A best practice guideline for evidence based teaching strategies for nurse educators
- Authors: Breytenbach, Cecile
- Date: 2015
- Subjects: Nursing -- Study and teaching -- Great Britain , Nurse educators , Evidence-based nursing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4831 , vital:20699
- Description: Evidence based practice (EBP) is a worldwide phenomena defined as the “conscientious explicit and judicious use of current best evidence in making decisions about the patient’s care”. The evidence based practice concept’s aim is to effectively guide health care professionals to build knowledge that will be supported by evidence. Evidence based practice must be supported by evidence based teaching. Nurse educators must be up to date with evidence based teaching as well as the latest evidence based teaching strategies, in order to teach the new millennial nursing students and for the new qualifications structure. Teaching the concept of evidence based practice by implementing evidence based teaching to nursing students will enable them to transform the future of healthcare by delivering high quality care practice. A paucity of evidence is available on evidence based teaching and teaching strategies in the South African context. Therefore the researcher used a systematic review methodology to explore and describe the best available evidence based teaching strategies and to develop a guideline on evidence based teaching strategies for nurse educators. The data bases searched included: MEDLINE, CINAHL, PubMed and Google Scholar. Manual searches were done and completed with the assistance of librarians. A total number of n=50 studies were identified as potentially relevant to the study. The number or articles included for critical appraisal were 20. On completion of the critical appraisal n=17 articles were identified for the review. The included studies for the review were n=7 Level 1, systematic reviews and n=10 Level 2, quasi-experimental studies. Three studies were excluded after critical appraisal from two reviewers, appraisal was done independently, and consensuses were reached between the two reviewers. The Joanna Briggs Institutes critical appraisal and data extraction instruments were used for the study. The descriptive data synthesis was done of the included studies as well as a comparison of teaching strategies to determine which one to better than the other one. Although n = 4 of the teaching strategies (concept mapping, internet-based learning, evidence based interactive strategy and cultural competence) significantly increased knowledge, the overall results found that a variety of teaching strategies to be implemented to increase the knowledge outcomes of the nursing students. The different teaching strategies found were: e-learning, concept mapping, internet-based learning, web-based learning, gaming, problem-based learning, and case studies, evidence based learning and cultural competence. However, more research is needed to investigate the best use of the different teaching strategies and compare the impact of a variety of teaching strategies on increasing knowledge of the nursing student.
- Full Text:
- Date Issued: 2015
- Authors: Breytenbach, Cecile
- Date: 2015
- Subjects: Nursing -- Study and teaching -- Great Britain , Nurse educators , Evidence-based nursing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/4831 , vital:20699
- Description: Evidence based practice (EBP) is a worldwide phenomena defined as the “conscientious explicit and judicious use of current best evidence in making decisions about the patient’s care”. The evidence based practice concept’s aim is to effectively guide health care professionals to build knowledge that will be supported by evidence. Evidence based practice must be supported by evidence based teaching. Nurse educators must be up to date with evidence based teaching as well as the latest evidence based teaching strategies, in order to teach the new millennial nursing students and for the new qualifications structure. Teaching the concept of evidence based practice by implementing evidence based teaching to nursing students will enable them to transform the future of healthcare by delivering high quality care practice. A paucity of evidence is available on evidence based teaching and teaching strategies in the South African context. Therefore the researcher used a systematic review methodology to explore and describe the best available evidence based teaching strategies and to develop a guideline on evidence based teaching strategies for nurse educators. The data bases searched included: MEDLINE, CINAHL, PubMed and Google Scholar. Manual searches were done and completed with the assistance of librarians. A total number of n=50 studies were identified as potentially relevant to the study. The number or articles included for critical appraisal were 20. On completion of the critical appraisal n=17 articles were identified for the review. The included studies for the review were n=7 Level 1, systematic reviews and n=10 Level 2, quasi-experimental studies. Three studies were excluded after critical appraisal from two reviewers, appraisal was done independently, and consensuses were reached between the two reviewers. The Joanna Briggs Institutes critical appraisal and data extraction instruments were used for the study. The descriptive data synthesis was done of the included studies as well as a comparison of teaching strategies to determine which one to better than the other one. Although n = 4 of the teaching strategies (concept mapping, internet-based learning, evidence based interactive strategy and cultural competence) significantly increased knowledge, the overall results found that a variety of teaching strategies to be implemented to increase the knowledge outcomes of the nursing students. The different teaching strategies found were: e-learning, concept mapping, internet-based learning, web-based learning, gaming, problem-based learning, and case studies, evidence based learning and cultural competence. However, more research is needed to investigate the best use of the different teaching strategies and compare the impact of a variety of teaching strategies on increasing knowledge of the nursing student.
- Full Text:
- Date Issued: 2015
Evaluation of the quality indices of the final effluents of two wastewater treatment plants in buffalo City Metropolitan Municipality in the Eastern Cape Province
- Authors: Osuolale, Olayinka O
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11292 , http://hdl.handle.net/10353/d1021079
- Description: Waste waters can be sources of pollution to surface water and the environment with severe implications for public health. Most treatment plants in the Buffalo City Municipality in the Eastern Cape Province discharge their treated effluent into the surface waters which directly and indirectly impacts on the quality of surface waters in the region. The objective of this study was to determine the microbiological and physicochemical qualities of the final effluents of two wastewater treatment plants in the Buffalo City Municipality in the Eastern Cape Province of South Africa over a period of 12 months (September 2012 to August 2013). The qualities of the final effluents of WW-Ama Wastewater Treatment Plant with respect to phosphate (3.9 mg/l - 20.6 mg/l), free chlorine (0.05 mg/l - 0.71 mg/l), chemical oxygen demand (COD) (4.7 mg/l - 211 mg/l), and faecal coliform (0 - 2.92 × 104 CFU/100 ml) were not in compliance with the permissible limits set for effluent discharged to surface water by South Africa guidelines for effluent discharge. Other physicochemical parameters like biological oxygen demand (BOD) (2.2 mg/l - 9.0 mg/l), total dissolve solid (TDS) (253 mg/l - 336.3 mg/l) and turbidity (4.8 NTU - 43.20 NTU) with no SA regulatory set limits were compared to other regulatory standards and they do not comply with the limits. Also, at the second WWTP’s, the WW-Dim Treatment Plant effluent quality for free chlorine (0.06 mg/l - 7.2 mg/l), BOD (0.1 mg/l - 7.4 mg/l), and turbidity (4.02 NTU - 24.3 NTU) also did not comply. For microbiological qualities, counts of presumptive E. coli and Vibrio ranged between 0 - 2.92 × PROFESSOR ANTHONY I. OKOHAntibiogram of the bacterial isolates were determined using the disk diffusion method. A total of 107 confirmed E. coli and 100 confirmed Vibrio spp. were used for this assay. Results of antibiotic sensitivity test revealed that 63.6% of the E. coli isolates were resistance to ampicillin while 49.5% were resistant to tetracycline and cephalothin. The least resistances were observed against gentamicin (3.7%) and cefotaxime (1.9%). No resistance was observed against meropenem. For the Vibrio spp, resistance was most frequently observed against tetracycline (38%) ampicillin (26%), chloramphenicol (16%), cefotaxime (14%), trimethoprim-sulfamethoxazole (13%) and the least resistance observed was against ciprofloxacin (1%). This study demonstrates that poorly treated wastewater effluent can be a source of eutrophic water with high nutrient levels and pathogenic bacteria and enteric viruses as well as antibiotic resistance determinants that could impact negatively on human health. The finding of this study also suggests that WWTPs have to be properly monitored and controlled to ensure compliance to set guidelines. This could be attained through the application of appropriate treatment processes, which will help to minimize possible dangers to public environment health.
