subjects: Automobile industry workers -- Pensions -- South Africa -- Port Elizabeth , Automobile industry workers -- Retirement -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:16131 , http://hdl.handle.net/10948/484 , Automobile industry workers -- Pensions -- South Africa -- Port Elizabeth , Automobile industry workers -- Retirement -- South Africa -- Port Elizabeth
- Description: Retirement has different meanings for different people. Retirement represents a significant transitional period in the life cycle of an individual. The aim of the study was to explore and describe the experiences and coping resources of retirees. The researcher applied an exploratory, descriptive research design employing the mixed methods of quantitative and qualitative research to gain an in-depth understanding of the phenomenon. A non-probability purposive sampling method was used to identify participants who retired from a specific vehicle manufacturing company in Port Elizabeth. Semi-structured interviewing techniques and a questionnaire called the Coping Resources Inventory were used for data collection. The rationale for using a mixed method approach was to increase the validity of the research findings. Descriptive statistics and the framework provided by Tesch (in Creswell, 2003) were used in data analysis of quantitative and qualitative data respectively. The results of the Coping Resources Inventory indicated that the participants perceived themselves as having an average level of coping resources. The results from the semi-structured interviews reflected that participants’ retirement experiences are mainly influenced by the following three factors: (a) economic resources, (b) social relationships and (c) personal resources. Recommendations were made for future research and intervention regarding retirement planning. The researcher included suggestions for the implementation of a retirement preparation programme. Lastly the limitations and the value of the study were outlined.
- Full Text:
- Authors: Cain, Bridgette
- Subjects: Automobile industry workers -- Pensions -- South Africa -- Port Elizabeth , Automobile industry workers -- Retirement -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:16131 , http://hdl.handle.net/10948/484 , Automobile industry workers -- Pensions -- South Africa -- Port Elizabeth , Automobile industry workers -- Retirement -- South Africa -- Port Elizabeth
- Description: Retirement has different meanings for different people. Retirement represents a significant transitional period in the life cycle of an individual. The aim of the study was to explore and describe the experiences and coping resources of retirees. The researcher applied an exploratory, descriptive research design employing the mixed methods of quantitative and qualitative research to gain an in-depth understanding of the phenomenon. A non-probability purposive sampling method was used to identify participants who retired from a specific vehicle manufacturing company in Port Elizabeth. Semi-structured interviewing techniques and a questionnaire called the Coping Resources Inventory were used for data collection. The rationale for using a mixed method approach was to increase the validity of the research findings. Descriptive statistics and the framework provided by Tesch (in Creswell, 2003) were used in data analysis of quantitative and qualitative data respectively. The results of the Coping Resources Inventory indicated that the participants perceived themselves as having an average level of coping resources. The results from the semi-structured interviews reflected that participants’ retirement experiences are mainly influenced by the following three factors: (a) economic resources, (b) social relationships and (c) personal resources. Recommendations were made for future research and intervention regarding retirement planning. The researcher included suggestions for the implementation of a retirement preparation programme. Lastly the limitations and the value of the study were outlined.
- Full Text:
The human resource department as a strategic business partner in organisations
- Authors: Sakonda, Archford
- Subjects: Human capital -- Management , Strategic planning , Employment agencies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9431 , http://hdl.handle.net/10948/d1020178
- Description: The human resource department in many organisations is at a crossroad of relevance, constantly being faced with the challenge to prove that it can add value towards the objectives of the business. The Human Resource (HR) department is also faced with a reality that, if the department does not add value to the organisation, it will be farmed out to independent contractors, who can deliver the HR functions at a more efficient and cost effective way. However, organisations have a great opportunity to achieve excellence and competitive advantage through the utilisation of the organisation‟s human resources. Many scholars and authors argued that organisations can achieve the most out of its human resources if the HR department is a Strategic Business Partner (SBP) in these organisations. A thorough literature review has led to the discovery that, despite the appraisal of the Strategic Business Partners (SBP) approach to the management of human resources, little progress has been made with the reinvention of the HR departments from support function towards being a SBP (Lawler & Morhman, 2003; Keith, 2007). The slow progress in the transformation of the HR department was attributed to a wide range of factors including the lack of competencies to take up Strategic Business Partnership roles, lack of management support, and incongruent organisational cultures (Keith, 2007; Sanders & Frenkel, 2009; Ulrich & Brockbank, 2005). Semi-structured interviews were conducted with HR professionals, Managing Directors and other Directors, who sit on a strategic table, to identify the challenges and opportunities the HR department faced as a SBP in organisations. A self-administered questionnaire, based on an existing questionnaire (Ulrich & Cornell (1997) HR role assessment survey) was used to gather the perception of employees regarding the roles the HR departments play in organisations. In this study organisational culture was identified as having a huge impact towards the implementation of HR departments as SBPs. The study also identified the competencies needed for the effective execution of SBP roles, the challenges HR departments may face in the process as well as the important roles the HR department should be devoting most of its time and resources to.