- Full Text:
- Date Issued: 2015
- Authors: Osuolale, Olayinka O
- Date: 2015
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11292 , http://hdl.handle.net/10353/d1021079
- Description: Waste waters can be sources of pollution to surface water and the environment with severe implications for public health. Most treatment plants in the Buffalo City Municipality in the Eastern Cape Province discharge their treated effluent into the surface waters which directly and indirectly impacts on the quality of surface waters in the region. The objective of this study was to determine the microbiological and physicochemical qualities of the final effluents of two wastewater treatment plants in the Buffalo City Municipality in the Eastern Cape Province of South Africa over a period of 12 months (September 2012 to August 2013). The qualities of the final effluents of WW-Ama Wastewater Treatment Plant with respect to phosphate (3.9 mg/l - 20.6 mg/l), free chlorine (0.05 mg/l - 0.71 mg/l), chemical oxygen demand (COD) (4.7 mg/l - 211 mg/l), and faecal coliform (0 - 2.92 × 104 CFU/100 ml) were not in compliance with the permissible limits set for effluent discharged to surface water by South Africa guidelines for effluent discharge. Other physicochemical parameters like biological oxygen demand (BOD) (2.2 mg/l - 9.0 mg/l), total dissolve solid (TDS) (253 mg/l - 336.3 mg/l) and turbidity (4.8 NTU - 43.20 NTU) with no SA regulatory set limits were compared to other regulatory standards and they do not comply with the limits. Also, at the second WWTP’s, the WW-Dim Treatment Plant effluent quality for free chlorine (0.06 mg/l - 7.2 mg/l), BOD (0.1 mg/l - 7.4 mg/l), and turbidity (4.02 NTU - 24.3 NTU) also did not comply. For microbiological qualities, counts of presumptive E. coli and Vibrio ranged between 0 - 2.92 × PROFESSOR ANTHONY I. OKOHAntibiogram of the bacterial isolates were determined using the disk diffusion method. A total of 107 confirmed E. coli and 100 confirmed Vibrio spp. were used for this assay. Results of antibiotic sensitivity test revealed that 63.6% of the E. coli isolates were resistance to ampicillin while 49.5% were resistant to tetracycline and cephalothin. The least resistances were observed against gentamicin (3.7%) and cefotaxime (1.9%). No resistance was observed against meropenem. For the Vibrio spp, resistance was most frequently observed against tetracycline (38%) ampicillin (26%), chloramphenicol (16%), cefotaxime (14%), trimethoprim-sulfamethoxazole (13%) and the least resistance observed was against ciprofloxacin (1%). This study demonstrates that poorly treated wastewater effluent can be a source of eutrophic water with high nutrient levels and pathogenic bacteria and enteric viruses as well as antibiotic resistance determinants that could impact negatively on human health. The finding of this study also suggests that WWTPs have to be properly monitored and controlled to ensure compliance to set guidelines. This could be attained through the application of appropriate treatment processes, which will help to minimize possible dangers to public environment health.
- Full Text:
- Date Issued: 2015
Understanding how Grade 11 life sciences teachers mediate biodiversity concepts in a second language context : a case study
- Authors: Gqoloqa, Zingisa
- Date: 2015
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Language and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2028 , http://hdl.handle.net/10962/d1017339
- Description: This research focused on an investigation of the pedagogy and strategies used by Grade 11 Life Sciences teachers when mediating Biodiversity concepts with English second language learners. My interest in this investigation was triggered by the Examiners’ Reports for Life Sciences from 2009 to 2012 which consistently noted learner challenges in answering, interpreting and analysing questions during exams. The reports highlighted learners’ lack of understanding of the questions which led to them providing irrelevant information in their exam scripts. These reports claimed that challenges experienced by these learners could be attributed to language issues experienced by English second language learners. Influenced by these reports, a qualitative case study of two Senior Secondary schools in East London, Eastern Cape South Africa was conducted. Underpinned by an interpretive paradigm and driven by the desire to achieve an in-depth understanding of the case under study, three phases of information gathering were followed. The first phase was that of gathering information through document analysis. Documents were analysed to gain insights and understanding of the issue before conducting interviews. The next phase was that of gathering information through semi-structured interviews followed by classroom observations. Findings from these observations were verified through stimulated recall interviews which provided clarity on the intentionality of choosing a certain method and strategy over another when assisting learners in making meaning of biodiversity concepts. The main findings of this study are that factors which limit learner understanding of biodiversity concepts are a result of a combination of factors such as failure to interpret questions, spelling problems which alter meaning of concepts and an inability to make distinctions among closely related concepts within the topic of Biodiversity. Responding to these factors, teachers demonstrated knowledge of a variety of teaching strategies to support learners. The choice of teaching strategies seemed to be guided by their experiences as well as the challenges they often encounter. Furthermore, teachers’ reflections on their practice provided opportunities for them to identify strengths and limitations of their choice of strategies and possibilities for improvement. It was also noted that factors such as large class sizes, gaps in content knowledge and a lack of detail in chalkboard summary limited the effectiveness of their teaching strategies. The study recommends that: • Teacher-learner ratio needs to be considered for effective support; • There is still a need to capacitate educators in environmental education. In-service training should focus on developing teacher understanding of foundational knowledge in life sciences; and • Teachers need to improve their chalkboard summary skills to increase the level of support that could be provided by comprehensive chalkboard summary through the elaboration of ideas
- Full Text:
- Date Issued: 2015
- Authors: Gqoloqa, Zingisa
- Date: 2015
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Language and education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2028 , http://hdl.handle.net/10962/d1017339
- Description: This research focused on an investigation of the pedagogy and strategies used by Grade 11 Life Sciences teachers when mediating Biodiversity concepts with English second language learners. My interest in this investigation was triggered by the Examiners’ Reports for Life Sciences from 2009 to 2012 which consistently noted learner challenges in answering, interpreting and analysing questions during exams. The reports highlighted learners’ lack of understanding of the questions which led to them providing irrelevant information in their exam scripts. These reports claimed that challenges experienced by these learners could be attributed to language issues experienced by English second language learners. Influenced by these reports, a qualitative case study of two Senior Secondary schools in East London, Eastern Cape South Africa was conducted. Underpinned by an interpretive paradigm and driven by the desire to achieve an in-depth understanding of the case under study, three phases of information gathering were followed. The first phase was that of gathering information through document analysis. Documents were analysed to gain insights and understanding of the issue before conducting interviews. The next phase was that of gathering information through semi-structured interviews followed by classroom observations. Findings from these observations were verified through stimulated recall interviews which provided clarity on the intentionality of choosing a certain method and strategy over another when assisting learners in making meaning of biodiversity concepts. The main findings of this study are that factors which limit learner understanding of biodiversity concepts are a result of a combination of factors such as failure to interpret questions, spelling problems which alter meaning of concepts and an inability to make distinctions among closely related concepts within the topic of Biodiversity. Responding to these factors, teachers demonstrated knowledge of a variety of teaching strategies to support learners. The choice of teaching strategies seemed to be guided by their experiences as well as the challenges they often encounter. Furthermore, teachers’ reflections on their practice provided opportunities for them to identify strengths and limitations of their choice of strategies and possibilities for improvement. It was also noted that factors such as large class sizes, gaps in content knowledge and a lack of detail in chalkboard summary limited the effectiveness of their teaching strategies. The study recommends that: • Teacher-learner ratio needs to be considered for effective support; • There is still a need to capacitate educators in environmental education. In-service training should focus on developing teacher understanding of foundational knowledge in life sciences; and • Teachers need to improve their chalkboard summary skills to increase the level of support that could be provided by comprehensive chalkboard summary through the elaboration of ideas
- Full Text:
- Date Issued: 2015
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D'Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
Teaching Mandarin in schools is another slap in the face for African languages
- Kaschula, Russell H, Nosilela, Bulelwa, Heugh, Kathleen, Hendricks, Monica, Maseko, Pamela
- Authors: Kaschula, Russell H , Nosilela, Bulelwa , Heugh, Kathleen , Hendricks, Monica , Maseko, Pamela
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67042 , vital:29023 , https://theconversation.com/teaching-mandarin-in-schools-is-another-slap-in-the-face-for-african-languages-48505
- Description: publisher version , It’s said that behind every powerful language is an army and money. Consider the case of English. In South Africa, as in its other colonies, the British arrived with the Bible in one hand and the breech-loader in the other. Behind them was the English language, military might and money. British missionaries wanted to convert Africa’s indigenous “heathens” to Christianity; to clone little English people on the continent through the medium of English. Next came the Afrikaners, descended from the Dutch. Their slaves created a “kitchen” language out of Dutch and called it Afrikaans. White Afrikaners appropriated it as their own and it became the language of apartheid. One of the tipping points of white rule was the 1976 Soweto uprising – a furious, powerful response to the news that Afrikaans would become a compulsory medium of instruction. Now there is a new potential coloniser on South Africa’s linguistic block. From 2016, Mandarin will be taught in the country’s schools as a Second Additional Language. This new government policy will see African languages bumped even further down the educational pecking order.