- Full Text:
- Authors: Sakonda, Archford
- Subjects: Human capital -- Management , Strategic planning , Employment agencies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9431 , http://hdl.handle.net/10948/d1020178
- Description: The human resource department in many organisations is at a crossroad of relevance, constantly being faced with the challenge to prove that it can add value towards the objectives of the business. The Human Resource (HR) department is also faced with a reality that, if the department does not add value to the organisation, it will be farmed out to independent contractors, who can deliver the HR functions at a more efficient and cost effective way. However, organisations have a great opportunity to achieve excellence and competitive advantage through the utilisation of the organisation‟s human resources. Many scholars and authors argued that organisations can achieve the most out of its human resources if the HR department is a Strategic Business Partner (SBP) in these organisations. A thorough literature review has led to the discovery that, despite the appraisal of the Strategic Business Partners (SBP) approach to the management of human resources, little progress has been made with the reinvention of the HR departments from support function towards being a SBP (Lawler & Morhman, 2003; Keith, 2007). The slow progress in the transformation of the HR department was attributed to a wide range of factors including the lack of competencies to take up Strategic Business Partnership roles, lack of management support, and incongruent organisational cultures (Keith, 2007; Sanders & Frenkel, 2009; Ulrich & Brockbank, 2005). Semi-structured interviews were conducted with HR professionals, Managing Directors and other Directors, who sit on a strategic table, to identify the challenges and opportunities the HR department faced as a SBP in organisations. A self-administered questionnaire, based on an existing questionnaire (Ulrich & Cornell (1997) HR role assessment survey) was used to gather the perception of employees regarding the roles the HR departments play in organisations. In this study organisational culture was identified as having a huge impact towards the implementation of HR departments as SBPs. The study also identified the competencies needed for the effective execution of SBP roles, the challenges HR departments may face in the process as well as the important roles the HR department should be devoting most of its time and resources to.
- Full Text:
The perceptions of educators, in the Queenstown education district, of the labour dispute resolution system
- Authors: Rataza, Themba Theophilus
- Subjects: Labor disputes -- South Africa -- Queenstown , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9434 , http://hdl.handle.net/10948/d1020542
- Description: The objective of this study is to conduct a survey concerning the perceptions of educators in the Queenstown education district of the labour dispute resolution system. The education department is one of the biggest departments in the Eastern Cape’s Provincial Administration system. The likelihood of disputes is high when there are many employees. The focus of the study therefore is on how educators perceive the role of the department in terms of ensuring that labour disputes with the department are resolved efficiently and speedily. The advent of a democratic dispensation resulted in the ushering in of progressive labour legislation such as Labour Relations Act 55 of 1995. The objective of this Act is to facilitate economic development, social justice, labour peace and democratization of the workplace. In other words this Act gave birth to the manner in which labour disputes should be resolved. The study was carried out not only to explore the perceptions of educators but also with a view to making recommendations on the findings in order to help contribute towards labour peace and productivity in the workplace. The attitudes of one hundred and forty-one educators were surveyed via questionnaires and six educators who have had labour disputes with the department were interviewed. The key findings of the study revealed that both the educators who were surveyed and those interviewed lack confidence in the effectiveness of the labour dispute procedures in the district; they perceive the system as being inaccessible to them; time taken to resolve disputes is too lengthy; the system lacks necessary independence from the department of education or government and the department is seen as not adhering to its own policies and legislation. Hence there are many disputes and there is a great need for more awareness and for improved training in handling labour dispute resolution systems for district officials and educators. The study recommends more awareness and training sessions for both district officials responsible for labour relations and educators at large. It also calls for an increasingly proactive role by teacher unions in partnership with the department of education to avoid labour disputes. Although the findings cannot be generalized toother districts of the province, they do however highlight critical areas in labour dispute resolution where attention can be paid and focus made in order to ensure labour peace in the workplace for improved productivity and effective teaching and learning.
- Full Text:
- Authors: Rataza, Themba Theophilus
- Subjects: Labor disputes -- South Africa -- Queenstown , Labor laws and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9434 , http://hdl.handle.net/10948/d1020542
- Description: The objective of this study is to conduct a survey concerning the perceptions of educators in the Queenstown education district of the labour dispute resolution system. The education department is one of the biggest departments in the Eastern Cape’s Provincial Administration system. The likelihood of disputes is high when there are many employees. The focus of the study therefore is on how educators perceive the role of the department in terms of ensuring that labour disputes with the department are resolved efficiently and speedily. The advent of a democratic dispensation resulted in the ushering in of progressive labour legislation such as Labour Relations Act 55 of 1995. The objective of this Act is to facilitate economic development, social justice, labour peace and democratization of the workplace. In other words this Act gave birth to the manner in which labour disputes should be resolved. The study was carried out not only to explore the perceptions of educators but also with a view to making recommendations on the findings in order to help contribute towards labour peace and productivity in the workplace. The attitudes of one hundred and forty-one educators were surveyed via questionnaires and six educators who have had labour disputes with the department were interviewed. The key findings of the study revealed that both the educators who were surveyed and those interviewed lack confidence in the effectiveness of the labour dispute procedures in the district; they perceive the system as being inaccessible to them; time taken to resolve disputes is too lengthy; the system lacks necessary independence from the department of education or government and the department is seen as not adhering to its own policies and legislation. Hence there are many disputes and there is a great need for more awareness and for improved training in handling labour dispute resolution systems for district officials and educators. The study recommends more awareness and training sessions for both district officials responsible for labour relations and educators at large. It also calls for an increasingly proactive role by teacher unions in partnership with the department of education to avoid labour disputes. Although the findings cannot be generalized toother districts of the province, they do however highlight critical areas in labour dispute resolution where attention can be paid and focus made in order to ensure labour peace in the workplace for improved productivity and effective teaching and learning.
- Full Text:
The relationship between work place well-being, psychological capital and work place trust
- Authors: Schoeman, Johannes Dames
- Subjects: Well-being , Trust , Work -- Psychological aspects , Job satisfaction
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9406 , http://hdl.handle.net/10948/d1013044
- Description: A study of the available literature on Workplace Well-being, Positive Organisational Capital and Workplace Trust revealed that enormous potential existed for further research. This is a relatively new field with limited literature and research evidence available. It became very clear from the beginning that the relationships between these constructs could successfully be researched. It was therefore decided to embark on an academic research journey in order to contribute to the existing knowledge available on these constructs within the South African business scenario. This quantitative research was used to obtain more clarity about the relationships between the three constructs and to gather the responses from the research population. This research group consisted of 228 managers from the manufacturing operation of a motor vehicle production company and 224 managers from their National Dealership network. The research sample consisted of 452 managers. Three questionnaires were integrated to develop the composite Workplace Wellbeing Questionnaire and consisted of i) Workplace Well-being questionnaire developed by Parker and Hyett (2011), ii) PSYCAP Questionnaire developed by Luthans, Youssef and Avolio (2007), and iii) Workplace Trust Survey developed by Ferres (2001). The managers (n = 452) responded to a 91–item electronic questionnaire. Seven research questions were formulated and covered areas such as: The content, validity and portability of the measuring instruments; The configuration of the various constructs; Relationships between some of the variables; The effect of demographical data on the research variables and; The building of a research model. The content and the structure of the measuring instruments were assessed by means of