- Full Text: false
- Date Issued: 2015
- Authors: Kaschula, Russell H , Nosilela, Bulelwa , Heugh, Kathleen , Hendricks, Monica , Maseko, Pamela
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67042 , vital:29023 , https://theconversation.com/teaching-mandarin-in-schools-is-another-slap-in-the-face-for-african-languages-48505
- Description: publisher version , It’s said that behind every powerful language is an army and money. Consider the case of English. In South Africa, as in its other colonies, the British arrived with the Bible in one hand and the breech-loader in the other. Behind them was the English language, military might and money. British missionaries wanted to convert Africa’s indigenous “heathens” to Christianity; to clone little English people on the continent through the medium of English. Next came the Afrikaners, descended from the Dutch. Their slaves created a “kitchen” language out of Dutch and called it Afrikaans. White Afrikaners appropriated it as their own and it became the language of apartheid. One of the tipping points of white rule was the 1976 Soweto uprising – a furious, powerful response to the news that Afrikaans would become a compulsory medium of instruction. Now there is a new potential coloniser on South Africa’s linguistic block. From 2016, Mandarin will be taught in the country’s schools as a Second Additional Language. This new government policy will see African languages bumped even further down the educational pecking order.
- Full Text: false
- Date Issued: 2015
A roller test bench for the evaluation of automotive vehicle noise, vibration and harshness
- Authors: Raffler, Oliver
- Date: 2015
- Subjects: Motor vehicles -- Transmission devices -- Noise Mechanical engineering Automobiles -- Noise
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/21646 , vital:29728
- Description: The purpose of this thesis is the construction of a test bench for the assessment of the NVH behaviour of a newly manufactured VW Polo 5. This will be done in collaboration with Volkswagen South Africa. Firstly, in order to gain a better understanding of the requirements such a test bench has to fulfill, the VW Polo, the guidelines prescribed by VW as well as the actual testing procedure implemented by VW Uitenhage will be analysed. Thereafter, the main section of the thesis will deal with the construction of the test bench. As agreed upon with Volkswagen Uitenhage, a test bench will be built during the course of the studies. This test bench will allow stimulation in low frequency as well as high frequency ranges and in addition to that, a second version of the test bench with optimised costing will be derived from the first one. The second model will only allow stimulation in high frequency ranges. During the thesis, a version of the test bench, the RTB-HC, has been developed which enables the stimulation of the high and low frequencies. In addition, a cost optimized version was developed. This version will be referred as RTB-LC. This version allows only a high frequency excitation.
- Full Text:
- Date Issued: 2015
- Authors: Raffler, Oliver
- Date: 2015
- Subjects: Motor vehicles -- Transmission devices -- Noise Mechanical engineering Automobiles -- Noise
- Language: English
- Type: Thesis , Masters , MEngineering
- Identifier: http://hdl.handle.net/10948/21646 , vital:29728
- Description: The purpose of this thesis is the construction of a test bench for the assessment of the NVH behaviour of a newly manufactured VW Polo 5. This will be done in collaboration with Volkswagen South Africa. Firstly, in order to gain a better understanding of the requirements such a test bench has to fulfill, the VW Polo, the guidelines prescribed by VW as well as the actual testing procedure implemented by VW Uitenhage will be analysed. Thereafter, the main section of the thesis will deal with the construction of the test bench. As agreed upon with Volkswagen Uitenhage, a test bench will be built during the course of the studies. This test bench will allow stimulation in low frequency as well as high frequency ranges and in addition to that, a second version of the test bench with optimised costing will be derived from the first one. The second model will only allow stimulation in high frequency ranges. During the thesis, a version of the test bench, the RTB-HC, has been developed which enables the stimulation of the high and low frequencies. In addition, a cost optimized version was developed. This version will be referred as RTB-LC. This version allows only a high frequency excitation.
- Full Text:
- Date Issued: 2015
The effectiveness of risk mangement in local government with reference to the Nelson Mandela Bay Minicipality
- Authors: Sihlali, Siphosihle
- Date: 2015
- Subjects: Risk management -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/4407 , vital:20596
- Description: In the 1960s, risk management primarily took the form of purchased insurance against force majeure events. Today, many corporate executives are worried about not only these types of events but also many others (Mair and Cendrowski, 2009:3). “People risks” versus environmental risks, financial risks and technical risks are examples of risks that are often overlooked. People risks include, succession planning (this refers to identifying and developing key talent) and competency and skills building (dealing with employees that do not have requisite skills for success), (William & Paul, 2007:4). Massingham (2010:464) mentions that corporate disasters, such as the collapse of Enron, have increased the need for effective corporate governance, while catastrophic natural disasters, man-made tragedies such as the September 11 terrorist attacks and tsunami of 2004, have increased risk awareness as well as its consequences.
- Full Text:
- Date Issued: 2015
- Authors: Sihlali, Siphosihle
- Date: 2015
- Subjects: Risk management -- South Africa -- Nelson Mandela Bay Municipality
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/4407 , vital:20596
- Description: In the 1960s, risk management primarily took the form of purchased insurance against force majeure events. Today, many corporate executives are worried about not only these types of events but also many others (Mair and Cendrowski, 2009:3). “People risks” versus environmental risks, financial risks and technical risks are examples of risks that are often overlooked. People risks include, succession planning (this refers to identifying and developing key talent) and competency and skills building (dealing with employees that do not have requisite skills for success), (William & Paul, 2007:4). Massingham (2010:464) mentions that corporate disasters, such as the collapse of Enron, have increased the need for effective corporate governance, while catastrophic natural disasters, man-made tragedies such as the September 11 terrorist attacks and tsunami of 2004, have increased risk awareness as well as its consequences.
- Full Text:
- Date Issued: 2015
The design of a seaside hydrotherapy facility in Nelson Mandela Bay, Beachview
- Authors: Van Jaarsveld, Nadine
- Date: 2015
- Subjects: Health resorts -- South Africa -- Port Elizabeth -- Designs and plans Hydrotherapy , Recreational therapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18663 , vital:28703
- Description: This treatise is about the design of a seaside hydrotherapy facility which will treat health conditions through the healing properties of water therapy and nature, as well as improving the wellness of the users. The purpose of this treatise is to understand the architectural aspects involved in a seaside hydrotherapy facility, such as the theoretical, the contextual, spatial, and the physical aspects. The facility will be located in Nelson Mandela Bay at Beachview in a therapeutic setting on the seafront, and will not only provide specialized thalassotherapy, but also give the users the benefit of the mental healing properties of the ocean. The building itself aims to promote healing and relaxation and challenges the designer to make maximum use of these elements. The nature of hydrotherapy facilities requires the provision for recovery, which indicates the setting up of overnight amenities as well as daily access. With this in mind, the relationship between these two groups of users and their connections, are explored. The facility proposes to use design as a way to connect the sea, land and architecture, in order to form an integrated relationship for the beneficial use of the user. An architectural design is proposed which is formed of specific sets of architectural issues that were identified and analysed. The work of professionals and other architectural designs with similar challenges were studied in terms of their particular responses and their relationships were analysed in relation to a seaside hydrotherapy facility.
- Full Text:
- Date Issued: 2015
- Authors: Van Jaarsveld, Nadine
- Date: 2015
- Subjects: Health resorts -- South Africa -- Port Elizabeth -- Designs and plans Hydrotherapy , Recreational therapy
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/18663 , vital:28703
- Description: This treatise is about the design of a seaside hydrotherapy facility which will treat health conditions through the healing properties of water therapy and nature, as well as improving the wellness of the users. The purpose of this treatise is to understand the architectural aspects involved in a seaside hydrotherapy facility, such as the theoretical, the contextual, spatial, and the physical aspects. The facility will be located in Nelson Mandela Bay at Beachview in a therapeutic setting on the seafront, and will not only provide specialized thalassotherapy, but also give the users the benefit of the mental healing properties of the ocean. The building itself aims to promote healing and relaxation and challenges the designer to make maximum use of these elements. The nature of hydrotherapy facilities requires the provision for recovery, which indicates the setting up of overnight amenities as well as daily access. With this in mind, the relationship between these two groups of users and their connections, are explored. The facility proposes to use design as a way to connect the sea, land and architecture, in order to form an integrated relationship for the beneficial use of the user. An architectural design is proposed which is formed of specific sets of architectural issues that were identified and analysed. The work of professionals and other architectural designs with similar challenges were studied in terms of their particular responses and their relationships were analysed in relation to a seaside hydrotherapy facility.
- Full Text:
- Date Issued: 2015
Pecha Kucha 3: Memories, photographs, and archives: On historicising ‘puberty’ in the present
- Authors: Pinto, Pedro
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143937 , vital:38296 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: In 1997, Valerie Walkerdine incited researchers to use memory and fantasy as devices to explore the gendered meanings of being a child and becoming adult. Since we all once were children, we are in the ambiguous – and therefore productive – position of being both informants and ethnographers of childhood experiences. Whilst drawing on a historical investigation on puberty science, this presentation is a hybrid experiment: it combines my memories of growing up in Portugal in the early 1980s and photographs of children taken in clinical interventions from the late nineteenth century to the first decades of the twentieth. In articulating these materials and their different temporalities, my purpose is to explore the techniques and the power relations in which pubertal development came to being thought of, and disciplined, in contemporary societies. In doing so, I invite the possibility of historicising experience as a strategy to critically analyse our medicalised present.
- Full Text:
- Date Issued: 2015
- Authors: Pinto, Pedro
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143937 , vital:38296 , https://ischp.files.wordpress.com/2015/08/ischp_2015_abstract_booklet.pdf
- Description: In 1997, Valerie Walkerdine incited researchers to use memory and fantasy as devices to explore the gendered meanings of being a child and becoming adult. Since we all once were children, we are in the ambiguous – and therefore productive – position of being both informants and ethnographers of childhood experiences. Whilst drawing on a historical investigation on puberty science, this presentation is a hybrid experiment: it combines my memories of growing up in Portugal in the early 1980s and photographs of children taken in clinical interventions from the late nineteenth century to the first decades of the twentieth. In articulating these materials and their different temporalities, my purpose is to explore the techniques and the power relations in which pubertal development came to being thought of, and disciplined, in contemporary societies. In doing so, I invite the possibility of historicising experience as a strategy to critically analyse our medicalised present.
- Full Text:
- Date Issued: 2015
Uncle Noodle
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229676 , vital:49699 , xlink:href="https://hdl.handle.net/10520/EJC176906"
- Description: “Ah,” he seemed surprised to see me, “Now you find out who really cares...” His kidneys hadn‟t been on the job in months, and with the machines failing, his hands were fattening into stubby yellow fingers, as the waste shored up inside of him. I touched his arm, and we joked about the broad blunt strokes of the casiotone the old dame played for the lunch-eaters next door. Uncle Noodle had always been my favourite. In a world where adults were always certain, ready to disdain and judge and pass verdict – I loved it that he was indecisive, insecure, unsure. Often wretched, often defeated. His heart had chasmed in the wake of his wife‟s leaving, finally dividing him from all his hopes, collapsing his dignity destroying his happiness machinery.
- Full Text:
- Date Issued: 2015
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229676 , vital:49699 , xlink:href="https://hdl.handle.net/10520/EJC176906"
- Description: “Ah,” he seemed surprised to see me, “Now you find out who really cares...” His kidneys hadn‟t been on the job in months, and with the machines failing, his hands were fattening into stubby yellow fingers, as the waste shored up inside of him. I touched his arm, and we joked about the broad blunt strokes of the casiotone the old dame played for the lunch-eaters next door. Uncle Noodle had always been my favourite. In a world where adults were always certain, ready to disdain and judge and pass verdict – I loved it that he was indecisive, insecure, unsure. Often wretched, often defeated. His heart had chasmed in the wake of his wife‟s leaving, finally dividing him from all his hopes, collapsing his dignity destroying his happiness machinery.
- Full Text:
- Date Issued: 2015
Determinants of student satisfaction with campus residence life at a South African university
- Botha, Ferdi, Snowball, Jeanette D, De Klerk, Vivian A, Radloff, Sarah E
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69277 , vital:29475 , https://doi.org/10.1007/978-3-319-15904-1_2
- Description: Factors outside the classroom can contribute to academic success as well as the achievement of important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2,000 respondents. The study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One main finding is that there are no significant differences in satisfaction with QoRL across racial and gender groups; suggesting significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.
- Full Text: false
- Date Issued: 2015
- Authors: Botha, Ferdi , Snowball, Jeanette D , De Klerk, Vivian A , Radloff, Sarah E
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69277 , vital:29475 , https://doi.org/10.1007/978-3-319-15904-1_2
- Description: Factors outside the classroom can contribute to academic success as well as the achievement of important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2,000 respondents. The study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One main finding is that there are no significant differences in satisfaction with QoRL across racial and gender groups; suggesting significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.
- Full Text: false
- Date Issued: 2015
Design, development and evaluation of novel lead compounds as HIV-1 enzyme inhibitors
- Authors: Sekgota, Khethobole Cassius
- Date: 2015
- Subjects: Enzyme inhibitors , Viruses -- Reproduction , HIV (Viruses)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4546 , http://hdl.handle.net/10962/d1017926
- Description: This project has been concerned with the application of the Baylis-Hillman methodology to the synthesis of medicinally important diketo acid analogues (cinnamate ester-AZT conjugates and 3-hydroxy ester-AZT conjugates) as dual-action HIV-1 IN/RT inhibitors; and on exploratory studies in the preparation of 3-(amidomethyl)-(1H)-2-quinolones as PR inhibitors; and (1H)-2- quinolone-AZT conjugates as dual action IN/RT inhibitors. A series of Baylis-Hillman adducts has been prepared, typically in moderate to excellent yield, by reacting 2-nitrobenzaldehyde with methyl acrylate, ethyl acrylate and methyl vinyl ketone in the presence of 1,4- diazabicyclo[2.2.2]octane (DABCO). Subsequently, various transformations that include conjugate addition of primary and secondary amines to the α,ß-unsaturated moiety to obtain 2- (aminomethyl)-3-hydroxy-3-(2-nitrophenyl)propanoate derivatives, effective SN2´ substitution of the BH ß-hydroxy by a Vilsmeier-Haack in situ-generated chloride to afford Baylis-Hillman allyl chlorides, iron in acetic acid-catalyzed cyclisation to 3-acetoxymethyl-(1H)-2-quinolone derivatives were achieved. Thus, using the Baylis-Hillman methodology, two nuanced classes of diketo acid analogues were constructed. These involved conjugating appropriate propargylamine derivatives with AZT using the „click‟ reaction. In an exploratory study, the quinolone derivative, precisely 3-acetoxymethyl- (1H)-quinol-2-one, was transformed into 3-hydroxymethyl-(1H)-quinol-2-one using potassium carbonate in a mixture of methanol and water (1:1). Following successful hydrolysis, the resulting alcohol was transformed to the corresponding chloride, 3-chloromethyl-(1H)-quinol-2- one, using thionyl chloride. Subsequent nucleophilic substitution afforded 3-(aminomethyl)- (1H)-2-quinolone derivatives which were subsequently transformed to 3-(amidomethyl)-(1H)-2- quinolones; and 3-[(propargylamino)-methyl]-(1H)-quinol-2-one as precursors to quinolone- AZT derivatives. All compounds were characterized by NMR, IR, and where appropriate, high resolution MS
- Full Text:
- Date Issued: 2015
- Authors: Sekgota, Khethobole Cassius
- Date: 2015
- Subjects: Enzyme inhibitors , Viruses -- Reproduction , HIV (Viruses)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4546 , http://hdl.handle.net/10962/d1017926
- Description: This project has been concerned with the application of the Baylis-Hillman methodology to the synthesis of medicinally important diketo acid analogues (cinnamate ester-AZT conjugates and 3-hydroxy ester-AZT conjugates) as dual-action HIV-1 IN/RT inhibitors; and on exploratory studies in the preparation of 3-(amidomethyl)-(1H)-2-quinolones as PR inhibitors; and (1H)-2- quinolone-AZT conjugates as dual action IN/RT inhibitors. A series of Baylis-Hillman adducts has been prepared, typically in moderate to excellent yield, by reacting 2-nitrobenzaldehyde with methyl acrylate, ethyl acrylate and methyl vinyl ketone in the presence of 1,4- diazabicyclo[2.2.2]octane (DABCO). Subsequently, various transformations that include conjugate addition of primary and secondary amines to the α,ß-unsaturated moiety to obtain 2- (aminomethyl)-3-hydroxy-3-(2-nitrophenyl)propanoate derivatives, effective SN2´ substitution of the BH ß-hydroxy by a Vilsmeier-Haack in situ-generated chloride to afford Baylis-Hillman allyl chlorides, iron in acetic acid-catalyzed cyclisation to 3-acetoxymethyl-(1H)-2-quinolone derivatives were achieved. Thus, using the Baylis-Hillman methodology, two nuanced classes of diketo acid analogues were constructed. These involved conjugating appropriate propargylamine derivatives with AZT using the „click‟ reaction. In an exploratory study, the quinolone derivative, precisely 3-acetoxymethyl- (1H)-quinol-2-one, was transformed into 3-hydroxymethyl-(1H)-quinol-2-one using potassium carbonate in a mixture of methanol and water (1:1). Following successful hydrolysis, the resulting alcohol was transformed to the corresponding chloride, 3-chloromethyl-(1H)-quinol-2- one, using thionyl chloride. Subsequent nucleophilic substitution afforded 3-(aminomethyl)- (1H)-2-quinolone derivatives which were subsequently transformed to 3-(amidomethyl)-(1H)-2- quinolones; and 3-[(propargylamino)-methyl]-(1H)-quinol-2-one as precursors to quinolone- AZT derivatives. All compounds were characterized by NMR, IR, and where appropriate, high resolution MS
- Full Text:
- Date Issued: 2015
Comparative electrocatalytic studies of nanocomposites of mixed and covalently linked multiwalled carbon nanotubes and 4-(4, 6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt (II)
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189285 , vital:44834 , xlink:href="https://doi.org/10.1016/j.poly.2015.05.038"
- Description: Electrocatalytic behavior of 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II) (CoPyPc) when mixed or covalently mixed to multiwalled carbon nanotubes (MWCNTs) is reported. Infra-red spectroscopy was used to confirm amide linkage of the covalently linked nanocomposite. Rotating disk electrode (RDE) and cyclic (CV) voltammetry studies were used for the electrochemical characterization of the prepared phthalocyanine and MWCNT nanocomposite. The electrocatalytic effects of the nanocomposites of the cobalt phthalocyanine derivative were then investigated towards L-cysteine oxidation using both RDE and CV experiments, and the electrocatalytic performance of the covalently linked cobalt phthalocyanine-MWCNT was found to be superior over the mixed nanocomposite.
- Full Text:
- Date Issued: 2015
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189285 , vital:44834 , xlink:href="https://doi.org/10.1016/j.poly.2015.05.038"
- Description: Electrocatalytic behavior of 4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninato cobalt(II) (CoPyPc) when mixed or covalently mixed to multiwalled carbon nanotubes (MWCNTs) is reported. Infra-red spectroscopy was used to confirm amide linkage of the covalently linked nanocomposite. Rotating disk electrode (RDE) and cyclic (CV) voltammetry studies were used for the electrochemical characterization of the prepared phthalocyanine and MWCNT nanocomposite. The electrocatalytic effects of the nanocomposites of the cobalt phthalocyanine derivative were then investigated towards L-cysteine oxidation using both RDE and CV experiments, and the electrocatalytic performance of the covalently linked cobalt phthalocyanine-MWCNT was found to be superior over the mixed nanocomposite.
- Full Text:
- Date Issued: 2015
Drought management strategies and poverty alleviation in Zimbabwe : the case of Mwenezi District
- Authors: Farai, Magaisa David
- Date: 2015
- Subjects: Droughts--Zimbabwe--Management Zimbabwe--Economic conditions Poverty--Zimbabwe
- Language: English
- Type: Thesis , Masters , Development Studies
- Identifier: http://hdl.handle.net/10353/16091 , vital:40663
- Description: Drought remains a huge challenge in Africa, particularly in Zimbabwe. The study investigated the effectiveness of drought management strategies and poverty alleviation in Zimbabwe with particular focus on Mwenezi District. In order to come up with a comprehensive investigation, the researcher grounded the study in sustainable livelihood approach and the community driven development theory. Due to drought being the number one disaster in Zimbabwe, the government and NGOs have collectively come up with strategies aimed at ameliorating the impact of drought in the area. The study employed a qualitative methodology as it provided an understanding and description of people’s personal experiences of drought. The study investigated the roles of both the government and NGOs involved in drought management in the district. NGOs and Government institutions charged with drought relief implement various programmes designed to manage drought in this area. This study’s findings were that cattle rearing, provision of food aid, provision of seed packs, supplementary feeding, among other programmes, are being implemented in the district to curb drought. Local people in the area have adopted a number of strategies so as to cope with drought effects. These strategies include growing of drought-resistant crops, livestock selling, change of farming methods, informal cross-border trading and establishing gardening plots. The Zimbabwean government has been criticised for being reactive rather than being proactive when it comes to drought management. The study further calls for improved and effective policies to tackle drought and poverty in the area. Effective monitoring and evaluation of programmes designed to manage drought should be prioritised if ever drought is to be effectively managed.
- Full Text:
- Date Issued: 2015
- Authors: Farai, Magaisa David
- Date: 2015
- Subjects: Droughts--Zimbabwe--Management Zimbabwe--Economic conditions Poverty--Zimbabwe
- Language: English
- Type: Thesis , Masters , Development Studies
- Identifier: http://hdl.handle.net/10353/16091 , vital:40663
- Description: Drought remains a huge challenge in Africa, particularly in Zimbabwe. The study investigated the effectiveness of drought management strategies and poverty alleviation in Zimbabwe with particular focus on Mwenezi District. In order to come up with a comprehensive investigation, the researcher grounded the study in sustainable livelihood approach and the community driven development theory. Due to drought being the number one disaster in Zimbabwe, the government and NGOs have collectively come up with strategies aimed at ameliorating the impact of drought in the area. The study employed a qualitative methodology as it provided an understanding and description of people’s personal experiences of drought. The study investigated the roles of both the government and NGOs involved in drought management in the district. NGOs and Government institutions charged with drought relief implement various programmes designed to manage drought in this area. This study’s findings were that cattle rearing, provision of food aid, provision of seed packs, supplementary feeding, among other programmes, are being implemented in the district to curb drought. Local people in the area have adopted a number of strategies so as to cope with drought effects. These strategies include growing of drought-resistant crops, livestock selling, change of farming methods, informal cross-border trading and establishing gardening plots. The Zimbabwean government has been criticised for being reactive rather than being proactive when it comes to drought management. The study further calls for improved and effective policies to tackle drought and poverty in the area. Effective monitoring and evaluation of programmes designed to manage drought should be prioritised if ever drought is to be effectively managed.
- Full Text:
- Date Issued: 2015
Changes in diet resource use by elephants, Loxodonta Africana, due to changes in resource availability in the Addo National Park
- Authors: Du Toit, Jana
- Date: 2015
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape , Wildlife conservation , Addo Elephant National Park (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10731 , ISSN http://hdl.handle.net/10948/d1021194
- Description: Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
- Full Text:
- Date Issued: 2015
- Authors: Du Toit, Jana
- Date: 2015
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape , Wildlife conservation , Addo Elephant National Park (South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10731 , ISSN http://hdl.handle.net/10948/d1021194
- Description: Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
- Full Text:
- Date Issued: 2015
An analysis of soil properties associated with badland and gully erosion in rural catchments of the Ngqushwa District, Eastern Cape Province
- Authors: De Jager, Megan Joan
- Date: 2015
- Subjects: Soil mechanics -- South Africa -- Eastern Cape , Soils -- South Africa -- Eastern Cape -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3519 , vital:20438
- Description: Accelerated soil erosion holds strong links to excessive land degradation, socioeconomic problems and accelerated climate change, particularly in developing countries such as South Africa. An analysis of the properties of severely eroded soils is undertaken to determine which characteristic properties influence the erodibility of the soils at several gully and badland sites in three catchments of the Ngqushwa rural municipality, which is tagged as one of the area’s most severely affected by soil erosion and degradation in the Eastern Cape. Physical, biological and chemical properties of the soils were analysed, including aggregate stability, soil texture, organic matter- and carbon content, clay mineralogy, sesquioxide content as Fe2O3 and cation composition. The distribution of a number of these properties was also determined, particularly between erosion sites, along hillslope profiles and with depth. The study area comprises three catchments, namely Mgwalana, Bira and Gqora which share common soil parent materials, land use history, exhibit similar topography and advanced degree of erosion. A total of 63 soil samples were strategically collected from identified erosion zones and site controls devoid of active erosion; where stability was evident by means of vegetation cover and soil surface condition. Surface samples were collected above 30cm depth and subsurface samples at depths greater than 30cm. To determine the fate of carbon additional samples were collected from runon and sink zones at the Mgwalana catchment along a transect from top to bottom slope. Laboratory analyses was performed to determine the soil properties, whereby C content was measured by the dry combustion method, Fe2O3- and cation content by Atomic Absorption (AA) Spectrometer, texture by the separation method described by Schlichting, Blume & Stahr (1995), clay mineralogy by X-Ray Diffraction and organic matter content by conversion of total C. In addition to these properties being used to infer aggregate stability, the wet sieving method was also used for this purpose and for validation of the other soil properties. The results revealed that no one soil property has a greater influence on aggregate stability than the others, but rather that the stability of the soil is dependent on the combinations of these properties in the soil and the interactions that occur between them. Based on this, the results indicated greater stability for runon, sink and control samples, mainly in the topsoil, which were characterised by a relatively higher C- and organic matter content, loam texture and higher concentrations of Ca2+. Furthermore, the less stable eroded samples were characterised by a more clay rich texture particularly in the subsoil, relatively lower C- and organic matter contents and a greater sodicity due to higher concentrations of Na+. The least stable soils belonged to the Gqora catchment, which were found to consist of higher silt content in the topsoil and a higher Fe2O3 content in the subsoil. The clay mineralogy was relatively uniform across all catchments, comprising of primarily illite and secondly kaolinite. The sample with the highest sodicity in terms of ESP contained smectite clay in addition to illite and kaolinite which is assumed to contribute to this increased Na+ concentration. These findings aid in the conclusion that the chemical characteristics of the soils, in association with biological and, to a less extent, physical properties of the soil exacerbate the erosion problem initiated by the extrinsic contributors, such as climate and topography. Investigation into the fate of carbon on eroded lands revealed a topographically driven dynamic whereby the total carbon content was found to be greater at the top and middle slope positions as well as in the sink zone. These hillslope sections were found to have a lower slope gradient and slightly more pronounced concave shape to those sections with lower C values. These topographic variables influence the degree of gully erosion taking place at different hillslope sections, which tends to be greater where slope angle is increased and convexity exists, resulting in the removal of soil C at these positions and its deposition in areas of accumulation, namely the runon and sink zones of low angle concave slope sections. The findings of this research may be used to develop restoration and management strategies with the ultimate goal to reduce the soils vulnerability to erosion by enhancing those soil properties conducive to greater aggregate stability as determined in the present study.
- Full Text:
- Date Issued: 2015
- Authors: De Jager, Megan Joan
- Date: 2015
- Subjects: Soil mechanics -- South Africa -- Eastern Cape , Soils -- South Africa -- Eastern Cape -- Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/3519 , vital:20438
- Description: Accelerated soil erosion holds strong links to excessive land degradation, socioeconomic problems and accelerated climate change, particularly in developing countries such as South Africa. An analysis of the properties of severely eroded soils is undertaken to determine which characteristic properties influence the erodibility of the soils at several gully and badland sites in three catchments of the Ngqushwa rural municipality, which is tagged as one of the area’s most severely affected by soil erosion and degradation in the Eastern Cape. Physical, biological and chemical properties of the soils were analysed, including aggregate stability, soil texture, organic matter- and carbon content, clay mineralogy, sesquioxide content as Fe2O3 and cation composition. The distribution of a number of these properties was also determined, particularly between erosion sites, along hillslope profiles and with depth. The study area comprises three catchments, namely Mgwalana, Bira and Gqora which share common soil parent materials, land use history, exhibit similar topography and advanced degree of erosion. A total of 63 soil samples were strategically collected from identified erosion zones and site controls devoid of active erosion; where stability was evident by means of vegetation cover and soil surface condition. Surface samples were collected above 30cm depth and subsurface samples at depths greater than 30cm. To determine the fate of carbon additional samples were collected from runon and sink zones at the Mgwalana catchment along a transect from top to bottom slope. Laboratory analyses was performed to determine the soil properties, whereby C content was measured by the dry combustion method, Fe2O3- and cation content by Atomic Absorption (AA) Spectrometer, texture by the separation method described by Schlichting, Blume & Stahr (1995), clay mineralogy by X-Ray Diffraction and organic matter content by conversion of total C. In addition to these properties being used to infer aggregate stability, the wet sieving method was also used for this purpose and for validation of the other soil properties. The results revealed that no one soil property has a greater influence on aggregate stability than the others, but rather that the stability of the soil is dependent on the combinations of these properties in the soil and the interactions that occur between them. Based on this, the results indicated greater stability for runon, sink and control samples, mainly in the topsoil, which were characterised by a relatively higher C- and organic matter content, loam texture and higher concentrations of Ca2+. Furthermore, the less stable eroded samples were characterised by a more clay rich texture particularly in the subsoil, relatively lower C- and organic matter contents and a greater sodicity due to higher concentrations of Na+. The least stable soils belonged to the Gqora catchment, which were found to consist of higher silt content in the topsoil and a higher Fe2O3 content in the subsoil. The clay mineralogy was relatively uniform across all catchments, comprising of primarily illite and secondly kaolinite. The sample with the highest sodicity in terms of ESP contained smectite clay in addition to illite and kaolinite which is assumed to contribute to this increased Na+ concentration. These findings aid in the conclusion that the chemical characteristics of the soils, in association with biological and, to a less extent, physical properties of the soil exacerbate the erosion problem initiated by the extrinsic contributors, such as climate and topography. Investigation into the fate of carbon on eroded lands revealed a topographically driven dynamic whereby the total carbon content was found to be greater at the top and middle slope positions as well as in the sink zone. These hillslope sections were found to have a lower slope gradient and slightly more pronounced concave shape to those sections with lower C values. These topographic variables influence the degree of gully erosion taking place at different hillslope sections, which tends to be greater where slope angle is increased and convexity exists, resulting in the removal of soil C at these positions and its deposition in areas of accumulation, namely the runon and sink zones of low angle concave slope sections. The findings of this research may be used to develop restoration and management strategies with the ultimate goal to reduce the soils vulnerability to erosion by enhancing those soil properties conducive to greater aggregate stability as determined in the present study.
- Full Text:
- Date Issued: 2015
The South African mining industry towards 2055: scenarios
- Authors: Du Plessis, Rudolf
- Date: 2015
- Subjects: Mines and mineral resources -- South Africa , Geology, Economic -- South Africa , Forecasting -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/4215 , vital:20568
- Description: The strained commodity price environment has triggered strong measures of cost containment and control by global and South African mining industries with workforce reductions, mine closures and shelved projects. Added to this, the South African mining industry is facing an unparalleled number of challenges, including an uncertain regulatory environment, infrastructure constraints, frequent industrial actions, rising costs and shortages of skills. The dynamism of discontinuous change has increased considerably and the South African mining industry is today facing an uncertain future with a blurred outlook. The results of the detailed analysis of future studies theory and practice in this research study support the argument that there is a strong need to fundamentally change the ways of planning for the future of the South African mining industry. The practice of developing new insight through the application of futures studies is central to this process. Today, collective decisions and strategies are progressively more founded on and informed by futures studies. The research study sought to develop insight regarding the future of the South African mining industry through the construction of four scenarios towards 2055: Divided We Fall, where a confident industry is threatened by social divisions as industry transformation is disregarded; Rock Bottom, where weak global economic conditions coincide with lacklustre industry innovation; Rising from Ashes, with similar economic conditions, but the industry responding positively through accelerated industry innovation; and Renaissance, set against positive global economic conditions with the South African mining industry adopting a collaborative, innovative approach to industry transformation. The research study further strived to uncover the preferred future for the South African mining industry as basis for the South African Mine of the Future Vision towards 2055. Throughout the research study, Inayatullah’s pillars of futures studies were applied as a guideline in mapping the present and future, deepening the future, broadening the future through the development of scenarios, and transforming the future by narrowing it down to the preferred. The study provides valuable insight into the driving forces relevant to the South African mining landscape. In addition, it provides insight on how to anticipate the changes these driving forces may bring about for the industry over the next 40 years from a decision-maker’s point of view. It is up to the mining industry to select the road to follow in terms of progress and sustainable development. Through an innovative approach, the creation of an environment of trust, the sharing of values, purposes and benefits, the South African Mine of the Future Vision is attainable. The South African mining industry must commit itself to working in collaborative partnerships with local communities, government, society and labour; stepping boldly into a world of social, environmental, technological and commercial innovation.
- Full Text:
- Date Issued: 2015
- Authors: Du Plessis, Rudolf
- Date: 2015
- Subjects: Mines and mineral resources -- South Africa , Geology, Economic -- South Africa , Forecasting -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/4215 , vital:20568
- Description: The strained commodity price environment has triggered strong measures of cost containment and control by global and South African mining industries with workforce reductions, mine closures and shelved projects. Added to this, the South African mining industry is facing an unparalleled number of challenges, including an uncertain regulatory environment, infrastructure constraints, frequent industrial actions, rising costs and shortages of skills. The dynamism of discontinuous change has increased considerably and the South African mining industry is today facing an uncertain future with a blurred outlook. The results of the detailed analysis of future studies theory and practice in this research study support the argument that there is a strong need to fundamentally change the ways of planning for the future of the South African mining industry. The practice of developing new insight through the application of futures studies is central to this process. Today, collective decisions and strategies are progressively more founded on and informed by futures studies. The research study sought to develop insight regarding the future of the South African mining industry through the construction of four scenarios towards 2055: Divided We Fall, where a confident industry is threatened by social divisions as industry transformation is disregarded; Rock Bottom, where weak global economic conditions coincide with lacklustre industry innovation; Rising from Ashes, with similar economic conditions, but the industry responding positively through accelerated industry innovation; and Renaissance, set against positive global economic conditions with the South African mining industry adopting a collaborative, innovative approach to industry transformation. The research study further strived to uncover the preferred future for the South African mining industry as basis for the South African Mine of the Future Vision towards 2055. Throughout the research study, Inayatullah’s pillars of futures studies were applied as a guideline in mapping the present and future, deepening the future, broadening the future through the development of scenarios, and transforming the future by narrowing it down to the preferred. The study provides valuable insight into the driving forces relevant to the South African mining landscape. In addition, it provides insight on how to anticipate the changes these driving forces may bring about for the industry over the next 40 years from a decision-maker’s point of view. It is up to the mining industry to select the road to follow in terms of progress and sustainable development. Through an innovative approach, the creation of an environment of trust, the sharing of values, purposes and benefits, the South African Mine of the Future Vision is attainable. The South African mining industry must commit itself to working in collaborative partnerships with local communities, government, society and labour; stepping boldly into a world of social, environmental, technological and commercial innovation.