Confirmatory Factor Analysis (CFA) and Exploratory Factor Analyses (EFA). These assessments showed that the original measuring instruments are not portable to a culture which is different to the one where they were originally developed. The relationships between the variables were determined by: Pearson product moment correlation; Multiple Regression co-efficient; ANOVA and Cohen’s d Test. The relationship between aspects of Workplace Well-being (Job satisfaction) and trust is a significant finding; so are some aspects of PSYCAP (sense of achievement and optimism) and Trust and Well-being. Trust has shown a definite relationship with Work- place well-being. A structural equation model was built to test the relationships between the elements of Workplace Well-being, PSYCAP and Workplace Trust. No satisfactory fit of the model on the data was obtained, although strong correlations between some of the variables existed. The significance of the findings of this study and the contribution that it makes to the existing theory is seen in the importance of the portability of measuring instruments. Recommendations in this regard have been made in Chapter 5. Various findings have also highlighted the relationships between Workplace Well-being, PSYCAP and Work-place Trust. The importance of future research topics has been recommended and a proposal has been made to consider a longitudinal well-being research study.
- Full Text:
- Authors: Schoeman, Johannes Dames
- Subjects: Well-being , Trust , Work -- Psychological aspects , Job satisfaction
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: vital:9406 , http://hdl.handle.net/10948/d1013044
- Description: A study of the available literature on Workplace Well-being, Positive Organisational Capital and Workplace Trust revealed that enormous potential existed for further research. This is a relatively new field with limited literature and research evidence available. It became very clear from the beginning that the relationships between these constructs could successfully be researched. It was therefore decided to embark on an academic research journey in order to contribute to the existing knowledge available on these constructs within the South African business scenario. This quantitative research was used to obtain more clarity about the relationships between the three constructs and to gather the responses from the research population. This research group consisted of 228 managers from the manufacturing operation of a motor vehicle production company and 224 managers from their National Dealership network. The research sample consisted of 452 managers. Three questionnaires were integrated to develop the composite Workplace Wellbeing Questionnaire and consisted of i) Workplace Well-being questionnaire developed by Parker and Hyett (2011), ii) PSYCAP Questionnaire developed by Luthans, Youssef and Avolio (2007), and iii) Workplace Trust Survey developed by Ferres (2001). The managers (n = 452) responded to a 91–item electronic questionnaire. Seven research questions were formulated and covered areas such as: The content, validity and portability of the measuring instruments; The configuration of the various constructs; Relationships between some of the variables; The effect of demographical data on the research variables and; The building of a research model. The content and the structure of the measuring instruments were assessed by means of Confirmatory Factor Analysis (CFA) and Exploratory Factor Analyses (EFA). These assessments showed that the original measuring instruments are not portable to a culture which is different to the one where they were originally developed. The relationships between the variables were determined by: Pearson product moment correlation; Multiple Regression co-efficient; ANOVA and Cohen’s d Test. The relationship between aspects of Workplace Well-being (Job satisfaction) and trust is a significant finding; so are some aspects of PSYCAP (sense of achievement and optimism) and Trust and Well-being. Trust has shown a definite relationship with Work- place well-being. A structural equation model was built to test the relationships between the elements of Workplace Well-being, PSYCAP and Workplace Trust. No satisfactory fit of the model on the data was obtained, although strong correlations between some of the variables existed. The significance of the findings of this study and the contribution that it makes to the existing theory is seen in the importance of the portability of measuring instruments. Recommendations in this regard have been made in Chapter 5. Various findings have also highlighted the relationships between Workplace Well-being, PSYCAP and Work-place Trust. The importance of future research topics has been recommended and a proposal has been made to consider a longitudinal well-being research study.
- Full Text:
The sustainability of Reconstruction and Development Programme Houses : 2004 to 2006 : a case study of Litchis Bay, East London
- Authors: Balani, Thobeka Virginia
- Subjects: Human services -- South Africa -- East London , Human settlements -- South Africa -- East London , Sustainable development -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8855 , http://hdl.handle.net/10948/d1020141
- Description: The South African government has endeavored to provide settlement to citizens and policies have been formulated since 1994 to guide these efforts. The South African Constitution (1996, section 26) stated that everyone has the right to have access to adequate housing. Furthermore the African National Congress’s Freedom Charter (1955) made it clear that: “there shall be houses, security and comfort for all, everybody shall have the right to live where they choose, to be decently housed, and to bring up their families in comfort and security. Slums shall be demolished and new suburbs built, where all shall have transport, roads, lights, playing fields, crèches and social centers”. However, after 19 years of democracy the state of housing is still a critical issue that addresses whether development has served to further the cause of sustainable development with respect to the pillars of human settlement such as shelter, infrastructure and economic opportunities. The study was conducted in the Litchis Bay settlement in East London, Eastern Cape Province. Mixed approaches of quantitative and qualitative methods were used to solicit data. Random Sampling techniques were conducted to select the sample population. Data was captured on Excel sheets to generate graphs. Findings of the study and conclusions were drawn. Therefore when measuring the term ‘sustainable human settlement’ against the findings on RDP houses in Litchis Bay, one can conclude that sustainable human settlement is not fully absorbed in defining the sustainability of RDP houses in Litchis Bay. Moreover the majority of houses have defects, and social amenities are not easily accessible.
- Full Text:
- Authors: Balani, Thobeka Virginia
- Subjects: Human services -- South Africa -- East London , Human settlements -- South Africa -- East London , Sustainable development -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8855 , http://hdl.handle.net/10948/d1020141
- Description: The South African government has endeavored to provide settlement to citizens and policies have been formulated since 1994 to guide these efforts. The South African Constitution (1996, section 26) stated that everyone has the right to have access to adequate housing. Furthermore the African National Congress’s Freedom Charter (1955) made it clear that: “there shall be houses, security and comfort for all, everybody shall have the right to live where they choose, to be decently housed, and to bring up their families in comfort and security. Slums shall be demolished and new suburbs built, where all shall have transport, roads, lights, playing fields, crèches and social centers”. However, after 19 years of democracy the state of housing is still a critical issue that addresses whether development has served to further the cause of sustainable development with respect to the pillars of human settlement such as shelter, infrastructure and economic opportunities. The study was conducted in the Litchis Bay settlement in East London, Eastern Cape Province. Mixed approaches of quantitative and qualitative methods were used to solicit data. Random Sampling techniques were conducted to select the sample population. Data was captured on Excel sheets to generate graphs. Findings of the study and conclusions were drawn. Therefore when measuring the term ‘sustainable human settlement’ against the findings on RDP houses in Litchis Bay, one can conclude that sustainable human settlement is not fully absorbed in defining the sustainability of RDP houses in Litchis Bay. Moreover the majority of houses have defects, and social amenities are not easily accessible.
- Full Text:
Tool wear monitoring in end milling of mould steel using acoustic emission
- Authors: Olufayo, Oluwole Ayodeji
- Subjects: Acoustic emission testing , Tool-steel
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9651 , http://hdl.handle.net/10948/d1014688
- Description: Today’s production industry is faced with the challenge of maximising its resources and productivity. Tool condition monitoring (TCM) is an important diagnostic tool and if integrated in manufacturing, machining efficiency will increase as a result of reducing downtime resulting from tool failures by intensive wear. The research work presented in the study highlights the principles in tool condition monitoring and identifies acoustic emission (AE) as a reliable sensing technique for the detection of wear conditions. It reviews the importance of acoustic emission as an efficient technique and proposes a TCM model for the prediction of tool wear. The study presents a TCM framework to monitor an end-milling operation of H13 tool steel at different cutting speeds and feed rates. For this, three industrial acoustic sensors were positioned on the workpiece. The framework identifies a feature selection, extraction and conditioning process and classifies AE signals using an artificial neural network algorithm to create an autonomous system. It concludes by recognizing the mean and rms features as viable features in the identification of tool state and observes that chip coloration provides direct correlation to the temperature of machining as well as tool condition. This proposed model is aimed at creating a timing schedule for tool change in industries. This model ultimately links the rate of wear formation to characteristic AE features.