- Full Text:
- Date Issued: 2015
Elder mixing traditional drink
- Unnamed
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303106 , vital:58291 , KHV-253
- Description: Elder mixing traditional drink , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
- Authors: Unnamed
- Date: 2015
- Subjects: UNCATALOGUED
- Type: Video
- Identifier: http://hdl.handle.net/10962/303106 , vital:58291 , KHV-253
- Description: Elder mixing traditional drink , Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-ShareAlike" License (http://creativecommons.org/licenses/by-nc-sa/2.0/) (NEVER CAHNGE THIS FIELD)
- Full Text: false
- Date Issued: 2015
Staff motivation and job performance in the Frere Hospital maternity ward
- Authors: Makapela, Lunathi Brian
- Date: 2015
- Subjects: Employee motivation -- South Africa -- East London , Employees -- Rating of -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/8769 , vital:26428
- Description: The topic of motivation continues to command substantial attention in the field of industrial or organisational psychology. Motivation has always been an essential factor in managing personnel and is a crucial variable in creating a high performance organization. Public administration research has largely ignored motivation as a topic, contrary to research of private sector management. Nurses represent one of the biggest profession group in South Africa's health care services and forms the vertebrae of the Primary Health Care in South Africa. South Africa has experienced large numbers of nurses immigrating to other foreign countries due to poor working conditions in South Africa. Government has a responsibility of ensuring that there is always a motivational climate in the institutions where nurses work. Several investigations have been conducted by various organisations regarding the state of South African Health Care System, due to a high rate of reported deaths in South African hospitals. Dispatch investigation team in 2005 revealed a number of findings that related to various motivational issues at the Eastern Cape Frere Hospital maternity ward. These motivational issues included but not limited shortage of nurses and doctors; use of interns on night duty without qualified doctors and anaesthetist; a cleaner confirmed to have been seen delivering a baby in the labour ward while wearing a doctor‟s coat, as well as accessing and dispensing medicine; no security to prevent people from wandering the labour ward and the entire maternity section; deaths due to negligence; inappropriate appointment of personnel, a situation causing problems for the nurses; employees complaining of work overload; absenteeism and sick leave leaving one nurse on duty at night in the nursery; lack of equipment like oxygen points, suction catheters, CPAPs and CTG machines, alleged by some nurses to be directly responsible for a number of avoidable deaths; staff shortages thus forcing inexperienced nurses to carry duties beyond their experience; detrimental shortages of labour beds; a general assistant dressed in a green nurse‟s gown rinsing blood-soaked linen before dishing up for, and serving food to patients, still wearing the same clothing. Since the Dispatch investigation and the subsequent investigations by political parties and the National Department of Health, no scientific research or investigation has been done around challenges at Frere Hospital maternity ward. The main purpose of this study is to investigate the levels of staff motivation and staff motivation levels' impact on job performance in the Frere Hospital maternity ward. In conducting this study the researcher explored five motivation theories which are amongst a group of motivational theories that have shaped worker motivation in both the public and private sectors. The study explored Maslow hierarchy of needs, Herzberg two factor theory, Vroom's expectancy theory, Locke's equity theory and Festinger‟s goal setting Theory. These theories were used with a view of gathering an understanding of staff motivation and job performance. The reasons for the researcher to choose these five motivational theories is that they are amongst the most popular theories used by scholars to measure staff motivation and performance both in the private and public sectors. These theories were also used due to their relevance to the organisation investigated. This study followed a quantitative approach and empirical study was conducted using a questionnaire with closed and open-ended questions. The empirical results from the nine sections researched showed some distinct findings, from which the following recommendations were drawn: management should consider employees' involvement during goal setting in the department; management should work towards building in job motivators into the employees’ jobs; management should ensure that there is a reputable performance reward and recognition system in place that is agreed upon with staff, instead of imposing the system; management should support nurses in ensuring that their working conditions and salaries and benefits are improved; and It is therefore the responsibility of managers to ensure that staff are always kept motivated in order to increase job performance.
- Full Text:
- Date Issued: 2015
- Authors: Makapela, Lunathi Brian
- Date: 2015
- Subjects: Employee motivation -- South Africa -- East London , Employees -- Rating of -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/8769 , vital:26428
- Description: The topic of motivation continues to command substantial attention in the field of industrial or organisational psychology. Motivation has always been an essential factor in managing personnel and is a crucial variable in creating a high performance organization. Public administration research has largely ignored motivation as a topic, contrary to research of private sector management. Nurses represent one of the biggest profession group in South Africa's health care services and forms the vertebrae of the Primary Health Care in South Africa. South Africa has experienced large numbers of nurses immigrating to other foreign countries due to poor working conditions in South Africa. Government has a responsibility of ensuring that there is always a motivational climate in the institutions where nurses work. Several investigations have been conducted by various organisations regarding the state of South African Health Care System, due to a high rate of reported deaths in South African hospitals. Dispatch investigation team in 2005 revealed a number of findings that related to various motivational issues at the Eastern Cape Frere Hospital maternity ward. These motivational issues included but not limited shortage of nurses and doctors; use of interns on night duty without qualified doctors and anaesthetist; a cleaner confirmed to have been seen delivering a baby in the labour ward while wearing a doctor‟s coat, as well as accessing and dispensing medicine; no security to prevent people from wandering the labour ward and the entire maternity section; deaths due to negligence; inappropriate appointment of personnel, a situation causing problems for the nurses; employees complaining of work overload; absenteeism and sick leave leaving one nurse on duty at night in the nursery; lack of equipment like oxygen points, suction catheters, CPAPs and CTG machines, alleged by some nurses to be directly responsible for a number of avoidable deaths; staff shortages thus forcing inexperienced nurses to carry duties beyond their experience; detrimental shortages of labour beds; a general assistant dressed in a green nurse‟s gown rinsing blood-soaked linen before dishing up for, and serving food to patients, still wearing the same clothing. Since the Dispatch investigation and the subsequent investigations by political parties and the National Department of Health, no scientific research or investigation has been done around challenges at Frere Hospital maternity ward. The main purpose of this study is to investigate the levels of staff motivation and staff motivation levels' impact on job performance in the Frere Hospital maternity ward. In conducting this study the researcher explored five motivation theories which are amongst a group of motivational theories that have shaped worker motivation in both the public and private sectors. The study explored Maslow hierarchy of needs, Herzberg two factor theory, Vroom's expectancy theory, Locke's equity theory and Festinger‟s goal setting Theory. These theories were used with a view of gathering an understanding of staff motivation and job performance. The reasons for the researcher to choose these five motivational theories is that they are amongst the most popular theories used by scholars to measure staff motivation and performance both in the private and public sectors. These theories were also used due to their relevance to the organisation investigated. This study followed a quantitative approach and empirical study was conducted using a questionnaire with closed and open-ended questions. The empirical results from the nine sections researched showed some distinct findings, from which the following recommendations were drawn: management should consider employees' involvement during goal setting in the department; management should work towards building in job motivators into the employees’ jobs; management should ensure that there is a reputable performance reward and recognition system in place that is agreed upon with staff, instead of imposing the system; management should support nurses in ensuring that their working conditions and salaries and benefits are improved; and It is therefore the responsibility of managers to ensure that staff are always kept motivated in order to increase job performance.
- Full Text:
- Date Issued: 2015
Mercaptopyridine-substituted indium, zinc, and metal-free phthalocyanines: nonlinear optical studies in solution and on polymer matrices
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7278 , http://hdl.handle.net/10962/d1020313
- Description: In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl3, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10−9 esu and 7.74 × 10−10 esu) and hyperpolarizability (2.13 × 10−28 and 8.37 × 10−29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters. , Original publication is available at http://dx.doi.org/10.1080/00958972.2015.1077237
- Full Text: false
- Date Issued: 2015