- Full Text:
- Authors: Olufayo, Oluwole Ayodeji
- Subjects: Acoustic emission testing , Tool-steel
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: vital:9651 , http://hdl.handle.net/10948/d1014688
- Description: Today’s production industry is faced with the challenge of maximising its resources and productivity. Tool condition monitoring (TCM) is an important diagnostic tool and if integrated in manufacturing, machining efficiency will increase as a result of reducing downtime resulting from tool failures by intensive wear. The research work presented in the study highlights the principles in tool condition monitoring and identifies acoustic emission (AE) as a reliable sensing technique for the detection of wear conditions. It reviews the importance of acoustic emission as an efficient technique and proposes a TCM model for the prediction of tool wear. The study presents a TCM framework to monitor an end-milling operation of H13 tool steel at different cutting speeds and feed rates. For this, three industrial acoustic sensors were positioned on the workpiece. The framework identifies a feature selection, extraction and conditioning process and classifies AE signals using an artificial neural network algorithm to create an autonomous system. It concludes by recognizing the mean and rms features as viable features in the identification of tool state and observes that chip coloration provides direct correlation to the temperature of machining as well as tool condition. This proposed model is aimed at creating a timing schedule for tool change in industries. This model ultimately links the rate of wear formation to characteristic AE features.
- Full Text:
Tribological characteristics of polymers under high force small oscillating angular contact
- Authors: Bradfield, Jarad Wade
- Subjects: Tribology , Polymers.
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:9637 , http://hdl.handle.net/10948/d1020598
- Description: This study was intended to establish which polymer material is best suited as the material for bushes used in high force small oscillating angular contact applications as typically found in a large sugar mill coupling. A Tribometer as well as a designed and manufactured Bearing Testing Machine, which simulates and accelerates the wear caused in the intended application, was used to determine the wear rates and coefficients of friction for seven polymer materials. Materials were selected for their superior mechanical and thermal properties. The Tribometer was fitted with a linear reciprocating rig, so as to simulate the small oscillating movement prevalent in the intended application. Each Tribometer test ran for a duration of two hours with a frequency of 33.1 Herts and a normal loading of 40N. Bearing Testing Machine tests were done under similar constraints but with 30kN loading present on the surface of a bushes inner race. These tests had a longer duration of 24 or 48 hours or until intense wearing occurred. Initially both testing methods will be analysed independently of each other in order to try and identify a relationship between the wear rate and coefficient of friction for the different polymers. The different testing methods’ results will be compared to each other in order to establish if a correlation between the materials tested could be found.
- Full Text:
- Authors: Bradfield, Jarad Wade
- Subjects: Tribology , Polymers.
- Language: English
- Type: Thesis , Masters , MTech (Mechanical Engineering)
- Identifier: vital:9637 , http://hdl.handle.net/10948/d1020598
- Description: This study was intended to establish which polymer material is best suited as the material for bushes used in high force small oscillating angular contact applications as typically found in a large sugar mill coupling. A Tribometer as well as a designed and manufactured Bearing Testing Machine, which simulates and accelerates the wear caused in the intended application, was used to determine the wear rates and coefficients of friction for seven polymer materials. Materials were selected for their superior mechanical and thermal properties. The Tribometer was fitted with a linear reciprocating rig, so as to simulate the small oscillating movement prevalent in the intended application. Each Tribometer test ran for a duration of two hours with a frequency of 33.1 Herts and a normal loading of 40N. Bearing Testing Machine tests were done under similar constraints but with 30kN loading present on the surface of a bushes inner race. These tests had a longer duration of 24 or 48 hours or until intense wearing occurred. Initially both testing methods will be analysed independently of each other in order to try and identify a relationship between the wear rate and coefficient of friction for the different polymers. The different testing methods’ results will be compared to each other in order to establish if a correlation between the materials tested could be found.
- Full Text: